如何在 MySQL 中将日期时间列拆分为日期和时间并单独进行比较?
mysqlmysqli database
首先我们创建一个表 −
mysql> create table DemoTable805(LoginDate datetime); Query OK, 0 rows affected (0.63 sec)
使用 insert 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 | +---------------------+ 4 rows in set (0.00 sec)
以下查询将 DateTime 列拆分为日期和时间并分别进行比较 −
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 | +-------------------------+-------------------------+ 4 rows in set (0.03 sec)
