RE: [xml-dev] key constraint question

[Jeff Lowery <Jeff.Lowery@creo.com>]

> Huh?
> 
> Jeff Lowery wrote:
> > 
> > Why not have a single, mandatory Primary relation A -> B, 
> with B maintaining
> > the secondary optional relation: B -> B'?   You can get 
> from A -> B' via
> > A->B->B' navigation.

You're going to make me type it out?

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";
elementFormDefault="qualified" attributeFormDefault="unqualified">
  <xs:element name="TableA">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="primaryKey"/>
        <xs:element name="TableB" type="TableB_Type" minOccurs="1"/>
<!---->
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:complexType name="TableB_Type">
     <xs:sequence>
      <xs:element name="primaryKey" type="xs:string"/>
      <xs:element name="secondaryB" type="TableB_Type" minOccurs="0"/>
<!---->
    </xs:sequence>
    <xs:attribute name="relationship">
                <xs:simpleType>
                  <xs:restriction base="xs:token">
                    <xs:pattern value="needed|optional"/>
                  </xs:restriction>
                </xs:simpleType>
    </xs:attribute>
  </xs:complexType>
</xs:schema>