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 qw(
10 fail_on_internal_wantarray is_plain_value is_literal_value
13 use Data::Compare (); # no imports!!! guard against insane architecture
15 # not importing first() as it will clash with our own method
19 # De-duplication in _merge_attr() is disabled, but left in for reference
20 # (the merger is used for other things that ought not to be de-duped)
21 *__HM_DEDUP = sub () { 0 };
31 # this is real - CDBICompat overrides it with insanity
32 # yes, prototype won't matter, but that's for now ;)
35 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
39 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
43 my $users_rs = $schema->resultset('User');
44 while( $user = $users_rs->next) {
45 print $user->username;
48 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
49 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
53 A ResultSet is an object which stores a set of conditions representing
54 a query. It is the backbone of DBIx::Class (i.e. the really
55 important/useful bit).
57 No SQL is executed on the database when a ResultSet is created, it
58 just stores all the conditions needed to create the query.
60 A basic ResultSet representing the data of an entire table is returned
61 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
62 L<Source|DBIx::Class::Manual::Glossary/Source> name.
64 my $users_rs = $schema->resultset('User');
66 A new ResultSet is returned from calling L</search> on an existing
67 ResultSet. The new one will contain all the conditions of the
68 original, plus any new conditions added in the C<search> call.
70 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
71 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
74 The query that the ResultSet represents is B<only> executed against
75 the database when these methods are called:
76 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
78 If a resultset is used in a numeric context it returns the L</count>.
79 However, if it is used in a boolean context it is B<always> true. So if
80 you want to check if a resultset has any results, you must use C<if $rs
83 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
85 If you want to make your custom ResultSet classes with L<Moose>, use a template
88 package MyApp::Schema::ResultSet::User;
92 extends 'DBIx::Class::ResultSet';
94 sub BUILDARGS { $_[2] }
98 __PACKAGE__->meta->make_immutable;
102 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
103 clash with the regular ResultSet constructor. Alternatively, you can use:
105 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
107 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
108 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
112 =head2 Chaining resultsets
114 Let's say you've got a query that needs to be run to return some data
115 to the user. But, you have an authorization system in place that
116 prevents certain users from seeing certain information. So, you want
117 to construct the basic query in one method, but add constraints to it in
122 my $request = $self->get_request; # Get a request object somehow.
123 my $schema = $self->result_source->schema;
125 my $cd_rs = $schema->resultset('CD')->search({
126 title => $request->param('title'),
127 year => $request->param('year'),
130 $cd_rs = $self->apply_security_policy( $cd_rs );
132 return $cd_rs->all();
135 sub apply_security_policy {
144 =head3 Resolving conditions and attributes
146 When a resultset is chained from another resultset (e.g.:
147 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
148 and attributes with the same keys need resolving.
150 If any of L</columns>, L</select>, L</as> are present, they reset the
151 original selection, and start the selection "clean".
153 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
154 are merged into the existing ones from the original resultset.
156 The L</where> and L</having> attributes, and any search conditions, are
157 merged with an SQL C<AND> to the existing condition from the original
160 All other attributes are overridden by any new ones supplied in the
163 =head2 Multiple queries
165 Since a resultset just defines a query, you can do all sorts of
166 things with it with the same object.
168 # Don't hit the DB yet.
169 my $cd_rs = $schema->resultset('CD')->search({
170 title => 'something',
174 # Each of these hits the DB individually.
175 my $count = $cd_rs->count;
176 my $most_recent = $cd_rs->get_column('date_released')->max();
177 my @records = $cd_rs->all;
179 And it's not just limited to SELECT statements.
185 $cd_rs->create({ artist => 'Fred' });
187 Which is the same as:
189 $schema->resultset('CD')->create({
190 title => 'something',
195 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
203 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
205 =item Return Value: L<$resultset|/search>
209 The resultset constructor. Takes a source object (usually a
210 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
211 L</ATTRIBUTES> below). Does not perform any queries -- these are
212 executed as needed by the other methods.
214 Generally you never construct a resultset manually. Instead you get one
216 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
217 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
220 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
226 If called on an object, proxies to L</new_result> instead, so
228 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
230 will return a CD object, not a ResultSet, and is equivalent to:
232 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
234 Please also keep in mind that many internals call L</new_result> directly,
235 so overloading this method with the idea of intercepting new result object
236 creation B<will not work>. See also warning pertaining to L</create>.
244 return $class->new_result(@_) if ref $class;
246 my ($source, $attrs) = @_;
247 $source = $source->resolve
248 if $source->isa('DBIx::Class::ResultSourceHandle');
250 $attrs = { %{$attrs||{}} };
251 delete @{$attrs}{qw(_last_sqlmaker_alias_map _related_results_construction)};
253 if ($attrs->{page}) {
254 $attrs->{rows} ||= 10;
257 $attrs->{alias} ||= 'me';
260 result_source => $source,
261 cond => $attrs->{where},
266 # if there is a dark selector, this means we are already in a
267 # chain and the cleanup/sanification was taken care of by
269 $self->_normalize_selection($attrs)
270 unless $attrs->{_dark_selector};
273 $attrs->{result_class} || $source->result_class
283 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
285 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
289 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
290 my $new_rs = $cd_rs->search({ year => 2005 });
292 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
293 # year = 2005 OR year = 2004
295 In list context, C<< ->all() >> is called implicitly on the resultset, thus
296 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
297 To avoid that, use L</search_rs>.
299 If you need to pass in additional attributes but no additional condition,
300 call it as C<search(undef, \%attrs)>.
302 # "SELECT name, artistid FROM $artist_table"
303 my @all_artists = $schema->resultset('Artist')->search(undef, {
304 columns => [qw/name artistid/],
307 For a list of attributes that can be passed to C<search>, see
308 L</ATTRIBUTES>. For more examples of using this function, see
309 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
310 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
311 and its extension L<DBIx::Class::SQLMaker>.
313 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
317 Note that L</search> does not process/deflate any of the values passed in the
318 L<SQL::Abstract>-compatible search condition structure. This is unlike other
319 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
320 manually that any value passed to this method will stringify to something the
321 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
322 objects, for more info see:
323 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
329 my $rs = $self->search_rs( @_ );
332 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray($rs);
335 elsif (defined wantarray) {
339 # we can be called by a relationship helper, which in
340 # turn may be called in void context due to some braindead
341 # overload or whatever else the user decided to be clever
342 # at this particular day. Thus limit the exception to
343 # external code calls only
344 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
345 if (caller)[0] !~ /^\QDBIx::Class::/;
355 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
357 =item Return Value: L<$resultset|/search>
361 This method does the same exact thing as search() except it will
362 always return a resultset, even in list context.
369 my $rsrc = $self->result_source;
370 my ($call_cond, $call_attrs);
372 # Special-case handling for (undef, undef) or (undef)
373 # Note that (foo => undef) is valid deprecated syntax
374 @_ = () if not scalar grep { defined $_ } @_;
380 # fish out attrs in the ($condref, $attr) case
381 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
382 ($call_cond, $call_attrs) = @_;
385 $self->throw_exception('Odd number of arguments to search')
389 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
390 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
392 for my $i (0 .. $#_) {
394 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
395 if (! defined $_[$i] or ref $_[$i] ne '');
401 # see if we can keep the cache (no $rs changes)
403 my %safe = (alias => 1, cache => 1);
404 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
407 ref $call_cond eq 'HASH' && ! keys %$call_cond
409 ref $call_cond eq 'ARRAY' && ! @$call_cond
411 $cache = $self->get_cache;
414 my $old_attrs = { %{$self->{attrs}} };
415 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
417 my $new_attrs = { %$old_attrs };
419 # take care of call attrs (only if anything is changing)
420 if ($call_attrs and keys %$call_attrs) {
422 # copy for _normalize_selection
423 $call_attrs = { %$call_attrs };
425 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
427 # reset the current selector list if new selectors are supplied
428 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
429 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
432 # Normalize the new selector list (operates on the passed-in attr structure)
433 # Need to do it on every chain instead of only once on _resolved_attrs, in
434 # order to allow detection of empty vs partial 'as'
435 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
436 if $old_attrs->{_dark_selector};
437 $self->_normalize_selection ($call_attrs);
439 # start with blind overwriting merge, exclude selector attrs
440 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
441 delete @{$new_attrs}{@selector_attrs};
443 for (@selector_attrs) {
444 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
445 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
448 # older deprecated name, use only if {columns} is not there
449 if (my $c = delete $new_attrs->{cols}) {
450 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
451 if ($new_attrs->{columns}) {
452 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
455 $new_attrs->{columns} = $c;
460 # join/prefetch use their own crazy merging heuristics
461 foreach my $key (qw/join prefetch/) {
462 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
463 if exists $call_attrs->{$key};
466 # stack binds together
467 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
471 for ($old_where, $call_cond) {
473 $new_attrs->{where} = $self->_stack_cond (
474 $_, $new_attrs->{where}
479 if (defined $old_having) {
480 $new_attrs->{having} = $self->_stack_cond (
481 $old_having, $new_attrs->{having}
485 my $rs = (ref $self)->new($rsrc, $new_attrs);
487 $rs->set_cache($cache) if ($cache);
493 sub _normalize_selection {
494 my ($self, $attrs) = @_;
497 if ( exists $attrs->{include_columns} ) {
498 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
499 $attrs->{'+columns'} = $self->_merge_attr(
500 $attrs->{'+columns'}, delete $attrs->{include_columns}
504 # columns are always placed first, however
506 # Keep the X vs +X separation until _resolved_attrs time - this allows to
507 # delay the decision on whether to use a default select list ($rsrc->columns)
508 # allowing stuff like the remove_columns helper to work
510 # select/as +select/+as pairs need special handling - the amount of select/as
511 # elements in each pair does *not* have to be equal (think multicolumn
512 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
513 # supplied at all) - try to infer the alias, either from the -as parameter
514 # of the selector spec, or use the parameter whole if it looks like a column
515 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
516 # is ok as well), but make sure no more additions to the 'as' chain take place
517 for my $pref ('', '+') {
519 my ($sel, $as) = map {
520 my $key = "${pref}${_}";
522 my $val = [ ref $attrs->{$key} eq 'ARRAY'
524 : $attrs->{$key} || ()
526 delete $attrs->{$key};
530 if (! @$as and ! @$sel ) {
533 elsif (@$as and ! @$sel) {
534 $self->throw_exception(
535 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
539 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
540 # if any @$as has been supplied we assume the user knows what (s)he is doing
541 # and blindly keep stacking up pieces
542 unless ($attrs->{_dark_selector}) {
545 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
546 push @$as, $_->{-as};
548 # assume any plain no-space, no-parenthesis string to be a column spec
549 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
550 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
553 # if all else fails - raise a flag that no more aliasing will be allowed
555 $attrs->{_dark_selector} = {
557 string => ($dark_sel_dumper ||= do {
558 require Data::Dumper::Concise;
559 Data::Dumper::Concise::DumperObject()->Indent(0);
560 })->Values([$_])->Dump
568 elsif (@$as < @$sel) {
569 $self->throw_exception(
570 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
573 elsif ($pref and $attrs->{_dark_selector}) {
574 $self->throw_exception(
575 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
581 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
582 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
587 my ($self, $left, $right) = @_;
590 (ref $_ eq 'ARRAY' and !@$_)
592 (ref $_ eq 'HASH' and ! keys %$_)
593 ) and $_ = undef for ($left, $right);
595 # either on of the two undef or both undef
596 if ( ( (defined $left) xor (defined $right) ) or ! defined $left ) {
597 return defined $left ? $left : $right;
600 my $cond = $self->result_source->schema->storage->_collapse_cond({ -and => [$left, $right] });
602 for my $c (grep { ref $cond->{$_} eq 'ARRAY' and ($cond->{$_}[0]||'') eq '-and' } keys %$cond) {
604 my @vals = sort @{$cond->{$c}}[ 1..$#{$cond->{$c}} ];
605 my @fin = shift @vals;
608 push @fin, $v unless Data::Compare::Compare( $fin[-1], $v );
611 $cond->{$c} = (@fin == 1) ? $fin[0] : [-and => @fin ];
617 =head2 search_literal
619 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
620 should only be used in that context. C<search_literal> is a convenience
621 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
622 want to ensure columns are bound correctly, use L</search>.
624 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
625 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
626 require C<search_literal>.
630 =item Arguments: $sql_fragment, @standalone_bind_values
632 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
636 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
637 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
639 Pass a literal chunk of SQL to be added to the conditional part of the
642 Example of how to use C<search> instead of C<search_literal>
644 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
645 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
650 my ($self, $sql, @bind) = @_;
652 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
655 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
662 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
664 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
668 Finds and returns a single row based on supplied criteria. Takes either a
669 hashref with the same format as L</create> (including inference of foreign
670 keys from related objects), or a list of primary key values in the same
671 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
672 declaration on the L</result_source>.
674 In either case an attempt is made to combine conditions already existing on
675 the resultset with the condition passed to this method.
677 To aid with preparing the correct query for the storage you may supply the
678 C<key> attribute, which is the name of a
679 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
680 unique constraint corresponding to the
681 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
682 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
683 to construct a query that satisfies the named unique constraint fully (
684 non-NULL values for each column member of the constraint) an exception is
687 If no C<key> is specified, the search is carried over all unique constraints
688 which are fully defined by the available condition.
690 If no such constraint is found, C<find> currently defaults to a simple
691 C<< search->(\%column_values) >> which may or may not do what you expect.
692 Note that this fallback behavior may be deprecated in further versions. If
693 you need to search with arbitrary conditions - use L</search>. If the query
694 resulting from this fallback produces more than one row, a warning to the
695 effect is issued, though only the first row is constructed and returned as
698 In addition to C<key>, L</find> recognizes and applies standard
699 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
701 Note that if you have extra concerns about the correctness of the resulting
702 query you need to specify the C<key> attribute and supply the entire condition
703 as an argument to find (since it is not always possible to perform the
704 combination of the resultset condition with the supplied one, especially if
705 the resultset condition contains literal sql).
707 For example, to find a row by its primary key:
709 my $cd = $schema->resultset('CD')->find(5);
711 You can also find a row by a specific unique constraint:
713 my $cd = $schema->resultset('CD')->find(
715 artist => 'Massive Attack',
716 title => 'Mezzanine',
718 { key => 'cd_artist_title' }
721 See also L</find_or_create> and L</update_or_create>.
727 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
729 my $rsrc = $self->result_source;
732 if (exists $attrs->{key}) {
733 $constraint_name = defined $attrs->{key}
735 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
739 # Parse out the condition from input
742 if (ref $_[0] eq 'HASH') {
743 $call_cond = { %{$_[0]} };
746 # if only values are supplied we need to default to 'primary'
747 $constraint_name = 'primary' unless defined $constraint_name;
749 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
751 $self->throw_exception(
752 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
755 $self->throw_exception (
756 'find() expects either a column/value hashref, or a list of values '
757 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
758 ) unless @c_cols == @_;
761 @{$call_cond}{@c_cols} = @_;
765 for my $key (keys %$call_cond) {
767 my $keyref = ref($call_cond->{$key})
769 my $relinfo = $rsrc->relationship_info($key)
771 my $val = delete $call_cond->{$key};
773 next if $keyref eq 'ARRAY'; # has_many for multi_create
775 my ($rel_cond, $crosstable) = $rsrc->_resolve_condition(
776 $relinfo->{cond}, $val, $key, $key
779 $self->throw_exception("Complex condition via relationship '$key' is unsupported in find()")
780 if $crosstable or ref($rel_cond) ne 'HASH';
783 @related{keys %$rel_cond} = values %$rel_cond;
787 # relationship conditions take precedence (?)
788 @{$call_cond}{keys %related} = values %related;
790 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
792 if (defined $constraint_name) {
793 $final_cond = $self->_qualify_cond_columns (
795 $self->_build_unique_cond (
803 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
804 # This means that we got here after a merger of relationship conditions
805 # in ::Relationship::Base::search_related (the row method), and furthermore
806 # the relationship is of the 'single' type. This means that the condition
807 # provided by the relationship (already attached to $self) is sufficient,
808 # as there can be only one row in the database that would satisfy the
812 # no key was specified - fall down to heuristics mode:
813 # run through all unique queries registered on the resultset, and
814 # 'OR' all qualifying queries together
815 my (@unique_queries, %seen_column_combinations);
816 for my $c_name ($rsrc->unique_constraint_names) {
817 next if $seen_column_combinations{
818 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
821 push @unique_queries, try {
822 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
826 $final_cond = @unique_queries
827 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
828 : $self->_non_unique_find_fallback ($call_cond, $attrs)
832 # Run the query, passing the result_class since it should propagate for find
833 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
834 if ($rs->_resolved_attrs->{collapse}) {
836 carp "Query returned more than one row" if $rs->next;
844 # This is a stop-gap method as agreed during the discussion on find() cleanup:
845 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
847 # It is invoked when find() is called in legacy-mode with insufficiently-unique
848 # condition. It is provided for overrides until a saner way forward is devised
850 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
851 # the road. Please adjust your tests accordingly to catch this situation early
852 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
854 # The method will not be removed without an adequately complete replacement
855 # for strict-mode enforcement
856 sub _non_unique_find_fallback {
857 my ($self, $cond, $attrs) = @_;
859 return $self->_qualify_cond_columns(
861 exists $attrs->{alias}
863 : $self->{attrs}{alias}
868 sub _qualify_cond_columns {
869 my ($self, $cond, $alias) = @_;
871 my %aliased = %$cond;
872 for (keys %aliased) {
873 $aliased{"$alias.$_"} = delete $aliased{$_}
880 sub _build_unique_cond {
881 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
883 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
885 # combination may fail if $self->{cond} is non-trivial
886 my ($final_cond) = try {
887 $self->_merge_with_rscond ($extra_cond)
892 # trim out everything not in $columns
893 $final_cond = { map {
894 exists $final_cond->{$_}
895 ? ( $_ => $final_cond->{$_} )
899 if (my @missing = grep
900 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
903 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
905 join (', ', map { "'$_'" } @missing),
912 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
914 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
916 carp_unique ( sprintf (
917 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
918 . 'values in column(s): %s). This is almost certainly not what you wanted, '
919 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
921 join (', ', map { "'$_'" } @undefs),
928 =head2 search_related
932 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
934 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
938 $new_rs = $cd_rs->search_related('artist', {
942 Searches the specified relationship, optionally specifying a condition and
943 attributes for matching records. See L</ATTRIBUTES> for more information.
945 In list context, C<< ->all() >> is called implicitly on the resultset, thus
946 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
948 See also L</search_related_rs>.
953 return shift->related_resultset(shift)->search(@_);
956 =head2 search_related_rs
958 This method works exactly the same as search_related, except that
959 it guarantees a resultset, even in list context.
963 sub search_related_rs {
964 return shift->related_resultset(shift)->search_rs(@_);
971 =item Arguments: none
973 =item Return Value: L<$cursor|DBIx::Class::Cursor>
977 Returns a storage-driven cursor to the given resultset. See
978 L<DBIx::Class::Cursor> for more information.
985 return $self->{cursor} ||= do {
986 my $attrs = $self->_resolved_attrs;
987 $self->result_source->storage->select(
988 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
997 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
999 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1003 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1005 Inflates the first result without creating a cursor if the resultset has
1006 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1009 While this method can take an optional search condition (just like L</search>)
1010 being a fast-code-path it does not recognize search attributes. If you need to
1011 add extra joins or similar, call L</search> and then chain-call L</single> on the
1012 L<DBIx::Class::ResultSet> returned.
1018 As of 0.08100, this method enforces the assumption that the preceding
1019 query returns only one row. If more than one row is returned, you will receive
1022 Query returned more than one row
1024 In this case, you should be using L</next> or L</find> instead, or if you really
1025 know what you are doing, use the L</rows> attribute to explicitly limit the size
1028 This method will also throw an exception if it is called on a resultset prefetching
1029 has_many, as such a prefetch implies fetching multiple rows from the database in
1030 order to assemble the resulting object.
1037 my ($self, $where) = @_;
1039 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1042 my $attrs = { %{$self->_resolved_attrs} };
1044 $self->throw_exception(
1045 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1046 ) if $attrs->{collapse};
1049 if (defined $attrs->{where}) {
1052 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1053 $where, delete $attrs->{where} ]
1056 $attrs->{where} = $where;
1060 my $data = [ $self->result_source->storage->select_single(
1061 $attrs->{from}, $attrs->{select},
1062 $attrs->{where}, $attrs
1065 return undef unless @$data;
1066 $self->{_stashed_rows} = [ $data ];
1067 $self->_construct_results->[0];
1074 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1076 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1080 my $max_length = $rs->get_column('length')->max;
1082 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1087 my ($self, $column) = @_;
1088 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1096 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1098 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1102 # WHERE title LIKE '%blue%'
1103 $cd_rs = $rs->search_like({ title => '%blue%'});
1105 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1106 that this is simply a convenience method retained for ex Class::DBI users.
1107 You most likely want to use L</search> with specific operators.
1109 For more information, see L<DBIx::Class::Manual::Cookbook>.
1111 This method is deprecated and will be removed in 0.09. Use L</search()>
1112 instead. An example conversion is:
1114 ->search_like({ foo => 'bar' });
1118 ->search({ foo => { like => 'bar' } });
1125 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1126 .' Instead use ->search({ x => { -like => "y%" } })'
1127 .' (note the outer pair of {}s - they are important!)'
1129 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1130 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1131 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1132 return $class->search($query, { %$attrs });
1139 =item Arguments: $first, $last
1141 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1145 Returns a resultset or object list representing a subset of elements from the
1146 resultset slice is called on. Indexes are from 0, i.e., to get the first
1147 three records, call:
1149 my ($one, $two, $three) = $rs->slice(0, 2);
1154 my ($self, $min, $max) = @_;
1155 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1156 $attrs->{offset} = $self->{attrs}{offset} || 0;
1157 $attrs->{offset} += $min;
1158 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1159 return $self->search(undef, $attrs);
1166 =item Arguments: none
1168 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1172 Returns the next element in the resultset (C<undef> is there is none).
1174 Can be used to efficiently iterate over records in the resultset:
1176 my $rs = $schema->resultset('CD')->search;
1177 while (my $cd = $rs->next) {
1181 Note that you need to store the resultset object, and call C<next> on it.
1182 Calling C<< resultset('Table')->next >> repeatedly will always return the
1183 first record from the resultset.
1190 if (my $cache = $self->get_cache) {
1191 $self->{all_cache_position} ||= 0;
1192 return $cache->[$self->{all_cache_position}++];
1195 if ($self->{attrs}{cache}) {
1196 delete $self->{pager};
1197 $self->{all_cache_position} = 1;
1198 return ($self->all)[0];
1201 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1203 $self->{_stashed_results} = $self->_construct_results
1206 return shift @{$self->{_stashed_results}};
1209 # Constructs as many results as it can in one pass while respecting
1210 # cursor laziness. Several modes of operation:
1212 # * Always builds everything present in @{$self->{_stashed_rows}}
1213 # * If called with $fetch_all true - pulls everything off the cursor and
1214 # builds all result structures (or objects) in one pass
1215 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1216 # and if the resultset is ordered properly by the left side:
1217 # * Fetches stuff off the cursor until the "master object" changes,
1218 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1220 # * Just fetches, and collapses/constructs everything as if $fetch_all
1221 # was requested (there is no other way to collapse except for an
1223 # * If no collapse is requested - just get the next row, construct and
1225 sub _construct_results {
1226 my ($self, $fetch_all) = @_;
1228 my $rsrc = $self->result_source;
1229 my $attrs = $self->_resolved_attrs;
1234 ! $attrs->{order_by}
1238 my @pcols = $rsrc->primary_columns
1240 # default order for collapsing unless the user asked for something
1241 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1242 $attrs->{_ordered_for_collapse} = 1;
1243 $attrs->{_order_is_artificial} = 1;
1246 # this will be used as both initial raw-row collector AND as a RV of
1247 # _construct_results. Not regrowing the array twice matters a lot...
