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 $input_query = { %{$_[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);
317 # use Data::Dumper; warn Dumper $self->result_source->name, $input_query, \@unique_queries, $self->{attrs}->{where};
320 my $query = \@unique_queries;
321 if (scalar @unique_queries == 0) {
322 # Handle cases where the ResultSet defines the query, or where the user is
324 $query = $input_query;
329 my $rs = $self->search($query, $attrs);
331 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
335 return (keys %{$self->{_attrs}->{collapse}})
336 ? $self->search($query)->next
337 : $self->single($query);
343 # Build a list of queries which satisfy unique constraints.
345 sub _unique_queries {
346 my ($self, $query, $attrs) = @_;
348 my @constraint_names = exists $attrs->{key}
350 : $self->result_source->unique_constraint_names;
353 foreach my $name (@constraint_names) {
354 my @unique_cols = $self->result_source->unique_constraint_columns($name);
355 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
357 next unless scalar keys %$unique_query;
359 # Add the ResultSet's alias
360 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
361 $unique_query->{"$self->{attrs}->{alias}.$key"} = delete $unique_query->{$key};
364 push @unique_queries, $unique_query;
367 return @unique_queries;
370 # _build_unique_query
372 # Constrain the specified query hash based on the specified column names.
374 sub _build_unique_query {
375 my ($self, $query, $unique_cols) = @_;
378 map { $_ => $query->{$_} }
379 grep { exists $query->{$_} }
382 return \%unique_query;
385 =head2 search_related
389 =item Arguments: $cond, \%attrs?
391 =item Return Value: $new_resultset
395 $new_rs = $cd_rs->search_related('artist', {
399 Searches the specified relationship, optionally specifying a condition and
400 attributes for matching records. See L</ATTRIBUTES> for more information.
405 return shift->related_resultset(shift)->search(@_);
412 =item Arguments: none
414 =item Return Value: $cursor
418 Returns a storage-driven cursor to the given resultset. See
419 L<DBIx::Class::Cursor> for more information.
427 my $attrs = { %{$self->{_attrs}} };
428 return $self->{cursor}
429 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
430 $attrs->{where},$attrs);
437 =item Arguments: $cond?
439 =item Return Value: $row_object?
443 my $cd = $schema->resultset('CD')->single({ year => 2001 });
445 Inflates the first result without creating a cursor if the resultset has
446 any records in it; if not returns nothing. Used by L</find> as an optimisation.
448 Can optionally take an additional condition *only* - this is a fast-code-path
449 method; if you need to add extra joins or similar call ->search and then
450 ->single without a condition on the $rs returned from that.
455 my ($self, $where) = @_;
457 my $attrs = { %{$self->{_attrs}} };
459 if (defined $attrs->{where}) {
462 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
463 $where, delete $attrs->{where} ]
466 $attrs->{where} = $where;
470 # use Data::Dumper; warn Dumper $attrs->{where};
471 unless ($self->_is_unique_query($attrs->{where})) {
472 carp "Query not guarnteed to return a single row"
473 . "; please declare your unique constraints or use search instead";
476 my @data = $self->result_source->storage->select_single(
477 $attrs->{from}, $attrs->{select},
478 $attrs->{where},$attrs);
479 return (@data ? $self->_construct_object(@data) : ());
484 # Try to determine if the specified query is guaranteed to be unique, based on
485 # the declared unique constraints.
487 sub _is_unique_query {
488 my ($self, $query) = @_;
490 my $collapsed = $self->_collapse_query($query);
491 # use Data::Dumper; warn Dumper $collapsed;
493 foreach my $name ($self->result_source->unique_constraint_names) {
494 my @unique_cols = map { "$self->{attrs}->{alias}.$_" }
495 $self->result_source->unique_constraint_columns($name);
497 # Count the values for each unique column
498 my %seen = map { $_ => 0 } @unique_cols;
500 foreach my $key (keys %$collapsed) {
502 $aliased = "$self->{attrs}->{alias}.$key" unless $key =~ /\./;
504 next unless exists $seen{$aliased}; # Additional constraints are okay
505 $seen{$aliased} = scalar @{ $collapsed->{$key} };
508 # If we get 0 or more than 1 value for a column, it's not necessarily unique
509 return 1 unless grep { $_ != 1 } values %seen;
517 # Recursively collapse the query, accumulating values for each column.
519 sub _collapse_query {
520 my ($self, $query, $collapsed) = @_;
522 # Accumulate fields in the AST
525 if (ref $query eq 'ARRAY') {
526 foreach my $subquery (@$query) {
527 next unless ref $subquery; # -or
528 # warn "ARRAY: " . Dumper $subquery;
529 $collapsed = $self->_collapse_query($subquery, $collapsed);
532 elsif (ref $query eq 'HASH') {
533 if (keys %$query and (keys %$query)[0] eq '-and') {
534 foreach my $subquery (@{$query->{-and}}) {
535 # warn "HASH: " . Dumper $subquery;
536 $collapsed = $self->_collapse_query($subquery, $collapsed);
540 # warn "LEAF: " . Dumper $query;
541 foreach my $key (keys %$query) {
542 push @{$collapsed->{$key}}, $query->{$key};
544 # warn Dumper $collapsed;
555 =item Arguments: $cond?
557 =item Return Value: $resultsetcolumn
561 my $max_length = $rs->get_column('length')->max;
563 Returns a ResultSetColumn instance for $column based on $self
568 my ($self, $column) = @_;
570 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
578 =item Arguments: $cond, \%attrs?
580 =item Return Value: $resultset (scalar context), @row_objs (list context)
584 # WHERE title LIKE '%blue%'
585 $cd_rs = $rs->search_like({ title => '%blue%'});
587 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
588 that this is simply a convenience method. You most likely want to use
589 L</search> with specific operators.
591 For more information, see L<DBIx::Class::Manual::Cookbook>.
597 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
598 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
599 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
600 return $class->search($query, { %$attrs });
607 =item Arguments: $first, $last
609 =item Return Value: $resultset (scalar context), @row_objs (list context)
613 Returns a resultset or object list representing a subset of elements from the
614 resultset slice is called on. Indexes are from 0, i.e., to get the first
617 my ($one, $two, $three) = $rs->slice(0, 2);
622 my ($self, $min, $max) = @_;
623 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
624 $attrs->{offset} = $self->{attrs}{offset} || 0;
625 $attrs->{offset} += $min;
626 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
627 return $self->search(undef(), $attrs);
628 #my $slice = (ref $self)->new($self->result_source, $attrs);
629 #return (wantarray ? $slice->all : $slice);
636 =item Arguments: none
638 =item Return Value: $result?
642 Returns the next element in the resultset (C<undef> is there is none).
644 Can be used to efficiently iterate over records in the resultset:
646 my $rs = $schema->resultset('CD')->search;
647 while (my $cd = $rs->next) {
651 Note that you need to store the resultset object, and call C<next> on it.
652 Calling C<< resultset('Table')->next >> repeatedly will always return the
653 first record from the resultset.
659 if (my $cache = $self->get_cache) {
660 $self->{all_cache_position} ||= 0;
661 return $cache->[$self->{all_cache_position}++];
663 if ($self->{attrs}{cache}) {
664 $self->{all_cache_position} = 1;
665 return ($self->all)[0];
667 my @row = (exists $self->{stashed_row} ?
