1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 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) = @_;
91 $attrs->{rows} ||= 10;
92 $attrs->{offset} ||= 0;
93 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
96 $attrs->{alias} ||= 'me';
99 result_source => $source,
100 result_class => $attrs->{result_class} || $source->result_class,
101 cond => $attrs->{where},
112 =item Arguments: $cond, \%attrs?
114 =item Return Value: $resultset (scalar context), @row_objs (list context)
118 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
119 my $new_rs = $cd_rs->search({ year => 2005 });
121 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
122 # year = 2005 OR year = 2004
124 If you need to pass in additional attributes but no additional condition,
125 call it as C<search(undef, \%attrs)>.
127 # "SELECT name, artistid FROM $artist_table"
128 my @all_artists = $schema->resultset('Artist')->search(undef, {
129 columns => [qw/name artistid/],
136 my $rs = $self->search_rs( @_ );
137 return (wantarray ? $rs->all : $rs);
144 =item Arguments: $cond, \%attrs?
146 =item Return Value: $resultset
150 This method does the same exact thing as search() except it will
151 always return a resultset, even in list context.
160 unless (@_) { # no search, effectively just a clone
161 $rows = $self->get_cache;
165 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
166 my $our_attrs = { %{$self->{attrs}} };
167 my $having = delete $our_attrs->{having};
169 # merge new attrs into inherited
170 foreach my $key (qw/join prefetch/) {
171 next unless exists $attrs->{$key};
172 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, delete $attrs->{$key});
175 my $new_attrs = { %{$our_attrs}, %{$attrs} };
178 (@_ == 1 || ref $_[0] eq "HASH")
182 ? $self->throw_exception("Odd number of arguments to search")
189 if (defined $where) {
190 $new_attrs->{where} = (
191 defined $new_attrs->{where}
194 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
195 } $where, $new_attrs->{where}
201 if (defined $having) {
202 $new_attrs->{having} = (
203 defined $new_attrs->{having}
206 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
207 } $having, $new_attrs->{having}
213 my $rs = (ref $self)->new($self->result_source, $new_attrs);
215 $rs->set_cache($rows);
220 =head2 search_literal
224 =item Arguments: $sql_fragment, @bind_values
226 =item Return Value: $resultset (scalar context), @row_objs (list context)
230 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
231 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
233 Pass a literal chunk of SQL to be added to the conditional part of the
239 my ($self, $cond, @vals) = @_;
240 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
241 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
242 return $self->search(\$cond, $attrs);
249 =item Arguments: @values | \%cols, \%attrs?
251 =item Return Value: $row_object
255 Finds a row based on its primary key or unique constraint. For example, to find
256 a row by its primary key:
258 my $cd = $schema->resultset('CD')->find(5);
260 You can also find a row by a specific unique constraint using the C<key>
261 attribute. For example:
263 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
264 key => 'cd_artist_title'
267 Additionally, you can specify the columns explicitly by name:
269 my $cd = $schema->resultset('CD')->find(
271 artist => 'Massive Attack',
272 title => 'Mezzanine',
274 { key => 'cd_artist_title' }
277 If the C<key> is specified as C<primary>, it searches only on the primary key.
279 If no C<key> is specified, it searches on all unique constraints defined on the
280 source, including the primary key.
282 See also L</find_or_create> and L</update_or_create>. For information on how to
283 declare unique constraints, see
284 L<DBIx::Class::ResultSource/add_unique_constraint>.
290 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
292 # Default to the primary key, but allow a specific key
293 my @cols = exists $attrs->{key}
294 ? $self->result_source->unique_constraint_columns($attrs->{key})
295 : $self->result_source->primary_columns;
296 $self->throw_exception(
297 "Can't find unless a primary key or unique constraint is defined"
300 # Parse out a hashref from input
302 if (ref $_[0] eq 'HASH') {
303 $input_query = { %{$_[0]} };
305 elsif (@_ == @cols) {
307 @{$input_query}{@cols} = @_;
310 # Compatibility: Allow e.g. find(id => $value)
311 carp "Find by key => value deprecated; please use a hashref instead";
315 my @unique_queries = $self->_unique_queries($input_query, $attrs);
317 # Handle cases where the ResultSet defines the query, or where the user is
319 my $query = @unique_queries ? \@unique_queries : $input_query;
323 my $rs = $self->search($query, $attrs);
324 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
327 return keys %{$self->_resolved_attrs->{collapse}}
328 ? $self->search($query)->next
329 : $self->single($query);
335 # Build a list of queries which satisfy unique constraints.
