Using SQL Server Compact 4.0.0.1 with Entity Framework 4.3

Question

Error:

Could not load System.Data.SqlServerCe.Entity.dll. Reinstall SQL Server Compact.

Inner Exception:

{"Could not load file or assembly 'System.Data.SqlServerCe.Entity, Version=4.0.0.1, Culture=neutral, PublicKeyToken=89845dcd8080cc91' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)":"System.Data.SqlServerCe.Entity, Version=4.0.0.1, Culture=neutral, PublicKeyToken=89845dcd8080cc91"}

Steps to Reproduce:

1. Create new MVC3 Application

2. Add Nuget Package EntityFramework.SqlServerCompact

   <package id="EntityFramework.SqlServerCompact" version="4.1.8482.2" />

3. Create Model

    public class TaskItem { [Key] public int Id { get; set; } public string Description { get; set; } } 

4. Create DbContext

    public class TestContext : DbContext { public DbSet<TaskItem> TaskItems { get; set; } } 

5. Home Controller

    public ActionResult Index() { var db = new TestContext(); // breakpoint on Add() below db.TaskItems.Add(new TaskItem { Description = "Get shit done."}); return View(); } 

6. Web.config Connection String and Runtime and System.Data

   <add name="ApplicationServices" connectionString="Data Source=|DataDirectory|Test.sdf" providerName="System.Data.SqlServerCe.4.0" />

    <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <dependentAssembly> <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" /> <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="3.0.0.0" /> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="System.Data.SqlServerCe" publicKeyToken="89845dcd8080cc91" culture="neutral" /> <bindingRedirect oldVersion="0.0.0.0-4.0.0.1" newVersion="4.0.0.1" /> </dependentAssembly> </assemblyBinding> </runtime> <system.data> <DbProviderFactories> <remove invariant="System.Data.SqlServerCe.4.0" /> <add name="Microsoft SQL Server Compact Data Provider 4.0" invariant="System.Data.SqlServerCe.4.0" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=4.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" /> </DbProviderFactories> </system.data> 

Question:

Web.config is all default... nothing funky here... all the DLLs are copy local and in bin... what am I missing? It's got to be something very simple.

---

Update:

Removing the Dependent Assembly section from web.config solved the problem, but I still need an explanation why in order to close the answer.

Answer 1

Remove the dependent assembly binding from your web.config

  <dependentAssembly>
    <assemblyIdentity name="System.Data.SqlServerCe" publicKeyToken="89845dcd8080cc91" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-4.0.0.1" newVersion="4.0.0.1" />
  </dependentAssembly>

Answer 2

Check this code is created or not on your project

EntityFramework.SqlServerCompact.cs under the App_Start folder

using System.Data.Entity;
using System.Data.Entity.Infrastructure;

[assembly: WebActivator.PreApplicationStartMethod(typeof(MyStory.Tests.App_Start.EntityFramework_SqlServerCompact), "Start")]

namespace MyStory.Tests.App_Start {
    public static class EntityFramework_SqlServerCompact {
        public static void Start() {
            Database.DefaultConnectionFactory = new SqlCeConnectionFactory("System.Data.SqlServerCe.4.0");
        }
    }
}