XQuery and XPath Data Model type hierarchy

The XQuery and XPath Data Model (XDM) is the

data model A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be c ...

shared by the

XPath XPath (XML Path Language) is an expression language designed to support the query or transformation of XML documents. It was defined by the World Wide Web Consortium (W3C) and can be used to compute values (e.g., strings, numbers, or Boolean v ...

2.0, XSLT 2.0,

XQuery XQuery (XML Query) is a query and functional programming language that queries and transforms collections of structured and unstructured data, usually in the form of XML, text and with vendor-specific extensions for other data formats (JSON, b ...

, and

XForms XForms is an XML format used for collecting inputs from web forms. XForms was designed to be the next generation of HTML / XHTML forms, but is generic enough that it can also be used in a standalone manner or with presentation languages other th ...

programming languages. It is defined in a

W3C recommendation The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working t ...

.Anders Berglund, ''et al.''
XQuery 1.0 and XPath 2.0 Data Model
W3C, 2010, revised, 2015, Originally, it was based on the XPath 1.0 data model which in turn is based on the

XML Information Set XML Information Set (XML Infoset) is a W3C recommendation, W3C specification describing an abstract data model of an XML document in terms of a set of ''information items''. The definitions in the XML Information Set specification are meant to be u ...

. The XDM consists of flat sequences of zero or more ''items'' which can be typed or untyped, and are either atomic values or

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...

nodes (of seven kinds: document, element, attribute, text, namespace, processing instruction, and comment). Instances of the XDM can optionally be XML schema-validated.

References

{{Reflist

External links

* IBM
XQuery and XPath data model
Data modeling XML data access