1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
92 $attrs->{rows} ||= 10;
93 $attrs->{offset} ||= 0;
94 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
97 $attrs->{alias} ||= 'me';
100 _source_handle => $source,
101 result_class => $attrs->{result_class} || $source->resolve->result_class,
102 cond => $attrs->{where},
117 =item Arguments: $cond, \%attrs?
119 =item Return Value: $resultset (scalar context), @row_objs (list context)
123 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
124 my $new_rs = $cd_rs->search({ year => 2005 });
126 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
127 # year = 2005 OR year = 2004
129 If you need to pass in additional attributes but no additional condition,
130 call it as C<search(undef, \%attrs)>.
132 # "SELECT name, artistid FROM $artist_table"
133 my @all_artists = $schema->resultset('Artist')->search(undef, {
134 columns => [qw/name artistid/],
137 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>.
143 my $rs = $self->search_rs( @_ );
144 return (wantarray ? $rs->all : $rs);
151 =item Arguments: $cond, \%attrs?
153 =item Return Value: $resultset
157 This method does the same exact thing as search() except it will
158 always return a resultset, even in list context.
167 unless (@_) { # no search, effectively just a clone
168 $rows = $self->get_cache;
172 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
173 my $our_attrs = { %{$self->{attrs}} };
174 my $having = delete $our_attrs->{having};
175 my $where = delete $our_attrs->{where};
177 my $new_attrs = { %{$our_attrs}, %{$attrs} };
179 # merge new attrs into inherited
180 foreach my $key (qw/join prefetch/) {
181 next unless exists $attrs->{$key};
182 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
187 (@_ == 1 || ref $_[0] eq "HASH")
189 (ref $_[0] eq 'HASH')
191 (keys %{ $_[0] } > 0)
199 ? $self->throw_exception("Odd number of arguments to search")
206 if (defined $where) {
207 $new_attrs->{where} = (
208 defined $new_attrs->{where}
211 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
212 } $where, $new_attrs->{where}
219 $new_attrs->{where} = (
220 defined $new_attrs->{where}
223 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
224 } $cond, $new_attrs->{where}
230 if (defined $having) {
231 $new_attrs->{having} = (
232 defined $new_attrs->{having}
235 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
236 } $having, $new_attrs->{having}
242 my $rs = (ref $self)->new($self->_source_handle, $new_attrs);
244 $rs->set_cache($rows);
249 =head2 search_literal
253 =item Arguments: $sql_fragment, @bind_values
255 =item Return Value: $resultset (scalar context), @row_objs (list context)
259 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
260 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
262 Pass a literal chunk of SQL to be added to the conditional part of the
268 my ($self, $cond, @vals) = @_;
269 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
270 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
271 return $self->search(\$cond, $attrs);
278 =item Arguments: @values | \%cols, \%attrs?
280 =item Return Value: $row_object
284 Finds a row based on its primary key or unique constraint. For example, to find
285 a row by its primary key:
287 my $cd = $schema->resultset('CD')->find(5);
289 You can also find a row by a specific unique constraint using the C<key>
290 attribute. For example:
292 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
293 key => 'cd_artist_title'
296 Additionally, you can specify the columns explicitly by name:
298 my $cd = $schema->resultset('CD')->find(
300 artist => 'Massive Attack',
301 title => 'Mezzanine',
303 { key => 'cd_artist_title' }
306 If the C<key> is specified as C<primary>, it searches only on the primary key.
308 If no C<key> is specified, it searches on all unique constraints defined on the
309 source, including the primary key.
