# {from} specs, aiding the RDBMS query optimizer
#
sub _prune_unused_joins {
- my $self = shift;
- my ($from, $select, $where, $attrs) = @_;
-
- return $from unless $self->_use_join_optimizer;
+ my ($self, $attrs) = @_;
- if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') {
- return $from; # only standard {from} specs are supported
- }
+ # only standard {from} specs are supported, and we could be disabled in general
+ return ($attrs->{from}, {}) unless (
+ ref $attrs->{from} eq 'ARRAY'
+ and
+ @{$attrs->{from}} > 1
+ and
+ ref $attrs->{from}[0] eq 'HASH'
+ and
+ ref $attrs->{from}[1] eq 'ARRAY'
+ and
+ $self->_use_join_optimizer
+ );
- my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_);
+ my $aliastypes = $self->_resolve_aliastypes_from_select_args($attrs);
my $orig_joins = delete $aliastypes->{joining};
my $orig_multiplying = $aliastypes->{multiplying};
delete $aliastypes->{multiplying}
if $attrs->{_force_prune_multiplying_joins} or $attrs->{group_by};
- my @newfrom = $from->[0]; # FROM head is always present
+ my @newfrom = $attrs->{from}[0]; # FROM head is always present
my %need_joins;
$need_joins{$_} = 1 for map { values %$_ } map { @{$_->{-parents}} } values %$_;
}
- for my $j (@{$from}[1..$#$from]) {
+ for my $j (@{$attrs->{from}}[1..$#{$attrs->{from}}]) {
push @newfrom, $j if (
(! defined $j->[0]{-alias}) # legacy crap
||
# SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
#
sub _adjust_select_args_for_complex_prefetch {
- my ($self, $from, $select, $where, $attrs) = @_;
+ my ($self, $attrs) = @_;
- $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
- if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY');
+ $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') unless (
+ ref $attrs->{from} eq 'ARRAY'
+ and
+ @{$attrs->{from}} > 1
+ and
+ ref $attrs->{from}[0] eq 'HASH'
+ and
+ ref $attrs->{from}[1] eq 'ARRAY'
+ );
my $root_alias = $attrs->{alias};
# generate inner/outer attribute lists, remove stuff that doesn't apply
my $outer_attrs = { %$attrs };
- delete @{$outer_attrs}{qw(where bind rows offset group_by _grouped_by_distinct having)};
+ delete @{$outer_attrs}{qw(from bind rows offset group_by _grouped_by_distinct having)};
my $inner_attrs = { %$attrs };
- delete @{$inner_attrs}{qw(from for collapse select as _related_results_construction)};
+ delete @{$inner_attrs}{qw(for collapse select as _related_results_construction)};
# there is no point of ordering the insides if there is no limit
delete $inner_attrs->{order_by} if (
# generate the inner/outer select lists
# for inside we consider only stuff *not* brought in by the prefetch
# on the outside we substitute any function for its alias
- my $outer_select = [ @$select ];
- my $inner_select;
+ $outer_attrs->{select} = [ @{$attrs->{select}} ];
my ($root_node, $root_node_offset);
- for my $i (0 .. $#$from) {
- my $node = $from->[$i];
+ for my $i (0 .. $#{$inner_attrs->{from}}) {
+ my $node = $inner_attrs->{from}[$i];
my $h = (ref $node eq 'HASH') ? $node
: (ref $node eq 'ARRAY' and ref $node->[0] eq 'HASH') ? $node->[0]
: next
unless $root_node;
# use the heavy duty resolver to take care of aliased/nonaliased naming
- my $colinfo = $self->_resolve_column_info($from);
+ my $colinfo = $self->_resolve_column_info($inner_attrs->{from});
my $selected_root_columns;
- for my $i (0 .. $#$outer_select) {
- my $sel = $outer_select->[$i];
+ for my $i (0 .. $#{$outer_attrs->{select}}) {
+ my $sel = $outer_attrs->{select}->[$i];
next if (
$colinfo->{$sel} and $colinfo->{$sel}{-source_alias} ne $root_alias
if (ref $sel eq 'HASH' ) {
$sel->{-as} ||= $attrs->{as}[$i];
- $outer_select->[$i] = join ('.', $root_alias, ($sel->{-as} || "inner_column_$i") );
+ $outer_attrs->{select}->[$i] = join ('.', $root_alias, ($sel->{-as} || "inner_column_$i") );
}
elsif (! ref $sel and my $ci = $colinfo->{$sel}) {
$selected_root_columns->{$ci->{-colname}} = 1;
}
- push @$inner_select, $sel;
+ push @{$inner_attrs->{select}}, $sel;
push @{$inner_attrs->{as}}, $attrs->{as}[$i];
}
# We will need to fetch all native columns in the inner subquery, which may
# be a part of an *outer* join condition, or an order_by (which needs to be
- # preserved outside)
