Hello Peter, thanks for your comment.
When I want to reconstruct my situation with the data structure given in https://metacpan.org/pod/DBIx::Class::Manual::Example my search call would be ... my $track_list_rs = $schema->resultset( 'Track' )->search( {}, { join => { 'cd' => 'artist' }, '+select' => [ 'artist.artistid' ], '+as' => [ 'artistid' ], alias => 'track_list_sub_rs' } ); my $rs = $schema->resultset('Artist')->search( { 'me.name' => 'Michael Jackson' }, { from => [ { 'me' => 'artist' }, [ { 'tracklíst' => $track_list_rs->as_query }, { 'me.artistid' => { -ident => 'tracklíst.artistid' } }, ] ], '+columns' => [ qw/ tracklíst.title / ], collapse => 1, result_class => 'DBIx::Class::ResultClass::HashRefInflator', } ); while( my $michael_jackson = $rs->next ) { # there can be only one... print Dumper( $michael_jackson ); } Here I simply want to build a list of tracks per artist and connect it to the artist directly. It is producing a good sql query string, but fails because of the missing accessor: SELECT me.artistid, me.name, tracklíst.title FROM artist me JOIN ( SELECT track_list_sub_rs.trackid, track_list_sub_rs.cd, track_list_sub_rs.title, artist.artistid FROM track track_list_sub_rs JOIN cd cd ON cd.cdid = track_list_sub_rs.cd JOIN artist artist ON artist.artistid = cd.artist ) tracklíst ON me.artistid = tracklíst.artistid WHERE me.name = 'Michael Jackson' ORDER BY me.artistid The error message is "No such relationship 'tracklíst' on Artist at /usr/local/share/perl/5.18.2/DBIx/Class/Schema.pm line 1081.". For prefetching the tracklist, I use '+columns' and 'collapse', because I expected those two not to check for the accessor "tracklist" (but this seemed to be a wrong assumption). Unfortunately I was not able to reconstruct the search call that was providing a result with only a single item out of the sub query results, since I made some changes in the meantime. Best regards Thilo 2015-02-12 16:47 GMT+01:00 Peter Rabbitson <rabbit+d...@rabbit.us>: > On 02/11/2015 11:13 AM, thilo.fes...@googlemail.com wrote: > >> >> At the beginning working around this problem seemed kind of trivial to >> me, but now I'm struggling. I thought, I could simply use a sub query in >> the from-attribute when searching the resultset and adding "+columns" >> and setting "collapse" to a true value. But this way, I am ending up >> with only a single property column. >> > > The short answer is - it's likely possible, or it can be made to work with > relatively few extra changes. > > But you need to show the actual search call you constructed, it's not > clear what you tried from your description alone. Also makes the "this is > what I want to get" example baseless and hard to interpret. > > Cheers > > _______________________________________________ > 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 >
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