- XQuery is to XML what SQL is to database tables.
- XQuery is designed to query XML data - not just XML files, but anything that can appear as XML, including databases.
- 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 compatible with several W3C standards, such as XML, Namespaces, XSLT, XPath, and XML Schema.
What You Should Already Know
Before you continue you should have a basic understanding of the following:
- HTML / XHTML
- XML / XML Namespaces
- XPath
Basic Syntax Rules
- XQuery is case-sensitive
- XQuery elements, attributes, and variables must be valid XML names
- An XQuery string value can be in single or double quotes
- An XQuery variable is defined with a $ followed by a name, e.g. $bookstore
- XQuery comments are delimited by (: and :), e.g. (: XQuery Comment :)