[TD-4480]<fix>: fix DatabaseMetaData get wrong column value (#6381)

* [TD-4480]<fix>: fix DatabaseMetaData has wrong column index bug

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* change test cases

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* change jdbc version

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cmake/install.inc

@@ -32,7 +32,7 @@ ELSEIF (TD_WINDOWS)
   #INSTALL(TARGETS taos RUNTIME DESTINATION driver)
   #INSTALL(TARGETS shell RUNTIME DESTINATION .)
   IF (TD_MVN_INSTALLED)
-    INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos-jdbcdriver-2.0.29.jar DESTINATION connector/jdbc)
+    INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos-jdbcdriver-2.0.30.jar DESTINATION connector/jdbc)
   ENDIF ()
 ELSEIF (TD_DARWIN)
   SET(TD_MAKE_INSTALL_SH "${TD_COMMUNITY_DIR}/packaging/tools/make_install.sh")

src/connector/jdbc/CMakeLists.txt

@@ -8,10 +8,9 @@ IF (TD_MVN_INSTALLED)
   ADD_CUSTOM_COMMAND(OUTPUT ${JDBC_CMD_NAME}
     POST_BUILD
     COMMAND mvn -Dmaven.test.skip=true install -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
-    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.29.jar ${LIBRARY_OUTPUT_PATH}
+    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.30.jar ${LIBRARY_OUTPUT_PATH}
     COMMAND mvn -Dmaven.test.skip=true clean -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
     COMMENT "build jdbc driver")
   ADD_CUSTOM_TARGET(${JDBC_TARGET_NAME} ALL WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH} DEPENDS ${JDBC_CMD_NAME})
 ENDIF ()
 
-

src/connector/jdbc/deploy-pom.xml

@@ -5,7 +5,7 @@
 
   <groupId>com.taosdata.jdbc</groupId>
   <artifactId>taos-jdbcdriver</artifactId>
-  <version>2.0.29</version>
+  <version>2.0.30</version>
   <packaging>jar</packaging>
 
   <name>JDBCDriver</name>

src/connector/jdbc/pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.taosdata.jdbc</groupId>
     <artifactId>taos-jdbcdriver</artifactId>
-    <version>2.0.29</version>
+    <version>2.0.30</version>
     <packaging>jar</packaging>
     <name>JDBCDriver</name>
     <url>https://github.com/taosdata/TDengine/tree/master/src/connector/jdbc</url>

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractDatabaseMetaData.java

@@ -12,6 +12,9 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
     private final static int DRIVER_MAJAR_VERSION = 2;
     private final static int DRIVER_MINOR_VERSION = 0;
 
+    private String precision = "ms";
+    private String database;
+
     public boolean allProceduresAreCallable() throws SQLException {
         return false;
     }
@@ -493,102 +496,105 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
 
     public abstract ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern, String[] types) throws SQLException;
 
-    protected ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern, String[] types, Connection connection) throws SQLException {
-        try (Statement stmt = connection.createStatement()) {
-            if (catalog == null || catalog.isEmpty())
-                return null;
-
-            ResultSet databases = stmt.executeQuery("show databases");
-            String dbname = null;
-            while (databases.next()) {
-                dbname = databases.getString("name");
-                if (dbname.equalsIgnoreCase(catalog))
-                    break;
-            }
-            databases.close();
-            if (dbname == null)
-                return null;
+    private List<ColumnMetaData> buildGetTablesColumnMetaDataList() {
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableCatalogMeta(1));          // 1. TABLE_CAT
+        columnMetaDataList.add(buildTableSchemaMeta(2));           // 2. TABLE_SCHEM
+        columnMetaDataList.add(buildTableNameMeta(3));             // 3. TABLE_NAME
+        columnMetaDataList.add(buildTableTypeMeta(4));             // 4. TABLE_TYPE
+        columnMetaDataList.add(buildRemarksMeta(5));                // 5. remarks
+        columnMetaDataList.add(buildTypeCatMeta(6));                // 6. TYPE_CAT
+        columnMetaDataList.add(buildTypeSchemaMeta(7));             // 7. TYPE_SCHEM
+        columnMetaDataList.add(buildTypeNameMeta(8));               // 8. TYPE_NAME
+        columnMetaDataList.add(buildSelfReferencingColName(9));     // 9. SELF_REFERENCING_COL_NAME
+        columnMetaDataList.add(buildRefGenerationMeta(10));         // 10. REF_GENERATION
+        return columnMetaDataList;
+    }
+
+    private ColumnMetaData buildTypeCatMeta(int colIndex) {
+        ColumnMetaData col6 = new ColumnMetaData();
+        col6.setColIndex(colIndex);
+        col6.setColName("TYPE_CAT");
+        col6.setColType(Types.NCHAR);
+        return col6;
+    }
+
+    private ColumnMetaData buildTypeSchemaMeta(int colIndex) {
+        ColumnMetaData col7 = new ColumnMetaData();
+        col7.setColIndex(colIndex);
+        col7.setColName("TYPE_SCHEM");
+        col7.setColType(Types.NCHAR);
+        return col7;
+    }
+
+    private ColumnMetaData buildTypeNameMeta(int colIndex) {
+        ColumnMetaData col8 = new ColumnMetaData();
+        col8.setColIndex(colIndex);
+        col8.setColName("TYPE_NAME");
+        col8.setColType(Types.NCHAR);
+        return col8;
+    }
+
+    private ColumnMetaData buildSelfReferencingColName(int colIndex) {
+        ColumnMetaData col9 = new ColumnMetaData();
+        col9.setColIndex(colIndex);
+        col9.setColName("SELF_REFERENCING_COL_NAME");
+        col9.setColType(Types.NCHAR);
+        return col9;
+    }
+
+    private ColumnMetaData buildRefGenerationMeta(int colIndex) {
+        ColumnMetaData col10 = new ColumnMetaData();
+        col10.setColIndex(colIndex);
+        col10.setColName("REF_GENERATION");
+        col10.setColType(Types.NCHAR);
+        return col10;
+    }
 
-            stmt.execute("use " + dbname);
-            DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
-            List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-            ColumnMetaData col1 = new ColumnMetaData();
-            col1.setColIndex(1);
-            col1.setColName("TABLE_CAT");
-            col1.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col1);
-            ColumnMetaData col2 = new ColumnMetaData();
-            col2.setColIndex(2);
-            col2.setColName("TABLE_SCHEM");
-            col2.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col2);
-            ColumnMetaData col3 = new ColumnMetaData();
-            col3.setColIndex(3);
-            col3.setColName("TABLE_NAME");
-            col3.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col3);
-            ColumnMetaData col4 = new ColumnMetaData();
-            col4.setColIndex(4);
-            col4.setColName("TABLE_TYPE");
-            col4.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col4);
-            ColumnMetaData col5 = new ColumnMetaData();
-            col5.setColIndex(5);
-            col5.setColName("REMARKS");
-            col5.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col5);
-            ColumnMetaData col6 = new ColumnMetaData();
-            col6.setColIndex(6);
-            col6.setColName("TYPE_CAT");
-            col6.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col6);
-            ColumnMetaData col7 = new ColumnMetaData();
-            col7.setColIndex(7);
-            col7.setColName("TYPE_SCHEM");
-            col7.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col7);
-            ColumnMetaData col8 = new ColumnMetaData();
-            col8.setColIndex(8);
-            col8.setColName("TYPE_NAME");
-            col8.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col8);
-            ColumnMetaData col9 = new ColumnMetaData();
-            col9.setColIndex(9);
-            col9.setColName("SELF_REFERENCING_COL_NAME");
-            col9.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col9);
-            ColumnMetaData col10 = new ColumnMetaData();
-            col10.setColIndex(10);
-            col10.setColName("REF_GENERATION");
-            col10.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col10);
-            resultSet.setColumnMetaDataList(columnMetaDataList);
+    protected ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern, String[] types, Connection connection) throws SQLException {
+        if (catalog == null || catalog.isEmpty())
+            return null;
+        if (!isAvailableCatalog(connection, catalog))
+            return new EmptyResultSet();
 
-            List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
+        DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        // set column metadata list
+        resultSet.setColumnMetaDataList(buildGetTablesColumnMetaDataList());
+        // set row data
+        List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
+        try (Statement stmt = connection.createStatement()) {
+            stmt.execute("use " + catalog);
             ResultSet tables = stmt.executeQuery("show tables");
             while (tables.next()) {
                 TSDBResultSetRowData rowData = new TSDBResultSetRowData(10);
-                rowData.setString(0, dbname);   //table_cat
-                rowData.setString(1, null); //TABLE_SCHEM
-                rowData.setString(2, tables.getString("table_name"));   //TABLE_NAME
-                rowData.setString(3, "TABLE");  //TABLE_TYPE
-                rowData.setString(4, "");   //REMARKS
+                rowData.setStringValue(1, catalog);                                     //TABLE_CAT
+                rowData.setStringValue(2, null);                                 //TABLE_SCHEM
+                rowData.setStringValue(3, tables.getString("table_name"));  //TABLE_NAME
+                rowData.setStringValue(4, "TABLE");                              //TABLE_TYPE
+                rowData.setStringValue(5, "");                                   //REMARKS
                 rowDataList.add(rowData);
             }
-
             ResultSet stables = stmt.executeQuery("show stables");
             while (stables.next()) {
                 TSDBResultSetRowData rowData = new TSDBResultSetRowData(10);
-                rowData.setString(0, dbname);   //TABLE_CAT
-                rowData.setString(1, null); //TABLE_SCHEM
-                rowData.setString(2, stables.getString("name"));    //TABLE_NAME
-                rowData.setString(3, "TABLE");  //TABLE_TYPE
-                rowData.setString(4, "STABLE"); //REMARKS
+                rowData.setStringValue(1, catalog);                                  //TABLE_CAT
+                rowData.setStringValue(2, null);                              //TABLE_SCHEM
+                rowData.setStringValue(3, stables.getString("name"));    //TABLE_NAME
+                rowData.setStringValue(4, "TABLE");                           //TABLE_TYPE
+                rowData.setStringValue(5, "STABLE");                          //REMARKS
                 rowDataList.add(rowData);
             }
             resultSet.setRowDataList(rowDataList);
-            return resultSet;
         }
+        return resultSet;
+    }
+
+    private ColumnMetaData buildTableTypeMeta(int colIndex) {
+        ColumnMetaData col4 = new ColumnMetaData();
+        col4.setColIndex(colIndex);
+        col4.setColName("TABLE_TYPE");
+        col4.setColType(Types.NCHAR);
+        return col4;
     }
 
     public ResultSet getSchemas() throws SQLException {
@@ -597,25 +603,24 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
 
     public abstract ResultSet getCatalogs() throws SQLException;
 
+    private List<ColumnMetaData> buildTableTypesColumnMetadataList() {
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableTypeMeta(1));
+        return columnMetaDataList;
+    }
+
     public ResultSet getTableTypes() throws SQLException {
         DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
         // set up ColumnMetaDataList
-        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-        ColumnMetaData colMetaData = new ColumnMetaData();
-        colMetaData.setColIndex(0);
-        colMetaData.setColName("TABLE_TYPE");
-        colMetaData.setColSize(10);
-        colMetaData.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-        columnMetaDataList.add(colMetaData);
-        resultSet.setColumnMetaDataList(columnMetaDataList);
+        resultSet.setColumnMetaDataList(buildTableTypesColumnMetadataList());
 
         // set up rowDataList
         List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
         TSDBResultSetRowData rowData = new TSDBResultSetRowData(1);
-        rowData.setString(0, "TABLE");
+        rowData.setStringValue(1, "TABLE");
         rowDataList.add(rowData);
         rowData = new TSDBResultSetRowData(1);
-        rowData.setString(0, "STABLE");
+        rowData.setStringValue(1, "STABLE");
         rowDataList.add(rowData);
         resultSet.setRowDataList(rowDataList);
 
@@ -625,278 +630,330 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
     public abstract ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern) throws SQLException;
 
     protected ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern, Connection conn) {
-        try (Statement stmt = conn.createStatement()) {
-            if (catalog == null || catalog.isEmpty())
-                return null;
-
-            ResultSet databases = stmt.executeQuery("show databases");
-            String dbname = null;
-            while (databases.next()) {
-                dbname = databases.getString("name");
-                if (dbname.equalsIgnoreCase(catalog))
-                    break;
-            }
-            databases.close();
-            if (dbname == null)
-                return null;
+        if (catalog == null || catalog.isEmpty())
+            return null;
+        if (!isAvailableCatalog(conn, catalog))
+            return new EmptyResultSet();
 
-            stmt.execute("use " + dbname);
-            DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
-            // set up ColumnMetaDataList
-
-            List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-            // TABLE_CAT
-            ColumnMetaData col1 = new ColumnMetaData();
-            col1.setColIndex(1);
-            col1.setColName("TABLE_CAT");
-            col1.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col1);
-            // TABLE_SCHEM
-            ColumnMetaData col2 = new ColumnMetaData();
-            col2.setColIndex(2);
-            col2.setColName("TABLE_SCHEM");
-            col2.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col2);
-            // TABLE_NAME
-            ColumnMetaData col3 = new ColumnMetaData();
-            col3.setColIndex(3);
-            col3.setColName("TABLE_NAME");
-            col3.setColSize(193);
-            col3.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col3);
-            // COLUMN_NAME
-            ColumnMetaData col4 = new ColumnMetaData();
-            col4.setColIndex(4);
-            col4.setColName("COLUMN_NAME");
-            col4.setColSize(65);
-            col4.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col4);
-            // DATA_TYPE
-            ColumnMetaData col5 = new ColumnMetaData();
-            col5.setColIndex(5);
-            col5.setColName("DATA_TYPE");
-            col5.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col5);
-            // TYPE_NAME
-            ColumnMetaData col6 = new ColumnMetaData();
-            col6.setColIndex(6);
-            col6.setColName("TYPE_NAME");
-            col6.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col6);
-            // COLUMN_SIZE
-            ColumnMetaData col7 = new ColumnMetaData();
-            col7.setColIndex(7);
-            col7.setColName("COLUMN_SIZE");
-            col7.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col7);
-            // BUFFER_LENGTH, not used
-            ColumnMetaData col8 = new ColumnMetaData();
-            col8.setColIndex(8);
-            col8.setColName("BUFFER_LENGTH");
-            columnMetaDataList.add(col8);
-            // DECIMAL_DIGITS
-            ColumnMetaData col9 = new ColumnMetaData();
-            col9.setColIndex(9);
-            col9.setColName("DECIMAL_DIGITS");
-            col9.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col9);
-            // add NUM_PREC_RADIX
-            ColumnMetaData col10 = new ColumnMetaData();
-            col10.setColIndex(10);
-            col10.setColName("NUM_PREC_RADIX");
-            col10.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col10);
-            // NULLABLE
-            ColumnMetaData col11 = new ColumnMetaData();
-            col11.setColIndex(11);
-            col11.setColName("NULLABLE");
-            col11.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col11);
-            // REMARKS
-            ColumnMetaData col12 = new ColumnMetaData();
-            col12.setColIndex(12);
-            col12.setColName("REMARKS");
-            col12.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col12);
-            // COLUMN_DEF
-            ColumnMetaData col13 = new ColumnMetaData();
-            col13.setColIndex(13);
-            col13.setColName("COLUMN_DEF");
-            col13.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col13);
-            //SQL_DATA_TYPE
-            ColumnMetaData col14 = new ColumnMetaData();
-            col14.setColIndex(14);
-            col14.setColName("SQL_DATA_TYPE");
-            col14.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col14);
-            //SQL_DATETIME_SUB
-            ColumnMetaData col15 = new ColumnMetaData();
-            col15.setColIndex(15);
-            col15.setColName("SQL_DATETIME_SUB");
-            col15.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col15);
-            //CHAR_OCTET_LENGTH
-            ColumnMetaData col16 = new ColumnMetaData();
-            col16.setColIndex(16);
-            col16.setColName("CHAR_OCTET_LENGTH");
-            col16.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col16);
-            //ORDINAL_POSITION
-            ColumnMetaData col17 = new ColumnMetaData();
-            col17.setColIndex(17);
-            col17.setColName("ORDINAL_POSITION");
-            col17.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col17);
-            // IS_NULLABLE
-            ColumnMetaData col18 = new ColumnMetaData();
-            col18.setColIndex(18);
-            col18.setColName("IS_NULLABLE");
-            col18.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col18);
-            //SCOPE_CATALOG
-            ColumnMetaData col19 = new ColumnMetaData();
-            col19.setColIndex(19);
-            col19.setColName("SCOPE_CATALOG");
-            col19.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col19);
-            //SCOPE_SCHEMA
-            ColumnMetaData col20 = new ColumnMetaData();
-            col20.setColIndex(20);
-            col20.setColName("SCOPE_SCHEMA");
-            col20.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col20);
-            //SCOPE_TABLE
-            ColumnMetaData col21 = new ColumnMetaData();
-            col21.setColIndex(21);
-            col21.setColName("SCOPE_TABLE");
-            col21.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col21);
-            //SOURCE_DATA_TYPE
-            ColumnMetaData col22 = new ColumnMetaData();
-            col22.setColIndex(22);
-            col22.setColName("SOURCE_DATA_TYPE");
-            col22.setColType(TSDBConstants.TSDB_DATA_TYPE_SMALLINT);
-            columnMetaDataList.add(col22);
-            //IS_AUTOINCREMENT
-            ColumnMetaData col23 = new ColumnMetaData();
-            col23.setColIndex(23);
-            col23.setColName("IS_AUTOINCREMENT");
-            col23.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col23);
-            //IS_GENERATEDCOLUMN
-            ColumnMetaData col24 = new ColumnMetaData();
-            col24.setColIndex(24);
-            col24.setColName("IS_GENERATEDCOLUMN");
-            col24.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col24);
-
-            resultSet.setColumnMetaDataList(columnMetaDataList);
-            // set up rowDataList
-            ResultSet rs = stmt.executeQuery("describe " + dbname + "." + tableNamePattern);
-            List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
-            int index = 0;
+        DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        // set up ColumnMetaDataList
+        resultSet.setColumnMetaDataList(buildGetColumnsColumnMetaDataList());
+        // set up rowDataList
+        List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("describe " + catalog + "." + tableNamePattern);
+            int rowIndex = 0;
             while (rs.next()) {
                 TSDBResultSetRowData rowData = new TSDBResultSetRowData(24);
                 // set TABLE_CAT
-                rowData.setString(0, dbname);
+                rowData.setStringValue(1, catalog);
+                // set TABLE_SCHEM
+                rowData.setStringValue(2, null);
                 // set TABLE_NAME
-                rowData.setString(2, tableNamePattern);
+                rowData.setStringValue(3, tableNamePattern);
                 // set COLUMN_NAME
-                rowData.setString(3, rs.getString("Field"));
+                rowData.setStringValue(4, rs.getString("Field"));
                 // set DATA_TYPE
                 String typeName = rs.getString("Type");
-                rowData.setInt(4, getDataType(typeName));
+                rowData.setIntValue(5, TSDBConstants.typeName2JdbcType(typeName));
                 // set TYPE_NAME
-                rowData.setString(5, typeName);
+                rowData.setStringValue(6, typeName);
                 // set COLUMN_SIZE
                 int length = rs.getInt("Length");
-                rowData.setInt(6, getColumnSize(typeName, length));
+                rowData.setIntValue(7, calculateColumnSize(typeName, precision, length));
+                // set BUFFER LENGTH
+                rowData.setStringValue(8, null);
                 // set DECIMAL_DIGITS
-                rowData.setInt(8, getDecimalDigits(typeName));
+                Integer decimalDigits = calculateDecimalDigits(typeName);
+                if (decimalDigits != null) {
+                    rowData.setIntValue(9, decimalDigits);
+                } else {
+                    rowData.setStringValue(9, null);
+                }
                 // set NUM_PREC_RADIX
-                rowData.setInt(9, 10);
+                rowData.setIntValue(10, 10);
                 // set NULLABLE
-                rowData.setInt(10, getNullable(index, typeName));
+                rowData.setIntValue(11, isNullable(rowIndex, typeName));
                 // set REMARKS
-                rowData.setString(11, rs.getString("Note"));
+                String note = rs.getString("Note");
+                rowData.setStringValue(12, note.trim().isEmpty() ? null : note);
                 rowDataList.add(rowData);
-                index++;
+                rowIndex++;
             }
             resultSet.setRowDataList(rowDataList);
-            return resultSet;
-
         } catch (SQLException e) {
             e.printStackTrace();
         }
-        return null;
+        return resultSet;
     }
 
-    protected int getNullable(int index, String typeName) {
+    private int isNullable(int index, String typeName) {
         if (index == 0 && "TIMESTAMP".equals(typeName))
             return DatabaseMetaData.columnNoNulls;
         return DatabaseMetaData.columnNullable;
     }
 
-    protected int getColumnSize(String typeName, int length) {
+    private Integer calculateColumnSize(String typeName, String precisionType, int length) {
         switch (typeName) {
             case "TIMESTAMP":
-                return 23;
-            default:
-                return 0;
-        }
-    }
-
-    protected int getDecimalDigits(String typeName) {
-        switch (typeName) {
+                return precisionType.equals("ms") ? TSDBConstants.TIMESTAMP_MS_PRECISION : TSDBConstants.TIMESTAMP_US_PRECISION;
+            case "BOOL":
+                return TSDBConstants.BOOLEAN_PRECISION;
+            case "TINYINT":
+                return TSDBConstants.TINYINT_PRECISION;
+            case "SMALLINT":
+                return TSDBConstants.SMALLINT_PRECISION;
+            case "INT":
+                return TSDBConstants.INT_PRECISION;
+            case "BIGINT":
+                return TSDBConstants.BIGINT_PRECISION;
             case "FLOAT":
-                return 5;
+                return TSDBConstants.FLOAT_PRECISION;
             case "DOUBLE":
-                return 9;
+                return TSDBConstants.DOUBLE_PRECISION;
+            case "NCHAR":
+            case "BINARY":
+                return length;
             default:
-                return 0;
+                return null;
         }
     }
 
-    protected int getDataType(String typeName) {
+    private Integer calculateDecimalDigits(String typeName) {
         switch (typeName) {
-            case "TIMESTAMP":
-                return Types.TIMESTAMP;
+            case "TINYINT":
+            case "SMALLINT":
             case "INT":
-                return Types.INTEGER;
             case "BIGINT":
-                return Types.BIGINT;
-            case "FLOAT":
-                return Types.FLOAT;
-            case "DOUBLE":
-                return Types.DOUBLE;
-            case "BINARY":
-                return Types.BINARY;
-            case "SMALLINT":
-                return Types.SMALLINT;
-            case "TINYINT":
-                return Types.TINYINT;
-            case "BOOL":
-                return Types.BOOLEAN;
-            case "NCHAR":
-                return Types.NCHAR;
+                return 0;
             default:
-                return Types.NULL;
+                return null;
         }
     }
 
