diff --git a/project/jimmer-sql/src/test/resources/database.sql b/project/jimmer-sql/src/test/resources/database.sql
index b629f2575..304a7f2b0 100644
--- a/project/jimmer-sql/src/test/resources/database.sql
+++ b/project/jimmer-sql/src/test/resources/database.sql
@@ -1402,6 +1402,10 @@ create table person(
 alter table person
     add constraint pk_person
         primary key(id);
+alter table person
+    add constraint fk_person__friend
+        foreign key(friend_id)
+            references person(id);
 
 insert into person(id, name, friend_id) values
     (1, 'Alex', null),