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},
116 =item Arguments: $cond, \%attrs?
118 =item Return Value: $resultset (scalar context), @row_objs (list context)
122 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
123 my $new_rs = $cd_rs->search({ year => 2005 });
125 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
126 # year = 2005 OR year = 2004
128 If you need to pass in additional attributes but no additional condition,
129 call it as C<search(undef, \%attrs)>.
131 # "SELECT name, artistid FROM $artist_table"
132 my @all_artists = $schema->resultset('Artist')->search(undef, {
133 columns => [qw/name artistid/],
136 For a list of attributes that can be passed to C<search>, see L</ATTRIBUTES>. For more examples of using this function, see L<Searching|DBIx::Class::Manual::Cookbook/Searching>.
142 my $rs = $self->search_rs( @_ );
143 return (wantarray ? $rs->all : $rs);
150 =item Arguments: $cond, \%attrs?
152 =item Return Value: $resultset
156 This method does the same exact thing as search() except it will
157 always return a resultset, even in list context.
166 unless (@_) { # no search, effectively just a clone
167 $rows = $self->get_cache;
171 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
172 my $our_attrs = { %{$self->{attrs}} };
173 my $having = delete $our_attrs->{having};
174 my $where = delete $our_attrs->{where};
176 my $new_attrs = { %{$our_attrs}, %{$attrs} };
178 # merge new attrs into inherited
179 foreach my $key (qw/join prefetch/) {
180 next unless exists $attrs->{$key};
181 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
186 (@_ == 1 || ref $_[0] eq "HASH")
188 (ref $_[0] eq 'HASH')
190 (keys %{ $_[0] } > 0)
198 ? $self->throw_exception("Odd number of arguments to search")
205 if (defined $where) {
206 $new_attrs->{where} = (
207 defined $new_attrs->{where}
210 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
211 } $where, $new_attrs->{where}
218 $new_attrs->{where} = (
219 defined $new_attrs->{where}
222 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
223 } $cond, $new_attrs->{where}
229 if (defined $having) {
230 $new_attrs->{having} = (
231 defined $new_attrs->{having}
234 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
235 } $having, $new_attrs->{having}
241 my $rs = (ref $self)->new($self->result_source, $new_attrs);
243 $rs->set_cache($rows);
248 =head2 search_literal
252 =item Arguments: $sql_fragment, @bind_values
254 =item Return Value: $resultset (scalar context), @row_objs (list context)
258 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
259 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
261 Pass a literal chunk of SQL to be added to the conditional part of the
267 my ($self, $cond, @vals) = @_;
268 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
269 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
270 return $self->search(\$cond, $attrs);
277 =item Arguments: @values | \%cols, \%attrs?
279 =item Return Value: $row_object
283 Finds a row based on its primary key or unique constraint. For example, to find
284 a row by its primary key:
286 my $cd = $schema->resultset('CD')->find(5);
288 You can also find a row by a specific unique constraint using the C<key>
289 attribute. For example:
291 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
292 key => 'cd_artist_title'
295 Additionally, you can specify the columns explicitly by name:
297 my $cd = $schema->resultset('CD')->find(
299 artist => 'Massive Attack',
300 title => 'Mezzanine',
302 { key => 'cd_artist_title' }
305 If the C<key> is specified as C<primary>, it searches only on the primary key.
307 If no C<key> is specified, it searches on all unique constraints defined on the
308 source, including the primary key.
310 If your table does not have a primary key, you B<must> provide a value for the
311 C<key> attribute matching one of the unique constraints on the source.
313 See also L</find_or_create> and L</update_or_create>. For information on how to
314 declare unique constraints, see
315 L<DBIx::Class::ResultSource/add_unique_constraint>.
321 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
323 # Default to the primary key, but allow a specific key
324 my @cols = exists $attrs->{key}
325 ? $self->result_source->unique_constraint_columns($attrs->{key})
326 : $self->result_source->primary_columns;
327 $self->throw_exception(
328 "Can't find unless a primary key is defined or unique constraint is specified"
331 # Parse out a hashref from input
333 if (ref $_[0] eq 'HASH') {
334 $input_query = { %{$_[0]} };
336 elsif (@_ == @cols) {
338 @{$input_query}{@cols} = @_;
341 # Compatibility: Allow e.g. find(id => $value)
342 carp "Find by key => value deprecated; please use a hashref instead";
346 my (%related, $info);
348 foreach my $key (keys %$input_query) {
349 if (ref($input_query->{$key})
350 && ($info = $self->result_source->relationship_info($key))) {
351 my $rel_q = $self->result_source->resolve_condition(
352 $info->{cond}, delete $input_query->{$key}, $key
354 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
355 @related{keys %$rel_q} = values %$rel_q;
358 if (my @keys = keys %related) {
359 @{$input_query}{@keys} = values %related;
362 my @unique_queries = $self->_unique_queries($input_query, $attrs);
364 # Build the final query: Default to the disjunction of the unique queries,
365 # but allow the input query in case the ResultSet defines the query or the
366 # user is abusing find
367 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
368 my $query = @unique_queries
369 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
370 : $self->_add_alias($input_query, $alias);
374 my $rs = $self->search($query, $attrs);
375 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
378 return keys %{$self->_resolved_attrs->{collapse}}
379 ? $self->search($query)->next
380 : $self->single($query);
386 # Add the specified alias to the specified query hash. A copy is made so the
387 # original query is not modified.
390 my ($self, $query, $alias) = @_;
392 my %aliased = %$query;
393 foreach my $col (grep { ! m/\./ } keys %aliased) {
394 $aliased{"$alias.$col"} = delete $aliased{$col};
402 # Build a list of queries which satisfy unique constraints.
404 sub _unique_queries {
405 my ($self, $query, $attrs) = @_;
407 my @constraint_names = exists $attrs->{key}
409 : $self->result_source->unique_constraint_names;
412 foreach my $name (@constraint_names) {
413 my @unique_cols = $self->result_source->unique_constraint_columns($name);
414 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
416 my $num_query = scalar keys %$unique_query;
417 next unless $num_query;
419 # XXX: Assuming quite a bit about $self->{attrs}{where}
420 my $num_cols = scalar @unique_cols;
421 my $num_where = exists $self->{attrs}{where}
422 ? scalar keys %{ $self->{attrs}{where} }
424 push @unique_queries, $unique_query
425 if $num_query + $num_where == $num_cols;
428 return @unique_queries;
431 # _build_unique_query
433 # Constrain the specified query hash based on the specified column names.
435 sub _build_unique_query {
436 my ($self, $query, $unique_cols) = @_;
439 map { $_ => $query->{$_} }
440 grep { exists $query->{$_} }
445 =head2 search_related
449 =item Arguments: $rel, $cond, \%attrs?
451 =item Return Value: $new_resultset
455 $new_rs = $cd_rs->search_related('artist', {
459 Searches the specified relationship, optionally specifying a condition and
460 attributes for matching records. See L</ATTRIBUTES> for more information.
465 return shift->related_resultset(shift)->search(@_);
472 =item Arguments: none
474 =item Return Value: $cursor
478 Returns a storage-driven cursor to the given resultset. See
479 L<DBIx::Class::Cursor> for more information.
486 my $attrs = { %{$self->_resolved_attrs} };
487 return $self->{cursor}
488 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
489 $attrs->{where},$attrs);
496 =item Arguments: $cond?
498 =item Return Value: $row_object?
502 my $cd = $schema->resultset('CD')->single({ year => 2001 });
504 Inflates the first result without creating a cursor if the resultset has
505 any records in it; if not returns nothing. Used by L</find> as an optimisation.
507 Can optionally take an additional condition *only* - this is a fast-code-path
508 method; if you need to add extra joins or similar call ->search and then
509 ->single without a condition on the $rs returned from that.
514 my ($self, $where) = @_;
515 my $attrs = { %{$self->_resolved_attrs} };
517 if (defined $attrs->{where}) {
520 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
521 $where, delete $attrs->{where} ]
524 $attrs->{where} = $where;
528 # XXX: Disabled since it doesn't infer uniqueness in all cases
529 # unless ($self->_is_unique_query($attrs->{where})) {
530 # carp "Query not guaranteed to return a single row"
531 # . "; please declare your unique constraints or use search instead";
534 my @data = $self->result_source->storage->select_single(
535 $attrs->{from}, $attrs->{select},
536 $attrs->{where}, $attrs
539 return (@data ? $self->_construct_object(@data) : ());
544 # Try to determine if the specified query is guaranteed to be unique, based on
545 # the declared unique constraints.
547 sub _is_unique_query {
548 my ($self, $query) = @_;
550 my $collapsed = $self->_collapse_query($query);
551 my $alias = $self->{attrs}{alias};
553 foreach my $name ($self->result_source->unique_constraint_names) {
554 my @unique_cols = map {
556 } $self->result_source->unique_constraint_columns($name);
558 # Count the values for each unique column
559 my %seen = map { $_ => 0 } @unique_cols;
561 foreach my $key (keys %$collapsed) {
562 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
563 next unless exists $seen{$aliased}; # Additional constraints are okay
564 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
567 # If we get 0 or more than 1 value for a column, it's not necessarily unique
568 return 1 unless grep { $_ != 1 } values %seen;
576 # Recursively collapse the query, accumulating values for each column.
578 sub _collapse_query {
579 my ($self, $query, $collapsed) = @_;
583 if (ref $query eq 'ARRAY') {
584 foreach my $subquery (@$query) {
585 next unless ref $subquery; # -or
586 # warn "ARRAY: " . Dumper $subquery;
587 $collapsed = $self->_collapse_query($subquery, $collapsed);
590 elsif (ref $query eq 'HASH') {
591 if (keys %$query and (keys %$query)[0] eq '-and') {
592 foreach my $subquery (@{$query->{-and}}) {
593 # warn "HASH: " . Dumper $subquery;
594 $collapsed = $self->_collapse_query($subquery, $collapsed);
598 # warn "LEAF: " . Dumper $query;
599 foreach my $col (keys %$query) {
600 my $value = $query->{$col};
601 $collapsed->{$col}{$value}++;
613 =item Arguments: $cond?
