1 package DBIx::Class::ResultSet;
11 use Scalar::Util qw/weaken/;
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) = @_;
88 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
89 #use Data::Dumper; warn Dumper($attrs);
90 my $alias = ($attrs->{alias} ||= 'me');
92 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
93 delete $attrs->{as} if $attrs->{columns};
94 $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select};
96 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
97 ] if $attrs->{columns};
99 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
101 if (my $include = delete $attrs->{include_columns}) {
102 push(@{$attrs->{select}}, @$include);
103 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
105 #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
107 $attrs->{from} ||= [ { $alias => $source->from } ];
108 $attrs->{seen_join} ||= {};
110 if (my $join = delete $attrs->{join}) {
111 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
112 if (ref $j eq 'HASH') {
113 $seen{$_} = 1 foreach keys %$j;
118 push(@{$attrs->{from}}, $source->resolve_join(
119 $join, $attrs->{alias}, $attrs->{seen_join})
123 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
124 $attrs->{order_by} = [ $attrs->{order_by} ] if
125 $attrs->{order_by} and !ref($attrs->{order_by});
126 $attrs->{order_by} ||= [];
128 my $collapse = $attrs->{collapse} || {};
129 if (my $prefetch = delete $attrs->{prefetch}) {
131 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
132 if ( ref $p eq 'HASH' ) {
133 foreach my $key (keys %$p) {
134 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
138 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
141 my @prefetch = $source->resolve_prefetch(
142 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
143 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
144 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
146 push(@{$attrs->{order_by}}, @pre_order);
148 $attrs->{collapse} = $collapse;
149 # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse};
151 if ($attrs->{page}) {
152 $attrs->{rows} ||= 10;
153 $attrs->{offset} ||= 0;
154 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
158 result_source => $source,
159 result_class => $attrs->{result_class} || $source->result_class,
160 cond => $attrs->{where},
161 from => $attrs->{from},
162 collapse => $collapse,
164 page => delete $attrs->{page},
174 =item Arguments: $cond, \%attrs?
176 =item Return Value: $resultset (scalar context), @row_objs (list context)
180 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
181 my $new_rs = $cd_rs->search({ year => 2005 });
183 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
184 # year = 2005 OR year = 2004
186 If you need to pass in additional attributes but no additional condition,
187 call it as C<search(undef, \%attrs)>.
189 # "SELECT name, artistid FROM $artist_table"
190 my @all_artists = $schema->resultset('Artist')->search(undef, {
191 columns => [qw/name artistid/],
199 my $attrs = { %{$self->{attrs}} };
200 my $having = delete $attrs->{having};
201 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
204 ? ((@_ == 1 || ref $_[0] eq "HASH")
207 ? $self->throw_exception(
208 "Odd number of arguments to search")
211 if (defined $where) {
212 $attrs->{where} = (defined $attrs->{where}
214 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
215 $where, $attrs->{where} ] }
219 if (defined $having) {
220 $attrs->{having} = (defined $attrs->{having}
222 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
223 $having, $attrs->{having} ] }
227 my $rs = (ref $self)->new($self->result_source, $attrs);
229 unless (@_) { # no search, effectively just a clone
230 my $rows = $self->get_cache;
232 $rs->set_cache($rows);
236 return (wantarray ? $rs->all : $rs);
239 =head2 search_literal
243 =item Arguments: $sql_fragment, @bind_values
245 =item Return Value: $resultset (scalar context), @row_objs (list context)
249 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
250 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
252 Pass a literal chunk of SQL to be added to the conditional part of the
258 my ($self, $cond, @vals) = @_;
259 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
260 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
261 return $self->search(\$cond, $attrs);
268 =item Arguments: @values | \%cols, \%attrs?
270 =item Return Value: $row_object
274 Finds a row based on its primary key or unique constraint. For example:
276 my $cd = $schema->resultset('CD')->find(5);
278 Also takes an optional C<key> attribute, to search by a specific key or unique
279 constraint. For example:
281 my $cd = $schema->resultset('CD')->find(
283 artist => 'Massive Attack',
284 title => 'Mezzanine',
286 { key => 'artist_title' }
289 See also L</find_or_create> and L</update_or_create>.
294 my ($self, @vals) = @_;
295 my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
297 my @cols = $self->result_source->primary_columns;
298 if (exists $attrs->{key}) {
299 my %uniq = $self->result_source->unique_constraints;
300 $self->throw_exception(
301 "Unknown key $attrs->{key} on '" . $self->result_source->name . "'"
302 ) unless exists $uniq{$attrs->{key}};
303 @cols = @{ $uniq{$attrs->{key}} };
305 #use Data::Dumper; warn Dumper($attrs, @vals, @cols);
306 $self->throw_exception(
307 "Can't find unless a primary key or unique constraint is defined"
311 if (ref $vals[0] eq 'HASH') {
312 $query = { %{$vals[0]} };
313 } elsif (@cols == @vals) {
315 @{$query}{@cols} = @vals;
319 foreach my $key (grep { ! m/\./ } keys %$query) {
320 $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key};
322 #warn Dumper($query);
325 my $rs = $self->search($query,$attrs);
326 return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
328 return keys %{$self->{collapse}} ?
329 $self->search($query)->next :
330 $self->single($query);
334 =head2 search_related
338 =item Arguments: $cond, \%attrs?
340 =item Return Value: $new_resultset
344 $new_rs = $cd_rs->search_related('artist', {
348 Searches the specified relationship, optionally specifying a condition and
349 attributes for matching records. See L</ATTRIBUTES> for more information.
354 return shift->related_resultset(shift)->search(@_);
361 =item Arguments: none
363 =item Return Value: $cursor
367 Returns a storage-driven cursor to the given resultset. See
368 L<DBIx::Class::Cursor> for more information.
374 my $attrs = { %{$self->{attrs}} };
375 return $self->{cursor}
376 ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
377 $attrs->{where},$attrs);
384 =item Arguments: $cond?
386 =item Return Value: $row_object?
390 my $cd = $schema->resultset('CD')->single({ year => 2001 });
392 Inflates the first result without creating a cursor if the resultset has
393 any records in it; if not returns nothing. Used by find() as an optimisation.
398 my ($self, $where) = @_;
399 my $attrs = { %{$self->{attrs}} };
401 if (defined $attrs->{where}) {
404 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
405 $where, delete $attrs->{where} ]
408 $attrs->{where} = $where;
411 my @data = $self->result_source->storage->select_single(
412 $self->{from}, $attrs->{select},
413 $attrs->{where},$attrs);
414 return (@data ? $self->_construct_object(@data) : ());
422 =item Arguments: $cond, \%attrs?
424 =item Return Value: $resultset (scalar context), @row_objs (list context)
428 # WHERE title LIKE '%blue%'
429 $cd_rs = $rs->search_like({ title => '%blue%'});
431 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
432 that this is simply a convenience method. You most likely want to use
433 L</search> with specific operators.
435 For more information, see L<DBIx::Class::Manual::Cookbook>.
441 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
442 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
443 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
444 return $class->search($query, { %$attrs });
451 =item Arguments: $first, $last
453 =item Return Value: $resultset (scalar context), @row_objs (list context)
457 Returns a resultset or object list representing a subset of elements from the
458 resultset slice is called on. Indexes are from 0, i.e., to get the first
461 my ($one, $two, $three) = $rs->slice(0, 2);
466 my ($self, $min, $max) = @_;
467 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
468 $attrs->{offset} = $self->{attrs}{offset} || 0;
469 $attrs->{offset} += $min;
470 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
471 return $self->search(undef(), $attrs);
472 #my $slice = (ref $self)->new($self->result_source, $attrs);
473 #return (wantarray ? $slice->all : $slice);
480 =item Arguments: none
482 =item Return Value: $result?
486 Returns the next element in the resultset (C<undef> is there is none).
488 Can be used to efficiently iterate over records in the resultset:
490 my $rs = $schema->resultset('CD')->search;
491 while (my $cd = $rs->next) {
495 Note that you need to store the resultset object, and call C<next> on it.
496 Calling C<< resultset('Table')->next >> repeatedly will always return the
497 first record from the resultset.
503 if (my $cache = $self->get_cache) {
504 $self->{all_cache_position} ||= 0;
505 return $cache->[$self->{all_cache_position}++];
507 if ($self->{attrs}{cache}) {
508 $self->{all_cache_position} = 1;
509 return ($self->all)[0];
511 my @row = (exists $self->{stashed_row} ?
