One-to-Many

painlessprod · **Posted:** Fri Dec 08, 2006 3:16 pm

I have something simple: please excuse my use of c#

Code:

public class Person 
{ 
private int m_PersonID 
List<Address> m_Addresses; 
  
public Person() 
{  
} 
public int PersonID{get{return m_PersonID;}set{m_personID=value;}} 
public List<Address> Addresses{get{return m_Addresses;}set{m_Addresses=value;}} 
} 
  
public class Address 
{ 
private int m_AddressID 
public Address() 
{ 
} 
public int AddressID{get{return m_AddressID;}set{m_AddressID=value;}} 
}  

I have 3 tables that create this mapping, since i want to support addresses belonging to things other than Person
TABLES: Person, Address, PersonAddress
I have Keys inside the tables that link the 2 classes together via PersonAddress, PersonAddress table contains PersonAddressID, PersonID, and AddressID.
Simple RDBMS
I have seen many examples on the help notes about linking direct ie Person directly Many to One on address, but since address is a property of Person and could also be a property of other classes such as Corporation(), i dont want to tie the classes together directly.
How do I represent this in hbm.xml

Thanks in advance and excuse my ignorance.

batmat · **Posted:** Fri Dec 08, 2006 4:16 pm

Hi, I don't have time to write your whole mapping, but I can give you some advice on the steps to follow.

First, have a look in the reference guide : http://www.hibernate.org/hib_docs/v3/re ... sociations

You'll find what to begin with as a mapping. Your case should be handled without much efforts. As I understand, you never used Hibernate before, so just try and begin by mapping only one class without any relationships, save it in the db and check that it's stored.

Then map your three classes and verify you can save them in the db separately (maybe you'll need to disable some db constraints temporarily to do it though). Then come back in this post and provide your mappings, and I'll help you :-).

See you.

painlessprod · **Posted:** Fri Dec 08, 2006 4:20 pm

Will do, there is obviously more than what i just posted here but i willc clean up for simpl;icity sake

painlessprod · **Posted:** Fri Dec 08, 2006 4:23 pm

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="WSL.ModelObjects.Person,WSL.ModelObjects" table="Person">

<id name="Personid" column="PersonID" type="Int32" unsaved-value="0">
<generator class="native"/>
</id>
</class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="WSL.ModelObjects.Address,WSL.ModelObjects" table="Address">

<id name="Addressid" column="AddressID" type="Int32" unsaved-value="0">
<generator class="native"/>
</id>
</class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="WSL.ModelObjects.PersonAddress,WSL.ModelObjects" table="PersonAddress">

<id name="PersonAddressid" column="PersonAddressID" type="Int32" unsaved-value="0">
<generator class="native"/>
</id>
<many-to-one name="Personid" column="PersonID" class="WSL.ModelObjects.Person,WSL.ModelObjects" />
<many-to-one name="Addressid" column="AddressID" class="WSL.ModelObjects.Address,WSL.ModelObjects" />

</class>
</hibernate-mapping>

there's all three, i didnt put anything in person yet to represent the List<Address>

painlessprod · **Posted:** Fri Dec 08, 2006 6:29 pm

that example was exactly what i was looking for, sorry i posted before looking at it, thanks u so much

batmat · **Posted:** Sun Dec 10, 2006 11:22 am

painlessprod wrote:

that example was exactly what i was looking for, sorry i posted before looking at it, thanks u so much

You're welcome :-)