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 return $self->_find($cond, $attrs);
321 # Helper method: search against the unique constraints.
324 my ($self, $cond, $attrs) = @_;
326 # Check the condition against our source's unique constraints
327 my @constraint_names = exists $attrs->{key}
329 : $self->result_source->unique_constraint_names;
332 foreach my $name (@constraint_names) {
333 my @unique_cols = $self->result_source->unique_constraint_columns($name);
334 my $unique_cond = $self->_build_unique_query($cond, \@unique_cols);
336 next unless scalar keys %$unique_cond == scalar @unique_cols;
338 # Add the ResultSet's alias
339 foreach my $key (grep { ! m/\./ } keys %$unique_cond) {
340 $unique_cond->{"$self->{attrs}{alias}.$key"} = delete $unique_cond->{$key};
343 push @unique_conds, $unique_cond;
345 # use Data::Dumper; warn Dumper $self->result_source->name, $cond, \@unique_conds;
348 my $query = \@unique_conds;
349 if (scalar @unique_conds == 0) {
350 if (exists $attrs->{key}) {
351 $self->throw_exception("required values for the $attrs->{key} key not provided");
354 # Compatibility: Allow broken find usage for now
355 carp "find requires values for the primary key or a unique constraint"
356 . "; please use search instead";
363 my $rs = $self->search($query, $attrs);
365 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
369 return (keys %{$self->{_attrs}->{collapse}})
370 ? $self->search($query)->next
371 : $self->single($query);
375 # _build_unique_query
377 # Constrain the specified query hash based on the specified column names.
379 sub _build_unique_query {
380 my ($self, $query, $unique_cols) = @_;
383 map { $_ => $query->{$_} }
384 grep { exists $query->{$_} }
387 return \%unique_query;
390 =head2 search_related
394 =item Arguments: $cond, \%attrs?
396 =item Return Value: $new_resultset
400 $new_rs = $cd_rs->search_related('artist', {
404 Searches the specified relationship, optionally specifying a condition and
405 attributes for matching records. See L</ATTRIBUTES> for more information.
410 return shift->related_resultset(shift)->search(@_);
417 =item Arguments: none
419 =item Return Value: $cursor
423 Returns a storage-driven cursor to the given resultset. See
424 L<DBIx::Class::Cursor> for more information.
432 my $attrs = { %{$self->{_attrs}} };
433 return $self->{cursor}
434 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
435 $attrs->{where},$attrs);
442 =item Arguments: $cond?
444 =item Return Value: $row_object?
448 my $cd = $schema->resultset('CD')->single({ year => 2001 });
450 Inflates the first result without creating a cursor if the resultset has
451 any records in it; if not returns nothing. Used by L</find> as an optimisation.
453 Can optionally take an additional condition *only* - this is a fast-code-path
454 method; if you need to add extra joins or similar call ->search and then
455 ->single without a condition on the $rs returned from that.
460 my ($self, $where) = @_;
462 my $attrs = { %{$self->{_attrs}} };
464 if (defined $attrs->{where}) {
467 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
468 $where, delete $attrs->{where} ]
471 $attrs->{where} = $where;
475 my @data = $self->result_source->storage->select_single(
476 $attrs->{from}, $attrs->{select},
477 $attrs->{where},$attrs);
478 return (@data ? $self->_construct_object(@data) : ());
485 =item Arguments: $cond?
487 =item Return Value: $resultsetcolumn
491 my $max_length = $rs->get_column('length')->max;
493 Returns a ResultSetColumn instance for $column based on $self
498 my ($self, $column) = @_;
500 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
508 =item Arguments: $cond, \%attrs?
