1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
13 use Scalar::Util qw/weaken/;
15 use DBIx::Class::ResultSetColumn;
16 use base qw/DBIx::Class/;
17 __PACKAGE__->load_components(qw/AccessorGroup/);
18 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
22 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
26 my $rs = $schema->resultset('User')->search(registered => 1);
27 my @rows = $schema->resultset('CD')->search(year => 2005);
31 The resultset is also known as an iterator. It is responsible for handling
32 queries that may return an arbitrary number of rows, e.g. via L</search>
33 or a C<has_many> relationship.
35 In the examples below, the following table classes are used:
37 package MyApp::Schema::Artist;
38 use base qw/DBIx::Class/;
39 __PACKAGE__->load_components(qw/Core/);
40 __PACKAGE__->table('artist');
41 __PACKAGE__->add_columns(qw/artistid name/);
42 __PACKAGE__->set_primary_key('artistid');
43 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
46 package MyApp::Schema::CD;
47 use base qw/DBIx::Class/;
48 __PACKAGE__->load_components(qw/Core/);
49 __PACKAGE__->table('cd');
50 __PACKAGE__->add_columns(qw/cdid artist title year/);
51 __PACKAGE__->set_primary_key('cdid');
52 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
61 =item Arguments: $source, \%$attrs
63 =item Return Value: $rs
67 The resultset constructor. Takes a source object (usually a
68 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
69 L</ATTRIBUTES> below). Does not perform any queries -- these are
70 executed as needed by the other methods.
72 Generally you won't need to construct a resultset manually. You'll
73 automatically get one from e.g. a L</search> called in scalar context:
75 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
77 IMPORTANT: If called on an object, proxies to new_result instead so
79 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
81 will return a CD object, not a ResultSet.
87 return $class->new_result(@_) if ref $class;
89 my ($source, $attrs) = @_;
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 result_source => $source,
102 result_class => $attrs->{result_class} || $source->result_class,
103 cond => $attrs->{where},
104 # from => $attrs->{from},
105 # collapse => $collapse,
107 page => delete $attrs->{page},
117 =item Arguments: $cond, \%attrs?
119 =item Return Value: $resultset (scalar context), @row_objs (list context)
123 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
124 my $new_rs = $cd_rs->search({ year => 2005 });
126 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
127 # year = 2005 OR year = 2004
129 If you need to pass in additional attributes but no additional condition,
130 call it as C<search(undef, \%attrs)>.
132 # "SELECT name, artistid FROM $artist_table"
133 my @all_artists = $schema->resultset('Artist')->search(undef, {
134 columns => [qw/name artistid/],
141 my $rs = $self->search_rs( @_ );
142 return (wantarray ? $rs->all : $rs);
149 =item Arguments: $cond, \%attrs?
151 =item Return Value: $resultset
155 This method does the same exact thing as search() except it will
156 always return a resultset, even in list context.
163 my $our_attrs = { %{$self->{attrs}} };
164 my $having = delete $our_attrs->{having};
166 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
168 # merge new attrs into old
169 foreach my $key (qw/join prefetch/) {
170 next unless (exists $attrs->{$key});
171 if (exists $our_attrs->{$key}) {
172 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
174 $our_attrs->{$key} = $attrs->{$key};
176 delete $attrs->{$key};
179 if (exists $our_attrs->{prefetch}) {
180 $our_attrs->{join} = $self->_merge_attr($our_attrs->{join}, $our_attrs->{prefetch}, 1);
183 my $new_attrs = { %{$our_attrs}, %{$attrs} };
185 # merge new where and having into old
187 ? ((@_ == 1 || ref $_[0] eq "HASH")
190 ? $self->throw_exception(
191 "Odd number of arguments to search")
194 if (defined $where) {
195 $new_attrs->{where} = (defined $new_attrs->{where}
197 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
198 $where, $new_attrs->{where} ] }
202 if (defined $having) {
203 $new_attrs->{having} = (defined $new_attrs->{having}
205 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
206 $having, $new_attrs->{having} ] }
210 my $rs = (ref $self)->new($self->result_source, $new_attrs);
211 $rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
213 unless (@_) { # no search, effectively just a clone
214 my $rows = $self->get_cache;
216 $rs->set_cache($rows);
223 =head2 search_literal
227 =item Arguments: $sql_fragment, @bind_values
229 =item Return Value: $resultset (scalar context), @row_objs (list context)
233 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
234 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
236 Pass a literal chunk of SQL to be added to the conditional part of the
242 my ($self, $cond, @vals) = @_;
243 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
244 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
245 return $self->search(\$cond, $attrs);
252 =item Arguments: @values | \%cols, \%attrs?
