X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBIHacks.pm;h=e3fef8b3470265212417dcd53c1d225851ff5b35;hb=0488c7e1294791e01dc75dfe633454d0f4201384;hp=9e5d5ac7eba09cb3b336af658699920c43753c3f;hpb=8e706b4ba26c096be20ed78e1af27de0acd6333f;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm index 9e5d5ac..e3fef8b 100644 --- a/lib/DBIx/Class/Storage/DBIHacks.pm +++ b/lib/DBIx/Class/Storage/DBIHacks.pm @@ -16,6 +16,7 @@ use mro 'c3'; use List::Util 'first'; use Scalar::Util 'blessed'; use Sub::Name 'subname'; +use Data::Query::Constants; use Data::Query::ExprHelpers; use namespace::clean; @@ -24,30 +25,43 @@ use namespace::clean; # {from} specs, aiding the RDBMS query optimizer # sub _prune_unused_joins { - my $self = shift; - my ($from, $select, $where, $attrs) = @_; + my ($self, $attrs) = @_; - return $from unless $self->_use_join_optimizer; + # only standard {from} specs are supported, and we could be disabled in general + return ($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 + ); - if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') { - return $from; # only standard {from} specs are supported - } + my $orig_aliastypes = $self->_resolve_aliastypes_from_select_args($attrs); - my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_); + my $new_aliastypes = { %$orig_aliastypes }; - my $orig_joins = delete $aliastypes->{joining}; - my $orig_multiplying = $aliastypes->{multiplying}; + # we will be recreating this entirely + my @reclassify = 'joining'; # a grouped set will not be affected by amount of rows. Thus any - # {multiplying} joins can go - delete $aliastypes->{multiplying} + # purely multiplicator classifications can go + # (will be reintroduced below if needed by something else) + push @reclassify, qw(multiplying premultiplied) if $attrs->{_force_prune_multiplying_joins} or $attrs->{group_by}; - my @newfrom = $from->[0]; # FROM head is always present + # nuke what will be recalculated + delete @{$new_aliastypes}{@reclassify}; - my %need_joins; + my @newfrom = $attrs->{from}[0]; # FROM head is always present - for (values %$aliastypes) { + # recalculate what we need once the multipliers are potentially gone + # ignore premultiplies, since they do not add any value to anything + my %need_joins; + for ( @{$new_aliastypes}{grep { $_ ne 'premultiplied' } keys %$new_aliastypes }) { # add all requested aliases $need_joins{$_} = 1 for keys %$_; @@ -55,7 +69,7 @@ sub _prune_unused_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 || @@ -63,11 +77,16 @@ sub _prune_unused_joins { ); } - return ( \@newfrom, { - multiplying => { map { $need_joins{$_} ? ($_ => $orig_multiplying->{$_}) : () } keys %$orig_multiplying }, - %$aliastypes, - joining => { map { $_ => $orig_joins->{$_} } keys %need_joins }, - } ); + # we have a new set of joiners - for everything we nuked pull the classification + # off the original stack + for my $ctype (@reclassify) { + $new_aliastypes->{$ctype} = { map + { $need_joins{$_} ? ( $_ => $orig_aliastypes->{$ctype}{$_} ) : () } + keys %{$orig_aliastypes->{$ctype}} + } + } + + return ( \@newfrom, $new_aliastypes ); } # @@ -75,19 +94,26 @@ sub _prune_unused_joins { # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... # sub _adjust_select_args_for_complex_prefetch { - my ($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 ( @@ -99,13 +125,12 @@ sub _adjust_select_args_for_complex_prefetch { # 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 @@ -122,11 +147,11 @@ sub _adjust_select_args_for_complex_prefetch { 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 @@ -134,28 +159,27 @@ sub _adjust_select_args_for_complex_prefetch { 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, - undef, - $where, - $inner_attrs - ); + my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args({ + %$inner_attrs, + select => undef, + }); for (sort map { keys %{$_->{-seen_columns}||{}} } map { values %$_ } values %$connecting_aliastypes) { my $ci = $colinfo->{$_} or next; @@ -165,158 +189,64 @@ sub _adjust_select_args_for_complex_prefetch { ! $selected_root_columns->{$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) + # (since