Input Functions

XQuery uses input functions to identify the data to be queried. There are two input functions:

  1. doc() returns an entire document, identifying the document by a Universal Resource Identifier (URI). To be more precise, it returns the document node.
  2. collection() returns a collection, which is any sequence of nodes that is associated with a URI. This is often used to identify a database to be used in a query.

TABLE 1.1 Entity References

Character Represented

Predefined in XQuery Entity Reference

 

<

<

&gt;

>

&amp;

&

&quot;

"

&apos;

'

If our sample data is in a file named books.xml, then the following query returns the entire document: 

doc("books.xml")

A dynamic error is raised if the doc() function is not able to locate the specified document or the collection() function is not able to locate the specified collection.

Next Section: Locating Nodes: Path Expressions