请帮忙看一下这个触发器

[TsungLee]

declare @writer bigint,@blackcount varchar,@sql varchar
set @writer=(select writer from B_mail where autoid=(select mailid from inserted))
set @sql=' ''%,'+str(@writer)+',%'' '

set @blackcount=(select count(*) from B_users where username=(select username from inserted) and blackmaillist like @sql)

if (@blackcount)<>'0'
delete from B_mailbox where autoid=(select autoid from inserted)



执行的时候，@blackcount总是为0，就是说(select count(*) from B_users where username=(select username from inserted) and blackmaillist like @sql)总是查不到结果。实际上是应该有的。
请大家帮忙看一下是什么问题。我想可能是like那里的单引号没处理好，但也不知道怎么弄了。

[samfeng_2003]

set @sql='%'+str(@writer)+'% '

这样试试呢？

[TsungLee]

不行啊

[WangZWang]

set @sql=' ''%,'+str(@writer)+',%'' '

--------改为

set @sql='%,'+cast(@writer as varchar)+',%'
--即可

[zlp321002]

set @blackcount=(select count(*) from B_users where username=(select username from inserted) and blackmaillist like @sql)

======
set @blackcount=(select count(*) from B_users where username=(select username from inserted) and blackmaillist like '%'+@sql+'%')

[TsungLee]

之前的@blackcount总是为0。
按WangZWang(阿来) 的方法去做，@blackcount就变得都不为0 了。

[-狙击手-]

set @writer=(select top 1 writer from B_mail where autoid=(select mailid from inserted))
set @sql=' ''%,'+str(rtrim(@writer))+',%'' '