refactor: do some internal refactor.

source/libs/executor/src/cachescanoperator.c

@@ -46,7 +46,7 @@ SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pScanNode, SRead
   pInfo->pColMatchInfo = extractColMatchInfo(pScanNode->pScanCols, pScanNode->node.pOutputDataBlockDesc, &numOfCols,
                                              COL_MATCH_FROM_COL_ID);
   int32_t* pCols = taosMemoryMalloc(numOfCols * sizeof(int32_t));
-  for (int32_t i = 0; i < numOfCols; ++i) {
+  for (int32_t i = 0; i < taosArrayGetSize(pInfo->pColMatchInfo); ++i) {
     SColMatchInfo* pColMatch = taosArrayGet(pInfo->pColMatchInfo, i);
     pCols[i] = pColMatch->colId;
   }
@@ -56,7 +56,7 @@ SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pScanNode, SRead
     goto _error;
   }
 
-  tsdbLastRowReaderOpen(readHandle->vnode, LASTROW_RETRIEVE_TYPE_ALL, pTableList, pCols, numOfCols,
+  tsdbLastRowReaderOpen(readHandle->vnode, LASTROW_RETRIEVE_TYPE_ALL, pTableList, taosArrayGetSize(pInfo->pColMatchInfo),
                         &pInfo->pLastrowReader);
   taosMemoryFree(pCols);
 

source/libs/executor/src/executorimpl.c

@@ -594,10 +594,14 @@ int32_t projectApplyFunctions(SExprInfo* pExpr, SSDataBlock* pResult, SSDataBloc
       SColumnInfoData* pColInfoData = taosArrayGet(pResult->pDataBlock, outputSlotId);
 
       int32_t offset = createNewColModel ? 0 : pResult->info.rows;
-      for (int32_t i = 0; i < pSrcBlock->info.rows; ++i) {
-        colDataAppend(pColInfoData, i + offset,
-                      taosVariantGet(&pExpr[k].base.pParam[0].param, pExpr[k].base.pParam[0].param.nType),
-                      TSDB_DATA_TYPE_NULL == pExpr[k].base.pParam[0].param.nType);
+
+      int32_t type = pExpr[k].base.pParam[0].param.nType;
+      if (TSDB_DATA_TYPE_NULL == type) {
+        colDataAppendNNULL(pColInfoData, offset, pSrcBlock->info.rows);
+      } else {
+        for (int32_t i = 0; i < pSrcBlock->info.rows; ++i) {
+          colDataAppend(pColInfoData, i + offset, taosVariantGet(&pExpr[k].base.pParam[0].param, type), false);
+        }
       }
 
       numOfRows = pSrcBlock->info.rows;