Help with inheritance greatly appreciated.

pelle_h · **Joined:** Wed Aug 02, 2006 5:53 am **Posts:** 1

Hi, I am new to NHibernate and have run in to some problems with my first test project.

I have the following classes:

Code:

public class BaseDomainObject
    {
        private int _Id = 0;

        public BaseDomainObject()
        {
        }

        protected BaseDomainObject(int id)
        {
            _Id = id;
        }

        public int Id
        {
            get
            {
                return _Id;
            }
        }
    }
    
    public class GolfCourseInfo : BaseDomainObject 
    {
        private string _Name;

        public GolfCourseInfo()
        {
        }

        public GolfCourseInfo(int id, string name) : base(id)
        {
            _Name = name;
        }

        public string Name
        {
            get
            {
                return _Name;
            }
        }
    }
    
     public class GolfCourse : GolfCourseInfo 
    {
        private IList _Holes;

        public GolfCourse()
        {
        }

        public GolfCourse(int id, string name, IList holes) : base(id, name)
        {
            _Holes = holes;
        }

        public IList Holes
        {
            get
            {
                return _Holes;
            }
        }
    }
    

And here are the mappings:

Code:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" schema="dbo">

  <class name="GarageDev.GolfBuddy.Domain.GolfCourseInfo, GarageDev.GolfBuddy.Domain" table="GolfCourse">
    <id name="Id" column="fldId" type="System.Int32" access="nosetter.pascalcase-underscore">
      <generator class="assigned" />
    </id>

    <property name="Name" column="fldName" type="System.String"  access="nosetter.pascalcase-underscore"/>

  </class>
</hibernate-mapping>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" schema="dbo">
  
  <class name="GarageDev.GolfBuddy.Domain.GolfCourse, GarageDev.GolfBuddy.Domain" table="GolfCourse">
    <id name="Id" column="fldId" type="System.Int32" access="nosetter.pascalcase-underscore">
      <generator class="assigned" />
    </id>

    <property name="Name" column="fldName" type="System.String"  access="nosetter.pascalcase-underscore"/>

    <bag name="Holes" inverse="false" table="GolfCourseHole" order-by="fldNumber" access="nosetter.pascalcase-underscore">
      <key column="fldGolfCourseId" />
      <one-to-many class="GarageDev.GolfBuddy.Domain.Hole, GarageDev.GolfBuddy.Domain" />
    </bag>
  
  </class> 
</hibernate-mapping>

And the code:

Code:

 public IList GetAllGolfCourses()
        {
            using (ISession session = factory.OpenSession())
            {
                return session.CreateCriteria(typeof(GolfCourse)).AddOrder(NHibernate.Expression.Order.Asc("Name")).List();
            }
        }

        public IList GetAllGolfCourseInfos()
        {
            using (ISession session = factory.OpenSession())
            {
                return session.CreateCriteria(typeof(GolfCourseInfo)).AddOrder(NHibernate.Expression.Order.Asc("Name")).List();
            }
        }

When I call the first method I get the expected result 3 items, but when I call the second I get six. When I ran the SQL Profiler I noticed that NHibernate makes calls for both GolfCourse and GolfCourseInfo when calling the second method. What have I done wrong?

Regards
Pelle

gert · **Joined:** Thu Jan 19, 2006 4:29 pm **Posts:** 348

pelle_h wrote:

When I call the first method I get the expected result 3 items, but when I call the second I get six. When I ran the SQL Profiler I noticed that NHibernate makes calls for both GolfCourse and GolfCourseInfo when calling the second method. What have I done wrong?

The subclasses must not be mapped using the <class> mapping, but with <subclass> mapping (If You want to use table-per-class hierarchy mapping)

For details, see http://www.hibernate.org/hib_docs/nhibernate/html/inheritance.html

Gert