1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use base qw/DBIx::Class/;
15 __PACKAGE__->load_components(qw/AccessorGroup/);
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
91 $attrs->{rows} ||= 10;
92 $attrs->{offset} ||= 0;
93 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
96 $attrs->{alias} ||= 'me';
99 result_source => $source,
100 result_class => $attrs->{result_class} || $source->result_class,
101 cond => $attrs->{where},
116 =item Arguments: $cond, \%attrs?
118 =item Return Value: $resultset (scalar context), @row_objs (list context)
122 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
123 my $new_rs = $cd_rs->search({ year => 2005 });
125 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
126 # year = 2005 OR year = 2004
128 If you need to pass in additional attributes but no additional condition,
129 call it as C<search(undef, \%attrs)>.
131 # "SELECT name, artistid FROM $artist_table"
132 my @all_artists = $schema->resultset('Artist')->search(undef, {
133 columns => [qw/name artistid/],
136 For a list of attributes that can be passed to C<search>, see L</ATTRIBUTES>. For more examples of using this function, see L<Searching|DBIx::Class::Manual::Cookbook/Searching>.
142 my $rs = $self->search_rs( @_ );
143 return (wantarray ? $rs->all : $rs);
150 =item Arguments: $cond, \%attrs?
152 =item Return Value: $resultset
156 This method does the same exact thing as search() except it will
157 always return a resultset, even in list context.
166 unless (@_) { # no search, effectively just a clone
167 $rows = $self->get_cache;
171 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
172 my $our_attrs = { %{$self->{attrs}} };
173 my $having = delete $our_attrs->{having};
174 my $where = delete $our_attrs->{where};
176 my $new_attrs = { %{$our_attrs}, %{$attrs} };
178 # merge new attrs into inherited
179 foreach my $key (qw/join prefetch/) {
180 next unless exists $attrs->{$key};
181 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
186 (@_ == 1 || ref $_[0] eq "HASH")
188 (ref $_[0] eq 'HASH')
190 (keys %{ $_[0] } > 0)
198 ? $self->throw_exception("Odd number of arguments to search")
205 if (defined $where) {
206 $new_attrs->{where} = (
207 defined $new_attrs->{where}
210 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
211 } $where, $new_attrs->{where}
218 $new_attrs->{where} = (
219 defined $new_attrs->{where}
222 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
223 } $cond, $new_attrs->{where}
229 if (defined $having) {
230 $new_attrs->{having} = (
231 defined $new_attrs->{having}
234 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
235 } $having, $new_attrs->{having}
241 my $rs = (ref $self)->new($self->result_source, $new_attrs);
243 $rs->set_cache($rows);
248 =head2 search_literal
252 =item Arguments: $sql_fragment, @bind_values
254 =item Return Value: $resultset (scalar context), @row_objs (list context)
258 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
259 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
261 Pass a literal chunk of SQL to be added to the conditional part of the
267 my ($self, $cond, @vals) = @_;
268 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
269 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
270 return $self->search(\$cond, $attrs);
277 =item Arguments: @values | \%cols, \%attrs?
279 =item Return Value: $row_object
283 Finds a row based on its primary key or unique constraint. For example, to find
284 a row by its primary key:
286 my $cd = $schema->resultset('CD')->find(5);
288 You can also find a row by a specific unique constraint using the C<key>
289 attribute. For example:
291 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
292 key => 'cd_artist_title'
295 Additionally, you can specify the columns explicitly by name:
297 my $cd = $schema->resultset('CD')->find(
299 artist => 'Massive Attack',
300 title => 'Mezzanine',
302 { key => 'cd_artist_title' }
305 If the C<key> is specified as C<primary>, it searches only on the primary key.
307 If no C<key> is specified, it searches on all unique constraints defined on the
308 source, including the primary key.
310 If your table does not have a primary key, you B<must> provide a value for the
311 C<key> attribute matching one of the unique constraints on the source.
313 See also L</find_or_create> and L</update_or_create>. For information on how to
314 declare unique constraints, see
315 L<DBIx::Class::ResultSource/add_unique_constraint>.
321 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
323 # Default to the primary key, but allow a specific key
324 my @cols = exists $attrs->{key}
325 ? $self->result_source->unique_constraint_columns($attrs->{key})
326 : $self->result_source->primary_columns;
327 $self->throw_exception(
328 "Can't find unless a primary key is defined or unique constraint is specified"
331 # Parse out a hashref from input
333 if (ref $_[0] eq 'HASH') {
334 $input_query = { %{$_[0]} };
336 elsif (@_ == @cols) {
338 @{$input_query}{@cols} = @_;
341 # Compatibility: Allow e.g. find(id => $value)
342 carp "Find by key => value deprecated; please use a hashref instead";
346 my (%related, $info);
348 foreach my $key (keys %$input_query) {
349 if (ref($input_query->{$key})
350 && ($info = $self->result_source->relationship_info($key))) {
351 my $rel_q = $self->result_source->resolve_condition(
352 $info->{cond}, delete $input_query->{$key}, $key
354 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
355 @related{keys %$rel_q} = values %$rel_q;
358 if (my @keys = keys %related) {
359 @{$input_query}{@keys} = values %related;
362 my @unique_queries = $self->_unique_queries($input_query, $attrs);
364 # Build the final query: Default to the disjunction of the unique queries,
365 # but allow the input query in case the ResultSet defines the query or the
366 # user is abusing find
367 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
368 my $query = @unique_queries
369 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
370 : $self->_add_alias($input_query, $alias);
374 my $rs = $self->search($query, $attrs);
375 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
378 return keys %{$self->_resolved_attrs->{collapse}}
379 ? $self->search($query)->next
380 : $self->single($query);
386 # Add the specified alias to the specified query hash. A copy is made so the
387 # original query is not modified.
