1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::Exception;
8 use DBIx::Class::ResultSetColumn;
9 use Scalar::Util qw/blessed weaken/;
11 use Data::Compare (); # no imports!!! guard against insane architecture
13 # not importing first() as it will clash with our own method
17 # De-duplication in _merge_attr() is disabled, but left in for reference
18 # (the merger is used for other things that ought not to be de-duped)
19 *__HM_DEDUP = sub () { 0 };
29 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
33 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
37 my $users_rs = $schema->resultset('User');
38 while( $user = $users_rs->next) {
39 print $user->username;
42 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
43 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
47 A ResultSet is an object which stores a set of conditions representing
48 a query. It is the backbone of DBIx::Class (i.e. the really
49 important/useful bit).
51 No SQL is executed on the database when a ResultSet is created, it
52 just stores all the conditions needed to create the query.
54 A basic ResultSet representing the data of an entire table is returned
55 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
56 L<Source|DBIx::Class::Manual::Glossary/Source> name.
58 my $users_rs = $schema->resultset('User');
60 A new ResultSet is returned from calling L</search> on an existing
61 ResultSet. The new one will contain all the conditions of the
62 original, plus any new conditions added in the C<search> call.
64 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
65 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
68 The query that the ResultSet represents is B<only> executed against
69 the database when these methods are called:
70 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
72 If a resultset is used in a numeric context it returns the L</count>.
73 However, if it is used in a boolean context it is B<always> true. So if
74 you want to check if a resultset has any results, you must use C<if $rs
77 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
79 If you want to make your custom ResultSet classes with L<Moose>, use a template
82 package MyApp::Schema::ResultSet::User;
85 use namespace::autoclean;
87 extends 'DBIx::Class::ResultSet';
89 sub BUILDARGS { $_[2] }
93 __PACKAGE__->meta->make_immutable;
97 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
98 clash with the regular ResultSet constructor. Alternatively, you can use:
100 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
102 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
103 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
107 =head2 Chaining resultsets
109 Let's say you've got a query that needs to be run to return some data
110 to the user. But, you have an authorization system in place that
111 prevents certain users from seeing certain information. So, you want
112 to construct the basic query in one method, but add constraints to it in
117 my $request = $self->get_request; # Get a request object somehow.
118 my $schema = $self->result_source->schema;
120 my $cd_rs = $schema->resultset('CD')->search({
121 title => $request->param('title'),
122 year => $request->param('year'),
125 $cd_rs = $self->apply_security_policy( $cd_rs );
127 return $cd_rs->all();
130 sub apply_security_policy {
139 =head3 Resolving conditions and attributes
141 When a resultset is chained from another resultset, conditions and
142 attributes with the same keys need resolving.
144 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
145 into the existing ones from the original resultset.
147 The L</where> and L</having> attributes, and any search conditions, are
148 merged with an SQL C<AND> to the existing condition from the original
151 All other attributes are overridden by any new ones supplied in the
154 =head2 Multiple queries
156 Since a resultset just defines a query, you can do all sorts of
157 things with it with the same object.
159 # Don't hit the DB yet.
160 my $cd_rs = $schema->resultset('CD')->search({
161 title => 'something',
165 # Each of these hits the DB individually.
166 my $count = $cd_rs->count;
167 my $most_recent = $cd_rs->get_column('date_released')->max();
168 my @records = $cd_rs->all;
170 And it's not just limited to SELECT statements.
176 $cd_rs->create({ artist => 'Fred' });
178 Which is the same as:
180 $schema->resultset('CD')->create({
181 title => 'something',
186 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
194 =item Arguments: $source, \%$attrs
196 =item Return Value: $rs
200 The resultset constructor. Takes a source object (usually a
201 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
202 L</ATTRIBUTES> below). Does not perform any queries -- these are
203 executed as needed by the other methods.
205 Generally you won't need to construct a resultset manually. You'll
206 automatically get one from e.g. a L</search> called in scalar context:
208 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
210 IMPORTANT: If called on an object, proxies to new_result instead so
212 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
214 will return a CD object, not a ResultSet.
220 return $class->new_result(@_) if ref $class;
222 my ($source, $attrs) = @_;
223 $source = $source->resolve
224 if $source->isa('DBIx::Class::ResultSourceHandle');
225 $attrs = { %{$attrs||{}} };
227 if ($attrs->{page}) {
228 $attrs->{rows} ||= 10;
231 $attrs->{alias} ||= 'me';
234 result_source => $source,
235 cond => $attrs->{where},
240 # if there is a dark selector, this means we are already in a
241 # chain and the cleanup/sanification was taken care of by
243 $self->_normalize_selection($attrs)
244 unless $attrs->{_dark_selector};
247 $attrs->{result_class} || $source->result_class
257 =item Arguments: $cond, \%attrs?
259 =item Return Value: $resultset (scalar context) || @row_objs (list context)
263 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
264 my $new_rs = $cd_rs->search({ year => 2005 });
266 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
267 # year = 2005 OR year = 2004
269 In list context, C<< ->all() >> is called implicitly on the resultset, thus
270 returning a list of row objects instead. To avoid that, use L</search_rs>.
272 If you need to pass in additional attributes but no additional condition,
273 call it as C<search(undef, \%attrs)>.
275 # "SELECT name, artistid FROM $artist_table"
276 my @all_artists = $schema->resultset('Artist')->search(undef, {
277 columns => [qw/name artistid/],
280 For a list of attributes that can be passed to C<search>, see
281 L</ATTRIBUTES>. For more examples of using this function, see
282 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
283 documentation for the first argument, see L<SQL::Abstract>
284 and its extension L<DBIx::Class::SQLMaker>.
286 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
290 Note that L</search> does not process/deflate any of the values passed in the
291 L<SQL::Abstract>-compatible search condition structure. This is unlike other
292 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
293 manually that any value passed to this method will stringify to something the
294 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
295 objects, for more info see:
296 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
302 my $rs = $self->search_rs( @_ );
307 elsif (defined wantarray) {
311 # we can be called by a relationship helper, which in
312 # turn may be called in void context due to some braindead
313 # overload or whatever else the user decided to be clever
314 # at this particular day. Thus limit the exception to
315 # external code calls only
316 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
317 if (caller)[0] !~ /^\QDBIx::Class::/;
327 =item Arguments: $cond, \%attrs?
329 =item Return Value: $resultset
333 This method does the same exact thing as search() except it will
334 always return a resultset, even in list context.
341 # Special-case handling for (undef, undef).
342 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
348 if (ref $_[-1] eq 'HASH') {
349 # copy for _normalize_selection
350 $call_attrs = { %{ pop @_ } };
352 elsif (! defined $_[-1] ) {
353 pop @_; # search({}, undef)
357 # see if we can keep the cache (no $rs changes)
359 my %safe = (alias => 1, cache => 1);
360 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
363 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
365 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
367 $cache = $self->get_cache;
370 my $rsrc = $self->result_source;
372 my $old_attrs = { %{$self->{attrs}} };
373 my $old_having = delete $old_attrs->{having};
374 my $old_where = delete $old_attrs->{where};
376 my $new_attrs = { %$old_attrs };
378 # take care of call attrs (only if anything is changing)
379 if (keys %$call_attrs) {
381 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
383 # reset the current selector list if new selectors are supplied
384 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
385 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
388 # Normalize the new selector list (operates on the passed-in attr structure)
389 # Need to do it on every chain instead of only once on _resolved_attrs, in
390 # order to allow detection of empty vs partial 'as'
391 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
392 if $old_attrs->{_dark_selector};
393 $self->_normalize_selection ($call_attrs);
395 # start with blind overwriting merge, exclude selector attrs
396 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
397 delete @{$new_attrs}{@selector_attrs};
399 for (@selector_attrs) {
400 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
401 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
404 # older deprecated name, use only if {columns} is not there
405 if (my $c = delete $new_attrs->{cols}) {
406 if ($new_attrs->{columns}) {
407 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
410 $new_attrs->{columns} = $c;
415 # join/prefetch use their own crazy merging heuristics
416 foreach my $key (qw/join prefetch/) {
417 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
418 if exists $call_attrs->{$key};
421 # stack binds together
422 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
426 # rip apart the rest of @_, parse a condition
429 if (ref $_[0] eq 'HASH') {
430 (keys %{$_[0]}) ? $_[0] : undef
436 $self->throw_exception('Odd number of arguments to search')
444 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
445 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
448 for ($old_where, $call_cond) {
450 $new_attrs->{where} = $self->_stack_cond (
451 $_, $new_attrs->{where}
456 if (defined $old_having) {
457 $new_attrs->{having} = $self->_stack_cond (
458 $old_having, $new_attrs->{having}
462 my $rs = (ref $self)->new($rsrc, $new_attrs);
464 $rs->set_cache($cache) if ($cache);
470 sub _normalize_selection {
471 my ($self, $attrs) = @_;
474 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
475 if exists $attrs->{include_columns};
477 # columns are always placed first, however
479 # Keep the X vs +X separation until _resolved_attrs time - this allows to
480 # delay the decision on whether to use a default select list ($rsrc->columns)
481 # allowing stuff like the remove_columns helper to work
483 # select/as +select/+as pairs need special handling - the amount of select/as
484 # elements in each pair does *not* have to be equal (think multicolumn
485 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
486 # supplied at all) - try to infer the alias, either from the -as parameter
487 # of the selector spec, or use the parameter whole if it looks like a column
488 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
489 # is ok as well), but make sure no more additions to the 'as' chain take place
490 for my $pref ('', '+') {
492 my ($sel, $as) = map {
493 my $key = "${pref}${_}";
495 my $val = [ ref $attrs->{$key} eq 'ARRAY'
497 : $attrs->{$key} || ()
499 delete $attrs->{$key};
503 if (! @$as and ! @$sel ) {
506 elsif (@$as and ! @$sel) {
507 $self->throw_exception(
508 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
512 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
513 # if any @$as has been supplied we assume the user knows what (s)he is doing
514 # and blindly keep stacking up pieces
515 unless ($attrs->{_dark_selector}) {
518 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
519 push @$as, $_->{-as};
521 # assume any plain no-space, no-parenthesis string to be a column spec
522 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
523 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
526 # if all else fails - raise a flag that no more aliasing will be allowed
528 $attrs->{_dark_selector} = {
530 string => ($dark_sel_dumper ||= do {
531 require Data::Dumper::Concise;
532 Data::Dumper::Concise::DumperObject()->Indent(0);
533 })->Values([$_])->Dump
541 elsif (@$as < @$sel) {
542 $self->throw_exception(
543 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
546 elsif ($pref and $attrs->{_dark_selector}) {
547 $self->throw_exception(
548 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
554 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
555 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
560 my ($self, $left, $right) = @_;
562 # collapse single element top-level conditions
563 # (single pass only, unlikely to need recursion)
564 for ($left, $right) {
565 if (ref $_ eq 'ARRAY') {
573 elsif (ref $_ eq 'HASH') {
574 my ($first, $more) = keys %$_;
577 if (! defined $first) {
581 elsif (! defined $more) {
582 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
585 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
592 # merge hashes with weeding out of duplicates (simple cases only)
593 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
595 # shallow copy to destroy
596 $right = { %$right };
597 for (grep { exists $right->{$_} } keys %$left) {
598 # the use of eq_deeply here is justified - the rhs of an
599 # expression can contain a lot of twisted weird stuff
600 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
603 $right = undef unless keys %$right;
607 if (defined $left xor defined $right) {
608 return defined $left ? $left : $right;
610 elsif (! defined $left) {
614 return { -and => [ $left, $right ] };
618 =head2 search_literal
622 =item Arguments: $sql_fragment, @bind_values
624 =item Return Value: $resultset (scalar context) || @row_objs (list context)
628 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
629 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
631 Pass a literal chunk of SQL to be added to the conditional part of the
634 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
635 only be used in that context. C<search_literal> is a convenience method.
636 It is equivalent to calling $schema->search(\[]), but if you want to ensure
637 columns are bound correctly, use C<search>.
639 Example of how to use C<search> instead of C<search_literal>
641 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
642 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
645 See L<DBIx::Class::Manual::Cookbook/Searching> and
646 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
647 require C<search_literal>.
652 my ($self, $sql, @bind) = @_;
654 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
657 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
664 =item Arguments: \%columns_values | @pk_values, \%attrs?
666 =item Return Value: $row_object | undef
670 Finds and returns a single row based on supplied criteria. Takes either a
671 hashref with the same format as L</create> (including inference of foreign
672 keys from related objects), or a list of primary key values in the same
673 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
674 declaration on the L</result_source>.
676 In either case an attempt is made to combine conditions already existing on
677 the resultset with the condition passed to this method.
679 To aid with preparing the correct query for the storage you may supply the
680 C<key> attribute, which is the name of a
681 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
682 unique constraint corresponding to the
683 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
684 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
685 to construct a query that satisfies the named unique constraint fully (
686 non-NULL values for each column member of the constraint) an exception is
689 If no C<key> is specified, the search is carried over all unique constraints
690 which are fully defined by the available condition.
692 If no such constraint is found, C<find> currently defaults to a simple
693 C<< search->(\%column_values) >> which may or may not do what you expect.
694 Note that this fallback behavior may be deprecated in further versions. If
695 you need to search with arbitrary conditions - use L</search>. If the query
696 resulting from this fallback produces more than one row, a warning to the
697 effect is issued, though only the first row is constructed and returned as
700 In addition to C<key>, L</find> recognizes and applies standard
701 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
703 Note that if you have extra concerns about the correctness of the resulting
704 query you need to specify the C<key> attribute and supply the entire condition
705 as an argument to find (since it is not always possible to perform the
706 combination of the resultset condition with the supplied one, especially if
707 the resultset condition contains literal sql).
709 For example, to find a row by its primary key:
711 my $cd = $schema->resultset('CD')->find(5);
713 You can also find a row by a specific unique constraint:
715 my $cd = $schema->resultset('CD')->find(
717 artist => 'Massive Attack',
718 title => 'Mezzanine',
720 { key => 'cd_artist_title' }
723 See also L</find_or_create> and L</update_or_create>.
729 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
731 my $rsrc = $self->result_source;
734 if (exists $attrs->{key}) {
735 $constraint_name = defined $attrs->{key}
737 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
741 # Parse out the condition from input
744 if (ref $_[0] eq 'HASH') {
745 $call_cond = { %{$_[0]} };
748 # if only values are supplied we need to default to 'primary'
749 $constraint_name = 'primary' unless defined $constraint_name;
751 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
753 $self->throw_exception(
754 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
757 $self->throw_exception (
758 'find() expects either a column/value hashref, or a list of values '
759 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
760 ) unless @c_cols == @_;
763 @{$call_cond}{@c_cols} = @_;
767 for my $key (keys %$call_cond) {
769 my $keyref = ref($call_cond->{$key})
771 my $relinfo = $rsrc->relationship_info($key)
773 my $val = delete $call_cond->{$key};
775 next if $keyref eq 'ARRAY'; # has_many for multi_create
777 my $rel_q = $rsrc->_resolve_condition(
778 $relinfo->{cond}, $val, $key, $key
780 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
781 @related{keys %$rel_q} = values %$rel_q;
785 # relationship conditions take precedence (?)
786 @{$call_cond}{keys %related} = values %related;
788 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
790 if (defined $constraint_name) {
791 $final_cond = $self->_qualify_cond_columns (
793 $self->_build_unique_cond (
801 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
802 # This means that we got here after a merger of relationship conditions
803 # in ::Relationship::Base::search_related (the row method), and furthermore
804 # the relationship is of the 'single' type. This means that the condition
805 # provided by the relationship (already attached to $self) is sufficient,
806 # as there can be only one row in the database that would satisfy the
810 # no key was specified - fall down to heuristics mode:
811 # run through all unique queries registered on the resultset, and
812 # 'OR' all qualifying queries together
813 my (@unique_queries, %seen_column_combinations);
814 for my $c_name ($rsrc->unique_constraint_names) {
815 next if $seen_column_combinations{
816 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
819 push @unique_queries, try {
820 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
824 $final_cond = @unique_queries
825 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
826 : $self->_non_unique_find_fallback ($call_cond, $attrs)
830 # Run the query, passing the result_class since it should propagate for find
831 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
832 if (keys %{$rs->_resolved_attrs->{collapse}}) {
834 carp "Query returned more than one row" if $rs->next;
842 # This is a stop-gap method as agreed during the discussion on find() cleanup:
843 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
845 # It is invoked when find() is called in legacy-mode with insufficiently-unique
846 # condition. It is provided for overrides until a saner way forward is devised
848 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
849 # the road. Please adjust your tests accordingly to catch this situation early
850 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
852 # The method will not be removed without an adequately complete replacement
853 # for strict-mode enforcement
854 sub _non_unique_find_fallback {
855 my ($self, $cond, $attrs) = @_;
857 return $self->_qualify_cond_columns(
859 exists $attrs->{alias}
861 : $self->{attrs}{alias}
866 sub _qualify_cond_columns {
867 my ($self, $cond, $alias) = @_;
869 my %aliased = %$cond;
870 for (keys %aliased) {
871 $aliased{"$alias.$_"} = delete $aliased{$_}
878 sub _build_unique_cond {
879 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
881 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
883 # combination may fail if $self->{cond} is non-trivial
884 my ($final_cond) = try {
885 $self->_merge_with_rscond ($extra_cond)
890 # trim out everything not in $columns
891 $final_cond = { map {
892 exists $final_cond->{$_}
893 ? ( $_ => $final_cond->{$_} )
897 if (my @missing = grep
898 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
901 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
903 join (', ', map { "'$_'" } @missing),
910 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
912 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
914 carp_unique ( sprintf (
915 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
916 . 'values in column(s): %s). This is almost certainly not what you wanted, '
917 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
919 join (', ', map { "'$_'" } @undefs),
926 =head2 search_related
930 =item Arguments: $rel, $cond, \%attrs?
932 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
936 $new_rs = $cd_rs->search_related('artist', {
940 Searches the specified relationship, optionally specifying a condition and
941 attributes for matching records. See L</ATTRIBUTES> for more information.
943 In list context, C<< ->all() >> is called implicitly on the resultset, thus
944 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
946 See also L</search_related_rs>.
951 return shift->related_resultset(shift)->search(@_);
954 =head2 search_related_rs
956 This method works exactly the same as search_related, except that
957 it guarantees a resultset, even in list context.
961 sub search_related_rs {
962 return shift->related_resultset(shift)->search_rs(@_);
969 =item Arguments: none
971 =item Return Value: $cursor
975 Returns a storage-driven cursor to the given resultset. See
976 L<DBIx::Class::Cursor> for more information.
983 my $attrs = $self->_resolved_attrs_copy;
985 return $self->{cursor}
986 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
987 $attrs->{where},$attrs);
994 =item Arguments: $cond?
996 =item Return Value: $row_object | undef
1000 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1002 Inflates the first result without creating a cursor if the resultset has
1003 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1006 While this method can take an optional search condition (just like L</search>)
1007 being a fast-code-path it does not recognize search attributes. If you need to
1008 add extra joins or similar, call L</search> and then chain-call L</single> on the
1009 L<DBIx::Class::ResultSet> returned.
1015 As of 0.08100, this method enforces the assumption that the preceding
1016 query returns only one row. If more than one row is returned, you will receive
1019 Query returned more than one row
1021 In this case, you should be using L</next> or L</find> instead, or if you really
1022 know what you are doing, use the L</rows> attribute to explicitly limit the size
1025 This method will also throw an exception if it is called on a resultset prefetching
1026 has_many, as such a prefetch implies fetching multiple rows from the database in
1027 order to assemble the resulting object.
1034 my ($self, $where) = @_;
1036 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1039 my $attrs = $self->_resolved_attrs_copy;
1041 if (keys %{$attrs->{collapse}}) {
1042 $self->throw_exception(
1043 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
1048 if (defined $attrs->{where}) {
1051 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1052 $where, delete $attrs->{where} ]
1055 $attrs->{where} = $where;
1059 my @data = $self->result_source->storage->select_single(
1060 $attrs->{from}, $attrs->{select},
1061 $attrs->{where}, $attrs
1064 return (@data ? ($self->_construct_object(@data))[0] : undef);
1070 # Recursively collapse the query, accumulating values for each column.
1072 sub _collapse_query {
1073 my ($self, $query, $collapsed) = @_;
1077 if (ref $query eq 'ARRAY') {
1078 foreach my $subquery (@$query) {
1079 next unless ref $subquery; # -or
1080 $collapsed = $self->_collapse_query($subquery, $collapsed);
1083 elsif (ref $query eq 'HASH') {
1084 if (keys %$query and (keys %$query)[0] eq '-and') {
1085 foreach my $subquery (@{$query->{-and}}) {
1086 $collapsed = $self->_collapse_query($subquery, $collapsed);
1090 foreach my $col (keys %$query) {
1091 my $value = $query->{$col};
1092 $collapsed->{$col}{$value}++;
1104 =item Arguments: $cond?
