The entity type <type> is not part of the model for the current context

StackOverflow https://stackoverflow.com/questions/20688922

Question

I am getting into the Entity Framework, but I am unsure if I am missing a critical point in the code-first approach.

I am using a generic repository pattern based on the code from https://genericunitofworkandrepositories.codeplex.com/ and have created my entities.

But when I try to access or modify the entity I run into the following:

System.InvalidOperationException: The entity type Estate is not part of the model for the current context.

It happens when I am trying to access it from my repository:

public virtual void Insert(TEntity entity)
{
    ((IObjectState)entity).ObjectState = ObjectState.Added;
    _dbSet.Attach(entity); // <-- The error occurs here
    _context.SyncObjectState(entity);
}

The database (./SQLEXPRESS) is created just fine, but the entities (tables) is just not created on startup.

I am wondering if I need to explicit set the mapping of the entities? Is EF not able to this by its own?

My Entity is:

public class Estate : EntityBase
{
    public int EstateId { get; set; }
    public string Name { get; set; }
}

My context is as so:

public partial class DimensionWebDbContext : DbContextBase // DbContextBase inherits DbContext
{
    public DimensionWebDbContext() :
        base("DimensionWebContext")
    {
        Database.SetInitializer<DimensionWebDbContext>(new CreateDatabaseIfNotExists<DimensionWebDbContext>());
        Configuration.ProxyCreationEnabled = false;
    }

    public new IDbSet<T> Set<T>() where T : class
    {
        return base.Set<T>();
    }

}

Is there any specific reason why this error occurs? I have tried enable migrations and enable automatic migrations without any help either.

Was it helpful?

Solution

Put this in your custom DbContext class:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Estate>().ToTable("Estate");
}

If your tables are not created on startup, this is why. You need to tell the DbContext about them in the OnModelCreating method override.

You can either do custom per-entity mappings here, or separate them out into separate EntityTypeConfiguration<T> classes.

OTHER TIPS

Apparently, this error is very generic, it could have a number of reasons. In my case, it was the following: The connection string (in Web.config) generated by the .edmx was invalid. After almost a day of trying everything, I changed the connection string from the EF string to an ADO.NET string. This solved my issue.

For example, the EF string looks something like this:

<connectionStrings> 
  <add name="BlogContext"  
    connectionString="metadata=res://*/BloggingModel.csdl| 
                               res://*/BloggingModel.ssdl| 
                               res://*/BloggingModel.msl; 
                               provider=System.Data.SqlClient 
                               provider connection string= 
                               &quot;data source=(localdb)\v11.0; 
                               initial catalog=Blogging;
                               integrated security=True; 
                               multipleactiveresultsets=True;&quot;" 
     providerName="System.Data.EntityClient" /> 
</connectionStrings>

And the ADO.NET string looks like this:

<connectionStrings>
  <add name="BlogContext"  
        providerName="System.Data.SqlClient"  
        connectionString="Server=.\SQLEXPRESS;Database=Blogging;
        Integrated Security=True;"/> 
</connectionStrings>

Source: http://msdn.microsoft.com/nl-nl/data/jj556606.aspx

For me the issue was that I had not included the Entity Class within my db set inside the context for entity framework.

public DbSet<ModelName> ModelName { get; set; }

You may try removing the table from the model and adding it again. You can do this visually by opening the .edmx file from the Solution Explorer.

Steps:

  1. Double click the .edmx file from the Solution Explorer
  2. Right click on the table head you want to remove and select "Delete from Model"
  3. Now again right click on the work area and select "Update Model from Database.."
  4. Add the table again from the table list
  5. Clean and build the solution

The problem may be in the connection string. Ensure your connection string is for SqlClient provider, with no metadata stuff related to EntityFramework.

My issue was resolved by updating the metadata part of the connection string. Apparently it was pointing at the wrong .csdl / .ssdl / .msl reference.

I've seen this error when an existing table in the database doesn't appropriately map to a code first model. Specifically I had a char(1) in the database table and a char in C#. Changing the model to a string resolved the problem.

One other thing to check with your connection string - the model name. I was using two entity models, DB first. In the config I copied the entity connection for one, renamed it, and changed the connection string part. What I didn't change was the model name, so while the entity model generated correctly, when the context was initiated EF was looking in the wrong model for the entities.

Looks obvious written down, but there are four hours I won't get back.

For me the issue was that I used the connection string generated by ADO.Net Model (.edmx). Changing the connection string solved my issue.

This can also occur if you are using a persisted model cache which is out of date for one reason or another. If your context has been cached to an EDMX file on a file system (via DbConfiguration.SetModelStore) then OnModelCreating will never be called as the cached version will be used. As a result if an entity is missing from your cached store then you will get the above error even though the connection string is correct, the table exists in the database and the entity is set up correctly in your DbContext.

The message was pretty clear but I didn't get it at first...

I'm working with two Entity Framework DB contexts sysContext and shardContext in the same method.

