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The error "Failed to install the database initializer of type MyNamespace.MyCustomInitializer, MyAssembly" failed to load the type MyContext

I am building a web application using .NET4.5 with Entity Framework 6 alpha3 that uses the new SQL Compact database. The database does not yet exist.

I have the following code in a web form:

public IQueryable<Job> listJobs_GetData() { var db = new JournalistContext(); IQueryable<Job> query = db.Jobs.Where(d => d.JobStart > DateTime.Now) .OrderBy(s => s.JobStart) .Take(10); return query; }

where JournalistContext comes from DbContext. It creates an instance of JournalistContext in order, but on the next line it throws an exception below. I assume that the database does not exist, it tries to call the initializer, but it fails.

 System.InvalidOperationException was unhandled by user code HResult=-2146233079 Message=Failed to set database initializer of type 'TSJ.Models.MyCustomInitializer, TSJ' for DbContext type 'TSJ.JournalistContext, TSJ' specified in the application configuration. See inner exception for details. Source=EntityFramework StackTrace: at System.Data.Entity.Internal.InitializerConfig.TryGetInitializer(Type requiredContextType, String contextTypeName, String initializerTypeName, Boolean isDisabled, Func`1 initializerArgs, Func`3 exceptionMessage) at System.Data.Entity.Internal.InitializerConfig.<>c__DisplayClass6.<TryGetInitializerFromEntityFrameworkSection>b__1(ContextElement e) at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext() at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate) at System.Data.Entity.Internal.InitializerConfig.TryGetInitializerFromEntityFrameworkSection(Type contextType) at System.Data.Entity.Internal.InitializerConfig.TryGetInitializer(Type contextType) at System.Data.Entity.Config.AppConfigDependencyResolver.GetServiceFactory(Type type, String name) at System.Data.Entity.Config.AppConfigDependencyResolver.<>c__DisplayClass1.<GetService>b__0(Tuple`2 t) at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) at System.Data.Entity.Config.AppConfigDependencyResolver.GetService(Type type, Object key) at System.Data.Entity.Config.ResolverChain.<>c__DisplayClass3.<GetService>b__0(IDbDependencyResolver r) at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext() at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate) at System.Data.Entity.Config.ResolverChain.GetService(Type type, Object key) at System.Data.Entity.Config.CompositeResolver`2.GetService(Type type, Object key) at System.Data.Entity.Config.IDbDependencyResolverExtensions.GetService(IDbDependencyResolver resolver, Type type) at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() at System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>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.get_InternalContext() at System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate) at TSJ.MainOverview.listJobs_GetData() in ....\Visual Studio 2012\Projects\TSJ\TSJ\MainOverview.aspx.cs:line 27 InnerException: System.TypeLoadException HResult=-2146233054 Message=Could not load type 'TSJ.JournalistContext' from assembly 'TSJ'. Source=mscorlib TypeName=TSJ.JournalistContext StackTrace: at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type) at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName) at System.RuntimeType.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) at System.Type.GetType(String typeName, Boolean throwOnError) at System.Data.Entity.Internal.InitializerConfig.TryGetInitializer(Type requiredContextType, String contextTypeName, String initializerTypeName, Boolean isDisabled, Func`1 initializerArgs, Func`3 exceptionMessage)

As described here http://msdn.microsoft.com/en-us/data/jj556606 I created a custom database initializer, which is currently an empty class:

  internal sealed class MyCustomInitializer : MigrateDatabaseToLatestVersion<JournalistContext, TSJ.Migrations.Configuration> { } public class JournalistContext : DbContext { public JournalistContext() : base("TSJ") { } ...

My web.config file refers to this initializer as follows:

  <entityFramework> <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlCeConnectionFactory, EntityFramework"> <parameters> <parameter value="System.Data.SqlServerCe.4.0" /> </parameters> </defaultConnectionFactory> <contexts> <context type="TSJ.JournalistContext, TSJ"> <databaseInitializer type="TSJ.Models.MyCustomInitializer, TSJ" /> </context> </contexts> <providers> <provider invariantName="System.Data.SqlServerCe.4.0" type="System.Data.Entity.SqlServerCompact.SqlCeProviderServices, EntityFramework.SqlServerCompact, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" /> </providers> </entityFramework>

I'm at a dead end! Any ideas?

Another thing I noticed: these lines appeared in my web.config file. I'm not sure how they were added or why.

  <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>

Thanks a lot, Mark.

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2 answers

I assume your initializer class is internal. In my project, I downloaded it from another assembly and did not see it. As soon as I became public, he worked like magic. I suppose this may be true, even if you have everything in one assembly.

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My problem is with my connection string.

Man, having tried the following links, I was not successful. I tried to connect to my SQLEXPRESS instance. I tried:

Error loading database initializer using EF6

Reset Migrations Entity-Framework

Try it - it finally worked for me. Replace the data source with an instance of SqlExpress / SqlServer if you are not using localdb.

 Enable-Migrations -ConnectionString "Data Source=.\SQLEXPRESS;Initial Catalog=[your database name];User Id=[your user name];Password=[your password];Integrated Security=SSPI;" -ConnectionProviderName "System.Data.SqlClient" -Force -Verbose Add-Migration -Name "Initial" -ConnectionString "Data Source=.\SQLEXPRESS;Initial Catalog=[your database name];User Id=[your user name];Password=[your password];Integrated Security=SSPI;" -ConnectionProviderName "System.Data.SqlClient" -Force -Verbose Update-Database -Force -ConnectionString "Data Source=.\SQLEXPRESS;Initial Catalog=[your database name];User Id=[your user name];Password=[your password];Integrated Security=SSPI;" -ConnectionProviderName "System.Data.SqlClient" -Verbose

Feel free to comment, and I can continue to try to help if you still have this problem.

It was a resource that I finally found that helped me understand a lot about what I am doing.

https://coding.abel.nu/2012/03/ef-migrations-command-reference/

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