MVC EntityFramework Code-First Migrations - Seed() Failing with AmbiguousMatchException?

Question

I'm working on a somewhat simple InventoryTracker MVC5 Application wherein I'm having some issues with getting my LocalDatabase to Seed().

When I run the update-database command on my below code, I get an exception as follows on the line context.INV_Assets.AddRange(invAssets):

An exception of type 'System.Reflection.AmbiguousMatchException' occurred in mscorlib.dll but was not handled in user code. Additional information: Ambiguous match found.

Anyone have thoughts on what in my INV_Assets - Seed() is causing the issue? There is no InnerException and I cannot seem to get more detail on it.

---

CODE:

internal sealed class Configuration : DbMigrationsConfiguration<InventoryTracker.DAL.InventoryTrackerContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
    }

    protected override void Seed(InventoryTracker.DAL.InventoryTrackerContext context)
    {
        if (System.Diagnostics.Debugger.IsAttached == false)
        {
            System.Diagnostics.Debugger.Launch();
        }

        List<INV_Locations> invLocs = getLocations();
        context.INV_Locations.AddRange(invLocs);
        context.SaveChanges(); 
        List<INV_Manufacturers> invManufacturers = getManufacturers();
        context.INV_Manufacturers.AddRange(invManufacturers);
        context.SaveChanges();
        List<INV_Models> invModels = getModels();
        context.INV_Models.AddRange(invModels);
        context.SaveChanges();
        List<INV_Statuses> invStatuses = getStatuses();
        context.INV_Statuses.AddRange(invStatuses);
        context.SaveChanges();
        List<INV_Types> invTypes = getTypes();
        context.INV_Types.AddRange(invTypes);
        context.SaveChanges();
        List<INV_Vendors> invVendors = getVendors();
        context.INV_Vendors.AddRange(invVendors);
        context.SaveChanges(); // Everything OK to this point.

        List<INV_Assets> invAssets = getAssets();
        context.INV_Assets.AddRange(invAssets); // System.Reflection.AmbiguousMatchException!

        context.SaveChanges();
    }

    private List<INV_Assets> getAssets()
        {
            List<INV_Assets> testAssets = new List<INV_Assets>
            {
              new INV_Assets
              {
                Id = 1,
                ip_address = "10.10.135.38",
                mac_address = "10.10.177.44",
                note = "",
                owner = "John Smith",
                cost = 35,
                po_number = "G348",
                invoice_number = 1447,
                serial_number = "JX14582Y",
                asset_tag_number = "293548195023",
                //acquired_date = Convert.ToDateTime(10212014),
                acquired_date = DateTime.ParseExact("10212014", "MMddyyyy", CultureInfo.InvariantCulture),
                disposed_date = null,
                created_by = "Admin",
                created_date = DateTime.Now,
                modified_by = "Admin",
                modified_date = DateTime.Now,
                Location_Id = 1,
                Manufacturer_Id = 1,
                Model_Id = 1,
                Status_Id = 2,
                Type_Id = 3,
                Vendor_Id = 3
            }
        };
        return testAssets;
    }

---

EDIT:

INV_Assets.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using GridMvc.DataAnnotations;
using System.Web.Mvc;
using InventoryTracker.Models;

namespace InventoryTracker.Models
{
    [GridTable(PagingEnabled = true, PageSize = 30)]
    public class INV_Assets
    {
        // Setting GridColumn Annotations allows you to use AutoGenerateColumns on view to auto create the Grid based on the model.


        public int Id { get; set; }

        public int Model_Id { get; set; }
        [ForeignKey("Model_Id")]
        public virtual INV_Models model_id { get; set; }

        [Required]
        public int Manufacturer_Id { get; set; }
        [ForeignKey("Manufacturer_Id")]
        public virtual INV_Manufacturers manufacturer_id { get; set; }

        [Required]
        public int Type_Id { get; set; }
        [ForeignKey("Type_Id")]
        public virtual INV_Types type_id { get; set; }

        [Required]
        public int Location_Id { get; set; }
        [ForeignKey("Location_Id")]
        public virtual INV_Locations location_id { get; set; }

        public int Vendor_Id { get; set; }
        [ForeignKey("Vendor_Id")]
        public virtual INV_Vendors vendor_id { get; set; }

        [Required]
        public int Status_Id { get; set; }
        [ForeignKey("Status_Id")]
        public virtual INV_Statuses status_id { get; set; }

        public string ip_address { get; set; }

        public string mac_address { get; set; }

        public string note { get; set; }
        public string owner { get; set; }
        public decimal cost { get; set; }
        public string po_number { get; set; }


        public int invoice_number{ get; set; }

        [Required]
        public string serial_number { get; set; }

        [Required]
        public string asset_tag_number { get; set; }

        [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
        public DateTime? acquired_date { get; set; }

