From 4e48e1ffad477ff78aa2a3e6d68c73ea332321ef Mon Sep 17 00:00:00 2001
From: Jussi Saurio <jussi.saurio@gmail.com>
Date: Tue, 28 Oct 2025 11:47:15 +0200
Subject: [PATCH] Make an exception for Expr::SubqueryResult in
 collect_result_columns()

---
 core/translate/group_by.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/core/translate/group_by.rs b/core/translate/group_by.rs
index 19f91c5bc..5d7524d40 100644
--- a/core/translate/group_by.rs
+++ b/core/translate/group_by.rs
@@ -321,6 +321,8 @@ fn collect_non_aggregate_expressions<'a>(
     Ok(())
 }
 
+/// Collects columns from different parts of a SELECT that are needed for
+/// GROUP BY.
 fn collect_result_columns<'a>(
     root_expr: &'a ast::Expr,
     plan: &SelectPlan,
@@ -337,6 +339,13 @@ fn collect_result_columns<'a>(
                     result_columns.push(expr);
                 }
             }
+            // SubqueryResult is an exception because we can't "extract" columns from it
+            // unlike other expressions like function calls or direct column references,
+            // so we must add it so that the subquery result gets collected to the GROUP BY
+            // columns.
+            ast::Expr::SubqueryResult { .. } => {
+                result_columns.push(expr);
+            }
             _ => {
                 if plan.aggregates.iter().any(|a| a.original_expr == *expr) {
                     return Ok(WalkControl::SkipChildren);