Re: setting up relationships

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hi tony--

my gift to you will be "the idiot's guide to CDBI", once i've mastered
the concepts enough myself that i can actually explain them.

thanks!
steve

On Tue, 2004-06-22 at 00:41, Tony Bowden wrote:
> On Mon, Jun 21, 2004 at 11:34:31PM -0700, steve shapero wrote:
> > I've studied your email several times now and messed around with my 
> > code to try out my understanding.  i finally get what this moniker 
> > business is all about.  note to documentation writers: it is implied 
> > (if i am finally actually getting a clue here) that you have named 
> > columns in your database according to this rubric.  or rather, the wise 
> > man will name his columns according to this rubric.  the foolish man 
> > will insist on confusion by using whatever naming convention his old 
> > russian app developer taught him as a young man.
> 
> Class::DBI should only be falling back on the moniker for relationships
> if you haven't set up your reciprocal has_a relationships. If you have,
> then it will use those instead.
> 
> So if you have
> 
> CD->has_a(artist_id => Artist);
> 
> then when you do
> 
> Artist->has_many(cds => CD);
> 
> It will know that the linking column is 'artist_id'. If you don't have
> that has_a() it will assume that it is simply 'artist'.
> 
> To avoid the confusion, just ensure that you have your has_a() set up.
> 
> 
> > to me, it is rather profound that there is some english language 
> > interpolation going on based on how you name things.  call me slow but 
> > this is in no way obvious from the documentation and ends up being 
> > really confusing to those of us who insist on doing everything the hard 
> > way (i.e. their own way).  
> 
> This is in the documentation for has_many:
> 
>   When setting up the relationship we examine the foreign class's has_a()
>   declarations to discover which of its columns reference our class.
>   (Note that because this happens at compile time, if the foreign class
>   is defined in the same file, the class with the has_a() must be defined
>   earlier than the class with the has_many(). If the classes are in dif-
>   ferent files, Class::DBI should be able to do the right thing). If no
>   such has_a() declarations can be found, or none link to us, we assume
>   that it is linking to us via a column named after the moniker() of our
>   class. If this is not true you can pass an additional third argument to
>   the has_many() declaration stating which column of the foreign class
>   references us.
> 
> Feel free to supply patches to make the documentation clearer!
> 
> Tony
>