Merge pull request #5533 from taosdata/feature/TD-3295

[TD-3295]support multiple tables join

src/client/inc/tscUtil.h

@@ -83,6 +83,22 @@ typedef struct SJoinSupporter {
   SArray*         pVgroupTables;
 } SJoinSupporter;
 
+
+typedef struct SMergeCtx {
+  SJoinSupporter* p;
+  int32_t         idx;
+  SArray*         res;
+  int8_t          compared;
+}SMergeCtx;
+
+typedef struct SMergeTsCtx {
+  SJoinSupporter* p;
+  STSBuf*         res;
+  int64_t         numOfInput;
+  int8_t          compared;
+}SMergeTsCtx;
+
+
 typedef struct SVgroupTableInfo {
   SVgroupInfo vgInfo;
   SArray*     itemList;   //SArray<STableIdInfo>
@@ -183,6 +199,7 @@ int32_t   tscSqlExprCopy(SArray* dst, const SArray* src, uint64_t uid, bool deep
 void      tscSqlExprInfoDestroy(SArray* pExprInfo);
 
 SColumn* tscColumnClone(const SColumn* src);
+bool tscColumnExists(SArray* pColumnList, SColumnIndex* pColIndex);
 SColumn* tscColumnListInsert(SArray* pColList, SColumnIndex* colIndex);
 SArray* tscColumnListClone(const SArray* src, int16_t tableIndex);
 void tscColumnListDestroy(SArray* pColList);

src/client/inc/tsclient.h

@@ -142,15 +142,15 @@ typedef struct SCond {
 } SCond;
 
 typedef struct SJoinNode {
-  char     tableName[TSDB_TABLE_FNAME_LEN];
   uint64_t uid;
   int16_t  tagColId;
+  SArray*  tsJoin;
+  SArray*  tagJoin;
 } SJoinNode;
 
 typedef struct SJoinInfo {
   bool      hasJoin;  
-  SJoinNode left;
-  SJoinNode right;
+  SJoinNode*  joinTables[TSDB_MAX_JOIN_TABLE_NUM];
 } SJoinInfo;
 
 typedef struct STagCond {

src/client/src/tscSQLParser.c

@@ -3353,23 +3353,25 @@ static int32_t getColumnQueryCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSq
   }
 }
 
-static int32_t getJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr* pExpr) {
-  const char* msg1 = "invalid join query condition";
-  const char* msg2 = "invalid table name in join query";
+static int32_t checkAndSetJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr* pExpr) {
+  int32_t code = 0;
+  const char* msg1 = "timestamp required for join tables";
   const char* msg3 = "type of join columns must be identical";
   const char* msg4 = "invalid column name in join condition";
+  const char* msg5 = "only support one join tag for each table";
 
   if (pExpr == NULL) {
     return TSDB_CODE_SUCCESS;
   }
 
   if (!tSqlExprIsParentOfLeaf(pExpr)) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
+    code = checkAndSetJoinCondInfo(pCmd, pQueryInfo, pExpr->pLeft);
+    if (code) {
+      return code;
     }
     
-  STagCond*  pTagCond = &pQueryInfo->tagCond;
-  SJoinNode* pLeft = &pTagCond->joinInfo.left;
-  SJoinNode* pRight = &pTagCond->joinInfo.right;
+    return checkAndSetJoinCondInfo(pCmd, pQueryInfo, pExpr->pRight);
+  }
 
   SColumnIndex index = COLUMN_INDEX_INITIALIZER;
   if (getColumnIndexByName(pCmd, &pExpr->pLeft->colInfo, pQueryInfo, &index) != TSDB_CODE_SUCCESS) {
@@ -3379,14 +3381,29 @@ static int32_t getJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr*
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, index.tableIndex);
   SSchema* pTagSchema1 = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, index.columnIndex);
 
-  pLeft->uid = pTableMetaInfo->pTableMeta->id.uid;
-  pLeft->tagColId = pTagSchema1->colId;
+  assert(index.tableIndex >= 0 && index.tableIndex < TSDB_MAX_JOIN_TABLE_NUM);
 
-  int32_t code = tNameExtractFullName(&pTableMetaInfo->name, pLeft->tableName);
-  if (code != TSDB_CODE_SUCCESS) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
+  SJoinNode **leftNode = &pQueryInfo->tagCond.joinInfo.joinTables[index.tableIndex];
+  if (*leftNode == NULL) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
   }
   
