Entity Framework Code First AddOrUpdate method insert Duplicate values

Question

I have simple entity:

public class Hall
{
    [Key]
    public int Id {get; set;}

    public string Name [get; set;}
}

Then in the S

Answer 1

I used the ID field as Identity/Key and add attributes not to assign Ids by the server. This solved the problem for me.

public class Hall
{
    [Key]
    [Required]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int Id {get; set;}

    public string Name [get; set;}
 }