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 => 'cd_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 => 'cd_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 $input_query = { %{$_[0]} };
306 elsif (@_ == @cols) {
308 @{$input_query}{@cols} = @_;
311 # Compatibility: Allow e.g. find(id => $value)
312 carp "Find by key => value deprecated; please use a hashref instead";
316 my @unique_queries = $self->_unique_queries($input_query, $attrs);
318 # Handle cases where the ResultSet defines the query, or where the user is
320 my $query = @unique_queries ? \@unique_queries : $input_query;
324 my $rs = $self->search($query, $attrs);
326 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
330 return (keys %{$self->{_attrs}->{collapse}})
331 ? $self->search($query)->next
332 : $self->single($query);
338 # Build a list of queries which satisfy unique constraints.
340 sub _unique_queries {
341 my ($self, $query, $attrs) = @_;
343 my @constraint_names = exists $attrs->{key}
345 : $self->result_source->unique_constraint_names;
348 foreach my $name (@constraint_names) {
349 my @unique_cols = $self->result_source->unique_constraint_columns($name);
350 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
352 next unless scalar keys %$unique_query;
354 # Add the ResultSet's alias
355 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
356 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
357 $unique_query->{"$alias.$key"} = delete $unique_query->{$key};
360 push @unique_queries, $unique_query;
363 return @unique_queries;
366 # _build_unique_query
368 # Constrain the specified query hash based on the specified column names.
370 sub _build_unique_query {
371 my ($self, $query, $unique_cols) = @_;
374 map { $_ => $query->{$_} }
375 grep { exists $query->{$_} }
378 return \%unique_query;
381 =head2 search_related
385 =item Arguments: $cond, \%attrs?
387 =item Return Value: $new_resultset
391 $new_rs = $cd_rs->search_related('artist', {
395 Searches the specified relationship, optionally specifying a condition and
396 attributes for matching records. See L</ATTRIBUTES> for more information.
401 return shift->related_resultset(shift)->search(@_);
408 =item Arguments: none
410 =item Return Value: $cursor
414 Returns a storage-driven cursor to the given resultset. See
415 L<DBIx::Class::Cursor> for more information.
423 my $attrs = { %{$self->{_attrs}} };
424 return $self->{cursor}
425 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
426 $attrs->{where},$attrs);
433 =item Arguments: $cond?
435 =item Return Value: $row_object?
439 my $cd = $schema->resultset('CD')->single({ year => 2001 });
441 Inflates the first result without creating a cursor if the resultset has
442 any records in it; if not returns nothing. Used by L</find> as an optimisation.
444 Can optionally take an additional condition *only* - this is a fast-code-path
445 method; if you need to add extra joins or similar call ->search and then
446 ->single without a condition on the $rs returned from that.
451 my ($self, $where) = @_;
453 my $attrs = { %{$self->{_attrs}} };
455 if (defined $attrs->{where}) {
458 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
459 $where, delete $attrs->{where} ]
462 $attrs->{where} = $where;
466 unless ($self->_is_unique_query($attrs->{where})) {
467 carp "Query not guarnteed to return a single row"
468 . "; please declare your unique constraints or use search instead";
471 my @data = $self->result_source->storage->select_single(
472 $attrs->{from}, $attrs->{select},
473 $attrs->{where},$attrs);
474 return (@data ? $self->_construct_object(@data) : ());
479 # Try to determine if the specified query is guaranteed to be unique, based on
480 # the declared unique constraints.
482 sub _is_unique_query {
483 my ($self, $query) = @_;
485 my $collapsed = $self->_collapse_query($query);
487 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
488 foreach my $name ($self->result_source->unique_constraint_names) {
489 my @unique_cols = map { "$alias.$_" }
490 $self->result_source->unique_constraint_columns($name);
492 # Count the values for each unique column
493 my %seen = map { $_ => 0 } @unique_cols;
495 foreach my $key (keys %$collapsed) {
497 $aliased = "$alias.$key" unless $key =~ /\./;
499 next unless exists $seen{$aliased}; # Additional constraints are okay
500 $seen{$aliased} = scalar @{ $collapsed->{$key} };
503 # If we get 0 or more than 1 value for a column, it's not necessarily unique
504 return 1 unless grep { $_ != 1 } values %seen;
512 # Recursively collapse the query, accumulating values for each column.
