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__->mk_group_accessors('simple' => qw/result_source result_class/);
19 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
23 my $rs = $schema->resultset('User')->search(registered => 1);
24 my @rows = $schema->resultset('CD')->search(year => 2005);
28 The resultset is also known as an iterator. It is responsible for handling
29 queries that may return an arbitrary number of rows, e.g. via L</search>
30 or a C<has_many> relationship.
32 In the examples below, the following table classes are used:
34 package MyApp::Schema::Artist;
35 use base qw/DBIx::Class/;
36 __PACKAGE__->load_components(qw/Core/);
37 __PACKAGE__->table('artist');
38 __PACKAGE__->add_columns(qw/artistid name/);
39 __PACKAGE__->set_primary_key('artistid');
40 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
43 package MyApp::Schema::CD;
44 use base qw/DBIx::Class/;
45 __PACKAGE__->load_components(qw/Core/);
46 __PACKAGE__->table('cd');
47 __PACKAGE__->add_columns(qw/cdid artist title year/);
48 __PACKAGE__->set_primary_key('cdid');
49 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
58 =item Arguments: $source, \%$attrs
60 =item Return Value: $rs
64 The resultset constructor. Takes a source object (usually a
65 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
66 L</ATTRIBUTES> below). Does not perform any queries -- these are
67 executed as needed by the other methods.
69 Generally you won't need to construct a resultset manually. You'll
70 automatically get one from e.g. a L</search> called in scalar context:
72 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
74 IMPORTANT: If called on an object, proxies to new_result instead so
76 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
78 will return a CD object, not a ResultSet.
84 return $class->new_result(@_) if ref $class;
86 my ($source, $attrs) = @_;
88 $attrs = { %{$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;
411 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
412 my $num_where = scalar keys %$where;
415 foreach my $name (@constraint_names) {
416 my @unique_cols = $self->result_source->unique_constraint_columns($name);
417 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
419 my $num_cols = scalar @unique_cols;
420 my $num_query = scalar keys %$unique_query;
422 my $total = $num_query + $num_where;
423 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
424 # The query is either unique on its own or is unique in combination with
425 # the existing where clause
426 push @unique_queries, $unique_query;
430 return @unique_queries;
433 # _build_unique_query
435 # Constrain the specified query hash based on the specified column names.
437 sub _build_unique_query {
438 my ($self, $query, $unique_cols) = @_;
441 map { $_ => $query->{$_} }
442 grep { exists $query->{$_} }
447 =head2 search_related
451 =item Arguments: $rel, $cond, \%attrs?
453 =item Return Value: $new_resultset
457 $new_rs = $cd_rs->search_related('artist', {
461 Searches the specified relationship, optionally specifying a condition and
462 attributes for matching records. See L</ATTRIBUTES> for more information.
467 return shift->related_resultset(shift)->search(@_);
474 =item Arguments: none
476 =item Return Value: $cursor
480 Returns a storage-driven cursor to the given resultset. See
481 L<DBIx::Class::Cursor> for more information.
488 my $attrs = { %{$self->_resolved_attrs} };
489 return $self->{cursor}
490 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
491 $attrs->{where},$attrs);
498 =item Arguments: $cond?
500 =item Return Value: $row_object?
504 my $cd = $schema->resultset('CD')->single({ year => 2001 });
506 Inflates the first result without creating a cursor if the resultset has
507 any records in it; if not returns nothing. Used by L</find> as an optimisation.
509 Can optionally take an additional condition *only* - this is a fast-code-path
510 method; if you need to add extra joins or similar call ->search and then
511 ->single without a condition on the $rs returned from that.
516 my ($self, $where) = @_;
517 my $attrs = { %{$self->_resolved_attrs} };
519 if (defined $attrs->{where}) {
522 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
523 $where, delete $attrs->{where} ]
526 $attrs->{where} = $where;
530 # XXX: Disabled since it doesn't infer uniqueness in all cases
531 # unless ($self->_is_unique_query($attrs->{where})) {
532 # carp "Query not guaranteed to return a single row"
533 # . "; please declare your unique constraints or use search instead";
536 my @data = $self->result_source->storage->select_single(
537 $attrs->{from}, $attrs->{select},
538 $attrs->{where}, $attrs
541 return (@data ? ($self->_construct_object(@data))[0] : ());
546 # Try to determine if the specified query is guaranteed to be unique, based on
547 # the declared unique constraints.
