1 package #hide from PAUSE
2 DBIx::Class::Storage::DBIHacks;
5 # This module contains code that should never have seen the light of day,
6 # does not belong in the Storage, or is otherwise unfit for public
7 # display. The arrival of SQLA2 should immediately obsolete 90% of this
13 use base 'DBIx::Class::Storage';
16 use List::Util 'first';
17 use Scalar::Util 'blessed';
18 use DBIx::Class::_Util qw(UNRESOLVABLE_CONDITION serialize);
19 use SQL::Abstract qw(is_plain_value is_literal_value);
20 use DBIx::Class::Carp;
24 # This code will remove non-selecting/non-restricting joins from
25 # {from} specs, aiding the RDBMS query optimizer
27 sub _prune_unused_joins {
28 my ($self, $attrs) = @_;
30 # only standard {from} specs are supported, and we could be disabled in general
31 return ($attrs->{from}, {}) unless (
32 ref $attrs->{from} eq 'ARRAY'
36 ref $attrs->{from}[0] eq 'HASH'
38 ref $attrs->{from}[1] eq 'ARRAY'
40 $self->_use_join_optimizer
44 $attrs->{_precalculated_aliastypes}
46 $self->_resolve_aliastypes_from_select_args($attrs)
49 my $new_aliastypes = { %$orig_aliastypes };
51 # we will be recreating this entirely
52 my @reclassify = 'joining';
54 # a grouped set will not be affected by amount of rows. Thus any
55 # purely multiplicator classifications can go
56 # (will be reintroduced below if needed by something else)
57 push @reclassify, qw(multiplying premultiplied)
58 if $attrs->{_force_prune_multiplying_joins} or $attrs->{group_by};
60 # nuke what will be recalculated
61 delete @{$new_aliastypes}{@reclassify};
63 my @newfrom = $attrs->{from}[0]; # FROM head is always present
65 # recalculate what we need once the multipliers are potentially gone
66 # ignore premultiplies, since they do not add any value to anything
68 for ( @{$new_aliastypes}{grep { $_ ne 'premultiplied' } keys %$new_aliastypes }) {
69 # add all requested aliases
70 $need_joins{$_} = 1 for keys %$_;
72 # add all their parents (as per joinpath which is an AoH { table => alias })
73 $need_joins{$_} = 1 for map { values %$_ } map { @{$_->{-parents}} } values %$_;
76 for my $j (@{$attrs->{from}}[1..$#{$attrs->{from}}]) {
77 push @newfrom, $j if (
78 (! defined $j->[0]{-alias}) # legacy crap
80 $need_joins{$j->[0]{-alias}}
84 # we have a new set of joiners - for everything we nuked pull the classification
85 # off the original stack
86 for my $ctype (@reclassify) {
87 $new_aliastypes->{$ctype} = { map
88 { $need_joins{$_} ? ( $_ => $orig_aliastypes->{$ctype}{$_} ) : () }
89 keys %{$orig_aliastypes->{$ctype}}
93 return ( \@newfrom, $new_aliastypes );
97 # This is the code producing joined subqueries like:
98 # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
100 sub _adjust_select_args_for_complex_prefetch {
101 my ($self, $attrs) = @_;
103 $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') unless (
104 ref $attrs->{from} eq 'ARRAY'
106 @{$attrs->{from}} > 1
108 ref $attrs->{from}[0] eq 'HASH'
110 ref $attrs->{from}[1] eq 'ARRAY'
113 my $root_alias = $attrs->{alias};
115 # generate inner/outer attribute lists, remove stuff that doesn't apply
116 my $outer_attrs = { %$attrs };
117 delete @{$outer_attrs}{qw(from bind rows offset group_by _grouped_by_distinct having)};
119 my $inner_attrs = { %$attrs, _simple_passthrough_construction => 1 };
120 delete @{$inner_attrs}{qw(for collapse select as)};
122 # there is no point of ordering the insides if there is no limit
123 delete $inner_attrs->{order_by} if (
124 delete $inner_attrs->{_order_is_artificial}
126 ! $inner_attrs->{rows}
129 # generate the inner/outer select lists
130 # for inside we consider only stuff *not* brought in by the prefetch
131 # on the outside we substitute any function for its alias
132 $outer_attrs->{select} = [ @{$attrs->{select}} ];
134 my ($root_node, $root_node_offset);
136 for my $i (0 .. $#{$inner_attrs->{from}}) {
137 my $node = $inner_attrs->{from}[$i];
138 my $h = (ref $node eq 'HASH') ? $node
139 : (ref $node eq 'ARRAY' and ref $node->[0] eq 'HASH') ? $node->[0]
143 if ( ($h->{-alias}||'') eq $root_alias and $h->{-rsrc} ) {
145 $root_node_offset = $i;
150 $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
153 # use the heavy duty resolver to take care of aliased/nonaliased naming
154 my $colinfo = $self->_resolve_column_info($inner_attrs->{from});
155 my $selected_root_columns;
157 for my $i (0 .. $#{$outer_attrs->{select}}) {
158 my $sel = $outer_attrs->{select}->[$i];
161 $colinfo->{$sel} and $colinfo->{$sel}{-source_alias} ne $root_alias
164 if (ref $sel eq 'HASH' ) {
165 $sel->{-as} ||= $attrs->{as}[$i];
166 $outer_attrs->{select}->[$i] = join ('.', $root_alias, ($sel->{-as} || "inner_column_$i") );
168 elsif (! ref $sel and my $ci = $colinfo->{$sel}) {
169 $selected_root_columns->{$ci->{-colname}} = 1;
172 push @{$inner_attrs->{select}}, $sel;
174 push @{$inner_attrs->{as}}, $attrs->{as}[$i];
177 my $inner_aliastypes = $self->_resolve_aliastypes_from_select_args($inner_attrs);
179 # In the inner subq we will need to fetch *only* native columns which may
180 # be a part of an *outer* join condition, or an order_by (which needs to be
181 # preserved outside), or wheres. In other words everything but the inner
183 # We can not just fetch everything because a potential has_many restricting
184 # join collapse *will not work* on heavy data types.
186 # essentially a map of all non-selecting seen columns
187 # the sort is there for a nicer select list
191 { keys %{$_->{-seen_columns}||{}} }
193 { values %{$inner_aliastypes->{$_}} }
195 { $_ ne 'selecting' }
196 keys %$inner_aliastypes
198 my $ci = $colinfo->{$_} or next;
200 $ci->{-source_alias} eq $root_alias
202 ! $selected_root_columns->{$ci->{-colname}}++
204 # adding it to both to keep limits not supporting dark selectors happy
205 push @{$inner_attrs->{select}}, $ci->{-fq_colname};
206 push @{$inner_attrs->{as}}, $ci->{-fq_colname};
210 # construct the inner {from} and lock it in a subquery
211 # we need to prune first, because this will determine if we need a group_by below
212 # throw away all non-selecting, non-restricting multijoins
213 # (since we def. do not care about multiplication of the contents of the subquery)
214 my $inner_subq = do {
216 # must use it here regardless of user requests (vastly gentler on optimizer)
217 local $self->{_use_join_optimizer} = 1;
219 # throw away multijoins since we def. do not care about those inside the subquery
220 # $inner_aliastypes *will* be redefined at this point
221 ($inner_attrs->{from}, $inner_aliastypes ) = $self->_prune_unused_joins ({
223 _force_prune_multiplying_joins => 1,
224 _precalculated_aliastypes => $inner_aliastypes,
227 # uh-oh a multiplier (which is not us) left in, this is a problem for limits
228 # we will need to add a group_by to collapse the resultset for proper counts
230 grep { $_ ne $root_alias } keys %{ $inner_aliastypes->{multiplying} || {} }
232 # if there are user-supplied groups - assume user knows wtf they are up to
233 ( ! $inner_aliastypes->{grouping} or $inner_attrs->{_grouped_by_distinct} )
236 my $cur_sel = { map { $_ => 1 } @{$inner_attrs->{select}} };
238 # *possibly* supplement the main selection with pks if not already
239 # there, as they will have to be a part of the group_by to collapse
241 my $inner_select_with_extras;
242 my @pks = map { "$root_alias.$_" } $root_node->{-rsrc}->primary_columns
243 or $self->throw_exception( sprintf
244 'Unable to perform complex limited prefetch off %s without declared primary key',
245 $root_node->{-rsrc}->source_name,
248 push @{ $inner_select_with_extras ||= [ @{$inner_attrs->{select}} ] }, $col
249 unless $cur_sel->{$col}++;
252 ($inner_attrs->{group_by}, $inner_attrs->{order_by}) = $self->_group_over_selection({
254 $inner_select_with_extras ? ( select => $inner_select_with_extras ) : (),
255 _aliastypes => $inner_aliastypes,
259 # we already optimized $inner_attrs->{from} above
260 # and already local()ized
261 $self->{_use_join_optimizer} = 0;
263 # generate the subquery
264 $self->_select_args_to_query (
265 @{$inner_attrs}{qw(from select where)},
270 # Generate the outer from - this is relatively easy (really just replace
271 # the join slot with the subquery), with a major caveat - we can not
272 # join anything that is non-selecting (not part of the prefetch), but at
273 # the same time is a multi-type relationship, as it will explode the result.
275 # There are two possibilities here
276 # - either the join is non-restricting, in which case we simply throw it away
277 # - it is part of the restrictions, in which case we need to collapse the outer
278 # result by tackling yet another group_by to the outside of the query
280 # work on a shallow copy
281 my @orig_from = @{$attrs->{from}};
284 $outer_attrs->{from} = \ my @outer_from;
286 # we may not be the head
287 if ($root_node_offset) {
288 # first generate the outer_from, up to the substitution point
289 @outer_from = splice @orig_from, 0, $root_node_offset;
291 # substitute the subq at the right spot
294 -alias => $root_alias,
295 -rsrc => $root_node->{-rsrc},
296 $root_alias => $inner_subq,
298 # preserve attrs from what is now the head of the from after the splice
299 @{$orig_from[0]}[1 .. $#{$orig_from[0]}],
304 -alias => $root_alias,
305 -rsrc => $root_node->{-rsrc},
306 $root_alias => $inner_subq,
310 shift @orig_from; # what we just replaced above
312 # scan the *remaining* from spec against different attributes, and see which joins are needed
314 my $outer_aliastypes = $outer_attrs->{_aliastypes} =
315 $self->_resolve_aliastypes_from_select_args({ %$outer_attrs, from => \@orig_from });
318 my ($outer_select_chain, @outer_nonselecting_chains) = map { +{
319 map { $_ => 1 } map { values %$_} map { @{$_->{-parents}} } values %{ $outer_aliastypes->{$_} || {} }
320 } } qw/selecting restricting grouping ordering/;
322 # see what's left - throw away if not selecting/restricting
323 my $may_need_outer_group_by;
324 while (my $j = shift @orig_from) {
325 my $alias = $j->[0]{-alias};
328 $outer_select_chain->{$alias}
332 elsif (first { $_->{$alias} } @outer_nonselecting_chains ) {
333 push @outer_from, $j;
334 $may_need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0;
338 # also throw in a synthetic group_by if a non-selecting multiplier,
339 # to guard against cross-join explosions
340 # the logic is somewhat fragile, but relies on the idea that if a user supplied
341 # a group by on their own - they know what they were doing
342 if ( $may_need_outer_group_by and $attrs->{_grouped_by_distinct} ) {
343 ($outer_attrs->{group_by}, $outer_attrs->{order_by}) = $self->_group_over_selection ({
345 from => \@outer_from,
349 # This is totally horrific - the {where} ends up in both the inner and outer query
350 # Unfortunately not much can be done until SQLA2 introspection arrives, and even
351 # then if where conditions apply to the *right* side of the prefetch, you may have
352 # to both filter the inner select (e.g. to apply a limit) and then have to re-filter
353 # the outer select to exclude joins you didn't want in the first place
355 # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
360 # I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE!
362 # Due to a lack of SQLA2 we fall back to crude scans of all the
363 # select/where/order/group attributes, in order to determine what
364 # aliases are needed to fulfill the query. This information is used
365 # throughout the code to prune unnecessary JOINs from the queries
366 # in an attempt to reduce the execution time.
367 # Although the method is pretty horrific, the worst thing that can
368 # happen is for it to fail due to some scalar SQL, which in turn will
369 # result in a vocal exception.
370 sub _resolve_aliastypes_from_select_args {
371 my ( $self, $attrs ) = @_;
373 $self->throw_exception ('Unable to analyze custom {from}')
374 if ref $attrs->{from} ne 'ARRAY';
376 # what we will return
379 # see what aliases are there to work with
380 # and record who is a multiplier and who is premultiplied
382 for my $node (@{$attrs->{from}}) {
385 $j = $j->[0] if ref $j eq 'ARRAY';
386 my $al = $j->{-alias}
389 $alias_list->{$al} = $j;
391 $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] }
392 # not array == {from} head == can't be multiplying
393 if ref($node) eq 'ARRAY' and ! $j->{-is_single};
395 $aliases_by_type->{premultiplied}{$al} ||= { -parents => $j->{-join_path}||[] }
396 # parts of the path that are not us but are multiplying
397 if grep { $aliases_by_type->{multiplying}{$_} }
400 @{ $j->{-join_path}||[] }
403 # get a column to source/alias map (including unambiguous unqualified ones)
404 my $colinfo = $self->_resolve_column_info ($attrs->{from});
406 # set up a botched SQLA
407 my $sql_maker = $self->sql_maker;
409 # these are throw away results, do not pollute the bind stack
410 local $sql_maker->{where_bind};
411 local $sql_maker->{group_bind};
412 local $sql_maker->{having_bind};
413 local $sql_maker->{from_bind};
415 # we can't scan properly without any quoting (\b doesn't cut it
416 # everywhere), so unless there is proper quoting set - use our
417 # own weird impossible character.
418 # Also in the case of no quoting, we need to explicitly disable
419 # name_sep, otherwise sorry nasty legacy syntax like
420 # { 'count(foo.id)' => { '>' => 3 } } will stop working >:(
421 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
422 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
424 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
425 $sql_maker->{quote_char} = ["\x00", "\xFF"];
426 # if we don't unset it we screw up retarded but unfortunately working
427 # 'MAX(foo.bar)' => { '>', 3 }
428 $sql_maker->{name_sep} = '';
431 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
433 # generate sql chunks
436 ($sql_maker->_recurse_where ($attrs->{where}))[0],
437 $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }),
440 $sql_maker->_parse_rs_attrs ({ group_by => $attrs->{group_by} }),
443 $sql_maker->_recurse_from (
444 ref $attrs->{from}[0] eq 'ARRAY' ? $attrs->{from}[0][0] : $attrs->{from}[0],
445 @{$attrs->{from}}[1 .. $#{$attrs->{from}}],
449 # kill all selectors which look like a proper subquery
450 # this is a sucky heuristic *BUT* - if we get it wrong the query will simply
451 # fail to run, so we are relatively safe
453 { $_ !~ / \A \s* \( \s* SELECT \s+ .+? \s+ FROM \s+ .+? \) \s* \z /xsi }
455 { ($sql_maker->_recurse_fields($_))[0] }
460 ( my $sql = (ref $_ ? $_->[0] : $_) ) =~ s/ \s+ (?: ASC | DESC ) \s* \z //xi;
463 $sql_maker->_order_by_chunks( $attrs->{order_by} ),
467 # throw away empty-string chunks, and make sure no binds snuck in
468 # note that we operate over @{$to_scan->{$type}}, hence the
469 # semi-mindbending ... map ... for values ...
473 : (length ref $_) ? (require Data::Dumper::Concise && $self->throw_exception(
474 "Unexpected ref in scan-plan: " . Data::Dumper::Concise::Dumper($_)
478 } @$_ ] ) for values %$to_scan;
480 # throw away empty to-scan's
484 delete $to_scan->{$_}
485 ) for keys %$to_scan;
488 # these will be used for matching in the loop below
489 my $all_aliases = join ' | ', map { quotemeta $_ } keys %$alias_list;
491 $lquote ( $all_aliases ) $rquote $sep (?: $lquote ([^$rquote]+) $rquote )?
493 \b ( $all_aliases ) \. ( [^\s\)\($rquote]+ )?
496 my $all_unq_columns = join ' | ',
500 # using a regex here shows up on profiles, boggle
501 { index( $_, '.') < 0 }
504 my $unq_col_re = $all_unq_columns
505 ? qr/ $lquote ( $all_unq_columns ) $rquote /x
510 # the actual scan, per type
511 for my $type (keys %$to_scan) {
513 # first see if we have any exact matches (qualified or unqualified)
514 for my $piece (@{$to_scan->{$type}}) {
515 if ($colinfo->{$piece} and my $alias = $colinfo->{$piece}{-source_alias}) {
516 $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
517 $aliases_by_type->{$type}{$alias}{-seen_columns}{$colinfo->{$piece}{-fq_colname}} = $piece;
522 # we will be bulk-scanning anyway - pieces will not matter in that case
523 # (unlike in the direct-equivalence above)
524 my $scan_string = join ' ', @{$to_scan->{$type}};
527 # now loop through all fully qualified columns and get the corresponding
528 # alias (should work even if they are in scalarrefs)
530 # The regex matches in multiples of 4, with one of the two pairs being
531 # undef. There may be a *lot* of matches, hence the convoluted loop
532 my @matches = $scan_string =~ /$fq_col_re/g;
534 while( $i < $#matches ) {
539 $aliases_by_type->{$type}{$matches[$i]} ||= { -parents => $alias_list->{$matches[$i]}{-join_path}||[] };
541 $aliases_by_type->{$type}{$matches[$i]}{-seen_columns}{"$matches[$i].$matches[$i+1]"} = "$matches[$i].$matches[$i+1]"
542 if defined $matches[$i+1];
551 # now loop through unqualified column names, and try to locate them within
552 # the chunks, if there are any unqualified columns in the 1st place
553 next unless $unq_col_re;
554 for ( $scan_string =~ /$unq_col_re/g ) {
555 my $alias = $colinfo->{$_}{-source_alias} or next;
556 $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
557 $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = $_
562 # Add any non-left joins to the restriction list (such joins are indeed restrictions)
566 ! $aliases_by_type->{restricting}{ $_->{-alias} }
571 $_->{-join_type} !~ /^left (?: \s+ outer)? $/xi
574 $aliases_by_type->{restricting}{ $_->{-alias} } = { -parents => $_->{-join_path}||[] }
575 ) for values %$alias_list;
580 keys %{$aliases_by_type->{$_}}
582 delete $aliases_by_type->{$_}
583 ) for keys %$aliases_by_type;
589 # This is the engine behind { distinct => 1 } and the general
590 # complex prefetch grouper
591 sub _group_over_selection {
592 my ($self, $attrs) = @_;
594 my $colinfos = $self->_resolve_column_info ($attrs->{from});
596 my (@group_by, %group_index);
598 # the logic is: if it is a { func => val } we assume an aggregate,
599 # otherwise if \'...' or \[...] we assume the user knows what is
600 # going on thus group over it
601 for (@{$attrs->{select}}) {
602 if (! ref($_) or ref ($_) ne 'HASH' ) {
605 if ($colinfos->{$_} and $_ !~ /\./ ) {
606 # add a fully qualified version as well
607 $group_index{"$colinfos->{$_}{-source_alias}.$_"}++;
612 my @order_by = $self->_extract_order_criteria($attrs->{order_by})
613 or return (\@group_by, $attrs->{order_by});
615 # add any order_by parts that are not already present in the group_by
616 # to maintain SQL cross-compatibility and general sanity
618 # also in case the original selection is *not* unique, or in case part
619 # of the ORDER BY refers to a multiplier - we will need to replace the
620 # skipped order_by elements with their MIN/MAX equivalents as to maintain
621 # the proper overall order without polluting the group criteria (and
622 # possibly changing the outcome entirely)
624 my ($leftovers, $sql_maker, @new_order_by, $order_chunks, $aliastypes);
626 my $group_already_unique = $self->_columns_comprise_identifying_set($colinfos, \@group_by);
628 for my $o_idx (0 .. $#order_by) {
630 # if the chunk is already a min/max function - there is nothing left to touch
631 next if $order_by[$o_idx][0] =~ /^ (?: min | max ) \s* \( .+ \) $/ix;
633 # only consider real columns (for functions the user got to do an explicit group_by)
636 @{$order_by[$o_idx]} != 1
638 # only declare an unknown *plain* identifier as "leftover" if we are called with
639 # aliastypes to examine. If there are none - we are still in _resolve_attrs, and
640 # can just assume the user knows what they want
641 ( ! ( $chunk_ci = $colinfos->{$order_by[$o_idx][0]} ) and $attrs->{_aliastypes} )
643 push @$leftovers, $order_by[$o_idx][0];
646 next unless $chunk_ci;
648 # no duplication of group criteria
649 next if $group_index{$chunk_ci->{-fq_colname}};
652 $attrs->{_aliastypes}
654 $self->_resolve_aliastypes_from_select_args({
655 from => $attrs->{from},
656 order_by => $attrs->{order_by},
658 ) if $group_already_unique;
660 # check that we are not ordering by a multiplier (if a check is requested at all)
662 $group_already_unique
664 ! $aliastypes->{multiplying}{$chunk_ci->{-source_alias}}
666 ! $aliastypes->{premultiplied}{$chunk_ci->{-source_alias}}
668 push @group_by, $chunk_ci->{-fq_colname};
669 $group_index{$chunk_ci->{-fq_colname}}++
672 # We need to order by external columns without adding them to the group
