1 package DBIx::Class::ResultSet;
11 use Scalar::Util qw/weaken/;
13 use DBIx::Class::ResultSetColumn;
14 use base qw/DBIx::Class/;
15 __PACKAGE__->load_components(qw/AccessorGroup/);
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
89 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
90 #use Data::Dumper; warn Dumper($attrs);
91 my $alias = ($attrs->{alias} ||= 'me');
93 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
94 delete $attrs->{as} if $attrs->{columns};
95 $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select};
97 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
98 ] if $attrs->{columns};
100 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
102 if (my $include = delete $attrs->{include_columns}) {
103 push(@{$attrs->{select}}, @$include);
104 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
106 #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
108 $attrs->{from} ||= [ { $alias => $source->from } ];
109 $attrs->{seen_join} ||= {};
111 if (my $join = delete $attrs->{join}) {
112 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
113 if (ref $j eq 'HASH') {
114 $seen{$_} = 1 foreach keys %$j;
119 push(@{$attrs->{from}}, $source->resolve_join(
120 $join, $attrs->{alias}, $attrs->{seen_join})
124 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
125 $attrs->{order_by} = [ $attrs->{order_by} ] if
126 $attrs->{order_by} and !ref($attrs->{order_by});
127 $attrs->{order_by} ||= [];
129 my $collapse = $attrs->{collapse} || {};
130 if (my $prefetch = delete $attrs->{prefetch}) {
132 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
133 if ( ref $p eq 'HASH' ) {
134 foreach my $key (keys %$p) {
135 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
139 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
142 my @prefetch = $source->resolve_prefetch(
143 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
144 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
145 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
147 push(@{$attrs->{order_by}}, @pre_order);
149 $attrs->{collapse} = $collapse;
150 # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse};
152 if ($attrs->{page}) {
153 $attrs->{rows} ||= 10;
154 $attrs->{offset} ||= 0;
155 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
159 result_source => $source,
160 result_class => $attrs->{result_class} || $source->result_class,
161 cond => $attrs->{where},
162 from => $attrs->{from},
163 collapse => $collapse,
165 page => delete $attrs->{page},
175 =item Arguments: $cond, \%attrs?
177 =item Return Value: $resultset (scalar context), @row_objs (list context)
181 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
182 my $new_rs = $cd_rs->search({ year => 2005 });
184 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
185 # year = 2005 OR year = 2004
187 If you need to pass in additional attributes but no additional condition,
188 call it as C<search(undef, \%attrs)>.
190 # "SELECT name, artistid FROM $artist_table"
191 my @all_artists = $schema->resultset('Artist')->search(undef, {
192 columns => [qw/name artistid/],
199 my $rs = $self->search_rs( @_ );
200 return (wantarray ? $rs->all : $rs);
207 =item Arguments: $cond, \%attrs?
209 =item Return Value: $resultset
213 This method does the same exact thing as search() except it will
214 always return a resultset, even in list context.
221 my $attrs = { %{$self->{attrs}} };
222 my $having = delete $attrs->{having};
223 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
226 ? ((@_ == 1 || ref $_[0] eq "HASH")
229 ? $self->throw_exception(
230 "Odd number of arguments to search")
233 if (defined $where) {
234 $attrs->{where} = (defined $attrs->{where}
236 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
237 $where, $attrs->{where} ] }
241 if (defined $having) {
242 $attrs->{having} = (defined $attrs->{having}
244 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
245 $having, $attrs->{having} ] }
249 my $rs = (ref $self)->new($self->result_source, $attrs);
251 unless (@_) { # no search, effectively just a clone
252 my $rows = $self->get_cache;
254 $rs->set_cache($rows);
261 =head2 search_literal
265 =item Arguments: $sql_fragment, @bind_values
267 =item Return Value: $resultset (scalar context), @row_objs (list context)
271 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
272 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
274 Pass a literal chunk of SQL to be added to the conditional part of the
280 my ($self, $cond, @vals) = @_;
281 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
282 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
283 return $self->search(\$cond, $attrs);
290 =item Arguments: @values | \%cols, \%attrs?
292 =item Return Value: $row_object
296 Finds a row based on its primary key or unique constraint. For example, to find
297 a row by its primary key:
299 my $cd = $schema->resultset('CD')->find(5);
301 You can also find a row by a specific unique constraint using the C<key>
302 attribute. For example:
304 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'artist_title' });
306 Additionally, you can specify the columns explicitly by name:
308 my $cd = $schema->resultset('CD')->find(
310 artist => 'Massive Attack',
311 title => 'Mezzanine',
313 { key => 'artist_title' }
316 If no C<key> is specified and you explicitly name columns, it searches on all
317 unique constraints defined on the source, including the primary key.
319 If the C<key> is specified as C<primary>, it searches only on the primary key.
321 See also L</find_or_create> and L</update_or_create>. For information on how to
322 declare unique constraints, see
323 L<DBIx::Class::ResultSource/add_unique_constraint>.
329 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
331 # Parse out a hash from input
332 my @cols = exists $attrs->{key}
333 ? $self->result_source->unique_constraint_columns($attrs->{key})
334 : $self->result_source->primary_columns;
337 if (ref $_[0] eq 'HASH') {
338 $hash = { %{$_[0]} };
340 elsif (@_ == @cols) {
342 @{$hash}{@cols} = @_;
345 $self->throw_exception(
346 "Arguments to find must be a hashref or match the number of columns in the "
347 . exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key"
351 # Check the hash we just parsed against our source's unique constraints
352 my @constraint_names = exists $attrs->{key}
354 : $self->result_source->unique_constraint_names;
355 $self->throw_exception(
356 "Can't find unless a primary key or unique constraint is defined"
357 ) unless @constraint_names;
360 foreach my $name (@constraint_names) {
361 my @unique_cols = $self->result_source->unique_constraint_columns($name);
362 my $unique_query = $self->_build_unique_query($hash, \@unique_cols);
364 # Add the ResultSet's alias
365 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
366 $unique_query->{"$self->{attrs}{alias}.$key"} = delete $unique_query->{$key};
369 push @unique_queries, $unique_query if %$unique_query;
372 # Handle cases where the ResultSet already defines the query
373 my $query = @unique_queries ? \@unique_queries : undef;
377 my $rs = $self->search($query, $attrs);
378 return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
381 return keys %{$self->{collapse}}
382 ? $self->search($query)->next
383 : $self->single($query);
387 # _build_unique_query
389 # Constrain the specified query hash based on the specified column names.
391 sub _build_unique_query {
392 my ($self, $query, $unique_cols) = @_;
395 map { $_ => $query->{$_} }
396 grep { exists $query->{$_} }
399 return \%unique_query;
402 =head2 search_related
406 =item Arguments: $cond, \%attrs?
408 =item Return Value: $new_resultset
412 $new_rs = $cd_rs->search_related('artist', {
416 Searches the specified relationship, optionally specifying a condition and
417 attributes for matching records. See L</ATTRIBUTES> for more information.
422 return shift->related_resultset(shift)->search(@_);
429 =item Arguments: none
431 =item Return Value: $cursor
435 Returns a storage-driven cursor to the given resultset. See
436 L<DBIx::Class::Cursor> for more information.
442 my $attrs = { %{$self->{attrs}} };
443 return $self->{cursor}
444 ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
445 $attrs->{where},$attrs);
452 =item Arguments: $cond?
454 =item Return Value: $row_object?
458 my $cd = $schema->resultset('CD')->single({ year => 2001 });
460 Inflates the first result without creating a cursor if the resultset has
461 any records in it; if not returns nothing. Used by L</find> as an optimisation.
466 my ($self, $where) = @_;
467 my $attrs = { %{$self->{attrs}} };
469 if (defined $attrs->{where}) {
472 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
473 $where, delete $attrs->{where} ]
476 $attrs->{where} = $where;
479 my @data = $self->result_source->storage->select_single(
480 $self->{from}, $attrs->{select},
481 $attrs->{where},$attrs);
482 return (@data ? $self->_construct_object(@data) : ());
489 =item Arguments: $cond?