549 sub _is_unique_query {
550 my ($self, $query) = @_;
552 my $collapsed = $self->_collapse_query($query);
553 my $alias = $self->{attrs}{alias};
555 foreach my $name ($self->result_source->unique_constraint_names) {
556 my @unique_cols = map {
558 } $self->result_source->unique_constraint_columns($name);
560 # Count the values for each unique column
561 my %seen = map { $_ => 0 } @unique_cols;
563 foreach my $key (keys %$collapsed) {
564 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
565 next unless exists $seen{$aliased}; # Additional constraints are okay
566 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
569 # If we get 0 or more than 1 value for a column, it's not necessarily unique
570 return 1 unless grep { $_ != 1 } values %seen;
578 # Recursively collapse the query, accumulating values for each column.
580 sub _collapse_query {
581 my ($self, $query, $collapsed) = @_;
585 if (ref $query eq 'ARRAY') {
586 foreach my $subquery (@$query) {
587 next unless ref $subquery; # -or
588 # warn "ARRAY: " . Dumper $subquery;
589 $collapsed = $self->_collapse_query($subquery, $collapsed);
592 elsif (ref $query eq 'HASH') {
593 if (keys %$query and (keys %$query)[0] eq '-and') {
594 foreach my $subquery (@{$query->{-and}}) {
595 # warn "HASH: " . Dumper $subquery;
596 $collapsed = $self->_collapse_query($subquery, $collapsed);
600 # warn "LEAF: " . Dumper $query;
601 foreach my $col (keys %$query) {
602 my $value = $query->{$col};
603 $collapsed->{$col}{$value}++;
615 =item Arguments: $cond?
617 =item Return Value: $resultsetcolumn
621 my $max_length = $rs->get_column('length')->max;
623 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
628 my ($self, $column) = @_;
629 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
637 =item Arguments: $cond, \%attrs?
639 =item Return Value: $resultset (scalar context), @row_objs (list context)
643 # WHERE title LIKE '%blue%'
644 $cd_rs = $rs->search_like({ title => '%blue%'});
646 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
647 that this is simply a convenience method. You most likely want to use
648 L</search> with specific operators.
650 For more information, see L<DBIx::Class::Manual::Cookbook>.
656 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
657 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
658 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
659 return $class->search($query, { %$attrs });
666 =item Arguments: $first, $last
668 =item Return Value: $resultset (scalar context), @row_objs (list context)
672 Returns a resultset or object list representing a subset of elements from the
673 resultset slice is called on. Indexes are from 0, i.e., to get the first
676 my ($one, $two, $three) = $rs->slice(0, 2);
681 my ($self, $min, $max) = @_;
682 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
683 $attrs->{offset} = $self->{attrs}{offset} || 0;
684 $attrs->{offset} += $min;
685 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
686 return $self->search(undef(), $attrs);
687 #my $slice = (ref $self)->new($self->result_source, $attrs);
688 #return (wantarray ? $slice->all : $slice);
695 =item Arguments: none
697 =item Return Value: $result?
701 Returns the next element in the resultset (C<undef> is there is none).
703 Can be used to efficiently iterate over records in the resultset:
705 my $rs = $schema->resultset('CD')->search;
706 while (my $cd = $rs->next) {
710 Note that you need to store the resultset object, and call C<next> on it.
711 Calling C<< resultset('Table')->next >> repeatedly will always return the
712 first record from the resultset.
718 if (my $cache = $self->get_cache) {
719 $self->{all_cache_position} ||= 0;
720 return $cache->[$self->{all_cache_position}++];
722 if ($self->{attrs}{cache}) {
723 $self->{all_cache_position} = 1;
724 return ($self->all)[0];
726 if ($self->{stashed_objects}) {
727 my $obj = shift(@{$self->{stashed_objects}});
728 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
732 exists $self->{stashed_row}
733 ? @{delete $self->{stashed_row}}
734 : $self->cursor->next
736 return unless (@row);
737 my ($row, @more) = $self->_construct_object(@row);
738 $self->{stashed_objects} = \@more if @more;
742 sub _construct_object {
743 my ($self, @row) = @_;
744 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
745 my @new = $self->result_class->inflate_result($self->result_source, @$info);
746 @new = $self->{_attrs}{record_filter}->(@new)
747 if exists $self->{_attrs}{record_filter};
751 sub _collapse_result {
752 my ($self, $as, $row, $prefix) = @_;
757 foreach my $this_as (@$as) {
758 my $val = shift @copy;
759 if (defined $prefix) {
760 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
762 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
763 $const{$1||''}{$2} = $val;
766 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
767 $const{$1||''}{$2} = $val;
771 my $alias = $self->{attrs}{alias};
772 my $info = [ {}, {} ];
773 foreach my $key (keys %const) {
774 if (length $key && $key ne $alias) {
776 my @parts = split(/\./, $key);
777 foreach my $p (@parts) {
778 $target = $target->[1]->{$p} ||= [];
780 $target->[0] = $const{$key};
782 $info->[0] = $const{$key};
787 if (defined $prefix) {
789 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
790 } keys %{$self->{_attrs}{collapse}}
792 @collapse = keys %{$self->{_attrs}{collapse}};
796 my ($c) = sort { length $a <=> length $b } @collapse;
798 foreach my $p (split(/\./, $c)) {
799 $target = $target->[1]->{$p} ||= [];
801 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
802 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
803 my $tree = $self->_collapse_result($as, $row, $c_prefix);
804 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
810 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
815 last unless (@raw = $self->cursor->next);
816 $row = $self->{stashed_row} = \@raw;
817 $tree = $self->_collapse_result($as, $row, $c_prefix);
819 @$target = (@final ? @final : [ {}, {} ]);
820 # single empty result to indicate an empty prefetched has_many
823 #print "final info: " . Dumper($info);
831 =item Arguments: $result_source?
833 =item Return Value: $result_source
837 An accessor for the primary ResultSource object from which this ResultSet
844 =item Arguments: $result_class?
846 =item Return Value: $result_class
850 An accessor for the class to use when creating row objects. Defaults to
851 C<< result_source->result_class >> - which in most cases is the name of the
852 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
861 =item Arguments: $cond, \%attrs??
863 =item Return Value: $count
867 Performs an SQL C<COUNT> with the same query as the resultset was built
868 with to find the number of elements. If passed arguments, does a search
869 on the resultset and counts the results of that.
871 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
872 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
873 not support C<DISTINCT> with multiple columns. If you are using such a
874 database, you should only use columns from the main table in your C<group_by>
881 return $self->search(@_)->count if @_ and defined $_[0];
882 return scalar @{ $self->get_cache } if $self->get_cache;
883 my $count = $self->_count;
884 return 0 unless $count;
886 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
887 $count = $self->{attrs}{rows} if
888 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
892 sub _count { # Separated out so pager can get the full count
894 my $select = { count => '*' };
896 my $attrs = { %{$self->_resolved_attrs} };
897 if (my $group_by = delete $attrs->{group_by}) {
898 delete $attrs->{having};
899 my @distinct = (ref $group_by ? @$group_by : ($group_by));
900 # todo: try CONCAT for multi-column pk
901 my @pk = $self->result_source->primary_columns;
903 my $alias = $attrs->{alias};
904 foreach my $column (@distinct) {
905 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
906 @distinct = ($column);
912 $select = { count => { distinct => \@distinct } };
915 $attrs->{select} = $select;
916 $attrs->{as} = [qw/count/];
918 # offset, order by and page are not needed to count. record_filter is cdbi
919 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
921 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
922 my ($count) = $tmp_rs->cursor->next;
930 =item Arguments: $sql_fragment, @bind_values
932 =item Return Value: $count
936 Counts the results in a literal query. Equivalent to calling L</search_literal>
937 with the passed arguments, then L</count>.
941 sub count_literal { shift->search_literal(@_)->count; }
947 =item Arguments: none
949 =item Return Value: @objects
953 Returns all elements in the resultset. Called implicitly if the resultset
954 is returned in list context.
960 return @{ $self->get_cache } if $self->get_cache;
964 # TODO: don't call resolve here
965 if (keys %{$self->_resolved_attrs->{collapse}}) {
966 # if ($self->{attrs}{prefetch}) {
967 # Using $self->cursor->all is really just an optimisation.
968 # If we're collapsing has_many prefetches it probably makes
969 # very little difference, and this is cleaner than hacking
970 # _construct_object to survive the approach
971 my @row = $self->cursor->next;
973 push(@obj, $self->_construct_object(@row));
974 @row = (exists $self->{stashed_row}
975 ? @{delete $self->{stashed_row}}
976 : $self->cursor->next);
979 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
982 $self->set_cache(\@obj) if $self->{attrs}{cache};
990 =item Arguments: none
992 =item Return Value: $self
996 Resets the resultset's cursor, so you can iterate through the elements again.
1002 delete $self->{_attrs} if exists $self->{_attrs};
1003 $self->{all_cache_position} = 0;
1004 $self->cursor->reset;
1012 =item Arguments: none
1014 =item Return Value: $object?
1018 Resets the resultset and returns an object for the first result (if the
1019 resultset returns anything).
1024 return $_[0]->reset->next;
1027 # _cond_for_update_delete
1029 # update/delete require the condition to be modified to handle
1030 # the differing SQL syntax available. This transforms the $self->{cond}
1031 # appropriately, returning the new condition.
1033 sub _cond_for_update_delete {
1034 my ($self, $full_cond) = @_;
1037 $full_cond ||= $self->{cond};
1038 # No-op. No condition, we're updating/deleting everything
1039 return $cond unless ref $full_cond;
1041 if (ref $full_cond eq 'ARRAY') {
1045 foreach my $key (keys %{$_}) {
1047 $hash{$1} = $_->{$key};
1053 elsif (ref $full_cond eq 'HASH') {
1054 if ((keys %{$full_cond})[0] eq '-and') {
1057 my @cond = @{$full_cond->{-and}};
1058 for (my $i = 0; $i < @cond; $i++) {
1059 my $entry = $cond[$i];
1062 if (ref $entry eq 'HASH') {
1063 $hash = $self->_cond_for_update_delete($entry);
1066 $entry =~ /([^.]+)$/;
1067 $hash->{$1} = $cond[++$i];
1070 push @{$cond->{-and}}, $hash;
1074 foreach my $key (keys %{$full_cond}) {
1076 $cond->{$1} = $full_cond->{$key};
1081 $self->throw_exception(
1082 "Can't update/delete on resultset with condition unless hash or array"
1094 =item Arguments: \%values
1096 =item Return Value: $storage_rv
1100 Sets the specified columns in the resultset to the supplied values in a
1101 single query. Return value will be true if the update succeeded or false
1102 if no records were updated; exact type of success value is storage-dependent.
1107 my ($self, $values) = @_;
1108 $self->throw_exception("Values for update must be a hash")
1109 unless ref $values eq 'HASH';
1111 my $cond = $self->_cond_for_update_delete;
1113 return $self->result_source->storage->update(
1114 $self->result_source->from, $values, $cond
1122 =item Arguments: \%values
1124 =item Return Value: 1
1128 Fetches all objects and updates them one at a time. Note that C<update_all>
1129 will run DBIC cascade triggers, while L</update> will not.
1134 my ($self, $values) = @_;
1135 $self->throw_exception("Values for update must be a hash")
1136 unless ref $values eq 'HASH';
1137 foreach my $obj ($self->all) {
1138 $obj->set_columns($values)->update;
1147 =item Arguments: none
1149 =item Return Value: 1
1153 Deletes the contents of the resultset from its result source. Note that this
1154 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1155 to run. See also L<DBIx::Class::Row/delete>.
1162 my $cond = $self->_cond_for_update_delete;
1164 $self->result_source->storage->delete($self->result_source->from, $cond);
1172 =item Arguments: none
1174 =item Return Value: 1
1178 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1179 will run DBIC cascade triggers, while L</delete> will not.
1185 $_->delete for $self->all;
1193 =item Arguments: none
1195 =item Return Value: $pager
1199 Return Value a L<Data::Page> object for the current resultset. Only makes
1200 sense for queries with a C<page> attribute.
1206 my $attrs = $self->{attrs};
1207 $self->throw_exception("Can't create pager for non-paged rs")
1208 unless $self->{attrs}{page};
1209 $attrs->{rows} ||= 10;
1210 return $self->{pager} ||= Data::Page->new(
1211 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1218 =item Arguments: $page_number
1220 =item Return Value: $rs
1224 Returns a resultset for the $page_number page of the resultset on which page
1225 is called, where each page contains a number of rows equal to the 'rows'
1226 attribute set on the resultset (10 by default).
1231 my ($self, $page) = @_;
1232 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1239 =item Arguments: \%vals
1241 =item Return Value: $object
1245 Creates an object in the resultset's result class and returns it.
1250 my ($self, $values) = @_;
1251 $self->throw_exception( "new_result needs a hash" )
1252 unless (ref $values eq 'HASH');
1253 $self->throw_exception(
1254 "Can't abstract implicit construct, condition not a hash"
1255 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1257 my $alias = $self->{attrs}{alias};
1258 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1260 %{ $self->_remove_alias($values, $alias) },
1261 %{ $self->_remove_alias($collapsed_cond, $alias) },
1262 -result_source => $self->result_source,
1265 my $obj = $self->result_class->new(\%new);
1271 # Recursively collapse the condition.
1273 sub _collapse_cond {
1274 my ($self, $cond, $collapsed) = @_;
1278 if (ref $cond eq 'ARRAY') {
1279 foreach my $subcond (@$cond) {
1280 next unless ref $subcond; # -or
1281 # warn "ARRAY: " . Dumper $subcond;
1282 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1285 elsif (ref $cond eq 'HASH') {
1286 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1287 foreach my $subcond (@{$cond->{-and}}) {
1288 # warn "HASH: " . Dumper $subcond;
1289 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1293 # warn "LEAF: " . Dumper $cond;
1294 foreach my $col (keys %$cond) {
1295 my $value = $cond->{$col};
1296 $collapsed->{$col} = $value;
1306 # Remove the specified alias from the specified query hash. A copy is made so
1307 # the original query is not modified.
1310 my ($self, $query, $alias) = @_;
1312 my %orig = %{ $query || {} };
1315 foreach my $key (keys %orig) {
1317 $unaliased{$key} = $orig{$key};
1320 $unaliased{$1} = $orig{$key}
1321 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1331 =item Arguments: \%vals, \%attrs?
1333 =item Return Value: $object
1337 Find an existing record from this resultset. If none exists, instantiate a new
1338 result object and return it. The object will not be saved into your storage
1339 until you call L<DBIx::Class::Row/insert> on it.
1341 If you want objects to be saved immediately, use L</find_or_create> instead.
1347 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1348 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1349 my $exists = $self->find($hash, $attrs);
1350 return defined $exists ? $exists : $self->new_result($hash);
1357 =item Arguments: \%vals
1359 =item Return Value: $object
1363 Inserts a record into the resultset and returns the object representing it.
1365 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1370 my ($self, $attrs) = @_;
1371 $self->throw_exception( "create needs a hashref" )
1372 unless ref $attrs eq 'HASH';
1373 return $self->new_result($attrs)->insert;
1376 =head2 find_or_create
1380 =item Arguments: \%vals, \%attrs?
1382 =item Return Value: $object
1386 $class->find_or_create({ key => $val, ... });
1388 Tries to find a record based on its primary key or unique constraint; if none
1389 is found, creates one and returns that instead.
1391 my $cd = $schema->resultset('CD')->find_or_create({
1393 artist => 'Massive Attack',
1394 title => 'Mezzanine',
1398 Also takes an optional C<key> attribute, to search by a specific key or unique
1399 constraint. For example:
1401 my $cd = $schema->resultset('CD')->find_or_create(
1403 artist => 'Massive Attack',
1404 title => 'Mezzanine',
1406 { key => 'cd_artist_title' }
1409 See also L</find> and L</update_or_create>. For information on how to declare
1410 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1414 sub find_or_create {
1416 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1417 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1418 my $exists = $self->find($hash, $attrs);
1419 return defined $exists ? $exists : $self->create($hash);
1422 =head2 update_or_create
1426 =item Arguments: \%col_values, { key => $unique_constraint }?
1428 =item Return Value: $object
1432 $class->update_or_create({ col => $val, ... });
1434 First, searches for an existing row matching one of the unique constraints
1435 (including the primary key) on the source of this resultset. If a row is
1436 found, updates it with the other given column values. Otherwise, creates a new
1439 Takes an optional C<key> attribute to search on a specific unique constraint.
1442 # In your application
1443 my $cd = $schema->resultset('CD')->update_or_create(
1445 artist => 'Massive Attack',
1446 title => 'Mezzanine',
1449 { key => 'cd_artist_title' }
1452 If no C<key> is specified, it searches on all unique constraints defined on the
1453 source, including the primary key.
1455 If the C<key> is specified as C<primary>, it searches only on the primary key.
1457 See also L</find> and L</find_or_create>. For information on how to declare
1458 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1462 sub update_or_create {
1464 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1465 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1467 my $row = $self->find($cond, $attrs);
1469 $row->update($cond);
1473 return $self->create($cond);
1480 =item Arguments: none
1482 =item Return Value: \@cache_objects?
1486 Gets the contents of the cache for the resultset, if the cache is set.
1498 =item Arguments: \@cache_objects
1500 =item Return Value: \@cache_objects
1504 Sets the contents of the cache for the resultset. Expects an arrayref
1505 of objects of the same class as those produced by the resultset. Note that
1506 if the cache is set the resultset will return the cached objects rather
1507 than re-querying the database even if the cache attr is not set.
1512 my ( $self, $data ) = @_;
1513 $self->throw_exception("set_cache requires an arrayref")
1514 if defined($data) && (ref $data ne 'ARRAY');
1515 $self->{all_cache} = $data;
1522 =item Arguments: none
1524 =item Return Value: []
1528 Clears the cache for the resultset.
1533 shift->set_cache(undef);
1536 =head2 related_resultset
1540 =item Arguments: $relationship_name
1542 =item Return Value: $resultset
1546 Returns a related resultset for the supplied relationship name.
1548 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1552 sub related_resultset {
1553 my ($self, $rel) = @_;
1555 $self->{related_resultsets} ||= {};
1556 return $self->{related_resultsets}{$rel} ||= do {
1557 my $rel_obj = $self->result_source->relationship_info($rel);
1559 $self->throw_exception(
1560 "search_related: result source '" . $self->result_source->name .