+  (*leftNode)->uid = pTableMetaInfo->pTableMeta->id.uid;
+  (*leftNode)->tagColId = pTagSchema1->colId;
+
+  if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+    index.columnIndex = index.columnIndex - tscGetNumOfColumns(pTableMetaInfo->pTableMeta);
+    if (!tscColumnExists(pTableMetaInfo->tagColList, &index)) {
+      tscColumnListInsert(pTableMetaInfo->tagColList, &index);
+      if (taosArrayGetSize(pTableMetaInfo->tagColList) > 1) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg5);
+      }
+    }
+  }
+
+  int16_t leftIdx = index.tableIndex;
+
+
   index = (SColumnIndex)COLUMN_INDEX_INITIALIZER;
   if (getColumnIndexByName(pCmd, &pExpr->pRight->colInfo, pQueryInfo, &index) != TSDB_CODE_SUCCESS) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
@@ -3395,20 +3412,55 @@ static int32_t getJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr*
   pTableMetaInfo = tscGetMetaInfo(pQueryInfo, index.tableIndex);
   SSchema* pTagSchema2 = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, index.columnIndex);
 
-  pRight->uid = pTableMetaInfo->pTableMeta->id.uid;
-  pRight->tagColId = pTagSchema2->colId;
+  assert(index.tableIndex >= 0 && index.tableIndex < TSDB_MAX_JOIN_TABLE_NUM);
 
-  code = tNameExtractFullName(&pTableMetaInfo->name, pRight->tableName);
-  if (code != TSDB_CODE_SUCCESS) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
+  SJoinNode **rightNode = &pQueryInfo->tagCond.joinInfo.joinTables[index.tableIndex];
+  if (*rightNode == NULL) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
   }
 
+  (*rightNode)->uid = pTableMetaInfo->pTableMeta->id.uid;
+  (*rightNode)->tagColId = pTagSchema2->colId;
+
+  if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+    index.columnIndex = index.columnIndex - tscGetNumOfColumns(pTableMetaInfo->pTableMeta);
+    if (!tscColumnExists(pTableMetaInfo->tagColList, &index)) {
+      tscColumnListInsert(pTableMetaInfo->tagColList, &index);
+      if (taosArrayGetSize(pTableMetaInfo->tagColList) > 1) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg5);
+      }
+    }
+  }
+
+  int16_t rightIdx = index.tableIndex;
+
   if (pTagSchema1->type != pTagSchema2->type) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
   }
 
-  pTagCond->joinInfo.hasJoin = true;
+  if ((*leftNode)->tagJoin == NULL) {
+    (*leftNode)->tagJoin = taosArrayInit(2, sizeof(int16_t));
+  }
+  
+  if ((*rightNode)->tagJoin == NULL) {
+    (*rightNode)->tagJoin = taosArrayInit(2, sizeof(int16_t));
+  }      
+  
+  taosArrayPush((*leftNode)->tagJoin, &rightIdx);
+  taosArrayPush((*rightNode)->tagJoin, &leftIdx);
+  
+  pQueryInfo->tagCond.joinInfo.hasJoin = true;
+  
   return TSDB_CODE_SUCCESS;
+
+}
+
+static int32_t getJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr* pExpr) {
+  if (pExpr == NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  return checkAndSetJoinCondInfo(pCmd, pQueryInfo, pExpr);
 }
 
 static int32_t validateSQLExpr(SSqlCmd* pCmd, tSqlExpr* pExpr, SQueryInfo* pQueryInfo, SColumnList* pList,
@@ -3674,7 +3726,7 @@ static int32_t handleExprInQueryCond(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSql
   const char* msg1 = "table query cannot use tags filter";
   const char* msg2 = "illegal column name";
   const char* msg3 = "only one query time range allowed";
-  const char* msg4 = "only one join condition allowed";
+  const char* msg4 = "too many join tables";
   const char* msg5 = "not support ordinary column join";
   const char* msg6 = "only one query condition on tbname allowed";
   const char* msg7 = "only in/like allowed in filter table name";
@@ -3705,6 +3757,47 @@ static int32_t handleExprInQueryCond(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSql
       TSDB_QUERY_SET_TYPE(pQueryInfo->type, TSDB_QUERY_TYPE_JOIN_QUERY);
       pCondExpr->tsJoin = true;
 