311 If your table does not have a primary key, you B<must> provide a value for the
312 C<key> attribute matching one of the unique constraints on the source.
314 See also L</find_or_create> and L</update_or_create>. For information on how to
315 declare unique constraints, see
316 L<DBIx::Class::ResultSource/add_unique_constraint>.
322 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
324 # Default to the primary key, but allow a specific key
325 my @cols = exists $attrs->{key}
326 ? $self->result_source->unique_constraint_columns($attrs->{key})
327 : $self->result_source->primary_columns;
328 $self->throw_exception(
329 "Can't find unless a primary key is defined or unique constraint is specified"
332 # Parse out a hashref from input
334 if (ref $_[0] eq 'HASH') {
335 $input_query = { %{$_[0]} };
337 elsif (@_ == @cols) {
339 @{$input_query}{@cols} = @_;
342 # Compatibility: Allow e.g. find(id => $value)
343 carp "Find by key => value deprecated; please use a hashref instead";
347 my (%related, $info);
349 foreach my $key (keys %$input_query) {
350 if (ref($input_query->{$key})
351 && ($info = $self->result_source->relationship_info($key))) {
352 my $rel_q = $self->result_source->resolve_condition(
353 $info->{cond}, delete $input_query->{$key}, $key
355 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
356 @related{keys %$rel_q} = values %$rel_q;
359 if (my @keys = keys %related) {
360 @{$input_query}{@keys} = values %related;
363 my @unique_queries = $self->_unique_queries($input_query, $attrs);
365 # Build the final query: Default to the disjunction of the unique queries,
366 # but allow the input query in case the ResultSet defines the query or the
367 # user is abusing find
368 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
369 my $query = @unique_queries
370 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
371 : $self->_add_alias($input_query, $alias);
375 my $rs = $self->search($query, $attrs);
376 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
379 return keys %{$self->_resolved_attrs->{collapse}}
380 ? $self->search($query)->next
381 : $self->single($query);
387 # Add the specified alias to the specified query hash. A copy is made so the
388 # original query is not modified.
391 my ($self, $query, $alias) = @_;
393 my %aliased = %$query;
394 foreach my $col (grep { ! m/\./ } keys %aliased) {
395 $aliased{"$alias.$col"} = delete $aliased{$col};
403 # Build a list of queries which satisfy unique constraints.
405 sub _unique_queries {
406 my ($self, $query, $attrs) = @_;
408 my @constraint_names = exists $attrs->{key}
410 : $self->result_source->unique_constraint_names;
413 foreach my $name (@constraint_names) {
414 my @unique_cols = $self->result_source->unique_constraint_columns($name);
415 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
417 my $num_query = scalar keys %$unique_query;
418 next unless $num_query;
420 # XXX: Assuming quite a bit about $self->{attrs}{where}
421 my $num_cols = scalar @unique_cols;
422 my $num_where = exists $self->{attrs}{where}
423 ? scalar keys %{ $self->{attrs}{where} }
425 push @unique_queries, $unique_query
426 if $num_query + $num_where == $num_cols;
429 return @unique_queries;
432 # _build_unique_query
434 # Constrain the specified query hash based on the specified column names.
436 sub _build_unique_query {
437 my ($self, $query, $unique_cols) = @_;
440 map { $_ => $query->{$_} }
441 grep { exists $query->{$_} }
446 =head2 search_related
450 =item Arguments: $rel, $cond, \%attrs?
452 =item Return Value: $new_resultset
456 $new_rs = $cd_rs->search_related('artist', {
460 Searches the specified relationship, optionally specifying a condition and
461 attributes for matching records. See L</ATTRIBUTES> for more information.
466 return shift->related_resultset(shift)->search(@_);
473 =item Arguments: none
475 =item Return Value: $cursor
479 Returns a storage-driven cursor to the given resultset. See
480 L<DBIx::Class::Cursor> for more information.
487 my $attrs = { %{$self->_resolved_attrs} };
488 return $self->{cursor}
489 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
490 $attrs->{where},$attrs);
497 =item Arguments: $cond?
499 =item Return Value: $row_object?
503 my $cd = $schema->resultset('CD')->single({ year => 2001 });
505 Inflates the first result without creating a cursor if the resultset has
506 any records in it; if not returns nothing. Used by L</find> as an optimisation.
508 Can optionally take an additional condition *only* - this is a fast-code-path
509 method; if you need to add extra joins or similar call ->search and then
510 ->single without a condition on the $rs returned from that.
