1 package DBIx::Class::ResultSet;
11 use Scalar::Util qw/weaken/;
13 use DBIx::Class::ResultSetColumn;
14 use base qw/DBIx::Class/;
15 __PACKAGE__->load_components(qw/AccessorGroup/);
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
89 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
90 #use Data::Dumper; warn Dumper($attrs);
91 my $alias = ($attrs->{alias} ||= 'me');
93 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
94 delete $attrs->{as} if $attrs->{columns};
95 $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select};
97 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
98 ] if $attrs->{columns};
100 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
102 if (my $include = delete $attrs->{include_columns}) {
103 push(@{$attrs->{select}}, @$include);
104 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
106 #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
108 $attrs->{from} ||= [ { $alias => $source->from } ];
109 $attrs->{seen_join} ||= {};
111 if (my $join = delete $attrs->{join}) {
112 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
113 if (ref $j eq 'HASH') {
114 $seen{$_} = 1 foreach keys %$j;
119 push(@{$attrs->{from}}, $source->resolve_join(
120 $join, $attrs->{alias}, $attrs->{seen_join})
124 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
125 $attrs->{order_by} = [ $attrs->{order_by} ] if
126 $attrs->{order_by} and !ref($attrs->{order_by});
127 $attrs->{order_by} ||= [];
129 my $collapse = $attrs->{collapse} || {};
130 if (my $prefetch = delete $attrs->{prefetch}) {
132 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
133 if ( ref $p eq 'HASH' ) {
134 foreach my $key (keys %$p) {
135 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
139 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
142 my @prefetch = $source->resolve_prefetch(
143 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
144 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
145 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
147 push(@{$attrs->{order_by}}, @pre_order);
149 $attrs->{collapse} = $collapse;
150 # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse};
152 if ($attrs->{page}) {
153 $attrs->{rows} ||= 10;
154 $attrs->{offset} ||= 0;
155 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
159 result_source => $source,
160 result_class => $attrs->{result_class} || $source->result_class,
161 cond => $attrs->{where},
162 from => $attrs->{from},
163 collapse => $collapse,
165 page => delete $attrs->{page},
175 =item Arguments: $cond, \%attrs?
177 =item Return Value: $resultset (scalar context), @row_objs (list context)
181 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
182 my $new_rs = $cd_rs->search({ year => 2005 });
184 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
185 # year = 2005 OR year = 2004
187 If you need to pass in additional attributes but no additional condition,
188 call it as C<search(undef, \%attrs)>.
190 # "SELECT name, artistid FROM $artist_table"
191 my @all_artists = $schema->resultset('Artist')->search(undef, {
192 columns => [qw/name artistid/],
199 my $rs = $self->search_rs( @_ );
200 return (wantarray ? $rs->all : $rs);
207 =item Arguments: $cond, \%attrs?
209 =item Return Value: $resultset
213 This method does the same exact thing as search() except it will
214 always return a resultset, even in list context.
221 my $attrs = { %{$self->{attrs}} };
222 my $having = delete $attrs->{having};
223 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
226 ? ((@_ == 1 || ref $_[0] eq "HASH")
229 ? $self->throw_exception(
230 "Odd number of arguments to search")
233 if (defined $where) {
234 $attrs->{where} = (defined $attrs->{where}
236 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
237 $where, $attrs->{where} ] }
241 if (defined $having) {
242 $attrs->{having} = (defined $attrs->{having}
244 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
245 $having, $attrs->{having} ] }
249 my $rs = (ref $self)->new($self->result_source, $attrs);
251 unless (@_) { # no search, effectively just a clone
252 my $rows = $self->get_cache;
254 $rs->set_cache($rows);
261 =head2 search_literal
265 =item Arguments: $sql_fragment, @bind_values
267 =item Return Value: $resultset (scalar context), @row_objs (list context)
271 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
272 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
274 Pass a literal chunk of SQL to be added to the conditional part of the
280 my ($self, $cond, @vals) = @_;
281 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
282 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
283 return $self->search(\$cond, $attrs);
290 =item Arguments: @values | \%cols, \%attrs?
