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}};
730 exists $self->{stashed_row}
731 ? @{delete $self->{stashed_row}}
732 : $self->cursor->next
734 return unless (@row);
735 my ($row, @more) = $self->_construct_object(@row);
736 $self->{stashed_objects} = \@more if @more;
740 sub _construct_object {
741 my ($self, @row) = @_;
742 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
743 my @new = $self->result_class->inflate_result($self->result_source, @$info);
744 @new = $self->{_attrs}{record_filter}->(@new)
745 if exists $self->{_attrs}{record_filter};
749 sub _collapse_result {
750 my ($self, $as, $row, $prefix) = @_;
755 foreach my $this_as (@$as) {
756 my $val = shift @copy;
757 if (defined $prefix) {
758 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
760 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
761 $const{$1||''}{$2} = $val;
764 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
765 $const{$1||''}{$2} = $val;
769 my $alias = $self->{attrs}{alias};
770 my $info = [ {}, {} ];
771 foreach my $key (keys %const) {
772 if (length $key && $key ne $alias) {
774 my @parts = split(/\./, $key);
775 foreach my $p (@parts) {
776 $target = $target->[1]->{$p} ||= [];
778 $target->[0] = $const{$key};
780 $info->[0] = $const{$key};
785 if (defined $prefix) {
787 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
788 } keys %{$self->{_attrs}{collapse}}
790 @collapse = keys %{$self->{_attrs}{collapse}};
794 my ($c) = sort { length $a <=> length $b } @collapse;
796 foreach my $p (split(/\./, $c)) {
797 $target = $target->[1]->{$p} ||= [];
799 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
800 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
801 my $tree = $self->_collapse_result($as, $row, $c_prefix);
802 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
808 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
813 last unless (@raw = $self->cursor->next);
814 $row = $self->{stashed_row} = \@raw;
815 $tree = $self->_collapse_result($as, $row, $c_prefix);
817 @$target = (@final ? @final : [ {}, {} ]);
818 # single empty result to indicate an empty prefetched has_many
821 #print "final info: " . Dumper($info);
829 =item Arguments: $result_source?
831 =item Return Value: $result_source
835 An accessor for the primary ResultSource object from which this ResultSet
842 =item Arguments: $result_class?
844 =item Return Value: $result_class
848 An accessor for the class to use when creating row objects. Defaults to
849 C<< result_source->result_class >> - which in most cases is the name of the
850 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
859 =item Arguments: $cond, \%attrs??
861 =item Return Value: $count
865 Performs an SQL C<COUNT> with the same query as the resultset was built
866 with to find the number of elements. If passed arguments, does a search
867 on the resultset and counts the results of that.
869 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
870 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
871 not support C<DISTINCT> with multiple columns. If you are using such a
872 database, you should only use columns from the main table in your C<group_by>
879 return $self->search(@_)->count if @_ and defined $_[0];
880 return scalar @{ $self->get_cache } if $self->get_cache;
881 my $count = $self->_count;
882 return 0 unless $count;
884 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
885 $count = $self->{attrs}{rows} if
886 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
890 sub _count { # Separated out so pager can get the full count
892 my $select = { count => '*' };
894 my $attrs = { %{$self->_resolved_attrs} };
895 if (my $group_by = delete $attrs->{group_by}) {
896 delete $attrs->{having};
897 my @distinct = (ref $group_by ? @$group_by : ($group_by));
898 # todo: try CONCAT for multi-column pk
899 my @pk = $self->result_source->primary_columns;
901 my $alias = $attrs->{alias};
902 foreach my $column (@distinct) {
903 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
904 @distinct = ($column);
910 $select = { count => { distinct => \@distinct } };
913 $attrs->{select} = $select;
914 $attrs->{as} = [qw/count/];
916 # offset, order by and page are not needed to count. record_filter is cdbi
917 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
919 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
920 my ($count) = $tmp_rs->cursor->next;
928 =item Arguments: $sql_fragment, @bind_values
930 =item Return Value: $count
934 Counts the results in a literal query. Equivalent to calling L</search_literal>
935 with the passed arguments, then L</count>.
