fix: unknow db error when query ins_tables with table_name=""

source/libs/parser/src/parUtil.c

@@ -444,7 +444,7 @@ static int32_t getInsTagsTableTargetNameFromOp(int32_t acctId, SOperatorNode* pO
   } else if (QUERY_NODE_VALUE == nodeType(pOper->pRight)) {
     pVal = (SValueNode*)pOper->pRight;
   }
-  if (NULL == pCol || NULL == pVal) {
+  if (NULL == pCol || NULL == pVal || NULL == pVal->literal || 0 == strcmp(pVal->literal, "")) {
     return TSDB_CODE_SUCCESS;
   }
 

tests/script/tsim/query/sys_tbname.sim

@@ -51,6 +51,11 @@ if $data00 != @ins_stables@ then
 	return -1
 endi
 
+sql select * from information_schema.ins_tables where table_name='';
+if $rows != 0 then 
+        return -1
+endi
+
 sql select tbname from information_schema.ins_tables;
 print $rows $data00
 if $rows != 33 then