-    public ResultSet getColumnPrivileges(String catalog, String schema, String table, String columnNamePattern)
-            throws SQLException {
+    private ColumnMetaData buildTableCatalogMeta(int colIndex) {
+        ColumnMetaData col1 = new ColumnMetaData();
+        col1.setColIndex(colIndex);
+        col1.setColName("TABLE_CAT");
+        col1.setColType(Types.NCHAR);
+        return col1;
+    }
+
+    private ColumnMetaData buildTableSchemaMeta(int colIndex) {
+        ColumnMetaData col2 = new ColumnMetaData();
+        col2.setColIndex(colIndex);
+        col2.setColName("TABLE_SCHEM");
+        col2.setColType(Types.NCHAR);
+        return col2;
+    }
+
+    private ColumnMetaData buildTableNameMeta(int colIndex) {
+        ColumnMetaData col3 = new ColumnMetaData();
+        col3.setColIndex(colIndex);
+        col3.setColName("TABLE_NAME");
+        col3.setColSize(193);
+        col3.setColType(Types.NCHAR);
+        return col3;
+    }
+
+    private ColumnMetaData buildColumnNameMeta(int colIndex) {
+        ColumnMetaData col4 = new ColumnMetaData();
+        col4.setColIndex(colIndex);
+        col4.setColName("COLUMN_NAME");
+        col4.setColSize(65);
+        col4.setColType(Types.NCHAR);
+        return col4;
+    }
+
+    private ColumnMetaData buildDataTypeMeta(int colIndex) {
+        ColumnMetaData col5 = new ColumnMetaData();
+        col5.setColIndex(colIndex);
+        col5.setColName("DATA_TYPE");
+        col5.setColType(Types.INTEGER);
+        return col5;
+    }
+
+    private ColumnMetaData buildColumnSizeMeta() {
+        ColumnMetaData col7 = new ColumnMetaData();
+        col7.setColIndex(7);
+        col7.setColName("COLUMN_SIZE");
+        col7.setColType(Types.INTEGER);
+        return col7;
+    }
+
+    private ColumnMetaData buildBufferLengthMeta() {
+        ColumnMetaData col8 = new ColumnMetaData();
+        col8.setColIndex(8);
+        col8.setColName("BUFFER_LENGTH");
+        return col8;
+    }
+
+    private ColumnMetaData buildDecimalDigitsMeta() {
+        ColumnMetaData col9 = new ColumnMetaData();
+        col9.setColIndex(9);
+        col9.setColName("DECIMAL_DIGITS");
+        col9.setColType(Types.INTEGER);
+        return col9;
+    }
+
+    private ColumnMetaData buildNumPrecRadixMeta() {
+        ColumnMetaData col10 = new ColumnMetaData();
+        col10.setColIndex(10);
+        col10.setColName("NUM_PREC_RADIX");
+        col10.setColType(Types.INTEGER);
+        return col10;
+    }
+
+    private ColumnMetaData buildNullableMeta() {
+        ColumnMetaData col11 = new ColumnMetaData();
+        col11.setColIndex(11);
+        col11.setColName("NULLABLE");
+        col11.setColType(Types.INTEGER);
+        return col11;
+    }
+
+    private ColumnMetaData buildRemarksMeta(int colIndex) {
+        ColumnMetaData col12 = new ColumnMetaData();
+        col12.setColIndex(colIndex);
+        col12.setColName("REMARKS");
+        col12.setColType(Types.NCHAR);
+        return col12;
+    }
+
+    private ColumnMetaData buildColumnDefMeta() {
+        ColumnMetaData col13 = new ColumnMetaData();
+        col13.setColIndex(13);
+        col13.setColName("COLUMN_DEF");
+        col13.setColType(Types.NCHAR);
+        return col13;
+    }
+
+    private ColumnMetaData buildSqlDataTypeMeta() {
+        ColumnMetaData col14 = new ColumnMetaData();
+        col14.setColIndex(14);
+        col14.setColName("SQL_DATA_TYPE");
+        col14.setColType(Types.INTEGER);
+        return col14;
+    }
+
+    private ColumnMetaData buildSqlDatetimeSubMeta() {
+        ColumnMetaData col15 = new ColumnMetaData();
+        col15.setColIndex(15);
+        col15.setColName("SQL_DATETIME_SUB");
+        col15.setColType(Types.INTEGER);
+        return col15;
+    }
+
+    private ColumnMetaData buildCharOctetLengthMeta() {
+        ColumnMetaData col16 = new ColumnMetaData();
+        col16.setColIndex(16);
+        col16.setColName("CHAR_OCTET_LENGTH");
+        col16.setColType(Types.INTEGER);
+        return col16;
+    }
+
+    private ColumnMetaData buildOrdinalPositionMeta() {
+        ColumnMetaData col17 = new ColumnMetaData();
+        col17.setColIndex(17);
+        col17.setColName("ORDINAL_POSITION");
+        col17.setColType(Types.INTEGER);
+        return col17;
+    }
+
+    private ColumnMetaData buildIsNullableMeta() {
+        ColumnMetaData col18 = new ColumnMetaData();
+        col18.setColIndex(18);
+        col18.setColName("IS_NULLABLE");
+        col18.setColType(Types.NCHAR);
+        return col18;
+    }
+
+    private ColumnMetaData buildScopeCatalogMeta() {
+        ColumnMetaData col19 = new ColumnMetaData();
+        col19.setColIndex(19);
+        col19.setColName("SCOPE_CATALOG");
+        col19.setColType(Types.NCHAR);
+        return col19;
+    }
+
+    private ColumnMetaData buildScopeSchemaMeta() {
+        ColumnMetaData col20 = new ColumnMetaData();
+        col20.setColIndex(20);
+        col20.setColName("SCOPE_SCHEMA");
+        col20.setColType(Types.NCHAR);
+        return col20;
+    }
+
+    private ColumnMetaData buildScopeTableMeta() {
+        ColumnMetaData col21 = new ColumnMetaData();
+        col21.setColIndex(21);
+        col21.setColName("SCOPE_TABLE");
+        col21.setColType(Types.NCHAR);
+        return col21;
+    }
+
+    private ColumnMetaData buildSourceDataTypeMeta() {
+        ColumnMetaData col22 = new ColumnMetaData();
+        col22.setColIndex(22);
+        col22.setColName("SOURCE_DATA_TYPE");
+        col22.setColType(TSDBConstants.TSDB_DATA_TYPE_SMALLINT);
+        return col22;
+    }
+
+    private ColumnMetaData buildIsAutoIncrementMeta() {
+        ColumnMetaData col23 = new ColumnMetaData();
+        col23.setColIndex(23);
+        col23.setColName("IS_AUTOINCREMENT");
+        col23.setColType(Types.NCHAR);
+        return col23;
+    }
+
+    private ColumnMetaData buildIsGeneratedColumnMeta() {
+        ColumnMetaData col24 = new ColumnMetaData();
+        col24.setColIndex(24);
+        col24.setColName("IS_GENERATEDCOLUMN");
+        col24.setColType(Types.NCHAR);
+        return col24;
+    }
+
+    private List<ColumnMetaData> buildGetColumnsColumnMetaDataList() {
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableCatalogMeta(1));        //1. TABLE_CAT
+        columnMetaDataList.add(buildTableSchemaMeta(2));         //2. TABLE_SCHEMA
+        columnMetaDataList.add(buildTableNameMeta(3));           //3. TABLE_NAME
+        columnMetaDataList.add(buildColumnNameMeta(4));          //4. COLUMN_NAME
+        columnMetaDataList.add(buildDataTypeMeta(5));            //5. DATA_TYPE
+        columnMetaDataList.add(buildTypeNameMeta(6));            //6. TYPE_NAME
+        columnMetaDataList.add(buildColumnSizeMeta());                    //7. COLUMN_SIZE
+        columnMetaDataList.add(buildBufferLengthMeta());                  //8. BUFFER_LENGTH, not used
+        columnMetaDataList.add(buildDecimalDigitsMeta());       //9. DECIMAL_DIGITS
+        columnMetaDataList.add(buildNumPrecRadixMeta());        //10. NUM_PREC_RADIX
+        columnMetaDataList.add(buildNullableMeta());            //11. NULLABLE
+        columnMetaDataList.add(buildRemarksMeta(12));  //12. REMARKS
+        columnMetaDataList.add(buildColumnDefMeta());           //13. COLUMN_DEF
+        columnMetaDataList.add(buildSqlDataTypeMeta());         //14. SQL_DATA_TYPE
+        columnMetaDataList.add(buildSqlDatetimeSubMeta());      //15. SQL_DATETIME_SUB
+        columnMetaDataList.add(buildCharOctetLengthMeta());     //16. CHAR_OCTET_LENGTH
+        columnMetaDataList.add(buildOrdinalPositionMeta());     //17. ORDINAL_POSITION
+        columnMetaDataList.add(buildIsNullableMeta());          //18. IS_NULLABLE
+        columnMetaDataList.add(buildScopeCatalogMeta());        //19. SCOPE_CATALOG
+        columnMetaDataList.add(buildScopeSchemaMeta());         //20. SCOPE_SCHEMA
+        columnMetaDataList.add(buildScopeTableMeta());          //21. SCOPE_TABLE
+        columnMetaDataList.add(buildSourceDataTypeMeta());      //22. SOURCE_DATA_TYPE
+        columnMetaDataList.add(buildIsAutoIncrementMeta());     //23. IS_AUTOINCREMENT
+        columnMetaDataList.add(buildIsGeneratedColumnMeta());   //24. IS_GENERATEDCOLUMN
+        return columnMetaDataList;
+    }
+
+    public ResultSet getColumnPrivileges(String catalog, String schema, String table, String columnNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
-    public ResultSet getTablePrivileges(String catalog, String schemaPattern, String tableNamePattern)
-            throws SQLException {
+    public ResultSet getTablePrivileges(String catalog, String schemaPattern, String tableNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
-    public ResultSet getBestRowIdentifier(String catalog, String schema, String table, int scope, boolean nullable)
-            throws SQLException {
+    public ResultSet getBestRowIdentifier(String catalog, String schema, String table, int scope, boolean nullable) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -914,8 +971,7 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
         return getEmptyResultSet();
     }
 
-    public ResultSet getCrossReference(String parentCatalog, String parentSchema, String parentTable,
-                                       String foreignCatalog, String foreignSchema, String foreignTable) throws SQLException {
+    public ResultSet getCrossReference(String parentCatalog, String parentSchema, String parentTable, String foreignCatalog, String foreignSchema, String foreignTable) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -923,8 +979,7 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
         return getEmptyResultSet();
     }
 
-    public ResultSet getIndexInfo(String catalog, String schema, String table, boolean unique, boolean approximate)
-            throws SQLException {
+    public ResultSet getIndexInfo(String catalog, String schema, String table, boolean unique, boolean approximate) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -976,8 +1031,7 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
         return false;
     }
 
-    public ResultSet getUDTs(String catalog, String schemaPattern, String typeNamePattern, int[] types)
-            throws SQLException {
+    public ResultSet getUDTs(String catalog, String schemaPattern, String typeNamePattern, int[] types) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -1005,8 +1059,7 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
 
     public abstract ResultSet getSuperTables(String catalog, String schemaPattern, String tableNamePattern) throws SQLException;
 
-    public ResultSet getAttributes(String catalog, String schemaPattern, String typeNamePattern,
-                                   String attributeNamePattern) throws SQLException {
+    public ResultSet getAttributes(String catalog, String schemaPattern, String typeNamePattern, String attributeNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -1069,18 +1122,15 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
         return getEmptyResultSet();
     }
 
-    public ResultSet getFunctions(String catalog, String schemaPattern, String functionNamePattern)
-            throws SQLException {
+    public ResultSet getFunctions(String catalog, String schemaPattern, String functionNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
-    public ResultSet getFunctionColumns(String catalog, String schemaPattern, String functionNamePattern,
-                                        String columnNamePattern) throws SQLException {
+    public ResultSet getFunctionColumns(String catalog, String schemaPattern, String functionNamePattern, String columnNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
-    public ResultSet getPseudoColumns(String catalog, String schemaPattern, String tableNamePattern,
-                                      String columnNamePattern) throws SQLException {
+    public ResultSet getPseudoColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern) throws SQLException {
         return getEmptyResultSet();
     }
 
@@ -1093,164 +1143,142 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
     }
 
     protected ResultSet getCatalogs(Connection conn) throws SQLException {
-        try (Statement stmt = conn.createStatement()) {
-            DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
-            // set up ColumnMetaDataList
-            List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-            // TABLE_CAT
-            ColumnMetaData col1 = new ColumnMetaData();
-            col1.setColIndex(1);
-            col1.setColName("TABLE_CAT");
-            col1.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col1);
-
-            resultSet.setColumnMetaDataList(columnMetaDataList);
+        DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        // set up ColumnMetaDataList
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableCatalogMeta(1));       // 1. TABLE_CAT
+        resultSet.setColumnMetaDataList(columnMetaDataList);
 
+        try (Statement stmt = conn.createStatement()) {
             List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
             ResultSet rs = stmt.executeQuery("show databases");
             while (rs.next()) {
                 TSDBResultSetRowData rowData = new TSDBResultSetRowData(1);
-                rowData.setString(0, rs.getString("name"));
+                rowData.setStringValue(1, rs.getString("name"));
                 rowDataList.add(rowData);
             }
             resultSet.setRowDataList(rowDataList);
-            return resultSet;
         }
+        return resultSet;
     }
 
 
     protected ResultSet getPrimaryKeys(String catalog, String schema, String table, Connection conn) throws SQLException {
-        try (Statement stmt = conn.createStatement()) {
-            if (catalog == null || catalog.isEmpty())
-                return null;
+        if (catalog == null || catalog.isEmpty())
+            return null;
+        if (!isAvailableCatalog(conn, catalog))
+            return new EmptyResultSet();
 
-            ResultSet databases = stmt.executeQuery("show databases");
-            String dbname = null;
-            while (databases.next()) {
-                dbname = databases.getString("name");
-                if (dbname.equalsIgnoreCase(catalog))
-                    break;
-            }
-            databases.close();
-            if (dbname == null)
-                return null;
-
-            stmt.execute("use " + dbname);
-            DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        try (Statement stmt = conn.createStatement()) {
             // set up ColumnMetaDataList
-            List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-            // TABLE_CAT
-            ColumnMetaData col1 = new ColumnMetaData();
-            col1.setColIndex(0);
-            col1.setColName("TABLE_CAT");
-            col1.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col1);
-            // TABLE_SCHEM
-            ColumnMetaData col2 = new ColumnMetaData();
-            col2.setColIndex(1);
-            col2.setColName("TABLE_SCHEM");
-            col2.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col2);
-            // TABLE_NAME
-            ColumnMetaData col3 = new ColumnMetaData();
-            col3.setColIndex(2);
-            col3.setColName("TABLE_NAME");
-            col3.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col3);
-            // COLUMN_NAME
-            ColumnMetaData col4 = new ColumnMetaData();
-            col4.setColIndex(3);
-            col4.setColName("COLUMN_NAME");
-            col4.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col4);
-            // KEY_SEQ
-            ColumnMetaData col5 = new ColumnMetaData();
-            col5.setColIndex(4);
-            col5.setColName("KEY_SEQ");
-            col5.setColType(TSDBConstants.TSDB_DATA_TYPE_INT);
-            columnMetaDataList.add(col5);
-            // PK_NAME
-            ColumnMetaData col6 = new ColumnMetaData();
-            col6.setColIndex(5);
-            col6.setColName("PK_NAME");
-            col6.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col6);
-            resultSet.setColumnMetaDataList(columnMetaDataList);
-
+            resultSet.setColumnMetaDataList(buildGetPrimaryKeysMetadataList());
             // set rowData
             List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
-            ResultSet rs = stmt.executeQuery("describe " + dbname + "." + table);
+            ResultSet rs = stmt.executeQuery("describe " + catalog + "." + table);
             rs.next();
             TSDBResultSetRowData rowData = new TSDBResultSetRowData(6);
-            rowData.setString(0, null);
-            rowData.setString(1, null);
-            rowData.setString(2, table);
-            String pkName = rs.getString(1);
-            rowData.setString(3, pkName);
-            rowData.setInt(4, 1);
-            rowData.setString(5, pkName);
+            rowData.setStringValue(1, catalog);
+            rowData.setStringValue(2, null);
+            rowData.setStringValue(3, table);
+            String primaryKey = rs.getString("Field");
+            rowData.setStringValue(4, primaryKey);
+            rowData.setShortValue(5, (short) 1);
+            rowData.setStringValue(6, primaryKey);
             rowDataList.add(rowData);
             resultSet.setRowDataList(rowDataList);
-            return resultSet;
         }
+        return resultSet;
     }
 
-    protected ResultSet getSuperTables(String catalog, String schemaPattern, String tableNamePattern, Connection conn) throws SQLException {
-        try (Statement stmt = conn.createStatement()) {
-            if (catalog == null || catalog.isEmpty())
-                return null;
+    private List<ColumnMetaData> buildGetPrimaryKeysMetadataList() {
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableCatalogMeta(1));   // 1. TABLE_CAT
+        columnMetaDataList.add(buildTableSchemaMeta(2));    // 2. TABLE_SCHEM
+        columnMetaDataList.add(buildTableNameMeta(3));      // 3. TABLE_NAME
+        columnMetaDataList.add(buildColumnNameMeta(4));     // 4. COLUMN_NAME
+        columnMetaDataList.add(buildKeySeqMeta(5));         // 5. KEY_SEQ
+        columnMetaDataList.add(buildPrimaryKeyNameMeta(6)); // 6. PK_NAME
+        return columnMetaDataList;
+    }
+
+    private ColumnMetaData buildKeySeqMeta(int colIndex) {
+        ColumnMetaData col5 = new ColumnMetaData();
+        col5.setColIndex(colIndex);
+        col5.setColName("KEY_SEQ");
+        col5.setColType(Types.SMALLINT);
+        return col5;
+    }
+
+    private ColumnMetaData buildPrimaryKeyNameMeta(int colIndex) {
+        ColumnMetaData col6 = new ColumnMetaData();
+        col6.setColIndex(colIndex);
+        col6.setColName("PK_NAME");
+        col6.setColType(Types.NCHAR);
+        return col6;
+    }
 
+    private boolean isAvailableCatalog(Connection connection, String catalog) {
+        try (Statement stmt = connection.createStatement()) {
             ResultSet databases = stmt.executeQuery("show databases");
-            String dbname = null;
             while (databases.next()) {
-                dbname = databases.getString("name");
+                String dbname = databases.getString("name");
+                this.database = dbname;
+                this.precision = databases.getString("precision");
                 if (dbname.equalsIgnoreCase(catalog))
-                    break;
+                    return true;
             }
             databases.close();
-            if (dbname == null)
-                return null;
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+        return false;
+    }
 
-            stmt.execute("use " + dbname);
-            DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
-            // set up ColumnMetaDataList
-            List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
-            // TABLE_CAT
-            ColumnMetaData col1 = new ColumnMetaData();
-            col1.setColIndex(0);
-            col1.setColName("TABLE_CAT");
-            col1.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col1);
-            // TABLE_SCHEM
-            ColumnMetaData col2 = new ColumnMetaData();
-            col2.setColIndex(1);
-            col2.setColName("TABLE_SCHEM");
-            col2.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col2);
-            // TABLE_NAME
-            ColumnMetaData col3 = new ColumnMetaData();
-            col3.setColIndex(2);
-            col3.setColName("TABLE_NAME");
-            col3.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col3);
-            // SUPERTABLE_NAME
-            ColumnMetaData col4 = new ColumnMetaData();
-            col4.setColIndex(3);
-            col4.setColName("SUPERTABLE_NAME");
-            col4.setColType(TSDBConstants.TSDB_DATA_TYPE_NCHAR);
-            columnMetaDataList.add(col4);
-            resultSet.setColumnMetaDataList(columnMetaDataList);
+    protected ResultSet getSuperTables(String catalog, String schemaPattern, String tableNamePattern, Connection conn) throws SQLException {
+        if (catalog == null || catalog.isEmpty())
+            return null;
+
+        if (!isAvailableCatalog(conn, catalog)) {
+            return new EmptyResultSet();
+        }
 
+        DatabaseMetaDataResultSet resultSet = new DatabaseMetaDataResultSet();
+        try (Statement stmt = conn.createStatement()) {
+            // set up ColumnMetaDataList
+            resultSet.setColumnMetaDataList(buildGetSuperTablesColumnMetaDataList());
+            // set result set row data
+            stmt.execute("use " + catalog);
             ResultSet rs = stmt.executeQuery("show tables like '" + tableNamePattern + "'");
             List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
             while (rs.next()) {
                 TSDBResultSetRowData rowData = new TSDBResultSetRowData(4);
-                rowData.setString(2, rs.getString(1));
-                rowData.setString(3, rs.getString(4));
+                rowData.setStringValue(1, catalog);
+                rowData.setStringValue(2, null);
+                rowData.setStringValue(3, rs.getString("table_name"));
+                rowData.setStringValue(4, rs.getString("stable_name"));
                 rowDataList.add(rowData);
             }
             resultSet.setRowDataList(rowDataList);
-            return resultSet;
         }
+        return resultSet;
+    }
+
+    private List<ColumnMetaData> buildGetSuperTablesColumnMetaDataList() {
+        List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+        columnMetaDataList.add(buildTableCatalogMeta(1));       // 1. TABLE_CAT
+        columnMetaDataList.add(buildTableSchemaMeta(2));        // 2. TABLE_SCHEM
+        columnMetaDataList.add(buildTableNameMeta(3));          // 3. TABLE_NAME
+        columnMetaDataList.add(buildSuperTableNameMeta(4));     // 4. SUPERTABLE_NAME
+        return columnMetaDataList;
     }
+
+    private ColumnMetaData buildSuperTableNameMeta(int colIndex) {
+        ColumnMetaData col4 = new ColumnMetaData();
+        col4.setColIndex(colIndex);
+        col4.setColName("SUPERTABLE_NAME");
+        col4.setColType(Types.NCHAR);
+        return col4;
+    }
+
 }
\ No newline at end of file

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractParameterMetaData.java

 package com.taosdata.jdbc;
 
+import com.sun.org.apache.xpath.internal.operations.Bool;
+
 import java.sql.ParameterMetaData;
 import java.sql.SQLException;
 import java.sql.Timestamp;
@@ -49,6 +51,22 @@ public abstract class AbstractParameterMetaData extends WrapperImpl implements P
         if (param < 1 && param >= parameters.length)
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_PARAMETER_INDEX_OUT_RANGE);
 
+        if (parameters[param - 1] instanceof Boolean)
+            return TSDBConstants.BOOLEAN_PRECISION;
+        if (parameters[param - 1] instanceof Byte)
+            return TSDBConstants.TINYINT_PRECISION;
+        if (parameters[param - 1] instanceof Short)
+            return TSDBConstants.SMALLINT_PRECISION;
+        if (parameters[param - 1] instanceof Integer)
+            return TSDBConstants.INT_PRECISION;
+        if (parameters[param - 1] instanceof Long)
+            return TSDBConstants.BIGINT_PRECISION;
+        if (parameters[param - 1] instanceof Timestamp)
+            return TSDBConstants.TIMESTAMP_MS_PRECISION;
+        if (parameters[param - 1] instanceof Float)
+            return TSDBConstants.FLOAT_PRECISION;
+        if (parameters[param - 1] instanceof Double)
+            return TSDBConstants.DOUBLE_PRECISION;
         if (parameters[param - 1] instanceof String)
             return ((String) parameters[param - 1]).length();
         if (parameters[param - 1] instanceof byte[])
@@ -60,6 +78,11 @@ public abstract class AbstractParameterMetaData extends WrapperImpl implements P
     public int getScale(int param) throws SQLException {
         if (param < 1 && param >= parameters.length)
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_PARAMETER_INDEX_OUT_RANGE);
+
+        if (parameters[param - 1] instanceof Float)
+            return TSDBConstants.FLOAT_SCALE;
+        if (parameters[param - 1] instanceof Double)
+            return TSDBConstants.DOUBLE_SCALE;
         return 0;
     }
 

