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/],
203 my $attrs = { %{$self->{attrs}} };
204 my $having = delete $attrs->{having};
205 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
208 ? ((@_ == 1 || ref $_[0] eq "HASH")
211 ? $self->throw_exception(
212 "Odd number of arguments to search")
215 if (defined $where) {
216 $attrs->{where} = (defined $attrs->{where}
218 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
219 $where, $attrs->{where} ] }
223 if (defined $having) {
224 $attrs->{having} = (defined $attrs->{having}
226 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
227 $having, $attrs->{having} ] }
231 $rs = (ref $self)->new($self->result_source, $attrs);
237 return (wantarray ? $rs->all : $rs);
240 =head2 search_literal
244 =item Arguments: $sql_fragment, @bind_values
246 =item Return Value: $resultset (scalar context), @row_objs (list context)
250 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
251 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
253 Pass a literal chunk of SQL to be added to the conditional part of the
259 my ($self, $cond, @vals) = @_;
260 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
261 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
262 return $self->search(\$cond, $attrs);
269 =item Arguments: @values | \%cols, \%attrs?
271 =item Return Value: $row_object
275 Finds a row based on its primary key or unique constraint. For example:
277 my $cd = $schema->resultset('CD')->find(5);
279 Also takes an optional C<key> attribute, to search by a specific key or unique
280 constraint. For example:
282 my $cd = $schema->resultset('CD')->find(
284 artist => 'Massive Attack',
285 title => 'Mezzanine',
287 { key => 'artist_title' }
290 See also L</find_or_create> and L</update_or_create>.
295 my ($self, @vals) = @_;
296 my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
298 my @cols = $self->result_source->primary_columns;
299 if (exists $attrs->{key}) {
300 my %uniq = $self->result_source->unique_constraints;
301 $self->throw_exception(
302 "Unknown key $attrs->{key} on '" . $self->result_source->name . "'"
303 ) unless exists $uniq{$attrs->{key}};
304 @cols = @{ $uniq{$attrs->{key}} };
306 #use Data::Dumper; warn Dumper($attrs, @vals, @cols);
307 $self->throw_exception(
308 "Can't find unless a primary key or unique constraint is defined"
312 if (ref $vals[0] eq 'HASH') {
313 $query = { %{$vals[0]} };
314 } elsif (@cols == @vals) {
316 @{$query}{@cols} = @vals;
320 foreach my $key (grep { ! m/\./ } keys %$query) {
321 $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key};
323 #warn Dumper($query);
326 my $rs = $self->search($query,$attrs);
327 return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
329 return keys %{$self->{collapse}} ?
330 $self->search($query)->next :
331 $self->single($query);
335 =head2 search_related
339 =item Arguments: $cond, \%attrs?
341 =item Return Value: $new_resultset
345 $new_rs = $cd_rs->search_related('artist', {
349 Searches the specified relationship, optionally specifying a condition and
350 attributes for matching records. See L</ATTRIBUTES> for more information.
355 return shift->related_resultset(shift)->search(@_);
362 =item Arguments: none
364 =item Return Value: $cursor
368 Returns a storage-driven cursor to the given resultset. See
369 L<DBIx::Class::Cursor> for more information.
375 my $attrs = { %{$self->{attrs}} };
376 return $self->{cursor}
377 ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
378 $attrs->{where},$attrs);
385 =item Arguments: $cond?
387 =item Return Value: $row_object?
391 my $cd = $schema->resultset('CD')->single({ year => 2001 });
393 Inflates the first result without creating a cursor if the resultset has
394 any records in it; if not returns nothing. Used by find() as an optimisation.
399 my ($self, $where) = @_;
400 my $attrs = { %{$self->{attrs}} };
402 if (defined $attrs->{where}) {
405 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
406 $where, delete $attrs->{where} ]
409 $attrs->{where} = $where;
412 my @data = $self->result_source->storage->select_single(
413 $self->{from}, $attrs->{select},
414 $attrs->{where},$attrs);
415 return (@data ? $self->_construct_object(@data) : ());
422 =item Arguments: $cond?
