XML/XQuery/where
Версия от 18:22, 25 мая 2010; (обсуждение)
A where clause with multiple expressions
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
let $prodmodel := $prod/@model
where $prod/id > 100
and starts-with($prod/name, "F")
and exists($prod/colorChoices)
and ($prodmodel = "B" or $prodmodel = "A")
return $prod
Embedding the where clause
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 $sortedProds := for $prod in doc("Data.xml")//car
where $prod/@model = "B" or $prod/@model = "C"
order by $prod/name
return $prod
for $sortedProd at $count in $sortedProds
return <p>{$count}. {data($sortedProd/name)}</p>
Output:
<?xml version="1.0" encoding="UTF-8"?>
<p>1. name 2</p>
<p>2. name 3</p>
<p>3. name 4</p>
where with or operator
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
for $prod in doc("Data.xml")//car
let $prodmodel := $prod/@model
where $prodmodel = "B" or $prodmodel = "A"
return $prod/name
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>