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I've tried several ways to achieve a xsd schema for the following xml
example, but failed to do so.

Valid:
<Person>
<Interest>Movies</Interest>
<Interest>Computers</Interest>
</Person>
<Person>
<Interest>Movies</Interest>
</Person>

Non-valid:
<Person>
<Interest>Movies</Interest>
<Interest>Movies</Interest>
</Person>

In this example the Interests are an enumeration.
Is it possible to make a restriction for the repeated elements so that
all elements have a different value?

All help is appreciated,

Hans

I'm not sure. But I know there is a "unique" keyword in schema for this
purpose.


wrote:
> I've tried several ways to achieve a xsd schema for the following xml
> example, but failed to do so.
>
> Valid:
> <Person>
> <Interest>Movies</Interest>
> <Interest>Computers</Interest>
> </Person>
> <Person>
> <Interest>Movies</Interest>
> </Person>
>
> Non-valid:
> <Person>
> <Interest>Movies</Interest>
> <Interest>Movies</Interest>
> </Person>
>
> In this example the Interests are an enumeration.
> Is it possible to make a restriction for the repeated elements so that
> all elements have a different value?
>
> All help is appreciated,
>
> Hans
>

Hi Hans,

The following schema does what you want.

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

<xs:schema targetNamespace="foo"

elementFormDefault="qualified"

xmlns="foo"

xmlns:foo="foo"

xmlnss="http://www.w3.org/2001/XMLSchema">

<xs:simpleType name="interestType">

<xs:restriction base="xs:string">

<xs:enumeration value="Movies"/>

<xs:enumeration value="Computers"/>

</xs:restriction>

</xs:simpleType>



<xs:complexType name="personType">

<xs:sequence>

<xs:element name="Interest" type="interestType"
maxOccurs="unbounded"/>

</xs:sequence>

</xs:complexType>

<xs:element name="Person" type="personType">

<xs:unique name="uniqueInterests">

<xs:selector xpath="foo:Interest"/>

<xs:field xpath="."/>

</xs:unique>

</xs:element>

</xs:schema>


--
Stan Kitsis
Program Manager, XML Technologies
Microsoft Corporation

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<> wrote in message
news: oups.com...
> I've tried several ways to achieve a xsd schema for the following xml
> example, but failed to do so.
>
> Valid:
> <Person>
> <Interest>Movies</Interest>
> <Interest>Computers</Interest>
> </Person>
> <Person>
> <Interest>Movies</Interest>
> </Person>
>
> Non-valid:
> <Person>
> <Interest>Movies</Interest>
> <Interest>Movies</Interest>
> </Person>
>
> In this example the Interests are an enumeration.
> Is it possible to make a restriction for the repeated elements so that
> all elements have a different value?
>
> All help is appreciated,
>
> Hans
>

Off the top of my head (and my syntax could be slightly off), ...

....
<xs:sequence>
<xs:element name="Person" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element ref="Interest"
type="InterestEnumType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>

<xs:unique name="UniqueInterestPerPersonKey">
<xs:select xpath="."/>
<xs:field xpath="Interest"/>
</xs:unique>

</xs:element>
</xs:sequence>
....

<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="Computers"/>
<xs:enumeration value="Movies"/>
</xs:restriction>
</xs:simpleType>


On 28 Jul 2005 15:09:41 -0700, wrote:

>I've tried several ways to achieve a xsd schema for the following xml
>example, but failed to do so.
>
>Valid:
><Person>
> <Interest>Movies</Interest>
> <Interest>Computers</Interest>
></Person>
><Person>
> <Interest>Movies</Interest>
></Person>
>
>Non-valid:
><Person>
> <Interest>Movies</Interest>
> <Interest>Movies</Interest>
></Person>
>
>In this example the Interests are an enumeration.
>Is it possible to make a restriction for the repeated elements so that
>all elements have a different value?
>
>All help is appreciated,
>
>Hans

On Thu, 28 Jul 2005 19:17:05 -0700, Steve Jorgensen <>
wrote:

>Off the top of my head (and my syntax could be slightly off), ...
>
>...

....

