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 $call_cond->isa('Data::Query::ExprBuilder')) {
402 my ($mapped_expr, $extra_join)
403 = $self->_remap_identifiers($call_cond->{expr});
404 $call_cond = \$mapped_expr;
406 $self->throw_exception("Can't handle join-requiring DQ expr when join attribute specified")
407 if $call_attrs->{join};
408 $call_attrs->{join} = $extra_join;
412 # see if we can keep the cache (no $rs changes)
414 my %safe = (alias => 1, cache => 1);
415 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
418 ref $call_cond eq 'HASH' && ! keys %$call_cond
420 ref $call_cond eq 'ARRAY' && ! @$call_cond
422 $cache = $self->get_cache;
425 my $old_attrs = { %{$self->{attrs}} };
426 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
428 my $new_attrs = { %$old_attrs };
430 # take care of call attrs (only if anything is changing)
431 if ($call_attrs and keys %$call_attrs) {
433 # copy for _normalize_selection
434 $call_attrs = { %$call_attrs };
436 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
438 # reset the current selector list if new selectors are supplied
439 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
440 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
443 # Normalize the new selector list (operates on the passed-in attr structure)
444 # Need to do it on every chain instead of only once on _resolved_attrs, in
445 # order to allow detection of empty vs partial 'as'
446 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
447 if $old_attrs->{_dark_selector};
448 $self->_normalize_selection ($call_attrs);
450 # start with blind overwriting merge, exclude selector attrs
451 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
452 delete @{$new_attrs}{@selector_attrs};
454 for (@selector_attrs) {
455 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
456 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
459 # older deprecated name, use only if {columns} is not there
460 if (my $c = delete $new_attrs->{cols}) {
461 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
462 if ($new_attrs->{columns}) {
463 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
466 $new_attrs->{columns} = $c;
471 # join/prefetch use their own crazy merging heuristics
472 foreach my $key (qw/join prefetch/) {
473 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
474 if exists $call_attrs->{$key};
477 # stack binds together
478 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
482 for ($old_where, $call_cond) {
484 $new_attrs->{where} = $self->_stack_cond (
485 $_, $new_attrs->{where}
490 if (defined $old_having) {
491 $new_attrs->{having} = $self->_stack_cond (
492 $old_having, $new_attrs->{having}
496 my $rs = (ref $self)->new($rsrc, $new_attrs);
498 $rs->set_cache($cache) if ($cache);
503 sub _remap_identifiers {
504 my ($self, $dq) = @_;
506 my $attrs = $self->_resolved_attrs;
507 foreach my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
508 next unless $j->[0]{-alias};
509 next unless $j->[0]{-join_path};
511 $p = $p->{$_} ||= {} for map { keys %$_ } @{$j->[0]{-join_path}};
512 $p->{''} = $j->[0]{-alias};
515 my $seen_join = { %{$attrs->{seen_join}||{}} };
516 my $storage = $self->result_source->storage;
518 my $mapped = map_dq_tree {
519 return $_ unless is_Identifier;
520 my @el = @{$_->{elements}};
523 return Identifier($attrs->{alias}, $last);
526 $p = $p->{$_} ||= {} for @el;
527 if (my $alias = $p->{''}) {
528 return Identifier($alias, $last);
530 my $need = my $j = {};
531 $j = $j->{$_} = {} for @el;
532 push @need_join, $need;
533 my $alias = $storage->relname_to_table_alias(
534 $el[-1], ++$seen_join->{$el[-1]}
536 return Identifier($alias, $last);
538 return ($mapped, \@need_join);
542 sub _normalize_selection {
543 my ($self, $attrs) = @_;
546 if ( exists $attrs->{include_columns} ) {
547 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
548 $attrs->{'+columns'} = $self->_merge_attr(
549 $attrs->{'+columns'}, delete $attrs->{include_columns}
553 # columns are always placed first, however
555 # Keep the X vs +X separation until _resolved_attrs time - this allows to
556 # delay the decision on whether to use a default select list ($rsrc->columns)
557 # allowing stuff like the remove_columns helper to work
559 # select/as +select/+as pairs need special handling - the amount of select/as
560 # elements in each pair does *not* have to be equal (think multicolumn
561 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
562 # supplied at all) - try to infer the alias, either from the -as parameter
563 # of the selector spec, or use the parameter whole if it looks like a column
564 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
565 # is ok as well), but make sure no more additions to the 'as' chain take place
566 for my $pref ('', '+') {
568 my ($sel, $as) = map {
569 my $key = "${pref}${_}";
571 my $val = [ ref $attrs->{$key} eq 'ARRAY'
573 : $attrs->{$key} || ()
575 delete $attrs->{$key};
579 if (! @$as and ! @$sel ) {
582 elsif (@$as and ! @$sel) {
583 $self->throw_exception(
584 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
588 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
589 # if any @$as has been supplied we assume the user knows what (s)he is doing
590 # and blindly keep stacking up pieces
591 unless ($attrs->{_dark_selector}) {
594 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
595 push @$as, $_->{-as};
597 # assume any plain no-space, no-parenthesis string to be a column spec
598 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
599 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
602 # if all else fails - raise a flag that no more aliasing will be allowed
604 $attrs->{_dark_selector} = {
606 string => ($dark_sel_dumper ||= do {
607 require Data::Dumper::Concise;
608 Data::Dumper::Concise::DumperObject()->Indent(0);
609 })->Values([$_])->Dump
617 elsif (@$as < @$sel) {
618 $self->throw_exception(
619 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
622 elsif ($pref and $attrs->{_dark_selector}) {
623 $self->throw_exception(
624 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
630 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
631 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
636 my ($self, $left, $right) = @_;
638 my $source = $self->result_source;
640 my $converter = $source->schema->storage->sql_maker->converter;
642 my @top = map $source->_extract_top_level_conditions(
643 $converter->_expr_to_dq($_)
644 ), grep defined, $left, $right;
646 return undef unless @top;
650 my @uniq = grep { !$seen{Data::Dumper::Concise::Dumper($_)}++ } @top;
652 return \$uniq[0] if @uniq == 1;
654 return \Operator({ 'SQL.Naive' => 'AND' }, \@uniq);
657 =head2 search_literal
659 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
660 should only be used in that context. C<search_literal> is a convenience
661 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
662 want to ensure columns are bound correctly, use L</search>.
664 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
665 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
666 require C<search_literal>.
670 =item Arguments: $sql_fragment, @standalone_bind_values
672 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
676 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
677 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
679 Pass a literal chunk of SQL to be added to the conditional part of the
682 Example of how to use C<search> instead of C<search_literal>
684 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
685 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
690 my ($self, $sql, @bind) = @_;
692 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
695 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
702 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
704 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
708 Finds and returns a single row based on supplied criteria. Takes either a
709 hashref with the same format as L</create> (including inference of foreign
710 keys from related objects), or a list of primary key values in the same
711 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
712 declaration on the L</result_source>.
714 In either case an attempt is made to combine conditions already existing on
715 the resultset with the condition passed to this method.
717 To aid with preparing the correct query for the storage you may supply the
718 C<key> attribute, which is the name of a
719 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
720 unique constraint corresponding to the
721 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
722 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
723 to construct a query that satisfies the named unique constraint fully (
724 non-NULL values for each column member of the constraint) an exception is
727 If no C<key> is specified, the search is carried over all unique constraints
728 which are fully defined by the available condition.
730 If no such constraint is found, C<find> currently defaults to a simple
731 C<< search->(\%column_values) >> which may or may not do what you expect.
732 Note that this fallback behavior may be deprecated in further versions. If
733 you need to search with arbitrary conditions - use L</search>. If the query
734 resulting from this fallback produces more than one row, a warning to the
735 effect is issued, though only the first row is constructed and returned as
738 In addition to C<key>, L</find> recognizes and applies standard
739 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
741 Note that if you have extra concerns about the correctness of the resulting
742 query you need to specify the C<key> attribute and supply the entire condition
743 as an argument to find (since it is not always possible to perform the
744 combination of the resultset condition with the supplied one, especially if
745 the resultset condition contains literal sql).
747 For example, to find a row by its primary key:
749 my $cd = $schema->resultset('CD')->find(5);
751 You can also find a row by a specific unique constraint:
753 my $cd = $schema->resultset('CD')->find(
755 artist => 'Massive Attack',
756 title => 'Mezzanine',
758 { key => 'cd_artist_title' }
761 See also L</find_or_create> and L</update_or_create>.
767 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
769 my $rsrc = $self->result_source;
772 if (exists $attrs->{key}) {
773 $constraint_name = defined $attrs->{key}
775 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
779 # Parse out the condition from input
782 if (ref $_[0] eq 'HASH') {
783 $call_cond = { %{$_[0]} };
786 # if only values are supplied we need to default to 'primary'
787 $constraint_name = 'primary' unless defined $constraint_name;
789 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
791 $self->throw_exception(
792 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
795 $self->throw_exception (
796 'find() expects either a column/value hashref, or a list of values '
797 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
798 ) unless @c_cols == @_;
801 @{$call_cond}{@c_cols} = @_;
805 for my $key (keys %$call_cond) {
807 my $keyref = ref($call_cond->{$key})
809 my $relinfo = $rsrc->relationship_info($key)
811 my $val = delete $call_cond->{$key};
813 next if $keyref eq 'ARRAY'; # has_many for multi_create
815 my $rel_q = $rsrc->_resolve_condition(
816 $relinfo->{cond}, $val, $key, $key
818 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
819 @related{keys %$rel_q} = values %$rel_q;
823 # relationship conditions take precedence (?)
824 @{$call_cond}{keys %related} = values %related;
826 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
828 if (defined $constraint_name) {
829 $final_cond = $self->_qualify_cond_columns (
831 $self->_build_unique_cond (
839 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
840 # This means that we got here after a merger of relationship conditions
841 # in ::Relationship::Base::search_related (the row method), and furthermore
842 # the relationship is of the 'single' type. This means that the condition
843 # provided by the relationship (already attached to $self) is sufficient,
844 # as there can be only one row in the database that would satisfy the
848 # no key was specified - fall down to heuristics mode:
849 # run through all unique queries registered on the resultset, and
850 # 'OR' all qualifying queries together
851 my (@unique_queries, %seen_column_combinations);
852 for my $c_name ($rsrc->unique_constraint_names) {
853 next if $seen_column_combinations{
854 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
857 push @unique_queries, try {
858 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
862 $final_cond = @unique_queries
863 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
864 : $self->_non_unique_find_fallback ($call_cond, $attrs)
868 # Run the query, passing the result_class since it should propagate for find
869 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
870 if ($rs->_resolved_attrs->{collapse}) {
872 carp "Query returned more than one row" if $rs->next;
880 # This is a stop-gap method as agreed during the discussion on find() cleanup:
881 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
883 # It is invoked when find() is called in legacy-mode with insufficiently-unique
884 # condition. It is provided for overrides until a saner way forward is devised
886 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
887 # the road. Please adjust your tests accordingly to catch this situation early
888 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
890 # The method will not be removed without an adequately complete replacement
891 # for strict-mode enforcement
892 sub _non_unique_find_fallback {
893 my ($self, $cond, $attrs) = @_;
895 return $self->_qualify_cond_columns(
897 exists $attrs->{alias}
899 : $self->{attrs}{alias}
904 sub _qualify_cond_columns {
905 my ($self, $cond, $alias) = @_;
907 my %aliased = %$cond;
908 for (keys %aliased) {
909 $aliased{"$alias.$_"} = delete $aliased{$_}
916 sub _build_unique_cond {
917 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
919 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
921 # combination may fail if $self->{cond} is non-trivial
922 my ($final_cond) = try {
923 $self->_merge_with_rscond ($extra_cond)
928 # trim out everything not in $columns
929 $final_cond = { map {
930 exists $final_cond->{$_}
931 ? ( $_ => $final_cond->{$_} )
935 if (my @missing = grep
936 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
939 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
941 join (', ', map { "'$_'" } @missing),
948 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
950 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
952 carp_unique ( sprintf (
953 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
954 . 'values in column(s): %s). This is almost certainly not what you wanted, '
955 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
957 join (', ', map { "'$_'" } @undefs),
964 =head2 search_related
968 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
970 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
974 $new_rs = $cd_rs->search_related('artist', {
978 Searches the specified relationship, optionally specifying a condition and
979 attributes for matching records. See L</ATTRIBUTES> for more information.
