SQLServer中用先进先出思想求成本价和平均成本单价

1、首先是创建表：

create table #in
(
id int identity(1,1),
TDate datetime not null,
goodcode varchar(10) ,
InNum decimal(20,4) null, --入库数量
Price money null --入库金额
)
 

create table #out
(
id int identity(1,1),
TDate datetime not null,
goodcode varchar(10) ,
OutNum decimal(20,4) null, --出库数量
salePrice money null, --销售价
costprice money null, --求成本价
costmoney money null --求成本金额
)

2、插入表数据：

--入库
insert into #in(tdate,goodcode,InNum,Price) values('2016-1-1','001',10,5)
insert into #in(tdate,goodcode,InNum,Price) values('2016-1-25','001',60,6)
insert into #in(tdate,goodcode,InNum,Price) values('2016-3-1','002',20,5.5)
insert into #in(tdate,goodcode,InNum,Price) values('2016-1-18','001',30,6)
insert into #in(tdate,goodcode,InNum,Price) values('2016-4-1','001',40,8)

--出库
insert into #out(tdate,goodcode,outnum,salePrice,costprice) values('2016-1-2','001',30,6,0)
insert into #out(tdate,goodcode,outnum,salePrice,costprice) values('2016-4-1','001',40,8,0)

select * from #in order by tdate
select * from #out order by tdate

3、

--按 先进先出法 算成本价
/*
1 2016-01-02 00:00:00.000 001 30.0000 6.0000 .0000 = （10*5 + 20 *6 ）/30
成本金额 = 10*5 + 20 *6
2 2016-04-01 00:00:00.000 001 40.0000 8.0000 .0000 = （10*6 + 30 *6 ）/40
成本金额 = 10*6 + 30 *6
*/

SELECT 
    o.id,o.tdate,o.goodcode,o.outnum,o.salePrice
    ,costprice=CAST(SUM((CASE WHEN i.SumInNum>o.Sumoutnum THEN o.Sumoutnum ELSE i.SumInNum END -CASE WHEN o.Sumoutnum-o.OutNum>i.SumInNum-i.InNum 
     THEN o.Sumoutnum-o.OutNum ELSE i.SumInNum-i.InNum END)*i.Price)/o.outnum AS MONEY)
    ,costmoney=CAST(SUM((CASE WHEN i.SumInNum>o.Sumoutnum THEN o.Sumoutnum ELSE i.SumInNum END -CASE WHEN o.Sumoutnum-o.OutNum>i.SumInNum-i.InNum
    THEN o.Sumoutnum-o.OutNum ELSE i.SumInNum-i.InNum END)*i.Price) AS MONEY)
FROM 
(SELECT *,SumInNum=(SELECT SUM(InNum) FROM #in WHERE goodcode=i.goodcode AND id<=i.id) FROM #in AS i) AS i,
(SELECT *,Sumoutnum=(SELECT SUM(outnum) FROM #out WHERE goodcode=i.goodcode AND id<=i.id) FROM #out AS i) AS o
WHERE i.goodcode=o.goodcode AND i.SumInNum-i.InNum<o.Sumoutnum AND o.Sumoutnum-o.OutNum<i.SumInNum
GROUP BY o.id,o.tdate,o.goodcode,o.outnum,o.salePrice

/*
id    tdate    goodcode    outnum    salePrice    costprice    costmoney
1    2016-01-02 00:00:00.000    001    30.0000    6.00    5.6667    170.00
2    2016-04-01 00:00:00.000    001    40.0000    8.00    6.00    240.00
*/