1561 "' has no such relationship $rel")
1564 my ($from,$seen) = $self->_resolve_from($rel);
1566 my $join_count = $seen->{$rel};
1567 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1569 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1571 %{$self->{attrs}||{}},
1577 where => $self->{cond},
1585 my ($self, $extra_join) = @_;
1586 my $source = $self->result_source;
1587 my $attrs = $self->{attrs};
1589 my $from = $attrs->{from}
1590 || [ { $attrs->{alias} => $source->from } ];
1592 my $seen = { %{$attrs->{seen_join}||{}} };
1594 my $join = ($attrs->{join}
1595 ? [ $attrs->{join}, $extra_join ]
1599 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1602 return ($from,$seen);
1605 sub _resolved_attrs {
1607 return $self->{_attrs} if $self->{_attrs};
1609 my $attrs = { %{$self->{attrs}||{}} };
1610 my $source = $self->{result_source};
1611 my $alias = $attrs->{alias};
1613 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1614 if ($attrs->{columns}) {
1615 delete $attrs->{as};
1616 } elsif (!$attrs->{select}) {
1617 $attrs->{columns} = [ $source->columns ];
1622 ? (ref $attrs->{select} eq 'ARRAY'
1623 ? [ @{$attrs->{select}} ]
1624 : [ $attrs->{select} ])
1625 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1629 ? (ref $attrs->{as} eq 'ARRAY'
1630 ? [ @{$attrs->{as}} ]
1632 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1636 if ($adds = delete $attrs->{include_columns}) {
1637 $adds = [$adds] unless ref $adds eq 'ARRAY';
1638 push(@{$attrs->{select}}, @$adds);
1639 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1641 if ($adds = delete $attrs->{'+select'}) {
1642 $adds = [$adds] unless ref $adds eq 'ARRAY';
1643 push(@{$attrs->{select}},
1644 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1646 if (my $adds = delete $attrs->{'+as'}) {
1647 $adds = [$adds] unless ref $adds eq 'ARRAY';
1648 push(@{$attrs->{as}}, @$adds);
1651 $attrs->{from} ||= [ { 'me' => $source->from } ];
1653 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1654 my $join = delete $attrs->{join} || {};
1656 if (defined $attrs->{prefetch}) {
1657 $join = $self->_merge_attr(
1658 $join, $attrs->{prefetch}
1662 $attrs->{from} = # have to copy here to avoid corrupting the original
1665 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1669 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1670 if ($attrs->{order_by}) {
1671 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1672 ? [ @{$attrs->{order_by}} ]
1673 : [ $attrs->{order_by} ]);
1675 $attrs->{order_by} = [];
1678 my $collapse = $attrs->{collapse} || {};
1679 if (my $prefetch = delete $attrs->{prefetch}) {
1680 $prefetch = $self->_merge_attr({}, $prefetch);
1682 my $seen = $attrs->{seen_join} || {};
1683 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1684 # bring joins back to level of current class
1685 my @prefetch = $source->resolve_prefetch(
1686 $p, $alias, $seen, \@pre_order, $collapse
1688 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1689 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1691 push(@{$attrs->{order_by}}, @pre_order);
1693 $attrs->{collapse} = $collapse;
1695 return $self->{_attrs} = $attrs;
1699 my ($self, $a, $b) = @_;
1700 return $b unless defined($a);
1701 return $a unless defined($b);
1703 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1704 foreach my $key (keys %{$b}) {
1705 if (exists $a->{$key}) {
1706 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1708 $a->{$key} = $b->{$key};
1713 $a = [$a] unless ref $a eq 'ARRAY';
1714 $b = [$b] unless ref $b eq 'ARRAY';
1718 foreach my $x ($a, $b) {
1719 foreach my $element (@{$x}) {
1720 if (ref $element eq 'HASH') {
1721 $hash = $self->_merge_attr($hash, $element);
1722 } elsif (ref $element eq 'ARRAY') {
1723 push(@array, @{$element});
1725 push(@array, $element) unless $b == $x
1726 && grep { $_ eq $element } @array;
1731 @array = grep { !exists $hash->{$_} } @array;
1733 return keys %{$hash}
1742 =head2 throw_exception
1744 See L<DBIx::Class::Schema/throw_exception> for details.
1748 sub throw_exception {
1750 $self->result_source->schema->throw_exception(@_);
1753 # XXX: FIXME: Attributes docs need clearing up
1757 The resultset takes various attributes that modify its behavior. Here's an
1764 =item Value: ($order_by | \@order_by)
1768 Which column(s) to order the results by. This is currently passed
1769 through directly to SQL, so you can give e.g. C<year DESC> for a
1770 descending order on the column `year'.
