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 = $rs->next) {
498 if (@{$self->{all_cache} || []}) {
499 $self->{all_cache_position} ||= 0;
500 return $self->{all_cache}->[$self->{all_cache_position}++];
502 if ($self->{attrs}{cache}) {
503 $self->{all_cache_position} = 1;
504 return ($self->all)[0];
506 my @row = (exists $self->{stashed_row} ?
507 @{delete $self->{stashed_row}} :
510 # warn Dumper(\@row); use Data::Dumper;
511 return unless (@row);
512 return $self->_construct_object(@row);
515 sub _construct_object {
516 my ($self, @row) = @_;
517 my @as = @{ $self->{attrs}{as} };
519 my $info = $self->_collapse_result(\@as, \@row);
521 my $new = $self->result_class->inflate_result($self->result_source, @$info);
523 $new = $self->{attrs}{record_filter}->($new)
524 if exists $self->{attrs}{record_filter};
528 sub _collapse_result {
529 my ($self, $as, $row, $prefix) = @_;
534 foreach my $this_as (@$as) {
535 my $val = shift @copy;
536 if (defined $prefix) {
537 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
539 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
540 $const{$1||''}{$2} = $val;
543 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
544 $const{$1||''}{$2} = $val;
548 my $info = [ {}, {} ];
549 foreach my $key (keys %const) {
552 my @parts = split(/\./, $key);
553 foreach my $p (@parts) {
554 $target = $target->[1]->{$p} ||= [];
556 $target->[0] = $const{$key};
558 $info->[0] = $const{$key};
563 if (defined $prefix) {
565 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
566 } keys %{$self->{collapse}}
568 @collapse = keys %{$self->{collapse}};
572 my ($c) = sort { length $a <=> length $b } @collapse;
574 foreach my $p (split(/\./, $c)) {
575 $target = $target->[1]->{$p} ||= [];
577 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
578 my @co_key = @{$self->{collapse}{$c_prefix}};
579 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
580 my $tree = $self->_collapse_result($as, $row, $c_prefix);
583 !defined($tree->[0]->{$_}) ||
584 $co_check{$_} ne $tree->[0]->{$_}
587 last unless (@raw = $self->cursor->next);
588 $row = $self->{stashed_row} = \@raw;
589 $tree = $self->_collapse_result($as, $row, $c_prefix);
590 #warn Data::Dumper::Dumper($tree, $row);
602 =item Arguments: $result_source?
604 =item Return Value: $result_source
608 An accessor for the primary ResultSource object from which this ResultSet
618 =item Arguments: $cond, \%attrs??
620 =item Return Value: $count
624 Performs an SQL C<COUNT> with the same query as the resultset was built
625 with to find the number of elements. If passed arguments, does a search
626 on the resultset and counts the results of that.
628 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
629 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
630 not support C<DISTINCT> with multiple columns. If you are using such a
631 database, you should only use columns from the main table in your C<group_by>
638 return $self->search(@_)->count if @_ and defined $_[0];
639 return scalar @{ $self->get_cache } if @{ $self->get_cache };
641 my $count = $self->_count;
642 return 0 unless $count;
644 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
645 $count = $self->{attrs}{rows} if
646 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
650 sub _count { # Separated out so pager can get the full count
652 my $select = { count => '*' };
653 my $attrs = { %{ $self->{attrs} } };
654 if (my $group_by = delete $attrs->{group_by}) {
655 delete $attrs->{having};
656 my @distinct = (ref $group_by ? @$group_by : ($group_by));
657 # todo: try CONCAT for multi-column pk
658 my @pk = $self->result_source->primary_columns;
660 foreach my $column (@distinct) {
661 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
662 @distinct = ($column);
668 $select = { count => { distinct => \@distinct } };
669 #use Data::Dumper; die Dumper $select;
672 $attrs->{select} = $select;
673 $attrs->{as} = [qw/count/];
675 # offset, order by and page are not needed to count. record_filter is cdbi
676 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
678 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
686 =item Arguments: $sql_fragment, @bind_values
688 =item Return Value: $count
692 Counts the results in a literal query. Equivalent to calling L</search_literal>
693 with the passed arguments, then L</count>.
697 sub count_literal { shift->search_literal(@_)->count; }
703 =item Arguments: none
705 =item Return Value: @objects
709 Returns all elements in the resultset. Called implicitly if the resultset
710 is returned in list context.
