1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
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) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
90 $attrs = { %{$attrs||{}} };
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 _source_handle => $source,
102 result_class => $attrs->{result_class} || $source->resolve->result_class,
103 cond => $attrs->{where},
118 =item Arguments: $cond, \%attrs?
120 =item Return Value: $resultset (scalar context), @row_objs (list context)
124 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
125 my $new_rs = $cd_rs->search({ year => 2005 });
127 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
128 # year = 2005 OR year = 2004
130 If you need to pass in additional attributes but no additional condition,
131 call it as C<search(undef, \%attrs)>.
133 # "SELECT name, artistid FROM $artist_table"
134 my @all_artists = $schema->resultset('Artist')->search(undef, {
135 columns => [qw/name artistid/],
138 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>.
144 my $rs = $self->search_rs( @_ );
145 return (wantarray ? $rs->all : $rs);
152 =item Arguments: $cond, \%attrs?
154 =item Return Value: $resultset
158 This method does the same exact thing as search() except it will
159 always return a resultset, even in list context.
168 unless (@_) { # no search, effectively just a clone
169 $rows = $self->get_cache;
173 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
174 my $our_attrs = { %{$self->{attrs}} };
175 my $having = delete $our_attrs->{having};
176 my $where = delete $our_attrs->{where};
178 my $new_attrs = { %{$our_attrs}, %{$attrs} };
180 # merge new attrs into inherited
181 foreach my $key (qw/join prefetch/) {
182 next unless exists $attrs->{$key};
183 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
188 (@_ == 1 || ref $_[0] eq "HASH")
190 (ref $_[0] eq 'HASH')
192 (keys %{ $_[0] } > 0)
200 ? $self->throw_exception("Odd number of arguments to search")
207 if (defined $where) {
208 $new_attrs->{where} = (
209 defined $new_attrs->{where}
212 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
213 } $where, $new_attrs->{where}
220 $new_attrs->{where} = (
221 defined $new_attrs->{where}
224 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
225 } $cond, $new_attrs->{where}
231 if (defined $having) {
232 $new_attrs->{having} = (
233 defined $new_attrs->{having}
236 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
237 } $having, $new_attrs->{having}
243 my $rs = (ref $self)->new($self->_source_handle, $new_attrs);
245 $rs->set_cache($rows);
250 =head2 search_literal
254 =item Arguments: $sql_fragment, @bind_values
256 =item Return Value: $resultset (scalar context), @row_objs (list context)
260 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
261 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
263 Pass a literal chunk of SQL to be added to the conditional part of the
269 my ($self, $cond, @vals) = @_;
270 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
271 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
272 return $self->search(\$cond, $attrs);
279 =item Arguments: @values | \%cols, \%attrs?
281 =item Return Value: $row_object
285 Finds a row based on its primary key or unique constraint. For example, to find
286 a row by its primary key:
288 my $cd = $schema->resultset('CD')->find(5);
290 You can also find a row by a specific unique constraint using the C<key>
291 attribute. For example:
293 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
294 key => 'cd_artist_title'
297 Additionally, you can specify the columns explicitly by name:
299 my $cd = $schema->resultset('CD')->find(
301 artist => 'Massive Attack',
302 title => 'Mezzanine',
304 { key => 'cd_artist_title' }
307 If the C<key> is specified as C<primary>, it searches only on the primary key.
309 If no C<key> is specified, it searches on all unique constraints defined on the
310 source, including the primary key.
312 If your table does not have a primary key, you B<must> provide a value for the
313 C<key> attribute matching one of the unique constraints on the source.
315 See also L</find_or_create> and L</update_or_create>. For information on how to
316 declare unique constraints, see
317 L<DBIx::Class::ResultSource/add_unique_constraint>.
323 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
325 # Default to the primary key, but allow a specific key
326 my @cols = exists $attrs->{key}
327 ? $self->result_source->unique_constraint_columns($attrs->{key})
328 : $self->result_source->primary_columns;
329 $self->throw_exception(
330 "Can't find unless a primary key is defined or unique constraint is specified"
333 # Parse out a hashref from input
335 if (ref $_[0] eq 'HASH') {
336 $input_query = { %{$_[0]} };
338 elsif (@_ == @cols) {
340 @{$input_query}{@cols} = @_;
343 # Compatibility: Allow e.g. find(id => $value)
344 carp "Find by key => value deprecated; please use a hashref instead";
348 my (%related, $info);
350 foreach my $key (keys %$input_query) {
351 if (ref($input_query->{$key})
352 && ($info = $self->result_source->relationship_info($key))) {
353 my $rel_q = $self->result_source->resolve_condition(
354 $info->{cond}, delete $input_query->{$key}, $key
356 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
357 @related{keys %$rel_q} = values %$rel_q;
360 if (my @keys = keys %related) {
361 @{$input_query}{@keys} = values %related;
364 my @unique_queries = $self->_unique_queries($input_query, $attrs);
366 # Build the final query: Default to the disjunction of the unique queries,
367 # but allow the input query in case the ResultSet defines the query or the
368 # user is abusing find
369 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
370 my $query = @unique_queries
371 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
372 : $self->_add_alias($input_query, $alias);
376 my $rs = $self->search($query, $attrs);
377 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
380 return keys %{$self->_resolved_attrs->{collapse}}
381 ? $self->search($query)->next
382 : $self->single($query);
388 # Add the specified alias to the specified query hash. A copy is made so the
389 # original query is not modified.