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractResultSet.java

@@ -66,10 +66,16 @@ public abstract class AbstractResultSet extends WrapperImpl implements ResultSet
     public abstract byte[] getBytes(int columnIndex) throws SQLException;
 
     @Override
-    public abstract Date getDate(int columnIndex) throws SQLException;
+    public Date getDate(int columnIndex) throws SQLException {
+        Timestamp timestamp = getTimestamp(columnIndex);
+        return timestamp == null ? null : new Date(timestamp.getTime());
+    }
 
     @Override
-    public abstract Time getTime(int columnIndex) throws SQLException;
+    public Time getTime(int columnIndex) throws SQLException {
+        Timestamp timestamp = getTimestamp(columnIndex);
+        return timestamp == null ? null : new Time(timestamp.getTime());
+    }
 
     @Override
     public abstract Timestamp getTimestamp(int columnIndex) throws SQLException;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/DatabaseMetaDataResultSet.java

@@ -14,76 +14,42 @@
  *****************************************************************************/
 package com.taosdata.jdbc;
 
-import java.io.InputStream;
-import java.io.Reader;
 import java.math.BigDecimal;
-import java.net.URL;
-import java.sql.Date;
 import java.sql.*;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Iterator;
+import java.util.List;
 
 /*
- * TDengine only supports a subset of the standard SQL, thus this implemetation of the
+ * TDengine only supports a subset of the standard SQL, thus this implementation of the
  * standard JDBC API contains more or less some adjustments customized for certain
  * compatibility needs.
  */
-public class DatabaseMetaDataResultSet implements ResultSet {
+public class DatabaseMetaDataResultSet extends AbstractResultSet {
 
-    private List<ColumnMetaData> columnMetaDataList;
-    private List<TSDBResultSetRowData> rowDataList;
+    private List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+    private List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
     private TSDBResultSetRowData rowCursor;
 
     // position of cursor, starts from 0 as beforeFirst, increases as next() is called
     private int cursorRowNumber = 0;
 
-    public DatabaseMetaDataResultSet() {
-        rowDataList = new ArrayList<TSDBResultSetRowData>();
-        columnMetaDataList = new ArrayList<ColumnMetaData>();
-    }
-
-    public List<TSDBResultSetRowData> getRowDataList() {
-        return rowDataList;
-    }
-
     public void setRowDataList(List<TSDBResultSetRowData> rowDataList) {
         this.rowDataList = rowDataList;
     }
 
-    public List<ColumnMetaData> getColumnMetaDataList() {
-        return columnMetaDataList;
-    }
-
     public void setColumnMetaDataList(List<ColumnMetaData> columnMetaDataList) {
         this.columnMetaDataList = columnMetaDataList;
     }
 
-    public TSDBResultSetRowData getRowCursor() {
-        return rowCursor;
-    }
-
-    public void setRowCursor(TSDBResultSetRowData rowCursor) {
-        this.rowCursor = rowCursor;
-    }
-
     @Override
     public boolean next() throws SQLException {
-//        boolean ret = false;
-//        if (rowDataList.size() > 0) {
-//            ret = rowDataList.iterator().hasNext();
-//            if (ret) {
-//                rowCursor = rowDataList.iterator().next();
-//                cursorRowNumber++;
-//            }
-//        }
-//        return ret;
-
-        /**** add by zyyang 2020-09-29 ****************/
         boolean ret = false;
         if (!rowDataList.isEmpty() && cursorRowNumber < rowDataList.size()) {
             rowCursor = rowDataList.get(cursorRowNumber++);
             ret = true;
         }
-
         return ret;
     }
 
@@ -99,189 +65,72 @@ public class DatabaseMetaDataResultSet implements ResultSet {
 
     @Override
     public String getString(int columnIndex) throws SQLException {
-        columnIndex--;
-        int colType = columnMetaDataList.get(columnIndex).getColType();
-        return rowCursor.getString(columnIndex, colType);
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getString(columnIndex, nativeType);
     }
 
     @Override
     public boolean getBoolean(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getBoolean(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getBoolean(columnIndex, nativeType);
     }
 
     @Override
     public byte getByte(int columnIndex) throws SQLException {
-        columnIndex--;
-        return (byte) rowCursor.getInt(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return (byte) rowCursor.getInt(columnIndex, nativeType);
     }
 
     @Override
     public short getShort(int columnIndex) throws SQLException {
-        columnIndex--;
-        return (short) rowCursor.getInt(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return (short) rowCursor.getInt(columnIndex, nativeType);
     }
 
     @Override
     public int getInt(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getInt(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getInt(columnIndex, nativeType);
     }
 
     @Override
     public long getLong(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getLong(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getLong(columnIndex, nativeType);
     }
 
     @Override
     public float getFloat(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getFloat(columnIndex, columnMetaDataList.get(columnIndex).getColType());
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getFloat(columnIndex, nativeType);
     }
 
     @Override
     public double getDouble(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getDouble(columnIndex, columnMetaDataList.get(columnIndex).getColType());
-    }
-
-    @Override
-    public BigDecimal getBigDecimal(int columnIndex, int scale) throws SQLException {
-        columnIndex--;
-        return new BigDecimal(rowCursor.getDouble(columnIndex, columnMetaDataList.get(columnIndex).getColType()));
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getDouble(columnIndex, nativeType);
     }
 
     @Override
     public byte[] getBytes(int columnIndex) throws SQLException {
-        columnIndex--;
-        return (rowCursor.getString(columnIndex, columnMetaDataList.get(columnIndex).getColType())).getBytes();
-    }
-
-    @Override
-    public Date getDate(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public Time getTime(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return (rowCursor.getString(columnIndex, nativeType)).getBytes();
     }
 
     @Override
     public Timestamp getTimestamp(int columnIndex) throws SQLException {
-        columnIndex--;
-        return rowCursor.getTimestamp(columnIndex);
-    }
-
-    @Override
-    public InputStream getAsciiStream(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public InputStream getUnicodeStream(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public InputStream getBinaryStream(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public String getString(String columnLabel) throws SQLException {
-        return getString(findColumn(columnLabel));
-    }
-
-    @Override
-    public boolean getBoolean(String columnLabel) throws SQLException {
-        return getBoolean(findColumn(columnLabel));
-    }
-
-    @Override
-    public byte getByte(String columnLabel) throws SQLException {
-        return getByte(findColumn(columnLabel));
-    }
-
-    @Override
-    public short getShort(String columnLabel) throws SQLException {
-        return getShort(findColumn(columnLabel));
-    }
-
-    @Override
-    public int getInt(String columnLabel) throws SQLException {
-        return getInt(findColumn(columnLabel));
-    }
-
-    @Override
-    public long getLong(String columnLabel) throws SQLException {
-        return getLong(findColumn(columnLabel));
-    }
-
-    @Override
-    public float getFloat(String columnLabel) throws SQLException {
-        return getFloat(findColumn(columnLabel));
-    }
-
-    @Override
-    public double getDouble(String columnLabel) throws SQLException {
-        return getDouble(findColumn(columnLabel));
-    }
-
-    @Override
-    public BigDecimal getBigDecimal(String columnLabel, int scale) throws SQLException {
-        return getBigDecimal(findColumn(columnLabel));
-    }
-
-    @Override
-    public byte[] getBytes(String columnLabel) throws SQLException {
-        return getBytes(findColumn(columnLabel));
-    }
-
-    @Override
-    public Date getDate(String columnLabel) throws SQLException {
-        return getDate(findColumn(columnLabel));
-    }
-
-    @Override
-    public Time getTime(String columnLabel) throws SQLException {
-        return getTime(findColumn(columnLabel));
-    }
-
-    @Override
-    public Timestamp getTimestamp(String columnLabel) throws SQLException {
-        return getTimestamp(findColumn(columnLabel));
-    }
-
-    @Override
-    public InputStream getAsciiStream(String columnLabel) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public InputStream getUnicodeStream(String columnLabel) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public InputStream getBinaryStream(String columnLabel) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public SQLWarning getWarnings() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void clearWarnings() throws SQLException {
-
-    }
-
-    @Override
-    public String getCursorName() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        return rowCursor.getTimestamp(columnIndex,nativeType);
     }
 
     @Override
@@ -291,12 +140,7 @@ public class DatabaseMetaDataResultSet implements ResultSet {
 
     @Override
     public Object getObject(int columnIndex) throws SQLException {
-        return rowCursor.get(columnIndex);
-    }
-
-    @Override
-    public Object getObject(String columnLabel) throws SQLException {
-        return rowCursor.get(findColumn(columnLabel));
+        return rowCursor.getObject(columnIndex);
     }
 
     @Override
@@ -304,31 +148,19 @@ public class DatabaseMetaDataResultSet implements ResultSet {
         Iterator<ColumnMetaData> colMetaDataIt = this.columnMetaDataList.iterator();
         while (colMetaDataIt.hasNext()) {
             ColumnMetaData colMetaData = colMetaDataIt.next();
-            if (colMetaData.getColName() != null && colMetaData.getColName().equalsIgnoreCase(columnLabel)) {
-                return colMetaData.getColIndex() + 1;
+            if (colMetaData.getColName() != null && colMetaData.getColName().equals(columnLabel)) {
+                return colMetaData.getColIndex();
             }
         }
         throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
     }
 
-    @Override
-    public Reader getCharacterStream(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public Reader getCharacterStream(String columnLabel) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
     @Override
     public BigDecimal getBigDecimal(int columnIndex) throws SQLException {
-        return new BigDecimal(rowCursor.getDouble(columnIndex, columnMetaDataList.get(columnIndex).getColType()));
-    }
-
-    @Override
-    public BigDecimal getBigDecimal(String columnLabel) throws SQLException {
-        return getBigDecimal(findColumn(columnLabel));
+        int colType = columnMetaDataList.get(columnIndex - 1).getColType();
+        int nativeType = TSDBConstants.jdbcType2TaosType(colType);
+        double value = rowCursor.getDouble(columnIndex, nativeType);
+        return new BigDecimal(value);
     }
 
     @Override
@@ -378,7 +210,6 @@ public class DatabaseMetaDataResultSet implements ResultSet {
         } else {
             return 0;
         }
-
     }
 
     @Override
@@ -397,680 +228,23 @@ public class DatabaseMetaDataResultSet implements ResultSet {
     }
 
     @Override
-    public void setFetchDirection(int direction) throws SQLException {
-
-    }
-
-    @Override
-    public int getFetchDirection() throws SQLException {
-        return ResultSet.FETCH_FORWARD;
-    }
-
-    @Override
-    public void setFetchSize(int rows) throws SQLException {
-
-    }
-
-    @Override
-    public int getFetchSize() throws SQLException {
-        return 0;
-    }
-
-    @Override
-    public int getType() throws SQLException {
-        return ResultSet.TYPE_FORWARD_ONLY;
-    }
-
-    @Override
-    public int getConcurrency() throws SQLException {
-        return ResultSet.CONCUR_READ_ONLY;
-    }
-
-    @Override
-    public boolean rowUpdated() throws SQLException {
-        return false;
+    public Statement getStatement() throws SQLException {
+        return null;
     }
 
-    @Override
-    public boolean rowInserted() throws SQLException {
-        return false;
+    public Timestamp getTimestamp(int columnIndex, Calendar cal) throws SQLException {
+        //TODO: calendar is not used
+        return getTimestamp(columnIndex);
     }
 
     @Override
-    public boolean rowDeleted() throws SQLException {
+    public boolean isClosed() throws SQLException {
         return false;
     }
 
     @Override
-    public void updateNull(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBoolean(int columnIndex, boolean x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateByte(int columnIndex, byte x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateShort(int columnIndex, short x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateInt(int columnIndex, int x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateLong(int columnIndex, long x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateFloat(int columnIndex, float x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateDouble(int columnIndex, double x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBigDecimal(int columnIndex, BigDecimal x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateString(int columnIndex, String x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBytes(int columnIndex, byte[] x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateDate(int columnIndex, Date x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateTime(int columnIndex, Time x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateTimestamp(int columnIndex, Timestamp x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateAsciiStream(int columnIndex, InputStream x, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBinaryStream(int columnIndex, InputStream x, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateCharacterStream(int columnIndex, Reader x, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateObject(int columnIndex, Object x, int scaleOrLength) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateObject(int columnIndex, Object x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateNull(String columnLabel) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBoolean(String columnLabel, boolean x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateByte(String columnLabel, byte x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateShort(String columnLabel, short x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateInt(String columnLabel, int x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateLong(String columnLabel, long x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateFloat(String columnLabel, float x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateDouble(String columnLabel, double x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBigDecimal(String columnLabel, BigDecimal x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateString(String columnLabel, String x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+    public String getNString(int columnIndex) throws SQLException {
+        return getString(columnIndex);
     }
 
-    @Override
-    public void updateBytes(String columnLabel, byte[] x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateDate(String columnLabel, Date x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateTime(String columnLabel, Time x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateTimestamp(String columnLabel, Timestamp x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateAsciiStream(String columnLabel, InputStream x, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateBinaryStream(String columnLabel, InputStream x, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateCharacterStream(String columnLabel, Reader reader, int length) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateObject(String columnLabel, Object x, int scaleOrLength) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateObject(String columnLabel, Object x) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void insertRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void updateRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void deleteRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void refreshRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void cancelRowUpdates() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void moveToInsertRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public void moveToCurrentRow() throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public Statement getStatement() throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Object getObject(int columnIndex, Map<String, Class<?>> map) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public Ref getRef(int columnIndex) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public Blob getBlob(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Clob getClob(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Array getArray(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Object getObject(String columnLabel, Map<String, Class<?>> map) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Ref getRef(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Blob getBlob(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Clob getClob(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Array getArray(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Date getDate(int columnIndex, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Date getDate(String columnLabel, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Time getTime(int columnIndex, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Time getTime(String columnLabel, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Timestamp getTimestamp(int columnIndex, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Timestamp getTimestamp(String columnLabel, Calendar cal) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public URL getURL(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public URL getURL(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public void updateRef(int columnIndex, Ref x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateRef(String columnLabel, Ref x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(int columnIndex, Blob x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(String columnLabel, Blob x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(int columnIndex, Clob x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(String columnLabel, Clob x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateArray(int columnIndex, Array x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateArray(String columnLabel, Array x) throws SQLException {
-
-    }
-
-    @Override
-    public RowId getRowId(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public RowId getRowId(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public void updateRowId(int columnIndex, RowId x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateRowId(String columnLabel, RowId x) throws SQLException {
-
-    }
-
-    @Override
-    public int getHoldability() throws SQLException {
-        return 0;
-    }
-
-    @Override
-    public boolean isClosed() throws SQLException {
-        return false;
-    }
-
-    @Override
-    public void updateNString(int columnIndex, String nString) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNString(String columnLabel, String nString) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(int columnIndex, NClob nClob) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(String columnLabel, NClob nClob) throws SQLException {
-
-    }
-
-    @Override
-    public NClob getNClob(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public NClob getNClob(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public SQLXML getSQLXML(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public SQLXML getSQLXML(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public void updateSQLXML(int columnIndex, SQLXML xmlObject) throws SQLException {
-
-    }
-
-    @Override
-    public void updateSQLXML(String columnLabel, SQLXML xmlObject) throws SQLException {
-
-    }
-
-    @Override
-    public String getNString(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public String getNString(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Reader getNCharacterStream(int columnIndex) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public Reader getNCharacterStream(String columnLabel) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public void updateNCharacterStream(int columnIndex, Reader x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNCharacterStream(String columnLabel, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateAsciiStream(int columnIndex, InputStream x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBinaryStream(int columnIndex, InputStream x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateCharacterStream(int columnIndex, Reader x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateAsciiStream(String columnLabel, InputStream x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBinaryStream(String columnLabel, InputStream x, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateCharacterStream(String columnLabel, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(int columnIndex, InputStream inputStream, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(String columnLabel, InputStream inputStream, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(int columnIndex, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(String columnLabel, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(int columnIndex, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(String columnLabel, Reader reader, long length) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNCharacterStream(int columnIndex, Reader x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNCharacterStream(String columnLabel, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public void updateAsciiStream(int columnIndex, InputStream x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBinaryStream(int columnIndex, InputStream x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateCharacterStream(int columnIndex, Reader x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateAsciiStream(String columnLabel, InputStream x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBinaryStream(String columnLabel, InputStream x) throws SQLException {
-
-    }
-
-    @Override
-    public void updateCharacterStream(String columnLabel, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(int columnIndex, InputStream inputStream) throws SQLException {
-
-    }
-
-    @Override
-    public void updateBlob(String columnLabel, InputStream inputStream) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(int columnIndex, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public void updateClob(String columnLabel, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(int columnIndex, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public void updateNClob(String columnLabel, Reader reader) throws SQLException {
-
-    }
-
-    @Override
-    public <T> T getObject(int columnIndex, Class<T> type) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public <T> T getObject(String columnLabel, Class<T> type) throws SQLException {
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-    }
-
-    @Override
-    public <T> T unwrap(Class<T> iface) throws SQLException {
-        return null;
-    }
-
-    @Override
-    public boolean isWrapperFor(Class<?> iface) throws SQLException {
-        return false;
-    }
-
-    private int getTrueColumnIndex(int columnIndex) throws SQLException {
-        if (columnIndex < 1) {
-            throw new SQLException("Column Index out of range, " + columnIndex + " < " + 1);
-        }
-
-        int numOfCols = this.columnMetaDataList.size();
-        if (columnIndex > numOfCols) {
-            throw new SQLException("Column Index out of range, " + columnIndex + " > " + numOfCols);
-        }
-
-        return columnIndex - 1;
-    }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBConstants.java

@@ -41,15 +41,15 @@ public abstract class TSDBConstants {
     public static final int TSDB_DATA_TYPE_BINARY = 8;
     public static final int TSDB_DATA_TYPE_TIMESTAMP = 9;
     public static final int TSDB_DATA_TYPE_NCHAR = 10;
-    /*
-    系统增加新的无符号数据类型，分别是：
-        unsigned tinyint， 数值范围：0-254, NULL 为255
-        unsigned smallint，数值范围： 0-65534， NULL 为65535
-        unsigned int，数值范围：0-4294967294，NULL 为4294967295u
-        unsigned bigint，数值范围：0-18446744073709551614u，NULL 为18446744073709551615u。
-    example:
-        create table tb(ts timestamp, a tinyint unsigned, b smallint unsigned, c int unsigned, d bigint unsigned);
-    */
+    /**
+     * 系统增加新的无符号数据类型，分别是：
+     * unsigned tinyint， 数值范围：0-254, NULL 为255
+     * unsigned smallint，数值范围： 0-65534， NULL 为65535
+     * unsigned int，数值范围：0-4294967294，NULL 为4294967295u
+     * unsigned bigint，数值范围：0-18446744073709551614u，NULL 为18446744073709551615u。
+     * example:
+     * create table tb(ts timestamp, a tinyint unsigned, b smallint unsigned, c int unsigned, d bigint unsigned);
+     */
     public static final int TSDB_DATA_TYPE_UTINYINT = 11;       //unsigned tinyint
     public static final int TSDB_DATA_TYPE_USMALLINT = 12;      //unsigned smallint
     public static final int TSDB_DATA_TYPE_UINT = 13;           //unsigned int
@@ -57,6 +57,47 @@ public abstract class TSDBConstants {
     // nchar column max length
     public static final int maxFieldSize = 16 * 1024;
 
+    // precision for data types
+    public static final int BOOLEAN_PRECISION = 1;
+    public static final int TINYINT_PRECISION = 4;
+    public static final int SMALLINT_PRECISION = 6;
+    public static final int INT_PRECISION = 11;
+    public static final int BIGINT_PRECISION = 20;
+    public static final int FLOAT_PRECISION = 12;
+    public static final int DOUBLE_PRECISION = 22;
+    public static final int TIMESTAMP_MS_PRECISION = 23;
+    public static final int TIMESTAMP_US_PRECISION = 26;
+    // scale for data types
+    public static final int FLOAT_SCALE = 31;
+    public static final int DOUBLE_SCALE = 31;
+
+    public static int typeName2JdbcType(String type) {
+        switch (type.toUpperCase()) {
+            case "TIMESTAMP":
+                return Types.TIMESTAMP;
+            case "INT":
+                return Types.INTEGER;
+            case "BIGINT":
+                return Types.BIGINT;
+            case "FLOAT":
+                return Types.FLOAT;
+            case "DOUBLE":
+                return Types.DOUBLE;
+            case "BINARY":
+                return Types.BINARY;
+            case "SMALLINT":
+                return Types.SMALLINT;
+            case "TINYINT":
+                return Types.TINYINT;
+            case "BOOL":
+                return Types.BOOLEAN;
+            case "NCHAR":
+                return Types.NCHAR;
+            default:
+                return Types.NULL;
+        }
+    }
+
     public static int taosType2JdbcType(int taosType) throws SQLException {
         switch (taosType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
@@ -88,7 +129,7 @@ public abstract class TSDBConstants {
     }
 
     public static String taosType2JdbcTypeName(int taosType) throws SQLException {
-        switch (taosType){
+        switch (taosType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return "BOOL";
             case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
@@ -119,7 +160,7 @@ public abstract class TSDBConstants {
     }
 
     public static int jdbcType2TaosType(int jdbcType) throws SQLException {
-        switch (jdbcType){
+        switch (jdbcType) {
             case Types.BOOLEAN:
                 return TSDBConstants.TSDB_DATA_TYPE_BOOL;
             case Types.TINYINT:
@@ -145,7 +186,7 @@ public abstract class TSDBConstants {
     }
 
     public static String jdbcType2TaosTypeName(int jdbcType) throws SQLException {
-        switch (jdbcType){
+        switch (jdbcType) {
             case Types.BOOLEAN:
                 return "BOOL";
             case Types.TINYINT:

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java

@@ -16,13 +16,13 @@
  */
 package com.taosdata.jdbc;
 
+import com.taosdata.jdbc.utils.TaosInfo;
+
 import java.nio.ByteBuffer;
 import java.sql.SQLException;
 import java.sql.SQLWarning;
 import java.util.List;
 
-import com.taosdata.jdbc.utils.TaosInfo;
-
 /**
  * JNI connector
  */
@@ -30,10 +30,10 @@ public class TSDBJNIConnector {
     private static volatile Boolean isInitialized = false;
 
     private TaosInfo taosInfo = TaosInfo.getInstance();
-    
+
     // Connection pointer used in C
     private long taos = TSDBConstants.JNI_NULL_POINTER;
-    
+
     // result set status in current connection
     private boolean isResultsetClosed;
 
@@ -194,7 +194,9 @@ public class TSDBJNIConnector {
      * Get schema metadata
      */
     public int getSchemaMetaData(long resultSet, List<ColumnMetaData> columnMetaData) {
-        return this.getSchemaMetaDataImp(this.taos, resultSet, columnMetaData);
+        int ret = this.getSchemaMetaDataImp(this.taos, resultSet, columnMetaData);
+        columnMetaData.stream().forEach(column -> column.setColIndex(column.getColIndex() + 1));
+        return ret;
     }
 
     private native int getSchemaMetaDataImp(long connection, long resultSet, List<ColumnMetaData> columnMetaData);
@@ -221,7 +223,7 @@ public class TSDBJNIConnector {
      */
     public void closeConnection() throws SQLException {
         int code = this.closeConnectionImp(this.taos);
-        
+
         if (code < 0) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL);
         } else if (code == 0) {
@@ -229,7 +231,7 @@ public class TSDBJNIConnector {
         } else {
             throw new SQLException("Undefined error code returned by TDengine when closing a connection");
         }
-        
+
         // invoke closeConnectionImpl only here
         taosInfo.connect_close_increment();
     }
@@ -274,67 +276,76 @@ public class TSDBJNIConnector {
     }
 
     private native int validateCreateTableSqlImp(long connection, byte[] sqlBytes);
-    
-	public long prepareStmt(String sql) throws SQLException {
-    	Long stmt = prepareStmtImp(sql.getBytes(), this.taos);
-		if (stmt == TSDBConstants.JNI_TDENGINE_ERROR) {
-			throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_SQL);
-		} else if (stmt == TSDBConstants.JNI_CONNECTION_NULL) {
+
+    public long prepareStmt(String sql) throws SQLException {
+        Long stmt;
+        try {
+            stmt = prepareStmtImp(sql.getBytes(), this.taos);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_ENCODING);
+        }
+
+        if (stmt == TSDBConstants.JNI_CONNECTION_NULL) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_CONNECTION_NULL);
-        } else if (stmt == TSDBConstants.JNI_SQL_NULL) {
+        }
+
+        if (stmt == TSDBConstants.JNI_SQL_NULL) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_SQL_NULL);
-        } else if (stmt == TSDBConstants.JNI_OUT_OF_MEMORY) {
+        }
+
+        if (stmt == TSDBConstants.JNI_OUT_OF_MEMORY) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_OUT_OF_MEMORY);
         }
-        
-    	return stmt;
+
+        return stmt;
     }
-    
+
     private native long prepareStmtImp(byte[] sql, long con);
-    
+
     public void setBindTableName(long stmt, String tableName) throws SQLException {
-		int code = setBindTableNameImp(stmt, tableName, this.taos);
-		if (code != TSDBConstants.JNI_SUCCESS) {
+        int code = setBindTableNameImp(stmt, tableName, this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to set table name");
-		}
-	}
-    
+        }
+    }
+
     private native int setBindTableNameImp(long stmt, String name, long conn);
-    
+
     public void setBindTableNameAndTags(long stmt, String tableName, int numOfTags, ByteBuffer tags, ByteBuffer typeList, ByteBuffer lengthList, ByteBuffer nullList) throws SQLException {
-    	int code = setTableNameTagsImp(stmt, tableName, numOfTags, tags.array(), typeList.array(), lengthList.array(), 
-    			nullList.array(), this.taos);
-    	if (code != TSDBConstants.JNI_SUCCESS) {
-    		throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to bind table name and corresponding tags");
-    	}
+        int code = setTableNameTagsImp(stmt, tableName, numOfTags, tags.array(), typeList.array(), lengthList.array(),
+                nullList.array(), this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to bind table name and corresponding tags");
+        }
     }
-    
+
     private native int setTableNameTagsImp(long stmt, String name, int numOfTags, byte[] tags, byte[] typeList, byte[] lengthList, byte[] nullList, long conn);
-    
-    public void bindColumnDataArray(long stmt, ByteBuffer colDataList, ByteBuffer lengthList, ByteBuffer isNullList, int type, int bytes, int numOfRows,int columnIndex) throws SQLException {
-    	int code = bindColDataImp(stmt, colDataList.array(), lengthList.array(), isNullList.array(), type, bytes, numOfRows, columnIndex, this.taos);
-    	if (code != TSDBConstants.JNI_SUCCESS) {
+
+    public void bindColumnDataArray(long stmt, ByteBuffer colDataList, ByteBuffer lengthList, ByteBuffer isNullList, int type, int bytes, int numOfRows, int columnIndex) throws SQLException {
+        int code = bindColDataImp(stmt, colDataList.array(), lengthList.array(), isNullList.array(), type, bytes, numOfRows, columnIndex, this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to bind column data");
-    	}
-	}
-    
+        }
+    }
+
     private native int bindColDataImp(long stmt, byte[] colDataList, byte[] lengthList, byte[] isNullList, int type, int bytes, int numOfRows, int columnIndex, long conn);
-    
+
     public void executeBatch(long stmt) throws SQLException {
-    	int code = executeBatchImp(stmt, this.taos);
-    	if (code != TSDBConstants.JNI_SUCCESS) {
+        int code = executeBatchImp(stmt, this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to execute batch bind");
-    	}
+        }
     }
-    
+
     private native int executeBatchImp(long stmt, long con);
-    
+
     public void closeBatch(long stmt) throws SQLException {
-    	int code = closeStmt(stmt, this.taos);
-    	if (code != TSDBConstants.JNI_SUCCESS) {
+        int code = closeStmt(stmt, this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to close batch bind");
-    	}
+        }
     }
-    
+
     private native int closeStmt(long stmt, long con);
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBPreparedStatement.java

@@ -39,18 +39,18 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
     private String rawSql;
     private Object[] parameters;
     private boolean isPrepared;
-    
+
     private ArrayList<ColumnInfo> colData;
     private ArrayList<TableTagInfo> tableTags;
     private int tagValueLength;
-    
+
     private String tableName;
     private long nativeStmtHandle = 0;
-    
+
     private volatile TSDBParameterMetaData parameterMetaData;
 
     TSDBPreparedStatement(TSDBConnection connection, String sql) {
-		super(connection);
+        super(connection);
         init(sql);
 
         int parameterCnt = 0;
@@ -64,11 +64,11 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
             this.isPrepared = true;
         }
 
-		if (parameterCnt > 1) {
-	        // the table name is also a parameter, so ignore it.
-	        this.colData = new ArrayList<ColumnInfo>();
-	        this.tableTags = new ArrayList<TableTagInfo>();
-		}
+        if (parameterCnt > 1) {
+            // the table name is also a parameter, so ignore it.
+            this.colData = new ArrayList<ColumnInfo>();
+            this.tableTags = new ArrayList<TableTagInfo>();
+        }
     }
 
     private void init(String sql) {
@@ -205,9 +205,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
 
     @Override
     public void setBigDecimal(int parameterIndex, BigDecimal x) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        setObject(parameterIndex, x.doubleValue());
     }
 
     @Override
@@ -222,16 +220,12 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
 
     @Override
     public void setDate(int parameterIndex, Date x) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        setObject(parameterIndex, new Timestamp(x.getTime()));
     }
 
     @Override
     public void setTime(int parameterIndex, Time x) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        setObject(parameterIndex, new Timestamp(x.getTime()));
     }
 
     @Override
@@ -279,11 +273,10 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         if (isClosed()) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
         }
-        
+
         if (parameterIndex < 1 && parameterIndex >= parameters.length) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_PARAMETER_INDEX_OUT_RANGE);
         }
-        
         parameters[parameterIndex - 1] = x;
     }
 
@@ -323,7 +316,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         if (isClosed()) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
         }
-        
+
         throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
     }
 
@@ -350,9 +343,9 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
 
     @Override
     public ResultSetMetaData getMetaData() throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        if (this.getResultSet() == null)
+            return null;
+        return getResultSet().getMetaData();
     }
 
     @Override
@@ -396,10 +389,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
 
-        if (parameterMetaData == null) {
-            this.parameterMetaData = new TSDBParameterMetaData(parameters);
-        }
-        return this.parameterMetaData;
+        return new TSDBParameterMetaData(parameters);
     }
 
     @Override
@@ -411,9 +401,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
 
     @Override
     public void setNString(int parameterIndex, String value) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        setString(parameterIndex, value);
     }
 
     @Override
@@ -536,489 +524,495 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
         throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
     }
-    
+
     ///////////////////////////////////////////////////////////////////////
     // NOTE: the following APIs are not JDBC compatible
     // set the bind table name
     private static class ColumnInfo {
-    	@SuppressWarnings("rawtypes")
-		private ArrayList data;
-    	private int       type;
-    	private int       bytes;
-    	private boolean   typeIsSet;
-    	
-    	public ColumnInfo() {
-    		this.typeIsSet = false;
-    	}
-    	
-    	public void setType(int type) throws SQLException {
-    		if (this.isTypeSet()) {
+        @SuppressWarnings("rawtypes")
+        private ArrayList data;
+        private int type;
+        private int bytes;
+        private boolean typeIsSet;
+
+        public ColumnInfo() {
+            this.typeIsSet = false;
+        }
+
+        public void setType(int type) throws SQLException {
+            if (this.isTypeSet()) {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data type has been set");
-    		}
-
-    		this.typeIsSet = true;
-    		this.type = type;
-    	}
-    	
-    	public boolean isTypeSet() {
-    		return this.typeIsSet;
-    	}
-    };
-    
+            }
+
+            this.typeIsSet = true;
+            this.type = type;
+        }
+
+        public boolean isTypeSet() {
+            return this.typeIsSet;
+        }
+    }
+
+    ;
+
     private static class TableTagInfo {
-    	private boolean isNull;
-    	private Object  value;
-    	private int     type;    	
-    	public TableTagInfo(Object value, int type) {
-    		this.value = value;
-    		this.type  = type;
-    	}
-    	
-    	public static TableTagInfo createNullTag(int type) {
-    		TableTagInfo info = new TableTagInfo(null, type);
-    		info.isNull = true;
-    		return info;
-    	}
-    };
-    
+        private boolean isNull;
+        private Object value;
+        private int type;
+
+        public TableTagInfo(Object value, int type) {
+            this.value = value;
+            this.type = type;
+        }
+
+        public static TableTagInfo createNullTag(int type) {
+            TableTagInfo info = new TableTagInfo(null, type);
+            info.isNull = true;
+            return info;
+        }
+    }
+
+    ;
+
     public void setTableName(String name) {
-    	this.tableName = name;
+        this.tableName = name;
     }
-    
+
     private void ensureTagCapacity(int index) {
-    	if (this.tableTags.size() < index + 1) {
-    		int delta = index + 1 - this.tableTags.size();
-    		this.tableTags.addAll(Collections.nCopies(delta, null));
-    	}
+        if (this.tableTags.size() < index + 1) {
+            int delta = index + 1 - this.tableTags.size();
+            this.tableTags.addAll(Collections.nCopies(delta, null));
+        }
     }
-    
+
     public void setTagNull(int index, int type) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, TableTagInfo.createNullTag(type));
+        ensureTagCapacity(index);
+        this.tableTags.set(index, TableTagInfo.createNullTag(type));
     }
-    
+
     public void setTagBoolean(int index, boolean value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BOOL));
-    	this.tagValueLength += Byte.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BOOL));
+        this.tagValueLength += Byte.BYTES;
     }
-    
+
     public void setTagInt(int index, int value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_INT));
-    	this.tagValueLength += Integer.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_INT));
+        this.tagValueLength += Integer.BYTES;
     }
-    
+
     public void setTagByte(int index, byte value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_TINYINT));
-    	this.tagValueLength += Byte.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_TINYINT));
+        this.tagValueLength += Byte.BYTES;
     }
-    
+
     public void setTagShort(int index, short value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_SMALLINT));
-    	this.tagValueLength += Short.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_SMALLINT));
+        this.tagValueLength += Short.BYTES;
     }
-    
+
     public void setTagLong(int index, long value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BIGINT));
-    	this.tagValueLength += Long.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BIGINT));
+        this.tagValueLength += Long.BYTES;
     }
-    
+
     public void setTagTimestamp(int index, long value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP));
-    	this.tagValueLength += Long.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP));
+        this.tagValueLength += Long.BYTES;
     }
-    
+
     public void setTagFloat(int index, float value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_FLOAT));
-    	this.tagValueLength += Float.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_FLOAT));
+        this.tagValueLength += Float.BYTES;
     }
-    
+
     public void setTagDouble(int index, double value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_DOUBLE));
-    	this.tagValueLength += Double.BYTES;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_DOUBLE));
+        this.tagValueLength += Double.BYTES;
     }
-    
+
     public void setTagString(int index, String value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BINARY));
-    	this.tagValueLength += value.getBytes().length;
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_BINARY));
+        this.tagValueLength += value.getBytes().length;
     }
-    
+
     public void setTagNString(int index, String value) {
-    	ensureTagCapacity(index);
-    	this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_NCHAR));
-    	
-		String charset = TaosGlobalConfig.getCharset();
-    	try {
-			this.tagValueLength += value.getBytes(charset).length;
-		} catch (UnsupportedEncodingException e) {
-			e.printStackTrace();
-		}
-    }
-    
+        ensureTagCapacity(index);
+        this.tableTags.set(index, new TableTagInfo(value, TSDBConstants.TSDB_DATA_TYPE_NCHAR));
+
+        String charset = TaosGlobalConfig.getCharset();
+        try {
+            this.tagValueLength += value.getBytes(charset).length;
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        }
+    }
+
     public <T> void setValueImpl(int columnIndex, ArrayList<T> list, int type, int bytes) throws SQLException {
-    	if (this.colData.size() == 0) {
-	        this.colData.addAll(Collections.nCopies(this.parameters.length - 1 - this.tableTags.size(), null));
-
-    	}
-    	ColumnInfo col = (ColumnInfo) this.colData.get(columnIndex);
-    	if (col == null) {
-    		ColumnInfo p = new ColumnInfo();
-    		p.setType(type);
-    		p.bytes = bytes;
-    		p.data = (ArrayList<?>) list.clone();
-    		this.colData.set(columnIndex, p);
-    	} else {
-    		if (col.type != type) {
+        if (this.colData.size() == 0) {
+            this.colData.addAll(Collections.nCopies(this.parameters.length - 1 - this.tableTags.size(), null));
+        }
+
+        ColumnInfo col = (ColumnInfo) this.colData.get(columnIndex);
+        if (col == null) {
+            ColumnInfo p = new ColumnInfo();
+            p.setType(type);
+            p.bytes = bytes;
+            p.data = (ArrayList<?>) list.clone();
+            this.colData.set(columnIndex, p);
+        } else {
+            if (col.type != type) {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data type mismatch");
-    		}
-    		col.data.addAll(list);
-    	}
+            }
+            col.data.addAll(list);
+        }
     }
-    
+
     public void setInt(int columnIndex, ArrayList<Integer> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_INT, Integer.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_INT, Integer.BYTES);
     }
-    
+
     public void setFloat(int columnIndex, ArrayList<Float> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_FLOAT, Float.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_FLOAT, Float.BYTES);
     }
-    
+
     public void setTimestamp(int columnIndex, ArrayList<Long> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP, Long.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP, Long.BYTES);
     }
-    
+
     public void setLong(int columnIndex, ArrayList<Long> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BIGINT, Long.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BIGINT, Long.BYTES);
     }
-    
+
     public void setDouble(int columnIndex, ArrayList<Double> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_DOUBLE, Double.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_DOUBLE, Double.BYTES);
     }
-    
+
     public void setBoolean(int columnIndex, ArrayList<Boolean> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BOOL, Byte.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BOOL, Byte.BYTES);
     }
-    
+
     public void setByte(int columnIndex, ArrayList<Byte> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_TINYINT, Byte.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_TINYINT, Byte.BYTES);
     }
-    
+
     public void setShort(int columnIndex, ArrayList<Short> list) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_SMALLINT, Short.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_SMALLINT, Short.BYTES);
     }
-    
+
     public void setString(int columnIndex, ArrayList<String> list, int size) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BINARY, size);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_BINARY, size);
     }
-    
+
     // note: expand the required space for each NChar character
     public void setNString(int columnIndex, ArrayList<String> list, int size) throws SQLException {
-    	setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_NCHAR, size * Integer.BYTES);
+        setValueImpl(columnIndex, list, TSDBConstants.TSDB_DATA_TYPE_NCHAR, size * Integer.BYTES);
     }
-    
+
     public void columnDataAddBatch() throws SQLException {
-    	// pass the data block to native code
-		if (rawSql == null) {
+        // pass the data block to native code
+        if (rawSql == null) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "sql statement not set yet");
-		}
-		
-		// table name is not set yet, abort
-		if (this.tableName == null) {
+        }
+
+        // table name is not set yet, abort
+        if (this.tableName == null) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "table name not set yet");
-		}
-		
-		int numOfCols = this.colData.size();
-		if (numOfCols == 0) {
-			throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
-		}
-		
-		TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
-		this.nativeStmtHandle = connector.prepareStmt(rawSql);
-		
-		if (this.tableTags == null) {
-			connector.setBindTableName(this.nativeStmtHandle, this.tableName);
-		} else {
-			int num = this.tableTags.size();
-			ByteBuffer tagDataList = ByteBuffer.allocate(this.tagValueLength);
-			tagDataList.order(ByteOrder.LITTLE_ENDIAN);
-
-			ByteBuffer typeList = ByteBuffer.allocate(num);
-			typeList.order(ByteOrder.LITTLE_ENDIAN);
-
-			ByteBuffer lengthList = ByteBuffer.allocate(num * Long.BYTES);
-			lengthList.order(ByteOrder.LITTLE_ENDIAN);
-
-			ByteBuffer isNullList = ByteBuffer.allocate(num * Integer.BYTES);
-			isNullList.order(ByteOrder.LITTLE_ENDIAN);
-
-			for (int i = 0; i < num; ++i) {
-				TableTagInfo tag = this.tableTags.get(i);
-				if (tag.isNull) {
-					typeList.put((byte) tag.type);
-					isNullList.putInt(1);
-					lengthList.putLong(0);
-					continue;
-				}
-				
-				switch (tag.type) {
-				case TSDBConstants.TSDB_DATA_TYPE_INT: {
-					Integer val = (Integer) tag.value;
-					tagDataList.putInt(val);
-					lengthList.putLong(Integer.BYTES);
-					break;
-				}
-				case TSDBConstants.TSDB_DATA_TYPE_TINYINT: {
-					Byte val = (Byte) tag.value;
-					tagDataList.put(val);
-					lengthList.putLong(Byte.BYTES);
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_BOOL: {
-					Boolean val = (Boolean) tag.value;
-					tagDataList.put((byte) (val ? 1 : 0));
-					lengthList.putLong(Byte.BYTES);
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_SMALLINT: {
-					Short val = (Short) tag.value;
-					tagDataList.putShort(val);
-					lengthList.putLong(Short.BYTES);
-
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
-				case TSDBConstants.TSDB_DATA_TYPE_BIGINT: {
-					Long val = (Long) tag.value;
-					tagDataList.putLong(val == null ? 0 : val);
-					lengthList.putLong(Long.BYTES);
-
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_FLOAT: {
-					Float val = (Float) tag.value;
-					tagDataList.putFloat(val == null ? 0 : val);
-					lengthList.putLong(Float.BYTES);
-
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_DOUBLE: {
-					Double val = (Double) tag.value;
-					tagDataList.putDouble(val == null ? 0 : val);
-					lengthList.putLong(Double.BYTES);
-
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
-				case TSDBConstants.TSDB_DATA_TYPE_BINARY: {
-					String charset = TaosGlobalConfig.getCharset();
-					String val = (String) tag.value;
-
-						byte[] b = null;
-						try {
-							if (tag.type == TSDBConstants.TSDB_DATA_TYPE_BINARY) {
-								b = val.getBytes();
-							} else {
-								b = val.getBytes(charset);
-							}
-						} catch (UnsupportedEncodingException e) {
-							e.printStackTrace();
-						}
-
-						tagDataList.put(b);
-						lengthList.putLong(b.length);
-					break;
-				}
-
-				case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
-				case TSDBConstants.TSDB_DATA_TYPE_USMALLINT:
-				case TSDBConstants.TSDB_DATA_TYPE_UINT:
-				case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
-					throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "not support data types");
-				}
-				}
-				
-				typeList.put((byte) tag.type);
-				isNullList.putInt(tag.isNull? 1 : 0);
-			}
-
-			connector.setBindTableNameAndTags(this.nativeStmtHandle, this.tableName, this.tableTags.size(), tagDataList,
-					typeList, lengthList, isNullList);
-		}
-		
-		ColumnInfo colInfo = (ColumnInfo) this.colData.get(0);
-		if (colInfo == null) {
-			throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
-		}
-		
-		int rows = colInfo.data.size();
-		for (int i = 0; i < numOfCols; ++i) {
-			ColumnInfo col1 = this.colData.get(i);
-			if (col1 == null || !col1.isTypeSet()) {
+        }
+
+        int numOfCols = this.colData.size();
+        if (numOfCols == 0) {
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
+        }
+
+        TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
+        this.nativeStmtHandle = connector.prepareStmt(rawSql);
+
+        if (this.tableTags == null) {
+            connector.setBindTableName(this.nativeStmtHandle, this.tableName);
+        } else {
+            int num = this.tableTags.size();
+            ByteBuffer tagDataList = ByteBuffer.allocate(this.tagValueLength);
+            tagDataList.order(ByteOrder.LITTLE_ENDIAN);
+
+            ByteBuffer typeList = ByteBuffer.allocate(num);
+            typeList.order(ByteOrder.LITTLE_ENDIAN);
+
+            ByteBuffer lengthList = ByteBuffer.allocate(num * Long.BYTES);
+            lengthList.order(ByteOrder.LITTLE_ENDIAN);
+
+            ByteBuffer isNullList = ByteBuffer.allocate(num * Integer.BYTES);
+            isNullList.order(ByteOrder.LITTLE_ENDIAN);
+
+            for (int i = 0; i < num; ++i) {
+                TableTagInfo tag = this.tableTags.get(i);
+                if (tag.isNull) {
+                    typeList.put((byte) tag.type);
+                    isNullList.putInt(1);
+                    lengthList.putLong(0);
+                    continue;
+                }
+
+                switch (tag.type) {
+                    case TSDBConstants.TSDB_DATA_TYPE_INT: {
+                        Integer val = (Integer) tag.value;
+                        tagDataList.putInt(val);
+                        lengthList.putLong(Integer.BYTES);
+                        break;
+                    }
+                    case TSDBConstants.TSDB_DATA_TYPE_TINYINT: {
+                        Byte val = (Byte) tag.value;
+                        tagDataList.put(val);
+                        lengthList.putLong(Byte.BYTES);
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_BOOL: {
+                        Boolean val = (Boolean) tag.value;
+                        tagDataList.put((byte) (val ? 1 : 0));
+                        lengthList.putLong(Byte.BYTES);
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_SMALLINT: {
+                        Short val = (Short) tag.value;
+                        tagDataList.putShort(val);
+                        lengthList.putLong(Short.BYTES);
+
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
+                    case TSDBConstants.TSDB_DATA_TYPE_BIGINT: {
+                        Long val = (Long) tag.value;
+                        tagDataList.putLong(val == null ? 0 : val);
+                        lengthList.putLong(Long.BYTES);
+
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_FLOAT: {
+                        Float val = (Float) tag.value;
+                        tagDataList.putFloat(val == null ? 0 : val);
+                        lengthList.putLong(Float.BYTES);
+
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_DOUBLE: {
+                        Double val = (Double) tag.value;
+                        tagDataList.putDouble(val == null ? 0 : val);
+                        lengthList.putLong(Double.BYTES);
+
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
+                    case TSDBConstants.TSDB_DATA_TYPE_BINARY: {
+                        String charset = TaosGlobalConfig.getCharset();
+                        String val = (String) tag.value;
+
+                        byte[] b = null;
+                        try {
+                            if (tag.type == TSDBConstants.TSDB_DATA_TYPE_BINARY) {
+                                b = val.getBytes();
+                            } else {
+                                b = val.getBytes(charset);
+                            }
+                        } catch (UnsupportedEncodingException e) {
+                            e.printStackTrace();
+                        }
+
+                        tagDataList.put(b);
+                        lengthList.putLong(b.length);
+                        break;
+                    }
+
+                    case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
+                    case TSDBConstants.TSDB_DATA_TYPE_USMALLINT:
+                    case TSDBConstants.TSDB_DATA_TYPE_UINT:
+                    case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
+                        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "not support data types");
+                    }
+                }
+
+                typeList.put((byte) tag.type);
+                isNullList.putInt(tag.isNull ? 1 : 0);
+            }
+
+            connector.setBindTableNameAndTags(this.nativeStmtHandle, this.tableName, this.tableTags.size(), tagDataList,
+                    typeList, lengthList, isNullList);
+        }
+
+        ColumnInfo colInfo = (ColumnInfo) this.colData.get(0);
+        if (colInfo == null) {
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
+        }
+
+        int rows = colInfo.data.size();
+        for (int i = 0; i < numOfCols; ++i) {
+            ColumnInfo col1 = this.colData.get(i);
+            if (col1 == null || !col1.isTypeSet()) {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
-			}
-			
-			if (rows != col1.data.size()) {
+            }
+
+            if (rows != col1.data.size()) {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "the rows in column data not identical");
-			}
-			
-			ByteBuffer colDataList = ByteBuffer.allocate(rows * col1.bytes);
-			colDataList.order(ByteOrder.LITTLE_ENDIAN);
-			
+            }
+
+            ByteBuffer colDataList = ByteBuffer.allocate(rows * col1.bytes);
+            colDataList.order(ByteOrder.LITTLE_ENDIAN);
+
             ByteBuffer lengthList = ByteBuffer.allocate(rows * Integer.BYTES);
             lengthList.order(ByteOrder.LITTLE_ENDIAN);
-            
+
             ByteBuffer isNullList = ByteBuffer.allocate(rows * Byte.BYTES);
             isNullList.order(ByteOrder.LITTLE_ENDIAN);
-            
-			switch (col1.type) {
-				case TSDBConstants.TSDB_DATA_TYPE_INT: {
-					for (int j = 0; j < rows; ++j) {
-						Integer val = (Integer) col1.data.get(j);
-						colDataList.putInt(val == null? Integer.MIN_VALUE:val);						
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_TINYINT: {
-					for (int j = 0; j < rows; ++j) {
-						Byte val = (Byte) col1.data.get(j);
-						colDataList.put(val == null? 0:val);
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_BOOL: {
-					for (int j = 0; j < rows; ++j) {
-						Boolean val = (Boolean) col1.data.get(j);
-						if (val == null) {
-							colDataList.put((byte) 0);
-						} else {
-							colDataList.put((byte) (val? 1:0));
-						}
-						
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_SMALLINT: {
-					for (int j = 0; j < rows; ++j) {
-						Short val = (Short) col1.data.get(j);
-						colDataList.putShort(val == null? 0:val);
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
-				case TSDBConstants.TSDB_DATA_TYPE_BIGINT: {
-					for (int j = 0; j < rows; ++j) {
-						Long val = (Long) col1.data.get(j);
-						colDataList.putLong(val == null? 0:val);
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_FLOAT: {
-					for (int j = 0; j < rows; ++j) {
-						Float val = (Float) col1.data.get(j);
-						colDataList.putFloat(val == null? 0:val);
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-	
-				case TSDBConstants.TSDB_DATA_TYPE_DOUBLE: {
-					for (int j = 0; j < rows; ++j) {
-						Double val = (Double) col1.data.get(j);
-						colDataList.putDouble(val == null? 0:val);
-						isNullList.put((byte) (val == null? 1:0));
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_NCHAR: 
-				case TSDBConstants.TSDB_DATA_TYPE_BINARY: {
-					String charset = TaosGlobalConfig.getCharset();
-					for (int j = 0; j < rows; ++j) {
-						String val = (String) col1.data.get(j);
-
-						colDataList.position(j * col1.bytes);  // seek to the correct position
-						if (val != null) {
-							byte[] b = null;
-							try {
-								if (col1.type == TSDBConstants.TSDB_DATA_TYPE_BINARY) {
-									b = val.getBytes();
-								} else {
-									b = val.getBytes(charset);
-								}
-							} catch (UnsupportedEncodingException e) {
-								e.printStackTrace();
-							}
-							
-							if (val.length() > col1.bytes) {
-				                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "string data too long");
-							}
-							
-							colDataList.put(b);
-							lengthList.putInt(b.length);
-							isNullList.put((byte) 0);
-						} else {
-							lengthList.putInt(0);
-							isNullList.put((byte) 1);
-						}
-					}
-					break;
-				}
-				
-				case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
-				case TSDBConstants.TSDB_DATA_TYPE_USMALLINT:
-				case TSDBConstants.TSDB_DATA_TYPE_UINT:
-				case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
-	                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "not support data types");
-				}
-			};
-			
-			connector.bindColumnDataArray(this.nativeStmtHandle, colDataList, lengthList, isNullList, col1.type, col1.bytes, rows, i);
-		}
-    }
-    
-	public void columnDataExecuteBatch() throws SQLException {
-		TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
-		connector.executeBatch(this.nativeStmtHandle);
-		this.columnDataClearBatch();
-	}
-    
+
+            switch (col1.type) {
+                case TSDBConstants.TSDB_DATA_TYPE_INT: {
+                    for (int j = 0; j < rows; ++j) {
+                        Integer val = (Integer) col1.data.get(j);
+                        colDataList.putInt(val == null ? Integer.MIN_VALUE : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_TINYINT: {
+                    for (int j = 0; j < rows; ++j) {
+                        Byte val = (Byte) col1.data.get(j);
+                        colDataList.put(val == null ? 0 : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_BOOL: {
+                    for (int j = 0; j < rows; ++j) {
+                        Boolean val = (Boolean) col1.data.get(j);
+                        if (val == null) {
+                            colDataList.put((byte) 0);
+                        } else {
+                            colDataList.put((byte) (val ? 1 : 0));
+                        }
+
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_SMALLINT: {
+                    for (int j = 0; j < rows; ++j) {
+                        Short val = (Short) col1.data.get(j);
+                        colDataList.putShort(val == null ? 0 : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
+                case TSDBConstants.TSDB_DATA_TYPE_BIGINT: {
+                    for (int j = 0; j < rows; ++j) {
+                        Long val = (Long) col1.data.get(j);
+                        colDataList.putLong(val == null ? 0 : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_FLOAT: {
+                    for (int j = 0; j < rows; ++j) {
+                        Float val = (Float) col1.data.get(j);
+                        colDataList.putFloat(val == null ? 0 : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_DOUBLE: {
+                    for (int j = 0; j < rows; ++j) {
+                        Double val = (Double) col1.data.get(j);
+                        colDataList.putDouble(val == null ? 0 : val);
+                        isNullList.put((byte) (val == null ? 1 : 0));
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
+                case TSDBConstants.TSDB_DATA_TYPE_BINARY: {
+                    String charset = TaosGlobalConfig.getCharset();
+                    for (int j = 0; j < rows; ++j) {
+                        String val = (String) col1.data.get(j);
+
+                        colDataList.position(j * col1.bytes);  // seek to the correct position
+                        if (val != null) {
+                            byte[] b = null;
+                            try {
+                                if (col1.type == TSDBConstants.TSDB_DATA_TYPE_BINARY) {
+                                    b = val.getBytes();
+                                } else {
+                                    b = val.getBytes(charset);
+                                }
+                            } catch (UnsupportedEncodingException e) {
+                                e.printStackTrace();
+                            }
+
+                            if (val.length() > col1.bytes) {
+                                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "string data too long");
+                            }
+
+                            colDataList.put(b);
+                            lengthList.putInt(b.length);
+                            isNullList.put((byte) 0);
+                        } else {
+                            lengthList.putInt(0);
+                            isNullList.put((byte) 1);
+                        }
+                    }
+                    break;
+                }
+
+                case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
+                case TSDBConstants.TSDB_DATA_TYPE_USMALLINT:
+                case TSDBConstants.TSDB_DATA_TYPE_UINT:
+                case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
+                    throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "not support data types");
+                }
+            }
+            ;
+
+            connector.bindColumnDataArray(this.nativeStmtHandle, colDataList, lengthList, isNullList, col1.type, col1.bytes, rows, i);
+        }
+    }
+
+    public void columnDataExecuteBatch() throws SQLException {
+        TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
+        connector.executeBatch(this.nativeStmtHandle);
+        this.columnDataClearBatch();
+    }
+
     public void columnDataClearBatch() {
-    	int size = this.colData.size();
-    	this.colData.clear();
-    	
+        int size = this.colData.size();
+        this.colData.clear();
+
         this.colData.addAll(Collections.nCopies(size, null));
         this.tableName = null;   // clear the table name
     }
-    
+
     public void columnDataCloseBatch() throws SQLException {
-		TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
-		connector.closeBatch(this.nativeStmtHandle);
-		
-		this.nativeStmtHandle = 0L;
-		this.tableName = null;
+        TSDBJNIConnector connector = ((TSDBConnection) this.getConnection()).getConnector();
+        connector.closeBatch(this.nativeStmtHandle);
+
+        this.nativeStmtHandle = 0L;
+        this.tableName = null;
     }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSet.java

