How can I get Id of inserted entity in Entity fram

Question

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?

Answer 1

The object you're saving should have a correct Id after propagating changes into database.

Answer 2

All answers are very well suited for their own scenarios, what i did different is that i assigned the int PK directly from object (TEntity) that Add() returned to an int variable like this;

using (Entities entities = new Entities())
{
      int employeeId = entities.Employee.Add(new Employee
                        {
                            EmployeeName = employeeComplexModel.EmployeeName,
                            EmployeeCreatedDate = DateTime.Now,
                            EmployeeUpdatedDate = DateTime.Now,
                            EmployeeStatus = true
                        }).EmployeeId;

      //...use id for other work
}

so instead of creating an entire new object, you just take what you want :)

EDIT For Mr. @GertArnold :

Answer 3

Repository.addorupdate(entity, entity.id);
Repository.savechanges();
Var id = entity.id;

This will work.

Answer 4

When you use EF 6.x code first

    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid Id { get; set; }

and initialize a database table, it will put a

(newsequentialid())

inside the table properties under the header Default Value or Binding, allowing the ID to be populated as it is inserted.

The problem is if you create a table and add the

[DatabaseGenerated(DatabaseGeneratedOption.Identity)]

part later, future update-databases won't add back the (newsequentialid())

To fix the proper way is to wipe migration, delete database and re-migrate... or you can just add (newsequentialid()) into the table designer.

Answer 5

There are two strategies:

1. Use Database-generated ID (int or GUID)

   Cons:

   You should perform SaveChanges() to get the ID for just saved entities.

   Pros:

   Can use int identity.

2. Use client generated ID - GUID only.

   Pros: Minification of SaveChanges operations. Able to insert a big graph of new objects per one operation.

   Cons:

   Allowed only for GUID