Merge branch 'develop' into feature/query

Jenkinsfile

@@ -104,6 +104,10 @@ pipeline {
             find pytest -name '*'sql|xargs rm -rf
             ./test-all.sh p2
             date'''
+            sh '''
+            cd ${WKC}/tests
+            ./test-all.sh b4fq
+            '''
           }
         }
         stage('test_b1') {

cmake/version.inc

@@ -4,7 +4,7 @@ PROJECT(TDengine)
 IF (DEFINED VERNUMBER)
   SET(TD_VER_NUMBER ${VERNUMBER})
 ELSE ()
-  SET(TD_VER_NUMBER "2.0.12.0")
+  SET(TD_VER_NUMBER "2.0.13.0")
 ENDIF ()
 
 IF (DEFINED VERCOMPATIBLE)

documentation20/webdocs/markdowndocs/Model-ch.md

@@ -4,6 +4,8 @@
 
 TDengine采用关系型数据模型，需要建库、建表。因此对于一个具体的应用场景，需要考虑库的设计，超级表和普通表的设计。本节不讨论细致的语法规则，只介绍概念。
 
+关于数据建模请参考<a href="https://www.taosdata.com/blog/2020/11/11/1945.html">视频教程</a>。
+
 ## 创建库
 
 不同类型的数据采集点往往具有不同的数据特征，包括数据采集频率的高低，数据保留时间的长短，副本的数目，数据块的大小，是否允许更新数据等等。为让各种场景下TDengine都能最大效率的工作，TDengine建议将不同数据特征的表创建在不同的库里，因为每个库可以配置不同的存储策略。创建一个库时，除SQL标准的选项外，应用还可以指定保留时长、副本数、内存块个数、时间精度、文件块里最大最小记录条数、是否压缩、一个数据文件覆盖的天数等多种参数。比如：
@@ -60,4 +62,3 @@ TDengine支持多列模型，只要物理量是一个数据采集点同时采集
 
 TDengine建议尽可能采用多列模型，因为插入效率以及存储效率更高。但对于有些场景，一个采集点的采集量的种类经常变化，这个时候，如果采用多列模型，就需要频繁修改超级表的结构定义，让应用变的复杂，这个时候，采用单列模型会显得简单。
 
-关于数据建模请参考<a href="https://www.taosdata.com/blog/2020/11/11/1945.html">视频教程</a>。

documentation20/webdocs/markdowndocs/cluster-ch.md

@@ -6,6 +6,8 @@
 
 TDengine的集群管理极其简单，除添加和删除节点需要人工干预之外，其他全部是自动完成，最大程度的降低了运维的工作量。本章对集群管理的操作做详细的描述。
 
+关于集群搭建请参考<a href="https://www.taosdata.com/blog/2020/11/11/1961.html">视频教程</a>。
+
 ## 准备工作
 
 **第零步**：规划集群所有物理节点的FQDN，将规划好的FQDN分别添加到每个物理节点的/etc/hostname；修改每个物理节点的/etc/hosts，将所有集群物理节点的IP与FQDN的对应添加好。【如部署了DNS，请联系网络管理员在DNS上做好相关配置】
@@ -227,4 +229,3 @@ SHOW MNODES;
 
 TDengine提供一个执行程序tarbitrator, 找任何一台Linux服务器运行它即可。请点击[安装包下载](https://www.taosdata.com/cn/all-downloads/)，在TDengine Arbitrator Linux一节中，选择适合的版本下载并安装。该程序对系统资源几乎没有要求，只需要保证有网络连接即可。该应用的命令行参数`-p`可以指定其对外服务的端口号，缺省是6042。配置每个taosd实例时，可以在配置文件taos.cfg里将参数arbitrator设置为arbitrator的End Point。如果该参数配置了，当副本数为偶数数，系统将自动连接配置的arbitrator。如果副本数为奇数，即使配置了arbitrator, 系统也不会去建立连接。
 
-关于集群搭建请参考<a href="https://www.taosdata.com/blog/2020/11/11/1961.html">视频教程</a>。

snap/snapcraft.yaml

 name: tdengine
 base: core18
-version: '2.0.12.0'
+version: '2.0.13.0'
 icon: snap/gui/t-dengine.svg
 summary: an open-source big data platform designed and optimized for IoT. 
 description: |
@@ -72,7 +72,7 @@ parts:
       - usr/bin/taosd
       - usr/bin/taos
       - usr/bin/taosdemo
-      - usr/lib/libtaos.so.2.0.12.0
+      - usr/lib/libtaos.so.2.0.13.0
       - usr/lib/libtaos.so.1
       - usr/lib/libtaos.so
 

src/balance/src/bnMain.c

@@ -237,21 +237,21 @@ static bool bnCheckVgroupReady(SVgObj *pVgroup, SVnodeGid *pRmVnode) {
   bool isReady = false;
   for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
     SVnodeGid *pVnode = pVgroup->vnodeGid + i;
+    SDnodeObj *pDnode = pVnode->pDnode;
     if (pVnode == pRmVnode) continue;
     int32_t vver = mnodeGetVgidVer(pVnode->vver);
 
-    mTrace("vgId:%d, check vgroup status, vindex:%d dnode:%d status:%s role:%s vver:%d, rmvver:%d" , pVgroup->vgId, i,
-           pVnode->dnodeId, dnodeStatus[pVnode->pDnode->status], syncRole[pVnode->role], vver, rmVnodeVer);
-    if (pVnode->pDnode->status == TAOS_DN_STATUS_DROPPING) continue;
-    if (pVnode->pDnode->status == TAOS_DN_STATUS_OFFLINE) continue;
+    mTrace("vgId:%d, check vgroup status, vindex:%d dnode:%d status:%s role:%s vver:%d, rmvver:%d", pVgroup->vgId, i,
+           pVnode->dnodeId, dnodeStatus[pDnode->status], syncRole[pVnode->role], vver, rmVnodeVer);
+    if (pDnode->status == TAOS_DN_STATUS_DROPPING) continue;
+    if (pDnode->status == TAOS_DN_STATUS_OFFLINE) continue;
     if (pVnode->role != TAOS_SYNC_ROLE_SLAVE && pVnode->role != TAOS_SYNC_ROLE_MASTER) continue;
 
     if (rmVnodeVer == 0 || vver >= rmVnodeVer) {
-      mInfo("vgId:%d, is ready for vindex:%d in dnode:%d status:%s role:%s vver:%d larger than rmvver:%d", pVgroup->vgId, i,
-             pVnode->dnodeId, dnodeStatus[pVnode->pDnode->status], syncRole[pVnode->role], vver, rmVnodeVer);
+      mInfo("vgId:%d, is ready for vindex:%d in dnode:%d status:%s role:%s vver:%d larger than rmvver:%d",
+            pVgroup->vgId, i, pVnode->dnodeId, dnodeStatus[pDnode->status], syncRole[pVnode->role], vver, rmVnodeVer);
+      isReady = true;
     }
-
-    isReady = true;
   }
 
   return isReady;

src/client/src/tscAsync.c

@@ -421,7 +421,7 @@ void tscTableMetaCallBack(void *param, TAOS_RES *res, int code) {
     SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
 
     // check if it is a sub-query of super table query first, if true, enter another routine
-    if (TSDB_QUERY_HAS_TYPE(pQueryInfo->type, (TSDB_QUERY_TYPE_STABLE_SUBQUERY|TSDB_QUERY_TYPE_TAG_FILTER_QUERY))) {
+    if (TSDB_QUERY_HAS_TYPE(pQueryInfo->type, (TSDB_QUERY_TYPE_STABLE_SUBQUERY|TSDB_QUERY_TYPE_SUBQUERY|TSDB_QUERY_TYPE_TAG_FILTER_QUERY))) {
       tscDebug("%p update local table meta, continue to process sql and send the corresponding query", pSql);
 
       STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);

src/client/src/tscSQLParser.c

@@ -75,11 +75,11 @@ static int32_t insertResultField(SQueryInfo* pQueryInfo, int32_t outputIndex, SC
 static int32_t convertFunctionId(int32_t optr, int16_t* functionId);
 static uint8_t convertOptr(SStrToken *pToken);
 