716 return @{ $self->get_cache } if @{ $self->get_cache };
720 if (keys %{$self->{collapse}}) {
721 # Using $self->cursor->all is really just an optimisation.
722 # If we're collapsing has_many prefetches it probably makes
723 # very little difference, and this is cleaner than hacking
724 # _construct_object to survive the approach
725 $self->cursor->reset;
726 my @row = $self->cursor->next;
728 push(@obj, $self->_construct_object(@row));
729 @row = (exists $self->{stashed_row}
730 ? @{delete $self->{stashed_row}}
731 : $self->cursor->next);
734 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
737 $self->set_cache(\@obj) if $self->{attrs}{cache};
745 =item Arguments: none
747 =item Return Value: $self
751 Resets the resultset's cursor, so you can iterate through the elements again.
757 $self->{all_cache_position} = 0;
758 $self->cursor->reset;
766 =item Arguments: none
768 =item Return Value: $object?
772 Resets the resultset and returns an object for the first result (if the
773 resultset returns anything).
778 return $_[0]->reset->next;
785 =item Arguments: \%values
787 =item Return Value: $storage_rv
791 Sets the specified columns in the resultset to the supplied values in a
792 single query. Return value will be true if the update succeeded or false
793 if no records were updated; exact type of success value is storage-dependent.
798 my ($self, $values) = @_;
799 $self->throw_exception("Values for update must be a hash")
800 unless ref $values eq 'HASH';
801 return $self->result_source->storage->update(
802 $self->result_source->from, $values, $self->{cond}
810 =item Arguments: \%values
812 =item Return Value: 1
816 Fetches all objects and updates them one at a time. Note that C<update_all>
817 will run DBIC cascade triggers, while L</update> will not.
822 my ($self, $values) = @_;
823 $self->throw_exception("Values for update must be a hash")
824 unless ref $values eq 'HASH';
825 foreach my $obj ($self->all) {
826 $obj->set_columns($values)->update;
835 =item Arguments: none
837 =item Return Value: 1
841 Deletes the contents of the resultset from its result source. Note that this
842 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
851 if (!ref($self->{cond})) {
853 # No-op. No condition, we're deleting everything
855 } elsif (ref $self->{cond} eq 'ARRAY') {
857 $del = [ map { my %hash;
858 foreach my $key (keys %{$_}) {
860 $hash{$1} = $_->{$key};
861 }; \%hash; } @{$self->{cond}} ];
863 } elsif (ref $self->{cond} eq 'HASH') {
865 if ((keys %{$self->{cond}})[0] eq '-and') {
867 $del->{-and} = [ map { my %hash;
868 foreach my $key (keys %{$_}) {
870 $hash{$1} = $_->{$key};
871 }; \%hash; } @{$self->{cond}{-and}} ];
875 foreach my $key (keys %{$self->{cond}}) {
877 $del->{$1} = $self->{cond}{$key};
882 $self->throw_exception(
883 "Can't delete on resultset with condition unless hash or array"
887 $self->result_source->storage->delete($self->result_source->from, $del);
895 =item Arguments: none
897 =item Return Value: 1
901 Fetches all objects and deletes them one at a time. Note that C<delete_all>
902 will run DBIC cascade triggers, while L</delete> will not.
908 $_->delete for $self->all;
916 =item Arguments: none
918 =item Return Value: $pager
922 Return Value a L<Data::Page> object for the current resultset. Only makes
923 sense for queries with a C<page> attribute.
929 my $attrs = $self->{attrs};
930 $self->throw_exception("Can't create pager for non-paged rs")
931 unless $self->{page};
932 $attrs->{rows} ||= 10;
933 return $self->{pager} ||= Data::Page->new(
934 $self->_count, $attrs->{rows}, $self->{page});
941 =item Arguments: $page_number
943 =item Return Value: $rs
947 Returns a resultset for the $page_number page of the resultset on which page
948 is called, where each page contains a number of rows equal to the 'rows'
949 attribute set on the resultset (10 by default).
