Return the first non-NULL value; NULL comparison rules require IS NULL / IS NOT NULL.
SELECT COALESCE(nickname, name) AS display_name FROM users WHERE deleted_at IS NULL;SQL COALESCE / NULL handling
Return the first non-NULL value; NULL comparison rules require IS NULL / IS NOT NULL.
Syntax
COALESCE(expression, fallback)Examples
SQLite-oriented example; consult the relevant dialect manual.
SELECT COALESCE(nickname, name) AS display_name FROM users WHERE deleted_at IS NULL;Parameters, options and clauses
| Option / clause | Description |
|---|---|
SELECT / expression | Choose output columns, expressions, aliases or functions. |
FROM / JOIN | Choose source tables and combine related rows. |
WHERE | Filter rows before grouping; use IS NULL for null checks. |
GROUP BY / HAVING | Group rows and filter aggregate groups. |
ORDER BY | Sort the result; ASC is commonly the default and DESC reverses it. |
LIMIT / OFFSET / FETCH | Limit or skip rows; syntax differs by database dialect. |
Dialect references
Review a command and its target before running it. Commands that alter files, services, accounts, disks, permissions or databases may be difficult to reverse. Test in a safe environment and keep backups.