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
79 =head2 Chaining resultsets
81 Let's say you've got a query that needs to be run to return some data
82 to the user. But, you have an authorization system in place that
83 prevents certain users from seeing certain information. So, you want
84 to construct the basic query in one method, but add constraints to it in
89 my $request = $self->get_request; # Get a request object somehow.
90 my $schema = $self->result_source->schema;
92 my $cd_rs = $schema->resultset('CD')->search({
93 title => $request->param('title'),
94 year => $request->param('year'),
97 $cd_rs = $self->apply_security_policy( $cd_rs );
102 sub apply_security_policy {
111 =head3 Resolving conditions and attributes
113 When a resultset is chained from another resultset, conditions and
114 attributes with the same keys need resolving.
116 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
117 into the existing ones from the original resultset.
119 The L</where> and L</having> attributes, and any search conditions, are
120 merged with an SQL C<AND> to the existing condition from the original
123 All other attributes are overridden by any new ones supplied in the
126 =head2 Multiple queries
128 Since a resultset just defines a query, you can do all sorts of
129 things with it with the same object.
131 # Don't hit the DB yet.
132 my $cd_rs = $schema->resultset('CD')->search({
133 title => 'something',
137 # Each of these hits the DB individually.
138 my $count = $cd_rs->count;
139 my $most_recent = $cd_rs->get_column('date_released')->max();
140 my @records = $cd_rs->all;
142 And it's not just limited to SELECT statements.
148 $cd_rs->create({ artist => 'Fred' });
150 Which is the same as:
152 $schema->resultset('CD')->create({
153 title => 'something',
158 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
166 =item Arguments: $source, \%$attrs
168 =item Return Value: $rs
172 The resultset constructor. Takes a source object (usually a
173 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
174 L</ATTRIBUTES> below). Does not perform any queries -- these are
175 executed as needed by the other methods.
177 Generally you won't need to construct a resultset manually. You'll
178 automatically get one from e.g. a L</search> called in scalar context:
180 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
182 IMPORTANT: If called on an object, proxies to new_result instead so
184 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
186 will return a CD object, not a ResultSet.
192 return $class->new_result(@_) if ref $class;
194 my ($source, $attrs) = @_;
195 $source = $source->resolve
196 if $source->isa('DBIx::Class::ResultSourceHandle');
197 $attrs = { %{$attrs||{}} };
199 if ($attrs->{page}) {
200 $attrs->{rows} ||= 10;
203 $attrs->{alias} ||= 'me';
206 result_source => $source,
207 cond => $attrs->{where},
212 # if there is a dark selector, this means we are already in a
213 # chain and the cleanup/sanification was taken care of by
215 $self->_normalize_selection($attrs)
216 unless $attrs->{_dark_selector};
219 $attrs->{result_class} || $source->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context) || @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 In list context, C<< ->all() >> is called implicitly on the resultset, thus
242 returning a list of row objects instead. To avoid that, use L</search_rs>.
244 If you need to pass in additional attributes but no additional condition,
245 call it as C<search(undef, \%attrs)>.
247 # "SELECT name, artistid FROM $artist_table"
248 my @all_artists = $schema->resultset('Artist')->search(undef, {
249 columns => [qw/name artistid/],
252 For a list of attributes that can be passed to C<search>, see
253 L</ATTRIBUTES>. For more examples of using this function, see
254 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
255 documentation for the first argument, see L<SQL::Abstract>
256 and its extension L<DBIx::Class::SQLMaker>.
258 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
262 Note that L</search> does not process/deflate any of the values passed in the
263 L<SQL::Abstract>-compatible search condition structure. This is unlike other
264 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
265 manually that any value passed to this method will stringify to something the
266 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
267 objects, for more info see:
268 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
274 my $rs = $self->search_rs( @_ );
279 elsif (defined wantarray) {
283 # we can be called by a relationship helper, which in
284 # turn may be called in void context due to some braindead
285 # overload or whatever else the user decided to be clever
286 # at this particular day. Thus limit the exception to
287 # external code calls only
288 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
289 if (caller)[0] !~ /^\QDBIx::Class::/;
299 =item Arguments: $cond, \%attrs?
301 =item Return Value: $resultset
305 This method does the same exact thing as search() except it will
306 always return a resultset, even in list context.
313 # Special-case handling for (undef, undef).
314 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
320 if (ref $_[-1] eq 'HASH') {
321 # copy for _normalize_selection
322 $call_attrs = { %{ pop @_ } };
324 elsif (! defined $_[-1] ) {
325 pop @_; # search({}, undef)
329 # see if we can keep the cache (no $rs changes)
331 my %safe = (alias => 1, cache => 1);
332 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
335 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
337 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
339 $cache = $self->get_cache;
342 my $rsrc = $self->result_source;
344 my $old_attrs = { %{$self->{attrs}} };
345 my $old_having = delete $old_attrs->{having};
346 my $old_where = delete $old_attrs->{where};
348 my $new_attrs = { %$old_attrs };
350 # take care of call attrs (only if anything is changing)
351 if (keys %$call_attrs) {
353 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
355 # reset the current selector list if new selectors are supplied
356 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
357 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
360 # Normalize the new selector list (operates on the passed-in attr structure)
361 # Need to do it on every chain instead of only once on _resolved_attrs, in
362 # order to allow detection of empty vs partial 'as'
363 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
364 if $old_attrs->{_dark_selector};
365 $self->_normalize_selection ($call_attrs);
367 # start with blind overwriting merge, exclude selector attrs
368 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
369 delete @{$new_attrs}{@selector_attrs};
371 for (@selector_attrs) {
372 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
373 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
376 # older deprecated name, use only if {columns} is not there
377 if (my $c = delete $new_attrs->{cols}) {
378 if ($new_attrs->{columns}) {
379 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
382 $new_attrs->{columns} = $c;
387 # join/prefetch use their own crazy merging heuristics
388 foreach my $key (qw/join prefetch/) {
389 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
390 if exists $call_attrs->{$key};
393 # stack binds together
394 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
398 # rip apart the rest of @_, parse a condition
401 if (ref $_[0] eq 'HASH') {
402 (keys %{$_[0]}) ? $_[0] : undef
408 $self->throw_exception('Odd number of arguments to search')
416 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
417 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
420 for ($old_where, $call_cond) {
422 $new_attrs->{where} = $self->_stack_cond (
423 $_, $new_attrs->{where}
428 if (defined $old_having) {
429 $new_attrs->{having} = $self->_stack_cond (
430 $old_having, $new_attrs->{having}
434 my $rs = (ref $self)->new($rsrc, $new_attrs);
436 $rs->set_cache($cache) if ($cache);
442 sub _normalize_selection {
443 my ($self, $attrs) = @_;
446 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
447 if exists $attrs->{include_columns};
449 # columns are always placed first, however
451 # Keep the X vs +X separation until _resolved_attrs time - this allows to
452 # delay the decision on whether to use a default select list ($rsrc->columns)
453 # allowing stuff like the remove_columns helper to work
455 # select/as +select/+as pairs need special handling - the amount of select/as
456 # elements in each pair does *not* have to be equal (think multicolumn
457 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
458 # supplied at all) - try to infer the alias, either from the -as parameter
459 # of the selector spec, or use the parameter whole if it looks like a column
460 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
461 # is ok as well), but make sure no more additions to the 'as' chain take place
462 for my $pref ('', '+') {
464 my ($sel, $as) = map {
465 my $key = "${pref}${_}";
467 my $val = [ ref $attrs->{$key} eq 'ARRAY'
469 : $attrs->{$key} || ()
471 delete $attrs->{$key};
475 if (! @$as and ! @$sel ) {
478 elsif (@$as and ! @$sel) {
479 $self->throw_exception(
480 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
484 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
485 # if any @$as has been supplied we assume the user knows what (s)he is doing
486 # and blindly keep stacking up pieces
487 unless ($attrs->{_dark_selector}) {
490 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
491 push @$as, $_->{-as};
493 # assume any plain no-space, no-parenthesis string to be a column spec
494 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
495 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
498 # if all else fails - raise a flag that no more aliasing will be allowed
500 $attrs->{_dark_selector} = {
502 string => ($dark_sel_dumper ||= do {
503 require Data::Dumper::Concise;
504 Data::Dumper::Concise::DumperObject()->Indent(0);
505 })->Values([$_])->Dump
513 elsif (@$as < @$sel) {
514 $self->throw_exception(
515 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
518 elsif ($pref and $attrs->{_dark_selector}) {
519 $self->throw_exception(
520 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
526 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
527 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
532 my ($self, $left, $right) = @_;
534 # collapse single element top-level conditions
535 # (single pass only, unlikely to need recursion)
536 for ($left, $right) {
537 if (ref $_ eq 'ARRAY') {
545 elsif (ref $_ eq 'HASH') {
546 my ($first, $more) = keys %$_;
549 if (! defined $first) {
553 elsif (! defined $more) {
554 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
557 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
564 # merge hashes with weeding out of duplicates (simple cases only)
565 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
567 # shallow copy to destroy
568 $right = { %$right };
569 for (grep { exists $right->{$_} } keys %$left) {
570 # the use of eq_deeply here is justified - the rhs of an
571 # expression can contain a lot of twisted weird stuff
572 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
575 $right = undef unless keys %$right;
579 if (defined $left xor defined $right) {
580 return defined $left ? $left : $right;
582 elsif (! defined $left) {
586 return { -and => [ $left, $right ] };
590 =head2 search_literal
594 =item Arguments: $sql_fragment, @bind_values
596 =item Return Value: $resultset (scalar context) || @row_objs (list context)
600 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
601 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
603 Pass a literal chunk of SQL to be added to the conditional part of the
606 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
607 only be used in that context. C<search_literal> is a convenience method.
608 It is equivalent to calling $schema->search(\[]), but if you want to ensure
609 columns are bound correctly, use C<search>.
611 Example of how to use C<search> instead of C<search_literal>
613 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
614 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
617 See L<DBIx::Class::Manual::Cookbook/Searching> and
618 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
619 require C<search_literal>.
624 my ($self, $sql, @bind) = @_;
626 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
629 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
636 =item Arguments: \%columns_values | @pk_values, \%attrs?
638 =item Return Value: $row_object | undef
642 Finds and returns a single row based on supplied criteria. Takes either a
643 hashref with the same format as L</create> (including inference of foreign
644 keys from related objects), or a list of primary key values in the same
645 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
646 declaration on the L</result_source>.
648 In either case an attempt is made to combine conditions already existing on
649 the resultset with the condition passed to this method.
651 To aid with preparing the correct query for the storage you may supply the
652 C<key> attribute, which is the name of a
653 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
654 unique constraint corresponding to the
655 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
656 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
657 to construct a query that satisfies the named unique constraint fully (
658 non-NULL values for each column member of the constraint) an exception is
661 If no C<key> is specified, the search is carried over all unique constraints
662 which are fully defined by the available condition.
664 If no such constraint is found, C<find> currently defaults to a simple
665 C<< search->(\%column_values) >> which may or may not do what you expect.
666 Note that this fallback behavior may be deprecated in further versions. If
667 you need to search with arbitrary conditions - use L</search>. If the query
668 resulting from this fallback produces more than one row, a warning to the
669 effect is issued, though only the first row is constructed and returned as
672 In addition to C<key>, L</find> recognizes and applies standard
673 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
675 Note that if you have extra concerns about the correctness of the resulting
676 query you need to specify the C<key> attribute and supply the entire condition
677 as an argument to find (since it is not always possible to perform the
678 combination of the resultset condition with the supplied one, especially if
679 the resultset condition contains literal sql).
681 For example, to find a row by its primary key:
683 my $cd = $schema->resultset('CD')->find(5);
685 You can also find a row by a specific unique constraint:
687 my $cd = $schema->resultset('CD')->find(
689 artist => 'Massive Attack',
690 title => 'Mezzanine',
692 { key => 'cd_artist_title' }
695 See also L</find_or_create> and L</update_or_create>.
701 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
703 my $rsrc = $self->result_source;
706 if (exists $attrs->{key}) {
707 $constraint_name = defined $attrs->{key}
709 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
713 # Parse out the condition from input
716 if (ref $_[0] eq 'HASH') {
717 $call_cond = { %{$_[0]} };
720 # if only values are supplied we need to default to 'primary'
721 $constraint_name = 'primary' unless defined $constraint_name;
723 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
725 $self->throw_exception(
726 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
729 $self->throw_exception (
730 'find() expects either a column/value hashref, or a list of values '
731 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
732 ) unless @c_cols == @_;
735 @{$call_cond}{@c_cols} = @_;
739 for my $key (keys %$call_cond) {
741 my $keyref = ref($call_cond->{$key})
743 my $relinfo = $rsrc->relationship_info($key)
745 my $val = delete $call_cond->{$key};
747 next if $keyref eq 'ARRAY'; # has_many for multi_create
749 my $rel_q = $rsrc->_resolve_condition(
750 $relinfo->{cond}, $val, $key, $key
752 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
753 @related{keys %$rel_q} = values %$rel_q;
757 # relationship conditions take precedence (?)
758 @{$call_cond}{keys %related} = values %related;
760 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
762 if (defined $constraint_name) {
763 $final_cond = $self->_qualify_cond_columns (
765 $self->_build_unique_cond (
773 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
774 # This means that we got here after a merger of relationship conditions
775 # in ::Relationship::Base::search_related (the row method), and furthermore
776 # the relationship is of the 'single' type. This means that the condition
777 # provided by the relationship (already attached to $self) is sufficient,
778 # as there can be only one row in the database that would satisfy the
782 # no key was specified - fall down to heuristics mode:
783 # run through all unique queries registered on the resultset, and
784 # 'OR' all qualifying queries together
785 my (@unique_queries, %seen_column_combinations);
786 for my $c_name ($rsrc->unique_constraint_names) {
787 next if $seen_column_combinations{
788 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
791 push @unique_queries, try {
792 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
796 $final_cond = @unique_queries
797 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
798 : $self->_non_unique_find_fallback ($call_cond, $attrs)
802 # Run the query, passing the result_class since it should propagate for find
803 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
804 if (keys %{$rs->_resolved_attrs->{collapse}}) {
806 carp "Query returned more than one row" if $rs->next;
814 # This is a stop-gap method as agreed during the discussion on find() cleanup:
815 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
817 # It is invoked when find() is called in legacy-mode with insufficiently-unique
818 # condition. It is provided for overrides until a saner way forward is devised
820 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
821 # the road. Please adjust your tests accordingly to catch this situation early
822 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
824 # The method will not be removed without an adequately complete replacement
825 # for strict-mode enforcement
826 sub _non_unique_find_fallback {
827 my ($self, $cond, $attrs) = @_;
829 return $self->_qualify_cond_columns(
831 exists $attrs->{alias}
833 : $self->{attrs}{alias}
838 sub _qualify_cond_columns {
839 my ($self, $cond, $alias) = @_;
841 my %aliased = %$cond;
842 for (keys %aliased) {
843 $aliased{"$alias.$_"} = delete $aliased{$_}
850 sub _build_unique_cond {
851 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
853 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
855 # combination may fail if $self->{cond} is non-trivial
856 my ($final_cond) = try {
857 $self->_merge_with_rscond ($extra_cond)
862 # trim out everything not in $columns
863 $final_cond = { map {
864 exists $final_cond->{$_}
865 ? ( $_ => $final_cond->{$_} )
869 if (my @missing = grep
870 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
873 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
875 join (', ', map { "'$_'" } @missing),
882 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
884 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
886 carp_unique ( sprintf (
887 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
888 . 'values in column(s): %s). This is almost certainly not what you wanted, '
889 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
891 join (', ', map { "'$_'" } @undefs),
898 =head2 search_related
902 =item Arguments: $rel, $cond, \%attrs?
904 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
908 $new_rs = $cd_rs->search_related('artist', {
912 Searches the specified relationship, optionally specifying a condition and
913 attributes for matching records. See L</ATTRIBUTES> for more information.
915 In list context, C<< ->all() >> is called implicitly on the resultset, thus
916 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
918 See also L</search_related_rs>.
923 return shift->related_resultset(shift)->search(@_);
926 =head2 search_related_rs
928 This method works exactly the same as search_related, except that
929 it guarantees a resultset, even in list context.
933 sub search_related_rs {
934 return shift->related_resultset(shift)->search_rs(@_);
941 =item Arguments: none
943 =item Return Value: $cursor
947 Returns a storage-driven cursor to the given resultset. See
948 L<DBIx::Class::Cursor> for more information.
955 my $attrs = $self->_resolved_attrs_copy;
957 return $self->{cursor}
958 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
959 $attrs->{where},$attrs);
966 =item Arguments: $cond?
968 =item Return Value: $row_object | undef
972 my $cd = $schema->resultset('CD')->single({ year => 2001 });
974 Inflates the first result without creating a cursor if the resultset has
975 any records in it; if not returns C<undef>. Used by L</find> as a lean version
978 While this method can take an optional search condition (just like L</search>)
979 being a fast-code-path it does not recognize search attributes. If you need to
980 add extra joins or similar, call L</search> and then chain-call L</single> on the
981 L<DBIx::Class::ResultSet> returned.
987 As of 0.08100, this method enforces the assumption that the preceding
988 query returns only one row. If more than one row is returned, you will receive
991 Query returned more than one row
993 In this case, you should be using L</next> or L</find> instead, or if you really
994 know what you are doing, use the L</rows> attribute to explicitly limit the size
997 This method will also throw an exception if it is called on a resultset prefetching
998 has_many, as such a prefetch implies fetching multiple rows from the database in
999 order to assemble the resulting object.
1006 my ($self, $where) = @_;
1008 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1011 my $attrs = $self->_resolved_attrs_copy;
1013 if (keys %{$attrs->{collapse}}) {
1014 $self->throw_exception(
1015 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
1020 if (defined $attrs->{where}) {
1023 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1024 $where, delete $attrs->{where} ]
1027 $attrs->{where} = $where;
1031 my @data = $self->result_source->storage->select_single(
1032 $attrs->{from}, $attrs->{select},
1033 $attrs->{where}, $attrs
1036 return (@data ? ($self->_construct_object(@data))[0] : undef);
1042 # Recursively collapse the query, accumulating values for each column.
1044 sub _collapse_query {
1045 my ($self, $query, $collapsed) = @_;
1049 if (ref $query eq 'ARRAY') {
1050 foreach my $subquery (@$query) {
1051 next unless ref $subquery; # -or
1052 $collapsed = $self->_collapse_query($subquery, $collapsed);
1055 elsif (ref $query eq 'HASH') {
1056 if (keys %$query and (keys %$query)[0] eq '-and') {
1057 foreach my $subquery (@{$query->{-and}}) {
1058 $collapsed = $self->_collapse_query($subquery, $collapsed);
1062 foreach my $col (keys %$query) {
1063 my $value = $query->{$col};
1064 $collapsed->{$col}{$value}++;
1076 =item Arguments: $cond?
1078 =item Return Value: $resultsetcolumn
1082 my $max_length = $rs->get_column('length')->max;
1084 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1089 my ($self, $column) = @_;
1090 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1098 =item Arguments: $cond, \%attrs?
1100 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1104 # WHERE title LIKE '%blue%'
1105 $cd_rs = $rs->search_like({ title => '%blue%'});
1107 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1108 that this is simply a convenience method retained for ex Class::DBI users.
1109 You most likely want to use L</search> with specific operators.
1111 For more information, see L<DBIx::Class::Manual::Cookbook>.
1113 This method is deprecated and will be removed in 0.09. Use L</search()>
1114 instead. An example conversion is:
1116 ->search_like({ foo => 'bar' });
1120 ->search({ foo => { like => 'bar' } });
1127 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1128 .' Instead use ->search({ x => { -like => "y%" } })'
1129 .' (note the outer pair of {}s - they are important!)'
1131 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1132 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1133 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1134 return $class->search($query, { %$attrs });
1141 =item Arguments: $first, $last
1143 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1147 Returns a resultset or object list representing a subset of elements from the
1148 resultset slice is called on. Indexes are from 0, i.e., to get the first
1149 three records, call:
1151 my ($one, $two, $three) = $rs->slice(0, 2);
1156 my ($self, $min, $max) = @_;
1157 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1158 $attrs->{offset} = $self->{attrs}{offset} || 0;
1159 $attrs->{offset} += $min;
1160 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1161 return $self->search(undef, $attrs);
1162 #my $slice = (ref $self)->new($self->result_source, $attrs);
1163 #return (wantarray ? $slice->all : $slice);
1170 =item Arguments: none
1172 =item Return Value: $result | undef
1176 Returns the next element in the resultset (C<undef> is there is none).
1178 Can be used to efficiently iterate over records in the resultset:
1180 my $rs = $schema->resultset('CD')->search;
1181 while (my $cd = $rs->next) {
1185 Note that you need to store the resultset object, and call C<next> on it.
1186 Calling C<< resultset('Table')->next >> repeatedly will always return the
1187 first record from the resultset.
1193 if (my $cache = $self->get_cache) {
1194 $self->{all_cache_position} ||= 0;
1195 return $cache->[$self->{all_cache_position}++];
1197 if ($self->{attrs}{cache}) {
1198 delete $self->{pager};
1199 $self->{all_cache_position} = 1;
1200 return ($self->all)[0];
1202 if ($self->{stashed_objects}) {
1203 my $obj = shift(@{$self->{stashed_objects}});
1204 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1208 exists $self->{stashed_row}
1209 ? @{delete $self->{stashed_row}}
1210 : $self->cursor->next
1212 return undef unless (@row);
1213 my ($row, @more) = $self->_construct_object(@row);
1214 $self->{stashed_objects} = \@more if @more;
1218 sub _construct_object {
1219 my ($self, @row) = @_;
1221 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1223 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1224 @new = $self->{_attrs}{record_filter}->(@new)
1225 if exists $self->{_attrs}{record_filter};
1229 sub _collapse_result {
1230 my ($self, $as_proto, $row) = @_;
1234 # 'foo' => [ undef, 'foo' ]
1235 # 'foo.bar' => [ 'foo', 'bar' ]
1236 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1238 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1240 my %collapse = %{$self->{_attrs}{collapse}||{}};
1244 # if we're doing collapsing (has_many prefetch) we need to grab records
1245 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1246 # we know we don't have to bother.
1248 # the reason for not using the collapse stuff directly is because if you
1249 # had for e.g. two artists in a row with no cds, the collapse info for
1250 # both would be NULL (undef) so you'd lose the second artist
1252 # store just the index so we can check the array positions from the row
1253 # without having to contruct the full hash
1255 if (keys %collapse) {
1256 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1257 foreach my $i (0 .. $#construct_as) {
1258 next if defined($construct_as[$i][0]); # only self table
1259 if (delete $pri{$construct_as[$i][1]}) {
1260 push(@pri_index, $i);
1262 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1266 # no need to do an if, it'll be empty if @pri_index is empty anyway
1268 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1272 do { # no need to check anything at the front, we always want the first row
1276 foreach my $this_as (@construct_as) {
1277 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1280 push(@const_rows, \%const);
1282 } until ( # no pri_index => no collapse => drop straight out
1285 do { # get another row, stash it, drop out if different PK
1287 @copy = $self->cursor->next;
1288 $self->{stashed_row} = \@copy;
1290 # last thing in do block, counts as true if anything doesn't match
1292 # check xor defined first for NULL vs. NOT NULL then if one is
1293 # defined the other must be so check string equality
1296 (defined $pri_vals{$_} ^ defined $copy[$_])
1297 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1302 my $alias = $self->{attrs}{alias};
1309 foreach my $const (@const_rows) {
1310 scalar @const_keys or do {
1311 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1313 foreach my $key (@const_keys) {
1316 my @parts = split(/\./, $key);
1318 my $data = $const->{$key};
1319 foreach my $p (@parts) {
1320 $target = $target->[1]->{$p} ||= [];
1322 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1323 # collapsing at this point and on final part
1324 my $pos = $collapse_pos{$cur};
1325 CK: foreach my $ck (@ckey) {
1326 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1327 $collapse_pos{$cur} = $data;
1328 delete @collapse_pos{ # clear all positioning for sub-entries
1329 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1336 if (exists $collapse{$cur}) {
1337 $target = $target->[-1];
1340 $target->[0] = $data;
1342 $info->[0] = $const->{$key};
1350 =head2 result_source
1354 =item Arguments: $result_source?
1356 =item Return Value: $result_source
1360 An accessor for the primary ResultSource object from which this ResultSet
1367 =item Arguments: $result_class?
1369 =item Return Value: $result_class
1373 An accessor for the class to use when creating row objects. Defaults to
1374 C<< result_source->result_class >> - which in most cases is the name of the
1375 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1377 Note that changing the result_class will also remove any components
1378 that were originally loaded in the source class via
1379 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1380 in the original source class will not run.
1385 my ($self, $result_class) = @_;
1386 if ($result_class) {
1387 unless (ref $result_class) { # don't fire this for an object
1388 $self->ensure_class_loaded($result_class);
1390 $self->_result_class($result_class);
1391 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1392 # permit the user to set result class on one result set only; it only
1393 # chains if provided to search()
1394 #$self->{attrs}{result_class} = $result_class if ref $self;
1396 $self->_result_class;
1403 =item Arguments: $cond, \%attrs??
1405 =item Return Value: $count
1409 Performs an SQL C<COUNT> with the same query as the resultset was built
1410 with to find the number of elements. Passing arguments is equivalent to
1411 C<< $rs->search ($cond, \%attrs)->count >>
1417 return $self->search(@_)->count if @_ and defined $_[0];
1418 return scalar @{ $self->get_cache } if $self->get_cache;
1420 my $attrs = $self->_resolved_attrs_copy;
1422 # this is a little optimization - it is faster to do the limit
1423 # adjustments in software, instead of a subquery
1424 my $rows = delete $attrs->{rows};
1425 my $offset = delete $attrs->{offset};
1428 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1429 $crs = $self->_count_subq_rs ($attrs);
1432 $crs = $self->_count_rs ($attrs);
1434 my $count = $crs->next;
1436 $count -= $offset if $offset;
1437 $count = $rows if $rows and $rows < $count;
1438 $count = 0 if ($count < 0);
1447 =item Arguments: $cond, \%attrs??
1449 =item Return Value: $count_rs
1453 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1454 This can be very handy for subqueries:
1456 ->search( { amount => $some_rs->count_rs->as_query } )
1458 As with regular resultsets the SQL query will be executed only after
1459 the resultset is accessed via L</next> or L</all>. That would return
1460 the same single value obtainable via L</count>.
1466 return $self->search(@_)->count_rs if @_;
1468 # this may look like a lack of abstraction (count() does about the same)
1469 # but in fact an _rs *must* use a subquery for the limits, as the
1470 # software based limiting can not be ported if this $rs is to be used
1471 # in a subquery itself (i.e. ->as_query)
1472 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1473 return $self->_count_subq_rs;
1476 return $self->_count_rs;
1481 # returns a ResultSetColumn object tied to the count query
1484 my ($self, $attrs) = @_;
1486 my $rsrc = $self->result_source;
1487 $attrs ||= $self->_resolved_attrs;
1489 my $tmp_attrs = { %$attrs };
1490 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1491 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1493 # overwrite the selector (supplied by the storage)
1494 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1495 $tmp_attrs->{as} = 'count';
1496 delete @{$tmp_attrs}{qw/columns/};
1498 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1504 # same as above but uses a subquery
1506 sub _count_subq_rs {
1507 my ($self, $attrs) = @_;
1509 my $rsrc = $self->result_source;
1510 $attrs ||= $self->_resolved_attrs;
1512 my $sub_attrs = { %$attrs };
1513 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1514 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1516 # if we multi-prefetch we group_by primary keys only as this is what we would
1517 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1518 if ( keys %{$attrs->{collapse}} ) {
1519 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1522 # Calculate subquery selector
1523 if (my $g = $sub_attrs->{group_by}) {
1525 my $sql_maker = $rsrc->storage->sql_maker;
1527 # necessary as the group_by may refer to aliased functions
1529 for my $sel (@{$attrs->{select}}) {
1530 $sel_index->{$sel->{-as}} = $sel
1531 if (ref $sel eq 'HASH' and $sel->{-as});
1534 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1535 # also look for named aggregates referred in the having clause
1536 # having often contains scalarrefs - thus parse it out entirely
1538 if ($attrs->{having}) {
1539 local $sql_maker->{having_bind};
1540 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1541 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1542 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1543 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1544 # if we don't unset it we screw up retarded but unfortunately working
1545 # 'MAX(foo.bar)' => { '>', 3 }
1546 $sql_maker->{name_sep} = '';
1549 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1551 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1553 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1554 # and if all fails for an utterly naive quoted scalar-with-function
1556 $rquote $sep $lquote (.+?) $rquote
1558 [\s,] \w+ \. (\w+) [\s,]
1560 [\s,] $lquote (.+?) $rquote [\s,]
1562 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1567 my $colpiece = $sel_index->{$_} || $_;
1569 # unqualify join-based group_by's. Arcane but possible query
1570 # also horrible horrible hack to alias a column (not a func.)
1571 # (probably need to introduce SQLA syntax)
1572 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1575 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1577 push @{$sub_attrs->{select}}, $colpiece;
1581 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1582 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1585 return $rsrc->resultset_class
1586 ->new ($rsrc, $sub_attrs)
1588 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1589 ->get_column ('count');
1596 =head2 count_literal
1600 =item Arguments: $sql_fragment, @bind_values
1602 =item Return Value: $count
1606 Counts the results in a literal query. Equivalent to calling L</search_literal>
1607 with the passed arguments, then L</count>.
1611 sub count_literal { shift->search_literal(@_)->count; }
1617 =item Arguments: none
1619 =item Return Value: @objects
1623 Returns all elements in the resultset.
1630 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1633 return @{ $self->get_cache } if $self->get_cache;
1637 if (keys %{$self->_resolved_attrs->{collapse}}) {
1638 # Using $self->cursor->all is really just an optimisation.
1639 # If we're collapsing has_many prefetches it probably makes
1640 # very little difference, and this is cleaner than hacking
1641 # _construct_object to survive the approach
1642 $self->cursor->reset;
1643 my @row = $self->cursor->next;
1645 push(@obj, $self->_construct_object(@row));
1646 @row = (exists $self->{stashed_row}
1647 ? @{delete $self->{stashed_row}}
1648 : $self->cursor->next);
1651 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1654 $self->set_cache(\@obj) if $self->{attrs}{cache};
1663 =item Arguments: none
1665 =item Return Value: $self
1669 Resets the resultset's cursor, so you can iterate through the elements again.
1670 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1677 delete $self->{_attrs} if exists $self->{_attrs};
1678 $self->{all_cache_position} = 0;
1679 $self->cursor->reset;
1687 =item Arguments: none
1689 =item Return Value: $object | undef
1693 Resets the resultset and returns an object for the first result (or C<undef>
1694 if the resultset is empty).
1699 return $_[0]->reset->next;
1705 # Determines whether and what type of subquery is required for the $rs operation.
1706 # If grouping is necessary either supplies its own, or verifies the current one
1707 # After all is done delegates to the proper storage method.
1709 sub _rs_update_delete {
1710 my ($self, $op, $values) = @_;
1712 my $rsrc = $self->result_source;
1714 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1715 my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
1717 if ($needs_group_by_subq or $needs_subq) {
1719 # make a new $rs selecting only the PKs (that's all we really need)
1720 my $attrs = $self->_resolved_attrs_copy;
1723 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1724 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1726 if ($needs_group_by_subq) {
1727 # make sure no group_by was supplied, or if there is one - make sure it matches
1728 # the columns compiled above perfectly. Anything else can not be sanely executed
1729 # on most databases so croak right then and there
1731 if (my $g = $attrs->{group_by}) {
1732 my @current_group_by = map
1733 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1738 join ("\x00", sort @current_group_by)
1740 join ("\x00", sort @{$attrs->{columns}} )
1742 $self->throw_exception (
1743 "You have just attempted a $op operation on a resultset which does group_by"
1744 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1745 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1746 . ' kind of queries. Please retry the operation with a modified group_by or'
1747 . ' without using one at all.'
1752 $attrs->{group_by} = $attrs->{columns};
1756 my $subrs = (ref $self)->new($rsrc, $attrs);
1757 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1760 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1761 # a condition containing 'me' or other table prefixes will not work
1762 # at all. What this code tries to do (badly) is to generate a condition
1763 # with the qualifiers removed, by exploiting the quote mechanism of sqla
1765 # this is atrocious and should be replaced by normal sqla introspection
1767 my ($sql, @bind) = do {
1768 my $sqla = $rsrc->storage->sql_maker;
1769 local $sqla->{_dequalify_idents} = 1;
1770 $sqla->_recurse_where($self->{cond});
1773 return $rsrc->storage->$op(
1775 $op eq 'update' ? $values : (),
1776 $self->{cond} ? \[$sql, @bind] : (),
1785 =item Arguments: \%values
1787 =item Return Value: $storage_rv
1791 Sets the specified columns in the resultset to the supplied values in a
1792 single query. Note that this will not run any accessor/set_column/update
1793 triggers, nor will it update any row object instances derived from this
1794 resultset (this includes the contents of the L<resultset cache|/set_cache>
1795 if any). See L</update_all> if you need to execute any on-update
1796 triggers or cascades defined either by you or a
1797 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1799 The return value is a pass through of what the underlying
1800 storage backend returned, and may vary. See L<DBI/execute> for the most
1805 Note that L</update> does not process/deflate any of the values passed in.
1806 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1807 ensure manually that any value passed to this method will stringify to
1808 something the RDBMS knows how to deal with. A notable example is the
1809 handling of L<DateTime> objects, for more info see:
1810 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1815 my ($self, $values) = @_;
1816 $self->throw_exception('Values for update must be a hash')
1817 unless ref $values eq 'HASH';
1819 return $self->_rs_update_delete ('update', $values);
1826 =item Arguments: \%values
1828 =item Return Value: 1
1832 Fetches all objects and updates them one at a time via
1833 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1834 triggers, while L</update> will not.
1839 my ($self, $values) = @_;
1840 $self->throw_exception('Values for update_all must be a hash')
1841 unless ref $values eq 'HASH';
1843 my $guard = $self->result_source->schema->txn_scope_guard;
1844 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
1853 =item Arguments: none
1855 =item Return Value: $storage_rv
1859 Deletes the rows matching this resultset in a single query. Note that this
1860 will not run any delete triggers, nor will it alter the
1861 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1862 derived from this resultset (this includes the contents of the
1863 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1864 execute any on-delete triggers or cascades defined either by you or a
1865 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1867 The return value is a pass through of what the underlying storage backend
1868 returned, and may vary. See L<DBI/execute> for the most common case.
1874 $self->throw_exception('delete does not accept any arguments')
1877 return $self->_rs_update_delete ('delete');
1884 =item Arguments: none
1886 =item Return Value: 1
1890 Fetches all objects and deletes them one at a time via
1891 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1892 triggers, while L</delete> will not.
1898 $self->throw_exception('delete_all does not accept any arguments')
1901 my $guard = $self->result_source->schema->txn_scope_guard;
1902 $_->delete for $self->all;
1911 =item Arguments: \@data;
1915 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1916 For the arrayref of hashrefs style each hashref should be a structure suitable
1917 for submitting to a $resultset->create(...) method.
1919 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1920 to insert the data, as this is a faster method.
1922 Otherwise, each set of data is inserted into the database using
1923 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1924 accumulated into an array. The array itself, or an array reference
1925 is returned depending on scalar or list context.
1927 Example: Assuming an Artist Class that has many CDs Classes relating:
1929 my $Artist_rs = $schema->resultset("Artist");
1931 ## Void Context Example
1932 $Artist_rs->populate([
1933 { artistid => 4, name => 'Manufactured Crap', cds => [
1934 { title => 'My First CD', year => 2006 },
1935 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1938 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1939 { title => 'My parents sold me to a record company', year => 2005 },
1940 { title => 'Why Am I So Ugly?', year => 2006 },
1941 { title => 'I Got Surgery and am now Popular', year => 2007 }
1946 ## Array Context Example
1947 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1948 { name => "Artist One"},
1949 { name => "Artist Two"},
1950 { name => "Artist Three", cds=> [
1951 { title => "First CD", year => 2007},
1952 { title => "Second CD", year => 2008},
1956 print $ArtistOne->name; ## response is 'Artist One'
1957 print $ArtistThree->cds->count ## reponse is '2'
1959 For the arrayref of arrayrefs style, the first element should be a list of the
1960 fieldsnames to which the remaining elements are rows being inserted. For
1963 $Arstist_rs->populate([
1964 [qw/artistid name/],
1965 [100, 'A Formally Unknown Singer'],
1966 [101, 'A singer that jumped the shark two albums ago'],
1967 [102, 'An actually cool singer'],
1970 Please note an important effect on your data when choosing between void and
1971 wantarray context. Since void context goes straight to C<insert_bulk> in
1972 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1973 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1974 create primary keys for you, you will find that your PKs are empty. In this
1975 case you will have to use the wantarray context in order to create those
1983 # cruft placed in standalone method
1984 my $data = $self->_normalize_populate_args(@_);
1986 return unless @$data;
1988 if(defined wantarray) {
1990 foreach my $item (@$data) {
1991 push(@created, $self->create($item));
1993 return wantarray ? @created : \@created;
1996 my $first = $data->[0];
1998 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1999 # it relationship data
2000 my (@rels, @columns);
2001 my $rsrc = $self->result_source;
2002 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2003 for (keys %$first) {
2004 my $ref = ref $first->{$_};
2005 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2011 my @pks = $rsrc->primary_columns;
2013 ## do the belongs_to relationships
2014 foreach my $index (0..$#$data) {
2016 # delegate to create() for any dataset without primary keys with specified relationships
2017 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2019 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2020 my @ret = $self->populate($data);
2026 foreach my $rel (@rels) {
2027 next unless ref $data->[$index]->{$rel} eq "HASH";
2028 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2029 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2030 my $related = $result->result_source->_resolve_condition(
2031 $reverse_relinfo->{cond},
2037 delete $data->[$index]->{$rel};
2038 $data->[$index] = {%{$data->[$index]}, %$related};
2040 push @columns, keys %$related if $index == 0;
2044 ## inherit the data locked in the conditions of the resultset
2045 my ($rs_data) = $self->_merge_with_rscond({});
2046 delete @{$rs_data}{@columns};
2047 my @inherit_cols = keys %$rs_data;
2048 my @inherit_data = values %$rs_data;
2050 ## do bulk insert on current row
2051 $rsrc->storage->insert_bulk(
2053 [@columns, @inherit_cols],
2054 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
2057 ## do the has_many relationships
2058 foreach my $item (@$data) {
2062 foreach my $rel (@rels) {
2063 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2065 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2067 my $child = $main_row->$rel;
2069 my $related = $child->result_source->_resolve_condition(
2070 $rels->{$rel}{cond},
2076 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2077 my @populate = map { {%$_, %$related} } @rows_to_add;
2079 $child->populate( \@populate );
2086 # populate() argumnets went over several incarnations
2087 # What we ultimately support is AoH
2088 sub _normalize_populate_args {
2089 my ($self, $arg) = @_;
2091 if (ref $arg eq 'ARRAY') {
2095 elsif (ref $arg->[0] eq 'HASH') {
2098 elsif (ref $arg->[0] eq 'ARRAY') {
2100 my @colnames = @{$arg->[0]};
2101 foreach my $values (@{$arg}[1 .. $#$arg]) {
2102 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2108 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2115 =item Arguments: none
2117 =item Return Value: $pager
2121 Return Value a L<Data::Page> object for the current resultset. Only makes
2122 sense for queries with a C<page> attribute.
2124 To get the full count of entries for a paged resultset, call
2125 C<total_entries> on the L<Data::Page> object.
2132 return $self->{pager} if $self->{pager};
2134 my $attrs = $self->{attrs};
2135 if (!defined $attrs->{page}) {
2136 $self->throw_exception("Can't create pager for non-paged rs");
2138 elsif ($attrs->{page} <= 0) {
2139 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2141 $attrs->{rows} ||= 10;
2143 # throw away the paging flags and re-run the count (possibly
2144 # with a subselect) to get the real total count
2145 my $count_attrs = { %$attrs };
2146 delete $count_attrs->{$_} for qw/rows offset page pager/;
2148 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2150 require DBIx::Class::ResultSet::Pager;
2151 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2152 sub { $total_rs->count }, #lazy-get the total
2154 $self->{attrs}{page},
2162 =item Arguments: $page_number
2164 =item Return Value: $rs
2168 Returns a resultset for the $page_number page of the resultset on which page
2169 is called, where each page contains a number of rows equal to the 'rows'
2170 attribute set on the resultset (10 by default).
