如何在select查询MySQL中select特定id的总和，Beego

Question

我想得到这样的结果

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

我尝试使用的查询

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

Table 我的数据库中的结构

table invoice_paid        
------------------------------------
id | uuid | paid_date | paid_amount
------------------------------------
1  | ABC  | 2019/5/1  | 15
2  | ABC  | 2019/5/5  | 80 

table invoice
-------------------------------------------------------
id | uuid | user_id |created_date |    amount    | name 
-------------------------------------------------------
1  | ABC  |    1    |   2019/5/1  |      100     | xa
2  | PQR  |    2    |   2019/5/5  |      150     | xb

我只能使用 sum 1 条件，例如 where id = 1，但我如何将 select 查询中的此查询与连接查询结合起来。我使用 beego(golang)，MariaDB

Answer 1

您可以使用这个查询。它将 invoice table 与从 invoice_paid 中每张发票支付的所有金额的 SUM 派生的 table 相结合，从发票金额中减去该总额获取未结金额：

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select查询MySQL中select特定id的总和，Beego

How to select sum of specific id in select query MySQL, Beego

mysql

go

controller

mariadb

beego