@@ -133,9 +133,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getString(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = this.rowData.getString(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getString(columnIndex, nativeType);
         }
         return res;
     }
@@ -147,9 +148,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getBoolean(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = this.rowData.getBoolean(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getBoolean(columnIndex, nativeType);
         }
         return res;
     }
@@ -161,9 +163,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return (byte) this.blockData.getInt(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = (byte) this.rowData.getInt(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = (byte) this.rowData.getInt(columnIndex, nativeType);
         }
         return res;
     }
@@ -175,9 +178,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return (short) this.blockData.getInt(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = (short) this.rowData.getInt(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = (short) this.rowData.getInt(columnIndex, nativeType);
         }
         return res;
     }
@@ -189,9 +193,11 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getInt(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = this.rowData.getInt(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getInt(columnIndex, nativeType);
         }
         return res;
     }
@@ -203,13 +209,15 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getLong(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            Object value = this.rowData.get(columnIndex - 1);
-            if (value instanceof Timestamp)
+            Object value = this.rowData.getObject(columnIndex);
+            if (value instanceof Timestamp) {
                 res = ((Timestamp) value).getTime();
-            else
-                res = this.rowData.getLong(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            } else {
+                int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+                res = this.rowData.getLong(columnIndex, nativeType);
+            }
         }
         return res;
     }
@@ -221,9 +229,11 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return (float) this.blockData.getDouble(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
-        if (!lastWasNull)
-            res = this.rowData.getFloat(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
+        if (!lastWasNull) {
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getFloat(columnIndex, nativeType);
+        }
 
         return res;
     }
@@ -235,9 +245,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getDouble(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = this.rowData.getDouble(columnIndex - 1, this.columnMetaDataList.get(columnIndex - 1).getColType());
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getDouble(columnIndex, nativeType);
         }
         return res;
     }
@@ -245,34 +256,27 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
     public byte[] getBytes(int columnIndex) throws SQLException {
         checkAvailability(columnIndex, this.columnMetaDataList.size());
 
-        Object value = this.rowData.get(columnIndex - 1);
+        Object value = this.rowData.getObject(columnIndex);
         if (value == null)
             return null;
 
-        int colType = this.columnMetaDataList.get(columnIndex - 1).getColType();
-        switch (colType) {
+        int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
-                return Longs.toByteArray((Long) value);
+                return Longs.toByteArray((long) value);
             case TSDBConstants.TSDB_DATA_TYPE_INT:
                 return Ints.toByteArray((int) value);
             case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
-                return Shorts.toByteArray((Short) value);
+                return Shorts.toByteArray((short) value);
             case TSDBConstants.TSDB_DATA_TYPE_TINYINT:
                 return new byte[]{(byte) value};
+            case TSDBConstants.TSDB_DATA_TYPE_BINARY:
+                return (byte[]) value;
+            case TSDBConstants.TSDB_DATA_TYPE_BOOL:
+            case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
+            default:
+                return value.toString().getBytes();
         }
-        return value.toString().getBytes();
-    }
-
-    @Override
-    public Date getDate(int columnIndex) throws SQLException {
-        Timestamp timestamp = getTimestamp(columnIndex);
-        return timestamp == null ? null : new Date(timestamp.getTime());
-    }
-
-    @Override
-    public Time getTime(int columnIndex) throws SQLException {
-        Timestamp timestamp = getTimestamp(columnIndex);
-        return timestamp == null ? null : new Time(timestamp.getTime());
     }
 
     public Timestamp getTimestamp(int columnIndex) throws SQLException {
@@ -282,9 +286,10 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.getTimestamp(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            res = this.rowData.getTimestamp(columnIndex - 1);
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            res = this.rowData.getTimestamp(columnIndex, nativeType);
         }
         return res;
     }
@@ -304,13 +309,9 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return this.blockData.get(columnIndex - 1);
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         if (!lastWasNull) {
-            int colType = this.columnMetaDataList.get(columnIndex - 1).getColType();
-            if (colType == TSDBConstants.TSDB_DATA_TYPE_BINARY)
-                res = ((String) this.rowData.get(columnIndex - 1)).getBytes();
-            else
-                res = this.rowData.get(columnIndex - 1);
+            res = this.rowData.getObject(columnIndex);
         }
         return res;
     }
@@ -318,7 +319,7 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
     public int findColumn(String columnLabel) throws SQLException {
         for (ColumnMetaData colMetaData : this.columnMetaDataList) {
             if (colMetaData.getColName() != null && colMetaData.getColName().equalsIgnoreCase(columnLabel)) {
-                return colMetaData.getColIndex() + 1;
+                return colMetaData.getColIndex();
             }
         }
         throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
@@ -329,25 +330,25 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
         if (this.getBatchFetch())
             return new BigDecimal(this.blockData.getLong(columnIndex - 1));
 
-        this.lastWasNull = this.rowData.wasNull(columnIndex - 1);
+        this.lastWasNull = this.rowData.wasNull(columnIndex);
         BigDecimal res = null;
         if (!lastWasNull) {
-            int colType = this.columnMetaDataList.get(columnIndex - 1).getColType();
-            switch (colType) {
+            int nativeType = this.columnMetaDataList.get(columnIndex - 1).getColType();
+            switch (nativeType) {
                 case TSDBConstants.TSDB_DATA_TYPE_TINYINT:
                 case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
                 case TSDBConstants.TSDB_DATA_TYPE_INT:
                 case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
-                    res = new BigDecimal(Long.valueOf(this.rowData.get(columnIndex - 1).toString()));
+                    res = new BigDecimal(Long.valueOf(this.rowData.getObject(columnIndex).toString()));
                     break;
                 case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
                 case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
-                    res = new BigDecimal(Double.valueOf(this.rowData.get(columnIndex - 1).toString()));
+                    res = new BigDecimal(Double.valueOf(this.rowData.getObject(columnIndex).toString()));
                     break;
                 case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
-                    return new BigDecimal(((Timestamp) this.rowData.get(columnIndex - 1)).getTime());
+                    return new BigDecimal(((Timestamp) this.rowData.getObject(columnIndex)).getTime());
                 default:
-                    res = new BigDecimal(this.rowData.get(columnIndex - 1).toString());
+                    res = new BigDecimal(this.rowData.getObject(columnIndex).toString());
             }
         }
         return res;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetMetaData.java

@@ -113,6 +113,7 @@ public class TSDBResultSetMetaData extends WrapperImpl implements ResultSetMetaD
 
         ColumnMetaData columnMetaData = this.colMetaDataList.get(column - 1);
         switch (columnMetaData.getColType()) {
+            
             case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
                 return 5;
             case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetRowData.java

@@ -14,6 +14,8 @@
  *****************************************************************************/
 package com.taosdata.jdbc;
 
+import com.taosdata.jdbc.utils.NullType;
+
 import java.math.BigDecimal;
 import java.sql.SQLException;
 import java.sql.Timestamp;
@@ -22,11 +24,13 @@ import java.util.ArrayList;
 import java.util.Collections;
 
 public class TSDBResultSetRowData {
+
     private ArrayList<Object> data;
-    private int colSize = 0;
+    private int colSize;
 
     public TSDBResultSetRowData(int colSize) {
-        this.setColSize(colSize);
+        this.colSize = colSize;
+        this.clear();
     }
 
     public void clear() {
@@ -41,68 +45,104 @@ public class TSDBResultSetRowData {
     }
 
     public boolean wasNull(int col) {
-        return data.get(col) == null;
+        return data.get(col - 1) == null;
+    }
+
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setBooleanValue(int col, boolean value) {
+        setBoolean(col - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setBoolean(int col, boolean value) {
         data.set(col, value);
     }
 
-    public boolean getBoolean(int col, int srcType) throws SQLException {
-        Object obj = data.get(col);
+    public boolean getBoolean(int col, int nativeType) throws SQLException {
+        Object obj = data.get(col - 1);
 
-        switch (srcType) {
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return (Boolean) obj;
-            case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
-                return ((Float) obj) == 1.0 ? Boolean.TRUE : Boolean.FALSE;
-            case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
-                return ((Double) obj) == 1.0 ? Boolean.TRUE : Boolean.FALSE;
             case TSDBConstants.TSDB_DATA_TYPE_TINYINT:
                 return ((Byte) obj) == 1 ? Boolean.TRUE : Boolean.FALSE;
             case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
                 return ((Short) obj) == 1 ? Boolean.TRUE : Boolean.FALSE;
             case TSDBConstants.TSDB_DATA_TYPE_INT:
                 return ((Integer) obj) == 1 ? Boolean.TRUE : Boolean.FALSE;
-            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
                 return ((Long) obj) == 1L ? Boolean.TRUE : Boolean.FALSE;
+            case TSDBConstants.TSDB_DATA_TYPE_BINARY:
+            case TSDBConstants.TSDB_DATA_TYPE_NCHAR: {
+                return obj.toString().contains("1");
+            }
             default:
                 return false;
         }
     }
 
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setByteValue(int colIndex, byte value) {
+        setByte(colIndex - 1, value);
+    }
+
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setByte(int col, byte value) {
         data.set(col, value);
     }
 
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setShortValue(int colIndex, short value) {
+        setShort(colIndex - 1, value);
+    }
+
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setShort(int col, short value) {
         data.set(col, value);
     }
 
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setIntValue(int colIndex, int value) {
+        setInt(colIndex - 1, value);
+    }
+
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setInt(int col, int value) {
         data.set(col, value);
     }
 
-    @SuppressWarnings("deprecation")
-	public int getInt(int col, int srcType) throws SQLException {
-        Object obj = data.get(col);
+    public int getInt(int col, int nativeType) throws SQLException {
+        Object obj = data.get(col - 1);
+        if (obj == null)
+            return NullType.getIntNull();
 
-        switch (srcType) {
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return Boolean.TRUE.equals(obj) ? 1 : 0;
-            case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
-                return ((Float) obj).intValue();
-            case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
-                return ((Double) obj).intValue();
             case TSDBConstants.TSDB_DATA_TYPE_TINYINT:
                 return (Byte) obj;
             case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
                 return (Short) obj;
             case TSDBConstants.TSDB_DATA_TYPE_INT:
                 return (Integer) obj;
-            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
+            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
                 return ((Long) obj).intValue();
             case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
             case TSDBConstants.TSDB_DATA_TYPE_BINARY:
@@ -131,33 +171,46 @@ public class TSDBResultSetRowData {
                     throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
                 return Long.valueOf(value).intValue();
             }
+            case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
+                return ((Float) obj).intValue();
+            case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
+                return ((Double) obj).intValue();
+            default:
+                return 0;
         }
+    }
 
-        return 0;
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setLongValue(int colIndex, long value) {
+        setLong(colIndex - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setLong(int col, long value) {
         data.set(col, value);
     }
 
-    public long getLong(int col, int srcType) throws SQLException {
-        Object obj = data.get(col);
+    public long getLong(int col, int nativeType) throws SQLException {
+        Object obj = data.get(col - 1);
+        if (obj == null) {
+            return NullType.getBigIntNull();
+        }
 
-        switch (srcType) {
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return Boolean.TRUE.equals(obj) ? 1 : 0;
-            case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
-                return ((Float) obj).longValue();
-            case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
-                return ((Double) obj).longValue();
             case TSDBConstants.TSDB_DATA_TYPE_TINYINT:
                 return (Byte) obj;
             case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
                 return (Short) obj;
             case TSDBConstants.TSDB_DATA_TYPE_INT:
                 return (Integer) obj;
-            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
+            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
                 return (Long) obj;
             case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
             case TSDBConstants.TSDB_DATA_TYPE_BINARY:
@@ -186,19 +239,35 @@ public class TSDBResultSetRowData {
                     throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
                 return value;
             }
+            case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
+                return ((Float) obj).longValue();
+            case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
+                return ((Double) obj).longValue();
+            default:
+                return 0;
         }
+    }
 
-        return 0;
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setFloatValue(int colIndex, float value) {
+        setFloat(colIndex - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setFloat(int col, float value) {
         data.set(col, value);
     }
 
-    public float getFloat(int col, int srcType) {
-        Object obj = data.get(col);
+    public float getFloat(int col, int nativeType) {
+        Object obj = data.get(col - 1);
+        if (obj == null)
+            return NullType.getFloatNull();
 
-        switch (srcType) {
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return Boolean.TRUE.equals(obj) ? 1 : 0;
             case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
@@ -214,19 +283,31 @@ public class TSDBResultSetRowData {
             case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
                 return (Long) obj;
+            default:
+                return NullType.getFloatNull();
         }
+    }
 
-        return 0;
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setDoubleValue(int colIndex, double value) {
+        setDouble(colIndex - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setDouble(int col, double value) {
         data.set(col, value);
     }
 