981 In list context, C<< ->all() >> is called implicitly on the resultset, thus
982 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
984 See also L</search_related_rs>.
989 return shift->related_resultset(shift)->search(@_);
992 =head2 search_related_rs
994 This method works exactly the same as search_related, except that
995 it guarantees a resultset, even in list context.
999 sub search_related_rs {
1000 return shift->related_resultset(shift)->search_rs(@_);
1007 =item Arguments: none
1009 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1013 Returns a storage-driven cursor to the given resultset. See
1014 L<DBIx::Class::Cursor> for more information.
1021 return $self->{cursor} ||= do {
1022 my $attrs = $self->_resolved_attrs;
1023 $self->result_source->storage->select(
1024 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1033 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1035 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1039 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1041 Inflates the first result without creating a cursor if the resultset has
1042 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1045 While this method can take an optional search condition (just like L</search>)
1046 being a fast-code-path it does not recognize search attributes. If you need to
1047 add extra joins or similar, call L</search> and then chain-call L</single> on the
1048 L<DBIx::Class::ResultSet> returned.
1054 As of 0.08100, this method enforces the assumption that the preceding
1055 query returns only one row. If more than one row is returned, you will receive
1058 Query returned more than one row
1060 In this case, you should be using L</next> or L</find> instead, or if you really
1061 know what you are doing, use the L</rows> attribute to explicitly limit the size
1064 This method will also throw an exception if it is called on a resultset prefetching
1065 has_many, as such a prefetch implies fetching multiple rows from the database in
1066 order to assemble the resulting object.
1073 my ($self, $where) = @_;
1075 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1078 my $attrs = { %{$self->_resolved_attrs} };
1080 $self->throw_exception(
1081 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1082 ) if $attrs->{collapse};
1085 if (defined $attrs->{where}) {
1088 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1089 $where, delete $attrs->{where} ]
1092 $attrs->{where} = $where;
1096 my $data = [ $self->result_source->storage->select_single(
1097 $attrs->{from}, $attrs->{select},
1098 $attrs->{where}, $attrs
1101 return undef unless @$data;
1102 $self->{_stashed_rows} = [ $data ];
1103 $self->_construct_results->[0];
1109 # Recursively collapse the query, accumulating values for each column.
1111 sub _collapse_query {
1112 my ($self, $query, $collapsed) = @_;
1116 if (ref $query eq 'ARRAY') {
1117 foreach my $subquery (@$query) {
1118 next unless ref $subquery; # -or
1119 $collapsed = $self->_collapse_query($subquery, $collapsed);
1122 elsif (ref $query eq 'HASH') {
1123 if (keys %$query and (keys %$query)[0] eq '-and') {
1124 foreach my $subquery (@{$query->{-and}}) {
1125 $collapsed = $self->_collapse_query($subquery, $collapsed);
1129 foreach my $col (keys %$query) {
1130 my $value = $query->{$col};
1131 $collapsed->{$col}{$value}++;
1143 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1145 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1149 my $max_length = $rs->get_column('length')->max;
1151 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1156 my ($self, $column) = @_;
1157 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1165 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1167 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1171 # WHERE title LIKE '%blue%'
1172 $cd_rs = $rs->search_like({ title => '%blue%'});
1174 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1175 that this is simply a convenience method retained for ex Class::DBI users.
1176 You most likely want to use L</search> with specific operators.
1178 For more information, see L<DBIx::Class::Manual::Cookbook>.
1180 This method is deprecated and will be removed in 0.09. Use L</search()>
1181 instead. An example conversion is:
1183 ->search_like({ foo => 'bar' });
1187 ->search({ foo => { like => 'bar' } });
1194 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1195 .' Instead use ->search({ x => { -like => "y%" } })'
1196 .' (note the outer pair of {}s - they are important!)'
1198 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1199 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1200 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1201 return $class->search($query, { %$attrs });
1208 =item Arguments: $first, $last
1210 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1214 Returns a resultset or object list representing a subset of elements from the
1215 resultset slice is called on. Indexes are from 0, i.e., to get the first
1216 three records, call:
1218 my ($one, $two, $three) = $rs->slice(0, 2);
1223 my ($self, $min, $max) = @_;
1224 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1225 $attrs->{offset} = $self->{attrs}{offset} || 0;
1226 $attrs->{offset} += $min;
1227 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1228 return $self->search(undef, $attrs);
1235 =item Arguments: none
1237 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1241 Returns the next element in the resultset (C<undef> is there is none).
1243 Can be used to efficiently iterate over records in the resultset:
1245 my $rs = $schema->resultset('CD')->search;
1246 while (my $cd = $rs->next) {
1250 Note that you need to store the resultset object, and call C<next> on it.
1251 Calling C<< resultset('Table')->next >> repeatedly will always return the
1252 first record from the resultset.
1259 if (my $cache = $self->get_cache) {
1260 $self->{all_cache_position} ||= 0;
1261 return $cache->[$self->{all_cache_position}++];
1264 if ($self->{attrs}{cache}) {
1265 delete $self->{pager};
1266 $self->{all_cache_position} = 1;
1267 return ($self->all)[0];
1270 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1272 $self->{_stashed_results} = $self->_construct_results
1275 return shift @{$self->{_stashed_results}};
1278 # Constructs as many results as it can in one pass while respecting
1279 # cursor laziness. Several modes of operation:
1281 # * Always builds everything present in @{$self->{_stashed_rows}}
1282 # * If called with $fetch_all true - pulls everything off the cursor and
1283 # builds all result structures (or objects) in one pass
1284 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1285 # and if the resultset is ordered properly by the left side:
1286 # * Fetches stuff off the cursor until the "master object" changes,
1287 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1289 # * Just fetches, and collapses/constructs everything as if $fetch_all
1290 # was requested (there is no other way to collapse except for an
1292 # * If no collapse is requested - just get the next row, construct and
1294 sub _construct_results {
1295 my ($self, $fetch_all) = @_;
1297 my $rsrc = $self->result_source;
1298 my $attrs = $self->_resolved_attrs;
1303 ! $attrs->{order_by}
1307 my @pcols = $rsrc->primary_columns
1309 # default order for collapsing unless the user asked for something
1310 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1311 $attrs->{_ordered_for_collapse} = 1;
1312 $attrs->{_order_is_artificial} = 1;
1315 # this will be used as both initial raw-row collector AND as a RV of
1316 # _construct_results. Not regrowing the array twice matters a lot...
1317 # a surprising amount actually
1318 my $rows = delete $self->{_stashed_rows};
1320 my $cursor; # we may not need one at all
1322 my $did_fetch_all = $fetch_all;
1325 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1326 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1328 elsif( $attrs->{collapse} ) {
1330 # a cursor will need to be closed over in case of collapse
1331 $cursor = $self->cursor;
1333 $attrs->{_ordered_for_collapse} = (
1339 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1341 ) unless defined $attrs->{_ordered_for_collapse};
1343 if (! $attrs->{_ordered_for_collapse}) {
1346 # instead of looping over ->next, use ->all in stealth mode
1347 # *without* calling a ->reset afterwards
1348 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1349 if (! $cursor->{_done}) {
1350 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1351 $cursor->{_done} = 1;
1356 if (! $did_fetch_all and ! @{$rows||[]} ) {
1357 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1358 $cursor ||= $self->cursor;
1359 if (scalar (my @r = $cursor->next) ) {
1364 return undef unless @{$rows||[]};
1366 # sanity check - people are too clever for their own good
1367 if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
1369 my $multiplied_selectors;
1370 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1372 $aliastypes->{multiplying}{$sel_alias}
1374 $aliastypes->{premultiplied}{$sel_alias}
1376 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1380 for my $i (0 .. $#{$attrs->{as}} ) {
1381 my $sel = $attrs->{select}[$i];
1383 if (ref $sel eq 'SCALAR') {
1386 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1390 $self->throw_exception(
1391 'Result collapse not possible - selection from a has_many source redirected to the main object'
1392 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1396 # hotspot - skip the setter
1397 my $res_class = $self->_result_class;
1399 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1400 $res_class->can ('inflate_result')
1401 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1404 my $infmap = $attrs->{as};
1406 $self->{_result_inflator}{is_core_row} = ( (
1409 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1410 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1412 $self->{_result_inflator}{is_hri} = ( (
1413 ! $self->{_result_inflator}{is_core_row}
1416 require DBIx::Class::ResultClass::HashRefInflator
1418 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1420 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1423 if (! $attrs->{_related_results_construction}) {
1424 # construct a much simpler array->hash folder for the one-table cases right here
1425 if ($self->{_result_inflator}{is_hri}) {
1426 for my $r (@$rows) {
1427 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1430 # FIXME SUBOPTIMAL this is a very very very hot spot
1431 # while rather optimal we can *still* do much better, by
1432 # building a smarter Row::inflate_result(), and
1433 # switch to feeding it data via a much leaner interface
1435 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1436 # this particular resultset size
1437 elsif (@$rows < 60) {
1438 for my $r (@$rows) {
1439 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1444 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1445 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1451 $self->{_result_inflator}{is_hri} ? 'hri'
1452 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1453 : 'classic_nonpruning'
1456 # $args and $attrs to _mk_row_parser are separated to delineate what is
1457 # core collapser stuff and what is dbic $rs specific
1458 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1460 inflate_map => $infmap,
1461 collapse => $attrs->{collapse},
1462 premultiplied => $attrs->{_main_source_premultiplied},
1463 hri_style => $self->{_result_inflator}{is_hri},
1464 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1465 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1467 # column_info metadata historically hasn't been too reliable.
1468 # We need to start fixing this somehow (the collapse resolver
1469 # can't work without it). Add an explicit check for the *main*
1470 # result, hopefully this will gradually weed out such errors
1472 # FIXME - this is a temporary kludge that reduces performance
1473 # It is however necessary for the time being
1474 my ($unrolled_non_null_cols_to_check, $err);
1476 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1479 'Collapse aborted due to invalid ResultSource metadata - the following '
1480 . 'selections are declared non-nullable but NULLs were retrieved: '
1484 COL: for my $i (@$check_non_null_cols) {
1485 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1488 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1491 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1495 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1496 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1498 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1499 my @r = $cursor->next or return;
1500 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1501 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1507 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1508 my @r = $cursor->next or return;
1513 $self->{_row_parser}{$parser_type}{cref}->(
1515 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1518 # Special-case multi-object HRI - there is no $inflator_cref pass
1519 unless ($self->{_result_inflator}{is_hri}) {
1520 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1524 # The @$rows check seems odd at first - why wouldn't we want to warn
1525 # regardless? The issue is things like find() etc, where the user
1526 # *knows* only one result will come back. In these cases the ->all
1527 # is not a pessimization, but rather something we actually want
1529 'Unable to properly collapse has_many results in iterator mode due '
1530 . 'to order criteria - performed an eager cursor slurp underneath. '
1531 . 'Consider using ->all() instead'
1532 ) if ( ! $fetch_all and @$rows > 1 );
1537 =head2 result_source
1541 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1543 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1547 An accessor for the primary ResultSource object from which this ResultSet
1554 =item Arguments: $result_class?