673 # (eiehter a non-unique selection, or a multi-external)
675 # This doesn't really make sense in SQL, however from DBICs point
676 # of view is rather valid (e.g. order the leftmost objects by whatever
677 # criteria and get the offset/rows many). There is a way around
678 # this however in SQL - we simply tae the direction of each piece
679 # of the external order and convert them to MIN(X) for ASC or MAX(X)
680 # for DESC, and group_by the root columns. The end result should be
681 # exactly what we expect
683 # FIXME - this code is a joke, will need to be completely rewritten in
684 # the DQ branch. But I need to push a POC here, otherwise the
685 # pesky tests won't pass
686 # wrap any part of the order_by that "responds" to an ordering alias
688 $sql_maker ||= $self->sql_maker;
690 map { ref $_ eq 'ARRAY' ? $_ : [ $_ ] } $sql_maker->_order_by_chunks($attrs->{order_by})
693 my ($chunk, $is_desc) = $sql_maker->_split_order_chunk($order_chunks->[$o_idx][0]);
695 $new_order_by[$o_idx] = \[
696 sprintf( '%s( %s )%s',
697 ($is_desc ? 'MAX' : 'MIN'),
699 ($is_desc ? ' DESC' : ''),
701 @ {$order_chunks->[$o_idx]} [ 1 .. $#{$order_chunks->[$o_idx]} ]
706 $self->throw_exception ( sprintf
707 'Unable to programatically derive a required group_by from the supplied '
708 . 'order_by criteria. To proceed either add an explicit group_by, or '
709 . 'simplify your order_by to only include plain columns '
710 . '(supplied order_by: %s)',
711 join ', ', map { "'$_'" } @$leftovers,
714 # recreate the untouched order parts
716 $new_order_by[$_] ||= \ $order_chunks->[$_] for ( 0 .. $#$order_chunks );
721 (@new_order_by ? \@new_order_by : $attrs->{order_by} ), # same ref as original == unchanged
725 sub _resolve_ident_sources {
726 my ($self, $ident) = @_;
728 my $alias2source = {};
730 # the reason this is so contrived is that $ident may be a {from}
731 # structure, specifying multiple tables to join
732 if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) {
733 # this is compat mode for insert/update/delete which do not deal with aliases
734 $alias2source->{me} = $ident;
736 elsif (ref $ident eq 'ARRAY') {
740 if (ref $_ eq 'HASH') {
743 if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') {
747 $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc}
748 if ($tabinfo->{-rsrc});
752 return $alias2source;
755 # Takes $ident, \@column_names
757 # returns { $column_name => \%column_info, ... }
758 # also note: this adds -result_source => $rsrc to the column info
760 # If no columns_names are supplied returns info about *all* columns
762 sub _resolve_column_info {
763 my ($self, $ident, $colnames) = @_;
765 return {} if $colnames and ! @$colnames;
767 my $sources = $self->_resolve_ident_sources($ident);
769 $_ = { rsrc => $_, colinfos => $_->columns_info }
770 for values %$sources;
772 my (%seen_cols, @auto_colnames);
774 # compile a global list of column names, to be able to properly
775 # disambiguate unqualified column names (if at all possible)
776 for my $alias (keys %$sources) {
778 ++$seen_cols{$_}{$alias}
782 push @auto_colnames, "$alias.$_"
783 ) for keys %{ $sources->{$alias}{colinfos} };
788 ( grep { keys %{$seen_cols{$_}} == 1 } keys %seen_cols ),
793 my ($colname, $source_alias) = reverse split /\./, $_;
798 # if the column was seen exactly once - we know which rsrc it came from
802 keys %{$seen_cols{$colname}} == 1
804 ( %{$seen_cols{$colname}} )[0]
810 $self->throw_exception(
811 "No such column '$colname' on source " . $sources->{$assumed_alias}{rsrc}->source_name
812 ) unless $seen_cols{$colname}{$assumed_alias};
815 %{ $sources->{$assumed_alias}{colinfos}{$colname} },
816 -result_source => $sources->{$assumed_alias}{rsrc},
817 -source_alias => $assumed_alias,
818 -fq_colname => "$assumed_alias.$colname",
819 -colname => $colname,
822 $return{"$assumed_alias.$colname"} = $return{$_}
823 unless $source_alias;
829 # The DBIC relationship chaining implementation is pretty simple - every
830 # new related_relationship is pushed onto the {from} stack, and the {select}
831 # window simply slides further in. This means that when we count somewhere
832 # in the middle, we got to make sure that everything in the join chain is an
833 # actual inner join, otherwise the count will come back with unpredictable
834 # results (a resultset may be generated with _some_ rows regardless of if
835 # the relation which the $rs currently selects has rows or not). E.g.
836 # $artist_rs->cds->count - normally generates:
837 # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid
838 # which actually returns the number of artists * (number of cds || 1)
840 # So what we do here is crawl {from}, determine if the current alias is at
841 # the top of the stack, and if not - make sure the chain is inner-joined down
844 sub _inner_join_to_node {
845 my ($self, $from, $alias) = @_;
847 my $switch_branch = $self->_find_join_path_to_node($from, $alias);
849 return $from unless @{$switch_branch||[]};
851 # So it looks like we will have to switch some stuff around.
