XQuery3.0 Group by example

	return
	<groups>
	{
	for $person in $persons/person
	group by
	$country := $person/country,
	$gender := $person/@gender
	return
	<group country="{$country}" gender="{$gender}">
	<averageAge>{avg($person/age)}</averageAge>
	</group>
	}
	</groups>
	(:
	**********************************************
	Logical result
	**********************************************
	Belgium Netherlands
	Male Female Male Female
	---------------------------------------------
	A 10 C 80 B 20 E 30
	D 40 F 36
	---- ---- ---- -----
	25 80 28 30
	**********************************************
	XQuery output:
	**********************************************
	<groups>
	<group country="Belgium" gender="male">
	<averageAge>25</averageAge>
	</group>
	<group country="Belgium" gender="female">
	<averageAge>80</averageAge>
	</group>
	<group country="Netherlands" gender="male">
	<averageAge>28</averageAge>
	</group>
	<group country="Netherlands" gender="female">
	<averageAge>30</averageAge>
	</group>
	</groups>
	:)

view raw gistfile1.xquery hosted with ❤ by GitHub