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/],
202 my $attrs = { %{$self->{attrs}} };
203 my $having = delete $attrs->{having};
204 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
207 ? ((@_ == 1 || ref $_[0] eq "HASH")
210 ? $self->throw_exception(
211 "Odd number of arguments to search")
214 if (defined $where) {
215 $attrs->{where} = (defined $attrs->{where}
217 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
218 $where, $attrs->{where} ] }
222 if (defined $having) {
223 $attrs->{having} = (defined $attrs->{having}
225 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
226 $having, $attrs->{having} ] }
230 $rs = (ref $self)->new($self->result_source, $attrs);
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} ||= 0;
469 $attrs->{offset} += $min;
470 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
471 my $slice = (ref $self)->new($self->result_source, $attrs);
472 return (wantarray ? $slice->all : $slice);
479 =item Arguments: none
481 =item Return Value: $result?
485 Returns the next element in the resultset (C<undef> is there is none).
487 Can be used to efficiently iterate over records in the resultset:
489 my $rs = $schema->resultset('CD')->search;
490 while (my $cd = $rs->next) {
494 Note that you need to store the resultset object, and call C<next> on it.
495 Calling C<< resultset('Table')->next >> repeatedly will always return the
496 first record from the resultset.
502 if (@{$self->{all_cache} || []}) {
503 $self->{all_cache_position} ||= 0;
504 return $self->{all_cache}->[$self->{all_cache_position}++];
506 if ($self->{attrs}{cache}) {
507 $self->{all_cache_position} = 1;
508 return ($self->all)[0];
510 my @row = (exists $self->{stashed_row} ?
511 @{delete $self->{stashed_row}} :
514 # warn Dumper(\@row); use Data::Dumper;
515 return unless (@row);
516 return $self->_construct_object(@row);
519 sub _construct_object {
520 my ($self, @row) = @_;
521 my @as = @{ $self->{attrs}{as} };
523 my $info = $self->_collapse_result(\@as, \@row);
525 my $new = $self->result_class->inflate_result($self->result_source, @$info);
527 $new = $self->{attrs}{record_filter}->($new)
528 if exists $self->{attrs}{record_filter};
532 sub _collapse_result {
533 my ($self, $as, $row, $prefix) = @_;
538 foreach my $this_as (@$as) {
539 my $val = shift @copy;
540 if (defined $prefix) {
541 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
543 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
544 $const{$1||''}{$2} = $val;
547 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
548 $const{$1||''}{$2} = $val;
552 my $info = [ {}, {} ];
553 foreach my $key (keys %const) {
556 my @parts = split(/\./, $key);
557 foreach my $p (@parts) {
558 $target = $target->[1]->{$p} ||= [];
560 $target->[0] = $const{$key};
562 $info->[0] = $const{$key};
567 if (defined $prefix) {
569 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
570 } keys %{$self->{collapse}}
572 @collapse = keys %{$self->{collapse}};
576 my ($c) = sort { length $a <=> length $b } @collapse;
578 foreach my $p (split(/\./, $c)) {
579 $target = $target->[1]->{$p} ||= [];
581 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
582 my @co_key = @{$self->{collapse}{$c_prefix}};
583 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
584 my $tree = $self->_collapse_result($as, $row, $c_prefix);
587 !defined($tree->[0]->{$_}) ||
588 $co_check{$_} ne $tree->[0]->{$_}
591 last unless (@raw = $self->cursor->next);
592 $row = $self->{stashed_row} = \@raw;
593 $tree = $self->_collapse_result($as, $row, $c_prefix);
594 #warn Data::Dumper::Dumper($tree, $row);
606 =item Arguments: $result_source?
608 =item Return Value: $result_source
612 An accessor for the primary ResultSource object from which this ResultSet
622 =item Arguments: $cond, \%attrs??
624 =item Return Value: $count
628 Performs an SQL C<COUNT> with the same query as the resultset was built
629 with to find the number of elements. If passed arguments, does a search
630 on the resultset and counts the results of that.
