1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use base qw/DBIx::Class/;
14 __PACKAGE__->load_components(qw/AccessorGroup/);
15 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
19 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
23 my $rs = $schema->resultset('User')->search(registered => 1);
24 my @rows = $schema->resultset('CD')->search(year => 2005);
28 The resultset is also known as an iterator. It is responsible for handling
29 queries that may return an arbitrary number of rows, e.g. via L</search>
30 or a C<has_many> relationship.
32 In the examples below, the following table classes are used:
34 package MyApp::Schema::Artist;
35 use base qw/DBIx::Class/;
36 __PACKAGE__->load_components(qw/Core/);
37 __PACKAGE__->table('artist');
38 __PACKAGE__->add_columns(qw/artistid name/);
39 __PACKAGE__->set_primary_key('artistid');
40 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
43 package MyApp::Schema::CD;
44 use base qw/DBIx::Class/;
45 __PACKAGE__->load_components(qw/Core/);
46 __PACKAGE__->table('cd');
47 __PACKAGE__->add_columns(qw/cdid artist title year/);
48 __PACKAGE__->set_primary_key('cdid');
49 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
58 =item Arguments: $source, \%$attrs
60 =item Return Value: $rs
64 The resultset constructor. Takes a source object (usually a
65 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
66 L</ATTRIBUTES> below). Does not perform any queries -- these are
67 executed as needed by the other methods.
69 Generally you won't need to construct a resultset manually. You'll
70 automatically get one from e.g. a L</search> called in scalar context:
72 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
74 IMPORTANT: If called on an object, proxies to new_result instead so
76 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
78 will return a CD object, not a ResultSet.
84 return $class->new_result(@_) if ref $class;
86 my ($source, $attrs) = @_;
90 $attrs->{rows} ||= 10;
91 $attrs->{offset} ||= 0;
92 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
95 $attrs->{alias} ||= 'me';
96 $attrs->{_orig_alias} ||= $attrs->{alias};
99 result_source => $source,
100 result_class => $attrs->{result_class} || $source->result_class,
101 cond => $attrs->{where},
102 # from => $attrs->{from},
103 # collapse => $collapse,
114 =item Arguments: $cond, \%attrs?
116 =item Return Value: $resultset (scalar context), @row_objs (list context)
120 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
121 my $new_rs = $cd_rs->search({ year => 2005 });
123 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
124 # year = 2005 OR year = 2004
126 If you need to pass in additional attributes but no additional condition,
127 call it as C<search(undef, \%attrs)>.
129 # "SELECT name, artistid FROM $artist_table"
130 my @all_artists = $schema->resultset('Artist')->search(undef, {
131 columns => [qw/name artistid/],
138 my $rs = $self->search_rs( @_ );
139 return (wantarray ? $rs->all : $rs);
146 =item Arguments: $cond, \%attrs?
148 =item Return Value: $resultset
152 This method does the same exact thing as search() except it will
153 always return a resultset, even in list context.
161 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
162 my $our_attrs = exists $attrs->{_parent_attrs}
163 ? { %{delete $attrs->{_parent_attrs}} }
164 : { %{$self->{attrs}} };
165 my $having = delete $our_attrs->{having};
167 # XXX should only maintain _live_join_stack and generate _live_join_h from that
168 if ($attrs->{_live_join_stack}) {
169 foreach my $join (reverse @{$attrs->{_live_join_stack}}) {
170 $attrs->{_live_join_h} = defined $attrs->{_live_join_h}
171 ? { $join => $attrs->{_live_join_h} }
176 # merge new attrs into inherited
177 foreach my $key (qw/join prefetch/) {
178 next unless exists $attrs->{$key};
179 if (my $live_join = $attrs->{_live_join_stack} || $our_attrs->{_live_join_stack}) {
180 foreach my $join (reverse @{$live_join}) {
181 $attrs->{$key} = { $join => $attrs->{$key} };
185 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, delete $attrs->{$key});
188 $our_attrs->{join} = $self->_merge_attr(
189 $our_attrs->{join}, $attrs->{_live_join_h}
190 ) if ($attrs->{_live_join_h});
192 if (defined $our_attrs->{prefetch}) {
193 $our_attrs->{join} = $self->_merge_attr(
194 $our_attrs->{join}, $our_attrs->{prefetch}
198 my $new_attrs = { %{$our_attrs}, %{$attrs} };
201 (@_ == 1 || ref $_[0] eq "HASH")
205 ? $self->throw_exception("Odd number of arguments to search")
212 if (defined $where) {
213 $new_attrs->{where} = (
214 defined $new_attrs->{where}
217 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
218 } $where, $new_attrs->{where}
224 if (defined $having) {
225 $new_attrs->{having} = (
226 defined $new_attrs->{having}
229 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
230 } $having, $new_attrs->{having}
236 my $rs = (ref $self)->new($self->result_source, $new_attrs);
237 $rs->{_parent_source} = $self->{_parent_source} if $self->{_parent_source};
239 unless (@_) { # no search, effectively just a clone
240 my $rows = $self->get_cache;
242 $rs->set_cache($rows);
248 =head2 search_literal
252 =item Arguments: $sql_fragment, @bind_values
254 =item Return Value: $resultset (scalar context), @row_objs (list context)
258 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
259 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
261 Pass a literal chunk of SQL to be added to the conditional part of the
267 my ($self, $cond, @vals) = @_;
268 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
269 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
270 return $self->search(\$cond, $attrs);
277 =item Arguments: @values | \%cols, \%attrs?
279 =item Return Value: $row_object
283 Finds a row based on its primary key or unique constraint. For example, to find
284 a row by its primary key:
286 my $cd = $schema->resultset('CD')->find(5);
288 You can also find a row by a specific unique constraint using the C<key>
289 attribute. For example:
291 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
292 key => 'cd_artist_title'
295 Additionally, you can specify the columns explicitly by name:
297 my $cd = $schema->resultset('CD')->find(
299 artist => 'Massive Attack',
300 title => 'Mezzanine',
302 { key => 'cd_artist_title' }
305 If the C<key> is specified as C<primary>, it searches only on the primary key.
307 If no C<key> is specified, it searches on all unique constraints defined on the
308 source, including the primary key.
310 See also L</find_or_create> and L</update_or_create>. For information on how to
311 declare unique constraints, see
312 L<DBIx::Class::ResultSource/add_unique_constraint>.
318 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
320 # Default to the primary key, but allow a specific key
321 my @cols = exists $attrs->{key}
322 ? $self->result_source->unique_constraint_columns($attrs->{key})
323 : $self->result_source->primary_columns;
324 $self->throw_exception(
325 "Can't find unless a primary key or unique constraint is defined"
328 # Parse out a hashref from input
330 if (ref $_[0] eq 'HASH') {
331 $input_query = { %{$_[0]} };
333 elsif (@_ == @cols) {
335 @{$input_query}{@cols} = @_;
338 # Compatibility: Allow e.g. find(id => $value)
339 carp "Find by key => value deprecated; please use a hashref instead";
343 my @unique_queries = $self->_unique_queries($input_query, $attrs);
345 # Handle cases where the ResultSet defines the query, or where the user is
347 my $query = @unique_queries ? \@unique_queries : $input_query;
351 my $rs = $self->search($query, $attrs);
352 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
355 return keys %{$self->_resolved_attrs->{collapse}}
356 ? $self->search($query)->next
357 : $self->single($query);
363 # Build a list of queries which satisfy unique constraints.
365 sub _unique_queries {
366 my ($self, $query, $attrs) = @_;
368 my $alias = $self->{attrs}{alias};
369 my @constraint_names = exists $attrs->{key}
371 : $self->result_source->unique_constraint_names;
374 foreach my $name (@constraint_names) {
375 my @unique_cols = $self->result_source->unique_constraint_columns($name);
376 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
378 my $num_query = scalar keys %$unique_query;
379 next unless $num_query;
381 # Add the ResultSet's alias
382 foreach my $col (grep { ! m/\./ } keys %$unique_query) {
383 $unique_query->{"$alias.$col"} = delete $unique_query->{$col};
386 # XXX: Assuming quite a bit about $self->{attrs}{where}
387 my $num_cols = scalar @unique_cols;
388 my $num_where = exists $self->{attrs}{where}
389 ? scalar keys %{ $self->{attrs}{where} }
391 push @unique_queries, $unique_query
392 if $num_query + $num_where == $num_cols;
395 return @unique_queries;
398 # _build_unique_query
400 # Constrain the specified query hash based on the specified column names.
402 sub _build_unique_query {
403 my ($self, $query, $unique_cols) = @_;
406 map { $_ => $query->{$_} }
407 grep { exists $query->{$_} }
412 =head2 search_related
416 =item Arguments: $rel, $cond, \%attrs?
418 =item Return Value: $new_resultset
422 $new_rs = $cd_rs->search_related('artist', {
426 Searches the specified relationship, optionally specifying a condition and
427 attributes for matching records. See L</ATTRIBUTES> for more information.
432 return shift->related_resultset(shift)->search(@_);
439 =item Arguments: none
441 =item Return Value: $cursor
445 Returns a storage-driven cursor to the given resultset. See
446 L<DBIx::Class::Cursor> for more information.
453 my $attrs = { %{$self->_resolved_attrs} };
454 return $self->{cursor}
455 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
456 $attrs->{where},$attrs);
463 =item Arguments: $cond?
465 =item Return Value: $row_object?
469 my $cd = $schema->resultset('CD')->single({ year => 2001 });
471 Inflates the first result without creating a cursor if the resultset has
472 any records in it; if not returns nothing. Used by L</find> as an optimisation.
474 Can optionally take an additional condition *only* - this is a fast-code-path
475 method; if you need to add extra joins or similar call ->search and then
476 ->single without a condition on the $rs returned from that.
481 my ($self, $where) = @_;
482 my $attrs = { %{$self->_resolved_attrs} };
484 if (defined $attrs->{where}) {
487 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
488 $where, delete $attrs->{where} ]
491 $attrs->{where} = $where;
495 unless ($self->_is_unique_query($attrs->{where})) {
496 carp "Query not guaranteed to return a single row"
497 . "; please declare your unique constraints or use search instead";
500 my @data = $self->result_source->storage->select_single(
501 $attrs->{from}, $attrs->{select},
502 $attrs->{where}, $attrs
505 return (@data ? $self->_construct_object(@data) : ());
510 # Try to determine if the specified query is guaranteed to be unique, based on
511 # the declared unique constraints.
513 sub _is_unique_query {
514 my ($self, $query) = @_;
516 my $collapsed = $self->_collapse_query($query);
517 my $alias = $self->{attrs}{alias};
519 foreach my $name ($self->result_source->unique_constraint_names) {
520 my @unique_cols = map {
522 } $self->result_source->unique_constraint_columns($name);
524 # Count the values for each unique column
525 my %seen = map { $_ => 0 } @unique_cols;
527 foreach my $key (keys %$collapsed) {
528 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
529 next unless exists $seen{$aliased}; # Additional constraints are okay
530 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
533 # If we get 0 or more than 1 value for a column, it's not necessarily unique
534 return 1 unless grep { $_ != 1 } values %seen;
542 # Recursively collapse the query, accumulating values for each column.
544 sub _collapse_query {
545 my ($self, $query, $collapsed) = @_;
549 if (ref $query eq 'ARRAY') {
550 foreach my $subquery (@$query) {
551 next unless ref $subquery; # -or
552 # warn "ARRAY: " . Dumper $subquery;
553 $collapsed = $self->_collapse_query($subquery, $collapsed);
556 elsif (ref $query eq 'HASH') {
557 if (keys %$query and (keys %$query)[0] eq '-and') {
558 foreach my $subquery (@{$query->{-and}}) {
559 # warn "HASH: " . Dumper $subquery;
560 $collapsed = $self->_collapse_query($subquery, $collapsed);
564 # warn "LEAF: " . Dumper $query;
565 foreach my $col (keys %$query) {
566 my $value = $query->{$col};
567 $collapsed->{$col}{$value}++;
579 =item Arguments: $cond?
581 =item Return Value: $resultsetcolumn
585 my $max_length = $rs->get_column('length')->max;
587 Returns a ResultSetColumn instance for $column based on $self
592 my ($self, $column) = @_;
593 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
601 =item Arguments: $cond, \%attrs?
603 =item Return Value: $resultset (scalar context), @row_objs (list context)
607 # WHERE title LIKE '%blue%'
608 $cd_rs = $rs->search_like({ title => '%blue%'});
610 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
611 that this is simply a convenience method. You most likely want to use
612 L</search> with specific operators.
614 For more information, see L<DBIx::Class::Manual::Cookbook>.
620 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
621 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
622 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
623 return $class->search($query, { %$attrs });
630 =item Arguments: $first, $last
632 =item Return Value: $resultset (scalar context), @row_objs (list context)
636 Returns a resultset or object list representing a subset of elements from the
637 resultset slice is called on. Indexes are from 0, i.e., to get the first
640 my ($one, $two, $three) = $rs->slice(0, 2);
645 my ($self, $min, $max) = @_;
646 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
647 $attrs->{offset} = $self->{attrs}{offset} || 0;
648 $attrs->{offset} += $min;
649 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
650 return $self->search(undef(), $attrs);
651 #my $slice = (ref $self)->new($self->result_source, $attrs);
652 #return (wantarray ? $slice->all : $slice);
659 =item Arguments: none
661 =item Return Value: $result?
665 Returns the next element in the resultset (C<undef> is there is none).
667 Can be used to efficiently iterate over records in the resultset:
669 my $rs = $schema->resultset('CD')->search;
670 while (my $cd = $rs->next) {
674 Note that you need to store the resultset object, and call C<next> on it.
675 Calling C<< resultset('Table')->next >> repeatedly will always return the
676 first record from the resultset.
682 if (my $cache = $self->get_cache) {
683 $self->{all_cache_position} ||= 0;
684 return $cache->[$self->{all_cache_position}++];
686 if ($self->{attrs}{cache}) {
687 $self->{all_cache_position} = 1;
688 return ($self->all)[0];
691 exists $self->{stashed_row}
692 ? @{delete $self->{stashed_row}}
693 : $self->cursor->next
695 return unless (@row);
696 return $self->_construct_object(@row);
699 sub _resolved_attrs {
701 return $self->{_attrs} if $self->{_attrs};
703 my $attrs = $self->{attrs};
704 my $source = $self->{_parent_source} || $self->{result_source};
705 my $alias = $attrs->{_orig_alias};
707 # XXX - lose storable dclone
708 my $record_filter = delete $attrs->{record_filter};
709 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
710 $attrs->{record_filter} = $record_filter if $record_filter;
712 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
713 if ($attrs->{columns}) {
715 } elsif (!$attrs->{select}) {
716 $attrs->{columns} = [ $self->{result_source}->columns ];
719 my $select_alias = $self->{attrs}{alias};
720 $attrs->{select} ||= [
721 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
724 map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
728 if ($adds = delete $attrs->{include_columns}) {
729 $adds = [$adds] unless ref $adds eq 'ARRAY';
730 push(@{$attrs->{select}}, @$adds);
731 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
733 if ($adds = delete $attrs->{'+select'}) {
