一个令我困惑良久的问题！！！

[pointer111]

我想在一个过程中传递一参数，总是说要申明变量@num.代码如下：
use mydb
go
create procedure kk
@num char（20）
as
alter trigger t1_insert
on t1
for insert
as
update t1 set t1.name='kk'
from t1 inner join inserted i
on t1.name=i.name
go

但如果在下面这个过程中，则完全正确
create procedure kk
@num char（20）
as
select * from t1
where name=@num
go

[guo]

@num没用吗?
join之后的结果也没使用吗?

[pointer111]

打错了，是：
use mydb
go
create procedure kk
@num char（20）
as
alter trigger t1_insert
on t1
for insert
as
update t1 set t1.name=@num
from t1 inner join inserted i
on t1.name=i.name
go

[guo]

我不知道
update t1 set t1.name=@num
from t1 inner join inserted i
on t1.name=i.name
和
update t1 set t1.name=@num
有什么区别

[ylm163net]

奇怪的代码

[RedGuest]

up

[pointer111]

我只是想改变新插入记录的name字段值，而update t1 set t1.name=@num
会改变了所有记录的。而且我问的是为什么每次都提示要定义@num.但是
@num已经在一开头就定义了阿！！！

[guo]

建表:create table t1 (name varchar(20))
建触发器: create trigger t1_insert on t1 for insert
as
update t1 set t1.name='ab' where t1.name in (select i.name from inserted i)
建存储过程
create proc kk @num char(20)
as
declare @sql varchar(100)
set @sql='alter trigger t1_insert on t1 for insert as
update t1 set t1.name='+quotename(@num,'''')+' where t1.name in (select i.name from inserted i)'
exec @sql