514 sub _collapse_query {
515 my ($self, $query, $collapsed) = @_;
519 if (ref $query eq 'ARRAY') {
520 foreach my $subquery (@$query) {
521 next unless ref $subquery; # -or
522 # warn "ARRAY: " . Dumper $subquery;
523 $collapsed = $self->_collapse_query($subquery, $collapsed);
526 elsif (ref $query eq 'HASH') {
527 if (keys %$query and (keys %$query)[0] eq '-and') {
528 foreach my $subquery (@{$query->{-and}}) {
529 # warn "HASH: " . Dumper $subquery;
530 $collapsed = $self->_collapse_query($subquery, $collapsed);
534 # warn "LEAF: " . Dumper $query;
535 foreach my $key (keys %$query) {
536 push @{$collapsed->{$key}}, $query->{$key};
548 =item Arguments: $cond?
550 =item Return Value: $resultsetcolumn
554 my $max_length = $rs->get_column('length')->max;
556 Returns a ResultSetColumn instance for $column based on $self
561 my ($self, $column) = @_;
563 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
571 =item Arguments: $cond, \%attrs?
573 =item Return Value: $resultset (scalar context), @row_objs (list context)
577 # WHERE title LIKE '%blue%'
578 $cd_rs = $rs->search_like({ title => '%blue%'});
580 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
581 that this is simply a convenience method. You most likely want to use
582 L</search> with specific operators.
584 For more information, see L<DBIx::Class::Manual::Cookbook>.
590 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
591 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
592 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
593 return $class->search($query, { %$attrs });
600 =item Arguments: $first, $last
602 =item Return Value: $resultset (scalar context), @row_objs (list context)
606 Returns a resultset or object list representing a subset of elements from the
607 resultset slice is called on. Indexes are from 0, i.e., to get the first
610 my ($one, $two, $three) = $rs->slice(0, 2);
615 my ($self, $min, $max) = @_;
616 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
617 $attrs->{offset} = $self->{attrs}{offset} || 0;
618 $attrs->{offset} += $min;
619 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
620 return $self->search(undef(), $attrs);
621 #my $slice = (ref $self)->new($self->result_source, $attrs);
622 #return (wantarray ? $slice->all : $slice);
629 =item Arguments: none
631 =item Return Value: $result?
635 Returns the next element in the resultset (C<undef> is there is none).
637 Can be used to efficiently iterate over records in the resultset:
639 my $rs = $schema->resultset('CD')->search;
640 while (my $cd = $rs->next) {
644 Note that you need to store the resultset object, and call C<next> on it.
645 Calling C<< resultset('Table')->next >> repeatedly will always return the
646 first record from the resultset.
652 if (my $cache = $self->get_cache) {
653 $self->{all_cache_position} ||= 0;
654 return $cache->[$self->{all_cache_position}++];
656 if ($self->{attrs}{cache}) {
657 $self->{all_cache_position} = 1;
658 return ($self->all)[0];
660 my @row = (exists $self->{stashed_row} ?
