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.
164 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
165 my $our_attrs = ($attrs->{_parent_attrs}) ? { %{$attrs->{_parent_attrs}} } : { %{$self->{attrs}} };
166 my $having = delete $our_attrs->{having};
168 # merge new attrs into old
169 foreach my $key (qw/join prefetch/) {
170 next unless (exists $attrs->{$key});
171 if ($attrs->{_live_join} || $our_attrs->{_live_join}) {
172 $attrs->{$key} = { ($attrs->{_live_join}) ? $attrs->{_live_join} : $our_attrs->{_live_join} => $attrs->{$key} };
174 if (exists $our_attrs->{$key}) {
175 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
177 $our_attrs->{$key} = $attrs->{$key};
179 delete $attrs->{$key};
182 $our_attrs->{join} = $self->_merge_attr($our_attrs->{join}, $attrs->{_live_join}, 1) if ($attrs->{_live_join});
183 if (exists $our_attrs->{prefetch}) {
184 $our_attrs->{join} = $self->_merge_attr($our_attrs->{join}, $our_attrs->{prefetch}, 1);
187 my $new_attrs = { %{$our_attrs}, %{$attrs} };
189 ? ((@_ == 1 || ref $_[0] eq "HASH")
192 ? $self->throw_exception(
193 "Odd number of arguments to search")
196 if (defined $where) {
197 $new_attrs->{where} = (defined $new_attrs->{where}
199 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
200 $where, $new_attrs->{where} ] }
204 if (defined $having) {
205 $new_attrs->{having} = (defined $new_attrs->{having}
207 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
208 $having, $new_attrs->{having} ] }
212 my $rs = (ref $self)->new($self->result_source, $new_attrs);
213 $rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
215 unless (@_) { # no search, effectively just a clone
216 my $rows = $self->get_cache;
218 $rs->set_cache($rows);
225 =head2 search_literal
229 =item Arguments: $sql_fragment, @bind_values
231 =item Return Value: $resultset (scalar context), @row_objs (list context)
235 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
236 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
238 Pass a literal chunk of SQL to be added to the conditional part of the
244 my ($self, $cond, @vals) = @_;
245 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
246 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
247 return $self->search(\$cond, $attrs);
254 =item Arguments: @values | \%cols, \%attrs?
256 =item Return Value: $row_object
260 Finds a row based on its primary key or unique constraint. For example, to find
261 a row by its primary key:
263 my $cd = $schema->resultset('CD')->find(5);
265 You can also find a row by a specific unique constraint using the C<key>
266 attribute. For example:
268 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'cd_artist_title' });
270 Additionally, you can specify the columns explicitly by name:
272 my $cd = $schema->resultset('CD')->find(
274 artist => 'Massive Attack',
275 title => 'Mezzanine',
277 { key => 'cd_artist_title' }
280 If the C<key> is specified as C<primary>, it searches only on the primary key.
282 If no C<key> is specified, it searches on all unique constraints defined on the
283 source, including the primary key.
285 See also L</find_or_create> and L</update_or_create>. For information on how to
286 declare unique constraints, see
287 L<DBIx::Class::ResultSource/add_unique_constraint>.
293 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
295 # Default to the primary key, but allow a specific key
296 my @cols = exists $attrs->{key}
297 ? $self->result_source->unique_constraint_columns($attrs->{key})
298 : $self->result_source->primary_columns;
299 $self->throw_exception(
300 "Can't find unless a primary key or unique constraint is defined"
303 # Parse out a hashref from input
305 if (ref $_[0] eq 'HASH') {
306 $input_query = { %{$_[0]} };
308 elsif (@_ == @cols) {
310 @{$input_query}{@cols} = @_;
313 # Compatibility: Allow e.g. find(id => $value)
314 carp "Find by key => value deprecated; please use a hashref instead";
318 my @unique_queries = $self->_unique_queries($input_query, $attrs);
320 # Handle cases where the ResultSet defines the query, or where the user is
322 my $query = @unique_queries ? \@unique_queries : $input_query;
326 my $rs = $self->search($query, $attrs);
328 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
332 return (keys %{$self->{_attrs}->{collapse}})
333 ? $self->search($query)->next
334 : $self->single($query);
340 # Build a list of queries which satisfy unique constraints.
342 sub _unique_queries {
343 my ($self, $query, $attrs) = @_;
345 my @constraint_names = exists $attrs->{key}
347 : $self->result_source->unique_constraint_names;
350 foreach my $name (@constraint_names) {
351 my @unique_cols = $self->result_source->unique_constraint_columns($name);
352 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
354 next unless scalar keys %$unique_query;
356 # Add the ResultSet's alias
357 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
358 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
359 $unique_query->{"$alias.$key"} = delete $unique_query->{$key};
362 push @unique_queries, $unique_query;
365 return @unique_queries;
368 # _build_unique_query
370 # Constrain the specified query hash based on the specified column names.
372 sub _build_unique_query {
373 my ($self, $query, $unique_cols) = @_;
376 map { $_ => $query->{$_} }
377 grep { exists $query->{$_} }
380 return \%unique_query;
383 =head2 search_related
387 =item Arguments: $cond, \%attrs?
389 =item Return Value: $new_resultset
393 $new_rs = $cd_rs->search_related('artist', {
397 Searches the specified relationship, optionally specifying a condition and
398 attributes for matching records. See L</ATTRIBUTES> for more information.
403 return shift->related_resultset(shift)->search(@_);
410 =item Arguments: none
412 =item Return Value: $cursor
416 Returns a storage-driven cursor to the given resultset. See
417 L<DBIx::Class::Cursor> for more information.
425 my $attrs = { %{$self->{_attrs}} };
426 return $self->{cursor}
427 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
428 $attrs->{where},$attrs);
435 =item Arguments: $cond?
437 =item Return Value: $row_object?
441 my $cd = $schema->resultset('CD')->single({ year => 2001 });
443 Inflates the first result without creating a cursor if the resultset has
444 any records in it; if not returns nothing. Used by L</find> as an optimisation.
446 Can optionally take an additional condition *only* - this is a fast-code-path
447 method; if you need to add extra joins or similar call ->search and then
448 ->single without a condition on the $rs returned from that.
453 my ($self, $where) = @_;
455 my $attrs = { %{$self->{_attrs}} };
457 if (defined $attrs->{where}) {
460 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
461 $where, delete $attrs->{where} ]
464 $attrs->{where} = $where;
468 unless ($self->_is_unique_query($attrs->{where})) {
469 carp "Query not guarnteed to return a single row"
470 . "; please declare your unique constraints or use search instead";
473 my @data = $self->result_source->storage->select_single(
474 $attrs->{from}, $attrs->{select},
475 $attrs->{where},$attrs);
476 return (@data ? $self->_construct_object(@data) : ());
481 # Try to determine if the specified query is guaranteed to be unique, based on
482 # the declared unique constraints.
484 sub _is_unique_query {
485 my ($self, $query) = @_;
487 my $collapsed = $self->_collapse_query($query);
489 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
490 foreach my $name ($self->result_source->unique_constraint_names) {
491 my @unique_cols = map { "$alias.$_" }
492 $self->result_source->unique_constraint_columns($name);
494 # Count the values for each unique column
495 my %seen = map { $_ => 0 } @unique_cols;
497 foreach my $key (keys %$collapsed) {
499 $aliased = "$alias.$key" unless $key =~ /\./;
501 next unless exists $seen{$aliased}; # Additional constraints are okay
502 $seen{$aliased} = scalar @{ $collapsed->{$key} };
505 # If we get 0 or more than 1 value for a column, it's not necessarily unique
506 return 1 unless grep { $_ != 1 } values %seen;
514 # Recursively collapse the query, accumulating values for each column.
516 sub _collapse_query {
517 my ($self, $query, $collapsed) = @_;
521 if (ref $query eq 'ARRAY') {
522 foreach my $subquery (@$query) {
523 next unless ref $subquery; # -or
524 # warn "ARRAY: " . Dumper $subquery;
525 $collapsed = $self->_collapse_query($subquery, $collapsed);
528 elsif (ref $query eq 'HASH') {
529 if (keys %$query and (keys %$query)[0] eq '-and') {
530 foreach my $subquery (@{$query->{-and}}) {
531 # warn "HASH: " . Dumper $subquery;
532 $collapsed = $self->_collapse_query($subquery, $collapsed);
536 # warn "LEAF: " . Dumper $query;
537 foreach my $key (keys %$query) {
538 push @{$collapsed->{$key}}, $query->{$key};
550 =item Arguments: $cond?
552 =item Return Value: $resultsetcolumn
556 my $max_length = $rs->get_column('length')->max;
558 Returns a ResultSetColumn instance for $column based on $self
563 my ($self, $column) = @_;
565 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
573 =item Arguments: $cond, \%attrs?
