1.CROSS APPLY ：
可以理解成INNER JOIN
适用：
* 表A 存储的是客户信息，每个客户ID一条记录；表B存储的是发布记录，每个客户ID对应多条记录，
需要取出每个客户最新的一条的发布信息记录
* 表A存储多客户发布的多条信息，想取得每个客户最新发布的单条信息
*
代码：
select
distinct info.UserID,id.DisplayDate
from view_InformationSimple as info
CROSS apply(select top(1)DisplayDate,UserId from view_Information as i where i.UserId=info.UserId order by DisplayDate DESC)as idCROSS APPLY ：可以理解成INNER JOIN 例如：select distinct info.UserID,id.DisplayDate from view_InformationSimple as info
CROSS apply(select top(1)DisplayDate,UserId from view_Information as i where i.UserId=info.UserId order by DisplayDate DESC)as id 取得唯一用户的最新发布的信息
Mikel
