XML Schema Constraint

Question

I have an XML schema that contains the following line.

<Customer Customer_Id = "c5" Age = "24" Years_Of_Membership = "26">

Is it possible for me to make a constraint that the value of Years_Of_Membership must be less than the value of Age?

Thanks

Answer 1

It is not possible to specify these kind of constraints with XSD 1.0.

It should be possible in XSD 1.1 using 'assertions':

<xs:element name="Customer">
  <xs:complexType>
    . . .
    <xs:assert test="@Years_Of_Membership lt @Age" />
  </xs:complexType>
</xs:element>

(I say 'should' because I don't have an XSD 1.1 processor to test it).

It might be possible with other schema technologies like Schematron.