575 =item Return Value: $resultset (scalar context), @row_objs (list context)
579 # WHERE title LIKE '%blue%'
580 $cd_rs = $rs->search_like({ title => '%blue%'});
582 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
583 that this is simply a convenience method. You most likely want to use
584 L</search> with specific operators.
586 For more information, see L<DBIx::Class::Manual::Cookbook>.
592 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
593 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
594 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
595 return $class->search($query, { %$attrs });
602 =item Arguments: $first, $last
604 =item Return Value: $resultset (scalar context), @row_objs (list context)
608 Returns a resultset or object list representing a subset of elements from the
609 resultset slice is called on. Indexes are from 0, i.e., to get the first
612 my ($one, $two, $three) = $rs->slice(0, 2);
617 my ($self, $min, $max) = @_;
618 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
619 $attrs->{offset} = $self->{attrs}{offset} || 0;
620 $attrs->{offset} += $min;
621 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
622 return $self->search(undef(), $attrs);
623 #my $slice = (ref $self)->new($self->result_source, $attrs);
624 #return (wantarray ? $slice->all : $slice);
631 =item Arguments: none
633 =item Return Value: $result?
637 Returns the next element in the resultset (C<undef> is there is none).
639 Can be used to efficiently iterate over records in the resultset:
641 my $rs = $schema->resultset('CD')->search;
642 while (my $cd = $rs->next) {
646 Note that you need to store the resultset object, and call C<next> on it.
647 Calling C<< resultset('Table')->next >> repeatedly will always return the
648 first record from the resultset.
654 if (my $cache = $self->get_cache) {
655 $self->{all_cache_position} ||= 0;
656 return $cache->[$self->{all_cache_position}++];
658 if ($self->{attrs}{cache}) {
659 $self->{all_cache_position} = 1;
660 return ($self->all)[0];
662 my @row = (exists $self->{stashed_row} ?
663 @{delete $self->{stashed_row}} :
666 return unless (@row);
667 return $self->_construct_object(@row);
673 return if(exists $self->{_attrs}); #return if _resolve has already been called
675 my $attrs = $self->{attrs};
676 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
678 # XXX - lose storable dclone
679 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
680 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
681 $attrs->{record_filter} = $record_filter if ($record_filter);
682 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
684 my $alias = $attrs->{alias};
686 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
687 delete $attrs->{as} if $attrs->{columns};
688 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
689 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
691 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
692 ] if $attrs->{columns};
694 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
696 if (my $include = delete $attrs->{include_columns}) {
697 push(@{$attrs->{select}}, @$include);
698 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
701 $attrs->{from} ||= [ { $alias => $source->from } ];
702 $attrs->{seen_join} ||= {};
704 if (my $join = delete $attrs->{join}) {
705 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
706 if (ref $j eq 'HASH') {
707 $seen{$_} = 1 foreach keys %$j;
713 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
715 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
716 $attrs->{order_by} = [ $attrs->{order_by} ] if
717 $attrs->{order_by} and !ref($attrs->{order_by});
718 $attrs->{order_by} ||= [];
720 if(my $seladds = delete($attrs->{'+select'})) {
721 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
723 @{ $attrs->{select} },
724 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
727 if(my $asadds = delete($attrs->{'+as'})) {
728 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
729 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
732 my $collapse = $attrs->{collapse} || {};
733 if (my $prefetch = delete $attrs->{prefetch}) {
735 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
736 if ( ref $p eq 'HASH' ) {
737 foreach my $key (keys %$p) {
738 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
742 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
745 my @prefetch = $source->resolve_prefetch(
746 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
747 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
748 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
750 push(@{$attrs->{order_by}}, @pre_order);
752 $attrs->{collapse} = $collapse;
753 $self->{_attrs} = $attrs;
757 my ($self, $a, $b, $is_prefetch) = @_;
760 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
761 foreach my $key (keys %{$b}) {
762 if (exists $a->{$key}) {
763 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
765 $a->{$key} = delete $b->{$key};
770 $a = [$a] unless (ref $a eq 'ARRAY');
771 $b = [$b] unless (ref $b eq 'ARRAY');
776 foreach my $element (@{$_}) {
777 if (ref $element eq 'HASH') {
778 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
779 } elsif (ref $element eq 'ARRAY') {
780 $array = [@{$array}, @{$element}];
