Hibernate version: 2

How do I map this situation with annotations or xml for that matter.

I have two pretty different tables, a and b. Each table has a collection of table c.

I'm confused as to how to do the mapping in table c back to tables a and b.

I had each a and b mapped in c with a ManyToOne, but it wasn't working correctly. It would populate the ref column back to a/b. parent_id.

My thought now is to inherit from c to two new classes mapped to the same table.

Thank you,

Marty

Can you post the table definitions and your current mapping ?

I believe below outlines what I'm trying to do basically. A party will only every be mapped to either an allocation or to a rptside. Never both.

I left out fields/properties which weren't relevant.

Thank you for the help!

table Allocation (
id number,
party_id number
)

table RptSide (
id number,
party_id number
)

table Party (
id number,
parent_id number
)

[Class(Table="tc_alloc")]
public class Allocations
{
decimal _id;
ISet<Party> _Party = new HashSet<Party>();

[Id(1, Column="id", Type="Decimal")]
[Generator(2, Class="sequence")]
[Param(3, Content="tc_party_parent_seq", Name="sequence)]
virtual public decimal Id
{
....
}

[Set(1, Inverse=true, Cascade="save-update")]
[Key(2, ForeignKey="parent_id", Column="id")]
[OneToMany( 3, Class="ClearingReportDAO.Domain.Party, ClearingReportDAO")]
virtual public ISet<Party> Party
{
...
}

.
.
.
}

The other table (RptSide) is exactly the same.

[Class(Table="tc_party")]
public class Party
{
decimal _id;
RptSide _RptSide;
Allocation _Allc;

[Id(1, Column="id", Type="Decimal")]
[Generator(2, Class="sequence")]
[Param(3, Content="tc_party_parent_seq", Name="sequence)]
virtual public decimal Id
{
....
}

[ManyToOne(1, ForeignKey = "id", Column="parent_id", Class="ClearingReportDAO.Domain.RptSide, ClearingReportDAO, Cascade="save-update")]
virtual public RptSide RptSide
{
...
}

[ManyToOne(1, ForeignKey = "id", Column="parent_id", Class="ClearingReportDAO.Domain.Allocation, ClearingReportDAO, Cascade="save-update")]
virtual public Allocation Allocation
{
...
}
}

I think there at least two solutions:

- build a class hierarchy for Allocation and RptSide (e.g. same interface IHasSomethingToDoWithParty). Remember, you can still use separate tables for Allocations and RptSide. Then you can map the many-to-one from Party to IHasSomethingToDoWithParty instead of Allocation or RptSide
- you can use a "any" mapping: http://nhforge.org/doc/nh/en/index.html#mapping-types-anymapping


But I'm afraid I can't tell you how to do this with attributes. I've never used them.

Thanks.

What I ended up doing was creating an interface to Party called IParty. Then two classes from that. One for allocations and one for rptside. Each had a discriminator.

Everything is working nicely now. Saving and retrieving.


[Class(Table = "tc_party")]
public interface IParty
{
[Id(1, Column = "id", Type = "Decimal", UnsavedValue = "-1")]
[Generator(2, Class = "sequence")]
[Param(3, Content = "tc_party_seq", Name = "sequence")]
decimal ID
{
get; set;
}

[Discriminator(Type = "string", Column = "parent_type")]
string ParentType
{
get; set;
}
}

[Subclass(DiscriminatorValue = "A", Extends = "ClearingReportDAO.Domain.IParty, ClearingReportDAO")]
public class AllocParty : IParty
{
private decimal _ID;
private string _ParentType;
private string _PartyID;
private decimal _PartyRole;

private Allocation _Allocation;

private ISet<SubParty> _SubParties = new HashedSet<SubParty>();

virtual public decimal ID
{
get { return _ID; }
set { _ID = value; }
}

[ManyToOne(1, ForeignKey = "id", Column = "parent_id", Class = "ClearingReportDAO.Domain.Allocation, ClearingReportDAO", Cascade = "save-update")]
virtual public Allocation Allocation
{
get { return _Allocation; }
set { _Allocation = value; }
}
.
.
.
}


[Subclass(DiscriminatorValue = "I", Extends = "ClearingReportDAO.Domain.IParty, ClearingReportDAO")]
public class RptSideParty : IParty
{
private decimal _ID;
//private decimal _ParentID;
private string _ParentType;
private string _PartyID;
private decimal _PartyRole;

private RptSide _rptSide;
private ISet<SubParty> _SubParties = new HashedSet<SubParty>();

virtual public decimal ID
{
get { return _ID; }
set { _ID = value; }
}

[ManyToOne(1, ForeignKey = "id", Column = "parent_id", Class = "ClearingReportDAO.Domain.RptSide, ClearingReportDAO")]
virtual public RptSide RptSide
{
get { return _rptSide; }
set { _rptSide = value; }
}
.
.
.
}