Updating a many-to-many relation using GraphDiff cause an error

c# ef-code-first entity-framework graphdiff many-to-many


I'm using EF code first 6.1 with .NET 4 in my application and have following classes in my model(I cut other unrelated parts of diagram. e.g Permission has other navigations): enter image description here

My business logic works with detached entities so I'm using RefactorThis.GraphDiff to perform updates. I want to update an applicationUserInApplication object, so I get an existing applicationUserInApplication with its SecurityRoles from database and return it as a View-Model then update it and map back it to applicationUserInApplication using Automapper (in update operation, I only change SecurityRoles collection of an applicationUserInApplication , these SecurityRoles saved before and I only select them), so I defined following configuration:

_dbContext.UpdateGraph(appUserInApplication, map => map
                .OwnedCollection(t => t.SecurityRoles, with=>
                                     .AssociatedEntity(t => t.ApplicationDescriptor))

and defined following mapping for AppUserInApplication in AppUserInApplication_Mapping class:

this.HasRequired(t => t.AppUser).WithMany(t => t.AppUserInApplications).HasForeignKey(d => d.AppUserId);
this.HasRequired(t => t.Applicationdescriptor).WithMany(t => t.AppUserInApplications).HasForeignKey(d => d.ApplicationId);
this.HasMany(t => t.SecurityRoles).WithMany(t => t.AppUserInApplications)
            .Map(m =>
this.HasRequired(t => t.UserProfile).WithMany().HasForeignKey(t=>t.UserProfileId);

After calling above UpdateGraph(), when I call _dbContext.SaveChange(); I get following error:

An unhandled exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll Additional information: The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.


I also, tried following mapping

_dbContext.UpdateGraph(appUserInApplication, map => map
           .AssociatedCollection(t => t.SecurityRoles)
           .AssociatedEntity(t => t.Application)
           .AssociatedEntity(t => t.UserProfile)
           .AssociatedEntity(t => t.AppUser);

But I get same error, yet.

Does anyone know where is the problem?


I uploaded a simplified version of my model, you can get it from https://www.dropbox.com/s/i9dvrb6ebd5wo7h/GraphdiffTest.rar?dl=0

10/26/2014 11:10:19 AM

Accepted Answer

The exception means that Entity Framework is complaining about navigation properties you've mapped as required but not set (they're null). After debugging your sample code, this was the case for all of your navigation properties except security roles.

If you change your code like this:

working code

The navigation properties are set and everything works as you expect.

10/26/2014 11:35:40 AM

Popular Answer

I've looked at your code and I think that the problem is in your mappings. AppUserInApplication table has a Many-To-Many relation with table SecurityRoles, and in your mappings you used "OwnedCollection" - which should be used in One-To-Many or One-To-One relations, try to use the AssociatedCollection instead.

  _dbContext.UpdateGraph(appUserInApplication, map => map
            .AssociatedCollection(t => t.SecurityRoles, with=> (....)

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