COALESCE

Description

Returns the first non-null expression from left to right in the parameter list. If all arguments are NULL, returns NULL.

Syntax

COALESCE(<expr> [, ...])

Parameters

Parameter	Description
<expr>	A sequence of expressions to evaluate. All expressions must be compatible data types.

Return Value

The first non-null expression in the parameter list. Returns NULL if all arguments are NULL.

Examples

SELECT COALESCE(NULL, '1111', '0000');

+--------------------------------+
| coalesce(NULL, '1111', '0000') |
+--------------------------------+
| 1111                           |
+--------------------------------+