782 if (($b == $_) && $is_prefetch) {
783 $self->_merge_array($array, $element, $is_prefetch);
785 push(@{$array}, $element);
791 my $final_array = [];
792 foreach my $element (@{$array}) {
793 push(@{$final_array}, $element) unless (exists $hash->{$element});
795 $array = $final_array;
797 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
798 return [$hash, @{$array}];
800 return (keys %{$hash}) ? $hash : $array;
806 my ($self, $a, $b) = @_;
808 $b = [$b] unless (ref $b eq 'ARRAY');
809 # add elements from @{$b} to @{$a} which aren't already in @{$a}
810 foreach my $b_element (@{$b}) {
811 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
815 sub _construct_object {
816 my ($self, @row) = @_;
817 my @as = @{ $self->{_attrs}{as} };
819 my $info = $self->_collapse_result(\@as, \@row);
820 my $new = $self->result_class->inflate_result($self->result_source, @$info);
821 $new = $self->{_attrs}{record_filter}->($new)
822 if exists $self->{_attrs}{record_filter};
826 sub _collapse_result {
827 my ($self, $as, $row, $prefix) = @_;
829 my $live_join = $self->{attrs}->{_live_join} ||="";
833 foreach my $this_as (@$as) {
834 my $val = shift @copy;
835 if (defined $prefix) {
836 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
838 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
839 $const{$1||''}{$2} = $val;
842 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
843 $const{$1||''}{$2} = $val;
847 my $info = [ {}, {} ];
848 foreach my $key (keys %const) {
849 if (length $key && $key ne $live_join) {
851 my @parts = split(/\./, $key);
852 foreach my $p (@parts) {
853 $target = $target->[1]->{$p} ||= [];
855 $target->[0] = $const{$key};
857 $info->[0] = $const{$key};
862 if (defined $prefix) {
864 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
865 } keys %{$self->{_attrs}->{collapse}}
867 @collapse = keys %{$self->{_attrs}->{collapse}};
871 my ($c) = sort { length $a <=> length $b } @collapse;
873 foreach my $p (split(/\./, $c)) {
874 $target = $target->[1]->{$p} ||= [];
876 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
877 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
878 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
879 my $tree = $self->_collapse_result($as, $row, $c_prefix);
882 !defined($tree->[0]->{$_}) ||
883 $co_check{$_} ne $tree->[0]->{$_}
886 last unless (@raw = $self->cursor->next);
887 $row = $self->{stashed_row} = \@raw;
888 $tree = $self->_collapse_result($as, $row, $c_prefix);
890 @$target = (@final ? @final : [ {}, {} ]);
891 # single empty result to indicate an empty prefetched has_many
900 =item Arguments: $result_source?
902 =item Return Value: $result_source
906 An accessor for the primary ResultSource object from which this ResultSet
916 =item Arguments: $cond, \%attrs??
918 =item Return Value: $count
922 Performs an SQL C<COUNT> with the same query as the resultset was built
923 with to find the number of elements. If passed arguments, does a search
924 on the resultset and counts the results of that.
926 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
927 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
928 not support C<DISTINCT> with multiple columns. If you are using such a
929 database, you should only use columns from the main table in your C<group_by>
936 return $self->search(@_)->count if @_ and defined $_[0];
937 return scalar @{ $self->get_cache } if $self->get_cache;
938 my $count = $self->_count;
939 return 0 unless $count;
941 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
942 $count = $self->{attrs}{rows} if
943 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
947 sub _count { # Separated out so pager can get the full count
949 my $select = { count => '*' };
952 my $attrs = { %{ $self->{_attrs} } };
953 if (my $group_by = delete $attrs->{group_by}) {
954 delete $attrs->{having};
955 my @distinct = (ref $group_by ? @$group_by : ($group_by));
956 # todo: try CONCAT for multi-column pk
957 my @pk = $self->result_source->primary_columns;
959 foreach my $column (@distinct) {
960 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
961 @distinct = ($column);
967 $select = { count => { distinct => \@distinct } };
970 $attrs->{select} = $select;
971 $attrs->{as} = [qw/count/];
973 # offset, order by and page are not needed to count. record_filter is cdbi
974 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
975 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
976 $tmp_rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
978 my ($count) = $tmp_rs->cursor->next;
986 =item Arguments: $sql_fragment, @bind_values
988 =item Return Value: $count
992 Counts the results in a literal query. Equivalent to calling L</search_literal>
993 with the passed arguments, then L</count>.
997 sub count_literal { shift->search_literal(@_)->count; }
1003 =item Arguments: none
1005 =item Return Value: @objects
1009 Returns all elements in the resultset. Called implicitly if the resultset
1010 is returned in list context.
1016 return @{ $self->get_cache } if $self->get_cache;
1020 # TODO: don't call resolve here
1022 if (keys %{$self->{_attrs}->{collapse}}) {
1023 # if ($self->{attrs}->{prefetch}) {
1024 # Using $self->cursor->all is really just an optimisation.