491 =item Return Value: $resultsetcolumn
495 my $max_length = $rs->get_column('length')->max;
497 Returns a ResultSetColumn instance for $column based on $self
502 my ($self, $column) = @_;
504 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
512 =item Arguments: $cond, \%attrs?
514 =item Return Value: $resultset (scalar context), @row_objs (list context)
518 # WHERE title LIKE '%blue%'
519 $cd_rs = $rs->search_like({ title => '%blue%'});
521 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
522 that this is simply a convenience method. You most likely want to use
523 L</search> with specific operators.
525 For more information, see L<DBIx::Class::Manual::Cookbook>.
531 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
532 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
533 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
534 return $class->search($query, { %$attrs });
541 =item Arguments: $first, $last
543 =item Return Value: $resultset (scalar context), @row_objs (list context)
547 Returns a resultset or object list representing a subset of elements from the
548 resultset slice is called on. Indexes are from 0, i.e., to get the first
551 my ($one, $two, $three) = $rs->slice(0, 2);
556 my ($self, $min, $max) = @_;
557 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
558 $attrs->{offset} = $self->{attrs}{offset} || 0;
559 $attrs->{offset} += $min;
560 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
561 return $self->search(undef(), $attrs);
562 #my $slice = (ref $self)->new($self->result_source, $attrs);
563 #return (wantarray ? $slice->all : $slice);
570 =item Arguments: none
572 =item Return Value: $result?
576 Returns the next element in the resultset (C<undef> is there is none).
578 Can be used to efficiently iterate over records in the resultset:
580 my $rs = $schema->resultset('CD')->search;
581 while (my $cd = $rs->next) {
585 Note that you need to store the resultset object, and call C<next> on it.
586 Calling C<< resultset('Table')->next >> repeatedly will always return the
587 first record from the resultset.
593 if (my $cache = $self->get_cache) {
594 $self->{all_cache_position} ||= 0;
595 return $cache->[$self->{all_cache_position}++];
597 if ($self->{attrs}{cache}) {
598 $self->{all_cache_position} = 1;
599 return ($self->all)[0];
601 my @row = (exists $self->{stashed_row} ?
602 @{delete $self->{stashed_row}} :
605 # warn Dumper(\@row); use Data::Dumper;
606 return unless (@row);
607 return $self->_construct_object(@row);
610 sub _construct_object {
611 my ($self, @row) = @_;
612 my @as = @{ $self->{attrs}{as} };
614 my $info = $self->_collapse_result(\@as, \@row);
616 my $new = $self->result_class->inflate_result($self->result_source, @$info);
618 $new = $self->{attrs}{record_filter}->($new)
619 if exists $self->{attrs}{record_filter};
623 sub _collapse_result {
624 my ($self, $as, $row, $prefix) = @_;
629 foreach my $this_as (@$as) {
630 my $val = shift @copy;
631 if (defined $prefix) {
632 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
634 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
635 $const{$1||''}{$2} = $val;
638 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
639 $const{$1||''}{$2} = $val;
643 my $info = [ {}, {} ];
644 foreach my $key (keys %const) {
647 my @parts = split(/\./, $key);
648 foreach my $p (@parts) {
649 $target = $target->[1]->{$p} ||= [];
651 $target->[0] = $const{$key};
653 $info->[0] = $const{$key};
658 if (defined $prefix) {
660 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
661 } keys %{$self->{collapse}}
663 @collapse = keys %{$self->{collapse}};
667 my ($c) = sort { length $a <=> length $b } @collapse;
669 foreach my $p (split(/\./, $c)) {
670 $target = $target->[1]->{$p} ||= [];
672 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
673 my @co_key = @{$self->{collapse}{$c_prefix}};
674 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
675 my $tree = $self->_collapse_result($as, $row, $c_prefix);
678 !defined($tree->[0]->{$_}) ||
679 $co_check{$_} ne $tree->[0]->{$_}
682 last unless (@raw = $self->cursor->next);
683 $row = $self->{stashed_row} = \@raw;
684 $tree = $self->_collapse_result($as, $row, $c_prefix);
686 @$target = (@final ? @final : [ {}, {} ]);
687 # single empty result to indicate an empty prefetched has_many
697 =item Arguments: $result_source?
