title: Entity framework table inheritance saving issue
body: <p>I have table inheritance in database:</p>
  
  <pre><code>Ticket{TicketId, TicketTypeId, CreatedBy, Title, Description etc.}
  UserInfo{TicketId etc.}
  </code></pre>
  
  <p><code>TicketId</code> is primary key auto increment. Table <code>UserInfo</code> inherit <code>Ticket</code> table so <code>TicketId</code> in <code>UserInfo</code> is actualy <code>FK</code> for <code>TicketId</code> from <code>Ticket</code> table.<br/>
  I have model in EF:</p>
  
  <pre><code>public abstract class Ticket
      {
          [Key]
          public int TicketId { get; set; }
          public int TicketTypeId { get; set; }        
          public string Title { get; set; }
          public string Description { get; set; }
  
          public Guid CreatedBy { get; set; }
          public virtual User User { get; set; }
      } 
  
  public class UserInfo :Ticket
      {
          ...
      }
  </code></pre>
  
  <p>When I try to insert new UserInfo object to database I write:</p>
  
  <pre><code>User u = context.Users.Find(Membership.GetUser().ProviderUserKey);
  
  
              UserInfo o = new UserInfo();
              o.CreatedBy = u.UserId;
              o.Description = "First EF user info to database!";
              o.TicketTypeId = 1;
              o.Title = "First User Info EF";
  
              context.Tickets.Add(o);
              context.SaveChanges();
  </code></pre>
  
  <p>But application break on SaveChanges().<br/>
  <strong>I get the following error:</strong></p>
  
  <p><del> {"Invalid column name 'User_UserId'."}</del><br/>
  <strong>UPDATE</strong><br/>
  I changed <code>CreatedBy</code> to <code>UserId</code> and I pass this error, but now I have two more issues here:<br/>
  I save UserInfo to database but there is nothing in UserInfo table. I thought that EF can add this field after save?<br/>
  This ticket table in database is bound to UserInfo but it's also bounded to few more tables in database by TicketID but when I try to save object UserInfo I get this error:</p>
  
  <pre><code>{"The INSERT statement conflicted with the FOREIGN KEY 
  constraint \"FK_Tickets_Groups\". The conflict occurred in database \"db_Example\", table \"dbo.Groups\", column 'TicketId'.\r\nThe statement has been terminated."}
  </code></pre>
  
  <p>So to save this I currently removed table references except UserInfo. Can EF handle this situation?<br/><br/></p>