392 my ($self, $query, $alias) = @_;
394 my %aliased = %$query;
395 foreach my $col (grep { ! m/\./ } keys %aliased) {
396 $aliased{"$alias.$col"} = delete $aliased{$col};
404 # Build a list of queries which satisfy unique constraints.
406 sub _unique_queries {
407 my ($self, $query, $attrs) = @_;
409 my @constraint_names = exists $attrs->{key}
411 : $self->result_source->unique_constraint_names;
413 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
414 my $num_where = scalar keys %$where;
417 foreach my $name (@constraint_names) {
418 my @unique_cols = $self->result_source->unique_constraint_columns($name);
419 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
421 my $num_cols = scalar @unique_cols;
422 my $num_query = scalar keys %$unique_query;
424 my $total = $num_query + $num_where;
425 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
426 # The query is either unique on its own or is unique in combination with
427 # the existing where clause
428 push @unique_queries, $unique_query;
432 return @unique_queries;
435 # _build_unique_query
437 # Constrain the specified query hash based on the specified column names.
439 sub _build_unique_query {
440 my ($self, $query, $unique_cols) = @_;
443 map { $_ => $query->{$_} }
444 grep { exists $query->{$_} }
449 =head2 search_related
453 =item Arguments: $rel, $cond, \%attrs?
455 =item Return Value: $new_resultset
459 $new_rs = $cd_rs->search_related('artist', {
463 Searches the specified relationship, optionally specifying a condition and
464 attributes for matching records. See L</ATTRIBUTES> for more information.
469 return shift->related_resultset(shift)->search(@_);
476 =item Arguments: none
478 =item Return Value: $cursor
482 Returns a storage-driven cursor to the given resultset. See
483 L<DBIx::Class::Cursor> for more information.
490 my $attrs = { %{$self->_resolved_attrs} };
491 return $self->{cursor}
492 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
493 $attrs->{where},$attrs);
500 =item Arguments: $cond?
502 =item Return Value: $row_object?
506 my $cd = $schema->resultset('CD')->single({ year => 2001 });
508 Inflates the first result without creating a cursor if the resultset has
509 any records in it; if not returns nothing. Used by L</find> as an optimisation.
511 Can optionally take an additional condition *only* - this is a fast-code-path
512 method; if you need to add extra joins or similar call ->search and then
513 ->single without a condition on the $rs returned from that.
518 my ($self, $where) = @_;
519 my $attrs = { %{$self->_resolved_attrs} };
521 if (defined $attrs->{where}) {
524 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
525 $where, delete $attrs->{where} ]
528 $attrs->{where} = $where;
532 # XXX: Disabled since it doesn't infer uniqueness in all cases
533 # unless ($self->_is_unique_query($attrs->{where})) {
534 # carp "Query not guaranteed to return a single row"
535 # . "; please declare your unique constraints or use search instead";
538 my @data = $self->result_source->storage->select_single(
539 $attrs->{from}, $attrs->{select},
540 $attrs->{where}, $attrs
543 return (@data ? ($self->_construct_object(@data))[0] : ());
548 # Try to determine if the specified query is guaranteed to be unique, based on
549 # the declared unique constraints.
551 sub _is_unique_query {
552 my ($self, $query) = @_;
554 my $collapsed = $self->_collapse_query($query);
555 my $alias = $self->{attrs}{alias};
557 foreach my $name ($self->result_source->unique_constraint_names) {
558 my @unique_cols = map {
560 } $self->result_source->unique_constraint_columns($name);
562 # Count the values for each unique column
563 my %seen = map { $_ => 0 } @unique_cols;
565 foreach my $key (keys %$collapsed) {
566 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
567 next unless exists $seen{$aliased}; # Additional constraints are okay
568 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
571 # If we get 0 or more than 1 value for a column, it's not necessarily unique
572 return 1 unless grep { $_ != 1 } values %seen;
580 # Recursively collapse the query, accumulating values for each column.
582 sub _collapse_query {
583 my ($self, $query, $collapsed) = @_;
587 if (ref $query eq 'ARRAY') {
588 foreach my $subquery (@$query) {
589 next unless ref $subquery; # -or
590 # warn "ARRAY: " . Dumper $subquery;
591 $collapsed = $self->_collapse_query($subquery, $collapsed);
594 elsif (ref $query eq 'HASH') {
595 if (keys %$query and (keys %$query)[0] eq '-and') {
596 foreach my $subquery (@{$query->{-and}}) {
597 # warn "HASH: " . Dumper $subquery;
598 $collapsed = $self->_collapse_query($subquery, $collapsed);
602 # warn "LEAF: " . Dumper $query;
603 foreach my $col (keys %$query) {
604 my $value = $query->{$col};
605 $collapsed->{$col}{$value}++;
617 =item Arguments: $cond?
