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::Compare (); # no imports!!! guard against insane architecture
13 # not importing first() as it will clash with our own method
17 # De-duplication in _merge_attr() is disabled, but left in for reference
18 # (the merger is used for other things that ought not to be de-duped)
19 *__HM_DEDUP = sub () { 0 };
29 # this is real - CDBICompat overrides it with insanity
30 # yes, prototype won't matter, but that's for now ;)
33 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
37 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
41 my $users_rs = $schema->resultset('User');
42 while( $user = $users_rs->next) {
43 print $user->username;
46 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
47 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
51 A ResultSet is an object which stores a set of conditions representing
52 a query. It is the backbone of DBIx::Class (i.e. the really
53 important/useful bit).
55 No SQL is executed on the database when a ResultSet is created, it
56 just stores all the conditions needed to create the query.
58 A basic ResultSet representing the data of an entire table is returned
59 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
60 L<Source|DBIx::Class::Manual::Glossary/Source> name.
62 my $users_rs = $schema->resultset('User');
64 A new ResultSet is returned from calling L</search> on an existing
65 ResultSet. The new one will contain all the conditions of the
66 original, plus any new conditions added in the C<search> call.
68 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
69 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
72 The query that the ResultSet represents is B<only> executed against
73 the database when these methods are called:
74 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
76 If a resultset is used in a numeric context it returns the L</count>.
77 However, if it is used in a boolean context it is B<always> true. So if
78 you want to check if a resultset has any results, you must use C<if $rs
81 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
83 If you want to make your custom ResultSet classes with L<Moose>, use a template
86 package MyApp::Schema::ResultSet::User;
89 use namespace::autoclean;
91 extends 'DBIx::Class::ResultSet';
93 sub BUILDARGS { $_[2] }
97 __PACKAGE__->meta->make_immutable;
101 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
102 clash with the regular ResultSet constructor. Alternatively, you can use:
104 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
106 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
107 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
111 =head2 Chaining resultsets
113 Let's say you've got a query that needs to be run to return some data
114 to the user. But, you have an authorization system in place that
115 prevents certain users from seeing certain information. So, you want
116 to construct the basic query in one method, but add constraints to it in
121 my $request = $self->get_request; # Get a request object somehow.
122 my $schema = $self->result_source->schema;
124 my $cd_rs = $schema->resultset('CD')->search({
125 title => $request->param('title'),
126 year => $request->param('year'),
129 $cd_rs = $self->apply_security_policy( $cd_rs );
131 return $cd_rs->all();
134 sub apply_security_policy {
143 =head3 Resolving conditions and attributes
145 When a resultset is chained from another resultset (e.g.:
146 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
147 and attributes with the same keys need resolving.
149 If any of L</columns>, L</select>, L</as> are present, they reset the
150 original selection, and start the selection "clean".
152 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
153 are merged into the existing ones from the original resultset.
155 The L</where> and L</having> attributes, and any search conditions, are
156 merged with an SQL C<AND> to the existing condition from the original
159 All other attributes are overridden by any new ones supplied in the
162 =head2 Multiple queries
164 Since a resultset just defines a query, you can do all sorts of
165 things with it with the same object.
167 # Don't hit the DB yet.
168 my $cd_rs = $schema->resultset('CD')->search({
169 title => 'something',
173 # Each of these hits the DB individually.
174 my $count = $cd_rs->count;
175 my $most_recent = $cd_rs->get_column('date_released')->max();
176 my @records = $cd_rs->all;
178 And it's not just limited to SELECT statements.
184 $cd_rs->create({ artist => 'Fred' });
186 Which is the same as:
188 $schema->resultset('CD')->create({
189 title => 'something',
194 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
202 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
204 =item Return Value: L<$resultset|/search>
208 The resultset constructor. Takes a source object (usually a
209 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
210 L</ATTRIBUTES> below). Does not perform any queries -- these are
211 executed as needed by the other methods.
213 Generally you never construct a resultset manually. Instead you get one
215 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
216 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
219 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
225 If called on an object, proxies to L</new_result> instead, so
227 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
229 will return a CD object, not a ResultSet, and is equivalent to:
231 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
233 Please also keep in mind that many internals call L</new_result> directly,
234 so overloading this method with the idea of intercepting new result object
235 creation B<will not work>. See also warning pertaining to L</create>.
243 return $class->new_result(@_) if ref $class;
245 my ($source, $attrs) = @_;
246 $source = $source->resolve
247 if $source->isa('DBIx::Class::ResultSourceHandle');
249 $attrs = { %{$attrs||{}} };
250 delete @{$attrs}{qw(_last_sqlmaker_alias_map _related_results_construction)};
252 if ($attrs->{page}) {
253 $attrs->{rows} ||= 10;
256 $attrs->{alias} ||= 'me';
259 result_source => $source,
260 cond => $attrs->{where},
265 # if there is a dark selector, this means we are already in a
266 # chain and the cleanup/sanification was taken care of by
268 $self->_normalize_selection($attrs)
269 unless $attrs->{_dark_selector};
272 $attrs->{result_class} || $source->result_class
282 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
284 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
288 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
289 my $new_rs = $cd_rs->search({ year => 2005 });
291 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
292 # year = 2005 OR year = 2004
294 In list context, C<< ->all() >> is called implicitly on the resultset, thus
295 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
296 To avoid that, use L</search_rs>.
298 If you need to pass in additional attributes but no additional condition,
299 call it as C<search(undef, \%attrs)>.
301 # "SELECT name, artistid FROM $artist_table"
302 my @all_artists = $schema->resultset('Artist')->search(undef, {
303 columns => [qw/name artistid/],
306 For a list of attributes that can be passed to C<search>, see
307 L</ATTRIBUTES>. For more examples of using this function, see
308 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
309 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
310 and its extension L<DBIx::Class::SQLMaker>.
312 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
316 Note that L</search> does not process/deflate any of the values passed in the
317 L<SQL::Abstract>-compatible search condition structure. This is unlike other
318 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
319 manually that any value passed to this method will stringify to something the
320 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
321 objects, for more info see:
322 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
328 my $rs = $self->search_rs( @_ );
331 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray($rs);
334 elsif (defined wantarray) {
338 # we can be called by a relationship helper, which in
339 # turn may be called in void context due to some braindead
340 # overload or whatever else the user decided to be clever
341 # at this particular day. Thus limit the exception to
342 # external code calls only
343 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
344 if (caller)[0] !~ /^\QDBIx::Class::/;
354 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
356 =item Return Value: L<$resultset|/search>
360 This method does the same exact thing as search() except it will
361 always return a resultset, even in list context.
368 my $rsrc = $self->result_source;
369 my ($call_cond, $call_attrs);
371 # Special-case handling for (undef, undef) or (undef)
372 # Note that (foo => undef) is valid deprecated syntax
373 @_ = () if not scalar grep { defined $_ } @_;
379 # fish out attrs in the ($condref, $attr) case
380 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
381 ($call_cond, $call_attrs) = @_;
384 $self->throw_exception('Odd number of arguments to search')
388 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
389 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
391 for my $i (0 .. $#_) {
393 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
394 if (! defined $_[$i] or ref $_[$i] ne '');
400 # see if we can keep the cache (no $rs changes)
402 my %safe = (alias => 1, cache => 1);
403 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
406 ref $call_cond eq 'HASH' && ! keys %$call_cond
408 ref $call_cond eq 'ARRAY' && ! @$call_cond
410 $cache = $self->get_cache;
413 my $old_attrs = { %{$self->{attrs}} };
414 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
416 my $new_attrs = { %$old_attrs };
418 # take care of call attrs (only if anything is changing)
419 if ($call_attrs and keys %$call_attrs) {
421 # copy for _normalize_selection
422 $call_attrs = { %$call_attrs };
424 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
426 # reset the current selector list if new selectors are supplied
427 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
428 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
431 # Normalize the new selector list (operates on the passed-in attr structure)
432 # Need to do it on every chain instead of only once on _resolved_attrs, in
433 # order to allow detection of empty vs partial 'as'
434 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
435 if $old_attrs->{_dark_selector};
436 $self->_normalize_selection ($call_attrs);
438 # start with blind overwriting merge, exclude selector attrs
439 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
440 delete @{$new_attrs}{@selector_attrs};
442 for (@selector_attrs) {
443 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
444 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
447 # older deprecated name, use only if {columns} is not there
448 if (my $c = delete $new_attrs->{cols}) {
449 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
450 if ($new_attrs->{columns}) {
451 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
454 $new_attrs->{columns} = $c;
459 # join/prefetch use their own crazy merging heuristics
460 foreach my $key (qw/join prefetch/) {
461 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
462 if exists $call_attrs->{$key};
465 # stack binds together
466 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
470 for ($old_where, $call_cond) {
472 $new_attrs->{where} = $self->_stack_cond (
473 $_, $new_attrs->{where}
478 if (defined $old_having) {
479 $new_attrs->{having} = $self->_stack_cond (
480 $old_having, $new_attrs->{having}
484 my $rs = (ref $self)->new($rsrc, $new_attrs);
486 $rs->set_cache($cache) if ($cache);
492 sub _normalize_selection {
493 my ($self, $attrs) = @_;
496 if ( exists $attrs->{include_columns} ) {
497 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
498 $attrs->{'+columns'} = $self->_merge_attr(
499 $attrs->{'+columns'}, delete $attrs->{include_columns}
503 # columns are always placed first, however
505 # Keep the X vs +X separation until _resolved_attrs time - this allows to
506 # delay the decision on whether to use a default select list ($rsrc->columns)
507 # allowing stuff like the remove_columns helper to work
509 # select/as +select/+as pairs need special handling - the amount of select/as
510 # elements in each pair does *not* have to be equal (think multicolumn
511 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
512 # supplied at all) - try to infer the alias, either from the -as parameter
513 # of the selector spec, or use the parameter whole if it looks like a column
514 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
515 # is ok as well), but make sure no more additions to the 'as' chain take place
516 for my $pref ('', '+') {
518 my ($sel, $as) = map {
519 my $key = "${pref}${_}";
521 my $val = [ ref $attrs->{$key} eq 'ARRAY'
523 : $attrs->{$key} || ()
525 delete $attrs->{$key};
529 if (! @$as and ! @$sel ) {
532 elsif (@$as and ! @$sel) {
533 $self->throw_exception(
534 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
538 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
539 # if any @$as has been supplied we assume the user knows what (s)he is doing
540 # and blindly keep stacking up pieces
541 unless ($attrs->{_dark_selector}) {
544 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
545 push @$as, $_->{-as};
547 # assume any plain no-space, no-parenthesis string to be a column spec
548 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
549 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
552 # if all else fails - raise a flag that no more aliasing will be allowed
554 $attrs->{_dark_selector} = {
556 string => ($dark_sel_dumper ||= do {
557 require Data::Dumper::Concise;
558 Data::Dumper::Concise::DumperObject()->Indent(0);
559 })->Values([$_])->Dump
567 elsif (@$as < @$sel) {
568 $self->throw_exception(
569 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
572 elsif ($pref and $attrs->{_dark_selector}) {
573 $self->throw_exception(
574 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
580 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
581 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
586 my ($self, $left, $right) = @_;
588 # collapse single element top-level conditions
589 # (single pass only, unlikely to need recursion)
590 for ($left, $right) {
591 if (ref $_ eq 'ARRAY') {
599 elsif (ref $_ eq 'HASH') {
600 my ($first, $more) = keys %$_;
603 if (! defined $first) {
607 elsif (! defined $more) {
608 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
611 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
618 # merge hashes with weeding out of duplicates (simple cases only)
619 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
621 # shallow copy to destroy
622 $right = { %$right };
623 for (grep { exists $right->{$_} } keys %$left) {
624 # the use of eq_deeply here is justified - the rhs of an
625 # expression can contain a lot of twisted weird stuff
626 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
629 $right = undef unless keys %$right;
633 if (defined $left xor defined $right) {
634 return defined $left ? $left : $right;
636 elsif (! defined $left) {
640 return { -and => [ $left, $right ] };
644 =head2 search_literal
646 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
647 should only be used in that context. C<search_literal> is a convenience
648 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
649 want to ensure columns are bound correctly, use L</search>.