510 =item Return Value: $resultset (scalar context), @row_objs (list context)
514 # WHERE title LIKE '%blue%'
515 $cd_rs = $rs->search_like({ title => '%blue%'});
517 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
518 that this is simply a convenience method. You most likely want to use
519 L</search> with specific operators.
521 For more information, see L<DBIx::Class::Manual::Cookbook>.
527 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
528 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
529 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
530 return $class->search($query, { %$attrs });
537 =item Arguments: $first, $last
539 =item Return Value: $resultset (scalar context), @row_objs (list context)
543 Returns a resultset or object list representing a subset of elements from the
544 resultset slice is called on. Indexes are from 0, i.e., to get the first
547 my ($one, $two, $three) = $rs->slice(0, 2);
552 my ($self, $min, $max) = @_;
553 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
554 $attrs->{offset} = $self->{attrs}{offset} || 0;
555 $attrs->{offset} += $min;
556 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
557 return $self->search(undef(), $attrs);
558 #my $slice = (ref $self)->new($self->result_source, $attrs);
559 #return (wantarray ? $slice->all : $slice);
566 =item Arguments: none
568 =item Return Value: $result?
572 Returns the next element in the resultset (C<undef> is there is none).
574 Can be used to efficiently iterate over records in the resultset:
576 my $rs = $schema->resultset('CD')->search;
577 while (my $cd = $rs->next) {
581 Note that you need to store the resultset object, and call C<next> on it.
582 Calling C<< resultset('Table')->next >> repeatedly will always return the
583 first record from the resultset.
589 if (my $cache = $self->get_cache) {
590 $self->{all_cache_position} ||= 0;
591 return $cache->[$self->{all_cache_position}++];
593 if ($self->{attrs}{cache}) {
594 $self->{all_cache_position} = 1;
595 return ($self->all)[0];
597 my @row = (exists $self->{stashed_row} ?
598 @{delete $self->{stashed_row}} :
601 return unless (@row);
602 return $self->_construct_object(@row);
608 return if(exists $self->{_attrs}); #return if _resolve has already been called
610 my $attrs = $self->{attrs};
611 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
613 # XXX - lose storable dclone
614 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
615 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
616 $attrs->{record_filter} = $record_filter if ($record_filter);
617 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
619 my $alias = $attrs->{alias};
621 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
622 delete $attrs->{as} if $attrs->{columns};
623 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
624 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
626 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
627 ] if $attrs->{columns};
629 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
631 if (my $include = delete $attrs->{include_columns}) {
632 push(@{$attrs->{select}}, @$include);
633 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
636 $attrs->{from} ||= [ { $alias => $source->from } ];
637 $attrs->{seen_join} ||= {};
639 if (my $join = delete $attrs->{join}) {
640 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
641 if (ref $j eq 'HASH') {
642 $seen{$_} = 1 foreach keys %$j;
648 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
650 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
651 $attrs->{order_by} = [ $attrs->{order_by} ] if
652 $attrs->{order_by} and !ref($attrs->{order_by});
653 $attrs->{order_by} ||= [];
655 if(my $seladds = delete($attrs->{'+select'})) {
656 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
658 @{ $attrs->{select} },
659 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
662 if(my $asadds = delete($attrs->{'+as'})) {
663 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
664 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
667 my $collapse = $attrs->{collapse} || {};
668 if (my $prefetch = delete $attrs->{prefetch}) {
670 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
671 if ( ref $p eq 'HASH' ) {
672 foreach my $key (keys %$p) {
673 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
677 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
680 my @prefetch = $source->resolve_prefetch(
681 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
682 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
683 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
685 push(@{$attrs->{order_by}}, @pre_order);
687 $attrs->{collapse} = $collapse;
688 $self->{_attrs} = $attrs;
692 my ($self, $a, $b, $is_prefetch) = @_;
695 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
696 foreach my $key (keys %{$b}) {
697 if (exists $a->{$key}) {