254 =item Return Value: $row_object
258 Finds a row based on its primary key or unique constraint. For example, to find
259 a row by its primary key:
261 my $cd = $schema->resultset('CD')->find(5);
263 You can also find a row by a specific unique constraint using the C<key>
264 attribute. For example:
266 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'artist_title' });
268 Additionally, you can specify the columns explicitly by name:
270 my $cd = $schema->resultset('CD')->find(
272 artist => 'Massive Attack',
273 title => 'Mezzanine',
275 { key => 'artist_title' }
278 If the C<key> is specified as C<primary>, it searches only on the primary key.
280 If no C<key> is specified, it searches on all unique constraints defined on the
281 source, including the primary key.
283 See also L</find_or_create> and L</update_or_create>. For information on how to
284 declare unique constraints, see
285 L<DBIx::Class::ResultSource/add_unique_constraint>.
291 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
293 # Default to the primary key, but allow a specific key
294 my @cols = exists $attrs->{key}
295 ? $self->result_source->unique_constraint_columns($attrs->{key})
296 : $self->result_source->primary_columns;
297 $self->throw_exception(
298 "Can't find unless a primary key or unique constraint is defined"
301 # Parse out a hashref from input
303 if (ref $_[0] eq 'HASH') {
304 $cond = { %{$_[0]} };
306 elsif (@_ == @cols) {
308 @{$cond}{@cols} = @_;
311 # Compatibility: Allow e.g. find(id => $value)
312 carp "find by key => value deprecated; please use a hashref instead";
316 my @unique_conds = $self->_unique_conds($cond, $attrs);
317 # use Data::Dumper; warn Dumper $self->result_source->name, $cond, \@unique_conds;
320 my $query = \@unique_conds;
321 if (scalar @unique_conds == 0) {
322 if (exists $attrs->{key}) {
323 $self->throw_exception("required values for the $attrs->{key} key not provided");
326 # Compatibility: Allow broken find usage for now
327 carp "find requires values for the primary key or a unique constraint"
328 . "; please use search instead";
335 my $rs = $self->search($query, $attrs);
337 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
341 return (keys %{$self->{_attrs}->{collapse}})
342 ? $self->search($query)->next
343 : $self->single($query);
349 # Build a list of conditions which satisfy unique constraints.
352 my ($self, $cond, $attrs) = @_;
354 # Check the condition against our source's unique constraints
355 my @constraint_names = exists $attrs->{key}
357 : $self->result_source->unique_constraint_names;
360 foreach my $name (@constraint_names) {
361 my @unique_cols = $self->result_source->unique_constraint_columns($name);
362 my $unique_cond = $self->_build_unique_cond($cond, \@unique_cols);
364 next unless scalar keys %$unique_cond == scalar @unique_cols;
366 # Add the ResultSet's alias
367 foreach my $key (grep { ! m/\./ } keys %$unique_cond) {
368 $unique_cond->{"$self->{attrs}{alias}.$key"} = delete $unique_cond->{$key};
371 push @unique_conds, $unique_cond;
374 return @unique_conds;
379 # Constrain the specified condition hash based on the specified column names.
381 sub _build_unique_cond {
382 my ($self, $cond, $unique_cols) = @_;
385 map { $_ => $cond->{$_} }
386 grep { exists $cond->{$_} }
389 return \%unique_cond;
392 =head2 search_related
396 =item Arguments: $cond, \%attrs?
398 =item Return Value: $new_resultset
402 $new_rs = $cd_rs->search_related('artist', {
406 Searches the specified relationship, optionally specifying a condition and
407 attributes for matching records. See L</ATTRIBUTES> for more information.
412 return shift->related_resultset(shift)->search(@_);
419 =item Arguments: none
421 =item Return Value: $cursor
425 Returns a storage-driven cursor to the given resultset. See
426 L<DBIx::Class::Cursor> for more information.
434 my $attrs = { %{$self->{_attrs}} };
435 return $self->{cursor}
436 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
437 $attrs->{where},$attrs);
444 =item Arguments: $cond?
446 =item Return Value: $row_object?
450 my $cd = $schema->resultset('CD')->single({ year => 2001 });
452 Inflates the first result without creating a cursor if the resultset has
453 any records in it; if not returns nothing. Used by L</find> as an optimisation.
455 Can optionally take an additional condition *only* - this is a fast-code-path
456 method; if you need to add extra joins or similar call ->search and then
457 ->single without a condition on the $rs returned from that.
462 my ($self, $where) = @_;
464 my $attrs = { %{$self->{_attrs}} };
466 if (defined $attrs->{where}) {
469 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
470 $where, delete $attrs->{where} ]
473 $attrs->{where} = $where;
477 my @data = $self->result_source->storage->select_single(
478 $attrs->{from}, $attrs->{select},
479 $attrs->{where},$attrs);
480 return (@data ? $self->_construct_object(@data) : ());
487 =item Arguments: $cond?
489 =item Return Value: $resultsetcolumn
493 my $max_length = $rs->get_column('length')->max;
495 Returns a ResultSetColumn instance for $column based on $self
500 my ($self, $column) = @_;
502 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
510 =item Arguments: $cond, \%attrs?
512 =item Return Value: $resultset (scalar context), @row_objs (list context)
516 # WHERE title LIKE '%blue%'
517 $cd_rs = $rs->search_like({ title => '%blue%'});
519 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
520 that this is simply a convenience method. You most likely want to use
521 L</search> with specific operators.
523 For more information, see L<DBIx::Class::Manual::Cookbook>.
529 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
530 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
531 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
532 return $class->search($query, { %$attrs });
539 =item Arguments: $first, $last
541 =item Return Value: $resultset (scalar context), @row_objs (list context)
545 Returns a resultset or object list representing a subset of elements from the
546 resultset slice is called on. Indexes are from 0, i.e., to get the first
549 my ($one, $two, $three) = $rs->slice(0, 2);
554 my ($self, $min, $max) = @_;
555 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
556 $attrs->{offset} = $self->{attrs}{offset} || 0;
557 $attrs->{offset} += $min;
558 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
559 return $self->search(undef(), $attrs);
560 #my $slice = (ref $self)->new($self->result_source, $attrs);
561 #return (wantarray ? $slice->all : $slice);
568 =item Arguments: none
570 =item Return Value: $result?
574 Returns the next element in the resultset (C<undef> is there is none).
576 Can be used to efficiently iterate over records in the resultset:
578 my $rs = $schema->resultset('CD')->search;
579 while (my $cd = $rs->next) {
583 Note that you need to store the resultset object, and call C<next> on it.
584 Calling C<< resultset('Table')->next >> repeatedly will always return the
585 first record from the resultset.
591 if (my $cache = $self->get_cache) {
592 $self->{all_cache_position} ||= 0;
593 return $cache->[$self->{all_cache_position}++];
595 if ($self->{attrs}{cache}) {
596 $self->{all_cache_position} = 1;
597 return ($self->all)[0];
599 my @row = (exists $self->{stashed_row} ?
600 @{delete $self->{stashed_row}} :
603 return unless (@row);
604 return $self->_construct_object(@row);
610 return if(exists $self->{_attrs}); #return if _resolve has already been called
612 my $attrs = $self->{attrs};
613 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
615 # XXX - lose storable dclone
616 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
617 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
618 $attrs->{record_filter} = $record_filter if ($record_filter);
619 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
621 my $alias = $attrs->{alias};
623 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
624 delete $attrs->{as} if $attrs->{columns};
625 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
626 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
628 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
629 ] if $attrs->{columns};
631 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
633 if (my $include = delete $attrs->{include_columns}) {
634 push(@{$attrs->{select}}, @$include);
635 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
638 $attrs->{from} ||= [ { $alias => $source->from } ];
639 $attrs->{seen_join} ||= {};
641 if (my $join = delete $attrs->{join}) {
642 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
643 if (ref $j eq 'HASH') {
644 $seen{$_} = 1 foreach keys %$j;
650 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
652 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
653 $attrs->{order_by} = [ $attrs->{order_by} ] if
654 $attrs->{order_by} and !ref($attrs->{order_by});
655 $attrs->{order_by} ||= [];
657 if(my $seladds = delete($attrs->{'+select'})) {
658 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
660 @{ $attrs->{select} },
661 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
664 if(my $asadds = delete($attrs->{'+as'})) {
665 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
666 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
669 my $collapse = $attrs->{collapse} || {};
670 if (my $prefetch = delete $attrs->{prefetch}) {
672 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
673 if ( ref $p eq 'HASH' ) {
674 foreach my $key (keys %$p) {
675 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
679 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
682 my @prefetch = $source->resolve_prefetch(
683 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
684 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
685 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
687 push(@{$attrs->{order_by}}, @pre_order);
689 $attrs->{collapse} = $collapse;
690 $self->{_attrs} = $attrs;
694 my ($self, $a, $b, $is_prefetch) = @_;
697 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
698 foreach my $key (keys %{$b}) {
699 if (exists $a->{$key}) {
700 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
702 $a->{$key} = delete $b->{$key};
707 $a = [$a] unless (ref $a eq 'ARRAY');
708 $b = [$b] unless (ref $b eq 'ARRAY');
713 foreach my $element (@{$_}) {
714 if (ref $element eq 'HASH') {
715 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
716 } elsif (ref $element eq 'ARRAY') {
717 $array = [@{$array}, @{$element}];
719 if (($b == $_) && $is_prefetch) {
720 $self->_merge_array($array, $element, $is_prefetch);
722 push(@{$array}, $element);
728 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
729 return [$hash, @{$array}];
731 return (keys %{$hash}) ? $hash : $array;
737 my ($self, $a, $b) = @_;
739 $b = [$b] unless (ref $b eq 'ARRAY');
740 # add elements from @{$b} to @{$a} which aren't already in @{$a}
741 foreach my $b_element (@{$b}) {
742 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
746 sub _construct_object {
747 my ($self, @row) = @_;
748 my @as = @{ $self->{_attrs}{as} };
750 my $info = $self->_collapse_result(\@as, \@row);
751 my $new = $self->result_class->inflate_result($self->result_source, @$info);
752 $new = $self->{_attrs}{record_filter}->($new)
753 if exists $self->{_attrs}{record_filter};
757 sub _collapse_result {
758 my ($self, $as, $row, $prefix) = @_;
760 my $live_join = $self->{attrs}->{_live_join} ||="";
764 foreach my $this_as (@$as) {
765 my $val = shift @copy;
766 if (defined $prefix) {
767 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
769 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
770 $const{$1||''}{$2} = $val;
773 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
774 $const{$1||''}{$2} = $val;
778 my $info = [ {}, {} ];
779 foreach my $key (keys %const) {
780 if (length $key && $key ne $live_join) {
782 my @parts = split(/\./, $key);
783 foreach my $p (@parts) {
784 $target = $target->[1]->{$p} ||= [];
786 $target->[0] = $const{$key};
788 $info->[0] = $const{$key};
793 if (defined $prefix) {
795 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
796 } keys %{$self->{_attrs}->{collapse}}
798 @collapse = keys %{$self->{_attrs}->{collapse}};
802 my ($c) = sort { length $a <=> length $b } @collapse;
804 foreach my $p (split(/\./, $c)) {
805 $target = $target->[1]->{$p} ||= [];
807 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
808 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
809 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
810 my $tree = $self->_collapse_result($as, $row, $c_prefix);
813 !defined($tree->[0]->{$_}) ||
814 $co_check{$_} ne $tree->[0]->{$_}
817 last unless (@raw = $self->cursor->next);
818 $row = $self->{stashed_row} = \@raw;
819 $tree = $self->_collapse_result($as, $row, $c_prefix);
821 @$target = (@final ? @final : [ {}, {} ]);
822 # single empty result to indicate an empty prefetched has_many
831 =item Arguments: $result_source?
833 =item Return Value: $result_source
837 An accessor for the primary ResultSource object from which this ResultSet
847 =item Arguments: $cond, \%attrs??
849 =item Return Value: $count
853 Performs an SQL C<COUNT> with the same query as the resultset was built
854 with to find the number of elements. If passed arguments, does a search
855 on the resultset and counts the results of that.
857 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
858 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
859 not support C<DISTINCT> with multiple columns. If you are using such a
860 database, you should only use columns from the main table in your C<group_by>
867 return $self->search(@_)->count if @_ and defined $_[0];
868 return scalar @{ $self->get_cache } if $self->get_cache;
870 my $count = $self->_count;
871 return 0 unless $count;
873 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
874 $count = $self->{attrs}{rows} if
875 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
879 sub _count { # Separated out so pager can get the full count
881 my $select = { count => '*' };
884 my $attrs = { %{ $self->{_attrs} } };
885 if (my $group_by = delete $attrs->{group_by}) {
886 delete $attrs->{having};
887 my @distinct = (ref $group_by ? @$group_by : ($group_by));
888 # todo: try CONCAT for multi-column pk
889 my @pk = $self->result_source->primary_columns;
891 foreach my $column (@distinct) {
892 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
893 @distinct = ($column);
899 $select = { count => { distinct => \@distinct } };
902 $attrs->{select} = $select;
903 $attrs->{as} = [qw/count/];
905 # offset, order by and page are not needed to count. record_filter is cdbi
906 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
907 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
915 =item Arguments: $sql_fragment, @bind_values
917 =item Return Value: $count
921 Counts the results in a literal query. Equivalent to calling L</search_literal>
922 with the passed arguments, then L</count>.
926 sub count_literal { shift->search_literal(@_)->count; }
932 =item Arguments: none
934 =item Return Value: @objects
938 Returns all elements in the resultset. Called implicitly if the resultset
939 is returned in list context.
945 return @{ $self->get_cache } if $self->get_cache;
949 # TODO: don't call resolve here
951 if (keys %{$self->{_attrs}->{collapse}}) {
952 # if ($self->{attrs}->{prefetch}) {
953 # Using $self->cursor->all is really just an optimisation.
954 # If we're collapsing has_many prefetches it probably makes
955 # very little difference, and this is cleaner than hacking
956 # _construct_object to survive the approach
957 my @row = $self->cursor->next;
959 push(@obj, $self->_construct_object(@row));
960 @row = (exists $self->{stashed_row}
961 ? @{delete $self->{stashed_row}}
962 : $self->cursor->next);
965 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
968 $self->set_cache(\@obj) if $self->{attrs}{cache};
976 =item Arguments: none
978 =item Return Value: $self
982 Resets the resultset's cursor, so you can iterate through the elements again.
988 delete $self->{_attrs} if (exists $self->{_attrs});
990 $self->{all_cache_position} = 0;
991 $self->cursor->reset;
999 =item Arguments: none
1001 =item Return Value: $object?
1005 Resets the resultset and returns an object for the first result (if the
1006 resultset returns anything).
1011 return $_[0]->reset->next;
1014 # _cond_for_update_delete
1016 # update/delete require the condition to be modified to handle
1017 # the differing SQL syntax available. This transforms the $self->{cond}
1018 # appropriately, returning the new condition.
1020 sub _cond_for_update_delete {
1024 if (!ref($self->{cond})) {
1025 # No-op. No condition, we're updating/deleting everything
1027 elsif (ref $self->{cond} eq 'ARRAY') {
1031 foreach my $key (keys %{$_}) {
1033 $hash{$1} = $_->{$key};
1039 elsif (ref $self->{cond} eq 'HASH') {
1040 if ((keys %{$self->{cond}})[0] eq '-and') {
1043 my @cond = @{$self->{cond}{-and}};
1044 for (my $i = 0; $i <= @cond - 1; $i++) {
1045 my $entry = $cond[$i];
1048 if (ref $entry eq 'HASH') {
1049 foreach my $key (keys %{$entry}) {
1051 $hash{$1} = $entry->{$key};
1055 $entry =~ /([^.]+)$/;
1056 $hash{$1} = $cond[++$i];
1059 push @{$cond->{-and}}, \%hash;
1063 foreach my $key (keys %{$self->{cond}}) {
1065 $cond->{$1} = $self->{cond}{$key};
1070 $self->throw_exception(
1071 "Can't update/delete on resultset with condition unless hash or array"
1083 =item Arguments: \%values
1085 =item Return Value: $storage_rv
1089 Sets the specified columns in the resultset to the supplied values in a
1090 single query. Return value will be true if the update succeeded or false
1091 if no records were updated; exact type of success value is storage-dependent.
1096 my ($self, $values) = @_;
1097 $self->throw_exception("Values for update must be a hash")
1098 unless ref $values eq 'HASH';
1100 my $cond = $self->_cond_for_update_delete;
1102 return $self->result_source->storage->update(
1103 $self->result_source->from, $values, $cond
1111 =item Arguments: \%values
1113 =item Return Value: 1
1117 Fetches all objects and updates them one at a time. Note that C<update_all>
1118 will run DBIC cascade triggers, while L</update> will not.
1123 my ($self, $values) = @_;
1124 $self->throw_exception("Values for update must be a hash")
1125 unless ref $values eq 'HASH';
1126 foreach my $obj ($self->all) {
1127 $obj->set_columns($values)->update;
1136 =item Arguments: none
1138 =item Return Value: 1
1142 Deletes the contents of the resultset from its result source. Note that this
1143 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1152 my $cond = $self->_cond_for_update_delete;
1154 $self->result_source->storage->delete($self->result_source->from, $cond);
1162 =item Arguments: none
1164 =item Return Value: 1
1168 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1169 will run DBIC cascade triggers, while L</delete> will not.
1175 $_->delete for $self->all;
1183 =item Arguments: none
1185 =item Return Value: $pager
1189 Return Value a L<Data::Page> object for the current resultset. Only makes
1190 sense for queries with a C<page> attribute.
1196 my $attrs = $self->{attrs};
1197 $self->throw_exception("Can't create pager for non-paged rs")
1198 unless $self->{page};
1199 $attrs->{rows} ||= 10;
1200 return $self->{pager} ||= Data::Page->new(
1201 $self->_count, $attrs->{rows}, $self->{page});
1208 =item Arguments: $page_number
1210 =item Return Value: $rs
1214 Returns a resultset for the $page_number page of the resultset on which page
1215 is called, where each page contains a number of rows equal to the 'rows'
1216 attribute set on the resultset (10 by default).