1772 Please note that if you have C<quote_char> enabled (see
1773 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1774 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1775 so you will need to manually quote things as appropriate.)
1781 =item Value: \@columns
1785 Shortcut to request a particular set of columns to be retrieved. Adds
1786 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1787 from that, then auto-populates C<as> from C<select> as normal. (You may also
1788 use the C<cols> attribute, as in earlier versions of DBIC.)
1790 =head2 include_columns
1794 =item Value: \@columns
1798 Shortcut to include additional columns in the returned results - for example
1800 $schema->resultset('CD')->search(undef, {
1801 include_columns => ['artist.name'],
1805 would return all CDs and include a 'name' column to the information
1806 passed to object inflation
1812 =item Value: \@select_columns
1816 Indicates which columns should be selected from the storage. You can use
1817 column names, or in the case of RDBMS back ends, function or stored procedure
1820 $rs = $schema->resultset('Employee')->search(undef, {
1823 { count => 'employeeid' },
1828 When you use function/stored procedure names and do not supply an C<as>
1829 attribute, the column names returned are storage-dependent. E.g. MySQL would
1830 return a column named C<count(employeeid)> in the above example.
1836 Indicates additional columns to be selected from storage. Works the same as
1837 L<select> but adds columns to the selection.
1845 Indicates additional column names for those added via L<+select>.
1853 =item Value: \@inflation_names
1857 Indicates column names for object inflation. This is used in conjunction with
1858 C<select>, usually when C<select> contains one or more function or stored
1861 $rs = $schema->resultset('Employee')->search(undef, {
1864 { count => 'employeeid' }
1866 as => ['name', 'employee_count'],
1869 my $employee = $rs->first(); # get the first Employee
1871 If the object against which the search is performed already has an accessor
1872 matching a column name specified in C<as>, the value can be retrieved using
1873 the accessor as normal:
1875 my $name = $employee->name();
1877 If on the other hand an accessor does not exist in the object, you need to
1878 use C<get_column> instead:
1880 my $employee_count = $employee->get_column('employee_count');
1882 You can create your own accessors if required - see
1883 L<DBIx::Class::Manual::Cookbook> for details.
1885 Please note: This will NOT insert an C<AS employee_count> into the SQL
1886 statement produced, it is used for internal access only. Thus
1887 attempting to use the accessor in an C<order_by> clause or similar
1888 will fail miserably.
1890 To get around this limitation, you can supply literal SQL to your
1891 C<select> attibute that contains the C<AS alias> text, eg:
1893 select => [\'myfield AS alias']
1899 =item Value: ($rel_name | \@rel_names | \%rel_names)
1903 Contains a list of relationships that should be joined for this query. For
1906 # Get CDs by Nine Inch Nails
1907 my $rs = $schema->resultset('CD')->search(
1908 { 'artist.name' => 'Nine Inch Nails' },
1909 { join => 'artist' }
1912 Can also contain a hash reference to refer to the other relation's relations.
1915 package MyApp::Schema::Track;
1916 use base qw/DBIx::Class/;
1917 __PACKAGE__->table('track');
1918 __PACKAGE__->add_columns(qw/trackid cd position title/);
1919 __PACKAGE__->set_primary_key('trackid');
1920 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1923 # In your application
1924 my $rs = $schema->resultset('Artist')->search(
1925 { 'track.title' => 'Teardrop' },
1927 join => { cd => 'track' },
1928 order_by => 'artist.name',
1932 You need to use the relationship (not the table) name in conditions,
1933 because they are aliased as such. The current table is aliased as "me", so
1934 you need to use me.column_name in order to avoid ambiguity. For example:
1936 # Get CDs from 1984 with a 'Foo' track
1937 my $rs = $schema->resultset('CD')->search(
1940 'tracks.name' => 'Foo'
1942 { join => 'tracks' }
1945 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1946 similarly for a third time). For e.g.
1948 my $rs = $schema->resultset('Artist')->search({
1949 'cds.title' => 'Down to Earth',
1950 'cds_2.title' => 'Popular',
1952 join => [ qw/cds cds/ ],
1955 will return a set of all artists that have both a cd with title 'Down
1956 to Earth' and a cd with title 'Popular'.