1025 # If we're collapsing has_many prefetches it probably makes
1026 # very little difference, and this is cleaner than hacking
1027 # _construct_object to survive the approach
1028 my @row = $self->cursor->next;
1030 push(@obj, $self->_construct_object(@row));
1031 @row = (exists $self->{stashed_row}
1032 ? @{delete $self->{stashed_row}}
1033 : $self->cursor->next);
1036 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1039 $self->set_cache(\@obj) if $self->{attrs}{cache};
1047 =item Arguments: none
1049 =item Return Value: $self
1053 Resets the resultset's cursor, so you can iterate through the elements again.
1059 delete $self->{_attrs} if (exists $self->{_attrs});
1061 $self->{all_cache_position} = 0;
1062 $self->cursor->reset;
1070 =item Arguments: none
1072 =item Return Value: $object?
1076 Resets the resultset and returns an object for the first result (if the
1077 resultset returns anything).
1082 return $_[0]->reset->next;
1085 # _cond_for_update_delete
1087 # update/delete require the condition to be modified to handle
1088 # the differing SQL syntax available. This transforms the $self->{cond}
1089 # appropriately, returning the new condition.
1091 sub _cond_for_update_delete {
1095 if (!ref($self->{cond})) {
1096 # No-op. No condition, we're updating/deleting everything
1098 elsif (ref $self->{cond} eq 'ARRAY') {
1102 foreach my $key (keys %{$_}) {
1104 $hash{$1} = $_->{$key};
1110 elsif (ref $self->{cond} eq 'HASH') {
1111 if ((keys %{$self->{cond}})[0] eq '-and') {
1114 my @cond = @{$self->{cond}{-and}};
1115 for (my $i = 0; $i <= @cond - 1; $i++) {
1116 my $entry = $cond[$i];
1119 if (ref $entry eq 'HASH') {
1120 foreach my $key (keys %{$entry}) {
1122 $hash{$1} = $entry->{$key};
1126 $entry =~ /([^.]+)$/;
1127 $hash{$1} = $cond[++$i];
1130 push @{$cond->{-and}}, \%hash;
1134 foreach my $key (keys %{$self->{cond}}) {
1136 $cond->{$1} = $self->{cond}{$key};
1141 $self->throw_exception(
1142 "Can't update/delete on resultset with condition unless hash or array"
1154 =item Arguments: \%values
1156 =item Return Value: $storage_rv
1160 Sets the specified columns in the resultset to the supplied values in a
1161 single query. Return value will be true if the update succeeded or false
1162 if no records were updated; exact type of success value is storage-dependent.
1167 my ($self, $values) = @_;
1168 $self->throw_exception("Values for update must be a hash")
1169 unless ref $values eq 'HASH';
1171 my $cond = $self->_cond_for_update_delete;
1173 return $self->result_source->storage->update(
1174 $self->result_source->from, $values, $cond
1182 =item Arguments: \%values
1184 =item Return Value: 1
1188 Fetches all objects and updates them one at a time. Note that C<update_all>
1189 will run DBIC cascade triggers, while L</update> will not.
1194 my ($self, $values) = @_;
1195 $self->throw_exception("Values for update must be a hash")
1196 unless ref $values eq 'HASH';
1197 foreach my $obj ($self->all) {
1198 $obj->set_columns($values)->update;
1207 =item Arguments: none
1209 =item Return Value: 1
1213 Deletes the contents of the resultset from its result source. Note that this
1214 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1223 my $cond = $self->_cond_for_update_delete;
1225 $self->result_source->storage->delete($self->result_source->from, $cond);
1233 =item Arguments: none
1235 =item Return Value: 1
1239 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1240 will run DBIC cascade triggers, while L</delete> will not.
1246 $_->delete for $self->all;
1254 =item Arguments: none
1256 =item Return Value: $pager
1260 Return Value a L<Data::Page> object for the current resultset. Only makes
1261 sense for queries with a C<page> attribute.
1267 my $attrs = $self->{attrs};
1268 $self->throw_exception("Can't create pager for non-paged rs")
1269 unless $self->{page};
1270 $attrs->{rows} ||= 10;
1271 return $self->{pager} ||= Data::Page->new(
1272 $self->_count, $attrs->{rows}, $self->{page});
1279 =item Arguments: $page_number
1281 =item Return Value: $rs
1285 Returns a resultset for the $page_number page of the resultset on which page
1286 is called, where each page contains a number of rows equal to the 'rows'
1287 attribute set on the resultset (10 by default).
