--示意语句
一个入库表,一个出库表,数据量大时每月生成结余表!
SELECT SUM(A.QTY) AS 库存数
FROM
(
SELECT 期初量 AS QTY ,GOODSID
FROM STOCK
UNION ALL
SELECT 入库数 as QTY,GOODSID --入库表
FROM INStock
UNION ALL
SELECT -入库数 as QTY,GOODSID --出库表
FROM OUTStock
) A
GROUP BY GOODSID)
一个入库表,一个出库表,数据量大时每月生成结余表!
SELECT SUM(A.QTY) AS 库存数
FROM
(
SELECT 期初量 AS QTY ,GOODSID
FROM STOCK
UNION ALL
SELECT 入库数 as QTY,GOODSID --入库表
FROM INStock
UNION ALL
SELECT -入库数 as QTY,GOODSID --出库表
FROM OUTStock
) A
GROUP BY GOODSID)
OUTStock中的出库写成入库了!!