use List::Util 'first';
use Scalar::Util 'blessed';
+use Sub::Name 'subname';
use namespace::clean;
#
#
sub _prune_unused_joins {
my $self = shift;
- my ($from, $select, $where, $attrs) = @_;
+ my ($from, $select, $where, $attrs, $ignore_multiplication) = @_;
return $from unless $self->_use_join_optimizer;
my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_);
+ # don't care
+ delete $aliastypes->{joining};
+
# a grouped set will not be affected by amount of rows. Thus any
# {multiplying} joins can go
- delete $aliastypes->{multiplying} if $attrs->{group_by};
+ delete $aliastypes->{multiplying}
+ if $ignore_multiplication or $attrs->{group_by};
my @newfrom = $from->[0]; # FROM head is always present
my %need_joins;
+
for (values %$aliastypes) {
# add all requested aliases
$need_joins{$_} = 1 for keys %$_;
# add all their parents (as per joinpath which is an AoH { table => alias })
- $need_joins{$_} = 1 for map { values %$_ } map { @$_ } values %$_;
+ $need_joins{$_} = 1 for map { values %$_ } map { @{$_->{-parents}} } values %$_;
}
+
for my $j (@{$from}[1..$#$from]) {
push @newfrom, $j if (
(! $j->[0]{-alias}) # legacy crap
#
# This is the code producing joined subqueries like:
-# SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
+# SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
#
sub _adjust_select_args_for_complex_prefetch {
my ($self, $from, $select, $where, $attrs) = @_;
- $self->throw_exception ('Nothing to prefetch... how did we get here?!')
- if not @{$attrs->{_prefetch_selector_range}};
-
$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');
+ my $root_alias = $attrs->{alias};
# generate inner/outer attribute lists, remove stuff that doesn't apply
my $outer_attrs = { %$attrs };
- delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/;
+ delete $outer_attrs->{$_} for qw/where bind rows offset group_by _grouped_by_distinct having/;
my $inner_attrs = { %$attrs };
- delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range _collapse_order_by select as/;
-
+ delete $inner_attrs->{$_} for qw/from for collapse select as _related_results_construction/;
- # bring over all non-collapse-induced order_by into the inner query (if any)
- # the outer one will have to keep them all
- delete $inner_attrs->{order_by};
- if (my $ord_cnt = @{$outer_attrs->{order_by}} - @{$outer_attrs->{_collapse_order_by}} ) {
- $inner_attrs->{order_by} = [
- @{$outer_attrs->{order_by}}[ 0 .. $ord_cnt - 1]
- ];
- }
+ # there is no point of ordering the insides if there is no limit
+ delete $inner_attrs->{order_by} if (
+ delete $inner_attrs->{_order_is_artificial}
+ or
+ ! $inner_attrs->{rows}
+ );
# 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 = [];
+ my $inner_select;
+
+ my ($root_node, $root_node_offset);
- my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}};
- for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) {
+ for my $i (0 .. $#$from) {
+ my $node = $from->[$i];
+ my $h = (ref $node eq 'HASH') ? $node
+ : (ref $node eq 'ARRAY' and ref $node->[0] eq 'HASH') ? $node->[0]
+ : next
+ ;
+
+ if ( ($h->{-alias}||'') eq $root_alias and $h->{-rsrc} ) {
+ $root_node = $h;
+ $root_node_offset = $i;
+ last;
+ }
+ }
+
+ $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
+ unless $root_node;
+
+ # use the heavy duty resolver to take care of aliased/nonaliased naming
+ my $colinfo = $self->_resolve_column_info($from);
+ my $selected_root_columns;
+
+ for my $i (0 .. $#$outer_select) {
my $sel = $outer_select->[$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 ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") );
+ $outer_select->[$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->{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)
+ # We can not just fetch everything because a potential has_many restricting
+ # join collapse *will not work* on heavy data types.