619 =item Return Value: $resultsetcolumn
623 my $max_length = $rs->get_column('length')->max;
625 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
630 my ($self, $column) = @_;
631 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
639 =item Arguments: $cond, \%attrs?
641 =item Return Value: $resultset (scalar context), @row_objs (list context)
645 # WHERE title LIKE '%blue%'
646 $cd_rs = $rs->search_like({ title => '%blue%'});
648 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
649 that this is simply a convenience method. You most likely want to use
650 L</search> with specific operators.
652 For more information, see L<DBIx::Class::Manual::Cookbook>.
658 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
659 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
660 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
661 return $class->search($query, { %$attrs });
668 =item Arguments: $first, $last
670 =item Return Value: $resultset (scalar context), @row_objs (list context)
674 Returns a resultset or object list representing a subset of elements from the
675 resultset slice is called on. Indexes are from 0, i.e., to get the first
678 my ($one, $two, $three) = $rs->slice(0, 2);
683 my ($self, $min, $max) = @_;
684 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
685 $attrs->{offset} = $self->{attrs}{offset} || 0;
686 $attrs->{offset} += $min;
687 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
688 return $self->search(undef(), $attrs);
689 #my $slice = (ref $self)->new($self->result_source, $attrs);
690 #return (wantarray ? $slice->all : $slice);
697 =item Arguments: none
699 =item Return Value: $result?
703 Returns the next element in the resultset (C<undef> is there is none).
705 Can be used to efficiently iterate over records in the resultset:
707 my $rs = $schema->resultset('CD')->search;
708 while (my $cd = $rs->next) {
712 Note that you need to store the resultset object, and call C<next> on it.
713 Calling C<< resultset('Table')->next >> repeatedly will always return the
714 first record from the resultset.
720 if (my $cache = $self->get_cache) {
721 $self->{all_cache_position} ||= 0;
722 return $cache->[$self->{all_cache_position}++];
724 if ($self->{attrs}{cache}) {
725 $self->{all_cache_position} = 1;
726 return ($self->all)[0];
728 if ($self->{stashed_objects}) {
729 my $obj = shift(@{$self->{stashed_objects}});
730 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
734 exists $self->{stashed_row}
735 ? @{delete $self->{stashed_row}}
736 : $self->cursor->next
738 return unless (@row);
739 my ($row, @more) = $self->_construct_object(@row);
740 $self->{stashed_objects} = \@more if @more;
744 sub _construct_object {
745 my ($self, @row) = @_;
746 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
747 my @new = $self->result_class->inflate_result($self->_source_handle, @$info);
748 @new = $self->{_attrs}{record_filter}->(@new)
749 if exists $self->{_attrs}{record_filter};
753 sub _collapse_result {
754 my ($self, $as, $row, $prefix) = @_;
759 foreach my $this_as (@$as) {
760 my $val = shift @copy;
761 if (defined $prefix) {
762 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
764 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
765 $const{$1||''}{$2} = $val;
768 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
769 $const{$1||''}{$2} = $val;
773 my $alias = $self->{attrs}{alias};
774 my $info = [ {}, {} ];
775 foreach my $key (keys %const) {
776 if (length $key && $key ne $alias) {
778 my @parts = split(/\./, $key);
779 foreach my $p (@parts) {
780 $target = $target->[1]->{$p} ||= [];
782 $target->[0] = $const{$key};
784 $info->[0] = $const{$key};
789 if (defined $prefix) {
791 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
792 } keys %{$self->{_attrs}{collapse}}
794 @collapse = keys %{$self->{_attrs}{collapse}};
798 my ($c) = sort { length $a <=> length $b } @collapse;
800 foreach my $p (split(/\./, $c)) {
801 $target = $target->[1]->{$p} ||= [];
803 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
804 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
805 my $tree = $self->_collapse_result($as, $row, $c_prefix);
806 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
812 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
817 last unless (@raw = $self->cursor->next);
818 $row = $self->{stashed_row} = \@raw;
819 $tree = $self->_collapse_result($as, $row, $c_prefix);
821 @$target = (@final ? @final : [ {}, {} ]);
822 # single empty result to indicate an empty prefetched has_many
825 #print "final info: " . Dumper($info);
833 =item Arguments: $result_source?
835 =item Return Value: $result_source
839 An accessor for the primary ResultSource object from which this ResultSet
846 =item Arguments: $result_class?
848 =item Return Value: $result_class
852 An accessor for the class to use when creating row objects. Defaults to
853 C<< result_source->result_class >> - which in most cases is the name of the
854 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
863 =item Arguments: $cond, \%attrs??
865 =item Return Value: $count
869 Performs an SQL C<COUNT> with the same query as the resultset was built
870 with to find the number of elements. If passed arguments, does a search
871 on the resultset and counts the results of that.
