逐月对比的交叉表处理

/*--原帖地址:
http://community.csdn.net/Expert/topic/3841/3841808.xml?temp=.4308588
--*/

--测试数据
create table tb(year int,month int,No varchar(10),Name varchar(10),部门 varchar(10),工资 int)
insert tb select 2004,10,'A001','AAA','DDD',1000
union all select 2004,10,'B001','BBB','DDD',800
union all select 2004,11,'A001','AAA','DDD',1100
union all select 2004,11,'B001','BBB','DDD',1000
union all select 2004,12,'A001','AAA','DDD',1200
union all select 2004,12,'B001','BBB','DDD',1050

/*--处理要求

 将月份做为字段,并且反应逐月的工资增幅,例如上面的数据要求结果如下,注意最小的年月是没有增幅的

No     Name   部门   2004_10   2004_11  2004_11增幅  2004_12  2004_12增幅 
------ ------ ------ --------- -------- ----------- --------- ------------
A001   AAA    DDD    1000      1100     10.00%      1200      9.09%
B001   BBB    DDD    800       1000     25.00%      1050      5.00%
--*/

go

--查询处理
declare @s nvarchar(4000),@i int
select @s='',@i=0
select @s=@s+','+quotename(fd)
  +'=sum(case when a.year='+year
  +' and a.month='+month
  +' then a.工资 end)'
 +case @i when 0 then ''
  else ','+quotename(fd+'增幅')
   +'=cast(cast(sum(case when a.year='+year
   +' and a.month='+month
   +' then a.工资-b.工资 end)*100.'
   +'/sum(case when a.year='+year
   +' and a.month='+month
   +' then b.工资 end)'
   +' as decimal(10,2)) as varchar)+''%'''
 end,@i=@i+1
from(
 select year=rtrim(year),month=rtrim(month),
  fd=rtrim(year)+'_'+rtrim(month)
 from tb group by year,month)a
exec('select a.No,a.Name,a.部门'+@s+'
from tb a
 left join tb b on a.No=b.No and a.Name=b.Name and a.部门=b.部门
  and a.year=b.year+(b.month)/12
  and a.month=b.month%12+1
 group by a.No,a.Name,a.部门')
go

--删除测试
drop table tb