+      assert(index.tableIndex >= 0 && index.tableIndex < TSDB_MAX_JOIN_TABLE_NUM);
+      SJoinNode **leftNode = &pQueryInfo->tagCond.joinInfo.joinTables[index.tableIndex];
+      if (*leftNode == NULL) {
+        *leftNode = calloc(1, sizeof(SJoinNode));
+        if (*leftNode == NULL) {
+          return TSDB_CODE_TSC_OUT_OF_MEMORY;
+        }
+      }
+      
+      int16_t leftIdx = index.tableIndex;
+
+      SColumnIndex index = COLUMN_INDEX_INITIALIZER;
+      if (getColumnIndexByName(pCmd, &pRight->colInfo, pQueryInfo, &index) != TSDB_CODE_SUCCESS) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
+      }
+
+      if (index.tableIndex < 0 || index.tableIndex >= TSDB_MAX_JOIN_TABLE_NUM) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
+      }
+
+      SJoinNode **rightNode = &pQueryInfo->tagCond.joinInfo.joinTables[index.tableIndex];
+      if (*rightNode == NULL) {
+        *rightNode = calloc(1, sizeof(SJoinNode));
+        if (*rightNode == NULL) {
+          return TSDB_CODE_TSC_OUT_OF_MEMORY;
+        }
+      }
+      
+      int16_t rightIdx = index.tableIndex;
+
+      if ((*leftNode)->tsJoin == NULL) {
+        (*leftNode)->tsJoin = taosArrayInit(2, sizeof(int16_t));
+      }
+      
+      if ((*rightNode)->tsJoin == NULL) {
+        (*rightNode)->tsJoin = taosArrayInit(2, sizeof(int16_t));
+      }      
+      
+      taosArrayPush((*leftNode)->tsJoin, &rightIdx);
+      taosArrayPush((*rightNode)->tsJoin, &leftIdx);
+      
       /*
        * to release expression, e.g., m1.ts = m2.ts,
        * since this expression is used to set the join query type
@@ -3762,10 +3855,6 @@ static int32_t handleExprInQueryCond(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSql
           return TSDB_CODE_TSC_INVALID_SQL;
         }
 
-        if (pCondExpr->pJoinExpr != NULL) {
-          return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
-        }
-
         pQueryInfo->type |= TSDB_QUERY_TYPE_JOIN_QUERY;
         ret = setExprToCond(&pCondExpr->pJoinExpr, *pExpr, NULL, parentOptr, pQueryInfo->msg);
         *pExpr = NULL;
@@ -3993,6 +4082,7 @@ static bool validateFilterExpr(SQueryInfo* pQueryInfo) {
 static int32_t getTimeRangeFromExpr(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr* pExpr) {
   const char* msg0 = "invalid timestamp";
   const char* msg1 = "only one time stamp window allowed";
+  int32_t code = 0;
   
   if (pExpr == NULL) {
     return TSDB_CODE_SUCCESS;
@@ -4003,7 +4093,10 @@ static int32_t getTimeRangeFromExpr(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlE
       return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
     }
 
-    getTimeRangeFromExpr(pCmd, pQueryInfo, pExpr->pLeft);
+    code = getTimeRangeFromExpr(pCmd, pQueryInfo, pExpr->pLeft);
+    if (code) {
+      return code;
+    }
     
     return getTimeRangeFromExpr(pCmd, pQueryInfo, pExpr->pRight);
   } else {
@@ -4085,6 +4178,7 @@ static void cleanQueryExpr(SCondExpr* pCondExpr) {
   }
 }
 
+/*
 static void doAddJoinTagsColumnsIntoTagList(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SCondExpr* pCondExpr) {
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   if (QUERY_IS_JOIN_QUERY(pQueryInfo->type) && UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
@@ -4107,6 +4201,7 @@ static void doAddJoinTagsColumnsIntoTagList(SSqlCmd* pCmd, SQueryInfo* pQueryInf
     tscColumnListInsert(pTableMetaInfo->tagColList, &index);
   }
 }
+*/
 
 static int32_t validateTagCondExpr(SSqlCmd* pCmd, tExprNode *p) {
   const char *msg1 = "invalid tag operator";
@@ -4250,6 +4345,102 @@ static int32_t getTagQueryCondExpr(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SCondE
   return ret;
 }
 