512 @{delete $self->{stashed_row}} :
515 # warn Dumper(\@row); use Data::Dumper;
516 return unless (@row);
517 return $self->_construct_object(@row);
520 sub _construct_object {
521 my ($self, @row) = @_;
522 my @as = @{ $self->{attrs}{as} };
524 my $info = $self->_collapse_result(\@as, \@row);
526 my $new = $self->result_class->inflate_result($self->result_source, @$info);
528 $new = $self->{attrs}{record_filter}->($new)
529 if exists $self->{attrs}{record_filter};
533 sub _collapse_result {
534 my ($self, $as, $row, $prefix) = @_;
539 foreach my $this_as (@$as) {
540 my $val = shift @copy;
541 if (defined $prefix) {
542 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
544 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
545 $const{$1||''}{$2} = $val;
548 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
549 $const{$1||''}{$2} = $val;
553 my $info = [ {}, {} ];
554 foreach my $key (keys %const) {
557 my @parts = split(/\./, $key);
558 foreach my $p (@parts) {
559 $target = $target->[1]->{$p} ||= [];
561 $target->[0] = $const{$key};
563 $info->[0] = $const{$key};
568 if (defined $prefix) {
570 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
571 } keys %{$self->{collapse}}
573 @collapse = keys %{$self->{collapse}};
577 my ($c) = sort { length $a <=> length $b } @collapse;
579 foreach my $p (split(/\./, $c)) {
580 $target = $target->[1]->{$p} ||= [];
582 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
583 my @co_key = @{$self->{collapse}{$c_prefix}};
584 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
585 my $tree = $self->_collapse_result($as, $row, $c_prefix);
588 !defined($tree->[0]->{$_}) ||
589 $co_check{$_} ne $tree->[0]->{$_}
592 last unless (@raw = $self->cursor->next);
593 $row = $self->{stashed_row} = \@raw;
594 $tree = $self->_collapse_result($as, $row, $c_prefix);
596 @$target = (@final ? @final : [ {}, {} ]);
597 # single empty result to indicate an empty prefetched has_many
607 =item Arguments: $result_source?
609 =item Return Value: $result_source
613 An accessor for the primary ResultSource object from which this ResultSet
623 =item Arguments: $cond, \%attrs??
625 =item Return Value: $count
629 Performs an SQL C<COUNT> with the same query as the resultset was built
630 with to find the number of elements. If passed arguments, does a search
631 on the resultset and counts the results of that.
633 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
634 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
635 not support C<DISTINCT> with multiple columns. If you are using such a
636 database, you should only use columns from the main table in your C<group_by>
643 return $self->search(@_)->count if @_ and defined $_[0];
644 return scalar @{ $self->get_cache } if $self->get_cache;
646 my $count = $self->_count;
647 return 0 unless $count;
649 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
650 $count = $self->{attrs}{rows} if
651 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
655 sub _count { # Separated out so pager can get the full count
657 my $select = { count => '*' };
658 my $attrs = { %{ $self->{attrs} } };
659 if (my $group_by = delete $attrs->{group_by}) {
660 delete $attrs->{having};
661 my @distinct = (ref $group_by ? @$group_by : ($group_by));
662 # todo: try CONCAT for multi-column pk
663 my @pk = $self->result_source->primary_columns;
665 foreach my $column (@distinct) {
666 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
667 @distinct = ($column);
673 $select = { count => { distinct => \@distinct } };
674 #use Data::Dumper; die Dumper $select;
677 $attrs->{select} = $select;
678 $attrs->{as} = [qw/count/];
680 # offset, order by and page are not needed to count. record_filter is cdbi
681 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
683 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
691 =item Arguments: $sql_fragment, @bind_values
693 =item Return Value: $count
697 Counts the results in a literal query. Equivalent to calling L</search_literal>
698 with the passed arguments, then L</count>.
702 sub count_literal { shift->search_literal(@_)->count; }
708 =item Arguments: none
710 =item Return Value: @objects
714 Returns all elements in the resultset. Called implicitly if the resultset
715 is returned in list context.
721 return @{ $self->get_cache } if $self->get_cache;
725 if (keys %{$self->{collapse}}) {
726 # Using $self->cursor->all is really just an optimisation.
