use strict;
-use warnings;
+use warnings;
use Test::More;
-use Test::Exception;
use lib qw(t/lib);
use DBICTest;
-use Data::Dumper;
my $schema = DBICTest->init_schema();
+my $sdebug = $schema->storage->debug;
-my $orig_debug = $schema->storage->debug;
+#( 1 -> M + M )
+my $cd_rs = $schema->resultset('CD')->search( { 'me.title' => 'Forkful of bees' } );
+my $pr_cd_rs = $cd_rs->search( {}, { prefetch => [qw/tracks tags/], } );
-use IO::File;
+my $tracks_rs = $cd_rs->first->tracks;
+my $tracks_count = $tracks_rs->count;
-BEGIN {
- eval "use DBD::SQLite";
- plan $@
- ? ( skip_all => 'needs DBD::SQLite for testing' )
-# : ( tests => 16 );
- : 'no_plan';
-}
+my ( $pr_tracks_rs, $pr_tracks_count );
-# once the following TODO is complete, remove the 2 warning tests immediately
-# after the TODO block
-# (the TODO block itself contains tests ensuring that the warns are removed)
-TODO: {
- local $TODO = 'Prefetch of multiple has_many rels at the same level (currently warn to protect the clueless git)';
+my $queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
- #( 1 -> M + M )
- my $cd_rs = $schema->resultset('CD')->search ({ 'me.title' => 'Forkful of bees' });
- my $pr_cd_rs = $cd_rs->search ({}, {
- prefetch => [qw/tracks tags/],
- });
-
- my $tracks_rs = $cd_rs->first->tracks;
- my $tracks_count = $tracks_rs->count;
-
- my ($pr_tracks_rs, $pr_tracks_count);
-
- my $queries = 0;
- $schema->storage->debugcb(sub { $queries++ });
- $schema->storage->debug(1);
-
- my $o_mm_warn;
- {
- local $SIG{__WARN__} = sub { $o_mm_warn = shift };
- $pr_tracks_rs = $pr_cd_rs->first->tracks;
- };
- $pr_tracks_count = $pr_tracks_rs->count;
-
- ok(! $o_mm_warn, 'no warning on attempt to prefetch several same level has_many\'s (1 -> M + M)');
-
- is($queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query');
- is($pr_tracks_count, $tracks_count, 'equal count of prefetched relations over several same level has_many\'s (1 -> M + M)');
-
- for ($pr_tracks_rs, $tracks_rs) {
- $_->result_class ('DBIx::Class::ResultClass::HashRefInflator');
- }
-
- is_deeply ([$pr_tracks_rs->all], [$tracks_rs->all], 'same structure returned with and without prefetch over several same level has_many\'s (1 -> M + M)');
-
- #( M -> 1 -> M + M )
- my $note_rs = $schema->resultset('LinerNotes')->search ({ notes => 'Buy Whiskey!' });
- my $pr_note_rs = $note_rs->search ({}, {
- prefetch => {
- cd => [qw/tags tracks/]
- },
- });
+my $o_mm_warn;
+{
+ local $SIG{__WARN__} = sub { $o_mm_warn = shift };
+ $pr_tracks_rs = $pr_cd_rs->first->tracks;
+};
+$pr_tracks_count = $pr_tracks_rs->count;
- my $tags_rs = $note_rs->first->cd->tags;
- my $tags_count = $tags_rs->count;
+ok( !$o_mm_warn,
+'no warning on attempt to prefetch several same level has_many\'s (1 -> M + M)'
+);
- my ($pr_tags_rs, $pr_tags_count);
+is( $queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query' );
+$schema->storage->debugcb(undef);
+$schema->storage->debug($sdebug);
- $queries = 0;
- $schema->storage->debugcb(sub { $queries++ });
- $schema->storage->debug(1);
+is( $pr_tracks_count, $tracks_count,
+'equal count of prefetched relations over several same level has_many\'s (1 -> M + M)'
+);
+is( $pr_tracks_rs->all, $tracks_rs->all,
+'equal amount of objects returned with and without prefetch over several same level has_many\'s (1 -> M + M)'
+);
- my $m_o_mm_warn;
- {
- local $SIG{__WARN__} = sub { $m_o_mm_warn = shift };
- $pr_tags_rs = $pr_note_rs->first->cd->tags;
- };
- $pr_tags_count = $pr_tags_rs->count;
+#( M -> 1 -> M + M )
+my $note_rs =
+ $schema->resultset('LinerNotes')->search( { notes => 'Buy Whiskey!' } );
+my $pr_note_rs =
+ $note_rs->search( {}, { prefetch => { cd => [qw/tracks tags/] }, } );
- ok(! $m_o_mm_warn, 'no warning on attempt to prefetch several same level has_many\'s (M -> 1 -> M + M)');
+my $tags_rs = $note_rs->first->cd->tags;
+my $tags_count = $tags_rs->count;
- is($queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query');
+my ( $pr_tags_rs, $pr_tags_count );
- is($pr_tags_count, $tags_count, 'equal count of prefetched relations over several same level has_many\'s (M -> 1 -> M + M)');
+$queries = 0;
+$schema->storage->debugcb( sub { $queries++ } );
+$schema->storage->debug(1);
- for ($pr_tags_rs, $tags_rs) {
- $_->result_class ('DBIx::Class::ResultClass::HashRefInflator');
- }
+my $m_o_mm_warn;
+{
+ local $SIG{__WARN__} = sub { $m_o_mm_warn = shift };
+ $pr_tags_rs = $pr_note_rs->first->cd->tags;
+};
+$pr_tags_count = $pr_tags_rs->count;