698 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
700 $a->{$key} = delete $b->{$key};
705 $a = [$a] unless (ref $a eq 'ARRAY');
706 $b = [$b] unless (ref $b eq 'ARRAY');
711 foreach my $element (@{$_}) {
712 if (ref $element eq 'HASH') {
713 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
714 } elsif (ref $element eq 'ARRAY') {
715 $array = [@{$array}, @{$element}];
717 if (($b == $_) && $is_prefetch) {
718 $self->_merge_array($array, $element, $is_prefetch);
720 push(@{$array}, $element);
726 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
727 return [$hash, @{$array}];
729 return (keys %{$hash}) ? $hash : $array;
735 my ($self, $a, $b) = @_;
737 $b = [$b] unless (ref $b eq 'ARRAY');
738 # add elements from @{$b} to @{$a} which aren't already in @{$a}
739 foreach my $b_element (@{$b}) {
740 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
744 sub _construct_object {
745 my ($self, @row) = @_;
746 my @as = @{ $self->{_attrs}{as} };
748 my $info = $self->_collapse_result(\@as, \@row);
749 my $new = $self->result_class->inflate_result($self->result_source, @$info);
750 $new = $self->{_attrs}{record_filter}->($new)
751 if exists $self->{_attrs}{record_filter};
755 sub _collapse_result {
756 my ($self, $as, $row, $prefix) = @_;
758 my $live_join = $self->{attrs}->{_live_join} ||="";
762 foreach my $this_as (@$as) {
763 my $val = shift @copy;
764 if (defined $prefix) {
765 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
767 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
768 $const{$1||''}{$2} = $val;
771 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
772 $const{$1||''}{$2} = $val;
776 my $info = [ {}, {} ];
777 foreach my $key (keys %const) {
778 if (length $key && $key ne $live_join) {
780 my @parts = split(/\./, $key);
781 foreach my $p (@parts) {
782 $target = $target->[1]->{$p} ||= [];
784 $target->[0] = $const{$key};
786 $info->[0] = $const{$key};
791 if (defined $prefix) {
793 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
794 } keys %{$self->{_attrs}->{collapse}}
796 @collapse = keys %{$self->{_attrs}->{collapse}};
800 my ($c) = sort { length $a <=> length $b } @collapse;
802 foreach my $p (split(/\./, $c)) {
803 $target = $target->[1]->{$p} ||= [];
805 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
806 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
807 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
808 my $tree = $self->_collapse_result($as, $row, $c_prefix);
811 !defined($tree->[0]->{$_}) ||
812 $co_check{$_} ne $tree->[0]->{$_}
815 last unless (@raw = $self->cursor->next);
816 $row = $self->{stashed_row} = \@raw;
817 $tree = $self->_collapse_result($as, $row, $c_prefix);
819 @$target = (@final ? @final : [ {}, {} ]);
820 # single empty result to indicate an empty prefetched has_many
829 =item Arguments: $result_source?
831 =item Return Value: $result_source
835 An accessor for the primary ResultSource object from which this ResultSet
845 =item Arguments: $cond, \%attrs??
847 =item Return Value: $count
851 Performs an SQL C<COUNT> with the same query as the resultset was built
852 with to find the number of elements. If passed arguments, does a search
853 on the resultset and counts the results of that.
855 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
856 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
857 not support C<DISTINCT> with multiple columns. If you are using such a
858 database, you should only use columns from the main table in your C<group_by>
865 return $self->search(@_)->count if @_ and defined $_[0];
866 return scalar @{ $self->get_cache } if $self->get_cache;
868 my $count = $self->_count;
869 return 0 unless $count;
871 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
872 $count = $self->{attrs}{rows} if
873 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
877 sub _count { # Separated out so pager can get the full count
879 my $select = { count => '*' };
882 my $attrs = { %{ $self->{_attrs} } };
883 if (my $group_by = delete $attrs->{group_by}) {
884 delete $attrs->{having};
885 my @distinct = (ref $group_by ? @$group_by : ($group_by));
886 # todo: try CONCAT for multi-column pk
887 my @pk = $self->result_source->primary_columns;
889 foreach my $column (@distinct) {
890 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
891 @distinct = ($column);
897 $select = { count => { distinct => \@distinct } };
900 $attrs->{select} = $select;
901 $attrs->{as} = [qw/count/];
903 # offset, order by and page are not needed to count. record_filter is cdbi
904 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
905 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
913 =item Arguments: $sql_fragment, @bind_values
915 =item Return Value: $count
919 Counts the results in a literal query. Equivalent to calling L</search_literal>
920 with the passed arguments, then L</count>.