873 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
874 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
875 not support C<DISTINCT> with multiple columns. If you are using such a
876 database, you should only use columns from the main table in your C<group_by>
883 return $self->search(@_)->count if @_ and defined $_[0];
884 return scalar @{ $self->get_cache } if $self->get_cache;
885 my $count = $self->_count;
886 return 0 unless $count;
888 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
889 $count = $self->{attrs}{rows} if
890 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
894 sub _count { # Separated out so pager can get the full count
896 my $select = { count => '*' };
898 my $attrs = { %{$self->_resolved_attrs} };
899 if (my $group_by = delete $attrs->{group_by}) {
900 delete $attrs->{having};
901 my @distinct = (ref $group_by ? @$group_by : ($group_by));
902 # todo: try CONCAT for multi-column pk
903 my @pk = $self->result_source->primary_columns;
905 my $alias = $attrs->{alias};
906 foreach my $column (@distinct) {
907 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
908 @distinct = ($column);
914 $select = { count => { distinct => \@distinct } };
917 $attrs->{select} = $select;
918 $attrs->{as} = [qw/count/];
920 # offset, order by and page are not needed to count. record_filter is cdbi
921 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
923 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
924 my ($count) = $tmp_rs->cursor->next;
932 =item Arguments: $sql_fragment, @bind_values
934 =item Return Value: $count
938 Counts the results in a literal query. Equivalent to calling L</search_literal>
939 with the passed arguments, then L</count>.
943 sub count_literal { shift->search_literal(@_)->count; }
949 =item Arguments: none
951 =item Return Value: @objects
955 Returns all elements in the resultset. Called implicitly if the resultset
956 is returned in list context.
962 return @{ $self->get_cache } if $self->get_cache;
966 # TODO: don't call resolve here
967 if (keys %{$self->_resolved_attrs->{collapse}}) {
968 # if ($self->{attrs}{prefetch}) {
969 # Using $self->cursor->all is really just an optimisation.
970 # If we're collapsing has_many prefetches it probably makes
971 # very little difference, and this is cleaner than hacking
972 # _construct_object to survive the approach
973 my @row = $self->cursor->next;
975 push(@obj, $self->_construct_object(@row));
976 @row = (exists $self->{stashed_row}
977 ? @{delete $self->{stashed_row}}
978 : $self->cursor->next);
981 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
984 $self->set_cache(\@obj) if $self->{attrs}{cache};
992 =item Arguments: none
994 =item Return Value: $self
998 Resets the resultset's cursor, so you can iterate through the elements again.
1004 delete $self->{_attrs} if exists $self->{_attrs};
1005 $self->{all_cache_position} = 0;
1006 $self->cursor->reset;
1014 =item Arguments: none
1016 =item Return Value: $object?
1020 Resets the resultset and returns an object for the first result (if the
1021 resultset returns anything).
1026 return $_[0]->reset->next;
1029 # _cond_for_update_delete
1031 # update/delete require the condition to be modified to handle
1032 # the differing SQL syntax available. This transforms the $self->{cond}
1033 # appropriately, returning the new condition.
1035 sub _cond_for_update_delete {
1036 my ($self, $full_cond) = @_;
1039 $full_cond ||= $self->{cond};
1040 # No-op. No condition, we're updating/deleting everything
1041 return $cond unless ref $full_cond;
1043 if (ref $full_cond eq 'ARRAY') {
1047 foreach my $key (keys %{$_}) {
1049 $hash{$1} = $_->{$key};
1055 elsif (ref $full_cond eq 'HASH') {
1056 if ((keys %{$full_cond})[0] eq '-and') {
1059 my @cond = @{$full_cond->{-and}};
1060 for (my $i = 0; $i < @cond; $i++) {
1061 my $entry = $cond[$i];
1064 if (ref $entry eq 'HASH') {
1065 $hash = $self->_cond_for_update_delete($entry);
1068 $entry =~ /([^.]+)$/;
1069 $hash->{$1} = $cond[++$i];
1072 push @{$cond->{-and}}, $hash;
1076 foreach my $key (keys %{$full_cond}) {
1078 $cond->{$1} = $full_cond->{$key};
1083 $self->throw_exception(
1084 "Can't update/delete on resultset with condition unless hash or array"
1096 =item Arguments: \%values
1098 =item Return Value: $storage_rv
1102 Sets the specified columns in the resultset to the supplied values in a
1103 single query. Return value will be true if the update succeeded or false
1104 if no records were updated; exact type of success value is storage-dependent.
1109 my ($self, $values) = @_;
1110 $self->throw_exception("Values for update must be a hash")
1111 unless ref $values eq 'HASH';
1113 my $cond = $self->_cond_for_update_delete;
1115 return $self->result_source->storage->update(
1116 $self->result_source, $values, $cond
1124 =item Arguments: \%values
1126 =item Return Value: 1
1130 Fetches all objects and updates them one at a time. Note that C<update_all>
1131 will run DBIC cascade triggers, while L</update> will not.
1136 my ($self, $values) = @_;
1137 $self->throw_exception("Values for update must be a hash")
1138 unless ref $values eq 'HASH';
1139 foreach my $obj ($self->all) {
1140 $obj->set_columns($values)->update;
1149 =item Arguments: none
1151 =item Return Value: 1
1155 Deletes the contents of the resultset from its result source. Note that this
1156 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1157 to run. See also L<DBIx::Class::Row/delete>.
1164 my $cond = $self->_cond_for_update_delete;
1166 $self->result_source->storage->delete($self->result_source, $cond);
1174 =item Arguments: none
1176 =item Return Value: 1
1180 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1181 will run DBIC cascade triggers, while L</delete> will not.
1187 $_->delete for $self->all;
1195 =item Arguments: none
1197 =item Return Value: $pager
1201 Return Value a L<Data::Page> object for the current resultset. Only makes
1202 sense for queries with a C<page> attribute.
1208 my $attrs = $self->{attrs};
1209 $self->throw_exception("Can't create pager for non-paged rs")
1210 unless $self->{attrs}{page};
1211 $attrs->{rows} ||= 10;
1212 return $self->{pager} ||= Data::Page->new(
1213 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1220 =item Arguments: $page_number
1222 =item Return Value: $rs
1226 Returns a resultset for the $page_number page of the resultset on which page
1227 is called, where each page contains a number of rows equal to the 'rows'
1228 attribute set on the resultset (10 by default).
1233 my ($self, $page) = @_;
1234 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1241 =item Arguments: \%vals
1243 =item Return Value: $object
1247 Creates an object in the resultset's result class and returns it.
1252 my ($self, $values) = @_;
1253 $self->throw_exception( "new_result needs a hash" )
1254 unless (ref $values eq 'HASH');
1255 $self->throw_exception(
1256 "Can't abstract implicit construct, condition not a hash"
1257 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1259 my $alias = $self->{attrs}{alias};
1260 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1262 %{ $self->_remove_alias($values, $alias) },
1263 %{ $self->_remove_alias($collapsed_cond, $alias) },
1266 return $self->result_class->new(\%new,$self->_source_handle);
1271 # Recursively collapse the condition.
1273 sub _collapse_cond {
1274 my ($self, $cond, $collapsed) = @_;
1278 if (ref $cond eq 'ARRAY') {
1279 foreach my $subcond (@$cond) {
1280 next unless ref $subcond; # -or
1281 # warn "ARRAY: " . Dumper $subcond;
1282 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1285 elsif (ref $cond eq 'HASH') {
1286 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1287 foreach my $subcond (@{$cond->{-and}}) {
1288 # warn "HASH: " . Dumper $subcond;
1289 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1293 # warn "LEAF: " . Dumper $cond;
1294 foreach my $col (keys %$cond) {
1295 my $value = $cond->{$col};
1296 $collapsed->{$col} = $value;
1306 # Remove the specified alias from the specified query hash. A copy is made so
1307 # the original query is not modified.
1310 my ($self, $query, $alias) = @_;
1312 my %orig = %{ $query || {} };
1315 foreach my $key (keys %orig) {
1317 $unaliased{$key} = $orig{$key};
1320 $unaliased{$1} = $orig{$key}
1321 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1331 =item Arguments: \%vals, \%attrs?
1333 =item Return Value: $object
1337 Find an existing record from this resultset. If none exists, instantiate a new
1338 result object and return it. The object will not be saved into your storage
1339 until you call L<DBIx::Class::Row/insert> on it.
1341 If you want objects to be saved immediately, use L</find_or_create> instead.
1347 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1348 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1349 my $exists = $self->find($hash, $attrs);
1350 return defined $exists ? $exists : $self->new_result($hash);
1357 =item Arguments: \%vals
1359 =item Return Value: $object
1363 Inserts a record into the resultset and returns the object representing it.
1365 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1370 my ($self, $attrs) = @_;
1371 $self->throw_exception( "create needs a hashref" )
1372 unless ref $attrs eq 'HASH';
1373 return $self->new_result($attrs)->insert;
1376 =head2 find_or_create
1380 =item Arguments: \%vals, \%attrs?
1382 =item Return Value: $object
1386 $class->find_or_create({ key => $val, ... });
1388 Tries to find a record based on its primary key or unique constraint; if none
1389 is found, creates one and returns that instead.
1391 my $cd = $schema->resultset('CD')->find_or_create({
1393 artist => 'Massive Attack',
1394 title => 'Mezzanine',
1398 Also takes an optional C<key> attribute, to search by a specific key or unique
1399 constraint. For example:
1401 my $cd = $schema->resultset('CD')->find_or_create(
1403 artist => 'Massive Attack',
1404 title => 'Mezzanine',
1406 { key => 'cd_artist_title' }
1409 See also L</find> and L</update_or_create>. For information on how to declare
1410 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1414 sub find_or_create {
1416 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1417 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1418 my $exists = $self->find($hash, $attrs);
1419 return defined $exists ? $exists : $self->create($hash);
1422 =head2 update_or_create
1426 =item Arguments: \%col_values, { key => $unique_constraint }?
1428 =item Return Value: $object
1432 $class->update_or_create({ col => $val, ... });
1434 First, searches for an existing row matching one of the unique constraints
1435 (including the primary key) on the source of this resultset. If a row is
1436 found, updates it with the other given column values. Otherwise, creates a new
1439 Takes an optional C<key> attribute to search on a specific unique constraint.
1442 # In your application
1443 my $cd = $schema->resultset('CD')->update_or_create(
1445 artist => 'Massive Attack',
1446 title => 'Mezzanine',
1449 { key => 'cd_artist_title' }
1452 If no C<key> is specified, it searches on all unique constraints defined on the
1453 source, including the primary key.