615 =item Return Value: $resultsetcolumn
619 my $max_length = $rs->get_column('length')->max;
621 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
626 my ($self, $column) = @_;
627 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
635 =item Arguments: $cond, \%attrs?
637 =item Return Value: $resultset (scalar context), @row_objs (list context)
641 # WHERE title LIKE '%blue%'
642 $cd_rs = $rs->search_like({ title => '%blue%'});
644 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
645 that this is simply a convenience method. You most likely want to use
646 L</search> with specific operators.
648 For more information, see L<DBIx::Class::Manual::Cookbook>.
654 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
655 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
656 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
657 return $class->search($query, { %$attrs });
664 =item Arguments: $first, $last
666 =item Return Value: $resultset (scalar context), @row_objs (list context)
670 Returns a resultset or object list representing a subset of elements from the
671 resultset slice is called on. Indexes are from 0, i.e., to get the first
674 my ($one, $two, $three) = $rs->slice(0, 2);
679 my ($self, $min, $max) = @_;
680 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
681 $attrs->{offset} = $self->{attrs}{offset} || 0;
682 $attrs->{offset} += $min;
683 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
684 return $self->search(undef(), $attrs);
685 #my $slice = (ref $self)->new($self->result_source, $attrs);
686 #return (wantarray ? $slice->all : $slice);
693 =item Arguments: none
695 =item Return Value: $result?
699 Returns the next element in the resultset (C<undef> is there is none).
701 Can be used to efficiently iterate over records in the resultset:
703 my $rs = $schema->resultset('CD')->search;
704 while (my $cd = $rs->next) {
708 Note that you need to store the resultset object, and call C<next> on it.
709 Calling C<< resultset('Table')->next >> repeatedly will always return the
710 first record from the resultset.
716 if (my $cache = $self->get_cache) {
717 $self->{all_cache_position} ||= 0;
718 return $cache->[$self->{all_cache_position}++];
720 if ($self->{attrs}{cache}) {
721 $self->{all_cache_position} = 1;
722 return ($self->all)[0];
725 exists $self->{stashed_row}
726 ? @{delete $self->{stashed_row}}
727 : $self->cursor->next
729 return unless (@row);
730 return $self->_construct_object(@row);
733 sub _construct_object {
734 my ($self, @row) = @_;
735 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
736 my $new = $self->result_class->inflate_result($self->result_source, @$info);
737 $new = $self->{_attrs}{record_filter}->($new)
738 if exists $self->{_attrs}{record_filter};
742 sub _collapse_result {
743 my ($self, $as, $row, $prefix) = @_;
748 foreach my $this_as (@$as) {
749 my $val = shift @copy;
750 if (defined $prefix) {
751 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
753 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
754 $const{$1||''}{$2} = $val;
757 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
758 $const{$1||''}{$2} = $val;
762 my $alias = $self->{attrs}{alias};
763 my $info = [ {}, {} ];
764 foreach my $key (keys %const) {
765 if (length $key && $key ne $alias) {
767 my @parts = split(/\./, $key);
768 foreach my $p (@parts) {
769 $target = $target->[1]->{$p} ||= [];
771 $target->[0] = $const{$key};
773 $info->[0] = $const{$key};
778 if (defined $prefix) {
780 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
781 } keys %{$self->{_attrs}{collapse}}
783 @collapse = keys %{$self->{_attrs}{collapse}};
787 my ($c) = sort { length $a <=> length $b } @collapse;
789 foreach my $p (split(/\./, $c)) {
790 $target = $target->[1]->{$p} ||= [];
792 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
793 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
794 my $tree = $self->_collapse_result($as, $row, $c_prefix);
795 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
801 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
806 last unless (@raw = $self->cursor->next);
807 $row = $self->{stashed_row} = \@raw;
808 $tree = $self->_collapse_result($as, $row, $c_prefix);
810 @$target = (@final ? @final : [ {}, {} ]);
811 # single empty result to indicate an empty prefetched has_many
814 #print "final info: " . Dumper($info);
822 =item Arguments: $result_source?
824 =item Return Value: $result_source
828 An accessor for the primary ResultSource object from which this ResultSet
835 =item Arguments: $result_class?
837 =item Return Value: $result_class
841 An accessor for the class to use when creating row objects. Defaults to
842 C<< result_source->result_class >> - which in most cases is the name of the
843 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
852 =item Arguments: $cond, \%attrs??
854 =item Return Value: $count
858 Performs an SQL C<COUNT> with the same query as the resultset was built
859 with to find the number of elements. If passed arguments, does a search
860 on the resultset and counts the results of that.
