Question

我想要得到这样的结果

ENTRYPOINT node dist/main.js

我尝试使用的查询

result 
-------------------------------------------------------
id | uuid | user_id |created_date |    amount    | name 
-------------------------------------------------------
1  | ABC  |    1    |   2019/5/1  |      5       | xa
2  | PQR  |    2    |   2019/5/5  |      150     | xb

数据库中的表结构

SELECT(SELECT SUM(paid_amount) WHERE ID = t1.**HERE**) AS sub1,
(t1.amount - sub1) AS sub2
FROM invoice t1 CROSS JOIN
invoice_paid t2;

我只能使用总和1个条件，例如id = 1，但是如何在选择查询中将此查询与联接查询结合起来。我使用beego（golang），MariaDB

Answer 1

您可以使用此查询。它将invoice表加入到SUM每张发票的所有已支付金额的invoice_paid s的派生表中，从发票金额中减去该总数即可得到未付金额：

SELECT i.id, i.uuid, i.user_id, i.created_date, i.amount - COALESCE(p.amount, 0) AS amount, i.name
FROM invoice i
LEFT JOIN (SELECT uuid, SUM(paid_amount) AS amount
           FROM invoice_paid
           GROUP BY uuid) p ON p.uuid = i.uuid
ORDER BY i.id

输出：

id  uuid    user_id created_date        name    amount
1   ABC     1       2019-05-01 00:00:00 xa      5
2   PQR     2       2019-05-05 00:00:00 xb      150

Demo on dbfiddle

如何在选择查询MySQL，Beego中选择特定ID的总和

1 个答案: