create proc wsp
@name varchar(50),--商品名称
@cost int --销售量
as
--先得出该货物的库存是否够
declare @spare float --剩余库存
select @spare=sum(j)-sum(c) from t where name=@name
if(@spare>=@cost)
begin
--根据入库日期采用先进先出原则对货物的库存进行处理
update t set c=
case when (select @cost-isnull(sum(j),0)+isnull(sum(c),0) from t where name=@name and jdate<=a.jdate and j!=c)>=0
then a.j
else
case when (select @cost-isnull(sum(j),0)+isnull(sum(c),0) from t where name=@name and jdate<a.jdate and j!=c)<0
then 0
else (select @cost-isnull(sum(j),0)+isnull(sum(c),0)+a.c from t where name=@name and jdate<a.jdate and j!=c)
end
end
from t a where name=@name and j!=c
end
else
raiserror('库存不足',16,1)
return
go