390 my ($self, $query, $alias) = @_;
392 my %aliased = %$query;
393 foreach my $col (grep { ! m/\./ } keys %aliased) {
394 $aliased{"$alias.$col"} = delete $aliased{$col};
402 # Build a list of queries which satisfy unique constraints.
404 sub _unique_queries {
405 my ($self, $query, $attrs) = @_;
407 my @constraint_names = exists $attrs->{key}
409 : $self->result_source->unique_constraint_names;
412 foreach my $name (@constraint_names) {
413 my @unique_cols = $self->result_source->unique_constraint_columns($name);
414 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
416 my $num_query = scalar keys %$unique_query;
417 next unless $num_query;
419 # XXX: Assuming quite a bit about $self->{attrs}{where}
420 my $num_cols = scalar @unique_cols;
421 my $num_where = exists $self->{attrs}{where}
422 ? scalar keys %{ $self->{attrs}{where} }
424 push @unique_queries, $unique_query
425 if $num_query + $num_where == $num_cols;
428 return @unique_queries;
431 # _build_unique_query
433 # Constrain the specified query hash based on the specified column names.
435 sub _build_unique_query {
436 my ($self, $query, $unique_cols) = @_;
439 map { $_ => $query->{$_} }
440 grep { exists $query->{$_} }
445 =head2 search_related
449 =item Arguments: $rel, $cond, \%attrs?
451 =item Return Value: $new_resultset
455 $new_rs = $cd_rs->search_related('artist', {
459 Searches the specified relationship, optionally specifying a condition and
460 attributes for matching records. See L</ATTRIBUTES> for more information.
465 return shift->related_resultset(shift)->search(@_);
472 =item Arguments: none
474 =item Return Value: $cursor
478 Returns a storage-driven cursor to the given resultset. See
479 L<DBIx::Class::Cursor> for more information.
486 my $attrs = { %{$self->_resolved_attrs} };
487 return $self->{cursor}
488 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
489 $attrs->{where},$attrs);
496 =item Arguments: $cond?
498 =item Return Value: $row_object?
502 my $cd = $schema->resultset('CD')->single({ year => 2001 });
504 Inflates the first result without creating a cursor if the resultset has
505 any records in it; if not returns nothing. Used by L</find> as an optimisation.
507 Can optionally take an additional condition *only* - this is a fast-code-path
508 method; if you need to add extra joins or similar call ->search and then
509 ->single without a condition on the $rs returned from that.
514 my ($self, $where) = @_;
515 my $attrs = { %{$self->_resolved_attrs} };
517 if (defined $attrs->{where}) {
520 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
521 $where, delete $attrs->{where} ]
524 $attrs->{where} = $where;
528 # XXX: Disabled since it doesn't infer uniqueness in all cases
529 # unless ($self->_is_unique_query($attrs->{where})) {
530 # carp "Query not guaranteed to return a single row"
531 # . "; please declare your unique constraints or use search instead";
534 my @data = $self->result_source->storage->select_single(
535 $attrs->{from}, $attrs->{select},
536 $attrs->{where}, $attrs
539 return (@data ? ($self->_construct_object(@data))[0] : ());
544 # Try to determine if the specified query is guaranteed to be unique, based on
545 # the declared unique constraints.
547 sub _is_unique_query {
548 my ($self, $query) = @_;
550 my $collapsed = $self->_collapse_query($query);
551 my $alias = $self->{attrs}{alias};
553 foreach my $name ($self->result_source->unique_constraint_names) {
554 my @unique_cols = map {
556 } $self->result_source->unique_constraint_columns($name);
558 # Count the values for each unique column
559 my %seen = map { $_ => 0 } @unique_cols;
561 foreach my $key (keys %$collapsed) {
562 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
563 next unless exists $seen{$aliased}; # Additional constraints are okay
564 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
567 # If we get 0 or more than 1 value for a column, it's not necessarily unique
568 return 1 unless grep { $_ != 1 } values %seen;
576 # Recursively collapse the query, accumulating values for each column.
578 sub _collapse_query {
579 my ($self, $query, $collapsed) = @_;
583 if (ref $query eq 'ARRAY') {
584 foreach my $subquery (@$query) {
585 next unless ref $subquery; # -or
586 # warn "ARRAY: " . Dumper $subquery;
587 $collapsed = $self->_collapse_query($subquery, $collapsed);
590 elsif (ref $query eq 'HASH') {
591 if (keys %$query and (keys %$query)[0] eq '-and') {
592 foreach my $subquery (@{$query->{-and}}) {
593 # warn "HASH: " . Dumper $subquery;
594 $collapsed = $self->_collapse_query($subquery, $collapsed);
598 # warn "LEAF: " . Dumper $query;
599 foreach my $col (keys %$query) {
600 my $value = $query->{$col};
601 $collapsed->{$col}{$value}++;
613 =item Arguments: $cond?
