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, $right;
601 return undef unless @top;
603 my %top = map +(Data::Dumper::Concise::Dumper($_) => $_), @top;
605 return \Operator({ 'SQL.Naive' => 'AND' }, [ values %top ]);
608 =head2 search_literal
610 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
611 should only be used in that context. C<search_literal> is a convenience
612 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
613 want to ensure columns are bound correctly, use L</search>.
615 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
616 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
617 require C<search_literal>.
621 =item Arguments: $sql_fragment, @standalone_bind_values
623 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
627 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
628 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
630 Pass a literal chunk of SQL to be added to the conditional part of the
633 Example of how to use C<search> instead of C<search_literal>
635 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
636 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
641 my ($self, $sql, @bind) = @_;
643 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
646 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
653 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
655 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
659 Finds and returns a single row based on supplied criteria. Takes either a
660 hashref with the same format as L</create> (including inference of foreign
661 keys from related objects), or a list of primary key values in the same
662 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
663 declaration on the L</result_source>.
665 In either case an attempt is made to combine conditions already existing on
666 the resultset with the condition passed to this method.
668 To aid with preparing the correct query for the storage you may supply the
669 C<key> attribute, which is the name of a
670 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
671 unique constraint corresponding to the
672 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
673 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
674 to construct a query that satisfies the named unique constraint fully (
675 non-NULL values for each column member of the constraint) an exception is
678 If no C<key> is specified, the search is carried over all unique constraints
679 which are fully defined by the available condition.
681 If no such constraint is found, C<find> currently defaults to a simple
682 C<< search->(\%column_values) >> which may or may not do what you expect.
683 Note that this fallback behavior may be deprecated in further versions. If
684 you need to search with arbitrary conditions - use L</search>. If the query
685 resulting from this fallback produces more than one row, a warning to the
686 effect is issued, though only the first row is constructed and returned as
689 In addition to C<key>, L</find> recognizes and applies standard
690 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
692 Note that if you have extra concerns about the correctness of the resulting
693 query you need to specify the C<key> attribute and supply the entire condition
694 as an argument to find (since it is not always possible to perform the
695 combination of the resultset condition with the supplied one, especially if
696 the resultset condition contains literal sql).
698 For example, to find a row by its primary key:
700 my $cd = $schema->resultset('CD')->find(5);
702 You can also find a row by a specific unique constraint:
704 my $cd = $schema->resultset('CD')->find(
706 artist => 'Massive Attack',
707 title => 'Mezzanine',
709 { key => 'cd_artist_title' }
712 See also L</find_or_create> and L</update_or_create>.
718 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
720 my $rsrc = $self->result_source;
723 if (exists $attrs->{key}) {
724 $constraint_name = defined $attrs->{key}
726 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
730 # Parse out the condition from input
733 if (ref $_[0] eq 'HASH') {
734 $call_cond = { %{$_[0]} };
737 # if only values are supplied we need to default to 'primary'
738 $constraint_name = 'primary' unless defined $constraint_name;
740 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
742 $self->throw_exception(
743 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
746 $self->throw_exception (
747 'find() expects either a column/value hashref, or a list of values '
748 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
749 ) unless @c_cols == @_;
752 @{$call_cond}{@c_cols} = @_;
756 for my $key (keys %$call_cond) {
758 my $keyref = ref($call_cond->{$key})
760 my $relinfo = $rsrc->relationship_info($key)
762 my $val = delete $call_cond->{$key};
764 next if $keyref eq 'ARRAY'; # has_many for multi_create
766 my $rel_q = $rsrc->_resolve_condition(
767 $relinfo->{cond}, $val, $key, $key
769 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
770 @related{keys %$rel_q} = values %$rel_q;
774 # relationship conditions take precedence (?)
775 @{$call_cond}{keys %related} = values %related;
777 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
779 if (defined $constraint_name) {
780 $final_cond = $self->_qualify_cond_columns (
782 $self->_build_unique_cond (
790 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
791 # This means that we got here after a merger of relationship conditions
792 # in ::Relationship::Base::search_related (the row method), and furthermore
793 # the relationship is of the 'single' type. This means that the condition
794 # provided by the relationship (already attached to $self) is sufficient,
795 # as there can be only one row in the database that would satisfy the
799 # no key was specified - fall down to heuristics mode:
800 # run through all unique queries registered on the resultset, and
801 # 'OR' all qualifying queries together
802 my (@unique_queries, %seen_column_combinations);
803 for my $c_name ($rsrc->unique_constraint_names) {
804 next if $seen_column_combinations{
805 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
808 push @unique_queries, try {
809 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
813 $final_cond = @unique_queries
814 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
815 : $self->_non_unique_find_fallback ($call_cond, $attrs)
819 # Run the query, passing the result_class since it should propagate for find
820 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
821 if ($rs->_resolved_attrs->{collapse}) {
823 carp "Query returned more than one row" if $rs->next;
831 # This is a stop-gap method as agreed during the discussion on find() cleanup:
832 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
834 # It is invoked when find() is called in legacy-mode with insufficiently-unique
835 # condition. It is provided for overrides until a saner way forward is devised
837 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
838 # the road. Please adjust your tests accordingly to catch this situation early
839 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
841 # The method will not be removed without an adequately complete replacement
842 # for strict-mode enforcement
843 sub _non_unique_find_fallback {
844 my ($self, $cond, $attrs) = @_;
846 return $self->_qualify_cond_columns(
848 exists $attrs->{alias}
850 : $self->{attrs}{alias}
855 sub _qualify_cond_columns {
856 my ($self, $cond, $alias) = @_;
858 my %aliased = %$cond;
859 for (keys %aliased) {
860 $aliased{"$alias.$_"} = delete $aliased{$_}
867 sub _build_unique_cond {
868 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
870 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
872 # combination may fail if $self->{cond} is non-trivial
873 my ($final_cond) = try {
874 $self->_merge_with_rscond ($extra_cond)
879 # trim out everything not in $columns
880 $final_cond = { map {
881 exists $final_cond->{$_}
882 ? ( $_ => $final_cond->{$_} )
886 if (my @missing = grep
887 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
890 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
892 join (', ', map { "'$_'" } @missing),
899 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
901 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
903 carp_unique ( sprintf (
904 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
905 . 'values in column(s): %s). This is almost certainly not what you wanted, '
906 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
908 join (', ', map { "'$_'" } @undefs),
915 =head2 search_related
919 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
921 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
925 $new_rs = $cd_rs->search_related('artist', {
929 Searches the specified relationship, optionally specifying a condition and
930 attributes for matching records. See L</ATTRIBUTES> for more information.
932 In list context, C<< ->all() >> is called implicitly on the resultset, thus
933 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
935 See also L</search_related_rs>.
940 return shift->related_resultset(shift)->search(@_);
943 =head2 search_related_rs
945 This method works exactly the same as search_related, except that
946 it guarantees a resultset, even in list context.
950 sub search_related_rs {
951 return shift->related_resultset(shift)->search_rs(@_);
958 =item Arguments: none
960 =item Return Value: L<$cursor|DBIx::Class::Cursor>
964 Returns a storage-driven cursor to the given resultset. See
965 L<DBIx::Class::Cursor> for more information.
972 return $self->{cursor} ||= do {
973 my $attrs = $self->_resolved_attrs;
974 $self->result_source->storage->select(
975 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
984 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
986 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
990 my $cd = $schema->resultset('CD')->single({ year => 2001 });
992 Inflates the first result without creating a cursor if the resultset has
993 any records in it; if not returns C<undef>. Used by L</find> as a lean version
996 While this method can take an optional search condition (just like L</search>)
997 being a fast-code-path it does not recognize search attributes. If you need to
998 add extra joins or similar, call L</search> and then chain-call L</single> on the
999 L<DBIx::Class::ResultSet> returned.
1005 As of 0.08100, this method enforces the assumption that the preceding
1006 query returns only one row. If more than one row is returned, you will receive
1009 Query returned more than one row
1011 In this case, you should be using L</next> or L</find> instead, or if you really
1012 know what you are doing, use the L</rows> attribute to explicitly limit the size
1015 This method will also throw an exception if it is called on a resultset prefetching
1016 has_many, as such a prefetch implies fetching multiple rows from the database in
1017 order to assemble the resulting object.
1024 my ($self, $where) = @_;
1026 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1029 my $attrs = { %{$self->_resolved_attrs} };
1031 $self->throw_exception(
1032 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1033 ) if $attrs->{collapse};
1036 if (defined $attrs->{where}) {
1039 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1040 $where, delete $attrs->{where} ]
1043 $attrs->{where} = $where;
1047 my $data = [ $self->result_source->storage->select_single(
1048 $attrs->{from}, $attrs->{select},
1049 $attrs->{where}, $attrs
1052 return undef unless @$data;
1053 $self->{_stashed_rows} = [ $data ];
1054 $self->_construct_results->[0];
1060 # Recursively collapse the query, accumulating values for each column.
1062 sub _collapse_query {
1063 my ($self, $query, $collapsed) = @_;
1067 if (ref $query eq 'ARRAY') {
1068 foreach my $subquery (@$query) {
1069 next unless ref $subquery; # -or
1070 $collapsed = $self->_collapse_query($subquery, $collapsed);
1073 elsif (ref $query eq 'HASH') {
1074 if (keys %$query and (keys %$query)[0] eq '-and') {
1075 foreach my $subquery (@{$query->{-and}}) {
1076 $collapsed = $self->_collapse_query($subquery, $collapsed);
1080 foreach my $col (keys %$query) {
1081 my $value = $query->{$col};
1082 $collapsed->{$col}{$value}++;
1094 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1096 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1100 my $max_length = $rs->get_column('length')->max;
1102 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1107 my ($self, $column) = @_;
1108 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1116 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1118 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1122 # WHERE title LIKE '%blue%'
1123 $cd_rs = $rs->search_like({ title => '%blue%'});
1125 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1126 that this is simply a convenience method retained for ex Class::DBI users.
1127 You most likely want to use L</search> with specific operators.
1129 For more information, see L<DBIx::Class::Manual::Cookbook>.
1131 This method is deprecated and will be removed in 0.09. Use L</search()>
1132 instead. An example conversion is:
1134 ->search_like({ foo => 'bar' });
1138 ->search({ foo => { like => 'bar' } });
1145 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1146 .' Instead use ->search({ x => { -like => "y%" } })'
1147 .' (note the outer pair of {}s - they are important!)'
1149 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1150 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1151 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1152 return $class->search($query, { %$attrs });
1159 =item Arguments: $first, $last
1161 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1165 Returns a resultset or object list representing a subset of elements from the
1166 resultset slice is called on. Indexes are from 0, i.e., to get the first
1167 three records, call:
1169 my ($one, $two, $three) = $rs->slice(0, 2);
1174 my ($self, $min, $max) = @_;
1175 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1176 $attrs->{offset} = $self->{attrs}{offset} || 0;
1177 $attrs->{offset} += $min;
1178 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1179 return $self->search(undef, $attrs);
1186 =item Arguments: none
1188 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1192 Returns the next element in the resultset (C<undef> is there is none).
1194 Can be used to efficiently iterate over records in the resultset:
1196 my $rs = $schema->resultset('CD')->search;
1197 while (my $cd = $rs->next) {
1201 Note that you need to store the resultset object, and call C<next> on it.
1202 Calling C<< resultset('Table')->next >> repeatedly will always return the
1203 first record from the resultset.
1210 if (my $cache = $self->get_cache) {
1211 $self->{all_cache_position} ||= 0;
1212 return $cache->[$self->{all_cache_position}++];
1215 if ($self->{attrs}{cache}) {
1216 delete $self->{pager};
1217 $self->{all_cache_position} = 1;
1218 return ($self->all)[0];
1221 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1223 $self->{_stashed_results} = $self->_construct_results
1226 return shift @{$self->{_stashed_results}};
1229 # Constructs as many results as it can in one pass while respecting
1230 # cursor laziness. Several modes of operation:
1232 # * Always builds everything present in @{$self->{_stashed_rows}}
1233 # * If called with $fetch_all true - pulls everything off the cursor and
1234 # builds all result structures (or objects) in one pass
1235 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1236 # and if the resultset is ordered properly by the left side:
1237 # * Fetches stuff off the cursor until the "master object" changes,
1238 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1240 # * Just fetches, and collapses/constructs everything as if $fetch_all
1241 # was requested (there is no other way to collapse except for an
1243 # * If no collapse is requested - just get the next row, construct and
1245 sub _construct_results {
1246 my ($self, $fetch_all) = @_;
1248 my $rsrc = $self->result_source;
1249 my $attrs = $self->_resolved_attrs;
1254 ! $attrs->{order_by}
1258 my @pcols = $rsrc->primary_columns
1260 # default order for collapsing unless the user asked for something
1261 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1262 $attrs->{_ordered_for_collapse} = 1;
1263 $attrs->{_order_is_artificial} = 1;
1266 # this will be used as both initial raw-row collector AND as a RV of
1267 # _construct_results. Not regrowing the array twice matters a lot...
1268 # a surprising amount actually
1269 my $rows = delete $self->{_stashed_rows};
1271 my $cursor; # we may not need one at all
1273 my $did_fetch_all = $fetch_all;
1276 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1277 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1279 elsif( $attrs->{collapse} ) {
1281 # a cursor will need to be closed over in case of collapse
1282 $cursor = $self->cursor;
1284 $attrs->{_ordered_for_collapse} = (
1290 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1292 ) unless defined $attrs->{_ordered_for_collapse};
1294 if (! $attrs->{_ordered_for_collapse}) {
1297 # instead of looping over ->next, use ->all in stealth mode
1298 # *without* calling a ->reset afterwards
1299 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1300 if (! $cursor->{_done}) {
1301 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1302 $cursor->{_done} = 1;
1307 if (! $did_fetch_all and ! @{$rows||[]} ) {
1308 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1309 $cursor ||= $self->cursor;
1310 if (scalar (my @r = $cursor->next) ) {
1315 return undef unless @{$rows||[]};
1317 # sanity check - people are too clever for their own good
1318 if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
1320 my $multiplied_selectors;
1321 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1323 $aliastypes->{multiplying}{$sel_alias}
1325 $aliastypes->{premultiplied}{$sel_alias}
1327 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1331 for my $i (0 .. $#{$attrs->{as}} ) {
1332 my $sel = $attrs->{select}[$i];
1334 if (ref $sel eq 'SCALAR') {
1337 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1341 $self->throw_exception(
1342 'Result collapse not possible - selection from a has_many source redirected to the main object'
1343 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1347 # hotspot - skip the setter
1348 my $res_class = $self->_result_class;
1350 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1351 $res_class->can ('inflate_result')
1352 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1355 my $infmap = $attrs->{as};
1357 $self->{_result_inflator}{is_core_row} = ( (
1360 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1361 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1363 $self->{_result_inflator}{is_hri} = ( (
1364 ! $self->{_result_inflator}{is_core_row}
1367 require DBIx::Class::ResultClass::HashRefInflator
1369 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1371 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1374 if (! $attrs->{_related_results_construction}) {
1375 # construct a much simpler array->hash folder for the one-table cases right here
1376 if ($self->{_result_inflator}{is_hri}) {
1377 for my $r (@$rows) {
1378 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1381 # FIXME SUBOPTIMAL this is a very very very hot spot
1382 # while rather optimal we can *still* do much better, by
1383 # building a smarter Row::inflate_result(), and
1384 # switch to feeding it data via a much leaner interface
1386 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1387 # this particular resultset size
1388 elsif (@$rows < 60) {
1389 for my $r (@$rows) {
1390 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1395 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1396 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1402 $self->{_result_inflator}{is_hri} ? 'hri'
1403 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1404 : 'classic_nonpruning'
1407 # $args and $attrs to _mk_row_parser are separated to delineate what is
1408 # core collapser stuff and what is dbic $rs specific
1409 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1411 inflate_map => $infmap,
1412 collapse => $attrs->{collapse},
1413 premultiplied => $attrs->{_main_source_premultiplied},
1414 hri_style => $self->{_result_inflator}{is_hri},
1415 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1416 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1418 # column_info metadata historically hasn't been too reliable.
1419 # We need to start fixing this somehow (the collapse resolver
1420 # can't work without it). Add an explicit check for the *main*
1421 # result, hopefully this will gradually weed out such errors
1423 # FIXME - this is a temporary kludge that reduces performance
1424 # It is however necessary for the time being
1425 my ($unrolled_non_null_cols_to_check, $err);
1427 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1430 'Collapse aborted due to invalid ResultSource metadata - the following '
1431 . 'selections are declared non-nullable but NULLs were retrieved: '
1435 COL: for my $i (@$check_non_null_cols) {
1436 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1439 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1442 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1446 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1447 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1449 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1450 my @r = $cursor->next or return;
1451 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1452 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1458 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1459 my @r = $cursor->next or return;
1464 $self->{_row_parser}{$parser_type}{cref}->(
1466 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1469 # Special-case multi-object HRI - there is no $inflator_cref pass
1470 unless ($self->{_result_inflator}{is_hri}) {
1471 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1475 # The @$rows check seems odd at first - why wouldn't we want to warn
1476 # regardless? The issue is things like find() etc, where the user
1477 # *knows* only one result will come back. In these cases the ->all
1478 # is not a pessimization, but rather something we actually want
1480 'Unable to properly collapse has_many results in iterator mode due '
1481 . 'to order criteria - performed an eager cursor slurp underneath. '
1482 . 'Consider using ->all() instead'
1483 ) if ( ! $fetch_all and @$rows > 1 );
1488 =head2 result_source
1492 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1494 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1498 An accessor for the primary ResultSource object from which this ResultSet
1505 =item Arguments: $result_class?
1507 =item Return Value: $result_class
1511 An accessor for the class to use when creating result objects. Defaults to
1512 C<< result_source->result_class >> - which in most cases is the name of the
1513 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1515 Note that changing the result_class will also remove any components
1516 that were originally loaded in the source class via
1517 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1518 in the original source class will not run.
1523 my ($self, $result_class) = @_;
1524 if ($result_class) {
1526 # don't fire this for an object
1527 $self->ensure_class_loaded($result_class)
1528 unless ref($result_class);
1530 if ($self->get_cache) {
1531 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1533 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1534 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1535 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1538 $self->_result_class($result_class);
1540 delete $self->{_result_inflator};
1542 $self->_result_class;
1549 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1551 =item Return Value: $count
1555 Performs an SQL C<COUNT> with the same query as the resultset was built
1556 with to find the number of elements. Passing arguments is equivalent to
1557 C<< $rs->search ($cond, \%attrs)->count >>
1563 return $self->search(@_)->count if @_ and defined $_[0];
1564 return scalar @{ $self->get_cache } if $self->get_cache;
1566 my $attrs = { %{ $self->_resolved_attrs } };
1568 # this is a little optimization - it is faster to do the limit
1569 # adjustments in software, instead of a subquery
1570 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1573 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1574 $crs = $self->_count_subq_rs ($attrs);
1577 $crs = $self->_count_rs ($attrs);
1579 my $count = $crs->next;
1581 $count -= $offset if $offset;
1582 $count = $rows if $rows and $rows < $count;
1583 $count = 0 if ($count < 0);
1592 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1594 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1598 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1599 This can be very handy for subqueries:
1601 ->search( { amount => $some_rs->count_rs->as_query } )
1603 As with regular resultsets the SQL query will be executed only after
1604 the resultset is accessed via L</next> or L</all>. That would return
1605 the same single value obtainable via L</count>.
1611 return $self->search(@_)->count_rs if @_;
1613 # this may look like a lack of abstraction (count() does about the same)
1614 # but in fact an _rs *must* use a subquery for the limits, as the
1615 # software based limiting can not be ported if this $rs is to be used
1616 # in a subquery itself (i.e. ->as_query)
1617 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1618 return $self->_count_subq_rs($self->{_attrs});
1621 return $self->_count_rs($self->{_attrs});
1626 # returns a ResultSetColumn object tied to the count query
1629 my ($self, $attrs) = @_;
1631 my $rsrc = $self->result_source;
1633 my $tmp_attrs = { %$attrs };
1634 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1635 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1637 # overwrite the selector (supplied by the storage)
1638 $rsrc->resultset_class->new($rsrc, {
1640 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1642 })->get_column ('count');
1646 # same as above but uses a subquery
1648 sub _count_subq_rs {
1649 my ($self, $attrs) = @_;
1651 my $rsrc = $self->result_source;
1653 my $sub_attrs = { %$attrs };
1654 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1655 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1657 # if we multi-prefetch we group_by something unique, as this is what we would
1658 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1659 if ( $attrs->{collapse} ) {
1660 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1661 $rsrc->_identifying_column_set || $self->throw_exception(
1662 'Unable to construct a unique group_by criteria properly collapsing the '
1663 . 'has_many prefetch before count()'
1668 # Calculate subquery selector
1669 if (my $g = $sub_attrs->{group_by}) {
1671 my $sql_maker = $rsrc->storage->sql_maker;
1673 # necessary as the group_by may refer to aliased functions
1675 for my $sel (@{$attrs->{select}}) {
1676 $sel_index->{$sel->{-as}} = $sel
1677 if (ref $sel eq 'HASH' and $sel->{-as});
1680 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1681 # also look for named aggregates referred in the having clause
1682 # having often contains scalarrefs - thus parse it out entirely
1684 if ($attrs->{having}) {
1685 local $sql_maker->{having_bind};
1686 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1687 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1688 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1689 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1690 # if we don't unset it we screw up retarded but unfortunately working
1691 # 'MAX(foo.bar)' => { '>', 3 }
1692 $sql_maker->{name_sep} = '';
1695 $sql_maker->clear_renderer;
1696 $sql_maker->clear_converter;
1698 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1700 my $having_sql = $sql_maker->_render_sqla(where => $attrs->{having});
1702 $sql_maker->clear_renderer;
1703 $sql_maker->clear_converter;
1707 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1708 # and if all fails for an utterly naive quoted scalar-with-function
1709 while ($having_sql =~ /
1710 (?: $rquote $sep)? $lquote (.+?) $rquote
1712 [\s,] \w+ \. (\w+) [\s,]
1714 [\s,] $lquote (.+?) $rquote [\s,]
1716 my $part = $1 || $2 || $3; # one of them matched if we got here
1717 unless ($seen_having{$part}++) {
1724 my $colpiece = $sel_index->{$_} || $_;
1726 # unqualify join-based group_by's. Arcane but possible query
1727 # also horrible horrible hack to alias a column (not a func.)
1728 # (probably need to introduce SQLA syntax)
1729 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1732 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1734 push @{$sub_attrs->{select}}, $colpiece;
1738 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1739 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1742 return $rsrc->resultset_class
1743 ->new ($rsrc, $sub_attrs)
1745 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1746 ->get_column ('count');
1750 =head2 count_literal
1752 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1753 should only be used in that context. See L</search_literal> for further info.
1757 =item Arguments: $sql_fragment, @standalone_bind_values
1759 =item Return Value: $count
1763 Counts the results in a literal query. Equivalent to calling L</search_literal>
1764 with the passed arguments, then L</count>.
1768 sub count_literal { shift->search_literal(@_)->count; }
1774 =item Arguments: none
1776 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1780 Returns all elements in the resultset.
1787 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1790 delete @{$self}{qw/_stashed_rows _stashed_results/};
1792 if (my $c = $self->get_cache) {
1796 $self->cursor->reset;
1798 my $objs = $self->_construct_results('fetch_all') || [];
1800 $self->set_cache($objs) if $self->{attrs}{cache};
1809 =item Arguments: none
1811 =item Return Value: $self
1815 Resets the resultset's cursor, so you can iterate through the elements again.
1816 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1824 delete @{$self}{qw/_stashed_rows _stashed_results/};
1825 $self->{all_cache_position} = 0;
1826 $self->cursor->reset;
1834 =item Arguments: none
1836 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1840 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1841 an object for the first result (or C<undef> if the resultset is empty).
1846 return $_[0]->reset->next;
1852 # Determines whether and what type of subquery is required for the $rs operation.
1853 # If grouping is necessary either supplies its own, or verifies the current one
1854 # After all is done delegates to the proper storage method.
1856 sub _rs_update_delete {
1857 my ($self, $op, $values) = @_;
1859 my $rsrc = $self->result_source;
1860 my $storage = $rsrc->schema->storage;
1862 my $attrs = { %{$self->_resolved_attrs} };
1864 my $join_classifications;
1865 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1867 # do we need a subquery for any reason?
1869 defined $existing_group_by
1871 # if {from} is unparseable wrap a subq
1872 ref($attrs->{from}) ne 'ARRAY'
1874 # limits call for a subq
1875 $self->_has_resolved_attr(qw/rows offset/)
1878 # simplify the joinmap, so we can further decide if a subq is necessary
1879 if (!$needs_subq and @{$attrs->{from}} > 1) {
1881 ($attrs->{from}, $join_classifications) =
1882 $storage->_prune_unused_joins ($attrs);
1884 # any non-pruneable non-local restricting joins imply subq
1885 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1888 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1890 (ref $attrs->{from}[0]) ne 'HASH'
1892 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1896 # do we need anything like a subquery?
1897 if (! $needs_subq) {
1898 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1899 # a condition containing 'me' or other table prefixes will not work
1900 # at all - so we convert the WHERE to a dq tree now, dequalify all
1901 # identifiers found therein via a scan across the tree, and then use
1902 # \{} style to pass the result onwards for use in the final query
1903 if ($self->{cond}) {
1905 my $converter = $rsrc->storage->sql_maker->converter;
1907 DQ_IDENTIFIER ,=> sub { $_ = [ $_->[-1] ] for $_[0]->{elements} }
1908 }, my $where_dq = $converter->_where_to_dq($self->{cond}));
1914 # we got this far - means it is time to wrap a subquery
1915 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1917 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1923 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1924 delete $attrs->{$_} for qw/select as collapse/;
1925 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1927 # this will be consumed by the pruner waaaaay down the stack
1928 $attrs->{_force_prune_multiplying_joins} = 1;
1930 my $subrs = (ref $self)->new($rsrc, $attrs);
1932 if (@$idcols == 1) {
1933 $cond = { $idcols->[0] => { -in => \$subrs->_as_select_dq } };
1935 elsif ($storage->_use_multicolumn_in) {
1936 # no syntax for calling this properly yet
1937 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1938 my $left = $storage->sql_maker->_render_sqla(select_select => $idcols);
1939 $left =~ s/^SELECT //i;
1940 my $right = $storage->sql_maker
1942 ->_literal_to_dq(${$subrs->as_query});
1944 { 'SQL.Naive' => 'in' },
1945 [ Literal(SQL => "( $left )"), $right ],
1949 # if all else fails - get all primary keys and operate over a ORed set
1950 # wrap in a transaction for consistency
1951 # this is where the group_by/multiplication starts to matter
1955 # we do not need to check pre-multipliers, since if the premulti is there, its
1956 # parent (who is multi) will be there too
1957 keys %{ $join_classifications->{multiplying} || {} }
1959 # make sure if there is a supplied group_by it matches the columns compiled above
1960 # perfectly. Anything else can not be sanely executed on most databases so croak
1961 # right then and there
1962 if ($existing_group_by) {
1963 my @current_group_by = map
1964 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1969 join ("\x00", sort @current_group_by)
1971 join ("\x00", sort @{$attrs->{columns}} )
1973 $self->throw_exception (
1974 "You have just attempted a $op operation on a resultset which does group_by"
1975 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1976 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1977 . ' kind of queries. Please retry the operation with a modified group_by or'
1978 . ' without using one at all.'
1983 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1986 $guard = $storage->txn_scope_guard;
1989 for my $row ($subrs->cursor->all) {
1991 { $idcols->[$_] => $row->[$_] }
1998 my $res = $storage->$op (
2000 $op eq 'update' ? $values : (),
2004 $guard->commit if $guard;
2013 =item Arguments: \%values
2015 =item Return Value: $underlying_storage_rv
2019 Sets the specified columns in the resultset to the supplied values in a
2020 single query. Note that this will not run any accessor/set_column/update
2021 triggers, nor will it update any result object instances derived from this
2022 resultset (this includes the contents of the L<resultset cache|/set_cache>
2023 if any). See L</update_all> if you need to execute any on-update
2024 triggers or cascades defined either by you or a
2025 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2027 The return value is a pass through of what the underlying
2028 storage backend returned, and may vary. See L<DBI/execute> for the most
2033 Note that L</update> does not process/deflate any of the values passed in.
2034 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2035 ensure manually that any value passed to this method will stringify to
2036 something the RDBMS knows how to deal with. A notable example is the
2037 handling of L<DateTime> objects, for more info see:
2038 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2043 my ($self, $values) = @_;
2044 $self->throw_exception('Values for update must be a hash')
2045 unless ref $values eq 'HASH';
2047 return $self->_rs_update_delete ('update', $values);
2054 =item Arguments: \%values
2056 =item Return Value: 1
2060 Fetches all objects and updates them one at a time via
2061 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2062 triggers, while L</update> will not.
2067 my ($self, $values) = @_;
2068 $self->throw_exception('Values for update_all must be a hash')
2069 unless ref $values eq 'HASH';
2071 my $guard = $self->result_source->schema->txn_scope_guard;
2072 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2081 =item Arguments: none
2083 =item Return Value: $underlying_storage_rv
2087 Deletes the rows matching this resultset in a single query. Note that this
2088 will not run any delete triggers, nor will it alter the
2089 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2090 derived from this resultset (this includes the contents of the
2091 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2092 execute any on-delete triggers or cascades defined either by you or a
2093 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2095 The return value is a pass through of what the underlying storage backend
2096 returned, and may vary. See L<DBI/execute> for the most common case.
2102 $self->throw_exception('delete does not accept any arguments')
2105 return $self->_rs_update_delete ('delete');
2112 =item Arguments: none
2114 =item Return Value: 1
2118 Fetches all objects and deletes them one at a time via
2119 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2120 triggers, while L</delete> will not.
2126 $self->throw_exception('delete_all does not accept any arguments')
2129 my $guard = $self->result_source->schema->txn_scope_guard;
2130 $_->delete for $self->all;
2139 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2141 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2145 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2152 The context of this method call has an important effect on what is
2153 submitted to storage. In void context data is fed directly to fastpath
2154 insertion routines provided by the underlying storage (most often
2155 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2156 L<insert|DBIx::Class::Row/insert> calls on the
2157 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2158 augmentation of these methods provided by components. For example if you
2159 are using something like L<DBIx::Class::UUIDColumns> to create primary
2160 keys for you, you will find that your PKs are empty. In this case you
2161 will have to explicitly force scalar or list context in order to create
2166 In non-void (scalar or list) context, this method is simply a wrapper
2167 for L</create>. Depending on list or scalar context either a list of
2168 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2169 containing these objects is returned.
2171 When supplying data in "arrayref of arrayrefs" invocation style, the
2172 first element should be a list of column names and each subsequent
2173 element should be a data value in the earlier specified column order.
2176 $schema->resultset("Artist")->populate([
2177 [ qw( artistid name ) ],
2178 [ 100, 'A Formally Unknown Singer' ],
2179 [ 101, 'A singer that jumped the shark two albums ago' ],
2180 [ 102, 'An actually cool singer' ],
2183 For the arrayref of hashrefs style each hashref should be a structure
2184 suitable for passing to L</create>. Multi-create is also permitted with
2187 $schema->resultset("Artist")->populate([
2188 { artistid => 4, name => 'Manufactured Crap', cds => [
2189 { title => 'My First CD', year => 2006 },
2190 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2193 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2194 { title => 'My parents sold me to a record company', year => 2005 },
2195 { title => 'Why Am I So Ugly?', year => 2006 },
2196 { title => 'I Got Surgery and am now Popular', year => 2007 }
2201 If you attempt a void-context multi-create as in the example above (each
2202 Artist also has the related list of CDs), and B<do not> supply the
2203 necessary autoinc foreign key information, this method will proxy to the
2204 less efficient L</create>, and then throw the Result objects away. In this
2205 case there are obviously no benefits to using this method over L</create>.
2212 # cruft placed in standalone method
2213 my $data = $self->_normalize_populate_args(@_);
2215 return unless @$data;
2217 if(defined wantarray) {
2218 my @created = map { $self->create($_) } @$data;
2219 return wantarray ? @created : \@created;
2222 my $first = $data->[0];
2224 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2225 # it relationship data
2226 my (@rels, @columns);
2227 my $rsrc = $self->result_source;
2228 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2229 for (keys %$first) {
2230 my $ref = ref $first->{$_};
2231 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2237 my @pks = $rsrc->primary_columns;
2239 ## do the belongs_to relationships
2240 foreach my $index (0..$#$data) {
2242 # delegate to create() for any dataset without primary keys with specified relationships
2243 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2245 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2246 my @ret = $self->populate($data);
2252 foreach my $rel (@rels) {
2253 next unless ref $data->[$index]->{$rel} eq "HASH";
2254 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2255 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2256 my $related = $result->result_source->_resolve_condition(
2257 $reverse_relinfo->{cond},
2263 delete $data->[$index]->{$rel};
2264 $data->[$index] = {%{$data->[$index]}, %$related};
2266 push @columns, keys %$related if $index == 0;
2270 ## inherit the data locked in the conditions of the resultset
2271 my ($rs_data) = $self->_merge_with_rscond({});
2272 delete @{$rs_data}{@columns};
2274 ## do bulk insert on current row
2275 $rsrc->storage->insert_bulk(
2277 [@columns, keys %$rs_data],
2278 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2281 ## do the has_many relationships
2282 foreach my $item (@$data) {
2286 foreach my $rel (@rels) {
2287 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2289 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2291 my $child = $main_row->$rel;
2293 my $related = $child->result_source->_resolve_condition(
2294 $rels->{$rel}{cond},
2300 if (ref($related) eq 'REF' and ref($$related) eq 'HASH') {
2301 $related = $self->result_source
2302 ->_extract_fixed_values_for($$related, $rel);
2305 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2306 my @populate = map { {%$_, %$related} } @rows_to_add;
2308 $child->populate( \@populate );
2314 # populate() arguments went over several incarnations
2315 # What we ultimately support is AoH
2316 sub _normalize_populate_args {
2317 my ($self, $arg) = @_;
2319 if (ref $arg eq 'ARRAY') {
2323 elsif (ref $arg->[0] eq 'HASH') {
2326 elsif (ref $arg->[0] eq 'ARRAY') {
2328 my @colnames = @{$arg->[0]};
2329 foreach my $values (@{$arg}[1 .. $#$arg]) {
2330 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2336 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2343 =item Arguments: none
2345 =item Return Value: L<$pager|Data::Page>
2349 Returns a L<Data::Page> object for the current resultset. Only makes
2350 sense for queries with a C<page> attribute.
2352 To get the full count of entries for a paged resultset, call
2353 C<total_entries> on the L<Data::Page> object.
2360 return $self->{pager} if $self->{pager};
2362 my $attrs = $self->{attrs};
2363 if (!defined $attrs->{page}) {
2364 $self->throw_exception("Can't create pager for non-paged rs");
2366 elsif ($attrs->{page} <= 0) {
2367 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2369 $attrs->{rows} ||= 10;
2371 # throw away the paging flags and re-run the count (possibly
2372 # with a subselect) to get the real total count
2373 my $count_attrs = { %$attrs };
2374 delete @{$count_attrs}{qw/rows offset page pager/};
2376 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2378 require DBIx::Class::ResultSet::Pager;
2379 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2380 sub { $total_rs->count }, #lazy-get the total
2382 $self->{attrs}{page},
2390 =item Arguments: $page_number
2392 =item Return Value: L<$resultset|/search>
2396 Returns a resultset for the $page_number page of the resultset on which page
2397 is called, where each page contains a number of rows equal to the 'rows'
2398 attribute set on the resultset (10 by default).
2403 my ($self, $page) = @_;
2404 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2411 =item Arguments: \%col_data
2413 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2417 Creates a new result object in the resultset's result class and returns
2418 it. The row is not inserted into the database at this point, call
2419 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2420 will tell you whether the result object has been inserted or not.
2422 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2427 my ($self, $values) = @_;
2429 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2432 $self->throw_exception( "new_result expects a hashref" )
2433 unless (ref $values eq 'HASH');
2435 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2437 my $new = $self->result_class->new({
2439 ( @$cols_from_relations
2440 ? (-cols_from_relations => $cols_from_relations)
2443 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2447 reftype($new) eq 'HASH'
2453 carp_unique (sprintf (
2454 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2455 $self->result_class,
2462 # _merge_with_rscond
2464 # Takes a simple hash of K/V data and returns its copy merged with the
2465 # condition already present on the resultset. Additionally returns an
2466 # arrayref of value/condition names, which were inferred from related
2467 # objects (this is needed for in-memory related objects)
2468 sub _merge_with_rscond {
2469 my ($self, $data) = @_;
2471 my (%new_data, @cols_from_relations);
2473 my $alias = $self->{attrs}{alias};
2475 if (! defined $self->{cond}) {
2476 # just massage $data below
2478 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2479 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2480 @cols_from_relations = keys %new_data;
2482 elsif (ref $self->{cond} eq 'HASH') {
2483 # precedence must be given to passed values over values inherited from
2484 # the cond, so the order here is important.
2485 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2486 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2488 while ( my($col, $value) = each %implied ) {
2489 my $vref = ref $value;
2495 (keys %$value)[0] eq '='
2497 $new_data{$col} = $value->{'='};
2499 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2500 $new_data{$col} = $value;
2504 elsif (ref $self->{cond} eq 'REF' and ref ${$self->{cond}} eq 'HASH') {
2505 %new_data = %{$self->result_source
2506 ->_extract_fixed_values_for(${$self->{cond}}, $alias)};
2509 $self->throw_exception(
2510 "Can't abstract implicit construct, resultset condition not a hash"
2516 %{ $self->_remove_alias($data, $alias) },
2519 return (\%new_data, \@cols_from_relations);
2522 # _has_resolved_attr
2524 # determines if the resultset defines at least one
2525 # of the attributes supplied
2527 # used to determine if a subquery is necessary
2529 # supports some virtual attributes:
2531 # This will scan for any joins being present on the resultset.
2532 # It is not a mere key-search but a deep inspection of {from}
2535 sub _has_resolved_attr {
2536 my ($self, @attr_names) = @_;
2538 my $attrs = $self->_resolved_attrs;
2542 for my $n (@attr_names) {
2543 if (grep { $n eq $_ } (qw/-join/) ) {
2544 $extra_checks{$n}++;
2548 my $attr = $attrs->{$n};
2550 next if not defined $attr;
2552 if (ref $attr eq 'HASH') {
2553 return 1 if keys %$attr;
2555 elsif (ref $attr eq 'ARRAY') {
2563 # a resolved join is expressed as a multi-level from
2565 $extra_checks{-join}
2567 ref $attrs->{from} eq 'ARRAY'
2569 @{$attrs->{from}} > 1
2577 # Recursively collapse the condition.
2579 sub _collapse_cond {
2580 my ($self, $cond, $collapsed) = @_;
2584 if (ref $cond eq 'ARRAY') {
2585 foreach my $subcond (@$cond) {
2586 next unless ref $subcond; # -or
2587 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2590 elsif (ref $cond eq 'HASH') {
2591 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2592 foreach my $subcond (@{$cond->{-and}}) {
2593 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2597 foreach my $col (keys %$cond) {
2598 my $value = $cond->{$col};
2599 $collapsed->{$col} = $value;
2609 # Remove the specified alias from the specified query hash. A copy is made so
2610 # the original query is not modified.
2613 my ($self, $query, $alias) = @_;
2615 my %orig = %{ $query || {} };
2618 foreach my $key (keys %orig) {
2620 $unaliased{$key} = $orig{$key};
2623 $unaliased{$1} = $orig{$key}
2624 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2634 =item Arguments: none
2636 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2640 Returns the SQL query and bind vars associated with the invocant.
2642 This is generally used as the RHS for a subquery.
2649 my $attrs = { %{ $self->_resolved_attrs } };
2651 my $aq = $self->result_source->storage->_select_args_to_query (
2652 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2655 $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
2662 my $attrs = { %{ $self->_resolved_attrs } };
2663 my $storage = $self->result_source->storage;
2664 my (undef, $ident, @args) = $storage->_select_args(
2665 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2667 $ident = $ident->from if blessed($ident);
2668 $storage->sql_maker->converter->_select_to_dq(
2677 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2679 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2683 my $artist = $schema->resultset('Artist')->find_or_new(
2684 { artist => 'fred' }, { key => 'artists' });
2686 $cd->cd_to_producer->find_or_new({ producer => $producer },
2687 { key => 'primary' });
2689 Find an existing record from this resultset using L</find>. if none exists,
2690 instantiate a new result object and return it. The object will not be saved
2691 into your storage until you call L<DBIx::Class::Row/insert> on it.
2693 You most likely want this method when looking for existing rows using a unique
2694 constraint that is not the primary key, or looking for related rows.
2696 If you want objects to be saved immediately, use L</find_or_create> instead.
2698 B<Note>: Make sure to read the documentation of L</find> and understand the
2699 significance of the C<key> attribute, as its lack may skew your search, and
2700 subsequently result in spurious new objects.
2702 B<Note>: Take care when using C<find_or_new> with a table having
2703 columns with default values that you intend to be automatically
2704 supplied by the database (e.g. an auto_increment primary key column).
2705 In normal usage, the value of such columns should NOT be included at
2706 all in the call to C<find_or_new>, even when set to C<undef>.
2712 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2713 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2714 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2717 return $self->new_result($hash);
2724 =item Arguments: \%col_data
2726 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2730 Attempt to create a single new row or a row with multiple related rows
2731 in the table represented by the resultset (and related tables). This
2732 will not check for duplicate rows before inserting, use
2733 L</find_or_create> to do that.
2735 To create one row for this resultset, pass a hashref of key/value
2736 pairs representing the columns of the table and the values you wish to
2737 store. If the appropriate relationships are set up, foreign key fields
2738 can also be passed an object representing the foreign row, and the
2739 value will be set to its primary key.
2741 To create related objects, pass a hashref of related-object column values
2742 B<keyed on the relationship name>. If the relationship is of type C<multi>
2743 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2744 The process will correctly identify columns holding foreign keys, and will
2745 transparently populate them from the keys of the corresponding relation.
2746 This can be applied recursively, and will work correctly for a structure
2747 with an arbitrary depth and width, as long as the relationships actually
2748 exists and the correct column data has been supplied.
2750 Instead of hashrefs of plain related data (key/value pairs), you may
2751 also pass new or inserted objects. New objects (not inserted yet, see
2752 L</new_result>), will be inserted into their appropriate tables.
2754 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2756 Example of creating a new row.
2758 $person_rs->create({
2759 name=>"Some Person",
2760 email=>"somebody@someplace.com"
2763 Example of creating a new row and also creating rows in a related C<has_many>
2764 or C<has_one> resultset. Note Arrayref.
2767 { artistid => 4, name => 'Manufactured Crap', cds => [
2768 { title => 'My First CD', year => 2006 },
2769 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2774 Example of creating a new row and also creating a row in a related
2775 C<belongs_to> resultset. Note Hashref.
2778 title=>"Music for Silly Walks",
2781 name=>"Silly Musician",
2789 When subclassing ResultSet never attempt to override this method. Since
2790 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2791 lot of the internals simply never call it, so your override will be
2792 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2793 or L<DBIx::Class::Row/insert> depending on how early in the
2794 L</create> process you need to intervene. See also warning pertaining to
2802 my ($self, $col_data) = @_;
2803 $self->throw_exception( "create needs a hashref" )
2804 unless ref $col_data eq 'HASH';
2805 return $self->new_result($col_data)->insert;
2808 =head2 find_or_create
2812 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2814 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2818 $cd->cd_to_producer->find_or_create({ producer => $producer },
2819 { key => 'primary' });
2821 Tries to find a record based on its primary key or unique constraints; if none
2822 is found, creates one and returns that instead.
2824 my $cd = $schema->resultset('CD')->find_or_create({
2826 artist => 'Massive Attack',
2827 title => 'Mezzanine',
2831 Also takes an optional C<key> attribute, to search by a specific key or unique
2832 constraint. For example:
2834 my $cd = $schema->resultset('CD')->find_or_create(
2836 artist => 'Massive Attack',
2837 title => 'Mezzanine',
2839 { key => 'cd_artist_title' }
2842 B<Note>: Make sure to read the documentation of L</find> and understand the
2843 significance of the C<key> attribute, as its lack may skew your search, and
2844 subsequently result in spurious row creation.
2846 B<Note>: Because find_or_create() reads from the database and then
2847 possibly inserts based on the result, this method is subject to a race
2848 condition. Another process could create a record in the table after
2849 the find has completed and before the create has started. To avoid
2850 this problem, use find_or_create() inside a transaction.
2852 B<Note>: Take care when using C<find_or_create> with a table having
2853 columns with default values that you intend to be automatically
2854 supplied by the database (e.g. an auto_increment primary key column).
2855 In normal usage, the value of such columns should NOT be included at
2856 all in the call to C<find_or_create>, even when set to C<undef>.
2858 See also L</find> and L</update_or_create>. For information on how to declare
2859 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2861 If you need to know if an existing row was found or a new one created use
2862 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2863 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2866 my $cd = $schema->resultset('CD')->find_or_new({
2868 artist => 'Massive Attack',
2869 title => 'Mezzanine',
2873 if( !$cd->in_storage ) {
2880 sub find_or_create {
2882 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2883 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2884 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2887 return $self->create($hash);
2890 =head2 update_or_create
2894 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2896 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2900 $resultset->update_or_create({ col => $val, ... });
2902 Like L</find_or_create>, but if a row is found it is immediately updated via
2903 C<< $found_row->update (\%col_data) >>.
2906 Takes an optional C<key> attribute to search on a specific unique constraint.
2909 # In your application
2910 my $cd = $schema->resultset('CD')->update_or_create(
2912 artist => 'Massive Attack',
2913 title => 'Mezzanine',
2916 { key => 'cd_artist_title' }
2919 $cd->cd_to_producer->update_or_create({
2920 producer => $producer,
2926 B<Note>: Make sure to read the documentation of L</find> and understand the
2927 significance of the C<key> attribute, as its lack may skew your search, and
2928 subsequently result in spurious row creation.
2930 B<Note>: Take care when using C<update_or_create> with a table having
2931 columns with default values that you intend to be automatically
2932 supplied by the database (e.g. an auto_increment primary key column).
2933 In normal usage, the value of such columns should NOT be included at
2934 all in the call to C<update_or_create>, even when set to C<undef>.
2936 See also L</find> and L</find_or_create>. For information on how to declare
2937 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2939 If you need to know if an existing row was updated or a new one created use
2940 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2941 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2946 sub update_or_create {
2948 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2949 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2951 my $row = $self->find($cond, $attrs);
2953 $row->update($cond);
2957 return $self->create($cond);
2960 =head2 update_or_new
2964 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2966 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2970 $resultset->update_or_new({ col => $val, ... });
2972 Like L</find_or_new> but if a row is found it is immediately updated via
2973 C<< $found_row->update (\%col_data) >>.
2977 # In your application
2978 my $cd = $schema->resultset('CD')->update_or_new(
2980 artist => 'Massive Attack',
2981 title => 'Mezzanine',
2984 { key => 'cd_artist_title' }
2987 if ($cd->in_storage) {
2988 # the cd was updated
2991 # the cd is not yet in the database, let's insert it
2995 B<Note>: Make sure to read the documentation of L</find> and understand the
2996 significance of the C<key> attribute, as its lack may skew your search, and
2997 subsequently result in spurious new objects.
2999 B<Note>: Take care when using C<update_or_new> with a table having
3000 columns with default values that you intend to be automatically
3001 supplied by the database (e.g. an auto_increment primary key column).
3002 In normal usage, the value of such columns should NOT be included at
3003 all in the call to C<update_or_new>, even when set to C<undef>.
3005 See also L</find>, L</find_or_create> and L</find_or_new>.
3011 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3012 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3014 my $row = $self->find( $cond, $attrs );
3015 if ( defined $row ) {
3016 $row->update($cond);
3020 return $self->new_result($cond);
3027 =item Arguments: none
3029 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3033 Gets the contents of the cache for the resultset, if the cache is set.
3035 The cache is populated either by using the L</prefetch> attribute to
3036 L</search> or by calling L</set_cache>.
3048 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3050 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3054 Sets the contents of the cache for the resultset. Expects an arrayref
3055 of objects of the same class as those produced by the resultset. Note that
3056 if the cache is set, the resultset will return the cached objects rather
3057 than re-querying the database even if the cache attr is not set.
3059 The contents of the cache can also be populated by using the
3060 L</prefetch> attribute to L</search>.
3065 my ( $self, $data ) = @_;
3066 $self->throw_exception("set_cache requires an arrayref")
3067 if defined($data) && (ref $data ne 'ARRAY');
3068 $self->{all_cache} = $data;
3075 =item Arguments: none
3077 =item Return Value: undef
3081 Clears the cache for the resultset.
3086 shift->set_cache(undef);
3093 =item Arguments: none
3095 =item Return Value: true, if the resultset has been paginated
3103 return !!$self->{attrs}{page};
3110 =item Arguments: none
3112 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3120 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3123 =head2 related_resultset
3127 =item Arguments: $rel_name
3129 =item Return Value: L<$resultset|/search>
3133 Returns a related resultset for the supplied relationship name.
3135 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3139 sub related_resultset {
3140 my ($self, $rel) = @_;
3142 return $self->{related_resultsets}{$rel}
3143 if defined $self->{related_resultsets}{$rel};
3145 return $self->{related_resultsets}{$rel} = do {
3146 my $rsrc = $self->result_source;
3147 my $rel_info = $rsrc->relationship_info($rel);
3149 $self->throw_exception(
3150 "search_related: result source '" . $rsrc->source_name .
3151 "' has no such relationship $rel")
3154 my $attrs = $self->_chain_relationship($rel);
3156 my $join_count = $attrs->{seen_join}{$rel};
3158 my $alias = $self->result_source->storage
3159 ->relname_to_table_alias($rel, $join_count);
3161 # since this is search_related, and we already slid the select window inwards
3162 # (the select/as attrs were deleted in the beginning), we need to flip all
3163 # left joins to inner, so we get the expected results
3164 # read the comment on top of the actual function to see what this does
3165 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3168 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3169 delete @{$attrs}{qw(result_class alias)};
3171 my $rel_source = $rsrc->related_source($rel);
3175 # The reason we do this now instead of passing the alias to the
3176 # search_rs below is that if you wrap/overload resultset on the
3177 # source you need to know what alias it's -going- to have for things
3178 # to work sanely (e.g. RestrictWithObject wants to be able to add
3179 # extra query restrictions, and these may need to be $alias.)
3181 my $rel_attrs = $rel_source->resultset_attributes;
3182 local $rel_attrs->{alias} = $alias;
3184 $rel_source->resultset
3188 where => $attrs->{where},
3192 if (my $cache = $self->get_cache) {
3193 my @related_cache = map
3194 { @{$_->related_resultset($rel)->get_cache||[]} }
3198 $new->set_cache(\@related_cache) if @related_cache;
3205 =head2 current_source_alias
3209 =item Arguments: none
3211 =item Return Value: $source_alias
3215 Returns the current table alias for the result source this resultset is built
3216 on, that will be used in the SQL query. Usually it is C<me>.
3218 Currently the source alias that refers to the result set returned by a
3219 L</search>/L</find> family method depends on how you got to the resultset: it's
3220 C<me> by default, but eg. L</search_related> aliases it to the related result
3221 source name (and keeps C<me> referring to the original result set). The long
3222 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3223 (and make this method unnecessary).
3225 Thus it's currently necessary to use this method in predefined queries (see
3226 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3227 source alias of the current result set:
3229 # in a result set class
3231 my ($self, $user) = @_;
3233 my $me = $self->current_source_alias;
3235 return $self->search({
3236 "$me.modified" => $user->id,
3242 sub current_source_alias {
3243 return (shift->{attrs} || {})->{alias} || 'me';
3246 =head2 as_subselect_rs
3250 =item Arguments: none
3252 =item Return Value: L<$resultset|/search>
3256 Act as a barrier to SQL symbols. The resultset provided will be made into a
3257 "virtual view" by including it as a subquery within the from clause. From this
3258 point on, any joined tables are inaccessible to ->search on the resultset (as if
3259 it were simply where-filtered without joins). For example:
3261 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3263 # 'x' now pollutes the query namespace
3265 # So the following works as expected
3266 my $ok_rs = $rs->search({'x.other' => 1});
3268 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3269 # def) we look for one row with contradictory terms and join in another table
3270 # (aliased 'x_2') which we never use
3271 my $broken_rs = $rs->search({'x.name' => 'def'});
3273 my $rs2 = $rs->as_subselect_rs;
3275 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3276 my $not_joined_rs = $rs2->search({'x.other' => 1});
3278 # works as expected: finds a 'table' row related to two x rows (abc and def)
3279 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3281 Another example of when one might use this would be to select a subset of
3282 columns in a group by clause:
3284 my $rs = $schema->resultset('Bar')->search(undef, {
3285 group_by => [qw{ id foo_id baz_id }],
3286 })->as_subselect_rs->search(undef, {
3287 columns => [qw{ id foo_id }]
3290 In the above example normally columns would have to be equal to the group by,
3291 but because we isolated the group by into a subselect the above works.
3295 sub as_subselect_rs {
3298 my $attrs = $self->_resolved_attrs;
3300 my $fresh_rs = (ref $self)->new (
3301 $self->result_source
3304 # these pieces will be locked in the subquery
3305 delete $fresh_rs->{cond};
3306 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3308 return $fresh_rs->search( {}, {
3310 $attrs->{alias} => $self->as_query,
3311 -alias => $attrs->{alias},
3312 -rsrc => $self->result_source,
3314 alias => $attrs->{alias},
3318 # This code is called by search_related, and makes sure there
3319 # is clear separation between the joins before, during, and
3320 # after the relationship. This information is needed later
3321 # in order to properly resolve prefetch aliases (any alias
3322 # with a relation_chain_depth less than the depth of the
3323 # current prefetch is not considered)
3325 # The increments happen twice per join. An even number means a
3326 # relationship specified via a search_related, whereas an odd
3327 # number indicates a join/prefetch added via attributes
3329 # Also this code will wrap the current resultset (the one we
3330 # chain to) in a subselect IFF it contains limiting attributes
3331 sub _chain_relationship {
3332 my ($self, $rel) = @_;
3333 my $source = $self->result_source;
3334 my $attrs = { %{$self->{attrs}||{}} };
3336 # we need to take the prefetch the attrs into account before we
3337 # ->_resolve_join as otherwise they get lost - captainL
3338 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3340 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3342 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3345 my @force_subq_attrs = qw/offset rows group_by having/;
3348 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3350 $self->_has_resolved_attr (@force_subq_attrs)
3352 # Nuke the prefetch (if any) before the new $rs attrs
3353 # are resolved (prefetch is useless - we are wrapping
3354 # a subquery anyway).
3355 my $rs_copy = $self->search;
3356 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3357 $rs_copy->{attrs}{join},
3358 delete $rs_copy->{attrs}{prefetch},
3363 -alias => $attrs->{alias},
3364 $attrs->{alias} => $rs_copy->as_query,
3366 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3367 $seen->{-relation_chain_depth} = 0;
3369 elsif ($attrs->{from}) { #shallow copy suffices
3370 $from = [ @{$attrs->{from}} ];
3375 -alias => $attrs->{alias},
3376 $attrs->{alias} => $source->from,
3380 my $jpath = ($seen->{-relation_chain_depth})
3381 ? $from->[-1][0]{-join_path}
3384 my @requested_joins = $source->_resolve_join(
3391 push @$from, @requested_joins;
3393 $seen->{-relation_chain_depth}++;
3395 # if $self already had a join/prefetch specified on it, the requested
3396 # $rel might very well be already included. What we do in this case
3397 # is effectively a no-op (except that we bump up the chain_depth on
3398 # the join in question so we could tell it *is* the search_related)
3401 # we consider the last one thus reverse
3402 for my $j (reverse @requested_joins) {
3403 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3404 if ($rel eq $last_j) {
3405 $j->[0]{-relation_chain_depth}++;
3411 unless ($already_joined) {
3412 push @$from, $source->_resolve_join(
3420 $seen->{-relation_chain_depth}++;
3422 return {%$attrs, from => $from, seen_join => $seen};
3425 sub _resolved_attrs {
3427 return $self->{_attrs} if $self->{_attrs};
3429 my $attrs = { %{ $self->{attrs} || {} } };
3430 my $source = $self->result_source;
3431 my $alias = $attrs->{alias};
3433 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3434 if $attrs->{collapse} and $attrs->{distinct};
3436 # default selection list
3437 $attrs->{columns} = [ $source->columns ]
3438 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3440 # merge selectors together
3441 for (qw/columns select as/) {
3442 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3443 if $attrs->{$_} or $attrs->{"+$_"};
3446 # disassemble columns
3448 if (my $cols = delete $attrs->{columns}) {
3449 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3450 if (ref $c eq 'HASH') {
3451 for my $as (sort keys %$c) {
3452 push @sel, $c->{$as};
3463 # when trying to weed off duplicates later do not go past this point -
3464 # everything added from here on is unbalanced "anyone's guess" stuff
3465 my $dedup_stop_idx = $#as;
3467 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3469 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3470 if $attrs->{select};
3472 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3473 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3475 # disqualify all $alias.col as-bits (inflate-map mandated)
3476 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3478 # de-duplicate the result (remove *identical* select/as pairs)
3479 # and also die on duplicate {as} pointing to different {select}s
3480 # not using a c-style for as the condition is prone to shrinkage
3483 while ($i <= $dedup_stop_idx) {
3484 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3489 elsif ($seen->{$as[$i]}++) {
3490 $self->throw_exception(
3491 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3499 $attrs->{select} = \@sel;
3500 $attrs->{as} = \@as;
3502 $attrs->{from} ||= [{
3504 -alias => $self->{attrs}{alias},
3505 $self->{attrs}{alias} => $source->from,
3508 if ( $attrs->{join} || $attrs->{prefetch} ) {
3510 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3511 if ref $attrs->{from} ne 'ARRAY';
3513 my $join = (delete $attrs->{join}) || {};
3515 if ( defined $attrs->{prefetch} ) {
3516 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3519 $attrs->{from} = # have to copy here to avoid corrupting the original
3521 @{ $attrs->{from} },
3522 $source->_resolve_join(
3525 { %{ $attrs->{seen_join} || {} } },
3526 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3527 ? $attrs->{from}[-1][0]{-join_path}
3534 if ( defined $attrs->{order_by} ) {
3535 $attrs->{order_by} = (
3536 ref( $attrs->{order_by} ) eq 'ARRAY'
3537 ? [ @{ $attrs->{order_by} } ]
3538 : [ $attrs->{order_by} || () ]
3542 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3543 $attrs->{group_by} = [ $attrs->{group_by} ];
3547 # generate selections based on the prefetch helper
3548 my ($prefetch, @prefetch_select, @prefetch_as);
3549 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3550 if defined $attrs->{prefetch};
3554 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3555 if $attrs->{_dark_selector};
3557 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3558 if defined $attrs->{collapse} and ! $attrs->{collapse};
3560 $attrs->{collapse} = 1;
3562 # this is a separate structure (we don't look in {from} directly)
3563 # as the resolver needs to shift things off the lists to work
3564 # properly (identical-prefetches on different branches)
3566 if (ref $attrs->{from} eq 'ARRAY') {
3568 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3570 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3571 next unless $j->[0]{-alias};
3572 next unless $j->[0]{-join_path};
3573 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3575 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3578 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3579 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3583 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3585 # save these for after distinct resolution
3586 @prefetch_select = map { $_->[0] } @prefetch;
3587 @prefetch_as = map { $_->[1] } @prefetch;
3590 # run through the resulting joinstructure (starting from our current slot)
3591 # and unset collapse if proven unnecessary
3593 # also while we are at it find out if the current root source has
3594 # been premultiplied by previous related_source chaining
3596 # this allows to predict whether a root object with all other relation
3597 # data set to NULL is in fact unique
3598 if ($attrs->{collapse}) {
3600 if (ref $attrs->{from} eq 'ARRAY') {
3602 if (@{$attrs->{from}} == 1) {
3603 # no joins - no collapse
3604 $attrs->{collapse} = 0;
3607 # find where our table-spec starts
3608 my @fromlist = @{$attrs->{from}};
3610 my $t = shift @fromlist;
3613 # me vs join from-spec distinction - a ref means non-root
3614 if (ref $t eq 'ARRAY') {
3616 $is_multi ||= ! $t->{-is_single};
3618 last if ($t->{-alias} && $t->{-alias} eq $alias);
3619 $attrs->{_main_source_premultiplied} ||= $is_multi;
3622 # no non-singles remaining, nor any premultiplication - nothing to collapse
3624 ! $attrs->{_main_source_premultiplied}
3626 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3628 $attrs->{collapse} = 0;
3634 # if we can not analyze the from - err on the side of safety
3635 $attrs->{_main_source_premultiplied} = 1;
3639 # generate the distinct induced group_by before injecting the prefetched select/as parts
3640 if (delete $attrs->{distinct}) {
3641 if ($attrs->{group_by}) {
3642 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3645 $attrs->{_grouped_by_distinct} = 1;
3646 # distinct affects only the main selection part, not what prefetch may add below
3647 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3649 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3650 # The thinking is: if we are collapsing the subquerying prefetch engine will
3651 # rip stuff apart for us anyway, and we do not want to have a potentially
3652 # function-converted external order_by
3653 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3654 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3658 # inject prefetch-bound selection (if any)
3659 push @{$attrs->{select}}, @prefetch_select;
3660 push @{$attrs->{as}}, @prefetch_as;
3662 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3663 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3664 $attrs->{_related_results_construction} = 1;
3667 # if both page and offset are specified, produce a combined offset
3668 # even though it doesn't make much sense, this is what pre 081xx has
3670 if (my $page = delete $attrs->{page}) {
3672 ($attrs->{rows} * ($page - 1))
3674 ($attrs->{offset} || 0)
3678 return $self->{_attrs} = $attrs;
3682 my ($self, $attr) = @_;
3684 if (ref $attr eq 'HASH') {
3685 return $self->_rollout_hash($attr);
3686 } elsif (ref $attr eq 'ARRAY') {
3687 return $self->_rollout_array($attr);
3693 sub _rollout_array {
3694 my ($self, $attr) = @_;
3697 foreach my $element (@{$attr}) {
3698 if (ref $element eq 'HASH') {
3699 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3700 } elsif (ref $element eq 'ARRAY') {
3701 # XXX - should probably recurse here
3702 push( @rolled_array, @{$self->_rollout_array($element)} );
3704 push( @rolled_array, $element );
3707 return \@rolled_array;
3711 my ($self, $attr) = @_;
3714 foreach my $key (keys %{$attr}) {
3715 push( @rolled_array, { $key => $attr->{$key} } );
3717 return \@rolled_array;
3720 sub _calculate_score {
3721 my ($self, $a, $b) = @_;
3723 if (defined $a xor defined $b) {
3726 elsif (not defined $a) {
3730 if (ref $b eq 'HASH') {
3731 my ($b_key) = keys %{$b};
3732 if (ref $a eq 'HASH') {
3733 my ($a_key) = keys %{$a};
3734 if ($a_key eq $b_key) {
3735 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3740 return ($a eq $b_key) ? 1 : 0;
3743 if (ref $a eq 'HASH') {
3744 my ($a_key) = keys %{$a};
3745 return ($b eq $a_key) ? 1 : 0;
3747 return ($b eq $a) ? 1 : 0;
3752 sub _merge_joinpref_attr {
3753 my ($self, $orig, $import) = @_;
3755 return $import unless defined($orig);
3756 return $orig unless defined($import);
3758 $orig = $self->_rollout_attr($orig);
3759 $import = $self->_rollout_attr($import);
3762 foreach my $import_element ( @{$import} ) {
3763 # find best candidate from $orig to merge $b_element into
3764 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3765 foreach my $orig_element ( @{$orig} ) {
3766 my $score = $self->_calculate_score( $orig_element, $import_element );
3767 if ($score > $best_candidate->{score}) {
3768 $best_candidate->{position} = $position;
3769 $best_candidate->{score} = $score;
3773 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3774 $import_key = '' if not defined $import_key;
3776 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3777 push( @{$orig}, $import_element );
3779 my $orig_best = $orig->[$best_candidate->{position}];
3780 # merge orig_best and b_element together and replace original with merged
3781 if (ref $orig_best ne 'HASH') {
3782 $orig->[$best_candidate->{position}] = $import_element;
3783 } elsif (ref $import_element eq 'HASH') {
3784 my ($key) = keys %{$orig_best};
3785 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3788 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3791 return @$orig ? $orig : ();
3799 require Hash::Merge;
3800 my $hm = Hash::Merge->new;
3802 $hm->specify_behavior({
3805 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3807 if ($defl xor $defr) {
3808 return [ $defl ? $_[0] : $_[1] ];
3813 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3817 return [$_[0], $_[1]];
3821 return $_[1] if !defined $_[0];
3822 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3823 return [$_[0], @{$_[1]}]
3826 return [] if !defined $_[0] and !keys %{$_[1]};
3827 return [ $_[1] ] if !defined $_[0];
3828 return [ $_[0] ] if !keys %{$_[1]};
3829 return [$_[0], $_[1]]
3834 return $_[0] if !defined $_[1];
3835 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3836 return [@{$_[0]}, $_[1]]
3839 my @ret = @{$_[0]} or return $_[1];
3840 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3841 my %idx = map { $_ => 1 } @ret;
3842 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3846 return [ $_[1] ] if ! @{$_[0]};
3847 return $_[0] if !keys %{$_[1]};
3848 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3849 return [ @{$_[0]}, $_[1] ];
3854 return [] if !keys %{$_[0]} and !defined $_[1];
3855 return [ $_[0] ] if !defined $_[1];
3856 return [ $_[1] ] if !keys %{$_[0]};
3857 return [$_[0], $_[1]]
3860 return [] if !keys %{$_[0]} and !@{$_[1]};
3861 return [ $_[0] ] if !@{$_[1]};
3862 return $_[1] if !keys %{$_[0]};
3863 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3864 return [ $_[0], @{$_[1]} ];
3867 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3868 return [ $_[0] ] if !keys %{$_[1]};
3869 return [ $_[1] ] if !keys %{$_[0]};
3870 return [ $_[0] ] if $_[0] eq $_[1];
3871 return [ $_[0], $_[1] ];
3874 } => 'DBIC_RS_ATTR_MERGER');
3878 return $hm->merge ($_[1], $_[2]);
3882 sub STORABLE_freeze {
3883 my ($self, $cloning) = @_;
3884 my $to_serialize = { %$self };
3886 # A cursor in progress can't be serialized (and would make little sense anyway)
3887 # the parser can be regenerated (and can't be serialized)
3888 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3890 # nor is it sensical to store a not-yet-fired-count pager
3891 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3892 delete $to_serialize->{pager};
3895 Storable::nfreeze($to_serialize);
3898 # need this hook for symmetry
3900 my ($self, $cloning, $serialized) = @_;
3902 %$self = %{ Storable::thaw($serialized) };
3908 =head2 throw_exception
3910 See L<DBIx::Class::Schema/throw_exception> for details.
3914 sub throw_exception {
3917 if (ref $self and my $rsrc = $self->result_source) {
3918 $rsrc->throw_exception(@_)
3921 DBIx::Class::Exception->throw(@_);
3929 # XXX: FIXME: Attributes docs need clearing up
3933 Attributes are used to refine a ResultSet in various ways when
3934 searching for data. They can be passed to any method which takes an
3935 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3938 Default attributes can be set on the result class using
3939 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3940 the CAVEATS on that feature before using it!)
3942 These are in no particular order:
3948 =item Value: ( $order_by | \@order_by | \%order_by )
3952 Which column(s) to order the results by.
3954 [The full list of suitable values is documented in
3955 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3958 If a single column name, or an arrayref of names is supplied, the
3959 argument is passed through directly to SQL. The hashref syntax allows
3960 for connection-agnostic specification of ordering direction:
3962 For descending order:
3964 order_by => { -desc => [qw/col1 col2 col3/] }
3966 For explicit ascending order:
3968 order_by => { -asc => 'col' }
3970 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3971 supported, although you are strongly encouraged to use the hashref
3972 syntax as outlined above.
3978 =item Value: \@columns | \%columns | $column
3982 Shortcut to request a particular set of columns to be retrieved. Each
3983 column spec may be a string (a table column name), or a hash (in which
3984 case the key is the C<as> value, and the value is used as the C<select>
3985 expression). Adds C<me.> onto the start of any column without a C<.> in
3986 it and sets C<select> from that, then auto-populates C<as> from
3987 C<select> as normal. (You may also use the C<cols> attribute, as in
3988 earlier versions of DBIC, but this is deprecated.)
3990 Essentially C<columns> does the same as L</select> and L</as>.
3992 columns => [ 'foo', { bar => 'baz' } ]
3996 select => [qw/foo baz/],
4003 =item Value: \@columns
4007 Indicates additional columns to be selected from storage. Works the same as
4008 L</columns> but adds columns to the selection. (You may also use the
4009 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4010 deprecated). For example:-
4012 $schema->resultset('CD')->search(undef, {
4013 '+columns' => ['artist.name'],
4017 would return all CDs and include a 'name' column to the information
4018 passed to object inflation. Note that the 'artist' is the name of the
4019 column (or relationship) accessor, and 'name' is the name of the column
4020 accessor in the related table.
4022 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4023 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4024 unary plus operator before it.
4026 =head2 include_columns
4030 =item Value: \@columns
4034 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4040 =item Value: \@select_columns
4044 Indicates which columns should be selected from the storage. You can use
4045 column names, or in the case of RDBMS back ends, function or stored procedure
4048 $rs = $schema->resultset('Employee')->search(undef, {
4051 { count => 'employeeid' },
4052 { max => { length => 'name' }, -as => 'longest_name' }
4057 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4059 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4060 use L</select>, to instruct DBIx::Class how to store the result of the column.
4061 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4062 identifier aliasing. You can however alias a function, so you can use it in
4063 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4064 attribute> supplied as shown in the example above.
4066 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4067 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4068 unary plus operator before it.
4074 Indicates additional columns to be selected from storage. Works the same as
4075 L</select> but adds columns to the default selection, instead of specifying
4084 =item Value: \@inflation_names
4088 Indicates column names for object inflation. That is L</as> indicates the
4089 slot name in which the column value will be stored within the
4090 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4091 identifier by the C<get_column> method (or via the object accessor B<if one
4092 with the same name already exists>) as shown below. The L</as> attribute has
4093 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4095 $rs = $schema->resultset('Employee')->search(undef, {
4098 { count => 'employeeid' },
4099 { max => { length => 'name' }, -as => 'longest_name' }
4108 If the object against which the search is performed already has an accessor
4109 matching a column name specified in C<as>, the value can be retrieved using
4110 the accessor as normal:
4112 my $name = $employee->name();
4114 If on the other hand an accessor does not exist in the object, you need to
4115 use C<get_column> instead:
4117 my $employee_count = $employee->get_column('employee_count');
4119 You can create your own accessors if required - see
4120 L<DBIx::Class::Manual::Cookbook> for details.
4126 Indicates additional column names for those added via L</+select>. See L</as>.
4134 =item Value: ($rel_name | \@rel_names | \%rel_names)
4138 Contains a list of relationships that should be joined for this query. For
4141 # Get CDs by Nine Inch Nails
4142 my $rs = $schema->resultset('CD')->search(
4143 { 'artist.name' => 'Nine Inch Nails' },
4144 { join => 'artist' }
4147 Can also contain a hash reference to refer to the other relation's relations.
4150 package MyApp::Schema::Track;
4151 use base qw/DBIx::Class/;
4152 __PACKAGE__->table('track');
4153 __PACKAGE__->add_columns(qw/trackid cd position title/);
4154 __PACKAGE__->set_primary_key('trackid');
4155 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4158 # In your application
4159 my $rs = $schema->resultset('Artist')->search(
4160 { 'track.title' => 'Teardrop' },
4162 join => { cd => 'track' },
4163 order_by => 'artist.name',
4167 You need to use the relationship (not the table) name in conditions,
4168 because they are aliased as such. The current table is aliased as "me", so
4169 you need to use me.column_name in order to avoid ambiguity. For example:
4171 # Get CDs from 1984 with a 'Foo' track
4172 my $rs = $schema->resultset('CD')->search(
4175 'tracks.name' => 'Foo'
4177 { join => 'tracks' }
4180 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4181 similarly for a third time). For e.g.
4183 my $rs = $schema->resultset('Artist')->search({
4184 'cds.title' => 'Down to Earth',
4185 'cds_2.title' => 'Popular',
4187 join => [ qw/cds cds/ ],
4190 will return a set of all artists that have both a cd with title 'Down
4191 to Earth' and a cd with title 'Popular'.
4193 If you want to fetch related objects from other tables as well, see L</prefetch>
4196 NOTE: An internal join-chain pruner will discard certain joins while
4197 constructing the actual SQL query, as long as the joins in question do not
4198 affect the retrieved result. This for example includes 1:1 left joins
4199 that are not part of the restriction specification (WHERE/HAVING) nor are
4200 a part of the query selection.
4202 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4208 =item Value: (0 | 1)
4212 When set to a true value, indicates that any rows fetched from joined has_many
4213 relationships are to be aggregated into the corresponding "parent" object. For
4214 example, the resultset:
4216 my $rs = $schema->resultset('CD')->search({}, {
4217 '+columns' => [ qw/ tracks.title tracks.position / ],
4222 While executing the following query:
4224 SELECT me.*, tracks.title, tracks.position
4226 LEFT JOIN track tracks
4227 ON tracks.cdid = me.cdid
4229 Will return only as many objects as there are rows in the CD source, even
4230 though the result of the query may span many rows. Each of these CD objects
4231 will in turn have multiple "Track" objects hidden behind the has_many
4232 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4233 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4234 product"), with each CD object containing exactly one of all fetched Track data.
4236 When a collapse is requested on a non-ordered resultset, an order by some
4237 unique part of the main source (the left-most table) is inserted automatically.
4238 This is done so that the resultset is allowed to be "lazy" - calling
4239 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4240 object with all of its related data.
4242 If an L</order_by> is already declared, and orders the resultset in a way that
4243 makes collapsing as described above impossible (e.g. C<< ORDER BY
4244 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4245 switch to "eager" mode and slurp the entire resultset before constructing the
4246 first object returned by L</next>.
4248 Setting this attribute on a resultset that does not join any has_many
4249 relations is a no-op.
4251 For a more in-depth discussion, see L</PREFETCHING>.
4257 =item Value: ($rel_name | \@rel_names | \%rel_names)
4261 This attribute is a shorthand for specifying a L</join> spec, adding all
4262 columns from the joined related sources as L</+columns> and setting
4263 L</collapse> to a true value. For example, the following two queries are
4266 my $rs = $schema->resultset('Artist')->search({}, {
4267 prefetch => { cds => ['genre', 'tracks' ] },
4272 my $rs = $schema->resultset('Artist')->search({}, {
4273 join => { cds => ['genre', 'tracks' ] },
4277 { +{ "cds.$_" => "cds.$_" } }
4278 $schema->source('Artist')->related_source('cds')->columns
4281 { +{ "cds.genre.$_" => "genre.$_" } }
4282 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4285 { +{ "cds.tracks.$_" => "tracks.$_" } }
4286 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4291 Both producing the following SQL:
4293 SELECT me.artistid, me.name, me.rank, me.charfield,
4294 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4295 genre.genreid, genre.name,
4296 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4299 ON cds.artist = me.artistid
4300 LEFT JOIN genre genre
4301 ON genre.genreid = cds.genreid
4302 LEFT JOIN track tracks
4303 ON tracks.cd = cds.cdid
4304 ORDER BY me.artistid
4306 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4307 the arguments are properly merged and generally do the right thing. For
4308 example, you may want to do the following:
4310 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4311 { 'genre.genreid' => undef },
4313 join => { cds => 'genre' },
4318 Which generates the following SQL:
4320 SELECT me.artistid, me.name, me.rank, me.charfield,
4321 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4324 ON cds.artist = me.artistid
4325 LEFT JOIN genre genre
4326 ON genre.genreid = cds.genreid
4327 WHERE genre.genreid IS NULL
4328 ORDER BY me.artistid
4330 For a more in-depth discussion, see L</PREFETCHING>.
4336 =item Value: $source_alias
4340 Sets the source alias for the query. Normally, this defaults to C<me>, but
4341 nested search queries (sub-SELECTs) might need specific aliases set to
4342 reference inner queries. For example:
4345 ->related_resultset('CDs')
4346 ->related_resultset('Tracks')
4348 'track.id' => { -ident => 'none_search.id' },
4352 my $ids = $self->search({
4355 alias => 'none_search',
4356 group_by => 'none_search.id',
4357 })->get_column('id')->as_query;
4359 $self->search({ id => { -in => $ids } })
4361 This attribute is directly tied to L</current_source_alias>.
4371 Makes the resultset paged and specifies the page to retrieve. Effectively
4372 identical to creating a non-pages resultset and then calling ->page($page)
4375 If L</rows> attribute is not specified it defaults to 10 rows per page.
4377 When you have a paged resultset, L</count> will only return the number
4378 of rows in the page. To get the total, use the L</pager> and call
4379 C<total_entries> on it.
4389 Specifies the maximum number of rows for direct retrieval or the number of
4390 rows per page if the page attribute or method is used.
4396 =item Value: $offset
4400 Specifies the (zero-based) row number for the first row to be returned, or the
4401 of the first row of the first page if paging is used.
4403 =head2 software_limit
4407 =item Value: (0 | 1)
4411 When combined with L</rows> and/or L</offset> the generated SQL will not
4412 include any limit dialect stanzas. Instead the entire result will be selected
4413 as if no limits were specified, and DBIC will perform the limit locally, by
4414 artificially advancing and finishing the resulting L</cursor>.
4416 This is the recommended way of performing resultset limiting when no sane RDBMS
4417 implementation is available (e.g.
4418 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4419 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4425 =item Value: \@columns
4429 A arrayref of columns to group by. Can include columns of joined tables.
4431 group_by => [qw/ column1 column2 ... /]
4437 =item Value: $condition
4441 HAVING is a select statement attribute that is applied between GROUP BY and
4442 ORDER BY. It is applied to the after the grouping calculations have been
4445 having => { 'count_employee' => { '>=', 100 } }
4447 or with an in-place function in which case literal SQL is required:
4449 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4455 =item Value: (0 | 1)
4459 Set to 1 to automatically generate a L</group_by> clause based on the selection
4460 (including intelligent handling of L</order_by> contents). Note that the group
4461 criteria calculation takes place over the B<final> selection. This includes
4462 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4463 L</search> calls, and standalone columns selected via
4464 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4465 extra selections specified via L</prefetch> - such selections are explicitly
4466 excluded from group criteria calculations.
4468 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4469 setting is ignored and an appropriate warning is issued.
4475 Adds to the WHERE clause.
4477 # only return rows WHERE deleted IS NULL for all searches
4478 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4480 Can be overridden by passing C<< { where => undef } >> as an attribute
4483 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4489 Set to 1 to cache search results. This prevents extra SQL queries if you
4490 revisit rows in your ResultSet:
4492 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4494 while( my $artist = $resultset->next ) {
4498 $rs->first; # without cache, this would issue a query
4500 By default, searches are not cached.
4502 For more examples of using these attributes, see
4503 L<DBIx::Class::Manual::Cookbook>.
4509 =item Value: ( 'update' | 'shared' | \$scalar )
4513 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4514 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4519 DBIx::Class supports arbitrary related data prefetching from multiple related
4520 sources. Any combination of relationship types and column sets are supported.
4521 If L<collapsing|/collapse> is requested, there is an additional requirement of
4522 selecting enough data to make every individual object uniquely identifiable.
4524 Here are some more involved examples, based on the following relationship map:
4527 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4528 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4529 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4531 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4533 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4537 my $rs = $schema->resultset('Tag')->search(
4546 The initial search results in SQL like the following:
4548 SELECT tag.*, cd.*, artist.* FROM tag
4549 JOIN cd ON tag.cd = cd.cdid
4550 JOIN artist ON cd.artist = artist.artistid
4552 L<DBIx::Class> has no need to go back to the database when we access the
4553 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4556 Simple prefetches will be joined automatically, so there is no need
4557 for a C<join> attribute in the above search.
4559 The L</prefetch> attribute can be used with any of the relationship types
4560 and multiple prefetches can be specified together. Below is a more complex
4561 example that prefetches a CD's artist, its liner notes (if present),
4562 the cover image, the tracks on that CD, and the guests on those
4565 my $rs = $schema->resultset('CD')->search(
4569 { artist => 'record_label'}, # belongs_to => belongs_to
4570 'liner_note', # might_have
4571 'cover_image', # has_one
4572 { tracks => 'guests' }, # has_many => has_many
4577 This will produce SQL like the following:
4579 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4583 ON artist.artistid = me.artistid
4584 JOIN record_label record_label
4585 ON record_label.labelid = artist.labelid
4586 LEFT JOIN track tracks
4587 ON tracks.cdid = me.cdid
4588 LEFT JOIN guest guests
4589 ON guests.trackid = track.trackid
4590 LEFT JOIN liner_notes liner_note
4591 ON liner_note.cdid = me.cdid
4592 JOIN cd_artwork cover_image
4593 ON cover_image.cdid = me.cdid
4596 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4597 C<tracks>, and C<guests> of the CD will all be available through the
4598 relationship accessors without the need for additional queries to the
4603 Prefetch does a lot of deep magic. As such, it may not behave exactly
4604 as you might expect.
4610 Prefetch uses the L</cache> to populate the prefetched relationships. This
4611 may or may not be what you want.
4615 If you specify a condition on a prefetched relationship, ONLY those
4616 rows that match the prefetched condition will be fetched into that relationship.
4617 This means that adding prefetch to a search() B<may alter> what is returned by
4618 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4620 my $artist_rs = $schema->resultset('Artist')->search({
4626 my $count = $artist_rs->first->cds->count;
4628 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4630 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4632 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4634 That cmp_ok() may or may not pass depending on the datasets involved. In other
4635 words the C<WHERE> condition would apply to the entire dataset, just like
4636 it would in regular SQL. If you want to add a condition only to the "right side"
4637 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4638 condition|DBIx::Class::Relationship::Base/condition>
4642 =head1 DBIC BIND VALUES
4644 Because DBIC may need more information to bind values than just the column name
4645 and value itself, it uses a special format for both passing and receiving bind
4646 values. Each bind value should be composed of an arrayref of
4647 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4653 If present (in any form), this is what is being passed directly to bind_param.
4654 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4655 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4657 If this is specified, all other bind options described below are ignored.
4661 If present, this is used to infer the actual bind attribute by passing to
4662 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4663 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4665 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4666 currently drivers are expected to "Do the Right Thing" when given a common
4667 datatype name. (Not ideal, but that's what we got at this point.)
4671 Currently used to correctly allocate buffers for bind_param_inout().
4672 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4673 or to a sensible value based on the "data_type".
4677 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4678 explicitly specified they are never overridden). Also used by some weird DBDs,
4679 where the column name should be available at bind_param time (e.g. Oracle).
4683 For backwards compatibility and convenience, the following shortcuts are
4686 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4687 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4688 [ undef, $val ] === [ {}, $val ]
4689 $val === [ {}, $val ]
4691 =head1 AUTHOR AND CONTRIBUTORS
4693 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4697 You may distribute this code under the same terms as Perl itself.