From 21ecacf40e04412eab7ca6a5875e2150e20d46c2 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 26 Jan 2022 15:53:08 +0800
Subject: [PATCH] [td-13288]fix crash when querying empty child table.

---
 source/libs/executor/src/executorimpl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 1322ec6b83..836b17a868 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -5896,7 +5896,7 @@ static SSDataBlock* doAggregate(void* param, bool* newgroup) {
   finalizeQueryResult(pOperator, pInfo->pCtx, &pInfo->resultRowInfo, pInfo->rowCellInfoOffset);
   pInfo->pRes->info.rows = getNumOfResult(pInfo->pCtx, pOperator->numOfOutput);
 
-  return pInfo->pRes;
+  return (pInfo->pRes->info.rows != 0)? pInfo->pRes:NULL;
 }
 
 static SSDataBlock* doSTableAggregate(void* param, bool* newgroup) {