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Re: [eclipselink-users] N-M-Table and Additional Fields
|
Hi,
yes, I take this way.
Thanks!
Mc.Joe
James Sutherland wrote:
>
> Modeling the join table as a domain class is the best solution.
>
> Another solution in JPA 2.0 (EclipseLink 2.0 dev stream), is to use the
> new MapKey support to define the relationship. The key could be the Job
> and the value the salary.
>
> But I would go with the class, as you may find you want other fields in
> the "Employment" object in the future (such as startDate, yearsOfService,
> etc.).
>
>
>
> Joe Mc. wrote:
>>
>> So, one solution could be to use explicit the n-m-Table as domain class
>> and use ManyToOne on both sides to this n-m-Table domain class.
>> The Person contains a list of Person_has_Job objects, instead of Job
>> objects. The same on the Job side.
>>
>> I do not like this solution.
>> Any (better) solutions?
>>
>>
>>
>> Joe Mc. wrote:
>>>
>>> Hi everybody,
>>>
>>> I have following scenario:
>>> 2 Tables with a n-m-relation. That means, I have a third table for the
>>> n-m-Relation. In this third table I have additional fields.
>>> artificial Example:
>>> Person has a Job and the Job could be done from more tha one Person. But
>>> the salary is not for every Person and Job the same.
>>> Tables:
>>> Person(id, name)
>>> Job(id, title)
>>> Person_has_Job(person_id, job_id, salary)
>>>
>>> Ok. How is the JPA realisation? ;-)
>>> I can work with ManyToMany and I can define with JoinTable the
>>> n-m-table. But how is it possible to set the salary value in a
>>> (transient) property of Job (Job#salary)
>>>
>>> I think the example and the reason are clear. Howevery I do not know the
>>> best solution with JPA.
>>> Any Hints?
>>>
>>> Thanks in advance!
>>>
>>> M.Joe
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
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