enh: improve error reporting information

source/libs/parser/src/parInsertSql.c

@@ -1492,6 +1492,7 @@ static void resetEnvPreTable(SInsertParseContext* pCxt, SVnodeModifyOpStmt* pStm
   pStmt->pBoundCols = NULL;
   pStmt->usingTableProcessing = false;
   pStmt->fileProcessing = false;
+  pStmt->usingTableName.type = 0;
 }
 
 // input pStmt->pSql: [(field1_name, ...)] [ USING ... ] VALUES ... | FILE ...
@@ -1539,6 +1540,10 @@ static int32_t checkTableClauseFirstToken(SInsertParseContext* pCxt, SVnodeModif
     }
   }
 
+  if (TK_NK_ID != pTbName->type && TK_NK_STRING != pTbName->type) {
+    return buildSyntaxErrMsg(&pCxt->msg, "table_name is expected", pTbName->z);
+  }
+
   *pHasData = true;
   return TSDB_CODE_SUCCESS;
 }