On 22/08/18 22:03, Andy Armstrong wrote: > On 22 Aug 2018, at 20:55, Matthew Somerville <matt...@mysociety.org> wrote: >> On 22 August 2018 at 20:22, Andy Armstrong <a...@hexten.net> wrote: >>> If I do prefetch => ['service', { service => 'parent' }] I only get results >>> for the cases where the service hierarchy is two levels deep. >> I think you might only want prefetch => { service => 'parent' } ? >> The "The "prefetch" attribute can be used with any of the relationship >> types" bit of the documentation seems relevant here, it sounds like >> there's no reason why it wouldn't work, as long as it knows the parent >> is optional (might_have). Like "liner_notes" in the example. > > That seems to generate a query that limits the results to only those services > that have multiple levels - which is understandable.
Sounds like the join type might be wrong for the 'parent' relationship. You can add: join_type => 'LEFT' https://metacpan.org/pod/DBIx::Class::Relationship::Base#join_type > I'm now contemplating whether the services really need to be hierarchical. > It's an awkward fit for a single query regardless of whether I use DBIC and > only works in the current implementation because the whole services table is > loaded once and converted at that point into a shallow tree. > _______________________________________________ List: http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/dbix-class IRC: irc.perl.org#dbix-class SVN: http://dev.catalyst.perl.org/repos/bast/DBIx-Class/ Searchable Archive: http://www.grokbase.com/group/dbix-class@lists.scsys.co.uk