651 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
652 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
653 require C<search_literal>.
657 =item Arguments: $sql_fragment, @standalone_bind_values
659 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
663 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
664 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
666 Pass a literal chunk of SQL to be added to the conditional part of the
669 Example of how to use C<search> instead of C<search_literal>
671 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
672 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
677 my ($self, $sql, @bind) = @_;
679 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
682 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
689 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
691 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
695 Finds and returns a single row based on supplied criteria. Takes either a
696 hashref with the same format as L</create> (including inference of foreign
697 keys from related objects), or a list of primary key values in the same
698 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
699 declaration on the L</result_source>.
701 In either case an attempt is made to combine conditions already existing on
702 the resultset with the condition passed to this method.
704 To aid with preparing the correct query for the storage you may supply the
705 C<key> attribute, which is the name of a
706 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
707 unique constraint corresponding to the
708 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
709 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
710 to construct a query that satisfies the named unique constraint fully (
711 non-NULL values for each column member of the constraint) an exception is
714 If no C<key> is specified, the search is carried over all unique constraints
715 which are fully defined by the available condition.
717 If no such constraint is found, C<find> currently defaults to a simple
718 C<< search->(\%column_values) >> which may or may not do what you expect.
719 Note that this fallback behavior may be deprecated in further versions. If
720 you need to search with arbitrary conditions - use L</search>. If the query
721 resulting from this fallback produces more than one row, a warning to the
722 effect is issued, though only the first row is constructed and returned as
725 In addition to C<key>, L</find> recognizes and applies standard
726 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
728 Note that if you have extra concerns about the correctness of the resulting
729 query you need to specify the C<key> attribute and supply the entire condition
730 as an argument to find (since it is not always possible to perform the
731 combination of the resultset condition with the supplied one, especially if
732 the resultset condition contains literal sql).
734 For example, to find a row by its primary key:
736 my $cd = $schema->resultset('CD')->find(5);
738 You can also find a row by a specific unique constraint:
740 my $cd = $schema->resultset('CD')->find(
742 artist => 'Massive Attack',
743 title => 'Mezzanine',
745 { key => 'cd_artist_title' }
748 See also L</find_or_create> and L</update_or_create>.
754 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
756 my $rsrc = $self->result_source;
759 if (exists $attrs->{key}) {
760 $constraint_name = defined $attrs->{key}
762 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
766 # Parse out the condition from input
769 if (ref $_[0] eq 'HASH') {
770 $call_cond = { %{$_[0]} };
773 # if only values are supplied we need to default to 'primary'
774 $constraint_name = 'primary' unless defined $constraint_name;
776 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
778 $self->throw_exception(
779 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
782 $self->throw_exception (
783 'find() expects either a column/value hashref, or a list of values '
784 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
785 ) unless @c_cols == @_;
788 @{$call_cond}{@c_cols} = @_;
792 for my $key (keys %$call_cond) {
794 my $keyref = ref($call_cond->{$key})
796 my $relinfo = $rsrc->relationship_info($key)
798 my $val = delete $call_cond->{$key};
800 next if $keyref eq 'ARRAY'; # has_many for multi_create
802 my $rel_q = $rsrc->_resolve_condition(
803 $relinfo->{cond}, $val, $key, $key
805 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
806 @related{keys %$rel_q} = values %$rel_q;
810 # relationship conditions take precedence (?)
811 @{$call_cond}{keys %related} = values %related;
813 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
815 if (defined $constraint_name) {
816 $final_cond = $self->_qualify_cond_columns (
818 $self->_build_unique_cond (
826 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
827 # This means that we got here after a merger of relationship conditions
828 # in ::Relationship::Base::search_related (the row method), and furthermore
829 # the relationship is of the 'single' type. This means that the condition
830 # provided by the relationship (already attached to $self) is sufficient,
831 # as there can be only one row in the database that would satisfy the
835 # no key was specified - fall down to heuristics mode:
836 # run through all unique queries registered on the resultset, and
837 # 'OR' all qualifying queries together
838 my (@unique_queries, %seen_column_combinations);
839 for my $c_name ($rsrc->unique_constraint_names) {
840 next if $seen_column_combinations{
841 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
844 push @unique_queries, try {
845 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
849 $final_cond = @unique_queries
850 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
851 : $self->_non_unique_find_fallback ($call_cond, $attrs)
855 # Run the query, passing the result_class since it should propagate for find
856 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
857 if ($rs->_resolved_attrs->{collapse}) {
859 carp "Query returned more than one row" if $rs->next;
867 # This is a stop-gap method as agreed during the discussion on find() cleanup:
868 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
870 # It is invoked when find() is called in legacy-mode with insufficiently-unique
871 # condition. It is provided for overrides until a saner way forward is devised
873 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
874 # the road. Please adjust your tests accordingly to catch this situation early
875 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
877 # The method will not be removed without an adequately complete replacement
878 # for strict-mode enforcement
879 sub _non_unique_find_fallback {
880 my ($self, $cond, $attrs) = @_;
882 return $self->_qualify_cond_columns(
884 exists $attrs->{alias}
886 : $self->{attrs}{alias}
891 sub _qualify_cond_columns {
892 my ($self, $cond, $alias) = @_;
894 my %aliased = %$cond;
895 for (keys %aliased) {
896 $aliased{"$alias.$_"} = delete $aliased{$_}
903 sub _build_unique_cond {
904 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
906 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
908 # combination may fail if $self->{cond} is non-trivial
909 my ($final_cond) = try {
910 $self->_merge_with_rscond ($extra_cond)
915 # trim out everything not in $columns
916 $final_cond = { map {
917 exists $final_cond->{$_}
918 ? ( $_ => $final_cond->{$_} )
922 if (my @missing = grep
923 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
926 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
928 join (', ', map { "'$_'" } @missing),
935 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
937 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
939 carp_unique ( sprintf (
940 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
941 . 'values in column(s): %s). This is almost certainly not what you wanted, '
942 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
944 join (', ', map { "'$_'" } @undefs),
951 =head2 search_related
955 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
957 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
961 $new_rs = $cd_rs->search_related('artist', {
965 Searches the specified relationship, optionally specifying a condition and
966 attributes for matching records. See L</ATTRIBUTES> for more information.
968 In list context, C<< ->all() >> is called implicitly on the resultset, thus
969 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
971 See also L</search_related_rs>.
976 return shift->related_resultset(shift)->search(@_);
979 =head2 search_related_rs
981 This method works exactly the same as search_related, except that
982 it guarantees a resultset, even in list context.
986 sub search_related_rs {
987 return shift->related_resultset(shift)->search_rs(@_);
994 =item Arguments: none
996 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1000 Returns a storage-driven cursor to the given resultset. See
1001 L<DBIx::Class::Cursor> for more information.
1008 return $self->{cursor} ||= do {
1009 my $attrs = $self->_resolved_attrs;
1010 $self->result_source->storage->select(
1011 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1020 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1022 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1026 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1028 Inflates the first result without creating a cursor if the resultset has
1029 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1032 While this method can take an optional search condition (just like L</search>)
1033 being a fast-code-path it does not recognize search attributes. If you need to
1034 add extra joins or similar, call L</search> and then chain-call L</single> on the
1035 L<DBIx::Class::ResultSet> returned.
1041 As of 0.08100, this method enforces the assumption that the preceding
1042 query returns only one row. If more than one row is returned, you will receive
1045 Query returned more than one row
1047 In this case, you should be using L</next> or L</find> instead, or if you really
1048 know what you are doing, use the L</rows> attribute to explicitly limit the size
1051 This method will also throw an exception if it is called on a resultset prefetching
1052 has_many, as such a prefetch implies fetching multiple rows from the database in
1053 order to assemble the resulting object.
1060 my ($self, $where) = @_;
1062 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1065 my $attrs = { %{$self->_resolved_attrs} };
1067 $self->throw_exception(
1068 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1069 ) if $attrs->{collapse};
1072 if (defined $attrs->{where}) {
1075 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1076 $where, delete $attrs->{where} ]
1079 $attrs->{where} = $where;
1083 my $data = [ $self->result_source->storage->select_single(
1084 $attrs->{from}, $attrs->{select},
1085 $attrs->{where}, $attrs
1088 return undef unless @$data;
1089 $self->{_stashed_rows} = [ $data ];
1090 $self->_construct_results->[0];
1096 # Recursively collapse the query, accumulating values for each column.
1098 sub _collapse_query {
1099 my ($self, $query, $collapsed) = @_;
1103 if (ref $query eq 'ARRAY') {
1104 foreach my $subquery (@$query) {
1105 next unless ref $subquery; # -or
1106 $collapsed = $self->_collapse_query($subquery, $collapsed);
1109 elsif (ref $query eq 'HASH') {
1110 if (keys %$query and (keys %$query)[0] eq '-and') {
1111 foreach my $subquery (@{$query->{-and}}) {
1112 $collapsed = $self->_collapse_query($subquery, $collapsed);
1116 foreach my $col (keys %$query) {
1117 my $value = $query->{$col};
1118 $collapsed->{$col}{$value}++;
1130 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1132 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1136 my $max_length = $rs->get_column('length')->max;
1138 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1143 my ($self, $column) = @_;
1144 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1152 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1154 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1158 # WHERE title LIKE '%blue%'
1159 $cd_rs = $rs->search_like({ title => '%blue%'});
1161 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1162 that this is simply a convenience method retained for ex Class::DBI users.
1163 You most likely want to use L</search> with specific operators.
1165 For more information, see L<DBIx::Class::Manual::Cookbook>.
1167 This method is deprecated and will be removed in 0.09. Use L</search()>
1168 instead. An example conversion is:
1170 ->search_like({ foo => 'bar' });
1174 ->search({ foo => { like => 'bar' } });
1181 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1182 .' Instead use ->search({ x => { -like => "y%" } })'
1183 .' (note the outer pair of {}s - they are important!)'
1185 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1186 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1187 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1188 return $class->search($query, { %$attrs });
1195 =item Arguments: $first, $last
1197 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1201 Returns a resultset or object list representing a subset of elements from the
1202 resultset slice is called on. Indexes are from 0, i.e., to get the first
1203 three records, call:
1205 my ($one, $two, $three) = $rs->slice(0, 2);
1210 my ($self, $min, $max) = @_;
1211 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1212 $attrs->{offset} = $self->{attrs}{offset} || 0;
1213 $attrs->{offset} += $min;
1214 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1215 return $self->search(undef, $attrs);
1222 =item Arguments: none
1224 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1228 Returns the next element in the resultset (C<undef> is there is none).
1230 Can be used to efficiently iterate over records in the resultset:
1232 my $rs = $schema->resultset('CD')->search;
1233 while (my $cd = $rs->next) {
1237 Note that you need to store the resultset object, and call C<next> on it.
1238 Calling C<< resultset('Table')->next >> repeatedly will always return the
1239 first record from the resultset.
