enable-migrations -ContextTypeName Contex -MigrationsDirectory ContexMigrations

Add-migration -configuration MVC.ContexMigrations.Configuration Initial

Update-database -configuration MVC.ContexMigrations.Configuration

public class Card
{
 public int CardId { set; get; }
 public Record Record { set; get; }
}

public class Record
{
 public int RecordId { set; get; }
}

modelBuilder.Entity<Card>()
    .HasRequired(x => x.Record)
    .WithRequiredPrincipal()
    .WillCascadeOnDelete(false);