424 =item Return Value: $resultsetcolumn
428 my $max_length = $rs->get_column('length')->max;
430 Returns a ResultSetColumn instance for $column based on $self
435 my ($self, $column) = @_;
437 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
445 =item Arguments: $cond, \%attrs?
447 =item Return Value: $resultset (scalar context), @row_objs (list context)
451 # WHERE title LIKE '%blue%'
452 $cd_rs = $rs->search_like({ title => '%blue%'});
454 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
455 that this is simply a convenience method. You most likely want to use
456 L</search> with specific operators.
458 For more information, see L<DBIx::Class::Manual::Cookbook>.
464 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
465 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
466 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
467 return $class->search($query, { %$attrs });
474 =item Arguments: $first, $last
476 =item Return Value: $resultset (scalar context), @row_objs (list context)
480 Returns a resultset or object list representing a subset of elements from the
481 resultset slice is called on. Indexes are from 0, i.e., to get the first
484 my ($one, $two, $three) = $rs->slice(0, 2);
489 my ($self, $min, $max) = @_;
490 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
491 $attrs->{offset} = $self->{attrs}{offset} || 0;
492 $attrs->{offset} += $min;
493 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
494 return $self->search(undef(), $attrs);
495 #my $slice = (ref $self)->new($self->result_source, $attrs);
496 #return (wantarray ? $slice->all : $slice);
503 =item Arguments: none
505 =item Return Value: $result?
509 Returns the next element in the resultset (C<undef> is there is none).
511 Can be used to efficiently iterate over records in the resultset:
513 my $rs = $schema->resultset('CD')->search;
514 while (my $cd = $rs->next) {
518 Note that you need to store the resultset object, and call C<next> on it.
519 Calling C<< resultset('Table')->next >> repeatedly will always return the
520 first record from the resultset.
526 if (@{$self->{all_cache} || []}) {
527 $self->{all_cache_position} ||= 0;
528 return $self->{all_cache}->[$self->{all_cache_position}++];
530 if ($self->{attrs}{cache}) {
531 $self->{all_cache_position} = 1;
532 return ($self->all)[0];
534 my @row = (exists $self->{stashed_row} ?
535 @{delete $self->{stashed_row}} :
538 # warn Dumper(\@row); use Data::Dumper;
539 return unless (@row);
540 return $self->_construct_object(@row);
543 sub _construct_object {
544 my ($self, @row) = @_;
545 my @as = @{ $self->{attrs}{as} };
547 my $info = $self->_collapse_result(\@as, \@row);
549 my $new = $self->result_class->inflate_result($self->result_source, @$info);
551 $new = $self->{attrs}{record_filter}->($new)
552 if exists $self->{attrs}{record_filter};
556 sub _collapse_result {
557 my ($self, $as, $row, $prefix) = @_;
562 foreach my $this_as (@$as) {
563 my $val = shift @copy;
564 if (defined $prefix) {
565 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
567 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
568 $const{$1||''}{$2} = $val;
571 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
572 $const{$1||''}{$2} = $val;
576 my $info = [ {}, {} ];
577 foreach my $key (keys %const) {
580 my @parts = split(/\./, $key);
581 foreach my $p (@parts) {
582 $target = $target->[1]->{$p} ||= [];
584 $target->[0] = $const{$key};
586 $info->[0] = $const{$key};
591 if (defined $prefix) {
593 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
594 } keys %{$self->{collapse}}
596 @collapse = keys %{$self->{collapse}};
600 my ($c) = sort { length $a <=> length $b } @collapse;
602 foreach my $p (split(/\./, $c)) {
603 $target = $target->[1]->{$p} ||= [];
605 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
606 my @co_key = @{$self->{collapse}{$c_prefix}};
607 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
608 my $tree = $self->_collapse_result($as, $row, $c_prefix);
611 !defined($tree->[0]->{$_}) ||
612 $co_check{$_} ne $tree->[0]->{$_}
615 last unless (@raw = $self->cursor->next);
616 $row = $self->{stashed_row} = \@raw;
617 $tree = $self->_collapse_result($as, $row, $c_prefix);
618 #warn Data::Dumper::Dumper($tree, $row);
630 =item Arguments: $result_source?
632 =item Return Value: $result_source
636 An accessor for the primary ResultSource object from which this ResultSet
646 =item Arguments: $cond, \%attrs??
648 =item Return Value: $count
652 Performs an SQL C<COUNT> with the same query as the resultset was built
653 with to find the number of elements. If passed arguments, does a search
654 on the resultset and counts the results of that.
656 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
657 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
658 not support C<DISTINCT> with multiple columns. If you are using such a
659 database, you should only use columns from the main table in your C<group_by>
666 return $self->search(@_)->count if @_ and defined $_[0];
667 return scalar @{ $self->get_cache } if @{ $self->get_cache };
669 my $count = $self->_count;
670 return 0 unless $count;
672 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
673 $count = $self->{attrs}{rows} if
674 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
678 sub _count { # Separated out so pager can get the full count
680 my $select = { count => '*' };
681 my $attrs = { %{ $self->{attrs} } };
682 if (my $group_by = delete $attrs->{group_by}) {
683 delete $attrs->{having};
684 my @distinct = (ref $group_by ? @$group_by : ($group_by));
685 # todo: try CONCAT for multi-column pk
686 my @pk = $self->result_source->primary_columns;
688 foreach my $column (@distinct) {
689 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
690 @distinct = ($column);
696 $select = { count => { distinct => \@distinct } };
697 #use Data::Dumper; die Dumper $select;
700 $attrs->{select} = $select;
701 $attrs->{as} = [qw/count/];
703 # offset, order by and page are not needed to count. record_filter is cdbi
704 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
706 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
714 =item Arguments: $sql_fragment, @bind_values
716 =item Return Value: $count
720 Counts the results in a literal query. Equivalent to calling L</search_literal>
721 with the passed arguments, then L</count>.
725 sub count_literal { shift->search_literal(@_)->count; }
731 =item Arguments: none
733 =item Return Value: @objects
737 Returns all elements in the resultset. Called implicitly if the resultset
738 is returned in list context.
744 return @{ $self->get_cache } if @{ $self->get_cache };
748 if (keys %{$self->{collapse}}) {
749 # Using $self->cursor->all is really just an optimisation.
750 # If we're collapsing has_many prefetches it probably makes
751 # very little difference, and this is cleaner than hacking
752 # _construct_object to survive the approach
753 $self->cursor->reset;
754 my @row = $self->cursor->next;
756 push(@obj, $self->_construct_object(@row));
757 @row = (exists $self->{stashed_row}
758 ? @{delete $self->{stashed_row}}
759 : $self->cursor->next);
762 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
765 $self->set_cache(\@obj) if $self->{attrs}{cache};
773 =item Arguments: none
775 =item Return Value: $self
779 Resets the resultset's cursor, so you can iterate through the elements again.
785 $self->{all_cache_position} = 0;
786 $self->cursor->reset;
794 =item Arguments: none
796 =item Return Value: $object?
800 Resets the resultset and returns an object for the first result (if the
801 resultset returns anything).
806 return $_[0]->reset->next;
809 # _cond_for_update_delete
811 # update/delete require the condition to be modified to handle
812 # the differing SQL syntax available. This transforms the $self->{cond}
813 # appropriately, returning the new condition.
