annotations and composite key mapping to objects

gyanesh_mk · **Joined:** Fri Jun 11, 2004 3:42 am **Posts:** 22

Hi,

I am trying to get this code working with the limited knowledge I have of
EJB3. Can some one point out where I am wrong?

Quote:

This is a Group Node that can have more than one parent and more than one children

Code:

@Entity(name="GroupNode", access = AccessType.FIELD)
@Table(name="GroupNode")
public class GroupNode {
   @Id
   @Column(name="`GroupNodeID`", length=100)
       public String GroupNodeID = new String();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ChildGroupID")
   public Set<GroupNodeRelationship> Parents = new HashSet();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ParentGroupID")
   public Set<GroupNodeRelationship> Children = new HashSet();

         ....................... more code here 

}

Quote:

This defines the relationship

Code:

@Entity(name="GroupNodeRelationship", access = AccessType.FIELD)
@Table(name="GroupNodeRelationship")
public class GroupNodeRelationship {
   @Id(generate = GeneratorType.NONE)
   @Dependent({@DependentAttribute(name = "ParentGroupID"), @DependentAttribute(name = "ChildGroupID")})
   public GroupNodeRelationshipPk GroupNodeRelationshipPkObj = new GroupNodeRelationshipPk();

         ....................... more code here 

}

Quote:

This defines the primary key for the relationship so that a node is not mapped twice (parent or children)

Code:

@DependentObject(access = AccessType.FIELD)
public class GroupNodeRelationshipPk {

   @ManyToOne(cascade = CascadeType.ALL)
   @Column(name="ParentGroupID")
   public GroupNode ParentGroupObject = null;
   
   @ManyToOne(cascade = CascadeType.ALL)
   @Column(name="ChildGroupID")
   public GroupNode ChildGroupObject = null;
}

emmanuel · **Posted:** Tue Jan 18, 2005 6:51 am

ManyToOne inside a dependent object is not supported by th spec.
You should put your ManyToOne in GroupNodeRelationship and set them insertable=false, updatable=false

gyanesh_mk · **Joined:** Fri Jun 11, 2004 3:42 am **Posts:** 22

I tried your suggestion. The new Structure looks like this:

Code:

@Entity(name="GroupNode", access = AccessType.FIELD)
@Table(name="GroupNode")
public class GroupNode {

   @Id
   @Column(name="`ID`", length=100)
        public String ID = new String();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ChildGroupID")
   public Set<GroupNodeRelationship> Parents = new HashSet();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ParentGroupID")
   public Set<GroupNodeRelationship> Children = new HashSet();
}

Code:

@Entity(name="GroupNodeRelationship", access = AccessType.FIELD)
@Table(name="GroupNodeRelationship")
public class GroupNodeRelationship {

   @Id
   @Column(name="`ID`", length=100)
   public String ID = new String();

   @ManyToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ChildGroupID", insertable=false, updatable=false)
   public GroupNode ChildGroupObject = null;

   @ManyToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ParentGroupID", insertable=false, updatable=false)
   public GroupNode ParentGroupObject = null;

   @OneToOne(cascade = CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="`ParentGroupThatOwnsThisLeaf`")
   public GroupNode GroupOwner = null;

}

Now, when I make a query to retrieve GroupNodeRelationship records, ChildGroupObject , ParentGroupObject , GroupOwner is not filled ! OneToMany works but with the same structure, ManyToOne is not filling the right Feilds!

emmanuel · **Posted:** Wed Jan 19, 2005 11:00 am

Still keep GroupNodeRelationshipPk as a PK and map the ids inside it

Code:

@DependentObject(access = AccessType.FIELD)
public class GroupNodeRelationshipPk {

   @Column(name="ParentGroupID")
   public Integer ParentGroupId = null;
   
   @Column(name="ChildGroupID")
   public GroupNode ChildGroupId = null;
}

gyanesh_mk · **Joined:** Fri Jun 11, 2004 3:42 am **Posts:** 22

I tried this and it does not still seem to work:

Code:

@Entity(name="GroupNode", access = AccessType.FIELD)
@Table(name="GroupNode")
public class GroupNode {

   @Id
   @Column(name="`ID`", length=100)
   public String ID = new String();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ChildGroupID")
   public Set<GroupNodeRelationship> Parents = new HashSet();

   @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="ParentGroupID")
   public Set<GroupNodeRelationship> Children = new HashSet();
}

Code:

@Entity(name="GroupNodeRelationship", access = AccessType.FIELD)
@Table(name="GroupNodeRelationship")
public class GroupNodeRelationship {

   @Id(generate = GeneratorType.NONE)
   @Dependent({@DependentAttribute(name = "ParentGroupID", column = @Column(name="`ParentGroupID1`")), @DependentAttribute(name = "ChildGroupID", column = @Column(name="`ParentGroupID`"))})
   public GroupNodeRelationshipPk GroupNodeRelationshipPkObj = null;
   
   @OneToOne(cascade = CascadeType.ALL, fetch=FetchType.EAGER)
   @JoinColumn(name="`ParentGroupThatOwnsThisLeaf`")
   public GroupNode ParentGroupThatOwnsThisLeaf = null;
}

Code:

@DependentObject(access = AccessType.FIELD)
public class GroupNodeRelationshipPk {

   @Column(name="ParentGroupID")
   public GroupNode ParentGroupObj = null;
   
   @Column(name="ChildGroupID")
   public GroupNode ChildGroupObj = null;
}

The exception I get is

Quote:

org.hibernate.MappingException: Could not determine type for: com.agileflow.affs.AFFSGroup.GroupNode, for columns: [org.hibernate.mapping.Column(ParentGroupID)]
at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:215)
at org.hibernate.mapping.Property.getType(Property.java:38)
at org.hibernate.mapping.Component.getType(Component.java:150)
at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:202)
at org.hibernate.mapping.RootClass.validate(RootClass.java:186)
at org.hibernate.cfg.Configuration.validate(Configuration.java:750)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:985)

emmanuel · **Posted:** Fri Jan 21, 2005 10:34 am

Come on! you join columns name does not match the defined column names in you @Dependent annotation