1455 If the C<key> is specified as C<primary>, it searches only on the primary key.
1457 See also L</find> and L</find_or_create>. For information on how to declare
1458 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1462 sub update_or_create {
1464 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1465 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1467 my $row = $self->find($cond, $attrs);
1469 $row->update($cond);
1473 return $self->create($cond);
1480 =item Arguments: none
1482 =item Return Value: \@cache_objects?
1486 Gets the contents of the cache for the resultset, if the cache is set.
1498 =item Arguments: \@cache_objects
1500 =item Return Value: \@cache_objects
1504 Sets the contents of the cache for the resultset. Expects an arrayref
1505 of objects of the same class as those produced by the resultset. Note that
1506 if the cache is set the resultset will return the cached objects rather
1507 than re-querying the database even if the cache attr is not set.
1512 my ( $self, $data ) = @_;
1513 $self->throw_exception("set_cache requires an arrayref")
1514 if defined($data) && (ref $data ne 'ARRAY');
1515 $self->{all_cache} = $data;
1522 =item Arguments: none
1524 =item Return Value: []
1528 Clears the cache for the resultset.
1533 shift->set_cache(undef);
1536 =head2 related_resultset
1540 =item Arguments: $relationship_name
1542 =item Return Value: $resultset
1546 Returns a related resultset for the supplied relationship name.
1548 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1552 sub related_resultset {
1553 my ($self, $rel) = @_;
1555 $self->{related_resultsets} ||= {};
1556 return $self->{related_resultsets}{$rel} ||= do {
1557 my $rel_obj = $self->result_source->relationship_info($rel);
1559 $self->throw_exception(
1560 "search_related: result source '" . $self->_source_handle->source_moniker .
1561 "' has no such relationship $rel")
1564 my ($from,$seen) = $self->_resolve_from($rel);
1566 my $join_count = $seen->{$rel};
1567 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1569 $self->_source_handle->schema->resultset($rel_obj->{class})->search_rs(
1571 %{$self->{attrs}||{}},
1577 where => $self->{cond},
1585 my ($self, $extra_join) = @_;
1586 my $source = $self->result_source;
1587 my $attrs = $self->{attrs};
1589 my $from = $attrs->{from}
1590 || [ { $attrs->{alias} => $source->from } ];
1592 my $seen = { %{$attrs->{seen_join}||{}} };
1594 my $join = ($attrs->{join}
1595 ? [ $attrs->{join}, $extra_join ]
1599 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1602 return ($from,$seen);
1605 sub _resolved_attrs {
1607 return $self->{_attrs} if $self->{_attrs};
1609 my $attrs = { %{$self->{attrs}||{}} };
1610 my $source = $self->result_source;
1611 my $alias = $attrs->{alias};
1613 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1614 if ($attrs->{columns}) {
1615 delete $attrs->{as};
1616 } elsif (!$attrs->{select}) {
1617 $attrs->{columns} = [ $source->columns ];
1622 ? (ref $attrs->{select} eq 'ARRAY'
1623 ? [ @{$attrs->{select}} ]
1624 : [ $attrs->{select} ])
1625 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1629 ? (ref $attrs->{as} eq 'ARRAY'
1630 ? [ @{$attrs->{as}} ]
1632 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1636 if ($adds = delete $attrs->{include_columns}) {
1637 $adds = [$adds] unless ref $adds eq 'ARRAY';
1638 push(@{$attrs->{select}}, @$adds);
1639 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1641 if ($adds = delete $attrs->{'+select'}) {
1642 $adds = [$adds] unless ref $adds eq 'ARRAY';
1643 push(@{$attrs->{select}},
1644 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1646 if (my $adds = delete $attrs->{'+as'}) {
1647 $adds = [$adds] unless ref $adds eq 'ARRAY';
1648 push(@{$attrs->{as}}, @$adds);
1651 $attrs->{from} ||= [ { 'me' => $source->from } ];
1653 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1654 my $join = delete $attrs->{join} || {};
1656 if (defined $attrs->{prefetch}) {
1657 $join = $self->_merge_attr(
1658 $join, $attrs->{prefetch}
1662 $attrs->{from} = # have to copy here to avoid corrupting the original
1665 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1669 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1670 if ($attrs->{order_by}) {
1671 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1672 ? [ @{$attrs->{order_by}} ]
1673 : [ $attrs->{order_by} ]);
1675 $attrs->{order_by} = [];
1678 my $collapse = $attrs->{collapse} || {};
1679 if (my $prefetch = delete $attrs->{prefetch}) {
1680 $prefetch = $self->_merge_attr({}, $prefetch);
1682 my $seen = $attrs->{seen_join} || {};
1683 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1684 # bring joins back to level of current class
1685 my @prefetch = $source->resolve_prefetch(
1686 $p, $alias, $seen, \@pre_order, $collapse
1688 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1689 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1691 push(@{$attrs->{order_by}}, @pre_order);
1693 $attrs->{collapse} = $collapse;
1695 return $self->{_attrs} = $attrs;
1699 my ($self, $a, $b) = @_;
1700 return $b unless defined($a);
1701 return $a unless defined($b);
1703 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1704 foreach my $key (keys %{$b}) {
1705 if (exists $a->{$key}) {
1706 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1708 $a->{$key} = $b->{$key};
1713 $a = [$a] unless ref $a eq 'ARRAY';
1714 $b = [$b] unless ref $b eq 'ARRAY';
1718 foreach my $x ($a, $b) {
1719 foreach my $element (@{$x}) {
1720 if (ref $element eq 'HASH') {
1721 $hash = $self->_merge_attr($hash, $element);
1722 } elsif (ref $element eq 'ARRAY') {
1723 push(@array, @{$element});
1725 push(@array, $element) unless $b == $x
1726 && grep { $_ eq $element } @array;
1731 @array = grep { !exists $hash->{$_} } @array;
1733 return keys %{$hash}
1746 $self->_source_handle($_[0]->handle);
1748 $self->_source_handle->resolve;