1292 my ($self, $page) = @_;
1293 my $attrs = { %{$self->{attrs}} };
1294 $attrs->{page} = $page;
1295 return (ref $self)->new($self->result_source, $attrs);
1302 =item Arguments: \%vals
1304 =item Return Value: $object
1308 Creates an object in the resultset's result class and returns it.
1313 my ($self, $values) = @_;
1314 $self->throw_exception( "new_result needs a hash" )
1315 unless (ref $values eq 'HASH');
1316 $self->throw_exception(
1317 "Can't abstract implicit construct, condition not a hash"
1318 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1320 my $alias = $self->{attrs}{alias};
1321 foreach my $key (keys %{$self->{cond}||{}}) {
1322 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1324 my $obj = $self->result_class->new(\%new);
1325 $obj->result_source($self->result_source) if $obj->can('result_source');
1333 =item Arguments: \%vals, \%attrs?
1335 =item Return Value: $object
1339 Find an existing record from this resultset. If none exists, instantiate a new
1340 result object and return it. The object will not be saved into your storage
1341 until you call L<DBIx::Class::Row/insert> on it.
1343 If you want objects to be saved immediately, use L</find_or_create> instead.
1349 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1350 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1351 my $exists = $self->find($hash, $attrs);
1352 return defined $exists ? $exists : $self->new_result($hash);
1359 =item Arguments: \%vals
1361 =item Return Value: $object
1365 Inserts a record into the resultset and returns the object representing it.
1367 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1372 my ($self, $attrs) = @_;
1373 $self->throw_exception( "create needs a hashref" )
1374 unless ref $attrs eq 'HASH';
1375 return $self->new_result($attrs)->insert;
1378 =head2 find_or_create
1382 =item Arguments: \%vals, \%attrs?
1384 =item Return Value: $object
1388 $class->find_or_create({ key => $val, ... });
1390 Tries to find a record based on its primary key or unique constraint; if none
1391 is found, creates one and returns that instead.
1393 my $cd = $schema->resultset('CD')->find_or_create({
1395 artist => 'Massive Attack',
1396 title => 'Mezzanine',
1400 Also takes an optional C<key> attribute, to search by a specific key or unique
1401 constraint. For example:
1403 my $cd = $schema->resultset('CD')->find_or_create(
1405 artist => 'Massive Attack',
1406 title => 'Mezzanine',
1408 { key => 'cd_artist_title' }
1411 See also L</find> and L</update_or_create>. For information on how to declare
1412 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1416 sub find_or_create {
1418 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1419 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1420 my $exists = $self->find($hash, $attrs);
1421 return defined $exists ? $exists : $self->create($hash);
1424 =head2 update_or_create
1428 =item Arguments: \%col_values, { key => $unique_constraint }?
1430 =item Return Value: $object
1434 $class->update_or_create({ col => $val, ... });
1436 First, searches for an existing row matching one of the unique constraints
1437 (including the primary key) on the source of this resultset. If a row is
1438 found, updates it with the other given column values. Otherwise, creates a new
1441 Takes an optional C<key> attribute to search on a specific unique constraint.
1444 # In your application
1445 my $cd = $schema->resultset('CD')->update_or_create(
1447 artist => 'Massive Attack',
1448 title => 'Mezzanine',
1451 { key => 'cd_artist_title' }
1454 If no C<key> is specified, it searches on all unique constraints defined on the
1455 source, including the primary key.
1457 If the C<key> is specified as C<primary>, it searches only on the primary key.
1459 See also L</find> and L</find_or_create>. For information on how to declare
1460 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1464 sub update_or_create {
1466 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1467 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1469 my $row = $self->find($cond);
1471 $row->update($cond);
1475 return $self->create($cond);
1482 =item Arguments: none
1484 =item Return Value: \@cache_objects?
1488 Gets the contents of the cache for the resultset, if the cache is set.
1500 =item Arguments: \@cache_objects
1502 =item Return Value: \@cache_objects
1506 Sets the contents of the cache for the resultset. Expects an arrayref
1507 of objects of the same class as those produced by the resultset. Note that
1508 if the cache is set the resultset will return the cached objects rather
1509 than re-querying the database even if the cache attr is not set.
1514 my ( $self, $data ) = @_;
1515 $self->throw_exception("set_cache requires an arrayref")
1516 if defined($data) && (ref $data ne 'ARRAY');
1517 $self->{all_cache} = $data;
1524 =item Arguments: none
1526 =item Return Value: []
1530 Clears the cache for the resultset.
1535 shift->set_cache(undef);
1538 =head2 related_resultset
1542 =item Arguments: $relationship_name
1544 =item Return Value: $resultset
1548 Returns a related resultset for the supplied relationship name.
1550 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1554 sub related_resultset {
1555 my ( $self, $rel ) = @_;
1557 $self->{related_resultsets} ||= {};
1558 return $self->{related_resultsets}{$rel} ||= do {
1559 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1560 my $rel_obj = $self->result_source->relationship_info($rel);
1561 $self->throw_exception(
1562 "search_related: result source '" . $self->result_source->name .