2175 my ($self, $page) = @_;
2176 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2183 =item Arguments: \%vals
2185 =item Return Value: $rowobject
2189 Creates a new row object in the resultset's result class and returns
2190 it. The row is not inserted into the database at this point, call
2191 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2192 will tell you whether the row object has been inserted or not.
2194 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2199 my ($self, $values) = @_;
2200 $self->throw_exception( "new_result needs a hash" )
2201 unless (ref $values eq 'HASH');
2203 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2207 @$cols_from_relations
2208 ? (-cols_from_relations => $cols_from_relations)
2210 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2213 return $self->result_class->new(\%new);
2216 # _merge_with_rscond
2218 # Takes a simple hash of K/V data and returns its copy merged with the
2219 # condition already present on the resultset. Additionally returns an
2220 # arrayref of value/condition names, which were inferred from related
2221 # objects (this is needed for in-memory related objects)
2222 sub _merge_with_rscond {
2223 my ($self, $data) = @_;
2225 my (%new_data, @cols_from_relations);
2227 my $alias = $self->{attrs}{alias};
2229 if (! defined $self->{cond}) {
2230 # just massage $data below
2232 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2233 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2234 @cols_from_relations = keys %new_data;
2236 elsif (ref $self->{cond} ne 'HASH') {
2237 $self->throw_exception(
2238 "Can't abstract implicit construct, resultset condition not a hash"
2242 # precendence must be given to passed values over values inherited from
2243 # the cond, so the order here is important.
2244 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2245 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2247 while ( my($col, $value) = each %implied ) {
2248 my $vref = ref $value;
2254 (keys %$value)[0] eq '='
2256 $new_data{$col} = $value->{'='};
2258 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2259 $new_data{$col} = $value;
2266 %{ $self->_remove_alias($data, $alias) },
2269 return (\%new_data, \@cols_from_relations);
2272 # _has_resolved_attr
2274 # determines if the resultset defines at least one
2275 # of the attributes supplied
2277 # used to determine if a subquery is neccessary
2279 # supports some virtual attributes:
2281 # This will scan for any joins being present on the resultset.
2282 # It is not a mere key-search but a deep inspection of {from}
2285 sub _has_resolved_attr {
2286 my ($self, @attr_names) = @_;
2288 my $attrs = $self->_resolved_attrs;
2292 for my $n (@attr_names) {
2293 if (grep { $n eq $_ } (qw/-join/) ) {
2294 $extra_checks{$n}++;
2298 my $attr = $attrs->{$n};
2300 next if not defined $attr;
2302 if (ref $attr eq 'HASH') {
2303 return 1 if keys %$attr;
2305 elsif (ref $attr eq 'ARRAY') {
2313 # a resolved join is expressed as a multi-level from
2315 $extra_checks{-join}
2317 ref $attrs->{from} eq 'ARRAY'
2319 @{$attrs->{from}} > 1
2327 # Recursively collapse the condition.
2329 sub _collapse_cond {
2330 my ($self, $cond, $collapsed) = @_;
2334 if (ref $cond eq 'ARRAY') {
2335 foreach my $subcond (@$cond) {
2336 next unless ref $subcond; # -or
2337 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2340 elsif (ref $cond eq 'HASH') {
2341 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2342 foreach my $subcond (@{$cond->{-and}}) {
2343 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2347 foreach my $col (keys %$cond) {
2348 my $value = $cond->{$col};
2349 $collapsed->{$col} = $value;
2359 # Remove the specified alias from the specified query hash. A copy is made so
2360 # the original query is not modified.
2363 my ($self, $query, $alias) = @_;
2365 my %orig = %{ $query || {} };
2368 foreach my $key (keys %orig) {
2370 $unaliased{$key} = $orig{$key};
2373 $unaliased{$1} = $orig{$key}
2374 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2384 =item Arguments: none
2386 =item Return Value: \[ $sql, @bind ]
2390 Returns the SQL query and bind vars associated with the invocant.
2392 This is generally used as the RHS for a subquery.
2399 my $attrs = $self->_resolved_attrs_copy;
2404 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2405 # $sql also has no wrapping parenthesis in list ctx
2407 my $sqlbind = $self->result_source->storage
2408 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2417 =item Arguments: \%vals, \%attrs?
2419 =item Return Value: $rowobject
2423 my $artist = $schema->resultset('Artist')->find_or_new(
2424 { artist => 'fred' }, { key => 'artists' });
2426 $cd->cd_to_producer->find_or_new({ producer => $producer },
2427 { key => 'primary });
2429 Find an existing record from this resultset using L</find>. if none exists,
2430 instantiate a new result object and return it. The object will not be saved
2431 into your storage until you call L<DBIx::Class::Row/insert> on it.
2433 You most likely want this method when looking for existing rows using a unique
2434 constraint that is not the primary key, or looking for related rows.
2436 If you want objects to be saved immediately, use L</find_or_create> instead.
2438 B<Note>: Make sure to read the documentation of L</find> and understand the
2439 significance of the C<key> attribute, as its lack may skew your search, and
2440 subsequently result in spurious new objects.
2442 B<Note>: Take care when using C<find_or_new> with a table having
2443 columns with default values that you intend to be automatically
2444 supplied by the database (e.g. an auto_increment primary key column).
2445 In normal usage, the value of such columns should NOT be included at
2446 all in the call to C<find_or_new>, even when set to C<undef>.
2452 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2453 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2454 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2457 return $self->new_result($hash);
2464 =item Arguments: \%vals
2466 =item Return Value: a L<DBIx::Class::Row> $object
2470 Attempt to create a single new row or a row with multiple related rows
2471 in the table represented by the resultset (and related tables). This
2472 will not check for duplicate rows before inserting, use
2473 L</find_or_create> to do that.
2475 To create one row for this resultset, pass a hashref of key/value
2476 pairs representing the columns of the table and the values you wish to
2477 store. If the appropriate relationships are set up, foreign key fields
2478 can also be passed an object representing the foreign row, and the
2479 value will be set to its primary key.
2481 To create related objects, pass a hashref of related-object column values
2482 B<keyed on the relationship name>. If the relationship is of type C<multi>
2483 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2484 The process will correctly identify columns holding foreign keys, and will
2485 transparently populate them from the keys of the corresponding relation.
2486 This can be applied recursively, and will work correctly for a structure
2487 with an arbitrary depth and width, as long as the relationships actually
2488 exists and the correct column data has been supplied.
2491 Instead of hashrefs of plain related data (key/value pairs), you may
2492 also pass new or inserted objects. New objects (not inserted yet, see
2493 L</new>), will be inserted into their appropriate tables.
2495 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2497 Example of creating a new row.
2499 $person_rs->create({
2500 name=>"Some Person",
2501 email=>"somebody@someplace.com"
2504 Example of creating a new row and also creating rows in a related C<has_many>
2505 or C<has_one> resultset. Note Arrayref.
2508 { artistid => 4, name => 'Manufactured Crap', cds => [
2509 { title => 'My First CD', year => 2006 },
2510 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2515 Example of creating a new row and also creating a row in a related
2516 C<belongs_to> resultset. Note Hashref.
2519 title=>"Music for Silly Walks",
2522 name=>"Silly Musician",
2530 When subclassing ResultSet never attempt to override this method. Since
2531 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2532 lot of the internals simply never call it, so your override will be
2533 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2534 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2535 L</create> process you need to intervene.
2542 my ($self, $attrs) = @_;
2543 $self->throw_exception( "create needs a hashref" )
2544 unless ref $attrs eq 'HASH';
2545 return $self->new_result($attrs)->insert;
2548 =head2 find_or_create
2552 =item Arguments: \%vals, \%attrs?
2554 =item Return Value: $rowobject
2558 $cd->cd_to_producer->find_or_create({ producer => $producer },
2559 { key => 'primary' });
2561 Tries to find a record based on its primary key or unique constraints; if none
2562 is found, creates one and returns that instead.
2564 my $cd = $schema->resultset('CD')->find_or_create({
2566 artist => 'Massive Attack',
2567 title => 'Mezzanine',
2571 Also takes an optional C<key> attribute, to search by a specific key or unique
2572 constraint. For example:
2574 my $cd = $schema->resultset('CD')->find_or_create(
2576 artist => 'Massive Attack',
2577 title => 'Mezzanine',
2579 { key => 'cd_artist_title' }
2582 B<Note>: Make sure to read the documentation of L</find> and understand the
2583 significance of the C<key> attribute, as its lack may skew your search, and
2584 subsequently result in spurious row creation.
2586 B<Note>: Because find_or_create() reads from the database and then
2587 possibly inserts based on the result, this method is subject to a race
2588 condition. Another process could create a record in the table after
2589 the find has completed and before the create has started. To avoid
2590 this problem, use find_or_create() inside a transaction.
2592 B<Note>: Take care when using C<find_or_create> with a table having
2593 columns with default values that you intend to be automatically
2594 supplied by the database (e.g. an auto_increment primary key column).
2595 In normal usage, the value of such columns should NOT be included at
2596 all in the call to C<find_or_create>, even when set to C<undef>.
2598 See also L</find> and L</update_or_create>. For information on how to declare
2599 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2603 sub find_or_create {
2605 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2606 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2607 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2610 return $self->create($hash);
2613 =head2 update_or_create
2617 =item Arguments: \%col_values, { key => $unique_constraint }?
2619 =item Return Value: $row_object
2623 $resultset->update_or_create({ col => $val, ... });
2625 Like L</find_or_create>, but if a row is found it is immediately updated via
2626 C<< $found_row->update (\%col_values) >>.
2629 Takes an optional C<key> attribute to search on a specific unique constraint.
2632 # In your application
2633 my $cd = $schema->resultset('CD')->update_or_create(
2635 artist => 'Massive Attack',
2636 title => 'Mezzanine',
2639 { key => 'cd_artist_title' }
2642 $cd->cd_to_producer->update_or_create({
2643 producer => $producer,
2649 B<Note>: Make sure to read the documentation of L</find> and understand the
2650 significance of the C<key> attribute, as its lack may skew your search, and
2651 subsequently result in spurious row creation.
2653 B<Note>: Take care when using C<update_or_create> with a table having
2654 columns with default values that you intend to be automatically
2655 supplied by the database (e.g. an auto_increment primary key column).
2656 In normal usage, the value of such columns should NOT be included at
2657 all in the call to C<update_or_create>, even when set to C<undef>.