1752 =head2 throw_exception
1754 See L<DBIx::Class::Schema/throw_exception> for details.
1758 sub throw_exception {
1760 $self->_source_handle->schema->throw_exception(@_);
1763 # XXX: FIXME: Attributes docs need clearing up
1767 The resultset takes various attributes that modify its behavior. Here's an
1774 =item Value: ($order_by | \@order_by)
1778 Which column(s) to order the results by. This is currently passed
1779 through directly to SQL, so you can give e.g. C<year DESC> for a
1780 descending order on the column `year'.
1782 Please note that if you have C<quote_char> enabled (see
1783 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1784 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1785 so you will need to manually quote things as appropriate.)
1791 =item Value: \@columns
1795 Shortcut to request a particular set of columns to be retrieved. Adds
1796 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1797 from that, then auto-populates C<as> from C<select> as normal. (You may also
1798 use the C<cols> attribute, as in earlier versions of DBIC.)
1800 =head2 include_columns
1804 =item Value: \@columns
1808 Shortcut to include additional columns in the returned results - for example
1810 $schema->resultset('CD')->search(undef, {
1811 include_columns => ['artist.name'],
1815 would return all CDs and include a 'name' column to the information
1816 passed to object inflation
1822 =item Value: \@select_columns
1826 Indicates which columns should be selected from the storage. You can use
1827 column names, or in the case of RDBMS back ends, function or stored procedure
1830 $rs = $schema->resultset('Employee')->search(undef, {
1833 { count => 'employeeid' },
1838 When you use function/stored procedure names and do not supply an C<as>
1839 attribute, the column names returned are storage-dependent. E.g. MySQL would
1840 return a column named C<count(employeeid)> in the above example.
1846 Indicates additional columns to be selected from storage. Works the same as
1847 L<select> but adds columns to the selection.
1855 Indicates additional column names for those added via L<+select>.
1863 =item Value: \@inflation_names
1867 Indicates column names for object inflation. This is used in conjunction with
1868 C<select>, usually when C<select> contains one or more function or stored
1871 $rs = $schema->resultset('Employee')->search(undef, {
1874 { count => 'employeeid' }
1876 as => ['name', 'employee_count'],
1879 my $employee = $rs->first(); # get the first Employee
1881 If the object against which the search is performed already has an accessor
1882 matching a column name specified in C<as>, the value can be retrieved using
1883 the accessor as normal:
1885 my $name = $employee->name();
1887 If on the other hand an accessor does not exist in the object, you need to
1888 use C<get_column> instead:
1890 my $employee_count = $employee->get_column('employee_count');
1892 You can create your own accessors if required - see
1893 L<DBIx::Class::Manual::Cookbook> for details.
1895 Please note: This will NOT insert an C<AS employee_count> into the SQL
1896 statement produced, it is used for internal access only. Thus
1897 attempting to use the accessor in an C<order_by> clause or similar
1898 will fail miserably.
1900 To get around this limitation, you can supply literal SQL to your
1901 C<select> attibute that contains the C<AS alias> text, eg:
1903 select => [\'myfield AS alias']
1909 =item Value: ($rel_name | \@rel_names | \%rel_names)
1913 Contains a list of relationships that should be joined for this query. For
1916 # Get CDs by Nine Inch Nails
1917 my $rs = $schema->resultset('CD')->search(
1918 { 'artist.name' => 'Nine Inch Nails' },
1919 { join => 'artist' }
1922 Can also contain a hash reference to refer to the other relation's relations.
1925 package MyApp::Schema::Track;
1926 use base qw/DBIx::Class/;
1927 __PACKAGE__->table('track');
1928 __PACKAGE__->add_columns(qw/trackid cd position title/);
1929 __PACKAGE__->set_primary_key('trackid');
1930 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1933 # In your application
1934 my $rs = $schema->resultset('Artist')->search(
1935 { 'track.title' => 'Teardrop' },
1937 join => { cd => 'track' },
1938 order_by => 'artist.name',
1942 You need to use the relationship (not the table) name in conditions,
1943 because they are aliased as such. The current table is aliased as "me", so
1944 you need to use me.column_name in order to avoid ambiguity. For example:
1946 # Get CDs from 1984 with a 'Foo' track
1947 my $rs = $schema->resultset('CD')->search(
1950 'tracks.name' => 'Foo'
1952 { join => 'tracks' }
1955 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1956 similarly for a third time). For e.g.
