如何通过查询从MySql表中获取矩阵
本文关键字:获取 MySql 何通过 查询 | 更新日期: 2023-09-27 18:26:15
我使用的mySql表如下所示:
ID mondend |MondStart |TuesEnd |TuesStrt |wedsEnd |wednStrt
120| 06:00:00 | 22:00:00 |06:00:00 |22:00:00 |06:00:00 |22:00:00
122| 06:00:00 | 22:00:00 |06:00:00 |22:00:00 |06:00:00 |22:00:00
有没有可能通过查询得到这样的表?:
120| monday | 22:00:00 |06:00:00 |
| tuesday | 22:00:00 |06:00:00 |
| tuesday | 22:00:00 |06:00:00 |
122|monday | 22:00:00 |06:00:00 |
| tuesday | 22:00:00 |06:00:00 |
| tuesday | 22:00:00 |06:00:00 |
一个解决方案是使用UNION ALL查询:
SELECT ID, 'monday' AS week_day, MondStart AS day_start, TuesEnd day_end
FROM tablename
UNION ALL
SELECT ID, 'tuesday' AS week_day, TuesStrt AS day_start, WedEnd day_end
FROM tablename
UNION ALL
...etc...
如果你想要一个表而不是查询,你可以使用:
CREATE TABLE final_table AS
...the select query above...