Question

I have 2 entities that are playing nice together when I am pulling data out of the database, but now that I am trying to save something I am getting a strange error and elimination isn’t helping me track down the cause:

Booking

public class Booking
{
    public virtual int Id { get; set; }
    public virtual Int32 bookingID { get; set; }
}

Booking Location

public class BookingLocation
{
    public virtual int Id { get; set; }
    public virtual Int32 bookingID { get; set; }
    public virtual Int32 locationID { get; set; } 
    public virtual DateTime startDateTime { get; set; }
    public virtual DateTime endDateTime { get; set; }
}

Booking Mapping

public class BookingMap : ClassMap<Booking>
{
    public BookingMap()
    {
        Table("Bookings");

        Id(x => x.Id).Column("ID");
        Map(x => x.bookingID).Column("BookingID");

        HasMany(x => x.BookingLocations)                
           .KeyColumn("BookingID")
          .Not.LazyLoad().Cascade.All(); 
    }
}

BookLocation Mapping

public class BookingLocationMap : ClassMap<BookingLocation>
{
    public BookingLocationMap()
    {
        Table("Bookings_Locations");

        Id(x => x.Id).Column("ID");
        Map(x => x.bookingID).Column("BookingID");

        Map(x => x.locationID).Column("LID");
        Map(x => x.startDateTime).Column("startdatetime");
        Map(x => x.endDateTime).Column("enddatetime");


        References(x => x.Booking)
         .Column("BookingID")
         .Not.LazyLoad().Nullable()
         .Cascade.All();
    }
}

Any ideas?

Answer 1

You are trying to map the same column twice (BookingId):

Map(x => x.bookingID).Column("BookingID");

References(x => x.Booking)
     .Column("BookingID")
     .Not.LazyLoad().Nullable()
     .Cascade.All();

If you need to reference the field BookingId you can just use your many to one (References) Booking.BookingId so your mapping would become:

public class BookingLocationMap : ClassMap<BookingLocation>
{
    public BookingLocationMap()
    {
        Table("Bookings_Locations");

        Id(x => x.Id).Column("ID");
        Map(x => x.locationID).Column("LID");
        Map(x => x.startDateTime).Column("startdatetime");
        Map(x => x.endDateTime).Column("enddatetime");

        References(x => x.Booking)
         .Column("BookingID")
         .Not.LazyLoad().Nullable()
         .Cascade.All();
    }
}

Example

I have read only access to my collections so I use the following methods to add and remove items from this collection:

    public virtual void AddBookingLocation(BookingLocation bookingLocationToAdd)
    {
        bookingLocationToAdd.Booking = this;
        this.bookingLocations.Add(bookingLocationToAdd);
    }

    public virtual void RemoveBookingLocation(BookingLocation bookingLocationToRemove)
    {
        this.bookingLocations.Remove(bookingLocationToRemove);
    }