852 # local() is useless here as we will be leaving the scope
853 # anyway, and deep cloning is just too fucking expensive
854 # So replace the first hashref in the node arrayref manually
855 my @new_from = ($from->[0]);
856 my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path
858 for my $j (@{$from}[1 .. $#$from]) {
859 my $jalias = $j->[0]{-alias};
861 if ($sw_idx->{$jalias}) {
862 my %attrs = %{$j->[0]};
863 delete $attrs{-join_type};
877 sub _find_join_path_to_node {
878 my ($self, $from, $target_alias) = @_;
880 # subqueries and other oddness are naturally not supported
884 ref $from->[0] ne 'HASH'
886 ! defined $from->[0]{-alias}
889 # no path - the head is the alias
890 return [] if $from->[0]{-alias} eq $target_alias;
892 for my $i (1 .. $#$from) {
893 return $from->[$i][0]{-join_path} if ( ($from->[$i][0]{-alias}||'') eq $target_alias );
896 # something else went quite wrong
900 sub _extract_order_criteria {
901 my ($self, $order_by, $sql_maker) = @_;
904 my ($sql_maker, $order_by, $orig_quote_chars) = @_;
906 return scalar $sql_maker->_order_by_chunks ($order_by)
909 my ($lq, $rq, $sep) = map { quotemeta($_) } (
910 ($orig_quote_chars ? @$orig_quote_chars : $sql_maker->_quote_chars),
915 for ($sql_maker->_order_by_chunks ($order_by) ) {
916 my $chunk = ref $_ ? [ @$_ ] : [ $_ ];
917 ($chunk->[0]) = $sql_maker->_split_order_chunk($chunk->[0]);
919 # order criteria may have come back pre-quoted (literals and whatnot)
920 # this is fragile, but the best we can currently do
921 $chunk->[0] =~ s/^ $lq (.+?) $rq $sep $lq (.+?) $rq $/"$1.$2"/xe
922 or $chunk->[0] =~ s/^ $lq (.+) $rq $/$1/x;
924 push @chunks, $chunk;
931 return $parser->($sql_maker, $order_by);
934 $sql_maker = $self->sql_maker;
936 # pass these in to deal with literals coming from
937 # the user or the deep guts of prefetch
938 my $orig_quote_chars = [$sql_maker->_quote_chars];
940 local $sql_maker->{quote_char};
941 return $parser->($sql_maker, $order_by, $orig_quote_chars);
945 sub _order_by_is_stable {
946 my ($self, $ident, $order_by, $where) = @_;
949 ( map { $_->[0] } $self->_extract_order_criteria($order_by) ),
950 ( $where ? keys %{ $self->_extract_fixed_condition_columns($where) } : () ),
953 my $colinfo = $self->_resolve_column_info($ident, \@cols);
955 return keys %$colinfo
956 ? $self->_columns_comprise_identifying_set( $colinfo, \@cols )
961 sub _columns_comprise_identifying_set {
962 my ($self, $colinfo, $columns) = @_;
965 $cols_per_src -> {$_->{-source_alias}} -> {$_->{-colname}} = $_
966 for grep { defined $_ } @{$colinfo}{@$columns};
968 for (values %$cols_per_src) {
969 my $src = (values %$_)[0]->{-result_source};
970 return 1 if $src->_identifying_column_set($_);
976 # this is almost similar to _order_by_is_stable, except it takes
977 # a single rsrc, and will succeed only if the first portion of the order
979 # returns that portion as a colinfo hashref on success
980 sub _extract_colinfo_of_stable_main_source_order_by_portion {
981 my ($self, $attrs) = @_;
983 my $nodes = $self->_find_join_path_to_node($attrs->{from}, $attrs->{alias});
985 return unless defined $nodes;
989 ( $self->_extract_order_criteria($attrs->{order_by}) )
991 return unless @ord_cols;
993 my $valid_aliases = { map { $_ => 1 } (
994 $attrs->{from}[0]{-alias},
995 map { values %$_ } @$nodes,
998 my $colinfos = $self->_resolve_column_info($attrs->{from});
1000 my ($colinfos_to_return, $seen_main_src_cols);
1002 for my $col (@ord_cols) {
1003 # if order criteria is unresolvable - there is nothing we can do
1004 my $colinfo = $colinfos->{$col} or last;
1006 # if we reached the end of the allowed aliases - also nothing we can do
1007 last unless $valid_aliases->{$colinfo->{-source_alias}};
1009 $colinfos_to_return->{$col} = $colinfo;
1011 $seen_main_src_cols->{$colinfo->{-colname}} = 1
1012 if $colinfo->{-source_alias} eq $attrs->{alias};
1015 # FIXME the condition may be singling out things on its own, so we
1016 # conceivable could come back wi "stable-ordered by nothing"
1017 # not confient enough in the parser yet, so punt for the time being
1018 return unless $seen_main_src_cols;
1020 my $main_src_fixed_cols_from_cond = [ $attrs->{where}
1024 ( $colinfos->{$_} and $colinfos->{$_}{-source_alias} eq $attrs->{alias} )
1025 ? $colinfos->{$_}{-colname}
1028 keys %{ $self->_extract_fixed_condition_columns($attrs->{where}) }
1033 return $attrs->{result_source}->_identifying_column_set([
1034 keys %$seen_main_src_cols,
1035 @$main_src_fixed_cols_from_cond,
1036 ]) ? $colinfos_to_return : ();
1039 # Attempts to flatten a passed in SQLA condition as much as possible towards
1040 # a plain hashref, *without* altering its semantics. Required by
1041 # create/populate being able to extract definitive conditions from preexisting
1042 # resultset {where} stacks
