MySQL查询仅更新一个月的日期？
要仅更新日期，请使用MONTH()。让我们首先创建一个表-
mysql> create table DemoTable861(AdmissionDate date);
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable861 values('2019-01-21');
mysql> insert into DemoTable861 values('2018-01-01');
mysql> insert into DemoTable861 values('2016-01-02');
mysql> insert into DemoTable861 values('2018-01-14');使用select语句显示表中的所有记录-
mysql> select *from DemoTable861;
这将产生以下输出-
+---------------+ | AdmissionDate | +---------------+ | 2019-01-21 | | 2018-01-01 | | 2016-01-02 | | 2018-01-14 | +---------------+ 4 rows in set (0.00 sec)
以下是仅更新月份的查询-
mysql> update DemoTable861 set AdmissionDate=date_add(AdmissionDate,Interval -1 month) where month(AdmissionDate)=01; Rows matched : 4 Changed : 4 Warnings : 0
让我们再次检查表记录-
mysql> select *from DemoTable861;
这将产生以下输出-
+---------------+ | AdmissionDate | +---------------+ | 2018-12-21 | | 2017-12-01 | | 2015-12-02 | | 2017-12-14 | +---------------+ 4 rows in set (0.00 sec)