337 sub _unique_queries {
338 my ($self, $query, $attrs) = @_;
340 my $alias = $self->{attrs}{alias};
341 my @constraint_names = exists $attrs->{key}
343 : $self->result_source->unique_constraint_names;
346 foreach my $name (@constraint_names) {
347 my @unique_cols = $self->result_source->unique_constraint_columns($name);
348 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
350 my $num_query = scalar keys %$unique_query;
351 next unless $num_query;
353 # Add the ResultSet's alias
354 foreach my $col (grep { ! m/\./ } keys %$unique_query) {
355 $unique_query->{"$alias.$col"} = delete $unique_query->{$col};
358 # XXX: Assuming quite a bit about $self->{attrs}{where}
359 my $num_cols = scalar @unique_cols;
360 my $num_where = exists $self->{attrs}{where}
361 ? scalar keys %{ $self->{attrs}{where} }
363 push @unique_queries, $unique_query
364 if $num_query + $num_where == $num_cols;
367 return @unique_queries;
370 # _build_unique_query
372 # Constrain the specified query hash based on the specified column names.
374 sub _build_unique_query {
375 my ($self, $query, $unique_cols) = @_;
378 map { $_ => $query->{$_} }
379 grep { exists $query->{$_} }
384 =head2 search_related
388 =item Arguments: $rel, $cond, \%attrs?
390 =item Return Value: $new_resultset
394 $new_rs = $cd_rs->search_related('artist', {
398 Searches the specified relationship, optionally specifying a condition and
399 attributes for matching records. See L</ATTRIBUTES> for more information.
404 return shift->related_resultset(shift)->search(@_);
411 =item Arguments: none
413 =item Return Value: $cursor
417 Returns a storage-driven cursor to the given resultset. See
418 L<DBIx::Class::Cursor> for more information.
425 my $attrs = { %{$self->_resolved_attrs} };
426 return $self->{cursor}
427 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
428 $attrs->{where},$attrs);
435 =item Arguments: $cond?
437 =item Return Value: $row_object?
441 my $cd = $schema->resultset('CD')->single({ year => 2001 });
443 Inflates the first result without creating a cursor if the resultset has
444 any records in it; if not returns nothing. Used by L</find> as an optimisation.
446 Can optionally take an additional condition *only* - this is a fast-code-path
447 method; if you need to add extra joins or similar call ->search and then
448 ->single without a condition on the $rs returned from that.
453 my ($self, $where) = @_;
454 my $attrs = { %{$self->_resolved_attrs} };
456 if (defined $attrs->{where}) {
459 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
460 $where, delete $attrs->{where} ]
463 $attrs->{where} = $where;
467 unless ($self->_is_unique_query($attrs->{where})) {
468 carp "Query not guaranteed to return a single row"
469 . "; please declare your unique constraints or use search instead";
472 my @data = $self->result_source->storage->select_single(
473 $attrs->{from}, $attrs->{select},
474 $attrs->{where}, $attrs
477 return (@data ? $self->_construct_object(@data) : ());
482 # Try to determine if the specified query is guaranteed to be unique, based on
483 # the declared unique constraints.
485 sub _is_unique_query {
486 my ($self, $query) = @_;
488 my $collapsed = $self->_collapse_query($query);
489 my $alias = $self->{attrs}{alias};
491 foreach my $name ($self->result_source->unique_constraint_names) {
492 my @unique_cols = map {
494 } $self->result_source->unique_constraint_columns($name);
496 # Count the values for each unique column
497 my %seen = map { $_ => 0 } @unique_cols;
499 foreach my $key (keys %$collapsed) {
500 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
501 next unless exists $seen{$aliased}; # Additional constraints are okay
502 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
505 # If we get 0 or more than 1 value for a column, it's not necessarily unique
506 return 1 unless grep { $_ != 1 } values %seen;
514 # Recursively collapse the query, accumulating values for each column.
516 sub _collapse_query {
517 my ($self, $query, $collapsed) = @_;
521 if (ref $query eq 'ARRAY') {
522 foreach my $subquery (@$query) {
523 next unless ref $subquery; # -or
524 # warn "ARRAY: " . Dumper $subquery;
525 $collapsed = $self->_collapse_query($subquery, $collapsed);
528 elsif (ref $query eq 'HASH') {
529 if (keys %$query and (keys %$query)[0] eq '-and') {
530 foreach my $subquery (@{$query->{-and}}) {
531 # warn "HASH: " . Dumper $subquery;
532 $collapsed = $self->_collapse_query($subquery, $collapsed);
536 # warn "LEAF: " . Dumper $query;
537 foreach my $col (keys %$query) {
538 my $value = $query->{$col};
539 $collapsed->{$col}{$value}++;
551 =item Arguments: $cond?
