support join for json tag

src/client/src/tscSQLParser.c

@@ -4025,6 +4025,9 @@ static int32_t checkAndSetJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tS
 
   (*leftNode)->uid = pTableMetaInfo->pTableMeta->id.uid;
   (*leftNode)->tagColId = pTagSchema1->colId;
+  if(pLeft->tokenId == TK_ARROW) {
+    tstrncpy((*leftNode)->tagJsonKeyName, pExpr->pLeft->pRight->value.pz, TSDB_MAX_JSON_KEY_LEN + 1);
+  }
 
   if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
     STableMeta* pTableMeta = pTableMetaInfo->pTableMeta;
@@ -4059,6 +4062,9 @@ static int32_t checkAndSetJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tS
 
   (*rightNode)->uid = pTableMetaInfo->pTableMeta->id.uid;
   (*rightNode)->tagColId = pTagSchema2->colId;
+  if(pRight->tokenId == TK_ARROW) {
+    tstrncpy((*rightNode)->tagJsonKeyName, pRight->pLeft->pRight->value.pz, TSDB_MAX_JSON_KEY_LEN + 1);
+  }
 
   if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
     STableMeta* pTableMeta = pTableMetaInfo->pTableMeta;
@@ -4304,6 +4310,7 @@ static bool validateJoinExprNode(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr
   const char* msg5 = "join table must be the same type(table to table, super table to super table)";
   const char* msg6 = "tag json key must be string";
   const char* msg7 = "tag json key in json must be same";
+  const char* msg8 = "tag json key is too long, no more than 256 bytes";
 
   tSqlExpr* pRight = pExpr->pRight;
   if(pRight->tokenId == TK_ARROW){
@@ -4311,11 +4318,15 @@ static bool validateJoinExprNode(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSqlExpr
       invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg6);
       return false;
     }
-   if(pExpr->pLeft->pRight->value.nLen != pExpr->pRight->pRight->value.nLen
+    if(pExpr->pLeft->pRight->value.nLen > TSDB_MAX_JSON_KEY_LEN){
+      invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg8);
+      return false;
+    }
+    if(pExpr->pLeft->pRight->value.nLen != pExpr->pRight->pRight->value.nLen
         || strncmp(pExpr->pLeft->pRight->value.pz, pExpr->pRight->pRight->value.pz, pExpr->pRight->pRight->value.nLen) != 0){
      invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg7);
      return false;
-   }
+    }
 
     pRight = pExpr->pRight->pLeft;
   }

src/client/src/tscSubquery.c

@@ -1912,7 +1912,12 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter
 
       // set get tags query type
       TSDB_QUERY_SET_TYPE(pNewQueryInfo->type, TSDB_QUERY_TYPE_TAG_FILTER_QUERY);
-      tscAddFuncInSelectClause(pNewQueryInfo, 0, TSDB_FUNC_TID_TAG, &colIndex, &s1, TSDB_COL_TAG, getNewResColId(pCmd));
+      SExprInfo* pExpr = tscAddFuncInSelectClause(pNewQueryInfo, 0, TSDB_FUNC_TID_TAG, &colIndex, &s1, TSDB_COL_TAG, getNewResColId(pCmd));
+      if(strlen(pTagCond->joinInfo.joinTables[0]->tagJsonKeyName) > 0){
+        tVariantCreateFromBinary(&(pExpr->base.param[pExpr->base.numOfParams]), pTagCond->joinInfo.joinTables[0]->tagJsonKeyName,
+           strlen(pTagCond->joinInfo.joinTables[0]->tagJsonKeyName), TSDB_DATA_TYPE_BINARY);
+        pExpr->base.numOfParams++;
+      }
       size_t numOfCols = taosArrayGetSize(pNewQueryInfo->colList);
   
       tscDebug(

src/query/inc/qTableMeta.h

@@ -28,6 +28,7 @@ typedef struct STblCond {
 typedef struct SJoinNode {
   uint64_t uid;
   int16_t  tagColId;
+  char  tagJsonKeyName[TSDB_MAX_JSON_KEY_LEN + 1];   // for tag json key
   SArray*  tsJoin;
   SArray*  tagJoin;
 } SJoinNode;