Returns the largest value in a list.
GREATEST(<value1>, <value2>, …)
Compares several values in the same row and returns the largest. Its mirror function is LEAST, which returns the smallest. Don't confuse it with MAX: that one searches across many rows, while GREATEST looks at values side by side. Handy for putting a floor under a number: “at least”.
employees
| name | department | salary | bonus | phone |
|---|---|---|---|---|
| Emma | backend | 1200 | 300 | +44 7700 900123 |
| Liam | backend | 1000 | NULL | NULL |
| Olivia | frontend | 1350 | 150 | +44 7700 900456 |
| Noah | frontend | 950 | NULL | +44 7700 900789 |
| Sophia | design | 1200 | 200 | NULL |
orders
| id | created_at | amount |
|---|---|---|
| 1 | 2026-07-03 10:15:00 | 120.50 |
| 2 | 2026-07-28 18:40:00 | 80.25 |
| 3 | 2026-08-09 09:05:00 | 199.99 |
| 4 | 2026-08-21 14:30:00 | 45.00 |
| 5 | 2026-09-02 11:00:00 | 64.75 |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| biggest |
|---|
| 7 |
| name | bonus | bonus_at_least_250 |
|---|---|---|
| Emma | 300 | 300 |
| Liam | NULL | 250 |
| Olivia | 150 | 250 |
| Noah | NULL | 250 |
| Sophia | 200 | 250 |
Liam and Noah have no bonus, yet the result isn't NULL: in PostgreSQL, GREATEST skips NULL.
| id | created_at | counted_from |
|---|---|---|
| 1 | 2026-07-03 10:15:00 | 2026-08-01 00:00:00 |
| 2 | 2026-07-28 18:40:00 | 2026-08-01 00:00:00 |
| 3 | 2026-08-09 09:05:00 | 2026-08-09 09:05:00 |
| 4 | 2026-08-21 14:30:00 | 2026-08-21 14:30:00 |
| 5 | 2026-09-02 11:00:00 | 2026-09-02 11:00:00 |
It works with more than numbers: for dates, the “largest” is the latest. July orders are counted from August 1, the rest from their own date.
PostgreSQL skips NULL: GREATEST(5, NULL) gives 5, and only when every value is NULL is the result NULL. In MySQL or Oracle, any NULL would give NULL.
The values must have compatible types: GREATEST(5, 'abc') throws invalid input syntax for type integer.
To find the largest value across table rows, use MAX. GREATEST(salary) with a single argument just returns each row's salary.