1248 # a surprising amount actually
1249 my $rows = delete $self->{_stashed_rows};
1251 my $cursor; # we may not need one at all
1253 my $did_fetch_all = $fetch_all;
1256 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1257 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1259 elsif( $attrs->{collapse} ) {
1261 # a cursor will need to be closed over in case of collapse
1262 $cursor = $self->cursor;
1264 $attrs->{_ordered_for_collapse} = (
1270 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1272 ) unless defined $attrs->{_ordered_for_collapse};
1274 if (! $attrs->{_ordered_for_collapse}) {
1277 # instead of looping over ->next, use ->all in stealth mode
1278 # *without* calling a ->reset afterwards
1279 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1280 if (! $cursor->{_done}) {
1281 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1282 $cursor->{_done} = 1;
1287 if (! $did_fetch_all and ! @{$rows||[]} ) {
1288 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1289 $cursor ||= $self->cursor;
1290 if (scalar (my @r = $cursor->next) ) {
1295 return undef unless @{$rows||[]};
1297 # sanity check - people are too clever for their own good
1298 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1300 my $multiplied_selectors;
1301 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1303 $aliastypes->{multiplying}{$sel_alias}
1305 $aliastypes->{premultiplied}{$sel_alias}
1307 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1311 for my $i (0 .. $#{$attrs->{as}} ) {
1312 my $sel = $attrs->{select}[$i];
1314 if (ref $sel eq 'SCALAR') {
1317 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1321 $self->throw_exception(
1322 'Result collapse not possible - selection from a has_many source redirected to the main object'
1323 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1327 # hotspot - skip the setter
1328 my $res_class = $self->_result_class;
1330 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1331 $res_class->can ('inflate_result')
1332 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1335 my $infmap = $attrs->{as};
1337 $self->{_result_inflator}{is_core_row} = ( (
1340 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1341 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1343 $self->{_result_inflator}{is_hri} = ( (
1344 ! $self->{_result_inflator}{is_core_row}
1347 require DBIx::Class::ResultClass::HashRefInflator
1349 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1351 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1354 if (! $attrs->{_related_results_construction}) {
1355 # construct a much simpler array->hash folder for the one-table cases right here
1356 if ($self->{_result_inflator}{is_hri}) {
1357 for my $r (@$rows) {
1358 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1361 # FIXME SUBOPTIMAL this is a very very very hot spot
1362 # while rather optimal we can *still* do much better, by
1363 # building a smarter Row::inflate_result(), and
1364 # switch to feeding it data via a much leaner interface
1366 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1367 # this particular resultset size
1368 elsif (@$rows < 60) {
1369 for my $r (@$rows) {
1370 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1375 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1376 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1382 $self->{_result_inflator}{is_hri} ? 'hri'
1383 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1384 : 'classic_nonpruning'
1387 # $args and $attrs to _mk_row_parser are separated to delineate what is
1388 # core collapser stuff and what is dbic $rs specific
1389 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1391 inflate_map => $infmap,
1392 collapse => $attrs->{collapse},
1393 premultiplied => $attrs->{_main_source_premultiplied},
1394 hri_style => $self->{_result_inflator}{is_hri},
1395 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1396 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1398 # column_info metadata historically hasn't been too reliable.
1399 # We need to start fixing this somehow (the collapse resolver
1400 # can't work without it). Add an explicit check for the *main*
1401 # result, hopefully this will gradually weed out such errors
1403 # FIXME - this is a temporary kludge that reduces performance
1404 # It is however necessary for the time being
1405 my ($unrolled_non_null_cols_to_check, $err);
1407 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1410 'Collapse aborted due to invalid ResultSource metadata - the following '
1411 . 'selections are declared non-nullable but NULLs were retrieved: '
1415 COL: for my $i (@$check_non_null_cols) {
1416 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1419 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1422 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1426 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1427 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1429 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1430 my @r = $cursor->next or return;
1431 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1432 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1438 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1439 my @r = $cursor->next or return;
1444 $self->{_row_parser}{$parser_type}{cref}->(
1446 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1449 # Special-case multi-object HRI - there is no $inflator_cref pass
1450 unless ($self->{_result_inflator}{is_hri}) {
1451 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1455 # The @$rows check seems odd at first - why wouldn't we want to warn
1456 # regardless? The issue is things like find() etc, where the user
1457 # *knows* only one result will come back. In these cases the ->all
1458 # is not a pessimization, but rather something we actually want
1460 'Unable to properly collapse has_many results in iterator mode due '
1461 . 'to order criteria - performed an eager cursor slurp underneath. '
1462 . 'Consider using ->all() instead'
1463 ) if ( ! $fetch_all and @$rows > 1 );
1468 =head2 result_source
1472 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1474 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1478 An accessor for the primary ResultSource object from which this ResultSet
1485 =item Arguments: $result_class?
1487 =item Return Value: $result_class
1491 An accessor for the class to use when creating result objects. Defaults to
1492 C<< result_source->result_class >> - which in most cases is the name of the
1493 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1495 Note that changing the result_class will also remove any components
1496 that were originally loaded in the source class via
1497 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1498 in the original source class will not run.
1503 my ($self, $result_class) = @_;
1504 if ($result_class) {
1506 # don't fire this for an object
1507 $self->ensure_class_loaded($result_class)
1508 unless ref($result_class);
1510 if ($self->get_cache) {
1511 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1513 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1514 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1515 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1518 $self->_result_class($result_class);
1520 delete $self->{_result_inflator};
1522 $self->_result_class;
1529 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1531 =item Return Value: $count
1535 Performs an SQL C<COUNT> with the same query as the resultset was built
1536 with to find the number of elements. Passing arguments is equivalent to
1537 C<< $rs->search ($cond, \%attrs)->count >>
1543 return $self->search(@_)->count if @_ and defined $_[0];
1544 return scalar @{ $self->get_cache } if $self->get_cache;
1546 my $attrs = { %{ $self->_resolved_attrs } };
1548 # this is a little optimization - it is faster to do the limit
1549 # adjustments in software, instead of a subquery
1550 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1553 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1554 $crs = $self->_count_subq_rs ($attrs);
1557 $crs = $self->_count_rs ($attrs);
1559 my $count = $crs->next;
1561 $count -= $offset if $offset;
1562 $count = $rows if $rows and $rows < $count;
1563 $count = 0 if ($count < 0);
1572 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1574 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1578 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1579 This can be very handy for subqueries:
1581 ->search( { amount => $some_rs->count_rs->as_query } )
1583 As with regular resultsets the SQL query will be executed only after
1584 the resultset is accessed via L</next> or L</all>. That would return
1585 the same single value obtainable via L</count>.
1591 return $self->search(@_)->count_rs if @_;
1593 # this may look like a lack of abstraction (count() does about the same)
1594 # but in fact an _rs *must* use a subquery for the limits, as the
1595 # software based limiting can not be ported if this $rs is to be used
1596 # in a subquery itself (i.e. ->as_query)
1597 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1598 return $self->_count_subq_rs($self->{_attrs});
1601 return $self->_count_rs($self->{_attrs});
1606 # returns a ResultSetColumn object tied to the count query
1609 my ($self, $attrs) = @_;
1611 my $rsrc = $self->result_source;
1613 my $tmp_attrs = { %$attrs };
1614 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1615 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1617 # overwrite the selector (supplied by the storage)
1618 $rsrc->resultset_class->new($rsrc, {
1620 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1622 })->get_column ('count');
1626 # same as above but uses a subquery
1628 sub _count_subq_rs {
1629 my ($self, $attrs) = @_;
1631 my $rsrc = $self->result_source;
1633 my $sub_attrs = { %$attrs };
1634 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1635 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1637 # if we multi-prefetch we group_by something unique, as this is what we would
1638 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1639 if ( $attrs->{collapse} ) {
1640 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1641 $rsrc->_identifying_column_set || $self->throw_exception(
1642 'Unable to construct a unique group_by criteria properly collapsing the '
1643 . 'has_many prefetch before count()'
1648 # Calculate subquery selector
1649 if (my $g = $sub_attrs->{group_by}) {
1651 my $sql_maker = $rsrc->storage->sql_maker;
1653 # necessary as the group_by may refer to aliased functions
1655 for my $sel (@{$attrs->{select}}) {
1656 $sel_index->{$sel->{-as}} = $sel
1657 if (ref $sel eq 'HASH' and $sel->{-as});
1660 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1661 # also look for named aggregates referred in the having clause
1662 # having often contains scalarrefs - thus parse it out entirely
1664 if ($attrs->{having}) {
1665 local $sql_maker->{having_bind};
1666 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1667 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1668 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1669 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1670 # if we don't unset it we screw up retarded but unfortunately working
1671 # 'MAX(foo.bar)' => { '>', 3 }
1672 $sql_maker->{name_sep} = '';
1675 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1677 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1680 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1681 # and if all fails for an utterly naive quoted scalar-with-function
1682 while ($having_sql =~ /
1683 $rquote $sep $lquote (.+?) $rquote
1685 [\s,] \w+ \. (\w+) [\s,]
1687 [\s,] $lquote (.+?) $rquote [\s,]
1689 my $part = $1 || $2 || $3; # one of them matched if we got here
1690 unless ($seen_having{$part}++) {
1697 my $colpiece = $sel_index->{$_} || $_;
1699 # unqualify join-based group_by's. Arcane but possible query
1700 # also horrible horrible hack to alias a column (not a func.)
1701 # (probably need to introduce SQLA syntax)
1702 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1705 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1707 push @{$sub_attrs->{select}}, $colpiece;
1711 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1712 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1715 return $rsrc->resultset_class
1716 ->new ($rsrc, $sub_attrs)
1718 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1719 ->get_column ('count');
1723 =head2 count_literal
1725 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1726 should only be used in that context. See L</search_literal> for further info.
1730 =item Arguments: $sql_fragment, @standalone_bind_values
1732 =item Return Value: $count
1736 Counts the results in a literal query. Equivalent to calling L</search_literal>
1737 with the passed arguments, then L</count>.
1741 sub count_literal { shift->search_literal(@_)->count; }
1747 =item Arguments: none
1749 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1753 Returns all elements in the resultset.
1760 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1763 delete @{$self}{qw/_stashed_rows _stashed_results/};
1765 if (my $c = $self->get_cache) {
1769 $self->cursor->reset;
1771 my $objs = $self->_construct_results('fetch_all') || [];
1773 $self->set_cache($objs) if $self->{attrs}{cache};
1782 =item Arguments: none
1784 =item Return Value: $self
1788 Resets the resultset's cursor, so you can iterate through the elements again.
1789 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1797 delete @{$self}{qw/_stashed_rows _stashed_results/};
1798 $self->{all_cache_position} = 0;
1799 $self->cursor->reset;
1807 =item Arguments: none
1809 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1813 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1814 an object for the first result (or C<undef> if the resultset is empty).
1819 return $_[0]->reset->next;
1825 # Determines whether and what type of subquery is required for the $rs operation.
1826 # If grouping is necessary either supplies its own, or verifies the current one
1827 # After all is done delegates to the proper storage method.
1829 sub _rs_update_delete {
1830 my ($self, $op, $values) = @_;
1832 my $rsrc = $self->result_source;
1833 my $storage = $rsrc->schema->storage;
1835 my $attrs = { %{$self->_resolved_attrs} };
1837 my $join_classifications;
1838 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1840 # do we need a subquery for any reason?