924 sub count_literal { shift->search_literal(@_)->count; }
930 =item Arguments: none
932 =item Return Value: @objects
936 Returns all elements in the resultset. Called implicitly if the resultset
937 is returned in list context.
943 return @{ $self->get_cache } if $self->get_cache;
947 # TODO: don't call resolve here
949 if (keys %{$self->{_attrs}->{collapse}}) {
950 # if ($self->{attrs}->{prefetch}) {
951 # Using $self->cursor->all is really just an optimisation.
952 # If we're collapsing has_many prefetches it probably makes
953 # very little difference, and this is cleaner than hacking
954 # _construct_object to survive the approach
955 my @row = $self->cursor->next;
957 push(@obj, $self->_construct_object(@row));
958 @row = (exists $self->{stashed_row}
959 ? @{delete $self->{stashed_row}}
960 : $self->cursor->next);
963 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
966 $self->set_cache(\@obj) if $self->{attrs}{cache};
974 =item Arguments: none
976 =item Return Value: $self
980 Resets the resultset's cursor, so you can iterate through the elements again.
986 delete $self->{_attrs} if (exists $self->{_attrs});
988 $self->{all_cache_position} = 0;
989 $self->cursor->reset;
997 =item Arguments: none
999 =item Return Value: $object?
1003 Resets the resultset and returns an object for the first result (if the
1004 resultset returns anything).
1009 return $_[0]->reset->next;
1012 # _cond_for_update_delete
1014 # update/delete require the condition to be modified to handle
1015 # the differing SQL syntax available. This transforms the $self->{cond}
1016 # appropriately, returning the new condition.
1018 sub _cond_for_update_delete {
1022 if (!ref($self->{cond})) {
1023 # No-op. No condition, we're updating/deleting everything
1025 elsif (ref $self->{cond} eq 'ARRAY') {
1029 foreach my $key (keys %{$_}) {
1031 $hash{$1} = $_->{$key};
1037 elsif (ref $self->{cond} eq 'HASH') {
1038 if ((keys %{$self->{cond}})[0] eq '-and') {
1041 my @cond = @{$self->{cond}{-and}};
1042 for (my $i = 0; $i <= @cond - 1; $i++) {
1043 my $entry = $cond[$i];
1046 if (ref $entry eq 'HASH') {
1047 foreach my $key (keys %{$entry}) {
1049 $hash{$1} = $entry->{$key};
1053 $entry =~ /([^.]+)$/;
1054 $hash{$1} = $cond[++$i];
1057 push @{$cond->{-and}}, \%hash;
1061 foreach my $key (keys %{$self->{cond}}) {
1063 $cond->{$1} = $self->{cond}{$key};
1068 $self->throw_exception(
1069 "Can't update/delete on resultset with condition unless hash or array"
1081 =item Arguments: \%values
1083 =item Return Value: $storage_rv
1087 Sets the specified columns in the resultset to the supplied values in a
1088 single query. Return value will be true if the update succeeded or false
1089 if no records were updated; exact type of success value is storage-dependent.
1094 my ($self, $values) = @_;
1095 $self->throw_exception("Values for update must be a hash")
1096 unless ref $values eq 'HASH';
1098 my $cond = $self->_cond_for_update_delete;
1100 return $self->result_source->storage->update(
1101 $self->result_source->from, $values, $cond
1109 =item Arguments: \%values
1111 =item Return Value: 1
1115 Fetches all objects and updates them one at a time. Note that C<update_all>
1116 will run DBIC cascade triggers, while L</update> will not.
