exclude ORDER BY clause when querying Relation#exists?

2 files changed, 6 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 7eeb3dde70..3c8e0f2052 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -191,7 +191,7 @@ module ActiveRecord
 
       join_dependency = construct_join_dependency_for_association_find
       relation = construct_relation_for_association_find(join_dependency)
-      relation = relation.except(:select).select("1").limit(1)
+      relation = relation.except(:select, :order).select("1").limit(1)
 
       case id
       when Array, Hash
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 3088ab012f..69754d23b9 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -57,6 +57,11 @@ class FinderTest < ActiveRecord::TestCase
     assert Topic.first.replies.exists?
   end
 
+  # ensures +exists?+ runs valid SQL by excluding order value
+  def test_exists_with_order
+    assert Topic.order(:id).uniq.exists?
+  end
+
   def test_does_not_exist_with_empty_table_and_no_args_given
     Topic.delete_all
     assert !Topic.exists?