954 my ($self, $page) = @_;
955 my $attrs = { %{$self->{attrs}} };
956 $attrs->{page} = $page;
957 return (ref $self)->new($self->result_source, $attrs);
964 =item Arguments: \%vals
966 =item Return Value: $object
970 Creates an object in the resultset's result class and returns it.
975 my ($self, $values) = @_;
976 $self->throw_exception( "new_result needs a hash" )
977 unless (ref $values eq 'HASH');
978 $self->throw_exception(
979 "Can't abstract implicit construct, condition not a hash"
980 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
982 my $alias = $self->{attrs}{alias};
983 foreach my $key (keys %{$self->{cond}||{}}) {
984 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
986 my $obj = $self->result_class->new(\%new);
987 $obj->result_source($self->result_source) if $obj->can('result_source');
995 =item Arguments: \%vals
997 =item Return Value: $object
1001 Inserts a record into the resultset and returns the object representing it.
1003 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1008 my ($self, $attrs) = @_;
1009 $self->throw_exception( "create needs a hashref" )
1010 unless ref $attrs eq 'HASH';
1011 return $self->new_result($attrs)->insert;
1014 =head2 find_or_create
1018 =item Arguments: \%vals, \%attrs?
1020 =item Return Value: $object
1024 $class->find_or_create({ key => $val, ... });
1026 Searches for a record matching the search condition; if it doesn't find one,
1027 creates one and returns that instead.
1029 my $cd = $schema->resultset('CD')->find_or_create({
1031 artist => 'Massive Attack',
1032 title => 'Mezzanine',
1036 Also takes an optional C<key> attribute, to search by a specific key or unique
1037 constraint. For example:
1039 my $cd = $schema->resultset('CD')->find_or_create(
1041 artist => 'Massive Attack',
1042 title => 'Mezzanine',
1044 { key => 'artist_title' }
1047 See also L</find> and L</update_or_create>.
1051 sub find_or_create {
1053 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1054 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1055 my $exists = $self->find($hash, $attrs);
1056 return defined $exists ? $exists : $self->create($hash);
1059 =head2 update_or_create
1063 =item Arguments: \%col_values, { key => $unique_constraint }?
1065 =item Return Value: $object
1069 $class->update_or_create({ col => $val, ... });
1071 First, searches for an existing row matching one of the unique constraints
1072 (including the primary key) on the source of this resultset. If a row is
1073 found, updates it with the other given column values. Otherwise, creates a new
1076 Takes an optional C<key> attribute to search on a specific unique constraint.
1079 # In your application
1080 my $cd = $schema->resultset('CD')->update_or_create(
1082 artist => 'Massive Attack',
1083 title => 'Mezzanine',
1086 { key => 'artist_title' }
1089 If no C<key> is specified, it searches on all unique constraints defined on the
1090 source, including the primary key.
1092 If the C<key> is specified as C<primary>, it searches only on the primary key.
1094 See also L</find> and L</find_or_create>.
1098 sub update_or_create {
1100 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1101 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1103 my %unique_constraints = $self->result_source->unique_constraints;
1104 my @constraint_names = (exists $attrs->{key}
1106 : keys %unique_constraints);
1109 foreach my $name (@constraint_names) {
1110 my @unique_cols = @{ $unique_constraints{$name} };
1112 map { $_ => $hash->{$_} }
1113 grep { exists $hash->{$_} }
1116 push @unique_hashes, \%unique_hash
1117 if (scalar keys %unique_hash == scalar @unique_cols);
1120 if (@unique_hashes) {
1121 my $row = $self->single(\@unique_hashes);
1123 $row->set_columns($hash);
1129 return $self->create($hash);
1136 =item Arguments: none
1138 =item Return Value: \@cache_objects?
1142 Gets the contents of the cache for the resultset, if the cache is set.
1147 shift->{all_cache} || [];
1154 =item Arguments: \@cache_objects
1156 =item Return Value: \@cache_objects
1160 Sets the contents of the cache for the resultset. Expects an arrayref
1161 of objects of the same class as those produced by the resultset. Note that
1162 if the cache is set the resultset will return the cached objects rather
1163 than re-querying the database even if the cache attr is not set.