292 =item Return Value: $row_object
296 Finds a row based on its primary key or unique constraint. For example, to find
297 a row by its primary key:
299 my $cd = $schema->resultset('CD')->find(5);
301 You can also find a row by a specific unique constraint using the C<key>
302 attribute. For example:
304 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'artist_title' });
306 Additionally, you can specify the columns explicitly by name:
308 my $cd = $schema->resultset('CD')->find(
310 artist => 'Massive Attack',
311 title => 'Mezzanine',
313 { key => 'artist_title' }
316 If no C<key> is specified and you explicitly name columns, it searches on all
317 unique constraints defined on the source, including the primary key.
319 If the C<key> is specified as C<primary>, it searches only on the primary key.
321 See also L</find_or_create> and L</update_or_create>. For information on how to
322 declare unique constraints, see
323 L<DBIx::Class::ResultSource/add_unique_constraint>.
329 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
331 # Parse out a hash from input
332 my @cols = exists $attrs->{key}
333 ? $self->result_source->unique_constraint_columns($attrs->{key})
334 : $self->result_source->primary_columns;
337 if (ref $_[0] eq 'HASH') {
338 $hash = { %{$_[0]} };
340 elsif (@_ == @cols) {
342 @{$hash}{@cols} = @_;
345 # For backwards compatibility
349 $self->throw_exception(
350 "Arguments to find must be a hashref or match the number of columns in the "
351 . (exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key")
355 # Check the hash we just parsed against our source's unique constraints
356 my @constraint_names = exists $attrs->{key}
358 : $self->result_source->unique_constraint_names;
359 $self->throw_exception(
360 "Can't find unless a primary key or unique constraint is defined"
361 ) unless @constraint_names;
364 foreach my $name (@constraint_names) {
365 my @unique_cols = $self->result_source->unique_constraint_columns($name);
366 my $unique_query = $self->_build_unique_query($hash, \@unique_cols);
368 # Add the ResultSet's alias
369 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
370 $unique_query->{"$self->{attrs}{alias}.$key"} = delete $unique_query->{$key};
373 push @unique_queries, $unique_query if %$unique_query;
376 # Handle cases where the ResultSet already defines the query
377 my $query = @unique_queries ? \@unique_queries : undef;
381 my $rs = $self->search($query, $attrs);
382 return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
385 return keys %{$self->{collapse}}
386 ? $self->search($query)->next
387 : $self->single($query);
391 # _build_unique_query
393 # Constrain the specified query hash based on the specified column names.
395 sub _build_unique_query {
396 my ($self, $query, $unique_cols) = @_;
399 map { $_ => $query->{$_} }
400 grep { exists $query->{$_} }
403 return \%unique_query;
406 =head2 search_related
410 =item Arguments: $cond, \%attrs?
412 =item Return Value: $new_resultset
416 $new_rs = $cd_rs->search_related('artist', {
420 Searches the specified relationship, optionally specifying a condition and
421 attributes for matching records. See L</ATTRIBUTES> for more information.
426 return shift->related_resultset(shift)->search(@_);
433 =item Arguments: none
435 =item Return Value: $cursor
439 Returns a storage-driven cursor to the given resultset. See
440 L<DBIx::Class::Cursor> for more information.
446 my $attrs = { %{$self->{attrs}} };
447 return $self->{cursor}
448 ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
449 $attrs->{where},$attrs);
456 =item Arguments: $cond?
458 =item Return Value: $row_object?
462 my $cd = $schema->resultset('CD')->single({ year => 2001 });
464 Inflates the first result without creating a cursor if the resultset has
465 any records in it; if not returns nothing. Used by L</find> as an optimisation.
470 my ($self, $where) = @_;
471 my $attrs = { %{$self->{attrs}} };
473 if (defined $attrs->{where}) {
476 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
477 $where, delete $attrs->{where} ]
480 $attrs->{where} = $where;
483 my @data = $self->result_source->storage->select_single(
484 $self->{from}, $attrs->{select},
485 $attrs->{where},$attrs);
486 return (@data ? $self->_construct_object(@data) : ());
493 =item Arguments: $cond?
495 =item Return Value: $resultsetcolumn
499 my $max_length = $rs->get_column('length')->max;
501 Returns a ResultSetColumn instance for $column based on $self
506 my ($self, $column) = @_;
508 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
516 =item Arguments: $cond, \%attrs?
518 =item Return Value: $resultset (scalar context), @row_objs (list context)
522 # WHERE title LIKE '%blue%'
523 $cd_rs = $rs->search_like({ title => '%blue%'});
525 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
526 that this is simply a convenience method. You most likely want to use
527 L</search> with specific operators.
529 For more information, see L<DBIx::Class::Manual::Cookbook>.
535 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
536 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
537 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
538 return $class->search($query, { %$attrs });
545 =item Arguments: $first, $last
547 =item Return Value: $resultset (scalar context), @row_objs (list context)
551 Returns a resultset or object list representing a subset of elements from the
552 resultset slice is called on. Indexes are from 0, i.e., to get the first
555 my ($one, $two, $three) = $rs->slice(0, 2);
560 my ($self, $min, $max) = @_;
561 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
562 $attrs->{offset} = $self->{attrs}{offset} || 0;
563 $attrs->{offset} += $min;
564 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
565 return $self->search(undef(), $attrs);
566 #my $slice = (ref $self)->new($self->result_source, $attrs);
567 #return (wantarray ? $slice->all : $slice);
574 =item Arguments: none
576 =item Return Value: $result?
580 Returns the next element in the resultset (C<undef> is there is none).
582 Can be used to efficiently iterate over records in the resultset:
584 my $rs = $schema->resultset('CD')->search;
585 while (my $cd = $rs->next) {
589 Note that you need to store the resultset object, and call C<next> on it.
590 Calling C<< resultset('Table')->next >> repeatedly will always return the
591 first record from the resultset.
597 if (my $cache = $self->get_cache) {
598 $self->{all_cache_position} ||= 0;
599 return $cache->[$self->{all_cache_position}++];
601 if ($self->{attrs}{cache}) {
602 $self->{all_cache_position} = 1;
603 return ($self->all)[0];
605 my @row = (exists $self->{stashed_row} ?
606 @{delete $self->{stashed_row}} :
609 # warn Dumper(\@row); use Data::Dumper;
610 return unless (@row);
611 return $self->_construct_object(@row);
614 sub _construct_object {
615 my ($self, @row) = @_;
616 my @as = @{ $self->{attrs}{as} };
618 my $info = $self->_collapse_result(\@as, \@row);
620 my $new = $self->result_class->inflate_result($self->result_source, @$info);
622 $new = $self->{attrs}{record_filter}->($new)
623 if exists $self->{attrs}{record_filter};
627 sub _collapse_result {
628 my ($self, $as, $row, $prefix) = @_;
633 foreach my $this_as (@$as) {
634 my $val = shift @copy;
635 if (defined $prefix) {
636 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
638 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
639 $const{$1||''}{$2} = $val;
642 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
643 $const{$1||''}{$2} = $val;
647 my $info = [ {}, {} ];
648 foreach my $key (keys %const) {
651 my @parts = split(/\./, $key);
652 foreach my $p (@parts) {
653 $target = $target->[1]->{$p} ||= [];
655 $target->[0] = $const{$key};
657 $info->[0] = $const{$key};
662 if (defined $prefix) {
664 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
665 } keys %{$self->{collapse}}
667 @collapse = keys %{$self->{collapse}};
671 my ($c) = sort { length $a <=> length $b } @collapse;
673 foreach my $p (split(/\./, $c)) {
674 $target = $target->[1]->{$p} ||= [];
676 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
677 my @co_key = @{$self->{collapse}{$c_prefix}};
678 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
679 my $tree = $self->_collapse_result($as, $row, $c_prefix);
682 !defined($tree->[0]->{$_}) ||
683 $co_check{$_} ne $tree->[0]->{$_}
686 last unless (@raw = $self->cursor->next);
687 $row = $self->{stashed_row} = \@raw;
688 $tree = $self->_collapse_result($as, $row, $c_prefix);
690 @$target = (@final ? @final : [ {}, {} ]);
691 # single empty result to indicate an empty prefetched has_many
701 =item Arguments: $result_source?