1842 defined $existing_group_by
1844 # if {from} is unparseable wrap a subq
1845 ref($attrs->{from}) ne 'ARRAY'
1847 # limits call for a subq
1848 $self->_has_resolved_attr(qw/rows offset/)
1851 # simplify the joinmap, so we can further decide if a subq is necessary
1852 if (!$needs_subq and @{$attrs->{from}} > 1) {
1854 ($attrs->{from}, $join_classifications) =
1855 $storage->_prune_unused_joins ($attrs);
1857 # any non-pruneable non-local restricting joins imply subq
1858 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1861 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1863 (ref $attrs->{from}[0]) ne 'HASH'
1865 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1869 # do we need anything like a subquery?
1870 if (! $needs_subq) {
1871 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1872 # a condition containing 'me' or other table prefixes will not work
1873 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1875 my $sqla = $rsrc->storage->sql_maker;
1876 local $sqla->{_dequalify_idents} = 1;
1877 \[ $sqla->_recurse_where($self->{cond}) ];
1881 # we got this far - means it is time to wrap a subquery
1882 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1884 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1890 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1891 delete $attrs->{$_} for qw/select as collapse/;
1892 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1894 # this will be consumed by the pruner waaaaay down the stack
1895 $attrs->{_force_prune_multiplying_joins} = 1;
1897 my $subrs = (ref $self)->new($rsrc, $attrs);
1899 if (@$idcols == 1) {
1900 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1902 elsif ($storage->_use_multicolumn_in) {
1903 # no syntax for calling this properly yet
1904 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1905 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1906 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1911 # if all else fails - get all primary keys and operate over a ORed set
1912 # wrap in a transaction for consistency
1913 # this is where the group_by/multiplication starts to matter
1917 # we do not need to check pre-multipliers, since if the premulti is there, its
1918 # parent (who is multi) will be there too
1919 keys %{ $join_classifications->{multiplying} || {} }
1921 # make sure if there is a supplied group_by it matches the columns compiled above
1922 # perfectly. Anything else can not be sanely executed on most databases so croak
1923 # right then and there
1924 if ($existing_group_by) {
1925 my @current_group_by = map
1926 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1931 join ("\x00", sort @current_group_by)
1933 join ("\x00", sort @{$attrs->{columns}} )
1935 $self->throw_exception (
1936 "You have just attempted a $op operation on a resultset which does group_by"
1937 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1938 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1939 . ' kind of queries. Please retry the operation with a modified group_by or'
1940 . ' without using one at all.'
1945 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1948 $guard = $storage->txn_scope_guard;
1950 for my $row ($subrs->cursor->all) {
1952 { $idcols->[$_] => $row->[$_] }
1959 my $res = $cond ? $storage->$op (
1961 $op eq 'update' ? $values : (),
1965 $guard->commit if $guard;
1974 =item Arguments: \%values
1976 =item Return Value: $underlying_storage_rv
1980 Sets the specified columns in the resultset to the supplied values in a
1981 single query. Note that this will not run any accessor/set_column/update
1982 triggers, nor will it update any result object instances derived from this
1983 resultset (this includes the contents of the L<resultset cache|/set_cache>
1984 if any). See L</update_all> if you need to execute any on-update
1985 triggers or cascades defined either by you or a
1986 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1988 The return value is a pass through of what the underlying
1989 storage backend returned, and may vary. See L<DBI/execute> for the most
1994 Note that L</update> does not process/deflate any of the values passed in.
1995 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1996 ensure manually that any value passed to this method will stringify to
1997 something the RDBMS knows how to deal with. A notable example is the
1998 handling of L<DateTime> objects, for more info see:
1999 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2004 my ($self, $values) = @_;
2005 $self->throw_exception('Values for update must be a hash')
2006 unless ref $values eq 'HASH';
2008 return $self->_rs_update_delete ('update', $values);
2015 =item Arguments: \%values
2017 =item Return Value: 1
2021 Fetches all objects and updates them one at a time via
2022 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2023 triggers, while L</update> will not.
2028 my ($self, $values) = @_;
2029 $self->throw_exception('Values for update_all must be a hash')
2030 unless ref $values eq 'HASH';
2032 my $guard = $self->result_source->schema->txn_scope_guard;
2033 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2042 =item Arguments: none
2044 =item Return Value: $underlying_storage_rv
2048 Deletes the rows matching this resultset in a single query. Note that this
2049 will not run any delete triggers, nor will it alter the
2050 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2051 derived from this resultset (this includes the contents of the
2052 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2053 execute any on-delete triggers or cascades defined either by you or a
2054 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2056 The return value is a pass through of what the underlying storage backend
2057 returned, and may vary. See L<DBI/execute> for the most common case.
2063 $self->throw_exception('delete does not accept any arguments')
2066 return $self->_rs_update_delete ('delete');
2073 =item Arguments: none
2075 =item Return Value: 1
2079 Fetches all objects and deletes them one at a time via
2080 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2081 triggers, while L</delete> will not.
2087 $self->throw_exception('delete_all does not accept any arguments')
2090 my $guard = $self->result_source->schema->txn_scope_guard;
2091 $_->delete for $self->all;
2100 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2102 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2106 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2113 The context of this method call has an important effect on what is
2114 submitted to storage. In void context data is fed directly to fastpath
2115 insertion routines provided by the underlying storage (most often
2116 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2117 L<insert|DBIx::Class::Row/insert> calls on the
2118 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2119 augmentation of these methods provided by components. For example if you
2120 are using something like L<DBIx::Class::UUIDColumns> to create primary
2121 keys for you, you will find that your PKs are empty. In this case you
2122 will have to explicitly force scalar or list context in order to create
2127 In non-void (scalar or list) context, this method is simply a wrapper
2128 for L</create>. Depending on list or scalar context either a list of
2129 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2130 containing these objects is returned.
2132 When supplying data in "arrayref of arrayrefs" invocation style, the
2133 first element should be a list of column names and each subsequent
2134 element should be a data value in the earlier specified column order.
2137 $schema->resultset("Artist")->populate([
2138 [ qw( artistid name ) ],
2139 [ 100, 'A Formally Unknown Singer' ],
2140 [ 101, 'A singer that jumped the shark two albums ago' ],
2141 [ 102, 'An actually cool singer' ],
2144 For the arrayref of hashrefs style each hashref should be a structure
2145 suitable for passing to L</create>. Multi-create is also permitted with
2148 $schema->resultset("Artist")->populate([
2149 { artistid => 4, name => 'Manufactured Crap', cds => [
2150 { title => 'My First CD', year => 2006 },
2151 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2154 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2155 { title => 'My parents sold me to a record company', year => 2005 },
2156 { title => 'Why Am I So Ugly?', year => 2006 },
2157 { title => 'I Got Surgery and am now Popular', year => 2007 }
2162 If you attempt a void-context multi-create as in the example above (each
2163 Artist also has the related list of CDs), and B<do not> supply the
2164 necessary autoinc foreign key information, this method will proxy to the
2165 less efficient L</create>, and then throw the Result objects away. In this
2166 case there are obviously no benefits to using this method over L</create>.
2173 # cruft placed in standalone method
2174 my $data = $self->_normalize_populate_args(@_);
2176 return unless @$data;
2178 if(defined wantarray) {
2179 my @created = map { $self->create($_) } @$data;
2180 return wantarray ? @created : \@created;
2183 my $first = $data->[0];
2185 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2186 # it relationship data
2187 my (@rels, @columns);
2188 my $rsrc = $self->result_source;
2189 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2190 for (keys %$first) {
2191 my $ref = ref $first->{$_};
2192 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2198 my @pks = $rsrc->primary_columns;
2200 ## do the belongs_to relationships
2201 foreach my $index (0..$#$data) {
2203 # delegate to create() for any dataset without primary keys with specified relationships
2204 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2206 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2207 my @ret = $self->populate($data);
2213 foreach my $rel (@rels) {
2214 next unless ref $data->[$index]->{$rel} eq "HASH";
2215 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2216 my (undef, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2217 my $related = $result->result_source->_resolve_condition(
2218 $reverse_relinfo->{cond},
2224 delete $data->[$index]->{$rel};
2225 $data->[$index] = {%{$data->[$index]}, %$related};
2227 push @columns, keys %$related if $index == 0;
2231 ## inherit the data locked in the conditions of the resultset
2232 my ($rs_data) = $self->_merge_with_rscond({});
2233 delete @{$rs_data}{@columns};
2235 ## do bulk insert on current row
2236 $rsrc->storage->insert_bulk(
2238 [@columns, keys %$rs_data],
2239 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2242 ## do the has_many relationships
2243 foreach my $item (@$data) {
2247 foreach my $rel (@rels) {
2248 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2250 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2252 my $child = $main_row->$rel;
2254 my $related = $child->result_source->_resolve_condition(
2255 $rels->{$rel}{cond},
2261 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2262 my @populate = map { {%$_, %$related} } @rows_to_add;
2264 $child->populate( \@populate );
2271 # populate() arguments went over several incarnations
2272 # What we ultimately support is AoH
2273 sub _normalize_populate_args {
2274 my ($self, $arg) = @_;
2276 if (ref $arg eq 'ARRAY') {
2280 elsif (ref $arg->[0] eq 'HASH') {
2283 elsif (ref $arg->[0] eq 'ARRAY') {
2285 my @colnames = @{$arg->[0]};
2286 foreach my $values (@{$arg}[1 .. $#$arg]) {
2287 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2293 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2300 =item Arguments: none
2302 =item Return Value: L<$pager|Data::Page>
2306 Returns a L<Data::Page> object for the current resultset. Only makes
2307 sense for queries with a C<page> attribute.
2309 To get the full count of entries for a paged resultset, call
2310 C<total_entries> on the L<Data::Page> object.
2317 return $self->{pager} if $self->{pager};
2319 my $attrs = $self->{attrs};
2320 if (!defined $attrs->{page}) {
2321 $self->throw_exception("Can't create pager for non-paged rs");
2323 elsif ($attrs->{page} <= 0) {
2324 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2326 $attrs->{rows} ||= 10;
2328 # throw away the paging flags and re-run the count (possibly
2329 # with a subselect) to get the real total count
2330 my $count_attrs = { %$attrs };
2331 delete @{$count_attrs}{qw/rows offset page pager/};
2333 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2335 require DBIx::Class::ResultSet::Pager;
2336 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2337 sub { $total_rs->count }, #lazy-get the total
2339 $self->{attrs}{page},
2347 =item Arguments: $page_number
2349 =item Return Value: L<$resultset|/search>
2353 Returns a resultset for the $page_number page of the resultset on which page
2354 is called, where each page contains a number of rows equal to the 'rows'
2355 attribute set on the resultset (10 by default).
2360 my ($self, $page) = @_;
2361 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2368 =item Arguments: \%col_data
2370 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2374 Creates a new result object in the resultset's result class and returns
2375 it. The row is not inserted into the database at this point, call
2376 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2377 will tell you whether the result object has been inserted or not.
