Entity Framework Code First Using One column as Primary Key and another as Auto Increment Column

Question

I have a class named Sale

public class Sale
{
    public int Id { get; set; }
    public string TrNo { get; set; }
    public DateTime Date          


        

Answer 1

Apparently the answer of @IronMan84 correct. But it didn't work for me. I slightly modified it to apply my another condition. And it worked. I did nothing else.

This is my solution.

public class Sale
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    [Key, Column(TypeName = "varchar"), MaxLength(50)]
    public string TrNo { get; set; }

    public DateTime Date { get; set; }
    public int CustomerID { get; set; }

    public ObservableCollection SaleDetails { get; set; }
}

Unfortunately I can't make the answer of @IronMan84 as the correct one as it didn't work for me.