703 =item Return Value: $result_source
707 An accessor for the primary ResultSource object from which this ResultSet
717 =item Arguments: $cond, \%attrs??
719 =item Return Value: $count
723 Performs an SQL C<COUNT> with the same query as the resultset was built
724 with to find the number of elements. If passed arguments, does a search
725 on the resultset and counts the results of that.
727 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
728 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
729 not support C<DISTINCT> with multiple columns. If you are using such a
730 database, you should only use columns from the main table in your C<group_by>
737 return $self->search(@_)->count if @_ and defined $_[0];
738 return scalar @{ $self->get_cache } if $self->get_cache;
740 my $count = $self->_count;
741 return 0 unless $count;
743 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
744 $count = $self->{attrs}{rows} if
745 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
749 sub _count { # Separated out so pager can get the full count
751 my $select = { count => '*' };
752 my $attrs = { %{ $self->{attrs} } };
753 if (my $group_by = delete $attrs->{group_by}) {
754 delete $attrs->{having};
755 my @distinct = (ref $group_by ? @$group_by : ($group_by));
756 # todo: try CONCAT for multi-column pk
757 my @pk = $self->result_source->primary_columns;
759 foreach my $column (@distinct) {
760 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
761 @distinct = ($column);
767 $select = { count => { distinct => \@distinct } };
768 #use Data::Dumper; die Dumper $select;
771 $attrs->{select} = $select;
772 $attrs->{as} = [qw/count/];
774 # offset, order by and page are not needed to count. record_filter is cdbi
775 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
777 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
785 =item Arguments: $sql_fragment, @bind_values
787 =item Return Value: $count
791 Counts the results in a literal query. Equivalent to calling L</search_literal>
792 with the passed arguments, then L</count>.
796 sub count_literal { shift->search_literal(@_)->count; }
802 =item Arguments: none
804 =item Return Value: @objects
808 Returns all elements in the resultset. Called implicitly if the resultset
809 is returned in list context.
815 return @{ $self->get_cache } if $self->get_cache;
819 if (keys %{$self->{collapse}}) {
820 # Using $self->cursor->all is really just an optimisation.
821 # If we're collapsing has_many prefetches it probably makes
822 # very little difference, and this is cleaner than hacking
823 # _construct_object to survive the approach
824 $self->cursor->reset;
825 my @row = $self->cursor->next;
827 push(@obj, $self->_construct_object(@row));
828 @row = (exists $self->{stashed_row}
829 ? @{delete $self->{stashed_row}}
830 : $self->cursor->next);
833 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
836 $self->set_cache(\@obj) if $self->{attrs}{cache};
844 =item Arguments: none
846 =item Return Value: $self
850 Resets the resultset's cursor, so you can iterate through the elements again.
856 $self->{all_cache_position} = 0;
857 $self->cursor->reset;
865 =item Arguments: none
867 =item Return Value: $object?
871 Resets the resultset and returns an object for the first result (if the
872 resultset returns anything).
877 return $_[0]->reset->next;
880 # _cond_for_update_delete
882 # update/delete require the condition to be modified to handle
883 # the differing SQL syntax available. This transforms the $self->{cond}
884 # appropriately, returning the new condition.
886 sub _cond_for_update_delete {
890 if (!ref($self->{cond})) {
891 # No-op. No condition, we're updating/deleting everything
893 elsif (ref $self->{cond} eq 'ARRAY') {
897 foreach my $key (keys %{$_}) {
899 $hash{$1} = $_->{$key};
905 elsif (ref $self->{cond} eq 'HASH') {
906 if ((keys %{$self->{cond}})[0] eq '-and') {
909 my @cond = @{$self->{cond}{-and}};
910 for (my $i = 0; $i < @cond - 1; $i++) {
911 my $entry = $cond[$i];
914 if (ref $entry eq 'HASH') {
915 foreach my $key (keys %{$entry}) {
917 $hash{$1} = $entry->{$key};
921 $entry =~ /([^.]+)$/;
922 $hash{$entry} = $cond[++$i];
925 push @{$cond->{-and}}, \%hash;
929 foreach my $key (keys %{$self->{cond}}) {
931 $cond->{$1} = $self->{cond}{$key};
936 $self->throw_exception(
937 "Can't update/delete on resultset with condition unless hash or array"
949 =item Arguments: \%values
951 =item Return Value: $storage_rv
955 Sets the specified columns in the resultset to the supplied values in a
956 single query. Return value will be true if the update succeeded or false
957 if no records were updated; exact type of success value is storage-dependent.
962 my ($self, $values) = @_;
963 $self->throw_exception("Values for update must be a hash")
964 unless ref $values eq 'HASH';
966 my $cond = $self->_cond_for_update_delete;
968 return $self->result_source->storage->update(
969 $self->result_source->from, $values, $cond
977 =item Arguments: \%values
979 =item Return Value: 1
983 Fetches all objects and updates them one at a time. Note that C<update_all>
984 will run DBIC cascade triggers, while L</update> will not.
989 my ($self, $values) = @_;
990 $self->throw_exception("Values for update must be a hash")
991 unless ref $values eq 'HASH';
992 foreach my $obj ($self->all) {
993 $obj->set_columns($values)->update;
1002 =item Arguments: none
1004 =item Return Value: 1
1008 Deletes the contents of the resultset from its result source. Note that this
1009 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1018 my $cond = $self->_cond_for_update_delete;
1020 $self->result_source->storage->delete($self->result_source->from, $cond);
1028 =item Arguments: none
1030 =item Return Value: 1
1034 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1035 will run DBIC cascade triggers, while L</delete> will not.
1041 $_->delete for $self->all;
1049 =item Arguments: none
1051 =item Return Value: $pager
1055 Return Value a L<Data::Page> object for the current resultset. Only makes
1056 sense for queries with a C<page> attribute.
1062 my $attrs = $self->{attrs};
1063 $self->throw_exception("Can't create pager for non-paged rs")
1064 unless $self->{page};
1065 $attrs->{rows} ||= 10;
1066 return $self->{pager} ||= Data::Page->new(
1067 $self->_count, $attrs->{rows}, $self->{page});
1074 =item Arguments: $page_number
1076 =item Return Value: $rs
1080 Returns a resultset for the $page_number page of the resultset on which page
1081 is called, where each page contains a number of rows equal to the 'rows'
1082 attribute set on the resultset (10 by default).
1087 my ($self, $page) = @_;
1088 my $attrs = { %{$self->{attrs}} };
1089 $attrs->{page} = $page;
1090 return (ref $self)->new($self->result_source, $attrs);
1097 =item Arguments: \%vals
1099 =item Return Value: $object
1103 Creates an object in the resultset's result class and returns it.
1108 my ($self, $values) = @_;
1109 $self->throw_exception( "new_result needs a hash" )
1110 unless (ref $values eq 'HASH');
1111 $self->throw_exception(
1112 "Can't abstract implicit construct, condition not a hash"
1113 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1115 my $alias = $self->{attrs}{alias};
1116 foreach my $key (keys %{$self->{cond}||{}}) {
1117 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1119 my $obj = $self->result_class->new(\%new);
1120 $obj->result_source($self->result_source) if $obj->can('result_source');
1128 =item Arguments: \%vals, \%attrs?
1130 =item Return Value: $object
1134 Find an existing record from this resultset. If none exists, instantiate a new
1135 result object and return it. The object will not be saved into your storage
1136 until you call L<DBIx::Class::Row/insert> on it.
