mysql - Sql 连接三表

Question

这个问题已经有答案了:

Joining three tables using MySQL (11 个回答)

已关闭 6 年前。

这是我的表格..我想要这个输出:

pid | pname | custname | quantity | total base price | sale price | profit

架构:

create table customers
(
    cid int,
    cname varchar(1000),
    cg varchar(1000)
)

create table prod
(
    pid int,
    pname varchar(1000),
    baseprice int,
    saleprice int
)

create table orders
(
    oid int,
    custid int,
    pid int,
    quantity int,
    odate date
)

如何为此编写查询？

Answer 1

--pid | pname | custname | quantity | total base price | sale price | profit
select o.pid, p.pname, c.cname AS custname, SUM(o.quantity) AS quantity, 
SUM(p.baseprice) AS 'total base price', SUM(p.saleprice) AS 'sale price', 
SUM(p.baseprice) - SUM(p.saleprice) AS profit -- change this math to what you need
from orders o join prod p
on o.pid = p.pid
join customers c
on o.custid = c.cid
group by o.pid, p.pname, c.cname