1121 my ($self, $values) = @_;
1122 $self->throw_exception("Values for update must be a hash")
1123 unless ref $values eq 'HASH';
1124 foreach my $obj ($self->all) {
1125 $obj->set_columns($values)->update;
1134 =item Arguments: none
1136 =item Return Value: 1
1140 Deletes the contents of the resultset from its result source. Note that this
1141 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1150 my $cond = $self->_cond_for_update_delete;
1152 $self->result_source->storage->delete($self->result_source->from, $cond);
1160 =item Arguments: none
1162 =item Return Value: 1
1166 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1167 will run DBIC cascade triggers, while L</delete> will not.
1173 $_->delete for $self->all;
1181 =item Arguments: none
1183 =item Return Value: $pager
1187 Return Value a L<Data::Page> object for the current resultset. Only makes
1188 sense for queries with a C<page> attribute.
1194 my $attrs = $self->{attrs};
1195 $self->throw_exception("Can't create pager for non-paged rs")
1196 unless $self->{page};
1197 $attrs->{rows} ||= 10;
1198 return $self->{pager} ||= Data::Page->new(
1199 $self->_count, $attrs->{rows}, $self->{page});
1206 =item Arguments: $page_number
1208 =item Return Value: $rs
1212 Returns a resultset for the $page_number page of the resultset on which page
1213 is called, where each page contains a number of rows equal to the 'rows'
1214 attribute set on the resultset (10 by default).
1219 my ($self, $page) = @_;
1220 my $attrs = { %{$self->{attrs}} };
1221 $attrs->{page} = $page;
1222 return (ref $self)->new($self->result_source, $attrs);
1229 =item Arguments: \%vals
1231 =item Return Value: $object
1235 Creates an object in the resultset's result class and returns it.
1240 my ($self, $values) = @_;
1241 $self->throw_exception( "new_result needs a hash" )
1242 unless (ref $values eq 'HASH');
1243 $self->throw_exception(
1244 "Can't abstract implicit construct, condition not a hash"
1245 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1247 my $alias = $self->{attrs}{alias};
1248 foreach my $key (keys %{$self->{cond}||{}}) {
1249 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1251 my $obj = $self->result_class->new(\%new);
1252 $obj->result_source($self->result_source) if $obj->can('result_source');
1260 =item Arguments: \%vals, \%attrs?
1262 =item Return Value: $object
1266 Find an existing record from this resultset. If none exists, instantiate a new
1267 result object and return it. The object will not be saved into your storage
1268 until you call L<DBIx::Class::Row/insert> on it.
1270 If you want objects to be saved immediately, use L</find_or_create> instead.
1276 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1277 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1278 my $exists = $self->find($hash, $attrs);
1279 return defined $exists ? $exists : $self->new_result($hash);
1286 =item Arguments: \%vals
1288 =item Return Value: $object
1292 Inserts a record into the resultset and returns the object representing it.
1294 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1299 my ($self, $attrs) = @_;
1300 $self->throw_exception( "create needs a hashref" )
1301 unless ref $attrs eq 'HASH';
1302 return $self->new_result($attrs)->insert;
1305 =head2 find_or_create
1309 =item Arguments: \%vals, \%attrs?
1311 =item Return Value: $object
1315 $class->find_or_create({ key => $val, ... });
1317 Searches for a record matching the search condition; if it doesn't find one,
1318 creates one and returns that instead.
1320 my $cd = $schema->resultset('CD')->find_or_create({
1322 artist => 'Massive Attack',
1323 title => 'Mezzanine',
1327 Also takes an optional C<key> attribute, to search by a specific key or unique
1328 constraint. For example:
1330 my $cd = $schema->resultset('CD')->find_or_create(
1332 artist => 'Massive Attack',
1333 title => 'Mezzanine',
1335 { key => 'artist_title' }
1338 See also L</find> and L</update_or_create>. For information on how to declare
1339 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1343 sub find_or_create {
1345 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1346 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1347 my $exists = $self->find($hash, $attrs);
1348 return defined $exists ? $exists : $self->create($hash);
1351 =head2 update_or_create
1355 =item Arguments: \%col_values, { key => $unique_constraint }?