2659 See also L</find> and L</find_or_create>. For information on how to declare
2660 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2664 sub update_or_create {
2666 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2667 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2669 my $row = $self->find($cond, $attrs);
2671 $row->update($cond);
2675 return $self->create($cond);
2678 =head2 update_or_new
2682 =item Arguments: \%col_values, { key => $unique_constraint }?
2684 =item Return Value: $rowobject
2688 $resultset->update_or_new({ col => $val, ... });
2690 Like L</find_or_new> but if a row is found it is immediately updated via
2691 C<< $found_row->update (\%col_values) >>.
2695 # In your application
2696 my $cd = $schema->resultset('CD')->update_or_new(
2698 artist => 'Massive Attack',
2699 title => 'Mezzanine',
2702 { key => 'cd_artist_title' }
2705 if ($cd->in_storage) {
2706 # the cd was updated
2709 # the cd is not yet in the database, let's insert it
2713 B<Note>: Make sure to read the documentation of L</find> and understand the
2714 significance of the C<key> attribute, as its lack may skew your search, and
2715 subsequently result in spurious new objects.
2717 B<Note>: Take care when using C<update_or_new> with a table having
2718 columns with default values that you intend to be automatically
2719 supplied by the database (e.g. an auto_increment primary key column).
2720 In normal usage, the value of such columns should NOT be included at
2721 all in the call to C<update_or_new>, even when set to C<undef>.
2723 See also L</find>, L</find_or_create> and L</find_or_new>.
2729 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2730 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2732 my $row = $self->find( $cond, $attrs );
2733 if ( defined $row ) {
2734 $row->update($cond);
2738 return $self->new_result($cond);
2745 =item Arguments: none
2747 =item Return Value: \@cache_objects | undef
2751 Gets the contents of the cache for the resultset, if the cache is set.
2753 The cache is populated either by using the L</prefetch> attribute to
2754 L</search> or by calling L</set_cache>.
2766 =item Arguments: \@cache_objects
2768 =item Return Value: \@cache_objects
2772 Sets the contents of the cache for the resultset. Expects an arrayref
2773 of objects of the same class as those produced by the resultset. Note that
2774 if the cache is set the resultset will return the cached objects rather
2775 than re-querying the database even if the cache attr is not set.
2777 The contents of the cache can also be populated by using the
2778 L</prefetch> attribute to L</search>.
2783 my ( $self, $data ) = @_;
2784 $self->throw_exception("set_cache requires an arrayref")
2785 if defined($data) && (ref $data ne 'ARRAY');
2786 $self->{all_cache} = $data;
2793 =item Arguments: none
2795 =item Return Value: undef
2799 Clears the cache for the resultset.
2804 shift->set_cache(undef);
2811 =item Arguments: none
2813 =item Return Value: true, if the resultset has been paginated
2821 return !!$self->{attrs}{page};
2828 =item Arguments: none
2830 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2838 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2841 =head2 related_resultset
2845 =item Arguments: $relationship_name
2847 =item Return Value: $resultset
2851 Returns a related resultset for the supplied relationship name.
2853 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2857 sub related_resultset {
2858 my ($self, $rel) = @_;
2860 $self->{related_resultsets} ||= {};
2861 return $self->{related_resultsets}{$rel} ||= do {
2862 my $rsrc = $self->result_source;
2863 my $rel_info = $rsrc->relationship_info($rel);
2865 $self->throw_exception(
2866 "search_related: result source '" . $rsrc->source_name .
2867 "' has no such relationship $rel")
2870 my $attrs = $self->_chain_relationship($rel);
2872 my $join_count = $attrs->{seen_join}{$rel};
2874 my $alias = $self->result_source->storage
2875 ->relname_to_table_alias($rel, $join_count);
2877 # since this is search_related, and we already slid the select window inwards
2878 # (the select/as attrs were deleted in the beginning), we need to flip all
2879 # left joins to inner, so we get the expected results
2880 # read the comment on top of the actual function to see what this does
2881 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2884 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2885 delete @{$attrs}{qw(result_class alias)};
2889 if (my $cache = $self->get_cache) {
2890 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2891 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2896 my $rel_source = $rsrc->related_source($rel);
2900 # The reason we do this now instead of passing the alias to the
2901 # search_rs below is that if you wrap/overload resultset on the
2902 # source you need to know what alias it's -going- to have for things
2903 # to work sanely (e.g. RestrictWithObject wants to be able to add
2904 # extra query restrictions, and these may need to be $alias.)
2906 my $rel_attrs = $rel_source->resultset_attributes;
2907 local $rel_attrs->{alias} = $alias;
2909 $rel_source->resultset
2913 where => $attrs->{where},
2916 $new->set_cache($new_cache) if $new_cache;
2921 =head2 current_source_alias
2925 =item Arguments: none
2927 =item Return Value: $source_alias
2931 Returns the current table alias for the result source this resultset is built
2932 on, that will be used in the SQL query. Usually it is C<me>.
2934 Currently the source alias that refers to the result set returned by a
2935 L</search>/L</find> family method depends on how you got to the resultset: it's
2936 C<me> by default, but eg. L</search_related> aliases it to the related result
2937 source name (and keeps C<me> referring to the original result set). The long
2938 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2939 (and make this method unnecessary).
2941 Thus it's currently necessary to use this method in predefined queries (see
2942 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2943 source alias of the current result set:
2945 # in a result set class
2947 my ($self, $user) = @_;
2949 my $me = $self->current_source_alias;
2951 return $self->search(
2952 "$me.modified" => $user->id,
2958 sub current_source_alias {
2961 return ($self->{attrs} || {})->{alias} || 'me';
2964 =head2 as_subselect_rs
2968 =item Arguments: none
2970 =item Return Value: $resultset
2974 Act as a barrier to SQL symbols. The resultset provided will be made into a
2975 "virtual view" by including it as a subquery within the from clause. From this
2976 point on, any joined tables are inaccessible to ->search on the resultset (as if
2977 it were simply where-filtered without joins). For example:
2979 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2981 # 'x' now pollutes the query namespace
2983 # So the following works as expected
2984 my $ok_rs = $rs->search({'x.other' => 1});
2986 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2987 # def) we look for one row with contradictory terms and join in another table
2988 # (aliased 'x_2') which we never use
2989 my $broken_rs = $rs->search({'x.name' => 'def'});
2991 my $rs2 = $rs->as_subselect_rs;
2993 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2994 my $not_joined_rs = $rs2->search({'x.other' => 1});
2996 # works as expected: finds a 'table' row related to two x rows (abc and def)
2997 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2999 Another example of when one might use this would be to select a subset of
3000 columns in a group by clause:
3002 my $rs = $schema->resultset('Bar')->search(undef, {
3003 group_by => [qw{ id foo_id baz_id }],
3004 })->as_subselect_rs->search(undef, {
3005 columns => [qw{ id foo_id }]
3008 In the above example normally columns would have to be equal to the group by,
3009 but because we isolated the group by into a subselect the above works.
3013 sub as_subselect_rs {
3016 my $attrs = $self->_resolved_attrs;
3018 my $fresh_rs = (ref $self)->new (
3019 $self->result_source
3022 # these pieces will be locked in the subquery
3023 delete $fresh_rs->{cond};
3024 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3026 return $fresh_rs->search( {}, {
3028 $attrs->{alias} => $self->as_query,
3029 -alias => $attrs->{alias},
3030 -rsrc => $self->result_source,
3032 alias => $attrs->{alias},
3036 # This code is called by search_related, and makes sure there
3037 # is clear separation between the joins before, during, and
3038 # after the relationship. This information is needed later
3039 # in order to properly resolve prefetch aliases (any alias
3040 # with a relation_chain_depth less than the depth of the
3041 # current prefetch is not considered)
3043 # The increments happen twice per join. An even number means a
3044 # relationship specified via a search_related, whereas an odd
3045 # number indicates a join/prefetch added via attributes
3047 # Also this code will wrap the current resultset (the one we
3048 # chain to) in a subselect IFF it contains limiting attributes
3049 sub _chain_relationship {
3050 my ($self, $rel) = @_;
3051 my $source = $self->result_source;
3052 my $attrs = { %{$self->{attrs}||{}} };
3054 # we need to take the prefetch the attrs into account before we
3055 # ->_resolve_join as otherwise they get lost - captainL
3056 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3058 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3060 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3063 my @force_subq_attrs = qw/offset rows group_by having/;
3066 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3068 $self->_has_resolved_attr (@force_subq_attrs)
3070 # Nuke the prefetch (if any) before the new $rs attrs
3071 # are resolved (prefetch is useless - we are wrapping
3072 # a subquery anyway).
