1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken reftype/;
9 use DBIx::Class::_Util 'fail_on_internal_wantarray';
11 use Data::Dumper::Concise ();
12 use Data::Query::Constants;
13 use Data::Query::ExprHelpers;
14 # not importing first() as it will clash with our own method
18 # De-duplication in _merge_attr() is disabled, but left in for reference
19 # (the merger is used for other things that ought not to be de-duped)
20 *__HM_DEDUP = sub () { 0 };
30 # this is real - CDBICompat overrides it with insanity
31 # yes, prototype won't matter, but that's for now ;)
34 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
38 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
42 my $users_rs = $schema->resultset('User');
43 while( $user = $users_rs->next) {
44 print $user->username;
47 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
48 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
52 A ResultSet is an object which stores a set of conditions representing
53 a query. It is the backbone of DBIx::Class (i.e. the really
54 important/useful bit).
56 No SQL is executed on the database when a ResultSet is created, it
57 just stores all the conditions needed to create the query.
59 A basic ResultSet representing the data of an entire table is returned
60 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
61 L<Source|DBIx::Class::Manual::Glossary/Source> name.
63 my $users_rs = $schema->resultset('User');
65 A new ResultSet is returned from calling L</search> on an existing
66 ResultSet. The new one will contain all the conditions of the
67 original, plus any new conditions added in the C<search> call.
69 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
70 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
73 The query that the ResultSet represents is B<only> executed against
74 the database when these methods are called:
75 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
77 If a resultset is used in a numeric context it returns the L</count>.
78 However, if it is used in a boolean context it is B<always> true. So if
79 you want to check if a resultset has any results, you must use C<if $rs
82 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
84 If you want to make your custom ResultSet classes with L<Moose>, use a template
87 package MyApp::Schema::ResultSet::User;
90 use namespace::autoclean;
92 extends 'DBIx::Class::ResultSet';
94 sub BUILDARGS { $_[2] }
98 __PACKAGE__->meta->make_immutable;
102 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
103 clash with the regular ResultSet constructor. Alternatively, you can use:
105 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
107 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
108 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
112 =head2 Chaining resultsets
114 Let's say you've got a query that needs to be run to return some data
115 to the user. But, you have an authorization system in place that
116 prevents certain users from seeing certain information. So, you want
117 to construct the basic query in one method, but add constraints to it in
122 my $request = $self->get_request; # Get a request object somehow.
123 my $schema = $self->result_source->schema;
125 my $cd_rs = $schema->resultset('CD')->search({
126 title => $request->param('title'),
127 year => $request->param('year'),
130 $cd_rs = $self->apply_security_policy( $cd_rs );
132 return $cd_rs->all();
135 sub apply_security_policy {
144 =head3 Resolving conditions and attributes
146 When a resultset is chained from another resultset (e.g.:
147 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
148 and attributes with the same keys need resolving.
150 If any of L</columns>, L</select>, L</as> are present, they reset the
151 original selection, and start the selection "clean".
153 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
154 are merged into the existing ones from the original resultset.
156 The L</where> and L</having> attributes, and any search conditions, are
157 merged with an SQL C<AND> to the existing condition from the original
160 All other attributes are overridden by any new ones supplied in the
163 =head2 Multiple queries
165 Since a resultset just defines a query, you can do all sorts of
166 things with it with the same object.
168 # Don't hit the DB yet.
169 my $cd_rs = $schema->resultset('CD')->search({
170 title => 'something',
174 # Each of these hits the DB individually.
175 my $count = $cd_rs->count;
176 my $most_recent = $cd_rs->get_column('date_released')->max();
177 my @records = $cd_rs->all;
179 And it's not just limited to SELECT statements.
185 $cd_rs->create({ artist => 'Fred' });
187 Which is the same as:
189 $schema->resultset('CD')->create({
190 title => 'something',
195 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
203 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
205 =item Return Value: L<$resultset|/search>
209 The resultset constructor. Takes a source object (usually a
210 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
211 L</ATTRIBUTES> below). Does not perform any queries -- these are
212 executed as needed by the other methods.
214 Generally you never construct a resultset manually. Instead you get one
216 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
217 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
220 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
226 If called on an object, proxies to L</new_result> instead, so
228 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
230 will return a CD object, not a ResultSet, and is equivalent to:
232 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
234 Please also keep in mind that many internals call L</new_result> directly,
235 so overloading this method with the idea of intercepting new result object
236 creation B<will not work>. See also warning pertaining to L</create>.
244 return $class->new_result(@_) if ref $class;
246 my ($source, $attrs) = @_;
247 $source = $source->resolve
248 if $source->isa('DBIx::Class::ResultSourceHandle');
250 $attrs = { %{$attrs||{}} };
251 delete @{$attrs}{qw(_sqlmaker_select_args _related_results_construction)};
253 if ($attrs->{page}) {
254 $attrs->{rows} ||= 10;
257 $attrs->{alias} ||= 'me';
260 result_source => $source,
261 cond => $attrs->{where},
266 # if there is a dark selector, this means we are already in a
267 # chain and the cleanup/sanification was taken care of by
269 $self->_normalize_selection($attrs)
270 unless $attrs->{_dark_selector};
273 $attrs->{result_class} || $source->result_class
283 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
285 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
289 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
290 my $new_rs = $cd_rs->search({ year => 2005 });
292 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
293 # year = 2005 OR year = 2004
295 In list context, C<< ->all() >> is called implicitly on the resultset, thus
296 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
297 To avoid that, use L</search_rs>.
299 If you need to pass in additional attributes but no additional condition,
300 call it as C<search(undef, \%attrs)>.
302 # "SELECT name, artistid FROM $artist_table"
303 my @all_artists = $schema->resultset('Artist')->search(undef, {
304 columns => [qw/name artistid/],
307 For a list of attributes that can be passed to C<search>, see
308 L</ATTRIBUTES>. For more examples of using this function, see
309 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
310 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
311 and its extension L<DBIx::Class::SQLMaker>.
313 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
317 Note that L</search> does not process/deflate any of the values passed in the
318 L<SQL::Abstract>-compatible search condition structure. This is unlike other
319 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
320 manually that any value passed to this method will stringify to something the
321 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
322 objects, for more info see:
323 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
329 my $rs = $self->search_rs( @_ );
332 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray($rs);
335 elsif (defined wantarray) {
339 # we can be called by a relationship helper, which in
340 # turn may be called in void context due to some braindead
341 # overload or whatever else the user decided to be clever
342 # at this particular day. Thus limit the exception to
343 # external code calls only
344 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
345 if (caller)[0] !~ /^\QDBIx::Class::/;
355 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
357 =item Return Value: L<$resultset|/search>
361 This method does the same exact thing as search() except it will
362 always return a resultset, even in list context.
369 my $rsrc = $self->result_source;
370 my ($call_cond, $call_attrs);
372 # Special-case handling for (undef, undef) or (undef)
373 # Note that (foo => undef) is valid deprecated syntax
374 @_ = () if not scalar grep { defined $_ } @_;
380 # fish out attrs in the ($condref, $attr) case
381 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
382 ($call_cond, $call_attrs) = @_;
385 $self->throw_exception('Odd number of arguments to search')
389 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
390 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
392 for my $i (0 .. $#_) {
394 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
395 if (! defined $_[$i] or ref $_[$i] ne '');
401 if (blessed($call_cond) and $call_cond->isa('Data::Query::ExprBuilder')) {
402 $call_cond = \$call_cond->{expr};
405 # see if we can keep the cache (no $rs changes)
407 my %safe = (alias => 1, cache => 1);
408 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
411 ref $call_cond eq 'HASH' && ! keys %$call_cond
413 ref $call_cond eq 'ARRAY' && ! @$call_cond
415 $cache = $self->get_cache;
418 my $old_attrs = { %{$self->{attrs}} };
419 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
421 my $new_attrs = { %$old_attrs };
423 # take care of call attrs (only if anything is changing)
424 if ($call_attrs and keys %$call_attrs) {
426 # copy for _normalize_selection
427 $call_attrs = { %$call_attrs };
429 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
431 # reset the current selector list if new selectors are supplied
432 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
433 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
436 # Normalize the new selector list (operates on the passed-in attr structure)
437 # Need to do it on every chain instead of only once on _resolved_attrs, in
438 # order to allow detection of empty vs partial 'as'
439 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
440 if $old_attrs->{_dark_selector};
441 $self->_normalize_selection ($call_attrs);
443 # start with blind overwriting merge, exclude selector attrs
444 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
445 delete @{$new_attrs}{@selector_attrs};
447 for (@selector_attrs) {
448 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
449 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
452 # older deprecated name, use only if {columns} is not there
453 if (my $c = delete $new_attrs->{cols}) {
454 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
455 if ($new_attrs->{columns}) {
456 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
459 $new_attrs->{columns} = $c;
464 # join/prefetch use their own crazy merging heuristics
465 foreach my $key (qw/join prefetch/) {
466 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
467 if exists $call_attrs->{$key};
470 # stack binds together
471 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
475 for ($old_where, $call_cond) {
477 $new_attrs->{where} = $self->_stack_cond (
478 $_, $new_attrs->{where}
483 if (defined $old_having) {
484 $new_attrs->{having} = $self->_stack_cond (
485 $old_having, $new_attrs->{having}
489 my $rs = (ref $self)->new($rsrc, $new_attrs);
491 $rs->set_cache($cache) if ($cache);
497 sub _normalize_selection {
498 my ($self, $attrs) = @_;
501 if ( exists $attrs->{include_columns} ) {
502 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
503 $attrs->{'+columns'} = $self->_merge_attr(
504 $attrs->{'+columns'}, delete $attrs->{include_columns}
508 # columns are always placed first, however
510 # Keep the X vs +X separation until _resolved_attrs time - this allows to
511 # delay the decision on whether to use a default select list ($rsrc->columns)
512 # allowing stuff like the remove_columns helper to work
514 # select/as +select/+as pairs need special handling - the amount of select/as
515 # elements in each pair does *not* have to be equal (think multicolumn
516 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
517 # supplied at all) - try to infer the alias, either from the -as parameter
518 # of the selector spec, or use the parameter whole if it looks like a column
519 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
520 # is ok as well), but make sure no more additions to the 'as' chain take place
521 for my $pref ('', '+') {
523 my ($sel, $as) = map {
524 my $key = "${pref}${_}";
526 my $val = [ ref $attrs->{$key} eq 'ARRAY'
528 : $attrs->{$key} || ()
530 delete $attrs->{$key};
534 if (! @$as and ! @$sel ) {
537 elsif (@$as and ! @$sel) {
538 $self->throw_exception(
539 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
543 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
544 # if any @$as has been supplied we assume the user knows what (s)he is doing
545 # and blindly keep stacking up pieces
546 unless ($attrs->{_dark_selector}) {
549 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
550 push @$as, $_->{-as};
552 # assume any plain no-space, no-parenthesis string to be a column spec
553 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
554 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
557 # if all else fails - raise a flag that no more aliasing will be allowed
559 $attrs->{_dark_selector} = {
561 string => ($dark_sel_dumper ||= do {
562 require Data::Dumper::Concise;
563 Data::Dumper::Concise::DumperObject()->Indent(0);
564 })->Values([$_])->Dump
572 elsif (@$as < @$sel) {
573 $self->throw_exception(
574 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
577 elsif ($pref and $attrs->{_dark_selector}) {
578 $self->throw_exception(
579 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
585 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
586 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
591 my ($self, $left, $right) = @_;
593 my $source = $self->result_source;
595 my $converter = $source->schema->storage->sql_maker->converter;
597 my @top = map $source->_extract_top_level_conditions(
598 $converter->_expr_to_dq($_)
599 ), grep defined, $left, $right;
601 return undef unless @top;
605 my @uniq = grep { !$seen{Data::Dumper::Concise::Dumper($_)}++ } @top;
607 return \Operator({ 'SQL.Naive' => 'AND' }, \@uniq);
610 =head2 search_literal
612 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
613 should only be used in that context. C<search_literal> is a convenience
614 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
615 want to ensure columns are bound correctly, use L</search>.
617 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
618 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
619 require C<search_literal>.
623 =item Arguments: $sql_fragment, @standalone_bind_values
625 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
629 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
630 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
632 Pass a literal chunk of SQL to be added to the conditional part of the
635 Example of how to use C<search> instead of C<search_literal>
637 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
638 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
643 my ($self, $sql, @bind) = @_;
645 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
648 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
655 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
657 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
661 Finds and returns a single row based on supplied criteria. Takes either a
662 hashref with the same format as L</create> (including inference of foreign
663 keys from related objects), or a list of primary key values in the same
664 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
665 declaration on the L</result_source>.
667 In either case an attempt is made to combine conditions already existing on
668 the resultset with the condition passed to this method.
670 To aid with preparing the correct query for the storage you may supply the
671 C<key> attribute, which is the name of a
672 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
673 unique constraint corresponding to the
674 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
675 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
676 to construct a query that satisfies the named unique constraint fully (
677 non-NULL values for each column member of the constraint) an exception is
680 If no C<key> is specified, the search is carried over all unique constraints
681 which are fully defined by the available condition.
683 If no such constraint is found, C<find> currently defaults to a simple
684 C<< search->(\%column_values) >> which may or may not do what you expect.
685 Note that this fallback behavior may be deprecated in further versions. If
686 you need to search with arbitrary conditions - use L</search>. If the query
687 resulting from this fallback produces more than one row, a warning to the
688 effect is issued, though only the first row is constructed and returned as
691 In addition to C<key>, L</find> recognizes and applies standard
692 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
694 Note that if you have extra concerns about the correctness of the resulting
695 query you need to specify the C<key> attribute and supply the entire condition
696 as an argument to find (since it is not always possible to perform the
697 combination of the resultset condition with the supplied one, especially if
698 the resultset condition contains literal sql).
700 For example, to find a row by its primary key:
702 my $cd = $schema->resultset('CD')->find(5);
704 You can also find a row by a specific unique constraint:
706 my $cd = $schema->resultset('CD')->find(
708 artist => 'Massive Attack',
709 title => 'Mezzanine',
711 { key => 'cd_artist_title' }
714 See also L</find_or_create> and L</update_or_create>.
720 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
722 my $rsrc = $self->result_source;
725 if (exists $attrs->{key}) {
726 $constraint_name = defined $attrs->{key}
728 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
732 # Parse out the condition from input
735 if (ref $_[0] eq 'HASH') {
736 $call_cond = { %{$_[0]} };
739 # if only values are supplied we need to default to 'primary'
740 $constraint_name = 'primary' unless defined $constraint_name;
742 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
744 $self->throw_exception(
745 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
748 $self->throw_exception (
749 'find() expects either a column/value hashref, or a list of values '
750 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
751 ) unless @c_cols == @_;
754 @{$call_cond}{@c_cols} = @_;
758 for my $key (keys %$call_cond) {
760 my $keyref = ref($call_cond->{$key})
762 my $relinfo = $rsrc->relationship_info($key)
764 my $val = delete $call_cond->{$key};
766 next if $keyref eq 'ARRAY'; # has_many for multi_create
768 my $rel_q = $rsrc->_resolve_condition(
769 $relinfo->{cond}, $val, $key, $key
771 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
772 @related{keys %$rel_q} = values %$rel_q;
776 # relationship conditions take precedence (?)
777 @{$call_cond}{keys %related} = values %related;
779 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
781 if (defined $constraint_name) {
782 $final_cond = $self->_qualify_cond_columns (
784 $self->_build_unique_cond (
792 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
793 # This means that we got here after a merger of relationship conditions
794 # in ::Relationship::Base::search_related (the row method), and furthermore
795 # the relationship is of the 'single' type. This means that the condition
796 # provided by the relationship (already attached to $self) is sufficient,
797 # as there can be only one row in the database that would satisfy the
801 # no key was specified - fall down to heuristics mode:
802 # run through all unique queries registered on the resultset, and
803 # 'OR' all qualifying queries together
804 my (@unique_queries, %seen_column_combinations);
805 for my $c_name ($rsrc->unique_constraint_names) {
806 next if $seen_column_combinations{
807 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
810 push @unique_queries, try {
811 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
815 $final_cond = @unique_queries
816 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
817 : $self->_non_unique_find_fallback ($call_cond, $attrs)
821 # Run the query, passing the result_class since it should propagate for find
822 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
823 if ($rs->_resolved_attrs->{collapse}) {
825 carp "Query returned more than one row" if $rs->next;
833 # This is a stop-gap method as agreed during the discussion on find() cleanup:
834 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
836 # It is invoked when find() is called in legacy-mode with insufficiently-unique
837 # condition. It is provided for overrides until a saner way forward is devised
839 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
840 # the road. Please adjust your tests accordingly to catch this situation early
841 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
843 # The method will not be removed without an adequately complete replacement
844 # for strict-mode enforcement
845 sub _non_unique_find_fallback {
846 my ($self, $cond, $attrs) = @_;
848 return $self->_qualify_cond_columns(
850 exists $attrs->{alias}
852 : $self->{attrs}{alias}
857 sub _qualify_cond_columns {
858 my ($self, $cond, $alias) = @_;
860 my %aliased = %$cond;
861 for (keys %aliased) {
862 $aliased{"$alias.$_"} = delete $aliased{$_}
869 sub _build_unique_cond {
870 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
872 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
874 # combination may fail if $self->{cond} is non-trivial
875 my ($final_cond) = try {
876 $self->_merge_with_rscond ($extra_cond)
881 # trim out everything not in $columns
882 $final_cond = { map {
883 exists $final_cond->{$_}
884 ? ( $_ => $final_cond->{$_} )
888 if (my @missing = grep
889 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
892 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
894 join (', ', map { "'$_'" } @missing),
901 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
903 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
905 carp_unique ( sprintf (
906 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
907 . 'values in column(s): %s). This is almost certainly not what you wanted, '
908 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
910 join (', ', map { "'$_'" } @undefs),
917 =head2 search_related
921 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
923 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
927 $new_rs = $cd_rs->search_related('artist', {
931 Searches the specified relationship, optionally specifying a condition and
932 attributes for matching records. See L</ATTRIBUTES> for more information.
934 In list context, C<< ->all() >> is called implicitly on the resultset, thus
935 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
937 See also L</search_related_rs>.
942 return shift->related_resultset(shift)->search(@_);
945 =head2 search_related_rs
947 This method works exactly the same as search_related, except that
948 it guarantees a resultset, even in list context.
952 sub search_related_rs {
953 return shift->related_resultset(shift)->search_rs(@_);
960 =item Arguments: none
962 =item Return Value: L<$cursor|DBIx::Class::Cursor>
966 Returns a storage-driven cursor to the given resultset. See
967 L<DBIx::Class::Cursor> for more information.
974 return $self->{cursor} ||= do {
975 my $attrs = $self->_resolved_attrs;
976 $self->result_source->storage->select(
977 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
986 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
988 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
992 my $cd = $schema->resultset('CD')->single({ year => 2001 });
994 Inflates the first result without creating a cursor if the resultset has
995 any records in it; if not returns C<undef>. Used by L</find> as a lean version
998 While this method can take an optional search condition (just like L</search>)
999 being a fast-code-path it does not recognize search attributes. If you need to
1000 add extra joins or similar, call L</search> and then chain-call L</single> on the
1001 L<DBIx::Class::ResultSet> returned.
1007 As of 0.08100, this method enforces the assumption that the preceding
1008 query returns only one row. If more than one row is returned, you will receive
1011 Query returned more than one row
1013 In this case, you should be using L</next> or L</find> instead, or if you really
1014 know what you are doing, use the L</rows> attribute to explicitly limit the size
1017 This method will also throw an exception if it is called on a resultset prefetching
1018 has_many, as such a prefetch implies fetching multiple rows from the database in
1019 order to assemble the resulting object.
1026 my ($self, $where) = @_;
1028 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1031 my $attrs = { %{$self->_resolved_attrs} };
1033 $self->throw_exception(
1034 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1035 ) if $attrs->{collapse};
1038 if (defined $attrs->{where}) {
1041 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1042 $where, delete $attrs->{where} ]
1045 $attrs->{where} = $where;
1049 my $data = [ $self->result_source->storage->select_single(
1050 $attrs->{from}, $attrs->{select},
1051 $attrs->{where}, $attrs
1054 return undef unless @$data;
1055 $self->{_stashed_rows} = [ $data ];
1056 $self->_construct_results->[0];
1062 # Recursively collapse the query, accumulating values for each column.
1064 sub _collapse_query {
1065 my ($self, $query, $collapsed) = @_;
1069 if (ref $query eq 'ARRAY') {
1070 foreach my $subquery (@$query) {
1071 next unless ref $subquery; # -or
1072 $collapsed = $self->_collapse_query($subquery, $collapsed);
1075 elsif (ref $query eq 'HASH') {
1076 if (keys %$query and (keys %$query)[0] eq '-and') {
1077 foreach my $subquery (@{$query->{-and}}) {
1078 $collapsed = $self->_collapse_query($subquery, $collapsed);
1082 foreach my $col (keys %$query) {
1083 my $value = $query->{$col};
1084 $collapsed->{$col}{$value}++;
1096 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1098 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1102 my $max_length = $rs->get_column('length')->max;
1104 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1109 my ($self, $column) = @_;
1110 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1118 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1120 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1124 # WHERE title LIKE '%blue%'
1125 $cd_rs = $rs->search_like({ title => '%blue%'});
1127 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1128 that this is simply a convenience method retained for ex Class::DBI users.
1129 You most likely want to use L</search> with specific operators.
1131 For more information, see L<DBIx::Class::Manual::Cookbook>.
1133 This method is deprecated and will be removed in 0.09. Use L</search()>
1134 instead. An example conversion is:
1136 ->search_like({ foo => 'bar' });
1140 ->search({ foo => { like => 'bar' } });
1147 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1148 .' Instead use ->search({ x => { -like => "y%" } })'
1149 .' (note the outer pair of {}s - they are important!)'
1151 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1152 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1153 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1154 return $class->search($query, { %$attrs });
1161 =item Arguments: $first, $last
1163 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1167 Returns a resultset or object list representing a subset of elements from the
1168 resultset slice is called on. Indexes are from 0, i.e., to get the first
1169 three records, call:
1171 my ($one, $two, $three) = $rs->slice(0, 2);
1176 my ($self, $min, $max) = @_;
1177 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1178 $attrs->{offset} = $self->{attrs}{offset} || 0;
1179 $attrs->{offset} += $min;
1180 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1181 return $self->search(undef, $attrs);
1188 =item Arguments: none
1190 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1194 Returns the next element in the resultset (C<undef> is there is none).
1196 Can be used to efficiently iterate over records in the resultset:
1198 my $rs = $schema->resultset('CD')->search;
1199 while (my $cd = $rs->next) {
1203 Note that you need to store the resultset object, and call C<next> on it.
1204 Calling C<< resultset('Table')->next >> repeatedly will always return the
1205 first record from the resultset.
1212 if (my $cache = $self->get_cache) {
1213 $self->{all_cache_position} ||= 0;
1214 return $cache->[$self->{all_cache_position}++];
1217 if ($self->{attrs}{cache}) {
1218 delete $self->{pager};
1219 $self->{all_cache_position} = 1;
1220 return ($self->all)[0];
1223 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1225 $self->{_stashed_results} = $self->_construct_results
1228 return shift @{$self->{_stashed_results}};
1231 # Constructs as many results as it can in one pass while respecting
1232 # cursor laziness. Several modes of operation:
1234 # * Always builds everything present in @{$self->{_stashed_rows}}
1235 # * If called with $fetch_all true - pulls everything off the cursor and
1236 # builds all result structures (or objects) in one pass
1237 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1238 # and if the resultset is ordered properly by the left side:
1239 # * Fetches stuff off the cursor until the "master object" changes,
1240 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1242 # * Just fetches, and collapses/constructs everything as if $fetch_all
1243 # was requested (there is no other way to collapse except for an
1245 # * If no collapse is requested - just get the next row, construct and
1247 sub _construct_results {
1248 my ($self, $fetch_all) = @_;
1250 my $rsrc = $self->result_source;
1251 my $attrs = $self->_resolved_attrs;
1256 ! $attrs->{order_by}
1260 my @pcols = $rsrc->primary_columns
1262 # default order for collapsing unless the user asked for something
1263 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1264 $attrs->{_ordered_for_collapse} = 1;
1265 $attrs->{_order_is_artificial} = 1;
1268 # this will be used as both initial raw-row collector AND as a RV of
1269 # _construct_results. Not regrowing the array twice matters a lot...
1270 # a surprising amount actually
1271 my $rows = delete $self->{_stashed_rows};
1273 my $cursor; # we may not need one at all
1275 my $did_fetch_all = $fetch_all;
1278 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1279 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1281 elsif( $attrs->{collapse} ) {
1283 # a cursor will need to be closed over in case of collapse
1284 $cursor = $self->cursor;
1286 $attrs->{_ordered_for_collapse} = (
1292 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1294 ) unless defined $attrs->{_ordered_for_collapse};
1296 if (! $attrs->{_ordered_for_collapse}) {
1299 # instead of looping over ->next, use ->all in stealth mode
1300 # *without* calling a ->reset afterwards
1301 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1302 if (! $cursor->{_done}) {
1303 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1304 $cursor->{_done} = 1;
1309 if (! $did_fetch_all and ! @{$rows||[]} ) {
1310 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1311 $cursor ||= $self->cursor;
1312 if (scalar (my @r = $cursor->next) ) {
1317 return undef unless @{$rows||[]};
1319 # sanity check - people are too clever for their own good
1320 if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
1322 my $multiplied_selectors;
1323 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1325 $aliastypes->{multiplying}{$sel_alias}
1327 $aliastypes->{premultiplied}{$sel_alias}
1329 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1333 for my $i (0 .. $#{$attrs->{as}} ) {
1334 my $sel = $attrs->{select}[$i];
1336 if (ref $sel eq 'SCALAR') {
1339 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1343 $self->throw_exception(
1344 'Result collapse not possible - selection from a has_many source redirected to the main object'
1345 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1349 # hotspot - skip the setter
1350 my $res_class = $self->_result_class;
1352 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1353 $res_class->can ('inflate_result')
1354 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1357 my $infmap = $attrs->{as};
1359 $self->{_result_inflator}{is_core_row} = ( (
1362 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1363 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1365 $self->{_result_inflator}{is_hri} = ( (
1366 ! $self->{_result_inflator}{is_core_row}
1369 require DBIx::Class::ResultClass::HashRefInflator
1371 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1373 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1376 if (! $attrs->{_related_results_construction}) {
1377 # construct a much simpler array->hash folder for the one-table cases right here
1378 if ($self->{_result_inflator}{is_hri}) {
1379 for my $r (@$rows) {
1380 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1383 # FIXME SUBOPTIMAL this is a very very very hot spot
1384 # while rather optimal we can *still* do much better, by
1385 # building a smarter Row::inflate_result(), and
1386 # switch to feeding it data via a much leaner interface
1388 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1389 # this particular resultset size
1390 elsif (@$rows < 60) {
1391 for my $r (@$rows) {
1392 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1397 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1398 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1404 $self->{_result_inflator}{is_hri} ? 'hri'
1405 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1406 : 'classic_nonpruning'
1409 # $args and $attrs to _mk_row_parser are separated to delineate what is
1410 # core collapser stuff and what is dbic $rs specific
1411 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1413 inflate_map => $infmap,
1414 collapse => $attrs->{collapse},
1415 premultiplied => $attrs->{_main_source_premultiplied},
1416 hri_style => $self->{_result_inflator}{is_hri},
1417 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1418 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1420 # column_info metadata historically hasn't been too reliable.
1421 # We need to start fixing this somehow (the collapse resolver
1422 # can't work without it). Add an explicit check for the *main*
1423 # result, hopefully this will gradually weed out such errors
1425 # FIXME - this is a temporary kludge that reduces performance
1426 # It is however necessary for the time being
1427 my ($unrolled_non_null_cols_to_check, $err);
1429 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1432 'Collapse aborted due to invalid ResultSource metadata - the following '
1433 . 'selections are declared non-nullable but NULLs were retrieved: '
1437 COL: for my $i (@$check_non_null_cols) {
1438 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1441 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1444 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1448 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1449 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1451 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1452 my @r = $cursor->next or return;
1453 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1454 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1460 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1461 my @r = $cursor->next or return;
1466 $self->{_row_parser}{$parser_type}{cref}->(
1468 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1471 # Special-case multi-object HRI - there is no $inflator_cref pass
1472 unless ($self->{_result_inflator}{is_hri}) {
1473 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1477 # The @$rows check seems odd at first - why wouldn't we want to warn
1478 # regardless? The issue is things like find() etc, where the user
1479 # *knows* only one result will come back. In these cases the ->all
1480 # is not a pessimization, but rather something we actually want
1482 'Unable to properly collapse has_many results in iterator mode due '
1483 . 'to order criteria - performed an eager cursor slurp underneath. '
1484 . 'Consider using ->all() instead'
1485 ) if ( ! $fetch_all and @$rows > 1 );
1490 =head2 result_source
1494 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1496 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1500 An accessor for the primary ResultSource object from which this ResultSet
1507 =item Arguments: $result_class?
1509 =item Return Value: $result_class
1513 An accessor for the class to use when creating result objects. Defaults to
1514 C<< result_source->result_class >> - which in most cases is the name of the
1515 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1517 Note that changing the result_class will also remove any components
1518 that were originally loaded in the source class via
1519 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1520 in the original source class will not run.
1525 my ($self, $result_class) = @_;
1526 if ($result_class) {
1528 # don't fire this for an object
1529 $self->ensure_class_loaded($result_class)
1530 unless ref($result_class);
1532 if ($self->get_cache) {
1533 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1535 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1536 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1537 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1540 $self->_result_class($result_class);
1542 delete $self->{_result_inflator};
1544 $self->_result_class;
1551 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1553 =item Return Value: $count
1557 Performs an SQL C<COUNT> with the same query as the resultset was built
1558 with to find the number of elements. Passing arguments is equivalent to
1559 C<< $rs->search ($cond, \%attrs)->count >>
1565 return $self->search(@_)->count if @_ and defined $_[0];
1566 return scalar @{ $self->get_cache } if $self->get_cache;
1568 my $attrs = { %{ $self->_resolved_attrs } };
1570 # this is a little optimization - it is faster to do the limit
1571 # adjustments in software, instead of a subquery
1572 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1575 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1576 $crs = $self->_count_subq_rs ($attrs);
1579 $crs = $self->_count_rs ($attrs);
1581 my $count = $crs->next;
1583 $count -= $offset if $offset;
1584 $count = $rows if $rows and $rows < $count;
1585 $count = 0 if ($count < 0);
1594 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1596 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1600 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1601 This can be very handy for subqueries:
1603 ->search( { amount => $some_rs->count_rs->as_query } )
1605 As with regular resultsets the SQL query will be executed only after
1606 the resultset is accessed via L</next> or L</all>. That would return
1607 the same single value obtainable via L</count>.
1613 return $self->search(@_)->count_rs if @_;
1615 # this may look like a lack of abstraction (count() does about the same)
1616 # but in fact an _rs *must* use a subquery for the limits, as the
1617 # software based limiting can not be ported if this $rs is to be used
1618 # in a subquery itself (i.e. ->as_query)
1619 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1620 return $self->_count_subq_rs($self->{_attrs});
1623 return $self->_count_rs($self->{_attrs});
1628 # returns a ResultSetColumn object tied to the count query
1631 my ($self, $attrs) = @_;
1633 my $rsrc = $self->result_source;
1635 my $tmp_attrs = { %$attrs };
1636 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1637 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1639 # overwrite the selector (supplied by the storage)
1640 $rsrc->resultset_class->new($rsrc, {
1642 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1644 })->get_column ('count');
1648 # same as above but uses a subquery
1650 sub _count_subq_rs {
1651 my ($self, $attrs) = @_;
1653 my $rsrc = $self->result_source;
1655 my $sub_attrs = { %$attrs };
1656 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1657 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1659 # if we multi-prefetch we group_by something unique, as this is what we would
1660 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1661 if ( $attrs->{collapse} ) {
1662 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1663 $rsrc->_identifying_column_set || $self->throw_exception(
1664 'Unable to construct a unique group_by criteria properly collapsing the '
1665 . 'has_many prefetch before count()'
1670 # Calculate subquery selector
1671 if (my $g = $sub_attrs->{group_by}) {
1673 my $sql_maker = $rsrc->storage->sql_maker;
1675 # necessary as the group_by may refer to aliased functions
1677 for my $sel (@{$attrs->{select}}) {
1678 $sel_index->{$sel->{-as}} = $sel
1679 if (ref $sel eq 'HASH' and $sel->{-as});
1682 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1683 # also look for named aggregates referred in the having clause
1684 # having often contains scalarrefs - thus parse it out entirely
1686 if ($attrs->{having}) {
1687 local $sql_maker->{having_bind};
1688 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1689 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1690 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1691 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1692 # if we don't unset it we screw up retarded but unfortunately working
1693 # 'MAX(foo.bar)' => { '>', 3 }
1694 $sql_maker->{name_sep} = '';
1697 $sql_maker->clear_renderer;
1698 $sql_maker->clear_converter;
1700 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1702 my $having_sql = $sql_maker->_render_sqla(where => $attrs->{having});
1704 $sql_maker->clear_renderer;
1705 $sql_maker->clear_converter;
1709 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1710 # and if all fails for an utterly naive quoted scalar-with-function
1711 while ($having_sql =~ /
1712 (?: $rquote $sep)? $lquote (.+?) $rquote
1714 [\s,] \w+ \. (\w+) [\s,]
1716 [\s,] $lquote (.+?) $rquote [\s,]
1718 my $part = $1 || $2 || $3; # one of them matched if we got here
1719 unless ($seen_having{$part}++) {
1726 my $colpiece = $sel_index->{$_} || $_;
1728 # unqualify join-based group_by's. Arcane but possible query
1729 # also horrible horrible hack to alias a column (not a func.)
1730 # (probably need to introduce SQLA syntax)
1731 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1734 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1736 push @{$sub_attrs->{select}}, $colpiece;
1740 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1741 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1744 return $rsrc->resultset_class
1745 ->new ($rsrc, $sub_attrs)
1747 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1748 ->get_column ('count');
1752 =head2 count_literal
1754 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1755 should only be used in that context. See L</search_literal> for further info.
1759 =item Arguments: $sql_fragment, @standalone_bind_values
1761 =item Return Value: $count
1765 Counts the results in a literal query. Equivalent to calling L</search_literal>
1766 with the passed arguments, then L</count>.
1770 sub count_literal { shift->search_literal(@_)->count; }
1776 =item Arguments: none
1778 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1782 Returns all elements in the resultset.
1789 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1792 delete @{$self}{qw/_stashed_rows _stashed_results/};
1794 if (my $c = $self->get_cache) {
1798 $self->cursor->reset;
1800 my $objs = $self->_construct_results('fetch_all') || [];
1802 $self->set_cache($objs) if $self->{attrs}{cache};
1811 =item Arguments: none
1813 =item Return Value: $self
1817 Resets the resultset's cursor, so you can iterate through the elements again.
1818 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1826 delete @{$self}{qw/_stashed_rows _stashed_results/};
1827 $self->{all_cache_position} = 0;
1828 $self->cursor->reset;
1836 =item Arguments: none
1838 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1842 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1843 an object for the first result (or C<undef> if the resultset is empty).
1848 return $_[0]->reset->next;
1854 # Determines whether and what type of subquery is required for the $rs operation.
1855 # If grouping is necessary either supplies its own, or verifies the current one
1856 # After all is done delegates to the proper storage method.
1858 sub _rs_update_delete {
1859 my ($self, $op, $values) = @_;
1861 my $rsrc = $self->result_source;
1862 my $storage = $rsrc->schema->storage;
1864 my $attrs = { %{$self->_resolved_attrs} };
1866 my $join_classifications;
1867 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1869 # do we need a subquery for any reason?
1871 defined $existing_group_by
1873 # if {from} is unparseable wrap a subq
1874 ref($attrs->{from}) ne 'ARRAY'
1876 # limits call for a subq
1877 $self->_has_resolved_attr(qw/rows offset/)
1880 # simplify the joinmap, so we can further decide if a subq is necessary
1881 if (!$needs_subq and @{$attrs->{from}} > 1) {
1883 ($attrs->{from}, $join_classifications) =
1884 $storage->_prune_unused_joins ($attrs);
1886 # any non-pruneable non-local restricting joins imply subq
1887 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1890 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1892 (ref $attrs->{from}[0]) ne 'HASH'
1894 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1898 # do we need anything like a subquery?
1899 if (! $needs_subq) {
1900 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1901 # a condition containing 'me' or other table prefixes will not work
1902 # at all - so we convert the WHERE to a dq tree now, dequalify all
1903 # identifiers found therein via a scan across the tree, and then use
1904 # \{} style to pass the result onwards for use in the final query
1905 if ($self->{cond}) {
1907 my $converter = $rsrc->storage->sql_maker->converter;
1909 DQ_IDENTIFIER ,=> sub { $_ = [ $_->[-1] ] for $_[0]->{elements} }
1910 }, my $where_dq = $converter->_where_to_dq($self->{cond}));
1916 # we got this far - means it is time to wrap a subquery
1917 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1919 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1925 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1926 delete $attrs->{$_} for qw/select as collapse/;
1927 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1929 # this will be consumed by the pruner waaaaay down the stack
1930 $attrs->{_force_prune_multiplying_joins} = 1;
1932 my $subrs = (ref $self)->new($rsrc, $attrs);
1934 if (@$idcols == 1) {
1935 $cond = { $idcols->[0] => { -in => \$subrs->_as_select_dq } };
1937 elsif ($storage->_use_multicolumn_in) {
1938 # no syntax for calling this properly yet
1939 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1940 my $left = $storage->sql_maker->_render_sqla(select_select => $idcols);
1941 $left =~ s/^SELECT //i;
1942 my $right = $storage->sql_maker
1944 ->_literal_to_dq(${$subrs->as_query});
1946 { 'SQL.Naive' => 'in' },
1947 [ Literal(SQL => "( $left )"), $right ],
1951 # if all else fails - get all primary keys and operate over a ORed set
1952 # wrap in a transaction for consistency
1953 # this is where the group_by/multiplication starts to matter
1957 # we do not need to check pre-multipliers, since if the premulti is there, its
1958 # parent (who is multi) will be there too
1959 keys %{ $join_classifications->{multiplying} || {} }
1961 # make sure if there is a supplied group_by it matches the columns compiled above
1962 # perfectly. Anything else can not be sanely executed on most databases so croak
1963 # right then and there
1964 if ($existing_group_by) {
1965 my @current_group_by = map
1966 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1971 join ("\x00", sort @current_group_by)
1973 join ("\x00", sort @{$attrs->{columns}} )
1975 $self->throw_exception (
1976 "You have just attempted a $op operation on a resultset which does group_by"
1977 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1978 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1979 . ' kind of queries. Please retry the operation with a modified group_by or'
1980 . ' without using one at all.'
1985 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1988 $guard = $storage->txn_scope_guard;
1991 for my $row ($subrs->cursor->all) {
1993 { $idcols->[$_] => $row->[$_] }
2000 my $res = $storage->$op (
2002 $op eq 'update' ? $values : (),
2006 $guard->commit if $guard;
2015 =item Arguments: \%values
2017 =item Return Value: $underlying_storage_rv
2021 Sets the specified columns in the resultset to the supplied values in a
2022 single query. Note that this will not run any accessor/set_column/update
2023 triggers, nor will it update any result object instances derived from this
2024 resultset (this includes the contents of the L<resultset cache|/set_cache>
2025 if any). See L</update_all> if you need to execute any on-update
2026 triggers or cascades defined either by you or a
2027 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2029 The return value is a pass through of what the underlying
2030 storage backend returned, and may vary. See L<DBI/execute> for the most
2035 Note that L</update> does not process/deflate any of the values passed in.
2036 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2037 ensure manually that any value passed to this method will stringify to
2038 something the RDBMS knows how to deal with. A notable example is the
2039 handling of L<DateTime> objects, for more info see:
2040 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2045 my ($self, $values) = @_;
2046 $self->throw_exception('Values for update must be a hash')
2047 unless ref $values eq 'HASH';
2049 return $self->_rs_update_delete ('update', $values);
2056 =item Arguments: \%values
2058 =item Return Value: 1
2062 Fetches all objects and updates them one at a time via
2063 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2064 triggers, while L</update> will not.
2069 my ($self, $values) = @_;
2070 $self->throw_exception('Values for update_all must be a hash')
2071 unless ref $values eq 'HASH';
2073 my $guard = $self->result_source->schema->txn_scope_guard;
2074 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2083 =item Arguments: none
2085 =item Return Value: $underlying_storage_rv
2089 Deletes the rows matching this resultset in a single query. Note that this
2090 will not run any delete triggers, nor will it alter the
2091 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2092 derived from this resultset (this includes the contents of the
2093 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2094 execute any on-delete triggers or cascades defined either by you or a
2095 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2097 The return value is a pass through of what the underlying storage backend
2098 returned, and may vary. See L<DBI/execute> for the most common case.
2104 $self->throw_exception('delete does not accept any arguments')
2107 return $self->_rs_update_delete ('delete');
2114 =item Arguments: none
2116 =item Return Value: 1
2120 Fetches all objects and deletes them one at a time via
2121 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2122 triggers, while L</delete> will not.
2128 $self->throw_exception('delete_all does not accept any arguments')
2131 my $guard = $self->result_source->schema->txn_scope_guard;
2132 $_->delete for $self->all;
2141 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2143 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2147 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2154 The context of this method call has an important effect on what is
2155 submitted to storage. In void context data is fed directly to fastpath
2156 insertion routines provided by the underlying storage (most often
2157 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2158 L<insert|DBIx::Class::Row/insert> calls on the
2159 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2160 augmentation of these methods provided by components. For example if you
2161 are using something like L<DBIx::Class::UUIDColumns> to create primary
2162 keys for you, you will find that your PKs are empty. In this case you
2163 will have to explicitly force scalar or list context in order to create
2168 In non-void (scalar or list) context, this method is simply a wrapper
2169 for L</create>. Depending on list or scalar context either a list of
2170 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2171 containing these objects is returned.
2173 When supplying data in "arrayref of arrayrefs" invocation style, the
2174 first element should be a list of column names and each subsequent
2175 element should be a data value in the earlier specified column order.
2178 $schema->resultset("Artist")->populate([
2179 [ qw( artistid name ) ],
2180 [ 100, 'A Formally Unknown Singer' ],
2181 [ 101, 'A singer that jumped the shark two albums ago' ],
2182 [ 102, 'An actually cool singer' ],
2185 For the arrayref of hashrefs style each hashref should be a structure
2186 suitable for passing to L</create>. Multi-create is also permitted with
2189 $schema->resultset("Artist")->populate([
2190 { artistid => 4, name => 'Manufactured Crap', cds => [
2191 { title => 'My First CD', year => 2006 },
2192 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2195 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2196 { title => 'My parents sold me to a record company', year => 2005 },
2197 { title => 'Why Am I So Ugly?', year => 2006 },
2198 { title => 'I Got Surgery and am now Popular', year => 2007 }
2203 If you attempt a void-context multi-create as in the example above (each
2204 Artist also has the related list of CDs), and B<do not> supply the
2205 necessary autoinc foreign key information, this method will proxy to the
2206 less efficient L</create>, and then throw the Result objects away. In this
2207 case there are obviously no benefits to using this method over L</create>.
2214 # cruft placed in standalone method
2215 my $data = $self->_normalize_populate_args(@_);
2217 return unless @$data;
2219 if(defined wantarray) {
2220 my @created = map { $self->create($_) } @$data;
2221 return wantarray ? @created : \@created;
2224 my $first = $data->[0];
2226 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2227 # it relationship data
2228 my (@rels, @columns);
2229 my $rsrc = $self->result_source;
2230 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2231 for (keys %$first) {
2232 my $ref = ref $first->{$_};
2233 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2239 my @pks = $rsrc->primary_columns;
2241 ## do the belongs_to relationships
2242 foreach my $index (0..$#$data) {
2244 # delegate to create() for any dataset without primary keys with specified relationships
2245 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2247 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2248 my @ret = $self->populate($data);
2254 foreach my $rel (@rels) {
2255 next unless ref $data->[$index]->{$rel} eq "HASH";
2256 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2257 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2258 my $related = $result->result_source->_resolve_condition(
2259 $reverse_relinfo->{cond},
2265 delete $data->[$index]->{$rel};
2266 $data->[$index] = {%{$data->[$index]}, %$related};
2268 push @columns, keys %$related if $index == 0;
2272 ## inherit the data locked in the conditions of the resultset
2273 my ($rs_data) = $self->_merge_with_rscond({});
2274 delete @{$rs_data}{@columns};
2276 ## do bulk insert on current row
2277 $rsrc->storage->insert_bulk(
2279 [@columns, keys %$rs_data],
2280 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2283 ## do the has_many relationships
2284 foreach my $item (@$data) {
2288 foreach my $rel (@rels) {
2289 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2291 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2293 my $child = $main_row->$rel;
2295 my $related = $child->result_source->_resolve_condition(
2296 $rels->{$rel}{cond},
2302 if (ref($related) eq 'REF' and ref($$related) eq 'HASH') {
2303 $related = $self->result_source
2304 ->_extract_fixed_values_for($$related, $rel);
2307 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2308 my @populate = map { {%$_, %$related} } @rows_to_add;
2310 $child->populate( \@populate );
2316 # populate() arguments went over several incarnations
2317 # What we ultimately support is AoH
2318 sub _normalize_populate_args {
2319 my ($self, $arg) = @_;
2321 if (ref $arg eq 'ARRAY') {
2325 elsif (ref $arg->[0] eq 'HASH') {
2328 elsif (ref $arg->[0] eq 'ARRAY') {
2330 my @colnames = @{$arg->[0]};
2331 foreach my $values (@{$arg}[1 .. $#$arg]) {
2332 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2338 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2345 =item Arguments: none
2347 =item Return Value: L<$pager|Data::Page>
2351 Returns a L<Data::Page> object for the current resultset. Only makes
2352 sense for queries with a C<page> attribute.
2354 To get the full count of entries for a paged resultset, call
2355 C<total_entries> on the L<Data::Page> object.
2362 return $self->{pager} if $self->{pager};
2364 my $attrs = $self->{attrs};
2365 if (!defined $attrs->{page}) {
2366 $self->throw_exception("Can't create pager for non-paged rs");
2368 elsif ($attrs->{page} <= 0) {
2369 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2371 $attrs->{rows} ||= 10;
2373 # throw away the paging flags and re-run the count (possibly
2374 # with a subselect) to get the real total count
2375 my $count_attrs = { %$attrs };
2376 delete @{$count_attrs}{qw/rows offset page pager/};
2378 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2380 require DBIx::Class::ResultSet::Pager;
2381 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2382 sub { $total_rs->count }, #lazy-get the total
2384 $self->{attrs}{page},
2392 =item Arguments: $page_number
2394 =item Return Value: L<$resultset|/search>
2398 Returns a resultset for the $page_number page of the resultset on which page
2399 is called, where each page contains a number of rows equal to the 'rows'
2400 attribute set on the resultset (10 by default).
2405 my ($self, $page) = @_;
2406 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2413 =item Arguments: \%col_data
2415 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2419 Creates a new result object in the resultset's result class and returns
2420 it. The row is not inserted into the database at this point, call
2421 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2422 will tell you whether the result object has been inserted or not.
2424 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2429 my ($self, $values) = @_;
2431 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2434 $self->throw_exception( "new_result expects a hashref" )
2435 unless (ref $values eq 'HASH');
2437 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2439 my $new = $self->result_class->new({
2441 ( @$cols_from_relations
2442 ? (-cols_from_relations => $cols_from_relations)
2445 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2449 reftype($new) eq 'HASH'
2455 carp_unique (sprintf (
2456 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2457 $self->result_class,
2464 # _merge_with_rscond
2466 # Takes a simple hash of K/V data and returns its copy merged with the
2467 # condition already present on the resultset. Additionally returns an
2468 # arrayref of value/condition names, which were inferred from related
2469 # objects (this is needed for in-memory related objects)
2470 sub _merge_with_rscond {
2471 my ($self, $data) = @_;
2473 my (%new_data, @cols_from_relations);
2475 my $alias = $self->{attrs}{alias};
2477 if (! defined $self->{cond}) {
2478 # just massage $data below
2480 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2481 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2482 @cols_from_relations = keys %new_data;
2484 elsif (ref $self->{cond} eq 'HASH') {
2485 # precedence must be given to passed values over values inherited from
2486 # the cond, so the order here is important.
2487 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2488 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2490 while ( my($col, $value) = each %implied ) {
2491 my $vref = ref $value;
2497 (keys %$value)[0] eq '='
2499 $new_data{$col} = $value->{'='};
2501 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2502 $new_data{$col} = $value;
2506 elsif (ref $self->{cond} eq 'REF' and ref ${$self->{cond}} eq 'HASH') {
2507 %new_data = %{$self->result_source
2508 ->_extract_fixed_values_for(${$self->{cond}}, $alias)};
2511 $self->throw_exception(
2512 "Can't abstract implicit construct, resultset condition not a hash"
2518 %{ $self->_remove_alias($data, $alias) },
2521 return (\%new_data, \@cols_from_relations);
2524 # _has_resolved_attr
2526 # determines if the resultset defines at least one
2527 # of the attributes supplied
2529 # used to determine if a subquery is necessary
2531 # supports some virtual attributes:
2533 # This will scan for any joins being present on the resultset.
2534 # It is not a mere key-search but a deep inspection of {from}
2537 sub _has_resolved_attr {
2538 my ($self, @attr_names) = @_;
2540 my $attrs = $self->_resolved_attrs;
2544 for my $n (@attr_names) {
2545 if (grep { $n eq $_ } (qw/-join/) ) {
2546 $extra_checks{$n}++;
2550 my $attr = $attrs->{$n};
2552 next if not defined $attr;
2554 if (ref $attr eq 'HASH') {
2555 return 1 if keys %$attr;
2557 elsif (ref $attr eq 'ARRAY') {
2565 # a resolved join is expressed as a multi-level from
2567 $extra_checks{-join}
2569 ref $attrs->{from} eq 'ARRAY'
2571 @{$attrs->{from}} > 1
2579 # Recursively collapse the condition.
2581 sub _collapse_cond {
2582 my ($self, $cond, $collapsed) = @_;
2586 if (ref $cond eq 'ARRAY') {
2587 foreach my $subcond (@$cond) {
2588 next unless ref $subcond; # -or
2589 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2592 elsif (ref $cond eq 'HASH') {
2593 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2594 foreach my $subcond (@{$cond->{-and}}) {
2595 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2599 foreach my $col (keys %$cond) {
2600 my $value = $cond->{$col};
2601 $collapsed->{$col} = $value;
2611 # Remove the specified alias from the specified query hash. A copy is made so
2612 # the original query is not modified.
2615 my ($self, $query, $alias) = @_;
2617 my %orig = %{ $query || {} };
2620 foreach my $key (keys %orig) {
2622 $unaliased{$key} = $orig{$key};
2625 $unaliased{$1} = $orig{$key}
2626 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2636 =item Arguments: none
2638 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2642 Returns the SQL query and bind vars associated with the invocant.
2644 This is generally used as the RHS for a subquery.
2651 my $attrs = { %{ $self->_resolved_attrs } };
2653 my $aq = $self->result_source->storage->_select_args_to_query (
2654 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2657 $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
2664 my $attrs = { %{ $self->_resolved_attrs } };
2665 my $storage = $self->result_source->storage;
2666 my (undef, $ident, @args) = $storage->_select_args(
2667 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2669 $ident = $ident->from if blessed($ident);
2670 $storage->sql_maker->converter->_select_to_dq(
2679 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2681 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2685 my $artist = $schema->resultset('Artist')->find_or_new(
2686 { artist => 'fred' }, { key => 'artists' });
2688 $cd->cd_to_producer->find_or_new({ producer => $producer },
2689 { key => 'primary' });
2691 Find an existing record from this resultset using L</find>. if none exists,
2692 instantiate a new result object and return it. The object will not be saved
2693 into your storage until you call L<DBIx::Class::Row/insert> on it.
2695 You most likely want this method when looking for existing rows using a unique
2696 constraint that is not the primary key, or looking for related rows.
2698 If you want objects to be saved immediately, use L</find_or_create> instead.
2700 B<Note>: Make sure to read the documentation of L</find> and understand the
2701 significance of the C<key> attribute, as its lack may skew your search, and
2702 subsequently result in spurious new objects.
2704 B<Note>: Take care when using C<find_or_new> with a table having
2705 columns with default values that you intend to be automatically
2706 supplied by the database (e.g. an auto_increment primary key column).
2707 In normal usage, the value of such columns should NOT be included at
2708 all in the call to C<find_or_new>, even when set to C<undef>.
2714 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2715 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2716 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2719 return $self->new_result($hash);
2726 =item Arguments: \%col_data
2728 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2732 Attempt to create a single new row or a row with multiple related rows
2733 in the table represented by the resultset (and related tables). This
2734 will not check for duplicate rows before inserting, use
2735 L</find_or_create> to do that.
2737 To create one row for this resultset, pass a hashref of key/value
2738 pairs representing the columns of the table and the values you wish to
2739 store. If the appropriate relationships are set up, foreign key fields
2740 can also be passed an object representing the foreign row, and the
2741 value will be set to its primary key.
2743 To create related objects, pass a hashref of related-object column values
2744 B<keyed on the relationship name>. If the relationship is of type C<multi>
2745 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2746 The process will correctly identify columns holding foreign keys, and will
2747 transparently populate them from the keys of the corresponding relation.
2748 This can be applied recursively, and will work correctly for a structure
2749 with an arbitrary depth and width, as long as the relationships actually
2750 exists and the correct column data has been supplied.
2752 Instead of hashrefs of plain related data (key/value pairs), you may
2753 also pass new or inserted objects. New objects (not inserted yet, see
2754 L</new_result>), will be inserted into their appropriate tables.
2756 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2758 Example of creating a new row.
2760 $person_rs->create({
2761 name=>"Some Person",
2762 email=>"somebody@someplace.com"
2765 Example of creating a new row and also creating rows in a related C<has_many>
2766 or C<has_one> resultset. Note Arrayref.
2769 { artistid => 4, name => 'Manufactured Crap', cds => [
2770 { title => 'My First CD', year => 2006 },
2771 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2776 Example of creating a new row and also creating a row in a related
2777 C<belongs_to> resultset. Note Hashref.
2780 title=>"Music for Silly Walks",
2783 name=>"Silly Musician",
2791 When subclassing ResultSet never attempt to override this method. Since
2792 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2793 lot of the internals simply never call it, so your override will be
2794 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2795 or L<DBIx::Class::Row/insert> depending on how early in the
2796 L</create> process you need to intervene. See also warning pertaining to
2804 my ($self, $col_data) = @_;
2805 $self->throw_exception( "create needs a hashref" )
2806 unless ref $col_data eq 'HASH';
2807 return $self->new_result($col_data)->insert;
2810 =head2 find_or_create
2814 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2816 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2820 $cd->cd_to_producer->find_or_create({ producer => $producer },
2821 { key => 'primary' });
2823 Tries to find a record based on its primary key or unique constraints; if none
2824 is found, creates one and returns that instead.
2826 my $cd = $schema->resultset('CD')->find_or_create({
2828 artist => 'Massive Attack',
2829 title => 'Mezzanine',
2833 Also takes an optional C<key> attribute, to search by a specific key or unique
2834 constraint. For example:
2836 my $cd = $schema->resultset('CD')->find_or_create(
2838 artist => 'Massive Attack',
2839 title => 'Mezzanine',
2841 { key => 'cd_artist_title' }
2844 B<Note>: Make sure to read the documentation of L</find> and understand the
2845 significance of the C<key> attribute, as its lack may skew your search, and
2846 subsequently result in spurious row creation.
2848 B<Note>: Because find_or_create() reads from the database and then
2849 possibly inserts based on the result, this method is subject to a race
2850 condition. Another process could create a record in the table after
2851 the find has completed and before the create has started. To avoid
2852 this problem, use find_or_create() inside a transaction.
2854 B<Note>: Take care when using C<find_or_create> with a table having
2855 columns with default values that you intend to be automatically
2856 supplied by the database (e.g. an auto_increment primary key column).
2857 In normal usage, the value of such columns should NOT be included at
2858 all in the call to C<find_or_create>, even when set to C<undef>.
2860 See also L</find> and L</update_or_create>. For information on how to declare
2861 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2863 If you need to know if an existing row was found or a new one created use
2864 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2865 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2868 my $cd = $schema->resultset('CD')->find_or_new({
2870 artist => 'Massive Attack',
2871 title => 'Mezzanine',
2875 if( !$cd->in_storage ) {
2882 sub find_or_create {
2884 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2885 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2886 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2889 return $self->create($hash);
2892 =head2 update_or_create
2896 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2898 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2902 $resultset->update_or_create({ col => $val, ... });
2904 Like L</find_or_create>, but if a row is found it is immediately updated via
2905 C<< $found_row->update (\%col_data) >>.
2908 Takes an optional C<key> attribute to search on a specific unique constraint.
2911 # In your application
2912 my $cd = $schema->resultset('CD')->update_or_create(
2914 artist => 'Massive Attack',
2915 title => 'Mezzanine',
2918 { key => 'cd_artist_title' }
2921 $cd->cd_to_producer->update_or_create({
2922 producer => $producer,
2928 B<Note>: Make sure to read the documentation of L</find> and understand the
2929 significance of the C<key> attribute, as its lack may skew your search, and
2930 subsequently result in spurious row creation.
2932 B<Note>: Take care when using C<update_or_create> with a table having
2933 columns with default values that you intend to be automatically
2934 supplied by the database (e.g. an auto_increment primary key column).
2935 In normal usage, the value of such columns should NOT be included at
2936 all in the call to C<update_or_create>, even when set to C<undef>.
2938 See also L</find> and L</find_or_create>. For information on how to declare
2939 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2941 If you need to know if an existing row was updated or a new one created use
2942 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2943 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2948 sub update_or_create {
2950 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2951 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2953 my $row = $self->find($cond, $attrs);
2955 $row->update($cond);
2959 return $self->create($cond);
2962 =head2 update_or_new
2966 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2968 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2972 $resultset->update_or_new({ col => $val, ... });
2974 Like L</find_or_new> but if a row is found it is immediately updated via
2975 C<< $found_row->update (\%col_data) >>.
2979 # In your application
2980 my $cd = $schema->resultset('CD')->update_or_new(
2982 artist => 'Massive Attack',
2983 title => 'Mezzanine',
2986 { key => 'cd_artist_title' }
2989 if ($cd->in_storage) {
2990 # the cd was updated
2993 # the cd is not yet in the database, let's insert it
2997 B<Note>: Make sure to read the documentation of L</find> and understand the
2998 significance of the C<key> attribute, as its lack may skew your search, and
2999 subsequently result in spurious new objects.
3001 B<Note>: Take care when using C<update_or_new> with a table having
3002 columns with default values that you intend to be automatically
3003 supplied by the database (e.g. an auto_increment primary key column).
3004 In normal usage, the value of such columns should NOT be included at
3005 all in the call to C<update_or_new>, even when set to C<undef>.
3007 See also L</find>, L</find_or_create> and L</find_or_new>.
3013 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3014 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3016 my $row = $self->find( $cond, $attrs );
3017 if ( defined $row ) {
3018 $row->update($cond);
3022 return $self->new_result($cond);
3029 =item Arguments: none
3031 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3035 Gets the contents of the cache for the resultset, if the cache is set.
3037 The cache is populated either by using the L</prefetch> attribute to
3038 L</search> or by calling L</set_cache>.
3050 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3052 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3056 Sets the contents of the cache for the resultset. Expects an arrayref
3057 of objects of the same class as those produced by the resultset. Note that
3058 if the cache is set, the resultset will return the cached objects rather
3059 than re-querying the database even if the cache attr is not set.
3061 The contents of the cache can also be populated by using the
3062 L</prefetch> attribute to L</search>.
3067 my ( $self, $data ) = @_;
3068 $self->throw_exception("set_cache requires an arrayref")
3069 if defined($data) && (ref $data ne 'ARRAY');
3070 $self->{all_cache} = $data;
3077 =item Arguments: none
3079 =item Return Value: undef
3083 Clears the cache for the resultset.
3088 shift->set_cache(undef);
3095 =item Arguments: none
3097 =item Return Value: true, if the resultset has been paginated
3105 return !!$self->{attrs}{page};
3112 =item Arguments: none
3114 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3122 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3125 =head2 related_resultset
3129 =item Arguments: $rel_name
3131 =item Return Value: L<$resultset|/search>
3135 Returns a related resultset for the supplied relationship name.
3137 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3141 sub related_resultset {
3142 my ($self, $rel) = @_;
3144 return $self->{related_resultsets}{$rel}
3145 if defined $self->{related_resultsets}{$rel};
3147 return $self->{related_resultsets}{$rel} = do {
3148 my $rsrc = $self->result_source;
3149 my $rel_info = $rsrc->relationship_info($rel);
3151 $self->throw_exception(
3152 "search_related: result source '" . $rsrc->source_name .
3153 "' has no such relationship $rel")
3156 my $attrs = $self->_chain_relationship($rel);
3158 my $join_count = $attrs->{seen_join}{$rel};
3160 my $alias = $self->result_source->storage
3161 ->relname_to_table_alias($rel, $join_count);
3163 # since this is search_related, and we already slid the select window inwards
3164 # (the select/as attrs were deleted in the beginning), we need to flip all
3165 # left joins to inner, so we get the expected results
3166 # read the comment on top of the actual function to see what this does
3167 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3170 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3171 delete @{$attrs}{qw(result_class alias)};
3173 my $rel_source = $rsrc->related_source($rel);
3177 # The reason we do this now instead of passing the alias to the
3178 # search_rs below is that if you wrap/overload resultset on the
3179 # source you need to know what alias it's -going- to have for things
3180 # to work sanely (e.g. RestrictWithObject wants to be able to add
3181 # extra query restrictions, and these may need to be $alias.)
3183 my $rel_attrs = $rel_source->resultset_attributes;
3184 local $rel_attrs->{alias} = $alias;
3186 $rel_source->resultset
3190 where => $attrs->{where},
3194 if (my $cache = $self->get_cache) {
3195 my @related_cache = map
3196 { @{$_->related_resultset($rel)->get_cache||[]} }
3200 $new->set_cache(\@related_cache) if @related_cache;
3207 =head2 current_source_alias
3211 =item Arguments: none
3213 =item Return Value: $source_alias
3217 Returns the current table alias for the result source this resultset is built
3218 on, that will be used in the SQL query. Usually it is C<me>.
3220 Currently the source alias that refers to the result set returned by a
3221 L</search>/L</find> family method depends on how you got to the resultset: it's
3222 C<me> by default, but eg. L</search_related> aliases it to the related result
3223 source name (and keeps C<me> referring to the original result set). The long
3224 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3225 (and make this method unnecessary).
3227 Thus it's currently necessary to use this method in predefined queries (see
3228 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3229 source alias of the current result set:
3231 # in a result set class
3233 my ($self, $user) = @_;
3235 my $me = $self->current_source_alias;
3237 return $self->search({
3238 "$me.modified" => $user->id,
3244 sub current_source_alias {
3245 return (shift->{attrs} || {})->{alias} || 'me';
3248 =head2 as_subselect_rs
3252 =item Arguments: none
3254 =item Return Value: L<$resultset|/search>
3258 Act as a barrier to SQL symbols. The resultset provided will be made into a
3259 "virtual view" by including it as a subquery within the from clause. From this
3260 point on, any joined tables are inaccessible to ->search on the resultset (as if
3261 it were simply where-filtered without joins). For example:
3263 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3265 # 'x' now pollutes the query namespace
3267 # So the following works as expected
3268 my $ok_rs = $rs->search({'x.other' => 1});
3270 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3271 # def) we look for one row with contradictory terms and join in another table
3272 # (aliased 'x_2') which we never use
3273 my $broken_rs = $rs->search({'x.name' => 'def'});
3275 my $rs2 = $rs->as_subselect_rs;
3277 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3278 my $not_joined_rs = $rs2->search({'x.other' => 1});
3280 # works as expected: finds a 'table' row related to two x rows (abc and def)
3281 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3283 Another example of when one might use this would be to select a subset of
3284 columns in a group by clause:
3286 my $rs = $schema->resultset('Bar')->search(undef, {
3287 group_by => [qw{ id foo_id baz_id }],
3288 })->as_subselect_rs->search(undef, {
3289 columns => [qw{ id foo_id }]
3292 In the above example normally columns would have to be equal to the group by,
3293 but because we isolated the group by into a subselect the above works.
3297 sub as_subselect_rs {
3300 my $attrs = $self->_resolved_attrs;
3302 my $fresh_rs = (ref $self)->new (
3303 $self->result_source
3306 # these pieces will be locked in the subquery
3307 delete $fresh_rs->{cond};
3308 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3310 return $fresh_rs->search( {}, {
3312 $attrs->{alias} => $self->as_query,
3313 -alias => $attrs->{alias},
3314 -rsrc => $self->result_source,
3316 alias => $attrs->{alias},
3320 # This code is called by search_related, and makes sure there
3321 # is clear separation between the joins before, during, and
3322 # after the relationship. This information is needed later
3323 # in order to properly resolve prefetch aliases (any alias
3324 # with a relation_chain_depth less than the depth of the
3325 # current prefetch is not considered)
3327 # The increments happen twice per join. An even number means a
3328 # relationship specified via a search_related, whereas an odd
3329 # number indicates a join/prefetch added via attributes
3331 # Also this code will wrap the current resultset (the one we
3332 # chain to) in a subselect IFF it contains limiting attributes
3333 sub _chain_relationship {
3334 my ($self, $rel) = @_;
3335 my $source = $self->result_source;
3336 my $attrs = { %{$self->{attrs}||{}} };
3338 # we need to take the prefetch the attrs into account before we
3339 # ->_resolve_join as otherwise they get lost - captainL
3340 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3342 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3344 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3347 my @force_subq_attrs = qw/offset rows group_by having/;
3350 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3352 $self->_has_resolved_attr (@force_subq_attrs)
3354 # Nuke the prefetch (if any) before the new $rs attrs
3355 # are resolved (prefetch is useless - we are wrapping
3356 # a subquery anyway).
3357 my $rs_copy = $self->search;
3358 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3359 $rs_copy->{attrs}{join},
3360 delete $rs_copy->{attrs}{prefetch},
3365 -alias => $attrs->{alias},
3366 $attrs->{alias} => $rs_copy->as_query,
3368 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3369 $seen->{-relation_chain_depth} = 0;
3371 elsif ($attrs->{from}) { #shallow copy suffices
3372 $from = [ @{$attrs->{from}} ];
3377 -alias => $attrs->{alias},
3378 $attrs->{alias} => $source->from,
3382 my $jpath = ($seen->{-relation_chain_depth})
3383 ? $from->[-1][0]{-join_path}
3386 my @requested_joins = $source->_resolve_join(
3393 push @$from, @requested_joins;
3395 $seen->{-relation_chain_depth}++;
3397 # if $self already had a join/prefetch specified on it, the requested
3398 # $rel might very well be already included. What we do in this case
3399 # is effectively a no-op (except that we bump up the chain_depth on
3400 # the join in question so we could tell it *is* the search_related)
3403 # we consider the last one thus reverse
3404 for my $j (reverse @requested_joins) {
3405 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3406 if ($rel eq $last_j) {
3407 $j->[0]{-relation_chain_depth}++;
3413 unless ($already_joined) {
3414 push @$from, $source->_resolve_join(
3422 $seen->{-relation_chain_depth}++;
3424 return {%$attrs, from => $from, seen_join => $seen};
3427 sub _resolved_attrs {
3429 return $self->{_attrs} if $self->{_attrs};
3431 my $attrs = { %{ $self->{attrs} || {} } };
3432 my $source = $self->result_source;
3433 my $alias = $attrs->{alias};
3435 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3436 if $attrs->{collapse} and $attrs->{distinct};
3438 # default selection list
3439 $attrs->{columns} = [ $source->columns ]
3440 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3442 # merge selectors together
3443 for (qw/columns select as/) {
3444 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3445 if $attrs->{$_} or $attrs->{"+$_"};
3448 # disassemble columns
3450 if (my $cols = delete $attrs->{columns}) {
3451 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3452 if (ref $c eq 'HASH') {
3453 for my $as (sort keys %$c) {
3454 push @sel, $c->{$as};
3465 # when trying to weed off duplicates later do not go past this point -
3466 # everything added from here on is unbalanced "anyone's guess" stuff
3467 my $dedup_stop_idx = $#as;
3469 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3471 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3472 if $attrs->{select};
3474 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3475 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3477 # disqualify all $alias.col as-bits (inflate-map mandated)
3478 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3480 # de-duplicate the result (remove *identical* select/as pairs)
3481 # and also die on duplicate {as} pointing to different {select}s
3482 # not using a c-style for as the condition is prone to shrinkage
3485 while ($i <= $dedup_stop_idx) {
3486 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3491 elsif ($seen->{$as[$i]}++) {
3492 $self->throw_exception(
3493 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3501 $attrs->{select} = \@sel;
3502 $attrs->{as} = \@as;
3504 $attrs->{from} ||= [{
3506 -alias => $self->{attrs}{alias},
3507 $self->{attrs}{alias} => $source->from,
3510 if ( $attrs->{join} || $attrs->{prefetch} ) {
3512 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3513 if ref $attrs->{from} ne 'ARRAY';
3515 my $join = (delete $attrs->{join}) || {};
3517 if ( defined $attrs->{prefetch} ) {
3518 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3521 $attrs->{from} = # have to copy here to avoid corrupting the original
3523 @{ $attrs->{from} },
3524 $source->_resolve_join(
3527 { %{ $attrs->{seen_join} || {} } },
3528 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3529 ? $attrs->{from}[-1][0]{-join_path}
3536 if ( defined $attrs->{order_by} ) {
3537 $attrs->{order_by} = (
3538 ref( $attrs->{order_by} ) eq 'ARRAY'
3539 ? [ @{ $attrs->{order_by} } ]
3540 : [ $attrs->{order_by} || () ]
3544 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3545 $attrs->{group_by} = [ $attrs->{group_by} ];
3549 # generate selections based on the prefetch helper
3550 my ($prefetch, @prefetch_select, @prefetch_as);
3551 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3552 if defined $attrs->{prefetch};
3556 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3557 if $attrs->{_dark_selector};
3559 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3560 if defined $attrs->{collapse} and ! $attrs->{collapse};
3562 $attrs->{collapse} = 1;
3564 # this is a separate structure (we don't look in {from} directly)
3565 # as the resolver needs to shift things off the lists to work
3566 # properly (identical-prefetches on different branches)
3568 if (ref $attrs->{from} eq 'ARRAY') {
3570 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3572 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3573 next unless $j->[0]{-alias};
3574 next unless $j->[0]{-join_path};
3575 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3577 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3580 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3581 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3585 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3587 # save these for after distinct resolution
3588 @prefetch_select = map { $_->[0] } @prefetch;
3589 @prefetch_as = map { $_->[1] } @prefetch;
3592 # run through the resulting joinstructure (starting from our current slot)
3593 # and unset collapse if proven unnecessary
3595 # also while we are at it find out if the current root source has
3596 # been premultiplied by previous related_source chaining
3598 # this allows to predict whether a root object with all other relation
3599 # data set to NULL is in fact unique
3600 if ($attrs->{collapse}) {
3602 if (ref $attrs->{from} eq 'ARRAY') {
3604 if (@{$attrs->{from}} == 1) {
3605 # no joins - no collapse
3606 $attrs->{collapse} = 0;
3609 # find where our table-spec starts
3610 my @fromlist = @{$attrs->{from}};
3612 my $t = shift @fromlist;
3615 # me vs join from-spec distinction - a ref means non-root
3616 if (ref $t eq 'ARRAY') {
3618 $is_multi ||= ! $t->{-is_single};
3620 last if ($t->{-alias} && $t->{-alias} eq $alias);
3621 $attrs->{_main_source_premultiplied} ||= $is_multi;
3624 # no non-singles remaining, nor any premultiplication - nothing to collapse
3626 ! $attrs->{_main_source_premultiplied}
3628 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3630 $attrs->{collapse} = 0;
3636 # if we can not analyze the from - err on the side of safety
3637 $attrs->{_main_source_premultiplied} = 1;
3641 # generate the distinct induced group_by before injecting the prefetched select/as parts
3642 if (delete $attrs->{distinct}) {
3643 if ($attrs->{group_by}) {
3644 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3647 $attrs->{_grouped_by_distinct} = 1;
3648 # distinct affects only the main selection part, not what prefetch may add below
3649 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3651 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3652 # The thinking is: if we are collapsing the subquerying prefetch engine will
3653 # rip stuff apart for us anyway, and we do not want to have a potentially
3654 # function-converted external order_by
3655 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3656 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3660 # inject prefetch-bound selection (if any)
3661 push @{$attrs->{select}}, @prefetch_select;
3662 push @{$attrs->{as}}, @prefetch_as;
3664 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3665 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3666 $attrs->{_related_results_construction} = 1;
3669 # if both page and offset are specified, produce a combined offset
3670 # even though it doesn't make much sense, this is what pre 081xx has
3672 if (my $page = delete $attrs->{page}) {
3674 ($attrs->{rows} * ($page - 1))
3676 ($attrs->{offset} || 0)
3680 return $self->{_attrs} = $attrs;
3684 my ($self, $attr) = @_;
3686 if (ref $attr eq 'HASH') {
3687 return $self->_rollout_hash($attr);
3688 } elsif (ref $attr eq 'ARRAY') {
3689 return $self->_rollout_array($attr);
3695 sub _rollout_array {
3696 my ($self, $attr) = @_;
3699 foreach my $element (@{$attr}) {
3700 if (ref $element eq 'HASH') {
3701 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3702 } elsif (ref $element eq 'ARRAY') {
3703 # XXX - should probably recurse here
3704 push( @rolled_array, @{$self->_rollout_array($element)} );
3706 push( @rolled_array, $element );
3709 return \@rolled_array;
3713 my ($self, $attr) = @_;
3716 foreach my $key (keys %{$attr}) {
3717 push( @rolled_array, { $key => $attr->{$key} } );
3719 return \@rolled_array;
3722 sub _calculate_score {
3723 my ($self, $a, $b) = @_;
3725 if (defined $a xor defined $b) {
3728 elsif (not defined $a) {
3732 if (ref $b eq 'HASH') {
3733 my ($b_key) = keys %{$b};
3734 if (ref $a eq 'HASH') {
3735 my ($a_key) = keys %{$a};
3736 if ($a_key eq $b_key) {
3737 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3742 return ($a eq $b_key) ? 1 : 0;
3745 if (ref $a eq 'HASH') {
3746 my ($a_key) = keys %{$a};
3747 return ($b eq $a_key) ? 1 : 0;
3749 return ($b eq $a) ? 1 : 0;
3754 sub _merge_joinpref_attr {
3755 my ($self, $orig, $import) = @_;
3757 return $import unless defined($orig);
3758 return $orig unless defined($import);
3760 $orig = $self->_rollout_attr($orig);
3761 $import = $self->_rollout_attr($import);
3764 foreach my $import_element ( @{$import} ) {
3765 # find best candidate from $orig to merge $b_element into
3766 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3767 foreach my $orig_element ( @{$orig} ) {
3768 my $score = $self->_calculate_score( $orig_element, $import_element );
3769 if ($score > $best_candidate->{score}) {
3770 $best_candidate->{position} = $position;
3771 $best_candidate->{score} = $score;
3775 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3776 $import_key = '' if not defined $import_key;
3778 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3779 push( @{$orig}, $import_element );
3781 my $orig_best = $orig->[$best_candidate->{position}];
3782 # merge orig_best and b_element together and replace original with merged
3783 if (ref $orig_best ne 'HASH') {
3784 $orig->[$best_candidate->{position}] = $import_element;
3785 } elsif (ref $import_element eq 'HASH') {
3786 my ($key) = keys %{$orig_best};
3787 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3790 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3793 return @$orig ? $orig : ();
3801 require Hash::Merge;
3802 my $hm = Hash::Merge->new;
3804 $hm->specify_behavior({
3807 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3809 if ($defl xor $defr) {
3810 return [ $defl ? $_[0] : $_[1] ];
3815 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3819 return [$_[0], $_[1]];
3823 return $_[1] if !defined $_[0];
3824 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3825 return [$_[0], @{$_[1]}]
3828 return [] if !defined $_[0] and !keys %{$_[1]};
3829 return [ $_[1] ] if !defined $_[0];
3830 return [ $_[0] ] if !keys %{$_[1]};
3831 return [$_[0], $_[1]]
3836 return $_[0] if !defined $_[1];
3837 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3838 return [@{$_[0]}, $_[1]]
3841 my @ret = @{$_[0]} or return $_[1];
3842 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3843 my %idx = map { $_ => 1 } @ret;
3844 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3848 return [ $_[1] ] if ! @{$_[0]};
3849 return $_[0] if !keys %{$_[1]};
3850 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3851 return [ @{$_[0]}, $_[1] ];
3856 return [] if !keys %{$_[0]} and !defined $_[1];
3857 return [ $_[0] ] if !defined $_[1];
3858 return [ $_[1] ] if !keys %{$_[0]};
3859 return [$_[0], $_[1]]
3862 return [] if !keys %{$_[0]} and !@{$_[1]};
3863 return [ $_[0] ] if !@{$_[1]};
3864 return $_[1] if !keys %{$_[0]};
3865 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3866 return [ $_[0], @{$_[1]} ];
3869 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3870 return [ $_[0] ] if !keys %{$_[1]};
3871 return [ $_[1] ] if !keys %{$_[0]};
3872 return [ $_[0] ] if $_[0] eq $_[1];
3873 return [ $_[0], $_[1] ];
3876 } => 'DBIC_RS_ATTR_MERGER');
3880 return $hm->merge ($_[1], $_[2]);
3884 sub STORABLE_freeze {
3885 my ($self, $cloning) = @_;
3886 my $to_serialize = { %$self };
3888 # A cursor in progress can't be serialized (and would make little sense anyway)
3889 # the parser can be regenerated (and can't be serialized)
3890 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3892 # nor is it sensical to store a not-yet-fired-count pager
3893 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3894 delete $to_serialize->{pager};
3897 Storable::nfreeze($to_serialize);
3900 # need this hook for symmetry
3902 my ($self, $cloning, $serialized) = @_;
3904 %$self = %{ Storable::thaw($serialized) };
3910 =head2 throw_exception
3912 See L<DBIx::Class::Schema/throw_exception> for details.
3916 sub throw_exception {
3919 if (ref $self and my $rsrc = $self->result_source) {
3920 $rsrc->throw_exception(@_)
3923 DBIx::Class::Exception->throw(@_);
3931 # XXX: FIXME: Attributes docs need clearing up
3935 Attributes are used to refine a ResultSet in various ways when
3936 searching for data. They can be passed to any method which takes an
3937 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3940 Default attributes can be set on the result class using
3941 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3942 the CAVEATS on that feature before using it!)
3944 These are in no particular order:
3950 =item Value: ( $order_by | \@order_by | \%order_by )
3954 Which column(s) to order the results by.
3956 [The full list of suitable values is documented in
3957 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3960 If a single column name, or an arrayref of names is supplied, the
3961 argument is passed through directly to SQL. The hashref syntax allows
3962 for connection-agnostic specification of ordering direction:
3964 For descending order:
3966 order_by => { -desc => [qw/col1 col2 col3/] }
3968 For explicit ascending order:
3970 order_by => { -asc => 'col' }
3972 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3973 supported, although you are strongly encouraged to use the hashref
3974 syntax as outlined above.
3980 =item Value: \@columns | \%columns | $column
3984 Shortcut to request a particular set of columns to be retrieved. Each
3985 column spec may be a string (a table column name), or a hash (in which
3986 case the key is the C<as> value, and the value is used as the C<select>
3987 expression). Adds C<me.> onto the start of any column without a C<.> in
3988 it and sets C<select> from that, then auto-populates C<as> from
3989 C<select> as normal. (You may also use the C<cols> attribute, as in
3990 earlier versions of DBIC, but this is deprecated.)
3992 Essentially C<columns> does the same as L</select> and L</as>.
3994 columns => [ 'foo', { bar => 'baz' } ]
3998 select => [qw/foo baz/],
4005 =item Value: \@columns
4009 Indicates additional columns to be selected from storage. Works the same as
4010 L</columns> but adds columns to the selection. (You may also use the
4011 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4012 deprecated). For example:-
4014 $schema->resultset('CD')->search(undef, {
4015 '+columns' => ['artist.name'],
4019 would return all CDs and include a 'name' column to the information
4020 passed to object inflation. Note that the 'artist' is the name of the
4021 column (or relationship) accessor, and 'name' is the name of the column
4022 accessor in the related table.
4024 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4025 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4026 unary plus operator before it.
4028 =head2 include_columns
4032 =item Value: \@columns
4036 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4042 =item Value: \@select_columns
4046 Indicates which columns should be selected from the storage. You can use
4047 column names, or in the case of RDBMS back ends, function or stored procedure
4050 $rs = $schema->resultset('Employee')->search(undef, {
4053 { count => 'employeeid' },
4054 { max => { length => 'name' }, -as => 'longest_name' }
4059 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4061 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4062 use L</select>, to instruct DBIx::Class how to store the result of the column.
4063 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4064 identifier aliasing. You can however alias a function, so you can use it in
4065 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4066 attribute> supplied as shown in the example above.
4068 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4069 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4070 unary plus operator before it.
4076 Indicates additional columns to be selected from storage. Works the same as
4077 L</select> but adds columns to the default selection, instead of specifying
4086 =item Value: \@inflation_names
4090 Indicates column names for object inflation. That is L</as> indicates the
4091 slot name in which the column value will be stored within the
4092 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4093 identifier by the C<get_column> method (or via the object accessor B<if one
4094 with the same name already exists>) as shown below. The L</as> attribute has
4095 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4097 $rs = $schema->resultset('Employee')->search(undef, {
4100 { count => 'employeeid' },
4101 { max => { length => 'name' }, -as => 'longest_name' }
4110 If the object against which the search is performed already has an accessor
4111 matching a column name specified in C<as>, the value can be retrieved using
4112 the accessor as normal:
4114 my $name = $employee->name();
4116 If on the other hand an accessor does not exist in the object, you need to
4117 use C<get_column> instead:
4119 my $employee_count = $employee->get_column('employee_count');
4121 You can create your own accessors if required - see
4122 L<DBIx::Class::Manual::Cookbook> for details.
4128 Indicates additional column names for those added via L</+select>. See L</as>.
4136 =item Value: ($rel_name | \@rel_names | \%rel_names)
4140 Contains a list of relationships that should be joined for this query. For
4143 # Get CDs by Nine Inch Nails
4144 my $rs = $schema->resultset('CD')->search(
4145 { 'artist.name' => 'Nine Inch Nails' },
4146 { join => 'artist' }
4149 Can also contain a hash reference to refer to the other relation's relations.
4152 package MyApp::Schema::Track;
4153 use base qw/DBIx::Class/;
4154 __PACKAGE__->table('track');
4155 __PACKAGE__->add_columns(qw/trackid cd position title/);
4156 __PACKAGE__->set_primary_key('trackid');
4157 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4160 # In your application
4161 my $rs = $schema->resultset('Artist')->search(
4162 { 'track.title' => 'Teardrop' },
4164 join => { cd => 'track' },
4165 order_by => 'artist.name',
4169 You need to use the relationship (not the table) name in conditions,
4170 because they are aliased as such. The current table is aliased as "me", so
4171 you need to use me.column_name in order to avoid ambiguity. For example:
4173 # Get CDs from 1984 with a 'Foo' track
4174 my $rs = $schema->resultset('CD')->search(
4177 'tracks.name' => 'Foo'
4179 { join => 'tracks' }
4182 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4183 similarly for a third time). For e.g.
4185 my $rs = $schema->resultset('Artist')->search({
4186 'cds.title' => 'Down to Earth',
4187 'cds_2.title' => 'Popular',
4189 join => [ qw/cds cds/ ],
4192 will return a set of all artists that have both a cd with title 'Down
4193 to Earth' and a cd with title 'Popular'.
4195 If you want to fetch related objects from other tables as well, see L</prefetch>
4198 NOTE: An internal join-chain pruner will discard certain joins while
4199 constructing the actual SQL query, as long as the joins in question do not
4200 affect the retrieved result. This for example includes 1:1 left joins
4201 that are not part of the restriction specification (WHERE/HAVING) nor are
4202 a part of the query selection.
4204 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4210 =item Value: (0 | 1)
4214 When set to a true value, indicates that any rows fetched from joined has_many
4215 relationships are to be aggregated into the corresponding "parent" object. For
4216 example, the resultset:
4218 my $rs = $schema->resultset('CD')->search({}, {
4219 '+columns' => [ qw/ tracks.title tracks.position / ],
4224 While executing the following query:
4226 SELECT me.*, tracks.title, tracks.position
4228 LEFT JOIN track tracks
4229 ON tracks.cdid = me.cdid
4231 Will return only as many objects as there are rows in the CD source, even
4232 though the result of the query may span many rows. Each of these CD objects
4233 will in turn have multiple "Track" objects hidden behind the has_many
4234 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4235 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4236 product"), with each CD object containing exactly one of all fetched Track data.
4238 When a collapse is requested on a non-ordered resultset, an order by some
4239 unique part of the main source (the left-most table) is inserted automatically.
4240 This is done so that the resultset is allowed to be "lazy" - calling
4241 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4242 object with all of its related data.
4244 If an L</order_by> is already declared, and orders the resultset in a way that
4245 makes collapsing as described above impossible (e.g. C<< ORDER BY
4246 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4247 switch to "eager" mode and slurp the entire resultset before constructing the
4248 first object returned by L</next>.
4250 Setting this attribute on a resultset that does not join any has_many
4251 relations is a no-op.
4253 For a more in-depth discussion, see L</PREFETCHING>.
4259 =item Value: ($rel_name | \@rel_names | \%rel_names)
4263 This attribute is a shorthand for specifying a L</join> spec, adding all
4264 columns from the joined related sources as L</+columns> and setting
4265 L</collapse> to a true value. For example, the following two queries are
4268 my $rs = $schema->resultset('Artist')->search({}, {
4269 prefetch => { cds => ['genre', 'tracks' ] },
4274 my $rs = $schema->resultset('Artist')->search({}, {
4275 join => { cds => ['genre', 'tracks' ] },
4279 { +{ "cds.$_" => "cds.$_" } }
4280 $schema->source('Artist')->related_source('cds')->columns
4283 { +{ "cds.genre.$_" => "genre.$_" } }
4284 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4287 { +{ "cds.tracks.$_" => "tracks.$_" } }
4288 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4293 Both producing the following SQL:
4295 SELECT me.artistid, me.name, me.rank, me.charfield,
4296 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4297 genre.genreid, genre.name,
4298 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4301 ON cds.artist = me.artistid
4302 LEFT JOIN genre genre
4303 ON genre.genreid = cds.genreid
4304 LEFT JOIN track tracks
4305 ON tracks.cd = cds.cdid
4306 ORDER BY me.artistid
4308 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4309 the arguments are properly merged and generally do the right thing. For
4310 example, you may want to do the following:
4312 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4313 { 'genre.genreid' => undef },
4315 join => { cds => 'genre' },
4320 Which generates the following SQL:
4322 SELECT me.artistid, me.name, me.rank, me.charfield,
4323 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4326 ON cds.artist = me.artistid
4327 LEFT JOIN genre genre
4328 ON genre.genreid = cds.genreid
4329 WHERE genre.genreid IS NULL
4330 ORDER BY me.artistid
4332 For a more in-depth discussion, see L</PREFETCHING>.
4338 =item Value: $source_alias
4342 Sets the source alias for the query. Normally, this defaults to C<me>, but
4343 nested search queries (sub-SELECTs) might need specific aliases set to
4344 reference inner queries. For example:
4347 ->related_resultset('CDs')
4348 ->related_resultset('Tracks')
4350 'track.id' => { -ident => 'none_search.id' },
4354 my $ids = $self->search({
4357 alias => 'none_search',
4358 group_by => 'none_search.id',
4359 })->get_column('id')->as_query;
4361 $self->search({ id => { -in => $ids } })
4363 This attribute is directly tied to L</current_source_alias>.
4373 Makes the resultset paged and specifies the page to retrieve. Effectively
4374 identical to creating a non-pages resultset and then calling ->page($page)
4377 If L</rows> attribute is not specified it defaults to 10 rows per page.
4379 When you have a paged resultset, L</count> will only return the number
4380 of rows in the page. To get the total, use the L</pager> and call
4381 C<total_entries> on it.
4391 Specifies the maximum number of rows for direct retrieval or the number of
4392 rows per page if the page attribute or method is used.
4398 =item Value: $offset
4402 Specifies the (zero-based) row number for the first row to be returned, or the
4403 of the first row of the first page if paging is used.
4405 =head2 software_limit
4409 =item Value: (0 | 1)
4413 When combined with L</rows> and/or L</offset> the generated SQL will not
4414 include any limit dialect stanzas. Instead the entire result will be selected
4415 as if no limits were specified, and DBIC will perform the limit locally, by
4416 artificially advancing and finishing the resulting L</cursor>.
4418 This is the recommended way of performing resultset limiting when no sane RDBMS
4419 implementation is available (e.g.
4420 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4421 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4427 =item Value: \@columns
4431 A arrayref of columns to group by. Can include columns of joined tables.
4433 group_by => [qw/ column1 column2 ... /]
4439 =item Value: $condition
4443 HAVING is a select statement attribute that is applied between GROUP BY and
4444 ORDER BY. It is applied to the after the grouping calculations have been
4447 having => { 'count_employee' => { '>=', 100 } }
4449 or with an in-place function in which case literal SQL is required:
4451 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4457 =item Value: (0 | 1)
4461 Set to 1 to automatically generate a L</group_by> clause based on the selection
4462 (including intelligent handling of L</order_by> contents). Note that the group
4463 criteria calculation takes place over the B<final> selection. This includes
4464 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4465 L</search> calls, and standalone columns selected via
4466 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4467 extra selections specified via L</prefetch> - such selections are explicitly
4468 excluded from group criteria calculations.
4470 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4471 setting is ignored and an appropriate warning is issued.
4477 Adds to the WHERE clause.
4479 # only return rows WHERE deleted IS NULL for all searches
4480 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4482 Can be overridden by passing C<< { where => undef } >> as an attribute
4485 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4491 Set to 1 to cache search results. This prevents extra SQL queries if you
4492 revisit rows in your ResultSet:
4494 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4496 while( my $artist = $resultset->next ) {
4500 $rs->first; # without cache, this would issue a query
4502 By default, searches are not cached.
4504 For more examples of using these attributes, see
4505 L<DBIx::Class::Manual::Cookbook>.
4511 =item Value: ( 'update' | 'shared' | \$scalar )
4515 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4516 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4521 DBIx::Class supports arbitrary related data prefetching from multiple related
4522 sources. Any combination of relationship types and column sets are supported.
4523 If L<collapsing|/collapse> is requested, there is an additional requirement of
4524 selecting enough data to make every individual object uniquely identifiable.
4526 Here are some more involved examples, based on the following relationship map:
4529 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4530 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4531 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4533 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4535 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4539 my $rs = $schema->resultset('Tag')->search(
4548 The initial search results in SQL like the following:
4550 SELECT tag.*, cd.*, artist.* FROM tag
4551 JOIN cd ON tag.cd = cd.cdid
4552 JOIN artist ON cd.artist = artist.artistid
4554 L<DBIx::Class> has no need to go back to the database when we access the
4555 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4558 Simple prefetches will be joined automatically, so there is no need
4559 for a C<join> attribute in the above search.
4561 The L</prefetch> attribute can be used with any of the relationship types
4562 and multiple prefetches can be specified together. Below is a more complex
4563 example that prefetches a CD's artist, its liner notes (if present),
4564 the cover image, the tracks on that CD, and the guests on those
4567 my $rs = $schema->resultset('CD')->search(
4571 { artist => 'record_label'}, # belongs_to => belongs_to
4572 'liner_note', # might_have
4573 'cover_image', # has_one
4574 { tracks => 'guests' }, # has_many => has_many
4579 This will produce SQL like the following:
4581 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4585 ON artist.artistid = me.artistid
4586 JOIN record_label record_label
4587 ON record_label.labelid = artist.labelid
4588 LEFT JOIN track tracks
4589 ON tracks.cdid = me.cdid
4590 LEFT JOIN guest guests
4591 ON guests.trackid = track.trackid
4592 LEFT JOIN liner_notes liner_note
4593 ON liner_note.cdid = me.cdid
4594 JOIN cd_artwork cover_image
4595 ON cover_image.cdid = me.cdid
4598 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4599 C<tracks>, and C<guests> of the CD will all be available through the
4600 relationship accessors without the need for additional queries to the
4605 Prefetch does a lot of deep magic. As such, it may not behave exactly
4606 as you might expect.
4612 Prefetch uses the L</cache> to populate the prefetched relationships. This
4613 may or may not be what you want.
4617 If you specify a condition on a prefetched relationship, ONLY those
4618 rows that match the prefetched condition will be fetched into that relationship.
4619 This means that adding prefetch to a search() B<may alter> what is returned by
4620 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4622 my $artist_rs = $schema->resultset('Artist')->search({
4628 my $count = $artist_rs->first->cds->count;
4630 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4632 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4634 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4636 That cmp_ok() may or may not pass depending on the datasets involved. In other
4637 words the C<WHERE> condition would apply to the entire dataset, just like
4638 it would in regular SQL. If you want to add a condition only to the "right side"
4639 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4640 condition|DBIx::Class::Relationship::Base/condition>
4644 =head1 DBIC BIND VALUES
4646 Because DBIC may need more information to bind values than just the column name
4647 and value itself, it uses a special format for both passing and receiving bind
4648 values. Each bind value should be composed of an arrayref of
4649 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4655 If present (in any form), this is what is being passed directly to bind_param.
4656 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4657 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4659 If this is specified, all other bind options described below are ignored.
4663 If present, this is used to infer the actual bind attribute by passing to
4664 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4665 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4667 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4668 currently drivers are expected to "Do the Right Thing" when given a common
4669 datatype name. (Not ideal, but that's what we got at this point.)
4673 Currently used to correctly allocate buffers for bind_param_inout().
4674 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4675 or to a sensible value based on the "data_type".
4679 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4680 explicitly specified they are never overridden). Also used by some weird DBDs,
4681 where the column name should be available at bind_param time (e.g. Oracle).
4685 For backwards compatibility and convenience, the following shortcuts are
4688 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4689 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4690 [ undef, $val ] === [ {}, $val ]
4691 $val === [ {}, $val ]
4693 =head1 AUTHOR AND CONTRIBUTORS
4695 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4699 You may distribute this code under the same terms as Perl itself.