Re: Constraint Specifications in XML Schemas

I guess I forgot to mention other languages besides RELAX NG, such as
Schematron or XCSL (extended constraint specification language) that
probably are more suitable.

Thanks,
Alexandre Martins

----- Original Message -----
From: "Dare Obasanjo" <dareo@microsoft.com>
To: "Alexandre Martins" <alex.martins@netc.pt>; <xmlschema-dev@w3.org>
Sent: Friday, October 25, 2002 11:13 PM
Subject: RE: Constraint Specifications in XML Schemas


> The schema you are trying to describe does not seem beyond the abilities
of xs:key and xs:keyref. However it is definitely beyond the abilities of
RELAX NG since I believe key/keyref was removed from the language.
>
> -----Original Message-----
> From: Alexandre Martins [mailto:alex.martins@netc.pt]
> Sent: Fri 10/25/2002 2:52 PM
> To: xmlschema-dev@w3.org
> Cc:
> Subject: Constraint Specifications in XML Schemas
>
>
>
>
>
> Hi!
>
> I've been trying to write a XML vocabulary to describe a relational
database
> schema, for example:
>
> <DataBase id="teste" url="jdbc:mysql://localhost/teste" user="xano"
> passwd="xpto" driver="com.mysql.jdbc.Driver"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:noNamespaceSchemaLocation="bd-v2.xsd">
>
>   <Table id="Film">
>     <Field id="idFilm" type="INTEGER">Film Number</Field>
>     <Field id="title" type="VARCHAR" size="40">Title</Field>
>     <Field id="year" type="INTEGER">Year</Field>
>     <PrimaryKey>
>       <KeyField fieldId="idFilm"/>
>     </PrimaryKey>
>   </Table>
>   <Table id="Actor">
>     <Field id="idActor" type="INTEGER">Actor Number</Field>
>     <Field id="name" type="VARCHAR" size="25">Name</Field>
>     <Field id="birthDate" type="DATE">Birthdate</Field>
>     <PrimaryKey>
>       <KeyField fieldId="idActor"/>
>     </PrimaryKey>
>   </Table>
>   <Table id="FilmActor">
>     <Field id="idFilm" type="INTEGER">Film Number</Field>
>     <Field id="idActor" type="INTEGER">Actor Number</Field>
>     <Field id="character" type="VARCHAR" size="20">Character</Field>
>     <PrimaryKey>
>       <KeyField fieldId="idFilm"/>
>       <KeyField fieldId="idActor"/>
>     </PrimaryKey>
>     <ForeignKey>
>       <FieldRef fieldId="idFilm"/>
>       <ForeignTable tableId="Film">
>         <ForeignField fieldId="idFilm"/>
>       </ForeignTable>
>     </ForeignKey>
>     <ForeignKey>
>       <FieldRef fieldId="idActor"/>
>       <ForeignTable tableId="Actor">
>         <ForeignField fieldId="idActor"/>
>       </ForeignTable>
>     </ForeignKey>
>   </Table>
> </DataBase>
>
> In order to validate certain constraints related with the relational model
> rules, I've been developing a XML Schema.
> But I've not been able to write a XML Schema constraint to guarantee
> that a ForeignKey element content must be a PrimaryKey on the other table
> (i've trying with key and keyref).
> Is it possible to write this using XML Schema or must I use Relax NG??
>
> Thanks,
> Alexandre Martins
>
>
>
>
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Received on Sunday, 27 October 2002 10:39:05 UTC