1221 my ($self, $page) = @_;
1222 my $attrs = { %{$self->{attrs}} };
1223 $attrs->{page} = $page;
1224 return (ref $self)->new($self->result_source, $attrs);
1231 =item Arguments: \%vals
1233 =item Return Value: $object
1237 Creates an object in the resultset's result class and returns it.
1242 my ($self, $values) = @_;
1243 $self->throw_exception( "new_result needs a hash" )
1244 unless (ref $values eq 'HASH');
1245 $self->throw_exception(
1246 "Can't abstract implicit construct, condition not a hash"
1247 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1249 my $alias = $self->{attrs}{alias};
1250 foreach my $key (keys %{$self->{cond}||{}}) {
1251 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1253 my $obj = $self->result_class->new(\%new);
1254 $obj->result_source($self->result_source) if $obj->can('result_source');
1262 =item Arguments: \%vals, \%attrs?
1264 =item Return Value: $object
1268 Find an existing record from this resultset. If none exists, instantiate a new
1269 result object and return it. The object will not be saved into your storage
1270 until you call L<DBIx::Class::Row/insert> on it.
1272 If you want objects to be saved immediately, use L</find_or_create> instead.
1278 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1279 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1280 my $exists = $self->find($hash, $attrs);
1281 return defined $exists ? $exists : $self->new_result($hash);
1288 =item Arguments: \%vals
1290 =item Return Value: $object
1294 Inserts a record into the resultset and returns the object representing it.
1296 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1301 my ($self, $attrs) = @_;
1302 $self->throw_exception( "create needs a hashref" )
1303 unless ref $attrs eq 'HASH';
1304 return $self->new_result($attrs)->insert;
1307 =head2 find_or_create
1311 =item Arguments: \%vals, \%attrs?
1313 =item Return Value: $object
1317 $class->find_or_create({ key => $val, ... });
1319 Tries to find a record based on its primary key or unique constraint; if none
1320 is found, creates one and returns that instead.
1322 my $cd = $schema->resultset('CD')->find_or_create({
1324 artist => 'Massive Attack',
1325 title => 'Mezzanine',
1329 Also takes an optional C<key> attribute, to search by a specific key or unique
1330 constraint. For example:
1332 my $cd = $schema->resultset('CD')->find_or_create(
1334 artist => 'Massive Attack',
1335 title => 'Mezzanine',
1337 { key => 'artist_title' }
1340 See also L</find> and L</update_or_create>. For information on how to declare
1341 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1345 sub find_or_create {
1347 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1348 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1349 my $exists = $self->find($hash, $attrs);
1350 return defined $exists ? $exists : $self->create($hash);
1353 =head2 update_or_create
1357 =item Arguments: \%col_values, { key => $unique_constraint }?
1359 =item Return Value: $object
1363 $class->update_or_create({ col => $val, ... });
1365 First, searches for an existing row matching one of the unique constraints
1366 (including the primary key) on the source of this resultset. If a row is
1367 found, updates it with the other given column values. Otherwise, creates a new
1370 Takes an optional C<key> attribute to search on a specific unique constraint.
1373 # In your application
1374 my $cd = $schema->resultset('CD')->update_or_create(
1376 artist => 'Massive Attack',
1377 title => 'Mezzanine',
1380 { key => 'artist_title' }
1383 If no C<key> is specified, it searches on all unique constraints defined on the
1384 source, including the primary key.
1386 If the C<key> is specified as C<primary>, it searches only on the primary key.
1388 See also L</find> and L</find_or_create>. For information on how to declare
1389 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1393 sub update_or_create {
1395 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1396 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1398 my $row = $self->find($cond);
1400 $row->update($cond);
1404 return $self->create($cond);
1411 =item Arguments: none
1413 =item Return Value: \@cache_objects?
1417 Gets the contents of the cache for the resultset, if the cache is set.
1429 =item Arguments: \@cache_objects
1431 =item Return Value: \@cache_objects
1435 Sets the contents of the cache for the resultset. Expects an arrayref
1436 of objects of the same class as those produced by the resultset. Note that
1437 if the cache is set the resultset will return the cached objects rather
1438 than re-querying the database even if the cache attr is not set.
1443 my ( $self, $data ) = @_;
1444 $self->throw_exception("set_cache requires an arrayref")
1445 if defined($data) && (ref $data ne 'ARRAY');
1446 $self->{all_cache} = $data;
1453 =item Arguments: none
1455 =item Return Value: []
1459 Clears the cache for the resultset.
1464 shift->set_cache(undef);
1467 =head2 related_resultset
1471 =item Arguments: $relationship_name
1473 =item Return Value: $resultset
1477 Returns a related resultset for the supplied relationship name.
1479 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1483 sub related_resultset {
1484 my ( $self, $rel ) = @_;
1486 $self->{related_resultsets} ||= {};
1487 return $self->{related_resultsets}{$rel} ||= do {
1488 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1489 my $rel_obj = $self->result_source->relationship_info($rel);
1490 $self->throw_exception(
1491 "search_related: result source '" . $self->result_source->name .