-    public double getDouble(int col, int srcType) {
-        Object obj = data.get(col);
+    public double getDouble(int col, int nativeType) {
+        Object obj = data.get(col - 1);
+        if (obj == null)
+            return NullType.getDoubleNull();
 
-        switch (srcType) {
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_BOOL:
                 return Boolean.TRUE.equals(obj) ? 1 : 0;
             case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
@@ -242,16 +323,46 @@ public class TSDBResultSetRowData {
             case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
             case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
                 return (Long) obj;
+            default:
+                return NullType.getDoubleNull();
         }
+    }
 
-        return 0;
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setStringValue(int colIndex, String value) {
+        data.set(colIndex - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setString(int col, String value) {
-        data.set(col, value);
+        // TODO:
+        //  !!!NOTE!!!
+        //  this is very confusing problem which related to JNI-method implementation,
+        //  the JNI method return a String(encoded in UTF) for BINARY value, which means the JNI method will invoke
+        //  this setString(int, String) to handle BINARY value, we need to build a byte[] with default charsetEncoding
+        data.set(col, value == null ? null : value.getBytes());
+    }
+
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setByteArrayValue(int colIndex, byte[] value) {
+        setByteArray(colIndex - 1, value);
     }
 
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setByteArray(int col, byte[] value) {
+        // TODO:
+        //  !!!NOTE!!!
+        //  this is very confusing problem which related to JNI-method implementation,
+        //  the JNI method return a byte[] for NCHAR value, which means the JNI method will invoke
+        //  this setByteArr(int, byte[]) to handle NCHAR value, we need to build a String with charsetEncoding by TaosGlobalConfig
         try {
             data.set(col, new String(value, TaosGlobalConfig.getCharset()));
         } catch (Exception e) {
@@ -259,47 +370,56 @@ public class TSDBResultSetRowData {
         }
     }
 
-    /**
-     * The original type may not be a string type, but will be converted to by calling this method
-     *
-     * @param col column index
-     * @return
-     */
-    public String getString(int col, int srcType) {
-        switch (srcType) {
-            case TSDBConstants.TSDB_DATA_TYPE_BINARY:
-            case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
-                return (String) data.get(col);
+    public String getString(int col, int nativeType) {
+        Object obj = data.get(col - 1);
+        if (obj == null)
+            return null;
+
+        switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_UTINYINT: {
-                Byte value = new Byte(String.valueOf(data.get(col)));
+                Byte value = new Byte(String.valueOf(obj));
                 if (value >= 0)
                     return value.toString();
                 return Integer.toString(value & 0xff);
             }
             case TSDBConstants.TSDB_DATA_TYPE_USMALLINT: {
-                Short value = new Short(String.valueOf(data.get(col)));
+                Short value = new Short(String.valueOf(obj));
                 if (value >= 0)
                     return value.toString();
                 return Integer.toString(value & 0xffff);
             }
             case TSDBConstants.TSDB_DATA_TYPE_UINT: {
-                Integer value = new Integer(String.valueOf(data.get(col)));
+                Integer value = new Integer(String.valueOf(obj));
                 if (value >= 0)
                     return value.toString();
                 return Long.toString(value & 0xffffffffl);
             }
             case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
-                Long value = new Long(String.valueOf(data.get(col)));
+                Long value = new Long(String.valueOf(obj));
                 if (value >= 0)
                     return value.toString();
                 long lowValue = value & 0x7fffffffffffffffL;
                 return BigDecimal.valueOf(lowValue).add(BigDecimal.valueOf(Long.MAX_VALUE)).add(BigDecimal.valueOf(1)).toString();
             }
+            case TSDBConstants.TSDB_DATA_TYPE_BINARY:
+                return new String((byte[]) obj);
+            case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
+                return (String) obj;
             default:
-                return String.valueOf(data.get(col));
+                return String.valueOf(obj);
         }
     }
 
+    /**
+     * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
+     */
+    public void setTimestampValue(int colIndex, long value) {
+        setTimestamp(colIndex - 1, value);
+    }
+
+    /**
+     * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     */
     public void setTimestamp(int col, long ts) {
         //TODO: this implementation contains logical error
         // when precision is us the (long ts) is 16 digital number
@@ -316,28 +436,20 @@ public class TSDBResultSetRowData {
         }
     }
 
-    public Timestamp getTimestamp(int col) {
-        return (Timestamp) data.get(col);
-    }
-
-    public Object get(int col) {
-        return data.get(col);
-    }
-
-    public int getColSize() {
-        return colSize;
-    }
-
-    private void setColSize(int colSize) {
-        this.colSize = colSize;
-        this.clear();
+    public Timestamp getTimestamp(int col, int nativeType) {
+        Object obj = data.get(col - 1);
+        if (obj == null)
+            return null;
+        switch (nativeType) {
+            case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
+                return new Timestamp((Long) obj);
+            default:
+                return (Timestamp) obj;
+        }
     }
 
-    public ArrayList<Object> getData() {
-        return data;
+    public Object getObject(int col) {
+        return data.get(col - 1);
     }
 
-    public void setData(ArrayList<Object> data) {
-        this.data = (ArrayList<Object>) data.clone();
-    }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBStatement.java

@@ -32,14 +32,15 @@ public class TSDBStatement extends AbstractStatement {
     }
 
     public ResultSet executeQuery(String sql) throws SQLException {
-        // check if closed
         if (isClosed()) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
         }
-        
-        //TODO: 如果在executeQuery方法中执行insert语句，那么先执行了SQL，再通过pSql来检查是否为一个insert语句，但这个insert SQL已经执行成功了
-
-        // execute query
+        //TODO:
+        // this is an unreasonable implementation, if the paratemer is a insert statement,
+        // the JNI connector will execute the sql at first and return a pointer: pSql,
+        // we use this pSql and invoke the isUpdateQuery(long pSql) method to decide .
+        // but the insert sql is already executed in database.
+        //execute query
         long pSql = this.connection.getConnector().executeQuery(sql);
         // if pSql is create/insert/update/delete/alter SQL
         if (this.connection.getConnector().isUpdateQuery(pSql)) {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/Utils.java

@@ -95,16 +95,7 @@ public class Utils {
     public static String getNativeSql(String rawSql, Object[] parameters) {
         // toLowerCase
         String preparedSql = rawSql.trim().toLowerCase();
-
-        String[] clause = new String[0];
-        if (SqlSyntaxValidator.isInsertSql(preparedSql)) {
-            // insert or import
-            clause = new String[]{"values\\s*\\(.*?\\)", "tags\\s*\\(.*?\\)"};
-        }
-        if (SqlSyntaxValidator.isSelectSql(preparedSql)) {
-            // select
-            clause = new String[]{"where\\s*.*"};
-        }
+        String[] clause = new String[]{"values\\s*\\(.*?\\)", "tags\\s*\\(.*?\\)", "where\\s*.*"};
         Map<Integer, Integer> placeholderPositions = new HashMap<>();
         RangeSet<Integer> clauseRangeSet = TreeRangeSet.create();
         findPlaceholderPosition(preparedSql, placeholderPositions);

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBConnectionTest.java

@@ -32,20 +32,34 @@ public class TSDBConnectionTest {
     }
 
     @Test
-    public void subscribe() {
+    public void runSubscribe() {
         try {
+            // given
             TSDBConnection unwrap = conn.unwrap(TSDBConnection.class);
             TSDBSubscribe subscribe = unwrap.subscribe("topic1", "select * from log.log", false);
+            // when
             TSDBResultSet rs = subscribe.consume();
             ResultSetMetaData metaData = rs.getMetaData();
-            for (int count = 0; count < 10 && rs.next(); count++) {
-                for (int i = 1; i <= metaData.getColumnCount(); i++) {
-                    String value = rs.getString(i);
-                    System.out.print(metaData.getColumnLabel(i) + ":" + value + "\t");
-                }
-                System.out.println();
-            }
+
+            // then
             Assert.assertNotNull(rs);
+            Assert.assertEquals(4, metaData.getColumnCount());
+            Assert.assertEquals("ts", metaData.getColumnLabel(1));
+            Assert.assertEquals("level", metaData.getColumnLabel(2));
+            Assert.assertEquals("content", metaData.getColumnLabel(3));
+            Assert.assertEquals("ipaddr", metaData.getColumnLabel(4));
+            rs.next();
+            // row 1
+            {
+                Assert.assertNotNull(rs.getTimestamp(1));
+                Assert.assertNotNull(rs.getTimestamp("ts"));
+                Assert.assertNotNull(rs.getByte(2));
+                Assert.assertNotNull(rs.getByte("level"));
+                Assert.assertNotNull(rs.getString(3));
+                Assert.assertNotNull(rs.getString("content"));
+                Assert.assertNotNull(rs.getString(4));
+                Assert.assertNotNull(rs.getString("ipaddr"));
+            }
             subscribe.close(false);
         } catch (SQLException e) {
             e.printStackTrace();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBDatabaseMetaDataTest.java

@@ -7,9 +7,11 @@ import java.util.Properties;
 
 public class TSDBDatabaseMetaDataTest {
     private static final String host = "127.0.0.1";
+    private static final String url = "jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata";
     private static Connection connection;
     private static TSDBDatabaseMetaData metaData;
 
+
     @Test
     public void unwrap() throws SQLException {
         TSDBDatabaseMetaData unwrap = metaData.unwrap(TSDBDatabaseMetaData.class);
@@ -33,7 +35,7 @@ public class TSDBDatabaseMetaDataTest {
 
     @Test
     public void getURL() throws SQLException {
-        Assert.assertEquals("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata", metaData.getURL());
+        Assert.assertEquals(url, metaData.getURL());
     }
 
     @Test
@@ -627,17 +629,32 @@ public class TSDBDatabaseMetaDataTest {
 
     @Test
     public void getTables() throws SQLException {
-        System.out.println("****************************************************");
-        ResultSet tables = metaData.getTables("log", "", null, null);
-        ResultSetMetaData metaData = tables.getMetaData();
-        while (tables.next()) {
-            System.out.print(metaData.getColumnLabel(1) + ":" + tables.getString(1) + "\t");
-            System.out.print(metaData.getColumnLabel(3) + ":" + tables.getString(3) + "\t");
-            System.out.print(metaData.getColumnLabel(4) + ":" + tables.getString(4) + "\t");
-            System.out.print(metaData.getColumnLabel(5) + ":" + tables.getString(5) + "\n");
+        ResultSet rs = metaData.getTables("log", "", null, null);
+        ResultSetMetaData meta = rs.getMetaData();
+        Assert.assertNotNull(rs);
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_SCHEM
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertNotNull(rs.getString(3));
+            Assert.assertNotNull(rs.getString("TABLE_NAME"));
+            // TABLE_TYPE
+            Assert.assertEquals("TABLE_TYPE", meta.getColumnLabel(4));
+            Assert.assertEquals("TABLE", rs.getString(4));
+            Assert.assertEquals("TABLE", rs.getString("TABLE_TYPE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(5));
+            Assert.assertEquals("", rs.getString(5));
+            Assert.assertEquals("", rs.getString("REMARKS"));
         }
-        System.out.println();
-        Assert.assertNotNull(tables);
     }
 
     @Test
@@ -647,46 +664,130 @@ public class TSDBDatabaseMetaDataTest {
 
     @Test
     public void getCatalogs() throws SQLException {
-        System.out.println("****************************************************");
-
-        ResultSet catalogs = metaData.getCatalogs();
-        ResultSetMetaData meta = catalogs.getMetaData();
-        while (catalogs.next()) {
-            for (int i = 1; i <= meta.getColumnCount(); i++) {
-                System.out.print(meta.getColumnLabel(i) + ": " + catalogs.getString(i));
-            }
-            System.out.println();
+        ResultSet rs = metaData.getCatalogs();
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertNotNull(rs.getString(1));
+            Assert.assertNotNull(rs.getString("TABLE_CAT"));
         }
     }
 
     @Test
     public void getTableTypes() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet tableTypes = metaData.getTableTypes();
-        while (tableTypes.next()) {
-            System.out.println(tableTypes.getString("TABLE_TYPE"));
+        tableTypes.next();
+        // tableTypes: table
+        {
+            Assert.assertEquals("TABLE", tableTypes.getString(1));
+            Assert.assertEquals("TABLE", tableTypes.getString("TABLE_TYPE"));
+        }
+        tableTypes.next();
+        // tableTypes: stable
+        {
+            Assert.assertEquals("STABLE", tableTypes.getString(1));
+            Assert.assertEquals("STABLE", tableTypes.getString("TABLE_TYPE"));
         }
-        Assert.assertNotNull(metaData.getTableTypes());
     }
 
     @Test
     public void getColumns() throws SQLException {
-        System.out.println("****************************************************");
-
+        // when
         ResultSet columns = metaData.getColumns("log", "", "dn", "");
+        // then
         ResultSetMetaData meta = columns.getMetaData();
-        while (columns.next()) {
-            System.out.print(meta.getColumnLabel(1) + ": " + columns.getString(1) + "\t");
-            System.out.print(meta.getColumnLabel(3) + ": " + columns.getString(3) + "\t");
-            System.out.print(meta.getColumnLabel(4) + ": " + columns.getString(4) + "\t");
-            System.out.print(meta.getColumnLabel(5) + ": " + columns.getString(5) + "\t");
-            System.out.print(meta.getColumnLabel(6) + ": " + columns.getString(6) + "\t");
-            System.out.print(meta.getColumnLabel(7) + ": " + columns.getString(7) + "\t");
-            System.out.print(meta.getColumnLabel(9) + ": " + columns.getString(9) + "\t");
-            System.out.print(meta.getColumnLabel(10) + ": " + columns.getString(10) + "\t");
-            System.out.print(meta.getColumnLabel(11) + ": " + columns.getString(11) + "\n");
-            System.out.print(meta.getColumnLabel(12) + ": " + columns.getString(12) + "\n");
+        columns.next();
+        // column: 1
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", columns.getString(1));
+            Assert.assertEquals("log", columns.getString("TABLE_CAT"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn", columns.getString(3));
+            Assert.assertEquals("dn", columns.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("ts", columns.getString(4));
+            Assert.assertEquals("ts", columns.getString("COLUMN_NAME"));
+            // DATA_TYPE
+            Assert.assertEquals("DATA_TYPE", meta.getColumnLabel(5));
+            Assert.assertEquals(Types.TIMESTAMP, columns.getInt(5));
+            Assert.assertEquals(Types.TIMESTAMP, columns.getInt("DATA_TYPE"));
+            // TYPE_NAME
+            Assert.assertEquals("TYPE_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("TIMESTAMP", columns.getString(6));
+            Assert.assertEquals("TIMESTAMP", columns.getString("TYPE_NAME"));
+            // COLUMN_SIZE
+            Assert.assertEquals("COLUMN_SIZE", meta.getColumnLabel(7));
+            Assert.assertEquals(26, columns.getInt(7));
+            Assert.assertEquals(26, columns.getInt("COLUMN_SIZE"));
+            // DECIMAL_DIGITS
+            Assert.assertEquals("DECIMAL_DIGITS", meta.getColumnLabel(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt("DECIMAL_DIGITS"));
+            Assert.assertEquals(null, columns.getString(9));
+            Assert.assertEquals(null, columns.getString("DECIMAL_DIGITS"));
+            // NUM_PREC_RADIX
+            Assert.assertEquals("NUM_PREC_RADIX", meta.getColumnLabel(10));
+            Assert.assertEquals(10, columns.getInt(10));
+            Assert.assertEquals(10, columns.getInt("NUM_PREC_RADIX"));
+            // NULLABLE
+            Assert.assertEquals("NULLABLE", meta.getColumnLabel(11));
+            Assert.assertEquals(DatabaseMetaData.columnNoNulls, columns.getInt(11));
+            Assert.assertEquals(DatabaseMetaData.columnNoNulls, columns.getInt("NULLABLE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(12));
+            Assert.assertEquals(null, columns.getString(12));
+            Assert.assertEquals(null, columns.getString("REMARKS"));
+        }
+        columns.next();
+        // column: 2
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", columns.getString(1));
+            Assert.assertEquals("log", columns.getString("TABLE_CAT"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn", columns.getString(3));
+            Assert.assertEquals("dn", columns.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("cpu_taosd", columns.getString(4));
+            Assert.assertEquals("cpu_taosd", columns.getString("COLUMN_NAME"));
+            // DATA_TYPE
+            Assert.assertEquals("DATA_TYPE", meta.getColumnLabel(5));
+            Assert.assertEquals(Types.FLOAT, columns.getInt(5));
+            Assert.assertEquals(Types.FLOAT, columns.getInt("DATA_TYPE"));
+            // TYPE_NAME
+            Assert.assertEquals("TYPE_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("FLOAT", columns.getString(6));
+            Assert.assertEquals("FLOAT", columns.getString("TYPE_NAME"));
+            // COLUMN_SIZE
+            Assert.assertEquals("COLUMN_SIZE", meta.getColumnLabel(7));
+            Assert.assertEquals(12, columns.getInt(7));
+            Assert.assertEquals(12, columns.getInt("COLUMN_SIZE"));
+            // DECIMAL_DIGITS
+            Assert.assertEquals("DECIMAL_DIGITS", meta.getColumnLabel(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt("DECIMAL_DIGITS"));
+            Assert.assertEquals(null, columns.getString(9));
+            Assert.assertEquals(null, columns.getString("DECIMAL_DIGITS"));
+            // NUM_PREC_RADIX
+            Assert.assertEquals("NUM_PREC_RADIX", meta.getColumnLabel(10));
+            Assert.assertEquals(10, columns.getInt(10));
+            Assert.assertEquals(10, columns.getInt("NUM_PREC_RADIX"));
+            // NULLABLE
+            Assert.assertEquals("NULLABLE", meta.getColumnLabel(11));
+            Assert.assertEquals(DatabaseMetaData.columnNullable, columns.getInt(11));
+            Assert.assertEquals(DatabaseMetaData.columnNullable, columns.getInt("NULLABLE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(12));
+            Assert.assertEquals(null, columns.getString(12));
         }
     }
 
@@ -712,17 +813,35 @@ public class TSDBDatabaseMetaDataTest {
 
     @Test
     public void getPrimaryKeys() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet rs = metaData.getPrimaryKeys("log", "", "dn1");
-        while (rs.next()) {
-            System.out.println("TABLE_NAME: " + rs.getString("TABLE_NAME"));
-            System.out.println("COLUMN_NAME: " + rs.getString("COLUMN_NAME"));
-            System.out.println("KEY_SEQ: " + rs.getString("KEY_SEQ"));
-            System.out.println("PK_NAME: " + rs.getString("PK_NAME"));
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_SCHEM
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn1", rs.getString(3));
+            Assert.assertEquals("dn1", rs.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("ts", rs.getString(4));
+            Assert.assertEquals("ts", rs.getString("COLUMN_NAME"));
+            // KEY_SEQ
+            Assert.assertEquals("KEY_SEQ", meta.getColumnLabel(5));
+            Assert.assertEquals(1, rs.getShort(5));
+            Assert.assertEquals(1, rs.getShort("KEY_SEQ"));
+            // DATA_TYPE
+            Assert.assertEquals("PK_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("ts", rs.getString(6));
+            Assert.assertEquals("ts", rs.getString("PK_NAME"));
         }
-
-        Assert.assertNotNull(rs);
     }
 
     @Test
@@ -847,14 +966,27 @@ public class TSDBDatabaseMetaDataTest {
 
     @Test
     public void getSuperTables() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet rs = metaData.getSuperTables("log", "", "dn1");
-        while (rs.next()) {
-            System.out.println("TABLE_NAME: " + rs.getString("TABLE_NAME"));
-            System.out.println("SUPERTABLE_NAME: " + rs.getString("SUPERTABLE_NAME"));
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn1", rs.getString(3));
+            Assert.assertEquals("dn1", rs.getString("TABLE_NAME"));
+            // TABLE_CAT
+            Assert.assertEquals("SUPERTABLE_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("dn", rs.getString(4));
+            Assert.assertEquals("dn", rs.getString("SUPERTABLE_NAME"));
         }
-        Assert.assertNotNull(rs);
     }
 
     @Test
@@ -951,15 +1083,12 @@ public class TSDBDatabaseMetaDataTest {
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
-            connection = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata", properties);
+            connection = DriverManager.getConnection(url, properties);
             metaData = connection.getMetaData().unwrap(TSDBDatabaseMetaData.class);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
         } catch (SQLException e) {
             e.printStackTrace();
         }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBJNIConnectorTest.java

@@ -45,9 +45,9 @@ public class TSDBJNIConnectorTest {
             rowData = new TSDBResultSetRowData(columnSize);
             // iterate resultSet
             for (int i = 0; next(connector, pSql); i++) {
-                System.out.println("col[" + i + "] size: " + rowData.getColSize());
-                rowData.getData().stream().forEach(col -> System.out.print(col + "\t"));
-                System.out.println();
+//                System.out.println("col[" + i + "] size: " + rowData.getColSize());
+//                rowData.getData().stream().forEach(col -> System.out.print(col + "\t"));
+//                System.out.println();
             }
             // close resultSet
             code = connector.freeResultSet(pSql);

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBParameterMetaDataTest.java

@@ -54,16 +54,17 @@ public class TSDBParameterMetaDataTest {
 
     @Test
     public void getPrecision() throws SQLException {
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(1));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(2));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(3));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(4));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(5));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(6));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(7));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(8));
-        Assert.assertEquals(5, parameterMetaData_insert.getPrecision(9));
-        Assert.assertEquals(5, parameterMetaData_insert.getPrecision(10));
+        //create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64))
+        Assert.assertEquals(TSDBConstants.TIMESTAMP_MS_PRECISION, parameterMetaData_insert.getPrecision(1));
+        Assert.assertEquals(TSDBConstants.INT_PRECISION, parameterMetaData_insert.getPrecision(2));
+        Assert.assertEquals(TSDBConstants.BIGINT_PRECISION, parameterMetaData_insert.getPrecision(3));
+        Assert.assertEquals(TSDBConstants.FLOAT_PRECISION, parameterMetaData_insert.getPrecision(4));
+        Assert.assertEquals(TSDBConstants.DOUBLE_PRECISION, parameterMetaData_insert.getPrecision(5));
+        Assert.assertEquals(TSDBConstants.SMALLINT_PRECISION, parameterMetaData_insert.getPrecision(6));
+        Assert.assertEquals(TSDBConstants.TINYINT_PRECISION, parameterMetaData_insert.getPrecision(7));
+        Assert.assertEquals(TSDBConstants.BOOLEAN_PRECISION, parameterMetaData_insert.getPrecision(8));
+        Assert.assertEquals("hello".getBytes().length, parameterMetaData_insert.getPrecision(9));
+        Assert.assertEquals("涛思数据".length(), parameterMetaData_insert.getPrecision(10));
     }
 
     @Test
@@ -71,8 +72,8 @@ public class TSDBParameterMetaDataTest {
         Assert.assertEquals(0, parameterMetaData_insert.getScale(1));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(2));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(3));
-        Assert.assertEquals(0, parameterMetaData_insert.getScale(4));
-        Assert.assertEquals(0, parameterMetaData_insert.getScale(5));
+        Assert.assertEquals(31, parameterMetaData_insert.getScale(4));
+        Assert.assertEquals(31, parameterMetaData_insert.getScale(5));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(6));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(7));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(8));
@@ -124,10 +125,16 @@ public class TSDBParameterMetaDataTest {
 
