From a4a991207bd481bb3bb96921e85532eaf40633bd Mon Sep 17 00:00:00 2001
From: starocean999 <40539150+starocean999@users.noreply.github.com>
Date: Thu, 3 Nov 2022 10:26:59 +0800
Subject: [PATCH] [fix](agg)fix group by constant value bug (#13827)

* [fix](agg)fix group by constant value bug

* keep only one const grouping exprs if no agg exprs
---
 .../org/apache/doris/analysis/SelectStmt.java |  7 +++++-
 .../sql/group_by/runConstantGroupBy_order.out | 24 -------------------
 2 files changed, 6 insertions(+), 25 deletions(-)

diff --git a/fe/fe-core/src/main/java/org/apache/doris/analysis/SelectStmt.java b/fe/fe-core/src/main/java/org/apache/doris/analysis/SelectStmt.java
index f522dcd898..55aebf9280 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/analysis/SelectStmt.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/analysis/SelectStmt.java
@@ -1092,8 +1092,13 @@ public class SelectStmt extends QueryStmt {
 
             substituteOrdinalsAliases(groupingExprs, "GROUP BY", analyzer);
 
-            if (!groupByClause.isGroupByExtension()) {
+            if (!groupByClause.isGroupByExtension() && !groupingExprs.isEmpty()) {
+                ArrayList<Expr> tempExprs = new ArrayList<>(groupingExprs);
                 groupingExprs.removeIf(Expr::isConstant);
+                if (groupingExprs.isEmpty() && aggExprs.isEmpty()) {
+                    // should keep at least one expr to make the result correct
+                    groupingExprs.add(tempExprs.get(0));
+                }
             }
 
             if (groupingInfo != null) {
diff --git a/regression-test/data/trino_p0/sql/group_by/runConstantGroupBy_order.out b/regression-test/data/trino_p0/sql/group_by/runConstantGroupBy_order.out
index 3e7855ddba..6a880dbc0a 100644
--- a/regression-test/data/trino_p0/sql/group_by/runConstantGroupBy_order.out
+++ b/regression-test/data/trino_p0/sql/group_by/runConstantGroupBy_order.out
@@ -1,28 +1,4 @@
 -- This file is automatically generated. You should know what you did if you want to edit this
 -- !runConstantGroupBy_order --
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