1492 "' has no such relationship ${rel}")
1493 unless $rel_obj; #die Dumper $self->{attrs};
1495 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1497 { %{$self->{attrs}},
1501 _live_join => $rel }
1504 # keep reference of the original resultset
1505 $rs->{_parent_rs} = $self->result_source;
1510 =head2 throw_exception
1512 See L<DBIx::Class::Schema/throw_exception> for details.
1516 sub throw_exception {
1518 $self->result_source->schema->throw_exception(@_);
1521 # XXX: FIXME: Attributes docs need clearing up
1525 The resultset takes various attributes that modify its behavior. Here's an
1532 =item Value: ($order_by | \@order_by)
1536 Which column(s) to order the results by. This is currently passed
1537 through directly to SQL, so you can give e.g. C<year DESC> for a
1538 descending order on the column `year'.
1540 Please note that if you have quoting enabled (see
1541 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1542 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1543 so you will need to manually quote things as appropriate.)
1549 =item Value: \@columns
1553 Shortcut to request a particular set of columns to be retrieved. Adds
1554 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1555 from that, then auto-populates C<as> from C<select> as normal. (You may also
1556 use the C<cols> attribute, as in earlier versions of DBIC.)
1558 =head2 include_columns
1562 =item Value: \@columns
1566 Shortcut to include additional columns in the returned results - for example
1568 $schema->resultset('CD')->search(undef, {
1569 include_columns => ['artist.name'],
1573 would return all CDs and include a 'name' column to the information
1574 passed to object inflation
1580 =item Value: \@select_columns
1584 Indicates which columns should be selected from the storage. You can use
1585 column names, or in the case of RDBMS back ends, function or stored procedure
1588 $rs = $schema->resultset('Employee')->search(undef, {
1591 { count => 'employeeid' },
1596 When you use function/stored procedure names and do not supply an C<as>
1597 attribute, the column names returned are storage-dependent. E.g. MySQL would
1598 return a column named C<count(employeeid)> in the above example.
1604 Indicates additional columns to be selected from storage. Works the same as
1605 L<select> but adds columns to the selection.
1613 Indicates additional column names for those added via L<+select>.
1621 =item Value: \@inflation_names
1625 Indicates column names for object inflation. This is used in conjunction with
1626 C<select>, usually when C<select> contains one or more function or stored
1629 $rs = $schema->resultset('Employee')->search(undef, {
1632 { count => 'employeeid' }
1634 as => ['name', 'employee_count'],
1637 my $employee = $rs->first(); # get the first Employee
1639 If the object against which the search is performed already has an accessor
1640 matching a column name specified in C<as>, the value can be retrieved using
1641 the accessor as normal:
1643 my $name = $employee->name();
1645 If on the other hand an accessor does not exist in the object, you need to
1646 use C<get_column> instead:
1648 my $employee_count = $employee->get_column('employee_count');
1650 You can create your own accessors if required - see
1651 L<DBIx::Class::Manual::Cookbook> for details.
1653 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1654 produced, it is used for internal access only. Thus attempting to use the accessor
1655 in an C<order_by> clause or similar will fail misrably.
1661 =item Value: ($rel_name | \@rel_names | \%rel_names)
1665 Contains a list of relationships that should be joined for this query. For
1668 # Get CDs by Nine Inch Nails
1669 my $rs = $schema->resultset('CD')->search(
1670 { 'artist.name' => 'Nine Inch Nails' },
1671 { join => 'artist' }
1674 Can also contain a hash reference to refer to the other relation's relations.
1677 package MyApp::Schema::Track;
1678 use base qw/DBIx::Class/;
1679 __PACKAGE__->table('track');
1680 __PACKAGE__->add_columns(qw/trackid cd position title/);
1681 __PACKAGE__->set_primary_key('trackid');
1682 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1685 # In your application
1686 my $rs = $schema->resultset('Artist')->search(
1687 { 'track.title' => 'Teardrop' },
1689 join => { cd => 'track' },
1690 order_by => 'artist.name',
1694 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1695 similarly for a third time). For e.g.
1697 my $rs = $schema->resultset('Artist')->search({
1698 'cds.title' => 'Down to Earth',
1699 'cds_2.title' => 'Popular',
1701 join => [ qw/cds cds/ ],
1704 will return a set of all artists that have both a cd with title 'Down
1705 to Earth' and a cd with title 'Popular'.
