Aggregation Functions

Functions that compute summary values across groups, as defined by the SELECT … GROUP BY clause.

• count() - Count the number of non-NULL occurrences of the argument.

• first() - Keep the first of the values seen.

• last() - Keep the last of the values seen.

• max() - Compute the maximum of the values.

• min() - Compute the minimum of the values.

• sum() - Calculate the sum of the amount.