515 my ($self, $where) = @_;
516 my $attrs = { %{$self->_resolved_attrs} };
518 if (defined $attrs->{where}) {
521 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
522 $where, delete $attrs->{where} ]
525 $attrs->{where} = $where;
529 # XXX: Disabled since it doesn't infer uniqueness in all cases
530 # unless ($self->_is_unique_query($attrs->{where})) {
531 # carp "Query not guaranteed to return a single row"
532 # . "; please declare your unique constraints or use search instead";
535 my @data = $self->result_source->storage->select_single(
536 $attrs->{from}, $attrs->{select},
537 $attrs->{where}, $attrs
540 return (@data ? ($self->_construct_object(@data))[0] : ());
545 # Try to determine if the specified query is guaranteed to be unique, based on
546 # the declared unique constraints.
548 sub _is_unique_query {
549 my ($self, $query) = @_;
551 my $collapsed = $self->_collapse_query($query);
552 my $alias = $self->{attrs}{alias};
554 foreach my $name ($self->result_source->unique_constraint_names) {
555 my @unique_cols = map {
557 } $self->result_source->unique_constraint_columns($name);
559 # Count the values for each unique column
560 my %seen = map { $_ => 0 } @unique_cols;
562 foreach my $key (keys %$collapsed) {
563 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
564 next unless exists $seen{$aliased}; # Additional constraints are okay
565 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
568 # If we get 0 or more than 1 value for a column, it's not necessarily unique
569 return 1 unless grep { $_ != 1 } values %seen;
577 # Recursively collapse the query, accumulating values for each column.
579 sub _collapse_query {
580 my ($self, $query, $collapsed) = @_;
584 if (ref $query eq 'ARRAY') {
585 foreach my $subquery (@$query) {
586 next unless ref $subquery; # -or
587 # warn "ARRAY: " . Dumper $subquery;
588 $collapsed = $self->_collapse_query($subquery, $collapsed);
591 elsif (ref $query eq 'HASH') {
592 if (keys %$query and (keys %$query)[0] eq '-and') {
593 foreach my $subquery (@{$query->{-and}}) {
594 # warn "HASH: " . Dumper $subquery;
595 $collapsed = $self->_collapse_query($subquery, $collapsed);
599 # warn "LEAF: " . Dumper $query;
600 foreach my $col (keys %$query) {
601 my $value = $query->{$col};
602 $collapsed->{$col}{$value}++;
614 =item Arguments: $cond?
616 =item Return Value: $resultsetcolumn
620 my $max_length = $rs->get_column('length')->max;
622 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
627 my ($self, $column) = @_;
628 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
636 =item Arguments: $cond, \%attrs?
638 =item Return Value: $resultset (scalar context), @row_objs (list context)
642 # WHERE title LIKE '%blue%'
643 $cd_rs = $rs->search_like({ title => '%blue%'});
645 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
646 that this is simply a convenience method. You most likely want to use
647 L</search> with specific operators.
649 For more information, see L<DBIx::Class::Manual::Cookbook>.
655 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
656 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
657 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
658 return $class->search($query, { %$attrs });
665 =item Arguments: $first, $last
667 =item Return Value: $resultset (scalar context), @row_objs (list context)
671 Returns a resultset or object list representing a subset of elements from the
672 resultset slice is called on. Indexes are from 0, i.e., to get the first
675 my ($one, $two, $three) = $rs->slice(0, 2);
680 my ($self, $min, $max) = @_;
681 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
682 $attrs->{offset} = $self->{attrs}{offset} || 0;
683 $attrs->{offset} += $min;
684 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
685 return $self->search(undef(), $attrs);
686 #my $slice = (ref $self)->new($self->result_source, $attrs);
687 #return (wantarray ? $slice->all : $slice);
694 =item Arguments: none
696 =item Return Value: $result?
700 Returns the next element in the resultset (C<undef> is there is none).
702 Can be used to efficiently iterate over records in the resultset:
704 my $rs = $schema->resultset('CD')->search;
705 while (my $cd = $rs->next) {
709 Note that you need to store the resultset object, and call C<next> on it.
710 Calling C<< resultset('Table')->next >> repeatedly will always return the
711 first record from the resultset.