615 =item Return Value: $resultsetcolumn
619 my $max_length = $rs->get_column('length')->max;
621 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
626 my ($self, $column) = @_;
627 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
635 =item Arguments: $cond, \%attrs?
637 =item Return Value: $resultset (scalar context), @row_objs (list context)
641 # WHERE title LIKE '%blue%'
642 $cd_rs = $rs->search_like({ title => '%blue%'});
644 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
645 that this is simply a convenience method. You most likely want to use
646 L</search> with specific operators.
648 For more information, see L<DBIx::Class::Manual::Cookbook>.
654 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
655 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
656 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
657 return $class->search($query, { %$attrs });
664 =item Arguments: $first, $last
666 =item Return Value: $resultset (scalar context), @row_objs (list context)
670 Returns a resultset or object list representing a subset of elements from the
671 resultset slice is called on. Indexes are from 0, i.e., to get the first
674 my ($one, $two, $three) = $rs->slice(0, 2);
679 my ($self, $min, $max) = @_;
680 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
681 $attrs->{offset} = $self->{attrs}{offset} || 0;
682 $attrs->{offset} += $min;
683 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
684 return $self->search(undef(), $attrs);
685 #my $slice = (ref $self)->new($self->result_source, $attrs);
686 #return (wantarray ? $slice->all : $slice);
693 =item Arguments: none
695 =item Return Value: $result?
699 Returns the next element in the resultset (C<undef> is there is none).
701 Can be used to efficiently iterate over records in the resultset:
703 my $rs = $schema->resultset('CD')->search;
704 while (my $cd = $rs->next) {
708 Note that you need to store the resultset object, and call C<next> on it.
709 Calling C<< resultset('Table')->next >> repeatedly will always return the
710 first record from the resultset.
716 if (my $cache = $self->get_cache) {
717 $self->{all_cache_position} ||= 0;
718 return $cache->[$self->{all_cache_position}++];
720 if ($self->{attrs}{cache}) {
721 $self->{all_cache_position} = 1;
722 return ($self->all)[0];
724 if ($self->{stashed_objects}) {
725 my $obj = shift(@{$self->{stashed_objects}});
726 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
729 exists $self->{stashed_row}
730 ? @{delete $self->{stashed_row}}
731 : $self->cursor->next
733 return unless (@row);
734 my ($row, @more) = $self->_construct_object(@row);
735 $self->{stashed_objects} = \@more if @more;
739 sub _construct_object {
740 my ($self, @row) = @_;
741 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
742 my @new = $self->result_class->inflate_result($self->result_source, @$info);
743 @new = $self->{_attrs}{record_filter}->(@new)
744 if exists $self->{_attrs}{record_filter};
748 sub _collapse_result {
749 my ($self, $as, $row, $prefix) = @_;
754 foreach my $this_as (@$as) {
755 my $val = shift @copy;
756 if (defined $prefix) {
757 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
759 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
760 $const{$1||''}{$2} = $val;
763 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
764 $const{$1||''}{$2} = $val;
768 my $alias = $self->{attrs}{alias};
769 my $info = [ {}, {} ];
770 foreach my $key (keys %const) {
771 if (length $key && $key ne $alias) {
773 my @parts = split(/\./, $key);
774 foreach my $p (@parts) {
775 $target = $target->[1]->{$p} ||= [];
777 $target->[0] = $const{$key};
779 $info->[0] = $const{$key};
784 if (defined $prefix) {
786 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
787 } keys %{$self->{_attrs}{collapse}}
789 @collapse = keys %{$self->{_attrs}{collapse}};
793 my ($c) = sort { length $a <=> length $b } @collapse;
795 foreach my $p (split(/\./, $c)) {
796 $target = $target->[1]->{$p} ||= [];
798 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
799 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
800 my $tree = $self->_collapse_result($as, $row, $c_prefix);
801 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
807 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
812 last unless (@raw = $self->cursor->next);
813 $row = $self->{stashed_row} = \@raw;
814 $tree = $self->_collapse_result($as, $row, $c_prefix);
816 @$target = (@final ? @final : [ {}, {} ]);
817 # single empty result to indicate an empty prefetched has_many
820 #print "final info: " . Dumper($info);
828 =item Arguments: $result_source?
830 =item Return Value: $result_source
834 An accessor for the primary ResultSource object from which this ResultSet
841 =item Arguments: $result_class?
843 =item Return Value: $result_class
847 An accessor for the class to use when creating row objects. Defaults to
848 C<< result_source->result_class >> - which in most cases is the name of the
849 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
858 =item Arguments: $cond, \%attrs??
860 =item Return Value: $count
864 Performs an SQL C<COUNT> with the same query as the resultset was built
865 with to find the number of elements. If passed arguments, does a search
866 on the resultset and counts the results of that.
868 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
869 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
870 not support C<DISTINCT> with multiple columns. If you are using such a
871 database, you should only use columns from the main table in your C<group_by>
878 return $self->search(@_)->count if @_ and defined $_[0];
879 return scalar @{ $self->get_cache } if $self->get_cache;
880 my $count = $self->_count;
881 return 0 unless $count;
883 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
884 $count = $self->{attrs}{rows} if
885 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
889 sub _count { # Separated out so pager can get the full count
891 my $select = { count => '*' };
893 my $attrs = { %{$self->_resolved_attrs} };
894 if (my $group_by = delete $attrs->{group_by}) {
895 delete $attrs->{having};
896 my @distinct = (ref $group_by ? @$group_by : ($group_by));
897 # todo: try CONCAT for multi-column pk
898 my @pk = $self->result_source->primary_columns;
900 my $alias = $attrs->{alias};
901 foreach my $column (@distinct) {
902 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
903 @distinct = ($column);
909 $select = { count => { distinct => \@distinct } };
912 $attrs->{select} = $select;
913 $attrs->{as} = [qw/count/];
915 # offset, order by and page are not needed to count. record_filter is cdbi
916 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
918 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
919 my ($count) = $tmp_rs->cursor->next;
927 =item Arguments: $sql_fragment, @bind_values
929 =item Return Value: $count
933 Counts the results in a literal query. Equivalent to calling L</search_literal>
934 with the passed arguments, then L</count>.
938 sub count_literal { shift->search_literal(@_)->count; }
944 =item Arguments: none
946 =item Return Value: @objects
950 Returns all elements in the resultset. Called implicitly if the resultset
951 is returned in list context.
957 return @{ $self->get_cache } if $self->get_cache;
961 # TODO: don't call resolve here
962 if (keys %{$self->_resolved_attrs->{collapse}}) {
963 # if ($self->{attrs}{prefetch}) {
964 # Using $self->cursor->all is really just an optimisation.
965 # If we're collapsing has_many prefetches it probably makes
966 # very little difference, and this is cleaner than hacking
967 # _construct_object to survive the approach
968 my @row = $self->cursor->next;
970 push(@obj, $self->_construct_object(@row));
971 @row = (exists $self->{stashed_row}
972 ? @{delete $self->{stashed_row}}
973 : $self->cursor->next);
976 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
979 $self->set_cache(\@obj) if $self->{attrs}{cache};
987 =item Arguments: none
989 =item Return Value: $self
993 Resets the resultset's cursor, so you can iterate through the elements again.
999 delete $self->{_attrs} if exists $self->{_attrs};
1000 $self->{all_cache_position} = 0;
1001 $self->cursor->reset;
1009 =item Arguments: none
1011 =item Return Value: $object?
1015 Resets the resultset and returns an object for the first result (if the
1016 resultset returns anything).
1021 return $_[0]->reset->next;
1024 # _cond_for_update_delete
1026 # update/delete require the condition to be modified to handle
1027 # the differing SQL syntax available. This transforms the $self->{cond}
1028 # appropriately, returning the new condition.
1030 sub _cond_for_update_delete {
1031 my ($self, $full_cond) = @_;
1034 $full_cond ||= $self->{cond};
1035 # No-op. No condition, we're updating/deleting everything
1036 return $cond unless ref $full_cond;
1038 if (ref $full_cond eq 'ARRAY') {
1042 foreach my $key (keys %{$_}) {
1044 $hash{$1} = $_->{$key};
1050 elsif (ref $full_cond eq 'HASH') {
1051 if ((keys %{$full_cond})[0] eq '-and') {
1054 my @cond = @{$full_cond->{-and}};
1055 for (my $i = 0; $i < @cond; $i++) {
1056 my $entry = $cond[$i];
1059 if (ref $entry eq 'HASH') {
1060 $hash = $self->_cond_for_update_delete($entry);
1063 $entry =~ /([^.]+)$/;
1064 $hash->{$1} = $cond[++$i];
1067 push @{$cond->{-and}}, $hash;
1071 foreach my $key (keys %{$full_cond}) {
1073 $cond->{$1} = $full_cond->{$key};
1078 $self->throw_exception(
1079 "Can't update/delete on resultset with condition unless hash or array"
1091 =item Arguments: \%values
1093 =item Return Value: $storage_rv
1097 Sets the specified columns in the resultset to the supplied values in a
1098 single query. Return value will be true if the update succeeded or false
1099 if no records were updated; exact type of success value is storage-dependent.
1104 my ($self, $values) = @_;
1105 $self->throw_exception("Values for update must be a hash")
1106 unless ref $values eq 'HASH';
1108 my $cond = $self->_cond_for_update_delete;
1110 return $self->result_source->storage->update(
1111 $self->result_source->from, $values, $cond
1119 =item Arguments: \%values
1121 =item Return Value: 1
1125 Fetches all objects and updates them one at a time. Note that C<update_all>
1126 will run DBIC cascade triggers, while L</update> will not.
1131 my ($self, $values) = @_;
1132 $self->throw_exception("Values for update must be a hash")
1133 unless ref $values eq 'HASH';
1134 foreach my $obj ($self->all) {
1135 $obj->set_columns($values)->update;
1144 =item Arguments: none
1146 =item Return Value: 1
1150 Deletes the contents of the resultset from its result source. Note that this
1151 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1152 to run. See also L<DBIx::Class::Row/delete>.