1246 if (my $cache = $self->get_cache) {
1247 $self->{all_cache_position} ||= 0;
1248 return $cache->[$self->{all_cache_position}++];
1251 if ($self->{attrs}{cache}) {
1252 delete $self->{pager};
1253 $self->{all_cache_position} = 1;
1254 return ($self->all)[0];
1257 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1259 $self->{_stashed_results} = $self->_construct_results
1262 return shift @{$self->{_stashed_results}};
1265 # Constructs as many results as it can in one pass while respecting
1266 # cursor laziness. Several modes of operation:
1268 # * Always builds everything present in @{$self->{_stashed_rows}}
1269 # * If called with $fetch_all true - pulls everything off the cursor and
1270 # builds all result structures (or objects) in one pass
1271 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1272 # and if the resultset is ordered properly by the left side:
1273 # * Fetches stuff off the cursor until the "master object" changes,
1274 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1276 # * Just fetches, and collapses/constructs everything as if $fetch_all
1277 # was requested (there is no other way to collapse except for an
1279 # * If no collapse is requested - just get the next row, construct and
1281 sub _construct_results {
1282 my ($self, $fetch_all) = @_;
1284 my $rsrc = $self->result_source;
1285 my $attrs = $self->_resolved_attrs;
1290 ! $attrs->{order_by}
1294 my @pcols = $rsrc->primary_columns
1296 # default order for collapsing unless the user asked for something
1297 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1298 $attrs->{_ordered_for_collapse} = 1;
1299 $attrs->{_order_is_artificial} = 1;
1302 # this will be used as both initial raw-row collector AND as a RV of
1303 # _construct_results. Not regrowing the array twice matters a lot...
1304 # a surprising amount actually
1305 my $rows = delete $self->{_stashed_rows};
1307 my $cursor; # we may not need one at all
1309 my $did_fetch_all = $fetch_all;
1312 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1313 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1315 elsif( $attrs->{collapse} ) {
1317 # a cursor will need to be closed over in case of collapse
1318 $cursor = $self->cursor;
1320 $attrs->{_ordered_for_collapse} = (
1326 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1328 ) unless defined $attrs->{_ordered_for_collapse};
1330 if (! $attrs->{_ordered_for_collapse}) {
1333 # instead of looping over ->next, use ->all in stealth mode
1334 # *without* calling a ->reset afterwards
1335 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1336 if (! $cursor->{_done}) {
1337 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1338 $cursor->{_done} = 1;
1343 if (! $did_fetch_all and ! @{$rows||[]} ) {
1344 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1345 $cursor ||= $self->cursor;
1346 if (scalar (my @r = $cursor->next) ) {
1351 return undef unless @{$rows||[]};
1353 # sanity check - people are too clever for their own good
1354 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1356 my $multiplied_selectors;
1357 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1359 $aliastypes->{multiplying}{$sel_alias}
1361 $aliastypes->{premultiplied}{$sel_alias}
1363 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1367 for my $i (0 .. $#{$attrs->{as}} ) {
1368 my $sel = $attrs->{select}[$i];
1370 if (ref $sel eq 'SCALAR') {
1373 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1377 $self->throw_exception(
1378 'Result collapse not possible - selection from a has_many source redirected to the main object'
1379 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1383 # hotspot - skip the setter
1384 my $res_class = $self->_result_class;
1386 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1387 $res_class->can ('inflate_result')
1388 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1391 my $infmap = $attrs->{as};
1393 $self->{_result_inflator}{is_core_row} = ( (
1396 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1397 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1399 $self->{_result_inflator}{is_hri} = ( (
1400 ! $self->{_result_inflator}{is_core_row}
1403 require DBIx::Class::ResultClass::HashRefInflator
1405 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1407 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1410 if (! $attrs->{_related_results_construction}) {
1411 # construct a much simpler array->hash folder for the one-table cases right here
1412 if ($self->{_result_inflator}{is_hri}) {
1413 for my $r (@$rows) {
1414 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1417 # FIXME SUBOPTIMAL this is a very very very hot spot
1418 # while rather optimal we can *still* do much better, by
1419 # building a smarter Row::inflate_result(), and
1420 # switch to feeding it data via a much leaner interface
1422 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1423 # this particular resultset size
1424 elsif (@$rows < 60) {
1425 for my $r (@$rows) {
1426 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1431 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1432 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1438 $self->{_result_inflator}{is_hri} ? 'hri'
1439 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1440 : 'classic_nonpruning'
1443 # $args and $attrs to _mk_row_parser are separated to delineate what is
1444 # core collapser stuff and what is dbic $rs specific
1445 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1447 inflate_map => $infmap,
1448 collapse => $attrs->{collapse},
1449 premultiplied => $attrs->{_main_source_premultiplied},
1450 hri_style => $self->{_result_inflator}{is_hri},
1451 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1452 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1454 # column_info metadata historically hasn't been too reliable.
1455 # We need to start fixing this somehow (the collapse resolver
1456 # can't work without it). Add an explicit check for the *main*
1457 # result, hopefully this will gradually weed out such errors
1459 # FIXME - this is a temporary kludge that reduces performance
1460 # It is however necessary for the time being
1461 my ($unrolled_non_null_cols_to_check, $err);
1463 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1466 'Collapse aborted due to invalid ResultSource metadata - the following '
1467 . 'selections are declared non-nullable but NULLs were retrieved: '
1471 COL: for my $i (@$check_non_null_cols) {
1472 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1475 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1478 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1482 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1483 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1485 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1486 my @r = $cursor->next or return;
1487 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1488 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1494 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1495 my @r = $cursor->next or return;
1500 $self->{_row_parser}{$parser_type}{cref}->(
1502 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1505 # Special-case multi-object HRI - there is no $inflator_cref pass
1506 unless ($self->{_result_inflator}{is_hri}) {
1507 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1511 # The @$rows check seems odd at first - why wouldn't we want to warn
1512 # regardless? The issue is things like find() etc, where the user
1513 # *knows* only one result will come back. In these cases the ->all
1514 # is not a pessimization, but rather something we actually want
1516 'Unable to properly collapse has_many results in iterator mode due '
1517 . 'to order criteria - performed an eager cursor slurp underneath. '
1518 . 'Consider using ->all() instead'
1519 ) if ( ! $fetch_all and @$rows > 1 );
1524 =head2 result_source
1528 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1530 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1534 An accessor for the primary ResultSource object from which this ResultSet
1541 =item Arguments: $result_class?
1543 =item Return Value: $result_class
1547 An accessor for the class to use when creating result objects. Defaults to
1548 C<< result_source->result_class >> - which in most cases is the name of the
1549 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1551 Note that changing the result_class will also remove any components
1552 that were originally loaded in the source class via
1553 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1554 in the original source class will not run.
1559 my ($self, $result_class) = @_;
1560 if ($result_class) {
1562 # don't fire this for an object
1563 $self->ensure_class_loaded($result_class)
1564 unless ref($result_class);
1566 if ($self->get_cache) {
1567 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1569 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1570 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1571 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1574 $self->_result_class($result_class);
1576 delete $self->{_result_inflator};
1578 $self->_result_class;
1585 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1587 =item Return Value: $count
1591 Performs an SQL C<COUNT> with the same query as the resultset was built
1592 with to find the number of elements. Passing arguments is equivalent to
1593 C<< $rs->search ($cond, \%attrs)->count >>
1599 return $self->search(@_)->count if @_ and defined $_[0];
1600 return scalar @{ $self->get_cache } if $self->get_cache;
1602 my $attrs = { %{ $self->_resolved_attrs } };
1604 # this is a little optimization - it is faster to do the limit
1605 # adjustments in software, instead of a subquery
1606 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1609 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1610 $crs = $self->_count_subq_rs ($attrs);
1613 $crs = $self->_count_rs ($attrs);
1615 my $count = $crs->next;
1617 $count -= $offset if $offset;
1618 $count = $rows if $rows and $rows < $count;
1619 $count = 0 if ($count < 0);
1628 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1630 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1634 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1635 This can be very handy for subqueries:
1637 ->search( { amount => $some_rs->count_rs->as_query } )
1639 As with regular resultsets the SQL query will be executed only after
1640 the resultset is accessed via L</next> or L</all>. That would return
1641 the same single value obtainable via L</count>.
1647 return $self->search(@_)->count_rs if @_;
1649 # this may look like a lack of abstraction (count() does about the same)
1650 # but in fact an _rs *must* use a subquery for the limits, as the
1651 # software based limiting can not be ported if this $rs is to be used
1652 # in a subquery itself (i.e. ->as_query)
1653 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1654 return $self->_count_subq_rs($self->{_attrs});
1657 return $self->_count_rs($self->{_attrs});
1662 # returns a ResultSetColumn object tied to the count query
1665 my ($self, $attrs) = @_;
1667 my $rsrc = $self->result_source;
1669 my $tmp_attrs = { %$attrs };
1670 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1671 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1673 # overwrite the selector (supplied by the storage)
1674 $rsrc->resultset_class->new($rsrc, {
1676 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1678 })->get_column ('count');
1682 # same as above but uses a subquery
1684 sub _count_subq_rs {
1685 my ($self, $attrs) = @_;
1687 my $rsrc = $self->result_source;
1689 my $sub_attrs = { %$attrs };
1690 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1691 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1693 # if we multi-prefetch we group_by something unique, as this is what we would
1694 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1695 if ( $attrs->{collapse} ) {
1696 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1697 $rsrc->_identifying_column_set || $self->throw_exception(
1698 'Unable to construct a unique group_by criteria properly collapsing the '
1699 . 'has_many prefetch before count()'
1704 # Calculate subquery selector
1705 if (my $g = $sub_attrs->{group_by}) {
1707 my $sql_maker = $rsrc->storage->sql_maker;
1709 # necessary as the group_by may refer to aliased functions
1711 for my $sel (@{$attrs->{select}}) {
1712 $sel_index->{$sel->{-as}} = $sel
1713 if (ref $sel eq 'HASH' and $sel->{-as});
1716 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1717 # also look for named aggregates referred in the having clause
1718 # having often contains scalarrefs - thus parse it out entirely
1720 if ($attrs->{having}) {
1721 local $sql_maker->{having_bind};
1722 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1723 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1724 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1725 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1726 # if we don't unset it we screw up retarded but unfortunately working
1727 # 'MAX(foo.bar)' => { '>', 3 }
1728 $sql_maker->{name_sep} = '';
1731 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1733 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1736 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1737 # and if all fails for an utterly naive quoted scalar-with-function
1738 while ($having_sql =~ /
1739 $rquote $sep $lquote (.+?) $rquote
1741 [\s,] \w+ \. (\w+) [\s,]
1743 [\s,] $lquote (.+?) $rquote [\s,]
1745 my $part = $1 || $2 || $3; # one of them matched if we got here
1746 unless ($seen_having{$part}++) {
1753 my $colpiece = $sel_index->{$_} || $_;
1755 # unqualify join-based group_by's. Arcane but possible query
1756 # also horrible horrible hack to alias a column (not a func.)
1757 # (probably need to introduce SQLA syntax)
1758 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1761 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1763 push @{$sub_attrs->{select}}, $colpiece;
1767 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1768 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1771 return $rsrc->resultset_class
1772 ->new ($rsrc, $sub_attrs)
1774 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1775 ->get_column ('count');
1779 =head2 count_literal
1781 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1782 should only be used in that context. See L</search_literal> for further info.
1786 =item Arguments: $sql_fragment, @standalone_bind_values
1788 =item Return Value: $count
1792 Counts the results in a literal query. Equivalent to calling L</search_literal>
1793 with the passed arguments, then L</count>.
1797 sub count_literal { shift->search_literal(@_)->count; }
1803 =item Arguments: none
1805 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1809 Returns all elements in the resultset.
1816 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1819 delete @{$self}{qw/_stashed_rows _stashed_results/};
1821 if (my $c = $self->get_cache) {
1825 $self->cursor->reset;
1827 my $objs = $self->_construct_results('fetch_all') || [];
1829 $self->set_cache($objs) if $self->{attrs}{cache};
1838 =item Arguments: none
1840 =item Return Value: $self
1844 Resets the resultset's cursor, so you can iterate through the elements again.
1845 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1853 delete @{$self}{qw/_stashed_rows _stashed_results/};
1854 $self->{all_cache_position} = 0;
1855 $self->cursor->reset;
1863 =item Arguments: none
1865 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1869 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1870 an object for the first result (or C<undef> if the resultset is empty).
1875 return $_[0]->reset->next;
1881 # Determines whether and what type of subquery is required for the $rs operation.
1882 # If grouping is necessary either supplies its own, or verifies the current one
1883 # After all is done delegates to the proper storage method.
