NHibernate mapping many-to-many lists not loading the objects right

I am attempting a many-to-many list in one of my objects.

I have three classes which I am attempting to save and load via NHibernate: Intersection, Vehicle and Zone. Intersection and Vehicle are both derived from Device.

The Intersection class contains a list of Zones, which each zone may only belong to 1 Intersection, but each Intersection may contain multiple Zones. I have this mapped correctly and it is saving the many-to-one association of Zones to the Intersections just fine.

The Vehicle class contains a List of Zones. The Vehicle may belong to multiple Zones. Also, the Zones contain a List of Vehicles. Each Zone may contain multiple Vehicles. Thus the many-to-many relationship between the two.

All the objects appear to be saved to the database correctly. I can go through my tables and all the fields for each Intersection, Vehicle, and Zone are propagated correctly; however, they are not loading the fields when I load the object using NHibernate.

I am hoping someone may be able to shed some light as to what may be going wrong here.

Here is my mapping of Device which includes the Intersection and Vehicle class mappings:

    <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
      <class xmlns="urn:nhibernate-mapping-2.2" name="EMTRAC.Devices.Device, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Device`" lazy="false">
        <id name="PK" type="System.Int64, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="PK" />
          <generator class="identity" />
        </id>
        <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="LocalConnection" lazy="false" cascade="all">
          <column name="LocalConnection_id" />
        </many-to-one>
        <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Connection" lazy="false" cascade="all">
          <column name="Connection_id" />
        </many-to-one>
        <many-to-one class="EMTRAC.Packets.Packet, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Configuration" lazy="false" cascade="all">
          <column name="Configuration_id" />
        </many-to-one>
        <joined-subclass name="EMTRAC.Intersections.Intersection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" lazy="false">
          <key>
            <column name="Device_id" />
          </key>
          <component name="Zones" access="property">
            <bag name="_list" cascade="all-delete-orphan" access="field" lazy="false" fetch="join">
              <key>
                <column name="Zone_PK" />
              </key> 
              <many-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
            </bag>
          </component>
          <many-to-one class="EMTRAC.Intersections.Streets, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Streets" lazy="false" cascade="all">
            <column name="Streets_id" />
          </many-to-one>
          <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Position" lazy="false" cascade="all">
            <column name="Position" />
          </many-to-one>
        </joined-subclass>
        <joined-subclass name="EMTRAC.Vehicles.Vehicle, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null">
          <key>
            <column name="Device_id" />
          </key>
          <component name="Zones" access="property">
            <bag name="_list" cascade="all-delete-orphan" access="field" lazy="false开发者_如何学Go" table="VehicleZones" inverse="false">
              <key>
                <column name="Vehicle_PK" />
              </key>
              <many-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
            </bag>
          </component>
          <property name="Active" type="System.Boolean, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Active" />
          </property>
          <property name="Status" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Status" />
          </property>
          <property name="Velocity" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Velocity" />
          </property>
          <property name="Heading" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Heading" />
          </property>
          <property name="Agency" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Agency" />
          </property>
          <property name="Unit" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Unit" />
          </property>
          <property name="Priority" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <column name="Priority" />
          </property>
          <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Position" lazy="false" cascade="all">
            <column name="Position_id" />
          </many-to-one>
          <many-to-one class="EMTRAC.VehicleClasses.VehicleClass, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="VehClass" lazy="false" cascade="all">
            <column name="VehClass_id" />
          </many-to-one>      
        </joined-subclass>
      </class>
    </hibernate-mapping>

And here is my mapping of the Zone class:

