max_by aggregate function (Databricks SQL)

Returns the value of an expr1 associated with the maximum value of expr2 in a group.

Syntax 

max_by(expr1, expr2) [FILTER ( WHERE cond ) ]

Arguments

  • expr1: An expression of any type.

  • expr2: An expression of a type that can be ordered.

  • cond: An optional boolean expression filtering the rows used for aggregation.

Returns

The result type matches the type of expr1.

This function is non-deterministic if expr2 is not unique within the group.

Examples 

> SELECT max_by(x, y) FROM VALUES (('a', 10)), (('b', 50)), (('c', 20)) AS tab(x, y);
 b