题目介绍: 每月交易II monthly-transactions-ii
难度中等
SQL架构
Transactions
记录表
+----------------+---------+
| Column Name | Type |
+----------------+---------+
| id | int |
| country | varchar |
| state | enum |
| amount | int |
| trans_date | date |
+----------------+---------+
id 是这个表的主键。
该表包含有关传入事务的信息。
状态列是类型为 [approved(已批准)、declined(已拒绝)] 的枚举。
Chargebacks
表
+----------------+---------+
| Column Name | Type |
+----------------+---------+
| trans_id | int |
| charge_date | date |
+----------------+---------+
退单包含有关放置在事务表中的某些事务的传入退单的基本信息。
trans_id 是 transactions 表的 id 列的外键。
每项退单都对应于之前进行的交易,即使未经批准。
编写一个 SQL 查询,以查找每个月和每个国家/地区的已批准交易的数量及其总金额、退单的数量及其总金额。
注意:在您的查询中,给定月份和国家,忽略所有为零的行。
查询结果格式如下所示:
``` Transactions 表: +------+---------+----------+--------+------------+ | id | country | state | amount | trans_date | +------+---------+----------+--------+------------+ | 101 | US | approved | 1000 | 2019-05-18 | | 102 | US | declined | 2000 | 2019-05-19 | | 103 | US | approved | 3000 | 2019-06-10 | | 104 | US | declined | 4000 | 2019-06-13 | | 105 | US | approved | 5000 | 2019-06-15 | +------+---------+----------+--------+------------+
Chargebacks 表: +------------+------------+ | trans_id | trans_date | +------------+------------+ | 102 | 2019-05-29 | | 101 | 2019-06-30 | | 105 | 2019-09-18 | +------------+------------+
Result 表: +----------+---------+----------------+-----------------+-------------------+--------------------+ | month | country | approved_count | approved_amount | chargeback_count | chargeback_amount | +----------+---------+----------------+-----------------+-------------------+--------------------+ | 2019-05 | US | 1 | 1000 | 1 | 2000 | | 2019-06 | US | 2 | 8000 | 1 | 1000 | | 2019-09 | US | 0 | 0 | 1 | 5000 | +----------+---------+----------------+-----------------+-------------------+--------------------+ ```
sql
select
date_format(trans_date, '%Y-%m') month,
country,
sum(state = 'approved') approved_count,
sum(if(state = 'approved', amount, 0)) approved_amount,
sum(state = 'chargeback') chargeback_count,
sum(if(state = 'chargeback', amount, 0)) chargeback_amount
from (
select * from transactions
union all
select id, country, 'chargeback' state, amount, c.trans_date
from chargebacks c left join transactions t
on c.trans_id = t.id
) tmp
group by month, country
having approved_amount or chargeback_amount