1106 =item Return Value: $resultsetcolumn
1110 my $max_length = $rs->get_column('length')->max;
1112 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1117 my ($self, $column) = @_;
1118 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1126 =item Arguments: $cond, \%attrs?
1128 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1132 # WHERE title LIKE '%blue%'
1133 $cd_rs = $rs->search_like({ title => '%blue%'});
1135 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1136 that this is simply a convenience method retained for ex Class::DBI users.
1137 You most likely want to use L</search> with specific operators.
1139 For more information, see L<DBIx::Class::Manual::Cookbook>.
1141 This method is deprecated and will be removed in 0.09. Use L</search()>
1142 instead. An example conversion is:
1144 ->search_like({ foo => 'bar' });
1148 ->search({ foo => { like => 'bar' } });
1155 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1156 .' Instead use ->search({ x => { -like => "y%" } })'
1157 .' (note the outer pair of {}s - they are important!)'
1159 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1160 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1161 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1162 return $class->search($query, { %$attrs });
1169 =item Arguments: $first, $last
1171 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1175 Returns a resultset or object list representing a subset of elements from the
1176 resultset slice is called on. Indexes are from 0, i.e., to get the first
1177 three records, call:
1179 my ($one, $two, $three) = $rs->slice(0, 2);
1184 my ($self, $min, $max) = @_;
1185 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1186 $attrs->{offset} = $self->{attrs}{offset} || 0;
1187 $attrs->{offset} += $min;
1188 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1189 return $self->search(undef, $attrs);
1190 #my $slice = (ref $self)->new($self->result_source, $attrs);
1191 #return (wantarray ? $slice->all : $slice);
1198 =item Arguments: none
1200 =item Return Value: $result | undef
1204 Returns the next element in the resultset (C<undef> is there is none).
1206 Can be used to efficiently iterate over records in the resultset:
1208 my $rs = $schema->resultset('CD')->search;
1209 while (my $cd = $rs->next) {
1213 Note that you need to store the resultset object, and call C<next> on it.
1214 Calling C<< resultset('Table')->next >> repeatedly will always return the
1215 first record from the resultset.
1221 if (my $cache = $self->get_cache) {
1222 $self->{all_cache_position} ||= 0;
1223 return $cache->[$self->{all_cache_position}++];
1225 if ($self->{attrs}{cache}) {
1226 delete $self->{pager};
1227 $self->{all_cache_position} = 1;
1228 return ($self->all)[0];
1230 if ($self->{stashed_objects}) {
1231 my $obj = shift(@{$self->{stashed_objects}});
1232 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1236 exists $self->{stashed_row}
1237 ? @{delete $self->{stashed_row}}
1238 : $self->cursor->next
1240 return undef unless (@row);
1241 my ($row, @more) = $self->_construct_object(@row);
1242 $self->{stashed_objects} = \@more if @more;
1246 sub _construct_object {
1247 my ($self, @row) = @_;
1249 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1251 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1252 @new = $self->{_attrs}{record_filter}->(@new)
1253 if exists $self->{_attrs}{record_filter};
1257 sub _collapse_result {
1258 my ($self, $as_proto, $row) = @_;
1262 # 'foo' => [ undef, 'foo' ]
1263 # 'foo.bar' => [ 'foo', 'bar' ]
1264 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1266 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1268 my %collapse = %{$self->{_attrs}{collapse}||{}};
1272 # if we're doing collapsing (has_many prefetch) we need to grab records
1273 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1274 # we know we don't have to bother.
1276 # the reason for not using the collapse stuff directly is because if you
1277 # had for e.g. two artists in a row with no cds, the collapse info for
1278 # both would be NULL (undef) so you'd lose the second artist
1280 # store just the index so we can check the array positions from the row
1281 # without having to contruct the full hash
1283 if (keys %collapse) {
1284 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1285 foreach my $i (0 .. $#construct_as) {
1286 next if defined($construct_as[$i][0]); # only self table
1287 if (delete $pri{$construct_as[$i][1]}) {
1288 push(@pri_index, $i);
1290 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1294 # no need to do an if, it'll be empty if @pri_index is empty anyway
1296 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1300 do { # no need to check anything at the front, we always want the first row
1304 foreach my $this_as (@construct_as) {
1305 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1308 push(@const_rows, \%const);
1310 } until ( # no pri_index => no collapse => drop straight out
1313 do { # get another row, stash it, drop out if different PK
1315 @copy = $self->cursor->next;
1316 $self->{stashed_row} = \@copy;
1318 # last thing in do block, counts as true if anything doesn't match
1320 # check xor defined first for NULL vs. NOT NULL then if one is
1321 # defined the other must be so check string equality
1324 (defined $pri_vals{$_} ^ defined $copy[$_])
1325 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1330 my $alias = $self->{attrs}{alias};
1337 foreach my $const (@const_rows) {
1338 scalar @const_keys or do {
1339 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1341 foreach my $key (@const_keys) {
1344 my @parts = split(/\./, $key);
1346 my $data = $const->{$key};
1347 foreach my $p (@parts) {
1348 $target = $target->[1]->{$p} ||= [];
1350 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1351 # collapsing at this point and on final part
1352 my $pos = $collapse_pos{$cur};
1353 CK: foreach my $ck (@ckey) {
1354 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1355 $collapse_pos{$cur} = $data;
1356 delete @collapse_pos{ # clear all positioning for sub-entries
1357 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1364 if (exists $collapse{$cur}) {
1365 $target = $target->[-1];
1368 $target->[0] = $data;
1370 $info->[0] = $const->{$key};
1378 =head2 result_source
1382 =item Arguments: $result_source?
1384 =item Return Value: $result_source
1388 An accessor for the primary ResultSource object from which this ResultSet
1395 =item Arguments: $result_class?
1397 =item Return Value: $result_class
1401 An accessor for the class to use when creating row objects. Defaults to
1402 C<< result_source->result_class >> - which in most cases is the name of the
1403 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1405 Note that changing the result_class will also remove any components
1406 that were originally loaded in the source class via
1407 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1408 in the original source class will not run.
1413 my ($self, $result_class) = @_;
1414 if ($result_class) {
1415 unless (ref $result_class) { # don't fire this for an object
1416 $self->ensure_class_loaded($result_class);
1418 $self->_result_class($result_class);
1419 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1420 # permit the user to set result class on one result set only; it only
1421 # chains if provided to search()
1422 #$self->{attrs}{result_class} = $result_class if ref $self;
1424 $self->_result_class;
1431 =item Arguments: $cond, \%attrs??
1433 =item Return Value: $count
1437 Performs an SQL C<COUNT> with the same query as the resultset was built
1438 with to find the number of elements. Passing arguments is equivalent to
1439 C<< $rs->search ($cond, \%attrs)->count >>
1445 return $self->search(@_)->count if @_ and defined $_[0];
1446 return scalar @{ $self->get_cache } if $self->get_cache;
1448 my $attrs = $self->_resolved_attrs_copy;
1450 # this is a little optimization - it is faster to do the limit
1451 # adjustments in software, instead of a subquery
1452 my $rows = delete $attrs->{rows};
1453 my $offset = delete $attrs->{offset};
1456 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1457 $crs = $self->_count_subq_rs ($attrs);
1460 $crs = $self->_count_rs ($attrs);
1462 my $count = $crs->next;
1464 $count -= $offset if $offset;
1465 $count = $rows if $rows and $rows < $count;
1466 $count = 0 if ($count < 0);
1475 =item Arguments: $cond, \%attrs??
1477 =item Return Value: $count_rs
1481 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1482 This can be very handy for subqueries:
1484 ->search( { amount => $some_rs->count_rs->as_query } )
1486 As with regular resultsets the SQL query will be executed only after
1487 the resultset is accessed via L</next> or L</all>. That would return
1488 the same single value obtainable via L</count>.
1494 return $self->search(@_)->count_rs if @_;
1496 # this may look like a lack of abstraction (count() does about the same)
1497 # but in fact an _rs *must* use a subquery for the limits, as the
1498 # software based limiting can not be ported if this $rs is to be used
1499 # in a subquery itself (i.e. ->as_query)
1500 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1501 return $self->_count_subq_rs;
1504 return $self->_count_rs;
1509 # returns a ResultSetColumn object tied to the count query
1512 my ($self, $attrs) = @_;
1514 my $rsrc = $self->result_source;
1515 $attrs ||= $self->_resolved_attrs;
1517 my $tmp_attrs = { %$attrs };
1518 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1519 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1521 # overwrite the selector (supplied by the storage)
1522 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1523 $tmp_attrs->{as} = 'count';
1524 delete @{$tmp_attrs}{qw/columns/};
1526 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1532 # same as above but uses a subquery
1534 sub _count_subq_rs {
1535 my ($self, $attrs) = @_;
1537 my $rsrc = $self->result_source;
1538 $attrs ||= $self->_resolved_attrs;
1540 my $sub_attrs = { %$attrs };
1541 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1542 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1544 # if we multi-prefetch we group_by primary keys only as this is what we would
1545 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1546 if ( keys %{$attrs->{collapse}} ) {
1547 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1550 # Calculate subquery selector
1551 if (my $g = $sub_attrs->{group_by}) {
1553 my $sql_maker = $rsrc->storage->sql_maker;
1555 # necessary as the group_by may refer to aliased functions
1557 for my $sel (@{$attrs->{select}}) {
1558 $sel_index->{$sel->{-as}} = $sel
1559 if (ref $sel eq 'HASH' and $sel->{-as});
1562 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1563 # also look for named aggregates referred in the having clause
1564 # having often contains scalarrefs - thus parse it out entirely
1566 if ($attrs->{having}) {
1567 local $sql_maker->{having_bind};
1568 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1569 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1570 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1571 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1572 # if we don't unset it we screw up retarded but unfortunately working
1573 # 'MAX(foo.bar)' => { '>', 3 }
1574 $sql_maker->{name_sep} = '';
1577 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1579 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1581 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1582 # and if all fails for an utterly naive quoted scalar-with-function
1584 $rquote $sep $lquote (.+?) $rquote
1586 [\s,] \w+ \. (\w+) [\s,]
1588 [\s,] $lquote (.+?) $rquote [\s,]
1590 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1595 my $colpiece = $sel_index->{$_} || $_;
1597 # unqualify join-based group_by's. Arcane but possible query
1598 # also horrible horrible hack to alias a column (not a func.)
