That's exactly it.
-----Original Message-----
From: Alexander ten Bruggencate [mailto:[EMAIL PROTECTED]]
Sent: 20 December 2000 13:39
To: jBoss
Subject: Re: [jBoss-User] design quesion
hold it, after thinking about what you said I now think I know what you
meant.
I should store the primary keys of the roles a person has in the
personbean and if findByRole("<rolename>") is called check the value of
the parameter against the keys the person has for his/her roles and add
the person to the list...
ok. thanks again you did help!
-Alexander.
Alexander ten Bruggencate wrote:
> Hi Edward,
>
> thank you for your reply.
> The query to find people who have a certain role would be used
> frequently,
> so following your advice i should "maintain the appropriate foreign
> keys and implement personHome.findByRole()"
> erm, this leaves me with one small problem...I don't know what you
> mean by maintaining foreign keys. :-)
>
> I understand the foreing keys (in this example) are the keys of all
> the roles.
> But other then that you've lost me...could you explain this in more
> detail? thnx.
>
> And yes I agree with you on not using Bi-directonal associations.
>
> -Alexander.
>
>
>
> Kenworthy, Edward wrote:
>
>> Hi Alexander
>>
>> Depends on how frequently you do "gives me all persons who have the
>> role of
>> "Instructor"?"
>>
>> If it's infrequently then don't implement an association from
>> role-->person.
>> Instead just implement person-->role and then provide a method on
>> role of
>> getAllPeople(). The *implementation* of which does a
>> personHome.findAll()
>> for each person if role == this then add to list of matching persons.
>>
>> If you do such a query frequently, or its time sensitive, then you'll
>> have
>> to maintain the appropriate foreign keys and implement
>> personHome.findByRole(). But this means you have to maintain the foreign
>> key.
>>
>> Basically maintaining bi-directional associations is a pain so avoid
>> them if
>> you can.
>>
>> Hope this helps.
>>
>> Edward
>>
>> -----Original Message-----
>> From: Alexander ten Bruggencate [mailto:[EMAIL PROTECTED]]
>> Sent: 20 December 2000 11:54
>> To: jBoss user mailing list
>> Subject: [jBoss-User] design quesion
>>
>>
>> Hi all,
>>
>> before i spend a lot of time implementing something which might not
>> work I want to know what the best way is to design something like the
>> following:
>>
>> In my application a person can have multiple roles, for example a
>> person can be an "Instructor" and/or a "Coordinator".
>>
>> Which leads to something like
>> Role[] person.getRoles(); and
>> bool person.hasRole("Instructor");
>>
>> but how do i design something that easily gives me all persons who
>> have the role of "Instructor"?
>> Is the best way for this to define a finder in RoleHome? e.g.
>> roleHome.findByPerson(...)?
>>
>> well if someony has a working design for this I would like to know
>> how it looks like...
>>
>> thnx,
>> -Alexander.
>>
>>
>>
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>
>
>
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