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 think it's likely that you need to back out existing database migrations (i.e. start your database from scratch) with something like Update-Database TargetMigration:0 followed by Update-Database.

As it is, you're not dropping the existing table or values, you're just add/updating those values. That needs to happen in order to get your desired result.