Hey John,
2011/6/14 John Robson <[email protected]>
> Thanks for the replies.
>
> Just to confirm. If you guys were creating the database of this model:
>
> http://imagebin.org/158118
>
> Would Not want a Wt::Dbo::ManyToMany relationship; But would use two
> Wt::Dbo::ManyToOne relations, right?
>
> That way I can create table 'users_has_projects' with 2 attributes and
> work with them without problems, right?
>
> Tks again,
> John
>
> ps: pardon the redundancy, DB is a very important part of the project.
>
> On 05/31/2011 05:59 PM, Dmitriy Igrishin wrote:
> > Strictly speaking, the join table does not represents a class of
> entities.
> > But only entity can contains attributes. Therefore, in you case,
> > "users_and_projects" must be considered as entity rather than the join
> table
> > (which always serves only as an implementation detail on the physical,
> i.e.
> > the database level, while entities are always should be considered on
> > logical,
> > i.e. the project level) because it contains attributes.
> >
> > PS, consider to rename "users" to "user" and "projects" to "project"
> > according to classical entity-relationship models, because
> > the terms "one-to-many" or "many-to-many" are meaningless
> > if entities are named in plural.
>
> Tks, what is the correct way?
>
As far as I understood you're trying to modeling a task manager.
Each User can participate in many projects. On the other hand,
obviously, that complex projects can be divided into many small
tasks (subprojects). Therefore, each User can participate in
some Project by solving some Task. So, there are 3 classes:
User, Task and Project. And as I mentioned before, a Task
is an entity (class, as the User and Project) rather than join table
(implementation detail), because it has attributes. So, it should be
named properly.
>
>
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// Dmitriy.
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