717 if (my $cache = $self->get_cache) {
718 $self->{all_cache_position} ||= 0;
719 return $cache->[$self->{all_cache_position}++];
721 if ($self->{attrs}{cache}) {
722 $self->{all_cache_position} = 1;
723 return ($self->all)[0];
725 if ($self->{stashed_objects}) {
726 my $obj = shift(@{$self->{stashed_objects}});
727 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
731 exists $self->{stashed_row}
732 ? @{delete $self->{stashed_row}}
733 : $self->cursor->next
735 return unless (@row);
736 my ($row, @more) = $self->_construct_object(@row);
737 $self->{stashed_objects} = \@more if @more;
741 sub _construct_object {
742 my ($self, @row) = @_;
743 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
744 my @new = $self->result_class->inflate_result($self->_source_handle, @$info);
745 @new = $self->{_attrs}{record_filter}->(@new)
746 if exists $self->{_attrs}{record_filter};
750 sub _collapse_result {
751 my ($self, $as, $row, $prefix) = @_;
756 foreach my $this_as (@$as) {
757 my $val = shift @copy;
758 if (defined $prefix) {
759 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
761 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
762 $const{$1||''}{$2} = $val;
765 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
766 $const{$1||''}{$2} = $val;
770 my $alias = $self->{attrs}{alias};
771 my $info = [ {}, {} ];
772 foreach my $key (keys %const) {
773 if (length $key && $key ne $alias) {
775 my @parts = split(/\./, $key);
776 foreach my $p (@parts) {
777 $target = $target->[1]->{$p} ||= [];
779 $target->[0] = $const{$key};
781 $info->[0] = $const{$key};
786 if (defined $prefix) {
788 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
789 } keys %{$self->{_attrs}{collapse}}
791 @collapse = keys %{$self->{_attrs}{collapse}};
795 my ($c) = sort { length $a <=> length $b } @collapse;
797 foreach my $p (split(/\./, $c)) {
798 $target = $target->[1]->{$p} ||= [];
800 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
801 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
802 my $tree = $self->_collapse_result($as, $row, $c_prefix);
803 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
809 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
814 last unless (@raw = $self->cursor->next);
815 $row = $self->{stashed_row} = \@raw;
816 $tree = $self->_collapse_result($as, $row, $c_prefix);
818 @$target = (@final ? @final : [ {}, {} ]);
819 # single empty result to indicate an empty prefetched has_many
822 #print "final info: " . Dumper($info);
830 =item Arguments: $result_source?
832 =item Return Value: $result_source
836 An accessor for the primary ResultSource object from which this ResultSet
843 =item Arguments: $result_class?
845 =item Return Value: $result_class
849 An accessor for the class to use when creating row objects. Defaults to
850 C<< result_source->result_class >> - which in most cases is the name of the
851 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
860 =item Arguments: $cond, \%attrs??
862 =item Return Value: $count
866 Performs an SQL C<COUNT> with the same query as the resultset was built
867 with to find the number of elements. If passed arguments, does a search
868 on the resultset and counts the results of that.
870 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
871 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
872 not support C<DISTINCT> with multiple columns. If you are using such a
873 database, you should only use columns from the main table in your C<group_by>
880 return $self->search(@_)->count if @_ and defined $_[0];
881 return scalar @{ $self->get_cache } if $self->get_cache;
882 my $count = $self->_count;
883 return 0 unless $count;
885 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
886 $count = $self->{attrs}{rows} if
887 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
891 sub _count { # Separated out so pager can get the full count
893 my $select = { count => '*' };
895 my $attrs = { %{$self->_resolved_attrs} };
896 if (my $group_by = delete $attrs->{group_by}) {
897 delete $attrs->{having};
898 my @distinct = (ref $group_by ? @$group_by : ($group_by));
899 # todo: try CONCAT for multi-column pk
900 my @pk = $self->result_source->primary_columns;
902 my $alias = $attrs->{alias};
903 foreach my $column (@distinct) {
904 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
905 @distinct = ($column);
911 $select = { count => { distinct => \@distinct } };
914 $attrs->{select} = $select;
915 $attrs->{as} = [qw/count/];
917 # offset, order by and page are not needed to count. record_filter is cdbi
918 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
920 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
921 my ($count) = $tmp_rs->cursor->next;
929 =item Arguments: $sql_fragment, @bind_values
931 =item Return Value: $count
935 Counts the results in a literal query. Equivalent to calling L</search_literal>
936 with the passed arguments, then L</count>.