1357 =item Return Value: $object
1361 $class->update_or_create({ col => $val, ... });
1363 First, searches for an existing row matching one of the unique constraints
1364 (including the primary key) on the source of this resultset. If a row is
1365 found, updates it with the other given column values. Otherwise, creates a new
1368 Takes an optional C<key> attribute to search on a specific unique constraint.
1371 # In your application
1372 my $cd = $schema->resultset('CD')->update_or_create(
1374 artist => 'Massive Attack',
1375 title => 'Mezzanine',
1378 { key => 'artist_title' }
1381 If no C<key> is specified, it searches on all unique constraints defined on the
1382 source, including the primary key.
1384 If the C<key> is specified as C<primary>, it searches only on the primary key.
1386 See also L</find> and L</find_or_create>. For information on how to declare
1387 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1391 sub update_or_create {
1393 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1394 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1396 my @constraint_names = exists $attrs->{key}
1398 : $self->result_source->unique_constraint_names;
1399 $self->throw_exception(
1400 "update_or_create requires a primary key or unique constraint; none is defined on "
1401 . $self->result_source->name
1402 ) unless @constraint_names;
1405 foreach my $name (@constraint_names) {
1406 my @unique_cols = $self->result_source->unique_constraint_columns($name);
1407 my $unique_query = $self->_build_unique_query($hash, \@unique_cols);
1409 push @unique_queries, $unique_query
1410 if keys %$unique_query == @unique_cols;
1413 if (@unique_queries) {
1414 my $row = $self->single(\@unique_queries);
1416 $row->update($hash);
1421 return $self->create($hash);
1428 =item Arguments: none
1430 =item Return Value: \@cache_objects?
1434 Gets the contents of the cache for the resultset, if the cache is set.
1446 =item Arguments: \@cache_objects
1448 =item Return Value: \@cache_objects
1452 Sets the contents of the cache for the resultset. Expects an arrayref
1453 of objects of the same class as those produced by the resultset. Note that
1454 if the cache is set the resultset will return the cached objects rather
1455 than re-querying the database even if the cache attr is not set.
1460 my ( $self, $data ) = @_;
1461 $self->throw_exception("set_cache requires an arrayref")
1462 if defined($data) && (ref $data ne 'ARRAY');
1463 $self->{all_cache} = $data;
1470 =item Arguments: none
1472 =item Return Value: []
1476 Clears the cache for the resultset.
1481 shift->set_cache(undef);
1484 =head2 related_resultset
1488 =item Arguments: $relationship_name
1490 =item Return Value: $resultset
1494 Returns a related resultset for the supplied relationship name.
1496 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1500 sub related_resultset {
1501 my ( $self, $rel ) = @_;
1503 $self->{related_resultsets} ||= {};
1504 return $self->{related_resultsets}{$rel} ||= do {
1505 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1506 my $rel_obj = $self->result_source->relationship_info($rel);
1507 $self->throw_exception(
1508 "search_related: result source '" . $self->result_source->name .
1509 "' has no such relationship ${rel}")
1510 unless $rel_obj; #die Dumper $self->{attrs};
1512 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1514 { %{$self->{attrs}},
1518 _live_join => $rel }
1521 # keep reference of the original resultset
1522 $rs->{_parent_rs} = $self->result_source;
1527 =head2 throw_exception
1529 See L<DBIx::Class::Schema/throw_exception> for details.
1533 sub throw_exception {
1535 $self->result_source->schema->throw_exception(@_);
1538 # XXX: FIXME: Attributes docs need clearing up
1542 The resultset takes various attributes that modify its behavior. Here's an
1549 =item Value: ($order_by | \@order_by)
1553 Which column(s) to order the results by. This is currently passed
1554 through directly to SQL, so you can give e.g. C<year DESC> for a
1555 descending order on the column `year'.
1557 Please note that if you have quoting enabled (see
1558 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1559 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1560 so you will need to manually quote things as appropriate.)