1885 sub _rs_update_delete {
1886 my ($self, $op, $values) = @_;
1888 my $rsrc = $self->result_source;
1889 my $storage = $rsrc->schema->storage;
1891 my $attrs = { %{$self->_resolved_attrs} };
1893 my $join_classifications;
1894 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1896 # do we need a subquery for any reason?
1898 defined $existing_group_by
1900 # if {from} is unparseable wrap a subq
1901 ref($attrs->{from}) ne 'ARRAY'
1903 # limits call for a subq
1904 $self->_has_resolved_attr(qw/rows offset/)
1907 # simplify the joinmap, so we can further decide if a subq is necessary
1908 if (!$needs_subq and @{$attrs->{from}} > 1) {
1910 ($attrs->{from}, $join_classifications) =
1911 $storage->_prune_unused_joins ($attrs);
1913 # any non-pruneable non-local restricting joins imply subq
1914 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1917 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1919 (ref $attrs->{from}[0]) ne 'HASH'
1921 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1925 # do we need anything like a subquery?
1926 if (! $needs_subq) {
1927 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1928 # a condition containing 'me' or other table prefixes will not work
1929 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1931 my $sqla = $rsrc->storage->sql_maker;
1932 local $sqla->{_dequalify_idents} = 1;
1933 \[ $sqla->_recurse_where($self->{cond}) ];
1937 # we got this far - means it is time to wrap a subquery
1938 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1940 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1946 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1947 delete $attrs->{$_} for qw/select as collapse/;
1948 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1950 # this will be consumed by the pruner waaaaay down the stack
1951 $attrs->{_force_prune_multiplying_joins} = 1;
1953 my $subrs = (ref $self)->new($rsrc, $attrs);
1955 if (@$idcols == 1) {
1956 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1958 elsif ($storage->_use_multicolumn_in) {
1959 # no syntax for calling this properly yet
1960 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1961 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1962 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1967 # if all else fails - get all primary keys and operate over a ORed set
1968 # wrap in a transaction for consistency
1969 # this is where the group_by/multiplication starts to matter
1973 # we do not need to check pre-multipliers, since if the premulti is there, its
1974 # parent (who is multi) will be there too
1975 keys %{ $join_classifications->{multiplying} || {} }
1977 # make sure if there is a supplied group_by it matches the columns compiled above
1978 # perfectly. Anything else can not be sanely executed on most databases so croak
1979 # right then and there
1980 if ($existing_group_by) {
1981 my @current_group_by = map
1982 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1987 join ("\x00", sort @current_group_by)
1989 join ("\x00", sort @{$attrs->{columns}} )
1991 $self->throw_exception (
1992 "You have just attempted a $op operation on a resultset which does group_by"
1993 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1994 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1995 . ' kind of queries. Please retry the operation with a modified group_by or'
1996 . ' without using one at all.'
2001 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2004 $guard = $storage->txn_scope_guard;
2007 for my $row ($subrs->cursor->all) {
2009 { $idcols->[$_] => $row->[$_] }
2016 my $res = $storage->$op (
2018 $op eq 'update' ? $values : (),
2022 $guard->commit if $guard;
2031 =item Arguments: \%values
2033 =item Return Value: $underlying_storage_rv
2037 Sets the specified columns in the resultset to the supplied values in a
2038 single query. Note that this will not run any accessor/set_column/update
2039 triggers, nor will it update any result object instances derived from this
2040 resultset (this includes the contents of the L<resultset cache|/set_cache>
2041 if any). See L</update_all> if you need to execute any on-update
2042 triggers or cascades defined either by you or a
2043 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2045 The return value is a pass through of what the underlying
2046 storage backend returned, and may vary. See L<DBI/execute> for the most
2051 Note that L</update> does not process/deflate any of the values passed in.
2052 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2053 ensure manually that any value passed to this method will stringify to
2054 something the RDBMS knows how to deal with. A notable example is the
2055 handling of L<DateTime> objects, for more info see:
2056 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2061 my ($self, $values) = @_;
2062 $self->throw_exception('Values for update must be a hash')
2063 unless ref $values eq 'HASH';
2065 return $self->_rs_update_delete ('update', $values);
2072 =item Arguments: \%values
2074 =item Return Value: 1
2078 Fetches all objects and updates them one at a time via
2079 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2080 triggers, while L</update> will not.
2085 my ($self, $values) = @_;
2086 $self->throw_exception('Values for update_all must be a hash')
2087 unless ref $values eq 'HASH';
2089 my $guard = $self->result_source->schema->txn_scope_guard;
2090 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2099 =item Arguments: none
2101 =item Return Value: $underlying_storage_rv
2105 Deletes the rows matching this resultset in a single query. Note that this
2106 will not run any delete triggers, nor will it alter the
2107 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2108 derived from this resultset (this includes the contents of the
2109 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2110 execute any on-delete triggers or cascades defined either by you or a
2111 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2113 The return value is a pass through of what the underlying storage backend
2114 returned, and may vary. See L<DBI/execute> for the most common case.
2120 $self->throw_exception('delete does not accept any arguments')
2123 return $self->_rs_update_delete ('delete');
2130 =item Arguments: none
2132 =item Return Value: 1
2136 Fetches all objects and deletes them one at a time via
2137 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2138 triggers, while L</delete> will not.
2144 $self->throw_exception('delete_all does not accept any arguments')
2147 my $guard = $self->result_source->schema->txn_scope_guard;
2148 $_->delete for $self->all;
2157 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2159 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2163 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2170 The context of this method call has an important effect on what is
2171 submitted to storage. In void context data is fed directly to fastpath
2172 insertion routines provided by the underlying storage (most often
2173 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2174 L<insert|DBIx::Class::Row/insert> calls on the
2175 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2176 augmentation of these methods provided by components. For example if you
2177 are using something like L<DBIx::Class::UUIDColumns> to create primary
2178 keys for you, you will find that your PKs are empty. In this case you
2179 will have to explicitly force scalar or list context in order to create
2184 In non-void (scalar or list) context, this method is simply a wrapper
2185 for L</create>. Depending on list or scalar context either a list of
2186 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2187 containing these objects is returned.
2189 When supplying data in "arrayref of arrayrefs" invocation style, the
2190 first element should be a list of column names and each subsequent
2191 element should be a data value in the earlier specified column order.
2194 $schema->resultset("Artist")->populate([
2195 [ qw( artistid name ) ],
2196 [ 100, 'A Formally Unknown Singer' ],
2197 [ 101, 'A singer that jumped the shark two albums ago' ],
2198 [ 102, 'An actually cool singer' ],
2201 For the arrayref of hashrefs style each hashref should be a structure
2202 suitable for passing to L</create>. Multi-create is also permitted with
2205 $schema->resultset("Artist")->populate([
2206 { artistid => 4, name => 'Manufactured Crap', cds => [
2207 { title => 'My First CD', year => 2006 },
2208 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2211 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2212 { title => 'My parents sold me to a record company', year => 2005 },
2213 { title => 'Why Am I So Ugly?', year => 2006 },
2214 { title => 'I Got Surgery and am now Popular', year => 2007 }
2219 If you attempt a void-context multi-create as in the example above (each
2220 Artist also has the related list of CDs), and B<do not> supply the
2221 necessary autoinc foreign key information, this method will proxy to the
2222 less efficient L</create>, and then throw the Result objects away. In this
2223 case there are obviously no benefits to using this method over L</create>.
2230 # cruft placed in standalone method
2231 my $data = $self->_normalize_populate_args(@_);
2233 return unless @$data;
2235 if(defined wantarray) {
2236 my @created = map { $self->create($_) } @$data;
2237 return wantarray ? @created : \@created;
2240 my $first = $data->[0];
2242 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2243 # it relationship data
2244 my (@rels, @columns);
2245 my $rsrc = $self->result_source;
2246 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2247 for (keys %$first) {
2248 my $ref = ref $first->{$_};
2249 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2255 my @pks = $rsrc->primary_columns;
2257 ## do the belongs_to relationships
2258 foreach my $index (0..$#$data) {
2260 # delegate to create() for any dataset without primary keys with specified relationships
2261 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2263 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2264 my @ret = $self->populate($data);
2270 foreach my $rel (@rels) {
2271 next unless ref $data->[$index]->{$rel} eq "HASH";
2272 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2273 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2274 my $related = $result->result_source->_resolve_condition(
2275 $reverse_relinfo->{cond},
2281 delete $data->[$index]->{$rel};
2282 $data->[$index] = {%{$data->[$index]}, %$related};
2284 push @columns, keys %$related if $index == 0;
2288 ## inherit the data locked in the conditions of the resultset
2289 my ($rs_data) = $self->_merge_with_rscond({});
2290 delete @{$rs_data}{@columns};
2292 ## do bulk insert on current row
2293 $rsrc->storage->insert_bulk(
2295 [@columns, keys %$rs_data],
2296 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2299 ## do the has_many relationships
2300 foreach my $item (@$data) {
2304 foreach my $rel (@rels) {
2305 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2307 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2309 my $child = $main_row->$rel;
2311 my $related = $child->result_source->_resolve_condition(
2312 $rels->{$rel}{cond},
2318 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2319 my @populate = map { {%$_, %$related} } @rows_to_add;
2321 $child->populate( \@populate );
2328 # populate() arguments went over several incarnations
2329 # What we ultimately support is AoH
2330 sub _normalize_populate_args {
2331 my ($self, $arg) = @_;
2333 if (ref $arg eq 'ARRAY') {
2337 elsif (ref $arg->[0] eq 'HASH') {
2340 elsif (ref $arg->[0] eq 'ARRAY') {
2342 my @colnames = @{$arg->[0]};
2343 foreach my $values (@{$arg}[1 .. $#$arg]) {
2344 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2350 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2357 =item Arguments: none
2359 =item Return Value: L<$pager|Data::Page>
2363 Returns a L<Data::Page> object for the current resultset. Only makes
2364 sense for queries with a C<page> attribute.
2366 To get the full count of entries for a paged resultset, call
2367 C<total_entries> on the L<Data::Page> object.
2374 return $self->{pager} if $self->{pager};
2376 my $attrs = $self->{attrs};
2377 if (!defined $attrs->{page}) {
2378 $self->throw_exception("Can't create pager for non-paged rs");
2380 elsif ($attrs->{page} <= 0) {
2381 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2383 $attrs->{rows} ||= 10;
2385 # throw away the paging flags and re-run the count (possibly
2386 # with a subselect) to get the real total count
2387 my $count_attrs = { %$attrs };
2388 delete @{$count_attrs}{qw/rows offset page pager/};
2390 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2392 require DBIx::Class::ResultSet::Pager;
2393 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2394 sub { $total_rs->count }, #lazy-get the total
2396 $self->{attrs}{page},
2404 =item Arguments: $page_number
2406 =item Return Value: L<$resultset|/search>
2410 Returns a resultset for the $page_number page of the resultset on which page
2411 is called, where each page contains a number of rows equal to the 'rows'
2412 attribute set on the resultset (10 by default).
2417 my ($self, $page) = @_;
2418 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2425 =item Arguments: \%col_data
2427 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2431 Creates a new result object in the resultset's result class and returns
2432 it. The row is not inserted into the database at this point, call
2433 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2434 will tell you whether the result object has been inserted or not.
2436 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2441 my ($self, $values) = @_;
2443 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2446 $self->throw_exception( "new_result expects a hashref" )
2447 unless (ref $values eq 'HASH');
2449 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2451 my $new = $self->result_class->new({
2453 ( @$cols_from_relations
2454 ? (-cols_from_relations => $cols_from_relations)
2457 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2461 reftype($new) eq 'HASH'
2467 carp_unique (sprintf (
2468 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2469 $self->result_class,
2476 # _merge_with_rscond
2478 # Takes a simple hash of K/V data and returns its copy merged with the
2479 # condition already present on the resultset. Additionally returns an
2480 # arrayref of value/condition names, which were inferred from related
2481 # objects (this is needed for in-memory related objects)
2482 sub _merge_with_rscond {
2483 my ($self, $data) = @_;
2485 my (%new_data, @cols_from_relations);
2487 my $alias = $self->{attrs}{alias};
2489 if (! defined $self->{cond}) {
2490 # just massage $data below
2492 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2493 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2494 @cols_from_relations = keys %new_data;
2496 elsif (ref $self->{cond} ne 'HASH') {
2497 $self->throw_exception(
2498 "Can't abstract implicit construct, resultset condition not a hash"
2502 # precedence must be given to passed values over values inherited from
2503 # the cond, so the order here is important.
