sql server 一点小疑点 _Sql Server

sql server 一点小问题在线等
select cValue from dbo.AccInformation where cname like 'iLastPeriod'

select cpdcode,iperiodindex,dbegindate,denddate
from Period 这是两张表
当查询这张表的时候判断 iperiodindex 和 select cValue from dbo.AccInformation where cname like 'iLastPeriod'
这张表的值是否相同自动添加一列来做标记

------解决方案--------------------

SQL code

select cpdcode,iperiodindex,dbegindate,denddate  ,case when iperiodindex = (select top 1 cValue from dbo.AccInformation where cname like 'iLastPeriod') then 1 else 0 end as 标记from Period
------解决方案--------------------
上面效率太差

SQL codedeclare @cValue  varchar(100)  --根据实际修改类型select top 1 @cValue = cValue from dbo.AccInformation where cname like 'iLastPeriod'select cpdcode,iperiodindex,dbegindate,denddate  ,case when iperiodindex = @cValue then 1 else 0 end as 标记from Period