-static int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable, bool joinQuery);
+static int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable, bool joinQuery, bool intervalQuery);
 
 static bool validateIpAddress(const char* ip, size_t size);
 static bool hasUnsupportFunctionsForSTableQuery(SSqlCmd* pCmd, SQueryInfo* pQueryInfo);
-static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery);
+static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery, bool intervalQuery);
 
 static int32_t parseGroupbyClause(SQueryInfo* pQueryInfo, SArray* pList, SSqlCmd* pCmd);
 
@@ -1475,7 +1475,7 @@ static void addPrimaryTsColIntoResult(SQueryInfo* pQueryInfo) {
   pQueryInfo->type |= TSDB_QUERY_TYPE_PROJECTION_QUERY;
 }
 
-int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable, bool joinQuery) {
+int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable, bool joinQuery, bool intervalQuery) {
   assert(pSelection != NULL && pCmd != NULL);
 
   const char* msg2 = "functions can not be mixed up";
@@ -1531,7 +1531,7 @@ int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSel
     addPrimaryTsColIntoResult(pQueryInfo);
   }
 
-  if (!functionCompatibleCheck(pQueryInfo, joinQuery)) {
+  if (!functionCompatibleCheck(pQueryInfo, joinQuery, intervalQuery)) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
   }
 
@@ -2810,7 +2810,7 @@ bool hasUnsupportFunctionsForSTableQuery(SSqlCmd* pCmd, SQueryInfo* pQueryInfo)
   return false;
 }
 
-static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery) {
+static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery, bool intervalQuery) {
   int32_t startIdx = 0;
 
   size_t numOfExpr = tscSqlExprNumOfExprs(pQueryInfo);
@@ -2826,6 +2826,10 @@ static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery) {
 
   int32_t factor = functionCompatList[tscSqlExprGet(pQueryInfo, startIdx)->functionId];
 
+  if (tscSqlExprGet(pQueryInfo, 0)->functionId == TSDB_FUNC_LAST_ROW && (joinQuery || intervalQuery)) {
+	return false;
+  }
+
   // diff function cannot be executed with other function
   // arithmetic function can be executed with other arithmetic functions
   size_t size = tscSqlExprNumOfExprs(pQueryInfo);
@@ -2850,7 +2854,7 @@ static bool functionCompatibleCheck(SQueryInfo* pQueryInfo, bool joinQuery) {
       }
     }
 
-    if (functionId == TSDB_FUNC_LAST_ROW && joinQuery) {
+    if (functionId == TSDB_FUNC_LAST_ROW && (joinQuery || intervalQuery)) {
       return false;
     }
   }
@@ -6303,7 +6307,7 @@ int32_t doCheckForStream(SSqlObj* pSql, SSqlInfo* pInfo) {
   }
 
   bool isSTable = UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo);
-  if (parseSelectClause(&pSql->cmd, 0, pQuerySql->pSelection, isSTable, false) != TSDB_CODE_SUCCESS) {
+  if (parseSelectClause(&pSql->cmd, 0, pQuerySql->pSelection, isSTable, false, false) != TSDB_CODE_SUCCESS) {
     return TSDB_CODE_TSC_INVALID_SQL;
   }
 
@@ -6552,7 +6556,9 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
 
   int32_t joinQuery = (pQuerySql->from != NULL && taosArrayGetSize(pQuerySql->from) > 2);
 
-  if (parseSelectClause(pCmd, index, pQuerySql->pSelection, isSTable, joinQuery) != TSDB_CODE_SUCCESS) {
+  int32_t intervalQuery = !(pQuerySql->interval.type == 0 || pQuerySql->interval.n == 0);
+
+  if (parseSelectClause(pCmd, index, pQuerySql->pSelection, isSTable, joinQuery, intervalQuery) != TSDB_CODE_SUCCESS) {
     return TSDB_CODE_TSC_INVALID_SQL;
   }
 

src/client/src/tscUtil.c

@@ -458,12 +458,13 @@ void tscFreeRegisteredSqlObj(void *pSql) {
 
   assert(RID_VALID(p->self));
 
-  tscFreeSqlObj(p);
-  taosReleaseRef(tscRefId, pTscObj->rid);
-
   int32_t num   = atomic_sub_fetch_32(&pTscObj->numOfObj, 1);
   int32_t total = atomic_sub_fetch_32(&tscNumOfObj, 1);
+
   tscDebug("%p free SqlObj, total in tscObj:%d, total:%d", pSql, num, total);
+  tscFreeSqlObj(p);
+  taosReleaseRef(tscRefId, pTscObj->rid);
+
 }
 
 void tscFreeSqlObj(SSqlObj* pSql) {

src/connector/C#/TDengineDriver.cs

@@ -19,136 +19,137 @@ using System.Runtime.InteropServices;
 
 namespace TDengineDriver
 {
-  enum TDengineDataType {
-    TSDB_DATA_TYPE_NULL = 0,     // 1 bytes
-    TSDB_DATA_TYPE_BOOL = 1,     // 1 bytes
-    TSDB_DATA_TYPE_TINYINT = 2,  // 1 bytes
-    TSDB_DATA_TYPE_SMALLINT = 3, // 2 bytes
-    TSDB_DATA_TYPE_INT = 4,      // 4 bytes
-    TSDB_DATA_TYPE_BIGINT = 5,   // 8 bytes
-    TSDB_DATA_TYPE_FLOAT = 6,    // 4 bytes
-    TSDB_DATA_TYPE_DOUBLE = 7,   // 8 bytes
-    TSDB_DATA_TYPE_BINARY = 8,   // string
-    TSDB_DATA_TYPE_TIMESTAMP = 9,// 8 bytes
-    TSDB_DATA_TYPE_NCHAR = 10    // unicode string
-  }
-
-  enum TDengineInitOption
-  {
-    TSDB_OPTION_LOCALE = 0,
-    TSDB_OPTION_CHARSET = 1,
-    TSDB_OPTION_TIMEZONE = 2,
-    TDDB_OPTION_CONFIGDIR = 3,
-    TDDB_OPTION_SHELL_ACTIVITY_TIMER = 4
-  }
-
-  class TDengineMeta
-  {
-    public string name;
-    public short size;
-    public byte type;
-    public string TypeName()
+    enum TDengineDataType
     {
-      switch ((TDengineDataType)type)
-      {
-        case TDengineDataType.TSDB_DATA_TYPE_BOOL:
-          return "BOOLEAN";
-        case TDengineDataType.TSDB_DATA_TYPE_TINYINT:
-          return "BYTE";
-        case TDengineDataType.TSDB_DATA_TYPE_SMALLINT:
-          return "SHORT";
-        case TDengineDataType.TSDB_DATA_TYPE_INT:
-          return "INT";
-        case TDengineDataType.TSDB_DATA_TYPE_BIGINT:
-          return "LONG";
-        case TDengineDataType.TSDB_DATA_TYPE_FLOAT:
-          return "FLOAT";
-        case TDengineDataType.TSDB_DATA_TYPE_DOUBLE:
-          return "DOUBLE";
-        case TDengineDataType.TSDB_DATA_TYPE_BINARY:
-          return "STRING";
-        case TDengineDataType.TSDB_DATA_TYPE_TIMESTAMP:
-          return "TIMESTAMP";
-        case TDengineDataType.TSDB_DATA_TYPE_NCHAR:
-          return "NCHAR";
-        default:
-          return "undefine";
-      }
+        TSDB_DATA_TYPE_NULL = 0,     // 1 bytes
+        TSDB_DATA_TYPE_BOOL = 1,     // 1 bytes
+        TSDB_DATA_TYPE_TINYINT = 2,  // 1 bytes
+        TSDB_DATA_TYPE_SMALLINT = 3, // 2 bytes
+        TSDB_DATA_TYPE_INT = 4,      // 4 bytes
+        TSDB_DATA_TYPE_BIGINT = 5,   // 8 bytes
+        TSDB_DATA_TYPE_FLOAT = 6,    // 4 bytes
+        TSDB_DATA_TYPE_DOUBLE = 7,   // 8 bytes
+        TSDB_DATA_TYPE_BINARY = 8,   // string
+        TSDB_DATA_TYPE_TIMESTAMP = 9,// 8 bytes
+        TSDB_DATA_TYPE_NCHAR = 10    // unicode string
     }
-  }
 
