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 $our_attrs->{having};
168 # XXX this is getting messy
169 if ($attrs->{_live_join_stack} || $our_attrs->{_live_join_stack}) {
170 my $live_join = $attrs->{_live_join_stack} || $our_attrs->{_live_join_stack};
171 foreach (reverse @{$live_join}) {
172 $attrs->{_live_join_h} = (defined $attrs->{_live_join_h}) ? { $_ => $attrs->{_live_join_h} } : $_;
176 # merge new attrs into old
177 foreach my $key (qw/join prefetch/) {
178 next unless (exists $attrs->{$key});
179 if ($attrs->{_live_join_stack} || $our_attrs->{_live_join_stack}) {
180 my $live_join = $attrs->{_live_join_stack} || $our_attrs->{_live_join_stack};
181 foreach (@{$live_join}) {
182 $attrs->{$key} = { $_ => $attrs->{$key} };
185 if ($attrs->{_live_join} || $our_attrs->{_live_join}) {
186 $attrs->{$key} = { ($attrs->{_live_join}) ? $attrs->{_live_join} : $our_attrs->{_live_join} => $attrs->{$key} };
188 if (exists $our_attrs->{$key}) {
189 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
191 $our_attrs->{$key} = $attrs->{$key};
193 delete $attrs->{$key};
196 $our_attrs->{join} = $self->_merge_attr($our_attrs->{join}, $attrs->{_live_join_h}, 1) if ($attrs->{_live_join_h});
198 if (exists $our_attrs->{prefetch}) {
199 $our_attrs->{join} = $self->_merge_attr($our_attrs->{join}, $our_attrs->{prefetch}, 1);
202 my $new_attrs = { %{$our_attrs}, %{$attrs} };
204 ? ((@_ == 1 || ref $_[0] eq "HASH")
207 ? $self->throw_exception(
208 "Odd number of arguments to search")
211 if (defined $where) {
212 $new_attrs->{where} = (defined $new_attrs->{where}
214 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
215 $where, $new_attrs->{where} ] }
219 if (defined $having) {
220 $new_attrs->{having} = (defined $new_attrs->{having}
222 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
223 $having, $new_attrs->{having} ] }
227 my $rs = (ref $self)->new($self->result_source, $new_attrs);
228 $rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
230 unless (@_) { # no search, effectively just a clone
231 my $rows = $self->get_cache;
233 $rs->set_cache($rows);
240 =head2 search_literal
244 =item Arguments: $sql_fragment, @bind_values
246 =item Return Value: $resultset (scalar context), @row_objs (list context)
250 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
251 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
253 Pass a literal chunk of SQL to be added to the conditional part of the
259 my ($self, $cond, @vals) = @_;
260 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
261 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
262 return $self->search(\$cond, $attrs);
269 =item Arguments: @values | \%cols, \%attrs?
271 =item Return Value: $row_object
275 Finds a row based on its primary key or unique constraint. For example, to find
276 a row by its primary key:
278 my $cd = $schema->resultset('CD')->find(5);
280 You can also find a row by a specific unique constraint using the C<key>
281 attribute. For example:
283 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'cd_artist_title' });
285 Additionally, you can specify the columns explicitly by name:
287 my $cd = $schema->resultset('CD')->find(
289 artist => 'Massive Attack',
290 title => 'Mezzanine',
292 { key => 'cd_artist_title' }
295 If the C<key> is specified as C<primary>, it searches only on the primary key.
297 If no C<key> is specified, it searches on all unique constraints defined on the
298 source, including the primary key.
300 See also L</find_or_create> and L</update_or_create>. For information on how to
301 declare unique constraints, see
302 L<DBIx::Class::ResultSource/add_unique_constraint>.
308 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
310 # Default to the primary key, but allow a specific key
311 my @cols = exists $attrs->{key}
312 ? $self->result_source->unique_constraint_columns($attrs->{key})
313 : $self->result_source->primary_columns;
314 $self->throw_exception(
315 "Can't find unless a primary key or unique constraint is defined"
318 # Parse out a hashref from input
320 if (ref $_[0] eq 'HASH') {
321 $input_query = { %{$_[0]} };
323 elsif (@_ == @cols) {
325 @{$input_query}{@cols} = @_;
328 # Compatibility: Allow e.g. find(id => $value)
329 carp "Find by key => value deprecated; please use a hashref instead";
333 my @unique_queries = $self->_unique_queries($input_query, $attrs);
335 # Handle cases where the ResultSet defines the query, or where the user is
337 my $query = @unique_queries ? \@unique_queries : $input_query;
341 my $rs = $self->search($query, $attrs);
343 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
347 return (keys %{$self->{_attrs}->{collapse}})
348 ? $self->search($query)->next
349 : $self->single($query);
355 # Build a list of queries which satisfy unique constraints.
