Question

I am learing Linq-to-SQL. I want to add a record, but get an exception on InsertOnSubmit():

Can’t perform Create, Update, or Delete operations on
‘Table(GuestbookEntry)’ because it has no primary key.

But my database does have a primary key.

Here is my code:

[Table(Name = "GuestbookEntry")]
public class GuestbookEntry
{
    [Column(DbType = "int not null, IsPrimaryKey=true, IsDBGenerated=true")]
    public int Id { get; set; }
    [Column]
    public string Name { get; set; }
    [Column]
    public string Message { get; set; }
    [Column]
    public DateTime DateAdded { get; set; }
}

public class GuestbookContext : DataContext
{
    public Table<GuestbookEntry> GuestBookEntries;
    //public Table<Order> Orders;
    public GuestbookContext(string connection) : base(connection) { }
}

...

private GuestbookContext dbGuestbook = new GuestbookContext("GuestBookConnection");

...

dbGuestbook.GuestBookEntries.InsertOnSubmit(entry);
dbGuestbook.SubmitChanges();

Could you please tell what is wrong?

Thanks.

Answer 1

It looks like you need to define a primary key for your table