734 $adds = [$adds] unless ref $adds eq 'ARRAY';
735 push(@{$attrs->{select}}, map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
737 if (my $adds = delete $attrs->{'+as'}) {
738 $adds = [$adds] unless ref $adds eq 'ARRAY';
739 push(@{$attrs->{as}}, @$adds);
742 $attrs->{from} ||= [ { $alias => $source->from } ];
743 $attrs->{seen_join} ||= {};
745 if (my $join = delete $attrs->{join}) {
746 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
747 if (ref $j eq 'HASH') {
748 $seen{$_} = 1 foreach keys %$j;
753 push(@{$attrs->{from}},
754 $source->resolve_join($join, $alias, $attrs->{seen_join})
758 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
759 if ($attrs->{order_by}) {
760 $attrs->{order_by} = [ $attrs->{order_by} ] unless ref $attrs->{order_by};
762 $attrs->{order_by} ||= [];
765 my $collapse = $attrs->{collapse} || {};
766 if (my $prefetch = delete $attrs->{prefetch}) {
768 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
769 if ( ref $p eq 'HASH' ) {
770 foreach my $key (keys %$p) {
771 push(@{$attrs->{from}}, $source->resolve_join($p, $alias))
775 push(@{$attrs->{from}}, $source->resolve_join($p, $alias))
778 # bring joins back to level of current class
779 $p = $self->_reduce_joins($p, $attrs) if $attrs->{_live_join_stack};
781 my @prefetch = $self->result_source->resolve_prefetch(
782 $p, $alias, {}, \@pre_order, $collapse
784 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
785 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
788 push(@{$attrs->{order_by}}, @pre_order);
790 $attrs->{collapse} = $collapse;
792 return $self->{_attrs} = $attrs;
796 my ($self, $a, $b) = @_;
799 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
800 foreach my $key (keys %{$b}) {
801 if (exists $a->{$key}) {
802 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
804 $a->{$key} = $b->{$key};
809 $a = [$a] unless ref $a eq 'ARRAY';
810 $b = [$b] unless ref $b eq 'ARRAY';
814 foreach my $x ($a, $b) {
815 foreach my $element (@{$x}) {
816 if (ref $element eq 'HASH') {
817 $hash = $self->_merge_attr($hash, $element);
818 } elsif (ref $element eq 'ARRAY') {
819 push(@array, @{$element});
821 push(@array, $element) unless $b == $x
822 && grep { $_ eq $element } @array;
827 @array = grep { !exists $hash->{$_} } @array;
838 # bring the joins (which are from the original class) to the level
839 # of the current class so that we can resolve them properly
841 my ($self, $p, $attrs) = @_;
844 foreach my $join (@{$attrs->{_live_join_stack}}) {
845 if (ref $p eq 'HASH') {
846 return undef unless exists $p->{$join};
848 } elsif (ref $p eq 'ARRAY') {
849 foreach my $pe (@{$p}) {
850 return undef if $pe eq $join;
851 if (ref $pe eq 'HASH' && exists $pe->{$join}) {
864 sub _construct_object {
865 my ($self, @row) = @_;
866 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
867 my $new = $self->result_class->inflate_result($self->result_source, @$info);
868 $new = $self->{_attrs}{record_filter}->($new)
869 if exists $self->{_attrs}{record_filter};
873 sub _collapse_result {
874 my ($self, $as, $row, $prefix) = @_;
879 foreach my $this_as (@$as) {
880 my $val = shift @copy;
881 if (defined $prefix) {
882 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
884 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
885 $const{$1||''}{$2} = $val;
888 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
889 $const{$1||''}{$2} = $val;
893 my $alias = $self->{attrs}{alias};
894 my $info = [ {}, {} ];
895 foreach my $key (keys %const) {
896 if (length $key && $key ne $alias) {
898 my @parts = split(/\./, $key);
899 foreach my $p (@parts) {
900 $target = $target->[1]->{$p} ||= [];
902 $target->[0] = $const{$key};
904 $info->[0] = $const{$key};
909 if (defined $prefix) {
911 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
912 } keys %{$self->{_attrs}{collapse}}
914 @collapse = keys %{$self->{_attrs}{collapse}};
918 my ($c) = sort { length $a <=> length $b } @collapse;
920 foreach my $p (split(/\./, $c)) {
921 $target = $target->[1]->{$p} ||= [];
923 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
924 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
925 my $tree = $self->_collapse_result($as, $row, $c_prefix);
926 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
932 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
937 last unless (@raw = $self->cursor->next);
938 $row = $self->{stashed_row} = \@raw;
939 $tree = $self->_collapse_result($as, $row, $c_prefix);
941 @$target = (@final ? @final : [ {}, {} ]);
942 # single empty result to indicate an empty prefetched has_many
945 #print "final info: " . Dumper($info);
953 =item Arguments: $result_source?
955 =item Return Value: $result_source
959 An accessor for the primary ResultSource object from which this ResultSet
969 =item Arguments: $cond, \%attrs??
971 =item Return Value: $count
975 Performs an SQL C<COUNT> with the same query as the resultset was built
976 with to find the number of elements. If passed arguments, does a search
977 on the resultset and counts the results of that.
979 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
980 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
981 not support C<DISTINCT> with multiple columns. If you are using such a
982 database, you should only use columns from the main table in your C<group_by>
989 return $self->search(@_)->count if @_ and defined $_[0];
990 return scalar @{ $self->get_cache } if $self->get_cache;
991 my $count = $self->_count;
992 return 0 unless $count;
994 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
995 $count = $self->{attrs}{rows} if
996 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1000 sub _count { # Separated out so pager can get the full count
1002 my $select = { count => '*' };
1004 my $attrs = { %{$self->_resolved_attrs} };
1005 if (my $group_by = delete $attrs->{group_by}) {
1006 delete $attrs->{having};
1007 my @distinct = (ref $group_by ? @$group_by : ($group_by));
1008 # todo: try CONCAT for multi-column pk
1009 my @pk = $self->result_source->primary_columns;
1011 my $alias = $attrs->{_orig_alias};
1012 foreach my $column (@distinct) {
1013 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
1014 @distinct = ($column);
1020 $select = { count => { distinct => \@distinct } };
1023 $attrs->{select} = $select;
1024 $attrs->{as} = [qw/count/];
1026 # offset, order by and page are not needed to count. record_filter is cdbi
1027 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
1028 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1029 $tmp_rs->{_parent_source} = $self->{_parent_source} if $self->{_parent_source};
1030 #XXX - hack to pass through parent of related resultsets
1032 my ($count) = $tmp_rs->cursor->next;
1036 =head2 count_literal
1040 =item Arguments: $sql_fragment, @bind_values
1042 =item Return Value: $count
1046 Counts the results in a literal query. Equivalent to calling L</search_literal>
1047 with the passed arguments, then L</count>.
1051 sub count_literal { shift->search_literal(@_)->count; }
1057 =item Arguments: none
1059 =item Return Value: @objects
1063 Returns all elements in the resultset. Called implicitly if the resultset
1064 is returned in list context.
1070 return @{ $self->get_cache } if $self->get_cache;
1074 # TODO: don't call resolve here
1075 if (keys %{$self->_resolved_attrs->{collapse}}) {
1076 # if ($self->{attrs}{prefetch}) {
1077 # Using $self->cursor->all is really just an optimisation.
1078 # If we're collapsing has_many prefetches it probably makes
1079 # very little difference, and this is cleaner than hacking
1080 # _construct_object to survive the approach
1081 my @row = $self->cursor->next;
1083 push(@obj, $self->_construct_object(@row));
1084 @row = (exists $self->{stashed_row}
1085 ? @{delete $self->{stashed_row}}
1086 : $self->cursor->next);
1089 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1092 $self->set_cache(\@obj) if $self->{attrs}{cache};
1100 =item Arguments: none
1102 =item Return Value: $self
1106 Resets the resultset's cursor, so you can iterate through the elements again.
1112 delete $self->{_attrs} if exists $self->{_attrs};
1113 $self->{all_cache_position} = 0;
1114 $self->cursor->reset;
1122 =item Arguments: none
1124 =item Return Value: $object?
1128 Resets the resultset and returns an object for the first result (if the
1129 resultset returns anything).
1134 return $_[0]->reset->next;
1137 # _cond_for_update_delete
1139 # update/delete require the condition to be modified to handle
1140 # the differing SQL syntax available. This transforms the $self->{cond}
1141 # appropriately, returning the new condition.
1143 sub _cond_for_update_delete {
1147 # No-op. No condition, we're updating/deleting everything
1148 return $cond unless ref $self->{cond};
1150 if (ref $self->{cond} eq 'ARRAY') {
1154 foreach my $key (keys %{$_}) {
1156 $hash{$1} = $_->{$key};
1162 elsif (ref $self->{cond} eq 'HASH') {
1163 if ((keys %{$self->{cond}})[0] eq '-and') {
1166 my @cond = @{$self->{cond}{-and}};
1167 for (my $i = 0; $i < @cond; $i++) {
1168 my $entry = $cond[$i];
1171 if (ref $entry eq 'HASH') {
1172 foreach my $key (keys %{$entry}) {
1174 $hash{$1} = $entry->{$key};
1178 $entry =~ /([^.]+)$/;
1179 $hash{$1} = $cond[++$i];
1182 push @{$cond->{-and}}, \%hash;
1186 foreach my $key (keys %{$self->{cond}}) {
1188 $cond->{$1} = $self->{cond}{$key};
1193 $self->throw_exception(
1194 "Can't update/delete on resultset with condition unless hash or array"
1206 =item Arguments: \%values
1208 =item Return Value: $storage_rv
1212 Sets the specified columns in the resultset to the supplied values in a
1213 single query. Return value will be true if the update succeeded or false
1214 if no records were updated; exact type of success value is storage-dependent.
1219 my ($self, $values) = @_;
1220 $self->throw_exception("Values for update must be a hash")
1221 unless ref $values eq 'HASH';
1223 my $cond = $self->_cond_for_update_delete;
1225 return $self->result_source->storage->update(
1226 $self->result_source->from, $values, $cond
1234 =item Arguments: \%values
1236 =item Return Value: 1
1240 Fetches all objects and updates them one at a time. Note that C<update_all>
1241 will run DBIC cascade triggers, while L</update> will not.