3073 my $rs_copy = $self->search;
3074 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3075 $rs_copy->{attrs}{join},
3076 delete $rs_copy->{attrs}{prefetch},
3081 -alias => $attrs->{alias},
3082 $attrs->{alias} => $rs_copy->as_query,
3084 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3085 $seen->{-relation_chain_depth} = 0;
3087 elsif ($attrs->{from}) { #shallow copy suffices
3088 $from = [ @{$attrs->{from}} ];
3093 -alias => $attrs->{alias},
3094 $attrs->{alias} => $source->from,
3098 my $jpath = ($seen->{-relation_chain_depth})
3099 ? $from->[-1][0]{-join_path}
3102 my @requested_joins = $source->_resolve_join(
3109 push @$from, @requested_joins;
3111 $seen->{-relation_chain_depth}++;
3113 # if $self already had a join/prefetch specified on it, the requested
3114 # $rel might very well be already included. What we do in this case
3115 # is effectively a no-op (except that we bump up the chain_depth on
3116 # the join in question so we could tell it *is* the search_related)
3119 # we consider the last one thus reverse
3120 for my $j (reverse @requested_joins) {
3121 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3122 if ($rel eq $last_j) {
3123 $j->[0]{-relation_chain_depth}++;
3129 unless ($already_joined) {
3130 push @$from, $source->_resolve_join(
3138 $seen->{-relation_chain_depth}++;
3140 return {%$attrs, from => $from, seen_join => $seen};
3143 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3144 sub _resolved_attrs_copy {
3146 return { %{$self->_resolved_attrs (@_)} };
3149 sub _resolved_attrs {
3151 return $self->{_attrs} if $self->{_attrs};
3153 my $attrs = { %{ $self->{attrs} || {} } };
3154 my $source = $self->result_source;
3155 my $alias = $attrs->{alias};
3157 # default selection list
3158 $attrs->{columns} = [ $source->columns ]
3159 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3161 # merge selectors together
3162 for (qw/columns select as/) {
3163 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3164 if $attrs->{$_} or $attrs->{"+$_"};
3167 # disassemble columns
3169 if (my $cols = delete $attrs->{columns}) {
3170 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3171 if (ref $c eq 'HASH') {
3172 for my $as (keys %$c) {
3173 push @sel, $c->{$as};
3184 # when trying to weed off duplicates later do not go past this point -
3185 # everything added from here on is unbalanced "anyone's guess" stuff
3186 my $dedup_stop_idx = $#as;
3188 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3190 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3191 if $attrs->{select};
3193 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3195 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3198 # disqualify all $alias.col as-bits (collapser mandated)
3200 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3203 # de-duplicate the result (remove *identical* select/as pairs)
3204 # and also die on duplicate {as} pointing to different {select}s
3205 # not using a c-style for as the condition is prone to shrinkage
3208 while ($i <= $dedup_stop_idx) {
3209 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3214 elsif ($seen->{$as[$i]}++) {
3215 $self->throw_exception(
3216 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3224 $attrs->{select} = \@sel;
3225 $attrs->{as} = \@as;
3227 $attrs->{from} ||= [{
3229 -alias => $self->{attrs}{alias},
3230 $self->{attrs}{alias} => $source->from,
3233 if ( $attrs->{join} || $attrs->{prefetch} ) {
3235 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3236 if ref $attrs->{from} ne 'ARRAY';
3238 my $join = (delete $attrs->{join}) || {};
3240 if ( defined $attrs->{prefetch} ) {
3241 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3244 $attrs->{from} = # have to copy here to avoid corrupting the original
3246 @{ $attrs->{from} },
3247 $source->_resolve_join(
3250 { %{ $attrs->{seen_join} || {} } },
3251 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3252 ? $attrs->{from}[-1][0]{-join_path}
3259 if ( defined $attrs->{order_by} ) {
3260 $attrs->{order_by} = (
3261 ref( $attrs->{order_by} ) eq 'ARRAY'
3262 ? [ @{ $attrs->{order_by} } ]
3263 : [ $attrs->{order_by} || () ]
3267 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3268 $attrs->{group_by} = [ $attrs->{group_by} ];
3271 # generate the distinct induced group_by early, as prefetch will be carried via a
3272 # subquery (since a group_by is present)
3273 if (delete $attrs->{distinct}) {
3274 if ($attrs->{group_by}) {
3275 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3278 # distinct affects only the main selection part, not what prefetch may
3280 $attrs->{group_by} = $source->storage->_group_over_selection (
3288 $attrs->{collapse} ||= {};
3289 if ($attrs->{prefetch}) {
3291 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3292 if $attrs->{_dark_selector};
3294 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3296 my $prefetch_ordering = [];
3298 # this is a separate structure (we don't look in {from} directly)
3299 # as the resolver needs to shift things off the lists to work
3300 # properly (identical-prefetches on different branches)
3302 if (ref $attrs->{from} eq 'ARRAY') {
3304 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3306 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3307 next unless $j->[0]{-alias};
3308 next unless $j->[0]{-join_path};
3309 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3311 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3314 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3315 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3320 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3322 # we need to somehow mark which columns came from prefetch
3324 my $sel_end = $#{$attrs->{select}};
3325 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3328 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3329 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3331 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3332 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3336 # if both page and offset are specified, produce a combined offset
3337 # even though it doesn't make much sense, this is what pre 081xx has
3339 if (my $page = delete $attrs->{page}) {
3341 ($attrs->{rows} * ($page - 1))
3343 ($attrs->{offset} || 0)
3347 return $self->{_attrs} = $attrs;
3351 my ($self, $attr) = @_;
3353 if (ref $attr eq 'HASH') {
3354 return $self->_rollout_hash($attr);
3355 } elsif (ref $attr eq 'ARRAY') {
3356 return $self->_rollout_array($attr);
3362 sub _rollout_array {
3363 my ($self, $attr) = @_;
3366 foreach my $element (@{$attr}) {
3367 if (ref $element eq 'HASH') {
3368 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3369 } elsif (ref $element eq 'ARRAY') {
3370 # XXX - should probably recurse here
3371 push( @rolled_array, @{$self->_rollout_array($element)} );
3373 push( @rolled_array, $element );
3376 return \@rolled_array;
3380 my ($self, $attr) = @_;
3383 foreach my $key (keys %{$attr}) {
3384 push( @rolled_array, { $key => $attr->{$key} } );
3386 return \@rolled_array;
3389 sub _calculate_score {
3390 my ($self, $a, $b) = @_;
3392 if (defined $a xor defined $b) {
3395 elsif (not defined $a) {
3399 if (ref $b eq 'HASH') {
3400 my ($b_key) = keys %{$b};
3401 if (ref $a eq 'HASH') {
3402 my ($a_key) = keys %{$a};
3403 if ($a_key eq $b_key) {
3404 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3409 return ($a eq $b_key) ? 1 : 0;
3412 if (ref $a eq 'HASH') {
3413 my ($a_key) = keys %{$a};
3414 return ($b eq $a_key) ? 1 : 0;
3416 return ($b eq $a) ? 1 : 0;
3421 sub _merge_joinpref_attr {
3422 my ($self, $orig, $import) = @_;
3424 return $import unless defined($orig);
3425 return $orig unless defined($import);
3427 $orig = $self->_rollout_attr($orig);
3428 $import = $self->_rollout_attr($import);
3431 foreach my $import_element ( @{$import} ) {
3432 # find best candidate from $orig to merge $b_element into
3433 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3434 foreach my $orig_element ( @{$orig} ) {
3435 my $score = $self->_calculate_score( $orig_element, $import_element );
3436 if ($score > $best_candidate->{score}) {
3437 $best_candidate->{position} = $position;
3438 $best_candidate->{score} = $score;
3442 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3444 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3445 push( @{$orig}, $import_element );
3447 my $orig_best = $orig->[$best_candidate->{position}];
3448 # merge orig_best and b_element together and replace original with merged
3449 if (ref $orig_best ne 'HASH') {
3450 $orig->[$best_candidate->{position}] = $import_element;
3451 } elsif (ref $import_element eq 'HASH') {
3452 my ($key) = keys %{$orig_best};
3453 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3456 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3467 require Hash::Merge;
3468 my $hm = Hash::Merge->new;
3470 $hm->specify_behavior({
3473 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3475 if ($defl xor $defr) {
3476 return [ $defl ? $_[0] : $_[1] ];
3481 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3485 return [$_[0], $_[1]];
3489 return $_[1] if !defined $_[0];
3490 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3491 return [$_[0], @{$_[1]}]
3494 return [] if !defined $_[0] and !keys %{$_[1]};
3495 return [ $_[1] ] if !defined $_[0];
3496 return [ $_[0] ] if !keys %{$_[1]};
3497 return [$_[0], $_[1]]
3502 return $_[0] if !defined $_[1];
3503 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3504 return [@{$_[0]}, $_[1]]
3507 my @ret = @{$_[0]} or return $_[1];
3508 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3509 my %idx = map { $_ => 1 } @ret;
3510 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3514 return [ $_[1] ] if ! @{$_[0]};
3515 return $_[0] if !keys %{$_[1]};
3516 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3517 return [ @{$_[0]}, $_[1] ];
3522 return [] if !keys %{$_[0]} and !defined $_[1];
3523 return [ $_[0] ] if !defined $_[1];
3524 return [ $_[1] ] if !keys %{$_[0]};
3525 return [$_[0], $_[1]]
3528 return [] if !keys %{$_[0]} and !@{$_[1]};
3529 return [ $_[0] ] if !@{$_[1]};
3530 return $_[1] if !keys %{$_[0]};
3531 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3532 return [ $_[0], @{$_[1]} ];
3535 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3536 return [ $_[0] ] if !keys %{$_[1]};
3537 return [ $_[1] ] if !keys %{$_[0]};
3538 return [ $_[0] ] if $_[0] eq $_[1];
3539 return [ $_[0], $_[1] ];
3542 } => 'DBIC_RS_ATTR_MERGER');
3546 return $hm->merge ($_[1], $_[2]);
3550 sub STORABLE_freeze {
3551 my ($self, $cloning) = @_;
3552 my $to_serialize = { %$self };
3554 # A cursor in progress can't be serialized (and would make little sense anyway)
3555 delete $to_serialize->{cursor};
3557 # nor is it sensical to store a not-yet-fired-count pager
3558 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3559 delete $to_serialize->{pager};
3562 Storable::nfreeze($to_serialize);
3565 # need this hook for symmetry
3567 my ($self, $cloning, $serialized) = @_;
3569 %$self = %{ Storable::thaw($serialized) };
3575 =head2 throw_exception
3577 See L<DBIx::Class::Schema/throw_exception> for details.
3581 sub throw_exception {
3584 if (ref $self and my $rsrc = $self->result_source) {
3585 $rsrc->throw_exception(@_)
3588 DBIx::Class::Exception->throw(@_);
3592 # XXX: FIXME: Attributes docs need clearing up
3596 Attributes are used to refine a ResultSet in various ways when
3597 searching for data. They can be passed to any method which takes an
3598 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3601 These are in no particular order:
3607 =item Value: ( $order_by | \@order_by | \%order_by )
3611 Which column(s) to order the results by.
3613 [The full list of suitable values is documented in
3614 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3617 If a single column name, or an arrayref of names is supplied, the
3618 argument is passed through directly to SQL. The hashref syntax allows
3619 for connection-agnostic specification of ordering direction:
3621 For descending order:
3623 order_by => { -desc => [qw/col1 col2 col3/] }
3625 For explicit ascending order:
3627 order_by => { -asc => 'col' }
3629 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3630 supported, although you are strongly encouraged to use the hashref
3631 syntax as outlined above.
3637 =item Value: \@columns
3641 Shortcut to request a particular set of columns to be retrieved. Each
3642 column spec may be a string (a table column name), or a hash (in which
3643 case the key is the C<as> value, and the value is used as the C<select>
3644 expression). Adds C<me.> onto the start of any column without a C<.> in
3645 it and sets C<select> from that, then auto-populates C<as> from
3646 C<select> as normal. (You may also use the C<cols> attribute, as in
3647 earlier versions of DBIC.)
