nullif function

Returns NULL if expr1 equals expr2, or expr1 otherwise.

Syntax

nullif(expr1, expr2)

Arguments

  • expr1: An expression of any type.

  • expr2: An expression of the same type as expr.

Returns

NULL if expr1 equals to expr2, or expr1 otherwise.

Examples

> SELECT nullif(2, 2);
 NULL
> SELECT nullif(2, 3);
 2