+ my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args(
+ [grep { ref($_) eq 'ARRAY' or ref($_) eq 'HASH' } @{$from}[$root_node_offset .. $#$from]],
+ [],
+ $where,
+ $inner_attrs
+ );
+
+ for (sort map { keys %{$_->{-seen_columns}||{}} } map { values %$_ } values %$connecting_aliastypes) {
+ my $ci = $colinfo->{$_} or next;
+ if (
+ $ci->{-source_alias} eq $root_alias
+ and
+ ! $selected_root_columns->{$ci->{-colname}}++
+ ) {
+ # adding it to both to keep limits not supporting dark selectors happy
+ push @$inner_select, $ci->{-fq_colname};
+ push @{$inner_attrs->{as}}, $ci->{-fq_colname};
+ }
+ }
+
# 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
- # 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)
-
+ # throw away all non-selecting, non-restricting multijoins
+ # (since we def. do not care about multiplication those inside the subquery)
my $inner_subq = 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,
- });
+ # throw away multijoins since we def. do not care about those inside the subquery
+ my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $inner_attrs, 'ignore_multiplication');
my $inner_aliastypes =
$self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs );
- # we need to simulate collapse in the subq if a multiplying join is pulled
- # by being a non-selecting restrictor
+ # uh-oh a multiplier (which is not us) left in, this is a problem
if (
- ! $inner_attrs->{group_by}
+ $inner_aliastypes->{multiplying}
+ and
+ !$inner_aliastypes->{grouping} # if there are groups - assume user knows wtf they are up to
and
- first {
- $inner_aliastypes->{restricting}{$_}
- and
- ! $inner_aliastypes->{selecting}{$_}
- } ( keys %{$inner_aliastypes->{multiplying}||{}} )
+ my @multipliers = grep { $_ ne $root_alias } keys %{$inner_aliastypes->{multiplying}}
) {
- my $unprocessed_order_chunks;
- ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
- $inner_from, $inner_select, $inner_attrs->{order_by}
- );
-
- $self->throw_exception (
- 'A required group_by clause could not be constructed automatically due to a complex '
- . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
- . 'group_by by hand'
- ) if $unprocessed_order_chunks;
+
+ # if none of the multipliers came from an order_by (guaranteed to have been combined
+ # with a limit) - easy - just slap a group_by to simulate a collape and be on our way
+ if (
+ ! $inner_aliastypes->{ordering}
+ or
+ ! first { $inner_aliastypes->{ordering}{$_} } @multipliers
+ ) {
+ my $unprocessed_order_chunks;
+ ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
+ $inner_from, $inner_select, $inner_attrs->{order_by}
+ );
+
+ $self->throw_exception (
+ 'A required group_by clause could not be constructed automatically due to a complex '
+ . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
+ . 'group_by by hand'
+ ) if $unprocessed_order_chunks;
+ }
+ else {
+ # We need to order by external columns and group at the same time
+ # so we can calculate the proper limit
+ # This doesn't really make sense in SQL, however from DBICs point
+ # of view is rather valid (order the leftmost objects by whatever
+ # criteria and get the offset/rows many). There is a way around
+ # this however in SQL - we simply tae the direction of each piece
+ # of the foreign order and convert them to MIN(X) for ASC or MAX(X)
+ # for DESC, and group_by the root columns. The end result should be
+ # exactly what we expect
+
+ # FIXME REMOVE LATER - (just a sanity check)
+ if (defined ( my $impostor = first
+ { $_ ne $root_alias }
+ keys %{ $inner_aliastypes->{selecting} }
+ ) ) {
+ $self->throw_exception(sprintf
+ 'Unexpected inner selection during complex prefetch (%s)...',
+ join ', ', keys %{ $inner_aliastypes->{joining}{$impostor}{-seen_columns} || {} }
+ );
+ }
+
+ # supplement the main selection with pks if not already there,
+ # as they will have to be a part of the group_by to colapse
+ # things properly
+ my $cur_sel = { map { $_ => 1 } @$inner_select };
+ my @pks = map { "$root_alias.$_" } $root_node->{-rsrc}->primary_columns
+ or $self->throw_exception( sprintf
+ 'Unable to perform complex limited prefetch off %s without declared primary key',
+ $root_node->{-rsrc}->source_name,
+ );
+ for my $col (@pks) {
+ push @$inner_select, $col
+ unless $cur_sel->{$col}++;
+ }
+
+ # wrap any part of the order_by that "responds" to an ordering alias
+ # into a MIN/MAX
+ # FIXME - this code is a joke, will need to be completely rewritten in
+ # the DQ branch. But I need to push a POC here, otherwise the
+ # pesky tests won't pass
+ my $sql_maker = $self->sql_maker;
+ my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
+ my $own_re = qr/ $lquote \Q$root_alias\E $rquote $sep | \b \Q$root_alias\E $sep /x;
+ my @order = @{$attrs->{order_by}};
+ my @order_chunks = map { ref $_ eq 'ARRAY' ? $_ : [ $_ ] } $sql_maker->_order_by_chunks (\@order);
+ $self->throw_exception ('Order By parsing failed...') if @order != @order_chunks;
+ for my $i (0 .. $#order) {
+ # skip ourselves, and anything that looks like a literal
+ next if $order_chunks[$i][0] =~ $own_re;
+ next if (ref $order[$i] and ref $order[$i] ne 'HASH');
+
+ my $is_desc = $order_chunks[$i][0] =~ s/\sDESC$//i;
+ $order_chunks[$i][0] =~ s/\sASC$//i;
+
+ $order[$i] = \[
+ sprintf(
+ '%s(%s)%s',
+ ($is_desc ? 'MAX' : 'MIN'),
+ $order_chunks[$i][0],
+ ($is_desc ? ' DESC' : ''),
+ ),
+ @ {$order_chunks[$i]} [ 1 .. $#{$order_chunks[$i]} ]
+ ];
+ }
+
+ $inner_attrs->{order_by} = \@order;
+ ($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;
+ # and already local()ized
+ $self->{_use_join_optimizer} = 0;
# generate the subquery
$self->_select_args_to_query (
# - 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
+ # work on a shallow copy
$from = [ @$from ];
- # 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 $attrs->{alias}) { # time to swap
+ # we may not be the head
+ if ($root_node_offset) {
+ # first generate the outer_from, up to the substitution point
+ @outer_from = splice @$from, 0, $root_node_offset;
- push @outer_from, [
- {
- -alias => $attrs->{alias},
- -rsrc => $j->[0]{-rsrc},
- $attrs->{alias} => $inner_subq,
- },
- @{$j}[1 .. $#$j],
- ];
- last; # we'll take care of what's left in $from below
- }
- else {
- push @outer_from, $j;
- }
+ push @outer_from, [
+ {
+ -alias => $root_alias,
+ -rsrc => $root_node->{-rsrc},
+ $root_alias => $inner_subq,
+ },
+ @{$from->[0]}[1 .. $#{$from->[0]}],
+ ];
+ }
+ else {
+ @outer_from = {
+ -alias => $root_alias,
+ -rsrc => $root_node->{-rsrc},
+ $root_alias => $inner_subq,
+ };
}
+ shift @$from; # it's replaced in @outer_from already
+
# 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, $outer_attrs );
# unroll parents
- my ($outer_select_chain, $outer_restrict_chain) = map { +{
- map { $_ => 1 } map { values %$_} map { @$_ } values %{ $outer_aliastypes->{$_} || {} }
- } } qw/selecting restricting/;
+ my ($outer_select_chain, @outer_nonselecting_chains) = map { +{
+ map { $_ => 1 } map { values %$_} map { @{$_->{-parents}} } values %{ $outer_aliastypes->{$_} || {} }
+ } } qw/selecting restricting grouping ordering/;
# see what's left - throw away if not selecting/restricting
# also throw in a group_by if a non-selecting multiplier,
) {
push @outer_from, $j
}
- elsif ($outer_restrict_chain->{$alias}) {
