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) {
501 next unless exists $seen{$key}; # Additional constraints are okay
502 $seen{$key} = 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) = @_;
519 # Accumulate fields in the AST
522 if (ref $query eq 'ARRAY') {
523 foreach my $subquery (@$query) {
524 next unless ref $subquery; # -or
525 # warn "ARRAY: " . Dumper $subquery;
526 $collapsed = $self->_collapse_query($subquery, $collapsed);
529 elsif (ref $query eq 'HASH') {
530 if (keys %$query and (keys %$query)[0] eq '-and') {
531 foreach my $subquery (@{$query->{-and}}) {
532 # warn "HASH: " . Dumper $subquery;
533 $collapsed = $self->_collapse_query($subquery, $collapsed);
537 # warn "LEAF: " . Dumper $query;
538 foreach my $key (keys %$query) {
539 push @{$collapsed->{$key}}, $query->{$key};
541 # warn Dumper $collapsed;
552 =item Arguments: $cond?
554 =item Return Value: $resultsetcolumn
558 my $max_length = $rs->get_column('length')->max;
560 Returns a ResultSetColumn instance for $column based on $self
565 my ($self, $column) = @_;
567 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
575 =item Arguments: $cond, \%attrs?
577 =item Return Value: $resultset (scalar context), @row_objs (list context)
581 # WHERE title LIKE '%blue%'
582 $cd_rs = $rs->search_like({ title => '%blue%'});
584 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
585 that this is simply a convenience method. You most likely want to use
586 L</search> with specific operators.
588 For more information, see L<DBIx::Class::Manual::Cookbook>.
594 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
595 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
596 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
597 return $class->search($query, { %$attrs });
604 =item Arguments: $first, $last
606 =item Return Value: $resultset (scalar context), @row_objs (list context)
610 Returns a resultset or object list representing a subset of elements from the
611 resultset slice is called on. Indexes are from 0, i.e., to get the first
614 my ($one, $two, $three) = $rs->slice(0, 2);
619 my ($self, $min, $max) = @_;
620 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
621 $attrs->{offset} = $self->{attrs}{offset} || 0;
622 $attrs->{offset} += $min;
623 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
624 return $self->search(undef(), $attrs);
625 #my $slice = (ref $self)->new($self->result_source, $attrs);
626 #return (wantarray ? $slice->all : $slice);
633 =item Arguments: none
635 =item Return Value: $result?
639 Returns the next element in the resultset (C<undef> is there is none).
641 Can be used to efficiently iterate over records in the resultset:
643 my $rs = $schema->resultset('CD')->search;
644 while (my $cd = $rs->next) {
648 Note that you need to store the resultset object, and call C<next> on it.
649 Calling C<< resultset('Table')->next >> repeatedly will always return the
650 first record from the resultset.
656 if (my $cache = $self->get_cache) {
657 $self->{all_cache_position} ||= 0;
658 return $cache->[$self->{all_cache_position}++];
660 if ($self->{attrs}{cache}) {
661 $self->{all_cache_position} = 1;
662 return ($self->all)[0];
664 my @row = (exists $self->{stashed_row} ?
665 @{delete $self->{stashed_row}} :
668 return unless (@row);
669 return $self->_construct_object(@row);
675 return if(exists $self->{_attrs}); #return if _resolve has already been called
677 my $attrs = $self->{attrs};
678 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
680 # XXX - lose storable dclone
681 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
682 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
683 $attrs->{record_filter} = $record_filter if ($record_filter);
684 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
686 my $alias = $attrs->{alias};
688 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
689 delete $attrs->{as} if $attrs->{columns};
690 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
691 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
693 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
694 ] if $attrs->{columns};
696 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
698 if (my $include = delete $attrs->{include_columns}) {
699 push(@{$attrs->{select}}, @$include);
700 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
703 $attrs->{from} ||= [ { $alias => $source->from } ];
704 $attrs->{seen_join} ||= {};
706 if (my $join = delete $attrs->{join}) {
707 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
708 if (ref $j eq 'HASH') {
709 $seen{$_} = 1 foreach keys %$j;
715 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
717 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
718 $attrs->{order_by} = [ $attrs->{order_by} ] if
719 $attrs->{order_by} and !ref($attrs->{order_by});
720 $attrs->{order_by} ||= [];
722 if(my $seladds = delete($attrs->{'+select'})) {
723 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
725 @{ $attrs->{select} },
726 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
729 if(my $asadds = delete($attrs->{'+as'})) {
730 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
731 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
734 my $collapse = $attrs->{collapse} || {};
735 if (my $prefetch = delete $attrs->{prefetch}) {
737 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
738 if ( ref $p eq 'HASH' ) {
739 foreach my $key (keys %$p) {
740 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
744 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
747 my @prefetch = $source->resolve_prefetch(
748 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
749 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
750 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
752 push(@{$attrs->{order_by}}, @pre_order);
754 $attrs->{collapse} = $collapse;
755 $self->{_attrs} = $attrs;
759 my ($self, $a, $b, $is_prefetch) = @_;
762 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
763 foreach my $key (keys %{$b}) {
764 if (exists $a->{$key}) {
765 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
767 $a->{$key} = delete $b->{$key};
772 $a = [$a] unless (ref $a eq 'ARRAY');
773 $b = [$b] unless (ref $b eq 'ARRAY');
778 foreach my $element (@{$_}) {
779 if (ref $element eq 'HASH') {
780 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
781 } elsif (ref $element eq 'ARRAY') {
782 $array = [@{$array}, @{$element}];
784 if (($b == $_) && $is_prefetch) {
785 $self->_merge_array($array, $element, $is_prefetch);
787 push(@{$array}, $element);
793 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
794 return [$hash, @{$array}];
796 return (keys %{$hash}) ? $hash : $array;
802 my ($self, $a, $b) = @_;
804 $b = [$b] unless (ref $b eq 'ARRAY');
805 # add elements from @{$b} to @{$a} which aren't already in @{$a}
806 foreach my $b_element (@{$b}) {
807 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
811 sub _construct_object {
812 my ($self, @row) = @_;
813 my @as = @{ $self->{_attrs}{as} };
815 my $info = $self->_collapse_result(\@as, \@row);
816 my $new = $self->result_class->inflate_result($self->result_source, @$info);
817 $new = $self->{_attrs}{record_filter}->($new)
818 if exists $self->{_attrs}{record_filter};
822 sub _collapse_result {
823 my ($self, $as, $row, $prefix) = @_;
825 my $live_join = $self->{attrs}->{_live_join} ||="";
829 foreach my $this_as (@$as) {
830 my $val = shift @copy;
831 if (defined $prefix) {
832 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
834 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
835 $const{$1||''}{$2} = $val;
838 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
839 $const{$1||''}{$2} = $val;
843 my $info = [ {}, {} ];
844 foreach my $key (keys %const) {
845 if (length $key && $key ne $live_join) {
847 my @parts = split(/\./, $key);
848 foreach my $p (@parts) {
849 $target = $target->[1]->{$p} ||= [];
851 $target->[0] = $const{$key};
853 $info->[0] = $const{$key};
858 if (defined $prefix) {
860 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
861 } keys %{$self->{_attrs}->{collapse}}
863 @collapse = keys %{$self->{_attrs}->{collapse}};
867 my ($c) = sort { length $a <=> length $b } @collapse;
869 foreach my $p (split(/\./, $c)) {
870 $target = $target->[1]->{$p} ||= [];
872 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
873 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
874 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
875 my $tree = $self->_collapse_result($as, $row, $c_prefix);
878 !defined($tree->[0]->{$_}) ||
879 $co_check{$_} ne $tree->[0]->{$_}
882 last unless (@raw = $self->cursor->next);
883 $row = $self->{stashed_row} = \@raw;
884 $tree = $self->_collapse_result($as, $row, $c_prefix);
886 @$target = (@final ? @final : [ {}, {} ]);
887 # single empty result to indicate an empty prefetched has_many
896 =item Arguments: $result_source?
898 =item Return Value: $result_source
902 An accessor for the primary ResultSource object from which this ResultSet
912 =item Arguments: $cond, \%attrs??
