将列日期时间值拆分为多列

Question

使用 MySQL 查询，我怎样才能像示例 A 中那样获取 table：
示例 A

ID	时间	log_type
1111	2021-06-01 07:13:42.000000	输入
1111	2021-06-01 17:13:42.000000	输出
1111	2021-06-03 07:00:42.000000	输入
1111	2021-06-03 17:00:42.000000	输出
2222	2021-06-01 07:13:42.000000	输入
2222	2021-06-01 17:13:42.000000	输出
2222	2021-06-03 07:00:42.000000	输入
2222	2021-06-03 17:00:42.000000	输出

并创建一个类似示例 B 的视图？
示例 B

ID	日期	输入	输出
1111	2021-06-01	上午 7:13	下午 4:30
1111	2021-06-02	不适用	不适用
1111	2021-06-03	上午 7:00	下午 4:00
2222	2021-06-01	上午 7:13	下午 4:30
2222	2021-06-02	不适用	不适用
2222	2021-06-03	上午 7:00	下午 4:00

Answer 1

WITH RECURSIVE
cte1 AS ( SELECT MIN(DATE(`time`)) `date`, MAX(DATE(`time`)) maxtime
          FROM test
          UNION ALL
          SELECT `date` + INTERVAL 1 DAY, maxtime
          FROM cte1
          WHERE `date` < maxtime ),
cte2 AS ( SELECT DISTINCT id
          FROM test )
SELECT cte2.id, 
       cte1.`date`, 
       COALESCE(TIME(t1.`time`), 'N/A') `IN`,
       COALESCE(TIME(t2.`time`), 'N/A') `OUT`
FROM cte1
CROSS JOIN cte2
LEFT JOIN test t1 ON t1.id = cte2.id 
                 AND cte1.`date` = DATE(t1.`time`) 
                 AND t1.log_type = 'IN'
LEFT JOIN test t2 ON t2.id = cte2.id 
                 AND cte1.`date` = DATE(t2.`time`)
                 AND t2.log_type = 'OUT'
ORDER BY 1,2

https://dbfiddle.uk/?rdbms=mariadb_10.4&fiddle=51236ef22fcaaba3f2d9af9acf7f6c55

where do we put our variable, to return from_date to_date – Ashanti

WITH RECURSIVE
cte1 AS ( SELECT '{from_date}' `date`
          UNION ALL
          SELECT `date` + INTERVAL 1 DAY
          FROM cte1
          WHERE `date` < '{to_date}' ),
...

将列日期时间值拆分为多列

Split column datetime values with into multiple columns

mysql

mariadb-10.2