Aggregate functions-PolarDB(PolarDB)-阿里云帮助中心

PolarDB-X supports the following aggregate functions.

Supported functions

Function	Description
`AVG(expression)`	Returns the average value of the expression. The expression is a field.
`COUNT(expression)`	Returns the number of records in the expression. The expression can be a field or an asterisk (`*`).
`COUNT(DISTINCT expression)`	Returns the number of unique records in the expression.
`MAX(expression)`	Returns the maximum value in the expression.
`MIN(expression)`	Returns the minimum value in the expression.
`SUM(expression)`	Returns the sum of all values in the expression.
`BIT_OR(expression)`	Returns the bitwise OR of all values in the expression.
`BIT_XOR(expression)`	Returns the bitwise exclusive OR (XOR) of all values in the expression.
`BIT_AND(expression)`	Returns the bitwise AND of all values in the expression.
`GROUP_CONCAT(expression)`	Returns a concatenated string based on the expression.
`STD(expression)` and `STDDEV(expression)`	Returns the standard deviation of the expression.
`STDDEV_POP(expression)`	Calculates the population standard deviation and returns the square root of the population variance.
`STDDEV_SAMP(expression)`	Calculates the cumulative sample standard deviation and returns the square root of the sample variance.