XML/XQuery/let

Adding a let clause

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

Intermingled for and let clauses

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
let $doc := doc("Data.xml")
for $prod in $doc//car
let $prodmodel := $prod/@model
let $prodName := $prod/name
where $prodmodel = "B" or $prodmodel = "A"
return $prodName
Output:
<?xml version="1.0" encoding="UTF-8"?>
<name language="en">name 1</name>
<name language="en">name 2</name>
<name language="en">name 3</name>

Let 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

let $doc := doc("Data.xml")
return $doc//number | $doc//name

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

Using a let clause with a range expression

File: Query.xquery
let $i := (1 to 3) 
return <oneEval>{$i}</oneEval>
Output:
<?xml version="1.0" encoding="UTF-8"?>
<oneEval>1 2 3</oneEval>