Related Languages and Standards
The designers of XQuery did not begin with a completely blank slate. The design of XQuery was strongly constrained by the requirement for compatibility with established standards and was also influenced by the design of other query languages with which the members of the working group were familiar. This section describes some of the ways in which XQuery was influenced by related languages and standards.
XML and Namespaces
Since XQuery is a query language for XML data sources, it is obvious that the language must be strongly influenced by the structure of XML itself [XML]. From XML comes the notion that information is represented as a hierarchy of elements that have names, optional attributes, and optional content. ...