# extra selectors do not go in the subquery and there is no point of ordering it
delete $sub_attrs->{$_} for qw/collapse select _prefetch_select as order_by/;
- # if we prefetch, we group_by primary keys only as this is what we would get out
- # of the rs via ->next/->all. We DO WANT to clobber old group_by regardless
- if ( keys %{$attrs->{collapse}} ) {
+ # if we multi-prefetch we group_by primary keys only as this is what we would
+ # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
+ if ( keys %{$attrs->{collapse}} ) {
$sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->primary_columns) ]
}
$sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $sub_attrs);
# this is so that the query can be simplified e.g.
- # * non-limiting joins can be pruned
# * ordering can be thrown away in things like Top limit
$sub_attrs->{-for_count_only} = 1;
my $jpath = $j->[0]{-join_path};
my $p = $paths;
- $p = $p->{$_} ||= {} for @{$jpath}[$cur_depth/2 .. $#$jpath]; #only even depths are actual jpath boundaries
+ $p = $p->{$_} ||= {} for @{$jpath}[ ($cur_depth/2) .. $#$jpath]; #only even depths are actual jpath boundaries
push @{$p->{-join_aliases} }, $j->[0]{-alias};
}
#
# This code will remove non-selecting/non-restricting joins from
-# {from} specs, aiding the RDBMS query optimizer. It will leave any
-# unused type-multi joins, if the amount of returned rows is
-# important (i.e. count without collapse)
+# {from} specs, aiding the RDBMS query optimizer.
#
sub _prune_unused_joins {
my $self = shift;
return $from; # only standard {from} specs are supported
}
- my $aliastypes = $self->_resolve_aliases_from_select_args($from, @_);
+ my $aliastypes = $self->_resolve_aliastypes_from_select_args($from, @_);
my @newfrom = $from->[0]; # FROM head is always present
my %need_joins = (map { %{$_||{}} } (values %$aliastypes) );
for my $j (@{$from}[1..$#$from]) {
- push @newfrom, $j if $need_joins{$j->[0]{-alias}};
+ push @newfrom, $j if (
+ ! $j->[0]{-alias} # legacy crap
+ ||
+ $need_joins{$j->[0]{-alias}}
+ );
}
return \@newfrom;
# construct the inner $from for the subquery
my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $inner_attrs);
- # if a multi-type join was needed in the subquery ("multi" is indicated by
- # presence in {collapse}) - add a group_by to simulate the collapse in the subq
- unless ($inner_attrs->{group_by}) {
- for my $alias (map { $_->[0]{-alias} } (@{$inner_from}[1 .. $#$inner_from]) ) {
-
- # the dot comes from some weirdness in collapse
- # remove after the rewrite
- if ($attrs->{collapse}{".$alias"}) {
- $inner_attrs->{group_by} ||= $inner_select;
- last;
- }
- }
- }
+ # if a multi-type join was needed in the subquery - add a group_by to simulate the
+ # collapse in the subq
+ $inner_attrs->{group_by} ||= $inner_select
+ if List::Util::first
+ { ! $_->[0]{-is_single} }
+ (@{$inner_from}[1 .. $#$inner_from])
+ ;
# generate the subquery
my $subq = $self->_select_args_to_query (
# scan the from spec against different attributes, and see which joins are needed
# in what role
my $outer_aliastypes =
- $self->_resolve_aliases_from_select_args( $from, $outer_select, $where, $outer_attrs );
+ $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs );
# see what's left - throw away if not selecting/restricting
# also throw in a group_by if restricting to guard against
}
elsif ($outer_aliastypes->{restrict}{$alias}) {
push @outer_from, $j;
-
- # FIXME - this should be obviated by SQLA2, as I'll be able to
- # have restrict_inner and restrict_outer... or something to that
- # effect... I think...
-
- # FIXME2 - I can't find a clean way to determine if a particular join
- # is a multi - instead I am just treating everything as a potential
- # explosive join (ribasushi)
- #
- # if (my $handle = $j->[0]{-source_handle}) {
- # my $rsrc = $handle->resolve;
- # ... need to bail out of the following if this is not a multi,
- # as it will be much easier on the db ...
-
- $outer_attrs->{group_by} ||= $outer_select;
- # }
+ $outer_attrs->{group_by} ||= $outer_select unless $j->[0]{-is_single};
}
}
# happen is for it to fail due to an unqualified column, which in
# turn will result in a vocal exception. Qualifying the column will
# invariably solve the problem.
-sub _resolve_aliases_from_select_args {
+sub _resolve_aliastypes_from_select_args {
my ( $self, $from, $select, $where, $attrs ) = @_;
$self->throw_exception ('Unable to analyze custom {from}')
# see what aliases are there to work with
my $alias_list;
- my @from = @$from; # if I don't copy weird shit happens
- for my $j (@from) {
+ for (@$from) {
+ my $j = $_;
$j = $j->[0] if ref $j eq 'ARRAY';
- $alias_list->{$j->{-alias}} = $j;
+ my $al = $j->{-alias}
+ or next;
+
+ $alias_list->{$al} = $j;
+ $aliases_by_type->{multiplying}{$al} = 1
+ unless $j->{-is_single};
}
# set up a botched SQLA
{
my $rs = $schema->resultset("CD")
->search_related('tracks',
- { position => [1,2] },
+ { position => [1,2], 'lyrics.lyric_id' => undef },
{ prefetch => [qw/disc lyrics/] },
);
is ($rs->all, 10, 'Correct number of objects');
JOIN track tracks ON tracks.cd = me.cdid
JOIN cd disc ON disc.cdid = tracks.cd
LEFT JOIN lyrics lyrics ON lyrics.track_id = tracks.trackid
- WHERE position = ? OR position = ?
+ WHERE lyrics.lyric_id IS NULL AND (position = ? OR position = ?)
)',
[ map { [ position => $_ ] } (1, 2) ],
);
projects / dbsrgits/DBIx-Class.git / commitdiff