357 sub _unique_queries {
358 my ($self, $query, $attrs) = @_;
360 my @constraint_names = exists $attrs->{key}
362 : $self->result_source->unique_constraint_names;
365 foreach my $name (@constraint_names) {
366 my @unique_cols = $self->result_source->unique_constraint_columns($name);
367 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
369 next unless scalar keys %$unique_query;
371 # Add the ResultSet's alias
372 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
373 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
374 $unique_query->{"$alias.$key"} = delete $unique_query->{$key};
377 push @unique_queries, $unique_query;
380 return @unique_queries;
383 # _build_unique_query
385 # Constrain the specified query hash based on the specified column names.
387 sub _build_unique_query {
388 my ($self, $query, $unique_cols) = @_;
391 map { $_ => $query->{$_} }
392 grep { exists $query->{$_} }
395 return \%unique_query;
398 =head2 search_related
402 =item Arguments: $cond, \%attrs?
404 =item Return Value: $new_resultset
408 $new_rs = $cd_rs->search_related('artist', {
412 Searches the specified relationship, optionally specifying a condition and
413 attributes for matching records. See L</ATTRIBUTES> for more information.
418 return shift->related_resultset(shift)->search(@_);
425 =item Arguments: none
427 =item Return Value: $cursor
431 Returns a storage-driven cursor to the given resultset. See
432 L<DBIx::Class::Cursor> for more information.
440 my $attrs = { %{$self->{_attrs}} };
441 return $self->{cursor}
442 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
443 $attrs->{where},$attrs);
450 =item Arguments: $cond?
452 =item Return Value: $row_object?
456 my $cd = $schema->resultset('CD')->single({ year => 2001 });
458 Inflates the first result without creating a cursor if the resultset has
459 any records in it; if not returns nothing. Used by L</find> as an optimisation.
461 Can optionally take an additional condition *only* - this is a fast-code-path
462 method; if you need to add extra joins or similar call ->search and then
463 ->single without a condition on the $rs returned from that.
468 my ($self, $where) = @_;
470 my $attrs = { %{$self->{_attrs}} };
472 if (defined $attrs->{where}) {
475 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
476 $where, delete $attrs->{where} ]
479 $attrs->{where} = $where;
483 unless ($self->_is_unique_query($attrs->{where})) {
484 carp "Query not guarnteed to return a single row"
485 . "; please declare your unique constraints or use search instead";
488 my @data = $self->result_source->storage->select_single(
489 $attrs->{from}, $attrs->{select},
490 $attrs->{where},$attrs);
491 return (@data ? $self->_construct_object(@data) : ());
496 # Try to determine if the specified query is guaranteed to be unique, based on
497 # the declared unique constraints.
499 sub _is_unique_query {
500 my ($self, $query) = @_;
502 my $collapsed = $self->_collapse_query($query);
504 my $alias = ($self->{attrs}->{_live_join}) ? $self->{attrs}->{_live_join} : $self->{attrs}->{alias};
505 foreach my $name ($self->result_source->unique_constraint_names) {
506 my @unique_cols = map { "$alias.$_" }
507 $self->result_source->unique_constraint_columns($name);
509 # Count the values for each unique column
510 my %seen = map { $_ => 0 } @unique_cols;
512 foreach my $key (keys %$collapsed) {
514 $aliased = "$alias.$key" unless $key =~ /\./;
516 next unless exists $seen{$aliased}; # Additional constraints are okay
517 $seen{$aliased} = scalar @{ $collapsed->{$key} };
520 # If we get 0 or more than 1 value for a column, it's not necessarily unique
521 return 1 unless grep { $_ != 1 } values %seen;
529 # Recursively collapse the query, accumulating values for each column.
531 sub _collapse_query {
532 my ($self, $query, $collapsed) = @_;
536 if (ref $query eq 'ARRAY') {
537 foreach my $subquery (@$query) {
538 next unless ref $subquery; # -or
539 # warn "ARRAY: " . Dumper $subquery;
540 $collapsed = $self->_collapse_query($subquery, $collapsed);
543 elsif (ref $query eq 'HASH') {
544 if (keys %$query and (keys %$query)[0] eq '-and') {
545 foreach my $subquery (@{$query->{-and}}) {
546 # warn "HASH: " . Dumper $subquery;
547 $collapsed = $self->_collapse_query($subquery, $collapsed);
551 # warn "LEAF: " . Dumper $query;
552 foreach my $key (keys %$query) {
553 push @{$collapsed->{$key}}, $query->{$key};
565 =item Arguments: $cond?