-  class TDengine
-  {
-    public const int TSDB_CODE_SUCCESS = 0;
+    enum TDengineInitOption
+    {
+        TSDB_OPTION_LOCALE = 0,
+        TSDB_OPTION_CHARSET = 1,
+        TSDB_OPTION_TIMEZONE = 2,
+        TDDB_OPTION_CONFIGDIR = 3,
+        TDDB_OPTION_SHELL_ACTIVITY_TIMER = 4
+    }
 
-    [DllImport("taos.dll", EntryPoint = "taos_init", CallingConvention = CallingConvention.Cdecl)]
-    static extern public void Init();
+    class TDengineMeta
+    {
+        public string name;
+        public short size;
+        public byte type;
+        public string TypeName()
+        {
+            switch ((TDengineDataType)type)
+            {
+                case TDengineDataType.TSDB_DATA_TYPE_BOOL:
+                    return "BOOLEAN";
+                case TDengineDataType.TSDB_DATA_TYPE_TINYINT:
+                    return "BYTE";
+                case TDengineDataType.TSDB_DATA_TYPE_SMALLINT:
+                    return "SHORT";
+                case TDengineDataType.TSDB_DATA_TYPE_INT:
+                    return "INT";
+                case TDengineDataType.TSDB_DATA_TYPE_BIGINT:
+                    return "LONG";
+                case TDengineDataType.TSDB_DATA_TYPE_FLOAT:
+                    return "FLOAT";
+                case TDengineDataType.TSDB_DATA_TYPE_DOUBLE:
+                    return "DOUBLE";
+                case TDengineDataType.TSDB_DATA_TYPE_BINARY:
+                    return "STRING";
+                case TDengineDataType.TSDB_DATA_TYPE_TIMESTAMP:
+                    return "TIMESTAMP";
+                case TDengineDataType.TSDB_DATA_TYPE_NCHAR:
+                    return "NCHAR";
+                default:
+                    return "undefine";
+            }
+        }
+    }
 
-    [DllImport("taos.dll", EntryPoint = "taos_cleanup", CallingConvention = CallingConvention.Cdecl)]
-    static extern public void Cleanup();
+    class TDengine
+    {
+        public const int TSDB_CODE_SUCCESS = 0;
 
-    [DllImport("taos.dll", EntryPoint = "taos_options", CallingConvention = CallingConvention.Cdecl)]
-    static extern public void Options(int option, string value);
+        [DllImport("taos", EntryPoint = "taos_init", CallingConvention = CallingConvention.Cdecl)]
+        static extern public void Init();
 
-    [DllImport("taos.dll", EntryPoint = "taos_connect", CallingConvention = CallingConvention.Cdecl)]
-    static extern public IntPtr Connect(string ip, string user, string password, string db, short port);
+        [DllImport("taos", EntryPoint = "taos_cleanup", CallingConvention = CallingConvention.Cdecl)]
+        static extern public void Cleanup();
 
-    [DllImport("taos.dll", EntryPoint = "taos_errstr", CallingConvention = CallingConvention.Cdecl)]
-    static extern private IntPtr taos_errstr(IntPtr res);
-    static public string Error(IntPtr res)
-    {
-      IntPtr errPtr = taos_errstr(res);
-      return Marshal.PtrToStringAnsi(errPtr);
-    }
+        [DllImport("taos", EntryPoint = "taos_options", CallingConvention = CallingConvention.Cdecl)]
+        static extern public void Options(int option, string value);
 
-    [DllImport("taos.dll", EntryPoint = "taos_errno", CallingConvention = CallingConvention.Cdecl)]
-    static extern public int ErrorNo(IntPtr res);
+        [DllImport("taos", EntryPoint = "taos_connect", CallingConvention = CallingConvention.Cdecl)]
+        static extern public IntPtr Connect(string ip, string user, string password, string db, short port);
 
-    [DllImport("taos.dll", EntryPoint = "taos_query", CallingConvention = CallingConvention.Cdecl)]
-    static extern public IntPtr Query(IntPtr conn, string sqlstr);
+        [DllImport("taos", EntryPoint = "taos_errstr", CallingConvention = CallingConvention.Cdecl)]
+        static extern private IntPtr taos_errstr(IntPtr res);
+        static public string Error(IntPtr res)
+        {
+            IntPtr errPtr = taos_errstr(res);
+            return Marshal.PtrToStringAnsi(errPtr);
+        }
 
-    [DllImport("taos.dll", EntryPoint = "taos_affected_rows", CallingConvention = CallingConvention.Cdecl)]
-    static extern public int AffectRows(IntPtr res);
+        [DllImport("taos", EntryPoint = "taos_errno", CallingConvention = CallingConvention.Cdecl)]
+        static extern public int ErrorNo(IntPtr res);
 
-    [DllImport("taos.dll", EntryPoint = "taos_field_count", CallingConvention = CallingConvention.Cdecl)]
-    static extern public int FieldCount(IntPtr res);
+        [DllImport("taos", EntryPoint = "taos_query", CallingConvention = CallingConvention.Cdecl)]
+        static extern public IntPtr Query(IntPtr conn, string sqlstr);
 
-    [DllImport("taos.dll", EntryPoint = "taos_fetch_fields", CallingConvention = CallingConvention.Cdecl)]
-    static extern private IntPtr taos_fetch_fields(IntPtr res);
-    static public List<TDengineMeta> FetchFields(IntPtr res)
-    {
-      const int fieldSize = 68;
-
-      List<TDengineMeta> metas = new List<TDengineMeta>();
-      if (res == IntPtr.Zero)
-      {
-        return metas;
-      }
-
-      int fieldCount = FieldCount(res);
-      IntPtr fieldsPtr = taos_fetch_fields(res);
-  
-      for (int i = 0; i < fieldCount; ++i)
-      {
-        int offset = i * fieldSize;
-        
-        TDengineMeta meta = new TDengineMeta();
-        meta.name = Marshal.PtrToStringAnsi(fieldsPtr + offset);
-        meta.type = Marshal.ReadByte(fieldsPtr + offset + 65);
-        meta.size = Marshal.ReadInt16(fieldsPtr + offset + 66);
-        metas.Add(meta);
-      }
-
-      return metas;
-    }
+        [DllImport("taos", EntryPoint = "taos_affected_rows", CallingConvention = CallingConvention.Cdecl)]
+        static extern public int AffectRows(IntPtr res);
 
-    [DllImport("taos.dll", EntryPoint = "taos_fetch_row", CallingConvention = CallingConvention.Cdecl)]
-    static extern public IntPtr FetchRows(IntPtr res);
+        [DllImport("taos", EntryPoint = "taos_field_count", CallingConvention = CallingConvention.Cdecl)]
+        static extern public int FieldCount(IntPtr res);
 
-    [DllImport("taos.dll", EntryPoint = "taos_free_result", CallingConvention = CallingConvention.Cdecl)]
-    static extern public IntPtr FreeResult(IntPtr res);
+        [DllImport("taos", EntryPoint = "taos_fetch_fields", CallingConvention = CallingConvention.Cdecl)]
+        static extern private IntPtr taos_fetch_fields(IntPtr res);
+        static public List<TDengineMeta> FetchFields(IntPtr res)
+        {
+            const int fieldSize = 68;
 