632 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
633 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
634 not support C<DISTINCT> with multiple columns. If you are using such a
635 database, you should only use columns from the main table in your C<group_by>
642 return $self->search(@_)->count if @_ and defined $_[0];
643 return scalar @{ $self->get_cache } if @{ $self->get_cache };
645 my $count = $self->_count;
646 return 0 unless $count;
648 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
649 $count = $self->{attrs}{rows} if
650 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
654 sub _count { # Separated out so pager can get the full count
656 my $select = { count => '*' };
657 my $attrs = { %{ $self->{attrs} } };
658 if (my $group_by = delete $attrs->{group_by}) {
659 delete $attrs->{having};
660 my @distinct = (ref $group_by ? @$group_by : ($group_by));
661 # todo: try CONCAT for multi-column pk
662 my @pk = $self->result_source->primary_columns;
664 foreach my $column (@distinct) {
665 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
666 @distinct = ($column);
672 $select = { count => { distinct => \@distinct } };
673 #use Data::Dumper; die Dumper $select;
676 $attrs->{select} = $select;
677 $attrs->{as} = [qw/count/];
679 # offset, order by and page are not needed to count. record_filter is cdbi
680 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
682 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
690 =item Arguments: $sql_fragment, @bind_values
692 =item Return Value: $count
696 Counts the results in a literal query. Equivalent to calling L</search_literal>
697 with the passed arguments, then L</count>.
701 sub count_literal { shift->search_literal(@_)->count; }
707 =item Arguments: none
709 =item Return Value: @objects
713 Returns all elements in the resultset. Called implicitly if the resultset
714 is returned in list context.
720 return @{ $self->get_cache } if @{ $self->get_cache };
724 if (keys %{$self->{collapse}}) {
725 # Using $self->cursor->all is really just an optimisation.
726 # If we're collapsing has_many prefetches it probably makes
727 # very little difference, and this is cleaner than hacking
728 # _construct_object to survive the approach
729 $self->cursor->reset;
730 my @row = $self->cursor->next;
732 push(@obj, $self->_construct_object(@row));
733 @row = (exists $self->{stashed_row}
734 ? @{delete $self->{stashed_row}}
735 : $self->cursor->next);
738 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
741 $self->set_cache(\@obj) if $self->{attrs}{cache};
749 =item Arguments: none
751 =item Return Value: $self
755 Resets the resultset's cursor, so you can iterate through the elements again.
761 $self->{all_cache_position} = 0;
762 $self->cursor->reset;
770 =item Arguments: none
772 =item Return Value: $object?
776 Resets the resultset and returns an object for the first result (if the
777 resultset returns anything).
782 return $_[0]->reset->next;
789 =item Arguments: \%values
791 =item Return Value: $storage_rv
795 Sets the specified columns in the resultset to the supplied values in a
796 single query. Return value will be true if the update succeeded or false
797 if no records were updated; exact type of success value is storage-dependent.
802 my ($self, $values) = @_;
803 $self->throw_exception("Values for update must be a hash")
804 unless ref $values eq 'HASH';
805 return $self->result_source->storage->update(
806 $self->result_source->from, $values, $self->{cond}
814 =item Arguments: \%values
816 =item Return Value: 1
820 Fetches all objects and updates them one at a time. Note that C<update_all>
821 will run DBIC cascade triggers, while L</update> will not.
826 my ($self, $values) = @_;
827 $self->throw_exception("Values for update must be a hash")
828 unless ref $values eq 'HASH';
829 foreach my $obj ($self->all) {
830 $obj->set_columns($values)->update;
839 =item Arguments: none
841 =item Return Value: 1
845 Deletes the contents of the resultset from its result source. Note that this
846 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
855 if (!ref($self->{cond})) {
857 # No-op. No condition, we're deleting everything
859 } elsif (ref $self->{cond} eq 'ARRAY') {
861 $del = [ map { my %hash;
862 foreach my $key (keys %{$_}) {
864 $hash{$1} = $_->{$key};
865 }; \%hash; } @{$self->{cond}} ];
867 } elsif (ref $self->{cond} eq 'HASH') {
869 if ((keys %{$self->{cond}})[0] eq '-and') {
871 $del->{-and} = [ map { my %hash;
872 foreach my $key (keys %{$_}) {
874 $hash{$1} = $_->{$key};
875 }; \%hash; } @{$self->{cond}{-and}} ];
879 foreach my $key (keys %{$self->{cond}}) {
881 $del->{$1} = $self->{cond}{$key};
886 $self->throw_exception(
887 "Can't delete on resultset with condition unless hash or array"
891 $self->result_source->storage->delete($self->result_source->from, $del);
899 =item Arguments: none
901 =item Return Value: 1
905 Fetches all objects and deletes them one at a time. Note that C<delete_all>
906 will run DBIC cascade triggers, while L</delete> will not.
912 $_->delete for $self->all;
920 =item Arguments: none
922 =item Return Value: $pager
926 Return Value a L<Data::Page> object for the current resultset. Only makes
927 sense for queries with a C<page> attribute.