699 =item Return Value: $result_source
703 An accessor for the primary ResultSource object from which this ResultSet
713 =item Arguments: $cond, \%attrs??
715 =item Return Value: $count
719 Performs an SQL C<COUNT> with the same query as the resultset was built
720 with to find the number of elements. If passed arguments, does a search
721 on the resultset and counts the results of that.
723 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
724 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
725 not support C<DISTINCT> with multiple columns. If you are using such a
726 database, you should only use columns from the main table in your C<group_by>
733 return $self->search(@_)->count if @_ and defined $_[0];
734 return scalar @{ $self->get_cache } if $self->get_cache;
736 my $count = $self->_count;
737 return 0 unless $count;
739 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
740 $count = $self->{attrs}{rows} if
741 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
745 sub _count { # Separated out so pager can get the full count
747 my $select = { count => '*' };
748 my $attrs = { %{ $self->{attrs} } };
749 if (my $group_by = delete $attrs->{group_by}) {
750 delete $attrs->{having};
751 my @distinct = (ref $group_by ? @$group_by : ($group_by));
752 # todo: try CONCAT for multi-column pk
753 my @pk = $self->result_source->primary_columns;
755 foreach my $column (@distinct) {
756 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
757 @distinct = ($column);
763 $select = { count => { distinct => \@distinct } };
764 #use Data::Dumper; die Dumper $select;
767 $attrs->{select} = $select;
768 $attrs->{as} = [qw/count/];
770 # offset, order by and page are not needed to count. record_filter is cdbi
771 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
773 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
781 =item Arguments: $sql_fragment, @bind_values
783 =item Return Value: $count
787 Counts the results in a literal query. Equivalent to calling L</search_literal>
788 with the passed arguments, then L</count>.
792 sub count_literal { shift->search_literal(@_)->count; }
798 =item Arguments: none
800 =item Return Value: @objects
804 Returns all elements in the resultset. Called implicitly if the resultset
805 is returned in list context.
811 return @{ $self->get_cache } if $self->get_cache;
815 if (keys %{$self->{collapse}}) {
816 # Using $self->cursor->all is really just an optimisation.
817 # If we're collapsing has_many prefetches it probably makes
818 # very little difference, and this is cleaner than hacking
819 # _construct_object to survive the approach
820 $self->cursor->reset;
821 my @row = $self->cursor->next;
823 push(@obj, $self->_construct_object(@row));
824 @row = (exists $self->{stashed_row}
825 ? @{delete $self->{stashed_row}}
826 : $self->cursor->next);
829 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
832 $self->set_cache(\@obj) if $self->{attrs}{cache};
840 =item Arguments: none
842 =item Return Value: $self
846 Resets the resultset's cursor, so you can iterate through the elements again.
852 $self->{all_cache_position} = 0;
853 $self->cursor->reset;
861 =item Arguments: none
863 =item Return Value: $object?
867 Resets the resultset and returns an object for the first result (if the
868 resultset returns anything).
873 return $_[0]->reset->next;
876 # _cond_for_update_delete
878 # update/delete require the condition to be modified to handle
879 # the differing SQL syntax available. This transforms the $self->{cond}
880 # appropriately, returning the new condition.
