Question

I’m using asp.net mvc 3 and EF 4.1 with visual studio 2010 and im new to it.

i have a problem about last inserted id. i have two table in my db “points_Order” and “points_OrderDetails”.

                            db.Order.Add(po);
                            db.SaveChanges();
                           //second thing i have tried
                            var orderID = (from oi in db.Order
                                           select oi.ID)
                                           .Max(i => i);
                           // and this first thing
                            pod.OrderID = po.ID;
                            pod.OrderID = orderID;
                            db.OrderDetails.Add(pod);
                            db.SaveChanges();

context class:

public class points_Order {
    [Key]
    public int ID { get; set; }
    public string Owner { get; set; }
    public DateTime Date { get; set; }
    public byte Status { get; set; }
    public int Total { get; set; }
    //public virtual points_OrderDetails OrderDetail { get; set; }
}

public class points_OrderDetails {
    [Key]
    public int OrderID { get; set; }
    public string OrderType { get; set; }
    public int Amount { get; set; }
    public int ItemID { get; set; }
    public int ItemRecord { get; set; }
    public string ItemCode { get; set; }
    public byte Plus { get; set; }
    public byte Degree { get; set; } 
    public string Kind { get; set; }
    public string Sex { get; set; }
    public string Race { get; set; }
    public string Tier { get; set; }
    public string SetItem { get; set; }
    public string SOX { get; set; }
    //public Blues Blue { get; set; }
}

public DbSet<points_Order> Order { get; set; }
public DbSet<points_OrderDetails> OrderDetails { get; set; }

im getting the error “{“Cannot insert the value NULL into column ‘OrderID’, table ‘db.dbo.points_OrderDetails’; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated.”}”

what can i do? am i doing something wrong?

Answer 1

If you define a relationship from order -> order details in your model, it should work like this:

po.Details.Add(pod); // or pod.Order = po;
db.Order.Add(po);
db.SaveChanges();

EF should figure out the relations for you, no need to set ID’s manually.

UPDATE: you’re trying to do something that is not supported. You have a one-to-one mapping; EF does not support it the way you intend to (shared primary key). See http://weblogs.asp.net/manavi/archive/2011/05/01/associations-in-ef-4-1-code-first-part-5-one-to-one-foreign-key-associations.aspx for an explanation on how to model one-to-one in EF.