1246 my ($self, $values) = @_;
1247 $self->throw_exception("Values for update must be a hash")
1248 unless ref $values eq 'HASH';
1249 foreach my $obj ($self->all) {
1250 $obj->set_columns($values)->update;
1259 =item Arguments: none
1261 =item Return Value: 1
1265 Deletes the contents of the resultset from its result source. Note that this
1266 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1274 my $cond = $self->_cond_for_update_delete;
1276 $self->result_source->storage->delete($self->result_source->from, $cond);
1284 =item Arguments: none
1286 =item Return Value: 1
1290 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1291 will run DBIC cascade triggers, while L</delete> will not.
1297 $_->delete for $self->all;
1305 =item Arguments: none
1307 =item Return Value: $pager
1311 Return Value a L<Data::Page> object for the current resultset. Only makes
1312 sense for queries with a C<page> attribute.
1318 my $attrs = $self->{attrs};
1319 $self->throw_exception("Can't create pager for non-paged rs")
1320 unless $self->{attrs}{page};
1321 $attrs->{rows} ||= 10;
1322 return $self->{pager} ||= Data::Page->new(
1323 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1330 =item Arguments: $page_number
1332 =item Return Value: $rs
1336 Returns a resultset for the $page_number page of the resultset on which page
1337 is called, where each page contains a number of rows equal to the 'rows'
1338 attribute set on the resultset (10 by default).
1343 my ($self, $page) = @_;
1344 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1351 =item Arguments: \%vals
1353 =item Return Value: $object
1357 Creates an object in the resultset's result class and returns it.
1362 my ($self, $values) = @_;
1363 $self->throw_exception( "new_result needs a hash" )
1364 unless (ref $values eq 'HASH');
1365 $self->throw_exception(
1366 "Can't abstract implicit construct, condition not a hash"
1367 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1369 my $alias = $self->{attrs}{_orig_alias};
1370 foreach my $key (keys %{$self->{cond}||{}}) {
1371 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1373 my $obj = $self->result_class->new(\%new);
1374 $obj->result_source($self->result_source) if $obj->can('result_source');
1382 =item Arguments: \%vals, \%attrs?
1384 =item Return Value: $object
1388 Find an existing record from this resultset. If none exists, instantiate a new
1389 result object and return it. The object will not be saved into your storage
1390 until you call L<DBIx::Class::Row/insert> on it.
1392 If you want objects to be saved immediately, use L</find_or_create> instead.
1398 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1399 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1400 my $exists = $self->find($hash, $attrs);
1401 return defined $exists ? $exists : $self->new_result($hash);
1408 =item Arguments: \%vals
1410 =item Return Value: $object
1414 Inserts a record into the resultset and returns the object representing it.
1416 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1421 my ($self, $attrs) = @_;
1422 $self->throw_exception( "create needs a hashref" )
1423 unless ref $attrs eq 'HASH';
1424 return $self->new_result($attrs)->insert;
1427 =head2 find_or_create
1431 =item Arguments: \%vals, \%attrs?
1433 =item Return Value: $object
1437 $class->find_or_create({ key => $val, ... });
1439 Tries to find a record based on its primary key or unique constraint; if none
1440 is found, creates one and returns that instead.
1442 my $cd = $schema->resultset('CD')->find_or_create({
1444 artist => 'Massive Attack',
1445 title => 'Mezzanine',
1449 Also takes an optional C<key> attribute, to search by a specific key or unique
1450 constraint. For example:
1452 my $cd = $schema->resultset('CD')->find_or_create(
1454 artist => 'Massive Attack',
1455 title => 'Mezzanine',
1457 { key => 'cd_artist_title' }
1460 See also L</find> and L</update_or_create>. For information on how to declare
1461 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1465 sub find_or_create {
1467 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1468 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1469 my $exists = $self->find($hash, $attrs);
1470 return defined $exists ? $exists : $self->create($hash);
1473 =head2 update_or_create
1477 =item Arguments: \%col_values, { key => $unique_constraint }?
1479 =item Return Value: $object
1483 $class->update_or_create({ col => $val, ... });
1485 First, searches for an existing row matching one of the unique constraints
1486 (including the primary key) on the source of this resultset. If a row is
1487 found, updates it with the other given column values. Otherwise, creates a new
1490 Takes an optional C<key> attribute to search on a specific unique constraint.
1493 # In your application
1494 my $cd = $schema->resultset('CD')->update_or_create(
1496 artist => 'Massive Attack',
1497 title => 'Mezzanine',
1500 { key => 'cd_artist_title' }
1503 If no C<key> is specified, it searches on all unique constraints defined on the
1504 source, including the primary key.
1506 If the C<key> is specified as C<primary>, it searches only on the primary key.
1508 See also L</find> and L</find_or_create>. For information on how to declare
1509 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1513 sub update_or_create {
1515 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1516 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1518 my $row = $self->find($cond);
1520 $row->update($cond);
1524 return $self->create($cond);
1531 =item Arguments: none
1533 =item Return Value: \@cache_objects?
1537 Gets the contents of the cache for the resultset, if the cache is set.
1549 =item Arguments: \@cache_objects
1551 =item Return Value: \@cache_objects
1555 Sets the contents of the cache for the resultset. Expects an arrayref
1556 of objects of the same class as those produced by the resultset. Note that
1557 if the cache is set the resultset will return the cached objects rather
1558 than re-querying the database even if the cache attr is not set.