882 sub _cond_for_update_delete {
886 if (!ref($self->{cond})) {
887 # No-op. No condition, we're updating/deleting everything
889 elsif (ref $self->{cond} eq 'ARRAY') {
893 foreach my $key (keys %{$_}) {
895 $hash{$1} = $_->{$key};
901 elsif (ref $self->{cond} eq 'HASH') {
902 if ((keys %{$self->{cond}})[0] eq '-and') {
905 my @cond = @{$self->{cond}{-and}};
906 for (my $i = 0; $i < @cond - 1; $i++) {
907 my $entry = $cond[$i];
910 if (ref $entry eq 'HASH') {
911 foreach my $key (keys %{$entry}) {
913 $hash{$1} = $entry->{$key};
917 $entry =~ /([^.]+)$/;
918 $hash{$entry} = $cond[++$i];
921 push @{$cond->{-and}}, \%hash;
925 foreach my $key (keys %{$self->{cond}}) {
927 $cond->{$1} = $self->{cond}{$key};
932 $self->throw_exception(
933 "Can't update/delete on resultset with condition unless hash or array"
945 =item Arguments: \%values
947 =item Return Value: $storage_rv
951 Sets the specified columns in the resultset to the supplied values in a
952 single query. Return value will be true if the update succeeded or false
953 if no records were updated; exact type of success value is storage-dependent.
958 my ($self, $values) = @_;
959 $self->throw_exception("Values for update must be a hash")
960 unless ref $values eq 'HASH';
962 my $cond = $self->_cond_for_update_delete;
964 return $self->result_source->storage->update(
965 $self->result_source->from, $values, $cond
973 =item Arguments: \%values
975 =item Return Value: 1
979 Fetches all objects and updates them one at a time. Note that C<update_all>
980 will run DBIC cascade triggers, while L</update> will not.
985 my ($self, $values) = @_;
986 $self->throw_exception("Values for update must be a hash")
987 unless ref $values eq 'HASH';
988 foreach my $obj ($self->all) {
989 $obj->set_columns($values)->update;
998 =item Arguments: none
1000 =item Return Value: 1
1004 Deletes the contents of the resultset from its result source. Note that this
1005 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1014 my $cond = $self->_cond_for_update_delete;
1016 $self->result_source->storage->delete($self->result_source->from, $cond);
1024 =item Arguments: none
1026 =item Return Value: 1
1030 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1031 will run DBIC cascade triggers, while L</delete> will not.
1037 $_->delete for $self->all;
1045 =item Arguments: none
1047 =item Return Value: $pager
1051 Return Value a L<Data::Page> object for the current resultset. Only makes
1052 sense for queries with a C<page> attribute.
1058 my $attrs = $self->{attrs};
1059 $self->throw_exception("Can't create pager for non-paged rs")
1060 unless $self->{page};
1061 $attrs->{rows} ||= 10;
1062 return $self->{pager} ||= Data::Page->new(
1063 $self->_count, $attrs->{rows}, $self->{page});
1070 =item Arguments: $page_number
1072 =item Return Value: $rs
1076 Returns a resultset for the $page_number page of the resultset on which page
1077 is called, where each page contains a number of rows equal to the 'rows'
1078 attribute set on the resultset (10 by default).
1083 my ($self, $page) = @_;
1084 my $attrs = { %{$self->{attrs}} };
1085 $attrs->{page} = $page;
1086 return (ref $self)->new($self->result_source, $attrs);
1093 =item Arguments: \%vals
1095 =item Return Value: $object
1099 Creates an object in the resultset's result class and returns it.
1104 my ($self, $values) = @_;
1105 $self->throw_exception( "new_result needs a hash" )
1106 unless (ref $values eq 'HASH');
1107 $self->throw_exception(
1108 "Can't abstract implicit construct, condition not a hash"
1109 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1111 my $alias = $self->{attrs}{alias};
1112 foreach my $key (keys %{$self->{cond}||{}}) {
1113 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1115 my $obj = $self->result_class->new(\%new);
1116 $obj->result_source($self->result_source) if $obj->can('result_source');
1124 =item Arguments: \%vals, \%attrs?
1126 =item Return Value: $object
1130 Find an existing record from this resultset. If none exists, instantiate a new
1131 result object and return it. The object will not be saved into your storage
1132 until you call L<DBIx::Class::Row/insert> on it.