The entity I had modified\updated is from one context but then I tried to save it to the other context like this:

invite.uid = user.uid;

sysContext.Entry(invite).State = EntityState.Modified;

sysContext.SaveChanges(); // Got the exception here

but the correct version should be this:

invite.uid = user.uid;

shardContext.Entry(invite).State = EntityState.Modified;

shardContext.SaveChanges();

After passing the entity to the correct context this error went away.

I was facing the same issue with EntityFrameworkCore trying to update a range of values.

This approach did not work

  _dbSet.AttachRange(entity);
  _context.Entry(entity).State = EntityState.Modified;
   await _context.SaveChangesAsync().ConfigureAwait(false);

After adding UpdateRange method and removing attach and entry everything work

  _dbSet.UpdateRange(entity);
  await _context.SaveChangesAsync().ConfigureAwait(false);

Sounds obvious, but make sure that you are not explicitly ignoring the type:

modelBuilder.Ignore<MyType>();

map of the entity (even an empty one) added to the configuration will lead to having the entity type be part of the context. We had an entity with no relationship to other entities that was fixed with an empty map.

if you are trying DB first then be sure that your table has primary key

Visual Studio 2019 seems to cause this for me. I fixed it by generating the edmx model again in 2017.

For me it was caused because I renamed the entity class.When I rolled it back it was Ok.

I had this

using (var context = new ATImporterContext(DBConnection))
{
    if (GetID(entity).Equals(0))
    {
        context.Set<T>().Add(entity);
    }
    else
    {
        int val = GetID(entity);
        var entry = GetEntryAsync(context, GetID(entity)).ConfigureAwait(false);
        context.Entry(entry).CurrentValues.SetValues(entity);

    }
    
    await context.SaveChangesAsync().ConfigureAwait(false);
}

This was in an async method, but I've forgot to put await before GetEntryAsync, and so I got this same error...

Make sure you have set up your mapping class to point to your SQL table

I've had the same problem and in my case, the reason why I got this error message was that the property identifiers in my class file did not match the identifiers defined in the database, e.g. I wrote an identifier with a beginning uppercase letter while in the database it was all lowercase.

I've faced this issue after publishing my project using web deploy. It happened because my the metadata in connection string of my publish profile was not same as connection string in my project because I dropped the edmx for some reason and added it back with different Name. To fix it I had to delete the publish profile and redeploy again so that the metadata matches the names.

With models created from database (First Database), it is not possible to replace the connection string (with metadata and providerName="System.Data.EntityClient", from EDMX) by one of SQL.

The only possibility I have found is to create another context that uses the SQL connection (providerName="System.Data.SqlClient")

<connectionStrings>
    <add name="DefaultConnection" providerName="System.Data.SqlClient"  connectionString="Max Pool Size=10000;Pooling=true;Data Source=MyIpServer;Initial Catalog=myDatabase;Persist Security Info=True;User ID=MyUser;Password=MyPassword;TrustServerCertificate=False" />
    <add name="Entities" providerName="System.Data.EntityClient"  connectionString="metadata=res://*/Datos.MyModel.csdl|res://*/Datos.MyModel.ssdl|res://*/Datos.MyModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Max Pool Size=10000;Pooling=true;data source=MyIpServer;initial catalog=myDatabase;persist security info=True;user id=MyUser;password=MyPassword;trustservercertificate=False;MultipleActiveResultSets=True;App=EntityFramework&quot;" />
</connectionStrings>

With the two context options, with Identity:

public partial class ContextWithUsers : IdentityDbContext<MyUser>
{
    public ContextWithUsers() : base("name=DefaultConnection")
    {
    }
}

public class MyUser : IdentityUser
{
    // aditional table user data
    //public virtual MyUserInfo MyUserInfo { get; set; }
}

Normal context:

public partial class ContextWithoutUsers : DbContext
{
    public ContextWithoutUsers () : base("name=Entities")
    {
    }
}

This solution works, but... Why is it not possible to use the same context with the First Database model + Identity ?

NOTE 1: if you force change connection string show:

System.Data.Entity.Infrastructure.UnintentionalCodeFirstException: 'The context is being used in Code First mode with code that was generated from an EDMX file for either Database First or Model First development. This will not work correctly. To fix this problem do not remove the line of code that throws this exception. If you wish to use Database First or Model First, then make sure that the Entity Framework connection string is included in the app.config or web.config of the start-up project. If you are creating your own DbConnection, then make sure that it is an EntityConnection and not some other type of DbConnection, and that you pass it to one of the base DbContext constructors that take a DbConnection. To learn more about Code First, Database First, and Model First see the Entity Framework documentation here: http://go.microsoft.com/fwlink/?LinkId=394715'

NOTE 2: External Class library with EDMX + Data and ASP.NET webform project

Delete the .edmx file and add it again. Especially, if you have upgraded the Entity Framework.

Could be stupid, but if you only got this error on some Table, dont forget to clean your project and rebuild (could save a lot of time)

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