fix(query): copy the hasNull attribute to destination SColumnInfoData.

source/common/src/tdatablock.c

@@ -311,6 +311,8 @@ int32_t colDataAssign(SColumnInfoData* pColumnInfoData, const SColumnInfoData* p
     memcpy(pColumnInfoData->pData, pSource->pData, pSource->info.bytes * numOfRows);
   }
 
+  pColumnInfoData->hasNull = pSource->hasNull;
+  pColumnInfoData->info = pSource->info;
   return 0;
 }
 

source/libs/executor/src/groupoperator.c

@@ -220,7 +220,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SSDataBlock* pBlock) {
     }
 
     // The first row of a new block does not belongs to the previous existed group
-    if (!equal && j == 0) {
+    if (j == 0) {
       num++;
       recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j, numOfGroupCols);
       continue;