只比较 MySQL 日期字段中的「日」和「月」?


借助 DATE_FORMAT(),你只能比较 MySQL 日期字段中的「日」和「月」。

语法如下:

select *from yourTableName
WHERE DATE_FORMAT(yourColumnName, '%m-%d') = DATE_FORMAT('yourValue', '%m-%d') and yourCondition;

为了理解上述语法,我们创建一个表。创建表的查询如下:

mysql> create table compareDayAndMonthDemo
   -> (
   -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> compareDayAndTime date
   -> );
Query OK, 0 rows affected (0.49 sec)

使用 insert 命令向表中插入一些记录。

查询如下:

mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2014-01-31');
Query OK, 1 row affected (0.20 sec)
mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2014-10-11');
Query OK, 1 row affected (0.16 sec)
mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2016-09-12');
Query OK, 1 row affected (0.08 sec)
mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2017-04-25');
Query OK, 1 row affected (0.08 sec)
mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2018-12-25');
Query OK, 1 row affected (0.08 sec)
mysql> insert into compareDayAndMonthDemo(compareDayAndTime) values('2019-02-27');
Query OK, 1 row affected (0.07 sec)

使用 select 语句从表中显示所有记录。

查询如下:

mysql> select *from compareDayAndMonthDemo;

输出如下:

+----+-------------------+
| Id | compareDayAndTime |
+----+-------------------+
| 1  | 2014-01-31        |
| 2  | 2014-10-11        |
| 3  | 2016-09-12        |
| 4  | 2017-04-25        |
| 5  | 2018-12-25        |
| 6  | 2019-02-27        |
+----+-------------------+
6 rows in set (0.00 sec)

以下是如何仅比较「日」和「月」的查询:

mysql> select *from compareDayAndMonthDemo
-> WHERE DATE_FORMAT(compareDayAndTime, '%m-%d') = DATE_FORMAT('2019-01-31', '%m-%d') and Id=1;

输出如下:

+----+-------------------+
| Id | compareDayAndTime |
+----+-------------------+
| 1  | 2014-01-31        |
+----+-------------------+
1 row in set (0.00 sec)

如果你只需要「日」和「月」,请使用以下查询:

mysql> select DATE_FORMAT(compareDayAndTime, '%m-%d') AS DayAndMonthOnly from compareDayAndMonthDemo
-> WHERE DATE_FORMAT(compareDayAndTime, '%m-%d') = DATE_FORMAT('2019-01-31', '%m-%d') and Id=1;

输出如下:

+-----------------+
| DayAndMonthOnly |
+-----------------+
| 01-31           |
+-----------------+
1 row in set (0.00 sec)

更新于:2019-07-30

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