668 @{delete $self->{stashed_row}} :
671 return unless (@row);
672 return $self->_construct_object(@row);
678 return if(exists $self->{_attrs}); #return if _resolve has already been called
680 my $attrs = $self->{attrs};
681 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
683 # XXX - lose storable dclone
684 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
685 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
686 $attrs->{record_filter} = $record_filter if ($record_filter);
687 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
689 my $alias = $attrs->{alias};
691 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
692 delete $attrs->{as} if $attrs->{columns};
693 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
694 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
696 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
697 ] if $attrs->{columns};
699 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
701 if (my $include = delete $attrs->{include_columns}) {
702 push(@{$attrs->{select}}, @$include);
703 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
706 $attrs->{from} ||= [ { $alias => $source->from } ];
707 $attrs->{seen_join} ||= {};
709 if (my $join = delete $attrs->{join}) {
710 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
711 if (ref $j eq 'HASH') {
712 $seen{$_} = 1 foreach keys %$j;
718 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
720 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
721 $attrs->{order_by} = [ $attrs->{order_by} ] if
722 $attrs->{order_by} and !ref($attrs->{order_by});
723 $attrs->{order_by} ||= [];
725 if(my $seladds = delete($attrs->{'+select'})) {
726 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
728 @{ $attrs->{select} },
729 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
732 if(my $asadds = delete($attrs->{'+as'})) {
733 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
734 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
737 my $collapse = $attrs->{collapse} || {};
738 if (my $prefetch = delete $attrs->{prefetch}) {
740 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
741 if ( ref $p eq 'HASH' ) {
742 foreach my $key (keys %$p) {
743 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
747 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
750 my @prefetch = $source->resolve_prefetch(
751 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
752 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
753 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
755 push(@{$attrs->{order_by}}, @pre_order);
757 $attrs->{collapse} = $collapse;
758 $self->{_attrs} = $attrs;
762 my ($self, $a, $b, $is_prefetch) = @_;
765 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
766 foreach my $key (keys %{$b}) {
767 if (exists $a->{$key}) {
768 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
770 $a->{$key} = delete $b->{$key};
775 $a = [$a] unless (ref $a eq 'ARRAY');
776 $b = [$b] unless (ref $b eq 'ARRAY');
781 foreach my $element (@{$_}) {
782 if (ref $element eq 'HASH') {
783 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
784 } elsif (ref $element eq 'ARRAY') {
785 $array = [@{$array}, @{$element}];
787 if (($b == $_) && $is_prefetch) {
788 $self->_merge_array($array, $element, $is_prefetch);
790 push(@{$array}, $element);
796 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
797 return [$hash, @{$array}];
799 return (keys %{$hash}) ? $hash : $array;
805 my ($self, $a, $b) = @_;
807 $b = [$b] unless (ref $b eq 'ARRAY');
808 # add elements from @{$b} to @{$a} which aren't already in @{$a}
809 foreach my $b_element (@{$b}) {
810 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
814 sub _construct_object {
815 my ($self, @row) = @_;
816 my @as = @{ $self->{_attrs}{as} };
818 my $info = $self->_collapse_result(\@as, \@row);
819 my $new = $self->result_class->inflate_result($self->result_source, @$info);
820 $new = $self->{_attrs}{record_filter}->($new)
821 if exists $self->{_attrs}{record_filter};
825 sub _collapse_result {
826 my ($self, $as, $row, $prefix) = @_;
828 my $live_join = $self->{attrs}->{_live_join} ||="";
832 foreach my $this_as (@$as) {
833 my $val = shift @copy;
834 if (defined $prefix) {
835 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
837 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
838 $const{$1||''}{$2} = $val;
841 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
842 $const{$1||''}{$2} = $val;
846 my $info = [ {}, {} ];
847 foreach my $key (keys %const) {
848 if (length $key && $key ne $live_join) {
850 my @parts = split(/\./, $key);
851 foreach my $p (@parts) {
852 $target = $target->[1]->{$p} ||= [];
854 $target->[0] = $const{$key};
856 $info->[0] = $const{$key};
861 if (defined $prefix) {
863 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
864 } keys %{$self->{_attrs}->{collapse}}
866 @collapse = keys %{$self->{_attrs}->{collapse}};
870 my ($c) = sort { length $a <=> length $b } @collapse;
872 foreach my $p (split(/\./, $c)) {
873 $target = $target->[1]->{$p} ||= [];
875 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
876 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
877 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
878 my $tree = $self->_collapse_result($as, $row, $c_prefix);
881 !defined($tree->[0]->{$_}) ||
882 $co_check{$_} ne $tree->[0]->{$_}
885 last unless (@raw = $self->cursor->next);
886 $row = $self->{stashed_row} = \@raw;
887 $tree = $self->_collapse_result($as, $row, $c_prefix);
889 @$target = (@final ? @final : [ {}, {} ]);
890 # single empty result to indicate an empty prefetched has_many
899 =item Arguments: $result_source?
901 =item Return Value: $result_source
905 An accessor for the primary ResultSource object from which this ResultSet
915 =item Arguments: $cond, \%attrs??
917 =item Return Value: $count
921 Performs an SQL C<COUNT> with the same query as the resultset was built
922 with to find the number of elements. If passed arguments, does a search
923 on the resultset and counts the results of that.
925 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
926 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
927 not support C<DISTINCT> with multiple columns. If you are using such a
928 database, you should only use columns from the main table in your C<group_by>
935 return $self->search(@_)->count if @_ and defined $_[0];
936 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 ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
983 =item Arguments: $sql_fragment, @bind_values
985 =item Return Value: $count
989 Counts the results in a literal query. Equivalent to calling L</search_literal>
990 with the passed arguments, then L</count>.
994 sub count_literal { shift->search_literal(@_)->count; }
1000 =item Arguments: none
1002 =item Return Value: @objects
1006 Returns all elements in the resultset. Called implicitly if the resultset
1007 is returned in list context.
1013 return @{ $self->get_cache } if $self->get_cache;
1017 # TODO: don't call resolve here
1019 if (keys %{$self->{_attrs}->{collapse}}) {
1020 # if ($self->{attrs}->{prefetch}) {
1021 # Using $self->cursor->all is really just an optimisation.
1022 # If we're collapsing has_many prefetches it probably makes
1023 # very little difference, and this is cleaner than hacking
1024 # _construct_object to survive the approach
1025 my @row = $self->cursor->next;
1027 push(@obj, $self->_construct_object(@row));
1028 @row = (exists $self->{stashed_row}
1029 ? @{delete $self->{stashed_row}}
1030 : $self->cursor->next);
1033 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1036 $self->set_cache(\@obj) if $self->{attrs}{cache};
1044 =item Arguments: none
1046 =item Return Value: $self
1050 Resets the resultset's cursor, so you can iterate through the elements again.
1056 delete $self->{_attrs} if (exists $self->{_attrs});
1058 $self->{all_cache_position} = 0;
1059 $self->cursor->reset;
1067 =item Arguments: none
1069 =item Return Value: $object?
1073 Resets the resultset and returns an object for the first result (if the
1074 resultset returns anything).
1079 return $_[0]->reset->next;
1082 # _cond_for_update_delete
1084 # update/delete require the condition to be modified to handle
1085 # the differing SQL syntax available. This transforms the $self->{cond}
1086 # appropriately, returning the new condition.
1088 sub _cond_for_update_delete {
1092 if (!ref($self->{cond})) {
1093 # No-op. No condition, we're updating/deleting everything
1095 elsif (ref $self->{cond} eq 'ARRAY') {
1099 foreach my $key (keys %{$_}) {
1101 $hash{$1} = $_->{$key};
1107 elsif (ref $self->{cond} eq 'HASH') {
1108 if ((keys %{$self->{cond}})[0] eq '-and') {
1111 my @cond = @{$self->{cond}{-and}};
1112 for (my $i = 0; $i <= @cond - 1; $i++) {
1113 my $entry = $cond[$i];
1116 if (ref $entry eq 'HASH') {
1117 foreach my $key (keys %{$entry}) {
1119 $hash{$1} = $entry->{$key};
1123 $entry =~ /([^.]+)$/;
1124 $hash{$1} = $cond[++$i];
1127 push @{$cond->{-and}}, \%hash;
1131 foreach my $key (keys %{$self->{cond}}) {
1133 $cond->{$1} = $self->{cond}{$key};
1138 $self->throw_exception(
1139 "Can't update/delete on resultset with condition unless hash or array"
1151 =item Arguments: \%values
1153 =item Return Value: $storage_rv
1157 Sets the specified columns in the resultset to the supplied values in a
1158 single query. Return value will be true if the update succeeded or false
1159 if no records were updated; exact type of success value is storage-dependent.
1164 my ($self, $values) = @_;
1165 $self->throw_exception("Values for update must be a hash")
1166 unless ref $values eq 'HASH';
1168 my $cond = $self->_cond_for_update_delete;
1170 return $self->result_source->storage->update(
1171 $self->result_source->from, $values, $cond
1179 =item Arguments: \%values
1181 =item Return Value: 1
1185 Fetches all objects and updates them one at a time. Note that C<update_all>
1186 will run DBIC cascade triggers, while L</update> will not.
1191 my ($self, $values) = @_;
1192 $self->throw_exception("Values for update must be a hash")
1193 unless ref $values eq 'HASH';
1194 foreach my $obj ($self->all) {
1195 $obj->set_columns($values)->update;
1204 =item Arguments: none
1206 =item Return Value: 1
1210 Deletes the contents of the resultset from its result source. Note that this
1211 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1220 my $cond = $self->_cond_for_update_delete;
1222 $self->result_source->storage->delete($self->result_source->from, $cond);
1230 =item Arguments: none
1232 =item Return Value: 1
1236 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1237 will run DBIC cascade triggers, while L</delete> will not.
1243 $_->delete for $self->all;
1251 =item Arguments: none
1253 =item Return Value: $pager
1257 Return Value a L<Data::Page> object for the current resultset. Only makes
1258 sense for queries with a C<page> attribute.
1264 my $attrs = $self->{attrs};
1265 $self->throw_exception("Can't create pager for non-paged rs")
1266 unless $self->{page};
1267 $attrs->{rows} ||= 10;
1268 return $self->{pager} ||= Data::Page->new(
1269 $self->_count, $attrs->{rows}, $self->{page});
1276 =item Arguments: $page_number
1278 =item Return Value: $rs
1282 Returns a resultset for the $page_number page of the resultset on which page
1283 is called, where each page contains a number of rows equal to the 'rows'
1284 attribute set on the resultset (10 by default).
1289 my ($self, $page) = @_;
1290 my $attrs = { %{$self->{attrs}} };
1291 $attrs->{page} = $page;
1292 return (ref $self)->new($self->result_source, $attrs);
1299 =item Arguments: \%vals
1301 =item Return Value: $object
1305 Creates an object in the resultset's result class and returns it.
1310 my ($self, $values) = @_;
1311 $self->throw_exception( "new_result needs a hash" )
1312 unless (ref $values eq 'HASH');
1313 $self->throw_exception(
1314 "Can't abstract implicit construct, condition not a hash"
1315 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1317 my $alias = $self->{attrs}{alias};
1318 foreach my $key (keys %{$self->{cond}||{}}) {
1319 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1321 my $obj = $self->result_class->new(\%new);
1322 $obj->result_source($self->result_source) if $obj->can('result_source');
1330 =item Arguments: \%vals, \%attrs?
1332 =item Return Value: $object
1336 Find an existing record from this resultset. If none exists, instantiate a new
1337 result object and return it. The object will not be saved into your storage
1338 until you call L<DBIx::Class::Row/insert> on it.
1340 If you want objects to be saved immediately, use L</find_or_create> instead.
1346 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1347 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1348 my $exists = $self->find($hash, $attrs);
1349 return defined $exists ? $exists : $self->new_result($hash);
1356 =item Arguments: \%vals
1358 =item Return Value: $object
1362 Inserts a record into the resultset and returns the object representing it.
1364 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1369 my ($self, $attrs) = @_;
1370 $self->throw_exception( "create needs a hashref" )
1371 unless ref $attrs eq 'HASH';
1372 return $self->new_result($attrs)->insert;
1375 =head2 find_or_create
1379 =item Arguments: \%vals, \%attrs?
1381 =item Return Value: $object
1385 $class->find_or_create({ key => $val, ... });
1387 Tries to find a record based on its primary key or unique constraint; if none
1388 is found, creates one and returns that instead.
1390 my $cd = $schema->resultset('CD')->find_or_create({
1392 artist => 'Massive Attack',
1393 title => 'Mezzanine',
1397 Also takes an optional C<key> attribute, to search by a specific key or unique
1398 constraint. For example:
1400 my $cd = $schema->resultset('CD')->find_or_create(
1402 artist => 'Massive Attack',
1403 title => 'Mezzanine',
1405 { key => 'artist_title' }
1408 See also L</find> and L</update_or_create>. For information on how to declare
1409 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1413 sub find_or_create {
1415 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1416 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1417 my $exists = $self->find($hash, $attrs);
1418 return defined $exists ? $exists : $self->create($hash);
1421 =head2 update_or_create
1425 =item Arguments: \%col_values, { key => $unique_constraint }?
1427 =item Return Value: $object
1431 $class->update_or_create({ col => $val, ... });
1433 First, searches for an existing row matching one of the unique constraints
1434 (including the primary key) on the source of this resultset. If a row is
1435 found, updates it with the other given column values. Otherwise, creates a new
1438 Takes an optional C<key> attribute to search on a specific unique constraint.
1441 # In your application
1442 my $cd = $schema->resultset('CD')->update_or_create(
1444 artist => 'Massive Attack',
1445 title => 'Mezzanine',
1448 { key => 'artist_title' }
1451 If no C<key> is specified, it searches on all unique constraints defined on the
1452 source, including the primary key.
1454 If the C<key> is specified as C<primary>, it searches only on the primary key.
1456 See also L</find> and L</find_or_create>. For information on how to declare
1457 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1461 sub update_or_create {
1463 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1464 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1466 my $row = $self->find($cond);
1468 $row->update($cond);
1472 return $self->create($cond);
1479 =item Arguments: none
1481 =item Return Value: \@cache_objects?
1485 Gets the contents of the cache for the resultset, if the cache is set.
1497 =item Arguments: \@cache_objects
1499 =item Return Value: \@cache_objects
1503 Sets the contents of the cache for the resultset. Expects an arrayref
1504 of objects of the same class as those produced by the resultset. Note that
1505 if the cache is set the resultset will return the cached objects rather
1506 than re-querying the database even if the cache attr is not set.
1511 my ( $self, $data ) = @_;
1512 $self->throw_exception("set_cache requires an arrayref")
1513 if defined($data) && (ref $data ne 'ARRAY');
1514 $self->{all_cache} = $data;
1521 =item Arguments: none
1523 =item Return Value: []
1527 Clears the cache for the resultset.
1532 shift->set_cache(undef);
1535 =head2 related_resultset
1539 =item Arguments: $relationship_name
1541 =item Return Value: $resultset
1545 Returns a related resultset for the supplied relationship name.
1547 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1551 sub related_resultset {
1552 my ( $self, $rel ) = @_;
1554 $self->{related_resultsets} ||= {};
1555 return $self->{related_resultsets}{$rel} ||= do {
1556 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1557 my $rel_obj = $self->result_source->relationship_info($rel);
1558 $self->throw_exception(
1559 "search_related: result source '" . $self->result_source->name .
1560 "' has no such relationship ${rel}")
1561 unless $rel_obj; #die Dumper $self->{attrs};
1563 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1565 { %{$self->{attrs}},
1569 _live_join => $rel }
1572 # keep reference of the original resultset
1573 $rs->{_parent_rs} = $self->result_source;
1578 =head2 throw_exception
1580 See L<DBIx::Class::Schema/throw_exception> for details.
1584 sub throw_exception {
1586 $self->result_source->schema->throw_exception(@_);
1589 # XXX: FIXME: Attributes docs need clearing up
1593 The resultset takes various attributes that modify its behavior. Here's an
1600 =item Value: ($order_by | \@order_by)
1604 Which column(s) to order the results by. This is currently passed
1605 through directly to SQL, so you can give e.g. C<year DESC> for a
1606 descending order on the column `year'.
1608 Please note that if you have quoting enabled (see
1609 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1610 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1611 so you will need to manually quote things as appropriate.)
