MySQL 如何将日期时间列拆分为日期和时间并分别比较

首先让我们创建一张表 −

mysql> create table DemoTable805(LoginDate datetime);
Query OK, 0 rows affected (0.63 sec)

使用插入命令在表中插入一些记录 −

mysql> insert into DemoTable805 values('2019-01-31 12:45:20');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable805 values('2017-11-01 10:20:30');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable805 values('2016-03-12 04:10:00');
Query OK, 1 row affected (0.35 sec)
mysql> insert into DemoTable805 values('2018-12-24 05:01:00');
Query OK, 1 row affected (0.13 sec)

使用select语句显示表中的所有记录 −

mysql> select *from DemoTable805;

这将产生以下输出 −

+---------------------+
| LoginDate           |
+---------------------+
| 2019-01-31 12:45:20 |
| 2017-11-01 10:20:30 |
| 2016-03-12 04:10:00 |
| 2018-12-24 05:01:00 |
+---------------------+
共4行 (0.00 sec)

以下是分割日期时间列并分别比较的查询 −

mysql> select cast(LoginDate AS date),cast(LoginDate AS Time) from DemoTable805;

这将产生以下输出 −

+-------------------------+-------------------------+
| cast(LoginDate AS date) | cast(LoginDate AS Time) |
+-------------------------+-------------------------+
| 2019-01-31              | 12:45:20                |
| 2017-11-01              | 10:20:30                |
| 2016-03-12              | 04:10:00                |
| 2018-12-24              | 05:01:00                |
+-------------------------+-------------------------+
共4行 (0.03 sec)

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