comments | difficulty | edit_url | tags | |
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true |
中等 |
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用户表: Users
+--------------+---------+ | Column Name | Type | +--------------+---------+ | user_id | int | | user_name | varchar | | credit | int | +--------------+---------+ user_id 是这个表的主键(具有唯一值的列)。 表中的每一列包含每一个用户当前的额度信息。
交易表:Transactions
+---------------+---------+ | Column Name | Type | +---------------+---------+ | trans_id | int | | paid_by | int | | paid_to | int | | amount | int | | transacted_on | date | +---------------+---------+ trans_id 是这个表的主键(具有唯一值的列)。 表中的每一列包含银行的交易信息。 ID 为 paid_by 的用户给 ID 为 paid_to 的用户转账。
力扣银行 (LCB) 帮助程序员们完成虚拟支付。我们的银行在表 Transaction 中记录每条交易信息,我们要查询每个用户的当前余额,并检查他们是否已透支(当前额度小于 0)。
编写解决方案报告:
user_id
用户 IDuser_name
用户名credit
完成交易后的余额credit_limit_breached
检查是否透支 ("Yes" 或 "No")
以任意顺序返回结果表。
结果格式见如下所示。
示例 1:
输入: Users
表: +------------+--------------+-------------+ | user_id | user_name | credit | +------------+--------------+-------------+ | 1 | Moustafa | 100 | | 2 | Jonathan | 200 | | 3 | Winston | 10000 | | 4 | Luis | 800 | +------------+--------------+-------------+Transactions
表: +------------+------------+------------+----------+---------------+ | trans_id | paid_by | paid_to | amount | transacted_on | +------------+------------+------------+----------+---------------+ | 1 | 1 | 3 | 400 | 2020-08-01 | | 2 | 3 | 2 | 500 | 2020-08-02 | | 3 | 2 | 1 | 200 | 2020-08-03 | +------------+------------+------------+----------+---------------+ 输出: +------------+------------+------------+-----------------------+ |user_id
|user_name
|credit
|credit_limit_breached
| +------------+------------+------------+-----------------------+ | 1 | Moustafa | -100 | Yes | | 2 | Jonathan | 500 | No | | 3 | Winston | 9900 | No | | 4 | Luis | 800 | No | +------------+------------+------------+-----------------------+ Moustafa 在 "2020-08-01" 支付了 $400 并在 "2020-08-03" 收到了 $200 ,当前额度 (100 -400 +200) = -$100 Jonathan 在 "2020-08-02" 收到了 $500 并在 "2020-08-08" 支付了 $200 ,当前额度 (200 +500 -200) = $500 Winston 在 "2020-08-01" 收到了 $400 并在 "2020-08-03" 支付了 $500 ,当前额度 (10000 +400 -500) = $9900 Luis 未收到任何转账信息,额度 = $800
# Write your MySQL query statement below
SELECT
t.user_id,
user_name,
SUM(t.credit) AS credit,
IF(SUM(t.credit) < 0, 'Yes', 'No') AS credit_limit_breached
FROM
(
SELECT paid_by AS user_id, -amount AS credit FROM Transactions
UNION ALL
SELECT paid_to AS user_id, amount AS credit FROM Transactions
UNION ALL
SELECT user_id, credit FROM Users
) AS t
JOIN Users AS u ON t.user_id = u.user_id
GROUP BY t.user_id;