815 sub _cond_for_update_delete {
819 if (!ref($self->{cond})) {
820 # No-op. No condition, we're updating/deleting everything
822 elsif (ref $self->{cond} eq 'ARRAY') {
826 foreach my $key (keys %{$_}) {
828 $hash{$1} = $_->{$key};
834 elsif (ref $self->{cond} eq 'HASH') {
835 if ((keys %{$self->{cond}})[0] eq '-and') {
838 my @cond = @{$self->{cond}{-and}};
839 for (my $i = 0; $i < @cond - 1; $i++) {
840 my $entry = $cond[$i];
843 if (ref $entry eq 'HASH') {
844 foreach my $key (keys %{$entry}) {
846 $hash{$1} = $entry->{$key};
850 $entry =~ /([^.]+)$/;
851 $hash{$entry} = $cond[++$i];
854 push @{$cond->{-and}}, \%hash;
858 foreach my $key (keys %{$self->{cond}}) {
860 $cond->{$1} = $self->{cond}{$key};
865 $self->throw_exception(
866 "Can't update/delete on resultset with condition unless hash or array"
878 =item Arguments: \%values
880 =item Return Value: $storage_rv
884 Sets the specified columns in the resultset to the supplied values in a
885 single query. Return value will be true if the update succeeded or false
886 if no records were updated; exact type of success value is storage-dependent.
891 my ($self, $values) = @_;
892 $self->throw_exception("Values for update must be a hash")
893 unless ref $values eq 'HASH';
895 my $cond = $self->_cond_for_update_delete;
897 return $self->result_source->storage->update(
898 $self->result_source->from, $values, $cond
906 =item Arguments: \%values
908 =item Return Value: 1
912 Fetches all objects and updates them one at a time. Note that C<update_all>
913 will run DBIC cascade triggers, while L</update> will not.
918 my ($self, $values) = @_;
919 $self->throw_exception("Values for update must be a hash")
920 unless ref $values eq 'HASH';
921 foreach my $obj ($self->all) {
922 $obj->set_columns($values)->update;
931 =item Arguments: none
933 =item Return Value: 1
937 Deletes the contents of the resultset from its result source. Note that this
938 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
947 my $cond = $self->_cond_for_update_delete;
949 $self->result_source->storage->delete($self->result_source->from, $cond);
957 =item Arguments: none
959 =item Return Value: 1
963 Fetches all objects and deletes them one at a time. Note that C<delete_all>
964 will run DBIC cascade triggers, while L</delete> will not.
970 $_->delete for $self->all;
978 =item Arguments: none
980 =item Return Value: $pager
984 Return Value a L<Data::Page> object for the current resultset. Only makes
985 sense for queries with a C<page> attribute.
991 my $attrs = $self->{attrs};
992 $self->throw_exception("Can't create pager for non-paged rs")
993 unless $self->{page};
994 $attrs->{rows} ||= 10;
995 return $self->{pager} ||= Data::Page->new(
996 $self->_count, $attrs->{rows}, $self->{page});
1003 =item Arguments: $page_number
1005 =item Return Value: $rs
1009 Returns a resultset for the $page_number page of the resultset on which page
1010 is called, where each page contains a number of rows equal to the 'rows'
1011 attribute set on the resultset (10 by default).
1016 my ($self, $page) = @_;
1017 my $attrs = { %{$self->{attrs}} };
1018 $attrs->{page} = $page;
1019 return (ref $self)->new($self->result_source, $attrs);
1026 =item Arguments: \%vals
1028 =item Return Value: $object
1032 Creates an object in the resultset's result class and returns it.
1037 my ($self, $values) = @_;
1038 $self->throw_exception( "new_result needs a hash" )
1039 unless (ref $values eq 'HASH');
1040 $self->throw_exception(
1041 "Can't abstract implicit construct, condition not a hash"
1042 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1044 my $alias = $self->{attrs}{alias};
1045 foreach my $key (keys %{$self->{cond}||{}}) {
1046 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1048 my $obj = $self->result_class->new(\%new);
1049 $obj->result_source($self->result_source) if $obj->can('result_source');
1057 =item Arguments: \%vals
1059 =item Return Value: $object
1063 Inserts a record into the resultset and returns the object representing it.
1065 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1070 my ($self, $attrs) = @_;
1071 $self->throw_exception( "create needs a hashref" )
1072 unless ref $attrs eq 'HASH';
1073 return $self->new_result($attrs)->insert;
1076 =head2 find_or_create
1080 =item Arguments: \%vals, \%attrs?
