Update detached POCO with modified relationships

Question

Hi,

 

I'm struggling with POCO update through ObjectDataSource using FormView;

the POCO is in detached state so I have to whire this:

 

var context = ((IObjectContextAdapter)HRDb.Instance).ObjectContext;

 

context.ObjectStateManager.ChangeObjectState(department, EntityState.Modified);

 

 

so I'm reattaching the department entity here;

this is ok but the proble is that it only updates the primitive properties this way, not the relations

my detachedEntity has property like department.ParentDepartment and this relation remainc unchanged.

when I try this 

 

 

context.ObjectStateManager.ChangeRelationshipState(department, department.ParentDepartment, "ParentDepartment", EntityState.Modified);

 

 

it says that the relation cannot be in the modified state.

So what should I do to update the reattached entity "completely"?

 

Thank you very much

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clarity vs precision

Answer 1

You might want to have at look at Self-Tracking entities.
These are designed to track all changes (both primitive properties and relations) for a disconnected object graph.

 

Regards,
Koen

Answer 2

Thanks Koen,

but I have to use POCOs, the project is designed this way already

 

Regards

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clarity vs precision

Answer 3

Ok,

in that case, you might want to have a look at this article:

http://msdn.microsoft.com/en-us/library/dd456829.aspx

 

Regards,
Koen

Answer 4

Thank you,

I took a look,

but this didn't help either;

In my case my detached object is already "in a relationship" :) with other POCOs and when I "detect changes" the context doesn't recognize these complex changes and tries to update only the primitive ones, here's a code snippet:

 

		public static int Edit(HRDepartment department)
		{
			//department is detached, coming from FormView update procedure
			//at this point it is in relationship with a parent department and this relationship needs to be persisted
 
			//HRDb.Instance gets a singleton (in a proper way:))
			var context = ((IObjectContextAdapter)HRDb.Instance).ObjectContext;
 
			//here I attach department to the appropriate entity set
			context.AttachTo("HRDepartments", department);
 
			//I'm telling the state manager to treat department as an old but changed object
			context.ObjectStateManager.ChangeObjectState(department, EntityState.Modified);
			//this wasn't necessary, but ok :)
			context.DetectChanges();
			//save changes
			context.SaveChanges();
			return department.Id;
		}

 

Regards

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clarity vs precision

Answer 5

Hello,

Thank you for posting.

The state of the modified properties changes to Modified when the DetectChanges method was called. After the changes are saved, the object state changes to Unchanged.

Best Regards,

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Larcolais Gong[MSFT]
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Answer 6

Hi,

as you can see in the snippet I'm not trying to change state after she changes are saved, why would I do so?

Ok, I'll try something else

Thank you

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clarity vs precision