COALESCE

Syntax

COALESCE(expr, expr, expr,...)

Description

COALESCE evaluates the expressions in order and returns the first non-NULL value. If all expressions are NULL, it returns NULL.

All expressions must be of the same type or implicitly convertible to the same type.

Examples

SELECT COALESCE(NULL,NULL,3,4,5), COALESCE(NULL,NULL,NULL);
+---------------------------+--------------------------+
| COALESCE(NULL,NULL,3,4,5) | COALESCE(NULL,NULL,NULL) |
+---------------------------+--------------------------+
|                         3 |                     NULL |
+---------------------------+--------------------------+
1 row in set (0.001 sec)