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 no C<key> is specified and you explicitly name columns, it searches on all
279 unique constraints defined on the source, including the primary key.
281 If the C<key> is specified as C<primary>, it searches only on 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 # Parse out a hash from input
294 my @cols = exists $attrs->{key}
295 ? $self->result_source->unique_constraint_columns($attrs->{key})
296 : $self->result_source->primary_columns;
299 if (ref $_[0] eq 'HASH') {
300 $hash = { %{$_[0]} };
302 elsif (@_ == @cols) {
304 @{$hash}{@cols} = @_;
307 # Compatibility: Allow e.g. find(id => $value)
308 carp "find by key => value deprecated; please use a hashref instead";
312 $self->throw_exception(
313 "Arguments to find must be a hashref or match the number of columns in the "
314 . (exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key")
318 # Check the hash we just parsed against our source's unique constraints
319 my @constraint_names = exists $attrs->{key}
321 : $self->result_source->unique_constraint_names;
322 carp "find now requires a primary key or unique constraint; none is defined on "
323 . $self->result_source->name unless @constraint_names;
326 foreach my $name (@constraint_names) {
327 my @unique_cols = $self->result_source->unique_constraint_columns($name);
328 my $unique_query = $self->_build_unique_query($hash, \@unique_cols);
330 # Add the ResultSet's alias
331 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
332 my $alias = $self->{attrs}->{alias};
333 $unique_query->{"$alias.$key"} = delete $unique_query->{$key};
336 push @unique_queries, $unique_query if %$unique_query;
339 # Compatibility: if we didn't get a unique query, take what the user provided
340 if (%$hash and not @unique_queries) {
341 carp "find now requires values for the primary key or a unique constraint"
342 . "; please use the search method instead";
343 push @unique_queries, $hash;
346 # Handle cases where the ResultSet already defines the query
347 my $query = @unique_queries ? \@unique_queries : undef;
351 my $rs = $self->search($query, $attrs);
353 return keys %{$rs->{_attrs}->{collapse}} ? $rs->next : $rs->single;
357 return (keys %{$self->{_attrs}->{collapse}})
358 ? $self->search($query)->next
359 : $self->single($query);
363 # _build_unique_query
365 # Constrain the specified query hash based on the specified column names.
367 sub _build_unique_query {
368 my ($self, $query, $unique_cols) = @_;
371 map { $_ => $query->{$_} }
372 grep { exists $query->{$_} }
375 return \%unique_query;
378 =head2 search_related
382 =item Arguments: $cond, \%attrs?
384 =item Return Value: $new_resultset
388 $new_rs = $cd_rs->search_related('artist', {
392 Searches the specified relationship, optionally specifying a condition and
393 attributes for matching records. See L</ATTRIBUTES> for more information.
398 return shift->related_resultset(shift)->search(@_);
405 =item Arguments: none
407 =item Return Value: $cursor
411 Returns a storage-driven cursor to the given resultset. See
412 L<DBIx::Class::Cursor> for more information.
420 my $attrs = { %{$self->{_attrs}} };
421 return $self->{cursor}
422 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
423 $attrs->{where},$attrs);
430 =item Arguments: $cond?
432 =item Return Value: $row_object?
436 my $cd = $schema->resultset('CD')->single({ year => 2001 });
438 Inflates the first result without creating a cursor if the resultset has
439 any records in it; if not returns nothing. Used by L</find> as an optimisation.
441 Can optionally take an additional condition *only* - this is a fast-code-path
442 method; if you need to add extra joins or similar call ->search and then
443 ->single without a condition on the $rs returned from that.
448 my ($self, $where) = @_;
450 my $attrs = { %{$self->{_attrs}} };
452 if (defined $attrs->{where}) {
455 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
456 $where, delete $attrs->{where} ]
459 $attrs->{where} = $where;
463 my @data = $self->result_source->storage->select_single(
464 $attrs->{from}, $attrs->{select},
465 $attrs->{where},$attrs);
466 return (@data ? $self->_construct_object(@data) : ());
473 =item Arguments: $cond?
475 =item Return Value: $resultsetcolumn
479 my $max_length = $rs->get_column('length')->max;
481 Returns a ResultSetColumn instance for $column based on $self
486 my ($self, $column) = @_;
488 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
496 =item Arguments: $cond, \%attrs?
498 =item Return Value: $resultset (scalar context), @row_objs (list context)
502 # WHERE title LIKE '%blue%'
503 $cd_rs = $rs->search_like({ title => '%blue%'});
505 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
506 that this is simply a convenience method. You most likely want to use
507 L</search> with specific operators.
509 For more information, see L<DBIx::Class::Manual::Cookbook>.
515 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
516 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
517 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
518 return $class->search($query, { %$attrs });
525 =item Arguments: $first, $last
527 =item Return Value: $resultset (scalar context), @row_objs (list context)
531 Returns a resultset or object list representing a subset of elements from the
532 resultset slice is called on. Indexes are from 0, i.e., to get the first
535 my ($one, $two, $three) = $rs->slice(0, 2);
540 my ($self, $min, $max) = @_;
541 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
542 $attrs->{offset} = $self->{attrs}{offset} || 0;
543 $attrs->{offset} += $min;
544 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
545 return $self->search(undef(), $attrs);
546 #my $slice = (ref $self)->new($self->result_source, $attrs);
547 #return (wantarray ? $slice->all : $slice);
554 =item Arguments: none
556 =item Return Value: $result?
560 Returns the next element in the resultset (C<undef> is there is none).
562 Can be used to efficiently iterate over records in the resultset:
564 my $rs = $schema->resultset('CD')->search;
565 while (my $cd = $rs->next) {
569 Note that you need to store the resultset object, and call C<next> on it.
570 Calling C<< resultset('Table')->next >> repeatedly will always return the
571 first record from the resultset.
577 if (my $cache = $self->get_cache) {
578 $self->{all_cache_position} ||= 0;
579 return $cache->[$self->{all_cache_position}++];
581 if ($self->{attrs}{cache}) {
582 $self->{all_cache_position} = 1;
583 return ($self->all)[0];
585 my @row = (exists $self->{stashed_row} ?
586 @{delete $self->{stashed_row}} :
589 return unless (@row);
590 return $self->_construct_object(@row);
596 return if(exists $self->{_attrs}); #return if _resolve has already been called
598 my $attrs = $self->{attrs};
599 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
601 # XXX - lose storable dclone
602 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
603 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
604 $attrs->{record_filter} = $record_filter if ($record_filter);
605 $self->{attrs}->{record_filter} = $record_filter if ($record_filter);
607 my $alias = $attrs->{alias};
609 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
610 delete $attrs->{as} if $attrs->{columns};
611 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
612 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
614 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
615 ] if $attrs->{columns};
617 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
619 if (my $include = delete $attrs->{include_columns}) {
620 push(@{$attrs->{select}}, @$include);
621 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
624 $attrs->{from} ||= [ { $alias => $source->from } ];
625 $attrs->{seen_join} ||= {};
627 if (my $join = delete $attrs->{join}) {
628 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
629 if (ref $j eq 'HASH') {
630 $seen{$_} = 1 foreach keys %$j;
636 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
638 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
639 $attrs->{order_by} = [ $attrs->{order_by} ] if
640 $attrs->{order_by} and !ref($attrs->{order_by});
641 $attrs->{order_by} ||= [];
643 if(my $seladds = delete($attrs->{'+select'})) {
644 my @seladds = (ref($seladds) eq 'ARRAY' ? @$seladds : ($seladds));
646 @{ $attrs->{select} },
647 map { (m/\./ || ref($_)) ? $_ : "${alias}.$_" } $seladds
650 if(my $asadds = delete($attrs->{'+as'})) {
651 my @asadds = (ref($asadds) eq 'ARRAY' ? @$asadds : ($asadds));
652 $attrs->{as} = [ @{ $attrs->{as} }, @asadds ];
655 my $collapse = $attrs->{collapse} || {};
656 if (my $prefetch = delete $attrs->{prefetch}) {
658 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
659 if ( ref $p eq 'HASH' ) {
660 foreach my $key (keys %$p) {
661 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
665 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
668 my @prefetch = $source->resolve_prefetch(
669 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
670 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
671 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
673 push(@{$attrs->{order_by}}, @pre_order);
675 $attrs->{collapse} = $collapse;
676 $self->{_attrs} = $attrs;
680 my ($self, $a, $b, $is_prefetch) = @_;
683 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
684 foreach my $key (keys %{$b}) {
685 if (exists $a->{$key}) {
686 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key}, $is_prefetch);
688 $a->{$key} = delete $b->{$key};
693 $a = [$a] unless (ref $a eq 'ARRAY');
694 $b = [$b] unless (ref $b eq 'ARRAY');
699 foreach my $element (@{$_}) {
700 if (ref $element eq 'HASH') {
701 $hash = $self->_merge_attr($hash, $element, $is_prefetch);
702 } elsif (ref $element eq 'ARRAY') {
703 $array = [@{$array}, @{$element}];
705 if (($b == $_) && $is_prefetch) {
706 $self->_merge_array($array, $element, $is_prefetch);
708 push(@{$array}, $element);
714 if ((keys %{$hash}) && (scalar(@{$array} > 0))) {
715 return [$hash, @{$array}];
717 return (keys %{$hash}) ? $hash : $array;
723 my ($self, $a, $b) = @_;
725 $b = [$b] unless (ref $b eq 'ARRAY');
726 # add elements from @{$b} to @{$a} which aren't already in @{$a}
727 foreach my $b_element (@{$b}) {
728 push(@{$a}, $b_element) unless grep {$b_element eq $_} @{$a};
732 sub _construct_object {
733 my ($self, @row) = @_;
734 my @as = @{ $self->{_attrs}{as} };
736 my $info = $self->_collapse_result(\@as, \@row);
737 my $new = $self->result_class->inflate_result($self->result_source, @$info);
738 $new = $self->{_attrs}{record_filter}->($new)
739 if exists $self->{_attrs}{record_filter};
743 sub _collapse_result {
744 my ($self, $as, $row, $prefix) = @_;
746 my $live_join = $self->{attrs}->{_live_join} ||="";
750 foreach my $this_as (@$as) {
751 my $val = shift @copy;
752 if (defined $prefix) {
753 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
755 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
756 $const{$1||''}{$2} = $val;
759 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
760 $const{$1||''}{$2} = $val;
764 my $info = [ {}, {} ];
765 foreach my $key (keys %const) {
766 if (length $key && $key ne $live_join) {
768 my @parts = split(/\./, $key);
769 foreach my $p (@parts) {
770 $target = $target->[1]->{$p} ||= [];
772 $target->[0] = $const{$key};
774 $info->[0] = $const{$key};
779 if (defined $prefix) {
781 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
782 } keys %{$self->{_attrs}->{collapse}}
784 @collapse = keys %{$self->{_attrs}->{collapse}};
788 my ($c) = sort { length $a <=> length $b } @collapse;
790 foreach my $p (split(/\./, $c)) {
791 $target = $target->[1]->{$p} ||= [];
793 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
794 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
795 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
796 my $tree = $self->_collapse_result($as, $row, $c_prefix);
799 !defined($tree->[0]->{$_}) ||
800 $co_check{$_} ne $tree->[0]->{$_}
803 last unless (@raw = $self->cursor->next);
804 $row = $self->{stashed_row} = \@raw;
805 $tree = $self->_collapse_result($as, $row, $c_prefix);
807 @$target = (@final ? @final : [ {}, {} ]);
808 # single empty result to indicate an empty prefetched has_many
817 =item Arguments: $result_source?
819 =item Return Value: $result_source
823 An accessor for the primary ResultSource object from which this ResultSet
833 =item Arguments: $cond, \%attrs??
835 =item Return Value: $count
839 Performs an SQL C<COUNT> with the same query as the resultset was built
840 with to find the number of elements. If passed arguments, does a search
841 on the resultset and counts the results of that.
843 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
844 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
845 not support C<DISTINCT> with multiple columns. If you are using such a
846 database, you should only use columns from the main table in your C<group_by>
853 return $self->search(@_)->count if @_ and defined $_[0];
854 return scalar @{ $self->get_cache } if $self->get_cache;
856 my $count = $self->_count;
857 return 0 unless $count;
859 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
860 $count = $self->{attrs}{rows} if
861 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
865 sub _count { # Separated out so pager can get the full count
867 my $select = { count => '*' };
870 my $attrs = { %{ $self->{_attrs} } };
871 if (my $group_by = delete $attrs->{group_by}) {
872 delete $attrs->{having};
873 my @distinct = (ref $group_by ? @$group_by : ($group_by));
874 # todo: try CONCAT for multi-column pk
875 my @pk = $self->result_source->primary_columns;
877 foreach my $column (@distinct) {
878 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
879 @distinct = ($column);
885 $select = { count => { distinct => \@distinct } };
888 $attrs->{select} = $select;
889 $attrs->{as} = [qw/count/];
891 # offset, order by and page are not needed to count. record_filter is cdbi
892 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
893 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
901 =item Arguments: $sql_fragment, @bind_values
903 =item Return Value: $count
907 Counts the results in a literal query. Equivalent to calling L</search_literal>
908 with the passed arguments, then L</count>.
912 sub count_literal { shift->search_literal(@_)->count; }
918 =item Arguments: none
920 =item Return Value: @objects
924 Returns all elements in the resultset. Called implicitly if the resultset
925 is returned in list context.
931 return @{ $self->get_cache } if $self->get_cache;
935 # TODO: don't call resolve here
937 if (keys %{$self->{_attrs}->{collapse}}) {
938 # if ($self->{attrs}->{prefetch}) {
939 # Using $self->cursor->all is really just an optimisation.
940 # If we're collapsing has_many prefetches it probably makes
941 # very little difference, and this is cleaner than hacking
942 # _construct_object to survive the approach
943 my @row = $self->cursor->next;
945 push(@obj, $self->_construct_object(@row));
946 @row = (exists $self->{stashed_row}
947 ? @{delete $self->{stashed_row}}
948 : $self->cursor->next);
951 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
954 $self->set_cache(\@obj) if $self->{attrs}{cache};
962 =item Arguments: none
964 =item Return Value: $self
968 Resets the resultset's cursor, so you can iterate through the elements again.
974 delete $self->{_attrs} if (exists $self->{_attrs});
976 $self->{all_cache_position} = 0;
977 $self->cursor->reset;
985 =item Arguments: none
987 =item Return Value: $object?
991 Resets the resultset and returns an object for the first result (if the
992 resultset returns anything).
997 return $_[0]->reset->next;
1000 # _cond_for_update_delete
1002 # update/delete require the condition to be modified to handle
1003 # the differing SQL syntax available. This transforms the $self->{cond}
1004 # appropriately, returning the new condition.
1006 sub _cond_for_update_delete {
1010 if (!ref($self->{cond})) {
1011 # No-op. No condition, we're updating/deleting everything
1013 elsif (ref $self->{cond} eq 'ARRAY') {
1017 foreach my $key (keys %{$_}) {
1019 $hash{$1} = $_->{$key};
1025 elsif (ref $self->{cond} eq 'HASH') {
1026 if ((keys %{$self->{cond}})[0] eq '-and') {
1029 my @cond = @{$self->{cond}{-and}};
1030 for (my $i = 0; $i <= @cond - 1; $i++) {
1031 my $entry = $cond[$i];
1034 if (ref $entry eq 'HASH') {
1035 foreach my $key (keys %{$entry}) {
1037 $hash{$1} = $entry->{$key};
1041 $entry =~ /([^.]+)$/;
1042 $hash{$1} = $cond[++$i];
1045 push @{$cond->{-and}}, \%hash;
1049 foreach my $key (keys %{$self->{cond}}) {
1051 $cond->{$1} = $self->{cond}{$key};
1056 $self->throw_exception(
1057 "Can't update/delete on resultset with condition unless hash or array"
1069 =item Arguments: \%values
1071 =item Return Value: $storage_rv
1075 Sets the specified columns in the resultset to the supplied values in a
1076 single query. Return value will be true if the update succeeded or false
1077 if no records were updated; exact type of success value is storage-dependent.
1082 my ($self, $values) = @_;
1083 $self->throw_exception("Values for update must be a hash")
1084 unless ref $values eq 'HASH';
1086 my $cond = $self->_cond_for_update_delete;
1088 return $self->result_source->storage->update(
1089 $self->result_source->from, $values, $cond
1097 =item Arguments: \%values
1099 =item Return Value: 1
1103 Fetches all objects and updates them one at a time. Note that C<update_all>
1104 will run DBIC cascade triggers, while L</update> will not.
1109 my ($self, $values) = @_;
1110 $self->throw_exception("Values for update must be a hash")
1111 unless ref $values eq 'HASH';
1112 foreach my $obj ($self->all) {
1113 $obj->set_columns($values)->update;
1122 =item Arguments: none
1124 =item Return Value: 1
1128 Deletes the contents of the resultset from its result source. Note that this
1129 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1138 my $cond = $self->_cond_for_update_delete;
1140 $self->result_source->storage->delete($self->result_source->from, $cond);
1148 =item Arguments: none
1150 =item Return Value: 1
1154 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1155 will run DBIC cascade triggers, while L</delete> will not.
1161 $_->delete for $self->all;
1169 =item Arguments: none
1171 =item Return Value: $pager
1175 Return Value a L<Data::Page> object for the current resultset. Only makes
1176 sense for queries with a C<page> attribute.
1182 my $attrs = $self->{attrs};
1183 $self->throw_exception("Can't create pager for non-paged rs")
1184 unless $self->{page};
1185 $attrs->{rows} ||= 10;
1186 return $self->{pager} ||= Data::Page->new(
1187 $self->_count, $attrs->{rows}, $self->{page});
1194 =item Arguments: $page_number
1196 =item Return Value: $rs
1200 Returns a resultset for the $page_number page of the resultset on which page
1201 is called, where each page contains a number of rows equal to the 'rows'
1202 attribute set on the resultset (10 by default).
1207 my ($self, $page) = @_;
1208 my $attrs = { %{$self->{attrs}} };
1209 $attrs->{page} = $page;
1210 return (ref $self)->new($self->result_source, $attrs);
1217 =item Arguments: \%vals
1219 =item Return Value: $object
1223 Creates an object in the resultset's result class and returns it.
1228 my ($self, $values) = @_;
1229 $self->throw_exception( "new_result needs a hash" )
1230 unless (ref $values eq 'HASH');
1231 $self->throw_exception(
1232 "Can't abstract implicit construct, condition not a hash"
1233 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1235 my $alias = $self->{attrs}{alias};
1236 foreach my $key (keys %{$self->{cond}||{}}) {
1237 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1239 my $obj = $self->result_class->new(\%new);
1240 $obj->result_source($self->result_source) if $obj->can('result_source');
1248 =item Arguments: \%vals, \%attrs?
1250 =item Return Value: $object
1254 Find an existing record from this resultset. If none exists, instantiate a new
1255 result object and return it. The object will not be saved into your storage
1256 until you call L<DBIx::Class::Row/insert> on it.
1258 If you want objects to be saved immediately, use L</find_or_create> instead.
1264 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1265 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1266 my $exists = $self->find($hash, $attrs);
1267 return defined $exists ? $exists : $self->new_result($hash);
1274 =item Arguments: \%vals
1276 =item Return Value: $object
1280 Inserts a record into the resultset and returns the object representing it.
1282 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1287 my ($self, $attrs) = @_;
1288 $self->throw_exception( "create needs a hashref" )
1289 unless ref $attrs eq 'HASH';
1290 return $self->new_result($attrs)->insert;
1293 =head2 find_or_create
1297 =item Arguments: \%vals, \%attrs?
1299 =item Return Value: $object
1303 $class->find_or_create({ key => $val, ... });
1305 Searches for a record matching the search condition; if it doesn't find one,
1306 creates one and returns that instead.
1308 my $cd = $schema->resultset('CD')->find_or_create({
1310 artist => 'Massive Attack',
1311 title => 'Mezzanine',
1315 Also takes an optional C<key> attribute, to search by a specific key or unique
1316 constraint. For example:
1318 my $cd = $schema->resultset('CD')->find_or_create(
1320 artist => 'Massive Attack',
1321 title => 'Mezzanine',
1323 { key => 'artist_title' }
1326 See also L</find> and L</update_or_create>. For information on how to declare
1327 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1331 sub find_or_create {
1333 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1334 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1335 my $exists = $self->find($hash, $attrs);
1336 return defined $exists ? $exists : $self->create($hash);
1339 =head2 update_or_create
1343 =item Arguments: \%col_values, { key => $unique_constraint }?
1345 =item Return Value: $object
1349 $class->update_or_create({ col => $val, ... });
1351 First, searches for an existing row matching one of the unique constraints
1352 (including the primary key) on the source of this resultset. If a row is
1353 found, updates it with the other given column values. Otherwise, creates a new
1356 Takes an optional C<key> attribute to search on a specific unique constraint.
1359 # In your application
1360 my $cd = $schema->resultset('CD')->update_or_create(
1362 artist => 'Massive Attack',
1363 title => 'Mezzanine',
1366 { key => 'artist_title' }
1369 If no C<key> is specified, it searches on all unique constraints defined on the
1370 source, including the primary key.
1372 If the C<key> is specified as C<primary>, it searches only on the primary key.
1374 See also L</find> and L</find_or_create>. For information on how to declare
1375 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1379 sub update_or_create {
1381 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1382 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1384 my $row = $self->find($hash, $attrs);
1386 $row->update($hash);
1390 return $self->create($hash);
1397 =item Arguments: none
1399 =item Return Value: \@cache_objects?
1403 Gets the contents of the cache for the resultset, if the cache is set.
1415 =item Arguments: \@cache_objects
1417 =item Return Value: \@cache_objects
1421 Sets the contents of the cache for the resultset. Expects an arrayref
1422 of objects of the same class as those produced by the resultset. Note that
1423 if the cache is set the resultset will return the cached objects rather
1424 than re-querying the database even if the cache attr is not set.
1429 my ( $self, $data ) = @_;
1430 $self->throw_exception("set_cache requires an arrayref")
1431 if defined($data) && (ref $data ne 'ARRAY');
1432 $self->{all_cache} = $data;
1439 =item Arguments: none
1441 =item Return Value: []
1445 Clears the cache for the resultset.
1450 shift->set_cache(undef);
1453 =head2 related_resultset
1457 =item Arguments: $relationship_name
1459 =item Return Value: $resultset
1463 Returns a related resultset for the supplied relationship name.
1465 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1469 sub related_resultset {
1470 my ( $self, $rel ) = @_;
1472 $self->{related_resultsets} ||= {};
1473 return $self->{related_resultsets}{$rel} ||= do {
1474 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1475 my $rel_obj = $self->result_source->relationship_info($rel);
1476 $self->throw_exception(
1477 "search_related: result source '" . $self->result_source->name .
1478 "' has no such relationship ${rel}")
1479 unless $rel_obj; #die Dumper $self->{attrs};
1481 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1483 { %{$self->{attrs}},
1487 _live_join => $rel }
1490 # keep reference of the original resultset
1491 $rs->{_parent_rs} = $self->result_source;
1496 =head2 throw_exception
1498 See L<DBIx::Class::Schema/throw_exception> for details.
1502 sub throw_exception {
1504 $self->result_source->schema->throw_exception(@_);
1507 # XXX: FIXME: Attributes docs need clearing up
1511 The resultset takes various attributes that modify its behavior. Here's an
1518 =item Value: ($order_by | \@order_by)
1522 Which column(s) to order the results by. This is currently passed
1523 through directly to SQL, so you can give e.g. C<year DESC> for a
1524 descending order on the column `year'.
1530 =item Value: \@columns
1534 Shortcut to request a particular set of columns to be retrieved. Adds
1535 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1536 from that, then auto-populates C<as> from C<select> as normal. (You may also
1537 use the C<cols> attribute, as in earlier versions of DBIC.)
1539 =head2 include_columns
1543 =item Value: \@columns
1547 Shortcut to include additional columns in the returned results - for example
1549 $schema->resultset('CD')->search(undef, {
1550 include_columns => ['artist.name'],
1554 would return all CDs and include a 'name' column to the information
1555 passed to object inflation
1561 =item Value: \@select_columns
1565 Indicates which columns should be selected from the storage. You can use
1566 column names, or in the case of RDBMS back ends, function or stored procedure
1569 $rs = $schema->resultset('Employee')->search(undef, {
1572 { count => 'employeeid' },
1577 When you use function/stored procedure names and do not supply an C<as>
1578 attribute, the column names returned are storage-dependent. E.g. MySQL would
1579 return a column named C<count(employeeid)> in the above example.
1585 Indicates additional columns to be selected from storage. Works the same as
1586 L<select> but adds columns to the selection.
1594 Indicates additional column names for those added via L<+select>.
1602 =item Value: \@inflation_names
1606 Indicates column names for object inflation. This is used in conjunction with
1607 C<select>, usually when C<select> contains one or more function or stored
1610 $rs = $schema->resultset('Employee')->search(undef, {
1613 { count => 'employeeid' }
1615 as => ['name', 'employee_count'],
1618 my $employee = $rs->first(); # get the first Employee
1620 If the object against which the search is performed already has an accessor
1621 matching a column name specified in C<as>, the value can be retrieved using
1622 the accessor as normal:
1624 my $name = $employee->name();
1626 If on the other hand an accessor does not exist in the object, you need to
1627 use C<get_column> instead:
1629 my $employee_count = $employee->get_column('employee_count');
1631 You can create your own accessors if required - see
1632 L<DBIx::Class::Manual::Cookbook> for details.
1634 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1635 produced, it is used for internal access only. Thus attempting to use the accessor
1636 in an C<order_by> clause or similar will fail misrably.
1642 =item Value: ($rel_name | \@rel_names | \%rel_names)
1646 Contains a list of relationships that should be joined for this query. For
1649 # Get CDs by Nine Inch Nails
1650 my $rs = $schema->resultset('CD')->search(
1651 { 'artist.name' => 'Nine Inch Nails' },
1652 { join => 'artist' }
1655 Can also contain a hash reference to refer to the other relation's relations.
1658 package MyApp::Schema::Track;
1659 use base qw/DBIx::Class/;
1660 __PACKAGE__->table('track');
1661 __PACKAGE__->add_columns(qw/trackid cd position title/);
1662 __PACKAGE__->set_primary_key('trackid');
1663 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1666 # In your application
1667 my $rs = $schema->resultset('Artist')->search(
1668 { 'track.title' => 'Teardrop' },
1670 join => { cd => 'track' },
1671 order_by => 'artist.name',
1675 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1676 similarly for a third time). For e.g.
1678 my $rs = $schema->resultset('Artist')->search({
1679 'cds.title' => 'Down to Earth',
1680 'cds_2.title' => 'Popular',
1682 join => [ qw/cds cds/ ],
1685 will return a set of all artists that have both a cd with title 'Down
1686 to Earth' and a cd with title 'Popular'.