1563 "' has no such relationship ${rel}")
1564 unless $rel_obj; #die Dumper $self->{attrs};
1566 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1572 _parent_attrs => $self->{attrs}}
1575 # keep reference of the original resultset
1576 $rs->{_parent_rs} = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->result_source;
1581 =head2 throw_exception
1583 See L<DBIx::Class::Schema/throw_exception> for details.
1587 sub throw_exception {
1589 $self->result_source->schema->throw_exception(@_);
1592 # XXX: FIXME: Attributes docs need clearing up
1596 The resultset takes various attributes that modify its behavior. Here's an
1603 =item Value: ($order_by | \@order_by)
1607 Which column(s) to order the results by. This is currently passed
1608 through directly to SQL, so you can give e.g. C<year DESC> for a
1609 descending order on the column `year'.
1611 Please note that if you have quoting enabled (see
1612 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1613 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1614 so you will need to manually quote things as appropriate.)
1620 =item Value: \@columns
1624 Shortcut to request a particular set of columns to be retrieved. Adds
1625 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1626 from that, then auto-populates C<as> from C<select> as normal. (You may also
1627 use the C<cols> attribute, as in earlier versions of DBIC.)
1629 =head2 include_columns
1633 =item Value: \@columns
1637 Shortcut to include additional columns in the returned results - for example
1639 $schema->resultset('CD')->search(undef, {
1640 include_columns => ['artist.name'],
1644 would return all CDs and include a 'name' column to the information
1645 passed to object inflation
1651 =item Value: \@select_columns
1655 Indicates which columns should be selected from the storage. You can use
1656 column names, or in the case of RDBMS back ends, function or stored procedure
1659 $rs = $schema->resultset('Employee')->search(undef, {
1662 { count => 'employeeid' },
1667 When you use function/stored procedure names and do not supply an C<as>
1668 attribute, the column names returned are storage-dependent. E.g. MySQL would
1669 return a column named C<count(employeeid)> in the above example.
1675 Indicates additional columns to be selected from storage. Works the same as
1676 L<select> but adds columns to the selection.
1684 Indicates additional column names for those added via L<+select>.
1692 =item Value: \@inflation_names
1696 Indicates column names for object inflation. This is used in conjunction with
1697 C<select>, usually when C<select> contains one or more function or stored
1700 $rs = $schema->resultset('Employee')->search(undef, {
1703 { count => 'employeeid' }
1705 as => ['name', 'employee_count'],
1708 my $employee = $rs->first(); # get the first Employee
1710 If the object against which the search is performed already has an accessor
1711 matching a column name specified in C<as>, the value can be retrieved using
1712 the accessor as normal:
1714 my $name = $employee->name();
1716 If on the other hand an accessor does not exist in the object, you need to
1717 use C<get_column> instead:
1719 my $employee_count = $employee->get_column('employee_count');
1721 You can create your own accessors if required - see
1722 L<DBIx::Class::Manual::Cookbook> for details.
1724 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1725 produced, it is used for internal access only. Thus attempting to use the accessor
1726 in an C<order_by> clause or similar will fail misrably.
1732 =item Value: ($rel_name | \@rel_names | \%rel_names)
1736 Contains a list of relationships that should be joined for this query. For
1739 # Get CDs by Nine Inch Nails
1740 my $rs = $schema->resultset('CD')->search(
1741 { 'artist.name' => 'Nine Inch Nails' },
1742 { join => 'artist' }
1745 Can also contain a hash reference to refer to the other relation's relations.
1748 package MyApp::Schema::Track;
1749 use base qw/DBIx::Class/;
1750 __PACKAGE__->table('track');
1751 __PACKAGE__->add_columns(qw/trackid cd position title/);
1752 __PACKAGE__->set_primary_key('trackid');
1753 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1756 # In your application
1757 my $rs = $schema->resultset('Artist')->search(
1758 { 'track.title' => 'Teardrop' },
1760 join => { cd => 'track' },
1761 order_by => 'artist.name',
1765 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1766 similarly for a third time). For e.g.
1768 my $rs = $schema->resultset('Artist')->search({
1769 'cds.title' => 'Down to Earth',
1770 'cds_2.title' => 'Popular',
1772 join => [ qw/cds cds/ ],
1775 will return a set of all artists that have both a cd with title 'Down
1776 to Earth' and a cd with title 'Popular'.