2504 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2505 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2507 while ( my($col, $value) = each %implied ) {
2508 my $vref = ref $value;
2514 (keys %$value)[0] eq '='
2516 $new_data{$col} = $value->{'='};
2518 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2519 $new_data{$col} = $value;
2526 %{ $self->_remove_alias($data, $alias) },
2529 return (\%new_data, \@cols_from_relations);
2532 # _has_resolved_attr
2534 # determines if the resultset defines at least one
2535 # of the attributes supplied
2537 # used to determine if a subquery is necessary
2539 # supports some virtual attributes:
2541 # This will scan for any joins being present on the resultset.
2542 # It is not a mere key-search but a deep inspection of {from}
2545 sub _has_resolved_attr {
2546 my ($self, @attr_names) = @_;
2548 my $attrs = $self->_resolved_attrs;
2552 for my $n (@attr_names) {
2553 if (grep { $n eq $_ } (qw/-join/) ) {
2554 $extra_checks{$n}++;
2558 my $attr = $attrs->{$n};
2560 next if not defined $attr;
2562 if (ref $attr eq 'HASH') {
2563 return 1 if keys %$attr;
2565 elsif (ref $attr eq 'ARRAY') {
2573 # a resolved join is expressed as a multi-level from
2575 $extra_checks{-join}
2577 ref $attrs->{from} eq 'ARRAY'
2579 @{$attrs->{from}} > 1
2587 # Recursively collapse the condition.
2589 sub _collapse_cond {
2590 my ($self, $cond, $collapsed) = @_;
2594 if (ref $cond eq 'ARRAY') {
2595 foreach my $subcond (@$cond) {
2596 next unless ref $subcond; # -or
2597 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2600 elsif (ref $cond eq 'HASH') {
2601 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2602 foreach my $subcond (@{$cond->{-and}}) {
2603 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2607 foreach my $col (keys %$cond) {
2608 my $value = $cond->{$col};
2609 $collapsed->{$col} = $value;
2619 # Remove the specified alias from the specified query hash. A copy is made so
2620 # the original query is not modified.
2623 my ($self, $query, $alias) = @_;
2625 my %orig = %{ $query || {} };
2628 foreach my $key (keys %orig) {
2630 $unaliased{$key} = $orig{$key};
2633 $unaliased{$1} = $orig{$key}
2634 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2644 =item Arguments: none
2646 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2650 Returns the SQL query and bind vars associated with the invocant.
2652 This is generally used as the RHS for a subquery.
2659 my $attrs = { %{ $self->_resolved_attrs } };
2661 my $aq = $self->result_source->storage->_select_args_to_query (
2662 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2672 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2674 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2678 my $artist = $schema->resultset('Artist')->find_or_new(
2679 { artist => 'fred' }, { key => 'artists' });
2681 $cd->cd_to_producer->find_or_new({ producer => $producer },
2682 { key => 'primary' });
2684 Find an existing record from this resultset using L</find>. if none exists,
2685 instantiate a new result object and return it. The object will not be saved
2686 into your storage until you call L<DBIx::Class::Row/insert> on it.
2688 You most likely want this method when looking for existing rows using a unique
2689 constraint that is not the primary key, or looking for related rows.
2691 If you want objects to be saved immediately, use L</find_or_create> instead.
2693 B<Note>: Make sure to read the documentation of L</find> and understand the
2694 significance of the C<key> attribute, as its lack may skew your search, and
2695 subsequently result in spurious new objects.
2697 B<Note>: Take care when using C<find_or_new> with a table having
2698 columns with default values that you intend to be automatically
2699 supplied by the database (e.g. an auto_increment primary key column).
2700 In normal usage, the value of such columns should NOT be included at
2701 all in the call to C<find_or_new>, even when set to C<undef>.
2707 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2708 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2709 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2712 return $self->new_result($hash);
2719 =item Arguments: \%col_data
2721 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2725 Attempt to create a single new row or a row with multiple related rows
2726 in the table represented by the resultset (and related tables). This
2727 will not check for duplicate rows before inserting, use
2728 L</find_or_create> to do that.
2730 To create one row for this resultset, pass a hashref of key/value
2731 pairs representing the columns of the table and the values you wish to
2732 store. If the appropriate relationships are set up, foreign key fields
2733 can also be passed an object representing the foreign row, and the
2734 value will be set to its primary key.
2736 To create related objects, pass a hashref of related-object column values
2737 B<keyed on the relationship name>. If the relationship is of type C<multi>
2738 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2739 The process will correctly identify columns holding foreign keys, and will
2740 transparently populate them from the keys of the corresponding relation.
2741 This can be applied recursively, and will work correctly for a structure
2742 with an arbitrary depth and width, as long as the relationships actually
2743 exists and the correct column data has been supplied.
2745 Instead of hashrefs of plain related data (key/value pairs), you may
2746 also pass new or inserted objects. New objects (not inserted yet, see
2747 L</new_result>), will be inserted into their appropriate tables.
2749 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2751 Example of creating a new row.
2753 $person_rs->create({
2754 name=>"Some Person",
2755 email=>"somebody@someplace.com"
2758 Example of creating a new row and also creating rows in a related C<has_many>
2759 or C<has_one> resultset. Note Arrayref.
2762 { artistid => 4, name => 'Manufactured Crap', cds => [
2763 { title => 'My First CD', year => 2006 },
2764 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2769 Example of creating a new row and also creating a row in a related
2770 C<belongs_to> resultset. Note Hashref.
2773 title=>"Music for Silly Walks",
2776 name=>"Silly Musician",
2784 When subclassing ResultSet never attempt to override this method. Since
2785 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2786 lot of the internals simply never call it, so your override will be
2787 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2788 or L<DBIx::Class::Row/insert> depending on how early in the
2789 L</create> process you need to intervene. See also warning pertaining to
2797 my ($self, $col_data) = @_;
2798 $self->throw_exception( "create needs a hashref" )
2799 unless ref $col_data eq 'HASH';
2800 return $self->new_result($col_data)->insert;
2803 =head2 find_or_create
2807 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2809 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2813 $cd->cd_to_producer->find_or_create({ producer => $producer },
2814 { key => 'primary' });
2816 Tries to find a record based on its primary key or unique constraints; if none
2817 is found, creates one and returns that instead.
2819 my $cd = $schema->resultset('CD')->find_or_create({
2821 artist => 'Massive Attack',
2822 title => 'Mezzanine',
2826 Also takes an optional C<key> attribute, to search by a specific key or unique
2827 constraint. For example:
2829 my $cd = $schema->resultset('CD')->find_or_create(
2831 artist => 'Massive Attack',
2832 title => 'Mezzanine',
2834 { key => 'cd_artist_title' }
2837 B<Note>: Make sure to read the documentation of L</find> and understand the
2838 significance of the C<key> attribute, as its lack may skew your search, and
2839 subsequently result in spurious row creation.
2841 B<Note>: Because find_or_create() reads from the database and then
2842 possibly inserts based on the result, this method is subject to a race
2843 condition. Another process could create a record in the table after
2844 the find has completed and before the create has started. To avoid
2845 this problem, use find_or_create() inside a transaction.
2847 B<Note>: Take care when using C<find_or_create> with a table having
2848 columns with default values that you intend to be automatically
2849 supplied by the database (e.g. an auto_increment primary key column).
2850 In normal usage, the value of such columns should NOT be included at
2851 all in the call to C<find_or_create>, even when set to C<undef>.
2853 See also L</find> and L</update_or_create>. For information on how to declare
2854 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2856 If you need to know if an existing row was found or a new one created use
2857 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2858 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2861 my $cd = $schema->resultset('CD')->find_or_new({
2863 artist => 'Massive Attack',
2864 title => 'Mezzanine',
2868 if( !$cd->in_storage ) {
2875 sub find_or_create {
2877 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2878 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2879 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2882 return $self->create($hash);
2885 =head2 update_or_create
2889 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2891 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2895 $resultset->update_or_create({ col => $val, ... });
2897 Like L</find_or_create>, but if a row is found it is immediately updated via
2898 C<< $found_row->update (\%col_data) >>.
2901 Takes an optional C<key> attribute to search on a specific unique constraint.
2904 # In your application
2905 my $cd = $schema->resultset('CD')->update_or_create(
2907 artist => 'Massive Attack',
2908 title => 'Mezzanine',
2911 { key => 'cd_artist_title' }
2914 $cd->cd_to_producer->update_or_create({
2915 producer => $producer,
2921 B<Note>: Make sure to read the documentation of L</find> and understand the
2922 significance of the C<key> attribute, as its lack may skew your search, and
2923 subsequently result in spurious row creation.
2925 B<Note>: Take care when using C<update_or_create> with a table having
2926 columns with default values that you intend to be automatically
2927 supplied by the database (e.g. an auto_increment primary key column).
2928 In normal usage, the value of such columns should NOT be included at
2929 all in the call to C<update_or_create>, even when set to C<undef>.
2931 See also L</find> and L</find_or_create>. For information on how to declare
2932 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2934 If you need to know if an existing row was updated or a new one created use
2935 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2936 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2941 sub update_or_create {
2943 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2944 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2946 my $row = $self->find($cond, $attrs);
2948 $row->update($cond);
2952 return $self->create($cond);
2955 =head2 update_or_new
2959 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2961 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2965 $resultset->update_or_new({ col => $val, ... });
2967 Like L</find_or_new> but if a row is found it is immediately updated via
2968 C<< $found_row->update (\%col_data) >>.
2972 # In your application
2973 my $cd = $schema->resultset('CD')->update_or_new(
2975 artist => 'Massive Attack',
2976 title => 'Mezzanine',
2979 { key => 'cd_artist_title' }
2982 if ($cd->in_storage) {
2983 # the cd was updated
2986 # the cd is not yet in the database, let's insert it
2990 B<Note>: Make sure to read the documentation of L</find> and understand the
2991 significance of the C<key> attribute, as its lack may skew your search, and
2992 subsequently result in spurious new objects.
2994 B<Note>: Take care when using C<update_or_new> with a table having
2995 columns with default values that you intend to be automatically
2996 supplied by the database (e.g. an auto_increment primary key column).
2997 In normal usage, the value of such columns should NOT be included at
2998 all in the call to C<update_or_new>, even when set to C<undef>.
3000 See also L</find>, L</find_or_create> and L</find_or_new>.
3006 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3007 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3009 my $row = $self->find( $cond, $attrs );
3010 if ( defined $row ) {
3011 $row->update($cond);
3015 return $self->new_result($cond);
3022 =item Arguments: none
3024 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3028 Gets the contents of the cache for the resultset, if the cache is set.
3030 The cache is populated either by using the L</prefetch> attribute to
3031 L</search> or by calling L</set_cache>.
3043 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3045 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3049 Sets the contents of the cache for the resultset. Expects an arrayref
3050 of objects of the same class as those produced by the resultset. Note that
3051 if the cache is set, the resultset will return the cached objects rather
3052 than re-querying the database even if the cache attr is not set.