2379 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2384 my ($self, $values) = @_;
2386 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2389 $self->throw_exception( "new_result expects a hashref" )
2390 unless (ref $values eq 'HASH');
2392 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2394 my $new = $self->result_class->new({
2396 ( @$cols_from_relations
2397 ? (-cols_from_relations => $cols_from_relations)
2400 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2404 reftype($new) eq 'HASH'
2410 carp_unique (sprintf (
2411 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2412 $self->result_class,
2419 # _merge_with_rscond
2421 # Takes a simple hash of K/V data and returns its copy merged with the
2422 # condition already present on the resultset. Additionally returns an
2423 # arrayref of value/condition names, which were inferred from related
2424 # objects (this is needed for in-memory related objects)
2425 sub _merge_with_rscond {
2426 my ($self, $data) = @_;
2428 my (%new_data, @cols_from_relations);
2430 my $alias = $self->{attrs}{alias};
2432 if (! defined $self->{cond}) {
2433 # just massage $data below
2435 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2436 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2437 @cols_from_relations = keys %new_data;
2439 elsif (ref $self->{cond} ne 'HASH') {
2440 $self->throw_exception(
2441 "Can't abstract implicit construct, resultset condition not a hash"
2445 if ($self->{cond}) {
2446 my $implied = $self->_remove_alias(
2447 $self->result_source->schema->storage->_collapse_cond($self->{cond}),
2451 for my $c (keys %$implied) {
2452 my $v = $implied->{$c};
2453 if ( ! length ref $v or is_plain_value($v) ) {
2457 ref $v eq 'HASH' and keys %$v == 1 and exists $v->{'='} and is_literal_value($v->{'='})
2459 $new_data{$c} = $v->{'='};
2465 # precedence must be given to passed values over values inherited from
2466 # the cond, so the order here is important.
2469 %{ $self->_remove_alias($data, $alias) },
2472 return (\%new_data, \@cols_from_relations);
2475 # _has_resolved_attr
2477 # determines if the resultset defines at least one
2478 # of the attributes supplied
2480 # used to determine if a subquery is necessary
2482 # supports some virtual attributes:
2484 # This will scan for any joins being present on the resultset.
2485 # It is not a mere key-search but a deep inspection of {from}
2488 sub _has_resolved_attr {
2489 my ($self, @attr_names) = @_;
2491 my $attrs = $self->_resolved_attrs;
2495 for my $n (@attr_names) {
2496 if (grep { $n eq $_ } (qw/-join/) ) {
2497 $extra_checks{$n}++;
2501 my $attr = $attrs->{$n};
2503 next if not defined $attr;
2505 if (ref $attr eq 'HASH') {
2506 return 1 if keys %$attr;
2508 elsif (ref $attr eq 'ARRAY') {
2516 # a resolved join is expressed as a multi-level from
2518 $extra_checks{-join}
2520 ref $attrs->{from} eq 'ARRAY'
2522 @{$attrs->{from}} > 1
2530 # Remove the specified alias from the specified query hash. A copy is made so
2531 # the original query is not modified.
2534 my ($self, $query, $alias) = @_;
2536 my %orig = %{ $query || {} };
2539 foreach my $key (keys %orig) {
2541 $unaliased{$key} = $orig{$key};
2544 $unaliased{$1} = $orig{$key}
2545 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2555 =item Arguments: none
2557 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2561 Returns the SQL query and bind vars associated with the invocant.
2563 This is generally used as the RHS for a subquery.
2570 my $attrs = { %{ $self->_resolved_attrs } };
2572 my $aq = $self->result_source->storage->_select_args_to_query (
2573 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2583 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2585 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2589 my $artist = $schema->resultset('Artist')->find_or_new(
2590 { artist => 'fred' }, { key => 'artists' });
2592 $cd->cd_to_producer->find_or_new({ producer => $producer },
2593 { key => 'primary' });
2595 Find an existing record from this resultset using L</find>. if none exists,
2596 instantiate a new result object and return it. The object will not be saved
2597 into your storage until you call L<DBIx::Class::Row/insert> on it.
2599 You most likely want this method when looking for existing rows using a unique
2600 constraint that is not the primary key, or looking for related rows.
2602 If you want objects to be saved immediately, use L</find_or_create> instead.
2604 B<Note>: Make sure to read the documentation of L</find> and understand the
2605 significance of the C<key> attribute, as its lack may skew your search, and
2606 subsequently result in spurious new objects.
2608 B<Note>: Take care when using C<find_or_new> with a table having
2609 columns with default values that you intend to be automatically
2610 supplied by the database (e.g. an auto_increment primary key column).
2611 In normal usage, the value of such columns should NOT be included at
2612 all in the call to C<find_or_new>, even when set to C<undef>.
2618 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2619 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2620 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2623 return $self->new_result($hash);
2630 =item Arguments: \%col_data
2632 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2636 Attempt to create a single new row or a row with multiple related rows
2637 in the table represented by the resultset (and related tables). This
2638 will not check for duplicate rows before inserting, use
2639 L</find_or_create> to do that.
2641 To create one row for this resultset, pass a hashref of key/value
2642 pairs representing the columns of the table and the values you wish to
2643 store. If the appropriate relationships are set up, foreign key fields
2644 can also be passed an object representing the foreign row, and the
2645 value will be set to its primary key.
2647 To create related objects, pass a hashref of related-object column values
2648 B<keyed on the relationship name>. If the relationship is of type C<multi>
2649 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2650 The process will correctly identify columns holding foreign keys, and will
2651 transparently populate them from the keys of the corresponding relation.
2652 This can be applied recursively, and will work correctly for a structure
2653 with an arbitrary depth and width, as long as the relationships actually
2654 exists and the correct column data has been supplied.
2656 Instead of hashrefs of plain related data (key/value pairs), you may
2657 also pass new or inserted objects. New objects (not inserted yet, see
2658 L</new_result>), will be inserted into their appropriate tables.
2660 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2662 Example of creating a new row.
2664 $person_rs->create({
2665 name=>"Some Person",
2666 email=>"somebody@someplace.com"
2669 Example of creating a new row and also creating rows in a related C<has_many>
2670 or C<has_one> resultset. Note Arrayref.
2673 { artistid => 4, name => 'Manufactured Crap', cds => [
2674 { title => 'My First CD', year => 2006 },
2675 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2680 Example of creating a new row and also creating a row in a related
2681 C<belongs_to> resultset. Note Hashref.
2684 title=>"Music for Silly Walks",
2687 name=>"Silly Musician",
2695 When subclassing ResultSet never attempt to override this method. Since
2696 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2697 lot of the internals simply never call it, so your override will be
2698 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2699 or L<DBIx::Class::Row/insert> depending on how early in the
2700 L</create> process you need to intervene. See also warning pertaining to
2708 my ($self, $col_data) = @_;
2709 $self->throw_exception( "create needs a hashref" )
2710 unless ref $col_data eq 'HASH';
2711 return $self->new_result($col_data)->insert;
2714 =head2 find_or_create
2718 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2720 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2724 $cd->cd_to_producer->find_or_create({ producer => $producer },
2725 { key => 'primary' });
2727 Tries to find a record based on its primary key or unique constraints; if none
2728 is found, creates one and returns that instead.
2730 my $cd = $schema->resultset('CD')->find_or_create({
2732 artist => 'Massive Attack',
2733 title => 'Mezzanine',
2737 Also takes an optional C<key> attribute, to search by a specific key or unique
2738 constraint. For example:
2740 my $cd = $schema->resultset('CD')->find_or_create(
2742 artist => 'Massive Attack',
2743 title => 'Mezzanine',
2745 { key => 'cd_artist_title' }
2748 B<Note>: Make sure to read the documentation of L</find> and understand the
2749 significance of the C<key> attribute, as its lack may skew your search, and
2750 subsequently result in spurious row creation.
2752 B<Note>: Because find_or_create() reads from the database and then
2753 possibly inserts based on the result, this method is subject to a race
2754 condition. Another process could create a record in the table after
2755 the find has completed and before the create has started. To avoid
2756 this problem, use find_or_create() inside a transaction.
2758 B<Note>: Take care when using C<find_or_create> with a table having
2759 columns with default values that you intend to be automatically
2760 supplied by the database (e.g. an auto_increment primary key column).
2761 In normal usage, the value of such columns should NOT be included at
2762 all in the call to C<find_or_create>, even when set to C<undef>.
2764 See also L</find> and L</update_or_create>. For information on how to declare
2765 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2767 If you need to know if an existing row was found or a new one created use
2768 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2769 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2772 my $cd = $schema->resultset('CD')->find_or_new({
2774 artist => 'Massive Attack',
2775 title => 'Mezzanine',
2779 if( !$cd->in_storage ) {
2786 sub find_or_create {
2788 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2789 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2790 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2793 return $self->create($hash);
2796 =head2 update_or_create
2800 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2802 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2806 $resultset->update_or_create({ col => $val, ... });
2808 Like L</find_or_create>, but if a row is found it is immediately updated via
2809 C<< $found_row->update (\%col_data) >>.
2812 Takes an optional C<key> attribute to search on a specific unique constraint.
2815 # In your application
2816 my $cd = $schema->resultset('CD')->update_or_create(
2818 artist => 'Massive Attack',
2819 title => 'Mezzanine',
2822 { key => 'cd_artist_title' }
2825 $cd->cd_to_producer->update_or_create({
2826 producer => $producer,
2832 B<Note>: Make sure to read the documentation of L</find> and understand the
2833 significance of the C<key> attribute, as its lack may skew your search, and
2834 subsequently result in spurious row creation.
2836 B<Note>: Take care when using C<update_or_create> with a table having
2837 columns with default values that you intend to be automatically
2838 supplied by the database (e.g. an auto_increment primary key column).
2839 In normal usage, the value of such columns should NOT be included at
2840 all in the call to C<update_or_create>, even when set to C<undef>.
2842 See also L</find> and L</find_or_create>. For information on how to declare
2843 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2845 If you need to know if an existing row was updated or a new one created use
2846 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2847 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2852 sub update_or_create {
2854 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2855 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2857 my $row = $self->find($cond, $attrs);
2859 $row->update($cond);
2863 return $self->create($cond);
2866 =head2 update_or_new
2870 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2872 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2876 $resultset->update_or_new({ col => $val, ... });
2878 Like L</find_or_new> but if a row is found it is immediately updated via
2879 C<< $found_row->update (\%col_data) >>.
2883 # In your application
2884 my $cd = $schema->resultset('CD')->update_or_new(
2886 artist => 'Massive Attack',
2887 title => 'Mezzanine',
2890 { key => 'cd_artist_title' }
2893 if ($cd->in_storage) {
2894 # the cd was updated
2897 # the cd is not yet in the database, let's insert it
2901 B<Note>: Make sure to read the documentation of L</find> and understand the
2902 significance of the C<key> attribute, as its lack may skew your search, and
2903 subsequently result in spurious new objects.
2905 B<Note>: Take care when using C<update_or_new> with a table having
2906 columns with default values that you intend to be automatically
2907 supplied by the database (e.g. an auto_increment primary key column).
2908 In normal usage, the value of such columns should NOT be included at
2909 all in the call to C<update_or_new>, even when set to C<undef>.
2911 See also L</find>, L</find_or_create> and L</find_or_new>.
2917 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2918 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2920 my $row = $self->find( $cond, $attrs );
2921 if ( defined $row ) {
2922 $row->update($cond);
2926 return $self->new_result($cond);
2933 =item Arguments: none
2935 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
2939 Gets the contents of the cache for the resultset, if the cache is set.
2941 The cache is populated either by using the L</prefetch> attribute to
2942 L</search> or by calling L</set_cache>.
2954 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2956 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2960 Sets the contents of the cache for the resultset. Expects an arrayref
2961 of objects of the same class as those produced by the resultset. Note that
2962 if the cache is set, the resultset will return the cached objects rather
2963 than re-querying the database even if the cache attr is not set.
2965 The contents of the cache can also be populated by using the
2966 L</prefetch> attribute to L</search>.
2971 my ( $self, $data ) = @_;
2972 $self->throw_exception("set_cache requires an arrayref")
2973 if defined($data) && (ref $data ne 'ARRAY');
2974 $self->{all_cache} = $data;
2981 =item Arguments: none
2983 =item Return Value: undef
2987 Clears the cache for the resultset.
2992 shift->set_cache(undef);
2999 =item Arguments: none
3001 =item Return Value: true, if the resultset has been paginated
3009 return !!$self->{attrs}{page};
3016 =item Arguments: none
3018 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3026 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3029 =head2 related_resultset
3033 =item Arguments: $rel_name
3035 =item Return Value: L<$resultset|/search>
3039 Returns a related resultset for the supplied relationship name.
3041 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3045 sub related_resultset {
3046 my ($self, $rel) = @_;
3048 return $self->{related_resultsets}{$rel}
3049 if defined $self->{related_resultsets}{$rel};
3051 return $self->{related_resultsets}{$rel} = do {
3052 my $rsrc = $self->result_source;
3053 my $rel_info = $rsrc->relationship_info($rel);
3055 $self->throw_exception(
3056 "search_related: result source '" . $rsrc->source_name .