3649 Essentially C<columns> does the same as L</select> and L</as>.
3651 columns => [ 'foo', { bar => 'baz' } ]
3655 select => [qw/foo baz/],
3662 =item Value: \@columns
3666 Indicates additional columns to be selected from storage. Works the same
3667 as L</columns> but adds columns to the selection. (You may also use the
3668 C<include_columns> attribute, as in earlier versions of DBIC). For
3671 $schema->resultset('CD')->search(undef, {
3672 '+columns' => ['artist.name'],
3676 would return all CDs and include a 'name' column to the information
3677 passed to object inflation. Note that the 'artist' is the name of the
3678 column (or relationship) accessor, and 'name' is the name of the column
3679 accessor in the related table.
3681 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3682 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3683 unary plus operator before it.
3685 =head2 include_columns
3689 =item Value: \@columns
3693 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3699 =item Value: \@select_columns
3703 Indicates which columns should be selected from the storage. You can use
3704 column names, or in the case of RDBMS back ends, function or stored procedure
3707 $rs = $schema->resultset('Employee')->search(undef, {
3710 { count => 'employeeid' },
3711 { max => { length => 'name' }, -as => 'longest_name' }
3716 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3718 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3719 use L</select>, to instruct DBIx::Class how to store the result of the column.
3720 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3721 identifier aliasing. You can however alias a function, so you can use it in
3722 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3723 attribute> supplied as shown in the example above.
3725 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3726 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3727 unary plus operator before it.
3733 Indicates additional columns to be selected from storage. Works the same as
3734 L</select> but adds columns to the default selection, instead of specifying
3743 Indicates additional column names for those added via L</+select>. See L</as>.
3751 =item Value: \@inflation_names
3755 Indicates column names for object inflation. That is L</as> indicates the
3756 slot name in which the column value will be stored within the
3757 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3758 identifier by the C<get_column> method (or via the object accessor B<if one
3759 with the same name already exists>) as shown below. The L</as> attribute has
3760 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3762 $rs = $schema->resultset('Employee')->search(undef, {
3765 { count => 'employeeid' },
3766 { max => { length => 'name' }, -as => 'longest_name' }
3775 If the object against which the search is performed already has an accessor
3776 matching a column name specified in C<as>, the value can be retrieved using
3777 the accessor as normal:
3779 my $name = $employee->name();
3781 If on the other hand an accessor does not exist in the object, you need to
3782 use C<get_column> instead:
3784 my $employee_count = $employee->get_column('employee_count');
3786 You can create your own accessors if required - see
3787 L<DBIx::Class::Manual::Cookbook> for details.
3793 =item Value: ($rel_name | \@rel_names | \%rel_names)
3797 Contains a list of relationships that should be joined for this query. For
3800 # Get CDs by Nine Inch Nails
3801 my $rs = $schema->resultset('CD')->search(
3802 { 'artist.name' => 'Nine Inch Nails' },
3803 { join => 'artist' }
3806 Can also contain a hash reference to refer to the other relation's relations.
3809 package MyApp::Schema::Track;
3810 use base qw/DBIx::Class/;
3811 __PACKAGE__->table('track');
3812 __PACKAGE__->add_columns(qw/trackid cd position title/);
3813 __PACKAGE__->set_primary_key('trackid');
3814 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3817 # In your application
3818 my $rs = $schema->resultset('Artist')->search(
3819 { 'track.title' => 'Teardrop' },
3821 join => { cd => 'track' },
3822 order_by => 'artist.name',
3826 You need to use the relationship (not the table) name in conditions,
3827 because they are aliased as such. The current table is aliased as "me", so
3828 you need to use me.column_name in order to avoid ambiguity. For example:
3830 # Get CDs from 1984 with a 'Foo' track
3831 my $rs = $schema->resultset('CD')->search(
3834 'tracks.name' => 'Foo'
3836 { join => 'tracks' }
3839 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3840 similarly for a third time). For e.g.
3842 my $rs = $schema->resultset('Artist')->search({
3843 'cds.title' => 'Down to Earth',
3844 'cds_2.title' => 'Popular',
3846 join => [ qw/cds cds/ ],
3849 will return a set of all artists that have both a cd with title 'Down
3850 to Earth' and a cd with title 'Popular'.
3852 If you want to fetch related objects from other tables as well, see C<prefetch>
3855 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3861 =item Value: ($rel_name | \@rel_names | \%rel_names)
3865 Contains one or more relationships that should be fetched along with
3866 the main query (when they are accessed afterwards the data will
3867 already be available, without extra queries to the database). This is
3868 useful for when you know you will need the related objects, because it
3869 saves at least one query:
3871 my $rs = $schema->resultset('Tag')->search(
3880 The initial search results in SQL like the following:
3882 SELECT tag.*, cd.*, artist.* FROM tag
3883 JOIN cd ON tag.cd = cd.cdid
3884 JOIN artist ON cd.artist = artist.artistid
3886 L<DBIx::Class> has no need to go back to the database when we access the
3887 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3890 Simple prefetches will be joined automatically, so there is no need
3891 for a C<join> attribute in the above search.
3893 L</prefetch> can be used with the any of the relationship types and
3894 multiple prefetches can be specified together. Below is a more complex
3895 example that prefetches a CD's artist, its liner notes (if present),
3896 the cover image, the tracks on that cd, and the guests on those
3900 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3901 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3902 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3903 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3905 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3907 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
3910 my $rs = $schema->resultset('CD')->search(
3914 { artist => 'record_label'}, # belongs_to => belongs_to
3915 'liner_note', # might_have
3916 'cover_image', # has_one
3917 { tracks => 'guests' }, # has_many => has_many
3922 This will produce SQL like the following:
3924 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
3928 ON artist.artistid = me.artistid
3929 JOIN record_label record_label
3930 ON record_label.labelid = artist.labelid
3931 LEFT JOIN track tracks
3932 ON tracks.cdid = me.cdid
3933 LEFT JOIN guest guests
3934 ON guests.trackid = track.trackid
3935 LEFT JOIN liner_notes liner_note
3936 ON liner_note.cdid = me.cdid
3937 JOIN cd_artwork cover_image
3938 ON cover_image.cdid = me.cdid
3941 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
3942 C<tracks>, and C<guests> of the CD will all be available through the
3943 relationship accessors without the need for additional queries to the
3946 However, there is one caveat to be observed: it can be dangerous to
3947 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
3948 relationship on a given level. e.g.:
3950 my $rs = $schema->resultset('CD')->search(
3954 'tracks', # has_many
3955 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
3960 In fact, C<DBIx::Class> will emit the following warning:
3962 Prefetching multiple has_many rels tracks and cd_to_producer at top
3963 level will explode the number of row objects retrievable via ->next
3964 or ->all. Use at your own risk.
3966 The collapser currently can't identify duplicate tuples for multiple
3967 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
3968 result the second L<has_many|DBIx::Class::Relationship/has_many>
3969 relation could contain redundant objects.
3971 =head3 Using L</prefetch> with L</join>
3973 L</prefetch> implies a L</join> with the equivalent argument, and is
3974 properly merged with any existing L</join> specification. So the
3977 my $rs = $schema->resultset('CD')->search(
3978 {'record_label.name' => 'Music Product Ltd.'},
3980 join => {artist => 'record_label'},
3981 prefetch => 'artist',
3985 ... will work, searching on the record label's name, but only
3986 prefetching the C<artist>.
3988 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
3990 L</prefetch> implies a L</+select>/L</+as> with the fields of the
3991 prefetched relations. So given:
3993 my $rs = $schema->resultset('CD')->search(
3996 select => ['cd.title'],
3998 prefetch => 'artist',
4002 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4003 becomes: C<'cd_title', 'artist.*'>.
4007 Prefetch does a lot of deep magic. As such, it may not behave exactly
4008 as you might expect.
4014 Prefetch uses the L</cache> to populate the prefetched relationships. This
4015 may or may not be what you want.
4019 If you specify a condition on a prefetched relationship, ONLY those
4020 rows that match the prefetched condition will be fetched into that relationship.
4021 This means that adding prefetch to a search() B<may alter> what is returned by
4022 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4024 my $artist_rs = $schema->resultset('Artist')->search({
4030 my $count = $artist_rs->first->cds->count;
4032 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4034 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4036 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4038 that cmp_ok() may or may not pass depending on the datasets involved. This
4039 behavior may or may not survive the 0.09 transition.
4051 Makes the resultset paged and specifies the page to retrieve. Effectively
4052 identical to creating a non-pages resultset and then calling ->page($page)
4055 If L</rows> attribute is not specified it defaults to 10 rows per page.
4057 When you have a paged resultset, L</count> will only return the number
4058 of rows in the page. To get the total, use the L</pager> and call
4059 C<total_entries> on it.
4069 Specifies the maximum number of rows for direct retrieval or the number of
4070 rows per page if the page attribute or method is used.
4076 =item Value: $offset
4080 Specifies the (zero-based) row number for the first row to be returned, or the
4081 of the first row of the first page if paging is used.
4087 =item Value: \@columns
4091 A arrayref of columns to group by. Can include columns of joined tables.
4093 group_by => [qw/ column1 column2 ... /]
4099 =item Value: $condition
4103 HAVING is a select statement attribute that is applied between GROUP BY and
4104 ORDER BY. It is applied to the after the grouping calculations have been
4107 having => { 'count_employee' => { '>=', 100 } }
4109 or with an in-place function in which case literal SQL is required:
4111 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4117 =item Value: (0 | 1)
4121 Set to 1 to group by all columns. If the resultset already has a group_by
4122 attribute, this setting is ignored and an appropriate warning is issued.
4128 Adds to the WHERE clause.
4130 # only return rows WHERE deleted IS NULL for all searches
4131 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4133 Can be overridden by passing C<< { where => undef } >> as an attribute
4140 Set to 1 to cache search results. This prevents extra SQL queries if you
4141 revisit rows in your ResultSet:
4143 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4145 while( my $artist = $resultset->next ) {
4149 $rs->first; # without cache, this would issue a query
4151 By default, searches are not cached.
4153 For more examples of using these attributes, see
4154 L<DBIx::Class::Manual::Cookbook>.
4160 =item Value: ( 'update' | 'shared' )
4164 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT