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;
414 foreach my $name (@constraint_names) {
415 my @unique_cols = $self->result_source->unique_constraint_columns($name);
416 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
418 my $num_query = scalar keys %$unique_query;
419 next unless $num_query;
421 # XXX: Assuming quite a bit about $self->{attrs}{where}
422 my $num_cols = scalar @unique_cols;
423 my $num_where = exists $self->{attrs}{where}
424 ? scalar keys %{ $self->{attrs}{where} }
426 push @unique_queries, $unique_query
427 if $num_query + $num_where == $num_cols;
430 return @unique_queries;
433 # _build_unique_query
435 # Constrain the specified query hash based on the specified column names.
437 sub _build_unique_query {
438 my ($self, $query, $unique_cols) = @_;
441 map { $_ => $query->{$_} }
442 grep { exists $query->{$_} }
447 =head2 search_related
451 =item Arguments: $rel, $cond, \%attrs?
453 =item Return Value: $new_resultset
457 $new_rs = $cd_rs->search_related('artist', {
461 Searches the specified relationship, optionally specifying a condition and
462 attributes for matching records. See L</ATTRIBUTES> for more information.
467 return shift->related_resultset(shift)->search(@_);
474 =item Arguments: none
476 =item Return Value: $cursor
480 Returns a storage-driven cursor to the given resultset. See
481 L<DBIx::Class::Cursor> for more information.
488 my $attrs = { %{$self->_resolved_attrs} };
489 return $self->{cursor}
490 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
491 $attrs->{where},$attrs);
498 =item Arguments: $cond?
500 =item Return Value: $row_object?
504 my $cd = $schema->resultset('CD')->single({ year => 2001 });
506 Inflates the first result without creating a cursor if the resultset has
507 any records in it; if not returns nothing. Used by L</find> as an optimisation.
509 Can optionally take an additional condition *only* - this is a fast-code-path
510 method; if you need to add extra joins or similar call ->search and then
511 ->single without a condition on the $rs returned from that.
516 my ($self, $where) = @_;
517 my $attrs = { %{$self->_resolved_attrs} };
519 if (defined $attrs->{where}) {
522 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
523 $where, delete $attrs->{where} ]
526 $attrs->{where} = $where;
530 # XXX: Disabled since it doesn't infer uniqueness in all cases
531 # unless ($self->_is_unique_query($attrs->{where})) {
532 # carp "Query not guaranteed to return a single row"
533 # . "; please declare your unique constraints or use search instead";
536 my @data = $self->result_source->storage->select_single(
537 $attrs->{from}, $attrs->{select},
538 $attrs->{where}, $attrs
541 return (@data ? ($self->_construct_object(@data))[0] : ());
546 # Try to determine if the specified query is guaranteed to be unique, based on
547 # the declared unique constraints.
549 sub _is_unique_query {
550 my ($self, $query) = @_;
552 my $collapsed = $self->_collapse_query($query);
553 my $alias = $self->{attrs}{alias};
555 foreach my $name ($self->result_source->unique_constraint_names) {
556 my @unique_cols = map {
558 } $self->result_source->unique_constraint_columns($name);
560 # Count the values for each unique column
561 my %seen = map { $_ => 0 } @unique_cols;
563 foreach my $key (keys %$collapsed) {
564 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
565 next unless exists $seen{$aliased}; # Additional constraints are okay
566 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
569 # If we get 0 or more than 1 value for a column, it's not necessarily unique
570 return 1 unless grep { $_ != 1 } values %seen;
578 # Recursively collapse the query, accumulating values for each column.
580 sub _collapse_query {
581 my ($self, $query, $collapsed) = @_;
585 if (ref $query eq 'ARRAY') {
586 foreach my $subquery (@$query) {
587 next unless ref $subquery; # -or
588 # warn "ARRAY: " . Dumper $subquery;
589 $collapsed = $self->_collapse_query($subquery, $collapsed);
592 elsif (ref $query eq 'HASH') {
593 if (keys %$query and (keys %$query)[0] eq '-and') {
594 foreach my $subquery (@{$query->{-and}}) {
595 # warn "HASH: " . Dumper $subquery;
596 $collapsed = $self->_collapse_query($subquery, $collapsed);
600 # warn "LEAF: " . Dumper $query;
601 foreach my $col (keys %$query) {
602 my $value = $query->{$col};
603 $collapsed->{$col}{$value}++;
615 =item Arguments: $cond?
617 =item Return Value: $resultsetcolumn
621 my $max_length = $rs->get_column('length')->max;
623 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
628 my ($self, $column) = @_;
629 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
637 =item Arguments: $cond, \%attrs?
639 =item Return Value: $resultset (scalar context), @row_objs (list context)
643 # WHERE title LIKE '%blue%'
644 $cd_rs = $rs->search_like({ title => '%blue%'});
646 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
647 that this is simply a convenience method. You most likely want to use
648 L</search> with specific operators.
650 For more information, see L<DBIx::Class::Manual::Cookbook>.
656 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
657 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
658 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
659 return $class->search($query, { %$attrs });
666 =item Arguments: $first, $last
668 =item Return Value: $resultset (scalar context), @row_objs (list context)
672 Returns a resultset or object list representing a subset of elements from the
673 resultset slice is called on. Indexes are from 0, i.e., to get the first
676 my ($one, $two, $three) = $rs->slice(0, 2);
681 my ($self, $min, $max) = @_;
682 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
683 $attrs->{offset} = $self->{attrs}{offset} || 0;
684 $attrs->{offset} += $min;
685 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
686 return $self->search(undef(), $attrs);
687 #my $slice = (ref $self)->new($self->result_source, $attrs);
688 #return (wantarray ? $slice->all : $slice);
695 =item Arguments: none
697 =item Return Value: $result?
701 Returns the next element in the resultset (C<undef> is there is none).
703 Can be used to efficiently iterate over records in the resultset:
705 my $rs = $schema->resultset('CD')->search;
706 while (my $cd = $rs->next) {
710 Note that you need to store the resultset object, and call C<next> on it.
711 Calling C<< resultset('Table')->next >> repeatedly will always return the
712 first record from the resultset.
718 if (my $cache = $self->get_cache) {
719 $self->{all_cache_position} ||= 0;
720 return $cache->[$self->{all_cache_position}++];
722 if ($self->{attrs}{cache}) {
723 $self->{all_cache_position} = 1;
724 return ($self->all)[0];
726 if ($self->{stashed_objects}) {
727 my $obj = shift(@{$self->{stashed_objects}});
728 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
732 exists $self->{stashed_row}
733 ? @{delete $self->{stashed_row}}
734 : $self->cursor->next
736 return unless (@row);
737 my ($row, @more) = $self->_construct_object(@row);
738 $self->{stashed_objects} = \@more if @more;
742 sub _construct_object {
743 my ($self, @row) = @_;
744 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
745 my @new = $self->result_class->inflate_result($self->_source_handle, @$info);
746 @new = $self->{_attrs}{record_filter}->(@new)
747 if exists $self->{_attrs}{record_filter};
751 sub _collapse_result {
752 my ($self, $as, $row, $prefix) = @_;
757 foreach my $this_as (@$as) {
758 my $val = shift @copy;
759 if (defined $prefix) {
760 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
762 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
763 $const{$1||''}{$2} = $val;
766 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
767 $const{$1||''}{$2} = $val;
771 my $alias = $self->{attrs}{alias};
772 my $info = [ {}, {} ];
773 foreach my $key (keys %const) {
774 if (length $key && $key ne $alias) {
776 my @parts = split(/\./, $key);
777 foreach my $p (@parts) {
778 $target = $target->[1]->{$p} ||= [];
780 $target->[0] = $const{$key};
782 $info->[0] = $const{$key};
787 if (defined $prefix) {
789 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
790 } keys %{$self->{_attrs}{collapse}}
792 @collapse = keys %{$self->{_attrs}{collapse}};
796 my ($c) = sort { length $a <=> length $b } @collapse;
798 foreach my $p (split(/\./, $c)) {
799 $target = $target->[1]->{$p} ||= [];
801 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
802 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
803 my $tree = $self->_collapse_result($as, $row, $c_prefix);
804 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
810 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
815 last unless (@raw = $self->cursor->next);
816 $row = $self->{stashed_row} = \@raw;
817 $tree = $self->_collapse_result($as, $row, $c_prefix);
819 @$target = (@final ? @final : [ {}, {} ]);
820 # single empty result to indicate an empty prefetched has_many
823 #print "final info: " . Dumper($info);
831 =item Arguments: $result_source?
833 =item Return Value: $result_source
837 An accessor for the primary ResultSource object from which this ResultSet
844 =item Arguments: $result_class?
846 =item Return Value: $result_class
850 An accessor for the class to use when creating row objects. Defaults to
851 C<< result_source->result_class >> - which in most cases is the name of the
852 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
861 =item Arguments: $cond, \%attrs??
863 =item Return Value: $count
867 Performs an SQL C<COUNT> with the same query as the resultset was built
868 with to find the number of elements. If passed arguments, does a search
869 on the resultset and counts the results of that.
871 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
872 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
873 not support C<DISTINCT> with multiple columns. If you are using such a
874 database, you should only use columns from the main table in your C<group_by>
881 return $self->search(@_)->count if @_ and defined $_[0];
882 return scalar @{ $self->get_cache } if $self->get_cache;
883 my $count = $self->_count;
884 return 0 unless $count;
886 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
887 $count = $self->{attrs}{rows} if
888 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
892 sub _count { # Separated out so pager can get the full count
894 my $select = { count => '*' };
896 my $attrs = { %{$self->_resolved_attrs} };
897 if (my $group_by = delete $attrs->{group_by}) {
898 delete $attrs->{having};
899 my @distinct = (ref $group_by ? @$group_by : ($group_by));
900 # todo: try CONCAT for multi-column pk
901 my @pk = $self->result_source->primary_columns;
903 my $alias = $attrs->{alias};
904 foreach my $column (@distinct) {
905 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
906 @distinct = ($column);
912 $select = { count => { distinct => \@distinct } };
915 $attrs->{select} = $select;
916 $attrs->{as} = [qw/count/];
918 # offset, order by and page are not needed to count. record_filter is cdbi
919 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
921 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
922 my ($count) = $tmp_rs->cursor->next;
930 =item Arguments: $sql_fragment, @bind_values
932 =item Return Value: $count
936 Counts the results in a literal query. Equivalent to calling L</search_literal>
937 with the passed arguments, then L</count>.
941 sub count_literal { shift->search_literal(@_)->count; }
947 =item Arguments: none
949 =item Return Value: @objects
953 Returns all elements in the resultset. Called implicitly if the resultset
954 is returned in list context.
960 return @{ $self->get_cache } if $self->get_cache;
964 # TODO: don't call resolve here
965 if (keys %{$self->_resolved_attrs->{collapse}}) {
966 # if ($self->{attrs}{prefetch}) {
967 # Using $self->cursor->all is really just an optimisation.
968 # If we're collapsing has_many prefetches it probably makes
969 # very little difference, and this is cleaner than hacking
970 # _construct_object to survive the approach
971 my @row = $self->cursor->next;
973 push(@obj, $self->_construct_object(@row));
974 @row = (exists $self->{stashed_row}
975 ? @{delete $self->{stashed_row}}
976 : $self->cursor->next);
979 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
982 $self->set_cache(\@obj) if $self->{attrs}{cache};
990 =item Arguments: none
992 =item Return Value: $self
996 Resets the resultset's cursor, so you can iterate through the elements again.
1002 delete $self->{_attrs} if exists $self->{_attrs};
1003 $self->{all_cache_position} = 0;
1004 $self->cursor->reset;
1012 =item Arguments: none
1014 =item Return Value: $object?
1018 Resets the resultset and returns an object for the first result (if the
1019 resultset returns anything).
1024 return $_[0]->reset->next;
1027 # _cond_for_update_delete
1029 # update/delete require the condition to be modified to handle
1030 # the differing SQL syntax available. This transforms the $self->{cond}
1031 # appropriately, returning the new condition.
1033 sub _cond_for_update_delete {
1034 my ($self, $full_cond) = @_;
1037 $full_cond ||= $self->{cond};
1038 # No-op. No condition, we're updating/deleting everything
1039 return $cond unless ref $full_cond;
1041 if (ref $full_cond eq 'ARRAY') {
1045 foreach my $key (keys %{$_}) {
1047 $hash{$1} = $_->{$key};
1053 elsif (ref $full_cond eq 'HASH') {
1054 if ((keys %{$full_cond})[0] eq '-and') {
1057 my @cond = @{$full_cond->{-and}};
1058 for (my $i = 0; $i < @cond; $i++) {
1059 my $entry = $cond[$i];
1062 if (ref $entry eq 'HASH') {
1063 $hash = $self->_cond_for_update_delete($entry);
1066 $entry =~ /([^.]+)$/;
1067 $hash->{$1} = $cond[++$i];
1070 push @{$cond->{-and}}, $hash;
1074 foreach my $key (keys %{$full_cond}) {
1076 $cond->{$1} = $full_cond->{$key};
1081 $self->throw_exception(
1082 "Can't update/delete on resultset with condition unless hash or array"
1094 =item Arguments: \%values
1096 =item Return Value: $storage_rv
1100 Sets the specified columns in the resultset to the supplied values in a
1101 single query. Return value will be true if the update succeeded or false
1102 if no records were updated; exact type of success value is storage-dependent.
1107 my ($self, $values) = @_;
1108 $self->throw_exception("Values for update must be a hash")
1109 unless ref $values eq 'HASH';
1111 my $cond = $self->_cond_for_update_delete;
1113 return $self->result_source->storage->update(
1114 $self->result_source->from, $values, $cond
1122 =item Arguments: \%values
1124 =item Return Value: 1
1128 Fetches all objects and updates them one at a time. Note that C<update_all>
1129 will run DBIC cascade triggers, while L</update> will not.
1134 my ($self, $values) = @_;
1135 $self->throw_exception("Values for update must be a hash")
1136 unless ref $values eq 'HASH';
1137 foreach my $obj ($self->all) {
1138 $obj->set_columns($values)->update;
1147 =item Arguments: none
1149 =item Return Value: 1
1153 Deletes the contents of the resultset from its result source. Note that this
1154 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1155 to run. See also L<DBIx::Class::Row/delete>.
1162 my $cond = $self->_cond_for_update_delete;
1164 $self->result_source->storage->delete($self->result_source->from, $cond);
1172 =item Arguments: none
1174 =item Return Value: 1
1178 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1179 will run DBIC cascade triggers, while L</delete> will not.
1185 $_->delete for $self->all;
1193 =item Arguments: none
1195 =item Return Value: $pager
1199 Return Value a L<Data::Page> object for the current resultset. Only makes
1200 sense for queries with a C<page> attribute.
1206 my $attrs = $self->{attrs};
1207 $self->throw_exception("Can't create pager for non-paged rs")
1208 unless $self->{attrs}{page};
1209 $attrs->{rows} ||= 10;
1210 return $self->{pager} ||= Data::Page->new(
1211 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1218 =item Arguments: $page_number
1220 =item Return Value: $rs
1224 Returns a resultset for the $page_number page of the resultset on which page
1225 is called, where each page contains a number of rows equal to the 'rows'
1226 attribute set on the resultset (10 by default).
1231 my ($self, $page) = @_;
1232 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1239 =item Arguments: \%vals
1241 =item Return Value: $object
1245 Creates an object in the resultset's result class and returns it.
1250 my ($self, $values) = @_;
1251 $self->throw_exception( "new_result needs a hash" )
1252 unless (ref $values eq 'HASH');
1253 $self->throw_exception(
1254 "Can't abstract implicit construct, condition not a hash"
1255 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1257 my $alias = $self->{attrs}{alias};
1258 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1260 %{ $self->_remove_alias($values, $alias) },
1261 %{ $self->_remove_alias($collapsed_cond, $alias) },
1264 return $self->result_class->new(\%new,$self->_source_handle);
1269 # Recursively collapse the condition.
1271 sub _collapse_cond {
1272 my ($self, $cond, $collapsed) = @_;
1276 if (ref $cond eq 'ARRAY') {
1277 foreach my $subcond (@$cond) {
1278 next unless ref $subcond; # -or
1279 # warn "ARRAY: " . Dumper $subcond;
1280 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1283 elsif (ref $cond eq 'HASH') {
1284 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1285 foreach my $subcond (@{$cond->{-and}}) {
1286 # warn "HASH: " . Dumper $subcond;
1287 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1291 # warn "LEAF: " . Dumper $cond;
1292 foreach my $col (keys %$cond) {
1293 my $value = $cond->{$col};
1294 $collapsed->{$col} = $value;
1304 # Remove the specified alias from the specified query hash. A copy is made so
1305 # the original query is not modified.
1308 my ($self, $query, $alias) = @_;
1310 my %orig = %{ $query || {} };
1313 foreach my $key (keys %orig) {
1315 $unaliased{$key} = $orig{$key};
1318 $unaliased{$1} = $orig{$key}
1319 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1329 =item Arguments: \%vals, \%attrs?
1331 =item Return Value: $object
1335 Find an existing record from this resultset. If none exists, instantiate a new
1336 result object and return it. The object will not be saved into your storage
1337 until you call L<DBIx::Class::Row/insert> on it.