1958 my $rs = $schema->resultset('Artist')->search({
1959 'cds.title' => 'Down to Earth',
1960 'cds_2.title' => 'Popular',
1962 join => [ qw/cds cds/ ],
1965 will return a set of all artists that have both a cd with title 'Down
1966 to Earth' and a cd with title 'Popular'.
1968 If you want to fetch related objects from other tables as well, see C<prefetch>
1975 =item Value: ($rel_name | \@rel_names | \%rel_names)
1979 Contains one or more relationships that should be fetched along with the main
1980 query (when they are accessed afterwards they will have already been
1981 "prefetched"). This is useful for when you know you will need the related
1982 objects, because it saves at least one query:
1984 my $rs = $schema->resultset('Tag')->search(
1993 The initial search results in SQL like the following:
1995 SELECT tag.*, cd.*, artist.* FROM tag
1996 JOIN cd ON tag.cd = cd.cdid
1997 JOIN artist ON cd.artist = artist.artistid
1999 L<DBIx::Class> has no need to go back to the database when we access the
2000 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2003 Simple prefetches will be joined automatically, so there is no need
2004 for a C<join> attribute in the above search. If you're prefetching to
2005 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2006 specify the join as well.
2008 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2009 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2010 with an accessor type of 'single' or 'filter').
2020 Makes the resultset paged and specifies the page to retrieve. Effectively
2021 identical to creating a non-pages resultset and then calling ->page($page)
2024 If L<rows> attribute is not specified it defualts to 10 rows per page.
2034 Specifes the maximum number of rows for direct retrieval or the number of
2035 rows per page if the page attribute or method is used.
2041 =item Value: $offset
2045 Specifies the (zero-based) row number for the first row to be returned, or the
2046 of the first row of the first page if paging is used.
2052 =item Value: \@columns
2056 A arrayref of columns to group by. Can include columns of joined tables.
2058 group_by => [qw/ column1 column2 ... /]
2064 =item Value: $condition
2068 HAVING is a select statement attribute that is applied between GROUP BY and
2069 ORDER BY. It is applied to the after the grouping calculations have been
2072 having => { 'count(employee)' => { '>=', 100 } }
2078 =item Value: (0 | 1)
2082 Set to 1 to group by all columns.
2088 Adds to the WHERE clause.
2090 # only return rows WHERE deleted IS NULL for all searches
2091 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2093 Can be overridden by passing C<{ where => undef }> as an attribute
2100 Set to 1 to cache search results. This prevents extra SQL queries if you
2101 revisit rows in your ResultSet:
2103 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2105 while( my $artist = $resultset->next ) {
2109 $rs->first; # without cache, this would issue a query
2111 By default, searches are not cached.
2113 For more examples of using these attributes, see
2114 L<DBIx::Class::Manual::Cookbook>.
2120 =item Value: \@from_clause
2124 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2125 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2128 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2130 C<join> will usually do what you need and it is strongly recommended that you
2131 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2132 And we really do mean "cannot", not just tried and failed. Attempting to use
2133 this because you're having problems with C<join> is like trying to use x86
2134 ASM because you've got a syntax error in your C. Trust us on this.
2136 Now, if you're still really, really sure you need to use this (and if you're
2137 not 100% sure, ask the mailing list first), here's an explanation of how this
2140 The syntax is as follows -
2143 { <alias1> => <table1> },
2145 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2146 [], # nested JOIN (optional)
2147 { <table1.column1> => <table2.column2>, ... (more conditions) },
2149 # More of the above [ ] may follow for additional joins
2156 ON <table1.column1> = <table2.column2>
2157 <more joins may follow>
2159 An easy way to follow the examples below is to remember the following:
2161 Anything inside "[]" is a JOIN
2162 Anything inside "{}" is a condition for the enclosing JOIN
2164 The following examples utilize a "person" table in a family tree application.
2165 In order to express parent->child relationships, this table is self-joined:
2167 # Person->belongs_to('father' => 'Person');
2168 # Person->belongs_to('mother' => 'Person');
2170 C<from> can be used to nest joins. Here we return all children with a father,
2171 then search against all mothers of those children:
2173 $rs = $schema->resultset('Person')->search(
2176 alias => 'mother', # alias columns in accordance with "from"
2178 { mother => 'person' },
2181 { child => 'person' },
2183 { father => 'person' },
2184 { 'father.person_id' => 'child.father_id' }
2187 { 'mother.person_id' => 'child.mother_id' }
2194 # SELECT mother.* FROM person mother
2197 # JOIN person father
2198 # ON ( father.person_id = child.father_id )
2200 # ON ( mother.person_id = child.mother_id )
2202 The type of any join can be controlled manually. To search against only people
2203 with a father in the person table, we could explicitly use C<INNER JOIN>:
2205 $rs = $schema->resultset('Person')->search(
2208 alias => 'child', # alias columns in accordance with "from"
2210 { child => 'person' },
2212 { father => 'person', -join_type => 'inner' },
2213 { 'father.id' => 'child.father_id' }
2220 # SELECT child.* FROM person child
2221 # INNER JOIN person father ON child.father_id = father.id