如何在 MySQL 中比较时间戳?
mysqlmysqli database
要在 MySQL 中比较时间戳，可以使用 DATE()。让我们首先创建一个表 −
mysql> create table comparingTimestampDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> AdmissionDate timestamp -> ); Query OK, 0 rows affected (0.54 sec)
下面是使用 insert 命令向表中插入记录的查询 −
mysql> insert into comparingTimestampDemo(AdmissionDate) values('2019-03-31');
Query OK, 1 row affected (0.13 sec)
mysql> insert into comparingTimestampDemo(AdmissionDate) values('2019-04-10');
Query OK, 1 row affected (0.12 sec)
mysql> insert into comparingTimestampDemo(AdmissionDate) values('2019-04-15');
Query OK, 1 row affected (0.17 sec)
mysql> insert into comparingTimestampDemo(AdmissionDate) values('2019-03-29');
Query OK, 1 row affected (0.15 sec)
mysql> insert into comparingTimestampDemo(AdmissionDate) values('2019-04-07');
Query OK, 1 row affected (0.18 sec)
以下是使用 select 语句显示表中的所有记录的查询 −
mysql> select * from comparingTimestampDemo;
这将产生以下输出 −
+----+---------------------+ | Id | AdmissionDate | +----+---------------------+ | 1 | 2019-03-31 00:00:00 | | 2 | 2019-04-10 00:00:00 | | 3 | 2019-04-15 00:00:00 | | 4 | 2019-03-29 00:00:00 | | 5 | 2019-04-07 00:00:00 | +----+---------------------+ 5 rows in set (0.00 sec)
现在让我们比较 MySQL 中的时间戳 −
mysql> SELECT DATE(`AdmissionDate`) FROM comparingTimestampDemo WHERE DATE(`AdmissionDate`) < CURDATE() - INTERVAL 3 DAY;
这将产生以下输出 −
+-----------------------+ | DATE(`AdmissionDate`) | +-----------------------+ | 2019-03-31 | | 2019-03-29 | +-----------------------+ 2 rows in set (0.00 sec)
