XQUERY

 

What is XQuery?

XQuery is to XML what SQL is to databases.

XQuery was designed to query XML data.


XQuary Example

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

where $x/price>30
order by $x/title
return $x/title

What is XQuery
  • Query is the language for querying XML data
  • XQuery for XML is like SQL for databases
  • XQuery is built on XPath expressions
  • XQuery is supported by all major databases
  • XQuery is a W3C Recommendation
XQuery is About Querying XML

XQuery is a language for finding and extracting elements and attributes from XML documents.

Here is an example of what XQuery could solve:

"Select all CD records with a price less than $10 from the CD collection stored in cd_catalog.xml"

XQuery and XPath

XQuery 1.0 and XPath 2.0 share the same data model and support the same functions and operators. If you have already studied XPath you will have no problems with understanding XQuery.

XQuery - Examples of Use

XQuery can be used to:

  • Extract information to use in a Web Service
  • Generate summary reports
  • Transform XML data to XHTML
  • Search Web documents for relevant information