XQuery

xs:anyURI

The primitive type xs:anyURI represents a Uniform Resource Identifier (URI) reference. The value has to be a lexically valid URI reference. Since the bare minimum rules for valid URI references are fairly generic, most implementations accept most character strings, including a zero-length string. The only values that are not accepted are those that make inappropriate use of reserved characters, such as those that contain multiple # characters or have % characters that are not followed by two hexadecimal digits.

Some URI processors require that certain non-ASCII characters be escaped using a percent sign (%) followed by a two-digit Unicode code point. However, the xs:anyURI type does accept these characters escaped or unescaped. Table B-1 shows some examples of valid and invalid URI references.

For more information on URIs, see "Working with URIs" in Chapter 20.

Table B-1. Values of the xs:anyURI type

Values	Explanation
Valid
http://datypic.com	Absolute URI (in this case, an HTTP URL)
http://datypic.com/prod.html#shirt	Absolute URI with fragment identifier
mailto:[e-mail]	Absolute URI using mailto scheme
../%C3%A9dition.html	Relative URI with escaped non-ASCII character
../édition.html	Relative URI with unescaped non-ASCII character
../prod.html#A557	Relative URI with fragment identifier
urn:datypic:com	Absolute URI (in this case, a URN)
	Empty values are allowed
Invalid
http://datypic.com#frag1#frag2	Too many fragment identifiers (# characters) ...