1134 If you want objects to be saved immediately, use L</find_or_create> instead.
1140 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1141 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1142 my $exists = $self->find($hash, $attrs);
1143 return defined $exists ? $exists : $self->new_result($hash);
1150 =item Arguments: \%vals
1152 =item Return Value: $object
1156 Inserts a record into the resultset and returns the object representing it.
1158 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1163 my ($self, $attrs) = @_;
1164 $self->throw_exception( "create needs a hashref" )
1165 unless ref $attrs eq 'HASH';
1166 return $self->new_result($attrs)->insert;
1169 =head2 find_or_create
1173 =item Arguments: \%vals, \%attrs?
1175 =item Return Value: $object
1179 $class->find_or_create({ key => $val, ... });
1181 Searches for a record matching the search condition; if it doesn't find one,
1182 creates one and returns that instead.
1184 my $cd = $schema->resultset('CD')->find_or_create({
1186 artist => 'Massive Attack',
1187 title => 'Mezzanine',
1191 Also takes an optional C<key> attribute, to search by a specific key or unique
1192 constraint. For example:
1194 my $cd = $schema->resultset('CD')->find_or_create(
1196 artist => 'Massive Attack',
1197 title => 'Mezzanine',
1199 { key => 'artist_title' }
1202 See also L</find> and L</update_or_create>. For information on how to declare
1203 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1207 sub find_or_create {
1209 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1210 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1211 my $exists = $self->find($hash, $attrs);
1212 return defined $exists ? $exists : $self->create($hash);
1215 =head2 update_or_create
1219 =item Arguments: \%col_values, { key => $unique_constraint }?
1221 =item Return Value: $object
1225 $class->update_or_create({ col => $val, ... });
1227 First, searches for an existing row matching one of the unique constraints
1228 (including the primary key) on the source of this resultset. If a row is
1229 found, updates it with the other given column values. Otherwise, creates a new
1232 Takes an optional C<key> attribute to search on a specific unique constraint.
1235 # In your application
1236 my $cd = $schema->resultset('CD')->update_or_create(
1238 artist => 'Massive Attack',
1239 title => 'Mezzanine',
1242 { key => 'artist_title' }
1245 If no C<key> is specified, it searches on all unique constraints defined on the
1246 source, including the primary key.
1248 If the C<key> is specified as C<primary>, it searches only on the primary key.
1250 See also L</find> and L</find_or_create>. For information on how to declare
1251 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1255 sub update_or_create {
1257 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1258 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1260 my $row = $self->find($hash, $attrs);
1262 $row->update($hash);
1266 return $self->create($hash);
1273 =item Arguments: none
1275 =item Return Value: \@cache_objects?
1279 Gets the contents of the cache for the resultset, if the cache is set.
1291 =item Arguments: \@cache_objects
1293 =item Return Value: \@cache_objects
1297 Sets the contents of the cache for the resultset. Expects an arrayref
1298 of objects of the same class as those produced by the resultset. Note that
1299 if the cache is set the resultset will return the cached objects rather
1300 than re-querying the database even if the cache attr is not set.
1305 my ( $self, $data ) = @_;
1306 $self->throw_exception("set_cache requires an arrayref")
1307 if defined($data) && (ref $data ne 'ARRAY');
1308 $self->{all_cache} = $data;
1315 =item Arguments: none
1317 =item Return Value: []
1321 Clears the cache for the resultset.
1326 shift->set_cache(undef);
1329 =head2 related_resultset
1333 =item Arguments: $relationship_name
1335 =item Return Value: $resultset
1339 Returns a related resultset for the supplied relationship name.
1341 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1345 sub related_resultset {
1346 my ( $self, $rel ) = @_;
1347 $self->{related_resultsets} ||= {};
1348 return $self->{related_resultsets}{$rel} ||= do {
1349 #warn "fetching related resultset for rel '$rel'";
1350 my $rel_obj = $self->result_source->relationship_info($rel);
1351 $self->throw_exception(
1352 "search_related: result source '" . $self->result_source->name .
1353 "' has no such relationship ${rel}")
1354 unless $rel_obj; #die Dumper $self->{attrs};
1356 my $rs = $self->search(undef, { join => $rel });
1357 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1358 && $rs->{attrs}{seen_join}{$rel} > 1
1359 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1362 $self->result_source->schema->resultset($rel_obj->{class}
1372 =head2 throw_exception
1374 See L<DBIx::Class::Schema/throw_exception> for details.
1378 sub throw_exception {
1380 $self->result_source->schema->throw_exception(@_);
1383 # XXX: FIXME: Attributes docs need clearing up
1387 The resultset takes various attributes that modify its behavior. Here's an
1394 =item Value: ($order_by | \@order_by)
1398 Which column(s) to order the results by. This is currently passed
1399 through directly to SQL, so you can give e.g. C<year DESC> for a
1400 descending order on the column `year'.
1406 =item Value: \@columns
1410 Shortcut to request a particular set of columns to be retrieved. Adds
1411 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1412 from that, then auto-populates C<as> from C<select> as normal. (You may also
1413 use the C<cols> attribute, as in earlier versions of DBIC.)
1415 =head2 include_columns
1419 =item Value: \@columns
1423 Shortcut to include additional columns in the returned results - for example
1425 $schema->resultset('CD')->search(undef, {
1426 include_columns => ['artist.name'],
1430 would return all CDs and include a 'name' column to the information
1431 passed to object inflation
1437 =item Value: \@select_columns
1441 Indicates which columns should be selected from the storage. You can use
1442 column names, or in the case of RDBMS back ends, function or stored procedure
1445 $rs = $schema->resultset('Employee')->search(undef, {
1448 { count => 'employeeid' },
1453 When you use function/stored procedure names and do not supply an C<as>
1454 attribute, the column names returned are storage-dependent. E.g. MySQL would
1455 return a column named C<count(employeeid)> in the above example.
1461 =item Value: \@inflation_names
1465 Indicates column names for object inflation. This is used in conjunction with
1466 C<select>, usually when C<select> contains one or more function or stored
1469 $rs = $schema->resultset('Employee')->search(undef, {
1472 { count => 'employeeid' }
1474 as => ['name', 'employee_count'],
1477 my $employee = $rs->first(); # get the first Employee
1479 If the object against which the search is performed already has an accessor
1480 matching a column name specified in C<as>, the value can be retrieved using
1481 the accessor as normal:
1483 my $name = $employee->name();
1485 If on the other hand an accessor does not exist in the object, you need to
1486 use C<get_column> instead:
1488 my $employee_count = $employee->get_column('employee_count');
1490 You can create your own accessors if required - see
1491 L<DBIx::Class::Manual::Cookbook> for details.
1497 =item Value: ($rel_name | \@rel_names | \%rel_names)
1501 Contains a list of relationships that should be joined for this query. For
1504 # Get CDs by Nine Inch Nails
1505 my $rs = $schema->resultset('CD')->search(
1506 { 'artist.name' => 'Nine Inch Nails' },
1507 { join => 'artist' }
1510 Can also contain a hash reference to refer to the other relation's relations.
1513 package MyApp::Schema::Track;
1514 use base qw/DBIx::Class/;
1515 __PACKAGE__->table('track');
1516 __PACKAGE__->add_columns(qw/trackid cd position title/);
1517 __PACKAGE__->set_primary_key('trackid');
1518 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1521 # In your application
1522 my $rs = $schema->resultset('Artist')->search(
1523 { 'track.title' => 'Teardrop' },
1525 join => { cd => 'track' },
1526 order_by => 'artist.name',
1530 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1531 similarly for a third time). For e.g.
1533 my $rs = $schema->resultset('Artist')->search({
1534 'cds.title' => 'Down to Earth',
1535 'cds_2.title' => 'Popular',
1537 join => [ qw/cds cds/ ],
1540 will return a set of all artists that have both a cd with title 'Down
1541 to Earth' and a cd with title 'Popular'.