1617 =item Value: \@columns
1621 Shortcut to request a particular set of columns to be retrieved. Adds
1622 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1623 from that, then auto-populates C<as> from C<select> as normal. (You may also
1624 use the C<cols> attribute, as in earlier versions of DBIC.)
1626 =head2 include_columns
1630 =item Value: \@columns
1634 Shortcut to include additional columns in the returned results - for example
1636 $schema->resultset('CD')->search(undef, {
1637 include_columns => ['artist.name'],
1641 would return all CDs and include a 'name' column to the information
1642 passed to object inflation
1648 =item Value: \@select_columns
1652 Indicates which columns should be selected from the storage. You can use
1653 column names, or in the case of RDBMS back ends, function or stored procedure
1656 $rs = $schema->resultset('Employee')->search(undef, {
1659 { count => 'employeeid' },
1664 When you use function/stored procedure names and do not supply an C<as>
1665 attribute, the column names returned are storage-dependent. E.g. MySQL would
1666 return a column named C<count(employeeid)> in the above example.
1672 Indicates additional columns to be selected from storage. Works the same as
1673 L<select> but adds columns to the selection.
1681 Indicates additional column names for those added via L<+select>.
1689 =item Value: \@inflation_names
1693 Indicates column names for object inflation. This is used in conjunction with
1694 C<select>, usually when C<select> contains one or more function or stored
1697 $rs = $schema->resultset('Employee')->search(undef, {
1700 { count => 'employeeid' }
1702 as => ['name', 'employee_count'],
1705 my $employee = $rs->first(); # get the first Employee
1707 If the object against which the search is performed already has an accessor
1708 matching a column name specified in C<as>, the value can be retrieved using
1709 the accessor as normal:
1711 my $name = $employee->name();
1713 If on the other hand an accessor does not exist in the object, you need to
1714 use C<get_column> instead:
1716 my $employee_count = $employee->get_column('employee_count');
1718 You can create your own accessors if required - see
1719 L<DBIx::Class::Manual::Cookbook> for details.
1721 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1722 produced, it is used for internal access only. Thus attempting to use the accessor
1723 in an C<order_by> clause or similar will fail misrably.
1729 =item Value: ($rel_name | \@rel_names | \%rel_names)
1733 Contains a list of relationships that should be joined for this query. For
1736 # Get CDs by Nine Inch Nails
1737 my $rs = $schema->resultset('CD')->search(
1738 { 'artist.name' => 'Nine Inch Nails' },
1739 { join => 'artist' }
1742 Can also contain a hash reference to refer to the other relation's relations.
1745 package MyApp::Schema::Track;
1746 use base qw/DBIx::Class/;
1747 __PACKAGE__->table('track');
1748 __PACKAGE__->add_columns(qw/trackid cd position title/);
1749 __PACKAGE__->set_primary_key('trackid');
1750 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1753 # In your application
1754 my $rs = $schema->resultset('Artist')->search(
1755 { 'track.title' => 'Teardrop' },
1757 join => { cd => 'track' },
1758 order_by => 'artist.name',
1762 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1763 similarly for a third time). For e.g.
1765 my $rs = $schema->resultset('Artist')->search({
1766 'cds.title' => 'Down to Earth',
1767 'cds_2.title' => 'Popular',
1769 join => [ qw/cds cds/ ],
1772 will return a set of all artists that have both a cd with title 'Down
1773 to Earth' and a cd with title 'Popular'.
1775 If you want to fetch related objects from other tables as well, see C<prefetch>
1782 =item Value: ($rel_name | \@rel_names | \%rel_names)
1786 Contains one or more relationships that should be fetched along with the main
1787 query (when they are accessed afterwards they will have already been
1788 "prefetched"). This is useful for when you know you will need the related
1789 objects, because it saves at least one query:
1791 my $rs = $schema->resultset('Tag')->search(
1800 The initial search results in SQL like the following:
1802 SELECT tag.*, cd.*, artist.* FROM tag
1803 JOIN cd ON tag.cd = cd.cdid
1804 JOIN artist ON cd.artist = artist.artistid
1806 L<DBIx::Class> has no need to go back to the database when we access the
1807 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1810 Simple prefetches will be joined automatically, so there is no need
1811 for a C<join> attribute in the above search. If you're prefetching to
1812 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1813 specify the join as well.