we def. do not care about multiplication of the contents of the subquery) my $inner_subq = do { - # must use it here regardless of user requests + # must use it here regardless of user requests (vastly gentler on optimizer) 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 }); - # uh-oh a multiplier (which is not us) left in, this is a problem + # uh-oh a multiplier (which is not us) left in, this is a problem for limits + # we will need to add a group_by to collapse the resultset for proper counts if ( - $inner_aliastypes->{multiplying} + grep { $_ ne $root_alias } keys %{ $inner_aliastypes->{multiplying} || {} } and # if there are user-supplied groups - assume user knows wtf they are up to ( ! $inner_aliastypes->{grouping} or $inner_attrs->{_grouped_by_distinct} ) - and - my @multipliers = grep { $_ ne $root_alias } keys %{$inner_aliastypes->{multiplying}} ) { - # 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 collapse 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_attrs, - from => $inner_from, - select => $inner_select, - }); - - $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; + my $cur_sel = { map { $_ => 1 } @{$inner_attrs->{select}} }; + + # *possibly* 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 $inner_select_with_extras; + my @pks = map { "$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 @{ $inner_select_with_extras ||= [ @{$inner_attrs->{select}} ] }, $col + unless $cur_sel->{$col}++; } - 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 - - # 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 @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 $inner_columns_info = $self->_resolve_column_info($inner_from); - - my $order_dq = $sql_maker->converter - ->_order_by_to_dq($attrs->{order_by}); - - my @new_order; - - # 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 - # quoted and stuff - while (is_Order($order_dq)) { - my ($chunk, @args) = $sql_maker->_render_dq(my $by = $order_dq->{by}); - - my $is_desc = $order_dq->{reverse}; - - push @new_order, $is_desc ? { -desc => \$by } : \$by; - - $order_dq = $order_dq->{from}; - # skip ourselves - next if $chunk =~ $own_re; - - # maybe our own unqualified column - my $ord_bit = ( - $lquote and $sep and $chunk =~ /^ $lquote ([^$sep]+) $rquote $/x - ) ? $1 : $chunk; - - next if ( - $ord_bit - and - $inner_columns_info->{$ord_bit} - and - $inner_columns_info->{$ord_bit}{-source_alias} eq $root_alias - ); - - ($new_order[-1]) = map { - ($is_desc ? { -desc => $_ } : $_) - } \[ - sprintf( - '%s(%s)', - ($is_desc ? 'MAX' : 'MIN'), - $chunk, - ), - @args - ]; - } - - $inner_attrs->{order_by} = \@new_order; - - # do not care about leftovers here - it will be all the functions - # we just created - ($inner_attrs->{group_by}) = $self->_group_over_selection ({ - %$inner_attrs, - from => $inner_from, - select => $inner_select, - }); - } + ($inner_attrs->{group_by}, $inner_attrs->{order_by}) = $self->_group_over_selection({ + %$inner_attrs, + $inner_select_with_extras ? ( select => $inner_select_with_extras ) : (), + _aliastypes => $inner_aliastypes, + }); } - # 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, ); }; @@ -332,22 +262,25 @@ sub _adjust_select_args_for_complex_prefetch { # 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 { @@ -358,12 +291,12 @@ sub _adjust_select_args_for_complex_prefetch { }; } - 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 { +{ @@ -371,10 +304,8 @@ sub _adjust_select_args_for_complex_prefetch { } } 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, - # to guard against cross-join explosions - my $need_outer_group_by; - while (my $j = shift @$from) { + my $may_need_outer_group_by; + while (my $j = shift @orig_from) { my $alias = $j->[0]{-alias}; if ( @@ -384,34 +315,29 @@ sub _adjust_select_args_for_complex_prefetch { } elsif (first { $_->{$alias} } @outer_nonselecting_chains ) { push @outer_from, $j; - $need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0; + $may_need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0; } } - 