661 @{delete $self->{stashed_row}} :
664 return unless (@row);
665 return $self->_construct_object(@row);
671 return if(exists $self->{_attrs}); #return if _resolve has already been called
673 my $attrs = $self->{attrs};
674 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
676 # XXX - lose storable dclone
677 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
678 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
679 $attrs->{record_filter} = $record_filter if ($record_filter);
680 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
682 my $alias = $attrs->{alias};
684 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
685 delete $attrs->{as} if $attrs->{columns};
686 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
687 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
689 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
690 ] if $attrs->{columns};
692 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
694 if (my $include = delete $attrs->{include_columns}) {
695 push(@{$attrs->{select}}, @$include);
696 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
699 $attrs->{from} ||= [ { $alias => $source->from } ];
700 $attrs->{seen_join} ||= {};
702 if (my $join = delete $attrs->{join}) {
703 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
704 if (ref $j eq 'HASH') {
705 $seen{$_} = 1 foreach keys %$j;
711 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
713 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
714 $attrs->{order_by} = [ $attrs->{order_by} ] if
715 $attrs->{order_by} and !ref($attrs->{order_by});
716 $attrs->{order_by} ||= [];
718 if(my $seladds = delete($attrs->{'+select'})) {
719 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
721 @{ $attrs->{select} },
722 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
725 if(my $asadds = delete($attrs->{'+as'})) {
726 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
727 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
730 my $collapse = $attrs->{collapse} || {};
731 if (my $prefetch = delete $attrs->{prefetch}) {
733 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
734 if ( ref $p eq 'HASH' ) {
735 foreach my $key (keys %$p) {
736 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
740 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
743 my @prefetch = $source->resolve_prefetch(
744 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
745 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
746 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
748 push(@{$attrs->{order_by}}, @pre_order);
750 $attrs->{collapse} = $collapse;
751 $self->{_attrs} = $attrs;
755 my ($self, $a, $b, $is_prefetch) = @_;
758 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
759 foreach my $key (keys %{$b}) {
760 if (exists $a->{$key}) {
761 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
763 $a->{$key} = delete $b->{$key};
768 $a = [$a] unless (ref $a eq 'ARRAY');
769 $b = [$b] unless (ref $b eq 'ARRAY');
774 foreach my $element (@{$_}) {
775 if (ref $element eq 'HASH') {
776 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
777 } elsif (ref $element eq 'ARRAY') {
778 $array = [@{$array}, @{$element}];
780 if (($b == $_) && $is_prefetch) {
781 $self->_merge_array($array, $element, $is_prefetch);
783 push(@{$array}, $element);
789 my $final_array = [];
790 foreach my $element (@{$array}) {
791 push(@{$final_array}, $element) unless (exists $hash->{$element});
793 $array = $final_array;
795 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
796 return [$hash, @{$array}];
798 return (keys %{$hash}) ? $hash : $array;
804 my ($self, $a, $b) = @_;
806 $b = [$b] unless (ref $b eq 'ARRAY');
807 # add elements from @{$b} to @{$a} which aren't already in @{$a}
808 foreach my $b_element (@{$b}) {
809 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
813 sub _construct_object {
814 my ($self, @row) = @_;
815 my @as = @{ $self->{_attrs}{as} };
817 my $info = $self->_collapse_result(\@as, \@row);
818 my $new = $self->result_class->inflate_result($self->result_source, @$info);
819 $new = $self->{_attrs}{record_filter}->($new)
820 if exists $self->{_attrs}{record_filter};
824 sub _collapse_result {
825 my ($self, $as, $row, $prefix) = @_;
827 my $live_join = $self->{attrs}->{_live_join} ||="";
831 foreach my $this_as (@$as) {
832 my $val = shift @copy;
833 if (defined $prefix) {
834 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
836 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
837 $const{$1||''}{$2} = $val;
840 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
841 $const{$1||''}{$2} = $val;
845 my $info = [ {}, {} ];
846 foreach my $key (keys %const) {
847 if (length $key && $key ne $live_join) {
849 my @parts = split(/\./, $key);
850 foreach my $p (@parts) {
851 $target = $target->[1]->{$p} ||= [];
853 $target->[0] = $const{$key};
855 $info->[0] = $const{$key};
860 if (defined $prefix) {
862 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
863 } keys %{$self->{_attrs}->{collapse}}
865 @collapse = keys %{$self->{_attrs}->{collapse}};
869 my ($c) = sort { length $a <=> length $b } @collapse;
871 foreach my $p (split(/\./, $c)) {
872 $target = $target->[1]->{$p} ||= [];
874 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
875 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
876 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
877 my $tree = $self->_collapse_result($as, $row, $c_prefix);
880 !defined($tree->[0]->{$_}) ||
881 $co_check{$_} ne $tree->[0]->{$_}
884 last unless (@raw = $self->cursor->next);
885 $row = $self->{stashed_row} = \@raw;
886 $tree = $self->_collapse_result($as, $row, $c_prefix);
888 @$target = (@final ? @final : [ {}, {} ]);
889 # single empty result to indicate an empty prefetched has_many
898 =item Arguments: $result_source?
900 =item Return Value: $result_source
904 An accessor for the primary ResultSource object from which this ResultSet
914 =item Arguments: $cond, \%attrs??
916 =item Return Value: $count
920 Performs an SQL C<COUNT> with the same query as the resultset was built
921 with to find the number of elements. If passed arguments, does a search
922 on the resultset and counts the results of that.
924 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
925 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
926 not support C<DISTINCT> with multiple columns. If you are using such a
927 database, you should only use columns from the main table in your C<group_by>
934 return $self->search(@_)->count if @_ and defined $_[0];
935 return scalar @{ $self->get_cache } if $self->get_cache;
936 my $count = $self->_count;
937 return 0 unless $count;
939 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
940 $count = $self->{attrs}{rows} if
941 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
945 sub _count { # Separated out so pager can get the full count
947 my $select = { count => '*' };
950 my $attrs = { %{ $self->{_attrs} } };
951 if (my $group_by = delete $attrs->{group_by}) {
952 delete $attrs->{having};
953 my @distinct = (ref $group_by ? @$group_by : ($group_by));
954 # todo: try CONCAT for multi-column pk
955 my @pk = $self->result_source->primary_columns;
957 foreach my $column (@distinct) {
958 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
959 @distinct = ($column);
965 $select = { count => { distinct => \@distinct } };
968 $attrs->{select} = $select;
969 $attrs->{as} = [qw/count/];
971 # offset, order by and page are not needed to count. record_filter is cdbi
972 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
973 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
974 $tmp_rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
976 my ($count) = $tmp_rs->cursor->next;
984 =item Arguments: $sql_fragment, @bind_values
986 =item Return Value: $count
990 Counts the results in a literal query. Equivalent to calling L</search_literal>
991 with the passed arguments, then L</count>.
995 sub count_literal { shift->search_literal(@_)->count; }
1001 =item Arguments: none
1003 =item Return Value: @objects
1007 Returns all elements in the resultset. Called implicitly if the resultset
1008 is returned in list context.
1014 return @{ $self->get_cache } if $self->get_cache;
1018 # TODO: don't call resolve here
1020 if (keys %{$self->{_attrs}->{collapse}}) {
1021 # if ($self->{attrs}->{prefetch}) {
1022 # Using $self->cursor->all is really just an optimisation.
1023 # If we're collapsing has_many prefetches it probably makes
1024 # very little difference, and this is cleaner than hacking
1025 # _construct_object to survive the approach
1026 my @row = $self->cursor->next;
1028 push(@obj, $self->_construct_object(@row));
1029 @row = (exists $self->{stashed_row}
1030 ? @{delete $self->{stashed_row}}
1031 : $self->cursor->next);
1034 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1037 $self->set_cache(\@obj) if $self->{attrs}{cache};
1045 =item Arguments: none
1047 =item Return Value: $self
1051 Resets the resultset's cursor, so you can iterate through the elements again.
1057 delete $self->{_attrs} if (exists $self->{_attrs});
1059 $self->{all_cache_position} = 0;
1060 $self->cursor->reset;
1068 =item Arguments: none
1070 =item Return Value: $object?
1074 Resets the resultset and returns an object for the first result (if the
1075 resultset returns anything).
1080 return $_[0]->reset->next;
1083 # _cond_for_update_delete
1085 # update/delete require the condition to be modified to handle
1086 # the differing SQL syntax available. This transforms the $self->{cond}
1087 # appropriately, returning the new condition.
1089 sub _cond_for_update_delete {
1093 if (!ref($self->{cond})) {
1094 # No-op. No condition, we're updating/deleting everything
1096 elsif (ref $self->{cond} eq 'ARRAY') {
1100 foreach my $key (keys %{$_}) {
1102 $hash{$1} = $_->{$key};
1108 elsif (ref $self->{cond} eq 'HASH') {
1109 if ((keys %{$self->{cond}})[0] eq '-and') {
1112 my @cond = @{$self->{cond}{-and}};
1113 for (my $i = 0; $i <= @cond - 1; $i++) {
1114 my $entry = $cond[$i];
1117 if (ref $entry eq 'HASH') {
1118 foreach my $key (keys %{$entry}) {
1120 $hash{$1} = $entry->{$key};
1124 $entry =~ /([^.]+)$/;
1125 $hash{$1} = $cond[++$i];
1128 push @{$cond->{-and}}, \%hash;
1132 foreach my $key (keys %{$self->{cond}}) {
1134 $cond->{$1} = $self->{cond}{$key};
1139 $self->throw_exception(
1140 "Can't update/delete on resultset with condition unless hash or array"
1152 =item Arguments: \%values
1154 =item Return Value: $storage_rv
1158 Sets the specified columns in the resultset to the supplied values in a
1159 single query. Return value will be true if the update succeeded or false
1160 if no records were updated; exact type of success value is storage-dependent.