+ elsif (first { $_->{$alias} } @outer_nonselecting_chains ) {
push @outer_from, $j;
$need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0;
}
}
- # demote the outer_from head
- $outer_from[0] = $outer_from[0][0];
-
- if ($need_outer_group_by and ! $outer_attrs->{group_by}) {
+ if ( $need_outer_group_by and $attrs->{_grouped_by_distinct} ) {
my $unprocessed_order_chunks;
($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
or next;
$alias_list->{$al} = $j;
- $aliases_by_type->{multiplying}{$al} ||= $j->{-join_path}||[] if (
+ $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] } if (
# not array == {from} head == can't be multiplying
( ref($_) eq 'ARRAY' and ! $j->{-is_single} )
or
local $sql_maker->{where_bind};
local $sql_maker->{group_bind};
local $sql_maker->{having_bind};
+ local $sql_maker->{from_bind};
# we can't scan properly without any quoting (\b doesn't cut it
# everywhere), so unless there is proper quoting set - use our
my $to_scan = {
restricting => [
$sql_maker->_recurse_where ($where),
- $sql_maker->_parse_rs_attrs ({
- map { $_ => $attrs->{$_} } (qw/group_by having/)
- }),
+ $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }),
+ ],
+ grouping => [
+ $sql_maker->_parse_rs_attrs ({ group_by => $attrs->{group_by} }),
+ ],
+ joining => [
+ $sql_maker->_recurse_from (
+ ref $from->[0] eq 'ARRAY' ? $from->[0][0] : $from->[0],
+ @{$from}[1 .. $#$from],
+ ),
],
selecting => [
$sql_maker->_recurse_fields ($select),
- ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ),
+ ],
+ ordering => [
+ map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker),
],
};
# alias (should work even if they are in scalarrefs)
for my $alias (keys %$alias_list) {
my $al_re = qr/
- $lquote $alias $rquote $sep
+ $lquote $alias $rquote $sep (?: $lquote ([^$rquote]+) $rquote )?
|
- \b $alias \.
+ \b $alias \. ([^\s\)\($rquote]+)?
/x;
for my $type (keys %$to_scan) {
for my $piece (@{$to_scan->{$type}}) {
- $aliases_by_type->{$type}{$alias} ||= $alias_list->{$alias}{-join_path}||[]
- if ($piece =~ $al_re);
+ if (my @matches = $piece =~ /$al_re/g) {
+ $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
+ $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = "$alias.$_"
+ for grep { defined $_ } @matches;
+ }
}
}
}
for my $col (keys %$colinfo) {
next if $col =~ / \. /x; # if column is qualified it was caught by the above
- my $col_re = qr/ $lquote $col $rquote /x;
+ my $col_re = qr/ $lquote ($col) $rquote /x;
for my $type (keys %$to_scan) {
for my $piece (@{$to_scan->{$type}}) {
- if ($piece =~ $col_re) {
+ if (my @matches = $piece =~ /$col_re/g) {
my $alias = $colinfo->{$col}{-source_alias};
- $aliases_by_type->{$type}{$alias} ||= $alias_list->{$alias}{-join_path}||[];
+ $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
+ $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = $_
+ for grep { defined $_ } @matches;
}
}
}
# Add any non-left joins to the restriction list (such joins are indeed restrictions)
for my $j (values %$alias_list) {
my $alias = $j->{-alias} or next;
- $aliases_by_type->{restricting}{$alias} ||= $j->{-join_path}||[] if (
+ $aliases_by_type->{restricting}{$alias} ||= { -parents => $j->{-join_path}||[] } if (
(not $j->{-join_type})
or
($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi)
);
}
+ for (keys %$aliases_by_type) {
+ delete $aliases_by_type->{$_} unless keys %{$aliases_by_type->{$_}};
+ }
+
return $aliases_by_type;
}
},
-result_source => $rsrc,
-source_alias => $source_alias,
+ -fq_colname => $col eq $colname ? "$source_alias.$col" : $col,
+ -colname => $colname,
};
+
+ $return{"$source_alias.$colname"} = $return{$col} if $col eq $colname;
}
return \%return;
