使用mysql在一个查询中在多个表中选择总数

问题描述：

我所有的下午都在尝试处理查询（或两三个），以便获取三个表的所有子元素的计数。看看我的设计：

All my afternoon was consumed trying to deal with a query (or two or three) in order to get the count of all childs of three tables. Take a look to my design:

用户表

id_user | name
1 | foo
2 | bar

wons表

id_won | user
1 | 1
2 | 1
3 | 2

绘制表格

id_draw | user
1 | 1
2 | 2
3 | 2

丢失表格

id_lose | user
1 | 1
2 | 1
3 | 1

我试图得到这样的东西：

I'm trying to get something like this:

name | wons | draws | loses
foo | 2 | 1 | 3
bar | 1 | 2 | 0

这是我的尝试：

select 
    u.name, w.total_w, d.total_d, l.total_l
from 
    user u
    LEFT JOIN 
    (select count(user) as total_w, user from wons group by user) as w
    ON w.user = u.id_user
    LEFT JOIN 
    (select count(user) as total_d, user from draws group by user) as d 
    ON d.user = w.user
    LEFT JOIN 
    (select count(user) as total_l, user from loses group by user) as l 
    ON d.user= .user

group by u.id_user;

答

select u.name, w.uw as wins, l.ul as loses, d.ud as draws from user
    left join (select user, COUNT(id_won) uw from wons group by user) w on w.user = u.user_id
    left join (select user, COUNT(id_lose) ul from loses group by user) l on l.user = u.user_id
    left join (select user, COUNT(id_draw) ud from draws group by user) d on d.user = u.user_id

这只需要所需的工作量为任务。

This one would just the needed amount of work for the task.

使用mysql在一个查询中在多个表中选择总数

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