1339 If you want objects to be saved immediately, use L</find_or_create> instead.
1345 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1346 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1347 my $exists = $self->find($hash, $attrs);
1348 return defined $exists ? $exists : $self->new_result($hash);
1355 =item Arguments: \%vals
1357 =item Return Value: $object
1361 Inserts a record into the resultset and returns the object representing it.
1363 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1368 my ($self, $attrs) = @_;
1369 $self->throw_exception( "create needs a hashref" )
1370 unless ref $attrs eq 'HASH';
1371 return $self->new_result($attrs)->insert;
1374 =head2 find_or_create
1378 =item Arguments: \%vals, \%attrs?
1380 =item Return Value: $object
1384 $class->find_or_create({ key => $val, ... });
1386 Tries to find a record based on its primary key or unique constraint; if none
1387 is found, creates one and returns that instead.
1389 my $cd = $schema->resultset('CD')->find_or_create({
1391 artist => 'Massive Attack',
1392 title => 'Mezzanine',
1396 Also takes an optional C<key> attribute, to search by a specific key or unique
1397 constraint. For example:
1399 my $cd = $schema->resultset('CD')->find_or_create(
1401 artist => 'Massive Attack',
1402 title => 'Mezzanine',
1404 { key => 'cd_artist_title' }
1407 See also L</find> and L</update_or_create>. For information on how to declare
1408 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1412 sub find_or_create {
1414 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1415 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1416 my $exists = $self->find($hash, $attrs);
1417 return defined $exists ? $exists : $self->create($hash);
1420 =head2 update_or_create
1424 =item Arguments: \%col_values, { key => $unique_constraint }?
1426 =item Return Value: $object
1430 $class->update_or_create({ col => $val, ... });
1432 First, searches for an existing row matching one of the unique constraints
1433 (including the primary key) on the source of this resultset. If a row is
1434 found, updates it with the other given column values. Otherwise, creates a new
1437 Takes an optional C<key> attribute to search on a specific unique constraint.
1440 # In your application
1441 my $cd = $schema->resultset('CD')->update_or_create(
1443 artist => 'Massive Attack',
1444 title => 'Mezzanine',
1447 { key => 'cd_artist_title' }
1450 If no C<key> is specified, it searches on all unique constraints defined on the
1451 source, including the primary key.
1453 If the C<key> is specified as C<primary>, it searches only on the primary key.
1455 See also L</find> and L</find_or_create>. For information on how to declare
1456 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1460 sub update_or_create {
1462 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1463 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1465 my $row = $self->find($cond, $attrs);
1467 $row->update($cond);
1471 return $self->create($cond);
1478 =item Arguments: none
1480 =item Return Value: \@cache_objects?
1484 Gets the contents of the cache for the resultset, if the cache is set.
1496 =item Arguments: \@cache_objects
1498 =item Return Value: \@cache_objects
1502 Sets the contents of the cache for the resultset. Expects an arrayref
1503 of objects of the same class as those produced by the resultset. Note that
1504 if the cache is set the resultset will return the cached objects rather
1505 than re-querying the database even if the cache attr is not set.
1510 my ( $self, $data ) = @_;
1511 $self->throw_exception("set_cache requires an arrayref")
1512 if defined($data) && (ref $data ne 'ARRAY');
1513 $self->{all_cache} = $data;
1520 =item Arguments: none
1522 =item Return Value: []
1526 Clears the cache for the resultset.
1531 shift->set_cache(undef);
1534 =head2 related_resultset
1538 =item Arguments: $relationship_name
1540 =item Return Value: $resultset
1544 Returns a related resultset for the supplied relationship name.
1546 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1550 sub related_resultset {
1551 my ($self, $rel) = @_;
1553 $self->{related_resultsets} ||= {};
1554 return $self->{related_resultsets}{$rel} ||= do {
1555 my $rel_obj = $self->result_source->relationship_info($rel);
1557 $self->throw_exception(
1558 "search_related: result source '" . $self->_source_handle->source_moniker .