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 ({ + # also throw in a synthetic group_by if a non-selecting multiplier, + # to guard against cross-join explosions + # the logic is somewhat fragile, but relies on the idea that if a user supplied + # a group by on their own - they know what they were doing + if ( $may_need_outer_group_by and $attrs->{_grouped_by_distinct} ) { + ($outer_attrs->{group_by}, $outer_attrs->{order_by}) = $self->_group_over_selection ({ %$outer_attrs, from => \@outer_from, - select => $outer_select, }); - - $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; - } - # 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: (notes that this query would make a DBA cry ;) - return (\@outer_from, $outer_select, $where, $outer_attrs); + return $outer_attrs; } # @@ -426,34 +352,40 @@ sub _adjust_select_args_for_complex_prefetch { # 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 + # and record who is a multiplier and who is premultiplied 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 ( + + $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] } # not array == {from} head == can't be multiplying - ( ref($_) eq 'ARRAY' and ! $j->{-is_single} ) - or - # a parent of ours is already a multiplier - ( grep { $aliases_by_type->{multiplying}{$_} } @{ $j->{-join_path}||[] } ) - ); + if ref($node) eq 'ARRAY' and ! $j->{-is_single}; + + $aliases_by_type->{premultiplied}{$al} ||= { -parents => $j->{-join_path}||[] } + # parts of the path that are not us but are multiplying + if grep { $aliases_by_type->{multiplying}{$_} } + grep { $_ ne $al } + map { values %$_ } + @{ $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; @@ -481,17 +413,17 @@ sub _resolve_aliastypes_from_select_args { $sql_maker->{name_sep} = ''; } - # local is not enough - need to ensure the inner objects get rebuilt - $sql_maker->clear_renderer; - $sql_maker->clear_converter; + # delete local is 5.12+ + local @{$sql_maker}{qw(renderer converter)}; + delete @{$sql_maker}{qw(renderer converter)}; my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); # generate sql chunks my $to_scan = { restricting => [ - ($where - ? ($sql_maker->_recurse_where($where))[0] + ($attrs->{where} + ? ($sql_maker->_recurse_where($attrs->{where}))[0] : () ), ($attrs->{having} @@ -507,26 +439,51 @@ sub _resolve_aliastypes_from_select_args { ], 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 => [ - ($select - ? ($sql_maker->_render_sqla(select_select => $select))[0] - : ()), + map { $sql_maker->_render_sqla(select_select => $_) =~ /^SELECT\s+(.+)/ } @{$attrs->{select}||[]}, ], ordering => [ map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker), ], }; - # local is not enough - need to ensure the inner objects get rebuilt - $sql_maker->clear_renderer; - $sql_maker->clear_converter; + # throw away empty chunks and all 2-value arrayrefs: the thinking is that these are + # bind value specs left in by the sloppy renderer above. It is ok to do this + # at this point, since we are going to end up rewriting this crap anyway + for my $v (values %$to_scan) { + my @nv; + for (@$v) { + next if ( + ! defined $_ + or + ( + ref $_ eq 'ARRAY' + and + ( @$_ == 0 or @$_ == 2 ) + ) + ); + + if (ref $_) { + require Data::Dumper::Concise; + $self->throw_exception("Unexpected ref in scan-plan: " . Data::Dumper::Concise::Dumper($v) ); + } + + push @nv, $_; + } + + $v = \@nv; + } - # throw away empty chunks - $_ = [ map { $_ || () } @$_ ] for values %$to_scan; + # kill all selectors which look like a proper subquery + # this is a sucky heuristic *BUT* - if we get it wrong the query will simply + # fail to run, so we are relatively safe + $to_scan->{selecting} = [ grep { + $_ !~ / \A \s* \( \s* SELECT \s+ .+? \s+ FROM \s+ .