1159 my $cond = $self->_cond_for_update_delete;
1161 $self->result_source->storage->delete($self->result_source->from, $cond);
1169 =item Arguments: none
1171 =item Return Value: 1
1175 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1176 will run DBIC cascade triggers, while L</delete> will not.
1182 $_->delete for $self->all;
1190 =item Arguments: none
1192 =item Return Value: $pager
1196 Return Value a L<Data::Page> object for the current resultset. Only makes
1197 sense for queries with a C<page> attribute.
1203 my $attrs = $self->{attrs};
1204 $self->throw_exception("Can't create pager for non-paged rs")
1205 unless $self->{attrs}{page};
1206 $attrs->{rows} ||= 10;
1207 return $self->{pager} ||= Data::Page->new(
1208 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1215 =item Arguments: $page_number
1217 =item Return Value: $rs
1221 Returns a resultset for the $page_number page of the resultset on which page
1222 is called, where each page contains a number of rows equal to the 'rows'
1223 attribute set on the resultset (10 by default).
1228 my ($self, $page) = @_;
1229 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1236 =item Arguments: \%vals
1238 =item Return Value: $object
1242 Creates an object in the resultset's result class and returns it.
1247 my ($self, $values) = @_;
1248 $self->throw_exception( "new_result needs a hash" )
1249 unless (ref $values eq 'HASH');
1250 $self->throw_exception(
1251 "Can't abstract implicit construct, condition not a hash"
1252 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1254 my $alias = $self->{attrs}{alias};
1255 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1257 %{ $self->_remove_alias($values, $alias) },
1258 %{ $self->_remove_alias($collapsed_cond, $alias) },
1259 -result_source => $self->result_source,
1262 my $obj = $self->result_class->new(\%new);
1268 # Recursively collapse the condition.
1270 sub _collapse_cond {
1271 my ($self, $cond, $collapsed) = @_;
1275 if (ref $cond eq 'ARRAY') {
1276 foreach my $subcond (@$cond) {
1277 next unless ref $subcond; # -or
1278 # warn "ARRAY: " . Dumper $subcond;
1279 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1282 elsif (ref $cond eq 'HASH') {
1283 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1284 foreach my $subcond (@{$cond->{-and}}) {
1285 # warn "HASH: " . Dumper $subcond;
1286 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1290 # warn "LEAF: " . Dumper $cond;
1291 foreach my $col (keys %$cond) {
1292 my $value = $cond->{$col};
1293 $collapsed->{$col} = $value;
1303 # Remove the specified alias from the specified query hash. A copy is made so
1304 # the original query is not modified.
1307 my ($self, $query, $alias) = @_;
1309 my %orig = %{ $query || {} };
1312 foreach my $key (keys %orig) {
1314 $unaliased{$key} = $orig{$key};
1317 $unaliased{$1} = $orig{$key}
1318 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1328 =item Arguments: \%vals, \%attrs?
1330 =item Return Value: $object
1334 Find an existing record from this resultset. If none exists, instantiate a new
1335 result object and return it. The object will not be saved into your storage
1336 until you call L<DBIx::Class::Row/insert> on it.
1338 If you want objects to be saved immediately, use L</find_or_create> instead.
1344 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1345 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1346 my $exists = $self->find($hash, $attrs);
1347 return defined $exists ? $exists : $self->new_result($hash);
1354 =item Arguments: \%vals
1356 =item Return Value: $object
1360 Inserts a record into the resultset and returns the object representing it.
1362 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1367 my ($self, $attrs) = @_;
1368 $self->throw_exception( "create needs a hashref" )
1369 unless ref $attrs eq 'HASH';
1370 return $self->new_result($attrs)->insert;
1373 =head2 find_or_create
1377 =item Arguments: \%vals, \%attrs?
1379 =item Return Value: $object
1383 $class->find_or_create({ key => $val, ... });
1385 Tries to find a record based on its primary key or unique constraint; if none
1386 is found, creates one and returns that instead.
1388 my $cd = $schema->resultset('CD')->find_or_create({
1390 artist => 'Massive Attack',
1391 title => 'Mezzanine',
1395 Also takes an optional C<key> attribute, to search by a specific key or unique
1396 constraint. For example:
1398 my $cd = $schema->resultset('CD')->find_or_create(
1400 artist => 'Massive Attack',
1401 title => 'Mezzanine',
1403 { key => 'cd_artist_title' }
1406 See also L</find> and L</update_or_create>. For information on how to declare
1407 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1411 sub find_or_create {
1413 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1414 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1415 my $exists = $self->find($hash, $attrs);
1416 return defined $exists ? $exists : $self->create($hash);
1419 =head2 update_or_create
1423 =item Arguments: \%col_values, { key => $unique_constraint }?
1425 =item Return Value: $object
1429 $class->update_or_create({ col => $val, ... });
1431 First, searches for an existing row matching one of the unique constraints
1432 (including the primary key) on the source of this resultset. If a row is
1433 found, updates it with the other given column values. Otherwise, creates a new
1436 Takes an optional C<key> attribute to search on a specific unique constraint.
1439 # In your application
1440 my $cd = $schema->resultset('CD')->update_or_create(
1442 artist => 'Massive Attack',
1443 title => 'Mezzanine',
1446 { key => 'cd_artist_title' }
1449 If no C<key> is specified, it searches on all unique constraints defined on the
1450 source, including the primary key.
