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

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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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
<outdoor.jellyrollgmail.com>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
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
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View archives and manage your subscription(s) at http://discuss.develop.com

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
<outdoor.jellyrollgmail.com>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
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com

Hi Lain,

Thanks for the quick response.  I finally found the answer
(through several
online posts).
The current design of the LINQ-SQL system does not allow
cross-assembly
inheritance nor conventional inheritance, per se.
Hopefully MS will rectify this situation with the next
release or perhaps
the ADO.NET entity framework will work on this account.

What I did find out is that I can mimic the behavior I need
by using
interfaces.  I'm not exceptionally fond of this, but I'm
going to give it a
try.

Thanks,
Mike


On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com>wrote:

> 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
> <outdoor.jellyrollgmail.com>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
> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com

Hi Lain,

Thanks for the quick response.  I finally found the answer
(through several
online posts).
The current design of the LINQ-SQL system does not allow
cross-assembly
inheritance nor conventional inheritance, per se.
Hopefully MS will rectify this situation with the next
release or perhaps
the ADO.NET entity framework will work on this account.

What I did find out is that I can mimic the behavior I need
by using
interfaces.  I'm not exceptionally fond of this, but I'm
going to give it a
try.

Thanks,
Mike


On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com>wrote:

> 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
> <outdoor.jellyrollgmail.com>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
> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com

Entity Framework or NHibernate both support the notion you
looking for
though separating your data access without inheritance (e.g.
composition
versus inheritance) might be a better solution overall.

-----Original Message-----
From: Discussion of advanced .NET topics.
[mailto:ADVANCED-DOTNETDISCUSS.DEVELOP.COM] On Behalf Of Mike
Andrews
Sent: Wednesday, September 17, 2008 10:13 AM
To: ADVANCED-DOTNETDISCUSS.DEVELOP.COM
Subject: Re: [ADVANCED-DOTNET] Inheritance in LINQ-SQL
Framework and/or
ADO.NET Entity Framework

Hi Lain,

Thanks for the quick response.  I finally found the answer
(through several
online posts).
The current design of the LINQ-SQL system does not allow
cross-assembly
inheritance nor conventional inheritance, per se.
Hopefully MS will rectify this situation with the next
release or perhaps
the ADO.NET entity framework will work on this account.

What I did find out is that I can mimic the behavior I need
by using
interfaces.  I'm not exceptionally fond of this, but I'm
going to give it a
try.

Thanks,
Mike


On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com>wrote:

> 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
> <outdoor.jellyrollgmail.com>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
> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
This list is hosted by DevelopMentorR  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com


===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com

Entity Framework or NHibernate both support the notion you
looking for
though separating your data access without inheritance (e.g.
composition
versus inheritance) might be a better solution overall.

-----Original Message-----
From: Discussion of advanced .NET topics.
[mailto:ADVANCED-DOTNETDISCUSS.DEVELOP.COM] On Behalf Of Mike
Andrews
Sent: Wednesday, September 17, 2008 10:13 AM
To: ADVANCED-DOTNETDISCUSS.DEVELOP.COM
Subject: Re: [ADVANCED-DOTNET] Inheritance in LINQ-SQL
Framework and/or
ADO.NET Entity Framework

Hi Lain,

Thanks for the quick response.  I finally found the answer
(through several
online posts).
The current design of the LINQ-SQL system does not allow
cross-assembly
inheritance nor conventional inheritance, per se.
Hopefully MS will rectify this situation with the next
release or perhaps
the ADO.NET entity framework will work on this account.

What I did find out is that I can mimic the behavior I need
by using
interfaces.  I'm not exceptionally fond of this, but I'm
going to give it a
try.

Thanks,
Mike


On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com>wrote:

> 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
> <outdoor.jellyrollgmail.com>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
> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
> ===================================
> This list is hosted by DevelopMentor(R)  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
This list is hosted by DevelopMentorR  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com


===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com

Does the ADO.NET Entity Framework support inheritance across
assemblies?
In other words, can I declare some "base" objects
in one assembly, then in
another assembly, inherit and extend those objects?

Thanks,
Mike

On Wed, Sep 17, 2008 at 3:21 PM, Shawn Wildermuth <
swildermuth.listsadoguy.com> wrote:

> Entity Framework or NHibernate both support the notion
you looking for
> though separating your data access without inheritance
(e.g. composition
> versus inheritance) might be a better solution
overall.
>
> -----Original Message-----
> From: Discussion of advanced .NET topics.
> [mailto:ADVANCED-DOTNETDISCUSS.DEVELOP.COM] On
Behalf Of Mike Andrews
> Sent: Wednesday, September 17, 2008 10:13 AM
> To: ADVANCED-DOTNETDISCUSS.DEVELOP.COM
> Subject: Re: [ADVANCED-DOTNET] Inheritance in LINQ-SQL
Framework and/or
> ADO.NET Entity Framework
>
> Hi Lain,
>
> Thanks for the quick response.  I finally found the
answer (through several
> online posts).
> The current design of the LINQ-SQL system does not
allow cross-assembly
> inheritance nor conventional inheritance, per se.
> Hopefully MS will rectify this situation with the next
release or perhaps
> the ADO.NET entity framework will work on this
account.
>
> What I did find out is that I can mimic the behavior I
need by using
> interfaces.  I'm not exceptionally fond of this, but
I'm going to give it a
> try.
>
> Thanks,
> Mike
>
>
> On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com
> >wrote:
>
> > 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
> > <outdoor.jellyrollgmail.com>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
> > >
> > > ===================================
> > > This list is hosted by DevelopMentor(R)  http://www.develop.com
> > >
> > > View archives and manage your subscription(s)
at
> > > http://discuss.develop.com

> > >
> >
> > ===================================
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> >
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> > http://discuss.develop.com

> >
>
> ===================================
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> http://discuss.develop.com

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Does the ADO.NET Entity Framework support inheritance across
assemblies?
In other words, can I declare some "base" objects
in one assembly, then in
another assembly, inherit and extend those objects?

