Hi,
Appreciate if you could share with me how to model this in Hibernate:

a USER has many-to-many with PROGRAM;
a PROGRAM has many-to-many with ROLE;
a USER has many-to-many with ROLE.

a USER is assigned a set of ROLEs for each PROGRAM.
^^^^^^^^^^

I think in database, I can have a table with (User_ID, Prog_ID, Role_ID).
How do I define these in Hibernate ?

thanks in advance!
li xin

I think I can define the first associations like this (unidirectional):

For class USER:
<set name="PROGRAMS" table="USER_PROGRAM" lazy="true"
cascade="save-update">
<key column="USER_ID"/>
<many-to-many class="program"/>
</set>

class User {
Set programs;
...
}


Similarly, I can have class PROGRAM:
<set name="ROLES" table="PROGRAM_ROLE" lazy="true"
cascade="save-update">
<key column="PROGRAM_ID"/>
<many-to-many class="role"/>
</set>

class Program {
Set roles;
...
}

But how do I define the User and Role association ?
Each User has a subset of Roles assigned to each Program.

Just leant a new term "ternary association". Here is a good link for Hibernate :
http://www.xylax.net/hibernate/ternary.html

So based on this info, I will try to map the class User like this:

<class name="User" table="USERS">
......
<set name="programRoles" table="User_Program_Role">
<key column="USER_ID"/>
<composite-element class="ProgramRole">
<many-to-many name="program" class="Program" column="PROGRAM_ID"/>
<many-to-many name="role" class="Role" column="ROLE_ID"/>
</composite-element>
</set>
......
</class>

Class User {
Set programRoles;

......
}

So now we can:

Set programRoles = user.getProgramRoles();

I hope it works.