+int32_t validateJoinNodes(SQueryInfo* pQueryInfo, SSqlObj* pSql) {
+  const char* msg1 = "timestamp required for join tables";
+  const char* msg2 = "tag required for join stables";
+  
+  for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+    SJoinNode *node = pQueryInfo->tagCond.joinInfo.joinTables[i];  
+    
+    if (node == NULL || node->tsJoin == NULL || taosArrayGetSize(node->tsJoin) <= 0) {
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg1);
+    }
+  }
+
+  STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+    for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+      SJoinNode *node = pQueryInfo->tagCond.joinInfo.joinTables[i];  
+      
+      if (node == NULL || node->tagJoin == NULL || taosArrayGetSize(node->tagJoin) <= 0) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg2);
+      }
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+
+void mergeJoinNodesImpl(int8_t* r, int8_t* p, int16_t* tidx, SJoinNode** nodes, int32_t type) {
+  SJoinNode *node = nodes[*tidx];  
+  SArray* arr = (type == 0) ? node->tsJoin : node->tagJoin;
+  size_t size = taosArrayGetSize(arr);
+
+  p[*tidx] = 1;
+  
+  for (int32_t j = 0; j < size; j++) {
+    int16_t* idx = taosArrayGet(arr, j);
+    r[*idx] = 1;
+    if (p[*idx] == 0) {
+      mergeJoinNodesImpl(r, p, idx, nodes, type);
+    }
+  }
+}
+
+int32_t mergeJoinNodes(SQueryInfo* pQueryInfo, SSqlObj* pSql) {
+  const char* msg1 = "not all join tables have same timestamp";
+  const char* msg2 = "not all join tables have same tag";
+  
+  int8_t r[TSDB_MAX_JOIN_TABLE_NUM] = {0};
+  int8_t p[TSDB_MAX_JOIN_TABLE_NUM] = {0};
+  
+  for (int16_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+    mergeJoinNodesImpl(r, p, &i, pQueryInfo->tagCond.joinInfo.joinTables, 0);
+    
+    taosArrayClear(pQueryInfo->tagCond.joinInfo.joinTables[i]->tsJoin);
+  
+    for (int32_t j = 0; j < TSDB_MAX_JOIN_TABLE_NUM; ++j) {
+      if (r[j]) {
+        taosArrayPush(pQueryInfo->tagCond.joinInfo.joinTables[i]->tsJoin, &j);
+      }
+    }
+    
+    memset(r, 0, sizeof(r));
+    memset(p, 0, sizeof(p));
+  }
+
+  if (taosArrayGetSize(pQueryInfo->tagCond.joinInfo.joinTables[0]->tsJoin) != pQueryInfo->numOfTables) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg1);
+  }
+  
+  STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+    for (int16_t i = 0; i < pQueryInfo->numOfTables; ++i) {
+      mergeJoinNodesImpl(r, p, &i, pQueryInfo->tagCond.joinInfo.joinTables, 1);
+      
+      taosArrayClear(pQueryInfo->tagCond.joinInfo.joinTables[i]->tagJoin);
+    
+      for (int32_t j = 0; j < TSDB_MAX_JOIN_TABLE_NUM; ++j) {
+        if (r[j]) {
+          taosArrayPush(pQueryInfo->tagCond.joinInfo.joinTables[i]->tagJoin, &j);
+        }
+      }
+      
+      memset(r, 0, sizeof(r));
+      memset(p, 0, sizeof(p));
+    }
+
+    if (taosArrayGetSize(pQueryInfo->tagCond.joinInfo.joinTables[0]->tagJoin) != pQueryInfo->numOfTables) {
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg2);
+    }
+
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+
 int32_t parseWhereClause(SQueryInfo* pQueryInfo, tSqlExpr** pExpr, SSqlObj* pSql) {
   if (pExpr == NULL) {
     return TSDB_CODE_SUCCESS;
@@ -4295,17 +4486,17 @@ int32_t parseWhereClause(SQueryInfo* pQueryInfo, tSqlExpr** pExpr, SSqlObj* pSql
 