1559 "' has no such relationship $rel")
1562 my ($from,$seen) = $self->_resolve_from($rel);
1564 my $join_count = $seen->{$rel};
1565 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1567 $self->_source_handle->schema->resultset($rel_obj->{class})->search_rs(
1569 %{$self->{attrs}||{}},
1575 where => $self->{cond},
1583 my ($self, $extra_join) = @_;
1584 my $source = $self->result_source;
1585 my $attrs = $self->{attrs};
1587 my $from = $attrs->{from}
1588 || [ { $attrs->{alias} => $source->from } ];
1590 my $seen = { %{$attrs->{seen_join}||{}} };
1592 my $join = ($attrs->{join}
1593 ? [ $attrs->{join}, $extra_join ]
1597 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1600 return ($from,$seen);
1603 sub _resolved_attrs {
1605 return $self->{_attrs} if $self->{_attrs};
1607 my $attrs = { %{$self->{attrs}||{}} };
1608 my $source = $self->result_source;
1609 my $alias = $attrs->{alias};
1611 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1612 if ($attrs->{columns}) {
1613 delete $attrs->{as};
1614 } elsif (!$attrs->{select}) {
1615 $attrs->{columns} = [ $source->columns ];
1620 ? (ref $attrs->{select} eq 'ARRAY'
1621 ? [ @{$attrs->{select}} ]
1622 : [ $attrs->{select} ])
1623 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1627 ? (ref $attrs->{as} eq 'ARRAY'
1628 ? [ @{$attrs->{as}} ]
1630 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1634 if ($adds = delete $attrs->{include_columns}) {
1635 $adds = [$adds] unless ref $adds eq 'ARRAY';
1636 push(@{$attrs->{select}}, @$adds);
1637 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1639 if ($adds = delete $attrs->{'+select'}) {
1640 $adds = [$adds] unless ref $adds eq 'ARRAY';
1641 push(@{$attrs->{select}},
1642 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1644 if (my $adds = delete $attrs->{'+as'}) {
1645 $adds = [$adds] unless ref $adds eq 'ARRAY';
1646 push(@{$attrs->{as}}, @$adds);
1649 $attrs->{from} ||= [ { 'me' => $source->from } ];
1651 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1652 my $join = delete $attrs->{join} || {};
1654 if (defined $attrs->{prefetch}) {
1655 $join = $self->_merge_attr(
1656 $join, $attrs->{prefetch}
1660 $attrs->{from} = # have to copy here to avoid corrupting the original
1663 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1667 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1668 if ($attrs->{order_by}) {
1669 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1670 ? [ @{$attrs->{order_by}} ]
1671 : [ $attrs->{order_by} ]);
1673 $attrs->{order_by} = [];
1676 my $collapse = $attrs->{collapse} || {};
1677 if (my $prefetch = delete $attrs->{prefetch}) {
1678 $prefetch = $self->_merge_attr({}, $prefetch);
1680 my $seen = $attrs->{seen_join} || {};
1681 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1682 # bring joins back to level of current class
1683 my @prefetch = $source->resolve_prefetch(
1684 $p, $alias, $seen, \@pre_order, $collapse
1686 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1687 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1689 push(@{$attrs->{order_by}}, @pre_order);
1691 $attrs->{collapse} = $collapse;
1693 return $self->{_attrs} = $attrs;
1697 my ($self, $a, $b) = @_;
1698 return $b unless defined($a);
1699 return $a unless defined($b);
1701 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1702 foreach my $key (keys %{$b}) {
1703 if (exists $a->{$key}) {
1704 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1706 $a->{$key} = $b->{$key};
1711 $a = [$a] unless ref $a eq 'ARRAY';
1712 $b = [$b] unless ref $b eq 'ARRAY';
1716 foreach my $x ($a, $b) {
1717 foreach my $element (@{$x}) {
1718 if (ref $element eq 'HASH') {
1719 $hash = $self->_merge_attr($hash, $element);
1720 } elsif (ref $element eq 'ARRAY') {
1721 push(@array, @{$element});
1723 push(@array, $element) unless $b == $x
1724 && grep { $_ eq $element } @array;
1729 @array = grep { !exists $hash->{$_} } @array;
1731 return keys %{$hash}
1744 $self->_source_handle($_[0]->handle);
1746 $self->_source_handle->resolve;
1750 =head2 throw_exception
1752 See L<DBIx::Class::Schema/throw_exception> for details.
1756 sub throw_exception {
1758 $self->_source_handle->schema->throw_exception(@_);
1761 # XXX: FIXME: Attributes docs need clearing up
1765 The resultset takes various attributes that modify its behavior. Here's an
1772 =item Value: ($order_by | \@order_by)
1776 Which column(s) to order the results by. This is currently passed
1777 through directly to SQL, so you can give e.g. C<year DESC> for a
1778 descending order on the column `year'.
1780 Please note that if you have C<quote_char> enabled (see
1781 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1782 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1783 so you will need to manually quote things as appropriate.)