1138 If you want objects to be saved immediately, use L</find_or_create> instead.
1144 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1145 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1146 my $exists = $self->find($hash, $attrs);
1147 return defined $exists ? $exists : $self->new_result($hash);
1154 =item Arguments: \%vals
1156 =item Return Value: $object
1160 Inserts a record into the resultset and returns the object representing it.
1162 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1167 my ($self, $attrs) = @_;
1168 $self->throw_exception( "create needs a hashref" )
1169 unless ref $attrs eq 'HASH';
1170 return $self->new_result($attrs)->insert;
1173 =head2 find_or_create
1177 =item Arguments: \%vals, \%attrs?
1179 =item Return Value: $object
1183 $class->find_or_create({ key => $val, ... });
1185 Searches for a record matching the search condition; if it doesn't find one,
1186 creates one and returns that instead.
1188 my $cd = $schema->resultset('CD')->find_or_create({
1190 artist => 'Massive Attack',
1191 title => 'Mezzanine',
1195 Also takes an optional C<key> attribute, to search by a specific key or unique
1196 constraint. For example:
1198 my $cd = $schema->resultset('CD')->find_or_create(
1200 artist => 'Massive Attack',
1201 title => 'Mezzanine',
1203 { key => 'artist_title' }
1206 See also L</find> and L</update_or_create>. For information on how to declare
1207 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1211 sub find_or_create {
1213 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1214 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1215 my $exists = $self->find($hash, $attrs);
1216 return defined $exists ? $exists : $self->create($hash);
1219 =head2 update_or_create
1223 =item Arguments: \%col_values, { key => $unique_constraint }?
1225 =item Return Value: $object
1229 $class->update_or_create({ col => $val, ... });
1231 First, searches for an existing row matching one of the unique constraints
1232 (including the primary key) on the source of this resultset. If a row is
1233 found, updates it with the other given column values. Otherwise, creates a new
1236 Takes an optional C<key> attribute to search on a specific unique constraint.
1239 # In your application
1240 my $cd = $schema->resultset('CD')->update_or_create(
1242 artist => 'Massive Attack',
1243 title => 'Mezzanine',
1246 { key => 'artist_title' }
1249 If no C<key> is specified, it searches on all unique constraints defined on the
1250 source, including the primary key.
1252 If the C<key> is specified as C<primary>, it searches only on the primary key.
1254 See also L</find> and L</find_or_create>. For information on how to declare
1255 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1259 sub update_or_create {
1261 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1262 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1264 my $row = $self->find($hash, $attrs);
1266 $row->update($hash);
1270 return $self->create($hash);
1277 =item Arguments: none
1279 =item Return Value: \@cache_objects?
1283 Gets the contents of the cache for the resultset, if the cache is set.
1295 =item Arguments: \@cache_objects
1297 =item Return Value: \@cache_objects
1301 Sets the contents of the cache for the resultset. Expects an arrayref
1302 of objects of the same class as those produced by the resultset. Note that
1303 if the cache is set the resultset will return the cached objects rather
1304 than re-querying the database even if the cache attr is not set.
1309 my ( $self, $data ) = @_;
1310 $self->throw_exception("set_cache requires an arrayref")
1311 if defined($data) && (ref $data ne 'ARRAY');
1312 $self->{all_cache} = $data;
1319 =item Arguments: none
1321 =item Return Value: []
1325 Clears the cache for the resultset.
1330 shift->set_cache(undef);
1333 =head2 related_resultset
1337 =item Arguments: $relationship_name
1339 =item Return Value: $resultset
1343 Returns a related resultset for the supplied relationship name.
1345 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1349 sub related_resultset {
1350 my ( $self, $rel ) = @_;
1351 $self->{related_resultsets} ||= {};
1352 return $self->{related_resultsets}{$rel} ||= do {
1353 #warn "fetching related resultset for rel '$rel'";
1354 my $rel_obj = $self->result_source->relationship_info($rel);
1355 $self->throw_exception(
1356 "search_related: result source '" . $self->result_source->name .