-    [DllImport("taos.dll", EntryPoint = "taos_close", CallingConvention = CallingConvention.Cdecl)]
-    static extern public int Close(IntPtr taos);
-  }
-}
+            List<TDengineMeta> metas = new List<TDengineMeta>();
+            if (res == IntPtr.Zero)
+            {
+                return metas;
\ No newline at end of file
+            }
+
+            int fieldCount = FieldCount(res);
+            IntPtr fieldsPtr = taos_fetch_fields(res);
+
+            for (int i = 0; i < fieldCount; ++i)
+            {
+                int offset = i * fieldSize;
+
+                TDengineMeta meta = new TDengineMeta();
+                meta.name = Marshal.PtrToStringAnsi(fieldsPtr + offset);
+                meta.type = Marshal.ReadByte(fieldsPtr + offset + 65);
+                meta.size = Marshal.ReadInt16(fieldsPtr + offset + 66);
+                metas.Add(meta);
+            }
+
+            return metas;
+        }
+
+        [DllImport("taos", EntryPoint = "taos_fetch_row", CallingConvention = CallingConvention.Cdecl)]
+        static extern public IntPtr FetchRows(IntPtr res);
+
+        [DllImport("taos", EntryPoint = "taos_free_result", CallingConvention = CallingConvention.Cdecl)]
+        static extern public IntPtr FreeResult(IntPtr res);
+
+        [DllImport("taos", EntryPoint = "taos_close", CallingConvention = CallingConvention.Cdecl)]
+        static extern public int Close(IntPtr taos);
+    }
+}

src/connector/jdbc/pom.xml

@@ -56,6 +56,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>5.1.47</version>
+        </dependency>
+
         <!-- for restful -->
         <dependency>
             <groupId>org.apache.httpcomponents</groupId>
@@ -73,7 +79,14 @@
             <version>1.2.58</version>
         </dependency>
 
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>5.1.49</version>
+        </dependency>
+
     </dependencies>
+
     <build>
         <plugins>
             <plugin>

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

@@ -19,68 +19,71 @@ import java.util.Map;
 
 public abstract class TSDBConstants {
 
-	public static final String DEFAULT_PORT = "6200";
-	public static final String UNSUPPORT_METHOD_EXCEPTIONZ_MSG = "this operation is NOT supported currently!";
-	public static final String INVALID_VARIABLES = "invalid variables";
-	public static Map<Integer, String> DATATYPE_MAP = null;
+    public static final String DEFAULT_PORT = "6200";
+    public static final String UNSUPPORT_METHOD_EXCEPTIONZ_MSG = "this operation is NOT supported currently!";
+    public static final String INVALID_VARIABLES = "invalid variables";
+    public static Map<Integer, String> DATATYPE_MAP = null;
 
-	public static final long JNI_NULL_POINTER = 0L;
+    public static final long JNI_NULL_POINTER = 0L;
 
-	public static final int JNI_SUCCESS = 0;
-	public static final int JNI_TDENGINE_ERROR = -1;
-	public static final int JNI_CONNECTION_NULL = -2;
-	public static final int JNI_RESULT_SET_NULL = -3;
-	public static final int JNI_NUM_OF_FIELDS_0 = -4;
-	public static final int JNI_SQL_NULL = -5;
-	public static final int JNI_FETCH_END = -6;
-	
-	public static final int TSDB_DATA_TYPE_NULL = 0;
-	public static final int TSDB_DATA_TYPE_BOOL = 1;
-	public static final int TSDB_DATA_TYPE_TINYINT = 2;
-	public static final int TSDB_DATA_TYPE_SMALLINT = 3;
-	public static final int TSDB_DATA_TYPE_INT = 4;
-	public static final int TSDB_DATA_TYPE_BIGINT = 5;
-	public static final int TSDB_DATA_TYPE_FLOAT = 6;
-	public static final int TSDB_DATA_TYPE_DOUBLE = 7;
-	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;
-	
-	public static String WrapErrMsg(String msg) {
-		return "TDengine Error: " + msg;
-	}
+    public static final int JNI_SUCCESS = 0;
+    public static final int JNI_TDENGINE_ERROR = -1;
+    public static final int JNI_CONNECTION_NULL = -2;
+    public static final int JNI_RESULT_SET_NULL = -3;
+    public static final int JNI_NUM_OF_FIELDS_0 = -4;
+    public static final int JNI_SQL_NULL = -5;
+    public static final int JNI_FETCH_END = -6;
 
-	public static String FixErrMsg(int code) {
-		switch (code) {
-		case JNI_TDENGINE_ERROR:
-			return WrapErrMsg("internal error of database!");
-		case JNI_CONNECTION_NULL:
-			return WrapErrMsg("invalid tdengine connection!");
-		case JNI_RESULT_SET_NULL:
-			return WrapErrMsg("invalid resultset pointer!");
-		case JNI_NUM_OF_FIELDS_0:
-			return WrapErrMsg("invalid num of fields!");
-		case JNI_SQL_NULL:
-			return WrapErrMsg("can't execute empty sql!");
-		case JNI_FETCH_END:
-			return WrapErrMsg("fetch to the end of resultset");
-		default:
-			break;
-		}
-		return WrapErrMsg("unkown error!");
-	}
+    public static final int TSDB_DATA_TYPE_NULL = 0;
+    public static final int TSDB_DATA_TYPE_BOOL = 1;
+    public static final int TSDB_DATA_TYPE_TINYINT = 2;
+    public static final int TSDB_DATA_TYPE_SMALLINT = 3;
+    public static final int TSDB_DATA_TYPE_INT = 4;
+    public static final int TSDB_DATA_TYPE_BIGINT = 5;
+    public static final int TSDB_DATA_TYPE_FLOAT = 6;
+    public static final int TSDB_DATA_TYPE_DOUBLE = 7;
+    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;
 
-	static {
-		DATATYPE_MAP = new HashMap<Integer, String>();
-		DATATYPE_MAP.put(1, "BOOL");
-		DATATYPE_MAP.put(2, "TINYINT");
-		DATATYPE_MAP.put(3, "SMALLINT");
-		DATATYPE_MAP.put(4, "INT");
-		DATATYPE_MAP.put(5, "BIGINT");
-		DATATYPE_MAP.put(6, "FLOAT");
-		DATATYPE_MAP.put(7, "DOUBLE");
-		DATATYPE_MAP.put(8, "BINARY");
-		DATATYPE_MAP.put(9, "TIMESTAMP");
-		DATATYPE_MAP.put(10, "NCHAR");
-	}
+    // nchar field's max length
+    public static final int maxFieldSize = 16 * 1024;
+
+    public static String WrapErrMsg(String msg) {
+        return "TDengine Error: " + msg;
+    }
+
+    public static String FixErrMsg(int code) {
+        switch (code) {
+            case JNI_TDENGINE_ERROR:
+                return WrapErrMsg("internal error of database!");
+            case JNI_CONNECTION_NULL:
+                return WrapErrMsg("invalid tdengine connection!");
+            case JNI_RESULT_SET_NULL:
+                return WrapErrMsg("invalid resultset pointer!");
+            case JNI_NUM_OF_FIELDS_0:
+                return WrapErrMsg("invalid num of fields!");
+            case JNI_SQL_NULL:
+                return WrapErrMsg("can't execute empty sql!");
+            case JNI_FETCH_END:
+                return WrapErrMsg("fetch to the end of resultset");
+            default:
+                break;
+        }
+        return WrapErrMsg("unkown error!");
+    }
+
+    static {
+        DATATYPE_MAP = new HashMap<Integer, String>();
+        DATATYPE_MAP.put(1, "BOOL");
+        DATATYPE_MAP.put(2, "TINYINT");
+        DATATYPE_MAP.put(3, "SMALLINT");
+        DATATYPE_MAP.put(4, "INT");
+        DATATYPE_MAP.put(5, "BIGINT");
+        DATATYPE_MAP.put(6, "FLOAT");
+        DATATYPE_MAP.put(7, "DOUBLE");
+        DATATYPE_MAP.put(8, "BINARY");
+        DATATYPE_MAP.put(9, "TIMESTAMP");
+        DATATYPE_MAP.put(10, "NCHAR");
+    }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java

 package com.taosdata.jdbc.rs;
 
 import com.taosdata.jdbc.TSDBConstants;
+import com.taosdata.jdbc.TSDBDriver;
 
 import java.sql.*;
+import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 import java.util.concurrent.Executor;
 
 public class RestfulConnection implements Connection {
 
+    private static final String CONNECTION_IS_CLOSED = "connection is closed.";
+    private static final String AUTO_COMMIT_IS_TRUE = "auto commit is true";
     private final String host;
     private final int port;
     private final Properties props;
-    private final String database;
+    private volatile String database;
     private final String url;
+    /******************************************************/
+    private boolean isClosed;
+    private DatabaseMetaData metadata;
+    private Map<String, Class<?>> typeMap;
+    private Properties clientInfoProps = new Properties();
 
     public RestfulConnection(String host, String port, Properties props, String database, String url) {
         this.host = host;
@@ -21,280 +31,424 @@ public class RestfulConnection implements Connection {
         this.props = props;
         this.database = database;
         this.url = url;
+        this.metadata = new RestfulDatabaseMetaData(url, props.getProperty(TSDBDriver.PROPERTY_KEY_USER), this);
     }
 
