COALESCE with multiple fallbacks

Question

Accepted Answer

COALESCE evaluates its arguments left to right and returns the first one that is not NULL. The first two arguments are NULL so they are skipped. The third argument is 42 - not NULL - so COALESCE returns 42 immediately without evaluating 99. You can chain as many fallbacks as you need; COALESCE is the standard tool for cascading defaults.