933 my $attrs = $self->{attrs};
934 $self->throw_exception("Can't create pager for non-paged rs")
935 unless $self->{page};
936 $attrs->{rows} ||= 10;
937 return $self->{pager} ||= Data::Page->new(
938 $self->_count, $attrs->{rows}, $self->{page});
945 =item Arguments: $page_number
947 =item Return Value: $rs
951 Returns a resultset for the $page_number page of the resultset on which page
952 is called, where each page contains a number of rows equal to the 'rows'
953 attribute set on the resultset (10 by default).
958 my ($self, $page) = @_;
959 my $attrs = { %{$self->{attrs}} };
960 $attrs->{page} = $page;
961 return (ref $self)->new($self->result_source, $attrs);
968 =item Arguments: \%vals
970 =item Return Value: $object
974 Creates an object in the resultset's result class and returns it.
979 my ($self, $values) = @_;
980 $self->throw_exception( "new_result needs a hash" )
981 unless (ref $values eq 'HASH');
982 $self->throw_exception(
983 "Can't abstract implicit construct, condition not a hash"
984 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
986 my $alias = $self->{attrs}{alias};
987 foreach my $key (keys %{$self->{cond}||{}}) {
988 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
990 my $obj = $self->result_class->new(\%new);
991 $obj->result_source($self->result_source) if $obj->can('result_source');
999 =item Arguments: \%vals
1001 =item Return Value: $object
1005 Inserts a record into the resultset and returns the object representing it.
1007 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1012 my ($self, $attrs) = @_;
1013 $self->throw_exception( "create needs a hashref" )
1014 unless ref $attrs eq 'HASH';
1015 return $self->new_result($attrs)->insert;
1018 =head2 find_or_create
1022 =item Arguments: \%vals, \%attrs?
1024 =item Return Value: $object
1028 $class->find_or_create({ key => $val, ... });
1030 Searches for a record matching the search condition; if it doesn't find one,
1031 creates one and returns that instead.
1033 my $cd = $schema->resultset('CD')->find_or_create({
1035 artist => 'Massive Attack',
1036 title => 'Mezzanine',
1040 Also takes an optional C<key> attribute, to search by a specific key or unique
1041 constraint. For example:
1043 my $cd = $schema->resultset('CD')->find_or_create(
1045 artist => 'Massive Attack',
1046 title => 'Mezzanine',
1048 { key => 'artist_title' }
1051 See also L</find> and L</update_or_create>.
1055 sub find_or_create {
1057 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1058 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1059 my $exists = $self->find($hash, $attrs);
1060 return defined $exists ? $exists : $self->create($hash);
1063 =head2 update_or_create
1067 =item Arguments: \%col_values, { key => $unique_constraint }?
1069 =item Return Value: $object
1073 $class->update_or_create({ col => $val, ... });
1075 First, searches for an existing row matching one of the unique constraints
1076 (including the primary key) on the source of this resultset. If a row is
1077 found, updates it with the other given column values. Otherwise, creates a new
1080 Takes an optional C<key> attribute to search on a specific unique constraint.
1083 # In your application
1084 my $cd = $schema->resultset('CD')->update_or_create(
1086 artist => 'Massive Attack',
1087 title => 'Mezzanine',
1090 { key => 'artist_title' }
1093 If no C<key> is specified, it searches on all unique constraints defined on the
1094 source, including the primary key.
1096 If the C<key> is specified as C<primary>, it searches only on the primary key.
1098 See also L</find> and L</find_or_create>.
1102 sub update_or_create {
1104 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1105 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1107 my %unique_constraints = $self->result_source->unique_constraints;
1108 my @constraint_names = (exists $attrs->{key}
1110 : keys %unique_constraints);
1113 foreach my $name (@constraint_names) {
1114 my @unique_cols = @{ $unique_constraints{$name} };
1116 map { $_ => $hash->{$_} }
1117 grep { exists $hash->{$_} }
1120 push @unique_hashes, \%unique_hash
1121 if (scalar keys %unique_hash == scalar @unique_cols);
1124 if (@unique_hashes) {
1125 my $row = $self->single(\@unique_hashes);
1127 $row->set_columns($hash);
1133 return $self->create($hash);
1140 =item Arguments: none
1142 =item Return Value: \@cache_objects?
1146 Gets the contents of the cache for the resultset, if the cache is set.
1151 shift->{all_cache} || [];
1158 =item Arguments: \@cache_objects
1160 =item Return Value: \@cache_objects
1164 Sets the contents of the cache for the resultset. Expects an arrayref
1165 of objects of the same class as those produced by the resultset. Note that
1166 if the cache is set the resultset will return the cached objects rather
1167 than re-querying the database even if the cache attr is not set.