1452 If the C<key> is specified as C<primary>, it searches only on the primary key.
1454 See also L</find> and L</find_or_create>. For information on how to declare
1455 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1459 sub update_or_create {
1461 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1462 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1464 my $row = $self->find($cond, $attrs);
1466 $row->update($cond);
1470 return $self->create($cond);
1477 =item Arguments: none
1479 =item Return Value: \@cache_objects?
1483 Gets the contents of the cache for the resultset, if the cache is set.
1495 =item Arguments: \@cache_objects
1497 =item Return Value: \@cache_objects
1501 Sets the contents of the cache for the resultset. Expects an arrayref
1502 of objects of the same class as those produced by the resultset. Note that
1503 if the cache is set the resultset will return the cached objects rather
1504 than re-querying the database even if the cache attr is not set.
1509 my ( $self, $data ) = @_;
1510 $self->throw_exception("set_cache requires an arrayref")
1511 if defined($data) && (ref $data ne 'ARRAY');
1512 $self->{all_cache} = $data;
1519 =item Arguments: none
1521 =item Return Value: []
1525 Clears the cache for the resultset.
1530 shift->set_cache(undef);
1533 =head2 related_resultset
1537 =item Arguments: $relationship_name
1539 =item Return Value: $resultset
1543 Returns a related resultset for the supplied relationship name.
1545 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1549 sub related_resultset {
1550 my ($self, $rel) = @_;
1552 $self->{related_resultsets} ||= {};
1553 return $self->{related_resultsets}{$rel} ||= do {
1554 my $rel_obj = $self->result_source->relationship_info($rel);
1556 $self->throw_exception(
1557 "search_related: result source '" . $self->result_source->name .
1558 "' has no such relationship $rel")
1561 my ($from,$seen) = $self->_resolve_from($rel);
1563 my $join_count = $seen->{$rel};
1564 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1566 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1568 %{$self->{attrs}||{}},
1574 where => $self->{cond},
1582 my ($self, $extra_join) = @_;
1583 my $source = $self->result_source;
1584 my $attrs = $self->{attrs};
1586 my $from = $attrs->{from}
1587 || [ { $attrs->{alias} => $source->from } ];
1589 my $seen = { %{$attrs->{seen_join}||{}} };
1591 my $join = ($attrs->{join}
1592 ? [ $attrs->{join}, $extra_join ]
1596 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1599 return ($from,$seen);
1602 sub _resolved_attrs {
1604 return $self->{_attrs} if $self->{_attrs};
1606 my $attrs = { %{$self->{attrs}||{}} };
1607 my $source = $self->{result_source};
1608 my $alias = $attrs->{alias};
1610 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1611 if ($attrs->{columns}) {
1612 delete $attrs->{as};
1613 } elsif (!$attrs->{select}) {
1614 $attrs->{columns} = [ $source->columns ];
1619 ? (ref $attrs->{select} eq 'ARRAY'
1620 ? [ @{$attrs->{select}} ]
1621 : [ $attrs->{select} ])
1622 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1626 ? (ref $attrs->{as} eq 'ARRAY'
1627 ? [ @{$attrs->{as}} ]
1629 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1633 if ($adds = delete $attrs->{include_columns}) {
1634 $adds = [$adds] unless ref $adds eq 'ARRAY';
1635 push(@{$attrs->{select}}, @$adds);
1636 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1638 if ($adds = delete $attrs->{'+select'}) {
1639 $adds = [$adds] unless ref $adds eq 'ARRAY';
1640 push(@{$attrs->{select}},
1641 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1643 if (my $adds = delete $attrs->{'+as'}) {
1644 $adds = [$adds] unless ref $adds eq 'ARRAY';
1645 push(@{$attrs->{as}}, @$adds);
1648 $attrs->{from} ||= [ { 'me' => $source->from } ];
1650 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1651 my $join = delete $attrs->{join} || {};
1653 if (defined $attrs->{prefetch}) {
1654 $join = $self->_merge_attr(
1655 $join, $attrs->{prefetch}
1659 $attrs->{from} = # have to copy here to avoid corrupting the original
1662 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1666 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1667 if ($attrs->{order_by}) {
1668 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1669 ? [ @{$attrs->{order_by}} ]
1670 : [ $attrs->{order_by} ]);
1672 $attrs->{order_by} = [];
1675 my $collapse = $attrs->{collapse} || {};
1676 if (my $prefetch = delete $attrs->{prefetch}) {
1677 $prefetch = $self->_merge_attr({}, $prefetch);
1679 my $seen = $attrs->{seen_join} || {};
1680 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1681 # bring joins back to level of current class
1682 my @prefetch = $source->resolve_prefetch(
1683 $p, $alias, $seen, \@pre_order, $collapse
1685 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1686 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1688 push(@{$attrs->{order_by}}, @pre_order);
1690 $attrs->{collapse} = $collapse;
1692 return $self->{_attrs} = $attrs;
1696 my ($self, $a, $b) = @_;
1697 return $b unless defined($a);
1698 return $a unless defined($b);
1700 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1701 foreach my $key (keys %{$b}) {
1702 if (exists $a->{$key}) {
1703 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1705 $a->{$key} = $b->{$key};
1710 $a = [$a] unless ref $a eq 'ARRAY';
1711 $b = [$b] unless ref $b eq 'ARRAY';
1715 foreach my $x ($a, $b) {
1716 foreach my $element (@{$x}) {
1717 if (ref $element eq 'HASH') {
1718 $hash = $self->_merge_attr($hash, $element);
1719 } elsif (ref $element eq 'ARRAY') {
1720 push(@array, @{$element});
1722 push(@array, $element) unless $b == $x
1723 && grep { $_ eq $element } @array;
1728 @array = grep { !exists $hash->{$_} } @array;