     @Override
     public Statement createStatement() throws SQLException {
         if (isClosed())
-            throw new SQLException(TSDBConstants.WrapErrMsg("restful TDengine connection is closed."));
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
         return new RestfulStatement(this, database);
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        //TODO: prepareStatement
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public CallableStatement prepareCall(String sql) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public String nativeSQL(String sql) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
+        //nothing did
+        return sql;
     }
 
     @Override
     public void setAutoCommit(boolean autoCommit) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (!autoCommit)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public boolean getAutoCommit() throws SQLException {
-        return false;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        return true;
     }
 
     @Override
     public void commit() throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (getAutoCommit())
+            throw new SQLException(AUTO_COMMIT_IS_TRUE);
+        //nothing to do
     }
 
     @Override
     public void rollback() throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (getAutoCommit())
+            throw new SQLException(AUTO_COMMIT_IS_TRUE);
+        //nothing to do
     }
 
     @Override
     public void close() throws SQLException {
-
+        if (isClosed)
+            return;
+        //TODO: release all resources
+        isClosed = true;
     }
 
     @Override
     public boolean isClosed() throws SQLException {
-        return false;
+        return isClosed;
     }
 
     @Override
     public DatabaseMetaData getMetaData() throws SQLException {
-        //TODO: RestfulDatabaseMetaData is not implemented
-        return new RestfulDatabaseMetaData();
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
+        return this.metadata;
     }
 
     @Override
     public void setReadOnly(boolean readOnly) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        // nothing to do
     }
 
     @Override
     public boolean isReadOnly() throws SQLException {
-        return false;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        return true;
     }
 
     @Override
     public void setCatalog(String catalog) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        synchronized (RestfulConnection.class) {
+            this.database = catalog;
+        }
     }
 
     @Override
     public String getCatalog() throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        return this.database;
     }
 
     @Override
     public void setTransactionIsolation(int level) throws SQLException {
-        //transaction is not supported
-        throw new SQLFeatureNotSupportedException("transactions are not supported");
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        switch (level) {
+            case Connection.TRANSACTION_NONE:
+                break;
+            case Connection.TRANSACTION_READ_UNCOMMITTED:
+            case Connection.TRANSACTION_READ_COMMITTED:
+            case Connection.TRANSACTION_REPEATABLE_READ:
+            case Connection.TRANSACTION_SERIALIZABLE:
+                throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
+            default:
+                throw new SQLException(TSDBConstants.INVALID_VARIABLES);
+        }
     }
 
-    /**
-     *
-     */
     @Override
     public int getTransactionIsolation() throws SQLException {
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
         //Connection.TRANSACTION_NONE specifies that transactions are not supported.
         return Connection.TRANSACTION_NONE;
     }
 
     @Override
     public SQLWarning getWarnings() throws SQLException {
-        //TODO: getWarnings not implemented
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
         return null;
     }
 
     @Override
     public void clearWarnings() throws SQLException {
-        throw new SQLFeatureNotSupportedException("clearWarnings not supported.");
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        //nothing to do
     }
 
     @Override
     public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
+        if (resultSetType != ResultSet.TYPE_FORWARD_ONLY) {
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
+        }
+        if (resultSetConcurrency != ResultSet.CONCUR_READ_ONLY)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
+        return createStatement();
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (resultSetType != ResultSet.TYPE_FORWARD_ONLY || resultSetConcurrency != ResultSet.CONCUR_READ_ONLY)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.INVALID_VARIABLES);
+
+        return this.prepareStatement(sql);
     }
 
     @Override
     public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (resultSetType != ResultSet.TYPE_FORWARD_ONLY || resultSetConcurrency != ResultSet.CONCUR_READ_ONLY)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.INVALID_VARIABLES);
+
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Map<String, Class<?>> getTypeMap() throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+
+        synchronized (RestfulConnection.class) {
+            if (this.typeMap == null) {
+                this.typeMap = new HashMap<>();
+            }
+            return this.typeMap;
+        }
     }
 
     @Override
     public void setTypeMap(Map<String, Class<?>> map) throws SQLException {
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
 
+        synchronized (RestfulConnection.class) {
+            this.typeMap = map;
+        }
     }
 
     @Override
     public void setHoldability(int holdability) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (holdability != ResultSet.HOLD_CURSORS_OVER_COMMIT)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public int getHoldability() throws SQLException {
-        return 0;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        return ResultSet.HOLD_CURSORS_OVER_COMMIT;
     }
 
     @Override
     public Savepoint setSavepoint() throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (getAutoCommit())
+            throw new SQLException(TSDBConstants.INVALID_VARIABLES);
+        //nothing to do
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Savepoint setSavepoint(String name) throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (getAutoCommit())
+            throw new SQLException(TSDBConstants.INVALID_VARIABLES);
+        //nothing to do
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public void rollback(Savepoint savepoint) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        if (getAutoCommit())
+            throw new SQLException(TSDBConstants.INVALID_VARIABLES);
+        //nothing to do
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public void releaseSavepoint(Savepoint savepoint) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
-        return null;
+        if (resultSetHoldability != ResultSet.HOLD_CURSORS_OVER_COMMIT)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
+        return createStatement(resultSetType, resultSetConcurrency);
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
-        return null;
+        if (resultSetHoldability != ResultSet.HOLD_CURSORS_OVER_COMMIT)
+            throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
+        return prepareStatement(sql, resultSetType, resultSetConcurrency);
     }
 
     @Override
     public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
-        return null;
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) throws SQLException {
-        return null;
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException {
-        return null;
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException {
-        return null;
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Clob createClob() throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Blob createBlob() throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public NClob createNClob() throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public SQLXML createSQLXML() throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public boolean isValid(int timeout) throws SQLException {
-        return false;
+        if (timeout < 0)
+            throw new SQLException(TSDBConstants.INVALID_VARIABLES);
+        // TODO:
+        /* The driver shall submit a query on the connection or use some other mechanism that positively verifies
+         the connection is still valid when this method is called.*/
+        return !isClosed();
     }
 
     @Override
     public void setClientInfo(String name, String value) throws SQLClientInfoException {
-
+        if (isClosed)
+            throw new SQLClientInfoException();
+        clientInfoProps.setProperty(name, value);
     }
 
     @Override
     public void setClientInfo(Properties properties) throws SQLClientInfoException {
+        if (isClosed)
+            throw new SQLClientInfoException();
 
+        for (Enumeration<Object> enumer = properties.keys(); enumer.hasMoreElements(); ) {
+            String name = (String) enumer.nextElement();
+            clientInfoProps.put(name, properties.getProperty(name));
+        }
     }
 
     @Override
     public String getClientInfo(String name) throws SQLException {
-        return null;
+        if (isClosed)
+            throw new SQLClientInfoException();
+
+        return clientInfoProps.getProperty(name);
     }
 
     @Override
     public Properties getClientInfo() throws SQLException {
-        return null;
+        if (isClosed)
+            throw new SQLClientInfoException();
+
+        return clientInfoProps;
     }
 
