从子查询中删除数据返回0已擦除

Question

我无法弄清楚这个查询中的错误！为什么这一行返回0但我的数据仍然存在？有人可以帮忙吗？

DELETE FROM tasks 
WHERE  task_id = 50 
AND createdby IN((SELECT u1.user_id 
                  FROM   users u1 
                  WHERE  u1.user_team IN(SELECT u2.user_team 
                                         FROM   users u2 
                                         WHERE  u2.user_role <= (SELECT u3.user_id 
                                                                 FROM users u3 
                                                                 WHERE u3.user_id = 1))))