1688 If you want to fetch related objects from other tables as well, see C<prefetch>
1695 =item Value: ($rel_name | \@rel_names | \%rel_names)
1699 Contains one or more relationships that should be fetched along with the main
1700 query (when they are accessed afterwards they will have already been
1701 "prefetched"). This is useful for when you know you will need the related
1702 objects, because it saves at least one query:
1704 my $rs = $schema->resultset('Tag')->search(
1713 The initial search results in SQL like the following:
1715 SELECT tag.*, cd.*, artist.* FROM tag
1716 JOIN cd ON tag.cd = cd.cdid
1717 JOIN artist ON cd.artist = artist.artistid
1719 L<DBIx::Class> has no need to go back to the database when we access the
1720 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1723 Simple prefetches will be joined automatically, so there is no need
1724 for a C<join> attribute in the above search. If you're prefetching to
1725 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1726 specify the join as well.
1728 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1729 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1730 with an accessor type of 'single' or 'filter').
1740 Makes the resultset paged and specifies the page to retrieve. Effectively
1741 identical to creating a non-pages resultset and then calling ->page($page)
1752 Specifes the maximum number of rows for direct retrieval or the number of
1753 rows per page if the page attribute or method is used.
1759 =item Value: \@columns
1763 A arrayref of columns to group by. Can include columns of joined tables.
1765 group_by => [qw/ column1 column2 ... /]
1771 =item Value: $condition
1775 HAVING is a select statement attribute that is applied between GROUP BY and
1776 ORDER BY. It is applied to the after the grouping calculations have been
1779 having => { 'count(employee)' => { '>=', 100 } }
1785 =item Value: (0 | 1)
1789 Set to 1 to group by all columns.
1793 Set to 1 to cache search results. This prevents extra SQL queries if you
1794 revisit rows in your ResultSet:
1796 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1798 while( my $artist = $resultset->next ) {
1802 $rs->first; # without cache, this would issue a query
1804 By default, searches are not cached.
1806 For more examples of using these attributes, see
1807 L<DBIx::Class::Manual::Cookbook>.
1813 =item Value: \@from_clause
1817 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1818 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1821 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1823 C<join> will usually do what you need and it is strongly recommended that you
1824 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1825 And we really do mean "cannot", not just tried and failed. Attempting to use
1826 this because you're having problems with C<join> is like trying to use x86
1827 ASM because you've got a syntax error in your C. Trust us on this.
1829 Now, if you're still really, really sure you need to use this (and if you're
1830 not 100% sure, ask the mailing list first), here's an explanation of how this
1833 The syntax is as follows -
1836 { <alias1> => <table1> },
1838 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1839 [], # nested JOIN (optional)
1840 { <table1.column1> => <table2.column2>, ... (more conditions) },
1842 # More of the above [ ] may follow for additional joins
1849 ON <table1.column1> = <table2.column2>
1850 <more joins may follow>
1852 An easy way to follow the examples below is to remember the following:
1854 Anything inside "[]" is a JOIN
1855 Anything inside "{}" is a condition for the enclosing JOIN
1857 The following examples utilize a "person" table in a family tree application.
1858 In order to express parent->child relationships, this table is self-joined:
1860 # Person->belongs_to('father' => 'Person');
1861 # Person->belongs_to('mother' => 'Person');
1863 C<from> can be used to nest joins. Here we return all children with a father,
1864 then search against all mothers of those children:
1866 $rs = $schema->resultset('Person')->search(
1869 alias => 'mother', # alias columns in accordance with "from"
1871 { mother => 'person' },
1874 { child => 'person' },
1876 { father => 'person' },
1877 { 'father.person_id' => 'child.father_id' }
1880 { 'mother.person_id' => 'child.mother_id' }
1887 # SELECT mother.* FROM person mother
1890 # JOIN person father
1891 # ON ( father.person_id = child.father_id )
1893 # ON ( mother.person_id = child.mother_id )
1895 The type of any join can be controlled manually. To search against only people
1896 with a father in the person table, we could explicitly use C<INNER JOIN>:
1898 $rs = $schema->resultset('Person')->search(
1901 alias => 'child', # alias columns in accordance with "from"
1903 { child => 'person' },
1905 { father => 'person', -join_type => 'inner' },
1906 { 'father.id' => 'child.father_id' }
1913 # SELECT child.* FROM person child
1914 # INNER JOIN person father ON child.father_id = father.id