/*--示例
--出处:邹建
在代码中，首先定义了一个最简单的出入库数据记录明细表（tb），用来记录每笔出入库的交易情况。
明细帐查询要求得到每种Item每天的期初数量、当天进货数、进货退回数、出货数、出货退回数及当天结余数。
--*/
--明细帐数据
CREATE TABLE tb(
ID int IDENTITY PRIMARY KEY,
Item varchar(10), --产品编号
Quantity int, --交易数量
Flag bit, --交易标志,1代表入库,0代表出库,这样可以有效区分退货(负数)
Date datetime) --交易日期
INSERT tb SELECT 'aa',100,1,'2005-1-1'
UNION ALL SELECT 'aa',90 ,1,'2005-2-1'
UNION ALL SELECT 'aa',55 ,0,'2005-2-1'
UNION ALL SELECT 'aa',-10,1,'2005-2-2'
UNION ALL SELECT 'aa',-5 ,0,'2005-2-3'
UNION ALL SELECT 'aa',200,1,'2005-2-2'
UNION ALL SELECT 'aa',90 ,1,'2005-2-1'
UNION ALL SELECT 'bb',95 ,1,'2005-2-2'
UNION ALL SELECT 'bb',65 ,0,'2005-2-3'
UNION ALL SELECT 'bb',-15,1,'2005-2-5'
UNION ALL SELECT 'bb',-20,0,'2005-2-5'
UNION ALL SELECT 'bb',100,1,'2005-2-7'
UNION ALL SELECT 'cc',100,1,'2005-1-7'
GO
--select * from TB
--结果
ID Item Quantity Flag Date
----------- ---------- ----------- ---- ------------------------------------------------------
1 aa 100 1 2005-01-01 00:00:00.000
2 aa 90 1 2005-02-01 00:00:00.000
3 aa 55 0 2005-02-01 00:00:00.000
4 aa -10 1 2005-02-02 00:00:00.000
5 aa -5 0 2005-02-03 00:00:00.000
6 aa 200 1 2005-02-02 00:00:00.000
7 aa 90 1 2005-02-01 00:00:00.000
8 bb 95 1 2005-02-02 00:00:00.000
9 bb 65 0 2005-02-03 00:00:00.000
10 bb -15 1 2005-02-05 00:00:00.000
11 bb -20 0 2005-02-05 00:00:00.000
12 bb 100 1 2005-02-07 00:00:00.000
13 cc 100 1 2005-01-07 00:00:00.000
--查询时间段定义
DECLARE @dt1 datetime,@dt2 datetime
SELECT @dt1='2005-2-1',@dt2='2005-2-10'
--查询
--统计时间段内无发生额的数据(如果这个不是查询需要的,去掉这段查询)
SELECT Item,
Date=CONVERT(char(10),@dt1,120),
Opening=SUM(CASE WHEN Flag=1 THEN Quantity ELSE -Quantity END),
[IN]=0,
[IN_Retrun]=0,
[OUT]=0,
[OUT_Return]=0,
Balance=SUM(CASE WHEN Flag=1 THEN Quantity ELSE -Quantity END)
FROM tb a
WHERE Date<@dt1 AND NOT EXISTS(
SELECT * FROM tb WHERE Item=a.Item AND Date>@dt1 AND Date<DATEADD(Day,1,@dt2))
GROUP BY Item
UNION ALL
--指定时间段内有交易发生的数据
SELECT Item,
Date=CONVERT(char(10),Date,120),
Opening=ISNULL((SELECT SUM(CASE WHEN Flag=1 THEN Quantity ELSE -Quantity END)
FROM tb WHERE Item=a.Item AND Date<MIN(a.Date)),0),
[IN]=ISNULL(SUM(CASE WHEN Flag=1 AND Quantity>0 THEN Quantity END),0),
[IN_Retrun]=ISNULL(SUM(CASE WHEN Flag=1 AND Quantity<0 THEN -Quantity END),0),
[OUT]=ISNULL(SUM(CASE WHEN Flag=0 AND Quantity>0 THEN Quantity END),0),
[OUT_Return]=ISNULL(SUM(CASE WHEN Flag=0 AND Quantity<0 THEN -Quantity END),0),
Balance=ISNULL((SELECT SUM(CASE WHEN Flag=1 THEN Quantity ELSE -Quantity END)
FROM tb WHERE Item=a.Item AND Date<=MAX(a.Date)),0)
FROM tb a
WHERE Date>=@dt1 AND Date<DATEADD(Day,1,@dt2)
GROUP BY CONVERT(char(10),Date,120),Item
ORDER BY Item,Date
--结果
Item Date Opening IN IN_Retrun OUT OUT_Return Balance
---------- ---------- ----------- ----------- ----------- ----------- ----------- -----------
aa 2005-02-01 100 180 0 55 0 225
aa 2005-02-02 225 200 10 0 0 415
aa 2005-02-03 415 0 0 0 5 420
bb 2005-02-02 0 95 0 0 0 95
bb 2005-02-03 95 0 0 65 0 30
bb 2005-02-05 30 0 15 0 20 35
bb 2005-02-07 35 100 0 0 0 135
cc 2005-02-01 100 0 0 0 0 100
（所影响的行数为 8 行）