862 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
863 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
864 not support C<DISTINCT> with multiple columns. If you are using such a
865 database, you should only use columns from the main table in your C<group_by>
872 return $self->search(@_)->count if @_ and defined $_[0];
873 return scalar @{ $self->get_cache } if $self->get_cache;
874 my $count = $self->_count;
875 return 0 unless $count;
877 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
878 $count = $self->{attrs}{rows} if
879 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
883 sub _count { # Separated out so pager can get the full count
885 my $select = { count => '*' };
887 my $attrs = { %{$self->_resolved_attrs} };
888 if (my $group_by = delete $attrs->{group_by}) {
889 delete $attrs->{having};
890 my @distinct = (ref $group_by ? @$group_by : ($group_by));
891 # todo: try CONCAT for multi-column pk
892 my @pk = $self->result_source->primary_columns;
894 my $alias = $attrs->{alias};
895 foreach my $column (@distinct) {
896 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
897 @distinct = ($column);
903 $select = { count => { distinct => \@distinct } };
906 $attrs->{select} = $select;
907 $attrs->{as} = [qw/count/];
909 # offset, order by and page are not needed to count. record_filter is cdbi
910 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
912 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
913 my ($count) = $tmp_rs->cursor->next;
921 =item Arguments: $sql_fragment, @bind_values
923 =item Return Value: $count
927 Counts the results in a literal query. Equivalent to calling L</search_literal>
928 with the passed arguments, then L</count>.
932 sub count_literal { shift->search_literal(@_)->count; }
938 =item Arguments: none
940 =item Return Value: @objects
944 Returns all elements in the resultset. Called implicitly if the resultset
945 is returned in list context.
951 return @{ $self->get_cache } if $self->get_cache;
955 # TODO: don't call resolve here
956 if (keys %{$self->_resolved_attrs->{collapse}}) {
957 # if ($self->{attrs}{prefetch}) {
958 # Using $self->cursor->all is really just an optimisation.
959 # If we're collapsing has_many prefetches it probably makes
960 # very little difference, and this is cleaner than hacking
961 # _construct_object to survive the approach
962 my @row = $self->cursor->next;
964 push(@obj, $self->_construct_object(@row));
965 @row = (exists $self->{stashed_row}
966 ? @{delete $self->{stashed_row}}
967 : $self->cursor->next);
970 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
973 $self->set_cache(\@obj) if $self->{attrs}{cache};
981 =item Arguments: none
983 =item Return Value: $self
987 Resets the resultset's cursor, so you can iterate through the elements again.
993 delete $self->{_attrs} if exists $self->{_attrs};
994 $self->{all_cache_position} = 0;
995 $self->cursor->reset;
1003 =item Arguments: none
1005 =item Return Value: $object?
1009 Resets the resultset and returns an object for the first result (if the
1010 resultset returns anything).
1015 return $_[0]->reset->next;
1018 # _cond_for_update_delete
1020 # update/delete require the condition to be modified to handle
1021 # the differing SQL syntax available. This transforms the $self->{cond}
1022 # appropriately, returning the new condition.
1024 sub _cond_for_update_delete {
1025 my ($self, $full_cond) = @_;
1028 $full_cond ||= $self->{cond};
1029 # No-op. No condition, we're updating/deleting everything
1030 return $cond unless ref $full_cond;
1032 if (ref $full_cond eq 'ARRAY') {
1036 foreach my $key (keys %{$_}) {
1038 $hash{$1} = $_->{$key};
1044 elsif (ref $full_cond eq 'HASH') {
1045 if ((keys %{$full_cond})[0] eq '-and') {
1048 my @cond = @{$full_cond->{-and}};
1049 for (my $i = 0; $i < @cond; $i++) {
1050 my $entry = $cond[$i];
1053 if (ref $entry eq 'HASH') {
1054 $hash = $self->_cond_for_update_delete($entry);
1057 $entry =~ /([^.]+)$/;
1058 $hash->{$1} = $cond[++$i];
1061 push @{$cond->{-and}}, $hash;
1065 foreach my $key (keys %{$full_cond}) {
1067 $cond->{$1} = $full_cond->{$key};
1072 $self->throw_exception(
1073 "Can't update/delete on resultset with condition unless hash or array"
1085 =item Arguments: \%values
1087 =item Return Value: $storage_rv
1091 Sets the specified columns in the resultset to the supplied values in a
1092 single query. Return value will be true if the update succeeded or false
1093 if no records were updated; exact type of success value is storage-dependent.
1098 my ($self, $values) = @_;
1099 $self->throw_exception("Values for update must be a hash")
1100 unless ref $values eq 'HASH';
1102 my $cond = $self->_cond_for_update_delete;
1104 return $self->result_source->storage->update(
1105 $self->result_source->from, $values, $cond
1113 =item Arguments: \%values
1115 =item Return Value: 1
1119 Fetches all objects and updates them one at a time. Note that C<update_all>
1120 will run DBIC cascade triggers, while L</update> will not.
1125 my ($self, $values) = @_;
1126 $self->throw_exception("Values for update must be a hash")
1127 unless ref $values eq 'HASH';
1128 foreach my $obj ($self->all) {
1129 $obj->set_columns($values)->update;
1138 =item Arguments: none
1140 =item Return Value: 1
1144 Deletes the contents of the resultset from its result source. Note that this
1145 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1146 to run. See also L<DBIx::Class::Row/delete>.
1153 my $cond = $self->_cond_for_update_delete;
1155 $self->result_source->storage->delete($self->result_source->from, $cond);
1163 =item Arguments: none
1165 =item Return Value: 1
1169 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1170 will run DBIC cascade triggers, while L</delete> will not.
