- COALESCE – show you how to substitute null with a more meaningful alternative.
- DECODE – learn how to add if-then-else logic to a SQL query.
- NVL – return the first argument if it is not null, otherwise, returns the second argument.
- NVL2 – show you how to substitute a null value with various options.
- NULLIF – return a null if the first argument equals the second one, otherwise, returns the first argument.