1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken reftype/;
10 use Data::Compare (); # no imports!!! guard against insane architecture
12 # not importing first() as it will clash with our own method
16 # De-duplication in _merge_attr() is disabled, but left in for reference
17 # (the merger is used for other things that ought not to be de-duped)
18 *__HM_DEDUP = sub () { 0 };
28 # this is real - CDBICompat overrides it with insanity
29 # yes, prototype won't matter, but that's for now ;)
32 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
36 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
40 my $users_rs = $schema->resultset('User');
41 while( $user = $users_rs->next) {
42 print $user->username;
45 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
46 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
50 A ResultSet is an object which stores a set of conditions representing
51 a query. It is the backbone of DBIx::Class (i.e. the really
52 important/useful bit).
54 No SQL is executed on the database when a ResultSet is created, it
55 just stores all the conditions needed to create the query.
57 A basic ResultSet representing the data of an entire table is returned
58 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
59 L<Source|DBIx::Class::Manual::Glossary/Source> name.
61 my $users_rs = $schema->resultset('User');
63 A new ResultSet is returned from calling L</search> on an existing
64 ResultSet. The new one will contain all the conditions of the
65 original, plus any new conditions added in the C<search> call.
67 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
68 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
71 The query that the ResultSet represents is B<only> executed against
72 the database when these methods are called:
73 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
75 If a resultset is used in a numeric context it returns the L</count>.
76 However, if it is used in a boolean context it is B<always> true. So if
77 you want to check if a resultset has any results, you must use C<if $rs
80 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
82 If you want to make your custom ResultSet classes with L<Moose>, use a template
85 package MyApp::Schema::ResultSet::User;
88 use namespace::autoclean;
90 extends 'DBIx::Class::ResultSet';
92 sub BUILDARGS { $_[2] }
96 __PACKAGE__->meta->make_immutable;
100 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
101 clash with the regular ResultSet constructor. Alternatively, you can use:
103 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
105 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
106 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
110 =head2 Chaining resultsets
112 Let's say you've got a query that needs to be run to return some data
113 to the user. But, you have an authorization system in place that
114 prevents certain users from seeing certain information. So, you want
115 to construct the basic query in one method, but add constraints to it in
120 my $request = $self->get_request; # Get a request object somehow.
121 my $schema = $self->result_source->schema;
123 my $cd_rs = $schema->resultset('CD')->search({
124 title => $request->param('title'),
125 year => $request->param('year'),
128 $cd_rs = $self->apply_security_policy( $cd_rs );
130 return $cd_rs->all();
133 sub apply_security_policy {
142 =head3 Resolving conditions and attributes
144 When a resultset is chained from another resultset (ie:
145 C<my $new_rs = $old_rs->search(\%extra_cond, \%attrs)>), conditions
146 and attributes with the same keys need resolving.
148 If any of L</columns>, L</select>, L</as> are present, they reset the
149 original selection, and start the selection "clean".
151 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
152 are merged into the existing ones from the original resultset.
154 The L</where> and L</having> attributes, and any search conditions, are
155 merged with an SQL C<AND> to the existing condition from the original
158 All other attributes are overridden by any new ones supplied in the
161 =head2 Multiple queries
163 Since a resultset just defines a query, you can do all sorts of
164 things with it with the same object.
166 # Don't hit the DB yet.
167 my $cd_rs = $schema->resultset('CD')->search({
168 title => 'something',
172 # Each of these hits the DB individually.
173 my $count = $cd_rs->count;
174 my $most_recent = $cd_rs->get_column('date_released')->max();
175 my @records = $cd_rs->all;
177 And it's not just limited to SELECT statements.
183 $cd_rs->create({ artist => 'Fred' });
185 Which is the same as:
187 $schema->resultset('CD')->create({
188 title => 'something',
193 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
201 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
203 =item Return Value: L<$resultset|/search>
207 The resultset constructor. Takes a source object (usually a
208 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
209 L</ATTRIBUTES> below). Does not perform any queries -- these are
210 executed as needed by the other methods.
212 Generally you never construct a resultset manually. Instead you get one
214 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
215 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
218 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
224 If called on an object, proxies to L</new_result> instead, so
226 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
228 will return a CD object, not a ResultSet, and is equivalent to:
230 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
232 Please also keep in mind that many internals call L</new_result> directly,
233 so overloading this method with the idea of intercepting new result object
234 creation B<will not work>. See also warning pertaining to L</create>.
242 return $class->new_result(@_) if ref $class;
244 my ($source, $attrs) = @_;
245 $source = $source->resolve
246 if $source->isa('DBIx::Class::ResultSourceHandle');
247 $attrs = { %{$attrs||{}} };
249 if ($attrs->{page}) {
250 $attrs->{rows} ||= 10;
253 $attrs->{alias} ||= 'me';
256 result_source => $source,
257 cond => $attrs->{where},
262 # if there is a dark selector, this means we are already in a
263 # chain and the cleanup/sanification was taken care of by
265 $self->_normalize_selection($attrs)
266 unless $attrs->{_dark_selector};
269 $attrs->{result_class} || $source->result_class
279 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
281 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
285 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
286 my $new_rs = $cd_rs->search({ year => 2005 });
288 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
289 # year = 2005 OR year = 2004
291 In list context, C<< ->all() >> is called implicitly on the resultset, thus
292 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
293 To avoid that, use L</search_rs>.
295 If you need to pass in additional attributes but no additional condition,
296 call it as C<search(undef, \%attrs)>.
298 # "SELECT name, artistid FROM $artist_table"
299 my @all_artists = $schema->resultset('Artist')->search(undef, {
300 columns => [qw/name artistid/],
303 For a list of attributes that can be passed to C<search>, see
304 L</ATTRIBUTES>. For more examples of using this function, see
305 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
306 documentation for the first argument, see L<SQL::Abstract>
307 and its extension L<DBIx::Class::SQLMaker>.
309 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
313 Note that L</search> does not process/deflate any of the values passed in the
314 L<SQL::Abstract>-compatible search condition structure. This is unlike other
315 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
316 manually that any value passed to this method will stringify to something the
317 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
318 objects, for more info see:
319 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
325 my $rs = $self->search_rs( @_ );
330 elsif (defined wantarray) {
334 # we can be called by a relationship helper, which in
335 # turn may be called in void context due to some braindead
336 # overload or whatever else the user decided to be clever
337 # at this particular day. Thus limit the exception to
338 # external code calls only
339 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
340 if (caller)[0] !~ /^\QDBIx::Class::/;
350 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
352 =item Return Value: L<$resultset|/search>
356 This method does the same exact thing as search() except it will
357 always return a resultset, even in list context.
364 my $rsrc = $self->result_source;
365 my ($call_cond, $call_attrs);
367 # Special-case handling for (undef, undef) or (undef)
368 # Note that (foo => undef) is valid deprecated syntax
369 @_ = () if not scalar grep { defined $_ } @_;
375 # fish out attrs in the ($condref, $attr) case
376 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
377 ($call_cond, $call_attrs) = @_;
380 $self->throw_exception('Odd number of arguments to search')
384 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
385 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
387 for my $i (0 .. $#_) {
389 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
390 if (! defined $_[$i] or ref $_[$i] ne '');
396 # see if we can keep the cache (no $rs changes)
398 my %safe = (alias => 1, cache => 1);
399 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
402 ref $call_cond eq 'HASH' && ! keys %$call_cond
404 ref $call_cond eq 'ARRAY' && ! @$call_cond
406 $cache = $self->get_cache;
409 my $old_attrs = { %{$self->{attrs}} };
410 my $old_having = delete $old_attrs->{having};
411 my $old_where = delete $old_attrs->{where};
413 my $new_attrs = { %$old_attrs };
415 # take care of call attrs (only if anything is changing)
416 if ($call_attrs and keys %$call_attrs) {
418 # copy for _normalize_selection
419 $call_attrs = { %$call_attrs };
421 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
423 # reset the current selector list if new selectors are supplied
424 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
425 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
428 # Normalize the new selector list (operates on the passed-in attr structure)
429 # Need to do it on every chain instead of only once on _resolved_attrs, in
430 # order to allow detection of empty vs partial 'as'
431 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
432 if $old_attrs->{_dark_selector};
433 $self->_normalize_selection ($call_attrs);
435 # start with blind overwriting merge, exclude selector attrs
436 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
437 delete @{$new_attrs}{@selector_attrs};
439 for (@selector_attrs) {
440 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
441 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
444 # older deprecated name, use only if {columns} is not there
445 if (my $c = delete $new_attrs->{cols}) {
446 if ($new_attrs->{columns}) {
447 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
450 $new_attrs->{columns} = $c;
455 # join/prefetch use their own crazy merging heuristics
456 foreach my $key (qw/join prefetch/) {
457 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
458 if exists $call_attrs->{$key};
461 # stack binds together
462 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
466 for ($old_where, $call_cond) {
468 $new_attrs->{where} = $self->_stack_cond (
469 $_, $new_attrs->{where}
474 if (defined $old_having) {
475 $new_attrs->{having} = $self->_stack_cond (
476 $old_having, $new_attrs->{having}
480 my $rs = (ref $self)->new($rsrc, $new_attrs);
482 $rs->set_cache($cache) if ($cache);
488 sub _normalize_selection {
489 my ($self, $attrs) = @_;
492 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
493 if exists $attrs->{include_columns};
495 # columns are always placed first, however
497 # Keep the X vs +X separation until _resolved_attrs time - this allows to
498 # delay the decision on whether to use a default select list ($rsrc->columns)
499 # allowing stuff like the remove_columns helper to work
501 # select/as +select/+as pairs need special handling - the amount of select/as
502 # elements in each pair does *not* have to be equal (think multicolumn
503 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
504 # supplied at all) - try to infer the alias, either from the -as parameter
505 # of the selector spec, or use the parameter whole if it looks like a column
506 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
507 # is ok as well), but make sure no more additions to the 'as' chain take place
508 for my $pref ('', '+') {
510 my ($sel, $as) = map {
511 my $key = "${pref}${_}";
513 my $val = [ ref $attrs->{$key} eq 'ARRAY'
515 : $attrs->{$key} || ()
517 delete $attrs->{$key};
521 if (! @$as and ! @$sel ) {
524 elsif (@$as and ! @$sel) {
525 $self->throw_exception(
526 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
530 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
531 # if any @$as has been supplied we assume the user knows what (s)he is doing
532 # and blindly keep stacking up pieces
533 unless ($attrs->{_dark_selector}) {
536 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
537 push @$as, $_->{-as};
539 # assume any plain no-space, no-parenthesis string to be a column spec
540 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
541 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
544 # if all else fails - raise a flag that no more aliasing will be allowed
546 $attrs->{_dark_selector} = {
548 string => ($dark_sel_dumper ||= do {
549 require Data::Dumper::Concise;
550 Data::Dumper::Concise::DumperObject()->Indent(0);
551 })->Values([$_])->Dump
559 elsif (@$as < @$sel) {
560 $self->throw_exception(
561 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
564 elsif ($pref and $attrs->{_dark_selector}) {
565 $self->throw_exception(
566 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
572 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
573 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
578 my ($self, $left, $right) = @_;
580 # collapse single element top-level conditions
581 # (single pass only, unlikely to need recursion)
582 for ($left, $right) {
583 if (ref $_ eq 'ARRAY') {
591 elsif (ref $_ eq 'HASH') {
592 my ($first, $more) = keys %$_;
595 if (! defined $first) {
599 elsif (! defined $more) {
600 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
603 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
610 # merge hashes with weeding out of duplicates (simple cases only)
611 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
613 # shallow copy to destroy
614 $right = { %$right };
615 for (grep { exists $right->{$_} } keys %$left) {
616 # the use of eq_deeply here is justified - the rhs of an
617 # expression can contain a lot of twisted weird stuff
618 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
621 $right = undef unless keys %$right;
625 if (defined $left xor defined $right) {
626 return defined $left ? $left : $right;
628 elsif (! defined $left) {
632 return { -and => [ $left, $right ] };
636 =head2 search_literal
638 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
639 should only be used in that context. C<search_literal> is a convenience
640 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
641 want to ensure columns are bound correctly, use L</search>.
643 See L<DBIx::Class::Manual::Cookbook/Searching> and
644 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
645 require C<search_literal>.
649 =item Arguments: $sql_fragment, @standalone_bind_values
651 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
655 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
656 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
658 Pass a literal chunk of SQL to be added to the conditional part of the
661 Example of how to use C<search> instead of C<search_literal>
663 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
664 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
669 my ($self, $sql, @bind) = @_;
671 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
674 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
681 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
683 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
687 Finds and returns a single row based on supplied criteria. Takes either a
688 hashref with the same format as L</create> (including inference of foreign
689 keys from related objects), or a list of primary key values in the same
690 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
691 declaration on the L</result_source>.
693 In either case an attempt is made to combine conditions already existing on
694 the resultset with the condition passed to this method.
696 To aid with preparing the correct query for the storage you may supply the
697 C<key> attribute, which is the name of a
698 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
699 unique constraint corresponding to the
700 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
701 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
702 to construct a query that satisfies the named unique constraint fully (
703 non-NULL values for each column member of the constraint) an exception is
706 If no C<key> is specified, the search is carried over all unique constraints
707 which are fully defined by the available condition.
709 If no such constraint is found, C<find> currently defaults to a simple
710 C<< search->(\%column_values) >> which may or may not do what you expect.
711 Note that this fallback behavior may be deprecated in further versions. If
712 you need to search with arbitrary conditions - use L</search>. If the query
713 resulting from this fallback produces more than one row, a warning to the
714 effect is issued, though only the first row is constructed and returned as
717 In addition to C<key>, L</find> recognizes and applies standard
718 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
720 Note that if you have extra concerns about the correctness of the resulting
721 query you need to specify the C<key> attribute and supply the entire condition
722 as an argument to find (since it is not always possible to perform the
723 combination of the resultset condition with the supplied one, especially if
724 the resultset condition contains literal sql).
726 For example, to find a row by its primary key:
728 my $cd = $schema->resultset('CD')->find(5);
730 You can also find a row by a specific unique constraint:
732 my $cd = $schema->resultset('CD')->find(
734 artist => 'Massive Attack',
735 title => 'Mezzanine',
737 { key => 'cd_artist_title' }
740 See also L</find_or_create> and L</update_or_create>.
746 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
748 my $rsrc = $self->result_source;
751 if (exists $attrs->{key}) {
752 $constraint_name = defined $attrs->{key}
754 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
758 # Parse out the condition from input
761 if (ref $_[0] eq 'HASH') {
762 $call_cond = { %{$_[0]} };
765 # if only values are supplied we need to default to 'primary'
766 $constraint_name = 'primary' unless defined $constraint_name;
768 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
770 $self->throw_exception(
771 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
774 $self->throw_exception (
775 'find() expects either a column/value hashref, or a list of values '
776 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
777 ) unless @c_cols == @_;
780 @{$call_cond}{@c_cols} = @_;
784 for my $key (keys %$call_cond) {
786 my $keyref = ref($call_cond->{$key})
788 my $relinfo = $rsrc->relationship_info($key)
790 my $val = delete $call_cond->{$key};
792 next if $keyref eq 'ARRAY'; # has_many for multi_create
794 my $rel_q = $rsrc->_resolve_condition(
795 $relinfo->{cond}, $val, $key, $key
797 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
798 @related{keys %$rel_q} = values %$rel_q;
802 # relationship conditions take precedence (?)
803 @{$call_cond}{keys %related} = values %related;
805 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
807 if (defined $constraint_name) {
808 $final_cond = $self->_qualify_cond_columns (
810 $self->_build_unique_cond (
818 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
819 # This means that we got here after a merger of relationship conditions
820 # in ::Relationship::Base::search_related (the row method), and furthermore
821 # the relationship is of the 'single' type. This means that the condition
822 # provided by the relationship (already attached to $self) is sufficient,
823 # as there can be only one row in the database that would satisfy the
827 # no key was specified - fall down to heuristics mode:
828 # run through all unique queries registered on the resultset, and
829 # 'OR' all qualifying queries together
830 my (@unique_queries, %seen_column_combinations);
831 for my $c_name ($rsrc->unique_constraint_names) {
832 next if $seen_column_combinations{
833 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
836 push @unique_queries, try {
837 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
841 $final_cond = @unique_queries
842 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
843 : $self->_non_unique_find_fallback ($call_cond, $attrs)
847 # Run the query, passing the result_class since it should propagate for find
848 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
849 if ($rs->_resolved_attrs->{collapse}) {
851 carp "Query returned more than one row" if $rs->next;
859 # This is a stop-gap method as agreed during the discussion on find() cleanup:
860 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
862 # It is invoked when find() is called in legacy-mode with insufficiently-unique
863 # condition. It is provided for overrides until a saner way forward is devised
865 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
866 # the road. Please adjust your tests accordingly to catch this situation early
867 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
869 # The method will not be removed without an adequately complete replacement
870 # for strict-mode enforcement
871 sub _non_unique_find_fallback {
872 my ($self, $cond, $attrs) = @_;
874 return $self->_qualify_cond_columns(
876 exists $attrs->{alias}
878 : $self->{attrs}{alias}
883 sub _qualify_cond_columns {
884 my ($self, $cond, $alias) = @_;
886 my %aliased = %$cond;
887 for (keys %aliased) {
888 $aliased{"$alias.$_"} = delete $aliased{$_}
895 sub _build_unique_cond {
896 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
898 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
900 # combination may fail if $self->{cond} is non-trivial
901 my ($final_cond) = try {
902 $self->_merge_with_rscond ($extra_cond)
907 # trim out everything not in $columns
908 $final_cond = { map {
909 exists $final_cond->{$_}
910 ? ( $_ => $final_cond->{$_} )
914 if (my @missing = grep
915 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
918 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
920 join (', ', map { "'$_'" } @missing),
927 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
929 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
931 carp_unique ( sprintf (
932 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
933 . 'values in column(s): %s). This is almost certainly not what you wanted, '
934 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
936 join (', ', map { "'$_'" } @undefs),
943 =head2 search_related
947 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
949 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
953 $new_rs = $cd_rs->search_related('artist', {
957 Searches the specified relationship, optionally specifying a condition and
958 attributes for matching records. See L</ATTRIBUTES> for more information.
960 In list context, C<< ->all() >> is called implicitly on the resultset, thus
961 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
963 See also L</search_related_rs>.
968 return shift->related_resultset(shift)->search(@_);
971 =head2 search_related_rs
973 This method works exactly the same as search_related, except that
974 it guarantees a resultset, even in list context.
978 sub search_related_rs {
979 return shift->related_resultset(shift)->search_rs(@_);
986 =item Arguments: none
988 =item Return Value: L<$cursor|DBIx::Class::Cursor>
992 Returns a storage-driven cursor to the given resultset. See
993 L<DBIx::Class::Cursor> for more information.
1000 return $self->{cursor} ||= do {
1001 my $attrs = { %{$self->_resolved_attrs } };
1002 $self->result_source->storage->select(
1003 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1012 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1014 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1018 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1020 Inflates the first result without creating a cursor if the resultset has
1021 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1024 While this method can take an optional search condition (just like L</search>)
1025 being a fast-code-path it does not recognize search attributes. If you need to
1026 add extra joins or similar, call L</search> and then chain-call L</single> on the
1027 L<DBIx::Class::ResultSet> returned.
1033 As of 0.08100, this method enforces the assumption that the preceding
1034 query returns only one row. If more than one row is returned, you will receive
1037 Query returned more than one row
1039 In this case, you should be using L</next> or L</find> instead, or if you really
1040 know what you are doing, use the L</rows> attribute to explicitly limit the size
1043 This method will also throw an exception if it is called on a resultset prefetching
1044 has_many, as such a prefetch implies fetching multiple rows from the database in
1045 order to assemble the resulting object.
1052 my ($self, $where) = @_;
1054 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1057 my $attrs = { %{$self->_resolved_attrs} };
1059 $self->throw_exception(
1060 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
1061 ) if $attrs->{collapse};
1064 if (defined $attrs->{where}) {
1067 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1068 $where, delete $attrs->{where} ]
1071 $attrs->{where} = $where;
1075 my $data = [ $self->result_source->storage->select_single(
1076 $attrs->{from}, $attrs->{select},
1077 $attrs->{where}, $attrs
1079 return undef unless @$data;
1080 $self->{stashed_rows} = [ $data ];
1081 $self->_construct_objects->[0];
1087 # Recursively collapse the query, accumulating values for each column.
1089 sub _collapse_query {
1090 my ($self, $query, $collapsed) = @_;
1094 if (ref $query eq 'ARRAY') {
1095 foreach my $subquery (@$query) {
1096 next unless ref $subquery; # -or
1097 $collapsed = $self->_collapse_query($subquery, $collapsed);
1100 elsif (ref $query eq 'HASH') {
1101 if (keys %$query and (keys %$query)[0] eq '-and') {
1102 foreach my $subquery (@{$query->{-and}}) {
1103 $collapsed = $self->_collapse_query($subquery, $collapsed);
1107 foreach my $col (keys %$query) {
1108 my $value = $query->{$col};
1109 $collapsed->{$col}{$value}++;
1121 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1123 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1127 my $max_length = $rs->get_column('length')->max;
1129 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1134 my ($self, $column) = @_;
1135 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1143 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1145 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1149 # WHERE title LIKE '%blue%'
1150 $cd_rs = $rs->search_like({ title => '%blue%'});
1152 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1153 that this is simply a convenience method retained for ex Class::DBI users.
1154 You most likely want to use L</search> with specific operators.
1156 For more information, see L<DBIx::Class::Manual::Cookbook>.
1158 This method is deprecated and will be removed in 0.09. Use L</search()>
1159 instead. An example conversion is:
1161 ->search_like({ foo => 'bar' });
1165 ->search({ foo => { like => 'bar' } });
1172 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1173 .' Instead use ->search({ x => { -like => "y%" } })'
1174 .' (note the outer pair of {}s - they are important!)'
1176 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1177 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1178 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1179 return $class->search($query, { %$attrs });
1186 =item Arguments: $first, $last
1188 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1192 Returns a resultset or object list representing a subset of elements from the
1193 resultset slice is called on. Indexes are from 0, i.e., to get the first
1194 three records, call:
1196 my ($one, $two, $three) = $rs->slice(0, 2);
1201 my ($self, $min, $max) = @_;
1202 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1203 $attrs->{offset} = $self->{attrs}{offset} || 0;
1204 $attrs->{offset} += $min;
1205 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1206 return $self->search(undef, $attrs);
1207 #my $slice = (ref $self)->new($self->result_source, $attrs);
1208 #return (wantarray ? $slice->all : $slice);
1215 =item Arguments: none
1217 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1221 Returns the next element in the resultset (C<undef> is there is none).
1223 Can be used to efficiently iterate over records in the resultset:
1225 my $rs = $schema->resultset('CD')->search;
1226 while (my $cd = $rs->next) {
1230 Note that you need to store the resultset object, and call C<next> on it.
1231 Calling C<< resultset('Table')->next >> repeatedly will always return the
1232 first record from the resultset.
1239 if (my $cache = $self->get_cache) {
1240 $self->{all_cache_position} ||= 0;
1241 return $cache->[$self->{all_cache_position}++];
1244 if ($self->{attrs}{cache}) {
1245 delete $self->{pager};
1246 $self->{all_cache_position} = 1;
1247 return ($self->all)[0];
1250 return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] };
1252 $self->{stashed_objects} = $self->_construct_objects
1255 return shift @{$self->{stashed_objects}};
1258 # Constructs as many objects as it can in one pass while respecting
1259 # cursor laziness. Several modes of operation:
1261 # * Always builds everything present in @{$self->{stashed_rows}}
1262 # * If called with $fetch_all true - pulls everything off the cursor and
1263 # builds all objects in one pass
1264 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1265 # and if the resultset is ordered properly by the left side:
1266 # * Fetches stuff off the cursor until the "master object" changes,
1267 # and saves the last extra row (if any) in @{$self->{stashed_rows}}
1269 # * Just fetches, and collapses/constructs everything as if $fetch_all
1270 # was requested (there is no other way to collapse except for an
1272 # * If no collapse is requested - just get the next row, construct and
1274 sub _construct_objects {
1275 my ($self, $fetch_all) = @_;
1277 my $rsrc = $self->result_source;
1278 my $attrs = $self->_resolved_attrs;
1280 if (!$fetch_all and ! $attrs->{order_by} and $attrs->{collapse}) {
1281 # default order for collapsing unless the user asked for something
1282 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} $rsrc->primary_columns ];
1283 $attrs->{_ordered_for_collapse} = 1;
1284 $attrs->{_order_is_artificial} = 1;
1287 my $cursor = $self->cursor;
1289 # this will be used as both initial raw-row collector AND as a RV of
1290 # _construct_objects. Not regrowing the array twice matters a lot...
1291 # a suprising amount actually
1292 my $rows = delete $self->{stashed_rows};
1295 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1296 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1298 elsif( $attrs->{collapse} ) {
1300 $attrs->{_ordered_for_collapse} = (!$attrs->{order_by}) ? 0 : do {
1301 my $st = $rsrc->schema->storage;
1304 ( $st->_extract_order_criteria($attrs->{order_by}) )
1307 my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
1309 for (0 .. $#ord_cols) {
1311 ! $colinfos->{$ord_cols[$_]}
1313 $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
1315 splice @ord_cols, $_;
1320 # since all we check here are the start of the order_by belonging to the
1321 # top level $rsrc, a present identifying set will mean that the resultset
1322 # is ordered by its leftmost table in a tsable manner
1323 (@ord_cols and $rsrc->_identifying_column_set({ map
1324 { $colinfos->{$_}{-colname} => $colinfos->{$_} }
1327 } unless defined $attrs->{_ordered_for_collapse};
1329 if (! $attrs->{_ordered_for_collapse}) {
1332 # instead of looping over ->next, use ->all in stealth mode
1333 # *without* calling a ->reset afterwards
1334 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1335 if (! $cursor->{_done}) {
1336 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1337 $cursor->{_done} = 1;
1342 if (! $fetch_all and ! @{$rows||[]} ) {
1343 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1344 if (scalar (my @r = $cursor->next) ) {
1349 return undef unless @{$rows||[]};
1351 my @extra_collapser_args;
1352 if ($attrs->{collapse} and ! $fetch_all ) {
1354 @extra_collapser_args = (
1355 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1356 sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
1357 ($self->{stashed_rows} = []), # where does it stuff excess
1361 # hotspot - skip the setter
1362 my $res_class = $self->_result_class;
1364 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1365 $res_class->can ('inflate_result')
1366 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1369 my $infmap = $attrs->{as};
1371 $self->{_result_inflator}{is_hri} = do { ( $inflator_cref == (
1372 require DBIx::Class::ResultClass::HashRefInflator
1374 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1376 } unless defined $self->{_result_inflator}{is_hri};
1378 if ($attrs->{_single_resultclass_inflation}) {
1379 # construct a much simpler array->hash folder for the one-table cases right here
1380 if ($self->{_result_inflator}{is_hri}) {
1381 for my $r (@$rows) {
1382 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1385 # FIXME SUBOPTIMAL this is a very very very hot spot
1386 # while rather optimal we can *still* do much better, by
1387 # building a smarter Row::inflate_result(), and
1388 # switch to feeding it data via a much leaner interface
1390 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1391 # this particular resultset size
1392 elsif (@$rows < 60) {
1393 for my $r (@$rows) {
1394 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1399 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1400 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1404 # Special-case multi-object HRI (we always prune)
1405 elsif ($self->{_result_inflator}{is_hri}) {
1406 ( $self->{_row_parser}{hri} ||= $rsrc->_mk_row_parser({
1408 inflate_map => $infmap,
1409 selection => $attrs->{select},
1410 collapse => $attrs->{collapse},
1411 premultiplied => $attrs->{_main_source_premultiplied},
1413 }) )->($rows, @extra_collapser_args);
1415 # Regular multi-object
1418 ( $self->{_row_parser}{classic} ||= $rsrc->_mk_row_parser({
1420 inflate_map => $infmap,
1421 selection => $attrs->{select},
1422 collapse => $attrs->{collapse},
1423 premultiplied => $attrs->{_main_source_premultiplied},
1424 }) )->($rows, @extra_collapser_args);
1426 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows;
1430 if ($attrs->{record_filter}) {
1431 $_ = $attrs->{record_filter}->($_) for @$rows;
1437 =head2 result_source
1441 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1443 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1447 An accessor for the primary ResultSource object from which this ResultSet
1454 =item Arguments: $result_class?
1456 =item Return Value: $result_class
1460 An accessor for the class to use when creating result objects. Defaults to
1461 C<< result_source->result_class >> - which in most cases is the name of the
1462 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1464 Note that changing the result_class will also remove any components
1465 that were originally loaded in the source class via
1466 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1467 in the original source class will not run.
1472 my ($self, $result_class) = @_;
1473 if ($result_class) {
1475 # don't fire this for an object
1476 $self->ensure_class_loaded($result_class)
1477 unless ref($result_class);
1479 if ($self->get_cache) {
1480 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1482 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1483 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1484 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1487 $self->_result_class($result_class);
1489 delete $self->{_result_inflator};
1491 $self->_result_class;
1498 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1500 =item Return Value: $count
1504 Performs an SQL C<COUNT> with the same query as the resultset was built
1505 with to find the number of elements. Passing arguments is equivalent to
1506 C<< $rs->search ($cond, \%attrs)->count >>
1512 return $self->search(@_)->count if @_ and defined $_[0];
1513 return scalar @{ $self->get_cache } if $self->get_cache;
1515 my $attrs = { %{ $self->_resolved_attrs } };
1517 # this is a little optimization - it is faster to do the limit
1518 # adjustments in software, instead of a subquery
1519 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1522 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1523 $crs = $self->_count_subq_rs ($attrs);
1526 $crs = $self->_count_rs ($attrs);
1528 my $count = $crs->next;
1530 $count -= $offset if $offset;
1531 $count = $rows if $rows and $rows < $count;
1532 $count = 0 if ($count < 0);
1541 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1543 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1547 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1548 This can be very handy for subqueries:
1550 ->search( { amount => $some_rs->count_rs->as_query } )
1552 As with regular resultsets the SQL query will be executed only after
1553 the resultset is accessed via L</next> or L</all>. That would return
1554 the same single value obtainable via L</count>.
1560 return $self->search(@_)->count_rs if @_;
1562 # this may look like a lack of abstraction (count() does about the same)
1563 # but in fact an _rs *must* use a subquery for the limits, as the
1564 # software based limiting can not be ported if this $rs is to be used
1565 # in a subquery itself (i.e. ->as_query)
1566 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1567 return $self->_count_subq_rs;
1570 return $self->_count_rs;
1575 # returns a ResultSetColumn object tied to the count query
1578 my ($self, $attrs) = @_;
1580 my $rsrc = $self->result_source;
1581 $attrs ||= $self->_resolved_attrs;
1583 my $tmp_attrs = { %$attrs };
1584 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1585 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1587 # overwrite the selector (supplied by the storage)
1588 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1589 $tmp_attrs->{as} = 'count';
1591 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1597 # same as above but uses a subquery
1599 sub _count_subq_rs {
1600 my ($self, $attrs) = @_;
1602 my $rsrc = $self->result_source;
1603 $attrs ||= $self->_resolved_attrs;
1605 my $sub_attrs = { %$attrs };
1606 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1607 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1609 # if we multi-prefetch we group_by something unique, as this is what we would
1610 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1611 if ( $attrs->{collapse} ) {
1612 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1613 $rsrc->_identifying_column_set || $self->throw_exception(
1614 'Unable to construct a unique group_by criteria properly collapsing the '
1615 . 'has_many prefetch before count()'
1620 # Calculate subquery selector
1621 if (my $g = $sub_attrs->{group_by}) {
1623 my $sql_maker = $rsrc->storage->sql_maker;
1625 # necessary as the group_by may refer to aliased functions
1627 for my $sel (@{$attrs->{select}}) {
1628 $sel_index->{$sel->{-as}} = $sel
1629 if (ref $sel eq 'HASH' and $sel->{-as});
1632 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1633 # also look for named aggregates referred in the having clause
1634 # having often contains scalarrefs - thus parse it out entirely
1636 if ($attrs->{having}) {
1637 local $sql_maker->{having_bind};
1638 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1639 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1640 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1641 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1642 # if we don't unset it we screw up retarded but unfortunately working
1643 # 'MAX(foo.bar)' => { '>', 3 }
1644 $sql_maker->{name_sep} = '';
1647 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1649 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1652 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1653 # and if all fails for an utterly naive quoted scalar-with-function
1654 while ($having_sql =~ /
1655 $rquote $sep $lquote (.+?) $rquote
1657 [\s,] \w+ \. (\w+) [\s,]
1659 [\s,] $lquote (.+?) $rquote [\s,]
1661 my $part = $1 || $2 || $3; # one of them matched if we got here
1662 unless ($seen_having{$part}++) {
1669 my $colpiece = $sel_index->{$_} || $_;
1671 # unqualify join-based group_by's. Arcane but possible query
1672 # also horrible horrible hack to alias a column (not a func.)
1673 # (probably need to introduce SQLA syntax)
1674 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1677 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1679 push @{$sub_attrs->{select}}, $colpiece;
1683 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1684 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1687 return $rsrc->resultset_class
1688 ->new ($rsrc, $sub_attrs)
1690 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1691 ->get_column ('count');
1695 =head2 count_literal
1697 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1698 should only be used in that context. See L</search_literal> for further info.
1702 =item Arguments: $sql_fragment, @standalone_bind_values
1704 =item Return Value: $count
1708 Counts the results in a literal query. Equivalent to calling L</search_literal>
1709 with the passed arguments, then L</count>.
1713 sub count_literal { shift->search_literal(@_)->count; }
1719 =item Arguments: none
1721 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1725 Returns all elements in the resultset.
1732 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1735 delete @{$self}{qw/stashed_rows stashed_objects/};
1737 if (my $c = $self->get_cache) {
1741 $self->cursor->reset;
1743 my $objs = $self->_construct_objects('fetch_all') || [];
1745 $self->set_cache($objs) if $self->{attrs}{cache};
1754 =item Arguments: none
1756 =item Return Value: $self
1760 Resets the resultset's cursor, so you can iterate through the elements again.
1761 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1769 delete @{$self}{qw/stashed_rows stashed_objects/};
1770 $self->{all_cache_position} = 0;
1771 $self->cursor->reset;
1779 =item Arguments: none
1781 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1785 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1786 an object for the first result (or C<undef> if the resultset is empty).
1791 return $_[0]->reset->next;
1797 # Determines whether and what type of subquery is required for the $rs operation.
1798 # If grouping is necessary either supplies its own, or verifies the current one
1799 # After all is done delegates to the proper storage method.
1801 sub _rs_update_delete {
1802 my ($self, $op, $values) = @_;
1804 my $rsrc = $self->result_source;
1805 my $storage = $rsrc->schema->storage;
1807 my $attrs = { %{$self->_resolved_attrs} };
1809 my $join_classifications;
1810 my $existing_group_by = delete $attrs->{group_by};
1812 # do we need a subquery for any reason?
1814 defined $existing_group_by
1816 # if {from} is unparseable wrap a subq
1817 ref($attrs->{from}) ne 'ARRAY'
1819 # limits call for a subq
1820 $self->_has_resolved_attr(qw/rows offset/)
1823 # simplify the joinmap, so we can further decide if a subq is necessary
1824 if (!$needs_subq and @{$attrs->{from}} > 1) {
1825 $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
1827 # check if there are any joins left after the prune
1828 if ( @{$attrs->{from}} > 1 ) {
1829 $join_classifications = $storage->_resolve_aliastypes_from_select_args (
1830 [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
1836 # any non-pruneable joins imply subq
1837 $needs_subq = scalar keys %{ $join_classifications->{restricting} || {} };
1841 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1843 (ref $attrs->{from}[0]) ne 'HASH'
1845 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1849 # do we need anything like a subquery?
1850 if (! $needs_subq) {
1851 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1852 # a condition containing 'me' or other table prefixes will not work
1853 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1855 my $sqla = $rsrc->storage->sql_maker;
1856 local $sqla->{_dequalify_idents} = 1;
1857 \[ $sqla->_recurse_where($self->{cond}) ];
1861 # we got this far - means it is time to wrap a subquery
1862 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1864 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1870 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1871 delete $attrs->{$_} for qw/collapse select _prefetch_selector_range as/;
1872 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1873 $attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
1874 my $subrs = (ref $self)->new($rsrc, $attrs);
1876 if (@$idcols == 1) {
1877 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1879 elsif ($storage->_use_multicolumn_in) {
1880 # no syntax for calling this properly yet
1881 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1882 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1883 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1888 # if all else fails - get all primary keys and operate over a ORed set
1889 # wrap in a transaction for consistency
1890 # this is where the group_by/multiplication starts to matter
1894 keys %{ $join_classifications->{multiplying} || {} }
1896 # make sure if there is a supplied group_by it matches the columns compiled above
1897 # perfectly. Anything else can not be sanely executed on most databases so croak
1898 # right then and there
1899 if ($existing_group_by) {
1900 my @current_group_by = map
1901 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1906 join ("\x00", sort @current_group_by)
1908 join ("\x00", sort @{$attrs->{columns}} )
1910 $self->throw_exception (
1911 "You have just attempted a $op operation on a resultset which does group_by"
1912 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1913 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1914 . ' kind of queries. Please retry the operation with a modified group_by or'
1915 . ' without using one at all.'
1920 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1923 $guard = $storage->txn_scope_guard;
1926 for my $row ($subrs->cursor->all) {
1928 { $idcols->[$_] => $row->[$_] }
1935 my $res = $storage->$op (
1937 $op eq 'update' ? $values : (),
1941 $guard->commit if $guard;
1950 =item Arguments: \%values
1952 =item Return Value: $underlying_storage_rv
1956 Sets the specified columns in the resultset to the supplied values in a
1957 single query. Note that this will not run any accessor/set_column/update
1958 triggers, nor will it update any result object instances derived from this
1959 resultset (this includes the contents of the L<resultset cache|/set_cache>
1960 if any). See L</update_all> if you need to execute any on-update
1961 triggers or cascades defined either by you or a
1962 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1964 The return value is a pass through of what the underlying
1965 storage backend returned, and may vary. See L<DBI/execute> for the most
1970 Note that L</update> does not process/deflate any of the values passed in.
1971 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1972 ensure manually that any value passed to this method will stringify to
1973 something the RDBMS knows how to deal with. A notable example is the
1974 handling of L<DateTime> objects, for more info see:
1975 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
1980 my ($self, $values) = @_;
1981 $self->throw_exception('Values for update must be a hash')
1982 unless ref $values eq 'HASH';
1984 return $self->_rs_update_delete ('update', $values);
1991 =item Arguments: \%values
1993 =item Return Value: 1
1997 Fetches all objects and updates them one at a time via
1998 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1999 triggers, while L</update> will not.
2004 my ($self, $values) = @_;
2005 $self->throw_exception('Values for update_all must be a hash')
2006 unless ref $values eq 'HASH';
2008 my $guard = $self->result_source->schema->txn_scope_guard;
2009 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2018 =item Arguments: none
2020 =item Return Value: $underlying_storage_rv
2024 Deletes the rows matching this resultset in a single query. Note that this
2025 will not run any delete triggers, nor will it alter the
2026 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2027 derived from this resultset (this includes the contents of the
2028 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2029 execute any on-delete triggers or cascades defined either by you or a
2030 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2032 The return value is a pass through of what the underlying storage backend
2033 returned, and may vary. See L<DBI/execute> for the most common case.
2039 $self->throw_exception('delete does not accept any arguments')
2042 return $self->_rs_update_delete ('delete');
2049 =item Arguments: none
2051 =item Return Value: 1
2055 Fetches all objects and deletes them one at a time via
2056 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2057 triggers, while L</delete> will not.
2063 $self->throw_exception('delete_all does not accept any arguments')
2066 my $guard = $self->result_source->schema->txn_scope_guard;
2067 $_->delete for $self->all;
2076 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2078 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2082 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2089 The context of this method call has an important effect on what is
2090 submitted to storage. In void context data is fed directly to fastpath
2091 insertion routines provided by the underlying storage (most often
2092 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2093 L<insert|DBIx::Class::Row/insert> calls on the
2094 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2095 augmentation of these methods provided by components. For example if you
2096 are using something like L<DBIx::Class::UUIDColumns> to create primary
2097 keys for you, you will find that your PKs are empty. In this case you
2098 will have to explicitly force scalar or list context in order to create
2103 In non-void (scalar or list) context, this method is simply a wrapper
2104 for L</create>. Depending on list or scalar context either a list of
2105 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2106 containing these objects is returned.
2108 When supplying data in "arrayref of arrayrefs" invocation style, the
2109 first element should be a list of column names and each subsequent
2110 element should be a data value in the earlier specified column order.
2113 $Arstist_rs->populate([
2114 [ qw( artistid name ) ],
2115 [ 100, 'A Formally Unknown Singer' ],
2116 [ 101, 'A singer that jumped the shark two albums ago' ],
2117 [ 102, 'An actually cool singer' ],
2120 For the arrayref of hashrefs style each hashref should be a structure
2121 suitable for passing to L</create>. Multi-create is also permitted with
2124 $schema->resultset("Artist")->populate([
2125 { artistid => 4, name => 'Manufactured Crap', cds => [
2126 { title => 'My First CD', year => 2006 },
2127 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2130 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2131 { title => 'My parents sold me to a record company', year => 2005 },
2132 { title => 'Why Am I So Ugly?', year => 2006 },
2133 { title => 'I Got Surgery and am now Popular', year => 2007 }
2138 If you attempt a void-context multi-create as in the example above (each
2139 Artist also has the related list of CDs), and B<do not> supply the
2140 necessary autoinc foreign key information, this method will proxy to the
2141 less efficient L</create>, and then throw the Result objects away. In this
2142 case there are obviously no benefits to using this method over L</create>.
2149 # cruft placed in standalone method
2150 my $data = $self->_normalize_populate_args(@_);
2152 return unless @$data;
2154 if(defined wantarray) {
2155 my @created = map { $self->create($_) } @$data;
2156 return wantarray ? @created : \@created;
2159 my $first = $data->[0];
2161 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2162 # it relationship data
2163 my (@rels, @columns);
2164 my $rsrc = $self->result_source;
2165 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2166 for (keys %$first) {
2167 my $ref = ref $first->{$_};
2168 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2174 my @pks = $rsrc->primary_columns;
2176 ## do the belongs_to relationships
2177 foreach my $index (0..$#$data) {
2179 # delegate to create() for any dataset without primary keys with specified relationships
2180 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2182 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2183 my @ret = $self->populate($data);
2189 foreach my $rel (@rels) {
2190 next unless ref $data->[$index]->{$rel} eq "HASH";
2191 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2192 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2193 my $related = $result->result_source->_resolve_condition(
2194 $reverse_relinfo->{cond},
2200 delete $data->[$index]->{$rel};
2201 $data->[$index] = {%{$data->[$index]}, %$related};
2203 push @columns, keys %$related if $index == 0;
2207 ## inherit the data locked in the conditions of the resultset
2208 my ($rs_data) = $self->_merge_with_rscond({});
2209 delete @{$rs_data}{@columns};
2211 ## do bulk insert on current row
2212 $rsrc->storage->insert_bulk(
2214 [@columns, keys %$rs_data],
2215 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2218 ## do the has_many relationships
2219 foreach my $item (@$data) {
2223 foreach my $rel (@rels) {
2224 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2226 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2228 my $child = $main_row->$rel;
2230 my $related = $child->result_source->_resolve_condition(
2231 $rels->{$rel}{cond},
2237 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2238 my @populate = map { {%$_, %$related} } @rows_to_add;
2240 $child->populate( \@populate );
2247 # populate() argumnets went over several incarnations
2248 # What we ultimately support is AoH
2249 sub _normalize_populate_args {
2250 my ($self, $arg) = @_;
2252 if (ref $arg eq 'ARRAY') {
2256 elsif (ref $arg->[0] eq 'HASH') {
2259 elsif (ref $arg->[0] eq 'ARRAY') {
2261 my @colnames = @{$arg->[0]};
2262 foreach my $values (@{$arg}[1 .. $#$arg]) {
2263 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2269 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2276 =item Arguments: none
2278 =item Return Value: L<$pager|Data::Page>
2282 Returns a L<Data::Page> object for the current resultset. Only makes
2283 sense for queries with a C<page> attribute.
2285 To get the full count of entries for a paged resultset, call
2286 C<total_entries> on the L<Data::Page> object.
2293 return $self->{pager} if $self->{pager};
2295 my $attrs = $self->{attrs};
2296 if (!defined $attrs->{page}) {
2297 $self->throw_exception("Can't create pager for non-paged rs");
2299 elsif ($attrs->{page} <= 0) {
2300 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2302 $attrs->{rows} ||= 10;
2304 # throw away the paging flags and re-run the count (possibly
2305 # with a subselect) to get the real total count
2306 my $count_attrs = { %$attrs };
2307 delete @{$count_attrs}{qw/rows offset page pager/};
2309 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2311 require DBIx::Class::ResultSet::Pager;
2312 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2313 sub { $total_rs->count }, #lazy-get the total
2315 $self->{attrs}{page},
2323 =item Arguments: $page_number
2325 =item Return Value: L<$resultset|/search>
2329 Returns a resultset for the $page_number page of the resultset on which page
2330 is called, where each page contains a number of rows equal to the 'rows'
2331 attribute set on the resultset (10 by default).
2336 my ($self, $page) = @_;
2337 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2344 =item Arguments: \%col_data
2346 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2350 Creates a new result object in the resultset's result class and returns
2351 it. The row is not inserted into the database at this point, call
2352 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2353 will tell you whether the result object has been inserted or not.
2355 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2360 my ($self, $values) = @_;
2362 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2365 $self->throw_exception( "new_result expects a hashref" )
2366 unless (ref $values eq 'HASH');
2368 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2370 my $new = $self->result_class->new({
2372 ( @$cols_from_relations
2373 ? (-cols_from_relations => $cols_from_relations)
2376 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2380 reftype($new) eq 'HASH'
2386 carp_unique (sprintf (
2387 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2388 $self->result_class,
2395 # _merge_with_rscond
2397 # Takes a simple hash of K/V data and returns its copy merged with the
2398 # condition already present on the resultset. Additionally returns an
2399 # arrayref of value/condition names, which were inferred from related
2400 # objects (this is needed for in-memory related objects)
2401 sub _merge_with_rscond {
2402 my ($self, $data) = @_;
2404 my (%new_data, @cols_from_relations);
2406 my $alias = $self->{attrs}{alias};
2408 if (! defined $self->{cond}) {
2409 # just massage $data below
2411 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2412 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2413 @cols_from_relations = keys %new_data;
2415 elsif (ref $self->{cond} ne 'HASH') {
2416 $self->throw_exception(
2417 "Can't abstract implicit construct, resultset condition not a hash"
2421 # precendence must be given to passed values over values inherited from
2422 # the cond, so the order here is important.
2423 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2424 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2426 while ( my($col, $value) = each %implied ) {
2427 my $vref = ref $value;
2433 (keys %$value)[0] eq '='
2435 $new_data{$col} = $value->{'='};
2437 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2438 $new_data{$col} = $value;
2445 %{ $self->_remove_alias($data, $alias) },
2448 return (\%new_data, \@cols_from_relations);
2451 # _has_resolved_attr
2453 # determines if the resultset defines at least one
2454 # of the attributes supplied
2456 # used to determine if a subquery is neccessary
2458 # supports some virtual attributes:
2460 # This will scan for any joins being present on the resultset.
2461 # It is not a mere key-search but a deep inspection of {from}
2464 sub _has_resolved_attr {
2465 my ($self, @attr_names) = @_;
2467 my $attrs = $self->_resolved_attrs;
2471 for my $n (@attr_names) {
2472 if (grep { $n eq $_ } (qw/-join/) ) {
2473 $extra_checks{$n}++;
2477 my $attr = $attrs->{$n};
2479 next if not defined $attr;
2481 if (ref $attr eq 'HASH') {
2482 return 1 if keys %$attr;
2484 elsif (ref $attr eq 'ARRAY') {
2492 # a resolved join is expressed as a multi-level from
2494 $extra_checks{-join}
2496 ref $attrs->{from} eq 'ARRAY'
2498 @{$attrs->{from}} > 1
2506 # Recursively collapse the condition.
2508 sub _collapse_cond {
2509 my ($self, $cond, $collapsed) = @_;
2513 if (ref $cond eq 'ARRAY') {
2514 foreach my $subcond (@$cond) {
2515 next unless ref $subcond; # -or
2516 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2519 elsif (ref $cond eq 'HASH') {
2520 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2521 foreach my $subcond (@{$cond->{-and}}) {
2522 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2526 foreach my $col (keys %$cond) {
2527 my $value = $cond->{$col};
2528 $collapsed->{$col} = $value;
2538 # Remove the specified alias from the specified query hash. A copy is made so
2539 # the original query is not modified.
2542 my ($self, $query, $alias) = @_;
2544 my %orig = %{ $query || {} };
2547 foreach my $key (keys %orig) {
2549 $unaliased{$key} = $orig{$key};
2552 $unaliased{$1} = $orig{$key}
2553 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2563 =item Arguments: none
2565 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2569 Returns the SQL query and bind vars associated with the invocant.
2571 This is generally used as the RHS for a subquery.
2578 my $attrs = { %{ $self->_resolved_attrs } };
2583 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2584 # $sql also has no wrapping parenthesis in list ctx
2586 my $sqlbind = $self->result_source->storage
2587 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2596 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2598 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2602 my $artist = $schema->resultset('Artist')->find_or_new(
2603 { artist => 'fred' }, { key => 'artists' });
2605 $cd->cd_to_producer->find_or_new({ producer => $producer },
2606 { key => 'primary });
2608 Find an existing record from this resultset using L</find>. if none exists,
2609 instantiate a new result object and return it. The object will not be saved
2610 into your storage until you call L<DBIx::Class::Row/insert> on it.
2612 You most likely want this method when looking for existing rows using a unique
2613 constraint that is not the primary key, or looking for related rows.
2615 If you want objects to be saved immediately, use L</find_or_create> instead.
2617 B<Note>: Make sure to read the documentation of L</find> and understand the
2618 significance of the C<key> attribute, as its lack may skew your search, and
2619 subsequently result in spurious new objects.
2621 B<Note>: Take care when using C<find_or_new> with a table having
2622 columns with default values that you intend to be automatically
2623 supplied by the database (e.g. an auto_increment primary key column).
2624 In normal usage, the value of such columns should NOT be included at
2625 all in the call to C<find_or_new>, even when set to C<undef>.
2631 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2632 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2633 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2636 return $self->new_result($hash);
2643 =item Arguments: \%col_data
2645 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2649 Attempt to create a single new row or a row with multiple related rows
2650 in the table represented by the resultset (and related tables). This
2651 will not check for duplicate rows before inserting, use
2652 L</find_or_create> to do that.
2654 To create one row for this resultset, pass a hashref of key/value
2655 pairs representing the columns of the table and the values you wish to
2656 store. If the appropriate relationships are set up, foreign key fields
2657 can also be passed an object representing the foreign row, and the
2658 value will be set to its primary key.
2660 To create related objects, pass a hashref of related-object column values
2661 B<keyed on the relationship name>. If the relationship is of type C<multi>
2662 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2663 The process will correctly identify columns holding foreign keys, and will
2664 transparently populate them from the keys of the corresponding relation.
2665 This can be applied recursively, and will work correctly for a structure
2666 with an arbitrary depth and width, as long as the relationships actually
2667 exists and the correct column data has been supplied.
2669 Instead of hashrefs of plain related data (key/value pairs), you may
2670 also pass new or inserted objects. New objects (not inserted yet, see
2671 L</new_result>), will be inserted into their appropriate tables.
2673 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2675 Example of creating a new row.
2677 $person_rs->create({
2678 name=>"Some Person",
2679 email=>"somebody@someplace.com"
2682 Example of creating a new row and also creating rows in a related C<has_many>
2683 or C<has_one> resultset. Note Arrayref.
2686 { artistid => 4, name => 'Manufactured Crap', cds => [
2687 { title => 'My First CD', year => 2006 },
2688 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2693 Example of creating a new row and also creating a row in a related
2694 C<belongs_to> resultset. Note Hashref.
2697 title=>"Music for Silly Walks",
2700 name=>"Silly Musician",
2708 When subclassing ResultSet never attempt to override this method. Since
2709 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2710 lot of the internals simply never call it, so your override will be
2711 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2712 or L<DBIx::Class::Row/insert> depending on how early in the
2713 L</create> process you need to intervene. See also warning pertaining to
2721 my ($self, $attrs) = @_;
2722 $self->throw_exception( "create needs a hashref" )
2723 unless ref $attrs eq 'HASH';
2724 return $self->new_result($attrs)->insert;
2727 =head2 find_or_create
2731 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2733 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2737 $cd->cd_to_producer->find_or_create({ producer => $producer },
2738 { key => 'primary' });
2740 Tries to find a record based on its primary key or unique constraints; if none
2741 is found, creates one and returns that instead.
2743 my $cd = $schema->resultset('CD')->find_or_create({
2745 artist => 'Massive Attack',
2746 title => 'Mezzanine',
2750 Also takes an optional C<key> attribute, to search by a specific key or unique
2751 constraint. For example:
2753 my $cd = $schema->resultset('CD')->find_or_create(
2755 artist => 'Massive Attack',
2756 title => 'Mezzanine',
2758 { key => 'cd_artist_title' }
2761 B<Note>: Make sure to read the documentation of L</find> and understand the
2762 significance of the C<key> attribute, as its lack may skew your search, and
2763 subsequently result in spurious row creation.
2765 B<Note>: Because find_or_create() reads from the database and then
2766 possibly inserts based on the result, this method is subject to a race
2767 condition. Another process could create a record in the table after
2768 the find has completed and before the create has started. To avoid
2769 this problem, use find_or_create() inside a transaction.
2771 B<Note>: Take care when using C<find_or_create> with a table having
2772 columns with default values that you intend to be automatically
2773 supplied by the database (e.g. an auto_increment primary key column).
2774 In normal usage, the value of such columns should NOT be included at
2775 all in the call to C<find_or_create>, even when set to C<undef>.
2777 See also L</find> and L</update_or_create>. For information on how to declare
2778 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2780 If you need to know if an existing row was found or a new one created use
2781 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2782 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2785 my $cd = $schema->resultset('CD')->find_or_new({
2787 artist => 'Massive Attack',
2788 title => 'Mezzanine',
2792 if( !$cd->in_storage ) {
2799 sub find_or_create {
2801 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2802 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2803 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2806 return $self->create($hash);
2809 =head2 update_or_create
2813 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2815 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2819 $resultset->update_or_create({ col => $val, ... });
2821 Like L</find_or_create>, but if a row is found it is immediately updated via
2822 C<< $found_row->update (\%col_data) >>.
2825 Takes an optional C<key> attribute to search on a specific unique constraint.
2828 # In your application
2829 my $cd = $schema->resultset('CD')->update_or_create(
2831 artist => 'Massive Attack',
2832 title => 'Mezzanine',
2835 { key => 'cd_artist_title' }
2838 $cd->cd_to_producer->update_or_create({
2839 producer => $producer,
2845 B<Note>: Make sure to read the documentation of L</find> and understand the
2846 significance of the C<key> attribute, as its lack may skew your search, and
2847 subsequently result in spurious row creation.
2849 B<Note>: Take care when using C<update_or_create> with a table having
2850 columns with default values that you intend to be automatically
2851 supplied by the database (e.g. an auto_increment primary key column).
2852 In normal usage, the value of such columns should NOT be included at
2853 all in the call to C<update_or_create>, even when set to C<undef>.
2855 See also L</find> and L</find_or_create>. For information on how to declare
2856 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2858 If you need to know if an existing row was updated or a new one created use
2859 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2860 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2865 sub update_or_create {
2867 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2868 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2870 my $row = $self->find($cond, $attrs);
2872 $row->update($cond);
2876 return $self->create($cond);
2879 =head2 update_or_new
2883 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2885 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2889 $resultset->update_or_new({ col => $val, ... });
2891 Like L</find_or_new> but if a row is found it is immediately updated via
2892 C<< $found_row->update (\%col_data) >>.
2896 # In your application
2897 my $cd = $schema->resultset('CD')->update_or_new(
2899 artist => 'Massive Attack',
2900 title => 'Mezzanine',
2903 { key => 'cd_artist_title' }
2906 if ($cd->in_storage) {
2907 # the cd was updated
2910 # the cd is not yet in the database, let's insert it
2914 B<Note>: Make sure to read the documentation of L</find> and understand the
2915 significance of the C<key> attribute, as its lack may skew your search, and
2916 subsequently result in spurious new objects.
2918 B<Note>: Take care when using C<update_or_new> with a table having
2919 columns with default values that you intend to be automatically
2920 supplied by the database (e.g. an auto_increment primary key column).
2921 In normal usage, the value of such columns should NOT be included at
2922 all in the call to C<update_or_new>, even when set to C<undef>.
2924 See also L</find>, L</find_or_create> and L</find_or_new>.
2930 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2931 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2933 my $row = $self->find( $cond, $attrs );
2934 if ( defined $row ) {
2935 $row->update($cond);
2939 return $self->new_result($cond);
2946 =item Arguments: none
2948 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
2952 Gets the contents of the cache for the resultset, if the cache is set.
2954 The cache is populated either by using the L</prefetch> attribute to
2955 L</search> or by calling L</set_cache>.
2967 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2969 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2973 Sets the contents of the cache for the resultset. Expects an arrayref
2974 of objects of the same class as those produced by the resultset. Note that
2975 if the cache is set, the resultset will return the cached objects rather
2976 than re-querying the database even if the cache attr is not set.
2978 The contents of the cache can also be populated by using the
2979 L</prefetch> attribute to L</search>.
2984 my ( $self, $data ) = @_;
2985 $self->throw_exception("set_cache requires an arrayref")
2986 if defined($data) && (ref $data ne 'ARRAY');
2987 $self->{all_cache} = $data;
2994 =item Arguments: none
2996 =item Return Value: undef
3000 Clears the cache for the resultset.
3005 shift->set_cache(undef);
3012 =item Arguments: none
3014 =item Return Value: true, if the resultset has been paginated
3022 return !!$self->{attrs}{page};
3029 =item Arguments: none
3031 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3039 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3042 =head2 related_resultset
3046 =item Arguments: $rel_name
3048 =item Return Value: L<$resultset|/search>
3052 Returns a related resultset for the supplied relationship name.
3054 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3058 sub related_resultset {
3059 my ($self, $rel) = @_;
3061 return $self->{related_resultsets}{$rel} ||= do {
3062 my $rsrc = $self->result_source;
3063 my $rel_info = $rsrc->relationship_info($rel);
3065 $self->throw_exception(
3066 "search_related: result source '" . $rsrc->source_name .
3067 "' has no such relationship $rel")
3070 my $attrs = $self->_chain_relationship($rel);
3072 my $join_count = $attrs->{seen_join}{$rel};
3074 my $alias = $self->result_source->storage
3075 ->relname_to_table_alias($rel, $join_count);
3077 # since this is search_related, and we already slid the select window inwards
3078 # (the select/as attrs were deleted in the beginning), we need to flip all
3079 # left joins to inner, so we get the expected results
3080 # read the comment on top of the actual function to see what this does
3081 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3084 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3085 delete @{$attrs}{qw(result_class alias)};
3089 if (my $cache = $self->get_cache) {
3090 $related_cache = [ map
3091 { @{$_->related_resultset($rel)->get_cache||[]} }
3096 my $rel_source = $rsrc->related_source($rel);
3100 # The reason we do this now instead of passing the alias to the
3101 # search_rs below is that if you wrap/overload resultset on the
3102 # source you need to know what alias it's -going- to have for things
3103 # to work sanely (e.g. RestrictWithObject wants to be able to add
3104 # extra query restrictions, and these may need to be $alias.)
3106 my $rel_attrs = $rel_source->resultset_attributes;
3107 local $rel_attrs->{alias} = $alias;
3109 $rel_source->resultset
3113 where => $attrs->{where},
3116 $new->set_cache($related_cache) if $related_cache;
3121 =head2 current_source_alias
3125 =item Arguments: none
3127 =item Return Value: $source_alias
3131 Returns the current table alias for the result source this resultset is built
3132 on, that will be used in the SQL query. Usually it is C<me>.
3134 Currently the source alias that refers to the result set returned by a
3135 L</search>/L</find> family method depends on how you got to the resultset: it's
3136 C<me> by default, but eg. L</search_related> aliases it to the related result
3137 source name (and keeps C<me> referring to the original result set). The long
3138 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3139 (and make this method unnecessary).
3141 Thus it's currently necessary to use this method in predefined queries (see
3142 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3143 source alias of the current result set:
3145 # in a result set class
3147 my ($self, $user) = @_;
3149 my $me = $self->current_source_alias;
3151 return $self->search({
3152 "$me.modified" => $user->id,
3158 sub current_source_alias {
3159 return (shift->{attrs} || {})->{alias} || 'me';
3162 =head2 as_subselect_rs
3166 =item Arguments: none
3168 =item Return Value: L<$resultset|/search>
3172 Act as a barrier to SQL symbols. The resultset provided will be made into a
3173 "virtual view" by including it as a subquery within the from clause. From this
3174 point on, any joined tables are inaccessible to ->search on the resultset (as if
3175 it were simply where-filtered without joins). For example:
3177 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3179 # 'x' now pollutes the query namespace
3181 # So the following works as expected
3182 my $ok_rs = $rs->search({'x.other' => 1});
3184 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3185 # def) we look for one row with contradictory terms and join in another table
3186 # (aliased 'x_2') which we never use
3187 my $broken_rs = $rs->search({'x.name' => 'def'});
3189 my $rs2 = $rs->as_subselect_rs;
3191 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3192 my $not_joined_rs = $rs2->search({'x.other' => 1});
3194 # works as expected: finds a 'table' row related to two x rows (abc and def)
3195 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3197 Another example of when one might use this would be to select a subset of
3198 columns in a group by clause:
3200 my $rs = $schema->resultset('Bar')->search(undef, {
3201 group_by => [qw{ id foo_id baz_id }],
3202 })->as_subselect_rs->search(undef, {
3203 columns => [qw{ id foo_id }]
3206 In the above example normally columns would have to be equal to the group by,
3207 but because we isolated the group by into a subselect the above works.
3211 sub as_subselect_rs {
3214 my $attrs = $self->_resolved_attrs;
3216 my $fresh_rs = (ref $self)->new (
3217 $self->result_source
3220 # these pieces will be locked in the subquery
3221 delete $fresh_rs->{cond};
3222 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3224 return $fresh_rs->search( {}, {
3226 $attrs->{alias} => $self->as_query,
3227 -alias => $attrs->{alias},
3228 -rsrc => $self->result_source,
3230 alias => $attrs->{alias},
3234 # This code is called by search_related, and makes sure there
3235 # is clear separation between the joins before, during, and
3236 # after the relationship. This information is needed later
3237 # in order to properly resolve prefetch aliases (any alias
3238 # with a relation_chain_depth less than the depth of the
3239 # current prefetch is not considered)
3241 # The increments happen twice per join. An even number means a
3242 # relationship specified via a search_related, whereas an odd
3243 # number indicates a join/prefetch added via attributes
3245 # Also this code will wrap the current resultset (the one we
3246 # chain to) in a subselect IFF it contains limiting attributes
3247 sub _chain_relationship {
3248 my ($self, $rel) = @_;
3249 my $source = $self->result_source;
3250 my $attrs = { %{$self->{attrs}||{}} };
3252 # we need to take the prefetch the attrs into account before we
3253 # ->_resolve_join as otherwise they get lost - captainL
3254 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3256 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3258 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3261 my @force_subq_attrs = qw/offset rows group_by having/;
3264 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3266 $self->_has_resolved_attr (@force_subq_attrs)
3268 # Nuke the prefetch (if any) before the new $rs attrs
3269 # are resolved (prefetch is useless - we are wrapping
3270 # a subquery anyway).
3271 my $rs_copy = $self->search;
3272 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3273 $rs_copy->{attrs}{join},
3274 delete $rs_copy->{attrs}{prefetch},
3279 -alias => $attrs->{alias},
3280 $attrs->{alias} => $rs_copy->as_query,
3282 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3283 $seen->{-relation_chain_depth} = 0;
3285 elsif ($attrs->{from}) { #shallow copy suffices
3286 $from = [ @{$attrs->{from}} ];
3291 -alias => $attrs->{alias},
3292 $attrs->{alias} => $source->from,
3296 my $jpath = ($seen->{-relation_chain_depth})
3297 ? $from->[-1][0]{-join_path}
3300 my @requested_joins = $source->_resolve_join(
3307 push @$from, @requested_joins;
3309 $seen->{-relation_chain_depth}++;
3311 # if $self already had a join/prefetch specified on it, the requested
3312 # $rel might very well be already included. What we do in this case
3313 # is effectively a no-op (except that we bump up the chain_depth on
3314 # the join in question so we could tell it *is* the search_related)
3317 # we consider the last one thus reverse
3318 for my $j (reverse @requested_joins) {
3319 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3320 if ($rel eq $last_j) {
3321 $j->[0]{-relation_chain_depth}++;
3327 unless ($already_joined) {
3328 push @$from, $source->_resolve_join(
3336 $seen->{-relation_chain_depth}++;
3338 return {%$attrs, from => $from, seen_join => $seen};
3341 sub _resolved_attrs {
3343 return $self->{_attrs} if $self->{_attrs};
3345 my $attrs = { %{ $self->{attrs} || {} } };
3346 my $source = $self->result_source;
3347 my $alias = $attrs->{alias};
3349 # default selection list
3350 $attrs->{columns} = [ $source->columns ]
3351 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3353 # merge selectors together
3354 for (qw/columns select as/) {
3355 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3356 if $attrs->{$_} or $attrs->{"+$_"};
3359 # disassemble columns
3361 if (my $cols = delete $attrs->{columns}) {
3362 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3363 if (ref $c eq 'HASH') {
3364 for my $as (sort keys %$c) {
3365 push @sel, $c->{$as};
3376 # when trying to weed off duplicates later do not go past this point -
3377 # everything added from here on is unbalanced "anyone's guess" stuff
3378 my $dedup_stop_idx = $#as;
3380 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3382 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3383 if $attrs->{select};
3385 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3386 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3388 # disqualify all $alias.col as-bits (inflate-map mandated)
3389 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3391 # de-duplicate the result (remove *identical* select/as pairs)
3392 # and also die on duplicate {as} pointing to different {select}s
3393 # not using a c-style for as the condition is prone to shrinkage
3396 while ($i <= $dedup_stop_idx) {
3397 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3402 elsif ($seen->{$as[$i]}++) {
3403 $self->throw_exception(
3404 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3412 $attrs->{select} = \@sel;
3413 $attrs->{as} = \@as;
3415 $attrs->{from} ||= [{
3417 -alias => $self->{attrs}{alias},
3418 $self->{attrs}{alias} => $source->from,
3421 if ( $attrs->{join} || $attrs->{prefetch} ) {
3423 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3424 if ref $attrs->{from} ne 'ARRAY';
3426 my $join = (delete $attrs->{join}) || {};
3428 if ( defined $attrs->{prefetch} ) {
3429 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3432 $attrs->{from} = # have to copy here to avoid corrupting the original
3434 @{ $attrs->{from} },
3435 $source->_resolve_join(
3438 { %{ $attrs->{seen_join} || {} } },
3439 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3440 ? $attrs->{from}[-1][0]{-join_path}
3447 if ( defined $attrs->{order_by} ) {
3448 $attrs->{order_by} = (
3449 ref( $attrs->{order_by} ) eq 'ARRAY'
3450 ? [ @{ $attrs->{order_by} } ]
3451 : [ $attrs->{order_by} || () ]
3455 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3456 $attrs->{group_by} = [ $attrs->{group_by} ];
3459 # generate the distinct induced group_by early, as prefetch will be carried via a
3460 # subquery (since a group_by is present)
3461 if (delete $attrs->{distinct}) {
3462 if ($attrs->{group_by}) {
3463 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3466 # distinct affects only the main selection part, not what prefetch may
3468 $attrs->{group_by} = $source->storage->_group_over_selection (
3476 # generate selections based on the prefetch helper
3478 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3479 if defined $attrs->{prefetch};
3483 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3484 if $attrs->{_dark_selector};
3486 $attrs->{collapse} = 1;
3488 # this is a separate structure (we don't look in {from} directly)
3489 # as the resolver needs to shift things off the lists to work
3490 # properly (identical-prefetches on different branches)
3492 if (ref $attrs->{from} eq 'ARRAY') {
3494 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3496 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3497 next unless $j->[0]{-alias};
3498 next unless $j->[0]{-join_path};
3499 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3501 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3504 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3505 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3509 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3511 # we need to somehow mark which columns came from prefetch
3513 my $sel_end = $#{$attrs->{select}};
3514 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3517 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3518 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3521 if ( ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3522 $attrs->{_single_resultclass_inflation} = 1;
3523 $attrs->{collapse} = 0;
3526 # run through the resulting joinstructure (starting from our current slot)
3527 # and unset collapse if proven unnesessary
3529 # also while we are at it find out if the current root source has
3530 # been premultiplied by previous related_source chaining
3532 # this allows to predict whether a root object with all other relation
3533 # data set to NULL is in fact unique
3534 if ($attrs->{collapse}) {
3536 if (ref $attrs->{from} eq 'ARRAY') {
3538 if (@{$attrs->{from}} <= 1) {
3539 # no joins - no collapse
3540 $attrs->{collapse} = 0;
3543 # find where our table-spec starts
3544 my @fromlist = @{$attrs->{from}};
3546 my $t = shift @fromlist;
3549 # me vs join from-spec distinction - a ref means non-root
3550 if (ref $t eq 'ARRAY') {
3552 $is_multi ||= ! $t->{-is_single};
3554 last if ($t->{-alias} && $t->{-alias} eq $alias);
3555 $attrs->{_main_source_premultiplied} ||= $is_multi;
3558 # no non-singles remaining, nor any premultiplication - nothing to collapse
3560 ! $attrs->{_main_source_premultiplied}
3562 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3564 $attrs->{collapse} = 0;
3570 # if we can not analyze the from - err on the side of safety
3571 $attrs->{_main_source_premultiplied} = 1;
3575 # if both page and offset are specified, produce a combined offset
3576 # even though it doesn't make much sense, this is what pre 081xx has
3578 if (my $page = delete $attrs->{page}) {
3580 ($attrs->{rows} * ($page - 1))
3582 ($attrs->{offset} || 0)
3586 return $self->{_attrs} = $attrs;
3590 my ($self, $attr) = @_;
3592 if (ref $attr eq 'HASH') {
3593 return $self->_rollout_hash($attr);
3594 } elsif (ref $attr eq 'ARRAY') {
3595 return $self->_rollout_array($attr);
3601 sub _rollout_array {
3602 my ($self, $attr) = @_;
3605 foreach my $element (@{$attr}) {
3606 if (ref $element eq 'HASH') {
3607 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3608 } elsif (ref $element eq 'ARRAY') {
3609 # XXX - should probably recurse here
3610 push( @rolled_array, @{$self->_rollout_array($element)} );
3612 push( @rolled_array, $element );
3615 return \@rolled_array;
3619 my ($self, $attr) = @_;
3622 foreach my $key (keys %{$attr}) {
3623 push( @rolled_array, { $key => $attr->{$key} } );
3625 return \@rolled_array;
3628 sub _calculate_score {
3629 my ($self, $a, $b) = @_;
3631 if (defined $a xor defined $b) {
3634 elsif (not defined $a) {
3638 if (ref $b eq 'HASH') {
3639 my ($b_key) = keys %{$b};
3640 if (ref $a eq 'HASH') {
3641 my ($a_key) = keys %{$a};
3642 if ($a_key eq $b_key) {
3643 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3648 return ($a eq $b_key) ? 1 : 0;
3651 if (ref $a eq 'HASH') {
3652 my ($a_key) = keys %{$a};
3653 return ($b eq $a_key) ? 1 : 0;
3655 return ($b eq $a) ? 1 : 0;
3660 sub _merge_joinpref_attr {
3661 my ($self, $orig, $import) = @_;
3663 return $import unless defined($orig);
3664 return $orig unless defined($import);
3666 $orig = $self->_rollout_attr($orig);
3667 $import = $self->_rollout_attr($import);
3670 foreach my $import_element ( @{$import} ) {
3671 # find best candidate from $orig to merge $b_element into
3672 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3673 foreach my $orig_element ( @{$orig} ) {
3674 my $score = $self->_calculate_score( $orig_element, $import_element );
3675 if ($score > $best_candidate->{score}) {
3676 $best_candidate->{position} = $position;
3677 $best_candidate->{score} = $score;
3681 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3682 $import_key = '' if not defined $import_key;
3684 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3685 push( @{$orig}, $import_element );
3687 my $orig_best = $orig->[$best_candidate->{position}];
3688 # merge orig_best and b_element together and replace original with merged
3689 if (ref $orig_best ne 'HASH') {
3690 $orig->[$best_candidate->{position}] = $import_element;
3691 } elsif (ref $import_element eq 'HASH') {
3692 my ($key) = keys %{$orig_best};
3693 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3696 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3699 return @$orig ? $orig : ();
3707 require Hash::Merge;
3708 my $hm = Hash::Merge->new;
3710 $hm->specify_behavior({
3713 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3715 if ($defl xor $defr) {
3716 return [ $defl ? $_[0] : $_[1] ];
3721 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3725 return [$_[0], $_[1]];
3729 return $_[1] if !defined $_[0];
3730 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3731 return [$_[0], @{$_[1]}]
3734 return [] if !defined $_[0] and !keys %{$_[1]};
3735 return [ $_[1] ] if !defined $_[0];
3736 return [ $_[0] ] if !keys %{$_[1]};
3737 return [$_[0], $_[1]]
3742 return $_[0] if !defined $_[1];
3743 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3744 return [@{$_[0]}, $_[1]]
3747 my @ret = @{$_[0]} or return $_[1];
3748 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3749 my %idx = map { $_ => 1 } @ret;
3750 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3754 return [ $_[1] ] if ! @{$_[0]};
3755 return $_[0] if !keys %{$_[1]};
3756 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3757 return [ @{$_[0]}, $_[1] ];
3762 return [] if !keys %{$_[0]} and !defined $_[1];
3763 return [ $_[0] ] if !defined $_[1];
3764 return [ $_[1] ] if !keys %{$_[0]};
3765 return [$_[0], $_[1]]
3768 return [] if !keys %{$_[0]} and !@{$_[1]};
3769 return [ $_[0] ] if !@{$_[1]};
3770 return $_[1] if !keys %{$_[0]};
3771 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3772 return [ $_[0], @{$_[1]} ];
3775 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3776 return [ $_[0] ] if !keys %{$_[1]};
3777 return [ $_[1] ] if !keys %{$_[0]};
3778 return [ $_[0] ] if $_[0] eq $_[1];
3779 return [ $_[0], $_[1] ];
3782 } => 'DBIC_RS_ATTR_MERGER');
3786 return $hm->merge ($_[1], $_[2]);
3790 sub STORABLE_freeze {
3791 my ($self, $cloning) = @_;
3792 my $to_serialize = { %$self };
3794 # A cursor in progress can't be serialized (and would make little sense anyway)
3795 # the parser can be regenerated (and can't be serialized)
3796 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3798 # nor is it sensical to store a not-yet-fired-count pager
3799 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3800 delete $to_serialize->{pager};
3803 Storable::nfreeze($to_serialize);
3806 # need this hook for symmetry
3808 my ($self, $cloning, $serialized) = @_;
3810 %$self = %{ Storable::thaw($serialized) };
3816 =head2 throw_exception
3818 See L<DBIx::Class::Schema/throw_exception> for details.
3822 sub throw_exception {
3825 if (ref $self and my $rsrc = $self->result_source) {
3826 $rsrc->throw_exception(@_)
3829 DBIx::Class::Exception->throw(@_);
3837 # XXX: FIXME: Attributes docs need clearing up
3841 Attributes are used to refine a ResultSet in various ways when
3842 searching for data. They can be passed to any method which takes an
3843 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3846 Default attributes can be set on the result class using
3847 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3848 the CAVEATS on that feature before using it!)
3850 These are in no particular order:
3856 =item Value: ( $order_by | \@order_by | \%order_by )
3860 Which column(s) to order the results by.
3862 [The full list of suitable values is documented in
3863 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3866 If a single column name, or an arrayref of names is supplied, the
3867 argument is passed through directly to SQL. The hashref syntax allows
3868 for connection-agnostic specification of ordering direction:
3870 For descending order:
3872 order_by => { -desc => [qw/col1 col2 col3/] }
3874 For explicit ascending order:
3876 order_by => { -asc => 'col' }
3878 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3879 supported, although you are strongly encouraged to use the hashref
3880 syntax as outlined above.
3886 =item Value: \@columns | \%columns | $column
3890 Shortcut to request a particular set of columns to be retrieved. Each
3891 column spec may be a string (a table column name), or a hash (in which
3892 case the key is the C<as> value, and the value is used as the C<select>
3893 expression). Adds C<me.> onto the start of any column without a C<.> in
3894 it and sets C<select> from that, then auto-populates C<as> from
3895 C<select> as normal. (You may also use the C<cols> attribute, as in
3896 earlier versions of DBIC.)
3898 Essentially C<columns> does the same as L</select> and L</as>.
3900 columns => [ 'foo', { bar => 'baz' } ]
3904 select => [qw/foo baz/],
3911 =item Value: \@columns
3915 Indicates additional columns to be selected from storage. Works the same
3916 as L</columns> but adds columns to the selection. (You may also use the
3917 C<include_columns> attribute, as in earlier versions of DBIC). For
3920 $schema->resultset('CD')->search(undef, {
3921 '+columns' => ['artist.name'],
3925 would return all CDs and include a 'name' column to the information
3926 passed to object inflation. Note that the 'artist' is the name of the
3927 column (or relationship) accessor, and 'name' is the name of the column
3928 accessor in the related table.
3930 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3931 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3932 unary plus operator before it.
3934 =head2 include_columns
3938 =item Value: \@columns
3942 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3948 =item Value: \@select_columns
3952 Indicates which columns should be selected from the storage. You can use
3953 column names, or in the case of RDBMS back ends, function or stored procedure
3956 $rs = $schema->resultset('Employee')->search(undef, {
3959 { count => 'employeeid' },
3960 { max => { length => 'name' }, -as => 'longest_name' }
3965 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3967 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3968 use L</select>, to instruct DBIx::Class how to store the result of the column.
3969 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3970 identifier aliasing. You can however alias a function, so you can use it in
3971 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3972 attribute> supplied as shown in the example above.
3974 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3975 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3976 unary plus operator before it.
3982 Indicates additional columns to be selected from storage. Works the same as
3983 L</select> but adds columns to the default selection, instead of specifying
3992 =item Value: \@inflation_names
3996 Indicates column names for object inflation. That is L</as> indicates the
3997 slot name in which the column value will be stored within the
3998 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3999 identifier by the C<get_column> method (or via the object accessor B<if one
4000 with the same name already exists>) as shown below. The L</as> attribute has
4001 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4003 $rs = $schema->resultset('Employee')->search(undef, {
4006 { count => 'employeeid' },
4007 { max => { length => 'name' }, -as => 'longest_name' }
4016 If the object against which the search is performed already has an accessor
4017 matching a column name specified in C<as>, the value can be retrieved using
4018 the accessor as normal:
4020 my $name = $employee->name();
4022 If on the other hand an accessor does not exist in the object, you need to
4023 use C<get_column> instead:
4025 my $employee_count = $employee->get_column('employee_count');
4027 You can create your own accessors if required - see
4028 L<DBIx::Class::Manual::Cookbook> for details.
4034 Indicates additional column names for those added via L</+select>. See L</as>.
4042 =item Value: ($rel_name | \@rel_names | \%rel_names)
4046 Contains a list of relationships that should be joined for this query. For
4049 # Get CDs by Nine Inch Nails
4050 my $rs = $schema->resultset('CD')->search(
4051 { 'artist.name' => 'Nine Inch Nails' },
4052 { join => 'artist' }
4055 Can also contain a hash reference to refer to the other relation's relations.
4058 package MyApp::Schema::Track;
4059 use base qw/DBIx::Class/;
4060 __PACKAGE__->table('track');
4061 __PACKAGE__->add_columns(qw/trackid cd position title/);
4062 __PACKAGE__->set_primary_key('trackid');
4063 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4066 # In your application
4067 my $rs = $schema->resultset('Artist')->search(
4068 { 'track.title' => 'Teardrop' },
4070 join => { cd => 'track' },
4071 order_by => 'artist.name',
4075 You need to use the relationship (not the table) name in conditions,
4076 because they are aliased as such. The current table is aliased as "me", so
4077 you need to use me.column_name in order to avoid ambiguity. For example:
4079 # Get CDs from 1984 with a 'Foo' track
4080 my $rs = $schema->resultset('CD')->search(
4083 'tracks.name' => 'Foo'
4085 { join => 'tracks' }
4088 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4089 similarly for a third time). For e.g.
4091 my $rs = $schema->resultset('Artist')->search({
4092 'cds.title' => 'Down to Earth',
4093 'cds_2.title' => 'Popular',
4095 join => [ qw/cds cds/ ],
4098 will return a set of all artists that have both a cd with title 'Down
4099 to Earth' and a cd with title 'Popular'.
4101 If you want to fetch related objects from other tables as well, see L</prefetch>
4104 NOTE: An internal join-chain pruner will discard certain joins while
4105 constructing the actual SQL query, as long as the joins in question do not
4106 affect the retrieved result. This for example includes 1:1 left joins
4107 that are not part of the restriction specification (WHERE/HAVING) nor are
4108 a part of the query selection.
4110 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4116 =item Value: (0 | 1)
4120 When set to a true value, indicates that any rows fetched from joined has_many
4121 relationships are to be aggregated into the corresponding "parent" object. For
4122 example, the resultset:
4124 my $rs = $schema->resultset('CD')->search({}, {
4125 '+columns' => [ qw/ tracks.title tracks.position / ],
4130 While executing the following query:
4132 SELECT me.*, tracks.title, tracks.position
4134 LEFT JOIN track tracks
4135 ON tracks.cdid = me.cdid
4137 Will return only as many objects as there are rows in the CD source, even
4138 though the result of the query may span many rows. Each of these CD objects
4139 will in turn have multiple "Track" objects hidden behind the has_many
4140 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4141 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4142 product"), with each CD object containing exactly one of all fetched Track data.
4144 When a collapse is requested on a non-ordered resultset, an order by some
4145 unique part of the main source (the left-most table) is inserted automatically.
4146 This is done so that the resultset is allowed to be "lazy" - calling
4147 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4148 object with all of its related data.
4150 If an L</order_by> is already declared, and orders the resultset in a way that
4151 makes collapsing as described above impossible (e.g. C<< ORDER BY
4152 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4153 switch to "eager" mode and slurp the entire resultset before consturcting the
4154 first object returned by L</next>.
4156 Setting this attribute on a resultset that does not join any has_many
4157 relations is a no-op.
4159 For a more in-depth discussion, see L</PREFETCHING>.
4165 =item Value: ($rel_name | \@rel_names | \%rel_names)
4169 This attribute is a shorthand for specifying a L</join> spec, adding all
4170 columns from the joined related sources as L</+columns> and setting
4171 L</collapse> to a true value. For example, the following two queries are
4174 my $rs = $schema->resultset('Artist')->search({}, {
4175 prefetch => { cds => ['genre', 'tracks' ] },
4180 my $rs = $schema->resultset('Artist')->search({}, {
4181 join => { cds => ['genre', 'tracks' ] },
4185 { +{ "cds.$_" => "cds.$_" } }
4186 $schema->source('Artist')->related_source('cds')->columns
4189 { +{ "cds.genre.$_" => "genre.$_" } }
4190 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4193 { +{ "cds.tracks.$_" => "tracks.$_" } }
4194 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4199 Both producing the following SQL:
4201 SELECT me.artistid, me.name, me.rank, me.charfield,
4202 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4203 genre.genreid, genre.name,
4204 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4207 ON cds.artist = me.artistid
4208 LEFT JOIN genre genre
4209 ON genre.genreid = cds.genreid
4210 LEFT JOIN track tracks
4211 ON tracks.cd = cds.cdid
4212 ORDER BY me.artistid
4214 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4215 the arguments are properly merged and generally do the right thing. For
4216 example, you may want to do the following:
4218 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4219 { 'genre.genreid' => undef },
4221 join => { cds => 'genre' },
4226 Which generates the following SQL:
4228 SELECT me.artistid, me.name, me.rank, me.charfield,
4229 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4232 ON cds.artist = me.artistid
4233 LEFT JOIN genre genre
4234 ON genre.genreid = cds.genreid
4235 WHERE genre.genreid IS NULL
4236 ORDER BY me.artistid
4238 For a more in-depth discussion, see L</PREFETCHING>.
4244 =item Value: $source_alias
4248 Sets the source alias for the query. Normally, this defaults to C<me>, but
4249 nested search queries (sub-SELECTs) might need specific aliases set to
4250 reference inner queries. For example:
4253 ->related_resultset('CDs')
4254 ->related_resultset('Tracks')
4256 'track.id' => { -ident => 'none_search.id' },
4260 my $ids = $self->search({
4263 alias => 'none_search',
4264 group_by => 'none_search.id',
4265 })->get_column('id')->as_query;
4267 $self->search({ id => { -in => $ids } })
4269 This attribute is directly tied to L</current_source_alias>.
4279 Makes the resultset paged and specifies the page to retrieve. Effectively
4280 identical to creating a non-pages resultset and then calling ->page($page)
4283 If L</rows> attribute is not specified it defaults to 10 rows per page.
4285 When you have a paged resultset, L</count> will only return the number
4286 of rows in the page. To get the total, use the L</pager> and call
4287 C<total_entries> on it.
4297 Specifies the maximum number of rows for direct retrieval or the number of
4298 rows per page if the page attribute or method is used.
4304 =item Value: $offset
4308 Specifies the (zero-based) row number for the first row to be returned, or the
4309 of the first row of the first page if paging is used.
4311 =head2 software_limit
4315 =item Value: (0 | 1)
4319 When combined with L</rows> and/or L</offset> the generated SQL will not
4320 include any limit dialect stanzas. Instead the entire result will be selected
4321 as if no limits were specified, and DBIC will perform the limit locally, by
4322 artificially advancing and finishing the resulting L</cursor>.
4324 This is the recommended way of performing resultset limiting when no sane RDBMS
4325 implementation is available (e.g.
4326 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4327 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4333 =item Value: \@columns
4337 A arrayref of columns to group by. Can include columns of joined tables.
4339 group_by => [qw/ column1 column2 ... /]
4345 =item Value: $condition
4349 HAVING is a select statement attribute that is applied between GROUP BY and
4350 ORDER BY. It is applied to the after the grouping calculations have been
4353 having => { 'count_employee' => { '>=', 100 } }
4355 or with an in-place function in which case literal SQL is required:
4357 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4363 =item Value: (0 | 1)
4367 Set to 1 to group by all columns. If the resultset already has a group_by
4368 attribute, this setting is ignored and an appropriate warning is issued.
4374 Adds to the WHERE clause.
4376 # only return rows WHERE deleted IS NULL for all searches
4377 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4379 Can be overridden by passing C<< { where => undef } >> as an attribute
4382 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4388 Set to 1 to cache search results. This prevents extra SQL queries if you
4389 revisit rows in your ResultSet:
4391 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4393 while( my $artist = $resultset->next ) {
4397 $rs->first; # without cache, this would issue a query
4399 By default, searches are not cached.
4401 For more examples of using these attributes, see
4402 L<DBIx::Class::Manual::Cookbook>.
4408 =item Value: ( 'update' | 'shared' | \$scalar )
4412 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4413 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4418 DBIx::Class supports arbitrary related data prefetching from multiple related
4419 sources. Any combination of relationship types and column sets are supported.
4420 If L<collapsing|/collapse> is requested, there is an additional requirement of
4421 selecting enough data to make every individual object uniquely identifiable.
4423 Here are some more involved examples, based on the following relationship map:
4426 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4427 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4428 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4430 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4432 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4436 my $rs = $schema->resultset('Tag')->search(
4445 The initial search results in SQL like the following:
4447 SELECT tag.*, cd.*, artist.* FROM tag
4448 JOIN cd ON tag.cd = cd.cdid
4449 JOIN artist ON cd.artist = artist.artistid
4451 L<DBIx::Class> has no need to go back to the database when we access the
4452 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4455 Simple prefetches will be joined automatically, so there is no need
4456 for a C<join> attribute in the above search.
4458 The L</prefetch> attribute can be used with any of the relationship types
4459 and multiple prefetches can be specified together. Below is a more complex
4460 example that prefetches a CD's artist, its liner notes (if present),
4461 the cover image, the tracks on that CD, and the guests on those
4464 my $rs = $schema->resultset('CD')->search(
4468 { artist => 'record_label'}, # belongs_to => belongs_to
4469 'liner_note', # might_have
4470 'cover_image', # has_one
4471 { tracks => 'guests' }, # has_many => has_many
4476 This will produce SQL like the following:
4478 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4482 ON artist.artistid = me.artistid
4483 JOIN record_label record_label
4484 ON record_label.labelid = artist.labelid
4485 LEFT JOIN track tracks
4486 ON tracks.cdid = me.cdid
4487 LEFT JOIN guest guests
4488 ON guests.trackid = track.trackid
4489 LEFT JOIN liner_notes liner_note
4490 ON liner_note.cdid = me.cdid
4491 JOIN cd_artwork cover_image
4492 ON cover_image.cdid = me.cdid
4495 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4496 C<tracks>, and C<guests> of the CD will all be available through the
4497 relationship accessors without the need for additional queries to the
4502 Prefetch does a lot of deep magic. As such, it may not behave exactly
4503 as you might expect.
4509 Prefetch uses the L</cache> to populate the prefetched relationships. This
4510 may or may not be what you want.
4514 If you specify a condition on a prefetched relationship, ONLY those
4515 rows that match the prefetched condition will be fetched into that relationship.
4516 This means that adding prefetch to a search() B<may alter> what is returned by
4517 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4519 my $artist_rs = $schema->resultset('Artist')->search({
4525 my $count = $artist_rs->first->cds->count;
4527 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4529 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4531 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4533 That cmp_ok() may or may not pass depending on the datasets involved. In other
4534 words the C<WHERE> condition would apply to the entire dataset, just like
4535 it would in regular SQL. If you want to add a condition only to the "right side"
4536 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4537 condition|DBIx::Class::Relationship::Base/condition>
4541 =head1 DBIC BIND VALUES
4543 Because DBIC may need more information to bind values than just the column name
4544 and value itself, it uses a special format for both passing and receiving bind
4545 values. Each bind value should be composed of an arrayref of
4546 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4552 If present (in any form), this is what is being passed directly to bind_param.
4553 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4554 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4556 If this is specified, all other bind options described below are ignored.
4560 If present, this is used to infer the actual bind attribute by passing to
4561 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4562 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4564 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4565 currently drivers are expected to "Do the Right Thing" when given a common
4566 datatype name. (Not ideal, but that's what we got at this point.)
4570 Currently used to correctly allocate buffers for bind_param_inout().
4571 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4572 or to a sensible value based on the "data_type".
4576 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4577 explicitly specified they are never overriden). Also used by some weird DBDs,
4578 where the column name should be available at bind_param time (e.g. Oracle).
4582 For backwards compatibility and convenience, the following shortcuts are
4585 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4586 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4587 [ undef, $val ] === [ {}, $val ]
4589 =head1 AUTHOR AND CONTRIBUTORS
4591 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4595 You may distribute this code under the same terms as Perl itself.