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 |
+----------+---------+----------------+-----------------+-------------------+--------------------+
来源:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/monthly-transactions-ii 著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
# Write your MySQL query statement below
select *
from
(
select t.month, t.country,
ifnull(sum(t1.approved_count),0) approved_count,
ifnull(sum(t1.approved_amount),0) approved_amount,
ifnull(sum(t2.chargeback_count),0) chargeback_count,
ifnull(sum(t2.chargeback_amount),0) chargeback_amount
from
(
select distinct country, date_format(trans_date, '%Y-%m') month
from Transactions
union
select distinct country, date_format(ch.trans_date, '%Y-%m') month
from Chargebacks ch left join Transactions tr
on ch.trans_id = tr.id
) t
left join
(
select date_format(trans_date, '%Y-%m') month,
country,
count(*) approved_count,
ifnull(sum(amount),0) approved_amount
from Transactions
where state='approved'
group by month, country
) t1
on t.month = t1.month and t.country = t1.country
left join
(
select date_format(ch.trans_date, '%Y-%m') month,
country,
count(*) chargeback_count,
ifnull(sum(amount),0) chargeback_amount
from Chargebacks ch left join Transactions tr
on ch.trans_id = tr.id
group by month, country
) t2
on t.month = t2.month and t.country = t2.country
group by month, country
) tmp
where tmp.approved_count != 0 or tmp.chargeback_count != 0
or 简单写法,创建一个 chargeback
state
select date_format(a.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
where state = 'approved'
union all
select id, country, 'chargeback' state, amount, c.trans_date
from chargebacks c left join transactions t
on c.trans_id = t.id
) a
group by month,country