sql高手请进~~~（exists和赋值的问题）
declare @ID bigint
if exists (select @ID=ID
from dbo.T_D_TA_WareHouseIn
where
MakerItemCD=@MakerItemCD and
Amount=@Amount and
MakeDate=@MakeDate and
BoxNo=@BoxNo and
UseFlag= ' ')
为什么加上@ID就不对呢，赋值的时候不能和exists共用还是怎么回事啊，帮帮忙啊
[解决办法]
declare @ID bigint
select @ID=ID
from dbo.T_D_TA_WareHouseIn
where
MakerItemCD=@MakerItemCD and
Amount=@Amount and
MakeDate=@MakeDate and
BoxNo=@BoxNo and
UseFlag= ' ')
if @ID is null then print '不存在 ' else print cast(@ID as varchar)