1556 =item Return Value: $result_class
1560 An accessor for the class to use when creating result objects. Defaults to
1561 C<< result_source->result_class >> - which in most cases is the name of the
1562 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1564 Note that changing the result_class will also remove any components
1565 that were originally loaded in the source class via
1566 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1567 in the original source class will not run.
1572 my ($self, $result_class) = @_;
1573 if ($result_class) {
1575 # don't fire this for an object
1576 $self->ensure_class_loaded($result_class)
1577 unless ref($result_class);
1579 if ($self->get_cache) {
1580 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1582 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1583 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1584 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1587 $self->_result_class($result_class);
1589 delete $self->{_result_inflator};
1591 $self->_result_class;
1598 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1600 =item Return Value: $count
1604 Performs an SQL C<COUNT> with the same query as the resultset was built
1605 with to find the number of elements. Passing arguments is equivalent to
1606 C<< $rs->search ($cond, \%attrs)->count >>
1612 return $self->search(@_)->count if @_ and defined $_[0];
1613 return scalar @{ $self->get_cache } if $self->get_cache;
1615 my $attrs = { %{ $self->_resolved_attrs } };
1617 # this is a little optimization - it is faster to do the limit
1618 # adjustments in software, instead of a subquery
1619 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1622 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1623 $crs = $self->_count_subq_rs ($attrs);
1626 $crs = $self->_count_rs ($attrs);
1628 my $count = $crs->next;
1630 $count -= $offset if $offset;
1631 $count = $rows if $rows and $rows < $count;
1632 $count = 0 if ($count < 0);
1641 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1643 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1647 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1648 This can be very handy for subqueries:
1650 ->search( { amount => $some_rs->count_rs->as_query } )
1652 As with regular resultsets the SQL query will be executed only after
1653 the resultset is accessed via L</next> or L</all>. That would return
1654 the same single value obtainable via L</count>.
1660 return $self->search(@_)->count_rs if @_;
1662 # this may look like a lack of abstraction (count() does about the same)
1663 # but in fact an _rs *must* use a subquery for the limits, as the
1664 # software based limiting can not be ported if this $rs is to be used
1665 # in a subquery itself (i.e. ->as_query)
1666 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1667 return $self->_count_subq_rs($self->{_attrs});
1670 return $self->_count_rs($self->{_attrs});
1675 # returns a ResultSetColumn object tied to the count query
1678 my ($self, $attrs) = @_;
1680 my $rsrc = $self->result_source;
1682 my $tmp_attrs = { %$attrs };
1683 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1684 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1686 # overwrite the selector (supplied by the storage)
1687 $rsrc->resultset_class->new($rsrc, {
1689 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1691 })->get_column ('count');
1695 # same as above but uses a subquery
1697 sub _count_subq_rs {
1698 my ($self, $attrs) = @_;
1700 my $rsrc = $self->result_source;
1702 my $sub_attrs = { %$attrs };
1703 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1704 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1706 # if we multi-prefetch we group_by something unique, as this is what we would
1707 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1708 if ( $attrs->{collapse} ) {
1709 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1710 $rsrc->_identifying_column_set || $self->throw_exception(
1711 'Unable to construct a unique group_by criteria properly collapsing the '
1712 . 'has_many prefetch before count()'
1717 # Calculate subquery selector
1718 if (my $g = $sub_attrs->{group_by}) {
1720 my $sql_maker = $rsrc->storage->sql_maker;
1722 # necessary as the group_by may refer to aliased functions
1724 for my $sel (@{$attrs->{select}}) {
1725 $sel_index->{$sel->{-as}} = $sel
1726 if (ref $sel eq 'HASH' and $sel->{-as});
1729 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1730 # also look for named aggregates referred in the having clause
1731 # having often contains scalarrefs - thus parse it out entirely
1733 if ($attrs->{having}) {
1734 local $sql_maker->{having_bind};
1735 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1736 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1737 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1738 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1739 # if we don't unset it we screw up retarded but unfortunately working
1740 # 'MAX(foo.bar)' => { '>', 3 }
1741 $sql_maker->{name_sep} = '';
1744 # delete local is 5.12+
1745 local @{$sql_maker}{qw(renderer converter)};
1746 delete @{$sql_maker}{qw(renderer converter)};
1748 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1750 my $having_sql = $sql_maker->_render_sqla(where => $attrs->{having});
1754 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1755 # and if all fails for an utterly naive quoted scalar-with-function
1756 while ($having_sql =~ /
1757 (?: $rquote $sep)? $lquote (.+?) $rquote
1759 [\s,] \w+ \. (\w+) [\s,]
1761 [\s,] $lquote (.+?) $rquote [\s,]
1763 my $part = $1 || $2 || $3; # one of them matched if we got here
1764 unless ($seen_having{$part}++) {
1771 my $colpiece = $sel_index->{$_} || $_;
1773 # unqualify join-based group_by's. Arcane but possible query
1774 # also horrible horrible hack to alias a column (not a func.)
1775 # (probably need to introduce SQLA syntax)
1776 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1779 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1781 push @{$sub_attrs->{select}}, $colpiece;
1785 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1786 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1789 return $rsrc->resultset_class
1790 ->new ($rsrc, $sub_attrs)
1792 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1793 ->get_column ('count');
1797 =head2 count_literal
1799 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1800 should only be used in that context. See L</search_literal> for further info.
1804 =item Arguments: $sql_fragment, @standalone_bind_values
1806 =item Return Value: $count
1810 Counts the results in a literal query. Equivalent to calling L</search_literal>
1811 with the passed arguments, then L</count>.
1815 sub count_literal { shift->search_literal(@_)->count; }
1821 =item Arguments: none
1823 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1827 Returns all elements in the resultset.
1834 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1837 delete @{$self}{qw/_stashed_rows _stashed_results/};
1839 if (my $c = $self->get_cache) {
1843 $self->cursor->reset;
1845 my $objs = $self->_construct_results('fetch_all') || [];
1847 $self->set_cache($objs) if $self->{attrs}{cache};
1856 =item Arguments: none
1858 =item Return Value: $self
1862 Resets the resultset's cursor, so you can iterate through the elements again.
1863 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1871 delete @{$self}{qw/_stashed_rows _stashed_results/};
1872 $self->{all_cache_position} = 0;
1873 $self->cursor->reset;
1881 =item Arguments: none
1883 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1887 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1888 an object for the first result (or C<undef> if the resultset is empty).
1893 return $_[0]->reset->next;
1899 # Determines whether and what type of subquery is required for the $rs operation.
1900 # If grouping is necessary either supplies its own, or verifies the current one
1901 # After all is done delegates to the proper storage method.
1903 sub _rs_update_delete {
1904 my ($self, $op, $values) = @_;
1906 my $rsrc = $self->result_source;
1907 my $storage = $rsrc->schema->storage;
1909 my $attrs = { %{$self->_resolved_attrs} };
1911 my $join_classifications;
1912 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1914 # do we need a subquery for any reason?
1916 defined $existing_group_by
1918 # if {from} is unparseable wrap a subq
1919 ref($attrs->{from}) ne 'ARRAY'
1921 # limits call for a subq
1922 $self->_has_resolved_attr(qw/rows offset/)
1925 # simplify the joinmap, so we can further decide if a subq is necessary
1926 if (!$needs_subq and @{$attrs->{from}} > 1) {
1928 ($attrs->{from}, $join_classifications) =
1929 $storage->_prune_unused_joins ($attrs);
1931 # any non-pruneable non-local restricting joins imply subq
1932 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1935 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1937 (ref $attrs->{from}[0]) ne 'HASH'
1939 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1943 # do we need anything like a subquery?
1944 if (! $needs_subq) {
1945 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1946 # a condition containing 'me' or other table prefixes will not work
1947 # at all - so we convert the WHERE to a dq tree now, dequalify all
1948 # identifiers found therein via a scan across the tree, and then use
1949 # \{} style to pass the result onwards for use in the final query
1950 if ($self->{cond}) {
1952 my $converter = $rsrc->storage->sql_maker->converter;
1954 DQ_IDENTIFIER ,=> sub { $_ = [ $_->[-1] ] for $_[0]->{elements} }
1955 }, my $where_dq = $converter->_where_to_dq($self->{cond}));
1961 # we got this far - means it is time to wrap a subquery
1962 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1964 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1970 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1971 delete $attrs->{$_} for qw/select as collapse/;
1972 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1974 # this will be consumed by the pruner waaaaay down the stack
1975 $attrs->{_force_prune_multiplying_joins} = 1;
1977 my $subrs = (ref $self)->new($rsrc, $attrs);
1979 if (@$idcols == 1) {
1980 $cond = { $idcols->[0] => { -in => \$subrs->_as_select_dq } };
1982 elsif ($storage->_use_multicolumn_in) {
1983 # no syntax for calling this properly yet
1984 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1985 my $left = $storage->sql_maker->_render_sqla(select_select => $idcols);
1986 $left =~ s/^SELECT //i;
1987 my $right = $storage->sql_maker
1989 ->_literal_to_dq(${$subrs->as_query});
1991 { 'SQL.Naive' => 'in' },
1992 [ Literal(SQL => "( $left )"), $right ],
1996 # if all else fails - get all primary keys and operate over a ORed set
1997 # wrap in a transaction for consistency
1998 # this is where the group_by/multiplication starts to matter
2002 # we do not need to check pre-multipliers, since if the premulti is there, its
2003 # parent (who is multi) will be there too
2004 keys %{ $join_classifications->{multiplying} || {} }
2006 # make sure if there is a supplied group_by it matches the columns compiled above
2007 # perfectly. Anything else can not be sanely executed on most databases so croak
2008 # right then and there
2009 if ($existing_group_by) {
2010 my @current_group_by = map
2011 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
2016 join ("\x00", sort @current_group_by)
2018 join ("\x00", sort @{$attrs->{columns}} )
2020 $self->throw_exception (
2021 "You have just attempted a $op operation on a resultset which does group_by"
2022 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2023 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2024 . ' kind of queries. Please retry the operation with a modified group_by or'
2025 . ' without using one at all.'