1958 If you want to fetch related objects from other tables as well, see C<prefetch>
1965 =item Value: ($rel_name | \@rel_names | \%rel_names)
1969 Contains one or more relationships that should be fetched along with the main
1970 query (when they are accessed afterwards they will have already been
1971 "prefetched"). This is useful for when you know you will need the related
1972 objects, because it saves at least one query:
1974 my $rs = $schema->resultset('Tag')->search(
1983 The initial search results in SQL like the following:
1985 SELECT tag.*, cd.*, artist.* FROM tag
1986 JOIN cd ON tag.cd = cd.cdid
1987 JOIN artist ON cd.artist = artist.artistid
1989 L<DBIx::Class> has no need to go back to the database when we access the
1990 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1993 Simple prefetches will be joined automatically, so there is no need
1994 for a C<join> attribute in the above search. If you're prefetching to
1995 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1996 specify the join as well.
1998 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1999 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2000 with an accessor type of 'single' or 'filter').
2010 Makes the resultset paged and specifies the page to retrieve. Effectively
2011 identical to creating a non-pages resultset and then calling ->page($page)
2014 If L<rows> attribute is not specified it defualts to 10 rows per page.
2024 Specifes the maximum number of rows for direct retrieval or the number of
2025 rows per page if the page attribute or method is used.
2031 =item Value: $offset
2035 Specifies the (zero-based) row number for the first row to be returned, or the
2036 of the first row of the first page if paging is used.
2042 =item Value: \@columns
2046 A arrayref of columns to group by. Can include columns of joined tables.
2048 group_by => [qw/ column1 column2 ... /]
2054 =item Value: $condition
2058 HAVING is a select statement attribute that is applied between GROUP BY and
2059 ORDER BY. It is applied to the after the grouping calculations have been
2062 having => { 'count(employee)' => { '>=', 100 } }
2068 =item Value: (0 | 1)
2072 Set to 1 to group by all columns.
2078 Adds to the WHERE clause.
2080 # only return rows WHERE deleted IS NULL for all searches
2081 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2083 Can be overridden by passing C<{ where => undef }> as an attribute
2090 Set to 1 to cache search results. This prevents extra SQL queries if you
2091 revisit rows in your ResultSet:
2093 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2095 while( my $artist = $resultset->next ) {
2099 $rs->first; # without cache, this would issue a query
2101 By default, searches are not cached.
2103 For more examples of using these attributes, see
2104 L<DBIx::Class::Manual::Cookbook>.
2110 =item Value: \@from_clause
2114 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2115 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2118 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2120 C<join> will usually do what you need and it is strongly recommended that you
2121 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2122 And we really do mean "cannot", not just tried and failed. Attempting to use
2123 this because you're having problems with C<join> is like trying to use x86
2124 ASM because you've got a syntax error in your C. Trust us on this.
2126 Now, if you're still really, really sure you need to use this (and if you're
2127 not 100% sure, ask the mailing list first), here's an explanation of how this
2130 The syntax is as follows -
2133 { <alias1> => <table1> },
2135 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2136 [], # nested JOIN (optional)
2137 { <table1.column1> => <table2.column2>, ... (more conditions) },
2139 # More of the above [ ] may follow for additional joins
2146 ON <table1.column1> = <table2.column2>
2147 <more joins may follow>
2149 An easy way to follow the examples below is to remember the following:
2151 Anything inside "[]" is a JOIN
2152 Anything inside "{}" is a condition for the enclosing JOIN
2154 The following examples utilize a "person" table in a family tree application.
2155 In order to express parent->child relationships, this table is self-joined:
2157 # Person->belongs_to('father' => 'Person');
2158 # Person->belongs_to('mother' => 'Person');
2160 C<from> can be used to nest joins. Here we return all children with a father,
2161 then search against all mothers of those children:
2163 $rs = $schema->resultset('Person')->search(
2166 alias => 'mother', # alias columns in accordance with "from"
2168 { mother => 'person' },
2171 { child => 'person' },
2173 { father => 'person' },
2174 { 'father.person_id' => 'child.father_id' }
2177 { 'mother.person_id' => 'child.mother_id' }
2184 # SELECT mother.* FROM person mother
2187 # JOIN person father
2188 # ON ( father.person_id = child.father_id )
2190 # ON ( mother.person_id = child.mother_id )
2192 The type of any join can be controlled manually. To search against only people
2193 with a father in the person table, we could explicitly use C<INNER JOIN>:
2195 $rs = $schema->resultset('Person')->search(
2198 alias => 'child', # alias columns in accordance with "from"
2200 { child => 'person' },
2202 { father => 'person', -join_type => 'inner' },
2203 { 'father.id' => 'child.father_id' }
2210 # SELECT child.* FROM person child
2211 # INNER JOIN person father ON child.father_id = father.id