1082 =item Return Value: $object
1086 $class->find_or_create({ key => $val, ... });
1088 Searches for a record matching the search condition; if it doesn't find one,
1089 creates one and returns that instead.
1091 my $cd = $schema->resultset('CD')->find_or_create({
1093 artist => 'Massive Attack',
1094 title => 'Mezzanine',
1098 Also takes an optional C<key> attribute, to search by a specific key or unique
1099 constraint. For example:
1101 my $cd = $schema->resultset('CD')->find_or_create(
1103 artist => 'Massive Attack',
1104 title => 'Mezzanine',
1106 { key => 'artist_title' }
1109 See also L</find> and L</update_or_create>.
1113 sub find_or_create {
1115 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1116 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1117 my $exists = $self->find($hash, $attrs);
1118 return defined $exists ? $exists : $self->create($hash);
1121 =head2 update_or_create
1125 =item Arguments: \%col_values, { key => $unique_constraint }?
1127 =item Return Value: $object
1131 $class->update_or_create({ col => $val, ... });
1133 First, searches for an existing row matching one of the unique constraints
1134 (including the primary key) on the source of this resultset. If a row is
1135 found, updates it with the other given column values. Otherwise, creates a new
1138 Takes an optional C<key> attribute to search on a specific unique constraint.
1141 # In your application
1142 my $cd = $schema->resultset('CD')->update_or_create(
1144 artist => 'Massive Attack',
1145 title => 'Mezzanine',
1148 { key => 'artist_title' }
1151 If no C<key> is specified, it searches on all unique constraints defined on the
1152 source, including the primary key.
1154 If the C<key> is specified as C<primary>, it searches only on the primary key.
1156 See also L</find> and L</find_or_create>.
1160 sub update_or_create {
1162 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1163 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1165 my %unique_constraints = $self->result_source->unique_constraints;
1166 my @constraint_names = (exists $attrs->{key}
1168 : keys %unique_constraints);
1171 foreach my $name (@constraint_names) {
1172 my @unique_cols = @{ $unique_constraints{$name} };
1174 map { $_ => $hash->{$_} }
1175 grep { exists $hash->{$_} }
1178 push @unique_hashes, \%unique_hash
1179 if (scalar keys %unique_hash == scalar @unique_cols);
1182 if (@unique_hashes) {
1183 my $row = $self->single(\@unique_hashes);
1185 $row->set_columns($hash);
1191 return $self->create($hash);
1198 =item Arguments: none
1200 =item Return Value: \@cache_objects?
1204 Gets the contents of the cache for the resultset, if the cache is set.
1209 shift->{all_cache} || [];
1216 =item Arguments: \@cache_objects
1218 =item Return Value: \@cache_objects
1222 Sets the contents of the cache for the resultset. Expects an arrayref
1223 of objects of the same class as those produced by the resultset. Note that
1224 if the cache is set the resultset will return the cached objects rather
1225 than re-querying the database even if the cache attr is not set.
1230 my ( $self, $data ) = @_;
1231 $self->throw_exception("set_cache requires an arrayref")
1232 if ref $data ne 'ARRAY';
1233 my $result_class = $self->result_class;
1235 $self->throw_exception(
1236 "cannot cache object of type '$_', expected '$result_class'"
1237 ) if ref $_ ne $result_class;
1239 $self->{all_cache} = $data;
1246 =item Arguments: none
1248 =item Return Value: []
1252 Clears the cache for the resultset.
1257 shift->set_cache([]);
1260 =head2 related_resultset
1264 =item Arguments: $relationship_name
1266 =item Return Value: $resultset
1270 Returns a related resultset for the supplied relationship name.
1272 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1276 sub related_resultset {
1277 my ( $self, $rel ) = @_;
1278 $self->{related_resultsets} ||= {};
1279 return $self->{related_resultsets}{$rel} ||= do {
1280 #warn "fetching related resultset for rel '$rel'";
1281 my $rel_obj = $self->result_source->relationship_info($rel);
1282 $self->throw_exception(
1283 "search_related: result source '" . $self->result_source->name .
1284 "' has no such relationship ${rel}")
1285 unless $rel_obj; #die Dumper $self->{attrs};
1287 my $rs = $self->search(undef, { join => $rel });
1288 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1289 && $rs->{attrs}{seen_join}{$rel} > 1
1290 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1293 $self->result_source->schema->resultset($rel_obj->{class}
1303 =head2 throw_exception
1305 See L<DBIx::Class::Schema/throw_exception> for details.
1309 sub throw_exception {
1311 $self->result_source->schema->throw_exception(@_);
1314 # XXX: FIXME: Attributes docs need clearing up
1318 The resultset takes various attributes that modify its behavior. Here's an
1325 =item Value: ($order_by | \@order_by)
1329 Which column(s) to order the results by. This is currently passed
1330 through directly to SQL, so you can give e.g. C<year DESC> for a
1331 descending order on the column `year'.
1337 =item Value: \@columns
1341 Shortcut to request a particular set of columns to be retrieved. Adds
1342 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1343 from that, then auto-populates C<as> from C<select> as normal. (You may also
1344 use the C<cols> attribute, as in earlier versions of DBIC.)
1346 =head2 include_columns
1350 =item Value: \@columns
1354 Shortcut to include additional columns in the returned results - for example
1356 $schema->resultset('CD')->search(undef, {
1357 include_columns => ['artist.name'],
1361 would return all CDs and include a 'name' column to the information
1362 passed to object inflation
1368 =item Value: \@select_columns
1372 Indicates which columns should be selected from the storage. You can use
1373 column names, or in the case of RDBMS back ends, function or stored procedure
1376 $rs = $schema->resultset('Employee')->search(undef, {
1379 { count => 'employeeid' },
1384 When you use function/stored procedure names and do not supply an C<as>
1385 attribute, the column names returned are storage-dependent. E.g. MySQL would
1386 return a column named C<count(employeeid)> in the above example.
1392 =item Value: \@inflation_names
1396 Indicates column names for object inflation. This is used in conjunction with
1397 C<select>, usually when C<select> contains one or more function or stored
1400 $rs = $schema->resultset('Employee')->search(undef, {
1403 { count => 'employeeid' }
1405 as => ['name', 'employee_count'],
1408 my $employee = $rs->first(); # get the first Employee
1410 If the object against which the search is performed already has an accessor
1411 matching a column name specified in C<as>, the value can be retrieved using
1412 the accessor as normal:
1414 my $name = $employee->name();
1416 If on the other hand an accessor does not exist in the object, you need to
1417 use C<get_column> instead:
1419 my $employee_count = $employee->get_column('employee_count');
1421 You can create your own accessors if required - see
1422 L<DBIx::Class::Manual::Cookbook> for details.
1428 =item Value: ($rel_name | \@rel_names | \%rel_names)
1432 Contains a list of relationships that should be joined for this query. For
1435 # Get CDs by Nine Inch Nails
1436 my $rs = $schema->resultset('CD')->search(
1437 { 'artist.name' => 'Nine Inch Nails' },
1438 { join => 'artist' }
1441 Can also contain a hash reference to refer to the other relation's relations.
1444 package MyApp::Schema::Track;
1445 use base qw/DBIx::Class/;
1446 __PACKAGE__->table('track');
1447 __PACKAGE__->add_columns(qw/trackid cd position title/);
1448 __PACKAGE__->set_primary_key('trackid');
1449 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1452 # In your application
1453 my $rs = $schema->resultset('Artist')->search(
1454 { 'track.title' => 'Teardrop' },
1456 join => { cd => 'track' },
1457 order_by => 'artist.name',
1461 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1462 similarly for a third time). For e.g.
1464 my $rs = $schema->resultset('Artist')->search({
1465 'cds.title' => 'Down to Earth',
1466 'cds_2.title' => 'Popular',
1468 join => [ qw/cds cds/ ],
1471 will return a set of all artists that have both a cd with title 'Down
1472 to Earth' and a cd with title 'Popular'.