1543 If you want to fetch related objects from other tables as well, see C<prefetch>
1550 =item Value: ($rel_name | \@rel_names | \%rel_names)
1554 Contains one or more relationships that should be fetched along with the main
1555 query (when they are accessed afterwards they will have already been
1556 "prefetched"). This is useful for when you know you will need the related
1557 objects, because it saves at least one query:
1559 my $rs = $schema->resultset('Tag')->search(
1568 The initial search results in SQL like the following:
1570 SELECT tag.*, cd.*, artist.* FROM tag
1571 JOIN cd ON tag.cd = cd.cdid
1572 JOIN artist ON cd.artist = artist.artistid
1574 L<DBIx::Class> has no need to go back to the database when we access the
1575 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1578 Simple prefetches will be joined automatically, so there is no need
1579 for a C<join> attribute in the above search. If you're prefetching to
1580 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1581 specify the join as well.
1583 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1584 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1585 with an accessor type of 'single' or 'filter').
1591 =item Value: \@from_clause
1595 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1596 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1599 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1600 C<join> will usually do what you need and it is strongly recommended that you
1601 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1603 In simple terms, C<from> works as follows:
1606 { <alias> => <table>, -join_type => 'inner|left|right' }
1607 [] # nested JOIN (optional)
1608 { <table.column> => <foreign_table.foreign_key> }
1614 ON <table.column> = <foreign_table.foreign_key>
1616 An easy way to follow the examples below is to remember the following:
1618 Anything inside "[]" is a JOIN
1619 Anything inside "{}" is a condition for the enclosing JOIN
1621 The following examples utilize a "person" table in a family tree application.
1622 In order to express parent->child relationships, this table is self-joined:
1624 # Person->belongs_to('father' => 'Person');
1625 # Person->belongs_to('mother' => 'Person');
1627 C<from> can be used to nest joins. Here we return all children with a father,
1628 then search against all mothers of those children:
1630 $rs = $schema->resultset('Person')->search(
1633 alias => 'mother', # alias columns in accordance with "from"
1635 { mother => 'person' },
1638 { child => 'person' },
1640 { father => 'person' },
1641 { 'father.person_id' => 'child.father_id' }
1644 { 'mother.person_id' => 'child.mother_id' }
1651 # SELECT mother.* FROM person mother
1654 # JOIN person father
1655 # ON ( father.person_id = child.father_id )
1657 # ON ( mother.person_id = child.mother_id )
1659 The type of any join can be controlled manually. To search against only people
1660 with a father in the person table, we could explicitly use C<INNER JOIN>:
1662 $rs = $schema->resultset('Person')->search(
1665 alias => 'child', # alias columns in accordance with "from"
1667 { child => 'person' },
1669 { father => 'person', -join_type => 'inner' },
1670 { 'father.id' => 'child.father_id' }
1677 # SELECT child.* FROM person child
1678 # INNER JOIN person father ON child.father_id = father.id
1688 Makes the resultset paged and specifies the page to retrieve. Effectively
1689 identical to creating a non-pages resultset and then calling ->page($page)
1700 Specifes the maximum number of rows for direct retrieval or the number of
1701 rows per page if the page attribute or method is used.
1707 =item Value: \@columns
1711 A arrayref of columns to group by. Can include columns of joined tables.
1713 group_by => [qw/ column1 column2 ... /]
1719 =item Value: $condition
1723 HAVING is a select statement attribute that is applied between GROUP BY and
1724 ORDER BY. It is applied to the after the grouping calculations have been
1727 having => { 'count(employee)' => { '>=', 100 } }
1733 =item Value: (0 | 1)
1737 Set to 1 to group by all columns.
1741 Set to 1 to cache search results. This prevents extra SQL queries if you
1742 revisit rows in your ResultSet:
1744 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1746 while( my $artist = $resultset->next ) {
1750 $rs->first; # without cache, this would issue a query
1752 By default, searches are not cached.
1754 For more examples of using these attributes, see
1755 L<DBIx::Class::Manual::Cookbook>.