Place a specific value for NULL values in a MySQL column

Use IFNULL() to find and place a specific value for NULL values. Let us first create a table −

mysql> create table DemoTable1878
   (
   FirstName varchar(20)
   );
Query OK, 0 rows affected (0.00 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1878 values('Chris');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1878 values(NULL);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1878 values('David');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1878 values(NULL);
Query OK, 1 row affected (0.00 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable1878;

This will produce the following output −

+-----------+
| FirstName |
+-----------+
| Chris     |
| NULL      |
| David     |
| NULL      |
+-----------+
4 rows in set (0.00 sec)

Here is the query to work with IFNULL() −

mysql> select ifnull(FirstName,'Robert') from DemoTable1878;

This will produce the following output −

+----------------------------+
| ifnull(FirstName,'Robert') |
+----------------------------+
| Chris                      |
| Robert                     |
| David                      |
| Robert                     |
+----------------------------+
4 rows in set (0.00 sec)