939 sub count_literal { shift->search_literal(@_)->count; }
945 =item Arguments: none
947 =item Return Value: @objects
951 Returns all elements in the resultset. Called implicitly if the resultset
952 is returned in list context.
958 return @{ $self->get_cache } if $self->get_cache;
962 # TODO: don't call resolve here
963 if (keys %{$self->_resolved_attrs->{collapse}}) {
964 # if ($self->{attrs}{prefetch}) {
965 # Using $self->cursor->all is really just an optimisation.
966 # If we're collapsing has_many prefetches it probably makes
967 # very little difference, and this is cleaner than hacking
968 # _construct_object to survive the approach
969 my @row = $self->cursor->next;
971 push(@obj, $self->_construct_object(@row));
972 @row = (exists $self->{stashed_row}
973 ? @{delete $self->{stashed_row}}
974 : $self->cursor->next);
977 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
980 $self->set_cache(\@obj) if $self->{attrs}{cache};
988 =item Arguments: none
990 =item Return Value: $self
994 Resets the resultset's cursor, so you can iterate through the elements again.
1000 delete $self->{_attrs} if exists $self->{_attrs};
1001 $self->{all_cache_position} = 0;
1002 $self->cursor->reset;
1010 =item Arguments: none
1012 =item Return Value: $object?
1016 Resets the resultset and returns an object for the first result (if the
1017 resultset returns anything).
1022 return $_[0]->reset->next;
1025 # _cond_for_update_delete
1027 # update/delete require the condition to be modified to handle
1028 # the differing SQL syntax available. This transforms the $self->{cond}
1029 # appropriately, returning the new condition.
1031 sub _cond_for_update_delete {
1032 my ($self, $full_cond) = @_;
1035 $full_cond ||= $self->{cond};
1036 # No-op. No condition, we're updating/deleting everything
1037 return $cond unless ref $full_cond;
1039 if (ref $full_cond eq 'ARRAY') {
1043 foreach my $key (keys %{$_}) {
1045 $hash{$1} = $_->{$key};
1051 elsif (ref $full_cond eq 'HASH') {
1052 if ((keys %{$full_cond})[0] eq '-and') {
1055 my @cond = @{$full_cond->{-and}};
1056 for (my $i = 0; $i < @cond; $i++) {
1057 my $entry = $cond[$i];
1060 if (ref $entry eq 'HASH') {
1061 $hash = $self->_cond_for_update_delete($entry);
1064 $entry =~ /([^.]+)$/;
1065 $hash->{$1} = $cond[++$i];
1068 push @{$cond->{-and}}, $hash;
1072 foreach my $key (keys %{$full_cond}) {
1074 $cond->{$1} = $full_cond->{$key};
1079 $self->throw_exception(
1080 "Can't update/delete on resultset with condition unless hash or array"
1092 =item Arguments: \%values
1094 =item Return Value: $storage_rv
1098 Sets the specified columns in the resultset to the supplied values in a
1099 single query. Return value will be true if the update succeeded or false
1100 if no records were updated; exact type of success value is storage-dependent.
1105 my ($self, $values) = @_;
1106 $self->throw_exception("Values for update must be a hash")
1107 unless ref $values eq 'HASH';
1109 my $cond = $self->_cond_for_update_delete;
1111 return $self->result_source->storage->update(
1112 $self->result_source->from, $values, $cond
1120 =item Arguments: \%values
1122 =item Return Value: 1
1126 Fetches all objects and updates them one at a time. Note that C<update_all>
1127 will run DBIC cascade triggers, while L</update> will not.