3057 "' has no such relationship $rel")
3060 my $attrs = $self->_chain_relationship($rel);
3062 my $join_count = $attrs->{seen_join}{$rel};
3064 my $alias = $self->result_source->storage
3065 ->relname_to_table_alias($rel, $join_count);
3067 # since this is search_related, and we already slid the select window inwards
3068 # (the select/as attrs were deleted in the beginning), we need to flip all
3069 # left joins to inner, so we get the expected results
3070 # read the comment on top of the actual function to see what this does
3071 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3074 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3075 delete @{$attrs}{qw(result_class alias)};
3077 my $rel_source = $rsrc->related_source($rel);
3081 # The reason we do this now instead of passing the alias to the
3082 # search_rs below is that if you wrap/overload resultset on the
3083 # source you need to know what alias it's -going- to have for things
3084 # to work sanely (e.g. RestrictWithObject wants to be able to add
3085 # extra query restrictions, and these may need to be $alias.)
3087 my $rel_attrs = $rel_source->resultset_attributes;
3088 local $rel_attrs->{alias} = $alias;
3090 $rel_source->resultset
3094 where => $attrs->{where},
3098 if (my $cache = $self->get_cache) {
3099 my @related_cache = map
3100 { $_->related_resultset($rel)->get_cache || () }
3104 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3111 =head2 current_source_alias
3115 =item Arguments: none
3117 =item Return Value: $source_alias
3121 Returns the current table alias for the result source this resultset is built
3122 on, that will be used in the SQL query. Usually it is C<me>.
3124 Currently the source alias that refers to the result set returned by a
3125 L</search>/L</find> family method depends on how you got to the resultset: it's
3126 C<me> by default, but eg. L</search_related> aliases it to the related result
3127 source name (and keeps C<me> referring to the original result set). The long
3128 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3129 (and make this method unnecessary).
3131 Thus it's currently necessary to use this method in predefined queries (see
3132 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3133 source alias of the current result set:
3135 # in a result set class
3137 my ($self, $user) = @_;
3139 my $me = $self->current_source_alias;
3141 return $self->search({
3142 "$me.modified" => $user->id,
3148 sub current_source_alias {
3149 return (shift->{attrs} || {})->{alias} || 'me';
3152 =head2 as_subselect_rs
3156 =item Arguments: none
3158 =item Return Value: L<$resultset|/search>
3162 Act as a barrier to SQL symbols. The resultset provided will be made into a
3163 "virtual view" by including it as a subquery within the from clause. From this
3164 point on, any joined tables are inaccessible to ->search on the resultset (as if
3165 it were simply where-filtered without joins). For example:
3167 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3169 # 'x' now pollutes the query namespace
3171 # So the following works as expected
3172 my $ok_rs = $rs->search({'x.other' => 1});
3174 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3175 # def) we look for one row with contradictory terms and join in another table
3176 # (aliased 'x_2') which we never use
3177 my $broken_rs = $rs->search({'x.name' => 'def'});
3179 my $rs2 = $rs->as_subselect_rs;
3181 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3182 my $not_joined_rs = $rs2->search({'x.other' => 1});
3184 # works as expected: finds a 'table' row related to two x rows (abc and def)
3185 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3187 Another example of when one might use this would be to select a subset of
3188 columns in a group by clause:
3190 my $rs = $schema->resultset('Bar')->search(undef, {
3191 group_by => [qw{ id foo_id baz_id }],
3192 })->as_subselect_rs->search(undef, {
3193 columns => [qw{ id foo_id }]
3196 In the above example normally columns would have to be equal to the group by,
3197 but because we isolated the group by into a subselect the above works.
3201 sub as_subselect_rs {
3204 my $attrs = $self->_resolved_attrs;
3206 my $fresh_rs = (ref $self)->new (
3207 $self->result_source
3210 # these pieces will be locked in the subquery
3211 delete $fresh_rs->{cond};
3212 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3214 return $fresh_rs->search( {}, {
3216 $attrs->{alias} => $self->as_query,
3217 -alias => $attrs->{alias},
3218 -rsrc => $self->result_source,
3220 alias => $attrs->{alias},
3224 # This code is called by search_related, and makes sure there
3225 # is clear separation between the joins before, during, and
3226 # after the relationship. This information is needed later
3227 # in order to properly resolve prefetch aliases (any alias
3228 # with a relation_chain_depth less than the depth of the
3229 # current prefetch is not considered)
3231 # The increments happen twice per join. An even number means a
3232 # relationship specified via a search_related, whereas an odd
3233 # number indicates a join/prefetch added via attributes
3235 # Also this code will wrap the current resultset (the one we
3236 # chain to) in a subselect IFF it contains limiting attributes
3237 sub _chain_relationship {
3238 my ($self, $rel) = @_;
3239 my $source = $self->result_source;
3240 my $attrs = { %{$self->{attrs}||{}} };
3242 # we need to take the prefetch the attrs into account before we
3243 # ->_resolve_join as otherwise they get lost - captainL
3244 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3246 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3248 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3251 my @force_subq_attrs = qw/offset rows group_by having/;
3254 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3256 $self->_has_resolved_attr (@force_subq_attrs)
3258 # Nuke the prefetch (if any) before the new $rs attrs
3259 # are resolved (prefetch is useless - we are wrapping
3260 # a subquery anyway).
3261 my $rs_copy = $self->search;
3262 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3263 $rs_copy->{attrs}{join},
3264 delete $rs_copy->{attrs}{prefetch},
3269 -alias => $attrs->{alias},
3270 $attrs->{alias} => $rs_copy->as_query,
3272 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3273 $seen->{-relation_chain_depth} = 0;
3275 elsif ($attrs->{from}) { #shallow copy suffices
3276 $from = [ @{$attrs->{from}} ];
3281 -alias => $attrs->{alias},
3282 $attrs->{alias} => $source->from,
3286 my $jpath = ($seen->{-relation_chain_depth})
3287 ? $from->[-1][0]{-join_path}
3290 my @requested_joins = $source->_resolve_join(
3297 push @$from, @requested_joins;
3299 $seen->{-relation_chain_depth}++;
3301 # if $self already had a join/prefetch specified on it, the requested
3302 # $rel might very well be already included. What we do in this case
3303 # is effectively a no-op (except that we bump up the chain_depth on
3304 # the join in question so we could tell it *is* the search_related)
3307 # we consider the last one thus reverse
3308 for my $j (reverse @requested_joins) {
3309 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3310 if ($rel eq $last_j) {
3311 $j->[0]{-relation_chain_depth}++;
3317 unless ($already_joined) {
3318 push @$from, $source->_resolve_join(
3326 $seen->{-relation_chain_depth}++;
3328 return {%$attrs, from => $from, seen_join => $seen};
3331 sub _resolved_attrs {
3333 return $self->{_attrs} if $self->{_attrs};
3335 my $attrs = { %{ $self->{attrs} || {} } };
3336 my $source = $self->result_source;
3337 my $alias = $attrs->{alias};
3339 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3340 if $attrs->{collapse} and $attrs->{distinct};
3342 # default selection list
3343 $attrs->{columns} = [ $source->columns ]
3344 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3346 # merge selectors together
3347 for (qw/columns select as/) {
3348 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3349 if $attrs->{$_} or $attrs->{"+$_"};
3352 # disassemble columns
3354 if (my $cols = delete $attrs->{columns}) {
3355 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3356 if (ref $c eq 'HASH') {
3357 for my $as (sort keys %$c) {
3358 push @sel, $c->{$as};
3369 # when trying to weed off duplicates later do not go past this point -
3370 # everything added from here on is unbalanced "anyone's guess" stuff
3371 my $dedup_stop_idx = $#as;
3373 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3375 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3376 if $attrs->{select};
3378 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3379 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3381 # disqualify all $alias.col as-bits (inflate-map mandated)
3382 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3384 # de-duplicate the result (remove *identical* select/as pairs)
3385 # and also die on duplicate {as} pointing to different {select}s
3386 # not using a c-style for as the condition is prone to shrinkage
3389 while ($i <= $dedup_stop_idx) {
3390 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3395 elsif ($seen->{$as[$i]}++) {
3396 $self->throw_exception(
3397 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3405 $attrs->{select} = \@sel;
3406 $attrs->{as} = \@as;
3408 $attrs->{from} ||= [{
3410 -alias => $self->{attrs}{alias},
3411 $self->{attrs}{alias} => $source->from,
3414 if ( $attrs->{join} || $attrs->{prefetch} ) {
3416 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3417 if ref $attrs->{from} ne 'ARRAY';
3419 my $join = (delete $attrs->{join}) || {};
3421 if ( defined $attrs->{prefetch} ) {
3422 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3425 $attrs->{from} = # have to copy here to avoid corrupting the original
3427 @{ $attrs->{from} },
3428 $source->_resolve_join(
3431 { %{ $attrs->{seen_join} || {} } },
3432 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3433 ? $attrs->{from}[-1][0]{-join_path}
3440 if ( defined $attrs->{order_by} ) {
3441 $attrs->{order_by} = (
3442 ref( $attrs->{order_by} ) eq 'ARRAY'
3443 ? [ @{ $attrs->{order_by} } ]
3444 : [ $attrs->{order_by} || () ]
3448 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3449 $attrs->{group_by} = [ $attrs->{group_by} ];
3453 # generate selections based on the prefetch helper
3454 my ($prefetch, @prefetch_select, @prefetch_as);
3455 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3456 if defined $attrs->{prefetch};
3460 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3461 if $attrs->{_dark_selector};
3463 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3464 if defined $attrs->{collapse} and ! $attrs->{collapse};
3466 $attrs->{collapse} = 1;
3468 # this is a separate structure (we don't look in {from} directly)
3469 # as the resolver needs to shift things off the lists to work
3470 # properly (identical-prefetches on different branches)
3472 if (ref $attrs->{from} eq 'ARRAY') {
3474 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3476 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3477 next unless $j->[0]{-alias};
3478 next unless $j->[0]{-join_path};
3479 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3481 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3484 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3485 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3489 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3491 # save these for after distinct resolution
3492 @prefetch_select = map { $_->[0] } @prefetch;
3493 @prefetch_as = map { $_->[1] } @prefetch;
3496 # run through the resulting joinstructure (starting from our current slot)
3497 # and unset collapse if proven unnecessary
3499 # also while we are at it find out if the current root source has
3500 # been premultiplied by previous related_source chaining
3502 # this allows to predict whether a root object with all other relation
3503 # data set to NULL is in fact unique
3504 if ($attrs->{collapse}) {
3506 if (ref $attrs->{from} eq 'ARRAY') {
3508 if (@{$attrs->{from}} == 1) {
3509 # no joins - no collapse
3510 $attrs->{collapse} = 0;
3513 # find where our table-spec starts
3514 my @fromlist = @{$attrs->{from}};
3516 my $t = shift @fromlist;
3519 # me vs join from-spec distinction - a ref means non-root
3520 if (ref $t eq 'ARRAY') {
3522 $is_multi ||= ! $t->{-is_single};
3524 last if ($t->{-alias} && $t->{-alias} eq $alias);
3525 $attrs->{_main_source_premultiplied} ||= $is_multi;
3528 # no non-singles remaining, nor any premultiplication - nothing to collapse
3530 ! $attrs->{_main_source_premultiplied}
3532 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3534 $attrs->{collapse} = 0;
3540 # if we can not analyze the from - err on the side of safety
3541 $attrs->{_main_source_premultiplied} = 1;
3545 # generate the distinct induced group_by before injecting the prefetched select/as parts
3546 if (delete $attrs->{distinct}) {
3547 if ($attrs->{group_by}) {
3548 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3551 $attrs->{_grouped_by_distinct} = 1;
3552 # distinct affects only the main selection part, not what prefetch may add below
3553 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3555 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3556 # The thinking is: if we are collapsing the subquerying prefetch engine will