1599 # (probably need to introduce SQLA syntax)
1600 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1603 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1605 push @{$sub_attrs->{select}}, $colpiece;
1609 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1610 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1613 return $rsrc->resultset_class
1614 ->new ($rsrc, $sub_attrs)
1616 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1617 ->get_column ('count');
1624 =head2 count_literal
1628 =item Arguments: $sql_fragment, @bind_values
1630 =item Return Value: $count
1634 Counts the results in a literal query. Equivalent to calling L</search_literal>
1635 with the passed arguments, then L</count>.
1639 sub count_literal { shift->search_literal(@_)->count; }
1645 =item Arguments: none
1647 =item Return Value: @objects
1651 Returns all elements in the resultset.
1658 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1661 return @{ $self->get_cache } if $self->get_cache;
1665 if (keys %{$self->_resolved_attrs->{collapse}}) {
1666 # Using $self->cursor->all is really just an optimisation.
1667 # If we're collapsing has_many prefetches it probably makes
1668 # very little difference, and this is cleaner than hacking
1669 # _construct_object to survive the approach
1670 $self->cursor->reset;
1671 my @row = $self->cursor->next;
1673 push(@obj, $self->_construct_object(@row));
1674 @row = (exists $self->{stashed_row}
1675 ? @{delete $self->{stashed_row}}
1676 : $self->cursor->next);
1679 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1682 $self->set_cache(\@obj) if $self->{attrs}{cache};
1691 =item Arguments: none
1693 =item Return Value: $self
1697 Resets the resultset's cursor, so you can iterate through the elements again.
1698 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1705 delete $self->{_attrs} if exists $self->{_attrs};
1706 $self->{all_cache_position} = 0;
1707 $self->cursor->reset;
1715 =item Arguments: none
1717 =item Return Value: $object | undef
1721 Resets the resultset and returns an object for the first result (or C<undef>
1722 if the resultset is empty).
1727 return $_[0]->reset->next;
1733 # Determines whether and what type of subquery is required for the $rs operation.
1734 # If grouping is necessary either supplies its own, or verifies the current one
1735 # After all is done delegates to the proper storage method.
1737 sub _rs_update_delete {
1738 my ($self, $op, $values) = @_;
1740 my $rsrc = $self->result_source;
1742 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1743 my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
1745 if ($needs_group_by_subq or $needs_subq) {
1747 # make a new $rs selecting only the PKs (that's all we really need)
1748 my $attrs = $self->_resolved_attrs_copy;
1751 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1752 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1754 if ($needs_group_by_subq) {
1755 # make sure no group_by was supplied, or if there is one - make sure it matches
1756 # the columns compiled above perfectly. Anything else can not be sanely executed
1757 # on most databases so croak right then and there
1759 if (my $g = $attrs->{group_by}) {
1760 my @current_group_by = map
1761 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1766 join ("\x00", sort @current_group_by)
1768 join ("\x00", sort @{$attrs->{columns}} )
1770 $self->throw_exception (
1771 "You have just attempted a $op operation on a resultset which does group_by"
1772 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1773 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1774 . ' kind of queries. Please retry the operation with a modified group_by or'
1775 . ' without using one at all.'
1780 $attrs->{group_by} = $attrs->{columns};
1784 my $subrs = (ref $self)->new($rsrc, $attrs);
1785 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1788 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1789 # a condition containing 'me' or other table prefixes will not work
1790 # at all. What this code tries to do (badly) is to generate a condition
1791 # with the qualifiers removed, by exploiting the quote mechanism of sqla
1793 # this is atrocious and should be replaced by normal sqla introspection
1795 my ($sql, @bind) = do {
1796 my $sqla = $rsrc->storage->sql_maker;
1797 local $sqla->{_dequalify_idents} = 1;
1798 $sqla->_recurse_where($self->{cond});
1801 return $rsrc->storage->$op(
1803 $op eq 'update' ? $values : (),
1804 $self->{cond} ? \[$sql, @bind] : (),
1813 =item Arguments: \%values
1815 =item Return Value: $storage_rv
1819 Sets the specified columns in the resultset to the supplied values in a
1820 single query. Note that this will not run any accessor/set_column/update
1821 triggers, nor will it update any row object instances derived from this
1822 resultset (this includes the contents of the L<resultset cache|/set_cache>
1823 if any). See L</update_all> if you need to execute any on-update
1824 triggers or cascades defined either by you or a
1825 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1827 The return value is a pass through of what the underlying
1828 storage backend returned, and may vary. See L<DBI/execute> for the most
1833 Note that L</update> does not process/deflate any of the values passed in.
1834 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1835 ensure manually that any value passed to this method will stringify to
1836 something the RDBMS knows how to deal with. A notable example is the
1837 handling of L<DateTime> objects, for more info see:
1838 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
1843 my ($self, $values) = @_;
1844 $self->throw_exception('Values for update must be a hash')
1845 unless ref $values eq 'HASH';
1847 return $self->_rs_update_delete ('update', $values);
1854 =item Arguments: \%values
1856 =item Return Value: 1
1860 Fetches all objects and updates them one at a time via
1861 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1862 triggers, while L</update> will not.
1867 my ($self, $values) = @_;
1868 $self->throw_exception('Values for update_all must be a hash')
1869 unless ref $values eq 'HASH';
1871 my $guard = $self->result_source->schema->txn_scope_guard;
1872 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
1881 =item Arguments: none
1883 =item Return Value: $storage_rv
1887 Deletes the rows matching this resultset in a single query. Note that this
1888 will not run any delete triggers, nor will it alter the
1889 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1890 derived from this resultset (this includes the contents of the
1891 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1892 execute any on-delete triggers or cascades defined either by you or a
1893 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1895 The return value is a pass through of what the underlying storage backend
1896 returned, and may vary. See L<DBI/execute> for the most common case.
1902 $self->throw_exception('delete does not accept any arguments')
1905 return $self->_rs_update_delete ('delete');
1912 =item Arguments: none
1914 =item Return Value: 1
1918 Fetches all objects and deletes them one at a time via
1919 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1920 triggers, while L</delete> will not.
1926 $self->throw_exception('delete_all does not accept any arguments')
1929 my $guard = $self->result_source->schema->txn_scope_guard;
1930 $_->delete for $self->all;
1939 =item Arguments: \@data;
1943 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1944 For the arrayref of hashrefs style each hashref should be a structure suitable
1945 for submitting to a $resultset->create(...) method.
1947 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1948 to insert the data, as this is a faster method.
1950 Otherwise, each set of data is inserted into the database using
1951 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1952 accumulated into an array. The array itself, or an array reference
1953 is returned depending on scalar or list context.
1955 Example: Assuming an Artist Class that has many CDs Classes relating:
1957 my $Artist_rs = $schema->resultset("Artist");
1959 ## Void Context Example
1960 $Artist_rs->populate([
1961 { artistid => 4, name => 'Manufactured Crap', cds => [
1962 { title => 'My First CD', year => 2006 },
1963 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1966 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1967 { title => 'My parents sold me to a record company', year => 2005 },
1968 { title => 'Why Am I So Ugly?', year => 2006 },
1969 { title => 'I Got Surgery and am now Popular', year => 2007 }
1974 ## Array Context Example
1975 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1976 { name => "Artist One"},
1977 { name => "Artist Two"},
1978 { name => "Artist Three", cds=> [
1979 { title => "First CD", year => 2007},
1980 { title => "Second CD", year => 2008},
1984 print $ArtistOne->name; ## response is 'Artist One'
1985 print $ArtistThree->cds->count ## reponse is '2'
1987 For the arrayref of arrayrefs style, the first element should be a list of the
1988 fieldsnames to which the remaining elements are rows being inserted. For
1991 $Arstist_rs->populate([
1992 [qw/artistid name/],
1993 [100, 'A Formally Unknown Singer'],
1994 [101, 'A singer that jumped the shark two albums ago'],
1995 [102, 'An actually cool singer'],
1998 Please note an important effect on your data when choosing between void and
1999 wantarray context. Since void context goes straight to C<insert_bulk> in
2000 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
2001 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
2002 create primary keys for you, you will find that your PKs are empty. In this
2003 case you will have to use the wantarray context in order to create those
2011 # cruft placed in standalone method
2012 my $data = $self->_normalize_populate_args(@_);
2014 return unless @$data;
2016 if(defined wantarray) {
2018 foreach my $item (@$data) {
2019 push(@created, $self->create($item));
2021 return wantarray ? @created : \@created;
2024 my $first = $data->[0];
2026 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2027 # it relationship data
2028 my (@rels, @columns);
2029 my $rsrc = $self->result_source;
2030 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2031 for (keys %$first) {
2032 my $ref = ref $first->{$_};
2033 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2039 my @pks = $rsrc->primary_columns;
2041 ## do the belongs_to relationships
2042 foreach my $index (0..$#$data) {
2044 # delegate to create() for any dataset without primary keys with specified relationships
2045 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2047 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2048 my @ret = $self->populate($data);
2054 foreach my $rel (@rels) {
2055 next unless ref $data->[$index]->{$rel} eq "HASH";
2056 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2057 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2058 my $related = $result->result_source->_resolve_condition(
2059 $reverse_relinfo->{cond},
2065 delete $data->[$index]->{$rel};
2066 $data->[$index] = {%{$data->[$index]}, %$related};
2068 push @columns, keys %$related if $index == 0;
2072 ## inherit the data locked in the conditions of the resultset
2073 my ($rs_data) = $self->_merge_with_rscond({});
2074 delete @{$rs_data}{@columns};
2075 my @inherit_cols = keys %$rs_data;
2076 my @inherit_data = values %$rs_data;
2078 ## do bulk insert on current row
2079 $rsrc->storage->insert_bulk(
2081 [@columns, @inherit_cols],
2082 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
2085 ## do the has_many relationships
2086 foreach my $item (@$data) {
2090 foreach my $rel (@rels) {
2091 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2093 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2095 my $child = $main_row->$rel;
2097 my $related = $child->result_source->_resolve_condition(
2098 $rels->{$rel}{cond},
2104 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2105 my @populate = map { {%$_, %$related} } @rows_to_add;
2107 $child->populate( \@populate );
2114 # populate() argumnets went over several incarnations
2115 # What we ultimately support is AoH
2116 sub _normalize_populate_args {
2117 my ($self, $arg) = @_;
2119 if (ref $arg eq 'ARRAY') {
2123 elsif (ref $arg->[0] eq 'HASH') {
2126 elsif (ref $arg->[0] eq 'ARRAY') {
2128 my @colnames = @{$arg->[0]};
2129 foreach my $values (@{$arg}[1 .. $#$arg]) {
2130 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2136 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2143 =item Arguments: none
2145 =item Return Value: $pager
2149 Return Value a L<Data::Page> object for the current resultset. Only makes
2150 sense for queries with a C<page> attribute.
2152 To get the full count of entries for a paged resultset, call
2153 C<total_entries> on the L<Data::Page> object.
2160 return $self->{pager} if $self->{pager};
2162 my $attrs = $self->{attrs};
2163 if (!defined $attrs->{page}) {
2164 $self->throw_exception("Can't create pager for non-paged rs");
2166 elsif ($attrs->{page} <= 0) {
2167 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2169 $attrs->{rows} ||= 10;
2171 # throw away the paging flags and re-run the count (possibly
2172 # with a subselect) to get the real total count
2173 my $count_attrs = { %$attrs };
2174 delete $count_attrs->{$_} for qw/rows offset page pager/;
2176 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2178 require DBIx::Class::ResultSet::Pager;
2179 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2180 sub { $total_rs->count }, #lazy-get the total
2182 $self->{attrs}{page},
2190 =item Arguments: $page_number
2192 =item Return Value: $rs
2196 Returns a resultset for the $page_number page of the resultset on which page
2197 is called, where each page contains a number of rows equal to the 'rows'
2198 attribute set on the resultset (10 by default).
2203 my ($self, $page) = @_;
2204 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2211 =item Arguments: \%vals
2213 =item Return Value: $rowobject
2217 Creates a new row object in the resultset's result class and returns
2218 it. The row is not inserted into the database at this point, call
2219 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2220 will tell you whether the row object has been inserted or not.
2222 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2227 my ($self, $values) = @_;
2228 $self->throw_exception( "new_result needs a hash" )
2229 unless (ref $values eq 'HASH');
2231 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2235 @$cols_from_relations
2236 ? (-cols_from_relations => $cols_from_relations)
2238 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2241 return $self->result_class->new(\%new);
2244 # _merge_with_rscond
2246 # Takes a simple hash of K/V data and returns its copy merged with the
2247 # condition already present on the resultset. Additionally returns an
2248 # arrayref of value/condition names, which were inferred from related
2249 # objects (this is needed for in-memory related objects)
2250 sub _merge_with_rscond {
2251 my ($self, $data) = @_;
2253 my (%new_data, @cols_from_relations);
2255 my $alias = $self->{attrs}{alias};
2257 if (! defined $self->{cond}) {
2258 # just massage $data below
2260 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2261 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2262 @cols_from_relations = keys %new_data;
2264 elsif (ref $self->{cond} ne 'HASH') {
2265 $self->throw_exception(
2266 "Can't abstract implicit construct, resultset condition not a hash"
2270 # precendence must be given to passed values over values inherited from
2271 # the cond, so the order here is important.
2272 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2273 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2275 while ( my($col, $value) = each %implied ) {
2276 my $vref = ref $value;
2282 (keys %$value)[0] eq '='
2284 $new_data{$col} = $value->{'='};
2286 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2287 $new_data{$col} = $value;
2294 %{ $self->_remove_alias($data, $alias) },
2297 return (\%new_data, \@cols_from_relations);
2300 # _has_resolved_attr
2302 # determines if the resultset defines at least one
2303 # of the attributes supplied
2305 # used to determine if a subquery is neccessary
2307 # supports some virtual attributes:
2309 # This will scan for any joins being present on the resultset.
2310 # It is not a mere key-search but a deep inspection of {from}
2313 sub _has_resolved_attr {
2314 my ($self, @attr_names) = @_;
2316 my $attrs = $self->_resolved_attrs;
2320 for my $n (@attr_names) {
2321 if (grep { $n eq $_ } (qw/-join/) ) {
2322 $extra_checks{$n}++;
2326 my $attr = $attrs->{$n};
2328 next if not defined $attr;
2330 if (ref $attr eq 'HASH') {
2331 return 1 if keys %$attr;
2333 elsif (ref $attr eq 'ARRAY') {
2341 # a resolved join is expressed as a multi-level from
2343 $extra_checks{-join}
2345 ref $attrs->{from} eq 'ARRAY'
2347 @{$attrs->{from}} > 1
2355 # Recursively collapse the condition.
2357 sub _collapse_cond {
2358 my ($self, $cond, $collapsed) = @_;
2362 if (ref $cond eq 'ARRAY') {
2363 foreach my $subcond (@$cond) {
2364 next unless ref $subcond; # -or
2365 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2368 elsif (ref $cond eq 'HASH') {
2369 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2370 foreach my $subcond (@{$cond->{-and}}) {
2371 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2375 foreach my $col (keys %$cond) {
2376 my $value = $cond->{$col};
2377 $collapsed->{$col} = $value;
2387 # Remove the specified alias from the specified query hash. A copy is made so
2388 # the original query is not modified.
2391 my ($self, $query, $alias) = @_;
2393 my %orig = %{ $query || {} };
2396 foreach my $key (keys %orig) {
2398 $unaliased{$key} = $orig{$key};
2401 $unaliased{$1} = $orig{$key}
2402 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2412 =item Arguments: none
2414 =item Return Value: \[ $sql, @bind ]
2418 Returns the SQL query and bind vars associated with the invocant.
2420 This is generally used as the RHS for a subquery.
2427 my $attrs = $self->_resolved_attrs_copy;
2432 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2433 # $sql also has no wrapping parenthesis in list ctx
2435 my $sqlbind = $self->result_source->storage
2436 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2445 =item Arguments: \%vals, \%attrs?
2447 =item Return Value: $rowobject
2451 my $artist = $schema->resultset('Artist')->find_or_new(
2452 { artist => 'fred' }, { key => 'artists' });
2454 $cd->cd_to_producer->find_or_new({ producer => $producer },
2455 { key => 'primary });
2457 Find an existing record from this resultset using L</find>. if none exists,
2458 instantiate a new result object and return it. The object will not be saved
2459 into your storage until you call L<DBIx::Class::Row/insert> on it.
2461 You most likely want this method when looking for existing rows using a unique
2462 constraint that is not the primary key, or looking for related rows.
2464 If you want objects to be saved immediately, use L</find_or_create> instead.
2466 B<Note>: Make sure to read the documentation of L</find> and understand the
2467 significance of the C<key> attribute, as its lack may skew your search, and
2468 subsequently result in spurious new objects.
2470 B<Note>: Take care when using C<find_or_new> with a table having
2471 columns with default values that you intend to be automatically
2472 supplied by the database (e.g. an auto_increment primary key column).
2473 In normal usage, the value of such columns should NOT be included at
2474 all in the call to C<find_or_new>, even when set to C<undef>.
2480 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2481 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2482 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2485 return $self->new_result($hash);
2492 =item Arguments: \%vals
2494 =item Return Value: a L<DBIx::Class::Row> $object
2498 Attempt to create a single new row or a row with multiple related rows
2499 in the table represented by the resultset (and related tables). This
2500 will not check for duplicate rows before inserting, use
2501 L</find_or_create> to do that.
2503 To create one row for this resultset, pass a hashref of key/value
2504 pairs representing the columns of the table and the values you wish to
2505 store. If the appropriate relationships are set up, foreign key fields
2506 can also be passed an object representing the foreign row, and the
2507 value will be set to its primary key.
2509 To create related objects, pass a hashref of related-object column values
2510 B<keyed on the relationship name>. If the relationship is of type C<multi>
2511 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2512 The process will correctly identify columns holding foreign keys, and will
2513 transparently populate them from the keys of the corresponding relation.
2514 This can be applied recursively, and will work correctly for a structure
2515 with an arbitrary depth and width, as long as the relationships actually
2516 exists and the correct column data has been supplied.
2519 Instead of hashrefs of plain related data (key/value pairs), you may
2520 also pass new or inserted objects. New objects (not inserted yet, see
2521 L</new>), will be inserted into their appropriate tables.
2523 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2525 Example of creating a new row.
2527 $person_rs->create({
2528 name=>"Some Person",
2529 email=>"somebody@someplace.com"
2532 Example of creating a new row and also creating rows in a related C<has_many>
2533 or C<has_one> resultset. Note Arrayref.
2536 { artistid => 4, name => 'Manufactured Crap', cds => [
2537 { title => 'My First CD', year => 2006 },
2538 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2543 Example of creating a new row and also creating a row in a related
2544 C<belongs_to> resultset. Note Hashref.
2547 title=>"Music for Silly Walks",
2550 name=>"Silly Musician",
2558 When subclassing ResultSet never attempt to override this method. Since
2559 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2560 lot of the internals simply never call it, so your override will be
2561 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2562 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2563 L</create> process you need to intervene.
2570 my ($self, $attrs) = @_;
2571 $self->throw_exception( "create needs a hashref" )
2572 unless ref $attrs eq 'HASH';
2573 return $self->new_result($attrs)->insert;
2576 =head2 find_or_create
2580 =item Arguments: \%vals, \%attrs?
2582 =item Return Value: $rowobject
2586 $cd->cd_to_producer->find_or_create({ producer => $producer },
2587 { key => 'primary' });
2589 Tries to find a record based on its primary key or unique constraints; if none
2590 is found, creates one and returns that instead.
2592 my $cd = $schema->resultset('CD')->find_or_create({
2594 artist => 'Massive Attack',
2595 title => 'Mezzanine',
2599 Also takes an optional C<key> attribute, to search by a specific key or unique
2600 constraint. For example:
2602 my $cd = $schema->resultset('CD')->find_or_create(
2604 artist => 'Massive Attack',
2605 title => 'Mezzanine',
2607 { key => 'cd_artist_title' }
2610 B<Note>: Make sure to read the documentation of L</find> and understand the
2611 significance of the C<key> attribute, as its lack may skew your search, and
2612 subsequently result in spurious row creation.
2614 B<Note>: Because find_or_create() reads from the database and then
2615 possibly inserts based on the result, this method is subject to a race
2616 condition. Another process could create a record in the table after
2617 the find has completed and before the create has started. To avoid
2618 this problem, use find_or_create() inside a transaction.
2620 B<Note>: Take care when using C<find_or_create> with a table having
2621 columns with default values that you intend to be automatically
2622 supplied by the database (e.g. an auto_increment primary key column).
2623 In normal usage, the value of such columns should NOT be included at
2624 all in the call to C<find_or_create>, even when set to C<undef>.
2626 See also L</find> and L</update_or_create>. For information on how to declare
2627 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2631 sub find_or_create {
2633 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2634 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2635 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2638 return $self->create($hash);
2641 =head2 update_or_create
2645 =item Arguments: \%col_values, { key => $unique_constraint }?
