[Dbix-class] relationship with additional constraints?

[Mitchell Elutovich]

The following (below) I sent to "Frew" upon which he updated the post to
indicate that the hack does not work.  (Some of his hack does work and some
not.)

In his example is:

my @rows = do {
   local $My::Schema::Result::Foo::SHARE_TYPE = [1, 2];
   $rs->search(undef, { join => 'output_devices' })->all
};

This usage still works having the local and "all" in the same scope.

----
someone shared with me your

https://blog.afoolishmanifesto.com/posts/dbix-class-parameterized-
relationships/#extended-relationship-refresher

I ran into a problem with the wrapping into a resultset method

At the time the "all" is called the "local" has gone out of scope so
the die gets triggered

   die "no share_type specified!" unless $SHARE_TYPE;

For myself I had to have this as the last in the chain and in the
resultset method call the all itself.

On Thu, May 17, 2018 at 12:35 PM, Andrew Beverley <andy at andybev.com> wrote:

> On Thu, 17 May 2018 11:12:45 +0200 dodds at united-domains.de wrote:
> > Is it possible to create a relationship which has, along with the
> > join condition, an additional constraint where the value could
> > somehow be passed when the search() method is called?
>
> This should answer your question:
>
> https://blog.afoolishmanifesto.com/posts/dbix-class-parameterized-
> relationships/
>
> Interestingly the post has been updated since I last looked at it
> saying that approach no longer works. I'm not sure why, as it still
> seems to work for me. Frew - can you elaborate?
>
> >  - Get a list of all movies, as well as a review by Sue if it exists
> >  - If a movie does not have a review by Sue then it should still be
> > returned with reviews.text = NULL.
> >  - If a movie does not have a review by Sue but it has a review by
> > someone else then it should also be returned with reviews.text = NULL
>
> The other method you might want to consider is using a correlated
> sub-query. It's a little cleaner from a DBIx::Class viewpoint, but I
> think you'd need to pull out each review column separately, so would
> depend what you want to retrieve. Another excellent blog from Frew:
>
> https://blog.afoolishmanifesto.com/posts/introducing-dbix-class-helper-
> resultset-correlaterelationship/
>
> It allows you to do something like this (untested):
>
>   '+columns' => {
>      sue_review => $self->schema->resultset('Review')
>        ->correlate('movies')
>        ->search({ person => 'sue' })
>        ->get_column('review_text')
>        ->as_query,
>   },
>
> Andy
>
>
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