553 =item Return Value: $resultsetcolumn
557 my $max_length = $rs->get_column('length')->max;
559 Returns a ResultSetColumn instance for $column based on $self
564 my ($self, $column) = @_;
565 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
573 =item Arguments: $cond, \%attrs?
575 =item Return Value: $resultset (scalar context), @row_objs (list context)
579 # WHERE title LIKE '%blue%'
580 $cd_rs = $rs->search_like({ title => '%blue%'});
582 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
583 that this is simply a convenience method. You most likely want to use
584 L</search> with specific operators.
586 For more information, see L<DBIx::Class::Manual::Cookbook>.
592 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
593 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
594 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
595 return $class->search($query, { %$attrs });
602 =item Arguments: $first, $last
604 =item Return Value: $resultset (scalar context), @row_objs (list context)
608 Returns a resultset or object list representing a subset of elements from the
609 resultset slice is called on. Indexes are from 0, i.e., to get the first
612 my ($one, $two, $three) = $rs->slice(0, 2);
617 my ($self, $min, $max) = @_;
618 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
619 $attrs->{offset} = $self->{attrs}{offset} || 0;
620 $attrs->{offset} += $min;
621 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
622 return $self->search(undef(), $attrs);
623 #my $slice = (ref $self)->new($self->result_source, $attrs);
624 #return (wantarray ? $slice->all : $slice);
631 =item Arguments: none
633 =item Return Value: $result?
637 Returns the next element in the resultset (C<undef> is there is none).
639 Can be used to efficiently iterate over records in the resultset:
641 my $rs = $schema->resultset('CD')->search;
642 while (my $cd = $rs->next) {
646 Note that you need to store the resultset object, and call C<next> on it.
647 Calling C<< resultset('Table')->next >> repeatedly will always return the
648 first record from the resultset.
654 if (my $cache = $self->get_cache) {
655 $self->{all_cache_position} ||= 0;
656 return $cache->[$self->{all_cache_position}++];
658 if ($self->{attrs}{cache}) {
659 $self->{all_cache_position} = 1;
660 return ($self->all)[0];
663 exists $self->{stashed_row}
664 ? @{delete $self->{stashed_row}}
665 : $self->cursor->next
667 return unless (@row);
668 return $self->_construct_object(@row);
671 sub _construct_object {
672 my ($self, @row) = @_;
673 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
674 my $new = $self->result_class->inflate_result($self->result_source, @$info);
675 $new = $self->{_attrs}{record_filter}->($new)
676 if exists $self->{_attrs}{record_filter};
680 sub _collapse_result {
681 my ($self, $as, $row, $prefix) = @_;
686 foreach my $this_as (@$as) {
687 my $val = shift @copy;
688 if (defined $prefix) {
689 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
691 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
692 $const{$1||''}{$2} = $val;
695 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
696 $const{$1||''}{$2} = $val;
700 my $alias = $self->{attrs}{alias};
701 my $info = [ {}, {} ];
702 foreach my $key (keys %const) {
703 if (length $key && $key ne $alias) {
705 my @parts = split(/\./, $key);
706 foreach my $p (@parts) {
707 $target = $target->[1]->{$p} ||= [];
709 $target->[0] = $const{$key};
711 $info->[0] = $const{$key};
716 if (defined $prefix) {
718 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
719 } keys %{$self->{_attrs}{collapse}}
721 @collapse = keys %{$self->{_attrs}{collapse}};
725 my ($c) = sort { length $a <=> length $b } @collapse;
727 foreach my $p (split(/\./, $c)) {
728 $target = $target->[1]->{$p} ||= [];
730 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
731 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
732 my $tree = $self->_collapse_result($as, $row, $c_prefix);
733 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
739 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
744 last unless (@raw = $self->cursor->next);
745 $row = $self->{stashed_row} = \@raw;
746 $tree = $self->_collapse_result($as, $row, $c_prefix);
748 @$target = (@final ? @final : [ {}, {} ]);
749 # single empty result to indicate an empty prefetched has_many
752 #print "final info: " . Dumper($info);
760 =item Arguments: $result_source?
762 =item Return Value: $result_source
766 An accessor for the primary ResultSource object from which this ResultSet
776 =item Arguments: $cond, \%attrs??
778 =item Return Value: $count
782 Performs an SQL C<COUNT> with the same query as the resultset was built
783 with to find the number of elements. If passed arguments, does a search
784 on the resultset and counts the results of that.