3557 # rip stuff apart for us anyway, and we do not want to have a potentially
3558 # function-converted external order_by
3559 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3560 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3564 # inject prefetch-bound selection (if any)
3565 push @{$attrs->{select}}, @prefetch_select;
3566 push @{$attrs->{as}}, @prefetch_as;
3568 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3569 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3570 $attrs->{_related_results_construction} = 1;
3573 # if both page and offset are specified, produce a combined offset
3574 # even though it doesn't make much sense, this is what pre 081xx has
3576 if (my $page = delete $attrs->{page}) {
3578 ($attrs->{rows} * ($page - 1))
3580 ($attrs->{offset} || 0)
3584 return $self->{_attrs} = $attrs;
3588 my ($self, $attr) = @_;
3590 if (ref $attr eq 'HASH') {
3591 return $self->_rollout_hash($attr);
3592 } elsif (ref $attr eq 'ARRAY') {
3593 return $self->_rollout_array($attr);
3599 sub _rollout_array {
3600 my ($self, $attr) = @_;
3603 foreach my $element (@{$attr}) {
3604 if (ref $element eq 'HASH') {
3605 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3606 } elsif (ref $element eq 'ARRAY') {
3607 # XXX - should probably recurse here
3608 push( @rolled_array, @{$self->_rollout_array($element)} );
3610 push( @rolled_array, $element );
3613 return \@rolled_array;
3617 my ($self, $attr) = @_;
3620 foreach my $key (keys %{$attr}) {
3621 push( @rolled_array, { $key => $attr->{$key} } );
3623 return \@rolled_array;
3626 sub _calculate_score {
3627 my ($self, $a, $b) = @_;
3629 if (defined $a xor defined $b) {
3632 elsif (not defined $a) {
3636 if (ref $b eq 'HASH') {
3637 my ($b_key) = keys %{$b};
3638 if (ref $a eq 'HASH') {
3639 my ($a_key) = keys %{$a};
3640 if ($a_key eq $b_key) {
3641 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3646 return ($a eq $b_key) ? 1 : 0;
3649 if (ref $a eq 'HASH') {
3650 my ($a_key) = keys %{$a};
3651 return ($b eq $a_key) ? 1 : 0;
3653 return ($b eq $a) ? 1 : 0;
3658 sub _merge_joinpref_attr {
3659 my ($self, $orig, $import) = @_;
3661 return $import unless defined($orig);
3662 return $orig unless defined($import);
3664 $orig = $self->_rollout_attr($orig);
3665 $import = $self->_rollout_attr($import);
3668 foreach my $import_element ( @{$import} ) {
3669 # find best candidate from $orig to merge $b_element into
3670 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3671 foreach my $orig_element ( @{$orig} ) {
3672 my $score = $self->_calculate_score( $orig_element, $import_element );
3673 if ($score > $best_candidate->{score}) {
3674 $best_candidate->{position} = $position;
3675 $best_candidate->{score} = $score;
3679 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3680 $import_key = '' if not defined $import_key;
3682 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3683 push( @{$orig}, $import_element );
3685 my $orig_best = $orig->[$best_candidate->{position}];
3686 # merge orig_best and b_element together and replace original with merged
3687 if (ref $orig_best ne 'HASH') {
3688 $orig->[$best_candidate->{position}] = $import_element;
3689 } elsif (ref $import_element eq 'HASH') {
3690 my ($key) = keys %{$orig_best};
3691 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3694 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3697 return @$orig ? $orig : ();
3705 require Hash::Merge;
3706 my $hm = Hash::Merge->new;
3708 $hm->specify_behavior({
3711 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3713 if ($defl xor $defr) {
3714 return [ $defl ? $_[0] : $_[1] ];
3719 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3723 return [$_[0], $_[1]];
3727 return $_[1] if !defined $_[0];
3728 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3729 return [$_[0], @{$_[1]}]
3732 return [] if !defined $_[0] and !keys %{$_[1]};
3733 return [ $_[1] ] if !defined $_[0];
3734 return [ $_[0] ] if !keys %{$_[1]};
3735 return [$_[0], $_[1]]
3740 return $_[0] if !defined $_[1];
3741 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3742 return [@{$_[0]}, $_[1]]
3745 my @ret = @{$_[0]} or return $_[1];
3746 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3747 my %idx = map { $_ => 1 } @ret;
3748 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3752 return [ $_[1] ] if ! @{$_[0]};
3753 return $_[0] if !keys %{$_[1]};
3754 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3755 return [ @{$_[0]}, $_[1] ];
3760 return [] if !keys %{$_[0]} and !defined $_[1];
3761 return [ $_[0] ] if !defined $_[1];
3762 return [ $_[1] ] if !keys %{$_[0]};
3763 return [$_[0], $_[1]]
3766 return [] if !keys %{$_[0]} and !@{$_[1]};
3767 return [ $_[0] ] if !@{$_[1]};
3768 return $_[1] if !keys %{$_[0]};
3769 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3770 return [ $_[0], @{$_[1]} ];
3773 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3774 return [ $_[0] ] if !keys %{$_[1]};
3775 return [ $_[1] ] if !keys %{$_[0]};
3776 return [ $_[0] ] if $_[0] eq $_[1];
3777 return [ $_[0], $_[1] ];
3780 } => 'DBIC_RS_ATTR_MERGER');
3784 return $hm->merge ($_[1], $_[2]);
3788 sub STORABLE_freeze {
3789 my ($self, $cloning) = @_;
3790 my $to_serialize = { %$self };
3792 # A cursor in progress can't be serialized (and would make little sense anyway)
3793 # the parser can be regenerated (and can't be serialized)
3794 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3796 # nor is it sensical to store a not-yet-fired-count pager
3797 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3798 delete $to_serialize->{pager};
3801 Storable::nfreeze($to_serialize);
3804 # need this hook for symmetry
3806 my ($self, $cloning, $serialized) = @_;
3808 %$self = %{ Storable::thaw($serialized) };
3814 =head2 throw_exception
3816 See L<DBIx::Class::Schema/throw_exception> for details.
3820 sub throw_exception {
3823 if (ref $self and my $rsrc = $self->result_source) {
3824 $rsrc->throw_exception(@_)
3827 DBIx::Class::Exception->throw(@_);
3835 # XXX: FIXME: Attributes docs need clearing up
3839 Attributes are used to refine a ResultSet in various ways when
3840 searching for data. They can be passed to any method which takes an
3841 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3844 Default attributes can be set on the result class using
3845 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3846 the CAVEATS on that feature before using it!)
3848 These are in no particular order:
3854 =item Value: ( $order_by | \@order_by | \%order_by )
3858 Which column(s) to order the results by.
3860 [The full list of suitable values is documented in
3861 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3864 If a single column name, or an arrayref of names is supplied, the
3865 argument is passed through directly to SQL. The hashref syntax allows
3866 for connection-agnostic specification of ordering direction:
3868 For descending order:
3870 order_by => { -desc => [qw/col1 col2 col3/] }
3872 For explicit ascending order:
3874 order_by => { -asc => 'col' }
3876 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3877 supported, although you are strongly encouraged to use the hashref
3878 syntax as outlined above.
3884 =item Value: \@columns | \%columns | $column
3888 Shortcut to request a particular set of columns to be retrieved. Each
3889 column spec may be a string (a table column name), or a hash (in which
3890 case the key is the C<as> value, and the value is used as the C<select>
3891 expression). Adds C<me.> onto the start of any column without a C<.> in
3892 it and sets C<select> from that, then auto-populates C<as> from
3893 C<select> as normal. (You may also use the C<cols> attribute, as in
3894 earlier versions of DBIC, but this is deprecated)
3896 Essentially C<columns> does the same as L</select> and L</as>.
3898 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
3902 select => [qw(some_column another_column)],
3903 as => [qw(some_column dbic_slot)]
3905 If you want to individually retrieve related columns (in essence perform
3906 manual prefetch) you have to make sure to specify the correct inflation slot
3907 chain such that it matches existing relationships:
3909 my $rs = $schema->resultset('Artist')->search({}, {
3910 # required to tell DBIC to collapse has_many relationships
3912 join => { cds => 'tracks'},
3914 'cds.cdid' => 'cds.cdid',
3915 'cds.tracks.title' => 'tracks.title',
3921 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
3922 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
3923 with a unary plus operator before it, which is the same as simply C<columns>.
3927 =item Value: \@extra_columns
3931 Indicates additional columns to be selected from storage. Works the same as
3932 L</columns> but adds columns to the current selection. (You may also use the
3933 C<include_columns> attribute, as in earlier versions of DBIC, but this is
3936 $schema->resultset('CD')->search(undef, {
3937 '+columns' => ['artist.name'],
3941 would return all CDs and include a 'name' column to the information
3942 passed to object inflation. Note that the 'artist' is the name of the
3943 column (or relationship) accessor, and 'name' is the name of the column
3944 accessor in the related table.
3950 =item Value: \@select_columns
3954 Indicates which columns should be selected from the storage. You can use
3955 column names, or in the case of RDBMS back ends, function or stored procedure
3958 $rs = $schema->resultset('Employee')->search(undef, {
3961 { count => 'employeeid' },
3962 { max => { length => 'name' }, -as => 'longest_name' }
3967 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3969 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3970 use L</select>, to instruct DBIx::Class how to store the result of the column.
3971 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3972 identifier aliasing. You can however alias a function, so you can use it in
3973 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3974 attribute> supplied as shown in the example above.
3978 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
3979 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
3980 with a unary plus operator before it, which is the same as simply C<select>.
3984 =item Value: \@extra_select_columns
3988 Indicates additional columns to be selected from storage. Works the same as
3989 L</select> but adds columns to the current selection, instead of specifying
3990 a new explicit list.
3996 =item Value: \@inflation_names
4000 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4001 slot name in which the column value will be stored within the
4002 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4003 identifier by the C<get_column> method (or via the object accessor B<if one
4004 with the same name already exists>) as shown below. The L</as> attribute has
4005 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4007 $rs = $schema->resultset('Employee')->search(undef, {
4010 { count => 'employeeid' },
4011 { max => { length => 'name' }, -as => 'longest_name' }
4020 If the object against which the search is performed already has an accessor
4021 matching a column name specified in C<as>, the value can be retrieved using
4022 the accessor as normal:
4024 my $name = $employee->name();
4026 If on the other hand an accessor does not exist in the object, you need to
4027 use C<get_column> instead:
4029 my $employee_count = $employee->get_column('employee_count');
4031 You can create your own accessors if required - see
4032 L<DBIx::Class::Manual::Cookbook> for details.
4036 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4037 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4038 with a unary plus operator before it, which is the same as simply C<as>.
4042 =item Value: \@extra_inflation_names
4046 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4052 =item Value: ($rel_name | \@rel_names | \%rel_names)
4056 Contains a list of relationships that should be joined for this query. For
4059 # Get CDs by Nine Inch Nails
4060 my $rs = $schema->resultset('CD')->search(
4061 { 'artist.name' => 'Nine Inch Nails' },
4062 { join => 'artist' }
4065 Can also contain a hash reference to refer to the other relation's relations.
4068 package MyApp::Schema::Track;
4069 use base qw/DBIx::Class/;
4070 __PACKAGE__->table('track');
4071 __PACKAGE__->add_columns(qw/trackid cd position title/);
4072 __PACKAGE__->set_primary_key('trackid');
4073 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4076 # In your application
4077 my $rs = $schema->resultset('Artist')->search(
4078 { 'track.title' => 'Teardrop' },
4080 join => { cd => 'track' },
4081 order_by => 'artist.name',
4085 You need to use the relationship (not the table) name in conditions,
4086 because they are aliased as such. The current table is aliased as "me", so
4087 you need to use me.column_name in order to avoid ambiguity. For example:
4089 # Get CDs from 1984 with a 'Foo' track
4090 my $rs = $schema->resultset('CD')->search(
4093 'tracks.name' => 'Foo'
4095 { join => 'tracks' }
4098 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4099 similarly for a third time). For e.g.