   // 4. get the table name query condition
   if ((ret = getTablenameCond(&pSql->cmd, pQueryInfo, condExpr.pTableCond, &sb)) != TSDB_CODE_SUCCESS) {
-    return ret;
+    goto PARSE_WHERE_EXIT;
   }
 
   // 5. other column query condition
   if ((ret = getColumnQueryCondInfo(&pSql->cmd, pQueryInfo, condExpr.pColumnCond, TK_AND)) != TSDB_CODE_SUCCESS) {
-    return ret;
+    goto PARSE_WHERE_EXIT;
   }
 
   // 6. join condition
   if ((ret = getJoinCondInfo(&pSql->cmd, pQueryInfo, condExpr.pJoinExpr)) != TSDB_CODE_SUCCESS) {
-    return ret;
+    goto PARSE_WHERE_EXIT;
   }
 
   // 7. query condition for table name
@@ -4313,12 +4504,29 @@ int32_t parseWhereClause(SQueryInfo* pQueryInfo, tSqlExpr** pExpr, SSqlObj* pSql
 
   ret = setTableCondForSTableQuery(&pSql->cmd, pQueryInfo, getAccountId(pSql), condExpr.pTableCond, condExpr.tableCondIndex, &sb);
   taosStringBuilderDestroy(&sb);
+  if (ret) {
+    goto PARSE_WHERE_EXIT;
+  }
 
   if (!validateFilterExpr(pQueryInfo)) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg2);
+    ret = invalidSqlErrMsg(tscGetErrorMsgPayload(&pSql->cmd), msg2);
+    goto PARSE_WHERE_EXIT;
+  }
+
+  //doAddJoinTagsColumnsIntoTagList(&pSql->cmd, pQueryInfo, &condExpr);
+  if (condExpr.tsJoin) {
+    ret = validateJoinNodes(pQueryInfo, pSql);
+    if (ret) {
+      goto PARSE_WHERE_EXIT;
+    }
+
+    ret = mergeJoinNodes(pQueryInfo, pSql);
+    if (ret) {
+      goto PARSE_WHERE_EXIT;
+    }    
   }
 
-  doAddJoinTagsColumnsIntoTagList(&pSql->cmd, pQueryInfo, &condExpr);
+PARSE_WHERE_EXIT:
 
   cleanQueryExpr(&condExpr);
   return ret;
@@ -6531,7 +6739,6 @@ int32_t doValidateSqlNode(SSqlObj* pSql, SQuerySqlNode* pQuerySqlNode, int32_t i
   const char* msg1 = "point interpolation query needs timestamp";
   const char* msg2 = "fill only available for interval query";
   const char* msg3 = "start(end) time of query range required or time range too large";
-  const char* msg4 = "illegal number of tables in from clause";
   const char* msg5 = "too many columns in selection clause";
   const char* msg6 = "too many tables in from clause";
   const char* msg7 = "invalid table alias name";
@@ -6568,14 +6775,11 @@ int32_t doValidateSqlNode(SSqlObj* pSql, SQuerySqlNode* pQuerySqlNode, int32_t i
   }
 
   size_t fromSize = taosArrayGetSize(pQuerySqlNode->from->tableList);
-  if (fromSize > TSDB_MAX_JOIN_TABLE_NUM) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
+  if (fromSize > TSDB_MAX_JOIN_TABLE_NUM * 2) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg6);
   }
 
   pQueryInfo->command = TSDB_SQL_SELECT;
-  if (fromSize > 2) {
-    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg6);
-  }
 
   // set all query tables, which are maybe more than one.
   for (int32_t i = 0; i < fromSize; ++i) {

src/client/src/tscUtil.c

@@ -1279,6 +1279,34 @@ int32_t tscSqlExprCopy(SArray* dst, const SArray* src, uint64_t uid, bool deepco
   return 0;
 }
 