1474 If you want to fetch related objects from other tables as well, see C<prefetch>
1481 =item Value: ($rel_name | \@rel_names | \%rel_names)
1485 Contains one or more relationships that should be fetched along with the main
1486 query (when they are accessed afterwards they will have already been
1487 "prefetched"). This is useful for when you know you will need the related
1488 objects, because it saves at least one query:
1490 my $rs = $schema->resultset('Tag')->search(
1499 The initial search results in SQL like the following:
1501 SELECT tag.*, cd.*, artist.* FROM tag
1502 JOIN cd ON tag.cd = cd.cdid
1503 JOIN artist ON cd.artist = artist.artistid
1505 L<DBIx::Class> has no need to go back to the database when we access the
1506 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1509 Simple prefetches will be joined automatically, so there is no need
1510 for a C<join> attribute in the above search. If you're prefetching to
1511 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1512 specify the join as well.
1514 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1515 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1516 with an accessor type of 'single' or 'filter').
1522 =item Value: \@from_clause
1526 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1527 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1530 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1531 C<join> will usually do what you need and it is strongly recommended that you
1532 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1534 In simple terms, C<from> works as follows:
1537 { <alias> => <table>, -join_type => 'inner|left|right' }
1538 [] # nested JOIN (optional)
1539 { <table.column> => <foreign_table.foreign_key> }
1545 ON <table.column> = <foreign_table.foreign_key>
1547 An easy way to follow the examples below is to remember the following:
1549 Anything inside "[]" is a JOIN
1550 Anything inside "{}" is a condition for the enclosing JOIN
1552 The following examples utilize a "person" table in a family tree application.
1553 In order to express parent->child relationships, this table is self-joined:
1555 # Person->belongs_to('father' => 'Person');
1556 # Person->belongs_to('mother' => 'Person');
1558 C<from> can be used to nest joins. Here we return all children with a father,
1559 then search against all mothers of those children:
1561 $rs = $schema->resultset('Person')->search(
1564 alias => 'mother', # alias columns in accordance with "from"
1566 { mother => 'person' },
1569 { child => 'person' },
1571 { father => 'person' },
1572 { 'father.person_id' => 'child.father_id' }
1575 { 'mother.person_id' => 'child.mother_id' }
1582 # SELECT mother.* FROM person mother
1585 # JOIN person father
1586 # ON ( father.person_id = child.father_id )
1588 # ON ( mother.person_id = child.mother_id )
1590 The type of any join can be controlled manually. To search against only people
1591 with a father in the person table, we could explicitly use C<INNER JOIN>:
1593 $rs = $schema->resultset('Person')->search(
1596 alias => 'child', # alias columns in accordance with "from"
1598 { child => 'person' },
1600 { father => 'person', -join_type => 'inner' },
1601 { 'father.id' => 'child.father_id' }
1608 # SELECT child.* FROM person child
1609 # INNER JOIN person father ON child.father_id = father.id
1619 Makes the resultset paged and specifies the page to retrieve. Effectively
1620 identical to creating a non-pages resultset and then calling ->page($page)
1631 Specifes the maximum number of rows for direct retrieval or the number of
1632 rows per page if the page attribute or method is used.
1638 =item Value: \@columns
1642 A arrayref of columns to group by. Can include columns of joined tables.
1644 group_by => [qw/ column1 column2 ... /]
1650 =item Value: $condition
1654 HAVING is a select statement attribute that is applied between GROUP BY and
1655 ORDER BY. It is applied to the after the grouping calculations have been
1658 having => { 'count(employee)' => { '>=', 100 } }
1664 =item Value: (0 | 1)
1668 Set to 1 to group by all columns.
1672 Set to 1 to cache search results. This prevents extra SQL queries if you
1673 revisit rows in your ResultSet:
1675 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1677 while( my $artist = $resultset->next ) {
1681 $rs->first; # without cache, this would issue a query
1683 By default, searches are not cached.
1685 For more examples of using these attributes, see
1686 L<DBIx::Class::Manual::Cookbook>.