940 sub count_literal { shift->search_literal(@_)->count; }
946 =item Arguments: none
948 =item Return Value: @objects
952 Returns all elements in the resultset. Called implicitly if the resultset
953 is returned in list context.
959 return @{ $self->get_cache } if $self->get_cache;
963 # TODO: don't call resolve here
964 if (keys %{$self->_resolved_attrs->{collapse}}) {
965 # if ($self->{attrs}{prefetch}) {
966 # Using $self->cursor->all is really just an optimisation.
967 # If we're collapsing has_many prefetches it probably makes
968 # very little difference, and this is cleaner than hacking
969 # _construct_object to survive the approach
970 my @row = $self->cursor->next;
972 push(@obj, $self->_construct_object(@row));
973 @row = (exists $self->{stashed_row}
974 ? @{delete $self->{stashed_row}}
975 : $self->cursor->next);
978 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
981 $self->set_cache(\@obj) if $self->{attrs}{cache};
989 =item Arguments: none
991 =item Return Value: $self
995 Resets the resultset's cursor, so you can iterate through the elements again.
1001 delete $self->{_attrs} if exists $self->{_attrs};
1002 $self->{all_cache_position} = 0;
1003 $self->cursor->reset;
1011 =item Arguments: none
1013 =item Return Value: $object?
1017 Resets the resultset and returns an object for the first result (if the
1018 resultset returns anything).
1023 return $_[0]->reset->next;
1026 # _cond_for_update_delete
1028 # update/delete require the condition to be modified to handle
1029 # the differing SQL syntax available. This transforms the $self->{cond}
1030 # appropriately, returning the new condition.
1032 sub _cond_for_update_delete {
1033 my ($self, $full_cond) = @_;
1036 $full_cond ||= $self->{cond};
1037 # No-op. No condition, we're updating/deleting everything
1038 return $cond unless ref $full_cond;
1040 if (ref $full_cond eq 'ARRAY') {
1044 foreach my $key (keys %{$_}) {
1046 $hash{$1} = $_->{$key};
1052 elsif (ref $full_cond eq 'HASH') {
1053 if ((keys %{$full_cond})[0] eq '-and') {
1056 my @cond = @{$full_cond->{-and}};
1057 for (my $i = 0; $i < @cond; $i++) {
1058 my $entry = $cond[$i];
1061 if (ref $entry eq 'HASH') {
1062 $hash = $self->_cond_for_update_delete($entry);
1065 $entry =~ /([^.]+)$/;
1066 $hash->{$1} = $cond[++$i];
1069 push @{$cond->{-and}}, $hash;
1073 foreach my $key (keys %{$full_cond}) {
1075 $cond->{$1} = $full_cond->{$key};
1080 $self->throw_exception(
1081 "Can't update/delete on resultset with condition unless hash or array"
1093 =item Arguments: \%values
1095 =item Return Value: $storage_rv
1099 Sets the specified columns in the resultset to the supplied values in a
1100 single query. Return value will be true if the update succeeded or false
1101 if no records were updated; exact type of success value is storage-dependent.
1106 my ($self, $values) = @_;
1107 $self->throw_exception("Values for update must be a hash")
1108 unless ref $values eq 'HASH';
1110 my $cond = $self->_cond_for_update_delete;
1112 return $self->result_source->storage->update(
1113 $self->result_source->from, $values, $cond
1121 =item Arguments: \%values
1123 =item Return Value: 1
1127 Fetches all objects and updates them one at a time. Note that C<update_all>
1128 will run DBIC cascade triggers, while L</update> will not.