+ # preserved outside), or wheres. In other words everything but the inner
+ # selector
# We can not just fetch everything because a potential has_many restricting
# join collapse *will not work* on heavy data types.
- my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args(
- $from,
- [],
- $where,
- $inner_attrs
- );
+ my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args({
+ %$inner_attrs,
+ select => [],
+ });
for (sort map { keys %{$_->{-seen_columns}||{}} } map { values %$_ } values %$connecting_aliastypes) {
my $ci = $colinfo->{$_} or next;
! $selected_root_columns->{$ci->{-colname}}++
) {
# adding it to both to keep limits not supporting dark selectors happy
- push @$inner_select, $ci->{-fq_colname};
+ push @{$inner_attrs->{select}}, $ci->{-fq_colname};
push @{$inner_attrs->{as}}, $ci->{-fq_colname};
}
}
- # construct the inner $from and lock it in a 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
# throw away all non-selecting, non-restricting multijoins
# (since we def. do not care about multiplication those inside the subquery)
local $self->{_use_join_optimizer} = 1;
# throw away multijoins since we def. do not care about those inside the subquery
- my ($inner_from, $inner_aliastypes) = $self->_prune_unused_joins ($from, $inner_select, $where, {
+ ($inner_attrs->{from}, my $inner_aliastypes) = $self->_prune_unused_joins ({
%$inner_attrs, _force_prune_multiplying_joins => 1
});
) {
my $unprocessed_order_chunks;
- ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ({
- %$inner_attrs,
- from => $inner_from,
- select => $inner_select,
- });
+ ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
+ $inner_attrs,
+ );
$self->throw_exception (
'A required group_by clause could not be constructed automatically due to a complex '
# supplement the main selection with pks if not already there,
# as they will have to be a part of the group_by to collapse
# things properly
- my $cur_sel = { map { $_ => 1 } @$inner_select };
+ my $cur_sel = { map { $_ => 1 } @{$inner_attrs->{select}} };
my @pks = map { "$root_alias.$_" } $root_node->{-rsrc}->primary_columns
or $self->throw_exception( sprintf
$root_node->{-rsrc}->source_name,
);
for my $col (@pks) {
- push @$inner_select, $col
+ push @{$inner_attrs->{select}}, $col
unless $cur_sel->{$col}++;
}
my $own_re = qr/ $lquote \Q$root_alias\E $rquote $sep | \b \Q$root_alias\E $sep /x;
my @order_chunks = map { ref $_ eq 'ARRAY' ? $_ : [ $_ ] } $sql_maker->_order_by_chunks($attrs->{order_by});
my @new_order = map { \$_ } @order_chunks;
- my $inner_columns_info = $self->_resolve_column_info($inner_from);
+ my $inner_columns_info = $self->_resolve_column_info($inner_attrs->{from});
# loop through and replace stuff that is not "ours" with a min/max func
# everything is a literal at this point, since we are likely properly
# do not care about leftovers here - it will be all the functions
# we just created
- ($inner_attrs->{group_by}) = $self->_group_over_selection ({
- %$inner_attrs,
- from => $inner_from,
- select => $inner_select,
- });
+ ($inner_attrs->{group_by}) = $self->_group_over_selection (
+ $inner_attrs,
+ );
}
}
- # we already optimized $inner_from above
+ # we already optimized $inner_attrs->{from} above
# and already local()ized
$self->{_use_join_optimizer} = 0;
# generate the subquery
$self->_select_args_to_query (
- $inner_from,
- $inner_select,
- $where,
+ @{$inner_attrs}{qw(from select where)},
$inner_attrs,
);
};
# result by tackling yet another group_by to the outside of the query
# work on a shallow copy
- $from = [ @$from ];
+ my @orig_from = @{$attrs->{from}};
+
- my @outer_from;
+ $outer_attrs->{from} = \ my @outer_from;
# we may not be the head
if ($root_node_offset) {
- # first generate the outer_from, up and including the substitution point
- @outer_from = splice @$from, 0, $root_node_offset;
+ # first generate the outer_from, up to the substitution point
+ @outer_from = splice @orig_from, 0, $root_node_offset;
+ # substitute the subq at the right spot
push @outer_from, [
{
-alias => $root_alias,
-rsrc => $root_node->{-rsrc},
$root_alias => $inner_subq,
},
- @{$from->[0]}[1 .. $#{$from->[0]}],
+ # preserve attrs from what is now the head of the from after the splice