2030 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2033 $guard = $storage->txn_scope_guard;
2036 for my $row ($subrs->cursor->all) {
2038 { $idcols->[$_] => $row->[$_] }
2045 my $res = $storage->$op (
2047 $op eq 'update' ? $values : (),
2051 $guard->commit if $guard;
2060 =item Arguments: \%values
2062 =item Return Value: $underlying_storage_rv
2066 Sets the specified columns in the resultset to the supplied values in a
2067 single query. Note that this will not run any accessor/set_column/update
2068 triggers, nor will it update any result object instances derived from this
2069 resultset (this includes the contents of the L<resultset cache|/set_cache>
2070 if any). See L</update_all> if you need to execute any on-update
2071 triggers or cascades defined either by you or a
2072 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2074 The return value is a pass through of what the underlying
2075 storage backend returned, and may vary. See L<DBI/execute> for the most
2080 Note that L</update> does not process/deflate any of the values passed in.
2081 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2082 ensure manually that any value passed to this method will stringify to
2083 something the RDBMS knows how to deal with. A notable example is the
2084 handling of L<DateTime> objects, for more info see:
2085 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2090 my ($self, $values) = @_;
2091 $self->throw_exception('Values for update must be a hash')
2092 unless ref $values eq 'HASH';
2094 return $self->_rs_update_delete ('update', $values);
2101 =item Arguments: \%values
2103 =item Return Value: 1
2107 Fetches all objects and updates them one at a time via
2108 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2109 triggers, while L</update> will not.
2114 my ($self, $values) = @_;
2115 $self->throw_exception('Values for update_all must be a hash')
2116 unless ref $values eq 'HASH';
2118 my $guard = $self->result_source->schema->txn_scope_guard;
2119 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2128 =item Arguments: none
2130 =item Return Value: $underlying_storage_rv
2134 Deletes the rows matching this resultset in a single query. Note that this
2135 will not run any delete triggers, nor will it alter the
2136 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2137 derived from this resultset (this includes the contents of the
2138 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2139 execute any on-delete triggers or cascades defined either by you or a
2140 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2142 The return value is a pass through of what the underlying storage backend
2143 returned, and may vary. See L<DBI/execute> for the most common case.
2149 $self->throw_exception('delete does not accept any arguments')
2152 return $self->_rs_update_delete ('delete');
2159 =item Arguments: none
2161 =item Return Value: 1
2165 Fetches all objects and deletes them one at a time via
2166 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2167 triggers, while L</delete> will not.
2173 $self->throw_exception('delete_all does not accept any arguments')
2176 my $guard = $self->result_source->schema->txn_scope_guard;
2177 $_->delete for $self->all;
2186 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2188 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2192 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2199 The context of this method call has an important effect on what is
2200 submitted to storage. In void context data is fed directly to fastpath
2201 insertion routines provided by the underlying storage (most often
2202 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2203 L<insert|DBIx::Class::Row/insert> calls on the
2204 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2205 augmentation of these methods provided by components. For example if you
2206 are using something like L<DBIx::Class::UUIDColumns> to create primary
2207 keys for you, you will find that your PKs are empty. In this case you
2208 will have to explicitly force scalar or list context in order to create
2213 In non-void (scalar or list) context, this method is simply a wrapper
2214 for L</create>. Depending on list or scalar context either a list of
2215 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2216 containing these objects is returned.
2218 When supplying data in "arrayref of arrayrefs" invocation style, the
2219 first element should be a list of column names and each subsequent
2220 element should be a data value in the earlier specified column order.
2223 $schema->resultset("Artist")->populate([
2224 [ qw( artistid name ) ],
2225 [ 100, 'A Formally Unknown Singer' ],
2226 [ 101, 'A singer that jumped the shark two albums ago' ],
2227 [ 102, 'An actually cool singer' ],
2230 For the arrayref of hashrefs style each hashref should be a structure
2231 suitable for passing to L</create>. Multi-create is also permitted with
2234 $schema->resultset("Artist")->populate([
2235 { artistid => 4, name => 'Manufactured Crap', cds => [
2236 { title => 'My First CD', year => 2006 },
2237 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2240 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2241 { title => 'My parents sold me to a record company', year => 2005 },
2242 { title => 'Why Am I So Ugly?', year => 2006 },
2243 { title => 'I Got Surgery and am now Popular', year => 2007 }
2248 If you attempt a void-context multi-create as in the example above (each
2249 Artist also has the related list of CDs), and B<do not> supply the
2250 necessary autoinc foreign key information, this method will proxy to the
2251 less efficient L</create>, and then throw the Result objects away. In this
2252 case there are obviously no benefits to using this method over L</create>.
2259 # cruft placed in standalone method
2260 my $data = $self->_normalize_populate_args(@_);
2262 return unless @$data;
2264 if(defined wantarray) {
2265 my @created = map { $self->create($_) } @$data;
2266 return wantarray ? @created : \@created;
2269 my $first = $data->[0];
2271 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2272 # it relationship data
2273 my (@rels, @columns);
2274 my $rsrc = $self->result_source;
2275 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2276 for (keys %$first) {
2277 my $ref = ref $first->{$_};
2278 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2284 my @pks = $rsrc->primary_columns;
2286 ## do the belongs_to relationships
2287 foreach my $index (0..$#$data) {
2289 # delegate to create() for any dataset without primary keys with specified relationships
2290 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2292 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2293 my @ret = $self->populate($data);
2299 foreach my $rel (@rels) {
2300 next unless ref $data->[$index]->{$rel} eq "HASH";
2301 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2302 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2303 my $related = $result->result_source->_resolve_condition(
2304 $reverse_relinfo->{cond},
2310 delete $data->[$index]->{$rel};
2311 $data->[$index] = {%{$data->[$index]}, %$related};
2313 push @columns, keys %$related if $index == 0;
2317 ## inherit the data locked in the conditions of the resultset
2318 my ($rs_data) = $self->_merge_with_rscond({});
2319 delete @{$rs_data}{@columns};
2321 ## do bulk insert on current row
2322 $rsrc->storage->insert_bulk(
2324 [@columns, keys %$rs_data],
2325 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2328 ## do the has_many relationships
2329 foreach my $item (@$data) {
2333 foreach my $rel (@rels) {
2334 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2336 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2338 my $child = $main_row->$rel;
2340 my $related = $child->result_source->_resolve_condition(
2341 $rels->{$rel}{cond},
2347 if (ref($related) eq 'REF' and ref($$related) eq 'HASH') {
2348 $related = $self->result_source
2349 ->_extract_fixed_values_for($$related, $rel);
2352 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2353 my @populate = map { {%$_, %$related} } @rows_to_add;
2355 $child->populate( \@populate );
2361 # populate() arguments went over several incarnations
2362 # What we ultimately support is AoH
2363 sub _normalize_populate_args {
2364 my ($self, $arg) = @_;
2366 if (ref $arg eq 'ARRAY') {
2370 elsif (ref $arg->[0] eq 'HASH') {
2373 elsif (ref $arg->[0] eq 'ARRAY') {
2375 my @colnames = @{$arg->[0]};
2376 foreach my $values (@{$arg}[1 .. $#$arg]) {
2377 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2383 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2390 =item Arguments: none
2392 =item Return Value: L<$pager|Data::Page>
2396 Returns a L<Data::Page> object for the current resultset. Only makes
2397 sense for queries with a C<page> attribute.
2399 To get the full count of entries for a paged resultset, call
2400 C<total_entries> on the L<Data::Page> object.
2407 return $self->{pager} if $self->{pager};
2409 my $attrs = $self->{attrs};
2410 if (!defined $attrs->{page}) {
2411 $self->throw_exception("Can't create pager for non-paged rs");
2413 elsif ($attrs->{page} <= 0) {
2414 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2416 $attrs->{rows} ||= 10;
2418 # throw away the paging flags and re-run the count (possibly
2419 # with a subselect) to get the real total count
2420 my $count_attrs = { %$attrs };
2421 delete @{$count_attrs}{qw/rows offset page pager/};
2423 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2425 require DBIx::Class::ResultSet::Pager;
2426 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2427 sub { $total_rs->count }, #lazy-get the total
2429 $self->{attrs}{page},
2437 =item Arguments: $page_number
2439 =item Return Value: L<$resultset|/search>
2443 Returns a resultset for the $page_number page of the resultset on which page
2444 is called, where each page contains a number of rows equal to the 'rows'
2445 attribute set on the resultset (10 by default).
2450 my ($self, $page) = @_;
2451 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2458 =item Arguments: \%col_data
2460 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2464 Creates a new result object in the resultset's result class and returns
2465 it. The row is not inserted into the database at this point, call
2466 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2467 will tell you whether the result object has been inserted or not.
2469 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2474 my ($self, $values) = @_;
2476 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2479 $self->throw_exception( "new_result expects a hashref" )
2480 unless (ref $values eq 'HASH');
2482 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2484 my $new = $self->result_class->new({
2486 ( @$cols_from_relations
2487 ? (-cols_from_relations => $cols_from_relations)
2490 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2494 reftype($new) eq 'HASH'
2500 carp_unique (sprintf (
2501 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2502 $self->result_class,
2509 # _merge_with_rscond
2511 # Takes a simple hash of K/V data and returns its copy merged with the
2512 # condition already present on the resultset. Additionally returns an
2513 # arrayref of value/condition names, which were inferred from related
2514 # objects (this is needed for in-memory related objects)
2515 sub _merge_with_rscond {
2516 my ($self, $data) = @_;
2518 my (%new_data, @cols_from_relations);
2520 my $alias = $self->{attrs}{alias};
2522 if (! defined $self->{cond}) {
2523 # just massage $data below
2525 elsif (ref $self->{cond} eq 'HASH') {
2526 # precedence must be given to passed values over values inherited from
2527 # the cond, so the order here is important.
2528 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2529 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2531 while ( my($col, $value) = each %implied ) {
2532 my $vref = ref $value;
2538 (keys %$value)[0] eq '='
2540 $new_data{$col} = $value->{'='};
2542 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2543 $new_data{$col} = $value;
2547 elsif (ref $self->{cond} eq 'REF' and ref ${$self->{cond}} eq 'HASH') {
2548 if ((${$self->{cond}})->{'DBIx::Class::ResultSource.UNRESOLVABLE'}) {
2549 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2550 @cols_from_relations = keys %new_data;
2552 %new_data = %{$self->_remove_alias(
2553 $self->result_source
2554 ->_extract_fixed_values_for(${$self->{cond}}),
2560 $self->throw_exception(
2561 "Can't abstract implicit construct, resultset condition not a hash"
2567 %{ $self->_remove_alias($data, $alias) },
2570 return (\%new_data, \@cols_from_relations);
2573 # _has_resolved_attr
2575 # determines if the resultset defines at least one
2576 # of the attributes supplied
2578 # used to determine if a subquery is necessary
2580 # supports some virtual attributes:
2582 # This will scan for any joins being present on the resultset.
2583 # It is not a mere key-search but a deep inspection of {from}
2586 sub _has_resolved_attr {
2587 my ($self, @attr_names) = @_;
2589 my $attrs = $self->_resolved_attrs;
2593 for my $n (@attr_names) {
2594 if (grep { $n eq $_ } (qw/-join/) ) {
2595 $extra_checks{$n}++;
2599 my $attr = $attrs->{$n};
2601 next if not defined $attr;
2603 if (ref $attr eq 'HASH') {
2604 return 1 if keys %$attr;
2606 elsif (ref $attr eq 'ARRAY') {
2614 # a resolved join is expressed as a multi-level from
2616 $extra_checks{-join}
2618 ref $attrs->{from} eq 'ARRAY'
2620 @{$attrs->{from}} > 1
2628 # Recursively collapse the condition.