Oops - I just realized why that unique constraint is wrong - and why this case
is confusing. This one might work. I'll test it out later and post back.

<xs:sequence>
<xs:element name="Person" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element ref="Interest"
type="InterestEnumType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>

<xs:unique name="UniqueInterestsPerPerson">
<xs:select xpath="Interest"/>
<xs:field xpath="."/>
</xs:unique>

</xs:element>
</xs:sequence>
>...
>
><xs:simpleType>
> <xs:restriction base="xs:string">
> <xs:enumeration value="Computers"/>
> <xs:enumeration value="Movies"/>
> </xs:restriction>
></xs:simpleType>
>
>
>On 28 Jul 2005 15:09:41 -0700, wrote:
>
>>I've tried several ways to achieve a xsd schema for the following xml
>>example, but failed to do so.
>>
>>Valid:
>><Person>
>> <Interest>Movies</Interest>
>> <Interest>Computers</Interest>
>></Person>
>><Person>
>> <Interest>Movies</Interest>
>></Person>
>>
>>Non-valid:
>><Person>
>> <Interest>Movies</Interest>
>> <Interest>Movies</Interest>
>></Person>
>>
>>In this example the Interests are an enumeration.
>>Is it possible to make a restriction for the repeated elements so that
>>all elements have a different value?
>>
>>All help is appreciated,
>>
>>Hans

On 28 Jul 2005 15:09:41 -0700, wrote:

>I've tried several ways to achieve a xsd schema for the following xml
>example, but failed to do so.
>
>Valid:
><Person>
> <Interest>Movies</Interest>
> <Interest>Computers</Interest>
></Person>
><Person>
> <Interest>Movies</Interest>
></Person>
>
>Non-valid:
><Person>
> <Interest>Movies</Interest>
> <Interest>Movies</Interest>
></Person>
>
>In this example the Interests are an enumeration.
>Is it possible to make a restriction for the repeated elements so that
>all elements have a different value?
>
>All help is appreciated,
>
>Hans

I have now tested the following schema, and it works...

<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema
xmlnss="http://www.w3.org/2001/XMLSchema"
targetNamespace="uri:fo2"
elementFormDefault="qualified"
attributeFormDefault="unqualified"
xmlns="uri:fo2"
xmlns:fo2="uri:fo2">

<xs:element name="Root">
<xs:complexType>
<xs:sequence>
<xs:element ref="Person"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>

<xs:element name="Person">
<xs:complexType>
<xs:sequence>
<xs:element name="Interest"
type="InterestEnumType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:unique name="PersonDistinctInterests">
<xs:selector xpath="fo2:Interest"/>
<xs:field xpath="."/>
</xs:unique>
</xs:element>

<xs:simpleType name="InterestEnumType">
<xs:restriction base="xs:string">
<xs:enumeration value="Computers"/>
<xs:enumeration value="Movies"/>
</xs:restriction>
</xs:simpleType>

</xs:schema>

In the example below, an error occurs on the second <Interest> having a value
of "Movies" in the final <Person> as a result of the xs:unique constraint.

Here's what's happening:

Because the unique constraint is defined within the Person element, the scope
of the constraint is the content of an individual Person element (descendants
of different <Person>s will not be compared to each other). <selection>
supplies an xpath expression of what self-or-descendant elements of the
<Person> need to be checked against each other for uniqueness, and the
combination of <field> items (in this case, 1 of them) indicate the
combination of self-or-descendant nodes of each selection containing the
combination of values used to determine uniqueness by. In this case, we have
one field (".") which is the element itself.

<?xml version="1.0" encoding="UTF-8"?>
<fo2:Root
xmlnssi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="uri:fo2 fo2.xsd"
xmlns:fo2="uri:fo2"
xmlns="uri:fo2">

<Person>
<Interest>Movies</Interest>
<Interest>Computers</Interest>
</Person>

<Person>
<Interest>Movies</Interest>
<Interest>Computers</Interest>
</Person>

<Person>
<Interest>Movies</Interest>
<Interest>Movies</Interest>
</Person>

</fo2:Root>

Thank you all,

It works like a charm! I wasn't aware of the unique keyword.

With regards,

Hans Bos