# {from} specs, aiding the RDBMS query optimizer
#
sub _prune_unused_joins {
- my ($self) = shift;
-
+ my $self = shift;
my ($from, $select, $where, $attrs) = @_;
+ return $from unless $self->_use_join_optimizer;
+
if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') {
return $from; # only standard {from} specs are supported
}
# {multiplying} joins can go
delete $aliastypes->{multiplying} if $attrs->{group_by};
-
my @newfrom = $from->[0]; # FROM head is always present
my %need_joins = (map { %{$_||{}} } (values %$aliastypes) );
push @{$inner_attrs->{as}}, $attrs->{as}[$i];
}
- # construct the inner $from for the subquery
+ # construct the inner $from and lock it in a subquery
# we need to prune first, because this will determine if we need a group_by below
- my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $inner_attrs);
-
- # 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 first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from]);
-
- # generate the subquery
- my $subq = $self->_select_args_to_query (
- $inner_from,
- $inner_select,
- $where,
- $inner_attrs,
- );
+ # the fake group_by is so that the pruner throws away all non-selecting, non-restricting
+ # multijoins (since we def. do not care about those inside the subquery)
+
+ my $subq_joinspec = do {
+
+ # must use it here regardless of user requests
+ local $self->{_use_join_optimizer} = 1;
+
+ my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, {
+ group_by => ['dummy'], %$inner_attrs,
+ });
+
+ # if a multi-type join was needed in the subquery - add a group_by to simulate the
+ # collapse in the subq
+ if (
+ ! $inner_attrs->{group_by}
+ and
+ first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from])
+ ) {
+ $inner_attrs->{group_by} = $self->_group_over_selection (
+ $inner_from, $inner_select, $inner_attrs->{order_by}
+ );
+ }
+
+ # we already optimized $inner_from above
+ local $self->{_use_join_optimizer} = 0;
+
+ # generate the subquery
+ my $subq = $self->_select_args_to_query (
+ $inner_from,
+ $inner_select,
+ $where,
+ $inner_attrs,
+ );
- my $subq_joinspec = {
- -alias => $attrs->{alias},
- -source_handle => $inner_from->[0]{-source_handle},
- $attrs->{alias} => $subq,
+ +{
+ -alias => $attrs->{alias},
+ -source_handle => $inner_from->[0]{-source_handle},
+ $attrs->{alias} => $subq,
+ };
};
# Generate the outer from - this is relatively easy (really just replace
# - it is part of the restrictions, in which case we need to collapse the outer
# result by tackling yet another group_by to the outside of the query
- # normalize a copy of $from, so it will be easier to work with further
- # down (i.e. promote the initial hashref to an AoH)
$from = [ @$from ];
- $from->[0] = [ $from->[0] ];
# so first generate the outer_from, up to the substitution point
my @outer_from;
while (my $j = shift @$from) {
+ $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH
+
if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap
push @outer_from, [
$subq_joinspec,
}
}
- # scan the from spec against different attributes, and see which joins are needed
+ # scan the *remaining* from spec against different attributes, and see which joins are needed
# in what role
my $outer_aliastypes =
$self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs );
$alias_list->{$al} = $j;
$aliases_by_type->{multiplying}{$al} = 1
- unless $j->{-is_single};
+ if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying
}
# get a column to source/alias map (including unqualified ones)
my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
-
# generate sql chunks
my $to_scan = {
restricting => [
);
}
- # mark all join parents as mentioned
+ # mark all restricting/selecting join parents as such
# (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too )
- for my $type (keys %$aliases_by_type) {
- for my $alias (keys %{$aliases_by_type->{$type}}) {
+ for my $type (qw/restricting selecting/) {
+ for my $alias (keys %{$aliases_by_type->{$type}||{}}) {
$aliases_by_type->{$type}{$_} = 1
for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] });
}
return $aliases_by_type;
}
+sub _group_over_selection {
+ my ($self, $from, $select, $order_by) = @_;
+
+ my $rs_column_list = $self->_resolve_column_info ($from);
+
+ my (@group_by, %group_index);
+
+ for (@$select) {
+ if (! ref($_) or ref ($_) ne 'HASH' ) {
+ push @group_by, $_;
+ $group_index{$_}++;
+ if ($rs_column_list->{$_} and $_ !~ /\./ ) {
+ # add a fully qualified version as well
+ $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
+ }
+ }
+ }
+
+ # add any order_by parts that are not already present in the group_by
+ # we need to be careful not to add any named functions/aggregates
+ # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
+ for my $chunk ($self->_extract_order_columns($order_by)) {
+ # only consider real columns (for functions the user got to do an explicit group_by)
+ my $colinfo = $rs_column_list->{$chunk}
+ or next;
+
+ $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
+ push @group_by, $chunk unless $group_index{$chunk}++;
+ }
+
+ return \@group_by;
+}
+
sub _resolve_ident_sources {
my ($self, $ident) = @_;
}
else {
foreach my $key (keys %$where) {
- $key =~ /([^.]+)$/;
- $cond->{$1} = $where->{$key};
+ if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') {
+ $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key});
+ }
+ else {
+ $key =~ /([^.]+)$/;
+ $cond->{$1} = $where->{$key};
+ }
}
}
}
projects / dbsrgits/DBIx-Class.git / blobdiff