4101 my $rs = $schema->resultset('Artist')->search({
4102 'cds.title' => 'Down to Earth',
4103 'cds_2.title' => 'Popular',
4105 join => [ qw/cds cds/ ],
4108 will return a set of all artists that have both a cd with title 'Down
4109 to Earth' and a cd with title 'Popular'.
4111 If you want to fetch related objects from other tables as well, see L</prefetch>
4114 NOTE: An internal join-chain pruner will discard certain joins while
4115 constructing the actual SQL query, as long as the joins in question do not
4116 affect the retrieved result. This for example includes 1:1 left joins
4117 that are not part of the restriction specification (WHERE/HAVING) nor are
4118 a part of the query selection.
4120 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4126 =item Value: (0 | 1)
4130 When set to a true value, indicates that any rows fetched from joined has_many
4131 relationships are to be aggregated into the corresponding "parent" object. For
4132 example, the resultset:
4134 my $rs = $schema->resultset('CD')->search({}, {
4135 '+columns' => [ qw/ tracks.title tracks.position / ],
4140 While executing the following query:
4142 SELECT me.*, tracks.title, tracks.position
4144 LEFT JOIN track tracks
4145 ON tracks.cdid = me.cdid
4147 Will return only as many objects as there are rows in the CD source, even
4148 though the result of the query may span many rows. Each of these CD objects
4149 will in turn have multiple "Track" objects hidden behind the has_many
4150 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4151 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4152 product"), with each CD object containing exactly one of all fetched Track data.
4154 When a collapse is requested on a non-ordered resultset, an order by some
4155 unique part of the main source (the left-most table) is inserted automatically.
4156 This is done so that the resultset is allowed to be "lazy" - calling
4157 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4158 object with all of its related data.
4160 If an L</order_by> is already declared, and orders the resultset in a way that
4161 makes collapsing as described above impossible (e.g. C<< ORDER BY
4162 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4163 switch to "eager" mode and slurp the entire resultset before constructing the
4164 first object returned by L</next>.
4166 Setting this attribute on a resultset that does not join any has_many
4167 relations is a no-op.
4169 For a more in-depth discussion, see L</PREFETCHING>.
4175 =item Value: ($rel_name | \@rel_names | \%rel_names)
4179 This attribute is a shorthand for specifying a L</join> spec, adding all
4180 columns from the joined related sources as L</+columns> and setting
4181 L</collapse> to a true value. For example, the following two queries are
4184 my $rs = $schema->resultset('Artist')->search({}, {
4185 prefetch => { cds => ['genre', 'tracks' ] },
4190 my $rs = $schema->resultset('Artist')->search({}, {
4191 join => { cds => ['genre', 'tracks' ] },
4195 { +{ "cds.$_" => "cds.$_" } }
4196 $schema->source('Artist')->related_source('cds')->columns
4199 { +{ "cds.genre.$_" => "genre.$_" } }
4200 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4203 { +{ "cds.tracks.$_" => "tracks.$_" } }
4204 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4209 Both producing the following SQL:
4211 SELECT me.artistid, me.name, me.rank, me.charfield,
4212 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4213 genre.genreid, genre.name,
4214 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4217 ON cds.artist = me.artistid
4218 LEFT JOIN genre genre
4219 ON genre.genreid = cds.genreid
4220 LEFT JOIN track tracks
4221 ON tracks.cd = cds.cdid
4222 ORDER BY me.artistid
4224 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4225 the arguments are properly merged and generally do the right thing. For
4226 example, you may want to do the following:
4228 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4229 { 'genre.genreid' => undef },
4231 join => { cds => 'genre' },
4236 Which generates the following SQL:
4238 SELECT me.artistid, me.name, me.rank, me.charfield,
4239 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4242 ON cds.artist = me.artistid
4243 LEFT JOIN genre genre
4244 ON genre.genreid = cds.genreid
4245 WHERE genre.genreid IS NULL
4246 ORDER BY me.artistid
4248 For a more in-depth discussion, see L</PREFETCHING>.
4254 =item Value: $source_alias
4258 Sets the source alias for the query. Normally, this defaults to C<me>, but
4259 nested search queries (sub-SELECTs) might need specific aliases set to
4260 reference inner queries. For example:
4263 ->related_resultset('CDs')
4264 ->related_resultset('Tracks')
4266 'track.id' => { -ident => 'none_search.id' },
4270 my $ids = $self->search({
4273 alias => 'none_search',
4274 group_by => 'none_search.id',
4275 })->get_column('id')->as_query;
4277 $self->search({ id => { -in => $ids } })
4279 This attribute is directly tied to L</current_source_alias>.
4289 Makes the resultset paged and specifies the page to retrieve. Effectively
4290 identical to creating a non-pages resultset and then calling ->page($page)
4293 If L</rows> attribute is not specified it defaults to 10 rows per page.
4295 When you have a paged resultset, L</count> will only return the number
4296 of rows in the page. To get the total, use the L</pager> and call
4297 C<total_entries> on it.
4307 Specifies the maximum number of rows for direct retrieval or the number of
4308 rows per page if the page attribute or method is used.
4314 =item Value: $offset
4318 Specifies the (zero-based) row number for the first row to be returned, or the
4319 of the first row of the first page if paging is used.
4321 =head2 software_limit
4325 =item Value: (0 | 1)
4329 When combined with L</rows> and/or L</offset> the generated SQL will not
4330 include any limit dialect stanzas. Instead the entire result will be selected
4331 as if no limits were specified, and DBIC will perform the limit locally, by
4332 artificially advancing and finishing the resulting L</cursor>.
4334 This is the recommended way of performing resultset limiting when no sane RDBMS
4335 implementation is available (e.g.
4336 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4337 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4343 =item Value: \@columns
4347 A arrayref of columns to group by. Can include columns of joined tables.
4349 group_by => [qw/ column1 column2 ... /]
4355 =item Value: $condition
4359 HAVING is a select statement attribute that is applied between GROUP BY and
4360 ORDER BY. It is applied to the after the grouping calculations have been
4363 having => { 'count_employee' => { '>=', 100 } }
4365 or with an in-place function in which case literal SQL is required:
4367 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4373 =item Value: (0 | 1)
4377 Set to 1 to automatically generate a L</group_by> clause based on the selection
4378 (including intelligent handling of L</order_by> contents). Note that the group
4379 criteria calculation takes place over the B<final> selection. This includes
4380 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4381 L</search> calls, and standalone columns selected via
4382 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4383 extra selections specified via L</prefetch> - such selections are explicitly
4384 excluded from group criteria calculations.
4386 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4387 setting is ignored and an appropriate warning is issued.
4393 Adds to the WHERE clause.
4395 # only return rows WHERE deleted IS NULL for all searches
4396 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4398 Can be overridden by passing C<< { where => undef } >> as an attribute
4401 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4407 Set to 1 to cache search results. This prevents extra SQL queries if you
4408 revisit rows in your ResultSet:
4410 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4412 while( my $artist = $resultset->next ) {
4416 $rs->first; # without cache, this would issue a query
4418 By default, searches are not cached.
4420 For more examples of using these attributes, see
4421 L<DBIx::Class::Manual::Cookbook>.
4427 =item Value: ( 'update' | 'shared' | \$scalar )
4431 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4432 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4437 DBIx::Class supports arbitrary related data prefetching from multiple related
4438 sources. Any combination of relationship types and column sets are supported.
4439 If L<collapsing|/collapse> is requested, there is an additional requirement of
4440 selecting enough data to make every individual object uniquely identifiable.
4442 Here are some more involved examples, based on the following relationship map:
4445 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4446 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4447 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4449 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4451 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4455 my $rs = $schema->resultset('Tag')->search(
4464 The initial search results in SQL like the following:
4466 SELECT tag.*, cd.*, artist.* FROM tag
4467 JOIN cd ON tag.cd = cd.cdid
4468 JOIN artist ON cd.artist = artist.artistid
4470 L<DBIx::Class> has no need to go back to the database when we access the
4471 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4474 Simple prefetches will be joined automatically, so there is no need
4475 for a C<join> attribute in the above search.
4477 The L</prefetch> attribute can be used with any of the relationship types
4478 and multiple prefetches can be specified together. Below is a more complex
4479 example that prefetches a CD's artist, its liner notes (if present),
4480 the cover image, the tracks on that CD, and the guests on those
4483 my $rs = $schema->resultset('CD')->search(
4487 { artist => 'record_label'}, # belongs_to => belongs_to
4488 'liner_note', # might_have
4489 'cover_image', # has_one
4490 { tracks => 'guests' }, # has_many => has_many
4495 This will produce SQL like the following:
4497 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4501 ON artist.artistid = me.artistid
4502 JOIN record_label record_label
4503 ON record_label.labelid = artist.labelid
4504 LEFT JOIN track tracks
4505 ON tracks.cdid = me.cdid
4506 LEFT JOIN guest guests
4507 ON guests.trackid = track.trackid
4508 LEFT JOIN liner_notes liner_note
4509 ON liner_note.cdid = me.cdid
4510 JOIN cd_artwork cover_image
4511 ON cover_image.cdid = me.cdid
4514 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4515 C<tracks>, and C<guests> of the CD will all be available through the
4516 relationship accessors without the need for additional queries to the
4521 Prefetch does a lot of deep magic. As such, it may not behave exactly
4522 as you might expect.
4528 Prefetch uses the L</cache> to populate the prefetched relationships. This
4529 may or may not be what you want.
4533 If you specify a condition on a prefetched relationship, ONLY those
4534 rows that match the prefetched condition will be fetched into that relationship.
4535 This means that adding prefetch to a search() B<may alter> what is returned by
4536 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4538 my $artist_rs = $schema->resultset('Artist')->search({
4544 my $count = $artist_rs->first->cds->count;
4546 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4548 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4550 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4552 That cmp_ok() may or may not pass depending on the datasets involved. In other
4553 words the C<WHERE> condition would apply to the entire dataset, just like
4554 it would in regular SQL. If you want to add a condition only to the "right side"
4555 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4556 condition|DBIx::Class::Relationship::Base/condition>
4560 =head1 DBIC BIND VALUES
4562 Because DBIC may need more information to bind values than just the column name
4563 and value itself, it uses a special format for both passing and receiving bind
4564 values. Each bind value should be composed of an arrayref of
4565 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4571 If present (in any form), this is what is being passed directly to bind_param.
4572 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4573 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4575 If this is specified, all other bind options described below are ignored.
4579 If present, this is used to infer the actual bind attribute by passing to
4580 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4581 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4583 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4584 currently drivers are expected to "Do the Right Thing" when given a common
4585 datatype name. (Not ideal, but that's what we got at this point.)
4589 Currently used to correctly allocate buffers for bind_param_inout().
4590 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4591 or to a sensible value based on the "data_type".
4595 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4596 explicitly specified they are never overridden). Also used by some weird DBDs,
4597 where the column name should be available at bind_param time (e.g. Oracle).
4601 For backwards compatibility and convenience, the following shortcuts are
4604 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4605 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4606 [ undef, $val ] === [ {}, $val ]
4607 $val === [ {}, $val ]
4609 =head1 AUTHOR AND CONTRIBUTORS
4611 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4615 You may distribute this code under the same terms as Perl itself.