1133 my ($self, $values) = @_;
1134 $self->throw_exception("Values for update must be a hash")
1135 unless ref $values eq 'HASH';
1136 foreach my $obj ($self->all) {
1137 $obj->set_columns($values)->update;
1146 =item Arguments: none
1148 =item Return Value: 1
1152 Deletes the contents of the resultset from its result source. Note that this
1153 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1154 to run. See also L<DBIx::Class::Row/delete>.
1161 my $cond = $self->_cond_for_update_delete;
1163 $self->result_source->storage->delete($self->result_source->from, $cond);
1171 =item Arguments: none
1173 =item Return Value: 1
1177 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1178 will run DBIC cascade triggers, while L</delete> will not.
1184 $_->delete for $self->all;
1192 =item Arguments: none
1194 =item Return Value: $pager
1198 Return Value a L<Data::Page> object for the current resultset. Only makes
1199 sense for queries with a C<page> attribute.
1205 my $attrs = $self->{attrs};
1206 $self->throw_exception("Can't create pager for non-paged rs")
1207 unless $self->{attrs}{page};
1208 $attrs->{rows} ||= 10;
1209 return $self->{pager} ||= Data::Page->new(
1210 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1217 =item Arguments: $page_number
1219 =item Return Value: $rs
1223 Returns a resultset for the $page_number page of the resultset on which page
1224 is called, where each page contains a number of rows equal to the 'rows'
1225 attribute set on the resultset (10 by default).
1230 my ($self, $page) = @_;
1231 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1238 =item Arguments: \%vals
1240 =item Return Value: $object
1244 Creates an object in the resultset's result class and returns it.
1249 my ($self, $values) = @_;
1250 $self->throw_exception( "new_result needs a hash" )
1251 unless (ref $values eq 'HASH');
1252 $self->throw_exception(
1253 "Can't abstract implicit construct, condition not a hash"
1254 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1256 my $alias = $self->{attrs}{alias};
1257 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1259 %{ $self->_remove_alias($values, $alias) },
1260 %{ $self->_remove_alias($collapsed_cond, $alias) },
1261 _source_handle => $self->_source_handle,
1264 my $obj = $self->result_class->new(\%new);
1270 # Recursively collapse the condition.
1272 sub _collapse_cond {
1273 my ($self, $cond, $collapsed) = @_;
1277 if (ref $cond eq 'ARRAY') {
1278 foreach my $subcond (@$cond) {
1279 next unless ref $subcond; # -or
1280 # warn "ARRAY: " . Dumper $subcond;
1281 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1284 elsif (ref $cond eq 'HASH') {
1285 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1286 foreach my $subcond (@{$cond->{-and}}) {
1287 # warn "HASH: " . Dumper $subcond;
1288 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1292 # warn "LEAF: " . Dumper $cond;
1293 foreach my $col (keys %$cond) {
1294 my $value = $cond->{$col};
1295 $collapsed->{$col} = $value;
1305 # Remove the specified alias from the specified query hash. A copy is made so
1306 # the original query is not modified.
1309 my ($self, $query, $alias) = @_;
1311 my %orig = %{ $query || {} };
1314 foreach my $key (keys %orig) {
1316 $unaliased{$key} = $orig{$key};
1319 $unaliased{$1} = $orig{$key}
1320 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1330 =item Arguments: \%vals, \%attrs?
1332 =item Return Value: $object
1336 Find an existing record from this resultset. If none exists, instantiate a new
1337 result object and return it. The object will not be saved into your storage
1338 until you call L<DBIx::Class::Row/insert> on it.