3054 The contents of the cache can also be populated by using the
3055 L</prefetch> attribute to L</search>.
3060 my ( $self, $data ) = @_;
3061 $self->throw_exception("set_cache requires an arrayref")
3062 if defined($data) && (ref $data ne 'ARRAY');
3063 $self->{all_cache} = $data;
3070 =item Arguments: none
3072 =item Return Value: undef
3076 Clears the cache for the resultset.
3081 shift->set_cache(undef);
3088 =item Arguments: none
3090 =item Return Value: true, if the resultset has been paginated
3098 return !!$self->{attrs}{page};
3105 =item Arguments: none
3107 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3115 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3118 =head2 related_resultset
3122 =item Arguments: $rel_name
3124 =item Return Value: L<$resultset|/search>
3128 Returns a related resultset for the supplied relationship name.
3130 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3134 sub related_resultset {
3135 my ($self, $rel) = @_;
3137 return $self->{related_resultsets}{$rel}
3138 if defined $self->{related_resultsets}{$rel};
3140 return $self->{related_resultsets}{$rel} = do {
3141 my $rsrc = $self->result_source;
3142 my $rel_info = $rsrc->relationship_info($rel);
3144 $self->throw_exception(
3145 "search_related: result source '" . $rsrc->source_name .
3146 "' has no such relationship $rel")
3149 my $attrs = $self->_chain_relationship($rel);
3151 my $join_count = $attrs->{seen_join}{$rel};
3153 my $alias = $self->result_source->storage
3154 ->relname_to_table_alias($rel, $join_count);
3156 # since this is search_related, and we already slid the select window inwards
3157 # (the select/as attrs were deleted in the beginning), we need to flip all
3158 # left joins to inner, so we get the expected results
3159 # read the comment on top of the actual function to see what this does
3160 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3163 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3164 delete @{$attrs}{qw(result_class alias)};
3166 my $rel_source = $rsrc->related_source($rel);
3170 # The reason we do this now instead of passing the alias to the
3171 # search_rs below is that if you wrap/overload resultset on the
3172 # source you need to know what alias it's -going- to have for things
3173 # to work sanely (e.g. RestrictWithObject wants to be able to add
3174 # extra query restrictions, and these may need to be $alias.)
3176 my $rel_attrs = $rel_source->resultset_attributes;
3177 local $rel_attrs->{alias} = $alias;
3179 $rel_source->resultset
3183 where => $attrs->{where},
3187 if (my $cache = $self->get_cache) {
3188 my @related_cache = map
3189 { $_->related_resultset($rel)->get_cache || () }
3193 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3200 =head2 current_source_alias
3204 =item Arguments: none
3206 =item Return Value: $source_alias
3210 Returns the current table alias for the result source this resultset is built
3211 on, that will be used in the SQL query. Usually it is C<me>.
3213 Currently the source alias that refers to the result set returned by a
3214 L</search>/L</find> family method depends on how you got to the resultset: it's
3215 C<me> by default, but eg. L</search_related> aliases it to the related result
3216 source name (and keeps C<me> referring to the original result set). The long
3217 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3218 (and make this method unnecessary).
3220 Thus it's currently necessary to use this method in predefined queries (see
3221 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3222 source alias of the current result set:
3224 # in a result set class
3226 my ($self, $user) = @_;
3228 my $me = $self->current_source_alias;
3230 return $self->search({
3231 "$me.modified" => $user->id,
3237 sub current_source_alias {
3238 return (shift->{attrs} || {})->{alias} || 'me';
3241 =head2 as_subselect_rs
3245 =item Arguments: none
3247 =item Return Value: L<$resultset|/search>
3251 Act as a barrier to SQL symbols. The resultset provided will be made into a
3252 "virtual view" by including it as a subquery within the from clause. From this
3253 point on, any joined tables are inaccessible to ->search on the resultset (as if
3254 it were simply where-filtered without joins). For example:
3256 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3258 # 'x' now pollutes the query namespace
3260 # So the following works as expected
3261 my $ok_rs = $rs->search({'x.other' => 1});
3263 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3264 # def) we look for one row with contradictory terms and join in another table
3265 # (aliased 'x_2') which we never use
3266 my $broken_rs = $rs->search({'x.name' => 'def'});
3268 my $rs2 = $rs->as_subselect_rs;
3270 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3271 my $not_joined_rs = $rs2->search({'x.other' => 1});
3273 # works as expected: finds a 'table' row related to two x rows (abc and def)
3274 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3276 Another example of when one might use this would be to select a subset of
3277 columns in a group by clause:
3279 my $rs = $schema->resultset('Bar')->search(undef, {
3280 group_by => [qw{ id foo_id baz_id }],
3281 })->as_subselect_rs->search(undef, {
3282 columns => [qw{ id foo_id }]
3285 In the above example normally columns would have to be equal to the group by,
3286 but because we isolated the group by into a subselect the above works.
3290 sub as_subselect_rs {
3293 my $attrs = $self->_resolved_attrs;
3295 my $fresh_rs = (ref $self)->new (
3296 $self->result_source
3299 # these pieces will be locked in the subquery
3300 delete $fresh_rs->{cond};
3301 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3303 return $fresh_rs->search( {}, {
3305 $attrs->{alias} => $self->as_query,
3306 -alias => $attrs->{alias},
3307 -rsrc => $self->result_source,
3309 alias => $attrs->{alias},
3313 # This code is called by search_related, and makes sure there
3314 # is clear separation between the joins before, during, and
3315 # after the relationship. This information is needed later
3316 # in order to properly resolve prefetch aliases (any alias
3317 # with a relation_chain_depth less than the depth of the
3318 # current prefetch is not considered)
3320 # The increments happen twice per join. An even number means a
3321 # relationship specified via a search_related, whereas an odd
3322 # number indicates a join/prefetch added via attributes
3324 # Also this code will wrap the current resultset (the one we
3325 # chain to) in a subselect IFF it contains limiting attributes
3326 sub _chain_relationship {
3327 my ($self, $rel) = @_;
3328 my $source = $self->result_source;
3329 my $attrs = { %{$self->{attrs}||{}} };
3331 # we need to take the prefetch the attrs into account before we
3332 # ->_resolve_join as otherwise they get lost - captainL
3333 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3335 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3337 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3340 my @force_subq_attrs = qw/offset rows group_by having/;
3343 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3345 $self->_has_resolved_attr (@force_subq_attrs)
3347 # Nuke the prefetch (if any) before the new $rs attrs
3348 # are resolved (prefetch is useless - we are wrapping
3349 # a subquery anyway).
3350 my $rs_copy = $self->search;
3351 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3352 $rs_copy->{attrs}{join},
3353 delete $rs_copy->{attrs}{prefetch},
3358 -alias => $attrs->{alias},
3359 $attrs->{alias} => $rs_copy->as_query,
3361 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3362 $seen->{-relation_chain_depth} = 0;
3364 elsif ($attrs->{from}) { #shallow copy suffices
3365 $from = [ @{$attrs->{from}} ];
3370 -alias => $attrs->{alias},
3371 $attrs->{alias} => $source->from,
3375 my $jpath = ($seen->{-relation_chain_depth})
3376 ? $from->[-1][0]{-join_path}
3379 my @requested_joins = $source->_resolve_join(
3386 push @$from, @requested_joins;
3388 $seen->{-relation_chain_depth}++;
3390 # if $self already had a join/prefetch specified on it, the requested
3391 # $rel might very well be already included. What we do in this case
3392 # is effectively a no-op (except that we bump up the chain_depth on
3393 # the join in question so we could tell it *is* the search_related)
3396 # we consider the last one thus reverse
3397 for my $j (reverse @requested_joins) {
3398 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3399 if ($rel eq $last_j) {
3400 $j->[0]{-relation_chain_depth}++;
3406 unless ($already_joined) {
3407 push @$from, $source->_resolve_join(
3415 $seen->{-relation_chain_depth}++;
3417 return {%$attrs, from => $from, seen_join => $seen};
3420 sub _resolved_attrs {
3422 return $self->{_attrs} if $self->{_attrs};
3424 my $attrs = { %{ $self->{attrs} || {} } };
3425 my $source = $self->result_source;
3426 my $alias = $attrs->{alias};
3428 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3429 if $attrs->{collapse} and $attrs->{distinct};
3431 # default selection list
3432 $attrs->{columns} = [ $source->columns ]
3433 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3435 # merge selectors together
3436 for (qw/columns select as/) {
3437 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3438 if $attrs->{$_} or $attrs->{"+$_"};
3441 # disassemble columns
3443 if (my $cols = delete $attrs->{columns}) {
3444 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3445 if (ref $c eq 'HASH') {
3446 for my $as (sort keys %$c) {
3447 push @sel, $c->{$as};
3458 # when trying to weed off duplicates later do not go past this point -
3459 # everything added from here on is unbalanced "anyone's guess" stuff
3460 my $dedup_stop_idx = $#as;
3462 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3464 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3465 if $attrs->{select};
3467 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3468 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3470 # disqualify all $alias.col as-bits (inflate-map mandated)
3471 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3473 # de-duplicate the result (remove *identical* select/as pairs)
3474 # and also die on duplicate {as} pointing to different {select}s
3475 # not using a c-style for as the condition is prone to shrinkage
3478 while ($i <= $dedup_stop_idx) {
3479 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3484 elsif ($seen->{$as[$i]}++) {
3485 $self->throw_exception(
3486 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3494 $attrs->{select} = \@sel;
3495 $attrs->{as} = \@as;
3497 $attrs->{from} ||= [{
3499 -alias => $self->{attrs}{alias},
3500 $self->{attrs}{alias} => $source->from,
3503 if ( $attrs->{join} || $attrs->{prefetch} ) {
3505 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3506 if ref $attrs->{from} ne 'ARRAY';
3508 my $join = (delete $attrs->{join}) || {};
3510 if ( defined $attrs->{prefetch} ) {
3511 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3514 $attrs->{from} = # have to copy here to avoid corrupting the original
3516 @{ $attrs->{from} },
3517 $source->_resolve_join(
3520 { %{ $attrs->{seen_join} || {} } },
3521 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3522 ? $attrs->{from}[-1][0]{-join_path}
3529 if ( defined $attrs->{order_by} ) {
3530 $attrs->{order_by} = (
3531 ref( $attrs->{order_by} ) eq 'ARRAY'
3532 ? [ @{ $attrs->{order_by} } ]
3533 : [ $attrs->{order_by} || () ]
3537 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3538 $attrs->{group_by} = [ $attrs->{group_by} ];
3542 # generate selections based on the prefetch helper
3543 my ($prefetch, @prefetch_select, @prefetch_as);
3544 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3545 if defined $attrs->{prefetch};
3549 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3550 if $attrs->{_dark_selector};
3552 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3553 if defined $attrs->{collapse} and ! $attrs->{collapse};
3555 $attrs->{collapse} = 1;
3557 # this is a separate structure (we don't look in {from} directly)
3558 # as the resolver needs to shift things off the lists to work
3559 # properly (identical-prefetches on different branches)
3561 if (ref $attrs->{from} eq 'ARRAY') {
3563 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3565 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3566 next unless $j->[0]{-alias};
3567 next unless $j->[0]{-join_path};
3568 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3570 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3573 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3574 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3578 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3580 # save these for after distinct resolution
3581 @prefetch_select = map { $_->[0] } @prefetch;
3582 @prefetch_as = map { $_->[1] } @prefetch;
3585 # run through the resulting joinstructure (starting from our current slot)
3586 # and unset collapse if proven unnecessary
3588 # also while we are at it find out if the current root source has
3589 # been premultiplied by previous related_source chaining
3591 # this allows to predict whether a root object with all other relation
3592 # data set to NULL is in fact unique
3593 if ($attrs->{collapse}) {
3595 if (ref $attrs->{from} eq 'ARRAY') {
3597 if (@{$attrs->{from}} == 1) {
3598 # no joins - no collapse
3599 $attrs->{collapse} = 0;
3602 # find where our table-spec starts
3603 my @fromlist = @{$attrs->{from}};
3605 my $t = shift @fromlist;
3608 # me vs join from-spec distinction - a ref means non-root
3609 if (ref $t eq 'ARRAY') {
3611 $is_multi ||= ! $t->{-is_single};
