NULLIF#
Returns a null value if the two specified expressions are equal.
Syntax#
NULLIF ( expression , expression )
Arguments#
expression
Is any valid scalar expression.
Return types#
Returns the same type as the first expression.
NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression.
Example#
SELECT dept
, NULLIF(current_year, previous_year) AS LastBudget
FROM budgets;