CREATE VIEW viewInv AS SELECT R.number,qtyRece-qtyShip FROM viewRece R LEFT JOIN viewShip S ON R.number=S.number
数据库如下:
viewRece
number qtyRece
11 400
12 300
viewShip
number qtyShip
11 200
结果是:
number qtyRece-qtyShip
11 200
12 NULL我希望的结果是number qtyRece-qtyShip
11 200
12 300
数据库如下:
viewRece
number qtyRece
11 400
12 300
viewShip
number qtyShip
11 200
结果是:
number qtyRece-qtyShip
11 200
12 NULL我希望的结果是number qtyRece-qtyShip
11 200
12 300
SELECT R.number,qtyRece-IFNULL(qtyShip,0)
FROM viewRece R LEFT JOIN viewShip S ON R.number=S.number