1563 my ( $self, $data ) = @_;
1564 $self->throw_exception("set_cache requires an arrayref")
1565 if defined($data) && (ref $data ne 'ARRAY');
1566 $self->{all_cache} = $data;
1573 =item Arguments: none
1575 =item Return Value: []
1579 Clears the cache for the resultset.
1584 shift->set_cache(undef);
1587 =head2 related_resultset
1591 =item Arguments: $relationship_name
1593 =item Return Value: $resultset
1597 Returns a related resultset for the supplied relationship name.
1599 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1603 sub related_resultset {
1604 my ($self, $rel) = @_;
1606 $self->{related_resultsets} ||= {};
1607 return $self->{related_resultsets}{$rel} ||= do {
1608 my $rel_obj = $self->result_source->relationship_info($rel);
1610 $self->throw_exception(
1611 "search_related: result source '" . $self->result_source->name .
1612 "' has no such relationship $rel")
1615 my @live_join_stack = @{$self->{attrs}{_live_join_stack}||[]};
1617 # XXX mst: I'm sure this is wrong, somehow
1618 # something with complex joins early on could die on search_rel
1619 # followed by a prefetch. I think. need a test case.
1621 my $join_count = scalar(grep { $_ eq $rel } @live_join_stack);
1622 my $alias = $join_count ? join('_', $rel, $join_count+1) : $rel;
1624 push(@live_join_stack, $rel);
1626 my $rs = $self->result_source->schema->resultset($rel_obj->{class})->search(
1631 _live_join_stack => \@live_join_stack,
1632 _parent_attrs => $self->{attrs}}
1635 # keep reference of the original resultset
1636 $rs->{_parent_source} = $self->{_parent_source} || $self->result_source;
1642 =head2 throw_exception
1644 See L<DBIx::Class::Schema/throw_exception> for details.
1648 sub throw_exception {
1650 $self->result_source->schema->throw_exception(@_);
1653 # XXX: FIXME: Attributes docs need clearing up
1657 The resultset takes various attributes that modify its behavior. Here's an
1664 =item Value: ($order_by | \@order_by)
1668 Which column(s) to order the results by. This is currently passed
1669 through directly to SQL, so you can give e.g. C<year DESC> for a
1670 descending order on the column `year'.
1672 Please note that if you have quoting enabled (see
1673 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1674 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1675 so you will need to manually quote things as appropriate.)
1681 =item Value: \@columns
1685 Shortcut to request a particular set of columns to be retrieved. Adds
1686 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1687 from that, then auto-populates C<as> from C<select> as normal. (You may also
1688 use the C<cols> attribute, as in earlier versions of DBIC.)
1690 =head2 include_columns
1694 =item Value: \@columns
1698 Shortcut to include additional columns in the returned results - for example
1700 $schema->resultset('CD')->search(undef, {
1701 include_columns => ['artist.name'],
1705 would return all CDs and include a 'name' column to the information
1706 passed to object inflation
1712 =item Value: \@select_columns
1716 Indicates which columns should be selected from the storage. You can use
1717 column names, or in the case of RDBMS back ends, function or stored procedure
1720 $rs = $schema->resultset('Employee')->search(undef, {
1723 { count => 'employeeid' },
1728 When you use function/stored procedure names and do not supply an C<as>
1729 attribute, the column names returned are storage-dependent. E.g. MySQL would
1730 return a column named C<count(employeeid)> in the above example.
1736 Indicates additional columns to be selected from storage. Works the same as
1737 L<select> but adds columns to the selection.
1745 Indicates additional column names for those added via L<+select>.
1753 =item Value: \@inflation_names
1757 Indicates column names for object inflation. This is used in conjunction with
1758 C<select>, usually when C<select> contains one or more function or stored
1761 $rs = $schema->resultset('Employee')->search(undef, {
1764 { count => 'employeeid' }
1766 as => ['name', 'employee_count'],
1769 my $employee = $rs->first(); # get the first Employee
1771 If the object against which the search is performed already has an accessor
1772 matching a column name specified in C<as>, the value can be retrieved using
1773 the accessor as normal:
1775 my $name = $employee->name();
1777 If on the other hand an accessor does not exist in the object, you need to
1778 use C<get_column> instead:
1780 my $employee_count = $employee->get_column('employee_count');
1782 You can create your own accessors if required - see
1783 L<DBIx::Class::Manual::Cookbook> for details.
1785 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1786 produced, it is used for internal access only. Thus attempting to use the accessor
1787 in an C<order_by> clause or similar will fail misrably.
1793 =item Value: ($rel_name | \@rel_names | \%rel_names)
1797 Contains a list of relationships that should be joined for this query. For
1800 # Get CDs by Nine Inch Nails
1801 my $rs = $schema->resultset('CD')->search(
1802 { 'artist.name' => 'Nine Inch Nails' },
1803 { join => 'artist' }
1806 Can also contain a hash reference to refer to the other relation's relations.
1809 package MyApp::Schema::Track;
1810 use base qw/DBIx::Class/;
1811 __PACKAGE__->table('track');
1812 __PACKAGE__->add_columns(qw/trackid cd position title/);
1813 __PACKAGE__->set_primary_key('trackid');
1814 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1817 # In your application
1818 my $rs = $schema->resultset('Artist')->search(
1819 { 'track.title' => 'Teardrop' },
1821 join => { cd => 'track' },
1822 order_by => 'artist.name',
1826 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1827 similarly for a third time). For e.g.