1730 return keys %{$hash}
1739 =head2 throw_exception
1741 See L<DBIx::Class::Schema/throw_exception> for details.
1745 sub throw_exception {
1747 $self->result_source->schema->throw_exception(@_);
1750 # XXX: FIXME: Attributes docs need clearing up
1754 The resultset takes various attributes that modify its behavior. Here's an
1761 =item Value: ($order_by | \@order_by)
1765 Which column(s) to order the results by. This is currently passed
1766 through directly to SQL, so you can give e.g. C<year DESC> for a
1767 descending order on the column `year'.
1769 Please note that if you have quoting enabled (see
1770 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1771 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1772 so you will need to manually quote things as appropriate.)
1778 =item Value: \@columns
1782 Shortcut to request a particular set of columns to be retrieved. Adds
1783 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1784 from that, then auto-populates C<as> from C<select> as normal. (You may also
1785 use the C<cols> attribute, as in earlier versions of DBIC.)
1787 =head2 include_columns
1791 =item Value: \@columns
1795 Shortcut to include additional columns in the returned results - for example
1797 $schema->resultset('CD')->search(undef, {
1798 include_columns => ['artist.name'],
1802 would return all CDs and include a 'name' column to the information
1803 passed to object inflation
1809 =item Value: \@select_columns
1813 Indicates which columns should be selected from the storage. You can use
1814 column names, or in the case of RDBMS back ends, function or stored procedure
1817 $rs = $schema->resultset('Employee')->search(undef, {
1820 { count => 'employeeid' },
1825 When you use function/stored procedure names and do not supply an C<as>
1826 attribute, the column names returned are storage-dependent. E.g. MySQL would
1827 return a column named C<count(employeeid)> in the above example.
1833 Indicates additional columns to be selected from storage. Works the same as
1834 L<select> but adds columns to the selection.
1842 Indicates additional column names for those added via L<+select>.
1850 =item Value: \@inflation_names
1854 Indicates column names for object inflation. This is used in conjunction with
1855 C<select>, usually when C<select> contains one or more function or stored
1858 $rs = $schema->resultset('Employee')->search(undef, {
1861 { count => 'employeeid' }
1863 as => ['name', 'employee_count'],
1866 my $employee = $rs->first(); # get the first Employee
1868 If the object against which the search is performed already has an accessor
1869 matching a column name specified in C<as>, the value can be retrieved using
1870 the accessor as normal:
1872 my $name = $employee->name();
1874 If on the other hand an accessor does not exist in the object, you need to
1875 use C<get_column> instead:
1877 my $employee_count = $employee->get_column('employee_count');
1879 You can create your own accessors if required - see
1880 L<DBIx::Class::Manual::Cookbook> for details.
1882 Please note: This will NOT insert an C<AS employee_count> into the SQL
1883 statement produced, it is used for internal access only. Thus
1884 attempting to use the accessor in an C<order_by> clause or similar
1885 will fail miserably.
1887 To get around this limitation, you can supply literal SQL to your
1888 C<select> attibute that contains the C<AS alias> text, eg:
1890 select => [\'myfield AS alias']
1896 =item Value: ($rel_name | \@rel_names | \%rel_names)
1900 Contains a list of relationships that should be joined for this query. For
1903 # Get CDs by Nine Inch Nails
1904 my $rs = $schema->resultset('CD')->search(
1905 { 'artist.name' => 'Nine Inch Nails' },
1906 { join => 'artist' }
1909 Can also contain a hash reference to refer to the other relation's relations.
1912 package MyApp::Schema::Track;
1913 use base qw/DBIx::Class/;
1914 __PACKAGE__->table('track');
1915 __PACKAGE__->add_columns(qw/trackid cd position title/);
1916 __PACKAGE__->set_primary_key('trackid');
1917 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1920 # In your application
1921 my $rs = $schema->resultset('Artist')->search(
1922 { 'track.title' => 'Teardrop' },
1924 join => { cd => 'track' },
1925 order_by => 'artist.name',
1929 You need to use the relationship (not the table) name in conditions,
1930 because they are aliased as such. The current table is aliased as "me", so
1931 you need to use me.column_name in order to avoid ambiguity. For example:
1933 # Get CDs from 1984 with a 'Foo' track
1934 my $rs = $schema->resultset('CD')->search(
1937 'tracks.name' => 'Foo'
1939 { join => 'tracks' }
1942 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1943 similarly for a third time). For e.g.
