如何通过聚合对特定用户组合的值求和

Question

我有 3 个表和以下条目：

*users [id, name]*
insert into users (1, 'jack')

*portfolios [id, user_id, status]*
insert into portfolios (1, 1, 'active')
insert into portfolios (2, 1, 'active')

*deposits [id, portfolio_id, amount]*
insert into deposits (1, 1, 10)
insert into deposits (2, 2, 5)

*users [id, name]*
insert into users (2, 'jill')

*portfolios [id, user_id, status]*
insert into portfolios (3, 2, 'active')
insert into portfolios (4, 2, 'pending')

insert into deposits (3, 3, 3)
insert into deposits (4, 4, 4)

我需要创建一个查询来显示每个用户的总金额，其中连接的投资组合是“活跃的”。基本上，根据上面的插入，我应该：

name: 'jack', total_amount: 15
name: 'jill', total_amount: 3

我需要使用聚合吗？

Answer 1

查询应该是

SELECT u.name, SUM(d.amount) as total_amount FROM users u, deposits d, portfolios p
 WHERE u.id=p.user_id and p.id=d.portfolio_id and p.status='active'
 GROUP BY  u.id

Answer 2

您应该加入，最好是显式加入，过滤 active portfolio.status 在 users.name 上聚合并求和 deposits.amount

select 
users.name, sum(deposits.amount) as total_amount /*each distinct user and the sum for their amount*/
from users
inner join  portfolio on users.id = portfolio.user_id  /*use explicit joins on corresponding ids*/
inner join  deposits on portfolio.id = deposits.portfolio_id
where portfolio.status = 'active' /*filter for active only*/
group by users.name  /*this gives unique list of users*/

如何通过聚合对特定用户组合的值求和

How to sum values for specific user portfolios with aggregation

mysql

sql