2630 sub _collapse_cond {
2631 my ($self, $cond, $collapsed) = @_;
2635 if (ref $cond eq 'ARRAY') {
2636 foreach my $subcond (@$cond) {
2637 next unless ref $subcond; # -or
2638 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2641 elsif (ref $cond eq 'HASH') {
2642 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2643 foreach my $subcond (@{$cond->{-and}}) {
2644 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2648 foreach my $col (keys %$cond) {
2649 my $value = $cond->{$col};
2650 $collapsed->{$col} = $value;
2660 # Remove the specified alias from the specified query hash. A copy is made so
2661 # the original query is not modified.
2664 my ($self, $query, $alias) = @_;
2666 my %orig = %{ $query || {} };
2669 foreach my $key (keys %orig) {
2671 $unaliased{$key} = $orig{$key};
2674 $unaliased{$1} = $orig{$key}
2675 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2685 =item Arguments: none
2687 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2691 Returns the SQL query and bind vars associated with the invocant.
2693 This is generally used as the RHS for a subquery.
2700 my $attrs = { %{ $self->_resolved_attrs } };
2702 my $aq = $self->result_source->storage->_select_args_to_query (
2703 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2706 $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
2713 my $attrs = { %{ $self->_resolved_attrs } };
2714 my $storage = $self->result_source->storage;
2715 my (undef, $ident, @args) = $storage->_select_args(
2716 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2718 $ident = $ident->from if blessed($ident);
2719 $storage->sql_maker->converter->_select_to_dq(
2728 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2730 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2734 my $artist = $schema->resultset('Artist')->find_or_new(
2735 { artist => 'fred' }, { key => 'artists' });
2737 $cd->cd_to_producer->find_or_new({ producer => $producer },
2738 { key => 'primary' });
2740 Find an existing record from this resultset using L</find>. if none exists,
2741 instantiate a new result object and return it. The object will not be saved
2742 into your storage until you call L<DBIx::Class::Row/insert> on it.
2744 You most likely want this method when looking for existing rows using a unique
2745 constraint that is not the primary key, or looking for related rows.
2747 If you want objects to be saved immediately, use L</find_or_create> instead.
2749 B<Note>: Make sure to read the documentation of L</find> and understand the
2750 significance of the C<key> attribute, as its lack may skew your search, and
2751 subsequently result in spurious new objects.
2753 B<Note>: Take care when using C<find_or_new> with a table having
2754 columns with default values that you intend to be automatically
2755 supplied by the database (e.g. an auto_increment primary key column).
2756 In normal usage, the value of such columns should NOT be included at
2757 all in the call to C<find_or_new>, even when set to C<undef>.
2763 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2764 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2765 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2768 return $self->new_result($hash);
2775 =item Arguments: \%col_data
2777 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2781 Attempt to create a single new row or a row with multiple related rows
2782 in the table represented by the resultset (and related tables). This
2783 will not check for duplicate rows before inserting, use
2784 L</find_or_create> to do that.
2786 To create one row for this resultset, pass a hashref of key/value
2787 pairs representing the columns of the table and the values you wish to
2788 store. If the appropriate relationships are set up, foreign key fields
2789 can also be passed an object representing the foreign row, and the
2790 value will be set to its primary key.
2792 To create related objects, pass a hashref of related-object column values
2793 B<keyed on the relationship name>. If the relationship is of type C<multi>
2794 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2795 The process will correctly identify columns holding foreign keys, and will
2796 transparently populate them from the keys of the corresponding relation.
2797 This can be applied recursively, and will work correctly for a structure
2798 with an arbitrary depth and width, as long as the relationships actually
2799 exists and the correct column data has been supplied.
2801 Instead of hashrefs of plain related data (key/value pairs), you may
2802 also pass new or inserted objects. New objects (not inserted yet, see
2803 L</new_result>), will be inserted into their appropriate tables.
2805 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2807 Example of creating a new row.
2809 $person_rs->create({
2810 name=>"Some Person",
2811 email=>"somebody@someplace.com"
2814 Example of creating a new row and also creating rows in a related C<has_many>
2815 or C<has_one> resultset. Note Arrayref.
2818 { artistid => 4, name => 'Manufactured Crap', cds => [
2819 { title => 'My First CD', year => 2006 },
2820 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2825 Example of creating a new row and also creating a row in a related
2826 C<belongs_to> resultset. Note Hashref.
2829 title=>"Music for Silly Walks",
2832 name=>"Silly Musician",
2840 When subclassing ResultSet never attempt to override this method. Since
2841 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2842 lot of the internals simply never call it, so your override will be
2843 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2844 or L<DBIx::Class::Row/insert> depending on how early in the
2845 L</create> process you need to intervene. See also warning pertaining to
2853 my ($self, $col_data) = @_;
2854 $self->throw_exception( "create needs a hashref" )
2855 unless ref $col_data eq 'HASH';
2856 return $self->new_result($col_data)->insert;
2859 =head2 find_or_create
2863 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2865 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2869 $cd->cd_to_producer->find_or_create({ producer => $producer },
2870 { key => 'primary' });
2872 Tries to find a record based on its primary key or unique constraints; if none
2873 is found, creates one and returns that instead.
2875 my $cd = $schema->resultset('CD')->find_or_create({
2877 artist => 'Massive Attack',
2878 title => 'Mezzanine',
2882 Also takes an optional C<key> attribute, to search by a specific key or unique
2883 constraint. For example:
2885 my $cd = $schema->resultset('CD')->find_or_create(
2887 artist => 'Massive Attack',
2888 title => 'Mezzanine',
2890 { key => 'cd_artist_title' }
2893 B<Note>: Make sure to read the documentation of L</find> and understand the
2894 significance of the C<key> attribute, as its lack may skew your search, and
2895 subsequently result in spurious row creation.
2897 B<Note>: Because find_or_create() reads from the database and then
2898 possibly inserts based on the result, this method is subject to a race
2899 condition. Another process could create a record in the table after
2900 the find has completed and before the create has started. To avoid
2901 this problem, use find_or_create() inside a transaction.
2903 B<Note>: Take care when using C<find_or_create> with a table having
2904 columns with default values that you intend to be automatically
2905 supplied by the database (e.g. an auto_increment primary key column).
2906 In normal usage, the value of such columns should NOT be included at
2907 all in the call to C<find_or_create>, even when set to C<undef>.
2909 See also L</find> and L</update_or_create>. For information on how to declare
2910 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2912 If you need to know if an existing row was found or a new one created use
2913 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2914 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2917 my $cd = $schema->resultset('CD')->find_or_new({
2919 artist => 'Massive Attack',
2920 title => 'Mezzanine',
2924 if( !$cd->in_storage ) {
2931 sub find_or_create {
2933 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2934 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2935 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2938 return $self->create($hash);
2941 =head2 update_or_create
2945 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2947 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2951 $resultset->update_or_create({ col => $val, ... });
2953 Like L</find_or_create>, but if a row is found it is immediately updated via
2954 C<< $found_row->update (\%col_data) >>.
2957 Takes an optional C<key> attribute to search on a specific unique constraint.
2960 # In your application
2961 my $cd = $schema->resultset('CD')->update_or_create(
2963 artist => 'Massive Attack',
2964 title => 'Mezzanine',
2967 { key => 'cd_artist_title' }
2970 $cd->cd_to_producer->update_or_create({
2971 producer => $producer,
2977 B<Note>: Make sure to read the documentation of L</find> and understand the
2978 significance of the C<key> attribute, as its lack may skew your search, and
2979 subsequently result in spurious row creation.
2981 B<Note>: Take care when using C<update_or_create> with a table having
2982 columns with default values that you intend to be automatically
2983 supplied by the database (e.g. an auto_increment primary key column).
2984 In normal usage, the value of such columns should NOT be included at
2985 all in the call to C<update_or_create>, even when set to C<undef>.
2987 See also L</find> and L</find_or_create>. For information on how to declare
2988 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2990 If you need to know if an existing row was updated or a new one created use
2991 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2992 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2997 sub update_or_create {
2999 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3000 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3002 my $row = $self->find($cond, $attrs);
3004 $row->update($cond);
3008 return $self->create($cond);
3011 =head2 update_or_new
3015 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3017 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3021 $resultset->update_or_new({ col => $val, ... });
3023 Like L</find_or_new> but if a row is found it is immediately updated via
3024 C<< $found_row->update (\%col_data) >>.
3028 # In your application
3029 my $cd = $schema->resultset('CD')->update_or_new(
3031 artist => 'Massive Attack',
3032 title => 'Mezzanine',
3035 { key => 'cd_artist_title' }
3038 if ($cd->in_storage) {
3039 # the cd was updated
3042 # the cd is not yet in the database, let's insert it
3046 B<Note>: Make sure to read the documentation of L</find> and understand the
3047 significance of the C<key> attribute, as its lack may skew your search, and
3048 subsequently result in spurious new objects.
3050 B<Note>: Take care when using C<update_or_new> with a table having
3051 columns with default values that you intend to be automatically
3052 supplied by the database (e.g. an auto_increment primary key column).
3053 In normal usage, the value of such columns should NOT be included at
3054 all in the call to C<update_or_new>, even when set to C<undef>.
3056 See also L</find>, L</find_or_create> and L</find_or_new>.
3062 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3063 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3065 my $row = $self->find( $cond, $attrs );
3066 if ( defined $row ) {
3067 $row->update($cond);
3071 return $self->new_result($cond);
3078 =item Arguments: none
3080 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3084 Gets the contents of the cache for the resultset, if the cache is set.
3086 The cache is populated either by using the L</prefetch> attribute to
3087 L</search> or by calling L</set_cache>.
3099 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3101 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3105 Sets the contents of the cache for the resultset. Expects an arrayref
3106 of objects of the same class as those produced by the resultset. Note that
3107 if the cache is set, the resultset will return the cached objects rather
3108 than re-querying the database even if the cache attr is not set.
3110 The contents of the cache can also be populated by using the
3111 L</prefetch> attribute to L</search>.
3116 my ( $self, $data ) = @_;
3117 $self->throw_exception("set_cache requires an arrayref")
3118 if defined($data) && (ref $data ne 'ARRAY');
3119 $self->{all_cache} = $data;
3126 =item Arguments: none
3128 =item Return Value: undef
3132 Clears the cache for the resultset.
3137 shift->set_cache(undef);
3144 =item Arguments: none
3146 =item Return Value: true, if the resultset has been paginated
3154 return !!$self->{attrs}{page};
3161 =item Arguments: none
3163 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3171 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3174 =head2 related_resultset
3178 =item Arguments: $rel_name
3180 =item Return Value: L<$resultset|/search>
3184 Returns a related resultset for the supplied relationship name.
3186 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3190 sub related_resultset {
3191 my ($self, $rel) = @_;
3193 return $self->{related_resultsets}{$rel}
3194 if defined $self->{related_resultsets}{$rel};
3196 return $self->{related_resultsets}{$rel} = do {
3197 my $rsrc = $self->result_source;
3198 my $rel_info = $rsrc->relationship_info($rel);
3200 $self->throw_exception(
3201 "search_related: result source '" . $rsrc->source_name .
3202 "' has no such relationship $rel")
3205 my $attrs = $self->_chain_relationship($rel);
3207 my $join_count = $attrs->{seen_join}{$rel};
3209 my $alias = $self->result_source->storage
3210 ->relname_to_table_alias($rel, $join_count);
3212 # since this is search_related, and we already slid the select window inwards
3213 # (the select/as attrs were deleted in the beginning), we need to flip all
3214 # left joins to inner, so we get the expected results
3215 # read the comment on top of the actual function to see what this does
3216 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3219 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3220 delete @{$attrs}{qw(result_class alias)};
3222 my $rel_source = $rsrc->related_source($rel);
3226 # The reason we do this now instead of passing the alias to the
3227 # search_rs below is that if you wrap/overload resultset on the
3228 # source you need to know what alias it's -going- to have for things
3229 # to work sanely (e.g. RestrictWithObject wants to be able to add
3230 # extra query restrictions, and these may need to be $alias.)
3232 my $rel_attrs = $rel_source->resultset_attributes;
3233 local $rel_attrs->{alias} = $alias;
3235 $rel_source->resultset
3239 where => $attrs->{where},
3243 if (my $cache = $self->get_cache) {
3244 my @related_cache = map
3245 { @{$_->related_resultset($rel)->get_cache||[]} }
3249 $new->set_cache(\@related_cache) if @related_cache;
3256 =head2 current_source_alias
3260 =item Arguments: none
3262 =item Return Value: $source_alias
3266 Returns the current table alias for the result source this resultset is built
3267 on, that will be used in the SQL query. Usually it is C<me>.
3269 Currently the source alias that refers to the result set returned by a
3270 L</search>/L</find> family method depends on how you got to the resultset: it's
3271 C<me> by default, but eg. L</search_related> aliases it to the related result
3272 source name (and keeps C<me> referring to the original result set). The long
3273 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3274 (and make this method unnecessary).
3276 Thus it's currently necessary to use this method in predefined queries (see
3277 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3278 source alias of the current result set:
3280 # in a result set class
3282 my ($self, $user) = @_;
3284 my $me = $self->current_source_alias;
3286 return $self->search({
3287 "$me.modified" => $user->id,
3293 sub current_source_alias {
3294 return (shift->{attrs} || {})->{alias} || 'me';
3297 =head2 as_subselect_rs
3301 =item Arguments: none
3303 =item Return Value: L<$resultset|/search>
3307 Act as a barrier to SQL symbols. The resultset provided will be made into a
3308 "virtual view" by including it as a subquery within the from clause. From this
3309 point on, any joined tables are inaccessible to ->search on the resultset (as if
3310 it were simply where-filtered without joins). For example:
3312 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3314 # 'x' now pollutes the query namespace
3316 # So the following works as expected
3317 my $ok_rs = $rs->search({'x.other' => 1});
3319 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3320 # def) we look for one row with contradictory terms and join in another table
3321 # (aliased 'x_2') which we never use
3322 my $broken_rs = $rs->search({'x.name' => 'def'});
3324 my $rs2 = $rs->as_subselect_rs;
3326 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3327 my $not_joined_rs = $rs2->search({'x.other' => 1});
3329 # works as expected: finds a 'table' row related to two x rows (abc and def)
3330 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3332 Another example of when one might use this would be to select a subset of
3333 columns in a group by clause:
3335 my $rs = $schema->resultset('Bar')->search(undef, {
3336 group_by => [qw{ id foo_id baz_id }],
3337 })->as_subselect_rs->search(undef, {
3338 columns => [qw{ id foo_id }]
3341 In the above example normally columns would have to be equal to the group by,
3342 but because we isolated the group by into a subselect the above works.
3346 sub as_subselect_rs {
3349 my $attrs = $self->_resolved_attrs;
3351 my $fresh_rs = (ref $self)->new (
3352 $self->result_source
3355 # these pieces will be locked in the subquery
3356 delete $fresh_rs->{cond};
3357 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3359 return $fresh_rs->search( {}, {
3361 $attrs->{alias} => $self->as_query,
3362 -alias => $attrs->{alias},
3363 -rsrc => $self->result_source,
3365 alias => $attrs->{alias},
3369 # This code is called by search_related, and makes sure there
3370 # is clear separation between the joins before, during, and
3371 # after the relationship. This information is needed later
3372 # in order to properly resolve prefetch aliases (any alias
3373 # with a relation_chain_depth less than the depth of the
3374 # current prefetch is not considered)
3376 # The increments happen twice per join. An even number means a
3377 # relationship specified via a search_related, whereas an odd
3378 # number indicates a join/prefetch added via attributes
3380 # Also this code will wrap the current resultset (the one we
3381 # chain to) in a subselect IFF it contains limiting attributes
3382 sub _chain_relationship {
3383 my ($self, $rel) = @_;
3384 my $source = $self->result_source;
3385 my $attrs = { %{$self->{attrs}||{}} };
3387 # we need to take the prefetch the attrs into account before we
3388 # ->_resolve_join as otherwise they get lost - captainL
3389 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3391 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3393 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3396 my @force_subq_attrs = qw/offset rows group_by having/;
3399 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3401 $self->_has_resolved_attr (@force_subq_attrs)
3403 # Nuke the prefetch (if any) before the new $rs attrs
3404 # are resolved (prefetch is useless - we are wrapping
3405 # a subquery anyway).
3406 my $rs_copy = $self->search;
3407 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3408 $rs_copy->{attrs}{join},
3409 delete $rs_copy->{attrs}{prefetch},
3414 -alias => $attrs->{alias},
3415 $attrs->{alias} => $rs_copy->as_query,
3417 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3418 $seen->{-relation_chain_depth} = 0;
3420 elsif ($attrs->{from}) { #shallow copy suffices
3421 $from = [ @{$attrs->{from}} ];
3426 -alias => $attrs->{alias},
3427 $attrs->{alias} => $source->from,
3431 my $jpath = ($seen->{-relation_chain_depth})
3432 ? $from->[-1][0]{-join_path}
3435 my @requested_joins = $source->_resolve_join(
3442 push @$from, @requested_joins;
3444 $seen->{-relation_chain_depth}++;
3446 # if $self already had a join/prefetch specified on it, the requested
3447 # $rel might very well be already included. What we do in this case
3448 # is effectively a no-op (except that we bump up the chain_depth on
3449 # the join in question so we could tell it *is* the search_related)
3452 # we consider the last one thus reverse
3453 for my $j (reverse @requested_joins) {
3454 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3455 if ($rel eq $last_j) {
3456 $j->[0]{-relation_chain_depth}++;
3462 unless ($already_joined) {
3463 push @$from, $source->_resolve_join(
3471 $seen->{-relation_chain_depth}++;
3473 return {%$attrs, from => $from, seen_join => $seen};
3476 sub _resolved_attrs {
3478 return $self->{_attrs} if $self->{_attrs};
3480 my $attrs = { %{ $self->{attrs} || {} } };
3481 my $source = $self->result_source;
3482 my $alias = $attrs->{alias};
3484 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3485 if $attrs->{collapse} and $attrs->{distinct};
3487 # default selection list
3488 $attrs->{columns} = [ $source->columns ]
3489 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3491 # merge selectors together
3492 for (qw/columns select as/) {
3493 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3494 if $attrs->{$_} or $attrs->{"+$_"};
3497 # disassemble columns
3499 if (my $cols = delete $attrs->{columns}) {
3500 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3501 if (ref $c eq 'HASH') {
3502 for my $as (sort keys %$c) {
3503 push @sel, $c->{$as};
3514 # when trying to weed off duplicates later do not go past this point -
3515 # everything added from here on is unbalanced "anyone's guess" stuff
3516 my $dedup_stop_idx = $#as;
3518 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3520 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3521 if $attrs->{select};
3523 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3524 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3526 # disqualify all $alias.col as-bits (inflate-map mandated)
3527 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3529 # de-duplicate the result (remove *identical* select/as pairs)
3530 # and also die on duplicate {as} pointing to different {select}s
3531 # not using a c-style for as the condition is prone to shrinkage
3534 while ($i <= $dedup_stop_idx) {
3535 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3540 elsif ($seen->{$as[$i]}++) {
3541 $self->throw_exception(
3542 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3550 $attrs->{select} = \@sel;
3551 $attrs->{as} = \@as;
3553 $attrs->{from} ||= [{
3555 -alias => $self->{attrs}{alias},
3556 $self->{attrs}{alias} => $source->from,
3559 if ( $attrs->{join} || $attrs->{prefetch} ) {
3561 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3562 if ref $attrs->{from} ne 'ARRAY';
3564 my $join = (delete $attrs->{join}) || {};
3566 if ( defined $attrs->{prefetch} ) {
3567 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3570 $attrs->{from} = # have to copy here to avoid corrupting the original
3572 @{ $attrs->{from} },
3573 $source->_resolve_join(
3576 ($attrs->{seen_join} = { %{ $attrs->{seen_join} || {} } }),
3577 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3578 ? $attrs->{from}[-1][0]{-join_path}
3585 if ( defined $attrs->{order_by} ) {
3586 $attrs->{order_by} = (
3587 ref( $attrs->{order_by} ) eq 'ARRAY'
3588 ? [ @{ $attrs->{order_by} } ]
3589 : [ $attrs->{order_by} || () ]
3593 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3594 $attrs->{group_by} = [ $attrs->{group_by} ];
3598 # generate selections based on the prefetch helper
3599 my ($prefetch, @prefetch_select, @prefetch_as);
3600 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3601 if defined $attrs->{prefetch};
3605 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3606 if $attrs->{_dark_selector};
3608 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3609 if defined $attrs->{collapse} and ! $attrs->{collapse};
3611 $attrs->{collapse} = 1;
3613 # this is a separate structure (we don't look in {from} directly)
3614 # as the resolver needs to shift things off the lists to work
3615 # properly (identical-prefetches on different branches)
3617 if (ref $attrs->{from} eq 'ARRAY') {
3619 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3621 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3622 next unless $j->[0]{-alias};
3623 next unless $j->[0]{-join_path};
3624 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3626 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3629 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3630 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3634 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3636 # save these for after distinct resolution
3637 @prefetch_select = map { $_->[0] } @prefetch;
3638 @prefetch_as = map { $_->[1] } @prefetch;
3641 # run through the resulting joinstructure (starting from our current slot)
3642 # and unset collapse if proven unnecessary
3644 # also while we are at it find out if the current root source has
3645 # been premultiplied by previous related_source chaining
3647 # this allows to predict whether a root object with all other relation
3648 # data set to NULL is in fact unique
3649 if ($attrs->{collapse}) {
3651 if (ref $attrs->{from} eq 'ARRAY') {
3653 if (@{$attrs->{from}} == 1) {
3654 # no joins - no collapse
3655 $attrs->{collapse} = 0;
3658 # find where our table-spec starts
3659 my @fromlist = @{$attrs->{from}};
3661 my $t = shift @fromlist;
3664 # me vs join from-spec distinction - a ref means non-root
3665 if (ref $t eq 'ARRAY') {
3667 $is_multi ||= ! $t->{-is_single};
3669 last if ($t->{-alias} && $t->{-alias} eq $alias);
3670 $attrs->{_main_source_premultiplied} ||= $is_multi;
3673 # no non-singles remaining, nor any premultiplication - nothing to collapse
3675 ! $attrs->{_main_source_premultiplied}
3677 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3679 $attrs->{collapse} = 0;
3685 # if we can not analyze the from - err on the side of safety
3686 $attrs->{_main_source_premultiplied} = 1;
3690 # generate the distinct induced group_by before injecting the prefetched select/as parts
3691 if (delete $attrs->{distinct}) {
3692 if ($attrs->{group_by}) {
3693 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3696 $attrs->{_grouped_by_distinct} = 1;
3697 # distinct affects only the main selection part, not what prefetch may add below
3698 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3700 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3701 # The thinking is: if we are collapsing the subquerying prefetch engine will
3702 # rip stuff apart for us anyway, and we do not want to have a potentially
3703 # function-converted external order_by
3704 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3705 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3709 # inject prefetch-bound selection (if any)
3710 push @{$attrs->{select}}, @prefetch_select;
3711 push @{$attrs->{as}}, @prefetch_as;
3713 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3714 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3715 $attrs->{_related_results_construction} = 1;
3718 # if both page and offset are specified, produce a combined offset
3719 # even though it doesn't make much sense, this is what pre 081xx has
3721 if (my $page = delete $attrs->{page}) {
3723 ($attrs->{rows} * ($page - 1))
3725 ($attrs->{offset} || 0)
3729 return $self->{_attrs} = $attrs;
3733 my ($self, $attr) = @_;
3735 if (ref $attr eq 'HASH') {
3736 return $self->_rollout_hash($attr);
3737 } elsif (ref $attr eq 'ARRAY') {
3738 return $self->_rollout_array($attr);
3744 sub _rollout_array {
3745 my ($self, $attr) = @_;
3748 foreach my $element (@{$attr}) {
3749 if (ref $element eq 'HASH') {
3750 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3751 } elsif (ref $element eq 'ARRAY') {
3752 # XXX - should probably recurse here
3753 push( @rolled_array, @{$self->_rollout_array($element)} );
3755 push( @rolled_array, $element );
3758 return \@rolled_array;
3762 my ($self, $attr) = @_;
3765 foreach my $key (keys %{$attr}) {
3766 push( @rolled_array, { $key => $attr->{$key} } );
3768 return \@rolled_array;
3771 sub _calculate_score {
3772 my ($self, $a, $b) = @_;
3774 if (defined $a xor defined $b) {
3777 elsif (not defined $a) {
3781 if (ref $b eq 'HASH') {
3782 my ($b_key) = keys %{$b};
3783 if (ref $a eq 'HASH') {
3784 my ($a_key) = keys %{$a};
3785 if ($a_key eq $b_key) {
3786 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3791 return ($a eq $b_key) ? 1 : 0;
3794 if (ref $a eq 'HASH') {
3795 my ($a_key) = keys %{$a};
3796 return ($b eq $a_key) ? 1 : 0;
3798 return ($b eq $a) ? 1 : 0;
3803 sub _merge_joinpref_attr {
3804 my ($self, $orig, $import) = @_;
3806 return $import unless defined($orig);
3807 return $orig unless defined($import);
3809 $orig = $self->_rollout_attr($orig);
3810 $import = $self->_rollout_attr($import);
3813 foreach my $import_element ( @{$import} ) {
3814 # find best candidate from $orig to merge $b_element into
3815 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3816 foreach my $orig_element ( @{$orig} ) {
3817 my $score = $self->_calculate_score( $orig_element, $import_element );
3818 if ($score > $best_candidate->{score}) {
3819 $best_candidate->{position} = $position;
3820 $best_candidate->{score} = $score;
3824 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3825 $import_key = '' if not defined $import_key;
3827 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3828 push( @{$orig}, $import_element );
3830 my $orig_best = $orig->[$best_candidate->{position}];
3831 # merge orig_best and b_element together and replace original with merged
3832 if (ref $orig_best ne 'HASH') {
3833 $orig->[$best_candidate->{position}] = $import_element;
3834 } elsif (ref $import_element eq 'HASH') {
3835 my ($key) = keys %{$orig_best};
3836 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3839 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3842 return @$orig ? $orig : ();
3850 require Hash::Merge;
3851 my $hm = Hash::Merge->new;
3853 $hm->specify_behavior({
3856 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3858 if ($defl xor $defr) {
3859 return [ $defl ? $_[0] : $_[1] ];
3864 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3868 return [$_[0], $_[1]];
3872 return $_[1] if !defined $_[0];
3873 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3874 return [$_[0], @{$_[1]}]
3877 return [] if !defined $_[0] and !keys %{$_[1]};
3878 return [ $_[1] ] if !defined $_[0];
3879 return [ $_[0] ] if !keys %{$_[1]};
3880 return [$_[0], $_[1]]
3885 return $_[0] if !defined $_[1];
3886 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3887 return [@{$_[0]}, $_[1]]
3890 my @ret = @{$_[0]} or return $_[1];
3891 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3892 my %idx = map { $_ => 1 } @ret;
3893 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3897 return [ $_[1] ] if ! @{$_[0]};
3898 return $_[0] if !keys %{$_[1]};
3899 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3900 return [ @{$_[0]}, $_[1] ];
3905 return [] if !keys %{$_[0]} and !defined $_[1];
3906 return [ $_[0] ] if !defined $_[1];
3907 return [ $_[1] ] if !keys %{$_[0]};
3908 return [$_[0], $_[1]]
3911 return [] if !keys %{$_[0]} and !@{$_[1]};
3912 return [ $_[0] ] if !@{$_[1]};
3913 return $_[1] if !keys %{$_[0]};
3914 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3915 return [ $_[0], @{$_[1]} ];
3918 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3919 return [ $_[0] ] if !keys %{$_[1]};
3920 return [ $_[1] ] if !keys %{$_[0]};
3921 return [ $_[0] ] if $_[0] eq $_[1];
3922 return [ $_[0], $_[1] ];
3925 } => 'DBIC_RS_ATTR_MERGER');
3929 return $hm->merge ($_[1], $_[2]);
3933 sub STORABLE_freeze {
3934 my ($self, $cloning) = @_;
3935 my $to_serialize = { %$self };
3937 # A cursor in progress can't be serialized (and would make little sense anyway)
3938 # the parser can be regenerated (and can't be serialized)
3939 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3941 # nor is it sensical to store a not-yet-fired-count pager
3942 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3943 delete $to_serialize->{pager};
3946 Storable::nfreeze($to_serialize);
3949 # need this hook for symmetry
3951 my ($self, $cloning, $serialized) = @_;
3953 %$self = %{ Storable::thaw($serialized) };
3959 =head2 throw_exception
3961 See L<DBIx::Class::Schema/throw_exception> for details.
3965 sub throw_exception {
3968 if (ref $self and my $rsrc = $self->result_source) {
3969 $rsrc->throw_exception(@_)
3972 DBIx::Class::Exception->throw(@_);
3980 # XXX: FIXME: Attributes docs need clearing up
3984 Attributes are used to refine a ResultSet in various ways when
3985 searching for data. They can be passed to any method which takes an
3986 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3989 Default attributes can be set on the result class using
3990 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3991 the CAVEATS on that feature before using it!)
3993 These are in no particular order:
3999 =item Value: ( $order_by | \@order_by | \%order_by )
4003 Which column(s) to order the results by.
4005 [The full list of suitable values is documented in
4006 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4009 If a single column name, or an arrayref of names is supplied, the
4010 argument is passed through directly to SQL. The hashref syntax allows
4011 for connection-agnostic specification of ordering direction:
4013 For descending order:
4015 order_by => { -desc => [qw/col1 col2 col3/] }
4017 For explicit ascending order:
4019 order_by => { -asc => 'col' }
4021 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4022 supported, although you are strongly encouraged to use the hashref
4023 syntax as outlined above.
4029 =item Value: \@columns | \%columns | $column
4033 Shortcut to request a particular set of columns to be retrieved. Each
4034 column spec may be a string (a table column name), or a hash (in which
4035 case the key is the C<as> value, and the value is used as the C<select>
4036 expression). Adds C<me.> onto the start of any column without a C<.> in
4037 it and sets C<select> from that, then auto-populates C<as> from
4038 C<select> as normal. (You may also use the C<cols> attribute, as in
4039 earlier versions of DBIC, but this is deprecated.)
4041 Essentially C<columns> does the same as L</select> and L</as>.
4043 columns => [ 'foo', { bar => 'baz' } ]
4047 select => [qw/foo baz/],
4054 =item Value: \@columns
4058 Indicates additional columns to be selected from storage. Works the same as
4059 L</columns> but adds columns to the selection. (You may also use the
4060 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4061 deprecated). For example:-
4063 $schema->resultset('CD')->search(undef, {
4064 '+columns' => ['artist.name'],
4068 would return all CDs and include a 'name' column to the information
4069 passed to object inflation. Note that the 'artist' is the name of the
4070 column (or relationship) accessor, and 'name' is the name of the column
4071 accessor in the related table.
4073 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4074 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4075 unary plus operator before it.
4077 =head2 include_columns
4081 =item Value: \@columns
4085 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4091 =item Value: \@select_columns
4095 Indicates which columns should be selected from the storage. You can use
4096 column names, or in the case of RDBMS back ends, function or stored procedure
4099 $rs = $schema->resultset('Employee')->search(undef, {
4102 { count => 'employeeid' },
4103 { max => { length => 'name' }, -as => 'longest_name' }
4108 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4110 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4111 use L</select>, to instruct DBIx::Class how to store the result of the column.
4112 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4113 identifier aliasing. You can however alias a function, so you can use it in
4114 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4115 attribute> supplied as shown in the example above.
4117 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4118 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4119 unary plus operator before it.
4125 Indicates additional columns to be selected from storage. Works the same as
4126 L</select> but adds columns to the default selection, instead of specifying
4135 =item Value: \@inflation_names
4139 Indicates column names for object inflation. That is L</as> indicates the
4140 slot name in which the column value will be stored within the
4141 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4142 identifier by the C<get_column> method (or via the object accessor B<if one
4143 with the same name already exists>) as shown below. The L</as> attribute has
4144 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4146 $rs = $schema->resultset('Employee')->search(undef, {
4149 { count => 'employeeid' },
4150 { max => { length => 'name' }, -as => 'longest_name' }
4159 If the object against which the search is performed already has an accessor
4160 matching a column name specified in C<as>, the value can be retrieved using
4161 the accessor as normal:
4163 my $name = $employee->name();
4165 If on the other hand an accessor does not exist in the object, you need to
4166 use C<get_column> instead:
4168 my $employee_count = $employee->get_column('employee_count');
4170 You can create your own accessors if required - see
4171 L<DBIx::Class::Manual::Cookbook> for details.
4177 Indicates additional column names for those added via L</+select>. See L</as>.
4185 =item Value: ($rel_name | \@rel_names | \%rel_names)
4189 Contains a list of relationships that should be joined for this query. For
4192 # Get CDs by Nine Inch Nails
4193 my $rs = $schema->resultset('CD')->search(
4194 { 'artist.name' => 'Nine Inch Nails' },
4195 { join => 'artist' }
4198 Can also contain a hash reference to refer to the other relation's relations.
4201 package MyApp::Schema::Track;
4202 use base qw/DBIx::Class/;
4203 __PACKAGE__->table('track');
4204 __PACKAGE__->add_columns(qw/trackid cd position title/);
4205 __PACKAGE__->set_primary_key('trackid');
4206 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4209 # In your application
4210 my $rs = $schema->resultset('Artist')->search(
4211 { 'track.title' => 'Teardrop' },
4213 join => { cd => 'track' },
4214 order_by => 'artist.name',
4218 You need to use the relationship (not the table) name in conditions,
4219 because they are aliased as such. The current table is aliased as "me", so
4220 you need to use me.column_name in order to avoid ambiguity. For example:
4222 # Get CDs from 1984 with a 'Foo' track
4223 my $rs = $schema->resultset('CD')->search(
4226 'tracks.name' => 'Foo'
4228 { join => 'tracks' }
4231 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4232 similarly for a third time). For e.g.
4234 my $rs = $schema->resultset('Artist')->search({
4235 'cds.title' => 'Down to Earth',
4236 'cds_2.title' => 'Popular',
4238 join => [ qw/cds cds/ ],
4241 will return a set of all artists that have both a cd with title 'Down
4242 to Earth' and a cd with title 'Popular'.
4244 If you want to fetch related objects from other tables as well, see L</prefetch>
4247 NOTE: An internal join-chain pruner will discard certain joins while
4248 constructing the actual SQL query, as long as the joins in question do not
4249 affect the retrieved result. This for example includes 1:1 left joins
4250 that are not part of the restriction specification (WHERE/HAVING) nor are
4251 a part of the query selection.
4253 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4259 =item Value: (0 | 1)
4263 When set to a true value, indicates that any rows fetched from joined has_many
4264 relationships are to be aggregated into the corresponding "parent" object. For
4265 example, the resultset:
4267 my $rs = $schema->resultset('CD')->search({}, {
4268 '+columns' => [ qw/ tracks.title tracks.position / ],
4273 While executing the following query:
4275 SELECT me.*, tracks.title, tracks.position
4277 LEFT JOIN track tracks
4278 ON tracks.cdid = me.cdid
4280 Will return only as many objects as there are rows in the CD source, even
4281 though the result of the query may span many rows. Each of these CD objects
4282 will in turn have multiple "Track" objects hidden behind the has_many
4283 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4284 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4285 product"), with each CD object containing exactly one of all fetched Track data.
4287 When a collapse is requested on a non-ordered resultset, an order by some
4288 unique part of the main source (the left-most table) is inserted automatically.
4289 This is done so that the resultset is allowed to be "lazy" - calling
4290 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4291 object with all of its related data.
4293 If an L</order_by> is already declared, and orders the resultset in a way that
4294 makes collapsing as described above impossible (e.g. C<< ORDER BY
4295 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4296 switch to "eager" mode and slurp the entire resultset before constructing the
4297 first object returned by L</next>.
4299 Setting this attribute on a resultset that does not join any has_many
4300 relations is a no-op.
4302 For a more in-depth discussion, see L</PREFETCHING>.
4308 =item Value: ($rel_name | \@rel_names | \%rel_names)
4312 This attribute is a shorthand for specifying a L</join> spec, adding all
4313 columns from the joined related sources as L</+columns> and setting
4314 L</collapse> to a true value. For example, the following two queries are
4317 my $rs = $schema->resultset('Artist')->search({}, {
4318 prefetch => { cds => ['genre', 'tracks' ] },
4323 my $rs = $schema->resultset('Artist')->search({}, {
4324 join => { cds => ['genre', 'tracks' ] },
4328 { +{ "cds.$_" => "cds.$_" } }
4329 $schema->source('Artist')->related_source('cds')->columns
4332 { +{ "cds.genre.$_" => "genre.$_" } }
4333 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4336 { +{ "cds.tracks.$_" => "tracks.$_" } }
4337 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4342 Both producing the following SQL:
4344 SELECT me.artistid, me.name, me.rank, me.charfield,
4345 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4346 genre.genreid, genre.name,
4347 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4350 ON cds.artist = me.artistid
4351 LEFT JOIN genre genre
4352 ON genre.genreid = cds.genreid
4353 LEFT JOIN track tracks
4354 ON tracks.cd = cds.cdid
4355 ORDER BY me.artistid
4357 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4358 the arguments are properly merged and generally do the right thing. For
4359 example, you may want to do the following:
4361 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4362 { 'genre.genreid' => undef },
4364 join => { cds => 'genre' },
4369 Which generates the following SQL:
4371 SELECT me.artistid, me.name, me.rank, me.charfield,
4372 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4375 ON cds.artist = me.artistid
4376 LEFT JOIN genre genre
4377 ON genre.genreid = cds.genreid
4378 WHERE genre.genreid IS NULL
4379 ORDER BY me.artistid
4381 For a more in-depth discussion, see L</PREFETCHING>.
4387 =item Value: $source_alias
4391 Sets the source alias for the query. Normally, this defaults to C<me>, but
4392 nested search queries (sub-SELECTs) might need specific aliases set to
4393 reference inner queries. For example:
4396 ->related_resultset('CDs')
4397 ->related_resultset('Tracks')
4399 'track.id' => { -ident => 'none_search.id' },
4403 my $ids = $self->search({
4406 alias => 'none_search',
4407 group_by => 'none_search.id',
4408 })->get_column('id')->as_query;
4410 $self->search({ id => { -in => $ids } })
4412 This attribute is directly tied to L</current_source_alias>.
4422 Makes the resultset paged and specifies the page to retrieve. Effectively
4423 identical to creating a non-pages resultset and then calling ->page($page)
4426 If L</rows> attribute is not specified it defaults to 10 rows per page.
4428 When you have a paged resultset, L</count> will only return the number
4429 of rows in the page. To get the total, use the L</pager> and call
4430 C<total_entries> on it.
4440 Specifies the maximum number of rows for direct retrieval or the number of
4441 rows per page if the page attribute or method is used.
4447 =item Value: $offset
4451 Specifies the (zero-based) row number for the first row to be returned, or the
4452 of the first row of the first page if paging is used.
4454 =head2 software_limit
4458 =item Value: (0 | 1)
4462 When combined with L</rows> and/or L</offset> the generated SQL will not
4463 include any limit dialect stanzas. Instead the entire result will be selected
4464 as if no limits were specified, and DBIC will perform the limit locally, by
4465 artificially advancing and finishing the resulting L</cursor>.
4467 This is the recommended way of performing resultset limiting when no sane RDBMS
4468 implementation is available (e.g.
4469 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4470 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4476 =item Value: \@columns
4480 A arrayref of columns to group by. Can include columns of joined tables.
4482 group_by => [qw/ column1 column2 ... /]
4488 =item Value: $condition
4492 HAVING is a select statement attribute that is applied between GROUP BY and
4493 ORDER BY. It is applied to the after the grouping calculations have been
4496 having => { 'count_employee' => { '>=', 100 } }
4498 or with an in-place function in which case literal SQL is required:
4500 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4506 =item Value: (0 | 1)
4510 Set to 1 to automatically generate a L</group_by> clause based on the selection
4511 (including intelligent handling of L</order_by> contents). Note that the group
4512 criteria calculation takes place over the B<final> selection. This includes
4513 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4514 L</search> calls, and standalone columns selected via
4515 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4516 extra selections specified via L</prefetch> - such selections are explicitly
4517 excluded from group criteria calculations.
4519 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4520 setting is ignored and an appropriate warning is issued.
4526 Adds to the WHERE clause.
4528 # only return rows WHERE deleted IS NULL for all searches
4529 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4531 Can be overridden by passing C<< { where => undef } >> as an attribute
4534 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4540 Set to 1 to cache search results. This prevents extra SQL queries if you
4541 revisit rows in your ResultSet:
4543 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4545 while( my $artist = $resultset->next ) {
4549 $rs->first; # without cache, this would issue a query
4551 By default, searches are not cached.
4553 For more examples of using these attributes, see
4554 L<DBIx::Class::Manual::Cookbook>.
4560 =item Value: ( 'update' | 'shared' | \$scalar )
4564 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4565 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4570 DBIx::Class supports arbitrary related data prefetching from multiple related
4571 sources. Any combination of relationship types and column sets are supported.
4572 If L<collapsing|/collapse> is requested, there is an additional requirement of
4573 selecting enough data to make every individual object uniquely identifiable.
4575 Here are some more involved examples, based on the following relationship map:
4578 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4579 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4580 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4582 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4584 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4588 my $rs = $schema->resultset('Tag')->search(
4597 The initial search results in SQL like the following:
4599 SELECT tag.*, cd.*, artist.* FROM tag
4600 JOIN cd ON tag.cd = cd.cdid
4601 JOIN artist ON cd.artist = artist.artistid
4603 L<DBIx::Class> has no need to go back to the database when we access the
4604 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4607 Simple prefetches will be joined automatically, so there is no need
4608 for a C<join> attribute in the above search.
4610 The L</prefetch> attribute can be used with any of the relationship types
4611 and multiple prefetches can be specified together. Below is a more complex
4612 example that prefetches a CD's artist, its liner notes (if present),
4613 the cover image, the tracks on that CD, and the guests on those
4616 my $rs = $schema->resultset('CD')->search(
4620 { artist => 'record_label'}, # belongs_to => belongs_to
4621 'liner_note', # might_have
4622 'cover_image', # has_one
4623 { tracks => 'guests' }, # has_many => has_many
4628 This will produce SQL like the following:
4630 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4634 ON artist.artistid = me.artistid
4635 JOIN record_label record_label
4636 ON record_label.labelid = artist.labelid
4637 LEFT JOIN track tracks
4638 ON tracks.cdid = me.cdid
4639 LEFT JOIN guest guests
4640 ON guests.trackid = track.trackid
4641 LEFT JOIN liner_notes liner_note
4642 ON liner_note.cdid = me.cdid
4643 JOIN cd_artwork cover_image
4644 ON cover_image.cdid = me.cdid
4647 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4648 C<tracks>, and C<guests> of the CD will all be available through the
4649 relationship accessors without the need for additional queries to the
4654 Prefetch does a lot of deep magic. As such, it may not behave exactly
4655 as you might expect.
4661 Prefetch uses the L</cache> to populate the prefetched relationships. This
4662 may or may not be what you want.
4666 If you specify a condition on a prefetched relationship, ONLY those
4667 rows that match the prefetched condition will be fetched into that relationship.
4668 This means that adding prefetch to a search() B<may alter> what is returned by
4669 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4671 my $artist_rs = $schema->resultset('Artist')->search({
4677 my $count = $artist_rs->first->cds->count;
4679 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4681 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4683 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4685 That cmp_ok() may or may not pass depending on the datasets involved. In other
4686 words the C<WHERE> condition would apply to the entire dataset, just like
4687 it would in regular SQL. If you want to add a condition only to the "right side"
4688 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4689 condition|DBIx::Class::Relationship::Base/condition>
4693 =head1 DBIC BIND VALUES
4695 Because DBIC may need more information to bind values than just the column name
4696 and value itself, it uses a special format for both passing and receiving bind
4697 values. Each bind value should be composed of an arrayref of
4698 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4704 If present (in any form), this is what is being passed directly to bind_param.
4705 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4706 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4708 If this is specified, all other bind options described below are ignored.
4712 If present, this is used to infer the actual bind attribute by passing to
4713 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4714 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4716 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4717 currently drivers are expected to "Do the Right Thing" when given a common
4718 datatype name. (Not ideal, but that's what we got at this point.)
4722 Currently used to correctly allocate buffers for bind_param_inout().
4723 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4724 or to a sensible value based on the "data_type".
4728 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4729 explicitly specified they are never overridden). Also used by some weird DBDs,
4730 where the column name should be available at bind_param time (e.g. Oracle).
4734 For backwards compatibility and convenience, the following shortcuts are
4737 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4738 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4739 [ undef, $val ] === [ {}, $val ]
4740 $val === [ {}, $val ]
4742 =head1 AUTHOR AND CONTRIBUTORS
4744 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4748 You may distribute this code under the same terms as Perl itself.