1165 my ($self, $values) = @_;
1166 $self->throw_exception("Values for update must be a hash")
1167 unless ref $values eq 'HASH';
1169 my $cond = $self->_cond_for_update_delete;
1171 return $self->result_source->storage->update(
1172 $self->result_source->from, $values, $cond
1180 =item Arguments: \%values
1182 =item Return Value: 1
1186 Fetches all objects and updates them one at a time. Note that C<update_all>
1187 will run DBIC cascade triggers, while L</update> will not.
1192 my ($self, $values) = @_;
1193 $self->throw_exception("Values for update must be a hash")
1194 unless ref $values eq 'HASH';
1195 foreach my $obj ($self->all) {
1196 $obj->set_columns($values)->update;
1205 =item Arguments: none
1207 =item Return Value: 1
1211 Deletes the contents of the resultset from its result source. Note that this
1212 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1221 my $cond = $self->_cond_for_update_delete;
1223 $self->result_source->storage->delete($self->result_source->from, $cond);
1231 =item Arguments: none
1233 =item Return Value: 1
1237 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1238 will run DBIC cascade triggers, while L</delete> will not.
1244 $_->delete for $self->all;
1252 =item Arguments: none
1254 =item Return Value: $pager
1258 Return Value a L<Data::Page> object for the current resultset. Only makes
1259 sense for queries with a C<page> attribute.
1265 my $attrs = $self->{attrs};
1266 $self->throw_exception("Can't create pager for non-paged rs")
1267 unless $self->{page};
1268 $attrs->{rows} ||= 10;
1269 return $self->{pager} ||= Data::Page->new(
1270 $self->_count, $attrs->{rows}, $self->{page});
1277 =item Arguments: $page_number
1279 =item Return Value: $rs
1283 Returns a resultset for the $page_number page of the resultset on which page
1284 is called, where each page contains a number of rows equal to the 'rows'
1285 attribute set on the resultset (10 by default).
1290 my ($self, $page) = @_;
1291 my $attrs = { %{$self->{attrs}} };
1292 $attrs->{page} = $page;
1293 return (ref $self)->new($self->result_source, $attrs);
1300 =item Arguments: \%vals
1302 =item Return Value: $object
1306 Creates an object in the resultset's result class and returns it.
1311 my ($self, $values) = @_;
1312 $self->throw_exception( "new_result needs a hash" )
1313 unless (ref $values eq 'HASH');
1314 $self->throw_exception(
1315 "Can't abstract implicit construct, condition not a hash"
1316 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1318 my $alias = $self->{attrs}{alias};
1319 foreach my $key (keys %{$self->{cond}||{}}) {
1320 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1322 my $obj = $self->result_class->new(\%new);
1323 $obj->result_source($self->result_source) if $obj->can('result_source');
1331 =item Arguments: \%vals, \%attrs?
1333 =item Return Value: $object
1337 Find an existing record from this resultset. If none exists, instantiate a new
1338 result object and return it. The object will not be saved into your storage
1339 until you call L<DBIx::Class::Row/insert> on it.
1341 If you want objects to be saved immediately, use L</find_or_create> instead.
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 : $self->new_result($hash);
1357 =item Arguments: \%vals
1359 =item Return Value: $object
1363 Inserts a record into the resultset and returns the object representing it.
1365 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1370 my ($self, $attrs) = @_;
1371 $self->throw_exception( "create needs a hashref" )
1372 unless ref $attrs eq 'HASH';
1373 return $self->new_result($attrs)->insert;
1376 =head2 find_or_create
1380 =item Arguments: \%vals, \%attrs?
