How to find largest, highest OR maximum value among columns of a row
There are certain scenarios when we need to fetch largest, maximum or highest value among multiple columns of a filtered row. In such case below function is useful.
GREATEST(value [, ...])
GREATESTfunction selects the largest / maximum / highest value from a list of columns/list of any number of expressions. The expressions must all be convertible to a common data type, which will be the type of the result.
- NULL values in the list are ignored. The result will be NULL only if all the expressions evaluate to NULL.
- Note that,
GREATESTnot in the SQL standard, but are a common extension. Some other databases make them return NULL if any argument is NULL, rather than only when all are NULL.