1340 If you want objects to be saved immediately, use L</find_or_create> instead.
1346 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1347 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1348 my $exists = $self->find($hash, $attrs);
1349 return defined $exists ? $exists : $self->new_result($hash);
1356 =item Arguments: \%vals
1358 =item Return Value: $object
1362 Inserts a record into the resultset and returns the object representing it.
1364 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1369 my ($self, $attrs) = @_;
1370 $self->throw_exception( "create needs a hashref" )
1371 unless ref $attrs eq 'HASH';
1372 return $self->new_result($attrs)->insert;
1375 =head2 find_or_create
1379 =item Arguments: \%vals, \%attrs?
1381 =item Return Value: $object
1385 $class->find_or_create({ key => $val, ... });
1387 Tries to find a record based on its primary key or unique constraint; if none
1388 is found, creates one and returns that instead.
1390 my $cd = $schema->resultset('CD')->find_or_create({
1392 artist => 'Massive Attack',
1393 title => 'Mezzanine',
1397 Also takes an optional C<key> attribute, to search by a specific key or unique
1398 constraint. For example:
1400 my $cd = $schema->resultset('CD')->find_or_create(
1402 artist => 'Massive Attack',
1403 title => 'Mezzanine',
1405 { key => 'cd_artist_title' }
1408 See also L</find> and L</update_or_create>. For information on how to declare
1409 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1413 sub find_or_create {
1415 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1416 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1417 my $exists = $self->find($hash, $attrs);
1418 return defined $exists ? $exists : $self->create($hash);
1421 =head2 update_or_create
1425 =item Arguments: \%col_values, { key => $unique_constraint }?
1427 =item Return Value: $object
1431 $class->update_or_create({ col => $val, ... });
1433 First, searches for an existing row matching one of the unique constraints
1434 (including the primary key) on the source of this resultset. If a row is
1435 found, updates it with the other given column values. Otherwise, creates a new
1438 Takes an optional C<key> attribute to search on a specific unique constraint.
1441 # In your application
1442 my $cd = $schema->resultset('CD')->update_or_create(
1444 artist => 'Massive Attack',
1445 title => 'Mezzanine',
1448 { key => 'cd_artist_title' }
1451 If no C<key> is specified, it searches on all unique constraints defined on the
1452 source, including the primary key.
1454 If the C<key> is specified as C<primary>, it searches only on the primary key.
1456 See also L</find> and L</find_or_create>. For information on how to declare
1457 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1461 sub update_or_create {
1463 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1464 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1466 my $row = $self->find($cond, $attrs);
1468 $row->update($cond);
1472 return $self->create($cond);
1479 =item Arguments: none
1481 =item Return Value: \@cache_objects?
1485 Gets the contents of the cache for the resultset, if the cache is set.
1497 =item Arguments: \@cache_objects
1499 =item Return Value: \@cache_objects
1503 Sets the contents of the cache for the resultset. Expects an arrayref
1504 of objects of the same class as those produced by the resultset. Note that
1505 if the cache is set the resultset will return the cached objects rather
1506 than re-querying the database even if the cache attr is not set.
1511 my ( $self, $data ) = @_;
1512 $self->throw_exception("set_cache requires an arrayref")
1513 if defined($data) && (ref $data ne 'ARRAY');
1514 $self->{all_cache} = $data;
1521 =item Arguments: none
1523 =item Return Value: []
1527 Clears the cache for the resultset.
1532 shift->set_cache(undef);
1535 =head2 related_resultset
1539 =item Arguments: $relationship_name
1541 =item Return Value: $resultset
1545 Returns a related resultset for the supplied relationship name.
1547 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1551 sub related_resultset {
1552 my ($self, $rel) = @_;
1554 $self->{related_resultsets} ||= {};
1555 return $self->{related_resultsets}{$rel} ||= do {
1556 my $rel_obj = $self->result_source->relationship_info($rel);
1558 $self->throw_exception(
1559 "search_related: result source '" . $self->_source_handle->source_moniker .