+bool tscColumnExists(SArray* pColumnList, SColumnIndex* pColIndex) {
+  // ignore the tbname columnIndex to be inserted into source list
+  if (pColIndex->columnIndex < 0) {
+    return false;
+  }
+  
+  size_t numOfCols = taosArrayGetSize(pColumnList);
+  int16_t col = pColIndex->columnIndex;
+
+  int32_t i = 0;
+  while (i < numOfCols) {
+    SColumn* pCol = taosArrayGetP(pColumnList, i);
+    if ((pCol->colIndex.columnIndex != col) || (pCol->colIndex.tableIndex != pColIndex->tableIndex)) {
+      ++i;
+      continue;
+    } else {
+      break;
+    }
+  }
+
+  if (i >= numOfCols || numOfCols == 0) {
+    return false;
+  }
+
+  return true;
+}
+
+
 SColumn* tscColumnListInsert(SArray* pColumnList, SColumnIndex* pColIndex) {
   // ignore the tbname columnIndex to be inserted into source list
   if (pColIndex->columnIndex < 0) {
@@ -1583,7 +1611,25 @@ int32_t tscTagCondCopy(STagCond* dest, const STagCond* src) {
   dest->tbnameCond.uid = src->tbnameCond.uid;
   dest->tbnameCond.len = src->tbnameCond.len;
 
-  memcpy(&dest->joinInfo, &src->joinInfo, sizeof(SJoinInfo));
+  dest->joinInfo.hasJoin = src->joinInfo.hasJoin;
+  
+  for (int32_t i = 0; i < TSDB_MAX_JOIN_TABLE_NUM; ++i) {
+    if (src->joinInfo.joinTables[i]) {
+      dest->joinInfo.joinTables[i] = calloc(1, sizeof(SJoinNode));
+
+      memcpy(dest->joinInfo.joinTables[i], src->joinInfo.joinTables[i], sizeof(SJoinNode));
+
+      if (src->joinInfo.joinTables[i]->tsJoin) {
+        dest->joinInfo.joinTables[i]->tsJoin = taosArrayDup(src->joinInfo.joinTables[i]->tsJoin);
+      }
+
+      if (src->joinInfo.joinTables[i]->tagJoin) {
+        dest->joinInfo.joinTables[i]->tagJoin = taosArrayDup(src->joinInfo.joinTables[i]->tagJoin);
+      }
+    }
+  }
+
+  
   dest->relType = src->relType;
   
   if (src->pCond == NULL) {
@@ -1629,6 +1675,23 @@ void tscTagCondRelease(STagCond* pTagCond) {
     taosArrayDestroy(pTagCond->pCond);
   }
 
+  for (int32_t i = 0; i < TSDB_MAX_JOIN_TABLE_NUM; ++i) {
+    SJoinNode *node = pTagCond->joinInfo.joinTables[i];
+    if (node == NULL) {
+      continue;
+    }
+
+    if (node->tsJoin != NULL) {
+      taosArrayDestroy(node->tsJoin);
+    }
+
+    if (node->tagJoin != NULL) {
+      taosArrayDestroy(node->tagJoin);
+    }
+
+    tfree(node);
+  }
+
   memset(pTagCond, 0, sizeof(STagCond));
 }
 
@@ -2318,16 +2381,21 @@ void tscDoQuery(SSqlObj* pSql) {
 }
 
 int16_t tscGetJoinTagColIdByUid(STagCond* pTagCond, uint64_t uid) {
-  if (pTagCond->joinInfo.left.uid == uid) {
-    return pTagCond->joinInfo.left.tagColId;
-  } else if (pTagCond->joinInfo.right.uid == uid) {
-    return pTagCond->joinInfo.right.tagColId;
-  } else {
+  int32_t i = 0;
+  while (i < TSDB_MAX_JOIN_TABLE_NUM) {
+    SJoinNode* node = pTagCond->joinInfo.joinTables[i];
+    if (node && node->uid == uid) {
+      return node->tagColId;
+    }
+
+    i++;
+  }
+
   assert(0);
   return -1;
-  }
 }
 
+
 int16_t tscGetTagColIndexById(STableMeta* pTableMeta, int16_t colId) {
   int32_t numOfTags = tscGetNumOfTags(pTableMeta);
 

src/inc/taosdef.h

@@ -317,7 +317,7 @@ do { \
 #define TSDB_MAX_DB_QUORUM_OPTION       2
 #define TSDB_DEFAULT_DB_QUORUM_OPTION   1
 
-#define TSDB_MAX_JOIN_TABLE_NUM         5
+#define TSDB_MAX_JOIN_TABLE_NUM         10
 #define TSDB_MAX_UNION_CLAUSE           5
 
 #define TSDB_MAX_BINARY_LEN            (TSDB_MAX_BYTES_PER_ROW-TSDB_KEYSIZE)