1168 my ( $self, $data ) = @_;
1169 $self->throw_exception("set_cache requires an arrayref")
1170 if ref $data ne 'ARRAY';
1171 my $result_class = $self->result_class;
1173 $self->throw_exception(
1174 "cannot cache object of type '$_', expected '$result_class'"
1175 ) if ref $_ ne $result_class;
1177 $self->{all_cache} = $data;
1184 =item Arguments: none
1186 =item Return Value: []
1190 Clears the cache for the resultset.
1195 shift->set_cache([]);
1198 =head2 related_resultset
1202 =item Arguments: $relationship_name
1204 =item Return Value: $resultset
1208 Returns a related resultset for the supplied relationship name.
1210 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1214 sub related_resultset {
1215 my ( $self, $rel ) = @_;
1216 $self->{related_resultsets} ||= {};
1217 return $self->{related_resultsets}{$rel} ||= do {
1218 #warn "fetching related resultset for rel '$rel'";
1219 my $rel_obj = $self->result_source->relationship_info($rel);
1220 $self->throw_exception(
1221 "search_related: result source '" . $self->result_source->name .
1222 "' has no such relationship ${rel}")
1223 unless $rel_obj; #die Dumper $self->{attrs};
1225 my $rs = $self->search(undef, { join => $rel });
1226 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1227 && $rs->{attrs}{seen_join}{$rel} > 1
1228 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1231 $self->result_source->schema->resultset($rel_obj->{class}
1241 =head2 throw_exception
1243 See L<DBIx::Class::Schema/throw_exception> for details.
1247 sub throw_exception {
1249 $self->result_source->schema->throw_exception(@_);
1252 # XXX: FIXME: Attributes docs need clearing up
1256 The resultset takes various attributes that modify its behavior. Here's an
1263 =item Value: ($order_by | \@order_by)
1267 Which column(s) to order the results by. This is currently passed
1268 through directly to SQL, so you can give e.g. C<year DESC> for a
1269 descending order on the column `year'.
1275 =item Value: \@columns
1279 Shortcut to request a particular set of columns to be retrieved. Adds
1280 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1281 from that, then auto-populates C<as> from C<select> as normal. (You may also
1282 use the C<cols> attribute, as in earlier versions of DBIC.)
1284 =head2 include_columns
1288 =item Value: \@columns
1292 Shortcut to include additional columns in the returned results - for example
1294 $schema->resultset('CD')->search(undef, {
1295 include_columns => ['artist.name'],
1299 would return all CDs and include a 'name' column to the information
1300 passed to object inflation
1306 =item Value: \@select_columns
1310 Indicates which columns should be selected from the storage. You can use
1311 column names, or in the case of RDBMS back ends, function or stored procedure
1314 $rs = $schema->resultset('Employee')->search(undef, {
1317 { count => 'employeeid' },
1322 When you use function/stored procedure names and do not supply an C<as>
1323 attribute, the column names returned are storage-dependent. E.g. MySQL would
1324 return a column named C<count(employeeid)> in the above example.
1330 =item Value: \@inflation_names
1334 Indicates column names for object inflation. This is used in conjunction with
1335 C<select>, usually when C<select> contains one or more function or stored
1338 $rs = $schema->resultset('Employee')->search(undef, {
1341 { count => 'employeeid' }
1343 as => ['name', 'employee_count'],
1346 my $employee = $rs->first(); # get the first Employee
1348 If the object against which the search is performed already has an accessor
1349 matching a column name specified in C<as>, the value can be retrieved using
1350 the accessor as normal:
1352 my $name = $employee->name();
1354 If on the other hand an accessor does not exist in the object, you need to
1355 use C<get_column> instead:
1357 my $employee_count = $employee->get_column('employee_count');
1359 You can create your own accessors if required - see
1360 L<DBIx::Class::Manual::Cookbook> for details.
1366 =item Value: ($rel_name | \@rel_names | \%rel_names)
1370 Contains a list of relationships that should be joined for this query. For
1373 # Get CDs by Nine Inch Nails
1374 my $rs = $schema->resultset('CD')->search(
1375 { 'artist.name' => 'Nine Inch Nails' },
1376 { join => 'artist' }
1379 Can also contain a hash reference to refer to the other relation's relations.
1382 package MyApp::Schema::Track;
1383 use base qw/DBIx::Class/;
1384 __PACKAGE__->table('track');
1385 __PACKAGE__->add_columns(qw/trackid cd position title/);
1386 __PACKAGE__->set_primary_key('trackid');
1387 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1390 # In your application
1391 my $rs = $schema->resultset('Artist')->search(
1392 { 'track.title' => 'Teardrop' },
1394 join => { cd => 'track' },
1395 order_by => 'artist.name',
1399 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1400 similarly for a third time). For e.g.
