diff --git a/source/dnode/vnode/src/tq/tqRead.c b/source/dnode/vnode/src/tq/tqRead.c
index ee85f42fbd..ea60d0ccc6 100644
--- a/source/dnode/vnode/src/tq/tqRead.c
+++ b/source/dnode/vnode/src/tq/tqRead.c
@@ -695,13 +695,16 @@ int32_t tqRetrieveDataBlock2(SSDataBlock* pBlock, STqReader* pReader) {
             }
 #endif
             if (IS_STR_DATA_TYPE(colVal.type)) {
-              char val[65535 + 2];
-              memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
-              varDataSetLen(val, colVal.value.nData);
-              if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-                goto FAIL;
+              if (colVal.value.pData != NULL) {
+                char val[65535 + 2];
+                memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
+                varDataSetLen(val, colVal.value.nData);
+                if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+                  goto FAIL;
+                }
+              } else {
+                colDataAppendNULL(pColData, i);
               }
-              /*val = colVal.value.pData;*/
             } else {
               if (colDataAppend(pColData, i, (void*)&colVal.value.val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
                 goto FAIL;
@@ -734,11 +737,15 @@ int32_t tqRetrieveDataBlock2(SSDataBlock* pBlock, STqReader* pReader) {
               continue;
             } else if (colVal.cid == pColData->info.colId) {
               if (IS_STR_DATA_TYPE(colVal.type)) {
-                char val[65535 + 2];
-                memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
-                varDataSetLen(val, colVal.value.nData);
-                if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
-                  goto FAIL;
+                if (colVal.value.pData != NULL) {
+                  char val[65535 + 2];
+                  memcpy(varDataVal(val), colVal.value.pData, colVal.value.nData);
+                  varDataSetLen(val, colVal.value.nData);
+                  if (colDataAppend(pColData, i, val, !COL_VAL_IS_VALUE(&colVal)) < 0) {
+                    goto FAIL;
+                  }
+                } else {
+                  colDataAppendNULL(pColData, i);
                 }
                 /*val = colVal.value.pData;*/
               } else {
diff --git a/source/dnode/vnode/src/tq/tqSink.c b/source/dnode/vnode/src/tq/tqSink.c
index 428a1a965a..3e772b1e1c 100644
--- a/source/dnode/vnode/src/tq/tqSink.c
+++ b/source/dnode/vnode/src/tq/tqSink.c
@@ -762,7 +762,6 @@ void tqSinkToTablePipeline2(SStreamTask* pTask, void* vnode, int64_t ver, void*
   tqDebug("vgId:%d, task %d write into table, block num: %d", TD_VID(pVnode), pTask->taskId, blockSz);
 
   void*        pBuf = NULL;
-  int32_t      len = 0;
   SSubmitReq2* pReq = NULL;
   SArray*      tagArray = NULL;
   SArray*      pVals = NULL;
@@ -931,6 +930,7 @@ void tqSinkToTablePipeline2(SStreamTask* pTask, void* vnode, int64_t ver, void*
       taosMemoryFree(pTbData);
 
       // encode
+      int32_t len;
       int32_t code;
       tEncodeSize(tEncodeSSubmitReq2, pReq, len, code);
       SEncoder encoder;