如何使用SQL语句实现这个功能？

[xiaoxu2002]

从产品的入库表（indepot)中减去产品出库表(outdepot)加上产品库存表(depot)的每种产品数据，得出当前产品的库存信息？如何用SQL语句实现?

[strongfisher]

select sum(indepot.a)-sum(outdepot.a)+sum(depot.a) as 总计 from depot,depot,indepot where indepot.id=outdepot.id and outdepot.id=depot.id

[golden24kcn]

select a.名称,a.库存 + (select sum(b.入库数量) from indepot b where b.id=a.id) - (select C.出库数量 from outdepot c where c.id=a.id) from depot a

试试!!!

[zjcxc]

--SQL数据库
select isnull(a.名称,b.名称,c.名称),a.入库-b.出库+c.库存
from indepot a full join outdepot b on a.名称=b.名称
full join depot c on a.名称=c.名称

[zjcxc]

ACCESS数据库不支持全连接.因此你需要一个商品表.

[zhongminsheng]

从产品的入库表（indepot)中减去产品出库表(outdepot)加上产品库存表(depot)的每种产品数据，得出当前产品的库存信息？如何用SQL语句实现?

select depot.*, rk.rsl as 入库数量,ck.csl as 出库数量,depot.kc+rk.sl-rck.csl as 当前库存 from depot left outer join (select indepot.bh, sum(indepot.sl) as rsl from indepot group by indepot.bh) as rk on rk.bh=depot.bh left outer join (select outdepot.bh, sum(outdepot.sl) as csl from outdepot group by outdepot.bh) as ck on ck.bh=depot.bh