Re: identity constraints and substitution groups

Hi Mark,

> Do the xpath expressions in an identity constraint have to match the
> actual name of an element or is it sufficient to match a
> substitution group?

I'm afraid that they have to match the actual name of the element.
This is one of the examples of how XPath and XML Schema don't really
gel.

> I.e.  suppose
>
> <xs:element name='column'/>
> <xs:element name='specialColumn' substitutionGroup='column'/>
>
> <xs:key name='kColumn'>
>     <xs:selector xpath='column'/>
>     <!-- etc -->
> </xs:key>

Here, you have to do:

  <xs:key name="kColumn">
    <xs:selector xpath="column | specialColumn" />
    ...
  </xs:key>

and remember to add prefixes if these elements have a target
namespace.

Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/