786 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
787 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
788 not support C<DISTINCT> with multiple columns. If you are using such a
789 database, you should only use columns from the main table in your C<group_by>
796 return $self->search(@_)->count if @_ and defined $_[0];
797 return scalar @{ $self->get_cache } if $self->get_cache;
798 my $count = $self->_count;
799 return 0 unless $count;
801 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
802 $count = $self->{attrs}{rows} if
803 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
807 sub _count { # Separated out so pager can get the full count
809 my $select = { count => '*' };
811 my $attrs = { %{$self->_resolved_attrs} };
812 if (my $group_by = delete $attrs->{group_by}) {
813 delete $attrs->{having};
814 my @distinct = (ref $group_by ? @$group_by : ($group_by));
815 # todo: try CONCAT for multi-column pk
816 my @pk = $self->result_source->primary_columns;
818 my $alias = $attrs->{alias};
819 foreach my $column (@distinct) {
820 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
821 @distinct = ($column);
827 $select = { count => { distinct => \@distinct } };
830 $attrs->{select} = $select;
831 $attrs->{as} = [qw/count/];
833 # offset, order by and page are not needed to count. record_filter is cdbi
834 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
836 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
837 my ($count) = $tmp_rs->cursor->next;
845 =item Arguments: $sql_fragment, @bind_values
847 =item Return Value: $count
851 Counts the results in a literal query. Equivalent to calling L</search_literal>
852 with the passed arguments, then L</count>.
856 sub count_literal { shift->search_literal(@_)->count; }
862 =item Arguments: none
864 =item Return Value: @objects
868 Returns all elements in the resultset. Called implicitly if the resultset
869 is returned in list context.
875 return @{ $self->get_cache } if $self->get_cache;
879 # TODO: don't call resolve here
880 if (keys %{$self->_resolved_attrs->{collapse}}) {
881 # if ($self->{attrs}{prefetch}) {
882 # Using $self->cursor->all is really just an optimisation.
883 # If we're collapsing has_many prefetches it probably makes
884 # very little difference, and this is cleaner than hacking
885 # _construct_object to survive the approach
886 my @row = $self->cursor->next;
888 push(@obj, $self->_construct_object(@row));
889 @row = (exists $self->{stashed_row}
890 ? @{delete $self->{stashed_row}}
891 : $self->cursor->next);
894 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
897 $self->set_cache(\@obj) if $self->{attrs}{cache};
905 =item Arguments: none
907 =item Return Value: $self
911 Resets the resultset's cursor, so you can iterate through the elements again.
917 delete $self->{_attrs} if exists $self->{_attrs};
918 $self->{all_cache_position} = 0;
919 $self->cursor->reset;
927 =item Arguments: none
929 =item Return Value: $object?
933 Resets the resultset and returns an object for the first result (if the
934 resultset returns anything).
939 return $_[0]->reset->next;
942 # _cond_for_update_delete
944 # update/delete require the condition to be modified to handle
945 # the differing SQL syntax available. This transforms the $self->{cond}
946 # appropriately, returning the new condition.
948 sub _cond_for_update_delete {
952 # No-op. No condition, we're updating/deleting everything
953 return $cond unless ref $self->{cond};
955 if (ref $self->{cond} eq 'ARRAY') {
959 foreach my $key (keys %{$_}) {
961 $hash{$1} = $_->{$key};
967 elsif (ref $self->{cond} eq 'HASH') {
968 if ((keys %{$self->{cond}})[0] eq '-and') {
971 my @cond = @{$self->{cond}{-and}};
972 for (my $i = 0; $i < @cond; $i++) {
973 my $entry = $cond[$i];
976 if (ref $entry eq 'HASH') {
977 foreach my $key (keys %{$entry}) {
979 $hash{$1} = $entry->{$key};
983 $entry =~ /([^.]+)$/;
984 $hash{$1} = $cond[++$i];
987 push @{$cond->{-and}}, \%hash;
991 foreach my $key (keys %{$self->{cond}}) {
993 $cond->{$1} = $self->{cond}{$key};
998 $self->throw_exception(
999 "Can't update/delete on resultset with condition unless hash or array"
1011 =item Arguments: \%values
1013 =item Return Value: $storage_rv
1017 Sets the specified columns in the resultset to the supplied values in a
1018 single query. Return value will be true if the update succeeded or false
1019 if no records were updated; exact type of success value is storage-dependent.
1024 my ($self, $values) = @_;
1025 $self->throw_exception("Values for update must be a hash")
1026 unless ref $values eq 'HASH';
1028 my $cond = $self->_cond_for_update_delete;
1030 return $self->result_source->storage->update(
1031 $self->result_source->from, $values, $cond
1039 =item Arguments: \%values
1041 =item Return Value: 1
1045 Fetches all objects and updates them one at a time. Note that C<update_all>
1046 will run DBIC cascade triggers, while L</update> will not.
1051 my ($self, $values) = @_;
1052 $self->throw_exception("Values for update must be a hash")
1053 unless ref $values eq 'HASH';
1054 foreach my $obj ($self->all) {
1055 $obj->set_columns($values)->update;
1064 =item Arguments: none
1066 =item Return Value: 1
1070 Deletes the contents of the resultset from its result source. Note that this
1071 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1079 my $cond = $self->_cond_for_update_delete;
1081 $self->result_source->storage->delete($self->result_source->from, $cond);
1089 =item Arguments: none
1091 =item Return Value: 1
1095 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1096 will run DBIC cascade triggers, while L</delete> will not.
1102 $_->delete for $self->all;
1110 =item Arguments: none
1112 =item Return Value: $pager
1116 Return Value a L<Data::Page> object for the current resultset. Only makes
1117 sense for queries with a C<page> attribute.
1123 my $attrs = $self->{attrs};
1124 $self->throw_exception("Can't create pager for non-paged rs")
1125 unless $self->{attrs}{page};
1126 $attrs->{rows} ||= 10;
1127 return $self->{pager} ||= Data::Page->new(
1128 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1135 =item Arguments: $page_number
1137 =item Return Value: $rs
1141 Returns a resultset for the $page_number page of the resultset on which page
1142 is called, where each page contains a number of rows equal to the 'rows'
1143 attribute set on the resultset (10 by default).
1148 my ($self, $page) = @_;
1149 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1156 =item Arguments: \%vals
1158 =item Return Value: $object
1162 Creates an object in the resultset's result class and returns it.
1167 my ($self, $values) = @_;
1168 $self->throw_exception( "new_result needs a hash" )
1169 unless (ref $values eq 'HASH');
1170 $self->throw_exception(
1171 "Can't abstract implicit construct, condition not a hash"
1172 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1174 my $alias = $self->{attrs}{alias};
1175 foreach my $key (keys %{$self->{cond}||{}}) {
1176 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1178 my $obj = $self->result_class->new(\%new);
1179 $obj->result_source($self->result_source) if $obj->can('result_source');
1187 =item Arguments: \%vals, \%attrs?
1189 =item Return Value: $object
1193 Find an existing record from this resultset. If none exists, instantiate a new
1194 result object and return it. The object will not be saved into your storage
1195 until you call L<DBIx::Class::Row/insert> on it.
1197 If you want objects to be saved immediately, use L</find_or_create> instead.
1203 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1204 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1205 my $exists = $self->find($hash, $attrs);
1206 return defined $exists ? $exists : $self->new_result($hash);
1213 =item Arguments: \%vals
1215 =item Return Value: $object
1219 Inserts a record into the resultset and returns the object representing it.
1221 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1226 my ($self, $attrs) = @_;
1227 $self->throw_exception( "create needs a hashref" )
1228 unless ref $attrs eq 'HASH';
1229 return $self->new_result($attrs)->insert;
1232 =head2 find_or_create
1236 =item Arguments: \%vals, \%attrs?
1238 =item Return Value: $object
1242 $class->find_or_create({ key => $val, ... });
1244 Tries to find a record based on its primary key or unique constraint; if none
1245 is found, creates one and returns that instead.
1247 my $cd = $schema->resultset('CD')->find_or_create({
1249 artist => 'Massive Attack',
1250 title => 'Mezzanine',
1254 Also takes an optional C<key> attribute, to search by a specific key or unique
1255 constraint. For example:
1257 my $cd = $schema->resultset('CD')->find_or_create(
1259 artist => 'Massive Attack',
1260 title => 'Mezzanine',
1262 { key => 'cd_artist_title' }
1265 See also L</find> and L</update_or_create>. For information on how to declare
1266 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1270 sub find_or_create {
1272 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1273 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1274 my $exists = $self->find($hash, $attrs);
1275 return defined $exists ? $exists : $self->create($hash);
1278 =head2 update_or_create
1282 =item Arguments: \%col_values, { key => $unique_constraint }?
1284 =item Return Value: $object
1288 $class->update_or_create({ col => $val, ... });
1290 First, searches for an existing row matching one of the unique constraints
1291 (including the primary key) on the source of this resultset. If a row is
1292 found, updates it with the other given column values. Otherwise, creates a new
1295 Takes an optional C<key> attribute to search on a specific unique constraint.
1298 # In your application
1299 my $cd = $schema->resultset('CD')->update_or_create(
1301 artist => 'Massive Attack',
1302 title => 'Mezzanine',
1305 { key => 'cd_artist_title' }
1308 If no C<key> is specified, it searches on all unique constraints defined on the
1309 source, including the primary key.
1311 If the C<key> is specified as C<primary>, it searches only on the primary key.
1313 See also L</find> and L</find_or_create>. For information on how to declare
1314 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1318 sub update_or_create {
1320 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1321 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1323 my $row = $self->find($cond);
1325 $row->update($cond);
1329 return $self->create($cond);
1336 =item Arguments: none
1338 =item Return Value: \@cache_objects?
