Conditional Expressions Conditional expressions return values that depend on the outcome of conditional tests. This diagram shows the syntax for Conditional Expressions. Conditional Expressions CASE Expressions 1 COALESCE Function 6 NVL Function 2 NVL2 Function 3 NULLIF Function 4 DECODE Function 5 1 See CASE Expressions2 See NVL Function3 See NVL2 Function4 See NULLIF Function5 See DECODE Function6 See COALESCE Function