1815 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1816 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1817 with an accessor type of 'single' or 'filter').
1827 Makes the resultset paged and specifies the page to retrieve. Effectively
1828 identical to creating a non-pages resultset and then calling ->page($page)
1831 If L<rows> attribute is not specified it defualts to 10 rows per page.
1841 Specifes the maximum number of rows for direct retrieval or the number of
1842 rows per page if the page attribute or method is used.
1848 =item Value: $offset
1852 Specifies the (zero-based) row number for the first row to be returned, or the
1853 of the first row of the first page if paging is used.
1859 =item Value: \@columns
1863 A arrayref of columns to group by. Can include columns of joined tables.
1865 group_by => [qw/ column1 column2 ... /]
1871 =item Value: $condition
1875 HAVING is a select statement attribute that is applied between GROUP BY and
1876 ORDER BY. It is applied to the after the grouping calculations have been
1879 having => { 'count(employee)' => { '>=', 100 } }
1885 =item Value: (0 | 1)
1889 Set to 1 to group by all columns.
1893 Set to 1 to cache search results. This prevents extra SQL queries if you
1894 revisit rows in your ResultSet:
1896 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1898 while( my $artist = $resultset->next ) {
1902 $rs->first; # without cache, this would issue a query
1904 By default, searches are not cached.
1906 For more examples of using these attributes, see
1907 L<DBIx::Class::Manual::Cookbook>.
1913 =item Value: \@from_clause
1917 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1918 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1921 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1923 C<join> will usually do what you need and it is strongly recommended that you
1924 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1925 And we really do mean "cannot", not just tried and failed. Attempting to use
1926 this because you're having problems with C<join> is like trying to use x86
1927 ASM because you've got a syntax error in your C. Trust us on this.
1929 Now, if you're still really, really sure you need to use this (and if you're
1930 not 100% sure, ask the mailing list first), here's an explanation of how this
1933 The syntax is as follows -
1936 { <alias1> => <table1> },
1938 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1939 [], # nested JOIN (optional)
1940 { <table1.column1> => <table2.column2>, ... (more conditions) },
1942 # More of the above [ ] may follow for additional joins
1949 ON <table1.column1> = <table2.column2>
1950 <more joins may follow>
1952 An easy way to follow the examples below is to remember the following:
1954 Anything inside "[]" is a JOIN
1955 Anything inside "{}" is a condition for the enclosing JOIN
1957 The following examples utilize a "person" table in a family tree application.
1958 In order to express parent->child relationships, this table is self-joined:
1960 # Person->belongs_to('father' => 'Person');
1961 # Person->belongs_to('mother' => 'Person');
1963 C<from> can be used to nest joins. Here we return all children with a father,
1964 then search against all mothers of those children:
1966 $rs = $schema->resultset('Person')->search(
1969 alias => 'mother', # alias columns in accordance with "from"
1971 { mother => 'person' },
1974 { child => 'person' },
1976 { father => 'person' },
1977 { 'father.person_id' => 'child.father_id' }
1980 { 'mother.person_id' => 'child.mother_id' }
1987 # SELECT mother.* FROM person mother
1990 # JOIN person father
1991 # ON ( father.person_id = child.father_id )
1993 # ON ( mother.person_id = child.mother_id )
1995 The type of any join can be controlled manually. To search against only people
1996 with a father in the person table, we could explicitly use C<INNER JOIN>:
1998 $rs = $schema->resultset('Person')->search(
2001 alias => 'child', # alias columns in accordance with "from"
2003 { child => 'person' },
2005 { father => 'person', -join_type => 'inner' },
2006 { 'father.id' => 'child.father_id' }
2013 # SELECT child.* FROM person child
2014 # INNER JOIN person father ON child.father_id = father.id