1945 my $rs = $schema->resultset('Artist')->search({
1946 'cds.title' => 'Down to Earth',
1947 'cds_2.title' => 'Popular',
1949 join => [ qw/cds cds/ ],
1952 will return a set of all artists that have both a cd with title 'Down
1953 to Earth' and a cd with title 'Popular'.
1955 If you want to fetch related objects from other tables as well, see C<prefetch>
1962 =item Value: ($rel_name | \@rel_names | \%rel_names)
1966 Contains one or more relationships that should be fetched along with the main
1967 query (when they are accessed afterwards they will have already been
1968 "prefetched"). This is useful for when you know you will need the related
1969 objects, because it saves at least one query:
1971 my $rs = $schema->resultset('Tag')->search(
1980 The initial search results in SQL like the following:
1982 SELECT tag.*, cd.*, artist.* FROM tag
1983 JOIN cd ON tag.cd = cd.cdid
1984 JOIN artist ON cd.artist = artist.artistid
1986 L<DBIx::Class> has no need to go back to the database when we access the
1987 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1990 Simple prefetches will be joined automatically, so there is no need
1991 for a C<join> attribute in the above search. If you're prefetching to
1992 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1993 specify the join as well.
1995 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1996 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1997 with an accessor type of 'single' or 'filter').
2007 Makes the resultset paged and specifies the page to retrieve. Effectively
2008 identical to creating a non-pages resultset and then calling ->page($page)
2011 If L<rows> attribute is not specified it defualts to 10 rows per page.
2021 Specifes the maximum number of rows for direct retrieval or the number of
2022 rows per page if the page attribute or method is used.
2028 =item Value: $offset
2032 Specifies the (zero-based) row number for the first row to be returned, or the
2033 of the first row of the first page if paging is used.
2039 =item Value: \@columns
2043 A arrayref of columns to group by. Can include columns of joined tables.
2045 group_by => [qw/ column1 column2 ... /]
2051 =item Value: $condition
2055 HAVING is a select statement attribute that is applied between GROUP BY and
2056 ORDER BY. It is applied to the after the grouping calculations have been
2059 having => { 'count(employee)' => { '>=', 100 } }
2065 =item Value: (0 | 1)
2069 Set to 1 to group by all columns.
2075 Adds to the WHERE clause.
2077 # only return rows WHERE deleted IS NULL for all searches
2078 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2080 Can be overridden by passing C<{ where => undef }> as an attribute
2087 Set to 1 to cache search results. This prevents extra SQL queries if you
2088 revisit rows in your ResultSet:
2090 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2092 while( my $artist = $resultset->next ) {
2096 $rs->first; # without cache, this would issue a query
2098 By default, searches are not cached.
2100 For more examples of using these attributes, see
2101 L<DBIx::Class::Manual::Cookbook>.
2107 =item Value: \@from_clause
2111 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2112 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2115 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2117 C<join> will usually do what you need and it is strongly recommended that you
2118 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2119 And we really do mean "cannot", not just tried and failed. Attempting to use
2120 this because you're having problems with C<join> is like trying to use x86
2121 ASM because you've got a syntax error in your C. Trust us on this.
2123 Now, if you're still really, really sure you need to use this (and if you're
2124 not 100% sure, ask the mailing list first), here's an explanation of how this
2127 The syntax is as follows -
2130 { <alias1> => <table1> },
2132 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2133 [], # nested JOIN (optional)
2134 { <table1.column1> => <table2.column2>, ... (more conditions) },
2136 # More of the above [ ] may follow for additional joins
2143 ON <table1.column1> = <table2.column2>
2144 <more joins may follow>
2146 An easy way to follow the examples below is to remember the following:
2148 Anything inside "[]" is a JOIN
2149 Anything inside "{}" is a condition for the enclosing JOIN
2151 The following examples utilize a "person" table in a family tree application.
2152 In order to express parent->child relationships, this table is self-joined:
2154 # Person->belongs_to('father' => 'Person');
2155 # Person->belongs_to('mother' => 'Person');
2157 C<from> can be used to nest joins. Here we return all children with a father,
2158 then search against all mothers of those children:
2160 $rs = $schema->resultset('Person')->search(
2163 alias => 'mother', # alias columns in accordance with "from"
2165 { mother => 'person' },
2168 { child => 'person' },
2170 { father => 'person' },
2171 { 'father.person_id' => 'child.father_id' }
2174 { 'mother.person_id' => 'child.mother_id' }
2181 # SELECT mother.* FROM person mother
2184 # JOIN person father
2185 # ON ( father.person_id = child.father_id )
2187 # ON ( mother.person_id = child.mother_id )
2189 The type of any join can be controlled manually. To search against only people
2190 with a father in the person table, we could explicitly use C<INNER JOIN>:
2192 $rs = $schema->resultset('Person')->search(
2195 alias => 'child', # alias columns in accordance with "from"
2197 { child => 'person' },
2199 { father => 'person', -join_type => 'inner' },
2200 { 'father.id' => 'child.father_id' }
2207 # SELECT child.* FROM person child
2208 # INNER JOIN person father ON child.father_id = father.id