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)