727 # If we're collapsing has_many prefetches it probably makes
728 # very little difference, and this is cleaner than hacking
729 # _construct_object to survive the approach
730 $self->cursor->reset;
731 my @row = $self->cursor->next;
733 push(@obj, $self->_construct_object(@row));
734 @row = (exists $self->{stashed_row}
735 ? @{delete $self->{stashed_row}}
736 : $self->cursor->next);
739 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
742 $self->set_cache(\@obj) if $self->{attrs}{cache};
750 =item Arguments: none
752 =item Return Value: $self
756 Resets the resultset's cursor, so you can iterate through the elements again.
762 $self->{all_cache_position} = 0;
763 $self->cursor->reset;
771 =item Arguments: none
773 =item Return Value: $object?
777 Resets the resultset and returns an object for the first result (if the
778 resultset returns anything).
783 return $_[0]->reset->next;
786 # _cond_for_update_delete
788 # update/delete require the condition to be modified to handle
789 # the differing SQL syntax available. This transforms the $self->{cond}
790 # appropriately, returning the new condition.
792 sub _cond_for_update_delete {
796 if (!ref($self->{cond})) {
797 # No-op. No condition, we're updating/deleting everything
799 elsif (ref $self->{cond} eq 'ARRAY') {
803 foreach my $key (keys %{$_}) {
805 $hash{$1} = $_->{$key};
811 elsif (ref $self->{cond} eq 'HASH') {
812 if ((keys %{$self->{cond}})[0] eq '-and') {
815 my @cond = @{$self->{cond}{-and}};
816 for (my $i = 0; $i < @cond - 1; $i++) {
817 my $entry = $cond[$i];
820 if (ref $entry eq 'HASH') {
821 foreach my $key (keys %{$entry}) {
823 $hash{$1} = $entry->{$key};
827 $entry =~ /([^.]+)$/;
828 $hash{$entry} = $cond[++$i];
831 push @{$cond->{-and}}, \%hash;
835 foreach my $key (keys %{$self->{cond}}) {
837 $cond->{$1} = $self->{cond}{$key};
842 $self->throw_exception(
843 "Can't update/delete on resultset with condition unless hash or array"
855 =item Arguments: \%values
857 =item Return Value: $storage_rv
861 Sets the specified columns in the resultset to the supplied values in a
862 single query. Return value will be true if the update succeeded or false
863 if no records were updated; exact type of success value is storage-dependent.
868 my ($self, $values) = @_;
869 $self->throw_exception("Values for update must be a hash")
870 unless ref $values eq 'HASH';
872 my $cond = $self->_cond_for_update_delete;
874 return $self->result_source->storage->update(
875 $self->result_source->from, $values, $cond
883 =item Arguments: \%values
885 =item Return Value: 1
889 Fetches all objects and updates them one at a time. Note that C<update_all>
890 will run DBIC cascade triggers, while L</update> will not.
895 my ($self, $values) = @_;
896 $self->throw_exception("Values for update must be a hash")
897 unless ref $values eq 'HASH';
898 foreach my $obj ($self->all) {
899 $obj->set_columns($values)->update;
908 =item Arguments: none
910 =item Return Value: 1
914 Deletes the contents of the resultset from its result source. Note that this
915 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
924 my $cond = $self->_cond_for_update_delete;
926 $self->result_source->storage->delete($self->result_source->from, $cond);
934 =item Arguments: none
936 =item Return Value: 1
940 Fetches all objects and deletes them one at a time. Note that C<delete_all>
941 will run DBIC cascade triggers, while L</delete> will not.
947 $_->delete for $self->all;
955 =item Arguments: none
957 =item Return Value: $pager
961 Return Value a L<Data::Page> object for the current resultset. Only makes
962 sense for queries with a C<page> attribute.
968 my $attrs = $self->{attrs};
969 $self->throw_exception("Can't create pager for non-paged rs")
970 unless $self->{page};
971 $attrs->{rows} ||= 10;
972 return $self->{pager} ||= Data::Page->new(
973 $self->_count, $attrs->{rows}, $self->{page});
980 =item Arguments: $page_number
982 =item Return Value: $rs
986 Returns a resultset for the $page_number page of the resultset on which page
987 is called, where each page contains a number of rows equal to the 'rows'
988 attribute set on the resultset (10 by default).
993 my ($self, $page) = @_;
994 my $attrs = { %{$self->{attrs}} };
995 $attrs->{page} = $page;
996 return (ref $self)->new($self->result_source, $attrs);
1003 =item Arguments: \%vals
1005 =item Return Value: $object
1009 Creates an object in the resultset's result class and returns it.
1014 my ($self, $values) = @_;
1015 $self->throw_exception( "new_result needs a hash" )
1016 unless (ref $values eq 'HASH');
1017 $self->throw_exception(
1018 "Can't abstract implicit construct, condition not a hash"
1019 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1021 my $alias = $self->{attrs}{alias};
1022 foreach my $key (keys %{$self->{cond}||{}}) {
1023 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1025 my $obj = $self->result_class->new(\%new);
1026 $obj->result_source($self->result_source) if $obj->can('result_source');
1034 =item Arguments: \%vals
1036 =item Return Value: $object
1040 Inserts a record into the resultset and returns the object representing it.
1042 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1047 my ($self, $attrs) = @_;
1048 $self->throw_exception( "create needs a hashref" )
1049 unless ref $attrs eq 'HASH';
1050 return $self->new_result($attrs)->insert;
1053 =head2 find_or_create
1057 =item Arguments: \%vals, \%attrs?
1059 =item Return Value: $object
1063 $class->find_or_create({ key => $val, ... });
1065 Searches for a record matching the search condition; if it doesn't find one,
1066 creates one and returns that instead.
1068 my $cd = $schema->resultset('CD')->find_or_create({
1070 artist => 'Massive Attack',
1071 title => 'Mezzanine',
1075 Also takes an optional C<key> attribute, to search by a specific key or unique
1076 constraint. For example:
1078 my $cd = $schema->resultset('CD')->find_or_create(
1080 artist => 'Massive Attack',
1081 title => 'Mezzanine',
1083 { key => 'artist_title' }
1086 See also L</find> and L</update_or_create>.
1090 sub find_or_create {
1092 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1093 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1094 my $exists = $self->find($hash, $attrs);
1095 return defined $exists ? $exists : $self->create($hash);
1098 =head2 update_or_create
1102 =item Arguments: \%col_values, { key => $unique_constraint }?
1104 =item Return Value: $object
1108 $class->update_or_create({ col => $val, ... });
1110 First, searches for an existing row matching one of the unique constraints
1111 (including the primary key) on the source of this resultset. If a row is
1112 found, updates it with the other given column values. Otherwise, creates a new
1115 Takes an optional C<key> attribute to search on a specific unique constraint.
1118 # In your application
1119 my $cd = $schema->resultset('CD')->update_or_create(
1121 artist => 'Massive Attack',
1122 title => 'Mezzanine',
1125 { key => 'artist_title' }
1128 If no C<key> is specified, it searches on all unique constraints defined on the
1129 source, including the primary key.
1131 If the C<key> is specified as C<primary>, it searches only on the primary key.
1133 See also L</find> and L</find_or_create>.
1137 sub update_or_create {
1139 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1140 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1142 my %unique_constraints = $self->result_source->unique_constraints;
1143 my @constraint_names = (exists $attrs->{key}
1145 : keys %unique_constraints);
1148 foreach my $name (@constraint_names) {
1149 my @unique_cols = @{ $unique_constraints{$name} };
1151 map { $_ => $hash->{$_} }
1152 grep { exists $hash->{$_} }
1155 push @unique_hashes, \%unique_hash
1156 if (scalar keys %unique_hash == scalar @unique_cols);
1159 if (@unique_hashes) {
1160 my $row = $self->single(\@unique_hashes);
1162 $row->set_columns($hash);
1168 return $self->create($hash);
1175 =item Arguments: none
1177 =item Return Value: \@cache_objects?
1181 Gets the contents of the cache for the resultset, if the cache is set.
1193 =item Arguments: \@cache_objects
1195 =item Return Value: \@cache_objects
1199 Sets the contents of the cache for the resultset. Expects an arrayref
1200 of objects of the same class as those produced by the resultset. Note that
1201 if the cache is set the resultset will return the cached objects rather
1202 than re-querying the database even if the cache attr is not set.