1402 my $rs = $schema->resultset('Artist')->search({
1403 'cds.title' => 'Down to Earth',
1404 'cds_2.title' => 'Popular',
1406 join => [ qw/cds cds/ ],
1409 will return a set of all artists that have both a cd with title 'Down
1410 to Earth' and a cd with title 'Popular'.
1412 If you want to fetch related objects from other tables as well, see C<prefetch>
1419 =item Value: ($rel_name | \@rel_names | \%rel_names)
1423 Contains one or more relationships that should be fetched along with the main
1424 query (when they are accessed afterwards they will have already been
1425 "prefetched"). This is useful for when you know you will need the related
1426 objects, because it saves at least one query:
1428 my $rs = $schema->resultset('Tag')->search(
1437 The initial search results in SQL like the following:
1439 SELECT tag.*, cd.*, artist.* FROM tag
1440 JOIN cd ON tag.cd = cd.cdid
1441 JOIN artist ON cd.artist = artist.artistid
1443 L<DBIx::Class> has no need to go back to the database when we access the
1444 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1447 Simple prefetches will be joined automatically, so there is no need
1448 for a C<join> attribute in the above search. If you're prefetching to
1449 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1450 specify the join as well.
1452 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1453 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1454 with an accessor type of 'single' or 'filter').
1460 =item Value: \@from_clause
1464 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1465 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1468 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1469 C<join> will usually do what you need and it is strongly recommended that you
1470 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1472 In simple terms, C<from> works as follows:
1475 { <alias> => <table>, -join_type => 'inner|left|right' }
1476 [] # nested JOIN (optional)
1477 { <table.column> => <foreign_table.foreign_key> }
1483 ON <table.column> = <foreign_table.foreign_key>
1485 An easy way to follow the examples below is to remember the following:
1487 Anything inside "[]" is a JOIN
1488 Anything inside "{}" is a condition for the enclosing JOIN
1490 The following examples utilize a "person" table in a family tree application.
1491 In order to express parent->child relationships, this table is self-joined:
1493 # Person->belongs_to('father' => 'Person');
1494 # Person->belongs_to('mother' => 'Person');
1496 C<from> can be used to nest joins. Here we return all children with a father,
1497 then search against all mothers of those children:
1499 $rs = $schema->resultset('Person')->search(
1502 alias => 'mother', # alias columns in accordance with "from"
1504 { mother => 'person' },
1507 { child => 'person' },
1509 { father => 'person' },
1510 { 'father.person_id' => 'child.father_id' }
1513 { 'mother.person_id' => 'child.mother_id' }
1520 # SELECT mother.* FROM person mother
1523 # JOIN person father
1524 # ON ( father.person_id = child.father_id )
1526 # ON ( mother.person_id = child.mother_id )
1528 The type of any join can be controlled manually. To search against only people
1529 with a father in the person table, we could explicitly use C<INNER JOIN>:
1531 $rs = $schema->resultset('Person')->search(
1534 alias => 'child', # alias columns in accordance with "from"
1536 { child => 'person' },
1538 { father => 'person', -join_type => 'inner' },
1539 { 'father.id' => 'child.father_id' }
1546 # SELECT child.* FROM person child
1547 # INNER JOIN person father ON child.father_id = father.id
1557 Makes the resultset paged and specifies the page to retrieve. Effectively
1558 identical to creating a non-pages resultset and then calling ->page($page)
1569 Specifes the maximum number of rows for direct retrieval or the number of
1570 rows per page if the page attribute or method is used.
1576 =item Value: \@columns
1580 A arrayref of columns to group by. Can include columns of joined tables.
1582 group_by => [qw/ column1 column2 ... /]
1588 =item Value: (0 | 1)
1592 Set to 1 to group by all columns.
1596 Set to 1 to cache search results. This prevents extra SQL queries if you
1597 revisit rows in your ResultSet:
1599 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1601 while( my $artist = $resultset->next ) {
1605 $rs->first; # without cache, this would issue a query
1607 By default, searches are not cached.
1609 For more examples of using these attributes, see
1610 L<DBIx::Class::Manual::Cookbook>.