1778 If you want to fetch related objects from other tables as well, see C<prefetch>
1785 =item Value: ($rel_name | \@rel_names | \%rel_names)
1789 Contains one or more relationships that should be fetched along with the main
1790 query (when they are accessed afterwards they will have already been
1791 "prefetched"). This is useful for when you know you will need the related
1792 objects, because it saves at least one query:
1794 my $rs = $schema->resultset('Tag')->search(
1803 The initial search results in SQL like the following:
1805 SELECT tag.*, cd.*, artist.* FROM tag
1806 JOIN cd ON tag.cd = cd.cdid
1807 JOIN artist ON cd.artist = artist.artistid
1809 L<DBIx::Class> has no need to go back to the database when we access the
1810 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1813 Simple prefetches will be joined automatically, so there is no need
1814 for a C<join> attribute in the above search. If you're prefetching to
1815 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1816 specify the join as well.
1818 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1819 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1820 with an accessor type of 'single' or 'filter').
1830 Makes the resultset paged and specifies the page to retrieve. Effectively
1831 identical to creating a non-pages resultset and then calling ->page($page)
1834 If L<rows> attribute is not specified it defualts to 10 rows per page.
1844 Specifes the maximum number of rows for direct retrieval or the number of
1845 rows per page if the page attribute or method is used.
1851 =item Value: $offset
1855 Specifies the (zero-based) row number for the first row to be returned, or the
1856 of the first row of the first page if paging is used.
1862 =item Value: \@columns
1866 A arrayref of columns to group by. Can include columns of joined tables.
1868 group_by => [qw/ column1 column2 ... /]
1874 =item Value: $condition
1878 HAVING is a select statement attribute that is applied between GROUP BY and
1879 ORDER BY. It is applied to the after the grouping calculations have been
1882 having => { 'count(employee)' => { '>=', 100 } }
1888 =item Value: (0 | 1)
1892 Set to 1 to group by all columns.
1896 Set to 1 to cache search results. This prevents extra SQL queries if you
1897 revisit rows in your ResultSet:
1899 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1901 while( my $artist = $resultset->next ) {
1905 $rs->first; # without cache, this would issue a query
1907 By default, searches are not cached.
1909 For more examples of using these attributes, see
1910 L<DBIx::Class::Manual::Cookbook>.
1916 =item Value: \@from_clause
1920 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1921 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1924 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1926 C<join> will usually do what you need and it is strongly recommended that you
1927 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1928 And we really do mean "cannot", not just tried and failed. Attempting to use
1929 this because you're having problems with C<join> is like trying to use x86
1930 ASM because you've got a syntax error in your C. Trust us on this.
1932 Now, if you're still really, really sure you need to use this (and if you're
1933 not 100% sure, ask the mailing list first), here's an explanation of how this
1936 The syntax is as follows -
1939 { <alias1> => <table1> },
1941 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1942 [], # nested JOIN (optional)
1943 { <table1.column1> => <table2.column2>, ... (more conditions) },
1945 # More of the above [ ] may follow for additional joins
1952 ON <table1.column1> = <table2.column2>
1953 <more joins may follow>
1955 An easy way to follow the examples below is to remember the following:
1957 Anything inside "[]" is a JOIN
1958 Anything inside "{}" is a condition for the enclosing JOIN
1960 The following examples utilize a "person" table in a family tree application.
1961 In order to express parent->child relationships, this table is self-joined:
1963 # Person->belongs_to('father' => 'Person');
1964 # Person->belongs_to('mother' => 'Person');
1966 C<from> can be used to nest joins. Here we return all children with a father,
1967 then search against all mothers of those children:
1969 $rs = $schema->resultset('Person')->search(
1972 alias => 'mother', # alias columns in accordance with "from"
1974 { mother => 'person' },
1977 { child => 'person' },
1979 { father => 'person' },
1980 { 'father.person_id' => 'child.father_id' }
1983 { 'mother.person_id' => 'child.mother_id' }
1990 # SELECT mother.* FROM person mother
1993 # JOIN person father
1994 # ON ( father.person_id = child.father_id )
1996 # ON ( mother.person_id = child.mother_id )
1998 The type of any join can be controlled manually. To search against only people
1999 with a father in the person table, we could explicitly use C<INNER JOIN>:
2001 $rs = $schema->resultset('Person')->search(
2004 alias => 'child', # alias columns in accordance with "from"
2006 { child => 'person' },
2008 { father => 'person', -join_type => 'inner' },
2009 { 'father.id' => 'child.father_id' }
2016 # SELECT child.* FROM person child
2017 # INNER JOIN person father ON child.father_id = father.id