高分求急求过滤号码的一段sql程序（在线等）

[pureblue007]

有两个表，一个表（user)中是大量的手机号码，字段user_num
还有个表(blackuser)是黑名单，也有一些号码，字段blackuser_num
现在要查查user表中的所有手机号码，在blackuser表中是不是存在，如果存在的话，就把该号码从user表中删除掉。
这样的一个需求应该写存储过程还是触发器呢？麻烦帮我写一下吧，谢谢

[lsqkeke]

delete from user a join blackuser b on a.user_num =b.blackuser_num

[-狙击手-]

select distinct a.user_num from user a where user_num in (select blackuser_num from blackuser)

[xueguang]

delete user where user_num in(select blackuser_num from blackuser)

[lsqkeke]

delete from user1
where exists(select * from blackuser where user1.user_num =blackuser.blackuser_num)

[handsome0916]

select user_num from user where user_num not in (select blackuser_num from blackuser)

[pureblue007]

感谢大家！搞定！