MySQL UPDATE column names and set None values with N/A?

Let us first create a table −

mysql> create table DemoTable1903    (    FirstName varchar(20),    LastName varchar(20) ,    Age int    ); Query OK, 0 rows affected (0.00 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1903 values('John','Smith',23); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None','Miller',28); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None','Taylor',26); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('Chris','Brown',26); Query OK, 1 row affected (0.00 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable1903;

This will produce the following output −

+-----------+----------+------+ | FirstName | LastName | Age  | +-----------+----------+------+ | John      | Smith    |   23 | | None      | Miller   |   28 | | None      | Taylor   |   26 | | Chris     | Brown    |   26 | +-----------+----------+------+ 4 rows in set (0.00 sec)

Here is the query to update column names and set NONE with N/A −

mysql> update DemoTable1903 set FirstName='N/A' where FirstName='None'; Query OK, 2 rows affected (0.00 sec) Rows matched: 2  Changed: 2 Warnings: 0

Let us check the table records once again −

mysql> select * from DemoTable1903;

This will produce the following output −

+-----------+----------+------+ | FirstName | LastName | Age  | +-----------+----------+------+ | John      |    Smith |   23 | | N/A       |   Miller |   28 | | N/A       |   Taylor |   26 | | Chris     |    Brown |   26 | +-----------+----------+------+ 4 rows in set (0.00 sec)