mysql - MySQL 报表查询

Question

我有以下数据库模式（我只提到查询所需的每个表的列）：

bills
-------
id
amount (decimal)
collection_case_id


collection_case
------------------
id


payments
----------
id
bill_id
amount (decimal)
type (char(2)) - "CH" stands for check payment, field used for polymorphism 

check_payments
---------------
payment_id

对于一组收款案例，我需要获取从支票付款中获得的总利息。在为我的收款案例标准集检索所有账单记录后，我目前正在内存中进行这些计算。对于每张账单，我只需添加收到的支票总和 - 如果收到的支票总和大于账单金额，则账单金额。

例如，我收到的总查询如下所示（收集案例 1 和 2）：

select sum(payment.amount) as received 
from bills bill
cross join payments payment inner join check_payments checkpayment 
on 
payment.id=checkpayment.payment_id 
where payment.type='CH'
 and payment.bill_id=bill.id 
 and (bill.collection_case_id in (1 , 2))

Answer 1

不确定这是否是您的意思。

select IF(sum(payment.amount) > bill.amount, sum(payment.amount)-bill.amount, 0) as interest  
from bills bill
cross join payments payment inner join check_payments checkpayment 
on 
payment.id=checkpayment.payment_id 
where payment.type='CH'
 and payment.bill_id=bill.id 
 and (bill.collection_case_id in (1 , 2))