How can I retrieve Id of inserted entity using Entity framework?

c# asp.net entity-framework
ahmet picture ahmet · Mar 6, 2011 · Viewed 442.7k times · Source

I have a problem with Entity Framework in ASP.NET. I want to get the Id value whenever I add an object to database. How can I do this?

According to Entity Framework the solution is:

using (var context = new EntityContext())
{
    var customer = new Customer()
    {
        Name = "John"
    };

    context.Customers.Add(customer);
    context.SaveChanges();
        
    int id = customer.CustomerID;
}

This doesn't get the database table identity, but gets the assigned ID of the entity, if we delete a record from the table the seed identity will not match the entity ID.

Answer

Ladislav Mrnka picture Ladislav Mrnka · Mar 6, 2011

It is pretty easy. If you are using DB generated Ids (like IDENTITY in MS SQL) you just need to add entity to ObjectSet and SaveChanges on related ObjectContext. Id will be automatically filled for you:

using (var context = new MyContext())
{
  context.MyEntities.Add(myNewObject);
  context.SaveChanges();

  int id = myNewObject.Id; // Yes it's here
}

Entity framework by default follows each INSERT with SELECT SCOPE_IDENTITY() when auto-generated Ids are used.

Related questions

Unable to update the EntitySet - because it has a DefiningQuery and no <UpdateFunction> element exist

I am using Entity Framework 1 with .net 3.5. I am doing something simple like this: var roomDetails = context.Rooms.ToList(); foreach (var room in roomDetails) { room.LastUpdated = DateTime.Now; } I am getting this error when I try to do: context.SaveChanges(); …

Read More
Entity Framework Timeouts

I am getting timeouts using the Entity Framework (EF) when using a function import that takes over 30 seconds to complete. I tried the following and have not been able to resolve this issue: I added Default Command Timeout=300000 to the …

Read More
The instance of entity type cannot be tracked because another instance of this type with the same key is already being tracked

I have a Service Object Update public bool Update(object original, object modified) { var originalClient = (Client)original; var modifiedClient = (Client)modified; _context.Clients.Update(originalClient); //<-- throws the error _context.SaveChanges(); //Variance checking and logging of changes between the …

Read More