比较MySQL中日期字段的月份和日份？

使用DATE_FORMAT()函数在MySQL中只比较日期字段的月份和日。以下是语法

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

为了理解上述语法，让我们创建一个表。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)

用插入命令在表中插入一些记录。

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;

以下是输出结果

+----+-------------------+
| 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)

以下是仅比较月份和日期的查询

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

以下是输出结果

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

如果您只想获取月份和日期，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;

以下是输出结果

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

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