1566 =item Value: \@columns
1570 Shortcut to request a particular set of columns to be retrieved. Adds
1571 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1572 from that, then auto-populates C<as> from C<select> as normal. (You may also
1573 use the C<cols> attribute, as in earlier versions of DBIC.)
1575 =head2 include_columns
1579 =item Value: \@columns
1583 Shortcut to include additional columns in the returned results - for example
1585 $schema->resultset('CD')->search(undef, {
1586 include_columns => ['artist.name'],
1590 would return all CDs and include a 'name' column to the information
1591 passed to object inflation
1597 =item Value: \@select_columns
1601 Indicates which columns should be selected from the storage. You can use
1602 column names, or in the case of RDBMS back ends, function or stored procedure
1605 $rs = $schema->resultset('Employee')->search(undef, {
1608 { count => 'employeeid' },
1613 When you use function/stored procedure names and do not supply an C<as>
1614 attribute, the column names returned are storage-dependent. E.g. MySQL would
1615 return a column named C<count(employeeid)> in the above example.
1621 Indicates additional columns to be selected from storage. Works the same as
1622 L<select> but adds columns to the selection.
1630 Indicates additional column names for those added via L<+select>.
1638 =item Value: \@inflation_names
1642 Indicates column names for object inflation. This is used in conjunction with
1643 C<select>, usually when C<select> contains one or more function or stored
1646 $rs = $schema->resultset('Employee')->search(undef, {
1649 { count => 'employeeid' }
1651 as => ['name', 'employee_count'],
1654 my $employee = $rs->first(); # get the first Employee
1656 If the object against which the search is performed already has an accessor
1657 matching a column name specified in C<as>, the value can be retrieved using
1658 the accessor as normal:
1660 my $name = $employee->name();
1662 If on the other hand an accessor does not exist in the object, you need to
1663 use C<get_column> instead:
1665 my $employee_count = $employee->get_column('employee_count');
1667 You can create your own accessors if required - see
1668 L<DBIx::Class::Manual::Cookbook> for details.
1670 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1671 produced, it is used for internal access only. Thus attempting to use the accessor
1672 in an C<order_by> clause or similar will fail misrably.
1678 =item Value: ($rel_name | \@rel_names | \%rel_names)
1682 Contains a list of relationships that should be joined for this query. For
1685 # Get CDs by Nine Inch Nails
1686 my $rs = $schema->resultset('CD')->search(
1687 { 'artist.name' => 'Nine Inch Nails' },
1688 { join => 'artist' }
1691 Can also contain a hash reference to refer to the other relation's relations.
1694 package MyApp::Schema::Track;
1695 use base qw/DBIx::Class/;
1696 __PACKAGE__->table('track');
1697 __PACKAGE__->add_columns(qw/trackid cd position title/);
1698 __PACKAGE__->set_primary_key('trackid');
1699 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1702 # In your application
1703 my $rs = $schema->resultset('Artist')->search(
1704 { 'track.title' => 'Teardrop' },
1706 join => { cd => 'track' },
1707 order_by => 'artist.name',
1711 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1712 similarly for a third time). For e.g.
1714 my $rs = $schema->resultset('Artist')->search({
1715 'cds.title' => 'Down to Earth',
1716 'cds_2.title' => 'Popular',
1718 join => [ qw/cds cds/ ],
1721 will return a set of all artists that have both a cd with title 'Down
1722 to Earth' and a cd with title 'Popular'.
1724 If you want to fetch related objects from other tables as well, see C<prefetch>
1731 =item Value: ($rel_name | \@rel_names | \%rel_names)
1735 Contains one or more relationships that should be fetched along with the main
1736 query (when they are accessed afterwards they will have already been
1737 "prefetched"). This is useful for when you know you will need the related
1738 objects, because it saves at least one query:
1740 my $rs = $schema->resultset('Tag')->search(
1749 The initial search results in SQL like the following:
1751 SELECT tag.*, cd.*, artist.* FROM tag
1752 JOIN cd ON tag.cd = cd.cdid
1753 JOIN artist ON cd.artist = artist.artistid
1755 L<DBIx::Class> has no need to go back to the database when we access the
1756 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1759 Simple prefetches will be joined automatically, so there is no need
1760 for a C<join> attribute in the above search. If you're prefetching to
1761 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1762 specify the join as well.