1207 my ( $self, $data ) = @_;
1208 $self->throw_exception("set_cache requires an arrayref")
1209 if defined($data) && (ref $data ne 'ARRAY');
1210 $self->{all_cache} = $data;
1217 =item Arguments: none
1219 =item Return Value: []
1223 Clears the cache for the resultset.
1228 shift->set_cache(undef);
1231 =head2 related_resultset
1235 =item Arguments: $relationship_name
1237 =item Return Value: $resultset
1241 Returns a related resultset for the supplied relationship name.
1243 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1247 sub related_resultset {
1248 my ( $self, $rel ) = @_;
1249 $self->{related_resultsets} ||= {};
1250 return $self->{related_resultsets}{$rel} ||= do {
1251 #warn "fetching related resultset for rel '$rel'";
1252 my $rel_obj = $self->result_source->relationship_info($rel);
1253 $self->throw_exception(
1254 "search_related: result source '" . $self->result_source->name .
1255 "' has no such relationship ${rel}")
1256 unless $rel_obj; #die Dumper $self->{attrs};
1258 my $rs = $self->search(undef, { join => $rel });
1259 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1260 && $rs->{attrs}{seen_join}{$rel} > 1
1261 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1264 $self->result_source->schema->resultset($rel_obj->{class}
1274 =head2 throw_exception
1276 See L<DBIx::Class::Schema/throw_exception> for details.
1280 sub throw_exception {
1282 $self->result_source->schema->throw_exception(@_);
1285 # XXX: FIXME: Attributes docs need clearing up
1289 The resultset takes various attributes that modify its behavior. Here's an
1296 =item Value: ($order_by | \@order_by)
1300 Which column(s) to order the results by. This is currently passed
1301 through directly to SQL, so you can give e.g. C<year DESC> for a
1302 descending order on the column `year'.
1308 =item Value: \@columns
1312 Shortcut to request a particular set of columns to be retrieved. Adds
1313 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1314 from that, then auto-populates C<as> from C<select> as normal. (You may also
1315 use the C<cols> attribute, as in earlier versions of DBIC.)
1317 =head2 include_columns
1321 =item Value: \@columns
1325 Shortcut to include additional columns in the returned results - for example
1327 $schema->resultset('CD')->search(undef, {
1328 include_columns => ['artist.name'],
1332 would return all CDs and include a 'name' column to the information
1333 passed to object inflation
1339 =item Value: \@select_columns
1343 Indicates which columns should be selected from the storage. You can use
1344 column names, or in the case of RDBMS back ends, function or stored procedure
1347 $rs = $schema->resultset('Employee')->search(undef, {
1350 { count => 'employeeid' },
1355 When you use function/stored procedure names and do not supply an C<as>
1356 attribute, the column names returned are storage-dependent. E.g. MySQL would
1357 return a column named C<count(employeeid)> in the above example.
1363 =item Value: \@inflation_names
1367 Indicates column names for object inflation. This is used in conjunction with
1368 C<select>, usually when C<select> contains one or more function or stored
1371 $rs = $schema->resultset('Employee')->search(undef, {
1374 { count => 'employeeid' }
1376 as => ['name', 'employee_count'],
1379 my $employee = $rs->first(); # get the first Employee
1381 If the object against which the search is performed already has an accessor
1382 matching a column name specified in C<as>, the value can be retrieved using
1383 the accessor as normal:
1385 my $name = $employee->name();
1387 If on the other hand an accessor does not exist in the object, you need to
1388 use C<get_column> instead:
1390 my $employee_count = $employee->get_column('employee_count');
1392 You can create your own accessors if required - see
1393 L<DBIx::Class::Manual::Cookbook> for details.
1399 =item Value: ($rel_name | \@rel_names | \%rel_names)
1403 Contains a list of relationships that should be joined for this query. For
1406 # Get CDs by Nine Inch Nails
1407 my $rs = $schema->resultset('CD')->search(
1408 { 'artist.name' => 'Nine Inch Nails' },
1409 { join => 'artist' }
1412 Can also contain a hash reference to refer to the other relation's relations.
1415 package MyApp::Schema::Track;
1416 use base qw/DBIx::Class/;
1417 __PACKAGE__->table('track');
1418 __PACKAGE__->add_columns(qw/trackid cd position title/);
1419 __PACKAGE__->set_primary_key('trackid');
1420 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1423 # In your application
1424 my $rs = $schema->resultset('Artist')->search(
1425 { 'track.title' => 'Teardrop' },
1427 join => { cd => 'track' },
1428 order_by => 'artist.name',
1432 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1433 similarly for a third time). For e.g.