# So it looks like we will have to switch some stuff around.
# local() is useless here as we will be leaving the scope
# anyway, and deep cloning is just too fucking expensive
- # So replace the first hashref in the node arrayref manually
+ # So replace the first hashref in the node arrayref manually
my @new_from = ($from->[0]);
my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path
}
}
+sub _order_by_is_stable {
+ my ($self, $ident, $order_by, $where) = @_;
+
+ my $colinfo = $self->_resolve_column_info($ident, [
+ (map { $_->[0] } $self->_extract_order_criteria($order_by)),
+ $where ? @{$self->_extract_fixed_condition_columns($where)} :(),
+ ]);
+
+ return undef unless keys %$colinfo;
+
+ my $cols_per_src;
+ $cols_per_src->{$_->{-source_alias}}{$_->{-colname}} = $_ for values %$colinfo;
+
+ for (values %$cols_per_src) {
+ my $src = (values %$_)[0]->{-result_source};
+ return 1 if $src->_identifying_column_set($_);
+ }
+
+ return undef;
+}
+
+# this is almost identical to the above, except it accepts only
+# a single rsrc, and will succeed only if the first portion of the order
+# by is stable.
+# returns that portion as a colinfo hashref on success
+sub _main_source_order_by_portion_is_stable {
+ my ($self, $main_rsrc, $order_by, $where) = @_;
+
+ die "Huh... I expect a blessed result_source..."
+ if ref($main_rsrc) eq 'ARRAY';
+
+ my @ord_cols = map
+ { $_->[0] }
+ ( $self->_extract_order_criteria($order_by) )
+ ;
+ return unless @ord_cols;
+
+ my $colinfos = $self->_resolve_column_info($main_rsrc, \@ord_cols);
+ for (0 .. $#ord_cols) {
+ if (
+ ! $colinfos->{$ord_cols[$_]}
+ or
+ $colinfos->{$ord_cols[$_]}{-result_source} != $main_rsrc
+ ) {
+ $#ord_cols = $_ - 1;
+ last;
+ }
+ }
+
+ # we just truncated it above
+ return unless @ord_cols;
+
+ # since all we check here are the start of the order_by belonging to the
+ # top level $rsrc, a present identifying set will mean that the resultset
+ # is ordered by its leftmost table in a stable manner
+ #
+ # single source - safely use both qualified and unqualified name
+ my $order_portion_ci = { map {
+ $colinfos->{$_}{-colname} => $colinfos->{$_},
+ $colinfos->{$_}{-fq_colname} => $colinfos->{$_},
+ } @ord_cols };
+
+ $where = $where ? $self->_resolve_column_info(
+ $main_rsrc, $self->_extract_fixed_condition_columns($where)
+ ) : {};
+
+ return (
+ $main_rsrc->_identifying_column_set({ %$where, %$order_portion_ci })
+ ? $order_portion_ci
+ : undef
+ );
+}
+
+# returns an arrayref of column names which *definitely* have som
+# sort of non-nullable equality requested in the given condition
+# specification. This is used to figure out if a resultset is
+# constrained to a column which is part of a unique constraint,
+# which in turn allows us to better predict how ordering will behave
+# etc.
+#
+# this is a rudimentary, incomplete, and error-prone extractor
+# however this is OK - it is conservative, and if we can not find
+# something that is in fact there - the stack will recover gracefully
+# Also - DQ and the mst it rode in on will save us all RSN!!!
+sub _extract_fixed_condition_columns {
+ my ($self, $where, $nested) = @_;
+
+ return unless ref $where eq 'HASH';
+
+ my @cols;
+ 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->{$lhs}, 1)
+ ;
+ }
+ elsif ($lhs !~ /^\-/) {
+ my $val = $where->{$lhs};
+
+ push @cols, $lhs if (defined $val and (
+ ! ref $val
+ or
+ (ref $val eq 'HASH' and keys %$val == 1 and defined $val->{'='})
+ ));
+ }
+ }
+ return $nested ? @cols : \@cols;
+}
+
1;
projects / dbsrgits/DBIx-Class.git / blobdiff