+ @{$orig_from[0]}[1 .. $#{$orig_from[0]}],
];
}
else {
};
}
- shift @$from; # what we just replaced above
+ shift @orig_from; # what we just replaced above
# scan the *remaining* from spec against different attributes, and see which joins are needed
# in what role
my $outer_aliastypes = $outer_attrs->{_aliastypes} =
- $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs );
+ $self->_resolve_aliastypes_from_select_args({ %$outer_attrs, from => \@orig_from });
# unroll parents
my ($outer_select_chain, @outer_nonselecting_chains) = map { +{
# also throw in a group_by if a non-selecting multiplier,
# to guard against cross-join explosions
my $need_outer_group_by;
- while (my $j = shift @$from) {
+ while (my $j = shift @orig_from) {
my $alias = $j->[0]{-alias};
if (
($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ({
%$outer_attrs,
from => \@outer_from,
- select => $outer_select,
});
$self->throw_exception (
}
- # This is totally horrific - the $where ends up in both the inner and outer query
+ # This is totally horrific - the {where} ends up in both the inner and outer query
# Unfortunately not much can be done until SQLA2 introspection arrives, and even
# then if where conditions apply to the *right* side of the prefetch, you may have
# to both filter the inner select (e.g. to apply a limit) and then have to re-filter
# the outer select to exclude joins you didn't want in the first place
#
# OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
- return (\@outer_from, $outer_select, $where, $outer_attrs);
+
+ return $outer_attrs;
}
#
# happen is for it to fail due to some scalar SQL, which in turn will
# result in a vocal exception.
sub _resolve_aliastypes_from_select_args {
- my ( $self, $from, $select, $where, $attrs ) = @_;
+ my ( $self, $attrs ) = @_;
$self->throw_exception ('Unable to analyze custom {from}')
- if ref $from ne 'ARRAY';
+ if ref $attrs->{from} ne 'ARRAY';
# what we will return
my $aliases_by_type;
# see what aliases are there to work with
my $alias_list;
- for (@$from) {
- my $j = $_;
+ for my $node (@{$attrs->{from}}) {
+
+ my $j = $node;
$j = $j->[0] if ref $j eq 'ARRAY';
my $al = $j->{-alias}
or next;
$alias_list->{$al} = $j;
$aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] } if (
# not array == {from} head == can't be multiplying
- ( ref($_) eq 'ARRAY' and ! $j->{-is_single} )
+ ( ref($node) eq 'ARRAY' and ! $j->{-is_single} )
or
# a parent of ours is already a multiplier
( grep { $aliases_by_type->{multiplying}{$_} } @{ $j->{-join_path}||[] } )
}
# get a column to source/alias map (including unambiguous unqualified ones)
- my $colinfo = $self->_resolve_column_info ($from);
+ my $colinfo = $self->_resolve_column_info ($attrs->{from});
# set up a botched SQLA
my $sql_maker = $self->sql_maker;
# generate sql chunks
my $to_scan = {
restricting => [
- $sql_maker->_recurse_where ($where),
+ $sql_maker->_recurse_where ($attrs->{where}),
$sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }),
],
grouping => [
],
joining => [
$sql_maker->_recurse_from (
- ref $from->[0] eq 'ARRAY' ? $from->[0][0] : $from->[0],
- @{$from}[1 .. $#$from],
+ ref $attrs->{from}[0] eq 'ARRAY' ? $attrs->{from}[0][0] : $attrs->{from}[0],
+ @{$attrs->{from}}[1 .. $#{$attrs->{from}}],
),
],
selecting => [
- $sql_maker->_recurse_fields ($select),
+ $sql_maker->_recurse_fields ($attrs->{select}),
],
ordering => [
map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker),
# something that is in fact there - the stack will recover gracefully
# Also - DQ and the mst it rode in on will save us all RSN!!!
sub _extract_fixed_condition_columns {
- my ($self, $where, $nested) = @_;
+ my ($self, $where) = @_;
return unless ref $where eq 'HASH';
for my $lhs (keys %$where) {
if ($lhs =~ /^\-and$/i) {
push @cols, ref $where->{$lhs} eq 'ARRAY'
- ? ( map { $self->_extract_fixed_condition_columns($_, 1) } @{$where->{$lhs}} )
- : $self->_extract_fixed_condition_columns($where->{$lhs}, 1)
+ ? ( map { @{ $self->_extract_fixed_condition_columns($_) } } @{$where->{$lhs}} )
+ : @{ $self->_extract_fixed_condition_columns($where->{$lhs}) }
;
}
elsif ($lhs !~ /^\-/) {
));
}
}
- return $nested ? @cols : \@cols;
+ return \@cols;
}
1;
projects / dbsrgits/DBIx-Class.git / commitdiff