567 =item Return Value: $resultsetcolumn
571 my $max_length = $rs->get_column('length')->max;
573 Returns a ResultSetColumn instance for $column based on $self
578 my ($self, $column) = @_;
580 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
588 =item Arguments: $cond, \%attrs?
590 =item Return Value: $resultset (scalar context), @row_objs (list context)
594 # WHERE title LIKE '%blue%'
595 $cd_rs = $rs->search_like({ title => '%blue%'});
597 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
598 that this is simply a convenience method. You most likely want to use
599 L</search> with specific operators.
601 For more information, see L<DBIx::Class::Manual::Cookbook>.
607 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
608 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
609 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
610 return $class->search($query, { %$attrs });
617 =item Arguments: $first, $last
619 =item Return Value: $resultset (scalar context), @row_objs (list context)
623 Returns a resultset or object list representing a subset of elements from the
624 resultset slice is called on. Indexes are from 0, i.e., to get the first
627 my ($one, $two, $three) = $rs->slice(0, 2);
632 my ($self, $min, $max) = @_;
633 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
634 $attrs->{offset} = $self->{attrs}{offset} || 0;
635 $attrs->{offset} += $min;
636 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
637 return $self->search(undef(), $attrs);
638 #my $slice = (ref $self)->new($self->result_source, $attrs);
639 #return (wantarray ? $slice->all : $slice);
646 =item Arguments: none
648 =item Return Value: $result?
652 Returns the next element in the resultset (C<undef> is there is none).
654 Can be used to efficiently iterate over records in the resultset:
656 my $rs = $schema->resultset('CD')->search;
657 while (my $cd = $rs->next) {
661 Note that you need to store the resultset object, and call C<next> on it.
662 Calling C<< resultset('Table')->next >> repeatedly will always return the
663 first record from the resultset.
669 if (my $cache = $self->get_cache) {
670 $self->{all_cache_position} ||= 0;
671 return $cache->[$self->{all_cache_position}++];
673 if ($self->{attrs}{cache}) {
674 $self->{all_cache_position} = 1;
675 return ($self->all)[0];
677 my @row = (exists $self->{stashed_row} ?
678 @{delete $self->{stashed_row}} :
681 return unless (@row);
682 return $self->_construct_object(@row);
688 return if(exists $self->{_attrs}); #return if _resolve has already been called
690 my $attrs = $self->{attrs};
691 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
693 # XXX - lose storable dclone
694 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
695 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
696 $attrs->{record_filter} = $record_filter if ($record_filter);
697 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
699 my $alias = $attrs->{alias};
701 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
702 delete $attrs->{as} if $attrs->{columns};
703 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
704 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
706 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
707 ] if $attrs->{columns};
709 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
711 if (my $include = delete $attrs->{include_columns}) {
712 push(@{$attrs->{select}}, @$include);
713 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
716 $attrs->{from} ||= [ { $alias => $source->from } ];
717 $attrs->{seen_join} ||= {};
719 if (my $join = delete $attrs->{join}) {
720 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
721 if (ref $j eq 'HASH') {
722 $seen{$_} = 1 foreach keys %$j;
728 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
730 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
731 $attrs->{order_by} = [ $attrs->{order_by} ] if
732 $attrs->{order_by} and !ref($attrs->{order_by});
733 $attrs->{order_by} ||= [];
735 if(my $seladds = delete($attrs->{'+select'})) {
736 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
738 @{ $attrs->{select} },
739 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
742 if(my $asadds = delete($attrs->{'+as'})) {
743 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
744 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
747 my $collapse = $attrs->{collapse} || {};
748 if (my $prefetch = delete $attrs->{prefetch}) {
750 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
751 if ( ref $p eq 'HASH' ) {
752 foreach my $key (keys %$p) {
753 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
757 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
760 my @prefetch = $source->resolve_prefetch(
761 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
762 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
763 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
765 push(@{$attrs->{order_by}}, @pre_order);
767 $attrs->{collapse} = $collapse;
768 $self->{_attrs} = $attrs;
772 my ($self, $a, $b, $is_prefetch) = @_;
775 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
776 foreach my $key (keys %{$b}) {
777 if (exists $a->{$key}) {
778 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
780 $a->{$key} = delete $b->{$key};
785 $a = [$a] unless (ref $a eq 'ARRAY');
786 $b = [$b] unless (ref $b eq 'ARRAY');
791 foreach my $element (@{$_}) {
792 if (ref $element eq 'HASH') {
793 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
794 } elsif (ref $element eq 'ARRAY') {
795 $array = [@{$array}, @{$element}];
797 if (($b == $_) && $is_prefetch) {
798 $self->_merge_array($array, $element, $is_prefetch);
800 push(@{$array}, $element);
806 my $final_array = [];
807 foreach my $element (@{$array}) {
808 push(@{$final_array}, $element) unless (exists $hash->{$element});
810 $array = $final_array;
812 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
813 return [$hash, @{$array}];
815 return (keys %{$hash}) ? $hash : $array;
821 my ($self, $a, $b) = @_;
823 $b = [$b] unless (ref $b eq 'ARRAY');
824 # add elements from @{$b} to @{$a} which aren't already in @{$a}
825 foreach my $b_element (@{$b}) {
826 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
830 sub _construct_object {
831 my ($self, @row) = @_;
832 my @as = @{ $self->{_attrs}{as} };
834 my $info = $self->_collapse_result(\@as, \@row);
835 my $new = $self->result_class->inflate_result($self->result_source, @$info);
836 $new = $self->{_attrs}{record_filter}->($new)
837 if exists $self->{_attrs}{record_filter};
841 sub _collapse_result {
842 my ($self, $as, $row, $prefix) = @_;
844 my $live_join = $self->{attrs}->{_live_join} ||="";
848 foreach my $this_as (@$as) {
849 my $val = shift @copy;
850 if (defined $prefix) {
851 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
853 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
854 $const{$1||''}{$2} = $val;
857 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
858 $const{$1||''}{$2} = $val;
862 my $info = [ {}, {} ];
863 foreach my $key (keys %const) {
864 if (length $key && $key ne $live_join) {
866 my @parts = split(/\./, $key);
867 foreach my $p (@parts) {
868 $target = $target->[1]->{$p} ||= [];
870 $target->[0] = $const{$key};
872 $info->[0] = $const{$key};
877 if (defined $prefix) {
879 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
880 } keys %{$self->{_attrs}->{collapse}}
882 @collapse = keys %{$self->{_attrs}->{collapse}};
886 my ($c) = sort { length $a <=> length $b } @collapse;
888 foreach my $p (split(/\./, $c)) {
889 $target = $target->[1]->{$p} ||= [];
891 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
892 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
893 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
894 my $tree = $self->_collapse_result($as, $row, $c_prefix);
897 !defined($tree->[0]->{$_}) ||
898 $co_check{$_} ne $tree->[0]->{$_}
901 last unless (@raw = $self->cursor->next);
902 $row = $self->{stashed_row} = \@raw;
903 $tree = $self->_collapse_result($as, $row, $c_prefix);
905 @$target = (@final ? @final : [ {}, {} ]);
906 # single empty result to indicate an empty prefetched has_many
915 =item Arguments: $result_source?
917 =item Return Value: $result_source
921 An accessor for the primary ResultSource object from which this ResultSet
931 =item Arguments: $cond, \%attrs??
933 =item Return Value: $count
937 Performs an SQL C<COUNT> with the same query as the resultset was built
938 with to find the number of elements. If passed arguments, does a search
939 on the resultset and counts the results of that.
941 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
942 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
943 not support C<DISTINCT> with multiple columns. If you are using such a
944 database, you should only use columns from the main table in your C<group_by>
951 return $self->search(@_)->count if @_ and defined $_[0];
952 return scalar @{ $self->get_cache } if $self->get_cache;
953 my $count = $self->_count;
954 return 0 unless $count;
956 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
957 $count = $self->{attrs}{rows} if
958 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
962 sub _count { # Separated out so pager can get the full count
964 my $select = { count => '*' };
967 my $attrs = { %{ $self->{_attrs} } };
968 if (my $group_by = delete $attrs->{group_by}) {
969 delete $attrs->{having};
970 my @distinct = (ref $group_by ? @$group_by : ($group_by));
971 # todo: try CONCAT for multi-column pk
972 my @pk = $self->result_source->primary_columns;
974 foreach my $column (@distinct) {
975 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
976 @distinct = ($column);
982 $select = { count => { distinct => \@distinct } };
985 $attrs->{select} = $select;
986 $attrs->{as} = [qw/count/];
988 # offset, order by and page are not needed to count. record_filter is cdbi
989 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
990 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
991 $tmp_rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
993 my ($count) = $tmp_rs->cursor->next;
1001 =item Arguments: $sql_fragment, @bind_values
1003 =item Return Value: $count
1007 Counts the results in a literal query. Equivalent to calling L</search_literal>
1008 with the passed arguments, then L</count>.
1012 sub count_literal { shift->search_literal(@_)->count; }
1018 =item Arguments: none
1020 =item Return Value: @objects
1024 Returns all elements in the resultset. Called implicitly if the resultset
1025 is returned in list context.
1031 return @{ $self->get_cache } if $self->get_cache;
1035 # TODO: don't call resolve here
1037 if (keys %{$self->{_attrs}->{collapse}}) {
1038 # if ($self->{attrs}->{prefetch}) {
1039 # Using $self->cursor->all is really just an optimisation.
1040 # If we're collapsing has_many prefetches it probably makes
1041 # very little difference, and this is cleaner than hacking
1042 # _construct_object to survive the approach
1043 my @row = $self->cursor->next;
1045 push(@obj, $self->_construct_object(@row));
1046 @row = (exists $self->{stashed_row}
1047 ? @{delete $self->{stashed_row}}
1048 : $self->cursor->next);
1051 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1054 $self->set_cache(\@obj) if $self->{attrs}{cache};
1062 =item Arguments: none
1064 =item Return Value: $self
1068 Resets the resultset's cursor, so you can iterate through the elements again.
1074 delete $self->{_attrs} if (exists $self->{_attrs});
1076 $self->{all_cache_position} = 0;
1077 $self->cursor->reset;
1085 =item Arguments: none
1087 =item Return Value: $object?
1091 Resets the resultset and returns an object for the first result (if the
1092 resultset returns anything).
1097 return $_[0]->reset->next;
1100 # _cond_for_update_delete
1102 # update/delete require the condition to be modified to handle
1103 # the differing SQL syntax available. This transforms the $self->{cond}
1104 # appropriately, returning the new condition.
1106 sub _cond_for_update_delete {
1110 if (!ref($self->{cond})) {
1111 # No-op. No condition, we're updating/deleting everything
1113 elsif (ref $self->{cond} eq 'ARRAY') {
1117 foreach my $key (keys %{$_}) {
1119 $hash{$1} = $_->{$key};
1125 elsif (ref $self->{cond} eq 'HASH') {
1126 if ((keys %{$self->{cond}})[0] eq '-and') {
1129 my @cond = @{$self->{cond}{-and}};
1130 for (my $i = 0; $i <= @cond - 1; $i++) {
1131 my $entry = $cond[$i];
1134 if (ref $entry eq 'HASH') {
1135 foreach my $key (keys %{$entry}) {
1137 $hash{$1} = $entry->{$key};
1141 $entry =~ /([^.]+)$/;
1142 $hash{$1} = $cond[++$i];
1145 push @{$cond->{-and}}, \%hash;
1149 foreach my $key (keys %{$self->{cond}}) {
1151 $cond->{$1} = $self->{cond}{$key};
1156 $self->throw_exception(
1157 "Can't update/delete on resultset with condition unless hash or array"
1169 =item Arguments: \%values
1171 =item Return Value: $storage_rv
1175 Sets the specified columns in the resultset to the supplied values in a
1176 single query. Return value will be true if the update succeeded or false
1177 if no records were updated; exact type of success value is storage-dependent.
1182 my ($self, $values) = @_;
1183 $self->throw_exception("Values for update must be a hash")
1184 unless ref $values eq 'HASH';
1186 my $cond = $self->_cond_for_update_delete;
1188 return $self->result_source->storage->update(
1189 $self->result_source->from, $values, $cond
1197 =item Arguments: \%values
1199 =item Return Value: 1
1203 Fetches all objects and updates them one at a time. Note that C<update_all>
1204 will run DBIC cascade triggers, while L</update> will not.
1209 my ($self, $values) = @_;
1210 $self->throw_exception("Values for update must be a hash")
1211 unless ref $values eq 'HASH';
1212 foreach my $obj ($self->all) {
1213 $obj->set_columns($values)->update;
1222 =item Arguments: none
1224 =item Return Value: 1
1228 Deletes the contents of the resultset from its result source. Note that this
1229 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1238 my $cond = $self->_cond_for_update_delete;
1240 $self->result_source->storage->delete($self->result_source->from, $cond);
1248 =item Arguments: none
1250 =item Return Value: 1
1254 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1255 will run DBIC cascade triggers, while L</delete> will not.
1261 $_->delete for $self->all;
1269 =item Arguments: none
1271 =item Return Value: $pager
1275 Return Value a L<Data::Page> object for the current resultset. Only makes
1276 sense for queries with a C<page> attribute.
1282 my $attrs = $self->{attrs};
1283 $self->throw_exception("Can't create pager for non-paged rs")
1284 unless $self->{page};
1285 $attrs->{rows} ||= 10;
1286 return $self->{pager} ||= Data::Page->new(
1287 $self->_count, $attrs->{rows}, $self->{page});
1294 =item Arguments: $page_number
1296 =item Return Value: $rs
1300 Returns a resultset for the $page_number page of the resultset on which page
1301 is called, where each page contains a number of rows equal to the 'rows'
1302 attribute set on the resultset (10 by default).
1307 my ($self, $page) = @_;
1308 my $attrs = { %{$self->{attrs}} };
1309 $attrs->{page} = $page;
1310 return (ref $self)->new($self->result_source, $attrs);
1317 =item Arguments: \%vals
1319 =item Return Value: $object
1323 Creates an object in the resultset's result class and returns it.
1328 my ($self, $values) = @_;
1329 $self->throw_exception( "new_result needs a hash" )
1330 unless (ref $values eq 'HASH');
1331 $self->throw_exception(
1332 "Can't abstract implicit construct, condition not a hash"
1333 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1335 my $alias = $self->{attrs}{alias};
1336 foreach my $key (keys %{$self->{cond}||{}}) {
1337 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1339 my $obj = $self->result_class->new(\%new);
1340 $obj->result_source($self->result_source) if $obj->can('result_source');
1348 =item Arguments: \%vals, \%attrs?
1350 =item Return Value: $object
1354 Find an existing record from this resultset. If none exists, instantiate a new
1355 result object and return it. The object will not be saved into your storage
1356 until you call L<DBIx::Class::Row/insert> on it.
1358 If you want objects to be saved immediately, use L</find_or_create> instead.
1364 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1365 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1366 my $exists = $self->find($hash, $attrs);
1367 return defined $exists ? $exists : $self->new_result($hash);
1374 =item Arguments: \%vals
1376 =item Return Value: $object
1380 Inserts a record into the resultset and returns the object representing it.
1382 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1387 my ($self, $attrs) = @_;
1388 $self->throw_exception( "create needs a hashref" )
1389 unless ref $attrs eq 'HASH';
1390 return $self->new_result($attrs)->insert;
1393 =head2 find_or_create
1397 =item Arguments: \%vals, \%attrs?
1399 =item Return Value: $object
1403 $class->find_or_create({ key => $val, ... });
1405 Tries to find a record based on its primary key or unique constraint; if none
1406 is found, creates one and returns that instead.
1408 my $cd = $schema->resultset('CD')->find_or_create({
1410 artist => 'Massive Attack',
1411 title => 'Mezzanine',
1415 Also takes an optional C<key> attribute, to search by a specific key or unique
1416 constraint. For example:
1418 my $cd = $schema->resultset('CD')->find_or_create(
1420 artist => 'Massive Attack',
1421 title => 'Mezzanine',
1423 { key => 'cd_artist_title' }
1426 See also L</find> and L</update_or_create>. For information on how to declare
1427 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1431 sub find_or_create {
1433 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1434 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1435 my $exists = $self->find($hash, $attrs);
1436 return defined $exists ? $exists : $self->create($hash);
1439 =head2 update_or_create
1443 =item Arguments: \%col_values, { key => $unique_constraint }?
1445 =item Return Value: $object
1449 $class->update_or_create({ col => $val, ... });
1451 First, searches for an existing row matching one of the unique constraints
1452 (including the primary key) on the source of this resultset. If a row is
1453 found, updates it with the other given column values. Otherwise, creates a new
1456 Takes an optional C<key> attribute to search on a specific unique constraint.
1459 # In your application
1460 my $cd = $schema->resultset('CD')->update_or_create(
1462 artist => 'Massive Attack',
1463 title => 'Mezzanine',
1466 { key => 'cd_artist_title' }
1469 If no C<key> is specified, it searches on all unique constraints defined on the
1470 source, including the primary key.
1472 If the C<key> is specified as C<primary>, it searches only on the primary key.
1474 See also L</find> and L</find_or_create>. For information on how to declare
1475 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1479 sub update_or_create {
1481 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1482 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1484 my $row = $self->find($cond);
1486 $row->update($cond);
1490 return $self->create($cond);
1497 =item Arguments: none
1499 =item Return Value: \@cache_objects?
1503 Gets the contents of the cache for the resultset, if the cache is set.
1515 =item Arguments: \@cache_objects
1517 =item Return Value: \@cache_objects
1521 Sets the contents of the cache for the resultset. Expects an arrayref
1522 of objects of the same class as those produced by the resultset. Note that
1523 if the cache is set the resultset will return the cached objects rather
1524 than re-querying the database even if the cache attr is not set.
1529 my ( $self, $data ) = @_;
1530 $self->throw_exception("set_cache requires an arrayref")
1531 if defined($data) && (ref $data ne 'ARRAY');
1532 $self->{all_cache} = $data;
1539 =item Arguments: none
1541 =item Return Value: []
1545 Clears the cache for the resultset.
1550 shift->set_cache(undef);
1553 =head2 related_resultset
1557 =item Arguments: $relationship_name
1559 =item Return Value: $resultset
1563 Returns a related resultset for the supplied relationship name.
1565 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1569 sub related_resultset {
1570 my ( $self, $rel ) = @_;
1572 $self->{related_resultsets} ||= {};
1573 return $self->{related_resultsets}{$rel} ||= do {
1574 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1575 my $rel_obj = $self->result_source->relationship_info($rel);
1576 $self->throw_exception(
1577 "search_related: result source '" . $self->result_source->name .
1578 "' has no such relationship ${rel}")
1579 unless $rel_obj; #die Dumper $self->{attrs};
1581 my $live_join_stack = $self->{attrs}->{_live_join_stack} || [];
1582 push(@{$live_join_stack}, $rel);
1584 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1590 _live_join_stack => $live_join_stack,
1591 _parent_attrs => $self->{attrs}}
1594 # keep reference of the original resultset
1595 $rs->{_parent_rs} = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->result_source;
1600 =head2 throw_exception
1602 See L<DBIx::Class::Schema/throw_exception> for details.
1606 sub throw_exception {
1608 $self->result_source->schema->throw_exception(@_);
1611 # XXX: FIXME: Attributes docs need clearing up
1615 The resultset takes various attributes that modify its behavior. Here's an
1622 =item Value: ($order_by | \@order_by)
1626 Which column(s) to order the results by. This is currently passed
1627 through directly to SQL, so you can give e.g. C<year DESC> for a
1628 descending order on the column `year'.
1630 Please note that if you have quoting enabled (see
1631 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1632 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1633 so you will need to manually quote things as appropriate.)
1639 =item Value: \@columns
1643 Shortcut to request a particular set of columns to be retrieved. Adds
1644 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1645 from that, then auto-populates C<as> from C<select> as normal. (You may also
1646 use the C<cols> attribute, as in earlier versions of DBIC.)
1648 =head2 include_columns
1652 =item Value: \@columns
1656 Shortcut to include additional columns in the returned results - for example
1658 $schema->resultset('CD')->search(undef, {
1659 include_columns => ['artist.name'],
1663 would return all CDs and include a 'name' column to the information
1664 passed to object inflation
1670 =item Value: \@select_columns
1674 Indicates which columns should be selected from the storage. You can use
1675 column names, or in the case of RDBMS back ends, function or stored procedure
1678 $rs = $schema->resultset('Employee')->search(undef, {
1681 { count => 'employeeid' },
1686 When you use function/stored procedure names and do not supply an C<as>
1687 attribute, the column names returned are storage-dependent. E.g. MySQL would
1688 return a column named C<count(employeeid)> in the above example.
1694 Indicates additional columns to be selected from storage. Works the same as
1695 L<select> but adds columns to the selection.
1703 Indicates additional column names for those added via L<+select>.
1711 =item Value: \@inflation_names
1715 Indicates column names for object inflation. This is used in conjunction with
1716 C<select>, usually when C<select> contains one or more function or stored
1719 $rs = $schema->resultset('Employee')->search(undef, {
1722 { count => 'employeeid' }
1724 as => ['name', 'employee_count'],
1727 my $employee = $rs->first(); # get the first Employee
1729 If the object against which the search is performed already has an accessor
1730 matching a column name specified in C<as>, the value can be retrieved using
1731 the accessor as normal:
1733 my $name = $employee->name();
1735 If on the other hand an accessor does not exist in the object, you need to
1736 use C<get_column> instead:
1738 my $employee_count = $employee->get_column('employee_count');
1740 You can create your own accessors if required - see
1741 L<DBIx::Class::Manual::Cookbook> for details.
1743 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1744 produced, it is used for internal access only. Thus attempting to use the accessor
1745 in an C<order_by> clause or similar will fail misrably.
1751 =item Value: ($rel_name | \@rel_names | \%rel_names)
1755 Contains a list of relationships that should be joined for this query. For
1758 # Get CDs by Nine Inch Nails
1759 my $rs = $schema->resultset('CD')->search(
1760 { 'artist.name' => 'Nine Inch Nails' },
1761 { join => 'artist' }
1764 Can also contain a hash reference to refer to the other relation's relations.
1767 package MyApp::Schema::Track;
1768 use base qw/DBIx::Class/;
1769 __PACKAGE__->table('track');
1770 __PACKAGE__->add_columns(qw/trackid cd position title/);
1771 __PACKAGE__->set_primary_key('trackid');
1772 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1775 # In your application
1776 my $rs = $schema->resultset('Artist')->search(
1777 { 'track.title' => 'Teardrop' },
1779 join => { cd => 'track' },
1780 order_by => 'artist.name',
1784 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1785 similarly for a third time). For e.g.
1787 my $rs = $schema->resultset('Artist')->search({
1788 'cds.title' => 'Down to Earth',
1789 'cds_2.title' => 'Popular',
1791 join => [ qw/cds cds/ ],
1794 will return a set of all artists that have both a cd with title 'Down
1795 to Earth' and a cd with title 'Popular'.