1342 Gets the contents of the cache for the resultset, if the cache is set.
1354 =item Arguments: \@cache_objects
1356 =item Return Value: \@cache_objects
1360 Sets the contents of the cache for the resultset. Expects an arrayref
1361 of objects of the same class as those produced by the resultset. Note that
1362 if the cache is set the resultset will return the cached objects rather
1363 than re-querying the database even if the cache attr is not set.
1368 my ( $self, $data ) = @_;
1369 $self->throw_exception("set_cache requires an arrayref")
1370 if defined($data) && (ref $data ne 'ARRAY');
1371 $self->{all_cache} = $data;
1378 =item Arguments: none
1380 =item Return Value: []
1384 Clears the cache for the resultset.
1389 shift->set_cache(undef);
1392 =head2 related_resultset
1396 =item Arguments: $relationship_name
1398 =item Return Value: $resultset
1402 Returns a related resultset for the supplied relationship name.
1404 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1408 sub related_resultset {
1409 my ($self, $rel) = @_;
1411 $self->{related_resultsets} ||= {};
1412 return $self->{related_resultsets}{$rel} ||= do {
1413 my $rel_obj = $self->result_source->relationship_info($rel);
1415 $self->throw_exception(
1416 "search_related: result source '" . $self->result_source->name .
1417 "' has no such relationship $rel")
1420 my ($from,$seen) = $self->_resolve_from($rel);
1422 my $join_count = $seen->{$rel};
1423 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1425 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1427 %{$self->{attrs}||{}},
1433 where => $self->{cond},
1441 my ($self, $extra_join) = @_;
1442 my $source = $self->result_source;
1443 my $attrs = $self->{attrs};
1445 my $from = $attrs->{from}
1446 || [ { $attrs->{alias} => $source->from } ];
1448 my $seen = { %{$attrs->{seen_join}||{}} };
1450 my $join = ($attrs->{join}
1451 ? [ $attrs->{join}, $extra_join ]
1454 $source->resolve_join($join, $attrs->{alias}, $seen)
1457 return ($from,$seen);
1460 sub _resolved_attrs {
1462 return $self->{_attrs} if $self->{_attrs};
1464 my $attrs = { %{$self->{attrs}||{}} };
1465 my $source = $self->{result_source};
1466 my $alias = $attrs->{alias};
1468 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1469 if ($attrs->{columns}) {
1470 delete $attrs->{as};
1471 } elsif (!$attrs->{select}) {
1472 $attrs->{columns} = [ $source->columns ];
1475 $attrs->{select} ||= [
1476 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
1479 map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
1483 if ($adds = delete $attrs->{include_columns}) {
1484 $adds = [$adds] unless ref $adds eq 'ARRAY';
1485 push(@{$attrs->{select}}, @$adds);
1486 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1488 if ($adds = delete $attrs->{'+select'}) {
1489 $adds = [$adds] unless ref $adds eq 'ARRAY';
1490 push(@{$attrs->{select}}, map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1492 if (my $adds = delete $attrs->{'+as'}) {
1493 $adds = [$adds] unless ref $adds eq 'ARRAY';
1494 push(@{$attrs->{as}}, @$adds);
1497 $attrs->{from} ||= [ { 'me' => $source->from } ];
1499 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1500 my $join = delete $attrs->{join} || {};
1502 if (defined $attrs->{prefetch}) {
1503 $join = $self->_merge_attr(
1504 $join, $attrs->{prefetch}
1508 push(@{$attrs->{from}},
1509 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1513 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1514 if ($attrs->{order_by}) {
1515 $attrs->{order_by} = [ $attrs->{order_by} ] unless ref $attrs->{order_by};
1517 $attrs->{order_by} ||= [];
1520 my $collapse = $attrs->{collapse} || {};
1521 if (my $prefetch = delete $attrs->{prefetch}) {
1523 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1524 # bring joins back to level of current class
1525 my @prefetch = $source->resolve_prefetch(
1526 $p, $alias, { %{$attrs->{seen_join}||{}} }, \@pre_order, $collapse
1528 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1529 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1531 push(@{$attrs->{order_by}}, @pre_order);
1533 $attrs->{collapse} = $collapse;
1535 return $self->{_attrs} = $attrs;
1539 my ($self, $a, $b) = @_;
1540 return $b unless $a;
1542 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1543 foreach my $key (keys %{$b}) {
1544 if (exists $a->{$key}) {
1545 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1547 $a->{$key} = $b->{$key};
1552 $a = [$a] unless ref $a eq 'ARRAY';
1553 $b = [$b] unless ref $b eq 'ARRAY';
1557 foreach my $x ($a, $b) {
1558 foreach my $element (@{$x}) {
1559 if (ref $element eq 'HASH') {
1560 $hash = $self->_merge_attr($hash, $element);
1561 } elsif (ref $element eq 'ARRAY') {
1562 push(@array, @{$element});
1564 push(@array, $element) unless $b == $x
1565 && grep { $_ eq $element } @array;
1570 @array = grep { !exists $hash->{$_} } @array;