1435 my $rs = $schema->resultset('Artist')->search({
1436 'cds.title' => 'Down to Earth',
1437 'cds_2.title' => 'Popular',
1439 join => [ qw/cds cds/ ],
1442 will return a set of all artists that have both a cd with title 'Down
1443 to Earth' and a cd with title 'Popular'.
1445 If you want to fetch related objects from other tables as well, see C<prefetch>
1452 =item Value: ($rel_name | \@rel_names | \%rel_names)
1456 Contains one or more relationships that should be fetched along with the main
1457 query (when they are accessed afterwards they will have already been
1458 "prefetched"). This is useful for when you know you will need the related
1459 objects, because it saves at least one query:
1461 my $rs = $schema->resultset('Tag')->search(
1470 The initial search results in SQL like the following:
1472 SELECT tag.*, cd.*, artist.* FROM tag
1473 JOIN cd ON tag.cd = cd.cdid
1474 JOIN artist ON cd.artist = artist.artistid
1476 L<DBIx::Class> has no need to go back to the database when we access the
1477 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1480 Simple prefetches will be joined automatically, so there is no need
1481 for a C<join> attribute in the above search. If you're prefetching to
1482 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1483 specify the join as well.
1485 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1486 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1487 with an accessor type of 'single' or 'filter').
1493 =item Value: \@from_clause
1497 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1498 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1501 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1502 C<join> will usually do what you need and it is strongly recommended that you
1503 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1505 In simple terms, C<from> works as follows:
1508 { <alias> => <table>, -join_type => 'inner|left|right' }
1509 [] # nested JOIN (optional)
1510 { <table.column> => <foreign_table.foreign_key> }
1516 ON <table.column> = <foreign_table.foreign_key>
1518 An easy way to follow the examples below is to remember the following:
1520 Anything inside "[]" is a JOIN
1521 Anything inside "{}" is a condition for the enclosing JOIN
1523 The following examples utilize a "person" table in a family tree application.
1524 In order to express parent->child relationships, this table is self-joined:
1526 # Person->belongs_to('father' => 'Person');
1527 # Person->belongs_to('mother' => 'Person');
1529 C<from> can be used to nest joins. Here we return all children with a father,
1530 then search against all mothers of those children:
1532 $rs = $schema->resultset('Person')->search(
1535 alias => 'mother', # alias columns in accordance with "from"
1537 { mother => 'person' },
1540 { child => 'person' },
1542 { father => 'person' },
1543 { 'father.person_id' => 'child.father_id' }
1546 { 'mother.person_id' => 'child.mother_id' }
1553 # SELECT mother.* FROM person mother
1556 # JOIN person father
1557 # ON ( father.person_id = child.father_id )
1559 # ON ( mother.person_id = child.mother_id )
1561 The type of any join can be controlled manually. To search against only people
1562 with a father in the person table, we could explicitly use C<INNER JOIN>:
1564 $rs = $schema->resultset('Person')->search(
1567 alias => 'child', # alias columns in accordance with "from"
1569 { child => 'person' },
1571 { father => 'person', -join_type => 'inner' },
1572 { 'father.id' => 'child.father_id' }
1579 # SELECT child.* FROM person child
1580 # INNER JOIN person father ON child.father_id = father.id
1590 Makes the resultset paged and specifies the page to retrieve. Effectively
1591 identical to creating a non-pages resultset and then calling ->page($page)
1602 Specifes the maximum number of rows for direct retrieval or the number of
1603 rows per page if the page attribute or method is used.
1609 =item Value: \@columns
1613 A arrayref of columns to group by. Can include columns of joined tables.
1615 group_by => [qw/ column1 column2 ... /]
1621 =item Value: $condition
1625 HAVING is a select statement attribute that is applied between GROUP BY and
1626 ORDER BY. It is applied to the after the grouping calculations have been
1629 having => { 'count(employee)' => { '>=', 100 } }
1635 =item Value: (0 | 1)
1639 Set to 1 to group by all columns.
1643 Set to 1 to cache search results. This prevents extra SQL queries if you
1644 revisit rows in your ResultSet:
1646 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1648 while( my $artist = $resultset->next ) {
1652 $rs->first; # without cache, this would issue a query
1654 By default, searches are not cached.
1656 For more examples of using these attributes, see
1657 L<DBIx::Class::Manual::Cookbook>.