1044 # FIXME - while relatively robust, this is still imperfect, one of the first
1045 # things to tackle with DQ
1046 sub _collapse_cond {
1047 my ($self, $where, $where_is_anded_array) = @_;
1054 elsif ($where_is_anded_array or ref $where eq 'HASH') {
1058 my @pieces = $where_is_anded_array ? @$where : $where;
1060 my $chunk = shift @pieces;
1062 if (ref $chunk eq 'HASH') {
1063 for (sort keys %$chunk) {
1065 # Match SQLA 1.79 behavior
1067 is_literal_value($chunk->{$_})
1068 ? carp 'Hash-pairs consisting of an empty string with a literal are deprecated, use -and => [ $literal ] instead'
1069 : $self->throw_exception("Supplying an empty left hand side argument is not supported in hash-pairs")
1073 push @pairs, $_ => $chunk->{$_};
1076 elsif (ref $chunk eq 'ARRAY') {
1077 push @pairs, -or => $chunk
1080 elsif ( ! length ref $chunk) {
1082 # Match SQLA 1.79 behavior
1083 $self->throw_exception("Supplying an empty left hand side argument is not supported in array-pairs")
1084 if $where_is_anded_array and (! defined $chunk or $chunk eq '');
1086 push @pairs, $chunk, shift @pieces;
1089 push @pairs, '', $chunk;
1093 return unless @pairs;
1095 my @conds = $self->_collapse_cond_unroll_pairs(\@pairs)
1098 # Consolidate various @conds back into something more compact
1099 for my $c (@conds) {
1100 if (ref $c ne 'HASH') {
1101 push @{$fin->{-and}}, $c;
1104 for my $col (sort keys %$c) {
1106 # consolidate all -and nodes
1107 if ($col =~ /^\-and$/i) {
1108 push @{$fin->{-and}},
1109 ref $c->{$col} eq 'ARRAY' ? @{$c->{$col}}
1110 : ref $c->{$col} eq 'HASH' ? %{$c->{$col}}
1111 : { $col => $c->{$col} }
1114 elsif ($col =~ /^\-/) {
1115 push @{$fin->{-and}}, { $col => $c->{$col} };
1117 elsif (exists $fin->{$col}) {
1118 $fin->{$col} = [ -and => map {
1119 (ref $_ eq 'ARRAY' and ($_->[0]||'') =~ /^\-and$/i )
1123 } ($fin->{$col}, $c->{$col}) ];
1126 $fin->{$col} = $c->{$col};
1132 elsif (ref $where eq 'ARRAY') {
1133 # we are always at top-level here, it is safe to dump empty *standalone* pieces
1136 for (my $i = 0; $i <= $#$where; $i++ ) {
1138 # Match SQLA 1.79 behavior
1139 $self->throw_exception(
1140 "Supplying an empty left hand side argument is not supported in array-pairs"
1141 ) if (! defined $where->[$i] or ! length $where->[$i]);
1143 my $logic_mod = lc ( ($where->[$i] =~ /^(\-(?:and|or))$/i)[0] || '' );
1147 $self->throw_exception("Unsupported top-level op/arg pair: [ $logic_mod => $where->[$i] ]")
1148 unless ref $where->[$i] eq 'HASH' or ref $where->[$i] eq 'ARRAY';
1150 my $sub_elt = $self->_collapse_cond({ $logic_mod => $where->[$i] })
1153 my @keys = keys %$sub_elt;
1154 if ( @keys == 1 and $keys[0] !~ /^\-/ ) {
1155 $fin_idx->{ "COL_$keys[0]_" . serialize $sub_elt } = $sub_elt;
1158 $fin_idx->{ "SER_" . serialize $sub_elt } = $sub_elt;
1161 elsif (! length ref $where->[$i] ) {
1162 my $sub_elt = $self->_collapse_cond({ @{$where}[$i, $i+1] })
1165 $fin_idx->{ "COL_$where->[$i]_" . serialize $sub_elt } = $sub_elt;
1169 $fin_idx->{ "SER_" . serialize $where->[$i] } = $self->_collapse_cond( $where->[$i] ) || next;
1176 elsif ( keys %$fin_idx == 1 ) {
1177 $fin = (values %$fin_idx)[0];
1182 # at this point everything is at most one level deep - unroll if needed
1183 for (sort keys %$fin_idx) {
1184 if ( ref $fin_idx->{$_} eq 'HASH' and keys %{$fin_idx->{$_}} == 1 ) {
1185 my ($l, $r) = %{$fin_idx->{$_}};
1191 ( @$r == 1 and $l =~ /^\-and$/i )
1204 $l =~ /^\-(?:and|or)$/i
1214 push @or, $fin_idx->{$_};
1222 # not a hash not an array
1223 $fin = { -and => [ $where ] };
1226 # unroll single-element -and's
1232 my $and = delete $fin->{-and};
1235 # at this point we have @$and == 1
1237 ref $and->[0] eq 'HASH'
1239 ! grep { exists $fin->{$_} } keys %{$and->[0]}
1246 $fin->{-and} = $and;
1251 # compress same-column conds found in $fin
1252 for my $col ( grep { $_ !~ /^\-/ } keys %$fin ) {
1253 next unless ref $fin->{$col} eq 'ARRAY' and ($fin->{$col}[0]||'') =~ /^\-and$/i;
1254 my $val_bag = { map {
1255 (! defined $_ ) ? ( UNDEF => undef )
1256 : ( ! length ref $_ or is_plain_value $_ ) ? ( "VAL_$_" => $_ )
1257 : ( ( 'SER_' . serialize $_ ) => $_ )
1258 } @{$fin->{$col}}[1 .. $#{$fin->{$col}}] };
1260 if (keys %$val_bag == 1 ) {
1261 ($fin->{$col}) = values %$val_bag;
1264 $fin->{$col} = [ -and => map { $val_bag->{$_} } sort keys %$val_bag ];
1268 return keys %$fin ? $fin : ();
1271 sub _collapse_cond_unroll_pairs {
1272 my ($self, $pairs) = @_;
1277 my ($lhs, $rhs) = splice @$pairs, 0, 2;
1280 push @conds, $self->_collapse_cond($rhs);
1282 elsif ( $lhs =~ /^\-and$/i ) {
1283 push @conds, $self->_collapse_cond($rhs, (ref $rhs eq 'ARRAY'));
1285 elsif ( $lhs =~ /^\-or$/i ) {
1286 push @conds, $self->_collapse_cond(
1287 (ref $rhs eq 'HASH') ? [ map { $_ => $rhs->{$_} } sort keys %$rhs ] : $rhs
1291 if (ref $rhs eq 'HASH' and ! keys %$rhs) {
1292 # FIXME - SQLA seems to be doing... nothing...?