1382 =item Return Value: $object
1386 $class->find_or_create({ key => $val, ... });
1388 Tries to find a record based on its primary key or unique constraint; if none
1389 is found, creates one and returns that instead.
1391 my $cd = $schema->resultset('CD')->find_or_create({
1393 artist => 'Massive Attack',
1394 title => 'Mezzanine',
1398 Also takes an optional C<key> attribute, to search by a specific key or unique
1399 constraint. For example:
1401 my $cd = $schema->resultset('CD')->find_or_create(
1403 artist => 'Massive Attack',
1404 title => 'Mezzanine',
1406 { key => 'cd_artist_title' }
1409 See also L</find> and L</update_or_create>. For information on how to declare
1410 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1414 sub find_or_create {
1416 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1417 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1418 my $exists = $self->find($hash, $attrs);
1419 return defined $exists ? $exists : $self->create($hash);
1422 =head2 update_or_create
1426 =item Arguments: \%col_values, { key => $unique_constraint }?
1428 =item Return Value: $object
1432 $class->update_or_create({ col => $val, ... });
1434 First, searches for an existing row matching one of the unique constraints
1435 (including the primary key) on the source of this resultset. If a row is
1436 found, updates it with the other given column values. Otherwise, creates a new
1439 Takes an optional C<key> attribute to search on a specific unique constraint.
1442 # In your application
1443 my $cd = $schema->resultset('CD')->update_or_create(
1445 artist => 'Massive Attack',
1446 title => 'Mezzanine',
1449 { key => 'cd_artist_title' }
1452 If no C<key> is specified, it searches on all unique constraints defined on the
1453 source, including the primary key.
1455 If the C<key> is specified as C<primary>, it searches only on the primary key.
1457 See also L</find> and L</find_or_create>. For information on how to declare
1458 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1462 sub update_or_create {
1464 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1465 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1467 my $row = $self->find($cond);
1469 $row->update($cond);
1473 return $self->create($cond);
1480 =item Arguments: none
1482 =item Return Value: \@cache_objects?
1486 Gets the contents of the cache for the resultset, if the cache is set.
1498 =item Arguments: \@cache_objects
1500 =item Return Value: \@cache_objects
1504 Sets the contents of the cache for the resultset. Expects an arrayref
1505 of objects of the same class as those produced by the resultset. Note that
1506 if the cache is set the resultset will return the cached objects rather
1507 than re-querying the database even if the cache attr is not set.
1512 my ( $self, $data ) = @_;
1513 $self->throw_exception("set_cache requires an arrayref")
1514 if defined($data) && (ref $data ne 'ARRAY');
1515 $self->{all_cache} = $data;
1522 =item Arguments: none
1524 =item Return Value: []
1528 Clears the cache for the resultset.
1533 shift->set_cache(undef);
1536 =head2 related_resultset
1540 =item Arguments: $relationship_name
1542 =item Return Value: $resultset
1546 Returns a related resultset for the supplied relationship name.
1548 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1552 sub related_resultset {
1553 my ( $self, $rel ) = @_;
1555 $self->{related_resultsets} ||= {};
1556 return $self->{related_resultsets}{$rel} ||= do {
1557 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1558 my $rel_obj = $self->result_source->relationship_info($rel);
1559 $self->throw_exception(
1560 "search_related: result source '" . $self->result_source->name .
1561 "' has no such relationship ${rel}")
1562 unless $rel_obj; #die Dumper $self->{attrs};
1564 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1566 { %{$self->{attrs}},
1570 _live_join => $rel }
1573 # keep reference of the original resultset
1574 $rs->{_parent_rs} = $self->result_source;
1579 =head2 throw_exception
1581 See L<DBIx::Class::Schema/throw_exception> for details.
1585 sub throw_exception {
1587 $self->result_source->schema->throw_exception(@_);
1590 # XXX: FIXME: Attributes docs need clearing up
1594 The resultset takes various attributes that modify its behavior. Here's an
1601 =item Value: ($order_by | \@order_by)
1605 Which column(s) to order the results by. This is currently passed
1606 through directly to SQL, so you can give e.g. C<year DESC> for a
1607 descending order on the column `year'.