1172 my ( $self, $data ) = @_;
1173 $self->throw_exception("set_cache requires an arrayref")
1174 if ref $data ne 'ARRAY';
1175 my $result_class = $self->result_class;
1177 $self->throw_exception(
1178 "cannot cache object of type '$_', expected '$result_class'"
1179 ) if ref $_ ne $result_class;
1181 $self->{all_cache} = $data;
1188 =item Arguments: none
1190 =item Return Value: []
1194 Clears the cache for the resultset.
1199 shift->set_cache([]);
1202 =head2 related_resultset
1206 =item Arguments: $relationship_name
1208 =item Return Value: $resultset
1212 Returns a related resultset for the supplied relationship name.
1214 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1218 sub related_resultset {
1219 my ( $self, $rel ) = @_;
1220 $self->{related_resultsets} ||= {};
1221 return $self->{related_resultsets}{$rel} ||= do {
1222 #warn "fetching related resultset for rel '$rel'";
1223 my $rel_obj = $self->result_source->relationship_info($rel);
1224 $self->throw_exception(
1225 "search_related: result source '" . $self->result_source->name .
1226 "' has no such relationship ${rel}")
1227 unless $rel_obj; #die Dumper $self->{attrs};
1229 my $rs = $self->search(undef, { join => $rel });
1230 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1231 && $rs->{attrs}{seen_join}{$rel} > 1
1232 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1235 $self->result_source->schema->resultset($rel_obj->{class}
1245 =head2 throw_exception
1247 See L<DBIx::Class::Schema/throw_exception> for details.
1251 sub throw_exception {
1253 $self->result_source->schema->throw_exception(@_);
1256 # XXX: FIXME: Attributes docs need clearing up
1260 The resultset takes various attributes that modify its behavior. Here's an
1267 =item Value: ($order_by | \@order_by)
1271 Which column(s) to order the results by. This is currently passed
1272 through directly to SQL, so you can give e.g. C<year DESC> for a
1273 descending order on the column `year'.
1279 =item Value: \@columns
1283 Shortcut to request a particular set of columns to be retrieved. Adds
1284 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1285 from that, then auto-populates C<as> from C<select> as normal. (You may also
1286 use the C<cols> attribute, as in earlier versions of DBIC.)
1288 =head2 include_columns
1292 =item Value: \@columns
1296 Shortcut to include additional columns in the returned results - for example
1298 $schema->resultset('CD')->search(undef, {
1299 include_columns => ['artist.name'],
1303 would return all CDs and include a 'name' column to the information
1304 passed to object inflation
1310 =item Value: \@select_columns
1314 Indicates which columns should be selected from the storage. You can use
1315 column names, or in the case of RDBMS back ends, function or stored procedure
1318 $rs = $schema->resultset('Employee')->search(undef, {
1321 { count => 'employeeid' },
1326 When you use function/stored procedure names and do not supply an C<as>
1327 attribute, the column names returned are storage-dependent. E.g. MySQL would
1328 return a column named C<count(employeeid)> in the above example.
1334 =item Value: \@inflation_names
1338 Indicates column names for object inflation. This is used in conjunction with
1339 C<select>, usually when C<select> contains one or more function or stored
1342 $rs = $schema->resultset('Employee')->search(undef, {
1345 { count => 'employeeid' }
1347 as => ['name', 'employee_count'],
1350 my $employee = $rs->first(); # get the first Employee
1352 If the object against which the search is performed already has an accessor
1353 matching a column name specified in C<as>, the value can be retrieved using
1354 the accessor as normal:
1356 my $name = $employee->name();
1358 If on the other hand an accessor does not exist in the object, you need to
1359 use C<get_column> instead:
1361 my $employee_count = $employee->get_column('employee_count');
1363 You can create your own accessors if required - see
1364 L<DBIx::Class::Manual::Cookbook> for details.
1370 =item Value: ($rel_name | \@rel_names | \%rel_names)
1374 Contains a list of relationships that should be joined for this query. For
1377 # Get CDs by Nine Inch Nails
1378 my $rs = $schema->resultset('CD')->search(
1379 { 'artist.name' => 'Nine Inch Nails' },
1380 { join => 'artist' }
1383 Can also contain a hash reference to refer to the other relation's relations.
1386 package MyApp::Schema::Track;
1387 use base qw/DBIx::Class/;
1388 __PACKAGE__->table('track');
1389 __PACKAGE__->add_columns(qw/trackid cd position title/);
1390 __PACKAGE__->set_primary_key('trackid');
1391 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1394 # In your application
1395 my $rs = $schema->resultset('Artist')->search(
1396 { 'track.title' => 'Teardrop' },
1398 join => { cd => 'track' },
1399 order_by => 'artist.name',
1403 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1404 similarly for a third time). For e.g.