914 =item Return Value: $count
918 Performs an SQL C<COUNT> with the same query as the resultset was built
919 with to find the number of elements. If passed arguments, does a search
920 on the resultset and counts the results of that.
922 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
923 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
924 not support C<DISTINCT> with multiple columns. If you are using such a
925 database, you should only use columns from the main table in your C<group_by>
932 return $self->search(@_)->count if @_ and defined $_[0];
933 return scalar @{ $self->get_cache } if $self->get_cache;
935 my $count = $self->_count;
936 return 0 unless $count;
938 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
939 $count = $self->{attrs}{rows} if
940 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
944 sub _count { # Separated out so pager can get the full count
946 my $select = { count => '*' };
949 my $attrs = { %{ $self->{_attrs} } };
950 if (my $group_by = delete $attrs->{group_by}) {
951 delete $attrs->{having};
952 my @distinct = (ref $group_by ? @$group_by : ($group_by));
953 # todo: try CONCAT for multi-column pk
954 my @pk = $self->result_source->primary_columns;
956 foreach my $column (@distinct) {
957 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
958 @distinct = ($column);
964 $select = { count => { distinct => \@distinct } };
967 $attrs->{select} = $select;
968 $attrs->{as} = [qw/count/];
970 # offset, order by and page are not needed to count. record_filter is cdbi
971 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
972 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
980 =item Arguments: $sql_fragment, @bind_values
982 =item Return Value: $count
986 Counts the results in a literal query. Equivalent to calling L</search_literal>
987 with the passed arguments, then L</count>.
991 sub count_literal { shift->search_literal(@_)->count; }
997 =item Arguments: none
999 =item Return Value: @objects
1003 Returns all elements in the resultset. Called implicitly if the resultset
1004 is returned in list context.
1010 return @{ $self->get_cache } if $self->get_cache;
1014 # TODO: don't call resolve here
1016 if (keys %{$self->{_attrs}->{collapse}}) {
1017 # if ($self->{attrs}->{prefetch}) {
1018 # Using $self->cursor->all is really just an optimisation.
1019 # If we're collapsing has_many prefetches it probably makes
1020 # very little difference, and this is cleaner than hacking
1021 # _construct_object to survive the approach
1022 my @row = $self->cursor->next;
1024 push(@obj, $self->_construct_object(@row));
1025 @row = (exists $self->{stashed_row}
1026 ? @{delete $self->{stashed_row}}
1027 : $self->cursor->next);
1030 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1033 $self->set_cache(\@obj) if $self->{attrs}{cache};
1041 =item Arguments: none
1043 =item Return Value: $self
1047 Resets the resultset's cursor, so you can iterate through the elements again.
1053 delete $self->{_attrs} if (exists $self->{_attrs});
1055 $self->{all_cache_position} = 0;
1056 $self->cursor->reset;
1064 =item Arguments: none
1066 =item Return Value: $object?
1070 Resets the resultset and returns an object for the first result (if the
1071 resultset returns anything).
1076 return $_[0]->reset->next;
1079 # _cond_for_update_delete
1081 # update/delete require the condition to be modified to handle
1082 # the differing SQL syntax available. This transforms the $self->{cond}
1083 # appropriately, returning the new condition.
1085 sub _cond_for_update_delete {
1089 if (!ref($self->{cond})) {
1090 # No-op. No condition, we're updating/deleting everything
1092 elsif (ref $self->{cond} eq 'ARRAY') {
1096 foreach my $key (keys %{$_}) {
1098 $hash{$1} = $_->{$key};
1104 elsif (ref $self->{cond} eq 'HASH') {
1105 if ((keys %{$self->{cond}})[0] eq '-and') {
1108 my @cond = @{$self->{cond}{-and}};
1109 for (my $i = 0; $i <= @cond - 1; $i++) {
1110 my $entry = $cond[$i];
1113 if (ref $entry eq 'HASH') {
1114 foreach my $key (keys %{$entry}) {
1116 $hash{$1} = $entry->{$key};
1120 $entry =~ /([^.]+)$/;
1121 $hash{$1} = $cond[++$i];
1124 push @{$cond->{-and}}, \%hash;
1128 foreach my $key (keys %{$self->{cond}}) {
1130 $cond->{$1} = $self->{cond}{$key};
1135 $self->throw_exception(
1136 "Can't update/delete on resultset with condition unless hash or array"
1148 =item Arguments: \%values
1150 =item Return Value: $storage_rv
1154 Sets the specified columns in the resultset to the supplied values in a
1155 single query. Return value will be true if the update succeeded or false
1156 if no records were updated; exact type of success value is storage-dependent.
1161 my ($self, $values) = @_;
1162 $self->throw_exception("Values for update must be a hash")
1163 unless ref $values eq 'HASH';
1165 my $cond = $self->_cond_for_update_delete;
1167 return $self->result_source->storage->update(
1168 $self->result_source->from, $values, $cond
1176 =item Arguments: \%values
1178 =item Return Value: 1
1182 Fetches all objects and updates them one at a time. Note that C<update_all>
1183 will run DBIC cascade triggers, while L</update> will not.
1188 my ($self, $values) = @_;
1189 $self->throw_exception("Values for update must be a hash")
1190 unless ref $values eq 'HASH';
1191 foreach my $obj ($self->all) {
1192 $obj->set_columns($values)->update;
1201 =item Arguments: none
1203 =item Return Value: 1
1207 Deletes the contents of the resultset from its result source. Note that this
1208 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1217 my $cond = $self->_cond_for_update_delete;
1219 $self->result_source->storage->delete($self->result_source->from, $cond);
1227 =item Arguments: none
1229 =item Return Value: 1
1233 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1234 will run DBIC cascade triggers, while L</delete> will not.
1240 $_->delete for $self->all;
1248 =item Arguments: none
1250 =item Return Value: $pager
1254 Return Value a L<Data::Page> object for the current resultset. Only makes
1255 sense for queries with a C<page> attribute.
1261 my $attrs = $self->{attrs};
1262 $self->throw_exception("Can't create pager for non-paged rs")
1263 unless $self->{page};
1264 $attrs->{rows} ||= 10;
1265 return $self->{pager} ||= Data::Page->new(
1266 $self->_count, $attrs->{rows}, $self->{page});
1273 =item Arguments: $page_number
1275 =item Return Value: $rs
1279 Returns a resultset for the $page_number page of the resultset on which page
1280 is called, where each page contains a number of rows equal to the 'rows'
1281 attribute set on the resultset (10 by default).
1286 my ($self, $page) = @_;
1287 my $attrs = { %{$self->{attrs}} };
1288 $attrs->{page} = $page;
1289 return (ref $self)->new($self->result_source, $attrs);
1296 =item Arguments: \%vals
1298 =item Return Value: $object
1302 Creates an object in the resultset's result class and returns it.
1307 my ($self, $values) = @_;
1308 $self->throw_exception( "new_result needs a hash" )
1309 unless (ref $values eq 'HASH');
1310 $self->throw_exception(
1311 "Can't abstract implicit construct, condition not a hash"
1312 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1314 my $alias = $self->{attrs}{alias};
1315 foreach my $key (keys %{$self->{cond}||{}}) {
1316 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1318 my $obj = $self->result_class->new(\%new);
1319 $obj->result_source($self->result_source) if $obj->can('result_source');
1327 =item Arguments: \%vals, \%attrs?
1329 =item Return Value: $object
1333 Find an existing record from this resultset. If none exists, instantiate a new
1334 result object and return it. The object will not be saved into your storage
1335 until you call L<DBIx::Class::Row/insert> on it.
1337 If you want objects to be saved immediately, use L</find_or_create> instead.
1343 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1344 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1345 my $exists = $self->find($hash, $attrs);
1346 return defined $exists ? $exists : $self->new_result($hash);
1353 =item Arguments: \%vals
1355 =item Return Value: $object
1359 Inserts a record into the resultset and returns the object representing it.
1361 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1366 my ($self, $attrs) = @_;
1367 $self->throw_exception( "create needs a hashref" )
1368 unless ref $attrs eq 'HASH';
1369 return $self->new_result($attrs)->insert;
1372 =head2 find_or_create
1376 =item Arguments: \%vals, \%attrs?
1378 =item Return Value: $object
1382 $class->find_or_create({ key => $val, ... });
1384 Tries to find a record based on its primary key or unique constraint; if none
1385 is found, creates one and returns that instead.
1387 my $cd = $schema->resultset('CD')->find_or_create({
1389 artist => 'Massive Attack',
1390 title => 'Mezzanine',
1394 Also takes an optional C<key> attribute, to search by a specific key or unique
1395 constraint. For example:
1397 my $cd = $schema->resultset('CD')->find_or_create(
1399 artist => 'Massive Attack',
1400 title => 'Mezzanine',
1402 { key => 'artist_title' }
1405 See also L</find> and L</update_or_create>. For information on how to declare
1406 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1410 sub find_or_create {
1412 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1413 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1414 my $exists = $self->find($hash, $attrs);
1415 return defined $exists ? $exists : $self->create($hash);
1418 =head2 update_or_create
1422 =item Arguments: \%col_values, { key => $unique_constraint }?
1424 =item Return Value: $object
1428 $class->update_or_create({ col => $val, ... });
1430 First, searches for an existing row matching one of the unique constraints
1431 (including the primary key) on the source of this resultset. If a row is
1432 found, updates it with the other given column values. Otherwise, creates a new
1435 Takes an optional C<key> attribute to search on a specific unique constraint.
1438 # In your application
1439 my $cd = $schema->resultset('CD')->update_or_create(
1441 artist => 'Massive Attack',
1442 title => 'Mezzanine',
1445 { key => 'artist_title' }
1448 If no C<key> is specified, it searches on all unique constraints defined on the
1449 source, including the primary key.
1451 If the C<key> is specified as C<primary>, it searches only on the primary key.
1453 See also L</find> and L</find_or_create>. For information on how to declare
1454 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1458 sub update_or_create {
1460 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1461 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1463 my $row = $self->find($cond);
1465 $row->update($cond);
1469 return $self->create($cond);
1476 =item Arguments: none
1478 =item Return Value: \@cache_objects?
1482 Gets the contents of the cache for the resultset, if the cache is set.
1494 =item Arguments: \@cache_objects
1496 =item Return Value: \@cache_objects
1500 Sets the contents of the cache for the resultset. Expects an arrayref
1501 of objects of the same class as those produced by the resultset. Note that
1502 if the cache is set the resultset will return the cached objects rather
1503 than re-querying the database even if the cache attr is not set.
1508 my ( $self, $data ) = @_;
1509 $self->throw_exception("set_cache requires an arrayref")
1510 if defined($data) && (ref $data ne 'ARRAY');
1511 $self->{all_cache} = $data;
1518 =item Arguments: none
1520 =item Return Value: []
1524 Clears the cache for the resultset.
1529 shift->set_cache(undef);
1532 =head2 related_resultset
1536 =item Arguments: $relationship_name
1538 =item Return Value: $resultset
1542 Returns a related resultset for the supplied relationship name.
1544 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1548 sub related_resultset {
1549 my ( $self, $rel ) = @_;
1551 $self->{related_resultsets} ||= {};
1552 return $self->{related_resultsets}{$rel} ||= do {
1553 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1554 my $rel_obj = $self->result_source->relationship_info($rel);
1555 $self->throw_exception(
1556 "search_related: result source '" . $self->result_source->name .
1557 "' has no such relationship ${rel}")
1558 unless $rel_obj; #die Dumper $self->{attrs};
1560 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1562 { %{$self->{attrs}},
1566 _live_join => $rel }
1569 # keep reference of the original resultset
1570 $rs->{_parent_rs} = $self->result_source;
1575 =head2 throw_exception
1577 See L<DBIx::Class::Schema/throw_exception> for details.
1581 sub throw_exception {
1583 $self->result_source->schema->throw_exception(@_);
1586 # XXX: FIXME: Attributes docs need clearing up
1590 The resultset takes various attributes that modify its behavior. Here's an
1597 =item Value: ($order_by | \@order_by)
1601 Which column(s) to order the results by. This is currently passed
1602 through directly to SQL, so you can give e.g. C<year DESC> for a
1603 descending order on the column `year'.
