有这样一个产品进出货表,product是产品名,qty为数量,type表示进或出货:
product qty type
-------------------------
phone 20 in
computer 22 in
phone 15 in
dc 15 in
computer 20 out
dc 30 in
phone 10 out
-------------------------要求编写SQL语句输出如下结构:产品 进货数 库存
-------------------------
phone 35 25
computer 22 2
dc 45 45
-------------------------请教各位大神该怎么写这条SQL?谢谢!
product qty type
-------------------------
phone 20 in
computer 22 in
phone 15 in
dc 15 in
computer 20 out
dc 30 in
phone 10 out
-------------------------要求编写SQL语句输出如下结构:产品 进货数 库存
-------------------------
phone 35 25
computer 22 2
dc 45 45
-------------------------请教各位大神该怎么写这条SQL?谢谢!
from tt group by product
SUM(IIF(type='in',qtp,-1*qty))as库存
FROM tb
GROUP BY product;