1609 Please note that if you have quoting enabled (see
1610 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1611 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1612 so you will need to manually quote things as appropriate.)
1618 =item Value: \@columns
1622 Shortcut to request a particular set of columns to be retrieved. Adds
1623 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1624 from that, then auto-populates C<as> from C<select> as normal. (You may also
1625 use the C<cols> attribute, as in earlier versions of DBIC.)
1627 =head2 include_columns
1631 =item Value: \@columns
1635 Shortcut to include additional columns in the returned results - for example
1637 $schema->resultset('CD')->search(undef, {
1638 include_columns => ['artist.name'],
1642 would return all CDs and include a 'name' column to the information
1643 passed to object inflation
1649 =item Value: \@select_columns
1653 Indicates which columns should be selected from the storage. You can use
1654 column names, or in the case of RDBMS back ends, function or stored procedure
1657 $rs = $schema->resultset('Employee')->search(undef, {
1660 { count => 'employeeid' },
1665 When you use function/stored procedure names and do not supply an C<as>
1666 attribute, the column names returned are storage-dependent. E.g. MySQL would
1667 return a column named C<count(employeeid)> in the above example.
1673 Indicates additional columns to be selected from storage. Works the same as
1674 L<select> but adds columns to the selection.
1682 Indicates additional column names for those added via L<+select>.
1690 =item Value: \@inflation_names
1694 Indicates column names for object inflation. This is used in conjunction with
1695 C<select>, usually when C<select> contains one or more function or stored
1698 $rs = $schema->resultset('Employee')->search(undef, {
1701 { count => 'employeeid' }
1703 as => ['name', 'employee_count'],
1706 my $employee = $rs->first(); # get the first Employee
1708 If the object against which the search is performed already has an accessor
1709 matching a column name specified in C<as>, the value can be retrieved using
1710 the accessor as normal:
1712 my $name = $employee->name();
1714 If on the other hand an accessor does not exist in the object, you need to
1715 use C<get_column> instead:
1717 my $employee_count = $employee->get_column('employee_count');
1719 You can create your own accessors if required - see
1720 L<DBIx::Class::Manual::Cookbook> for details.
1722 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1723 produced, it is used for internal access only. Thus attempting to use the accessor
1724 in an C<order_by> clause or similar will fail misrably.
1730 =item Value: ($rel_name | \@rel_names | \%rel_names)
1734 Contains a list of relationships that should be joined for this query. For
1737 # Get CDs by Nine Inch Nails
1738 my $rs = $schema->resultset('CD')->search(
1739 { 'artist.name' => 'Nine Inch Nails' },
1740 { join => 'artist' }
1743 Can also contain a hash reference to refer to the other relation's relations.
1746 package MyApp::Schema::Track;
1747 use base qw/DBIx::Class/;
1748 __PACKAGE__->table('track');
1749 __PACKAGE__->add_columns(qw/trackid cd position title/);
1750 __PACKAGE__->set_primary_key('trackid');
1751 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1754 # In your application
1755 my $rs = $schema->resultset('Artist')->search(
1756 { 'track.title' => 'Teardrop' },
1758 join => { cd => 'track' },
1759 order_by => 'artist.name',
1763 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1764 similarly for a third time). For e.g.
1766 my $rs = $schema->resultset('Artist')->search({
1767 'cds.title' => 'Down to Earth',
1768 'cds_2.title' => 'Popular',
1770 join => [ qw/cds cds/ ],
1773 will return a set of all artists that have both a cd with title 'Down
1774 to Earth' and a cd with title 'Popular'.
1776 If you want to fetch related objects from other tables as well, see C<prefetch>
1783 =item Value: ($rel_name | \@rel_names | \%rel_names)
1787 Contains one or more relationships that should be fetched along with the main
1788 query (when they are accessed afterwards they will have already been
1789 "prefetched"). This is useful for when you know you will need the related
1790 objects, because it saves at least one query:
1792 my $rs = $schema->resultset('Tag')->search(
1801 The initial search results in SQL like the following:
1803 SELECT tag.*, cd.*, artist.* FROM tag
1804 JOIN cd ON tag.cd = cd.cdid
1805 JOIN artist ON cd.artist = artist.artistid
1807 L<DBIx::Class> has no need to go back to the database when we access the
1808 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1811 Simple prefetches will be joined automatically, so there is no need
1812 for a C<join> attribute in the above search. If you're prefetching to
1813 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1814 specify the join as well.