1764 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1765 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1766 with an accessor type of 'single' or 'filter').
1776 Makes the resultset paged and specifies the page to retrieve. Effectively
1777 identical to creating a non-pages resultset and then calling ->page($page)
1780 If L<rows> attribute is not specified it defualts to 10 rows per page.
1790 Specifes the maximum number of rows for direct retrieval or the number of
1791 rows per page if the page attribute or method is used.
1797 =item Value: $offset
1801 Specifies the (zero-based) row number for the first row to be returned, or the
1802 of the first row of the first page if paging is used.
1808 =item Value: \@columns
1812 A arrayref of columns to group by. Can include columns of joined tables.
1814 group_by => [qw/ column1 column2 ... /]
1820 =item Value: $condition
1824 HAVING is a select statement attribute that is applied between GROUP BY and
1825 ORDER BY. It is applied to the after the grouping calculations have been
1828 having => { 'count(employee)' => { '>=', 100 } }
1834 =item Value: (0 | 1)
1838 Set to 1 to group by all columns.
1842 Set to 1 to cache search results. This prevents extra SQL queries if you
1843 revisit rows in your ResultSet:
1845 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1847 while( my $artist = $resultset->next ) {
1851 $rs->first; # without cache, this would issue a query
1853 By default, searches are not cached.
1855 For more examples of using these attributes, see
1856 L<DBIx::Class::Manual::Cookbook>.
1862 =item Value: \@from_clause
1866 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1867 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1870 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1872 C<join> will usually do what you need and it is strongly recommended that you
1873 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1874 And we really do mean "cannot", not just tried and failed. Attempting to use
1875 this because you're having problems with C<join> is like trying to use x86
1876 ASM because you've got a syntax error in your C. Trust us on this.
1878 Now, if you're still really, really sure you need to use this (and if you're
1879 not 100% sure, ask the mailing list first), here's an explanation of how this
1882 The syntax is as follows -
1885 { <alias1> => <table1> },
1887 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1888 [], # nested JOIN (optional)
1889 { <table1.column1> => <table2.column2>, ... (more conditions) },
1891 # More of the above [ ] may follow for additional joins
1898 ON <table1.column1> = <table2.column2>
1899 <more joins may follow>
1901 An easy way to follow the examples below is to remember the following:
1903 Anything inside "[]" is a JOIN
1904 Anything inside "{}" is a condition for the enclosing JOIN
1906 The following examples utilize a "person" table in a family tree application.
1907 In order to express parent->child relationships, this table is self-joined:
1909 # Person->belongs_to('father' => 'Person');
1910 # Person->belongs_to('mother' => 'Person');
1912 C<from> can be used to nest joins. Here we return all children with a father,
1913 then search against all mothers of those children:
1915 $rs = $schema->resultset('Person')->search(
1918 alias => 'mother', # alias columns in accordance with "from"
1920 { mother => 'person' },
1923 { child => 'person' },
1925 { father => 'person' },
1926 { 'father.person_id' => 'child.father_id' }
1929 { 'mother.person_id' => 'child.mother_id' }
1936 # SELECT mother.* FROM person mother
1939 # JOIN person father
1940 # ON ( father.person_id = child.father_id )
1942 # ON ( mother.person_id = child.mother_id )
1944 The type of any join can be controlled manually. To search against only people
1945 with a father in the person table, we could explicitly use C<INNER JOIN>:
1947 $rs = $schema->resultset('Person')->search(
1950 alias => 'child', # alias columns in accordance with "from"
1952 { child => 'person' },
1954 { father => 'person', -join_type => 'inner' },
1955 { 'father.id' => 'child.father_id' }
1962 # SELECT child.* FROM person child
1963 # INNER JOIN person father ON child.father_id = father.id