diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 071b034fa298678d83a655a32ce26e39bf195eaf..4fd814ee72cd3735485af1b55410ae9e0bc97c55 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -3947,6 +3947,10 @@ int32_t setShowInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     if (pShowInfo->prefix.type == TK_STRING) {
       pShowInfo->prefix.n = stringProcess(pShowInfo->prefix.z, pShowInfo->prefix.n);
     }
+
+    if (pShowInfo->prefix.n <= 0) {
+      return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg6);
+    }
   } 
   return TSDB_CODE_SUCCESS;
 }