14.19 Aggregate Functions

14.19.1 Aggregate Function Descriptions

14.19.2 GROUP BY Modifiers

14.19.3 MySQL Handling of GROUP BY

14.19.4 Detection of Functional Dependence

Aggregate functions operate on sets of values. They are often used with a GROUP BY clause to group values into subsets. This section describes most aggregate functions. For information about aggregate functions that operate on geometry values, see Section 14.16.12, “Spatial Aggregate Functions”.