Re: Inheritance in LINQ-SQL Framework and/or ADO.NET Entity Framework

Hi Mike,

I do not use the dbml designer, as it seems to get a bit too complicated
once you get many tables etc involved or want to change the schenma - I
prefer SQLMetal, though it should amount to the same thing.

I am not sure what is causing your problem but I am able to a) extend the
class in another assembly b) add extra gubbins to the class through an
additional partial class in the same assembly, using this approach.

From the look of your error I would suspect a critical difference in some of
the attribute decorations for the extra columns or something of that nature.
Sorry if I am not much help - just trying to get going on this side of
things myself and answered as no-one else did.

cheers,
Iain

On Tue, Sep 16, 2008 at 9:26 PM, Mike Andrews
<[email protected]>wrote:

> I have a problem for which I cannot seem to discern a reasonable solution.
> I would like to use the LINQ-SQL classes and objects for doing my database
> manipulations but both seem to be lacking in the area that I need and I
> would like to know if any of you have a reasonable solution/answer (or just
> to tell me it can't be done would be fine).
>
> I currently have a base set of classes setup in a dbml file and the
> corresponding code (built using the built-in designer) contained in library
> assembly.
> I now want to re-use that work that was done and extend those classes in
> another assembly.
>
> For example, lets say have I have table Employee in the main database
> schema
> from which I'm deriving this project.
> I now have a new database with the exact same schema save that the Employee
> table now has an added column that was not previously present in the other
> schema.
> I want to be able to "inherit" the "Employee" class from the primary
> assembly and extend it with an added column.
> I have been able to accomplish this feat, and the designer seems to "allow"
> this sort of behavior, however, an exception occurs when I try to execute
> the code.
>
> The exception reads:
>
> Data member 'System.Guid SetID' of type 'Lib1.Set' is not part of the
> mapping for type 'E2Set'. Is the member above the root of an inheritance
> hierarchy?
>
> I'm really at a loss here on what to do next or how to overcome this.  Any
> help would be most appreciated.
>
> Thanks,
> Mike
>
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