MySQL IFNULL() function

IFNULL() function

MySQL IFNULL() takes two expressions and if the first expression is not NULL, it returns the first expression. Otherwise, it returns the second expression.

Depending on the context in which it is used, it returns either numeric or string value.

Syntax:

IFNULL(expression1, expression2);

Arguments:

MySQL Version: 8.0

Example: MySQL IFNULL() function

The following MySQL statement returns the first expression, i.e. 0, since the first expression is not NULL.

Code:

SELECT IFNULL(0,2);

Output:

mysql> SELECT IFNULL(0,2);
+-------------+
| IFNULL(0,2) |
+-------------+
|           0 | 
+-------------+
1 row in set (0.03 sec)

Example: IFNULL() function with non zero 1st argument

The following MySQL statement returns the first expression, i.e. 1, since the first expression is not NULL.

Code:

SELECT IFNULL(1,2);

Output:

mysql> SELECT IFNULL(1,2);
+-------------+
| IFNULL(1,2) |
+-------------+
|           1 | 
+-------------+
1 row in set (0.00 sec)

Example: IFNULL() function NULL

The following MySQL statement returns the second expression, i.e. 2, since the first expression is NULL.

Code:

SELECT IFNULL(NULL,2);

Output:

mysql> SELECT IFNULL(NULL,2);
+----------------+
| IFNULL(NULL,2) |
+----------------+
|              2 | 
+----------------+
1 row in set (0.00 sec)

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