Resource on Blog Topics 2

XML Schema
- What are ID, IDREF, and IDREFS simple types in XSD?
- How is xs:unique used to constrain values?
- Give examples to explain the usage of these XSD constructs.

Resource:
http://www.w3.org/TR/xmlschema-2/#ID
http://www.w3.org/TR/xmlschema-2/#IDREF
http://www.w3.org/TR/xmlschema-1/#d0e13819
http://www.w3.org/2002/ws/databinding/examples/6/09/Unique/
http://documentation.softwareag.com/webmethods/wmsuite8_ga/Tamino/tslref/xsunique.htm

http://www.oxygenxml.com/forum/topic1188.html
http://stackoverflow.com/questions/2386633/how-do-i-ensure-unique-element-values-in-an-xml-schema

http://examples.oreilly.com/9780596002527/unique.html
http://www.oxygenxml.com/search.html?cx=004642928127942995072%3Aqm0jpe24lpo&cof=FORID%3A11&q=xsd+unique#1210

http://www.oxygenxml.com/forum/topic1188.html

http://zvon.org/xxl/DTDTutorial/General/contents.html
http://en.wikibooks.org/wiki/XML_-_Managing_Data_Exchange/The_many-to-many_relationship