Purpose of relations in datasets?

[Bobby Edward]

I have a fully relational mysql database (pk, fk, etc)

If I setup a xsd dataset with 2 related tables do I have to create the
relation there too? What's the purpose? Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???

Thanks

[sloan]

Re: Purpose of relations in datasets?


Here is an article:

http://msdn.microsoft.com/en-us/library/dbwcse3d(VS.80).aspx

I would say that the GetChildRows based on the relationship (name) is kinda
the useful method from my experience:

http://msdn.microsoft.com/en-us/library/system.data.datarow.getchildrows(VS.80).aspx

So if you have Orders and OrderDetails, and you name the relationship
"OrderToOrderDe tailsRelationsh ip"....you can use that name to pull the child
records of course.

This is kinda obvious observations, I'm just expressing what I've used in
the past with that exact feature.

If you write a self referencing relationship, you can use this to populate
something like a TreeView.



"Bobby Edward" <bobby@nobody.c omwrote in message
news:Oij2Lj7OJH A.4372@TK2MSFTN GP04.phx.gbl...

>I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too? What's the purpose? Is it just a 'reminder' or does
it have an effect on whether the pk/fk constraints are enforced or not at
the db level???
>
Thanks
>

[Alexey Smirnov]

Re: Purpose of relations in datasets?

On Nov 1, 1:28 am, "Bobby Edward" <bo...@nobody.c omwrote:

I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too?  What's the purpose?  Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???
>
Thanks

Could be useful with nested controls, for example when you have a
Repeater with a nested GridView

http://groups.google.com/group/microsoft.public.dotnet.framework.aspnet/browse_thread/thread/e7bf33bdf43e6d5d/7cf1f7a4128c5ad7

[Alexey Smirnov]

Re: Purpose of relations in datasets?

On Nov 1, 1:28 am, "Bobby Edward" <bo...@nobody.c omwrote:

I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too?  What's the purpose?  Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???
>
Thanks

Could be useful with nested controls, for example when you have a
Repeater with a nested GridView

http://groups.google.com/group/microsoft.public.dotnet.framework.aspnet/browse_thread/thread/e7bf33bdf43e6d5d/7cf1f7a4128c5ad7

[Alexey Smirnov]

Re: Purpose of relations in datasets?

On Nov 1, 1:28 am, "Bobby Edward" <bo...@nobody.c omwrote:

I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too?  What's the purpose?  Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???
>
Thanks

Could be useful with nested controls, for example when you have a
Repeater with a nested GridView

http://groups.google.com/group/microsoft.public.dotnet.framework.aspnet/browse_thread/thread/e7bf33bdf43e6d5d/7cf1f7a4128c5ad7

[Alexey Smirnov]

Re: Purpose of relations in datasets?

On Nov 1, 1:28 am, "Bobby Edward" <bo...@nobody.c omwrote:

I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too?  What's the purpose?  Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???
>
Thanks

Could be useful with nested controls, for example when you have a
Repeater with a nested GridView

http://groups.google.com/group/microsoft.public.dotnet.framework.aspnet/browse_thread/thread/e7bf33bdf43e6d5d/7cf1f7a4128c5ad7

[Alexey Smirnov]

Re: Purpose of relations in datasets?

On Nov 1, 1:28 am, "Bobby Edward" <bo...@nobody.c omwrote:

I have a fully relational mysql database (pk, fk, etc)
>
If I setup a xsd dataset with 2 related tables do I have to create the
relation there too?  What's the purpose?  Is it just a 'reminder' or does it
have an effect on whether the pk/fk constraints are enforced or not at the
db level???
>
Thanks

Could be useful with nested controls, for example when you have a
Repeater with a nested GridView

http://groups.google.com/group/microsoft.public.dotnet.framework.aspnet/browse_thread/thread/e7bf33bdf43e6d5d/7cf1f7a4128c5ad7