RE: [Hibernate] How to model this using hibernate? (OR mapping quest)

Sat, 18 Oct 2003 21:03:25 -0700

Title: Message
It all depends on what you are trying to do. Meaning, first figure out what kind traversals you will need to do and then things will become clearer.
 
One way of mapping things could be:
 
class Role {//..}
class Domain {//..}
class User{
    private Set domainRoles;
    //..
}
class DomainRole {
    private Role role;
    private Domain domain;
    //..
}
 
Note that you can change the structure of the relationship - creating what I call "inversions". So you can have a DomainRole class, or a UserRole, or a DomainUser class. Or all three. and have three separate mapping elements in each hbm file. Also note that the choice of "Set" is my default way of modeling collections. This might not be the semantics that you need. This is easily changed!
 
<class name="User" table="user">
    ...
    <set role="domainRoles" table="user_domain_roles">
        <key column="user_id"/>
        <composite-element class="DomainRole">
            <many-to-one name="domain" class="Domain" column="domain_id"/>
            <many-to-one name="role" class="Role" column="role_id"/>
        </composite-element>
    </set>
</class>
 
Sandeep Dath
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kenneth Foo
Sent: Saturday, October 18, 2003 3:11 AM
To: [EMAIL PROTECTED]
Subject: [Hibernate] How to model this using hibernate? (OR mapping quest)

Hi..
 
A bit stumped here.
My database structure is something like this...
 
1) There can be several domains in the system
2) Each user can be assigned to one or more domains
3) For each of these assigned domains, the user can have one or more assigned roles for the domain.
 
How do I efficiently model the USER_DOMAIN_ROLES table in terms of objects?
For simple one-many relationship it would be easy but I'm not sure how this is done using hibernate.
 
PS: Table structure below
 
Thanks!
Regards
Kenneth
 
CREATE TABLE DOMAINS (
 ID NUMERIC(18,0) NOT NULL PRIMARY KEY,
 NAME VARCHAR(100) CHARACTER SET UNICODE_FSS,
 PARENT_ID NUMERIC(18,0)
   REFERENCES DOMAINS(ID)
   ON UPDATE CASCADE
   ON DELETE CASCADE,
 CREATE_TIME TIMESTAMP DEFAULT 'NOW'
);
 
CREATE TABLE ROLES (
 ID SMALLINT NOT NULL,
 NAME VARCHAR(20) NOT NULL,
);
 
CREATE TABLE USERS (
 ID NUMERIC(18,0) PRIMARY KEY,
 NAME VARCHAR(100),
 PASSWORDHASH CHAR(32)
);
CREATE TABLE USER_DOMAIN_ROLES (
 USER_ID  NUMERIC(18,0)
   REFERENCES USERS(ID)
   ON UPDATE CASCADE
   ON DELETE CASCADE,
 DOMAIN_ID NUMERIC(18,0) NOT NULL
   REFERENCES DOMAINS(ID)
   ON UPDATE CASCADE
   ON DELETE CASCADE,
 ROLE_ID  SMALLINT NOT NULL
   REFERENCES ROLES(ID)
   ON UPDATE CASCADE
   ON DELETE CASCADE,
 PRIMARY KEY (USER_ID, DOMAIN_ID, ROLE_ID)
);
 
 
 
------------
My try at the object model ...
------------
 
class Domain {
    private long id;
    private String name;
    private Timestamp createTime;
   
}
 
class Roles {
    private long id;
    private String name;
}
 
class User {
    private long id;
    private String name;
    private String password;
}
 
class UserDomainRoles {
    ??
 
};
 
 

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