[XML Schema] Extending types in imported schema instance

But I'd like to use this (doesn't validate with the xml) (in mysql.xsd):

    <xs:complexType name="table"> 
        <xs:sequence> 
            <xs:element name="field" type="mysql:field" minOccurs="0" maxOccurs="unbounded" /> <!-- or type="field" //--> 
        </xs:sequence> 
        <xs:attribute name="name" type="xs:string" use="required" /> 
    </xs:complexType> 
[..] 
    <xs:complexType name="field"> 
        <xs:attribute name="name" type="xs:string" use="required" /> 
        <xs:attribute name="table" type="xs:string" use="optional" /> 
    </xs:complexType>

This is probably the only way out, if I'm trying to extend using the same tagname (but stronger validation because of parent element). This doesnt work (in mysql.xsd):

    <xs:complexType name="cond"> 
        <xs:sequence> 
            <xs:element name="field" minOccurs="0" maxOccurs="unbounded"> 
                <xs:complexType> 
                    <xs:complexContent> 
                        <xs:extension base="field"> 
                            <xs:attribute name="operator" type="xs:string" use="required" /> 
                        </xs:extension> 
                    </xs:complexContent> 
                </xs:complexType>         
            </xs:element> 
        </xs:sequence> 
    </xs:complexType>

I don't understand what I'm doing wrong, because all google code snippets + w3 works does say this should be right. I've been shuffling around with targetnamespace and so on, but it didn't work out

This error i get very much:

Warning: DOMDocument::schemaValidate() [http://sove.nl/function.DOMDocument-schemaValidate]: Validation failed: no DTD found !Element '{http://sove.nl/ns/system/mysql/}field': This element is not expected. Expected is ( field ). in /var/www/client/sove.nl/httpdocs/xmysql_mysql.php on line 34

So it's expecting an element with a blank namespace, but it's defined inside the MYSQL namespace (but is ignored)

How can I get my extension to work? Please help, been trying for days now.

Big thanks,

Robert de Wilde

Here are my full source codes (better don't quote them i guess):

XMYSQL_MYSQL.PHP

<?php

 $library = new SchemaDOMDocument("1.0"); 
 $library->validateOnParse = true; 
 
 $library->load('xmysql_mysql.xml'); 
 $library->validateXMLSchemas(); 
 
 class SchemaDOMDocument extends DOMDocument 
 { 
     public function validateXMLSchemas() 
     { 
         $schemaLocation = $this->documentElement->getAttributeNS('http://www.w3.org/2001/XMLSchema-instance', 'schemaLocation'); 
 
         if (! $schemaLocation) { 
             throw new DOMException('No schemas found'); 
         } 
 
         /* the schemaLocation contains pairs of values separated by spaces the first value in each pair 
            is the name space to be validated. The second is a URI defining the location of the schema 
            
            validate each namespace using the provided URI 
          */ 
 
          $pairs = preg_split('/\s+/', $schemaLocation); 
          $pairCount = count($pairs); 
          
          if ($pairCount <= 1) { 
              throw new DOMException('Invalid schema location value.'); 
          } 
 
          $valid = true; 
          for($x = 1; $x < $pairCount; $x+=2) { 
              $valid = $this->schemaValidate($pairs[$x]) && $valid; 
          } 
          
          if(! $valid) { 
              throw new DOMException('XML Schema Validation Failure'); 
          } 
 
          return true; 
     } 
 }  

?>

XMYSQL_MYSQL.XML:

<?xml version="1.0" encoding="utf-8"?>

<stream xmlns="http://sove.nl/ns/core/" 
    xmlns:mysql="http://sove.nl/ns/system/mysql/"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://sove.nl/ns/core/ http://sove.nl/ns/core.xsd">
    
    
 <mysql:set>  
  <mysql:query type="select">
   <mysql:table name="objects">
    <mysql:field name="objectid" />
    <mysql:field name="objectname" />
    <mysql:field name="objectgroup" />
   </mysql:table>
   <mysql:table name="settings">
    <mysql:field name="settingtimezone" />
   </mysql:table>
   <mysql:join>
    <mysql:table name="extended">
     <mysql:field name="extendedobjectid" />
     <mysql:field name="extendedinfo" />
    </mysql:table>
    <mysql:cond>
     <mysql:field name="extendedobjectid" table="extended" />
    </mysql:cond>
   </mysql:join>
   <mysql:cond>
    <mysql:field name="objectid" table="objects" />
   </mysql:cond>
   <mysql:order type="desc">
    <mysql:field name="objectid" table="objects" />
   </mysql:order>
   <mysql:group>
    <mysql:field name="objectid" table="objects" />
   </mysql:group>
  </mysql:query>
 </mysql:set>
  
