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POUnable to determine the principal end of the relationship - Multiple added entities may have the same primary key
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  1. POUnable to determine the principal end of the relationship - Multiple added entities may have the same primary key
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    copied!<p>I'm using Entity Framework 5 Code First and I have the following model for car manufacturers, cars, and trucks:</p> <pre class="lang-cs prettyprint-override"><code>public class Manufacturer { public int Id { get; set; } public string Name { get; set; } [ForeignKey("ManufacturerId")] public virtual List&lt;Car&gt; Cars { get; set; } [ForeignKey("ManufacturerId")] public virtual List&lt;Truck&gt; Trucks { get; set; } } public class Vehicle { public int Id { get; set; } public string Colour { get; set; } public int ManufacturerId { get; set; } public virtual Manufacturer Manufacturer { get; set; } } public class Car : Vehicle { } public class Truck : Vehicle { } public class Context : DbContext { public DbSet&lt;Manufacturer&gt; Manufacturers { get; set; } public DbSet&lt;Vehicle&gt; Vehicles { get; set; } } </code></pre> <p>For development and testing I'm seeding the data as follows:</p> <pre class="lang-cs prettyprint-override"><code>public class DbInitialiser : DropCreateDatabaseAlways&lt;Context&gt; { protected override void Seed(Context context) { var manufacturers = new List&lt;Manufacturer&gt; { new Manufacturer { Name = "Test Manufacturer", Cars = new List&lt;Car&gt; { new Car { Colour = "Blue" }, new Car { Colour = "Green" } }, Trucks = new List&lt;Truck&gt; { new Truck { Colour = "Red" } } }, new Manufacturer { Name = "Another Manufacturer", Cars = new List&lt;Car&gt; { new Car { Colour = "Pink" } } } }; manufacturers.ForEach(x =&gt; context.Manufacturers.Add(x)); } } </code></pre> <p>However when I use the context I get the following exception: <strong>Unable to determine the principal end of the 'EF_Associations.Vehicle_Manufacturer' relationship. Multiple added entities may have the same primary key.</strong></p> <p>Stack trace:</p> <pre><code>System.Data.DataException was unhandled HResult=-2146233087 Message=An exception occurred while initializing the database. See the InnerException for details. Source=EntityFramework StackTrace: at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() at System.Data.Entity.Internal.LazyInternalContext.&lt;InitializeDatabase&gt;b__4(InternalContext c) at System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input) at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action) at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase() at System.Data.Entity.Internal.InternalContext.Initialize() at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() at System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator() at System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable&lt;TResult&gt;.GetEnumerator() at EF_Associations.Program.Main(String[] args) in c:\temp\EF-Associations\Program.cs:line 19 ... InnerException: System.Data.Entity.Infrastructure.DbUpdateException HResult=-2146233087 Message=Unable to determine the principal end of the 'EF_Associations.Vehicle_Manufacturer' relationship. Multiple added entities may have the same primary key. Source=EntityFramework StackTrace: at System.Data.Entity.Internal.InternalContext.SaveChanges() at System.Data.Entity.Internal.LazyInternalContext.SaveChanges() at System.Data.Entity.DbContext.SaveChanges() at System.Data.Entity.DropCreateDatabaseAlways`1.InitializeDatabase(TContext context) at System.Data.Entity.Database.&lt;&gt;c__DisplayClass2`1.&lt;SetInitializerInternal&gt;b__0(DbContext c) at System.Data.Entity.Internal.InternalContext.&lt;&gt;c__DisplayClass8.&lt;PerformDatabaseInitialization&gt;b__6() at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) InnerException: System.Data.UpdateException HResult=-2146233087 Message=Unable to determine the principal end of the 'EF_Associations.Vehicle_Manufacturer' relationship. Multiple added entities may have the same primary key. Source=System.Data.Entity StackTrace: at System.Data.Mapping.Update.Internal.UpdateTranslator.RegisterEntityReferentialConstraints(IEntityStateEntry stateEntry, Boolean currentValues) at System.Data.Mapping.Update.Internal.UpdateTranslator.RegisterReferentialConstraints(IEntityStateEntry stateEntry) at System.Data.Mapping.Update.Internal.UpdateTranslator.PullModifiedEntriesFromStateManager() at System.Data.Mapping.Update.Internal.UpdateTranslator.ProduceCommands() at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter) at System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache) at System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options) at System.Data.Entity.Internal.InternalContext.SaveChanges() InnerException: </code></pre> <p>How would I go about specifying the principle end of this relationship?</p> <p>I've tried adding the following configuration via the model builder fluent API but without success:</p> <pre><code>protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity&lt;Vehicle&gt;() .HasRequired(v =&gt; v.Manufacturer) .WithRequiredDependent(); } </code></pre>
 

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