     @Test
     public void getParameterMode() throws SQLException {
-        for (int i = 1; i <= parameterMetaData_insert.getParameterCount(); i++) {
-            int parameterMode = parameterMetaData_insert.getParameterMode(i);
-            Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMode);
-        }
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(1));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(2));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(3));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(4));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(5));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(6));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(7));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(8));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(9));
+        Assert.assertEquals(ParameterMetaData.parameterModeUnknown, parameterMetaData_insert.getParameterMode(10));
     }
 
     @Test
@@ -144,7 +151,6 @@ public class TSDBParameterMetaDataTest {
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
             try (Statement stmt = conn.createStatement()) {
                 stmt.execute("drop database if exists test_pstmt");
@@ -164,7 +170,7 @@ public class TSDBParameterMetaDataTest {
             pstmt_insert.setObject(7, Byte.MAX_VALUE);
             pstmt_insert.setObject(8, true);
             pstmt_insert.setObject(9, "hello".getBytes());
-            pstmt_insert.setObject(10, "Hello");
+            pstmt_insert.setObject(10, "涛思数据");
             parameterMetaData_insert = pstmt_insert.getParameterMetaData();
 
             pstmt_select = conn.prepareStatement(sql_select);
@@ -173,7 +179,7 @@ public class TSDBParameterMetaDataTest {
             pstmt_select.setInt(3, 0);
             parameterMetaData_select = pstmt_select.getParameterMetaData();
 
-        } catch (ClassNotFoundException | SQLException e) {
+        } catch (SQLException e) {
             e.printStackTrace();
         }
     }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBPreparedStatementTest.java

 package com.taosdata.jdbc;
 
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
+import org.junit.*;
 
 import java.io.IOException;
-import java.io.Serializable;
+import java.math.BigDecimal;
 import java.sql.*;
-import java.util.ArrayList;
-import java.util.Random;
+import java.time.LocalTime;
 
 public class TSDBPreparedStatementTest {
+
     private static final String host = "127.0.0.1";
     private static Connection conn;
     private static final String sql_insert = "insert into t1 values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
-    private static PreparedStatement pstmt_insert;
-    private static final String sql_select = "select * from t1 where ts > ? and ts <= ? and f1 >= ?";
-    private static PreparedStatement pstmt_select;
+    private static final String sql_select = "select * from t1 where ts >= ? and ts < ? and f1 >= ?";
+
+    private PreparedStatement pstmt_insert;
+    private PreparedStatement pstmt_select;
+    //create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64)) tags(loc nchar(64))
 
     @Test
     public void executeQuery() throws SQLException {
-        long end = System.currentTimeMillis();
-        long start = end - 1000 * 60 * 60;
+        // given
+        long ts = System.currentTimeMillis();
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setInt(2, 2);
+        pstmt_insert.setLong(3, 3l);
+        pstmt_insert.setFloat(4, 3.14f);
+        pstmt_insert.setDouble(5, 3.1415);
+        pstmt_insert.setShort(6, (short) 6);
+        pstmt_insert.setByte(7, (byte) 7);
+        pstmt_insert.setBoolean(8, true);
+        pstmt_insert.setBytes(9, "abc".getBytes());
+        pstmt_insert.setString(10, "涛思数据");
+        pstmt_insert.executeUpdate();
+        long start = ts - 1000 * 60 * 60;
+        long end = ts + 1000 * 60 * 60;
         pstmt_select.setTimestamp(1, new Timestamp(start));
         pstmt_select.setTimestamp(2, new Timestamp(end));
         pstmt_select.setInt(3, 0);
 
+        // when
         ResultSet rs = pstmt_select.executeQuery();
-        Assert.assertNotNull(rs);
         ResultSetMetaData meta = rs.getMetaData();
-        while (rs.next()) {
-            for (int i = 1; i <= meta.getColumnCount(); i++) {
-                System.out.print(meta.getColumnLabel(i) + ": " + rs.getString(i) + "\t");
-            }
-            System.out.println();
+        rs.next();
+
+        // then
+        assertMetaData(meta);
+        {
+            Assert.assertNotNull(rs);
+            Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+            Assert.assertEquals(2, rs.getInt(2));
+            Assert.assertEquals(2, rs.getInt("f1"));
+            Assert.assertEquals(3l, rs.getLong(3));
+            Assert.assertEquals(3l, rs.getLong("f2"));
+            Assert.assertEquals(3.14f, rs.getFloat(4), 0.0);
+            Assert.assertEquals(3.14f, rs.getFloat("f3"), 0.0);
+            Assert.assertEquals(3.1415, rs.getDouble(5), 0.0);
+            Assert.assertEquals(3.1415, rs.getDouble("f4"), 0.0);
+            Assert.assertEquals((short) 6, rs.getShort(6));
+            Assert.assertEquals((short) 6, rs.getShort("f5"));
+            Assert.assertEquals((byte) 7, rs.getByte(7));
+            Assert.assertEquals((byte) 7, rs.getByte("f6"));
+            Assert.assertTrue(rs.getBoolean(8));
+            Assert.assertTrue(rs.getBoolean("f7"));
+            Assert.assertArrayEquals("abc".getBytes(), rs.getBytes(9));
+            Assert.assertArrayEquals("abc".getBytes(), rs.getBytes("f8"));
+            Assert.assertEquals("涛思数据", rs.getString(10));
+            Assert.assertEquals("涛思数据", rs.getString("f9"));
         }
     }
 
-    @Test
-    public void executeUpdate() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setFloat(4, 3.14f);
-        int result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+    private void assertMetaData(ResultSetMetaData meta) throws SQLException {
+        Assert.assertEquals(10, meta.getColumnCount());
+        Assert.assertEquals("ts", meta.getColumnLabel(1));
+        Assert.assertEquals("f1", meta.getColumnLabel(2));
+        Assert.assertEquals("f2", meta.getColumnLabel(3));
+        Assert.assertEquals("f3", meta.getColumnLabel(4));
+        Assert.assertEquals("f4", meta.getColumnLabel(5));
+        Assert.assertEquals("f5", meta.getColumnLabel(6));
+        Assert.assertEquals("f6", meta.getColumnLabel(7));
+        Assert.assertEquals("f7", meta.getColumnLabel(8));
+        Assert.assertEquals("f8", meta.getColumnLabel(9));
+        Assert.assertEquals("f9", meta.getColumnLabel(10));
     }
 
     @Test
-    public void setNull() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+    public void setNullForTimestamp() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setNull(2, Types.INTEGER);
         int result = pstmt_insert.executeUpdate();
+
+        // then
         Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
+        }
+    }
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+    private void assertAllNullExceptTimestamp(ResultSet rs, long ts) throws SQLException {
+        Assert.assertNotNull(rs);
+        Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+        Assert.assertEquals(0, rs.getInt(2));
+        Assert.assertEquals(0, rs.getInt("f1"));
+        Assert.assertEquals(0, rs.getLong(3));
+        Assert.assertEquals(0, rs.getLong("f2"));
+        Assert.assertEquals(0, rs.getFloat(4), 0.0);
+        Assert.assertEquals(0, rs.getFloat("f3"), 0.0);
+        Assert.assertEquals(0, rs.getDouble(5), 0.0);
+        Assert.assertEquals(0, rs.getDouble("f4"), 0.0);
+        Assert.assertEquals(0, rs.getShort(6));
+        Assert.assertEquals(0, rs.getShort("f5"));
+        Assert.assertEquals(0, rs.getByte(7));
+        Assert.assertEquals(0, rs.getByte("f6"));
+        Assert.assertFalse(rs.getBoolean(8));
+        Assert.assertFalse(rs.getBoolean("f7"));
+        Assert.assertNull(rs.getBytes(9));
+        Assert.assertNull(rs.getBytes("f8"));
+        Assert.assertNull(rs.getString(10));
+        Assert.assertNull(rs.getString("f9"));
+    }
+
+    @Test
+    public void setNullForInteger() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setNull(3, Types.BIGINT);
-        result = pstmt_insert.executeUpdate();
+        int result = pstmt_insert.executeUpdate();
+
+        // then
         Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
+        }
+    }
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+    @Test
+    public void setNullForFloat() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setNull(4, Types.FLOAT);
-        result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+        int result = pstmt_insert.executeUpdate();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(5, Types.DOUBLE);
-        result = pstmt_insert.executeUpdate();
+        // then
         Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
+        }
+    }
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(6, Types.SMALLINT);
-        result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+    @Test
+    public void setNullForDouble() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(7, Types.TINYINT);
-        result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(5, Types.DOUBLE);
+        int result = pstmt_insert.executeUpdate();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(8, Types.BOOLEAN);
-        result = pstmt_insert.executeUpdate();
+        // then
         Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
+        }
+    }
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(9, Types.BINARY);
-        result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+    @Test
+    public void setNullForSmallInt() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(10, Types.NCHAR);
-        result = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, result);
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(6, Types.SMALLINT);
+        int result = pstmt_insert.executeUpdate();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setNull(10, Types.OTHER);
-        result = pstmt_insert.executeUpdate();
+        // then
         Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
+        }
     }
 
     @Test
-    public void executeTest() throws SQLException {   
-        Statement stmt = conn.createStatement();            
-
-        int numOfRows = 1000;        
-
-        for (int loop = 0; loop < 10; loop++){
-            stmt.execute("drop table if exists weather_test");
-            stmt.execute("create table weather_test(ts timestamp, f1 nchar(4), f2 float, f3 double, f4 timestamp, f5 int, f6 bool, f7 binary(10))");            
-
-            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? values(?, ?, ?, ?, ?, ?, ?, ?)");
-            Random r = new Random();
-            s.setTableName("weather_test");
-            
-            ArrayList<Long> ts = new ArrayList<Long>();
-            for(int i = 0; i < numOfRows; i++) {
-                ts.add(System.currentTimeMillis() + i);
-            }        
-            s.setTimestamp(0, ts);
-
-            int random = 10 + r.nextInt(5);
-            ArrayList<String> s2 = new ArrayList<String>();        
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s2.add(null);
-                }else{
-                    s2.add("分支" + i % 4);
-                }
-            }        
-            s.setNString(1, s2, 4);      
-
-            random = 10 + r.nextInt(5);
-            ArrayList<Float> s3 = new ArrayList<Float>();        
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s3.add(null);
-                }else{
-                    s3.add(r.nextFloat());
-                }
-            }        
-            s.setFloat(2, s3);
-
-            random = 10 + r.nextInt(5);
-            ArrayList<Double> s4 = new ArrayList<Double>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s4.add(null);
-                }else{
-                    s4.add(r.nextDouble());
-                }
-            }
-            s.setDouble(3, s4);
-
-            random = 10 + r.nextInt(5);
-            ArrayList<Long> ts2 = new ArrayList<Long>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    ts2.add(null);
-                }else{
-                    ts2.add(System.currentTimeMillis() + i);
-                }
-            }
-            s.setTimestamp(4, ts2);
-
-            random = 10 + r.nextInt(5);
-            ArrayList<Integer>  vals = new ArrayList<>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    vals.add(null);
-                }else{
-                    vals.add(r.nextInt());
-                }                
-            }
-            s.setInt(5, vals);
-
-            random = 10 + r.nextInt(5);
-            ArrayList<Boolean> sb = new ArrayList<>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    sb.add(null);
-                }else{
-                    sb.add(i % 2 == 0 ? true : false);
-                }
-            }
-            s.setBoolean(6, sb);        
-
-            random = 10 + r.nextInt(5);
-            ArrayList<String> s5 = new ArrayList<String>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s5.add(null);
-                }else{
-                    s5.add("test" + i % 10);
-                }
-            }
-            s.setString(7, s5, 10);        
-
-            s.columnDataAddBatch();
-            s.columnDataExecuteBatch();
-            s.columnDataCloseBatch();
-
-            String sql = "select * from weather_test";
-            PreparedStatement statement = conn.prepareStatement(sql);
-            ResultSet rs = statement.executeQuery();
-            int rows = 0;
-            while(rs.next()) {
-                rows++;
-            }
-            Assert.assertEquals(numOfRows, rows);            
+    public void setNullForTinyInt() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(7, Types.TINYINT);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
         }
     }
 
     @Test
-    public void bindDataSelectColumnTest() throws SQLException {   
-        Statement stmt = conn.createStatement();            
-
-        int numOfRows = 1000;        
-
-        for (int loop = 0; loop < 10; loop++){
-            stmt.execute("drop table if exists weather_test");
-            stmt.execute("create table weather_test(ts timestamp, f1 nchar(4), f2 float, f3 double, f4 timestamp, f5 int, f6 bool, f7 binary(10))");            
-
-            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? (ts, f1, f7) values(?, ?, ?)");
-            Random r = new Random();
-            s.setTableName("weather_test");
-            
-            ArrayList<Long> ts = new ArrayList<Long>();
-            for(int i = 0; i < numOfRows; i++) {
-                ts.add(System.currentTimeMillis() + i);
-            }        
-            s.setTimestamp(0, ts);
-
-            int random = 10 + r.nextInt(5);
-            ArrayList<String> s2 = new ArrayList<String>();        
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s2.add(null);
-                }else{
-                    s2.add("分支" + i % 4);
-                }
-            }        
-            s.setNString(1, s2, 4);                   
-
-            random = 10 + r.nextInt(5);
-            ArrayList<String> s3 = new ArrayList<String>();
-            for(int i = 0; i < numOfRows; i++) {
-                if(i % random == 0) {
-                    s3.add(null);
-                }else{
-                    s3.add("test" + i % 10);
-                }
-            }
-            s.setString(2, s3, 10);        
-
-            s.columnDataAddBatch();
-            s.columnDataExecuteBatch();
-            s.columnDataCloseBatch();
-
-            String sql = "select * from weather_test";
-            PreparedStatement statement = conn.prepareStatement(sql);
-            ResultSet rs = statement.executeQuery();
-            int rows = 0;
-            while(rs.next()) {
-                rows++;
-            }
-            Assert.assertEquals(numOfRows, rows);            
+    public void setNullForBoolean() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(8, Types.BOOLEAN);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
         }
     }
 
     @Test
-    public void bindDataWithSingleTagTest() throws SQLException { 
-        Statement stmt = conn.createStatement();                
-
-        String types[] = new String[] {"tinyint", "smallint", "int", "bigint", "bool", "float", "double", "binary(10)", "nchar(10)"};                
-
-        for (String type : types) {
-            stmt.execute("drop table if exists weather_test");
-            stmt.execute("create table weather_test(ts timestamp, f1 nchar(10), f2 binary(10)) tags (t " + type + ")");
-
-            int numOfRows = 1;
-    
-            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? using weather_test tags(?) values(?, ?, ?)");
-            Random r = new Random();
-            s.setTableName("w1");
-            
-            switch(type) {
-                case "tinyint":
-                case "smallint":
-                case "int":
-                case "bigint":
-                    s.setTagInt(0, 1);
-                    break;
-                case "float":
-                    s.setTagFloat(0, 1.23f);
-                    break;
-                case "double":
-                    s.setTagDouble(0, 3.14159265);
-                    break;
-                case "bool":
-                    s.setTagBoolean(0, true);
-                    break;
-                case "binary(10)":
-                    s.setTagString(0, "test");
-                    break;
-                case "nchar(10)":
-                    s.setTagNString(0, "test");
-                    break;
-                default:
-                    break;
-            }
-            
-            
-            ArrayList<Long> ts = new ArrayList<Long>();
-            for(int i = 0; i < numOfRows; i++) {
-                ts.add(System.currentTimeMillis() + i);
-            }        
-            s.setTimestamp(0, ts);
-    
-            int random = 10 + r.nextInt(5);
-            ArrayList<String> s2 = new ArrayList<String>();        
-            for(int i = 0; i < numOfRows; i++) {            
-                s2.add("分支" + i % 4);            
-            }        
-            s.setNString(1, s2, 10);
-            
-            random = 10 + r.nextInt(5);
-            ArrayList<String> s3 = new ArrayList<String>();        
-            for(int i = 0; i < numOfRows; i++) {            
-                s3.add("test" + i % 4);            
-            }        
-            s.setString(2, s3, 10);
-    
-            s.columnDataAddBatch();
-            s.columnDataExecuteBatch();
-            s.columnDataCloseBatch();
-    
-            String sql = "select * from weather_test";
-            PreparedStatement statement = conn.prepareStatement(sql);
-            ResultSet rs = statement.executeQuery();
-            int rows = 0;
-            while(rs.next()) {
-                rows++;
-            }
-            Assert.assertEquals(numOfRows, rows);
+    public void setNullForBinary() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(9, Types.BINARY);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
         }
     }
 
-
     @Test
-    public void bindDataWithMultipleTagsTest() throws SQLException { 
-        Statement stmt = conn.createStatement();                
-        
-        stmt.execute("drop table if exists weather_test");
-        stmt.execute("create table weather_test(ts timestamp, f1 nchar(10), f2 binary(10)) tags (t1 int, t2 binary(10))");
-
-        int numOfRows = 1;
-
-        TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? using weather_test tags(?,?) (ts, f2) values(?, ?)");        
-        s.setTableName("w2");  
-        s.setTagInt(0, 1);
-        s.setTagString(1, "test");
-        
-        
-        ArrayList<Long> ts = new ArrayList<Long>();
-        for(int i = 0; i < numOfRows; i++) {
-            ts.add(System.currentTimeMillis() + i);
-        }        
-        s.setTimestamp(0, ts);
-        
-        ArrayList<String> s2 = new ArrayList<String>();        
-        for(int i = 0; i < numOfRows; i++) {            
-            s2.add("test" + i % 4);
-        }
-        s.setString(1, s2, 10);
-    
-        s.columnDataAddBatch();
-        s.columnDataExecuteBatch();
-        s.columnDataCloseBatch();
-
-        String sql = "select * from weather_test";
-        PreparedStatement statement = conn.prepareStatement(sql);
-        ResultSet rs = statement.executeQuery();
-        int rows = 0;
-        while(rs.next()) {
-            rows++;
+    public void setNullForNchar() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setNull(10, Types.NCHAR);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            assertAllNullExceptTimestamp(rs, ts);
         }
-        Assert.assertEquals(numOfRows, rows);
-        
     }
 
     @Test
     public void setBoolean() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setBoolean(8, true);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertTrue(rs.getBoolean(8));
+                Assert.assertTrue(rs.getBoolean("f7"));
+            }
+        }
     }
 
     @Test
     public void setByte() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setByte(7, (byte) 0x001);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals((byte) 0x001, rs.getByte(7));
+                Assert.assertEquals((byte) 0x001, rs.getByte("f6"));
+            }
+        }
     }
 
     @Test
     public void setShort() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setShort(6, (short) 2);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals((short) 2, rs.getByte(6));
+                Assert.assertEquals((short) 2, rs.getByte("f5"));
+            }
+        }
     }
 
     @Test
     public void setInt() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setInt(2, 10086);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(10086, rs.getInt(2));
+                Assert.assertEquals(10086, rs.getInt("f1"));
+            }
+        }
     }
 
     @Test
     public void setLong() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setLong(3, Long.MAX_VALUE);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(Long.MAX_VALUE, rs.getLong(3));
+                Assert.assertEquals(Long.MAX_VALUE, rs.getLong("f2"));
+            }
+        }
     }
 
     @Test
     public void setFloat() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setFloat(4, 3.14f);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(3.14f, rs.getFloat(4), 0.0f);
+                Assert.assertEquals(3.14f, rs.getFloat("f3"), 0.0f);
+            }
+        }
     }
 
     @Test
     public void setDouble() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setDouble(5, 3.14444);
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-    }
+        int result = pstmt_insert.executeUpdate();
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
-    public void setBigDecimal() throws SQLException {
-        pstmt_insert.setBigDecimal(1, null);
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(3.14444, rs.getDouble(5), 0.0);
+                Assert.assertEquals(3.14444, rs.getDouble("f4"), 0.0);
+            }
+        }
     }
 
     @Test
-    public void setString() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setString(10, "aaaa");
-        boolean execute = pstmt_insert.execute();
-        Assert.assertFalse(execute);
+    public void setBigDecimal() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+        BigDecimal bigDecimal = new BigDecimal(3.14444);
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setString(10, new Person("john", 33, true).toString());
-        Assert.assertFalse(pstmt_insert.execute());
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setBigDecimal(5, bigDecimal);
+        int result = pstmt_insert.executeUpdate();
 
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setString(10, new Person("john", 33, true).toString().replaceAll("'", "\""));
-        Assert.assertFalse(pstmt_insert.execute());
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(3.14444, rs.getDouble(5), 0.0);
+                Assert.assertEquals(3.14444, rs.getDouble("f4"), 0.0);
+            }
+        }
     }
 
-    class Person {
-        String name;
-        int age;
-        boolean sex;
+    @Test
+    public void setString() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+        String f9 = "{\"name\": \"john\", \"age\": 10, \"address\": \"192.168.1.100\"}";
 
-        public Person(String name, int age, boolean sex) {
-            this.name = name;
-            this.age = age;
-            this.sex = sex;
-        }
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setString(10, f9);
+        int result = pstmt_insert.executeUpdate();
 
-        @Override
-        public String toString() {
-            return "Person{" +
-                    "name='" + name + '\'' +
-                    ", age=" + age +
-                    ", sex=" + sex +
-                    '}';
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertEquals(f9, rs.getString(10));
+                Assert.assertEquals(f9, rs.getString("f9"));
+            }
         }
     }
 
     @Test
     public void setBytes() throws SQLException, IOException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+        byte[] f8 = "{\"name\": \"john\", \"age\": 10, \"address\": \"192.168.1.100\"}".getBytes();
 
-//        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-//        ObjectOutputStream oos = new ObjectOutputStream(baos);
-//        oos.writeObject(new Person("john", 33, true));
-//        oos.flush();
-//        byte[] bytes = baos.toByteArray();
-//        pstmt_insert.setBytes(9, bytes);
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        pstmt_insert.setBytes(9, f8);
+        int result = pstmt_insert.executeUpdate();
 
-        pstmt_insert.setBytes(9, new Person("john", 33, true).toString().getBytes());
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+                Assert.assertArrayEquals(f8, rs.getBytes(9));
+                Assert.assertArrayEquals(f8, rs.getBytes("f8"));
+            }
+        }
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void setDate() throws SQLException {
-        pstmt_insert.setDate(1, new Date(System.currentTimeMillis()));
+        // given
+        long ts = new java.util.Date().getTime();
+
+        // when
+        pstmt_insert.setDate(1, new Date(ts));
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+            }
+        }
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void setTime() throws SQLException {
-        pstmt_insert.setTime(1, new Time(System.currentTimeMillis()));
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTime(1, new Time(ts));
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+            }
+        }
     }
 
     @Test
     public void setTimestamp() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        int result = pstmt_insert.executeUpdate();
+
+        // then
+        Assert.assertEquals(1, result);
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from t1");
+            ResultSetMetaData meta = rs.getMetaData();
+            assertMetaData(meta);
+            rs.next();
+            {
+                Assert.assertNotNull(rs);
+                Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
+                Assert.assertEquals(ts, rs.getTimestamp("ts").getTime());
+            }
+        }
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)
@@ -530,72 +651,6 @@ public class TSDBPreparedStatementTest {
         pstmt_insert.setBinaryStream(1, null);
     }
 
