@@ -744,7 +744,7 @@ id select_type table type possible_keys key key_len ref rows Extra
3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
Warnings:
Note 1003 select `test`.`t2`.`id` AS `id` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`id`,<exists>(select 1 AS `Not_used` having (<cache>(`test`.`t2`.`id`) = <null_helper>(1)) union select 1 AS `Not_used` having (<cache>(`test`.`t2`.`id`) = <null_helper>(3))))
Note 1003 select `test`.`t2`.`id` AS `id` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`id`,<exists>(select 1 AS `1` having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(1)) union select 3 AS `3` having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(3))))
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 3);
id
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 2);