1176 $_->delete for $self->all;
1184 =item Arguments: none
1186 =item Return Value: $pager
1190 Return Value a L<Data::Page> object for the current resultset. Only makes
1191 sense for queries with a C<page> attribute.
1197 my $attrs = $self->{attrs};
1198 $self->throw_exception("Can't create pager for non-paged rs")
1199 unless $self->{attrs}{page};
1200 $attrs->{rows} ||= 10;
1201 return $self->{pager} ||= Data::Page->new(
1202 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1209 =item Arguments: $page_number
1211 =item Return Value: $rs
1215 Returns a resultset for the $page_number page of the resultset on which page
1216 is called, where each page contains a number of rows equal to the 'rows'
1217 attribute set on the resultset (10 by default).
1222 my ($self, $page) = @_;
1223 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1230 =item Arguments: \%vals
1232 =item Return Value: $object
1236 Creates an object in the resultset's result class and returns it.
1241 my ($self, $values) = @_;
1242 $self->throw_exception( "new_result needs a hash" )
1243 unless (ref $values eq 'HASH');
1244 $self->throw_exception(
1245 "Can't abstract implicit construct, condition not a hash"
1246 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1248 my $alias = $self->{attrs}{alias};
1249 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1251 %{ $self->_remove_alias($values, $alias) },
1252 %{ $self->_remove_alias($collapsed_cond, $alias) },
1253 -result_source => $self->result_source,
1256 my $obj = $self->result_class->new(\%new);
1262 # Recursively collapse the condition.
1264 sub _collapse_cond {
1265 my ($self, $cond, $collapsed) = @_;
1269 if (ref $cond eq 'ARRAY') {
1270 foreach my $subcond (@$cond) {
1271 next unless ref $subcond; # -or
1272 # warn "ARRAY: " . Dumper $subcond;
1273 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1276 elsif (ref $cond eq 'HASH') {
1277 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1278 foreach my $subcond (@{$cond->{-and}}) {
1279 # warn "HASH: " . Dumper $subcond;
1280 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1284 # warn "LEAF: " . Dumper $cond;
1285 foreach my $col (keys %$cond) {
1286 my $value = $cond->{$col};
1287 $collapsed->{$col} = $value;
1297 # Remove the specified alias from the specified query hash. A copy is made so
1298 # the original query is not modified.
1301 my ($self, $query, $alias) = @_;
1303 my %orig = %{ $query || {} };
1306 foreach my $key (keys %orig) {
1308 $unaliased{$key} = $orig{$key};
1311 $unaliased{$1} = $orig{$key}
1312 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1322 =item Arguments: \%vals, \%attrs?
1324 =item Return Value: $object
1328 Find an existing record from this resultset. If none exists, instantiate a new
1329 result object and return it. The object will not be saved into your storage
1330 until you call L<DBIx::Class::Row/insert> on it.
1332 If you want objects to be saved immediately, use L</find_or_create> instead.
1338 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1339 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1340 my $exists = $self->find($hash, $attrs);
1341 return defined $exists ? $exists : $self->new_result($hash);
1348 =item Arguments: \%vals
1350 =item Return Value: $object
1354 Inserts a record into the resultset and returns the object representing it.
1356 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1361 my ($self, $attrs) = @_;
1362 $self->throw_exception( "create needs a hashref" )
1363 unless ref $attrs eq 'HASH';
1364 return $self->new_result($attrs)->insert;
1367 =head2 find_or_create
1371 =item Arguments: \%vals, \%attrs?
1373 =item Return Value: $object
1377 $class->find_or_create({ key => $val, ... });
1379 Tries to find a record based on its primary key or unique constraint; if none
1380 is found, creates one and returns that instead.
1382 my $cd = $schema->resultset('CD')->find_or_create({
1384 artist => 'Massive Attack',
1385 title => 'Mezzanine',
1389 Also takes an optional C<key> attribute, to search by a specific key or unique
1390 constraint. For example:
1392 my $cd = $schema->resultset('CD')->find_or_create(
1394 artist => 'Massive Attack',
1395 title => 'Mezzanine',
1397 { key => 'cd_artist_title' }
1400 See also L</find> and L</update_or_create>. For information on how to declare
1401 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1405 sub find_or_create {
1407 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1408 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1409 my $exists = $self->find($hash, $attrs);
1410 return defined $exists ? $exists : $self->create($hash);
1413 =head2 update_or_create
1417 =item Arguments: \%col_values, { key => $unique_constraint }?
1419 =item Return Value: $object
1423 $class->update_or_create({ col => $val, ... });
1425 First, searches for an existing row matching one of the unique constraints
1426 (including the primary key) on the source of this resultset. If a row is
1427 found, updates it with the other given column values. Otherwise, creates a new
1430 Takes an optional C<key> attribute to search on a specific unique constraint.
1433 # In your application
1434 my $cd = $schema->resultset('CD')->update_or_create(
1436 artist => 'Massive Attack',
1437 title => 'Mezzanine',
1440 { key => 'cd_artist_title' }
1443 If no C<key> is specified, it searches on all unique constraints defined on the
1444 source, including the primary key.
