XPath Aggregate Functions

Last modified: November 4, 2024

Introduction

This document describes XPath query aggregate functions.

These functions are for use in Java code only and must contain full XPath queries as their arguments.

The functions avg, max, min, and sum functions must specify an attribute in the query to aggregate (for example, /TotalPrice).

The functions avg, max, min, and sum functions must also specify an attribute that has a numeric type.

The following XPath query aggregate functions are available:

The avg() function returns the average of its argument.

This query returns the average total price of all placed orders:

avg(//Sales.Order/TotalPrice)

This query returns the average total price of all orders placed by a customer named “Jansen”:

avg(//Sales.Order[Sales.Customer_Order/Sales.Customer = 'Jansen']/TotalPrice)

The count() function counts all objects retrieved by the enclosed query and returns the value as an integer.

This query returns a count of all the placed orders:

count(//Sales.Order)

This query returns a count of all the orders placed by a customer named “Jansen”:

count(//Sales.Order[Sales.Customer_Order/Sales.Customer/Name = 'Jansen'])

The max() function returns the maximum value of its argument.

This query returns the highest total price found in any object:

max(//Sales.Order/TotalPrice)

This query returns the highest total price of an order placed by a customer named “Jansen”:

max(//Sales.Order[Sales.Customer_Order/Sales.Customer/Name = 'Jansen']/TotalPrice)

The min() function returns the minimum value of its argument.

This query returns the lowest total price found in any object:

min(//Sales.Order/TotalPrice)

This query returns the lowest total price of an order placed by a customer named “Jansen”:

min(//Sales.Order[Sales.Customer_Order/Sales.Customer/Name = 'Jansen']/TotalPrice)

The sum() function returns the sum of its argument.

This query returns the sum of the total prices of all placed orders:

sum(//Sales.Order/TotalPrice)

This query returns the sum of the total prices of all the orders placed by a customer named “Jansen”:

sum(//Sales.Order[Sales.Customer_Order/Sales.Customer/Name = 'Jansen']/TotalPrice)