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date: Fri, 3 Jul 2009 16:57:23 -0700 (PDT),
group: microsoft.public.dotnet.framework.aspnet
back
Re: Entity Framework - Reassigning child entity's parent
"Norm" wrote in message
news:74735735-6430-47c6-b29c-65091d724647@v23g2000pro.googlegroups.com...
> The following seems like a simple enough operation, but for some
> reason I can't figure it out.
>
> In a parent-child relationship I want to move a child to a different
> parent. I figured that it would be as easy as
> "Parent.ChildCollection.Attach(ChildToTransfer)" but it doesn't work.
> All of the entities are attached to the same object context and
> already exist in the database. No inserting here, just updating.
>
> At the time that ".SaveChanges()" is called on the container, the
> states of the various entities are thus:
> Parent.EntityState = Modified (Due to other code)
> Parent.ChildCollection contains the ChildToTransfer
> Child.Parent = The new Parent (correct)
> BUT Child.EntityState = Unchanged
>
> The parent gets updated, but the child record doesn't.
>
> Any help would be appreciated and thanks in advance.
>
Well, I have over 40 entities on the EF model using a WCF Web service on the
backend that has the BLL and the DAL behind the WCF Web service SOA
solution, used by an ASP.NET UI front-end.
I learned to remove the associations/relationships between entities on the
model, keeping the constants on the SQL tables themselves.
That way, I have complete control of the EF model, no surprises.
__________ Information from ESET NOD32 Antivirus, version of virus signature database 4214 (20090703) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
date: Fri, 3 Jul 2009 20:38:18 -0400
author: Mr. Arnold MR.
Re: Entity Framework - Reassigning child entity's parent
On Jul 3, 5:38 pm, "Mr. Arnold" <MR. Arn...@Arnold.com> wrote:
> "Norm" wrote in message
>
> news:74735735-6430-47c6-b29c-65091d724647@v23g2000pro.googlegroups.com...
>
>
>
>
>
> > The following seems like a simple enough operation, but for some
> > reason I can't figure it out.
>
> > In a parent-child relationship I want to move a child to a different
> > parent. I figured that it would be as easy as
> > "Parent.ChildCollection.Attach(ChildToTransfer)" but it doesn't work.
> > All of the entities are attached to the same object context and
> > already exist in the database. No inserting here, just updating.
>
> > At the time that ".SaveChanges()" is called on the container, the
> > states of the various entities are thus:
> > Parent.EntityState = Modified (Due to other code)
> > Parent.ChildCollection contains the ChildToTransfer
> > Child.Parent = The new Parent (correct)
> > BUT Child.EntityState = Unchanged
>
> > The parent gets updated, but the child record doesn't.
>
> > Any help would be appreciated and thanks in advance.
>
> Well, I have over 40 entities on the EF model using a WCF Web service on the
> backend that has the BLL and the DAL behind the WCF Web service SOA
> solution, used by an ASP.NET UI front-end.
>
> I learned to remove the associations/relationships between entities on the
> model, keeping the constants on the SQL tables themselves.
>
> That way, I have complete control of the EF model, no surprises.
>
> __________ Information from ESET NOD32 Antivirus, version of virus signature database 4214 (20090703) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com- Hide quoted text -
>
> - Show quoted text -
Mr. Arnold,
While that is a valid answer, I am not in a posistion where I can redo
the model in such a way. After running into this and seeing your
answer (and the lack of anyone elses), I am inclined to not use EF in
the future. However, I am still in need of a solution for my current
project.
- Norm
date: Mon, 6 Jul 2009 10:32:20 -0700 (PDT)
author: Norm
Re: Entity Framework - Reassigning child entity's parent
On Jul 6, 10:32 am, Norm wrote:
> On Jul 3, 5:38 pm, "Mr. Arnold" <MR. Arn...@Arnold.com> wrote:
>
>
>
>
>
> > "Norm" wrote in message
>
> >news:74735735-6430-47c6-b29c-65091d724647@v23g2000pro.googlegroups.com..> > > The following seems like a simple enough operation, but for some
> > > reason I can't figure it out.
>
> > > In a parent-child relationship I want to move a child to a different
> > > parent. I figured that it would be as easy as
> > > "Parent.ChildCollection.Attach(ChildToTransfer)" but it doesn't work.
> > > All of the entities are attached to the same object context and
> > > already exist in the database. No inserting here, just updating.