1605 Please note that if you have quoting enabled (see
1606 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1607 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1608 so you will need to manually quote things as appropriate.)
1614 =item Value: \@columns
1618 Shortcut to request a particular set of columns to be retrieved. Adds
1619 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1620 from that, then auto-populates C<as> from C<select> as normal. (You may also
1621 use the C<cols> attribute, as in earlier versions of DBIC.)
1623 =head2 include_columns
1627 =item Value: \@columns
1631 Shortcut to include additional columns in the returned results - for example
1633 $schema->resultset('CD')->search(undef, {
1634 include_columns => ['artist.name'],
1638 would return all CDs and include a 'name' column to the information
1639 passed to object inflation
1645 =item Value: \@select_columns
1649 Indicates which columns should be selected from the storage. You can use
1650 column names, or in the case of RDBMS back ends, function or stored procedure
1653 $rs = $schema->resultset('Employee')->search(undef, {
1656 { count => 'employeeid' },
1661 When you use function/stored procedure names and do not supply an C<as>
1662 attribute, the column names returned are storage-dependent. E.g. MySQL would
1663 return a column named C<count(employeeid)> in the above example.
1669 Indicates additional columns to be selected from storage. Works the same as
1670 L<select> but adds columns to the selection.
1678 Indicates additional column names for those added via L<+select>.
1686 =item Value: \@inflation_names
1690 Indicates column names for object inflation. This is used in conjunction with
1691 C<select>, usually when C<select> contains one or more function or stored
1694 $rs = $schema->resultset('Employee')->search(undef, {
1697 { count => 'employeeid' }
1699 as => ['name', 'employee_count'],
1702 my $employee = $rs->first(); # get the first Employee
1704 If the object against which the search is performed already has an accessor
1705 matching a column name specified in C<as>, the value can be retrieved using
1706 the accessor as normal:
1708 my $name = $employee->name();
1710 If on the other hand an accessor does not exist in the object, you need to
1711 use C<get_column> instead:
1713 my $employee_count = $employee->get_column('employee_count');
1715 You can create your own accessors if required - see
1716 L<DBIx::Class::Manual::Cookbook> for details.
1718 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1719 produced, it is used for internal access only. Thus attempting to use the accessor
1720 in an C<order_by> clause or similar will fail misrably.
1726 =item Value: ($rel_name | \@rel_names | \%rel_names)
1730 Contains a list of relationships that should be joined for this query. For
1733 # Get CDs by Nine Inch Nails
1734 my $rs = $schema->resultset('CD')->search(
1735 { 'artist.name' => 'Nine Inch Nails' },
1736 { join => 'artist' }
1739 Can also contain a hash reference to refer to the other relation's relations.
1742 package MyApp::Schema::Track;
1743 use base qw/DBIx::Class/;
1744 __PACKAGE__->table('track');
1745 __PACKAGE__->add_columns(qw/trackid cd position title/);
1746 __PACKAGE__->set_primary_key('trackid');
1747 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1750 # In your application
1751 my $rs = $schema->resultset('Artist')->search(
1752 { 'track.title' => 'Teardrop' },
1754 join => { cd => 'track' },
1755 order_by => 'artist.name',
1759 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1760 similarly for a third time). For e.g.
1762 my $rs = $schema->resultset('Artist')->search({
1763 'cds.title' => 'Down to Earth',
1764 'cds_2.title' => 'Popular',
1766 join => [ qw/cds cds/ ],
1769 will return a set of all artists that have both a cd with title 'Down
1770 to Earth' and a cd with title 'Popular'.
1772 If you want to fetch related objects from other tables as well, see C<prefetch>
1779 =item Value: ($rel_name | \@rel_names | \%rel_names)
1783 Contains one or more relationships that should be fetched along with the main
1784 query (when they are accessed afterwards they will have already been
1785 "prefetched"). This is useful for when you know you will need the related
1786 objects, because it saves at least one query:
1788 my $rs = $schema->resultset('Tag')->search(
1797 The initial search results in SQL like the following:
1799 SELECT tag.*, cd.*, artist.* FROM tag
1800 JOIN cd ON tag.cd = cd.cdid
1801 JOIN artist ON cd.artist = artist.artistid
1803 L<DBIx::Class> has no need to go back to the database when we access the
1804 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1807 Simple prefetches will be joined automatically, so there is no need
1808 for a C<join> attribute in the above search. If you're prefetching to
1809 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1810 specify the join as well.