1446 If the C<key> is specified as C<primary>, it searches only on the primary key.
1448 See also L</find> and L</find_or_create>. For information on how to declare
1449 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1453 sub update_or_create {
1455 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1456 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1458 my $row = $self->find($cond, $attrs);
1460 $row->update($cond);
1464 return $self->create($cond);
1471 =item Arguments: none
1473 =item Return Value: \@cache_objects?
1477 Gets the contents of the cache for the resultset, if the cache is set.
1489 =item Arguments: \@cache_objects
1491 =item Return Value: \@cache_objects
1495 Sets the contents of the cache for the resultset. Expects an arrayref
1496 of objects of the same class as those produced by the resultset. Note that
1497 if the cache is set the resultset will return the cached objects rather
1498 than re-querying the database even if the cache attr is not set.
1503 my ( $self, $data ) = @_;
1504 $self->throw_exception("set_cache requires an arrayref")
1505 if defined($data) && (ref $data ne 'ARRAY');
1506 $self->{all_cache} = $data;
1513 =item Arguments: none
1515 =item Return Value: []
1519 Clears the cache for the resultset.
1524 shift->set_cache(undef);
1527 =head2 related_resultset
1531 =item Arguments: $relationship_name
1533 =item Return Value: $resultset
1537 Returns a related resultset for the supplied relationship name.
1539 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1543 sub related_resultset {
1544 my ($self, $rel) = @_;
1546 $self->{related_resultsets} ||= {};
1547 return $self->{related_resultsets}{$rel} ||= do {
1548 my $rel_obj = $self->result_source->relationship_info($rel);
1550 $self->throw_exception(
1551 "search_related: result source '" . $self->result_source->name .
1552 "' has no such relationship $rel")
1555 my ($from,$seen) = $self->_resolve_from($rel);
1557 my $join_count = $seen->{$rel};
1558 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1560 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1562 %{$self->{attrs}||{}},
1568 where => $self->{cond},
1576 my ($self, $extra_join) = @_;
1577 my $source = $self->result_source;
1578 my $attrs = $self->{attrs};
1580 my $from = $attrs->{from}
1581 || [ { $attrs->{alias} => $source->from } ];
1583 my $seen = { %{$attrs->{seen_join}||{}} };
1585 my $join = ($attrs->{join}
1586 ? [ $attrs->{join}, $extra_join ]
1590 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1593 return ($from,$seen);
1596 sub _resolved_attrs {
1598 return $self->{_attrs} if $self->{_attrs};
1600 my $attrs = { %{$self->{attrs}||{}} };
1601 my $source = $self->{result_source};
1602 my $alias = $attrs->{alias};
1604 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1605 if ($attrs->{columns}) {
1606 delete $attrs->{as};
1607 } elsif (!$attrs->{select}) {
1608 $attrs->{columns} = [ $source->columns ];
1613 ? (ref $attrs->{select} eq 'ARRAY'
1614 ? [ @{$attrs->{select}} ]
1615 : [ $attrs->{select} ])
1616 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1620 ? (ref $attrs->{as} eq 'ARRAY'
1621 ? [ @{$attrs->{as}} ]
1623 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1627 if ($adds = delete $attrs->{include_columns}) {
1628 $adds = [$adds] unless ref $adds eq 'ARRAY';
1629 push(@{$attrs->{select}}, @$adds);
1630 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1632 if ($adds = delete $attrs->{'+select'}) {
1633 $adds = [$adds] unless ref $adds eq 'ARRAY';
1634 push(@{$attrs->{select}},
1635 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1637 if (my $adds = delete $attrs->{'+as'}) {
1638 $adds = [$adds] unless ref $adds eq 'ARRAY';
1639 push(@{$attrs->{as}}, @$adds);
1642 $attrs->{from} ||= [ { 'me' => $source->from } ];
1644 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1645 my $join = delete $attrs->{join} || {};
1647 if (defined $attrs->{prefetch}) {
1648 $join = $self->_merge_attr(
1649 $join, $attrs->{prefetch}
1653 $attrs->{from} = # have to copy here to avoid corrupting the original
1656 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1660 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1661 if ($attrs->{order_by}) {
1662 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1663 ? [ @{$attrs->{order_by}} ]
1664 : [ $attrs->{order_by} ]);
1666 $attrs->{order_by} = [];
1669 my $collapse = $attrs->{collapse} || {};
1670 if (my $prefetch = delete $attrs->{prefetch}) {
1671 $prefetch = $self->_merge_attr({}, $prefetch);
1673 my $seen = $attrs->{seen_join} || {};
1674 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1675 # bring joins back to level of current class
1676 my @prefetch = $source->resolve_prefetch(
1677 $p, $alias, $seen, \@pre_order, $collapse
1679 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1680 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1682 push(@{$attrs->{order_by}}, @pre_order);
1684 $attrs->{collapse} = $collapse;
1686 return $self->{_attrs} = $attrs;
1690 my ($self, $a, $b) = @_;
1691 return $b unless defined($a);
1692 return $a unless defined($b);
1694 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1695 foreach my $key (keys %{$b}) {
1696 if (exists $a->{$key}) {
1697 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1699 $a->{$key} = $b->{$key};
1704 $a = [$a] unless ref $a eq 'ARRAY';
1705 $b = [$b] unless ref $b eq 'ARRAY';
1709 foreach my $x ($a, $b) {
1710 foreach my $element (@{$x}) {
1711 if (ref $element eq 'HASH') {
1712 $hash = $self->_merge_attr($hash, $element);
1713 } elsif (ref $element eq 'ARRAY') {
1714 push(@array, @{$element});
1716 push(@array, $element) unless $b == $x
1717 && grep { $_ eq $element } @array;
1722 @array = grep { !exists $hash->{$_} } @array;
1724 return keys %{$hash}
1733 =head2 throw_exception
1735 See L<DBIx::Class::Schema/throw_exception> for details.
1739 sub throw_exception {
1741 $self->result_source->schema->throw_exception(@_);
1744 # XXX: FIXME: Attributes docs need clearing up
1748 The resultset takes various attributes that modify its behavior. Here's an
1755 =item Value: ($order_by | \@order_by)
1759 Which column(s) to order the results by. This is currently passed
1760 through directly to SQL, so you can give e.g. C<year DESC> for a
1761 descending order on the column `year'.
1763 Please note that if you have C<quote_char> enabled (see
1764 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1765 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1766 so you will need to manually quote things as appropriate.)
1772 =item Value: \@columns
1776 Shortcut to request a particular set of columns to be retrieved. Adds
1777 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1778 from that, then auto-populates C<as> from C<select> as normal. (You may also
1779 use the C<cols> attribute, as in earlier versions of DBIC.)
1781 =head2 include_columns
1785 =item Value: \@columns
1789 Shortcut to include additional columns in the returned results - for example
1791 $schema->resultset('CD')->search(undef, {
1792 include_columns => ['artist.name'],
1796 would return all CDs and include a 'name' column to the information
1797 passed to object inflation
1803 =item Value: \@select_columns
1807 Indicates which columns should be selected from the storage. You can use
1808 column names, or in the case of RDBMS back ends, function or stored procedure
1811 $rs = $schema->resultset('Employee')->search(undef, {
1814 { count => 'employeeid' },
1819 When you use function/stored procedure names and do not supply an C<as>
1820 attribute, the column names returned are storage-dependent. E.g. MySQL would
1821 return a column named C<count(employeeid)> in the above example.
1827 Indicates additional columns to be selected from storage. Works the same as
1828 L<select> but adds columns to the selection.
1836 Indicates additional column names for those added via L<+select>.
1844 =item Value: \@inflation_names
1848 Indicates column names for object inflation. This is used in conjunction with
1849 C<select>, usually when C<select> contains one or more function or stored
1852 $rs = $schema->resultset('Employee')->search(undef, {
1855 { count => 'employeeid' }
1857 as => ['name', 'employee_count'],
1860 my $employee = $rs->first(); # get the first Employee
1862 If the object against which the search is performed already has an accessor
1863 matching a column name specified in C<as>, the value can be retrieved using
1864 the accessor as normal:
1866 my $name = $employee->name();
1868 If on the other hand an accessor does not exist in the object, you need to
1869 use C<get_column> instead:
1871 my $employee_count = $employee->get_column('employee_count');
1873 You can create your own accessors if required - see
1874 L<DBIx::Class::Manual::Cookbook> for details.
1876 Please note: This will NOT insert an C<AS employee_count> into the SQL
1877 statement produced, it is used for internal access only. Thus
1878 attempting to use the accessor in an C<order_by> clause or similar
1879 will fail miserably.
1881 To get around this limitation, you can supply literal SQL to your
1882 C<select> attibute that contains the C<AS alias> text, eg:
1884 select => [\'myfield AS alias']
1890 =item Value: ($rel_name | \@rel_names | \%rel_names)
1894 Contains a list of relationships that should be joined for this query. For
1897 # Get CDs by Nine Inch Nails
1898 my $rs = $schema->resultset('CD')->search(
1899 { 'artist.name' => 'Nine Inch Nails' },
1900 { join => 'artist' }
1903 Can also contain a hash reference to refer to the other relation's relations.
1906 package MyApp::Schema::Track;
1907 use base qw/DBIx::Class/;
1908 __PACKAGE__->table('track');
1909 __PACKAGE__->add_columns(qw/trackid cd position title/);
1910 __PACKAGE__->set_primary_key('trackid');
1911 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1914 # In your application
1915 my $rs = $schema->resultset('Artist')->search(
1916 { 'track.title' => 'Teardrop' },
1918 join => { cd => 'track' },
1919 order_by => 'artist.name',
1923 You need to use the relationship (not the table) name in conditions,
1924 because they are aliased as such. The current table is aliased as "me", so
1925 you need to use me.column_name in order to avoid ambiguity. For example:
1927 # Get CDs from 1984 with a 'Foo' track
1928 my $rs = $schema->resultset('CD')->search(
1931 'tracks.name' => 'Foo'
1933 { join => 'tracks' }
1936 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1937 similarly for a third time). For e.g.
