change

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

@@ -551,16 +551,91 @@ public class TSDBDatabaseMetaData implements java.sql.DatabaseMetaData {
                 return null;
 
             ResultSet databases = stmt.executeQuery("show databases");
+            String dbname = null;
             while (databases.next()) {
-                String dbname = databases.getString("name");
+                dbname = databases.getString("name");
+                if (dbname.equalsIgnoreCase(catalog))
+                    break;
             }
             databases.close();
+            if (dbname == null)
+                return null;
 
-            stmt.execute("use " + catalog);
-            ResultSet resultSet0 = stmt.executeQuery("show tables");
-
+            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);
 
+
+            List<TSDBResultSetRowData> rowDataList = new ArrayList<>();
+            ResultSet tables = stmt.executeQuery("show tables");
+            while (tables.next()) {
+                TSDBResultSetRowData rowData = new TSDBResultSetRowData(10);
+                rowData.setString(3, tables.getString("name"));
+                rowData.setString(4, "TABLE");
+                rowData.setString(5, "");
+                rowDataList.add(rowData);
+            }
+
+            ResultSet stables = stmt.executeQuery("show stables");
+            while (stables.next()) {
+                TSDBResultSetRowData rowData = new TSDBResultSetRowData(10);
+                rowData.setString(3, tables.getString("name"));
+                rowData.setString(4, "TABLE");
+                rowData.setString(5, "STABLE");
+                rowDataList.add(rowData);
+            }
+            resultSet.setRowDataList(rowDataList);
             return resultSet;
         }
     }
@@ -606,6 +681,7 @@ public class TSDBDatabaseMetaData implements java.sql.DatabaseMetaData {
     }
 
     public ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern) throws SQLException {
+        // add by zyyang-taosdata
         Statement stmt;
         if (null != conn && !conn.isClosed()) {
             stmt = conn.createStatement();

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

@@ -28,7 +28,7 @@ public class TSDBResultSetRowData {
 	}
 	
 	public TSDBResultSetRowData() {
-		this.data = new ArrayList<Object>();
+		this.data = new ArrayList<>();
 		this.setColSize(0);
 	}
 
@@ -39,7 +39,7 @@ public class TSDBResultSetRowData {
 		if (this.colSize == 0) {
 			return;
 		}
-		this.data = new ArrayList<Object>(colSize);
+		this.data = new ArrayList<>(colSize);
 		this.data.addAll(Collections.nCopies(this.colSize, null));
 	}