Aggregate functions

The following table describes the supported aggregate functions.

Function Description
AVG Returns the average of the non-NULL values in a group of expressions.
COUNT Returns the number of rows or non-NULL expressions in a group.
GROUP_CONCAT Concatenates values from a group into a single string.
MAX Returns the maximum value from a group of expressions.
MIN Returns the minimum value from a group of expressions.
STD Returns the standard deviation of a group of expressions. This is a legacy synonym for STDDEV_POP.
STDDEV_POP Returns the population standard deviation of a group of expressions.
STDDEV_SAMP Returns the sample standard deviation of a group of expressions.
SUM Returns the sum of the values in a group of expressions.
VAR_POP Returns the population variance of a group of expressions.
VAR_SAMP Returns the sample variance of a group of expressions.

For more information, see the MySQL documentation: Aggregate Function Descriptions.