1707 If you want to fetch related objects from other tables as well, see C<prefetch>
1714 =item Value: ($rel_name | \@rel_names | \%rel_names)
1718 Contains one or more relationships that should be fetched along with the main
1719 query (when they are accessed afterwards they will have already been
1720 "prefetched"). This is useful for when you know you will need the related
1721 objects, because it saves at least one query:
1723 my $rs = $schema->resultset('Tag')->search(
1732 The initial search results in SQL like the following:
1734 SELECT tag.*, cd.*, artist.* FROM tag
1735 JOIN cd ON tag.cd = cd.cdid
1736 JOIN artist ON cd.artist = artist.artistid
1738 L<DBIx::Class> has no need to go back to the database when we access the
1739 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1742 Simple prefetches will be joined automatically, so there is no need
1743 for a C<join> attribute in the above search. If you're prefetching to
1744 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1745 specify the join as well.
1747 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1748 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1749 with an accessor type of 'single' or 'filter').
1759 Makes the resultset paged and specifies the page to retrieve. Effectively
1760 identical to creating a non-pages resultset and then calling ->page($page)
1763 If L<rows> attribute is not specified it defualts to 10 rows per page.
1773 Specifes the maximum number of rows for direct retrieval or the number of
1774 rows per page if the page attribute or method is used.
1780 =item Value: $offset
1784 Specifies the (zero-based) row number for the first row to be returned, or the
1785 of the first row of the first page if paging is used.
1791 =item Value: \@columns
1795 A arrayref of columns to group by. Can include columns of joined tables.
1797 group_by => [qw/ column1 column2 ... /]
1803 =item Value: $condition
1807 HAVING is a select statement attribute that is applied between GROUP BY and
1808 ORDER BY. It is applied to the after the grouping calculations have been
1811 having => { 'count(employee)' => { '>=', 100 } }
1817 =item Value: (0 | 1)
1821 Set to 1 to group by all columns.
1825 Set to 1 to cache search results. This prevents extra SQL queries if you
1826 revisit rows in your ResultSet:
1828 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1830 while( my $artist = $resultset->next ) {
1834 $rs->first; # without cache, this would issue a query
1836 By default, searches are not cached.
1838 For more examples of using these attributes, see
1839 L<DBIx::Class::Manual::Cookbook>.
1845 =item Value: \@from_clause
1849 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1850 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1853 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1855 C<join> will usually do what you need and it is strongly recommended that you
1856 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1857 And we really do mean "cannot", not just tried and failed. Attempting to use
1858 this because you're having problems with C<join> is like trying to use x86
1859 ASM because you've got a syntax error in your C. Trust us on this.
1861 Now, if you're still really, really sure you need to use this (and if you're
1862 not 100% sure, ask the mailing list first), here's an explanation of how this
1865 The syntax is as follows -
1868 { <alias1> => <table1> },
1870 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1871 [], # nested JOIN (optional)
1872 { <table1.column1> => <table2.column2>, ... (more conditions) },
1874 # More of the above [ ] may follow for additional joins
1881 ON <table1.column1> = <table2.column2>
1882 <more joins may follow>
1884 An easy way to follow the examples below is to remember the following:
1886 Anything inside "[]" is a JOIN
1887 Anything inside "{}" is a condition for the enclosing JOIN
1889 The following examples utilize a "person" table in a family tree application.
1890 In order to express parent->child relationships, this table is self-joined:
1892 # Person->belongs_to('father' => 'Person');
1893 # Person->belongs_to('mother' => 'Person');
1895 C<from> can be used to nest joins. Here we return all children with a father,
1896 then search against all mothers of those children:
1898 $rs = $schema->resultset('Person')->search(
1901 alias => 'mother', # alias columns in accordance with "from"
1903 { mother => 'person' },
1906 { child => 'person' },
1908 { father => 'person' },
1909 { 'father.person_id' => 'child.father_id' }
1912 { 'mother.person_id' => 'child.mother_id' }
1919 # SELECT mother.* FROM person mother
1922 # JOIN person father
1923 # ON ( father.person_id = child.father_id )
1925 # ON ( mother.person_id = child.mother_id )
1927 The type of any join can be controlled manually. To search against only people
1928 with a father in the person table, we could explicitly use C<INNER JOIN>:
1930 $rs = $schema->resultset('Person')->search(
1933 alias => 'child', # alias columns in accordance with "from"
1935 { child => 'person' },
1937 { father => 'person', -join_type => 'inner' },
1938 { 'father.id' => 'child.father_id' }
1945 # SELECT child.* FROM person child
1946 # INNER JOIN person father ON child.father_id = father.id