XML/XQuery/order by

Inadvertent resorting in document inventory

File: Data.xml
<order>
  <car model="A">
    <id>0001</id>
    <name language="en">name 1</name>
    <colorChoices>navy black</colorChoices>
  </car>
  <car model="B">
    <id>0002</id>
    <name language="en">name 2</name>
  </car>
  <car model="B">
    <id>0003</id>
    <name language="en">name 3</name>
  </car>
  <car model="C">
    <id>0004</id>
    <name language="en">name 4</name>
  </car>
</order>
File: Query.xquery
let $sortedProds := for $prod in doc("Data.xml")//car
                    order by $prod/id
                    return $prod
for $prodName in $sortedProds/name
return <li>{string($prodName)}</li>
Output:
<?xml version="1.0" encoding="UTF-8"?>
<li>name 1</li>
<li>name 2</li>
<li>name 3</li>
<li>name 4</li>

order by clause demo

File: Data.xml
<order>
  <car model="A">
    <name language="en">name 1</name>
  </car>
  <car model="B">
    <name language="en">name 2</name>
  </car>
  <car model="B">
    <name language="en">name 3</name>
  </car>
</order>

File: Query.xquery
for $prod in doc("Data.xml")/order/car
where $prod/@model = "B"
order by $prod/name
return $prod/name
Output:
<?xml version="1.0" encoding="UTF-8"?>
<name language="en">name 2</name>
<name language="en">name 3</name>

order by stateCt

File: Data.xml

<order>
  <car dept="A">
    <number>1</number>
    <name language="en">name 1</name>
  </car>
  <car dept="B">
    <number>2</number>
    <name language="en">name 2</name>
  </car>
  <car dept="B">
    <number>3</number>
    <name language="en">name 3</name>
  </car>
  <car dept="C">
    <number>4</number>
    <name language="en">name 4</name>
  </car>
</order>

File: Query.xquery

for $prod in doc("Data.xml")//car
where $prod/@dept = "B"
order by $prod/name
return $prod/name

Output:
<?xml version="1.0" encoding="UTF-8"?>
<name language="en">name 2</name>
<name language="en">name 3</name>

The order by clause

File: Data.xml
<inventory>
  <car model="A" id="0001" />
  <car model="B" id="0002" />
  <car model="B" id="0003" />
  <car model="C" id="0004" />
  <car model="C" id="0004" />
  <car model="A" id="0001" />
</inventory>

File: Query.xquery
for $car in doc("Data.xml")//car
order by $car/@id
return $car
Output:
<?xml version="1.0" encoding="UTF-8"?>
<car model="A" id="0001"/>
<car model="A" id="0001"/>
<car model="B" id="0002"/>
<car model="B" id="0003"/>
<car model="C" id="0004"/>
<car model="C" id="0004"/>

Using an inventory comparison

File: Data.xml
<order>
  <car model="A">
    <id>0001</id>
    <name language="en">name 1</name>
  </car>
  <car model="B">
    <id>0002</id>
    <name language="en">name 2</name>
  </car>
  <car model="B">
    <id>0003</id>
    <name language="en">name 3</name>
  </car>
</order>
File: Query.xquery
let $prods := doc("Data.xml")//car
for $prod in $prods
where $prod << $prods[@model = $prod/@model][last()]
return $prod

Output:
<?xml version="1.0" encoding="UTF-8"?>
<car model="B">
    <id>0002</id>
    <name language="en">name 2</name>
  </car>

Using multiple inventorying specifications

File: Data.xml
<inventory>
  <car model="A" id="0001"/>
  <car model="B" id="0002"/>
  <car model="B" id="0003"/>
  <car model="C" id="0004"/>
  <car model="C" id="0004"/>
  <car model="A" id="0001"/>
</inventory>

File: Query.xquery

for $car in doc("Data.xml")//car
order by $car/@model, $car/@id
return $car
Output:
<?xml version="1.0" encoding="UTF-8"?>
<car model="A" id="0001"/>
<car model="A" id="0001"/>
<car model="B" id="0002"/>
<car model="B" id="0003"/>
<car model="C" id="0004"/>
<car model="C" id="0004"/>

without inadvertent resorting

File: Data.xml
<order>
  <car model="A">
    <id>0001</id>
    <name language="en">name 1</name>
  </car>
  <car model="B">
    <id>0002</id>
    <name language="en">name 2</name>
  </car>
  <car model="B">
    <id>0003</id>
    <name language="en">name 3</name>
  </car>
  <car model="C">
    <id>0004</id>
    <name language="en">name 4</name>
  </car>
</order>
File: Query.xquery
for $prod in doc("Data.xml")//car
order by $prod/id
return <li>{string($prod/name)}</li>

Output:
<?xml version="1.0" encoding="UTF-8"?>
<li>name 1</li>
<li>name 2</li>
<li>name 3</li>
<li>name 4</li>