1939 my $rs = $schema->resultset('Artist')->search({
1940 'cds.title' => 'Down to Earth',
1941 'cds_2.title' => 'Popular',
1943 join => [ qw/cds cds/ ],
1946 will return a set of all artists that have both a cd with title 'Down
1947 to Earth' and a cd with title 'Popular'.
1949 If you want to fetch related objects from other tables as well, see C<prefetch>
1956 =item Value: ($rel_name | \@rel_names | \%rel_names)
1960 Contains one or more relationships that should be fetched along with the main
1961 query (when they are accessed afterwards they will have already been
1962 "prefetched"). This is useful for when you know you will need the related
1963 objects, because it saves at least one query:
1965 my $rs = $schema->resultset('Tag')->search(
1974 The initial search results in SQL like the following:
1976 SELECT tag.*, cd.*, artist.* FROM tag
1977 JOIN cd ON tag.cd = cd.cdid
1978 JOIN artist ON cd.artist = artist.artistid
1980 L<DBIx::Class> has no need to go back to the database when we access the
1981 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1984 Simple prefetches will be joined automatically, so there is no need
1985 for a C<join> attribute in the above search. If you're prefetching to
1986 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1987 specify the join as well.
1989 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1990 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1991 with an accessor type of 'single' or 'filter').
2001 Makes the resultset paged and specifies the page to retrieve. Effectively
2002 identical to creating a non-pages resultset and then calling ->page($page)
2005 If L<rows> attribute is not specified it defualts to 10 rows per page.
2015 Specifes the maximum number of rows for direct retrieval or the number of
2016 rows per page if the page attribute or method is used.
2022 =item Value: $offset
2026 Specifies the (zero-based) row number for the first row to be returned, or the
2027 of the first row of the first page if paging is used.
2033 =item Value: \@columns
2037 A arrayref of columns to group by. Can include columns of joined tables.
2039 group_by => [qw/ column1 column2 ... /]
2045 =item Value: $condition
2049 HAVING is a select statement attribute that is applied between GROUP BY and
2050 ORDER BY. It is applied to the after the grouping calculations have been
2053 having => { 'count(employee)' => { '>=', 100 } }
2059 =item Value: (0 | 1)
2063 Set to 1 to group by all columns.
2069 Adds to the WHERE clause.
2071 # only return rows WHERE deleted IS NULL for all searches
2072 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2074 Can be overridden by passing C<{ where => undef }> as an attribute
2081 Set to 1 to cache search results. This prevents extra SQL queries if you
2082 revisit rows in your ResultSet:
2084 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2086 while( my $artist = $resultset->next ) {
2090 $rs->first; # without cache, this would issue a query
2092 By default, searches are not cached.
2094 For more examples of using these attributes, see
2095 L<DBIx::Class::Manual::Cookbook>.
2101 =item Value: \@from_clause
2105 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2106 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2109 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2111 C<join> will usually do what you need and it is strongly recommended that you
2112 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2113 And we really do mean "cannot", not just tried and failed. Attempting to use
2114 this because you're having problems with C<join> is like trying to use x86
2115 ASM because you've got a syntax error in your C. Trust us on this.
2117 Now, if you're still really, really sure you need to use this (and if you're
2118 not 100% sure, ask the mailing list first), here's an explanation of how this
2121 The syntax is as follows -
2124 { <alias1> => <table1> },
2126 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2127 [], # nested JOIN (optional)
2128 { <table1.column1> => <table2.column2>, ... (more conditions) },
2130 # More of the above [ ] may follow for additional joins
2137 ON <table1.column1> = <table2.column2>
2138 <more joins may follow>
2140 An easy way to follow the examples below is to remember the following:
2142 Anything inside "[]" is a JOIN
2143 Anything inside "{}" is a condition for the enclosing JOIN
2145 The following examples utilize a "person" table in a family tree application.
2146 In order to express parent->child relationships, this table is self-joined:
2148 # Person->belongs_to('father' => 'Person');
2149 # Person->belongs_to('mother' => 'Person');
2151 C<from> can be used to nest joins. Here we return all children with a father,
2152 then search against all mothers of those children:
2154 $rs = $schema->resultset('Person')->search(
2157 alias => 'mother', # alias columns in accordance with "from"
2159 { mother => 'person' },
2162 { child => 'person' },
2164 { father => 'person' },
2165 { 'father.person_id' => 'child.father_id' }
2168 { 'mother.person_id' => 'child.mother_id' }
2175 # SELECT mother.* FROM person mother
2178 # JOIN person father
2179 # ON ( father.person_id = child.father_id )
2181 # ON ( mother.person_id = child.mother_id )
2183 The type of any join can be controlled manually. To search against only people
2184 with a father in the person table, we could explicitly use C<INNER JOIN>:
2186 $rs = $schema->resultset('Person')->search(
2189 alias => 'child', # alias columns in accordance with "from"
2191 { child => 'person' },
2193 { father => 'person', -join_type => 'inner' },
2194 { 'father.id' => 'child.father_id' }
2201 # SELECT child.* FROM person child
2202 # INNER JOIN person father ON child.father_id = father.id