    <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
      <class xmlns="urn:nhibernate-mapping-2.2" name="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Zone`" lazy="false">
        <id name="ID" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="PK" />
          <generator class="identity" />
        </id>
        <property name="Active" type="System.Boolean, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="Active" />
        </property>
        <property name="Dir" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="Dir" />
        </property>
        <property name="IntID" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="IntID" />
        </property>
        <property name="Width" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="Width" />
        </property>
        <property name="Distance" type="System.Double, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
          <column name="Distance" />
        </property>
        <many-to-one class="EMTRAC.Headings.Heading, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Heading" cascade="all-delete-orphan">
          <column name="Heading_id" />
        </many-to-one>
        <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Start" cascade="all-delete-orphan">
          <column name="Start_id" />
        </many-to-one>
        <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Finish" cascade="all-delete-orphan">
          <column name="Finish_id" />
        </many-to-one>
        <component name="Vehicles" access="property">
          <bag name="_list" cascade="all-delete-orphan" access="field" lazy="false" table="ZoneVehicles" fetch="join" inverse="true">
            <key>
              <column name="Zone_PK" />
            </key>
            <many-to-many class="EMTRAC.Vehicles.Vehicle, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
          </bag>
        </component>
      </class>
    </hibernate-mapping>

And finally here are my Vehicle and Zone classes:

    public class Vehicle : Device
    {
        #region Fields

        protected bool active;
        protected int id;
        protected Position position = new Position();
        protected int status;
        protected VehicleClass vehClass;
        protected int velocity;
        protected int heading;
        protected string agency;
        protected string unit;
        protected int priority;
        private ZoneCollection zones = new ZoneCollection();

        #endregion

        #region Properties

        [Browsable(false)]
        public virtual long PK { get; set; }

        [Browsable(false)]
        public virtual bool Active
        {
            get { return active; }
            set { active = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("Vehicle Identification Number")]
        public virtual int ID
        {
            get { return id; }
            set { id = value; }
        }

        [Browsable(false)]
        public virtual Position Position
        {
            get { return position; }
            set { position = value; }
        }

        [Browsable(false)]
        public virtual int Status
        {
            get { return status; }
            set { status = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("This is the type of vehicle.")]
        public virtual VehicleClass VehClass
        {
            get { return vehClass; }
            set { vehClass = value; }
        }

        [Browsable(false)]
        public virtual int Velocity
        {
            get { return velocity; }
            set { velocity = value; }
        }

        [Browsable(false)]
        public virtual int Heading
        {
            get { return heading; }
            set { heading = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("This is the name of the city agency that owns the vehicle.")]
        public virtual string Agency
        {
            get { return agency; }
            set { agency = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("This is the ID number assigned to the vehicle by the city or agency and is also used for identification purposes. This field accepts both alpha and numeric entries.")]
        public virtual string Unit
        {
            get { return unit; }
            set { unit = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("This is the priority level that the vehicle has over other vehicles with priority control capabilities (1 being the highest, 5 being the lowest). This is not the same as the priority control levels assigned to emergency vehicles (priority 1 for EVP) and mass-transit vehicles (priority 2 for TSP).")]
        public virtual int Priority
        {
            get { return priority; }
            set { priority = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("Zones associated with the Vehicle.")]
        [System.ComponentModel.Browsable(true)]
        [System.ComponentModel.Editor(typeof(VehicleCollectionModalEditor), typeof(System.Drawing.Design.UITypeEditor))]
        public virtual ZoneCollection Zones
        {
            get { return zones; }
            set { zones = value; }
        }

        [Browsable(false)]
        public virtual string IPLocal
        {
            get
            {
                if (LocalConnection.GetType() == typeof(Connections.ConnectionSerial))
                {
                    return (
                        ((Connections.ConnectionSerial)LocalConnection).SerialConn.PortName + " :: " +
                        ((Connections.ConnectionSerial)LocalConnection).SerialConn.BaudRate.ToString()
                        );
                }
                else if (LocalConnection.GetType() == typeof(Connections.ConnectionTCP))
                {
                    return (
                        ((IPEndPoint)((Connections.ConnectionTCP)LocalConnection).Client.Client.RemoteEndPoint).Address.ToString() + " :: " +
                        ((IPEndPoint)((Connections.ConnectionTCP)LocalConnection).Client.Client.RemoteEndPoint).Port.ToString()
                        );
                }
                else
                {
                    return string.Empty;
                }
            }
        }