1829 my $rs = $schema->resultset('Artist')->search({
1830 'cds.title' => 'Down to Earth',
1831 'cds_2.title' => 'Popular',
1833 join => [ qw/cds cds/ ],
1836 will return a set of all artists that have both a cd with title 'Down
1837 to Earth' and a cd with title 'Popular'.
1839 If you want to fetch related objects from other tables as well, see C<prefetch>
1846 =item Value: ($rel_name | \@rel_names | \%rel_names)
1850 Contains one or more relationships that should be fetched along with the main
1851 query (when they are accessed afterwards they will have already been
1852 "prefetched"). This is useful for when you know you will need the related
1853 objects, because it saves at least one query:
1855 my $rs = $schema->resultset('Tag')->search(
1864 The initial search results in SQL like the following:
1866 SELECT tag.*, cd.*, artist.* FROM tag
1867 JOIN cd ON tag.cd = cd.cdid
1868 JOIN artist ON cd.artist = artist.artistid
1870 L<DBIx::Class> has no need to go back to the database when we access the
1871 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1874 Simple prefetches will be joined automatically, so there is no need
1875 for a C<join> attribute in the above search. If you're prefetching to
1876 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1877 specify the join as well.
1879 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1880 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1881 with an accessor type of 'single' or 'filter').
1891 Makes the resultset paged and specifies the page to retrieve. Effectively
1892 identical to creating a non-pages resultset and then calling ->page($page)
1895 If L<rows> attribute is not specified it defualts to 10 rows per page.
1905 Specifes the maximum number of rows for direct retrieval or the number of
1906 rows per page if the page attribute or method is used.
1912 =item Value: $offset
1916 Specifies the (zero-based) row number for the first row to be returned, or the
1917 of the first row of the first page if paging is used.
1923 =item Value: \@columns
1927 A arrayref of columns to group by. Can include columns of joined tables.
1929 group_by => [qw/ column1 column2 ... /]
1935 =item Value: $condition
1939 HAVING is a select statement attribute that is applied between GROUP BY and
1940 ORDER BY. It is applied to the after the grouping calculations have been
1943 having => { 'count(employee)' => { '>=', 100 } }
1949 =item Value: (0 | 1)
1953 Set to 1 to group by all columns.
1959 Adds to the WHERE clause.
1961 # only return rows WHERE deleted IS NULL for all searches
1962 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
1964 Can be overridden by passing C<{ where => undef }> as an attribute
1971 Set to 1 to cache search results. This prevents extra SQL queries if you
1972 revisit rows in your ResultSet:
1974 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1976 while( my $artist = $resultset->next ) {
1980 $rs->first; # without cache, this would issue a query
1982 By default, searches are not cached.
1984 For more examples of using these attributes, see
1985 L<DBIx::Class::Manual::Cookbook>.
1991 =item Value: \@from_clause
1995 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1996 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1999 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2001 C<join> will usually do what you need and it is strongly recommended that you
2002 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2003 And we really do mean "cannot", not just tried and failed. Attempting to use
2004 this because you're having problems with C<join> is like trying to use x86
2005 ASM because you've got a syntax error in your C. Trust us on this.
2007 Now, if you're still really, really sure you need to use this (and if you're
2008 not 100% sure, ask the mailing list first), here's an explanation of how this
2011 The syntax is as follows -
2014 { <alias1> => <table1> },
2016 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2017 [], # nested JOIN (optional)
2018 { <table1.column1> => <table2.column2>, ... (more conditions) },
2020 # More of the above [ ] may follow for additional joins
2027 ON <table1.column1> = <table2.column2>
2028 <more joins may follow>
2030 An easy way to follow the examples below is to remember the following:
2032 Anything inside "[]" is a JOIN
2033 Anything inside "{}" is a condition for the enclosing JOIN
2035 The following examples utilize a "person" table in a family tree application.
2036 In order to express parent->child relationships, this table is self-joined:
2038 # Person->belongs_to('father' => 'Person');
2039 # Person->belongs_to('mother' => 'Person');
2041 C<from> can be used to nest joins. Here we return all children with a father,
2042 then search against all mothers of those children:
2044 $rs = $schema->resultset('Person')->search(
2047 alias => 'mother', # alias columns in accordance with "from"
2049 { mother => 'person' },
2052 { child => 'person' },
2054 { father => 'person' },
2055 { 'father.person_id' => 'child.father_id' }
2058 { 'mother.person_id' => 'child.mother_id' }
2065 # SELECT mother.* FROM person mother
2068 # JOIN person father
2069 # ON ( father.person_id = child.father_id )
2071 # ON ( mother.person_id = child.mother_id )
2073 The type of any join can be controlled manually. To search against only people
2074 with a father in the person table, we could explicitly use C<INNER JOIN>:
2076 $rs = $schema->resultset('Person')->search(
2079 alias => 'child', # alias columns in accordance with "from"
2081 { child => 'person' },
2083 { father => 'person', -join_type => 'inner' },
2084 { 'father.id' => 'child.father_id' }
2091 # SELECT child.* FROM person child
2092 # INNER JOIN person father ON child.father_id = father.id