        [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
        public DateTime? disposed_date { get; set; }

        [Required]
        [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
        public DateTime created_date { get; set; }

        [Required]
        public string created_by { get; set; }

        [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
        public DateTime modified_date { get; set; }

        public string modified_by { get; set; }

        // Flag to specify if item is available? (Not signed out, not auctioned, recycled, etc.)
        //public bool available { get; set; }
    }
}

---

EDIT2:

Full Result in Package Manager Console from entering command update-database to the result of Ambiguous Match found:

PM> update-database
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
No pending explicit migrations.
Running Seed method.
System.Reflection.AmbiguousMatchException: Ambiguous match found.
   at System.RuntimeType.GetPropertyImpl(String name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers)
   at System.Type.GetProperty(String name, BindingFlags bindingAttr)
   at System.Linq.Expressions.Expression.PropertyOrField(Expression expression, String propertyOrFieldName)
   at System.Data.Entity.Core.Objects.Internal.EntityProxyFactory.CreateBaseGetter(Type declaringType, PropertyInfo propertyInfo)
   at System.Data.Entity.Core.Objects.Internal.PocoPropertyAccessorStrategy.GetNavigationPropertyValue(RelatedEnd relatedEnd)
   at System.Data.Entity.Core.Objects.Internal.EntityWrapper`1.GetNavigationPropertyValue(RelatedEnd relatedEnd)
   at System.Data.Entity.Core.Objects.EntityEntry.FixupFKValuesFromNonAddedReferences()
   at System.Data.Entity.Core.Objects.ObjectContext.AddSingleObject(EntitySet entitySet, IEntityWrapper wrappedEntity, String argumentName)
   at System.Data.Entity.Core.Objects.ObjectContext.AddObject(String entitySetName, Object entity)
   at System.Data.Entity.Internal.Linq.InternalSet`1.<AddRange>b__f(Object entity)
   at System.Data.Entity.Internal.Linq.InternalSet`1.ActOnSet(Action`1 action, EntityState newState, IEnumerable entities, String methodName)
   at System.Data.Entity.Internal.Linq.InternalSet`1.AddRange(IEnumerable entities)
   at System.Data.Entity.DbSet`1.AddRange(IEnumerable`1 entities)
   at InventoryTracker.Migrations.Configuration.Seed(InventoryTrackerContext context) in c:\James-Projects\InventoryTracker\InventoryTracker\Migrations\Configuration.cs:line 91
   at System.Data.Entity.Migrations.DbMigrationsConfiguration`1.OnSeed(DbContext context)
   at System.Data.Entity.Migrations.DbMigrator.SeedDatabase()
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.SeedDatabase()
   at System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
   at System.Data.Entity.Migrations.DbMigrator.UpdateInternal(String targetMigration)
   at System.Data.Entity.Migrations.DbMigrator.<>c__DisplayClassc.<Update>b__b()
   at System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
   at System.Data.Entity.Migrations.Infrastructure.MigratorBase.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
   at System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration)
   at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update(String targetMigration)
   at System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.Run()
   at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
   at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
   at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
   at System.Data.Entity.Migrations.Design.ToolingFacade.Update(String targetMigration, Boolean force)
   at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
   at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
Ambiguous match found.

Answer 1

Your issue is in the very similar property names. For example in INV_Assets you have

public int Model_Id { get; set; }

[ForeignKey("Model_Id")]
public virtual INV_Models model_id { get; set; }

Both of them are named almost identically. The difference is just in first symbol case. Based on the stack trace and Entity framework source it doing such thing in EntityProxyFactory class:

public virtual Func<object, object> CreateBaseGetter(Type declaringType, PropertyInfo propertyInfo)
{
  Func<object, object> nonProxyGetter = 
        ((Expression<Func<object, object>>) (instance 
            => 
                Expression.PropertyOrField(
                    (Expression) Expression.Convert(instance, declaringType),
                    propertyInfo.Name))
        ).Compile();

It passes property name as string. And Reflection can't understand what property it should use, because there are two properties with the same name and different case.

Here is a sample program with the same logic that also fails with the same Ambiguous match found. exception - https://dotnetfiddle.net/BUIAwK

As usual referenced object named with ID in the property name, so you just need to update your code to

public int Model_Id { get; set; }

[ForeignKey("Model_Id")]
public virtual INV_Models Model { get; set; }

Answer 2

Hello again Analytic Lunatic :)

Well if you look here http://msdn.microsoft.com/en-us/library/system.reflection.ambiguousmatchexception%28v=vs.110%29.aspx Then you will see that quote: "The exception that is thrown when binding to a member results in more than one member matching the binding criteria. This class cannot be inherited."

Do you have more properties in INV_Assets that we cant see ? Can you please show us the class?