1406 my $rs = $schema->resultset('Artist')->search({
1407 'cds.title' => 'Down to Earth',
1408 'cds_2.title' => 'Popular',
1410 join => [ qw/cds cds/ ],
1413 will return a set of all artists that have both a cd with title 'Down
1414 to Earth' and a cd with title 'Popular'.
1416 If you want to fetch related objects from other tables as well, see C<prefetch>
1423 =item Value: ($rel_name | \@rel_names | \%rel_names)
1427 Contains one or more relationships that should be fetched along with the main
1428 query (when they are accessed afterwards they will have already been
1429 "prefetched"). This is useful for when you know you will need the related
1430 objects, because it saves at least one query:
1432 my $rs = $schema->resultset('Tag')->search(
1441 The initial search results in SQL like the following:
1443 SELECT tag.*, cd.*, artist.* FROM tag
1444 JOIN cd ON tag.cd = cd.cdid
1445 JOIN artist ON cd.artist = artist.artistid
1447 L<DBIx::Class> has no need to go back to the database when we access the
1448 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1451 Simple prefetches will be joined automatically, so there is no need
1452 for a C<join> attribute in the above search. If you're prefetching to
1453 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1454 specify the join as well.
1456 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1457 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1458 with an accessor type of 'single' or 'filter').
1464 =item Value: \@from_clause
1468 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1469 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1472 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1473 C<join> will usually do what you need and it is strongly recommended that you
1474 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1476 In simple terms, C<from> works as follows:
1479 { <alias> => <table>, -join_type => 'inner|left|right' }
1480 [] # nested JOIN (optional)
1481 { <table.column> => <foreign_table.foreign_key> }
1487 ON <table.column> = <foreign_table.foreign_key>
1489 An easy way to follow the examples below is to remember the following:
1491 Anything inside "[]" is a JOIN
1492 Anything inside "{}" is a condition for the enclosing JOIN
1494 The following examples utilize a "person" table in a family tree application.
1495 In order to express parent->child relationships, this table is self-joined:
1497 # Person->belongs_to('father' => 'Person');
1498 # Person->belongs_to('mother' => 'Person');
1500 C<from> can be used to nest joins. Here we return all children with a father,
1501 then search against all mothers of those children:
1503 $rs = $schema->resultset('Person')->search(
1506 alias => 'mother', # alias columns in accordance with "from"
1508 { mother => 'person' },
1511 { child => 'person' },
1513 { father => 'person' },
1514 { 'father.person_id' => 'child.father_id' }
1517 { 'mother.person_id' => 'child.mother_id' }
1524 # SELECT mother.* FROM person mother
1527 # JOIN person father
1528 # ON ( father.person_id = child.father_id )
1530 # ON ( mother.person_id = child.mother_id )
1532 The type of any join can be controlled manually. To search against only people
1533 with a father in the person table, we could explicitly use C<INNER JOIN>:
1535 $rs = $schema->resultset('Person')->search(
1538 alias => 'child', # alias columns in accordance with "from"
1540 { child => 'person' },
1542 { father => 'person', -join_type => 'inner' },
1543 { 'father.id' => 'child.father_id' }
1550 # SELECT child.* FROM person child
1551 # INNER JOIN person father ON child.father_id = father.id
1561 Makes the resultset paged and specifies the page to retrieve. Effectively
1562 identical to creating a non-pages resultset and then calling ->page($page)
1573 Specifes the maximum number of rows for direct retrieval or the number of
1574 rows per page if the page attribute or method is used.
1580 =item Value: \@columns
1584 A arrayref of columns to group by. Can include columns of joined tables.
1586 group_by => [qw/ column1 column2 ... /]
1592 =item Value: $condition
1596 HAVING is a select statement attribute that is applied between GROUP BY and
1597 ORDER BY. It is applied to the after the grouping calculations have been
1600 having => { 'count(employee)' => { '>=', 100 } }
1606 =item Value: (0 | 1)
1610 Set to 1 to group by all columns.
1614 Set to 1 to cache search results. This prevents extra SQL queries if you
1615 revisit rows in your ResultSet:
1617 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1619 while( my $artist = $resultset->next ) {
1623 $rs->first; # without cache, this would issue a query
1625 By default, searches are not cached.
1627 For more examples of using these attributes, see
1628 L<DBIx::Class::Manual::Cookbook>.