1789 =item Value: \@columns
1793 Shortcut to request a particular set of columns to be retrieved. Adds
1794 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1795 from that, then auto-populates C<as> from C<select> as normal. (You may also
1796 use the C<cols> attribute, as in earlier versions of DBIC.)
1798 =head2 include_columns
1802 =item Value: \@columns
1806 Shortcut to include additional columns in the returned results - for example
1808 $schema->resultset('CD')->search(undef, {
1809 include_columns => ['artist.name'],
1813 would return all CDs and include a 'name' column to the information
1814 passed to object inflation
1820 =item Value: \@select_columns
1824 Indicates which columns should be selected from the storage. You can use
1825 column names, or in the case of RDBMS back ends, function or stored procedure
1828 $rs = $schema->resultset('Employee')->search(undef, {
1831 { count => 'employeeid' },
1836 When you use function/stored procedure names and do not supply an C<as>
1837 attribute, the column names returned are storage-dependent. E.g. MySQL would
1838 return a column named C<count(employeeid)> in the above example.
1844 Indicates additional columns to be selected from storage. Works the same as
1845 L<select> but adds columns to the selection.
1853 Indicates additional column names for those added via L<+select>.
1861 =item Value: \@inflation_names
1865 Indicates column names for object inflation. This is used in conjunction with
1866 C<select>, usually when C<select> contains one or more function or stored
1869 $rs = $schema->resultset('Employee')->search(undef, {
1872 { count => 'employeeid' }
1874 as => ['name', 'employee_count'],
1877 my $employee = $rs->first(); # get the first Employee
1879 If the object against which the search is performed already has an accessor
1880 matching a column name specified in C<as>, the value can be retrieved using
1881 the accessor as normal:
1883 my $name = $employee->name();
1885 If on the other hand an accessor does not exist in the object, you need to
1886 use C<get_column> instead:
1888 my $employee_count = $employee->get_column('employee_count');
1890 You can create your own accessors if required - see
1891 L<DBIx::Class::Manual::Cookbook> for details.
1893 Please note: This will NOT insert an C<AS employee_count> into the SQL
1894 statement produced, it is used for internal access only. Thus
1895 attempting to use the accessor in an C<order_by> clause or similar
1896 will fail miserably.
1898 To get around this limitation, you can supply literal SQL to your
1899 C<select> attibute that contains the C<AS alias> text, eg:
1901 select => [\'myfield AS alias']
1907 =item Value: ($rel_name | \@rel_names | \%rel_names)
1911 Contains a list of relationships that should be joined for this query. For
1914 # Get CDs by Nine Inch Nails
1915 my $rs = $schema->resultset('CD')->search(
1916 { 'artist.name' => 'Nine Inch Nails' },
1917 { join => 'artist' }
1920 Can also contain a hash reference to refer to the other relation's relations.
1923 package MyApp::Schema::Track;
1924 use base qw/DBIx::Class/;
1925 __PACKAGE__->table('track');
1926 __PACKAGE__->add_columns(qw/trackid cd position title/);
1927 __PACKAGE__->set_primary_key('trackid');
1928 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1931 # In your application
1932 my $rs = $schema->resultset('Artist')->search(
1933 { 'track.title' => 'Teardrop' },
1935 join => { cd => 'track' },
1936 order_by => 'artist.name',
1940 You need to use the relationship (not the table) name in conditions,
1941 because they are aliased as such. The current table is aliased as "me", so
1942 you need to use me.column_name in order to avoid ambiguity. For example:
1944 # Get CDs from 1984 with a 'Foo' track
1945 my $rs = $schema->resultset('CD')->search(
1948 'tracks.name' => 'Foo'
1950 { join => 'tracks' }
1953 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1954 similarly for a third time). For e.g.
1956 my $rs = $schema->resultset('Artist')->search({
1957 'cds.title' => 'Down to Earth',
1958 'cds_2.title' => 'Popular',
1960 join => [ qw/cds cds/ ],
1963 will return a set of all artists that have both a cd with title 'Down
1964 to Earth' and a cd with title 'Popular'.