1132 my ($self, $values) = @_;
1133 $self->throw_exception("Values for update must be a hash")
1134 unless ref $values eq 'HASH';
1135 foreach my $obj ($self->all) {
1136 $obj->set_columns($values)->update;
1145 =item Arguments: none
1147 =item Return Value: 1
1151 Deletes the contents of the resultset from its result source. Note that this
1152 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1153 to run. See also L<DBIx::Class::Row/delete>.
1160 my $cond = $self->_cond_for_update_delete;
1162 $self->result_source->storage->delete($self->result_source->from, $cond);
1170 =item Arguments: none
1172 =item Return Value: 1
1176 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1177 will run DBIC cascade triggers, while L</delete> will not.
1183 $_->delete for $self->all;
1191 =item Arguments: none
1193 =item Return Value: $pager
1197 Return Value a L<Data::Page> object for the current resultset. Only makes
1198 sense for queries with a C<page> attribute.
1204 my $attrs = $self->{attrs};
1205 $self->throw_exception("Can't create pager for non-paged rs")
1206 unless $self->{attrs}{page};
1207 $attrs->{rows} ||= 10;
1208 return $self->{pager} ||= Data::Page->new(
1209 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1216 =item Arguments: $page_number
1218 =item Return Value: $rs
1222 Returns a resultset for the $page_number page of the resultset on which page
1223 is called, where each page contains a number of rows equal to the 'rows'
1224 attribute set on the resultset (10 by default).
1229 my ($self, $page) = @_;
1230 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1237 =item Arguments: \%vals
1239 =item Return Value: $object
1243 Creates an object in the resultset's result class and returns it.
1248 my ($self, $values) = @_;
1249 $self->throw_exception( "new_result needs a hash" )
1250 unless (ref $values eq 'HASH');
1251 $self->throw_exception(
1252 "Can't abstract implicit construct, condition not a hash"
1253 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1255 my $alias = $self->{attrs}{alias};
1256 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1258 %{ $self->_remove_alias($values, $alias) },
1259 %{ $self->_remove_alias($collapsed_cond, $alias) },
1260 -result_source => $self->result_source,
1263 my $obj = $self->result_class->new(\%new);
1269 # Recursively collapse the condition.
1271 sub _collapse_cond {
1272 my ($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->result_source->name .
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 $self->result_source->schema->resultset($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}
1740 =head2 throw_exception
1742 See L<DBIx::Class::Schema/throw_exception> for details.
1746 sub throw_exception {
1748 $self->result_source->schema->throw_exception(@_);
1751 # XXX: FIXME: Attributes docs need clearing up
1755 The resultset takes various attributes that modify its behavior. Here's an
1762 =item Value: ($order_by | \@order_by)
1766 Which column(s) to order the results by. This is currently passed
1767 through directly to SQL, so you can give e.g. C<year DESC> for a
1768 descending order on the column `year'.
1770 Please note that if you have quoting enabled (see
1771 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1772 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1773 so you will need to manually quote things as appropriate.)
1779 =item Value: \@columns
1783 Shortcut to request a particular set of columns to be retrieved. Adds
1784 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1785 from that, then auto-populates C<as> from C<select> as normal. (You may also
1786 use the C<cols> attribute, as in earlier versions of DBIC.)
1788 =head2 include_columns
1792 =item Value: \@columns
1796 Shortcut to include additional columns in the returned results - for example
1798 $schema->resultset('CD')->search(undef, {
1799 include_columns => ['artist.name'],
1803 would return all CDs and include a 'name' column to the information
1804 passed to object inflation
1810 =item Value: \@select_columns
1814 Indicates which columns should be selected from the storage. You can use
1815 column names, or in the case of RDBMS back ends, function or stored procedure
1818 $rs = $schema->resultset('Employee')->search(undef, {
1821 { count => 'employeeid' },
1826 When you use function/stored procedure names and do not supply an C<as>
1827 attribute, the column names returned are storage-dependent. E.g. MySQL would
1828 return a column named C<count(employeeid)> in the above example.
1834 Indicates additional columns to be selected from storage. Works the same as
1835 L<select> but adds columns to the selection.
1843 Indicates additional column names for those added via L<+select>.
1851 =item Value: \@inflation_names
1855 Indicates column names for object inflation. This is used in conjunction with
1856 C<select>, usually when C<select> contains one or more function or stored
1859 $rs = $schema->resultset('Employee')->search(undef, {
1862 { count => 'employeeid' }
1864 as => ['name', 'employee_count'],
1867 my $employee = $rs->first(); # get the first Employee
1869 If the object against which the search is performed already has an accessor
1870 matching a column name specified in C<as>, the value can be retrieved using
1871 the accessor as normal:
1873 my $name = $employee->name();
1875 If on the other hand an accessor does not exist in the object, you need to
1876 use C<get_column> instead:
1878 my $employee_count = $employee->get_column('employee_count');
1880 You can create your own accessors if required - see
1881 L<DBIx::Class::Manual::Cookbook> for details.
1883 Please note: This will NOT insert an C<AS employee_count> into the SQL
1884 statement produced, it is used for internal access only. Thus
1885 attempting to use the accessor in an C<order_by> clause or similar
1886 will fail miserably.
1888 To get around this limitation, you can supply literal SQL to your
1889 C<select> attibute that contains the C<AS alias> text, eg:
1891 select => [\'myfield AS alias']
1897 =item Value: ($rel_name | \@rel_names | \%rel_names)
1901 Contains a list of relationships that should be joined for this query. For
1904 # Get CDs by Nine Inch Nails
1905 my $rs = $schema->resultset('CD')->search(
1906 { 'artist.name' => 'Nine Inch Nails' },
1907 { join => 'artist' }
1910 Can also contain a hash reference to refer to the other relation's relations.
1913 package MyApp::Schema::Track;
1914 use base qw/DBIx::Class/;
1915 __PACKAGE__->table('track');
1916 __PACKAGE__->add_columns(qw/trackid cd position title/);
1917 __PACKAGE__->set_primary_key('trackid');
1918 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1921 # In your application
1922 my $rs = $schema->resultset('Artist')->search(
1923 { 'track.title' => 'Teardrop' },
1925 join => { cd => 'track' },
1926 order_by => 'artist.name',
1930 You need to use the relationship (not the table) name in conditions,
1931 because they are aliased as such. The current table is aliased as "me", so
1932 you need to use me.column_name in order to avoid ambiguity. For example:
1934 # Get CDs from 1984 with a 'Foo' track
1935 my $rs = $schema->resultset('CD')->search(
1938 'tracks.name' => 'Foo'
1940 { join => 'tracks' }
1943 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1944 similarly for a third time). For e.g.
1946 my $rs = $schema->resultset('Artist')->search({
1947 'cds.title' => 'Down to Earth',
1948 'cds_2.title' => 'Popular',
1950 join => [ qw/cds cds/ ],
1953 will return a set of all artists that have both a cd with title 'Down
1954 to Earth' and a cd with title 'Popular'.
1956 If you want to fetch related objects from other tables as well, see C<prefetch>
1963 =item Value: ($rel_name | \@rel_names | \%rel_names)
1967 Contains one or more relationships that should be fetched along with the main
1968 query (when they are accessed afterwards they will have already been
1969 "prefetched"). This is useful for when you know you will need the related
1970 objects, because it saves at least one query:
1972 my $rs = $schema->resultset('Tag')->search(
1981 The initial search results in SQL like the following:
1983 SELECT tag.*, cd.*, artist.* FROM tag
1984 JOIN cd ON tag.cd = cd.cdid
1985 JOIN artist ON cd.artist = artist.artistid
1987 L<DBIx::Class> has no need to go back to the database when we access the
1988 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1991 Simple prefetches will be joined automatically, so there is no need
1992 for a C<join> attribute in the above search. If you're prefetching to
1993 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1994 specify the join as well.