  
</stream>

CORE.XSD

<?xml version="1.0" encoding="UTF-8"?>

<xs:schema xmlns="http://sove.nl/ns/core/" xmlns:mysql="http://sove.nl/ns/system/mysql/" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://sove.nl/ns/core/">
 
 <!-- ## SYSTEM ## //-->
 <xs:import namespace="http://sove.nl/ns/system/mysql/" schemaLocation="http://sove.nl/ns/system/mysql.xsd"/>
 
 <!-- ## TYPES ## //-->
 <!--<xs:import namespace="http://sove.nl/ns/types/boek/" schemaLocation="http://sove.nl/ns/types/boek.xsd"/>//-->
 
 <xs:complexType name="stream">
  <xs:sequence>
   <xs:element ref="mysql:set"/>
  </xs:sequence>
 </xs:complexType>
 
 <xs:element name="stream" type="stream" />
</xs:schema>

MYSQL.XSD

<?xml version="1.0" encoding="UTF-8"?>

<xs:schema xmlns="http://sove.nl/ns/system/mysql/" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://sove.nl/ns/system/mysql/">
 

 <xs:complexType name="set">
  <xs:sequence>
   <xs:element ref="query"/>
  </xs:sequence>     
 </xs:complexType>

 <xs:complexType name="query">
  <xs:sequence>
   <xs:element ref="table"   minOccurs="1" maxOccurs="unbounded" />
   <xs:element ref="query"   minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="join"    minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="cond"    minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="order"   minOccurs="0" maxOccurs="1" />
   <xs:element ref="group"   minOccurs="0" maxOccurs="1" />
  </xs:sequence>
  <xs:attribute name="type" type="xs:string" />
 </xs:complexType>
 
 <xs:complexType name="table">
  <xs:sequence>
   <xs:element ref="field" minOccurs="0" maxOccurs="unbounded" />
  </xs:sequence>
  <xs:attribute name="name" type="xs:string" use="required" />
 </xs:complexType>
 
 <xs:complexType name="field">
  <xs:attribute name="name" type="xs:string" use="required" />
  <xs:attribute name="table" type="xs:string" use="optional" />
 </xs:complexType>

 <xs:complexType name="join">
  <xs:sequence>
   <xs:element ref="table" minOccurs="1" />
   <xs:element ref="join" minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="cond" minOccurs="1" />
  </xs:sequence>
 </xs:complexType>

 <xs:complexType name="cond">
  <xs:sequence>
   <xs:element name="field" minOccurs="0" maxOccurs="unbounded">
    <xs:complexType>
     <xs:complexContent>
      <xs:extension base="field">
       <xs:attribute name="operator" type="xs:string" use="required" />
      </xs:extension>
     </xs:complexContent>
    </xs:complexType>  
   </xs:element>
  </xs:sequence>
 </xs:complexType>

 <xs:complexType name="order">
  <xs:sequence>
   <xs:element ref="field" minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="table" minOccurs="0" maxOccurs="unbounded" />
  </xs:sequence>
  <xs:attribute name="type" type="xs:string" />
 </xs:complexType>

 <xs:complexType name="group">
  <xs:sequence>
   <xs:element ref="field" minOccurs="0" maxOccurs="unbounded" />
   <xs:element ref="table" minOccurs="0" maxOccurs="unbounded" />
  </xs:sequence>
 </xs:complexType>

 <xs:element name="set"     type="set" />
 <xs:element name="query"    type="query" />
 <xs:element name="table"   type="table" />
 <xs:element name="field"    type="field" />
 <xs:element name="join"    type="join" />
 <xs:element name="cond"    type="cond" />
 <xs:element name="order"    type="order" />
 <xs:element name="group"    type="group" />
 
</xs:schema>

Robert de Wilde
wilde825@p...