SQL 触发器的编写问题

[douliang]

现在要编写一个触发器在表Case上，触发的事件是delete.如果
deleted中一个字段ID（int 4）不为空(NULL)的话,就要删除表Link
中所有LID(int 4)等于该值的纪录。

注：delete是一条一条删除的

也不复杂阿，不过我是刚开始写触发器，判断deleted里的一个字段
是否为空----该怎么写?我查了一些T-SQL的语法，没有找到。

请大家帮帮我。

[IronPromises]

......
delete l from Link l,deleted d
where l.LID = d.ID and d.ID is not null
......

[caiyunxia]

CREATE TRIGGER tr_case_del ON [case]
FOR DELETE
if exists(select * from delete where id is not null)
delete from link where lid in (select id from deleted )

[j9988]

create trigger t1 on T_case
for deleted
as
delete from link a,deleted b where a.lid=b.id and b.id<>null

[IronPromises]

and d.ID is not null
这个条件不写也可。

[j9988]

铁斑好快! 我的错了....
create trigger t1 on T_case
for deleted
as
delete from link a,deleted b where a.lid=b.id and b.id is not null

[j9988]

对! is not null 可不写

[IronPromises]

呵呵，j9988，你也很快呀。和我是同一分钟的。

[AWP365]

delete from link where lid in (select id from deleted where id is not null )

你们写的我怎么刊布明白阿，能不能解释以下阿，我的这个行不行？

[IronPromises]

BluePig(吹猪) :

行