Re: key, keyref, min, max, .... and so on

Hi Abdalhmed,

> Is it possible to restrict the number of <A> element referencing <B>
> the child of <doc>? For example, three <B> elements in <A> are
> referencing the same <B>three<B> (child of <doc>). Is it possible to
> say that for each <B> appearing in <doc>, it is referenced at least
> by one <A> element and at most by 2 <A> elements? A kind of min and
> max Occurs for referenced elements and not for referencing elements.

You might be able to get part way there.

Saying that each of the B elements inside A must point to a separate
B element is another way of saying that each of the B elements within
a particular A element must have a different value. You can do this
with another key, this time defined on the A element (since that's the
scope):

<xs:element name="A">
  ...
  <xs:key name="UniqueBKeyRef">
    <xs:selector xpath="B" />
    <xs:field xpath="." />
  </xs:key>
</xs:element>

The difficulty is saying that there are a maximum of two A elements
that hold a reference to any particular B element. I don't think that
you can state this in XML Schema.

Cheers,

Jeni

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