1996 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1997 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1998 with an accessor type of 'single' or 'filter').
2008 Makes the resultset paged and specifies the page to retrieve. Effectively
2009 identical to creating a non-pages resultset and then calling ->page($page)
2012 If L<rows> attribute is not specified it defualts to 10 rows per page.
2022 Specifes the maximum number of rows for direct retrieval or the number of
2023 rows per page if the page attribute or method is used.
2029 =item Value: $offset
2033 Specifies the (zero-based) row number for the first row to be returned, or the
2034 of the first row of the first page if paging is used.
2040 =item Value: \@columns
2044 A arrayref of columns to group by. Can include columns of joined tables.
2046 group_by => [qw/ column1 column2 ... /]
2052 =item Value: $condition
2056 HAVING is a select statement attribute that is applied between GROUP BY and
2057 ORDER BY. It is applied to the after the grouping calculations have been
2060 having => { 'count(employee)' => { '>=', 100 } }
2066 =item Value: (0 | 1)
2070 Set to 1 to group by all columns.
2076 Adds to the WHERE clause.
2078 # only return rows WHERE deleted IS NULL for all searches
2079 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2081 Can be overridden by passing C<{ where => undef }> as an attribute
2088 Set to 1 to cache search results. This prevents extra SQL queries if you
2089 revisit rows in your ResultSet:
2091 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2093 while( my $artist = $resultset->next ) {
2097 $rs->first; # without cache, this would issue a query
2099 By default, searches are not cached.
2101 For more examples of using these attributes, see
2102 L<DBIx::Class::Manual::Cookbook>.
2108 =item Value: \@from_clause
2112 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2113 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2116 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2118 C<join> will usually do what you need and it is strongly recommended that you
2119 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2120 And we really do mean "cannot", not just tried and failed. Attempting to use
2121 this because you're having problems with C<join> is like trying to use x86
2122 ASM because you've got a syntax error in your C. Trust us on this.
2124 Now, if you're still really, really sure you need to use this (and if you're
2125 not 100% sure, ask the mailing list first), here's an explanation of how this
2128 The syntax is as follows -
2131 { <alias1> => <table1> },
2133 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2134 [], # nested JOIN (optional)
2135 { <table1.column1> => <table2.column2>, ... (more conditions) },
2137 # More of the above [ ] may follow for additional joins
2144 ON <table1.column1> = <table2.column2>
2145 <more joins may follow>
2147 An easy way to follow the examples below is to remember the following:
2149 Anything inside "[]" is a JOIN
2150 Anything inside "{}" is a condition for the enclosing JOIN
2152 The following examples utilize a "person" table in a family tree application.
2153 In order to express parent->child relationships, this table is self-joined:
2155 # Person->belongs_to('father' => 'Person');
2156 # Person->belongs_to('mother' => 'Person');
2158 C<from> can be used to nest joins. Here we return all children with a father,
2159 then search against all mothers of those children:
2161 $rs = $schema->resultset('Person')->search(
2164 alias => 'mother', # alias columns in accordance with "from"
2166 { mother => 'person' },
2169 { child => 'person' },
2171 { father => 'person' },
2172 { 'father.person_id' => 'child.father_id' }
2175 { 'mother.person_id' => 'child.mother_id' }
2182 # SELECT mother.* FROM person mother
2185 # JOIN person father
2186 # ON ( father.person_id = child.father_id )
2188 # ON ( mother.person_id = child.mother_id )
2190 The type of any join can be controlled manually. To search against only people
2191 with a father in the person table, we could explicitly use C<INNER JOIN>:
2193 $rs = $schema->resultset('Person')->search(
2196 alias => 'child', # alias columns in accordance with "from"
2198 { child => 'person' },
2200 { father => 'person', -join_type => 'inner' },
2201 { 'father.id' => 'child.father_id' }
2208 # SELECT child.* FROM person child
2209 # INNER JOIN person father ON child.father_id = father.id