>
> > > At the time that ".SaveChanges()" is called on the container, the
> > > states of the various entities are thus:
> > > Parent.EntityState = Modified (Due to other code)
> > > Parent.ChildCollection contains the ChildToTransfer
> > > Child.Parent = The new Parent (correct)
> > > BUT Child.EntityState = Unchanged
>
> > > The parent gets updated, but the child record doesn't.
>
> > > Any help would be appreciated and thanks in advance.
>
> > Well, I have over 40 entities on the EF model using a WCF Web service on the
> > backend that has the BLL and the DAL behind the WCF Web service SOA
> > solution, used by an ASP.NET UI front-end.
>
> > I learned to remove the associations/relationships between entities on the
> > model, keeping the constants on the SQL tables themselves.
>
> > That way, I have complete control of the EF model, no surprises.
>
> > __________ Information from ESET NOD32 Antivirus, version of virus signature database 4214 (20090703) __________
>
> > The message was checked by ESET NOD32 Antivirus.
>
> >http://www.eset.com-Hide quoted text -
>
> > - Show quoted text -
>
> Mr. Arnold,
>
> While that is a valid answer, I am not in a posistion where I can redo
> the model in such a way. After running into this and seeing your
> answer (and the lack of anyone elses), I am inclined to not use EF in
> the future. However, I am still in need of a solution for my current
> project.
>
> - Norm- Hide quoted text -
>
> - Show quoted text -
I have found the problem. It (of course) had nothing to do with the
Entity Framework.
/sigh
Note: "Parent.ChildCollection.Attach(ChildToTransfer)" is not correct.
Use "ChildToTransfer.Parent = NewParent"
- Norm
date: Mon, 6 Jul 2009 12:28:10 -0700 (PDT)
author: Norm
Re: Entity Framework - Reassigning child entity's parent
"Norm" wrote in message
news:2dafade8-02bb-4265-82a4-09ef58176782@j9g2000prh.googlegroups.com...
On Jul 6, 10:32 am, Norm wrote:
> On Jul 3, 5:38 pm, "Mr. Arnold" <MR. Arn...@Arnold.com> wrote:
>
>
>
>
>
> > "Norm" wrote in message
>
> >news:74735735-6430-47c6-b29c-65091d724647@v23g2000pro.googlegroups.com...
>
> > > The following seems like a simple enough operation, but for some
> > > reason I can't figure it out.
>
> > > In a parent-child relationship I want to move a child to a different
> > > parent. I figured that it would be as easy as
> > > "Parent.ChildCollection.Attach(ChildToTransfer)" but it doesn't work.
> > > All of the entities are attached to the same object context and
> > > already exist in the database. No inserting here, just updating.
>
> > > At the time that ".SaveChanges()" is called on the container, the
> > > states of the various entities are thus:
> > > Parent.EntityState = Modified (Due to other code)
> > > Parent.ChildCollection contains the ChildToTransfer
> > > Child.Parent = The new Parent (correct)
> > > BUT Child.EntityState = Unchanged
>
> > > The parent gets updated, but the child record doesn't.
>
> > > Any help would be appreciated and thanks in advance.
>
> > Well, I have over 40 entities on the EF model using a WCF Web service on
> > the
> > backend that has the BLL and the DAL behind the WCF Web service SOA
> > solution, used by an ASP.NET UI front-end.
>
> > I learned to remove the associations/relationships between entities on
> > the
> > model, keeping the constants on the SQL tables themselves.
>
> > That way, I have complete control of the EF model, no surprises.
>
> > __________ Information from ESET NOD32 Antivirus, version of virus
> > signature database 4214 (20090703) __________
>
> > The message was checked by ESET NOD32 Antivirus.
>
> >http://www.eset.com-Hide quoted text -
>
> > - Show quoted text -
>
> Mr. Arnold,
>
> While that is a valid answer, I am not in a posistion where I can redo
> the model in such a way. After running into this and seeing your
> answer (and the lack of anyone elses), I am inclined to not use EF in
> the future. However, I am still in need of a solution for my current
> project.
>
> - Norm- Hide quoted text -
>
> - Show quoted text -
I have found the problem. It (of course) had nothing to do with the
Entity Framework.
/sigh
Note: "Parent.ChildCollection.Attach(ChildToTransfer)" is not correct.
Use "ChildToTransfer.Parent = NewParent"
Well, no matter what ORM solution one uses including nHibernate and others,
there is always going to be a learning curve.
__________ Information from ESET NOD32 Antivirus, version of virus signature database 4219 (20090705) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
date: Mon, 6 Jul 2009 16:09:37 -0400
author: Mr. Arnold MR.
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