3613 last if ($t->{-alias} && $t->{-alias} eq $alias);
3614 $attrs->{_main_source_premultiplied} ||= $is_multi;
3617 # no non-singles remaining, nor any premultiplication - nothing to collapse
3619 ! $attrs->{_main_source_premultiplied}
3621 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3623 $attrs->{collapse} = 0;
3629 # if we can not analyze the from - err on the side of safety
3630 $attrs->{_main_source_premultiplied} = 1;
3634 # generate the distinct induced group_by before injecting the prefetched select/as parts
3635 if (delete $attrs->{distinct}) {
3636 if ($attrs->{group_by}) {
3637 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3640 $attrs->{_grouped_by_distinct} = 1;
3641 # distinct affects only the main selection part, not what prefetch may add below
3642 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3644 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3645 # The thinking is: if we are collapsing the subquerying prefetch engine will
3646 # rip stuff apart for us anyway, and we do not want to have a potentially
3647 # function-converted external order_by
3648 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3649 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3653 # inject prefetch-bound selection (if any)
3654 push @{$attrs->{select}}, @prefetch_select;
3655 push @{$attrs->{as}}, @prefetch_as;
3657 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3658 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3659 $attrs->{_related_results_construction} = 1;
3662 # if both page and offset are specified, produce a combined offset
3663 # even though it doesn't make much sense, this is what pre 081xx has
3665 if (my $page = delete $attrs->{page}) {
3667 ($attrs->{rows} * ($page - 1))
3669 ($attrs->{offset} || 0)
3673 return $self->{_attrs} = $attrs;
3677 my ($self, $attr) = @_;
3679 if (ref $attr eq 'HASH') {
3680 return $self->_rollout_hash($attr);
3681 } elsif (ref $attr eq 'ARRAY') {
3682 return $self->_rollout_array($attr);
3688 sub _rollout_array {
3689 my ($self, $attr) = @_;
3692 foreach my $element (@{$attr}) {
3693 if (ref $element eq 'HASH') {
3694 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3695 } elsif (ref $element eq 'ARRAY') {
3696 # XXX - should probably recurse here
3697 push( @rolled_array, @{$self->_rollout_array($element)} );
3699 push( @rolled_array, $element );
3702 return \@rolled_array;
3706 my ($self, $attr) = @_;
3709 foreach my $key (keys %{$attr}) {
3710 push( @rolled_array, { $key => $attr->{$key} } );
3712 return \@rolled_array;
3715 sub _calculate_score {
3716 my ($self, $a, $b) = @_;
3718 if (defined $a xor defined $b) {
3721 elsif (not defined $a) {
3725 if (ref $b eq 'HASH') {
3726 my ($b_key) = keys %{$b};
3727 if (ref $a eq 'HASH') {
3728 my ($a_key) = keys %{$a};
3729 if ($a_key eq $b_key) {
3730 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3735 return ($a eq $b_key) ? 1 : 0;
3738 if (ref $a eq 'HASH') {
3739 my ($a_key) = keys %{$a};
3740 return ($b eq $a_key) ? 1 : 0;
3742 return ($b eq $a) ? 1 : 0;
3747 sub _merge_joinpref_attr {
3748 my ($self, $orig, $import) = @_;
3750 return $import unless defined($orig);
3751 return $orig unless defined($import);
3753 $orig = $self->_rollout_attr($orig);
3754 $import = $self->_rollout_attr($import);
3757 foreach my $import_element ( @{$import} ) {
3758 # find best candidate from $orig to merge $b_element into
3759 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3760 foreach my $orig_element ( @{$orig} ) {
3761 my $score = $self->_calculate_score( $orig_element, $import_element );
3762 if ($score > $best_candidate->{score}) {
3763 $best_candidate->{position} = $position;
3764 $best_candidate->{score} = $score;
3768 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3769 $import_key = '' if not defined $import_key;
3771 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3772 push( @{$orig}, $import_element );
3774 my $orig_best = $orig->[$best_candidate->{position}];
3775 # merge orig_best and b_element together and replace original with merged
3776 if (ref $orig_best ne 'HASH') {
3777 $orig->[$best_candidate->{position}] = $import_element;
3778 } elsif (ref $import_element eq 'HASH') {
3779 my ($key) = keys %{$orig_best};
3780 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3783 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3786 return @$orig ? $orig : ();
3794 require Hash::Merge;
3795 my $hm = Hash::Merge->new;
3797 $hm->specify_behavior({
3800 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3802 if ($defl xor $defr) {
3803 return [ $defl ? $_[0] : $_[1] ];
3808 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3812 return [$_[0], $_[1]];
3816 return $_[1] if !defined $_[0];
3817 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3818 return [$_[0], @{$_[1]}]
3821 return [] if !defined $_[0] and !keys %{$_[1]};
3822 return [ $_[1] ] if !defined $_[0];
3823 return [ $_[0] ] if !keys %{$_[1]};
3824 return [$_[0], $_[1]]
3829 return $_[0] if !defined $_[1];
3830 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3831 return [@{$_[0]}, $_[1]]
3834 my @ret = @{$_[0]} or return $_[1];
3835 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3836 my %idx = map { $_ => 1 } @ret;
3837 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3841 return [ $_[1] ] if ! @{$_[0]};
3842 return $_[0] if !keys %{$_[1]};
3843 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3844 return [ @{$_[0]}, $_[1] ];
3849 return [] if !keys %{$_[0]} and !defined $_[1];
3850 return [ $_[0] ] if !defined $_[1];
3851 return [ $_[1] ] if !keys %{$_[0]};
3852 return [$_[0], $_[1]]
3855 return [] if !keys %{$_[0]} and !@{$_[1]};
3856 return [ $_[0] ] if !@{$_[1]};
3857 return $_[1] if !keys %{$_[0]};
3858 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3859 return [ $_[0], @{$_[1]} ];
3862 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3863 return [ $_[0] ] if !keys %{$_[1]};
3864 return [ $_[1] ] if !keys %{$_[0]};
3865 return [ $_[0] ] if $_[0] eq $_[1];
3866 return [ $_[0], $_[1] ];
3869 } => 'DBIC_RS_ATTR_MERGER');
3873 return $hm->merge ($_[1], $_[2]);
3877 sub STORABLE_freeze {
3878 my ($self, $cloning) = @_;
3879 my $to_serialize = { %$self };
3881 # A cursor in progress can't be serialized (and would make little sense anyway)
3882 # the parser can be regenerated (and can't be serialized)
3883 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3885 # nor is it sensical to store a not-yet-fired-count pager
3886 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3887 delete $to_serialize->{pager};
3890 Storable::nfreeze($to_serialize);
3893 # need this hook for symmetry
3895 my ($self, $cloning, $serialized) = @_;
3897 %$self = %{ Storable::thaw($serialized) };
3903 =head2 throw_exception
3905 See L<DBIx::Class::Schema/throw_exception> for details.
3909 sub throw_exception {
3912 if (ref $self and my $rsrc = $self->result_source) {
3913 $rsrc->throw_exception(@_)
3916 DBIx::Class::Exception->throw(@_);
3924 # XXX: FIXME: Attributes docs need clearing up
3928 Attributes are used to refine a ResultSet in various ways when
3929 searching for data. They can be passed to any method which takes an
3930 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3933 Default attributes can be set on the result class using
3934 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3935 the CAVEATS on that feature before using it!)
3937 These are in no particular order:
3943 =item Value: ( $order_by | \@order_by | \%order_by )
3947 Which column(s) to order the results by.
3949 [The full list of suitable values is documented in
3950 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3953 If a single column name, or an arrayref of names is supplied, the
3954 argument is passed through directly to SQL. The hashref syntax allows
3955 for connection-agnostic specification of ordering direction:
3957 For descending order:
3959 order_by => { -desc => [qw/col1 col2 col3/] }
3961 For explicit ascending order:
3963 order_by => { -asc => 'col' }
3965 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3966 supported, although you are strongly encouraged to use the hashref
3967 syntax as outlined above.
3973 =item Value: \@columns | \%columns | $column
3977 Shortcut to request a particular set of columns to be retrieved. Each
3978 column spec may be a string (a table column name), or a hash (in which
3979 case the key is the C<as> value, and the value is used as the C<select>
3980 expression). Adds C<me.> onto the start of any column without a C<.> in
3981 it and sets C<select> from that, then auto-populates C<as> from
3982 C<select> as normal. (You may also use the C<cols> attribute, as in
3983 earlier versions of DBIC, but this is deprecated.)
3985 Essentially C<columns> does the same as L</select> and L</as>.
3987 columns => [ 'foo', { bar => 'baz' } ]
3991 select => [qw/foo baz/],
3994 Like elsewhere, literal SQL or literal values can be included by
3995 using a scalar reference, and these values will be available in the result
3998 # equivalent SQL: SELECT 1, 'a string', IF(x,1,2) ...
3999 columns => [ { foo => \1, bar => \q{'a string'}, baz => \'IF(x,1,2)' } ]
4005 =item Value: \@columns
4009 Indicates additional columns to be selected from storage. Works the same as
4010 L</columns> but adds columns to the selection. (You may also use the
4011 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4012 deprecated). For example:-
4014 $schema->resultset('CD')->search(undef, {
4015 '+columns' => ['artist.name'],
4019 would return all CDs and include a 'name' column to the information
4020 passed to object inflation. Note that the 'artist' is the name of the
4021 column (or relationship) accessor, and 'name' is the name of the column
4022 accessor in the related table.
4024 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4025 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4026 unary plus operator before it.
4028 =head2 include_columns
4032 =item Value: \@columns
4036 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4042 =item Value: \@select_columns
4046 Indicates which columns should be selected from the storage. You can use
4047 column names, or in the case of RDBMS back ends, function or stored procedure
4050 $rs = $schema->resultset('Employee')->search(undef, {
4053 { count => 'employeeid' },
4054 { max => { length => 'name' }, -as => 'longest_name' }
4059 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4061 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4062 use L</select>, to instruct DBIx::Class how to store the result of the column.
4063 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4064 identifier aliasing. You can however alias a function, so you can use it in
4065 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4066 attribute> supplied as shown in the example above.
4068 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4069 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4070 unary plus operator before it.
4076 Indicates additional columns to be selected from storage. Works the same as
4077 L</select> but adds columns to the default selection, instead of specifying
4086 =item Value: \@inflation_names
4090 Indicates column names for object inflation. That is L</as> indicates the
4091 slot name in which the column value will be stored within the
4092 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4093 identifier by the C<get_column> method (or via the object accessor B<if one
4094 with the same name already exists>) as shown below. The L</as> attribute has
4095 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4097 $rs = $schema->resultset('Employee')->search(undef, {
4100 { count => 'employeeid' },
4101 { max => { length => 'name' }, -as => 'longest_name' }
4110 If the object against which the search is performed already has an accessor
4111 matching a column name specified in C<as>, the value can be retrieved using
4112 the accessor as normal:
4114 my $name = $employee->name();
4116 If on the other hand an accessor does not exist in the object, you need to
4117 use C<get_column> instead:
4119 my $employee_count = $employee->get_column('employee_count');
4121 You can create your own accessors if required - see
4122 L<DBIx::Class::Manual::Cookbook> for details.
4128 Indicates additional column names for those added via L</+select>. See L</as>.
4136 =item Value: ($rel_name | \@rel_names | \%rel_names)
4140 Contains a list of relationships that should be joined for this query. For
4143 # Get CDs by Nine Inch Nails
4144 my $rs = $schema->resultset('CD')->search(
4145 { 'artist.name' => 'Nine Inch Nails' },
4146 { join => 'artist' }
4149 Can also contain a hash reference to refer to the other relation's relations.
4152 package MyApp::Schema::Track;
4153 use base qw/DBIx::Class/;
4154 __PACKAGE__->table('track');
4155 __PACKAGE__->add_columns(qw/trackid cd position title/);
4156 __PACKAGE__->set_primary_key('trackid');
4157 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4160 # In your application
4161 my $rs = $schema->resultset('Artist')->search(
4162 { 'track.title' => 'Teardrop' },
4164 join => { cd => 'track' },
4165 order_by => 'artist.name',
4169 You need to use the relationship (not the table) name in conditions,
4170 because they are aliased as such. The current table is aliased as "me", so
4171 you need to use me.column_name in order to avoid ambiguity. For example:
4173 # Get CDs from 1984 with a 'Foo' track
4174 my $rs = $schema->resultset('CD')->search(
4177 'tracks.name' => 'Foo'
4179 { join => 'tracks' }
4182 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4183 similarly for a third time). For e.g.