Thanks,
Mike

On Wed, Sep 17, 2008 at 3:21 PM, Shawn Wildermuth <
swildermuth.listsadoguy.com> wrote:

> Entity Framework or NHibernate both support the notion
you looking for
> though separating your data access without inheritance
(e.g. composition
> versus inheritance) might be a better solution
overall.
>
> -----Original Message-----
> From: Discussion of advanced .NET topics.
> [mailto:ADVANCED-DOTNETDISCUSS.DEVELOP.COM] On
Behalf Of Mike Andrews
> Sent: Wednesday, September 17, 2008 10:13 AM
> To: ADVANCED-DOTNETDISCUSS.DEVELOP.COM
> Subject: Re: [ADVANCED-DOTNET] Inheritance in LINQ-SQL
Framework and/or
> ADO.NET Entity Framework
>
> Hi Lain,
>
> Thanks for the quick response.  I finally found the
answer (through several
> online posts).
> The current design of the LINQ-SQL system does not
allow cross-assembly
> inheritance nor conventional inheritance, per se.
> Hopefully MS will rectify this situation with the next
release or perhaps
> the ADO.NET entity framework will work on this
account.
>
> What I did find out is that I can mimic the behavior I
need by using
> interfaces.  I'm not exceptionally fond of this, but
I'm going to give it a
> try.
>
> Thanks,
> Mike
>
>
> On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com
> >wrote:
>
> > 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
> > <outdoor.jellyrollgmail.com>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
> > >
> > > ===================================
> > > This list is hosted by DevelopMentor(R)  http://www.develop.com
> > >
> > > View archives and manage your subscription(s)
at
> > > http://discuss.develop.com

> > >
> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
> ===================================
> This list is hosted by DevelopMentorR  http://www.develop.com
>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>
> ===================================
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>
> View archives and manage your subscription(s) at
> http://discuss.develop.com

>

===================================
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View archives and manage your subscription(s) at http://discuss.develop.com

> Does the ADO.NET Entity Framework support inheritance
across assemblies?
> In other words, can I declare some "base"
objects in one assembly, then in
> another assembly, inherit and extend those objects?

        Not sure, but I really don't think it's wise to do
so anyway. Having
two schemas which have fields in common in perhaps a subset
of the entities
isn't a reason to share code among the two projects: if one
schema needs a
change in a table which is apparently 'the same' you are in
trouble.

                FB

>
> Thanks,
> Mike
>
> On Wed, Sep 17, 2008 at 3:21 PM, Shawn Wildermuth <
> swildermuth.listsadoguy.com> wrote:
>
> > Entity Framework or NHibernate both support the
notion you looking for
> > though separating your data access without
inheritance (e.g. composition
> > versus inheritance) might be a better solution
overall.
> >
> > -----Original Message-----
> > From: Discussion of advanced .NET topics.
> > [mailto:ADVANCED-DOTNETDISCUSS.DEVELOP.COM] On
Behalf Of Mike Andrews
> > Sent: Wednesday, September 17, 2008 10:13 AM
> > To: ADVANCED-DOTNETDISCUSS.DEVELOP.COM
> > Subject: Re: [ADVANCED-DOTNET] Inheritance in
LINQ-SQL Framework and/or
> > ADO.NET Entity Framework
> >
> > Hi Lain,
> >
> > Thanks for the quick response.  I finally found
the answer (through
several
> > online posts).
> > The current design of the LINQ-SQL system does not
allow cross-assembly
> > inheritance nor conventional inheritance, per se.
> > Hopefully MS will rectify this situation with the
next release or perhaps
> > the ADO.NET entity framework will work on this
account.
> >
> > What I did find out is that I can mimic the
behavior I need by using
> > interfaces.  I'm not exceptionally fond of this,
but I'm going to give it
a
> > try.
> >
> > Thanks,
> > Mike
> >
> >
> > On Wed, Sep 17, 2008 at 3:45 AM, Iain Smallwood
<call.copsegmail.com
> > >wrote:
> >
> > > 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
> > > <outdoor.jellyrollgmail.com>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
> > > >
> > > > ===================================
> > > > This list is hosted by DevelopMentor(R) 
http://www.develop.com
> > > >
> > > > View archives and manage your
subscription(s) at
> > > > http://discuss.develop.com

> > > >
> > >
> > > ===================================
> > > This list is hosted by DevelopMentor(R)  http://www.develop.com
> > >
> > > View archives and manage your subscription(s)
at
> > > http://discuss.develop.com

> > >
> >
> > ===================================
> > This list is hosted by DevelopMentorR  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
> > ===================================
> > This list is hosted by DevelopMentor(R)  http://www.develop.com
> >
> > View archives and manage your subscription(s) at
> > http://discuss.develop.com

> >
>
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>
> View archives and manage your subscription(s) at http://discuss.develop.com


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