PRS表数据如下：
SerialNO uType sNO sDate
107792 1 5 20140609
107792 1 3 20140609
107792 2 5 20140610
100785 1 8 20140610
我想用SerialNO相同的，uType类型为1的减去类型是2的，sDate取最大，结果就像这样：
SerialNO sNO sDate
107792 3 20140610
100785 8 20140610
请问这个怎么求？
------解决方案--------------------
select SerialNO,sum(case uType when 2 then -sNo else sNo end),max(sDate)
from PRS
group by SerialNO
------解决方案--------------------
----------------------------------------------------------------
-- Author :DBA_HuangZJ(發糞塗牆)
-- Date :2014-07-07 13:40:35
-- Version:
-- Microsoft SQL Server 2012 - 11.0.5058.0 (X64)
-- May 14 2014 18:34:29
-- Copyright (c) Microsoft Corporation
-- Enterprise Edition: Core-based Licensing (64-bit) on Windows NT 6.3 <X64> (Build 9600: ) (Hypervisor)
--
----------------------------------------------------------------
--> 测试数据：[PRS]
if object_id('[PRS]') is not null drop table [PRS]
go
create table [PRS]([SerialNO] int,[uType] int,[sNO] int,[sDate] datetime)
insert [PRS]
select 107792,1,5,'20140609' union all
select 107792,1,3,'20140609' union all
select 107792,2,5,'20140610' union all
select 100785,1,8,'20140610'
--------------开始查询--------------------------
SELECT SerialNO,SUM(sNO)sNO,MAX([sDate])[sDate]
FROM (
select SerialNO , sNO ,[sDate] from [PRS]
WHERE utype=1
UNION ALL
select SerialNO , -1*sNO ,[sDate] from [PRS]
WHERE utype=2)a
GROUP BY SerialNO
ORDER BY SerialNO DESC
----------------结果----------------------------
/*
SerialNO sNO sDate
----------- ----------- -----------------------
107792 3 2014-06-10 00:00:00.000
100785 8 2014-06-10 00:00:00.000
*/
------解决方案--------------------
SELECT [SerialNO],SUM(CASE uTYPE WHEN 2 THEN -1*sNo ELSE sNo end )AS Quantity,MAX(sDate)sDate
FROM A_J
GROUP BY [SerialNO]
ORDER BY SerialNo desc