1966 If you want to fetch related objects from other tables as well, see C<prefetch>
1973 =item Value: ($rel_name | \@rel_names | \%rel_names)
1977 Contains one or more relationships that should be fetched along with the main
1978 query (when they are accessed afterwards they will have already been
1979 "prefetched"). This is useful for when you know you will need the related
1980 objects, because it saves at least one query:
1982 my $rs = $schema->resultset('Tag')->search(
1991 The initial search results in SQL like the following:
1993 SELECT tag.*, cd.*, artist.* FROM tag
1994 JOIN cd ON tag.cd = cd.cdid
1995 JOIN artist ON cd.artist = artist.artistid
1997 L<DBIx::Class> has no need to go back to the database when we access the
1998 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2001 Simple prefetches will be joined automatically, so there is no need
2002 for a C<join> attribute in the above search. If you're prefetching to
2003 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2004 specify the join as well.
2006 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2007 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2008 with an accessor type of 'single' or 'filter').
2018 Makes the resultset paged and specifies the page to retrieve. Effectively
2019 identical to creating a non-pages resultset and then calling ->page($page)
2022 If L<rows> attribute is not specified it defualts to 10 rows per page.
2032 Specifes the maximum number of rows for direct retrieval or the number of
2033 rows per page if the page attribute or method is used.
2039 =item Value: $offset
2043 Specifies the (zero-based) row number for the first row to be returned, or the
2044 of the first row of the first page if paging is used.
2050 =item Value: \@columns
2054 A arrayref of columns to group by. Can include columns of joined tables.
2056 group_by => [qw/ column1 column2 ... /]
2062 =item Value: $condition
2066 HAVING is a select statement attribute that is applied between GROUP BY and
2067 ORDER BY. It is applied to the after the grouping calculations have been
2070 having => { 'count(employee)' => { '>=', 100 } }
2076 =item Value: (0 | 1)
2080 Set to 1 to group by all columns.
2086 Adds to the WHERE clause.
2088 # only return rows WHERE deleted IS NULL for all searches
2089 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2091 Can be overridden by passing C<{ where => undef }> as an attribute
2098 Set to 1 to cache search results. This prevents extra SQL queries if you
2099 revisit rows in your ResultSet:
2101 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2103 while( my $artist = $resultset->next ) {
2107 $rs->first; # without cache, this would issue a query
2109 By default, searches are not cached.
2111 For more examples of using these attributes, see
2112 L<DBIx::Class::Manual::Cookbook>.
2118 =item Value: \@from_clause
2122 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2123 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2126 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2128 C<join> will usually do what you need and it is strongly recommended that you
2129 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2130 And we really do mean "cannot", not just tried and failed. Attempting to use
2131 this because you're having problems with C<join> is like trying to use x86
2132 ASM because you've got a syntax error in your C. Trust us on this.
2134 Now, if you're still really, really sure you need to use this (and if you're
2135 not 100% sure, ask the mailing list first), here's an explanation of how this
2138 The syntax is as follows -
2141 { <alias1> => <table1> },
2143 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2144 [], # nested JOIN (optional)
2145 { <table1.column1> => <table2.column2>, ... (more conditions) },
2147 # More of the above [ ] may follow for additional joins
2154 ON <table1.column1> = <table2.column2>
2155 <more joins may follow>
2157 An easy way to follow the examples below is to remember the following:
2159 Anything inside "[]" is a JOIN
2160 Anything inside "{}" is a condition for the enclosing JOIN
2162 The following examples utilize a "person" table in a family tree application.
2163 In order to express parent->child relationships, this table is self-joined:
2165 # Person->belongs_to('father' => 'Person');
2166 # Person->belongs_to('mother' => 'Person');
2168 C<from> can be used to nest joins. Here we return all children with a father,
2169 then search against all mothers of those children:
2171 $rs = $schema->resultset('Person')->search(
2174 alias => 'mother', # alias columns in accordance with "from"
2176 { mother => 'person' },
2179 { child => 'person' },
2181 { father => 'person' },
2182 { 'father.person_id' => 'child.father_id' }
2185 { 'mother.person_id' => 'child.mother_id' }
2192 # SELECT mother.* FROM person mother
2195 # JOIN person father
2196 # ON ( father.person_id = child.father_id )
2198 # ON ( mother.person_id = child.mother_id )
2200 The type of any join can be controlled manually. To search against only people
2201 with a father in the person table, we could explicitly use C<INNER JOIN>:
2203 $rs = $schema->resultset('Person')->search(
2206 alias => 'child', # alias columns in accordance with "from"
2208 { child => 'person' },
2210 { father => 'person', -join_type => 'inner' },
2211 { 'father.id' => 'child.father_id' }
2218 # SELECT child.* FROM person child
2219 # INNER JOIN person father ON child.father_id = father.id