1816 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1817 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1818 with an accessor type of 'single' or 'filter').
1828 Makes the resultset paged and specifies the page to retrieve. Effectively
1829 identical to creating a non-pages resultset and then calling ->page($page)
1832 If L<rows> attribute is not specified it defualts to 10 rows per page.
1842 Specifes the maximum number of rows for direct retrieval or the number of
1843 rows per page if the page attribute or method is used.
1849 =item Value: $offset
1853 Specifies the (zero-based) row number for the first row to be returned, or the
1854 of the first row of the first page if paging is used.
1860 =item Value: \@columns
1864 A arrayref of columns to group by. Can include columns of joined tables.
1866 group_by => [qw/ column1 column2 ... /]
1872 =item Value: $condition
1876 HAVING is a select statement attribute that is applied between GROUP BY and
1877 ORDER BY. It is applied to the after the grouping calculations have been
1880 having => { 'count(employee)' => { '>=', 100 } }
1886 =item Value: (0 | 1)
1890 Set to 1 to group by all columns.
1894 Set to 1 to cache search results. This prevents extra SQL queries if you
1895 revisit rows in your ResultSet:
1897 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1899 while( my $artist = $resultset->next ) {
1903 $rs->first; # without cache, this would issue a query
1905 By default, searches are not cached.
1907 For more examples of using these attributes, see
1908 L<DBIx::Class::Manual::Cookbook>.
1914 =item Value: \@from_clause
1918 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1919 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1922 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1924 C<join> will usually do what you need and it is strongly recommended that you
1925 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1926 And we really do mean "cannot", not just tried and failed. Attempting to use
1927 this because you're having problems with C<join> is like trying to use x86
1928 ASM because you've got a syntax error in your C. Trust us on this.
1930 Now, if you're still really, really sure you need to use this (and if you're
1931 not 100% sure, ask the mailing list first), here's an explanation of how this
1934 The syntax is as follows -
1937 { <alias1> => <table1> },
1939 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1940 [], # nested JOIN (optional)
1941 { <table1.column1> => <table2.column2>, ... (more conditions) },
1943 # More of the above [ ] may follow for additional joins
1950 ON <table1.column1> = <table2.column2>
1951 <more joins may follow>
1953 An easy way to follow the examples below is to remember the following:
1955 Anything inside "[]" is a JOIN
1956 Anything inside "{}" is a condition for the enclosing JOIN
1958 The following examples utilize a "person" table in a family tree application.
1959 In order to express parent->child relationships, this table is self-joined:
1961 # Person->belongs_to('father' => 'Person');
1962 # Person->belongs_to('mother' => 'Person');
1964 C<from> can be used to nest joins. Here we return all children with a father,
1965 then search against all mothers of those children:
1967 $rs = $schema->resultset('Person')->search(
1970 alias => 'mother', # alias columns in accordance with "from"
1972 { mother => 'person' },
1975 { child => 'person' },
1977 { father => 'person' },
1978 { 'father.person_id' => 'child.father_id' }
1981 { 'mother.person_id' => 'child.mother_id' }
1988 # SELECT mother.* FROM person mother
1991 # JOIN person father
1992 # ON ( father.person_id = child.father_id )
1994 # ON ( mother.person_id = child.mother_id )
1996 The type of any join can be controlled manually. To search against only people
1997 with a father in the person table, we could explicitly use C<INNER JOIN>:
1999 $rs = $schema->resultset('Person')->search(
2002 alias => 'child', # alias columns in accordance with "from"
2004 { child => 'person' },
2006 { father => 'person', -join_type => 'inner' },
2007 { 'father.id' => 'child.father_id' }
2014 # SELECT child.* FROM person child
2015 # INNER JOIN person father ON child.father_id = father.id