     @Override
     public Array createArrayOf(String typeName, Object[] elements) throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
-        //TODO: not supported
-        throw new SQLFeatureNotSupportedException();
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public void setSchema(String schema) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        synchronized (RestfulConnection.class) {
+            this.database = schema;
+        }
     }
 
     @Override
     public String getSchema() throws SQLException {
-        return null;
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        return this.database;
     }
 
     @Override
     public void abort(Executor executor) throws SQLException {
+        if (executor == null) {
+            throw new SQLException("Executor can not be null");
+        }
 
+        executor.execute(() -> {
+            try {
+                close();
+            } catch (SQLException e) {
+                e.printStackTrace();
+            }
+        });
     }
 
     @Override
     public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException {
-
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
+        throw new SQLFeatureNotSupportedException(TSDBConstants.UNSUPPORT_METHOD_EXCEPTIONZ_MSG);
     }
 
     @Override
     public int getNetworkTimeout() throws SQLException {
+        if (isClosed())
+            throw new SQLException(CONNECTION_IS_CLOSED);
         return 0;
     }
 

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulDriver.java

@@ -33,7 +33,7 @@ public class RestfulDriver extends AbstractTaosDriver {
             return null;
 
         Properties props = parseURL(url, info);
-        String host = props.getProperty(TSDBDriver.PROPERTY_KEY_HOST, "localhost");
+        String host = props.getProperty(TSDBDriver.PROPERTY_KEY_HOST);
         String port = props.getProperty(TSDBDriver.PROPERTY_KEY_PORT, "6041");
         String database = props.containsKey(TSDBDriver.PROPERTY_KEY_DBNAME) ? props.getProperty(TSDBDriver.PROPERTY_KEY_DBNAME) : null;
 

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulResultSetMetaData.java

@@ -2,13 +2,15 @@ package com.taosdata.jdbc.rs;
 
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
-import java.util.List;
+import java.util.ArrayList;
 
 public class RestfulResultSetMetaData implements ResultSetMetaData {
 
-    private List<String> fields;
+    private final String database;
+    private ArrayList<RestfulResultSet.Field> fields;
 
-    public RestfulResultSetMetaData(List<String> fields) {
+    public RestfulResultSetMetaData(String database, ArrayList<RestfulResultSet.Field> fields) {
+        this.database = database;
         this.fields = fields;
     }
 
@@ -24,6 +26,7 @@ public class RestfulResultSetMetaData implements ResultSetMetaData {
 
     @Override
     public boolean isCaseSensitive(int column) throws SQLException {
+        //TODO
         return false;
     }
 
@@ -39,7 +42,7 @@ public class RestfulResultSetMetaData implements ResultSetMetaData {
 
     @Override
     public int isNullable(int column) throws SQLException {
-        return 0;
+        return ResultSetMetaData.columnNullable;
     }
 
     @Override
@@ -54,7 +57,7 @@ public class RestfulResultSetMetaData implements ResultSetMetaData {
 
     @Override
     public String getColumnLabel(int column) throws SQLException {
-        return fields.get(column - 1);
+        return fields.get(column - 1).name;
     }
 
     @Override
@@ -64,7 +67,7 @@ public class RestfulResultSetMetaData implements ResultSetMetaData {
 
     @Override
     public String getSchemaName(int column) throws SQLException {
-        return null;
+        return this.database;
     }
 
     @Override
@@ -84,7 +87,7 @@ public class RestfulResultSetMetaData implements ResultSetMetaData {
 
     @Override
     public String getCatalogName(int column) throws SQLException {
-        return null;
+        return this.database;
     }
 
     @Override

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/util/HttpClientPoolUtil.java

@@ -17,6 +17,8 @@ import org.apache.http.protocol.HTTP;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.util.EntityUtils;
 
+import java.nio.charset.Charset;
+
 
 public class HttpClientPoolUtil {
     public static PoolingHttpClientConnectionManager cm = null;
@@ -94,7 +96,9 @@ public class HttpClientPoolUtil {
                 initPools();
             }
             method = (HttpEntityEnclosingRequestBase) getRequest(uri, HttpPost.METHOD_NAME, DEFAULT_CONTENT_TYPE, 0);
-            method.setEntity(new StringEntity(data));
+            method.setHeader("Authorization", "Basic cm9vdDp0YW9zZGF0YQ==");
+            method.setHeader("Content-Type", "text/plain");
+            method.setEntity(new StringEntity(data, Charset.forName("UTF-8")));
             HttpContext context = HttpClientContext.create();
             CloseableHttpResponse httpResponse = httpClient.execute(method, context);
             httpEntity = httpResponse.getEntity();
@@ -105,26 +109,13 @@ public class HttpClientPoolUtil {
             if (method != null) {
                 method.abort();
             }
-//            e.printStackTrace();
-//            logger.error("execute post request exception, url:" + uri + ", exception:" + e.toString()
-//                    + ", cost time(ms):" + (System.currentTimeMillis() - startTime));
-            new Exception("execute post request exception, url:"
-                    + uri + ", exception:" + e.toString() +
-                    ", cost time(ms):" + (System.currentTimeMillis() - startTime))
-                    .printStackTrace();
+            new Exception("execute post request exception, url:" + uri + ", exception:" + e.toString() + ", cost time(ms):" + (System.currentTimeMillis() - startTime)).printStackTrace();
         } finally {
             if (httpEntity != null) {
                 try {
                     EntityUtils.consumeQuietly(httpEntity);
                 } catch (Exception e) {
-//                    e.printStackTrace();
-//                    logger.error("close response exception, url:" + uri + ", exception:" + e.toString()
-//                            + ", cost time(ms):" + (System.currentTimeMillis() - startTime));
-                    new Exception(
-                            "close response exception, url:" + uri +
-                                    ", exception:" + e.toString()
-                                    + ", cost time(ms):" + (System.currentTimeMillis() - startTime))
-                            .printStackTrace();
+                    new Exception("close response exception, url:" + uri + ", exception:" + e.toString() + ", cost time(ms):" + (System.currentTimeMillis() - startTime)).printStackTrace();
                 }
             }
         }

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

@@ -15,14 +15,12 @@
 package com.taosdata.jdbc.utils;
 
 import com.taosdata.jdbc.TSDBConnection;
-import com.taosdata.jdbc.TSDBJNIConnector;
 
 import java.sql.Connection;
-import java.sql.SQLException;
 
 public class SqlSyntaxValidator {
 
-    private static final String[] updateSQL = {"insert", "update", "delete", "create", "alter", "drop", "show", "describe", "use"};
+    private static final String[] updateSQL = {"insert", "update", "delete", "create", "alter", "drop", "show", "describe", "use", "import"};
     private static final String[] querySQL = {"select"};
 
     private TSDBConnection tsdbConnection;
@@ -31,22 +29,6 @@ public class SqlSyntaxValidator {
         this.tsdbConnection = (TSDBConnection) connection;
     }
 
-    public boolean validateSqlSyntax(String sql) throws SQLException {
-
-        boolean res = false;
-        if (tsdbConnection == null || tsdbConnection.isClosed()) {
-            throw new SQLException("invalid connection");
-        } else {
-            TSDBJNIConnector jniConnector = tsdbConnection.getConnection();
-            if (jniConnector == null) {
-                throw new SQLException("jniConnector is null");
-            } else {
-                res = jniConnector.validateCreateTableSql(sql);
-            }
-        }
-        return res;
-    }
-
     public static boolean isValidForExecuteUpdate(String sql) {
         for (String prefix : updateSQL) {
             if (sql.trim().toLowerCase().startsWith(prefix))
@@ -56,18 +38,28 @@ public class SqlSyntaxValidator {
     }
 
     public static boolean isUseSql(String sql) {
-        return sql.trim().toLowerCase().startsWith(updateSQL[8]) || sql.trim().toLowerCase().matches("create\\s*database.*") || sql.toLowerCase().toLowerCase().matches("drop\\s*database.*");
+        return sql.trim().toLowerCase().startsWith("use") || sql.trim().toLowerCase().matches("create\\s*database.*") || sql.toLowerCase().toLowerCase().matches("drop\\s*database.*");
+    }
+
+    public static boolean isShowSql(String sql) {
+        return sql.trim().toLowerCase().startsWith("show");
     }
 