2647 =item Return Value: $row_object
2651 $resultset->update_or_create({ col => $val, ... });
2653 Like L</find_or_create>, but if a row is found it is immediately updated via
2654 C<< $found_row->update (\%col_values) >>.
2657 Takes an optional C<key> attribute to search on a specific unique constraint.
2660 # In your application
2661 my $cd = $schema->resultset('CD')->update_or_create(
2663 artist => 'Massive Attack',
2664 title => 'Mezzanine',
2667 { key => 'cd_artist_title' }
2670 $cd->cd_to_producer->update_or_create({
2671 producer => $producer,
2677 B<Note>: Make sure to read the documentation of L</find> and understand the
2678 significance of the C<key> attribute, as its lack may skew your search, and
2679 subsequently result in spurious row creation.
2681 B<Note>: Take care when using C<update_or_create> with a table having
2682 columns with default values that you intend to be automatically
2683 supplied by the database (e.g. an auto_increment primary key column).
2684 In normal usage, the value of such columns should NOT be included at
2685 all in the call to C<update_or_create>, even when set to C<undef>.
2687 See also L</find> and L</find_or_create>. For information on how to declare
2688 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2692 sub update_or_create {
2694 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2695 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2697 my $row = $self->find($cond, $attrs);
2699 $row->update($cond);
2703 return $self->create($cond);
2706 =head2 update_or_new
2710 =item Arguments: \%col_values, { key => $unique_constraint }?
2712 =item Return Value: $rowobject
2716 $resultset->update_or_new({ col => $val, ... });
2718 Like L</find_or_new> but if a row is found it is immediately updated via
2719 C<< $found_row->update (\%col_values) >>.
2723 # In your application
2724 my $cd = $schema->resultset('CD')->update_or_new(
2726 artist => 'Massive Attack',
2727 title => 'Mezzanine',
2730 { key => 'cd_artist_title' }
2733 if ($cd->in_storage) {
2734 # the cd was updated
2737 # the cd is not yet in the database, let's insert it
2741 B<Note>: Make sure to read the documentation of L</find> and understand the
2742 significance of the C<key> attribute, as its lack may skew your search, and
2743 subsequently result in spurious new objects.
2745 B<Note>: Take care when using C<update_or_new> with a table having
2746 columns with default values that you intend to be automatically
2747 supplied by the database (e.g. an auto_increment primary key column).
2748 In normal usage, the value of such columns should NOT be included at
2749 all in the call to C<update_or_new>, even when set to C<undef>.
2751 See also L</find>, L</find_or_create> and L</find_or_new>.
2757 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2758 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2760 my $row = $self->find( $cond, $attrs );
2761 if ( defined $row ) {
2762 $row->update($cond);
2766 return $self->new_result($cond);
2773 =item Arguments: none
2775 =item Return Value: \@cache_objects | undef
2779 Gets the contents of the cache for the resultset, if the cache is set.
2781 The cache is populated either by using the L</prefetch> attribute to
2782 L</search> or by calling L</set_cache>.
2794 =item Arguments: \@cache_objects
2796 =item Return Value: \@cache_objects
2800 Sets the contents of the cache for the resultset. Expects an arrayref
2801 of objects of the same class as those produced by the resultset. Note that
2802 if the cache is set the resultset will return the cached objects rather
2803 than re-querying the database even if the cache attr is not set.
2805 The contents of the cache can also be populated by using the
2806 L</prefetch> attribute to L</search>.
2811 my ( $self, $data ) = @_;
2812 $self->throw_exception("set_cache requires an arrayref")
2813 if defined($data) && (ref $data ne 'ARRAY');
2814 $self->{all_cache} = $data;
2821 =item Arguments: none
2823 =item Return Value: undef
2827 Clears the cache for the resultset.
2832 shift->set_cache(undef);
2839 =item Arguments: none
2841 =item Return Value: true, if the resultset has been paginated
2849 return !!$self->{attrs}{page};
2856 =item Arguments: none
2858 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2866 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2869 =head2 related_resultset
2873 =item Arguments: $relationship_name
2875 =item Return Value: $resultset
2879 Returns a related resultset for the supplied relationship name.
2881 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2885 sub related_resultset {
2886 my ($self, $rel) = @_;
2888 $self->{related_resultsets} ||= {};
2889 return $self->{related_resultsets}{$rel} ||= do {
2890 my $rsrc = $self->result_source;
2891 my $rel_info = $rsrc->relationship_info($rel);
2893 $self->throw_exception(
2894 "search_related: result source '" . $rsrc->source_name .
2895 "' has no such relationship $rel")
2898 my $attrs = $self->_chain_relationship($rel);
2900 my $join_count = $attrs->{seen_join}{$rel};
2902 my $alias = $self->result_source->storage
2903 ->relname_to_table_alias($rel, $join_count);
2905 # since this is search_related, and we already slid the select window inwards
2906 # (the select/as attrs were deleted in the beginning), we need to flip all
2907 # left joins to inner, so we get the expected results
2908 # read the comment on top of the actual function to see what this does
2909 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2912 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2913 delete @{$attrs}{qw(result_class alias)};
2917 if (my $cache = $self->get_cache) {
2918 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2919 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2924 my $rel_source = $rsrc->related_source($rel);
2928 # The reason we do this now instead of passing the alias to the
2929 # search_rs below is that if you wrap/overload resultset on the
2930 # source you need to know what alias it's -going- to have for things
2931 # to work sanely (e.g. RestrictWithObject wants to be able to add
2932 # extra query restrictions, and these may need to be $alias.)
2934 my $rel_attrs = $rel_source->resultset_attributes;
2935 local $rel_attrs->{alias} = $alias;
2937 $rel_source->resultset
2941 where => $attrs->{where},
2944 $new->set_cache($new_cache) if $new_cache;
2949 =head2 current_source_alias
2953 =item Arguments: none
2955 =item Return Value: $source_alias
2959 Returns the current table alias for the result source this resultset is built
2960 on, that will be used in the SQL query. Usually it is C<me>.
2962 Currently the source alias that refers to the result set returned by a
2963 L</search>/L</find> family method depends on how you got to the resultset: it's
2964 C<me> by default, but eg. L</search_related> aliases it to the related result
2965 source name (and keeps C<me> referring to the original result set). The long
2966 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2967 (and make this method unnecessary).
2969 Thus it's currently necessary to use this method in predefined queries (see
2970 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2971 source alias of the current result set:
2973 # in a result set class
2975 my ($self, $user) = @_;
2977 my $me = $self->current_source_alias;
2979 return $self->search(
2980 "$me.modified" => $user->id,
2986 sub current_source_alias {
2989 return ($self->{attrs} || {})->{alias} || 'me';
2992 =head2 as_subselect_rs
2996 =item Arguments: none
2998 =item Return Value: $resultset
3002 Act as a barrier to SQL symbols. The resultset provided will be made into a
3003 "virtual view" by including it as a subquery within the from clause. From this
3004 point on, any joined tables are inaccessible to ->search on the resultset (as if
3005 it were simply where-filtered without joins). For example:
3007 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3009 # 'x' now pollutes the query namespace
3011 # So the following works as expected
3012 my $ok_rs = $rs->search({'x.other' => 1});
3014 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3015 # def) we look for one row with contradictory terms and join in another table
3016 # (aliased 'x_2') which we never use
3017 my $broken_rs = $rs->search({'x.name' => 'def'});
3019 my $rs2 = $rs->as_subselect_rs;
3021 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3022 my $not_joined_rs = $rs2->search({'x.other' => 1});
3024 # works as expected: finds a 'table' row related to two x rows (abc and def)
3025 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3027 Another example of when one might use this would be to select a subset of
3028 columns in a group by clause:
3030 my $rs = $schema->resultset('Bar')->search(undef, {
3031 group_by => [qw{ id foo_id baz_id }],
3032 })->as_subselect_rs->search(undef, {
3033 columns => [qw{ id foo_id }]
3036 In the above example normally columns would have to be equal to the group by,
3037 but because we isolated the group by into a subselect the above works.
3041 sub as_subselect_rs {
3044 my $attrs = $self->_resolved_attrs;
3046 my $fresh_rs = (ref $self)->new (
3047 $self->result_source
3050 # these pieces will be locked in the subquery
3051 delete $fresh_rs->{cond};
3052 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3054 return $fresh_rs->search( {}, {
3056 $attrs->{alias} => $self->as_query,
3057 -alias => $attrs->{alias},
3058 -rsrc => $self->result_source,
3060 alias => $attrs->{alias},
3064 # This code is called by search_related, and makes sure there
3065 # is clear separation between the joins before, during, and
3066 # after the relationship. This information is needed later
3067 # in order to properly resolve prefetch aliases (any alias
3068 # with a relation_chain_depth less than the depth of the
3069 # current prefetch is not considered)
3071 # The increments happen twice per join. An even number means a
3072 # relationship specified via a search_related, whereas an odd
3073 # number indicates a join/prefetch added via attributes
3075 # Also this code will wrap the current resultset (the one we
3076 # chain to) in a subselect IFF it contains limiting attributes
3077 sub _chain_relationship {
3078 my ($self, $rel) = @_;
3079 my $source = $self->result_source;
3080 my $attrs = { %{$self->{attrs}||{}} };
3082 # we need to take the prefetch the attrs into account before we
3083 # ->_resolve_join as otherwise they get lost - captainL
3084 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3086 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3088 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3091 my @force_subq_attrs = qw/offset rows group_by having/;
3094 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3096 $self->_has_resolved_attr (@force_subq_attrs)
3098 # Nuke the prefetch (if any) before the new $rs attrs
3099 # are resolved (prefetch is useless - we are wrapping
3100 # a subquery anyway).
3101 my $rs_copy = $self->search;
3102 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3103 $rs_copy->{attrs}{join},
3104 delete $rs_copy->{attrs}{prefetch},
3109 -alias => $attrs->{alias},
3110 $attrs->{alias} => $rs_copy->as_query,
3112 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3113 $seen->{-relation_chain_depth} = 0;
3115 elsif ($attrs->{from}) { #shallow copy suffices
3116 $from = [ @{$attrs->{from}} ];
3121 -alias => $attrs->{alias},
3122 $attrs->{alias} => $source->from,
3126 my $jpath = ($seen->{-relation_chain_depth})
3127 ? $from->[-1][0]{-join_path}
3130 my @requested_joins = $source->_resolve_join(
3137 push @$from, @requested_joins;
3139 $seen->{-relation_chain_depth}++;
3141 # if $self already had a join/prefetch specified on it, the requested
3142 # $rel might very well be already included. What we do in this case
3143 # is effectively a no-op (except that we bump up the chain_depth on
3144 # the join in question so we could tell it *is* the search_related)
3147 # we consider the last one thus reverse
3148 for my $j (reverse @requested_joins) {
3149 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3150 if ($rel eq $last_j) {
3151 $j->[0]{-relation_chain_depth}++;
3157 unless ($already_joined) {
3158 push @$from, $source->_resolve_join(
3166 $seen->{-relation_chain_depth}++;
3168 return {%$attrs, from => $from, seen_join => $seen};
3171 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3172 sub _resolved_attrs_copy {
3174 return { %{$self->_resolved_attrs (@_)} };
3177 sub _resolved_attrs {
3179 return $self->{_attrs} if $self->{_attrs};
3181 my $attrs = { %{ $self->{attrs} || {} } };
3182 my $source = $self->result_source;
3183 my $alias = $attrs->{alias};
3185 # default selection list
3186 $attrs->{columns} = [ $source->columns ]
3187 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3189 # merge selectors together
3190 for (qw/columns select as/) {
3191 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3192 if $attrs->{$_} or $attrs->{"+$_"};
3195 # disassemble columns
3197 if (my $cols = delete $attrs->{columns}) {
3198 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3199 if (ref $c eq 'HASH') {
3200 for my $as (keys %$c) {
3201 push @sel, $c->{$as};
3212 # when trying to weed off duplicates later do not go past this point -
3213 # everything added from here on is unbalanced "anyone's guess" stuff
3214 my $dedup_stop_idx = $#as;
3216 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3218 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3219 if $attrs->{select};
3221 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3223 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3226 # disqualify all $alias.col as-bits (collapser mandated)
3228 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3231 # de-duplicate the result (remove *identical* select/as pairs)
3232 # and also die on duplicate {as} pointing to different {select}s
3233 # not using a c-style for as the condition is prone to shrinkage
3236 while ($i <= $dedup_stop_idx) {
3237 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3242 elsif ($seen->{$as[$i]}++) {
3243 $self->throw_exception(
3244 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3252 $attrs->{select} = \@sel;
3253 $attrs->{as} = \@as;
3255 $attrs->{from} ||= [{
3257 -alias => $self->{attrs}{alias},
3258 $self->{attrs}{alias} => $source->from,
3261 if ( $attrs->{join} || $attrs->{prefetch} ) {
3263 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3264 if ref $attrs->{from} ne 'ARRAY';
3266 my $join = (delete $attrs->{join}) || {};
3268 if ( defined $attrs->{prefetch} ) {
3269 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3272 $attrs->{from} = # have to copy here to avoid corrupting the original
3274 @{ $attrs->{from} },
3275 $source->_resolve_join(
3278 { %{ $attrs->{seen_join} || {} } },
3279 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3280 ? $attrs->{from}[-1][0]{-join_path}
3287 if ( defined $attrs->{order_by} ) {
3288 $attrs->{order_by} = (
3289 ref( $attrs->{order_by} ) eq 'ARRAY'
3290 ? [ @{ $attrs->{order_by} } ]
3291 : [ $attrs->{order_by} || () ]
3295 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3296 $attrs->{group_by} = [ $attrs->{group_by} ];
3299 # generate the distinct induced group_by early, as prefetch will be carried via a
3300 # subquery (since a group_by is present)
3301 if (delete $attrs->{distinct}) {
3302 if ($attrs->{group_by}) {
3303 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3306 # distinct affects only the main selection part, not what prefetch may
3308 $attrs->{group_by} = $source->storage->_group_over_selection (
3316 $attrs->{collapse} ||= {};
3317 if ($attrs->{prefetch}) {
3319 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3320 if $attrs->{_dark_selector};
3322 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3324 my $prefetch_ordering = [];
3326 # this is a separate structure (we don't look in {from} directly)
3327 # as the resolver needs to shift things off the lists to work
3328 # properly (identical-prefetches on different branches)
3330 if (ref $attrs->{from} eq 'ARRAY') {
3332 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3334 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3335 next unless $j->[0]{-alias};
3336 next unless $j->[0]{-join_path};
3337 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3339 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3342 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3343 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3348 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3350 # we need to somehow mark which columns came from prefetch
3352 my $sel_end = $#{$attrs->{select}};
3353 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3356 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3357 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3359 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3360 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3364 # if both page and offset are specified, produce a combined offset
3365 # even though it doesn't make much sense, this is what pre 081xx has
3367 if (my $page = delete $attrs->{page}) {
3369 ($attrs->{rows} * ($page - 1))
3371 ($attrs->{offset} || 0)
3375 return $self->{_attrs} = $attrs;
3379 my ($self, $attr) = @_;
3381 if (ref $attr eq 'HASH') {
3382 return $self->_rollout_hash($attr);
3383 } elsif (ref $attr eq 'ARRAY') {
3384 return $self->_rollout_array($attr);
3390 sub _rollout_array {
3391 my ($self, $attr) = @_;
3394 foreach my $element (@{$attr}) {
3395 if (ref $element eq 'HASH') {
3396 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3397 } elsif (ref $element eq 'ARRAY') {
3398 # XXX - should probably recurse here
3399 push( @rolled_array, @{$self->_rollout_array($element)} );
3401 push( @rolled_array, $element );
3404 return \@rolled_array;
3408 my ($self, $attr) = @_;
3411 foreach my $key (keys %{$attr}) {
3412 push( @rolled_array, { $key => $attr->{$key} } );
3414 return \@rolled_array;
3417 sub _calculate_score {
3418 my ($self, $a, $b) = @_;
3420 if (defined $a xor defined $b) {
3423 elsif (not defined $a) {
3427 if (ref $b eq 'HASH') {
3428 my ($b_key) = keys %{$b};
3429 if (ref $a eq 'HASH') {
3430 my ($a_key) = keys %{$a};
3431 if ($a_key eq $b_key) {
3432 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3437 return ($a eq $b_key) ? 1 : 0;
3440 if (ref $a eq 'HASH') {
3441 my ($a_key) = keys %{$a};
3442 return ($b eq $a_key) ? 1 : 0;
3444 return ($b eq $a) ? 1 : 0;
3449 sub _merge_joinpref_attr {
3450 my ($self, $orig, $import) = @_;
3452 return $import unless defined($orig);
3453 return $orig unless defined($import);
3455 $orig = $self->_rollout_attr($orig);
3456 $import = $self->_rollout_attr($import);
3459 foreach my $import_element ( @{$import} ) {
3460 # find best candidate from $orig to merge $b_element into
3461 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3462 foreach my $orig_element ( @{$orig} ) {
3463 my $score = $self->_calculate_score( $orig_element, $import_element );
3464 if ($score > $best_candidate->{score}) {
3465 $best_candidate->{position} = $position;
3466 $best_candidate->{score} = $score;
3470 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3471 $import_key = '' if not defined $import_key;
3473 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3474 push( @{$orig}, $import_element );
3476 my $orig_best = $orig->[$best_candidate->{position}];
3477 # merge orig_best and b_element together and replace original with merged
3478 if (ref $orig_best ne 'HASH') {
3479 $orig->[$best_candidate->{position}] = $import_element;
3480 } elsif (ref $import_element eq 'HASH') {
3481 my ($key) = keys %{$orig_best};
3482 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3485 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3496 require Hash::Merge;
3497 my $hm = Hash::Merge->new;
3499 $hm->specify_behavior({
3502 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3504 if ($defl xor $defr) {
3505 return [ $defl ? $_[0] : $_[1] ];
3510 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3514 return [$_[0], $_[1]];
3518 return $_[1] if !defined $_[0];
3519 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3520 return [$_[0], @{$_[1]}]
3523 return [] if !defined $_[0] and !keys %{$_[1]};
3524 return [ $_[1] ] if !defined $_[0];
3525 return [ $_[0] ] if !keys %{$_[1]};
3526 return [$_[0], $_[1]]
3531 return $_[0] if !defined $_[1];
3532 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3533 return [@{$_[0]}, $_[1]]
3536 my @ret = @{$_[0]} or return $_[1];
3537 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3538 my %idx = map { $_ => 1 } @ret;
3539 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3543 return [ $_[1] ] if ! @{$_[0]};
3544 return $_[0] if !keys %{$_[1]};
3545 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3546 return [ @{$_[0]}, $_[1] ];
3551 return [] if !keys %{$_[0]} and !defined $_[1];
3552 return [ $_[0] ] if !defined $_[1];
3553 return [ $_[1] ] if !keys %{$_[0]};
3554 return [$_[0], $_[1]]
3557 return [] if !keys %{$_[0]} and !@{$_[1]};
3558 return [ $_[0] ] if !@{$_[1]};
3559 return $_[1] if !keys %{$_[0]};
3560 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3561 return [ $_[0], @{$_[1]} ];
3564 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3565 return [ $_[0] ] if !keys %{$_[1]};
3566 return [ $_[1] ] if !keys %{$_[0]};
3567 return [ $_[0] ] if $_[0] eq $_[1];
3568 return [ $_[0], $_[1] ];
3571 } => 'DBIC_RS_ATTR_MERGER');
3575 return $hm->merge ($_[1], $_[2]);
3579 sub STORABLE_freeze {
3580 my ($self, $cloning) = @_;
3581 my $to_serialize = { %$self };
3583 # A cursor in progress can't be serialized (and would make little sense anyway)
3584 delete $to_serialize->{cursor};
3586 # nor is it sensical to store a not-yet-fired-count pager
3587 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3588 delete $to_serialize->{pager};
3591 Storable::nfreeze($to_serialize);
3594 # need this hook for symmetry
3596 my ($self, $cloning, $serialized) = @_;
3598 %$self = %{ Storable::thaw($serialized) };
3604 =head2 throw_exception
3606 See L<DBIx::Class::Schema/throw_exception> for details.
3610 sub throw_exception {
3613 if (ref $self and my $rsrc = $self->result_source) {
3614 $rsrc->throw_exception(@_)
3617 DBIx::Class::Exception->throw(@_);
3621 # XXX: FIXME: Attributes docs need clearing up
3625 Attributes are used to refine a ResultSet in various ways when
3626 searching for data. They can be passed to any method which takes an
3627 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3630 These are in no particular order:
3636 =item Value: ( $order_by | \@order_by | \%order_by )
3640 Which column(s) to order the results by.
3642 [The full list of suitable values is documented in
3643 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3646 If a single column name, or an arrayref of names is supplied, the
3647 argument is passed through directly to SQL. The hashref syntax allows
3648 for connection-agnostic specification of ordering direction:
3650 For descending order:
3652 order_by => { -desc => [qw/col1 col2 col3/] }
3654 For explicit ascending order:
3656 order_by => { -asc => 'col' }
3658 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3659 supported, although you are strongly encouraged to use the hashref
3660 syntax as outlined above.
3666 =item Value: \@columns
3670 Shortcut to request a particular set of columns to be retrieved. Each
3671 column spec may be a string (a table column name), or a hash (in which
3672 case the key is the C<as> value, and the value is used as the C<select>
3673 expression). Adds C<me.> onto the start of any column without a C<.> in
3674 it and sets C<select> from that, then auto-populates C<as> from
3675 C<select> as normal. (You may also use the C<cols> attribute, as in
3676 earlier versions of DBIC.)
3678 Essentially C<columns> does the same as L</select> and L</as>.
3680 columns => [ 'foo', { bar => 'baz' } ]
3684 select => [qw/foo baz/],
3691 =item Value: \@columns
3695 Indicates additional columns to be selected from storage. Works the same
3696 as L</columns> but adds columns to the selection. (You may also use the
3697 C<include_columns> attribute, as in earlier versions of DBIC). For
3700 $schema->resultset('CD')->search(undef, {
3701 '+columns' => ['artist.name'],
3705 would return all CDs and include a 'name' column to the information
3706 passed to object inflation. Note that the 'artist' is the name of the
3707 column (or relationship) accessor, and 'name' is the name of the column
3708 accessor in the related table.
3710 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3711 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3712 unary plus operator before it.
3714 =head2 include_columns
3718 =item Value: \@columns
3722 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3728 =item Value: \@select_columns
3732 Indicates which columns should be selected from the storage. You can use
3733 column names, or in the case of RDBMS back ends, function or stored procedure
3736 $rs = $schema->resultset('Employee')->search(undef, {
3739 { count => 'employeeid' },
3740 { max => { length => 'name' }, -as => 'longest_name' }
3745 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3747 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3748 use L</select>, to instruct DBIx::Class how to store the result of the column.
3749 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3750 identifier aliasing. You can however alias a function, so you can use it in
3751 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3752 attribute> supplied as shown in the example above.
3754 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3755 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3756 unary plus operator before it.
3762 Indicates additional columns to be selected from storage. Works the same as
3763 L</select> but adds columns to the default selection, instead of specifying
3772 Indicates additional column names for those added via L</+select>. See L</as>.
3780 =item Value: \@inflation_names
3784 Indicates column names for object inflation. That is L</as> indicates the
3785 slot name in which the column value will be stored within the
3786 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3787 identifier by the C<get_column> method (or via the object accessor B<if one
3788 with the same name already exists>) as shown below. The L</as> attribute has
3789 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3791 $rs = $schema->resultset('Employee')->search(undef, {
3794 { count => 'employeeid' },
3795 { max => { length => 'name' }, -as => 'longest_name' }
3804 If the object against which the search is performed already has an accessor
3805 matching a column name specified in C<as>, the value can be retrieved using
3806 the accessor as normal:
3808 my $name = $employee->name();
3810 If on the other hand an accessor does not exist in the object, you need to
3811 use C<get_column> instead:
3813 my $employee_count = $employee->get_column('employee_count');
3815 You can create your own accessors if required - see
3816 L<DBIx::Class::Manual::Cookbook> for details.
3822 =item Value: ($rel_name | \@rel_names | \%rel_names)
3826 Contains a list of relationships that should be joined for this query. For
3829 # Get CDs by Nine Inch Nails
3830 my $rs = $schema->resultset('CD')->search(
3831 { 'artist.name' => 'Nine Inch Nails' },
3832 { join => 'artist' }
3835 Can also contain a hash reference to refer to the other relation's relations.
3838 package MyApp::Schema::Track;
3839 use base qw/DBIx::Class/;
3840 __PACKAGE__->table('track');
3841 __PACKAGE__->add_columns(qw/trackid cd position title/);
3842 __PACKAGE__->set_primary_key('trackid');
3843 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3846 # In your application
3847 my $rs = $schema->resultset('Artist')->search(
3848 { 'track.title' => 'Teardrop' },
3850 join => { cd => 'track' },
3851 order_by => 'artist.name',
3855 You need to use the relationship (not the table) name in conditions,
3856 because they are aliased as such. The current table is aliased as "me", so
3857 you need to use me.column_name in order to avoid ambiguity. For example:
3859 # Get CDs from 1984 with a 'Foo' track
3860 my $rs = $schema->resultset('CD')->search(
3863 'tracks.name' => 'Foo'
3865 { join => 'tracks' }
3868 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3869 similarly for a third time). For e.g.
3871 my $rs = $schema->resultset('Artist')->search({
3872 'cds.title' => 'Down to Earth',
3873 'cds_2.title' => 'Popular',
3875 join => [ qw/cds cds/ ],
3878 will return a set of all artists that have both a cd with title 'Down
3879 to Earth' and a cd with title 'Popular'.
3881 If you want to fetch related objects from other tables as well, see C<prefetch>
3884 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3890 =item Value: ($rel_name | \@rel_names | \%rel_names)
3894 Contains one or more relationships that should be fetched along with
3895 the main query (when they are accessed afterwards the data will
3896 already be available, without extra queries to the database). This is
3897 useful for when you know you will need the related objects, because it
3898 saves at least one query:
3900 my $rs = $schema->resultset('Tag')->search(
3909 The initial search results in SQL like the following:
3911 SELECT tag.*, cd.*, artist.* FROM tag
3912 JOIN cd ON tag.cd = cd.cdid
3913 JOIN artist ON cd.artist = artist.artistid
3915 L<DBIx::Class> has no need to go back to the database when we access the
3916 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3919 Simple prefetches will be joined automatically, so there is no need
3920 for a C<join> attribute in the above search.
3922 L</prefetch> can be used with the any of the relationship types and
3923 multiple prefetches can be specified together. Below is a more complex
3924 example that prefetches a CD's artist, its liner notes (if present),
3925 the cover image, the tracks on that cd, and the guests on those
3929 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3930 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3931 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3932 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3934 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3936 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
3939 my $rs = $schema->resultset('CD')->search(
3943 { artist => 'record_label'}, # belongs_to => belongs_to
3944 'liner_note', # might_have
3945 'cover_image', # has_one
3946 { tracks => 'guests' }, # has_many => has_many
3951 This will produce SQL like the following:
3953 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
3957 ON artist.artistid = me.artistid
3958 JOIN record_label record_label
3959 ON record_label.labelid = artist.labelid
3960 LEFT JOIN track tracks
3961 ON tracks.cdid = me.cdid
3962 LEFT JOIN guest guests
3963 ON guests.trackid = track.trackid
3964 LEFT JOIN liner_notes liner_note
3965 ON liner_note.cdid = me.cdid
3966 JOIN cd_artwork cover_image
3967 ON cover_image.cdid = me.cdid
3970 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
3971 C<tracks>, and C<guests> of the CD will all be available through the
3972 relationship accessors without the need for additional queries to the
3975 However, there is one caveat to be observed: it can be dangerous to
3976 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
3977 relationship on a given level. e.g.:
3979 my $rs = $schema->resultset('CD')->search(
3983 'tracks', # has_many
3984 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
3989 In fact, C<DBIx::Class> will emit the following warning:
3991 Prefetching multiple has_many rels tracks and cd_to_producer at top
3992 level will explode the number of row objects retrievable via ->next
3993 or ->all. Use at your own risk.
3995 The collapser currently can't identify duplicate tuples for multiple
3996 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
3997 result the second L<has_many|DBIx::Class::Relationship/has_many>
3998 relation could contain redundant objects.
4000 =head3 Using L</prefetch> with L</join>
4002 L</prefetch> implies a L</join> with the equivalent argument, and is
4003 properly merged with any existing L</join> specification. So the
4006 my $rs = $schema->resultset('CD')->search(
4007 {'record_label.name' => 'Music Product Ltd.'},
4009 join => {artist => 'record_label'},
4010 prefetch => 'artist',
4014 ... will work, searching on the record label's name, but only
4015 prefetching the C<artist>.
4017 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4019 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4020 prefetched relations. So given:
4022 my $rs = $schema->resultset('CD')->search(
4025 select => ['cd.title'],
4027 prefetch => 'artist',
4031 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4032 becomes: C<'cd_title', 'artist.*'>.
4036 Prefetch does a lot of deep magic. As such, it may not behave exactly
4037 as you might expect.
4043 Prefetch uses the L</cache> to populate the prefetched relationships. This
4044 may or may not be what you want.
4048 If you specify a condition on a prefetched relationship, ONLY those
4049 rows that match the prefetched condition will be fetched into that relationship.
4050 This means that adding prefetch to a search() B<may alter> what is returned by
4051 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4053 my $artist_rs = $schema->resultset('Artist')->search({
4059 my $count = $artist_rs->first->cds->count;
4061 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4063 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4065 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4067 that cmp_ok() may or may not pass depending on the datasets involved. This
4068 behavior may or may not survive the 0.09 transition.
4080 Makes the resultset paged and specifies the page to retrieve. Effectively
4081 identical to creating a non-pages resultset and then calling ->page($page)
4084 If L</rows> attribute is not specified it defaults to 10 rows per page.
4086 When you have a paged resultset, L</count> will only return the number
4087 of rows in the page. To get the total, use the L</pager> and call
4088 C<total_entries> on it.
4098 Specifies the maximum number of rows for direct retrieval or the number of
4099 rows per page if the page attribute or method is used.
4105 =item Value: $offset
4109 Specifies the (zero-based) row number for the first row to be returned, or the
4110 of the first row of the first page if paging is used.
4116 =item Value: \@columns
4120 A arrayref of columns to group by. Can include columns of joined tables.
4122 group_by => [qw/ column1 column2 ... /]
4128 =item Value: $condition
4132 HAVING is a select statement attribute that is applied between GROUP BY and
4133 ORDER BY. It is applied to the after the grouping calculations have been
4136 having => { 'count_employee' => { '>=', 100 } }
4138 or with an in-place function in which case literal SQL is required:
4140 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4146 =item Value: (0 | 1)
4150 Set to 1 to group by all columns. If the resultset already has a group_by
4151 attribute, this setting is ignored and an appropriate warning is issued.
4157 Adds to the WHERE clause.
4159 # only return rows WHERE deleted IS NULL for all searches
4160 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4162 Can be overridden by passing C<< { where => undef } >> as an attribute
4165 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4171 Set to 1 to cache search results. This prevents extra SQL queries if you
4172 revisit rows in your ResultSet:
4174 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4176 while( my $artist = $resultset->next ) {
4180 $rs->first; # without cache, this would issue a query
4182 By default, searches are not cached.
4184 For more examples of using these attributes, see
4185 L<DBIx::Class::Manual::Cookbook>.
4191 =item Value: ( 'update' | 'shared' )
4195 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT