MySQL in a Nutshell, 2nd Edition

Name

IFNULL()

Synopsis

IFNULL(condition, result)

This function returns the results of the condition given in the first argument of the function if its results are not NULL. If the condition results are NULL, the results of the expression or string given in the second argument are returned. It will return a numeric or a string value depending on the context:

SELECT CONCAT(name_first, SPACE(1), name_last) AS Client,
telephone_home AS Telephone,
IFNULL(goals, 'No Goals Given') AS Goals
FROM clients LIMIT 2;

+----------------+-----------+----------------+
| Client         | Telephone | Goals          |
+----------------+-----------+----------------+
| Janice Sogard  | 835-1821  | No Goals Given |
| Kenneth Bilich | 488-3325  | Long Term      |
+----------------+-----------+----------------+

This SQL statement provides a list of clients and their telephone numbers, along with their investment goals. If the client never told the broker of an investment goal (i.e., the goals column is NULL), the text “No Goals Given” is displayed.