善用临时表---同时查询多张表的存储过程

一个存储过程的需求是这样的：
1、取出三张表里的符合条件的数据，合成一张表，并对这一张表分页；

2、计算合成的这张表总共多少条数据

存储过程语句如下：

Create PROCEDURE  GetAnnouncementList
    @pageSize int,
    @pageIndex int
AS
BEGIN

--不返回影响的行数，提高性能--
    SET NOCOUNT ON;

    declare @rowCount int

--将数据查询出来放入临时表#temptable中，语法：“ select  字段 into 临时表名 from ” --
select ROW_NUMBER()over (order by #temptable.CreatedOn desc)as tempNum, * into #temptable from
(select 'markNews' as mark, News.NewsID,News.NewsTitle,News.CreatedOn from dbo.News where CategoryID ='8b041bf4-24bf-4b35-85c7-f72717dc5752'
union all
select 'markActivity' as mark, Activities.ActivityID,Activities.Subject,Activities.CreatedOn from dbo.Activities where Activities.CheckStatus=1 and IsDeleted=0 and Activities.RealEndTime>(select GETDATE())
union all
select 'markTrain' as mark, Train.TrainID,Train.Subject,Train.CreatedOn from dbo.Train where CheckStatus=1 and Train.PlannedEndTime>(select GETDATE()))as #temptable

--计算临时表中的数据条数--
select @rowCount=COUNT(*) from #temptable

--对临时表中的数据分页读取--
select * from #temptable where #temptable.tempNum>(@pageIndex-1)*@pageSize and #temptable.tempNum<=(@pageIndex*@pageSize)

return @rowCount
END