-    @Test
-    public void clearParameters() throws SQLException {
-        pstmt_insert.clearParameters();
-    }
-
-    @Test
-    public void setObject() throws SQLException {
-        pstmt_insert.setObject(1, new Timestamp(System.currentTimeMillis()));
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(2, 111);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(3, Long.MAX_VALUE);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(4, 3.14159265354f);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(5, Double.MAX_VALUE);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(6, Short.MAX_VALUE);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(7, Byte.MAX_VALUE);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(8, true);
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(9, "hello".getBytes());
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        pstmt_insert.setObject(10, "Hello");
-        ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-    }
-
-    @Test
-    public void execute() throws SQLException {
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
-        int ret = pstmt_insert.executeUpdate();
-        Assert.assertEquals(1, ret);
-
-        executeQuery();
-    }
-
     @Test(expected = SQLFeatureNotSupportedException.class)
     public void setCharacterStream() throws SQLException {
         pstmt_insert.setCharacterStream(1, null);
@@ -621,9 +676,17 @@ public class TSDBPreparedStatementTest {
         pstmt_insert.setArray(1, null);
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void getMetaData() throws SQLException {
-        pstmt_insert.getMetaData();
+        // given
+        long ts = System.currentTimeMillis();
+
+        // when
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        ResultSetMetaData metaData = pstmt_insert.getMetaData();
+
+        // then
+        Assert.assertNull(metaData);
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)
@@ -633,9 +696,46 @@ public class TSDBPreparedStatementTest {
 
     @Test
     public void getParameterMetaData() throws SQLException {
+        // given
+        long ts = System.currentTimeMillis();
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
+        pstmt_insert.setInt(2, 2);
+        pstmt_insert.setLong(3, 3l);
+        pstmt_insert.setFloat(4, 3.14f);
+        pstmt_insert.setDouble(5, 3.1415);
+        pstmt_insert.setShort(6, (short) 6);
+        pstmt_insert.setByte(7, (byte) 7);
+        pstmt_insert.setBoolean(8, true);
+        pstmt_insert.setBytes(9, "abc".getBytes());
+        pstmt_insert.setString(10, "涛思数据");
+
+        // when
         ParameterMetaData parameterMetaData = pstmt_insert.getParameterMetaData();
+
+        // then
         Assert.assertNotNull(parameterMetaData);
-        //TODO: modify the test case
+        Assert.assertEquals(10, parameterMetaData.getParameterCount());
+        Assert.assertEquals(Types.TIMESTAMP, parameterMetaData.getParameterType(1));
+        Assert.assertEquals(Types.INTEGER, parameterMetaData.getParameterType(2));
+        Assert.assertEquals(Types.BIGINT, parameterMetaData.getParameterType(3));
+        Assert.assertEquals(Types.FLOAT, parameterMetaData.getParameterType(4));
+        Assert.assertEquals(Types.DOUBLE, parameterMetaData.getParameterType(5));
+        Assert.assertEquals(Types.SMALLINT, parameterMetaData.getParameterType(6));
+        Assert.assertEquals(Types.TINYINT, parameterMetaData.getParameterType(7));
+        Assert.assertEquals(Types.BOOLEAN, parameterMetaData.getParameterType(8));
+        Assert.assertEquals(Types.BINARY, parameterMetaData.getParameterType(9));
+        Assert.assertEquals(Types.NCHAR, parameterMetaData.getParameterType(10));
+
+        Assert.assertEquals("TIMESTAMP", parameterMetaData.getParameterTypeName(1));
+        Assert.assertEquals("INT", parameterMetaData.getParameterTypeName(2));
+        Assert.assertEquals("BIGINT", parameterMetaData.getParameterTypeName(3));
+        Assert.assertEquals("FLOAT", parameterMetaData.getParameterTypeName(4));
+        Assert.assertEquals("DOUBLE", parameterMetaData.getParameterTypeName(5));
+        Assert.assertEquals("SMALLINT", parameterMetaData.getParameterTypeName(6));
+        Assert.assertEquals("TINYINT", parameterMetaData.getParameterTypeName(7));
+        Assert.assertEquals("BOOL", parameterMetaData.getParameterTypeName(8));
+        Assert.assertEquals("BINARY", parameterMetaData.getParameterTypeName(9));
+        Assert.assertEquals("NCHAR", parameterMetaData.getParameterTypeName(10));
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)
@@ -643,9 +743,9 @@ public class TSDBPreparedStatementTest {
         pstmt_insert.setRowId(1, null);
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void setNString() throws SQLException {
-        pstmt_insert.setNString(1, null);
+        setString();
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)
@@ -663,22 +763,45 @@ public class TSDBPreparedStatementTest {
         pstmt_insert.setSQLXML(1, null);
     }
 
+    @Before
+    public void before() {
+        try {
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop table if exists weather");
+            stmt.execute("create table if not exists weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64)) tags(loc nchar(64))");
+            stmt.execute("create table if not exists t1 using weather tags('beijing')");
+            stmt.close();
+
+            pstmt_insert = conn.prepareStatement(sql_insert);
+            pstmt_select = conn.prepareStatement(sql_select);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @After
+    public void after() {
+        try {
+            if (pstmt_insert != null)
+                pstmt_insert.close();
+            if (pstmt_select != null)
+                pstmt_select.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+    }
 
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
             try (Statement stmt = conn.createStatement()) {
                 stmt.execute("drop database if exists test_pstmt_jni");
                 stmt.execute("create database if not exists test_pstmt_jni");
                 stmt.execute("use test_pstmt_jni");
-                stmt.execute("create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64)) tags(loc nchar(64))");
-                stmt.execute("create table t1 using weather tags('beijing')");
             }
-            pstmt_insert = conn.prepareStatement(sql_insert);
-            pstmt_select = conn.prepareStatement(sql_select);
-        } catch (ClassNotFoundException | SQLException e) {
+        } catch (SQLException e) {
             e.printStackTrace();
         }
     }
@@ -686,10 +809,6 @@ public class TSDBPreparedStatementTest {
     @AfterClass
     public static void afterClass() {
         try {
-            if (pstmt_insert != null)
-                pstmt_insert.close();
-            if (pstmt_select != null)
-                pstmt_select.close();
             if (conn != null)
                 conn.close();
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBResultSetTest.java

@@ -14,6 +14,7 @@ import java.math.BigDecimal;
 import java.sql.*;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.util.Arrays;
 
 public class TSDBResultSetTest {
 
@@ -133,7 +134,7 @@ public class TSDBResultSetTest {
         Assert.assertEquals(3.1415926, Double.valueOf(new String(f5)), 0.000000f);
 
         byte[] f6 = rs.getBytes("f6");
-        Assert.assertEquals("abc", new String(f6));
+        Assert.assertTrue(Arrays.equals("abc".getBytes(), f6));
 
         byte[] f7 = rs.getBytes("f7");
         Assert.assertEquals((short) 10, Shorts.fromByteArray(f7));
@@ -176,8 +177,7 @@ public class TSDBResultSetTest {
         rs.getAsciiStream("f1");
     }
 
-    @SuppressWarnings("deprecation")
-	@Test(expected = SQLFeatureNotSupportedException.class)
+    @Test(expected = SQLFeatureNotSupportedException.class)
     public void getUnicodeStream() throws SQLException {
         rs.getUnicodeStream("f1");
     }
@@ -646,7 +646,6 @@ public class TSDBResultSetTest {
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
             stmt = conn.createStatement();
             stmt.execute("create database if not exists restful_test");
@@ -656,10 +655,9 @@ public class TSDBResultSetTest {
             stmt.execute("insert into restful_test.weather values('2021-01-01 00:00:00.000', 1, 100, 3.1415, 3.1415926, 'abc', 10, 10, true, '涛思数据')");
             rs = stmt.executeQuery("select * from restful_test.weather");
             rs.next();
-        } catch (ClassNotFoundException | SQLException e) {
+        } catch (SQLException e) {
             e.printStackTrace();
         }
-
     }
 
     @AfterClass

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBStatementTest.java

@@ -387,15 +387,12 @@ public class TSDBStatementTest {
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
             conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata", properties);
             stmt = conn.createStatement();
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
         } catch (SQLException e) {
             e.printStackTrace();
         }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/RestfulDatabaseMetaDataTest.java

@@ -10,6 +10,7 @@ import java.sql.*;
 import java.util.Properties;
 
 public class RestfulDatabaseMetaDataTest {
+
     private static final String host = "127.0.0.1";
     private static final String url = "jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata";
     private static Connection connection;
@@ -632,17 +633,32 @@ public class RestfulDatabaseMetaDataTest {
 
     @Test
     public void getTables() throws SQLException {
-        System.out.println("****************************************************");
-        ResultSet tables = metaData.getTables("log", "", null, null);
-        ResultSetMetaData metaData = tables.getMetaData();
-        while (tables.next()) {
-            System.out.print(metaData.getColumnLabel(1) + ":" + tables.getString(1) + "\t");
-            System.out.print(metaData.getColumnLabel(3) + ":" + tables.getString(3) + "\t");
-            System.out.print(metaData.getColumnLabel(4) + ":" + tables.getString(4) + "\t");
-            System.out.print(metaData.getColumnLabel(5) + ":" + tables.getString(5) + "\n");
+        ResultSet rs = metaData.getTables("log", "", null, null);
+        ResultSetMetaData meta = rs.getMetaData();
+        Assert.assertNotNull(rs);
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_SCHEM
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertNotNull(rs.getString(3));
+            Assert.assertNotNull(rs.getString("TABLE_NAME"));
+            // TABLE_TYPE
+            Assert.assertEquals("TABLE_TYPE", meta.getColumnLabel(4));
+            Assert.assertEquals("TABLE", rs.getString(4));
+            Assert.assertEquals("TABLE", rs.getString("TABLE_TYPE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(5));
+            Assert.assertEquals("", rs.getString(5));
+            Assert.assertEquals("", rs.getString("REMARKS"));
         }
-        System.out.println();
-        Assert.assertNotNull(tables);
     }
 
     @Test
@@ -652,46 +668,130 @@ public class RestfulDatabaseMetaDataTest {
 
     @Test
     public void getCatalogs() throws SQLException {
-        System.out.println("****************************************************");
-
-        ResultSet catalogs = metaData.getCatalogs();
-        ResultSetMetaData meta = catalogs.getMetaData();
-        while (catalogs.next()) {
-            for (int i = 1; i <= meta.getColumnCount(); i++) {
-                System.out.print(meta.getColumnLabel(i) + ": " + catalogs.getString(i));
-            }
-            System.out.println();
+        ResultSet rs = metaData.getCatalogs();
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertNotNull(rs.getString(1));
+            Assert.assertNotNull(rs.getString("TABLE_CAT"));
         }
     }
 
     @Test
     public void getTableTypes() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet tableTypes = metaData.getTableTypes();
-        while (tableTypes.next()) {
-            System.out.println(tableTypes.getString("TABLE_TYPE"));
+        tableTypes.next();
+        // tableTypes: table
+        {
+            Assert.assertEquals("TABLE", tableTypes.getString(1));
+            Assert.assertEquals("TABLE", tableTypes.getString("TABLE_TYPE"));
+        }
+        tableTypes.next();
+        // tableTypes: stable
+        {
+            Assert.assertEquals("STABLE", tableTypes.getString(1));
+            Assert.assertEquals("STABLE", tableTypes.getString("TABLE_TYPE"));
         }
-        Assert.assertNotNull(metaData.getTableTypes());
     }
 
     @Test
     public void getColumns() throws SQLException {
-        System.out.println("****************************************************");
-
+        // when
         ResultSet columns = metaData.getColumns("log", "", "dn", "");
+        // then
         ResultSetMetaData meta = columns.getMetaData();
-        while (columns.next()) {
-            System.out.print(meta.getColumnLabel(1) + ": " + columns.getString(1) + "\t");
-            System.out.print(meta.getColumnLabel(3) + ": " + columns.getString(3) + "\t");
-            System.out.print(meta.getColumnLabel(4) + ": " + columns.getString(4) + "\t");
-            System.out.print(meta.getColumnLabel(5) + ": " + columns.getString(5) + "\t");
-            System.out.print(meta.getColumnLabel(6) + ": " + columns.getString(6) + "\t");
-            System.out.print(meta.getColumnLabel(7) + ": " + columns.getString(7) + "\t");
-            System.out.print(meta.getColumnLabel(9) + ": " + columns.getString(9) + "\t");
-            System.out.print(meta.getColumnLabel(10) + ": " + columns.getString(10) + "\t");
-            System.out.print(meta.getColumnLabel(11) + ": " + columns.getString(11) + "\n");
-            System.out.print(meta.getColumnLabel(12) + ": " + columns.getString(12) + "\n");
+        columns.next();
+        // column: 1
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", columns.getString(1));
+            Assert.assertEquals("log", columns.getString("TABLE_CAT"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn", columns.getString(3));
+            Assert.assertEquals("dn", columns.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("ts", columns.getString(4));
+            Assert.assertEquals("ts", columns.getString("COLUMN_NAME"));
+            // DATA_TYPE
+            Assert.assertEquals("DATA_TYPE", meta.getColumnLabel(5));
+            Assert.assertEquals(Types.TIMESTAMP, columns.getInt(5));
+            Assert.assertEquals(Types.TIMESTAMP, columns.getInt("DATA_TYPE"));
+            // TYPE_NAME
+            Assert.assertEquals("TYPE_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("TIMESTAMP", columns.getString(6));
+            Assert.assertEquals("TIMESTAMP", columns.getString("TYPE_NAME"));
+            // COLUMN_SIZE
+            Assert.assertEquals("COLUMN_SIZE", meta.getColumnLabel(7));
+            Assert.assertEquals(26, columns.getInt(7));
+            Assert.assertEquals(26, columns.getInt("COLUMN_SIZE"));
+            // DECIMAL_DIGITS
+            Assert.assertEquals("DECIMAL_DIGITS", meta.getColumnLabel(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt("DECIMAL_DIGITS"));
+            Assert.assertEquals(null, columns.getString(9));
+            Assert.assertEquals(null, columns.getString("DECIMAL_DIGITS"));
+            // NUM_PREC_RADIX
+            Assert.assertEquals("NUM_PREC_RADIX", meta.getColumnLabel(10));
+            Assert.assertEquals(10, columns.getInt(10));
+            Assert.assertEquals(10, columns.getInt("NUM_PREC_RADIX"));
+            // NULLABLE
+            Assert.assertEquals("NULLABLE", meta.getColumnLabel(11));
+            Assert.assertEquals(DatabaseMetaData.columnNoNulls, columns.getInt(11));
+            Assert.assertEquals(DatabaseMetaData.columnNoNulls, columns.getInt("NULLABLE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(12));
+            Assert.assertEquals(null, columns.getString(12));
+            Assert.assertEquals(null, columns.getString("REMARKS"));
+        }
+        columns.next();
+        // column: 2
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", columns.getString(1));
+            Assert.assertEquals("log", columns.getString("TABLE_CAT"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn", columns.getString(3));
+            Assert.assertEquals("dn", columns.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("cpu_taosd", columns.getString(4));
+            Assert.assertEquals("cpu_taosd", columns.getString("COLUMN_NAME"));
+            // DATA_TYPE
+            Assert.assertEquals("DATA_TYPE", meta.getColumnLabel(5));
+            Assert.assertEquals(Types.FLOAT, columns.getInt(5));
+            Assert.assertEquals(Types.FLOAT, columns.getInt("DATA_TYPE"));
+            // TYPE_NAME
+            Assert.assertEquals("TYPE_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("FLOAT", columns.getString(6));
+            Assert.assertEquals("FLOAT", columns.getString("TYPE_NAME"));
+            // COLUMN_SIZE
+            Assert.assertEquals("COLUMN_SIZE", meta.getColumnLabel(7));
+            Assert.assertEquals(12, columns.getInt(7));
+            Assert.assertEquals(12, columns.getInt("COLUMN_SIZE"));
+            // DECIMAL_DIGITS
+            Assert.assertEquals("DECIMAL_DIGITS", meta.getColumnLabel(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt(9));
+            Assert.assertEquals(Integer.MIN_VALUE, columns.getInt("DECIMAL_DIGITS"));
+            Assert.assertEquals(null, columns.getString(9));
+            Assert.assertEquals(null, columns.getString("DECIMAL_DIGITS"));
+            // NUM_PREC_RADIX
+            Assert.assertEquals("NUM_PREC_RADIX", meta.getColumnLabel(10));
+            Assert.assertEquals(10, columns.getInt(10));
+            Assert.assertEquals(10, columns.getInt("NUM_PREC_RADIX"));
+            // NULLABLE
+            Assert.assertEquals("NULLABLE", meta.getColumnLabel(11));
+            Assert.assertEquals(DatabaseMetaData.columnNullable, columns.getInt(11));
+            Assert.assertEquals(DatabaseMetaData.columnNullable, columns.getInt("NULLABLE"));
+            // REMARKS
+            Assert.assertEquals("REMARKS", meta.getColumnLabel(12));
+            Assert.assertEquals(null, columns.getString(12));
         }
     }
 
@@ -717,17 +817,35 @@ public class RestfulDatabaseMetaDataTest {
 
     @Test
     public void getPrimaryKeys() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet rs = metaData.getPrimaryKeys("log", "", "dn1");
-        while (rs.next()) {
-            System.out.println("TABLE_NAME: " + rs.getString("TABLE_NAME"));
-            System.out.println("COLUMN_NAME: " + rs.getString("COLUMN_NAME"));
-            System.out.println("KEY_SEQ: " + rs.getString("KEY_SEQ"));
-            System.out.println("PK_NAME: " + rs.getString("PK_NAME"));
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_SCHEM
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_NAME
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn1", rs.getString(3));
+            Assert.assertEquals("dn1", rs.getString("TABLE_NAME"));
+            // COLUMN_NAME
+            Assert.assertEquals("COLUMN_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("ts", rs.getString(4));
+            Assert.assertEquals("ts", rs.getString("COLUMN_NAME"));
+            // KEY_SEQ
+            Assert.assertEquals("KEY_SEQ", meta.getColumnLabel(5));
+            Assert.assertEquals(1, rs.getShort(5));
+            Assert.assertEquals(1, rs.getShort("KEY_SEQ"));
+            // DATA_TYPE
+            Assert.assertEquals("PK_NAME", meta.getColumnLabel(6));
+            Assert.assertEquals("ts", rs.getString(6));
+            Assert.assertEquals("ts", rs.getString("PK_NAME"));
         }
-
-        Assert.assertNotNull(rs);
     }
 
     @Test
@@ -852,14 +970,27 @@ public class RestfulDatabaseMetaDataTest {
 
     @Test
     public void getSuperTables() throws SQLException {
-        System.out.println("****************************************************");
-
         ResultSet rs = metaData.getSuperTables("log", "", "dn1");
-        while (rs.next()) {
-            System.out.println("TABLE_NAME: " + rs.getString("TABLE_NAME"));
-            System.out.println("SUPERTABLE_NAME: " + rs.getString("SUPERTABLE_NAME"));
+        ResultSetMetaData meta = rs.getMetaData();
+        rs.next();
+        {
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_CAT", meta.getColumnLabel(1));
+            Assert.assertEquals("log", rs.getString(1));
+            Assert.assertEquals("log", rs.getString("TABLE_CAT"));
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_SCHEM", meta.getColumnLabel(2));
+            Assert.assertEquals(null, rs.getString(2));
+            Assert.assertEquals(null, rs.getString("TABLE_SCHEM"));
+            // TABLE_CAT
+            Assert.assertEquals("TABLE_NAME", meta.getColumnLabel(3));
+            Assert.assertEquals("dn1", rs.getString(3));
+            Assert.assertEquals("dn1", rs.getString("TABLE_NAME"));
+            // TABLE_CAT
+            Assert.assertEquals("SUPERTABLE_NAME", meta.getColumnLabel(4));
+            Assert.assertEquals("dn", rs.getString(4));
+            Assert.assertEquals("dn", rs.getString("SUPERTABLE_NAME"));
         }
-        Assert.assertNotNull(rs);
     }
 
     @Test

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/RestfulParameterMetaDataTest.java

@@ -54,16 +54,17 @@ public class RestfulParameterMetaDataTest {
 
     @Test
     public void getPrecision() throws SQLException {
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(1));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(2));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(3));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(4));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(5));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(6));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(7));
-        Assert.assertEquals(0, parameterMetaData_insert.getPrecision(8));
-        Assert.assertEquals(5, parameterMetaData_insert.getPrecision(9));
-        Assert.assertEquals(5, parameterMetaData_insert.getPrecision(10));
+        //create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64))
+        Assert.assertEquals(TSDBConstants.TIMESTAMP_MS_PRECISION, parameterMetaData_insert.getPrecision(1));
+        Assert.assertEquals(TSDBConstants.INT_PRECISION, parameterMetaData_insert.getPrecision(2));
+        Assert.assertEquals(TSDBConstants.BIGINT_PRECISION, parameterMetaData_insert.getPrecision(3));
+        Assert.assertEquals(TSDBConstants.FLOAT_PRECISION, parameterMetaData_insert.getPrecision(4));
+        Assert.assertEquals(TSDBConstants.DOUBLE_PRECISION, parameterMetaData_insert.getPrecision(5));
+        Assert.assertEquals(TSDBConstants.SMALLINT_PRECISION, parameterMetaData_insert.getPrecision(6));
+        Assert.assertEquals(TSDBConstants.TINYINT_PRECISION, parameterMetaData_insert.getPrecision(7));
+        Assert.assertEquals(TSDBConstants.BOOLEAN_PRECISION, parameterMetaData_insert.getPrecision(8));
+        Assert.assertEquals("hello".getBytes().length, parameterMetaData_insert.getPrecision(9));
+        Assert.assertEquals("涛思数据".length(), parameterMetaData_insert.getPrecision(10));
     }
 
     @Test
@@ -71,8 +72,8 @@ public class RestfulParameterMetaDataTest {
         Assert.assertEquals(0, parameterMetaData_insert.getScale(1));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(2));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(3));
-        Assert.assertEquals(0, parameterMetaData_insert.getScale(4));
-        Assert.assertEquals(0, parameterMetaData_insert.getScale(5));
+        Assert.assertEquals(31, parameterMetaData_insert.getScale(4));
+        Assert.assertEquals(31, parameterMetaData_insert.getScale(5));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(6));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(7));
         Assert.assertEquals(0, parameterMetaData_insert.getScale(8));
@@ -164,7 +165,7 @@ public class RestfulParameterMetaDataTest {
             pstmt_insert.setObject(7, Byte.MAX_VALUE);
             pstmt_insert.setObject(8, true);
             pstmt_insert.setObject(9, "hello".getBytes());
-            pstmt_insert.setObject(10, "Hello");
+            pstmt_insert.setObject(10, "涛思数据");
             parameterMetaData_insert = pstmt_insert.getParameterMetaData();
 
             pstmt_select = conn.prepareStatement(sql_select);