1812 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1813 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1814 with an accessor type of 'single' or 'filter').
1824 Makes the resultset paged and specifies the page to retrieve. Effectively
1825 identical to creating a non-pages resultset and then calling ->page($page)
1828 If L<rows> attribute is not specified it defualts to 10 rows per page.
1838 Specifes the maximum number of rows for direct retrieval or the number of
1839 rows per page if the page attribute or method is used.
1845 =item Value: $offset
1849 Specifies the (zero-based) row number for the first row to be returned, or the
1850 of the first row of the first page if paging is used.
1856 =item Value: \@columns
1860 A arrayref of columns to group by. Can include columns of joined tables.
1862 group_by => [qw/ column1 column2 ... /]
1868 =item Value: $condition
1872 HAVING is a select statement attribute that is applied between GROUP BY and
1873 ORDER BY. It is applied to the after the grouping calculations have been
1876 having => { 'count(employee)' => { '>=', 100 } }
1882 =item Value: (0 | 1)
1886 Set to 1 to group by all columns.
1890 Set to 1 to cache search results. This prevents extra SQL queries if you
1891 revisit rows in your ResultSet:
1893 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1895 while( my $artist = $resultset->next ) {
1899 $rs->first; # without cache, this would issue a query
1901 By default, searches are not cached.
1903 For more examples of using these attributes, see
1904 L<DBIx::Class::Manual::Cookbook>.
1910 =item Value: \@from_clause
1914 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1915 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1918 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1920 C<join> will usually do what you need and it is strongly recommended that you
1921 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1922 And we really do mean "cannot", not just tried and failed. Attempting to use
1923 this because you're having problems with C<join> is like trying to use x86
1924 ASM because you've got a syntax error in your C. Trust us on this.
1926 Now, if you're still really, really sure you need to use this (and if you're
1927 not 100% sure, ask the mailing list first), here's an explanation of how this
1930 The syntax is as follows -
1933 { <alias1> => <table1> },
1935 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1936 [], # nested JOIN (optional)
1937 { <table1.column1> => <table2.column2>, ... (more conditions) },
1939 # More of the above [ ] may follow for additional joins
1946 ON <table1.column1> = <table2.column2>
1947 <more joins may follow>
1949 An easy way to follow the examples below is to remember the following:
1951 Anything inside "[]" is a JOIN
1952 Anything inside "{}" is a condition for the enclosing JOIN
1954 The following examples utilize a "person" table in a family tree application.
1955 In order to express parent->child relationships, this table is self-joined:
1957 # Person->belongs_to('father' => 'Person');
1958 # Person->belongs_to('mother' => 'Person');
1960 C<from> can be used to nest joins. Here we return all children with a father,
1961 then search against all mothers of those children:
1963 $rs = $schema->resultset('Person')->search(
1966 alias => 'mother', # alias columns in accordance with "from"
1968 { mother => 'person' },
1971 { child => 'person' },
1973 { father => 'person' },
1974 { 'father.person_id' => 'child.father_id' }
1977 { 'mother.person_id' => 'child.mother_id' }
1984 # SELECT mother.* FROM person mother
1987 # JOIN person father
1988 # ON ( father.person_id = child.father_id )
1990 # ON ( mother.person_id = child.mother_id )
1992 The type of any join can be controlled manually. To search against only people
1993 with a father in the person table, we could explicitly use C<INNER JOIN>:
1995 $rs = $schema->resultset('Person')->search(
1998 alias => 'child', # alias columns in accordance with "from"
2000 { child => 'person' },
2002 { father => 'person', -join_type => 'inner' },
2003 { 'father.id' => 'child.father_id' }
2010 # SELECT child.* FROM person child
2011 # INNER JOIN person father ON child.father_id = father.id