Question

我有users表和3个用户收入表我要做的是根据这3张表选择收入最高的前10位用户我从昨天起就一直在努力解决这个问题，我无法让它发挥作用我想将这3个收入表总计为总数。

对此有任何帮助吗？

SELECT 
    users.first_name, 
    users.last_name,
    (select SUM(`value`) from `earnings1`  where users.id = earnings1.user)  as earnings1,
    (select SUM(`value`) from `earnings2`  where users.id = earnings2.user)  as earnings2,
    (select SUM(`value`) from `earnings3`  where users.id = earnings3.user)  as earnings3,
    (earnings1 + earnings2 + earnings3) as total    
FROM users   
GROUP BY users.id
ORDER BY total DESC    
LIMIT 10

我现在得到的错误是：

未知栏目＆＃39;收入1＆＃39;在＆＃39;字段列表＆＃39;

Answer 1

这应该适合你：

select first_name, last_name, 
(earnings1 + earnings2 + earnings3) total from
(select users.id, users.first_name, users.last_name,
(select sum(`value`) from `earnings1` where users.id = earnings1.user) as earnings1,
(select sum(`value`) from `earnings2` where users.id = earnings2.user) as earnings2,
(select sum(`value`) from `earnings3` where users.id = earnings3.user) as earnings3
from users group by 1,2,3) t
order by 3 desc limit 10

t 是您从内部查询中为结果集提供的名称。它有点类似于公用表表达式但不精确。 MySQL要求您为此结果集命名。

1,2,3 您可以使用1,2,3或者您可以使用列名 users.id，users.first_name，users.last_name 作为您的分组列。 1,2,3表示select语句中的第一，第二和第三列。

从3个表中获得总收入

1 个答案: