Xquery xpath
1 like•247 views
XQuery is compliant with XPath and uses XPath expressions to restrict searches on XML collections. The document provides an XML collection of books and demonstrates three versions of an XQuery statement that returns the titles of books with a price greater than 30. Each version returns the same two book titles, but uses a different method to filter the books by price.
![Output
<title lang="en">Learn .Net in 24 hours</title>
<title lang="en">Learn XQuery in 24 hours</title>
XQuery – Version 2
(: read all books :)
let $books := doc("books.xml")/books/book
for $x in $books
where $x/price > 30
return $x/title
Output
<title lang="en">Learn .Net in 24 hours</title>
<title lang="en">Learn XQuery in 24 hours</title>
XQuery – Version 3
(: read books with price > 30 :)
let $books := doc("books.xml")/books/book[price > 30]
for $x in $books
return $x/title
Output
<title lang="en">Learn .Net in 24 hours</title>
<title lang="en">Learn XQuery in 24 hours</title>
Verify the Result
To verify the result, replace the contents of books.xqy (given in the Environment Setup chapter)
with the above XQuery expression and execute the XQueryTester java program.](https://image.slidesharecdn.com/xqueryxpath-180620080846/85/Xquery-xpath-2-320.jpg)
Xquery xpath
- 1. http://www.tutorialspoint.com/xquery/xquery_xpath.htm Copyright © tutorialspoint.com XQUERY - XPATHXQUERY - XPATH XQuery is XPath compliant. It uses XPath expressions to restrict the search results on XML collections. For more details on how to use XPath, see our XPath Tutorial. Recall the following XPath expression which we have used earlier to get the list of books. doc("books.xml")/books/book XPath Examples We will use the books.xml file and apply XQuery to it. 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>40.50</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> We have given here three versions of an XQuery statement that fulfil the same objective of displaying the book titles having a price value greater than 30. XQuery – Version 1 (: read the entire xml document :) let $books := doc("books.xml") for $x in $books/books/book where $x/price > 30 return $x/title
- 2. Output <title lang="en">Learn .Net in 24 hours</title> <title lang="en">Learn XQuery in 24 hours</title> XQuery – Version 2 (: read all books :) let $books := doc("books.xml")/books/book for $x in $books where $x/price > 30 return $x/title Output <title lang="en">Learn .Net in 24 hours</title> <title lang="en">Learn XQuery in 24 hours</title> XQuery – Version 3 (: read books with price > 30 :) let $books := doc("books.xml")/books/book[price > 30] for $x in $books return $x/title Output <title lang="en">Learn .Net in 24 hours</title> <title lang="en">Learn XQuery in 24 hours</title> Verify the Result To verify the result, replace the contents of books.xqy (given in the Environment Setup chapter) with the above XQuery expression and execute the XQueryTester java program.