xsd:unique issue

[reachkaruna]

Hi All,

I have the following XSD where my "number" is having unique constarint

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:element ref="number"/>
<xs:element ref="digit"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="number" type="xs:integer">
<xs:unique name="numberUnique">
<xs:selector xpath="number"></xs:selector>
<xs:field xpath="."></xs:field>
</xs:unique>
</xs:element>
<xs:element name="digit" type="xs:integer"/>
</xs:schema>

My corresponding XML is like below

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="Unique.xsd">
<number> 2</number>
<digit>2</digit>
</root>

As i understand, since number has xsd:unique constraint, the value should be unique in its parent scope. But in my above XML, the values for "number" and "digit" are same, which is 2. When i validate the XML with XSD, i am not seeing any error.

SO i believe my understanding is not correct. Can someone explain how xsd:unique works?

Thanks a lot,
Karuna

[jkmyoung]

First off:
Your constraint is in the wrong place.
This makes sure that the number element's number children are unique. eg,

<root>
 <number>
   <number>2</number>
   <number>2</number>
 </number>
</root>
 

Move the constraint to the root node.

Secondly, your selector xpath on lists numbers
you want "number|digit", or perhaps "*"

http://www.w3schools.com/schema/el_unique.asp