enh: ignore single row null data type validation

source/common/src/tdataformat.c

@@ -2503,9 +2503,11 @@ _exit:
 int32_t tColDataAddValueByBind(SColData *pColData, TAOS_MULTI_BIND *pBind) {
   int32_t code = 0;
 
+  if (!(pBind->num == 1 && pBind->is_null && *pBind->is_null)) {
     ASSERT(pColData->type == pBind->buffer_type);
+  }
   
-  if (IS_VAR_DATA_TYPE(pBind->buffer_type)) {  // var-length data type
+  if (IS_VAR_DATA_TYPE(pColData->type)) {  // var-length data type
     for (int32_t i = 0; i < pBind->num; ++i) {
       if (pBind->is_null && pBind->is_null[i]) {
         code = tColDataAppendValueImpl[pColData->flag][CV_FLAG_NULL](pColData, NULL, 0);

source/libs/parser/src/parInsertStmt.c

@@ -251,7 +251,7 @@ int32_t qBindStmtColsValue(void* pBlock, TAOS_MULTI_BIND* bind, char* msgBuf, in
       goto _return;
     }
 
-    if (bind[c].buffer_type != pColSchema->type) {
+    if ((!(rowNum == 1 && bind[c].is_null && *bind[c].is_null)) && bind[c].buffer_type != pColSchema->type) { // for rowNum ==1 , connector may not set buffer_type
       code = buildInvalidOperationMsg(&pBuf, "column type mis-match with buffer type");
       goto _return;
     }