Answer
COALESCE returns the first non-null argument. • Arguments are considered from left to right. • All arguments must be convertible to a compatible result type. • It is useful for defaults, but it does not change stored data.
💡 SQL Example
SELECT COALESCE(nickname, full_name, 'Unknown') AS display_name
FROM customers;
Result
Maya Rao
⚡ Quick Revision
COALESCE returns the first available non-null value.