为什么nhibernate 不能保存ontomany的结构

下面是主类文件

Code
namespace EasyTalk.Module
{
    /**//// <summary>
    /// SiteAddress object for NHibernate mapped table 'SiteAddress'.
    /// </summary>
    [Serializable]
    public class SiteAddress
    {
        Member Variables#region Member Variables
        protected string _siteid;
        protected string _alias;
        protected string _address;
        protected string _transporttype;
        protected string _description;
        protected string _iscurrent;
        protected IList<AddressAttributes> _addressattributes;
        #endregion
        Constructors#region Constructors
            
        public SiteAddress() {}
                    
        public SiteAddress(string siteid, string alias, string address, string transporttype, string description, string iscurrent) 
        {
            this._siteid= siteid;
            this._alias= alias;
            this._address= address;
            this._transporttype= transporttype;
            this._description= description;
            this._iscurrent= iscurrent;
        }

        public SiteAddress(string siteid)
        {
            this._siteid= siteid;
        }
        
        #endregion
        Public Properties#region Public Properties
        public  virtual string SiteId
        {
            get { return _siteid; }
            set {_siteid= value; }
        }
        public  virtual string Alias
        {
            get { return _alias; }
            set {_alias= value; }
        }
        public  virtual string Address
        {
            get { return _address; }
            set {_address= value; }
        }
        public  virtual string TransportType
        {
            get { return _transporttype; }
            set {_transporttype= value; }
        }
        public  virtual string Description
        {
            get { return _description; }
            set {_description= value; }
        }
        public  virtual string IsCurrent
        {
            get { return _iscurrent; }
            set {_iscurrent= value; }
        }
        public  virtual IList<AddressAttributes> AddressAttributes
        {
            get { return _addressattributes; }
            set {_addressattributes= value; }
        }

        public virtual void AddItem(AddressAttributes item)
        {
            if (_addressattributes == null)
                _addressattributes = new List<AddressAttributes>();
            _addressattributes.Add(item);
        }
        #endregion
        
        Equals And HashCode Overrides#region Equals And HashCode Overrides
        /**//// <summary>
        /// local implementation of Equals based on unique value members
        /// </summary>
        public override bool Equals( object obj )
        {
            if( this == obj ) return true;
            if( ( obj == null ) || ( obj.GetType() != this.GetType() ) ) return false;
            SiteAddress castObj = (SiteAddress)obj;
            return ( castObj != null ) &&
            this._siteid == castObj.SiteId;
        }
        /**//// <summary>
        /// local implementation of GetHashCode based on unique value members
        /// </summary>
        public override int GetHashCode()
        {
            int hash = 57;
            hash = 27 * hash * _siteid.GetHashCode();
            return hash;
        }
        #endregion
        
    }
}

下面是明细

Code
namespace EasyTalk.Module
{
    /**//// <summary>
    /// AddressAttributes object for NHibernate mapped table 'AddressAttributes'.
    /// </summary>
    [Serializable]
    public class AddressAttributes
    {
        Member Variables#region Member Variables
        protected decimal _attrid;
        protected string _attributekey;
        protected string _attributevalue;
        protected string _endpointid;
        protected string _transporttype;
        #endregion
        Constructors#region Constructors
            
        public AddressAttributes() {}
                    
        public AddressAttributes(string attributekey, string attributevalue, string endpointid, string transporttype) 
        {
            this._attributekey= attributekey;
            this._attributevalue= attributevalue;
            this._endpointid= endpointid;
            this._transporttype= transporttype;
        }

        public AddressAttributes(string endpointid)
        {
            this._endpointid= endpointid;
        }
        
        #endregion
        Public Properties#region Public Properties
        public  virtual decimal AttrId
        {
            get { return _attrid; }
            set {_attrid= value; }
        }
        public  virtual string AttributeKey
        {
            get { return _attributekey; }
            set {_attributekey= value; }
        }
        public  virtual string AttributeValue
        {
            get { return _attributevalue; }
            set {_attributevalue= value; }
        }
        public  virtual string EndpointId
        {
            get { return _endpointid; }
            set {_endpointid= value; }
        }
        public  virtual string TransportType
        {
            get { return _transporttype; }
            set {_transporttype= value; }
        }
        #endregion
        
        Equals And HashCode Overrides#region Equals And HashCode Overrides
        /**//// <summary>
        /// local implementation of Equals based on unique value members
        /// </summary>
        public override bool Equals( object obj )
        {
            if( this == obj ) return true;
            if( ( obj == null ) || ( obj.GetType() != this.GetType() ) ) return false;
            AddressAttributes castObj = (AddressAttributes)obj;
            return ( castObj != null ) &&
            this._attrid == castObj.AttrId;
        }
        /**//// <summary>
        /// local implementation of GetHashCode based on unique value members
        /// </summary>
        public override int GetHashCode()
        {
            int hash = 57;
            hash = 27 * hash * _attrid.GetHashCode();
            return hash;
        }
        #endregion
        
    }
}

配置文件

Code
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <!--Build: with lujan99@usa.net Nhibernate template-->
  <class name="EasyTalk.Module.SiteAddress,EasyTalk.Module" table="SiteAddress" lazy="true">
      <id name="SiteId" column="Site_ID" type="string" unsaved-value="0">
          <generator class="assigned" />
      </id>
    <property name="Alias" column="Alias" type="string" />
    <property name="Address" column="Address" type="string" />
    <property name="TransportType" column="TransportType" type="string" />
    <property name="Description" column="Description" type="string" />
    <property name="IsCurrent" column="isCurrent" type="string" />
    <bag name="AddressAttributes"   lazy="true"   cascade="all">
      <key column="Endpoint_ID" />
      <one-to-many class="EasyTalk.Module.AddressAttributes,EasyTalk.Module" />
    </bag>
  </class>
</hibernate-mapping>

Code
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <!--Build: with lujan99@usa.net Nhibernate template-->
  <class name="EasyTalk.Module.AddressAttributes,EasyTalk.Module" table="AddressAttributes" lazy="true">
    <id name="AttrId" column="Attr_ID" type="Decimal" unsaved-value="0">
      <generator class="native" />
    </id>
    <property name="AttributeKey" column="AttributeKey" type="string" />
    <property name="AttributeValue" column="AttributeValue" type="string" />
    <property name="EndpointId" column="Endpoint_ID" type="string" a="true" />
    <property name="TransportType" column="TransportType" type="string" />
  </class>
</hibernate-mapping>

代码

Code
AddressAttributes s = new AddressAttributes();
        //s.Endpoints = e;
        //s.AttrId = 1002;
        s.EndpointId = "100";
        s.AttributeKey = "test";
        s.AttributeValue = "test";
        s.TransportType = "msmq";
        //=====================
        //a.Endpoints.Add(e);
        a.AddItem(e);
        //e.AddressAttributes.Add(s);
        e.AddItem(s);

        SiteAddress sa = new SiteAddress();
        sa.Address = "add";
        //sa.AddItem(s);
        sa.Alias = "alias";
        sa.Description = "desc";
        sa.IsCurrent = "1";
        sa.SiteId = "100";
        sa.TransportType = "msmq";
        

        session.Save(sa);

保存也没有提示错误，但是就是保存不了数据，我单个保存主表也不行，单个保存明细表可以。