From 41b2c2d8fd84a331e8d12ba83a5eed94a3933773 Mon Sep 17 00:00:00 2001
From: Xiaoyu Wang <xiaoyuwang@taosdata.com>
Date: Fri, 31 Mar 2023 16:16:14 +0800
Subject: [PATCH] fix: error in optimizing useless columns for multi-level set
 operators

---
 source/libs/parser/src/parCalcConst.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/source/libs/parser/src/parCalcConst.c b/source/libs/parser/src/parCalcConst.c
index a7f6d7cb3c..c25d0e7036 100644
--- a/source/libs/parser/src/parCalcConst.c
+++ b/source/libs/parser/src/parCalcConst.c
@@ -337,8 +337,14 @@ static SNodeList* getChildProjection(SNode* pStmt) {
 static void eraseSetOpChildProjection(SSetOperator* pSetOp, int32_t index) {
   SNodeList* pLeftProjs = getChildProjection(pSetOp->pLeft);
   nodesListErase(pLeftProjs, nodesListGetCell(pLeftProjs, index));
+  if (QUERY_NODE_SET_OPERATOR == nodeType(pSetOp->pLeft)) {
+    eraseSetOpChildProjection((SSetOperator*)pSetOp->pLeft, index);
+  }
   SNodeList* pRightProjs = getChildProjection(pSetOp->pRight);
   nodesListErase(pRightProjs, nodesListGetCell(pRightProjs, index));
+  if (QUERY_NODE_SET_OPERATOR == nodeType(pSetOp->pRight)) {
+    eraseSetOpChildProjection((SSetOperator*)pSetOp->pRight, index);
+  }
 }
 
 typedef struct SNotRefByOrderByCxt {