XQuery - First Apppcation

Example

以下是XML文件样本,其中载有各书店的记录。

books.xml

<?xml version="1.0" encoding="UTF-8"?>
<books>
   
   <book category="JAVA">
      <title lang="en">Learn Java in 24 Hours</title>
      <author>Robert</author>
      <year>2005</year>
      <price>30.00</price>
   </book>
   
   <book category="DOTNET">
      <title lang="en">Learn .Net in 24 hours</title>
      <author>Peter</author>
      <year>2011</year>
      <price>70.50</price>
   </book>
   
   <book category="XML">
      <title lang="en">Learn XQuery in 24 hours</title>
      <author>Robert</author>
      <author>Peter</author> 
      <year>2013</year>
      <price>50.00</price>
   </book>
   
   <book category="XML">
      <title lang="en">Learn XPath in 24 hours</title>
      <author>Jay Ban</author>
      <year>2010</year>
      <price>16.50</price>
   </book>
   
</books>

下面是一份Xquery文件样本,其中载有在上述XML文件中将要执行的询问。 目的是在价格大于30的地方获得XML节点的名称。

books.xqy

for $x in doc("books.xml")/books/book
where $x/price>30
return $x/title

Result

<title lang="en">Learn .Net in 24 hours</title>
<title lang="en">Learn XQuery in 24 hours</title>

Verify Result

为核实结果,取代books.xqy。 (见。

doc("books.xml")

doc("books.xml")/books/book

for $x in doc("books.xml")/books/book

where $x/price>30

return $x/title