1572 return keys %{$hash}
1581 =head2 throw_exception
1583 See L<DBIx::Class::Schema/throw_exception> for details.
1587 sub throw_exception {
1589 $self->result_source->schema->throw_exception(@_);
1592 # XXX: FIXME: Attributes docs need clearing up
1596 The resultset takes various attributes that modify its behavior. Here's an
1603 =item Value: ($order_by | \@order_by)
1607 Which column(s) to order the results by. This is currently passed
1608 through directly to SQL, so you can give e.g. C<year DESC> for a
1609 descending order on the column `year'.
1611 Please note that if you have quoting enabled (see
1612 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1613 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1614 so you will need to manually quote things as appropriate.)
1620 =item Value: \@columns
1624 Shortcut to request a particular set of columns to be retrieved. Adds
1625 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1626 from that, then auto-populates C<as> from C<select> as normal. (You may also
1627 use the C<cols> attribute, as in earlier versions of DBIC.)
1629 =head2 include_columns
1633 =item Value: \@columns
1637 Shortcut to include additional columns in the returned results - for example
1639 $schema->resultset('CD')->search(undef, {
1640 include_columns => ['artist.name'],
1644 would return all CDs and include a 'name' column to the information
1645 passed to object inflation
1651 =item Value: \@select_columns
1655 Indicates which columns should be selected from the storage. You can use
1656 column names, or in the case of RDBMS back ends, function or stored procedure
1659 $rs = $schema->resultset('Employee')->search(undef, {
1662 { count => 'employeeid' },
1667 When you use function/stored procedure names and do not supply an C<as>
1668 attribute, the column names returned are storage-dependent. E.g. MySQL would
1669 return a column named C<count(employeeid)> in the above example.
1675 Indicates additional columns to be selected from storage. Works the same as
1676 L<select> but adds columns to the selection.
1684 Indicates additional column names for those added via L<+select>.
1692 =item Value: \@inflation_names
1696 Indicates column names for object inflation. This is used in conjunction with
1697 C<select>, usually when C<select> contains one or more function or stored
1700 $rs = $schema->resultset('Employee')->search(undef, {
1703 { count => 'employeeid' }
1705 as => ['name', 'employee_count'],
1708 my $employee = $rs->first(); # get the first Employee
1710 If the object against which the search is performed already has an accessor
1711 matching a column name specified in C<as>, the value can be retrieved using
1712 the accessor as normal:
1714 my $name = $employee->name();
1716 If on the other hand an accessor does not exist in the object, you need to
1717 use C<get_column> instead:
1719 my $employee_count = $employee->get_column('employee_count');
1721 You can create your own accessors if required - see
1722 L<DBIx::Class::Manual::Cookbook> for details.
1724 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1725 produced, it is used for internal access only. Thus attempting to use the accessor
1726 in an C<order_by> clause or similar will fail misrably.
1732 =item Value: ($rel_name | \@rel_names | \%rel_names)
1736 Contains a list of relationships that should be joined for this query. For
1739 # Get CDs by Nine Inch Nails
1740 my $rs = $schema->resultset('CD')->search(
1741 { 'artist.name' => 'Nine Inch Nails' },
1742 { join => 'artist' }
1745 Can also contain a hash reference to refer to the other relation's relations.
1748 package MyApp::Schema::Track;
1749 use base qw/DBIx::Class/;
1750 __PACKAGE__->table('track');
1751 __PACKAGE__->add_columns(qw/trackid cd position title/);
1752 __PACKAGE__->set_primary_key('trackid');
1753 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1756 # In your application
1757 my $rs = $schema->resultset('Artist')->search(
1758 { 'track.title' => 'Teardrop' },
1760 join => { cd => 'track' },
1761 order_by => 'artist.name',
1765 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1766 similarly for a third time). For e.g.
1768 my $rs = $schema->resultset('Artist')->search({
1769 'cds.title' => 'Down to Earth',
1770 'cds_2.title' => 'Popular',
1772 join => [ qw/cds cds/ ],
1775 will return a set of all artists that have both a cd with title 'Down
1776 to Earth' and a cd with title 'Popular'.
