XML模式中ID / IDREFS的使用

<!ELEMENT role EMPTY>
<!ATTLIST role
   name   ID    #REQUIRED>
<!ELEMENT usecases (usecase)+>
<!ELEMENT usecase EMPTY>
<!ATTLIST usecase
   roles IDREFS  #REQUIRED
   name   CDATA   #REQUIRED>

<xsl:key name=\"usecase2role\" match=\"usecase\" use=\"id(@roles)/@name\" />
<xsl:template match=\"role\">
    <xsl:apply-templates select=\"key(\'usecase2role\', @name)\" mode=\"byrole\">
        <xsl:with-param name=\"roleName\" select=\"@name\"/>
    </xsl:apply-templates>
</xsl:template>
<xsl:template match=\"usecase\" mode=\"byrole\">
    <xsl:param name=\"roleName\"/>
insert into permission(roleId, usecaseId) values (<xsl:value-of select=\"$roleName\"/>, <xsl:value-of select=\"@name\"/>);
</xsl:template>

<xsd:complexType name=\"role\">
    <xsd:attribute name=\"name\" type=\"xsd:ID\" use=\"required\"/>
</xsd:complexType>
<xsd:complexType name=\"usecase\">
    <xsd:attribute name=\"name\" use=\"required\"/>
    <xsd:attribute name=\"roles\" use=\"required\" type=\"xsd:IDREFS\"/>
</xsd:complexType>