+? \) \s* \z /xsi + } @{ $to_scan->{selecting} || [] } ]; # first see if we have any exact matches (qualified or unqualified) for my $type (keys %$to_scan) { @@ -594,7 +551,8 @@ sub _resolve_aliastypes_from_select_args { return $aliases_by_type; } -# This is the engine behind { distinct => 1 } +# This is the engine behind { distinct => 1 } and the general +# complex prefetch grouper sub _group_over_selection { my ($self, $attrs) = @_; @@ -616,36 +574,133 @@ sub _group_over_selection { } } - # add any order_by parts *from the main source* that are not already - # present in the group_by - # we need to be careful not to add any named functions/aggregates - # i.e. order_by => [ ... { count => 'foo' } ... ] - my @leftovers; - for ($self->_extract_order_criteria($attrs->{order_by})) { + my $sql_maker = $self->sql_maker; + my @order_by = $self->_extract_order_criteria($attrs->{order_by}, $sql_maker) + or return (\@group_by, $attrs->{order_by}); + + # add any order_by parts that are not already present in the group_by + # to maintain SQL cross-compatibility and general sanity + # + # also in case the original selection is *not* unique, or in case part + # of the ORDER BY refers to a multiplier - we will need to replace the + # skipped order_by elements with their MIN/MAX equivalents as to maintain + # the proper overall order without polluting the group criteria (and + # possibly changing the outcome entirely) + + my ($leftovers, @new_order_by, $order_chunks, $aliastypes); + + my $group_already_unique = $self->_columns_comprise_identifying_set($colinfos, \@group_by); + + for my $o_idx (0 .. $#order_by) { + + # if the chunk is already a min/max function - there is nothing left to touch + next if $order_by[$o_idx][0] =~ /^ (?: min | max ) \s* \( .+ \) $/ix; + # only consider real columns (for functions the user got to do an explicit group_by) - if (@$_ != 1) { - push @leftovers, $_; - next; + my $chunk_ci; + if ( + @{$order_by[$o_idx]} != 1 + or + # only declare an unknown *plain* identifier as "leftover" if we are called with + # aliastypes to examine. If there are none - we are still in _resolve_attrs, and + # can just assume the user knows what they want + ( ! ( $chunk_ci = $colinfos->{$order_by[$o_idx][0]} ) and $attrs->{_aliastypes} ) + ) { + push @$leftovers, $order_by[$o_idx][0]; } - my $chunk = $_->[0]; - if ( - !$colinfos->{$chunk} + next unless $chunk_ci; + + # no duplication of group criteria + next if $group_index{$chunk_ci->{-fq_colname}}; + + $aliastypes ||= ( + $attrs->{_aliastypes} or - $colinfos->{$chunk}{-source_alias} ne $attrs->{alias} + $self->_resolve_aliastypes_from_select_args({ + from => $attrs->{from}, + order_by => $attrs->{order_by}, + }) + ) if $group_already_unique; + + # check that we are not ordering by a multiplier (if a check is requested at all) + if ( + $group_already_unique + and + ! $aliastypes->{multiplying}{$chunk_ci->{-source_alias}} + and + ! $aliastypes->{premultiplied}{$chunk_ci->{-source_alias}} ) { - push @leftovers, $_; - next; + push @group_by, $chunk_ci->{-fq_colname}; + $group_index{$chunk_ci->{-fq_colname}}++ } + else { + # We need to order by external columns without adding them to the group + # (eiehter a non-unique selection, or a multi-external) + # + # This doesn't really make sense in SQL, however from DBICs point + # of view is rather valid (e.g. 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 external 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 - 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 + # wrap any part of the order_by that "responds" to an ordering alias + # into a MIN/MAX + + $order_chunks ||= do { + my @c; + my $dq_node = $sql_maker->converter->_order_by_to_dq($attrs->{order_by}); + + while (is_Order($dq_node)) { + push @c, { + is_desc => $dq_node->{reverse}, + dq_node => $dq_node->{by}, + }; + + @{$c[-1]}{qw(sql bind)} = $sql_maker->_render_dq($dq_node->{by}); + + $dq_node = $dq_node->{from}; + } - $chunk = $colinfos->{$chunk}{-fq_colname}; - push @group_by, $chunk unless $group_index{$chunk}++; + \@c; + }; + + $new_order_by[$o_idx] = { + ($order_chunks->[$o_idx]{is_desc} ? '-desc' : '-asc') => \[ + sprintf ( '%s( %s )', + ($order_chunks->[$o_idx]{is_desc} ? 'MAX' : 'MIN'), + $order_chunks->[$o_idx]{sql}, + ), + @{ $order_chunks->[$o_idx]{bind} || [] } + ] + }; + } } - return wantarray - ? (\@group_by, (@leftovers ? \@leftovers : undef) ) - : \@group_by - ; + $self->throw_exception ( sprintf + 'A required group_by clause could not be constructed automatically due to a complex ' + . 'order_by criteria (%s). Either order_by columns only (no functions) or construct a suitable ' + . 'group_by by hand', + join ', ', map { "'$_'" } @$leftovers, + ) if $leftovers; + + # recreate the untouched order parts + if (@new_order_by) { + $new_order_by[$_] ||= { + ( $order_chunks->[$_]{is_desc} ? '-desc' : '-asc' ) + => \ $order_chunks->[$_]{dq_node} + } for ( 0 .. $#$order_chunks ); + } + + return ( + \@group_by, + (@new_order_by ? \@new_order_by : $attrs->{order_by} ), # same ref as original == unchanged + ); } sub _resolve_ident_sources { @@ -810,7 +865,7 @@ sub _inner_join_to_node { } sub _extract_order_criteria { - my ($self, $order_by, $sql_maker) = @_; + my ($self, $order_by, $sql_maker, $ident_only) = @_; $sql_maker ||= $self->sql_maker; @@ -822,64 +877,43 @@ sub _extract_order_criteria { $order_dq = $order_dq->{from}; } - delete local @{$sql_maker}{qw(quote_char renderer converter)}; - - return map { [ $sql_maker->_render_dq($_) ] } @by; - - my $parser = sub { - my ($sql_maker, $order_by, $orig_quote_chars) = @_; - - return scalar $sql_maker->_order_by_chunks ($order_by) - unless wantarray; - - my ($lq, $rq, $sep) = map { quotemeta($_) } ( - ($orig_quote_chars ? @$orig_quote_chars : $sql_maker->_quote_chars), - $sql_maker->name_sep - ); - - my @chunks; - for ($sql_maker->_order_by_chunks ($order_by) ) { - my $chunk = ref $_ ? [ @$_ ] : [ $_ ]; - ($chunk->[0]) = $sql_maker->_split_order_chunk($chunk->[0]); - - # order criteria may have come back pre-quoted (literals and whatnot) - # this is fragile, but the best we can currently do - $chunk->[0] =~ s/^ $lq (.+?) $rq $sep $lq (.+?) $rq $/"$1.$2"/xe - or $chunk->[0] =~ s/^ $lq (.+) $rq $/$1/x; - - push @chunks, $chunk; + # delete local is 5.12+ + local @{$sql_maker}{qw(quote_char renderer converter)}; + delete @{$sql_maker}{qw(quote_char renderer converter)}; + + return map { [ $sql_maker->_render_dq($_) ] } do { + if ($ident_only) { + my @by_ident; + scan_dq_nodes({ DQ_IDENTIFIER ,=> sub { push @by_ident, $_[0] } }, @by); + @by_ident + } else { + @by } - - return @chunks; }; - - if ($sql_maker) { - return $parser->($sql_maker, $order_by); - } - else { - $sql_maker = $self->sql_maker; - - # pass these in to deal with literals coming from - # the user or the deep guts of prefetch - my $orig_quote_chars = [$sql_maker->_quote_chars]; - - local $sql_maker->{quote_char}; - return $parser->($sql_maker, $order_by, $orig_quote_chars); - } } sub _order_by_is_stable { my ($self, $ident, $order_by, $where) = @_; - my $colinfo = $self->_resolve_column_info($ident, [ - (map { $_->[0] } $self->_extract_order_criteria($order_by)), + my @cols = ( + (map { $_->[0] } $self->_extract_order_criteria($order_by, undef, 1)), $where ? @{$self->_extract_fixed_condition_columns($where)} :(), - ]); + ) or return undef; - return undef unless keys %$colinfo; + my $colinfo = $self->_resolve_column_info($ident, \@cols); + + return keys %$colinfo + ? $self->_columns_comprise_identifying_set( $colinfo, \@cols ) + : undef + ; +} + +sub _columns_comprise_identifying_set { + my ($self, $colinfo, $columns) = @_; my $cols_per_src; - $cols_per_src->{$_->{-source_alias}}{$_->{-colname}} = $_ for values %$colinfo; + $cols_per_src -> {$_->{-source_alias}} -> {$_->{-colname}} = $_ + for grep { defined $_ } @{$colinfo}{@$columns}; for (values %$cols_per_src) { my $src = (values %$_)[0]->{-result_source}; @@ -972,7 +1006,13 @@ sub _main_source_order_by_portion_is_stable { # 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, $where) = @_; + + if (ref($where) eq 'REF' and ref($$where) eq 'HASH') { + # Yes. I know. + my $fixed = DBIx::Class::ResultSource->_extract_fixed_values_for($$where); + return [ keys %$fixed ]; + } return unless ref $where eq 'HASH'; @@ -980,8 +1020,8 @@ sub _extract_fixed_condition_columns { 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 !~ /^\-/) { @@ -994,7 +1034,7 @@ sub _extract_fixed_condition_columns { )); } } - return $nested ? @cols : \@cols; + return \@cols; } 1;