1778 If you want to fetch related objects from other tables as well, see C<prefetch>
1785 =item Value: ($rel_name | \@rel_names | \%rel_names)
1789 Contains one or more relationships that should be fetched along with the main
1790 query (when they are accessed afterwards they will have already been
1791 "prefetched"). This is useful for when you know you will need the related
1792 objects, because it saves at least one query:
1794 my $rs = $schema->resultset('Tag')->search(
1803 The initial search results in SQL like the following:
1805 SELECT tag.*, cd.*, artist.* FROM tag
1806 JOIN cd ON tag.cd = cd.cdid
1807 JOIN artist ON cd.artist = artist.artistid
1809 L<DBIx::Class> has no need to go back to the database when we access the
1810 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1813 Simple prefetches will be joined automatically, so there is no need
1814 for a C<join> attribute in the above search. If you're prefetching to
1815 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1816 specify the join as well.
1818 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1819 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1820 with an accessor type of 'single' or 'filter').
1830 Makes the resultset paged and specifies the page to retrieve. Effectively
1831 identical to creating a non-pages resultset and then calling ->page($page)
1834 If L<rows> attribute is not specified it defualts to 10 rows per page.
1844 Specifes the maximum number of rows for direct retrieval or the number of
1845 rows per page if the page attribute or method is used.
1851 =item Value: $offset
1855 Specifies the (zero-based) row number for the first row to be returned, or the
1856 of the first row of the first page if paging is used.
1862 =item Value: \@columns
1866 A arrayref of columns to group by. Can include columns of joined tables.
1868 group_by => [qw/ column1 column2 ... /]
1874 =item Value: $condition
1878 HAVING is a select statement attribute that is applied between GROUP BY and
1879 ORDER BY. It is applied to the after the grouping calculations have been
1882 having => { 'count(employee)' => { '>=', 100 } }
1888 =item Value: (0 | 1)
1892 Set to 1 to group by all columns.
1898 Adds to the WHERE clause.
1900 # only return rows WHERE deleted IS NULL for all searches
1901 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
1903 Can be overridden by passing C<{ where => undef }> as an attribute
1910 Set to 1 to cache search results. This prevents extra SQL queries if you
1911 revisit rows in your ResultSet:
1913 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1915 while( my $artist = $resultset->next ) {
1919 $rs->first; # without cache, this would issue a query
1921 By default, searches are not cached.
1923 For more examples of using these attributes, see
1924 L<DBIx::Class::Manual::Cookbook>.
1930 =item Value: \@from_clause
1934 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1935 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1938 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1940 C<join> will usually do what you need and it is strongly recommended that you
1941 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1942 And we really do mean "cannot", not just tried and failed. Attempting to use
1943 this because you're having problems with C<join> is like trying to use x86
1944 ASM because you've got a syntax error in your C. Trust us on this.
1946 Now, if you're still really, really sure you need to use this (and if you're
1947 not 100% sure, ask the mailing list first), here's an explanation of how this
1950 The syntax is as follows -
1953 { <alias1> => <table1> },
1955 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1956 [], # nested JOIN (optional)
1957 { <table1.column1> => <table2.column2>, ... (more conditions) },
1959 # More of the above [ ] may follow for additional joins
1966 ON <table1.column1> = <table2.column2>
1967 <more joins may follow>
1969 An easy way to follow the examples below is to remember the following:
1971 Anything inside "[]" is a JOIN
1972 Anything inside "{}" is a condition for the enclosing JOIN
1974 The following examples utilize a "person" table in a family tree application.
1975 In order to express parent->child relationships, this table is self-joined:
1977 # Person->belongs_to('father' => 'Person');
1978 # Person->belongs_to('mother' => 'Person');
1980 C<from> can be used to nest joins. Here we return all children with a father,
1981 then search against all mothers of those children:
1983 $rs = $schema->resultset('Person')->search(
1986 alias => 'mother', # alias columns in accordance with "from"
1988 { mother => 'person' },
1991 { child => 'person' },
1993 { father => 'person' },
1994 { 'father.person_id' => 'child.father_id' }
1997 { 'mother.person_id' => 'child.mother_id' }
2004 # SELECT mother.* FROM person mother
2007 # JOIN person father
2008 # ON ( father.person_id = child.father_id )
2010 # ON ( mother.person_id = child.mother_id )
2012 The type of any join can be controlled manually. To search against only people
2013 with a father in the person table, we could explicitly use C<INNER JOIN>:
2015 $rs = $schema->resultset('Person')->search(
2018 alias => 'child', # alias columns in accordance with "from"
2020 { child => 'person' },
2022 { father => 'person', -join_type => 'inner' },
2023 { 'father.id' => 'child.father_id' }
2030 # SELECT child.* FROM person child
2031 # INNER JOIN person father ON child.father_id = father.id