4185 my $rs = $schema->resultset('Artist')->search({
4186 'cds.title' => 'Down to Earth',
4187 'cds_2.title' => 'Popular',
4189 join => [ qw/cds cds/ ],
4192 will return a set of all artists that have both a cd with title 'Down
4193 to Earth' and a cd with title 'Popular'.
4195 If you want to fetch related objects from other tables as well, see L</prefetch>
4198 NOTE: An internal join-chain pruner will discard certain joins while
4199 constructing the actual SQL query, as long as the joins in question do not
4200 affect the retrieved result. This for example includes 1:1 left joins
4201 that are not part of the restriction specification (WHERE/HAVING) nor are
4202 a part of the query selection.
4204 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4210 =item Value: (0 | 1)
4214 When set to a true value, indicates that any rows fetched from joined has_many
4215 relationships are to be aggregated into the corresponding "parent" object. For
4216 example, the resultset:
4218 my $rs = $schema->resultset('CD')->search({}, {
4219 '+columns' => [ qw/ tracks.title tracks.position / ],
4224 While executing the following query:
4226 SELECT me.*, tracks.title, tracks.position
4228 LEFT JOIN track tracks
4229 ON tracks.cdid = me.cdid
4231 Will return only as many objects as there are rows in the CD source, even
4232 though the result of the query may span many rows. Each of these CD objects
4233 will in turn have multiple "Track" objects hidden behind the has_many
4234 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4235 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4236 product"), with each CD object containing exactly one of all fetched Track data.
4238 When a collapse is requested on a non-ordered resultset, an order by some
4239 unique part of the main source (the left-most table) is inserted automatically.
4240 This is done so that the resultset is allowed to be "lazy" - calling
4241 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4242 object with all of its related data.
4244 If an L</order_by> is already declared, and orders the resultset in a way that
4245 makes collapsing as described above impossible (e.g. C<< ORDER BY
4246 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4247 switch to "eager" mode and slurp the entire resultset before constructing the
4248 first object returned by L</next>.
4250 Setting this attribute on a resultset that does not join any has_many
4251 relations is a no-op.
4253 For a more in-depth discussion, see L</PREFETCHING>.
4259 =item Value: ($rel_name | \@rel_names | \%rel_names)
4263 This attribute is a shorthand for specifying a L</join> spec, adding all
4264 columns from the joined related sources as L</+columns> and setting
4265 L</collapse> to a true value. For example, the following two queries are
4268 my $rs = $schema->resultset('Artist')->search({}, {
4269 prefetch => { cds => ['genre', 'tracks' ] },
4274 my $rs = $schema->resultset('Artist')->search({}, {
4275 join => { cds => ['genre', 'tracks' ] },
4279 { +{ "cds.$_" => "cds.$_" } }
4280 $schema->source('Artist')->related_source('cds')->columns
4283 { +{ "cds.genre.$_" => "genre.$_" } }
4284 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4287 { +{ "cds.tracks.$_" => "tracks.$_" } }
4288 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4293 Both producing the following SQL:
4295 SELECT me.artistid, me.name, me.rank, me.charfield,
4296 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4297 genre.genreid, genre.name,
4298 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4301 ON cds.artist = me.artistid
4302 LEFT JOIN genre genre
4303 ON genre.genreid = cds.genreid
4304 LEFT JOIN track tracks
4305 ON tracks.cd = cds.cdid
4306 ORDER BY me.artistid
4308 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4309 the arguments are properly merged and generally do the right thing. For
4310 example, you may want to do the following:
4312 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4313 { 'genre.genreid' => undef },
4315 join => { cds => 'genre' },
4320 Which generates the following SQL:
4322 SELECT me.artistid, me.name, me.rank, me.charfield,
4323 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4326 ON cds.artist = me.artistid
4327 LEFT JOIN genre genre
4328 ON genre.genreid = cds.genreid
4329 WHERE genre.genreid IS NULL
4330 ORDER BY me.artistid
4332 For a more in-depth discussion, see L</PREFETCHING>.
4338 =item Value: $source_alias
4342 Sets the source alias for the query. Normally, this defaults to C<me>, but
4343 nested search queries (sub-SELECTs) might need specific aliases set to
4344 reference inner queries. For example:
4347 ->related_resultset('CDs')
4348 ->related_resultset('Tracks')
4350 'track.id' => { -ident => 'none_search.id' },
4354 my $ids = $self->search({
4357 alias => 'none_search',
4358 group_by => 'none_search.id',
4359 })->get_column('id')->as_query;
4361 $self->search({ id => { -in => $ids } })
4363 This attribute is directly tied to L</current_source_alias>.
4373 Makes the resultset paged and specifies the page to retrieve. Effectively
4374 identical to creating a non-pages resultset and then calling ->page($page)
4377 If L</rows> attribute is not specified it defaults to 10 rows per page.
4379 When you have a paged resultset, L</count> will only return the number
4380 of rows in the page. To get the total, use the L</pager> and call
4381 C<total_entries> on it.
4391 Specifies the maximum number of rows for direct retrieval or the number of
4392 rows per page if the page attribute or method is used.
4398 =item Value: $offset
4402 Specifies the (zero-based) row number for the first row to be returned, or the
4403 of the first row of the first page if paging is used.
4405 =head2 software_limit
4409 =item Value: (0 | 1)
4413 When combined with L</rows> and/or L</offset> the generated SQL will not
4414 include any limit dialect stanzas. Instead the entire result will be selected
4415 as if no limits were specified, and DBIC will perform the limit locally, by
4416 artificially advancing and finishing the resulting L</cursor>.
4418 This is the recommended way of performing resultset limiting when no sane RDBMS
4419 implementation is available (e.g.
4420 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4421 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4427 =item Value: \@columns
4431 A arrayref of columns to group by. Can include columns of joined tables.
4433 group_by => [qw/ column1 column2 ... /]
4439 =item Value: $condition
4443 HAVING is a select statement attribute that is applied between GROUP BY and
4444 ORDER BY. It is applied to the after the grouping calculations have been
4447 having => { 'count_employee' => { '>=', 100 } }
4449 or with an in-place function in which case literal SQL is required:
4451 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4457 =item Value: (0 | 1)
4461 Set to 1 to automatically generate a L</group_by> clause based on the selection
4462 (including intelligent handling of L</order_by> contents). Note that the group
4463 criteria calculation takes place over the B<final> selection. This includes
4464 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4465 L</search> calls, and standalone columns selected via
4466 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4467 extra selections specified via L</prefetch> - such selections are explicitly
4468 excluded from group criteria calculations.
4470 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4471 setting is ignored and an appropriate warning is issued.
4477 Adds to the WHERE clause.
4479 # only return rows WHERE deleted IS NULL for all searches
4480 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4482 Can be overridden by passing C<< { where => undef } >> as an attribute
4485 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4491 Set to 1 to cache search results. This prevents extra SQL queries if you
4492 revisit rows in your ResultSet:
4494 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4496 while( my $artist = $resultset->next ) {
4500 $rs->first; # without cache, this would issue a query
4502 By default, searches are not cached.
4504 For more examples of using these attributes, see
4505 L<DBIx::Class::Manual::Cookbook>.
4511 =item Value: ( 'update' | 'shared' | \$scalar )
4515 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4516 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4521 DBIx::Class supports arbitrary related data prefetching from multiple related
4522 sources. Any combination of relationship types and column sets are supported.
4523 If L<collapsing|/collapse> is requested, there is an additional requirement of
4524 selecting enough data to make every individual object uniquely identifiable.
4526 Here are some more involved examples, based on the following relationship map:
4529 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4530 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4531 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4533 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4535 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4539 my $rs = $schema->resultset('Tag')->search(
4548 The initial search results in SQL like the following:
4550 SELECT tag.*, cd.*, artist.* FROM tag
4551 JOIN cd ON tag.cd = cd.cdid
4552 JOIN artist ON cd.artist = artist.artistid
4554 L<DBIx::Class> has no need to go back to the database when we access the
4555 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4558 Simple prefetches will be joined automatically, so there is no need
4559 for a C<join> attribute in the above search.
4561 The L</prefetch> attribute can be used with any of the relationship types
4562 and multiple prefetches can be specified together. Below is a more complex
4563 example that prefetches a CD's artist, its liner notes (if present),
4564 the cover image, the tracks on that CD, and the guests on those
4567 my $rs = $schema->resultset('CD')->search(
4571 { artist => 'record_label'}, # belongs_to => belongs_to
4572 'liner_note', # might_have
4573 'cover_image', # has_one
4574 { tracks => 'guests' }, # has_many => has_many
4579 This will produce SQL like the following:
4581 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4585 ON artist.artistid = me.artistid
4586 JOIN record_label record_label
4587 ON record_label.labelid = artist.labelid
4588 LEFT JOIN track tracks
4589 ON tracks.cdid = me.cdid
4590 LEFT JOIN guest guests
4591 ON guests.trackid = track.trackid
4592 LEFT JOIN liner_notes liner_note
4593 ON liner_note.cdid = me.cdid
4594 JOIN cd_artwork cover_image
4595 ON cover_image.cdid = me.cdid
4598 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4599 C<tracks>, and C<guests> of the CD will all be available through the
4600 relationship accessors without the need for additional queries to the
4605 Prefetch does a lot of deep magic. As such, it may not behave exactly
4606 as you might expect.
4612 Prefetch uses the L</cache> to populate the prefetched relationships. This
4613 may or may not be what you want.
4617 If you specify a condition on a prefetched relationship, ONLY those
4618 rows that match the prefetched condition will be fetched into that relationship.
4619 This means that adding prefetch to a search() B<may alter> what is returned by
4620 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4622 my $artist_rs = $schema->resultset('Artist')->search({
4628 my $count = $artist_rs->first->cds->count;
4630 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4632 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4634 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4636 That cmp_ok() may or may not pass depending on the datasets involved. In other
4637 words the C<WHERE> condition would apply to the entire dataset, just like
4638 it would in regular SQL. If you want to add a condition only to the "right side"
4639 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4640 condition|DBIx::Class::Relationship::Base/condition>
4644 =head1 DBIC BIND VALUES
4646 Because DBIC may need more information to bind values than just the column name
4647 and value itself, it uses a special format for both passing and receiving bind
4648 values. Each bind value should be composed of an arrayref of
4649 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4655 If present (in any form), this is what is being passed directly to bind_param.
4656 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4657 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4659 If this is specified, all other bind options described below are ignored.
4663 If present, this is used to infer the actual bind attribute by passing to
4664 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4665 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4667 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4668 currently drivers are expected to "Do the Right Thing" when given a common
4669 datatype name. (Not ideal, but that's what we got at this point.)
4673 Currently used to correctly allocate buffers for bind_param_inout().
4674 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4675 or to a sensible value based on the "data_type".
4679 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4680 explicitly specified they are never overridden). Also used by some weird DBDs,
4681 where the column name should be available at bind_param time (e.g. Oracle).
4685 For backwards compatibility and convenience, the following shortcuts are
4688 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4689 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4690 [ undef, $val ] === [ {}, $val ]
4691 $val === [ {}, $val ]
4693 =head1 AUTHOR AND CONTRIBUTORS
4695 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4699 You may distribute this code under the same terms as Perl itself.