-    public static boolean isUpdateSql(String sql) {
-        return sql.trim().toLowerCase().startsWith(updateSQL[1]);
+    public static boolean isDescribeSql(String sql) {
+        return sql.trim().toLowerCase().startsWith("describe");
     }
 
+
     public static boolean isInsertSql(String sql) {
-        return sql.trim().toLowerCase().startsWith(updateSQL[0]);
+        return sql.trim().toLowerCase().startsWith("insert") || sql.trim().toLowerCase().startsWith("import");
     }
 
     public static boolean isSelectSql(String sql) {
-        return sql.trim().toLowerCase().startsWith(querySQL[0]);
+        return sql.trim().toLowerCase().startsWith("select");
+    }
+
+
+    public static boolean isShowDatabaseSql(String sql) {
+        return sql.trim().toLowerCase().matches("show\\s*databases");
     }
 }

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

@@ -7,7 +7,7 @@ import org.junit.Test;
 import java.sql.*;
 import java.util.Properties;
 
-public class DatabaseMetaDataTest extends BaseTest {
+public class DatabaseMetaDataTest {
     static Connection connection = null;
     static PreparedStatement statement = null;
     static String dbName = "test";
@@ -23,20 +23,21 @@ public class DatabaseMetaDataTest extends BaseTest {
         }
         Properties properties = new Properties();
         properties.setProperty(TSDBDriver.PROPERTY_KEY_HOST, host);
+        properties.setProperty(TSDBDriver.PROPERTY_KEY_USER, "root");
+        properties.setProperty(TSDBDriver.PROPERTY_KEY_PASSWORD, "taosdata");
         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 + ":0/", properties);
 
         String sql = "drop database if exists " + dbName;
-        statement = (TSDBPreparedStatement) connection.prepareStatement(sql);
+        statement = connection.prepareStatement(sql);
         statement.executeUpdate("create database if not exists " + dbName);
         statement.executeUpdate("create table if not exists " + dbName + "." + tName + " (ts timestamp, k int, v int)");
     }
 
     @Test
     public void testMetaDataTest() throws SQLException {
-
         DatabaseMetaData databaseMetaData = connection.getMetaData();
         ResultSet resultSet = databaseMetaData.getTables(dbName, "t*", "t*", new String[]{"t"});
         while (resultSet.next()) {
@@ -180,7 +181,7 @@ public class DatabaseMetaDataTest extends BaseTest {
         databaseMetaData.getCatalogs();
 //        databaseMetaData.getTableTypes();
 
-        databaseMetaData.getColumns("", "", "", "");
+        databaseMetaData.getColumns(dbName, "", tName, "");
         databaseMetaData.getColumnPrivileges("", "", "", "");
         databaseMetaData.getTablePrivileges("", "", "");
         databaseMetaData.getBestRowIdentifier("", "", "", 0, false);

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/AppMemoryLeakTest.java

@@ -19,7 +19,7 @@ public class AppMemoryLeakTest {
         }
     }
 
-    @Test
+    @Test(expected = Exception.class)
     public void testCreateTooManyStatement() throws ClassNotFoundException, SQLException {
         Class.forName("com.taosdata.jdbc.TSDBDriver");
         int stmtCnt = 0;
@@ -30,15 +30,4 @@ public class AppMemoryLeakTest {
         }
     }
 
-    public static void main(String[] args) throws ClassNotFoundException, SQLException {
-        Class.forName("com.taosdata.jdbc.TSDBDriver");
-        int stmtCnt = 0;
-        Connection conn = DriverManager.getConnection("jdbc:TAOS://localhost:6030/?user=root&password=taosdata");
-        while (true) {
-            Statement stmt = conn.createStatement();
-            System.out.println(++stmtCnt + " : " + stmt);
-        }
-    }
-
-
 }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectWrongDatabaseTest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.sql.DriverManager;
+import java.sql.SQLException;
+
+public class ConnectWrongDatabaseTest {
+
+    @Test
+    public void connect() {
+        try {
+            Class.forName("com.taosdata.jdbc.TSDBDriver");
+            DriverManager.getConnection("jdbc:TAOS://localhost:6030/wrong_db?user=root&password=taosdata");
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            Assert.assertEquals("TDengine Error: Invalid database name", e.getMessage());
+        }
+    }
+
+}

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

 package com.taosdata.jdbc.rs;
 
+
 import org.junit.*;
 import org.junit.runners.MethodSorters;
 

src/connector/jdbc/src/test/java/com/taosdata/jdbc/utils/SqlSyntaxValidatorTest.java

@@ -5,10 +5,6 @@ import org.junit.Test;
 
 public class SqlSyntaxValidatorTest {
 
-    @Test
-    public void validateSqlSyntax() {
-    }
-
     @Test
     public void isSelectSQL() {
         Assert.assertTrue(SqlSyntaxValidator.isSelectSql("select * from test.weather"));

src/connector/nodejs/nodetaos/cinterface.js

@@ -4,6 +4,7 @@
  */
 
 const ref = require('ref');
+const os = require('os');
 const ffi = require('ffi');
 const ArrayType = require('ref-array');
 const Struct = require('ref-struct');
@@ -188,7 +189,13 @@ function CTaosInterface (config = null, pass = false) {
   ref.types.void_ptr2 = ref.refType(ref.types.void_ptr);
   /*Declare a bunch of functions first*/
   /* Note, pointers to TAOS_RES, TAOS, are ref.types.void_ptr. The connection._conn buffer is supplied for pointers to TAOS *  */
-  this.libtaos = ffi.Library('libtaos', {
+
+  if ('win32' == os.platform()) {
+    taoslibname = 'taos';
+  } else {
+    taoslibname = 'libtaos';
+  }
+  this.libtaos = ffi.Library(taoslibname, {
     'taos_options': [ ref.types.int, [ ref.types.int , ref.types.void_ptr ] ],
     'taos_init': [ ref.types.void, [ ] ],
     //TAOS *taos_connect(char *ip, char *user, char *pass, char *db, int port)

src/connector/nodejs/package.json

 {
   "name": "td2.0-connector",
-  "version": "2.0.4",
+  "version": "2.0.5",
   "description": "A Node.js connector for TDengine.",
   "main": "tdengine.js",
   "scripts": {

src/dnode/inc/dnodeModule.h

@@ -23,8 +23,7 @@ extern "C" {
 
 int32_t dnodeInitModules();
 void    dnodeCleanupModules();
-bool    dnodeStartMnode(SMInfos *pMinfos);
-void    dnodeProcessModuleStatus(uint32_t moduleStatus);
+int32_t dnodeStartMnode(SMInfos *pMinfos);
 
 #ifdef __cplusplus
 }

src/dnode/src/dnodeMWrite.c

@@ -184,7 +184,19 @@ void dnodeReprocessMWriteMsg(void *pMsg) {
     dDebug("msg:%p, app:%p type:%s is redirected for mnode not running, retry times:%d", pWrite, pWrite->rpcMsg.ahandle,
            taosMsg[pWrite->rpcMsg.msgType], pWrite->retry);
 
-    dnodeSendRedirectMsg(pMsg, true);
+    if (pWrite->pBatchMasterMsg) {
+      ++pWrite->pBatchMasterMsg->received;
+      if (pWrite->pBatchMasterMsg->successed + pWrite->pBatchMasterMsg->received
+	  >= pWrite->pBatchMasterMsg->expected) {
+        dnodeSendRedirectMsg(&pWrite->pBatchMasterMsg->rpcMsg, true);
+        dnodeFreeMWriteMsg(pWrite->pBatchMasterMsg);
+      }
+
+      mnodeDestroySubMsg(pWrite);
+
+      return;
+    }
+    dnodeSendRedirectMsg(&pWrite->rpcMsg, true);
     dnodeFreeMWriteMsg(pWrite);
   } else {
     dDebug("msg:%p, app:%p type:%s is reput into mwrite queue:%p, retry times:%d", pWrite, pWrite->rpcMsg.ahandle,

src/dnode/src/dnodeModule.c

@@ -127,14 +127,16 @@ int32_t dnodeInitModules() {
   return dnodeStartModules();
 }
 