1357 "' has no such relationship ${rel}")
1358 unless $rel_obj; #die Dumper $self->{attrs};
1360 my $rs = $self->search(undef, { join => $rel });
1361 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1362 && $rs->{attrs}{seen_join}{$rel} > 1
1363 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1366 $self->result_source->schema->resultset($rel_obj->{class}
1376 =head2 throw_exception
1378 See L<DBIx::Class::Schema/throw_exception> for details.
1382 sub throw_exception {
1384 $self->result_source->schema->throw_exception(@_);
1387 # XXX: FIXME: Attributes docs need clearing up
1391 The resultset takes various attributes that modify its behavior. Here's an
1398 =item Value: ($order_by | \@order_by)
1402 Which column(s) to order the results by. This is currently passed
1403 through directly to SQL, so you can give e.g. C<year DESC> for a
1404 descending order on the column `year'.
1410 =item Value: \@columns
1414 Shortcut to request a particular set of columns to be retrieved. Adds
1415 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1416 from that, then auto-populates C<as> from C<select> as normal. (You may also
1417 use the C<cols> attribute, as in earlier versions of DBIC.)
1419 =head2 include_columns
1423 =item Value: \@columns
1427 Shortcut to include additional columns in the returned results - for example
1429 $schema->resultset('CD')->search(undef, {
1430 include_columns => ['artist.name'],
1434 would return all CDs and include a 'name' column to the information
1435 passed to object inflation
1441 =item Value: \@select_columns
1445 Indicates which columns should be selected from the storage. You can use
1446 column names, or in the case of RDBMS back ends, function or stored procedure
1449 $rs = $schema->resultset('Employee')->search(undef, {
1452 { count => 'employeeid' },
1457 When you use function/stored procedure names and do not supply an C<as>
1458 attribute, the column names returned are storage-dependent. E.g. MySQL would
1459 return a column named C<count(employeeid)> in the above example.
1465 =item Value: \@inflation_names
1469 Indicates column names for object inflation. This is used in conjunction with
1470 C<select>, usually when C<select> contains one or more function or stored
1473 $rs = $schema->resultset('Employee')->search(undef, {
1476 { count => 'employeeid' }
1478 as => ['name', 'employee_count'],
1481 my $employee = $rs->first(); # get the first Employee
1483 If the object against which the search is performed already has an accessor
1484 matching a column name specified in C<as>, the value can be retrieved using
1485 the accessor as normal:
1487 my $name = $employee->name();
1489 If on the other hand an accessor does not exist in the object, you need to
1490 use C<get_column> instead:
1492 my $employee_count = $employee->get_column('employee_count');
1494 You can create your own accessors if required - see
1495 L<DBIx::Class::Manual::Cookbook> for details.
1501 =item Value: ($rel_name | \@rel_names | \%rel_names)
1505 Contains a list of relationships that should be joined for this query. For
1508 # Get CDs by Nine Inch Nails
1509 my $rs = $schema->resultset('CD')->search(
1510 { 'artist.name' => 'Nine Inch Nails' },
1511 { join => 'artist' }
1514 Can also contain a hash reference to refer to the other relation's relations.
1517 package MyApp::Schema::Track;
1518 use base qw/DBIx::Class/;
1519 __PACKAGE__->table('track');
1520 __PACKAGE__->add_columns(qw/trackid cd position title/);
1521 __PACKAGE__->set_primary_key('trackid');
1522 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1525 # In your application
1526 my $rs = $schema->resultset('Artist')->search(
1527 { 'track.title' => 'Teardrop' },
1529 join => { cd => 'track' },
1530 order_by => 'artist.name',
1534 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1535 similarly for a third time). For e.g.
1537 my $rs = $schema->resultset('Artist')->search({
1538 'cds.title' => 'Down to Earth',
1539 'cds_2.title' => 'Popular',
1541 join => [ qw/cds cds/ ],
1544 will return a set of all artists that have both a cd with title 'Down
1545 to Earth' and a cd with title 'Popular'.
