MySQL query to update only month in date?

To update only month in date, use MONTH(). Let us first create a table −

mysql> create table DemoTable861(AdmissionDate date); Query OK, 0 rows affected (1.22 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable861 values('2019-01-21'); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable861 values('2018-01-01'); Query OK, 1 row affected (0.49 sec) mysql> insert into DemoTable861 values('2016-01-02'); Query OK, 1 row affected (1.27 sec) mysql> insert into DemoTable861 values('2018-01-14'); Query OK, 1 row affected (0.47 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable861;

This will produce the following output −

+---------------+ | AdmissionDate | +---------------+ | 2019-01-21    | | 2018-01-01    | | 2016-01-02    | | 2018-01-14    | +---------------+ 4 rows in set (0.00 sec)

Following is the query to update only month −

mysql> update DemoTable861    set AdmissionDate=date_add(AdmissionDate,Interval -1 month)    where month(AdmissionDate)=01; Query OK, 4 rows affected (0.42 sec) Rows matched : 4 Changed : 4 Warnings : 0

Let us check the table records once again −

mysql> select *from DemoTable861;

This will produce the following output −

+---------------+ | AdmissionDate | +---------------+ | 2018-12-21    | | 2017-12-01    | | 2015-12-02    | | 2017-12-14    | +---------------+ 4 rows in set (0.00 sec)