-void dnodeProcessModuleStatus(uint32_t moduleStatus) {
+int32_t dnodeProcessModuleStatus(uint32_t moduleStatus) {
+  int32_t code = 0;
+
   for (int32_t module = TSDB_MOD_MNODE; module < TSDB_MOD_HTTP; ++module) {
     bool enableModule = moduleStatus & (1 << module);
     if (!tsModule[module].enable && enableModule) {
       dInfo("module status:%u is set, start %s module", moduleStatus, tsModule[module].name);
       tsModule[module].enable = true;
       dnodeSetModuleStatus(module);
-      (*tsModule[module].startFp)();
+      code = (*tsModule[module].startFp)();
     }
 
     if (tsModule[module].enable && !enableModule) {
@@ -144,21 +146,29 @@ void dnodeProcessModuleStatus(uint32_t moduleStatus) {
       (*tsModule[module].stopFp)();
     }
   }
-}
 
-bool dnodeStartMnode(SMInfos *pMinfos) {
-  SMInfos *pMnodes = pMinfos;
+  return code;
+}
 
+int32_t dnodeStartMnode(SMInfos *pMinfos) {
   if (tsModuleStatus & (1 << TSDB_MOD_MNODE)) {
     dDebug("mnode module is already started, module status:%d", tsModuleStatus);
-    return false;
+    return 0;
   }
 
   uint32_t moduleStatus = tsModuleStatus | (1 << TSDB_MOD_MNODE);
   dInfo("start mnode module, module status:%d, new status:%d", tsModuleStatus, moduleStatus);
-  dnodeProcessModuleStatus(moduleStatus);
 
-  sdbUpdateSync(pMnodes);
+  int32_t code = dnodeProcessModuleStatus(moduleStatus);
+  if (code == 0) {
+    code = sdbUpdateSync(pMinfos);
+  }
+
+  if (code != 0) {
+    dError("failed to start mnode module since %s", tstrerror(code));
+    moduleStatus = tsModuleStatus & ~(1 << TSDB_MOD_MNODE);
+    dnodeProcessModuleStatus(moduleStatus);
+  }
 
-  return true;
+  return code;
 }

src/dnode/src/dnodePeer.c

@@ -60,7 +60,7 @@ int32_t dnodeInitServer() {
   rpcInit.label        = "DND-S";
   rpcInit.numOfThreads = 1;
   rpcInit.cfp          = dnodeProcessReqMsgFromDnode;
-  rpcInit.sessions     = TSDB_MAX_VNODES;
+  rpcInit.sessions     = TSDB_MAX_VNODES << 4;
   rpcInit.connType     = TAOS_CONN_SERVER;
   rpcInit.idleTime     = tsShellActivityTimer * 1000;
 
@@ -123,7 +123,7 @@ int32_t dnodeInitClient() {
   rpcInit.label        = "DND-C";
   rpcInit.numOfThreads = 1;
   rpcInit.cfp          = dnodeProcessRspFromDnode;
-  rpcInit.sessions     = TSDB_MAX_VNODES;
+  rpcInit.sessions     = TSDB_MAX_VNODES << 4;
   rpcInit.connType     = TAOS_CONN_CLIENT;
   rpcInit.idleTime     = tsShellActivityTimer * 1000;
   rpcInit.user         = "t";

src/dnode/src/dnodeVMgmt.c

@@ -214,7 +214,5 @@ static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg) {
     dDebug("mnode index:%d, mnode:%d:%s", i, pCfg->mnodes.mnodeInfos[i].mnodeId, pCfg->mnodes.mnodeInfos[i].mnodeEp);
   }
 
-  dnodeStartMnode(&pCfg->mnodes);
-
-  return TSDB_CODE_SUCCESS;
+  return dnodeStartMnode(&pCfg->mnodes);
 }

src/dnode/src/dnodeVnodes.c

@@ -73,7 +73,8 @@ static int32_t dnodeGetVnodeList(int32_t vnodeList[], int32_t *numOfVnodes) {
 
       if (*numOfVnodes >= TSDB_MAX_VNODES) {
         dError("vgId:%d, too many vnode directory in disk, exist:%d max:%d", vnode, *numOfVnodes, TSDB_MAX_VNODES);
-        continue;
+        closedir(dir);
+        return TSDB_CODE_DND_TOO_MANY_VNODES;
       } else {
         vnodeList[*numOfVnodes - 1] = vnode;
       }
@@ -288,4 +289,4 @@ void dnodeSendStatusMsgToMnode() {
     dInfo("force send status msg to mnode");
     taosTmrReset(dnodeSendStatusMsg, 3, NULL, tsDnodeTmr, &tsStatusTimer);
   }
-}
+}
\ No newline at end of file

src/inc/dnode.h

@@ -40,7 +40,7 @@ void    dnodeGetClusterId(char *clusterId);
 
 void    dnodeUpdateEp(int32_t dnodeId, char *ep, char *fqdn, uint16_t *port);
 bool    dnodeCheckEpChanged(int32_t dnodeId, char *epstr);
-bool    dnodeStartMnode(SMInfos *pMinfos);
+int32_t dnodeStartMnode(SMInfos *pMinfos);
 
 void  dnodeAddClientRspHandle(uint8_t msgType, void (*fp)(SRpcMsg *rpcMsg));
 void  dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg);

src/inc/query.h

@@ -86,6 +86,7 @@ void qDestroyQueryInfo(qinfo_t qHandle);
 
 void* qOpenQueryMgmt(int32_t vgId);
 void  qQueryMgmtNotifyClosed(void* pExecutor);
+void  qQueryMgmtReOpen(void *pExecutor);
 void  qCleanupQueryMgmt(void* pExecutor);
 void** qRegisterQInfo(void* pMgmt, uint64_t qInfo);
 void** qAcquireQInfo(void* pMgmt, uint64_t key);

src/inc/taoserror.h

@@ -126,6 +126,11 @@ TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_SHOWOBJ,          0, 0x030B, "Data expir
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_QUERY_ID,         0, 0x030C, "Invalid query id")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_STREAM_ID,        0, 0x030D, "Invalid stream id")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_CONN_ID,          0, 0x030E, "Invalid connection id")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_MNODE_IS_RUNNING,         0, 0x0310, "mnode is alreay running")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_FAILED_TO_CONFIG_SYNC,    0, 0x0311, "failed to config sync")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_FAILED_TO_START_SYNC,     0, 0x0312, "failed to start sync")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_FAILED_TO_CREATE_DIR,     0, 0x0313, "failed to create mnode dir")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_FAILED_TO_INIT_STEP,      0, 0x0314, "failed to init components")
 
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_SDB_OBJ_ALREADY_THERE,    0, 0x0320, "Object already there")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_SDB_ERROR,                0, 0x0321, "Unexpected generic error in sdb")
@@ -194,6 +199,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_DND_OUT_OF_MEMORY,            0, 0x0401, "Dnode out
 TAOS_DEFINE_ERROR(TSDB_CODE_DND_NO_WRITE_ACCESS,          0, 0x0402, "No permission for disk files in dnode")
 TAOS_DEFINE_ERROR(TSDB_CODE_DND_INVALID_MSG_LEN,          0, 0x0403, "Invalid message length")
 TAOS_DEFINE_ERROR(TSDB_CODE_DND_ACTION_IN_PROGRESS,       0, 0x0404, "Action in progress")
+TAOS_DEFINE_ERROR(TSDB_CODE_DND_TOO_MANY_VNODES,          0, 0x0405, "Too many vnode directories")
 
 // vnode 
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_ACTION_IN_PROGRESS,       0, 0x0500, "Action in progress")

tests/examples/JDBC/taosdemo/readme.md

+需求：
+1. 可以读lowa的配置文件
+2. 支持对JNI方式和Restful方式的taos-driver
\ No newline at end of file