SQL查询问题

[xfj3526]

在SQL中有这样的情况
在表Table_a 中查找以'a'开头的名字
select * from TAble_a where name like 'a%'
但是我如果把a定义成变量
即:
declare @tt varchar (20)
set @tt='a'
再做查询
该如何做?

[中国风]

declare @tt varchar (20)
set @tt='a'
select * from TAble_a where name like @tt+'%'

[userqin]

declare @sql varchar(8000)
declare @tt varchar(20)

set @tt='a'
select @sql='select * from TAble_a where name like '''+@tt+'%'''

exec(@sql)

[IT_zen]

declare @tt nvarchar (20)
set @tt='a'
declare @sql nvarchar(4000)
set @sql = 'select * from TAble_a where name like ''a%'''

exec (@sql)

[IT_zen]

declare @tt nvarchar (20)
set @tt='a'
declare @sql nvarchar(4000)
set @sql = 'select * from TAble_a where name like '''+@tt+'%'''

exec (@sql)