1547 If you want to fetch related objects from other tables as well, see C<prefetch>
1554 =item Value: ($rel_name | \@rel_names | \%rel_names)
1558 Contains one or more relationships that should be fetched along with the main
1559 query (when they are accessed afterwards they will have already been
1560 "prefetched"). This is useful for when you know you will need the related
1561 objects, because it saves at least one query:
1563 my $rs = $schema->resultset('Tag')->search(
1572 The initial search results in SQL like the following:
1574 SELECT tag.*, cd.*, artist.* FROM tag
1575 JOIN cd ON tag.cd = cd.cdid
1576 JOIN artist ON cd.artist = artist.artistid
1578 L<DBIx::Class> has no need to go back to the database when we access the
1579 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1582 Simple prefetches will be joined automatically, so there is no need
1583 for a C<join> attribute in the above search. If you're prefetching to
1584 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1585 specify the join as well.
1587 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1588 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1589 with an accessor type of 'single' or 'filter').
1595 =item Value: \@from_clause
1599 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1600 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1603 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1604 C<join> will usually do what you need and it is strongly recommended that you
1605 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1607 In simple terms, C<from> works as follows:
1610 { <alias> => <table>, -join_type => 'inner|left|right' }
1611 [] # nested JOIN (optional)
1612 { <table.column> => <foreign_table.foreign_key> }
1618 ON <table.column> = <foreign_table.foreign_key>
1620 An easy way to follow the examples below is to remember the following:
1622 Anything inside "[]" is a JOIN
1623 Anything inside "{}" is a condition for the enclosing JOIN
1625 The following examples utilize a "person" table in a family tree application.
1626 In order to express parent->child relationships, this table is self-joined:
1628 # Person->belongs_to('father' => 'Person');
1629 # Person->belongs_to('mother' => 'Person');
1631 C<from> can be used to nest joins. Here we return all children with a father,
1632 then search against all mothers of those children:
1634 $rs = $schema->resultset('Person')->search(
1637 alias => 'mother', # alias columns in accordance with "from"
1639 { mother => 'person' },
1642 { child => 'person' },
1644 { father => 'person' },
1645 { 'father.person_id' => 'child.father_id' }
1648 { 'mother.person_id' => 'child.mother_id' }
1655 # SELECT mother.* FROM person mother
1658 # JOIN person father
1659 # ON ( father.person_id = child.father_id )
1661 # ON ( mother.person_id = child.mother_id )
1663 The type of any join can be controlled manually. To search against only people
1664 with a father in the person table, we could explicitly use C<INNER JOIN>:
1666 $rs = $schema->resultset('Person')->search(
1669 alias => 'child', # alias columns in accordance with "from"
1671 { child => 'person' },
1673 { father => 'person', -join_type => 'inner' },
1674 { 'father.id' => 'child.father_id' }
1681 # SELECT child.* FROM person child
1682 # INNER JOIN person father ON child.father_id = father.id
1692 Makes the resultset paged and specifies the page to retrieve. Effectively
1693 identical to creating a non-pages resultset and then calling ->page($page)
1704 Specifes the maximum number of rows for direct retrieval or the number of
1705 rows per page if the page attribute or method is used.
1711 =item Value: \@columns
1715 A arrayref of columns to group by. Can include columns of joined tables.
1717 group_by => [qw/ column1 column2 ... /]
1723 =item Value: $condition
1727 HAVING is a select statement attribute that is applied between GROUP BY and
1728 ORDER BY. It is applied to the after the grouping calculations have been
1731 having => { 'count(employee)' => { '>=', 100 } }
1737 =item Value: (0 | 1)
1741 Set to 1 to group by all columns.
1745 Set to 1 to cache search results. This prevents extra SQL queries if you
1746 revisit rows in your ResultSet:
1748 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1750 while( my $artist = $resultset->next ) {
1754 $rs->first; # without cache, this would issue a query
1756 By default, searches are not cached.
1758 For more examples of using these attributes, see
1759 L<DBIx::Class::Manual::Cookbook>.