I'm using an XSD DataSet and i've put all the
DataRelations into it. A nunber of my table use composite
(in particular, 2 column keys). This is reflected by the
following Constraint in the xsd:

<xs:unique name="Installation_Constraint1"
msdata:ConstraintName="PrimaryKey"
msdata:PrimaryKey="true">
<xs:selector xpath=".//mstns:Installation" />
<xs:field xpath="mstns:Company" />
<xs:field xpath="mstns:Name" />
</xs:unique>

Which has the side effect of requiring both feilds to be
Unique. This is not the case, which is why they are a
composite key.
I can drop the constraint but that damages the data model
and ignoring the error with exceptions is ineffcient as
this will likly mean 10-20 exceptions a second in
standard operation.
Does anyone know an alternate constraint syntax? Or
another (cleaner) way for dealing with this kind of issue?

Thanks in advance
Jan

Hi Jan,

Try this:
<xs:key name="Installation_Constraint1" msdata:PrimaryKey="true">

<xs:selector xpath=".//mstns:Installation" />

<xs:field xpath="mstns:Company" />

<xs:field xpath="mstns:Name" />

</xs:key>


--
Miha Markic - RightHand .NET consulting & software development
miha at rthand com

"Jan Bannister" <(E-Mail Removed)> wrote in message
news:0b3d01c3c3c8$e3bfa8d0$(E-Mail Removed)...
> I'm using an XSD DataSet and i've put all the
> DataRelations into it. A nunber of my table use composite
> (in particular, 2 column keys). This is reflected by the
> following Constraint in the xsd:
>
> <xs:unique name="Installation_Constraint1"
> msdata:ConstraintName="PrimaryKey"
> msdata:PrimaryKey="true">
> <xs:selector xpath=".//mstns:Installation" />
> <xs:field xpath="mstns:Company" />
> <xs:field xpath="mstns:Name" />
> </xs:unique>
>
> Which has the side effect of requiring both feilds to be
> Unique. This is not the case, which is why they are a
> composite key.
> I can drop the constraint but that damages the data model
> and ignoring the error with exceptions is ineffcient as
> this will likly mean 10-20 exceptions a second in
> standard operation.
> Does anyone know an alternate constraint syntax? Or
> another (cleaner) way for dealing with this kind of issue?
>
> Thanks in advance
> Jan
>
>
>
>

Thanks *again* Miha,

You seem to be the one greasin' the wheels. That worked
perfectly. I can't believe I was looking at an
<xs:unique> tag and wondering why it wasnt behaving like
an key.
I'm still relativly new to the whole XSD thing but its
really cool. Modelling your data before you plough into
gui work is a really comforting feeling and XSD really
helps.

Many Thanks
Jan



>-----Original Message-----
>Hi Jan,
>
>Try this:
><xs:key name="Installation_Constraint1"
msdata:PrimaryKey="true">
>
><xs:selector xpath=".//mstns:Installation" />
>
><xs:field xpath="mstns:Company" />
>
><xs:field xpath="mstns:Name" />
>
></xs:key>
>
>
>--
>Miha Markic - RightHand .NET consulting & software
development
>miha at rthand com
>
>"Jan Bannister" <(E-Mail Removed)> wrote in message
>news:0b3d01c3c3c8$e3bfa8d0$(E-Mail Removed)...
>> I'm using an XSD DataSet and i've put all the
>> DataRelations into it. A nunber of my table use
composite
>> (in particular, 2 column keys). This is reflected by
the
>> following Constraint in the xsd:
>>
>> <xs:unique name="Installation_Constraint1"
>> msdata:ConstraintName="PrimaryKey"
>> msdata:PrimaryKey="true">
>> <xs:selector xpath=".//mstns:Installation" />
>> <xs:field xpath="mstns:Company" />
>> <xs:field xpath="mstns:Name" />
>> </xs:unique>
>>
>> Which has the side effect of requiring both feilds to
be
>> Unique. This is not the case, which is why they are a
>> composite key.
>> I can drop the constraint but that damages the data
model
>> and ignoring the error with exceptions is ineffcient as
>> this will likly mean 10-20 exceptions a second in
>> standard operation.
>> Does anyone know an alternate constraint syntax? Or
>> another (cleaner) way for dealing with this kind of
issue?
>>
>> Thanks in advance
>> Jan
>>
>>
>>
>>
>
>
>.
>

Hi Jan,

"Jan Bannister" <(E-Mail Removed)> wrote in message
news:0b1301c3c3d9$b07282c0$(E-Mail Removed)...
> Thanks *again* Miha,
>
> You seem to be the one greasin' the wheels. That worked
> perfectly. I can't believe I was looking at an
> <xs:unique> tag and wondering why it wasnt behaving like
> an key.

Great

> I'm still relativly new to the whole XSD thing but its
> really cool. Modelling your data before you plough into
> gui work is a really comforting feeling and XSD really
> helps.

Yup, very usefull.

--
Miha Markic - RightHand .NET consulting & software development
miha at rthand com