MySQL内连接和两列求和

Question

我有以下表格

表格：约会

ID | PRICE | PAID
48 |  100  | 180

表格：约会产品

ID | APPOINTMENT_ID | PRODUCT_ID | TOTAL
10 |       48       |      1     | 30
11 |       48       |      9     | 30
12 |       48       |      6     | 30

我想以某种方式运行一个 MySQL 查询：

a) 加入这两个表，对每个约会 ID 的约会产品的“总计”求和，如果“付费”不等于价格（来自约会表）+总计（来自约会产品表），则显示它。

这是我到目前为止所做的：

select a.*, b.appointment_id as AppId, b.total as ProdTotal 
from appointments a 
INNER JOIN appointments_products b ON a.id = b.appointment_id

但是这个查询并没有对每个约会id的总数求和

Answer 1

select a.ID,a.PRICE,a.PAID,a.id as AppId,
       sum(b.total) as ProdTotal 
from appointments a 
INNER JOIN appointments_products b ON a.id = b.appointment_id
group by a.ID,a.PRICE,a.PAID;

Answer 2

使用 where 来检查价格是否等于已支付，并使用 group by 来与约会 ID 分组。

Answer 3

选择 b.Appointment_Id, a.price, a.PAID, a.id, sum(b.total) AS TotalProd FROMointments_products AS b 内部加入约会作为 On Appointment_Id = a.Id group by Appointment_Id, a.Price , a.PAID , a.id HAVING a.PAID != (a.Price + sum(b.Total))