- is_deeply ([$pr_tags_rs->all], [$tags_rs->all], 'same structure returned with and without prefetch over several same level has_many\'s (M -> 1 -> M + M)');
-}
+ok( !$m_o_mm_warn,
+'no warning on attempt to prefetch several same level has_many\'s (M -> 1 -> M + M)'
+);
-# remove this closure once the TODO above is working
-my $w;
-{
- local $SIG{__WARN__} = sub { $w = shift };
-
- my $rs = $schema->resultset('CD')->search ({ 'me.title' => 'Forkful of bees' }, { prefetch => [qw/tracks tags/] });
- for (qw/all count next first/) {
- undef $w;
- my @stuff = $rs->search()->$_;
- like ($w, qr/will currently disrupt both the functionality of .rs->count\(\), and the amount of objects retrievable via .rs->next\(\)/,
- "warning on ->$_ attempt prefetching several same level has_manys (1 -> M + M)");
- }
- my $rs2 = $schema->resultset('LinerNotes')->search ({ notes => 'Buy Whiskey!' }, { prefetch => { cd => [qw/tags tracks/] } });
- for (qw/all count next first/) {
- undef $w;
- my @stuff = $rs2->search()->$_;
- like ($w, qr/will currently disrupt both the functionality of .rs->count\(\), and the amount of objects retrievable via .rs->next\(\)/,
- "warning on ->$_ attempt prefetching several same level has_manys (M -> 1 -> M + M)");
- }
-}
-
-
-# Illustration purposes only
+is( $queries, 1, 'prefetch one->(has_many,has_many) ran exactly 1 query' );
+$schema->storage->debugcb(undef);
+$schema->storage->debug($sdebug);
-{
- package Inf::Dump;
- sub inflate_result {
- return [ @_[2,3] ];
- }
-}
-
-my $cd = $schema->resultset ('CD')->create ({
- artist => 1,
- title => 'bad cd',
- year => 1313,
- tags => [ map { { tag => "bad tag $_" } } (1 .. 3) ],
- tracks => [
- { title => 'bad track 1', cd_single => {
- artist => 1,
- title => 'bad_single',
- year => 1313,
- }},
- map { { title => "bad track $_" } } (2 .. 3),
- ],
-});
-
-my $rs = $schema->resultset ('CD')->search (
- { 'me.cdid' => $cd->id },
- { prefetch => [ 'tags', { tracks => 'cd_single' } ], result_class => 'Inf::Dump' },
+is( $pr_tags_count, $tags_count,
+'equal count of prefetched relations over several same level has_many\'s (M -> 1 -> M + M)'
+);
+is( $pr_tags_rs->all, $tags_rs->all,
+'equal amount of objects with and without prefetch over several same level has_many\'s (M -> 1 -> M + M)'
);
-use Text::Table;
-my $query = ${$rs->as_query}->[0];
-my ($cols) = ( $query =~ /SELECT (.+) FROM/);
-my $tb = Text::Table->new (map { $_ => \ ' | ' } (split /,\s*/, $cols) );
-
-my $c = $rs->cursor;
-while (my @stuff = $c->next) {
- $tb->add (map { defined $_ ? $_ : 'NULL' } (@stuff) );
-}
-
-$rs->reset;
-note Dumper [
- "\n$query",
- "\n$tb",
- $rs->next
-];
-
-
-
-
-__END__
-The solution is to rewrite ResultSet->_collapse_result() and
-ResultSource->resolve_prefetch() to focus on the final results from the collapse
-of the data. Right now, the code doesn't treat the columns from the various
-tables as grouped entities. While there is a concept of hierarchy (so that
-prefetching down relationships does work as expected), there is no idea of what
-the final product should look like and how the various columns in the row would
-play together. So, the actual prefetch datastructure from the search would be
-very useful in working through this problem. We already have access to the PKs
-and sundry for those. So, when collapsing the search result, we know we are
-looking for 1 cd object. We also know we're looking for tracks and tags records
--independently- of each other. So, we can grab the data for tracks and data for
-tags separately, uniqueing on the PK as appropriate. Then, when we're done with
-the given cd object's datastream, we know we're good. This should work for all
-the various scenarios.
-
-My reccommendation is the row's data is preprocessed first, breaking it up into
-the data for each of the component tables. (This could be done in the single
-table case, too, but probably isn't necessary.) So, starting with something
-like:
- my $row = {
- t1.col1 => 1,
- t1.col2 => 2,
- t2.col1 => 3,
- t2.col2 => 4,
- t3.col1 => 5,
- t3.col2 => 6,
- };
-it is massaged to look something like:
- my $row_massaged = {
- t1 => { col1 => 1, col2 => 2 },
- t2 => { col1 => 3, col2 => 4 },
- t3 => { col1 => 5, col2 => 6 },
- };
-At this point, find the stuff that's different is easy enough to do and slotting
-things into the right spot is, likewise, pretty straightforward.
-
-This implies that the collapse attribute can probably disappear or, at the
-least, be turned into a boolean (which is how it's used in every other place).
+done_testing;
projects / dbsrgits/DBIx-Class.git / blobdiff