1797 If you want to fetch related objects from other tables as well, see C<prefetch>
1804 =item Value: ($rel_name | \@rel_names | \%rel_names)
1808 Contains one or more relationships that should be fetched along with the main
1809 query (when they are accessed afterwards they will have already been
1810 "prefetched"). This is useful for when you know you will need the related
1811 objects, because it saves at least one query:
1813 my $rs = $schema->resultset('Tag')->search(
1822 The initial search results in SQL like the following:
1824 SELECT tag.*, cd.*, artist.* FROM tag
1825 JOIN cd ON tag.cd = cd.cdid
1826 JOIN artist ON cd.artist = artist.artistid
1828 L<DBIx::Class> has no need to go back to the database when we access the
1829 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1832 Simple prefetches will be joined automatically, so there is no need
1833 for a C<join> attribute in the above search. If you're prefetching to
1834 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1835 specify the join as well.
1837 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1838 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1839 with an accessor type of 'single' or 'filter').
1849 Makes the resultset paged and specifies the page to retrieve. Effectively
1850 identical to creating a non-pages resultset and then calling ->page($page)
1853 If L<rows> attribute is not specified it defualts to 10 rows per page.
1863 Specifes the maximum number of rows for direct retrieval or the number of
1864 rows per page if the page attribute or method is used.
1870 =item Value: $offset
1874 Specifies the (zero-based) row number for the first row to be returned, or the
1875 of the first row of the first page if paging is used.
1881 =item Value: \@columns
1885 A arrayref of columns to group by. Can include columns of joined tables.
1887 group_by => [qw/ column1 column2 ... /]
1893 =item Value: $condition
1897 HAVING is a select statement attribute that is applied between GROUP BY and
1898 ORDER BY. It is applied to the after the grouping calculations have been
1901 having => { 'count(employee)' => { '>=', 100 } }
1907 =item Value: (0 | 1)
1911 Set to 1 to group by all columns.
1915 Set to 1 to cache search results. This prevents extra SQL queries if you
1916 revisit rows in your ResultSet:
1918 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1920 while( my $artist = $resultset->next ) {
1924 $rs->first; # without cache, this would issue a query
1926 By default, searches are not cached.
1928 For more examples of using these attributes, see
1929 L<DBIx::Class::Manual::Cookbook>.
1935 =item Value: \@from_clause
1939 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1940 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1943 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1945 C<join> will usually do what you need and it is strongly recommended that you
1946 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1947 And we really do mean "cannot", not just tried and failed. Attempting to use
1948 this because you're having problems with C<join> is like trying to use x86
1949 ASM because you've got a syntax error in your C. Trust us on this.
1951 Now, if you're still really, really sure you need to use this (and if you're
1952 not 100% sure, ask the mailing list first), here's an explanation of how this
1955 The syntax is as follows -
1958 { <alias1> => <table1> },
1960 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1961 [], # nested JOIN (optional)
1962 { <table1.column1> => <table2.column2>, ... (more conditions) },
1964 # More of the above [ ] may follow for additional joins
1971 ON <table1.column1> = <table2.column2>
1972 <more joins may follow>
1974 An easy way to follow the examples below is to remember the following:
1976 Anything inside "[]" is a JOIN
1977 Anything inside "{}" is a condition for the enclosing JOIN
1979 The following examples utilize a "person" table in a family tree application.
1980 In order to express parent->child relationships, this table is self-joined:
1982 # Person->belongs_to('father' => 'Person');
1983 # Person->belongs_to('mother' => 'Person');
1985 C<from> can be used to nest joins. Here we return all children with a father,
1986 then search against all mothers of those children:
1988 $rs = $schema->resultset('Person')->search(
1991 alias => 'mother', # alias columns in accordance with "from"
1993 { mother => 'person' },
1996 { child => 'person' },
1998 { father => 'person' },
1999 { 'father.person_id' => 'child.father_id' }
2002 { 'mother.person_id' => 'child.mother_id' }
2009 # SELECT mother.* FROM person mother
2012 # JOIN person father
2013 # ON ( father.person_id = child.father_id )
2015 # ON ( mother.person_id = child.mother_id )
2017 The type of any join can be controlled manually. To search against only people
2018 with a father in the person table, we could explicitly use C<INNER JOIN>:
2020 $rs = $schema->resultset('Person')->search(
2023 alias => 'child', # alias columns in accordance with "from"
2025 { child => 'person' },
2027 { father => 'person', -join_type => 'inner' },
2028 { 'father.id' => 'child.father_id' }
2035 # SELECT child.* FROM person child
2036 # INNER JOIN person father ON child.father_id = father.id