1294 # normalize top level -ident, for saner extract_fixed_condition_columns code
1295 elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-ident}) {
1296 push @conds, { $lhs => { '=', $rhs } };
1298 elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-value} and is_plain_value $rhs->{-value}) {
1299 push @conds, { $lhs => $rhs->{-value} };
1301 elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}) {
1302 if ( length ref $rhs->{'='} and is_literal_value $rhs->{'='} ) {
1303 push @conds, { $lhs => $rhs };
1306 for my $p ($self->_collapse_cond_unroll_pairs([ $lhs => $rhs->{'='} ])) {
1308 # extra sanity check
1310 require Data::Dumper::Concise;
1311 local $Data::Dumper::Deepcopy = 1;
1312 $self->throw_exception(
1313 "Internal error: unexpected collapse unroll:"
1314 . Data::Dumper::Concise::Dumper { in => { $lhs => $rhs }, out => $p }
1323 # the unroller recursion may return a '=' prepended value already
1324 ref $r eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}
1329 : { $l => { '=' => $r } }
1334 elsif (ref $rhs eq 'ARRAY') {
1335 # some of these conditionals encounter multi-values - roll them out using
1336 # an unshift, which will cause extra looping in the while{} above
1338 push @conds, { $lhs => [] };
1340 elsif ( ($rhs->[0]||'') =~ /^\-(?:and|or)$/i ) {
1341 $self->throw_exception("Value modifier not followed by any values: $lhs => [ $rhs->[0] ] ")
1344 if( $rhs->[0] =~ /^\-and$/i ) {
1345 unshift @$pairs, map { $lhs => $_ } @{$rhs}[1..$#$rhs];
1347 # if not an AND then it's an OR
1349 unshift @$pairs, $lhs => $rhs->[1];
1352 push @conds, { $lhs => [ @{$rhs}[1..$#$rhs] ] };
1355 elsif (@$rhs == 1) {
1356 unshift @$pairs, $lhs => $rhs->[0];
1359 push @conds, { $lhs => $rhs };
1362 # unroll func + { -value => ... }
1366 ( my ($subop) = keys %$rhs ) == 1
1368 length ref ((values %$rhs)[0])
1370 my $vref = is_plain_value( (values %$rhs)[0] )
1372 push @conds, { $lhs => { $subop => $$vref } }
1375 push @conds, { $lhs => $rhs };
1383 # Analyzes a given condition and attempts to extract all columns
1384 # with a definitive fixed-condition criteria. Returns a hashref
1385 # of k/v pairs suitable to be passed to set_columns(), with a
1386 # MAJOR CAVEAT - multi-value (contradictory) equalities are still
1387 # represented as a reference to the UNRESOVABLE_CONDITION constant
1388 # The reason we do this is that some codepaths only care about the
1389 # codition being stable, as opposed to actually making sense
1391 # The normal mode is used to figure out if a resultset is constrained
1392 # to a column which is part of a unique constraint, which in turn
1393 # allows us to better predict how ordering will behave etc.
1395 # With the optional "consider_nulls" boolean argument, the function
1396 # is instead used to infer inambiguous values from conditions
1397 # (e.g. the inheritance of resultset conditions on new_result)
1399 sub _extract_fixed_condition_columns {
1400 my ($self, $where, $consider_nulls) = @_;
1401 my $where_hash = $self->_collapse_cond($_[1]);
1405 for $c (keys %$where_hash) {
1408 if (!defined ($v = $where_hash->{$c}) ) {
1409 $vals->{UNDEF} = $v if $consider_nulls
1416 if (exists $v->{-value}) {
1417 if (defined $v->{-value}) {
1418 $vals->{"VAL_$v->{-value}"} = $v->{-value}
1420 elsif( $consider_nulls ) {
1421 $vals->{UNDEF} = $v->{-value};
1424 # do not need to check for plain values - _collapse_cond did it for us
1426 length ref $v->{'='}
1429 ( ref $v->{'='} eq 'HASH' and keys %{$v->{'='}} == 1 and exists $v->{'='}{-ident} )
1431 is_literal_value($v->{'='})
1434 $vals->{ 'SER_' . serialize $v->{'='} } = $v->{'='};
1442 $vals->{"VAL_$v"} = $v;
1444 elsif (ref $v eq 'ARRAY' and ($v->[0]||'') eq '-and') {
1445 for ( @{$v}[1..$#$v] ) {
1446 my $subval = $self->_extract_fixed_condition_columns({ $c => $_ }, 'consider nulls'); # always fish nulls out on recursion
1447 next unless exists $subval->{$c}; # didn't find anything
1449 ! defined $subval->{$c} ? 'UNDEF'
1450 : ( ! length ref $subval->{$c} or is_plain_value $subval->{$c} ) ? "VAL_$subval->{$c}"
1451 : ( 'SER_' . serialize $subval->{$c} )
1456 if (keys %$vals == 1) {
1457 ($res->{$c}) = (values %$vals)
1458 unless !$consider_nulls and exists $vals->{UNDEF};
1460 elsif (keys %$vals > 1) {
1461 $res->{$c} = UNRESOLVABLE_CONDITION;