        [Browsable(false)]
        public virtual string IPNetwork
        {
            get
            {
                if (Connection.GetType() == typeof(Connections.ConnectionSerial))
                {
                    return (
                        ((Connections.ConnectionSerial)Connection).SerialConn.PortName + " :: " +
                        ((Connections.ConnectionSerial)Connection).SerialConn.BaudRate.ToString()
                        );
                }
                else if (Connection.GetType() == typeof(Connections.ConnectionTCP))
                {
                    return (
                        ((IPEndPoint)((Connections.ConnectionTCP)Connection).Client.Client.RemoteEndPoint).Address.ToString() + " :: " +
                        ((IPEndPoint)((Connections.ConnectionTCP)Connection).Client.Client.RemoteEndPoint).Port.ToString()
                        );
                }
                else
                {
                    return string.Empty;
                }
            }
        }

        #endregion
    }


    public class Zone
    {
        #region Private Fields

        private bool active;
        private string dir;
        private Heading heading = new Heading();
        private int id;
        private int intID;
        private Position start = new Position();
        private Position finish = new Position();
        private int width;
        private Position[] corners = new Position[4];
        private Streets streets = new Streets();
        private VehicleCollection vehicles = new VehicleCollection();
        private double distance;

        #endregion

        #region Constructors

        public Zone()
        {
            if (Program.main != null)
            {
                IntID = Program.main.intID;

                Intersection intersection = Program.data.Intersections.list.Find(
                    delegate(Intersection tInt)
                    {
                        return tInt.ID == IntID;
                    }
                );

                if (intersection != null)
                {
                    Streets.Crossing = intersection.Streets.Crossing;
                    Streets.Route = intersection.Streets.Route;
                }
            }
        }

        #endregion

        #region Properties

        [Browsable(false)]
        public virtual long PK { get; set; }

        [Browsable(false)]
        public virtual bool Active
        {
            get { return active; }
            set { active = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The direction for the Zone.")]
        public virtual string Dir
        {
            get { return dir; }
            set { dir = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("This is the amount of heading variance (clockwise and counter-clockwise) in actual degrees.")]
        public virtual Heading Heading
        {
            get { return heading; }
            set { heading = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The Zone Identification Number.")]
        public virtual int ID
        {
            get { return id; }
            set { id = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The Identification Number associated with the Priority Detector of the Zone.")]
        public virtual int IntID
        {
            get { return intID; }
            set { intID = value; }
        }

        [CategoryAttribute("Position"),
            DescriptionAttribute("The location of the Zone's Start.")]
        public virtual Position Start
        {
            get { return start; }
            set { start = value; }
        }

        [CategoryAttribute("Position"),
            DescriptionAttribute("The location of the Zone's Finish.")]
        public virtual Position Finish
        {
            get { return finish; }
            set { finish = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The width of the Zone.")]
        public virtual int Width
        {
            get { return width; }
            set { width = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The distance of the Zone.")]
        public virtual double Distance
        {
            get { return distance; }
            set { distance = value; }
        }

        [Browsable(false)]
        public virtual Position[] Corners
        {
            get { return corners; }
            set { corners = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The streets associated with the Zone."),
            DisplayName("Zone Streets")]
        public virtual Streets Streets
        {
            get { return streets; }
            set { streets = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("Vehicles associated with the Zone.")]
        [System.ComponentModel.Browsable(true)]
        [System.ComponentModel.Editor(typeof(VehicleCollectionModalEditor), typeof(System.Drawing.Design.UITypeEditor))]
        public virtual VehicleCollection Vehicles
        {
            get { return vehicles; }
            set { vehicles = value; }
        }

        #endregion
    }

I'm sure it is probably something really small I am missing. Any ideas?

---

1) your many-to-many tables a missing a foreign key definition. The foreign key will be generated by NH, but it must be the same for both sides, so it doesn't work.

eg.

          <many-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null">
            <column name="Zone_PK"/>
          </many-to-many>

2) The bags are mapped using fetch="join" which isn't a good idea.