1560 "' has no such relationship $rel")
1563 my ($from,$seen) = $self->_resolve_from($rel);
1565 my $join_count = $seen->{$rel};
1566 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1568 $self->_source_handle->schema->resultset($rel_obj->{class})->search_rs(
1570 %{$self->{attrs}||{}},
1576 where => $self->{cond},
1584 my ($self, $extra_join) = @_;
1585 my $source = $self->result_source;
1586 my $attrs = $self->{attrs};
1588 my $from = $attrs->{from}
1589 || [ { $attrs->{alias} => $source->from } ];
1591 my $seen = { %{$attrs->{seen_join}||{}} };
1593 my $join = ($attrs->{join}
1594 ? [ $attrs->{join}, $extra_join ]
1598 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1601 return ($from,$seen);
1604 sub _resolved_attrs {
1606 return $self->{_attrs} if $self->{_attrs};
1608 my $attrs = { %{$self->{attrs}||{}} };
1609 my $source = $self->result_source;
1610 my $alias = $attrs->{alias};
1612 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1613 if ($attrs->{columns}) {
1614 delete $attrs->{as};
1615 } elsif (!$attrs->{select}) {
1616 $attrs->{columns} = [ $source->columns ];
1621 ? (ref $attrs->{select} eq 'ARRAY'
1622 ? [ @{$attrs->{select}} ]
1623 : [ $attrs->{select} ])
1624 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1628 ? (ref $attrs->{as} eq 'ARRAY'
1629 ? [ @{$attrs->{as}} ]
1631 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1635 if ($adds = delete $attrs->{include_columns}) {
1636 $adds = [$adds] unless ref $adds eq 'ARRAY';
1637 push(@{$attrs->{select}}, @$adds);
1638 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1640 if ($adds = delete $attrs->{'+select'}) {
1641 $adds = [$adds] unless ref $adds eq 'ARRAY';
1642 push(@{$attrs->{select}},
1643 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1645 if (my $adds = delete $attrs->{'+as'}) {
1646 $adds = [$adds] unless ref $adds eq 'ARRAY';
1647 push(@{$attrs->{as}}, @$adds);
1650 $attrs->{from} ||= [ { 'me' => $source->from } ];
1652 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1653 my $join = delete $attrs->{join} || {};
1655 if (defined $attrs->{prefetch}) {
1656 $join = $self->_merge_attr(
1657 $join, $attrs->{prefetch}
1661 $attrs->{from} = # have to copy here to avoid corrupting the original
1664 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1668 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1669 if ($attrs->{order_by}) {
1670 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1671 ? [ @{$attrs->{order_by}} ]
1672 : [ $attrs->{order_by} ]);
1674 $attrs->{order_by} = [];
1677 my $collapse = $attrs->{collapse} || {};
1678 if (my $prefetch = delete $attrs->{prefetch}) {
1679 $prefetch = $self->_merge_attr({}, $prefetch);
1681 my $seen = $attrs->{seen_join} || {};
1682 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1683 # bring joins back to level of current class
1684 my @prefetch = $source->resolve_prefetch(
1685 $p, $alias, $seen, \@pre_order, $collapse
1687 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1688 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1690 push(@{$attrs->{order_by}}, @pre_order);
1692 $attrs->{collapse} = $collapse;
1694 return $self->{_attrs} = $attrs;
1698 my ($self, $a, $b) = @_;
1699 return $b unless defined($a);
1700 return $a unless defined($b);
1702 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1703 foreach my $key (keys %{$b}) {
1704 if (exists $a->{$key}) {
1705 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1707 $a->{$key} = $b->{$key};
1712 $a = [$a] unless ref $a eq 'ARRAY';
1713 $b = [$b] unless ref $b eq 'ARRAY';
1717 foreach my $x ($a, $b) {
1718 foreach my $element (@{$x}) {
1719 if (ref $element eq 'HASH') {
1720 $hash = $self->_merge_attr($hash, $element);
1721 } elsif (ref $element eq 'ARRAY') {
1722 push(@array, @{$element});
1724 push(@array, $element) unless $b == $x
1725 && grep { $_ eq $element } @array;
1730 @array = grep { !exists $hash->{$_} } @array;
1732 return keys %{$hash}
1745 $self->_source_handle($_[0]->handle);
1747 $self->_source_handle->resolve;
1751 =head2 throw_exception
1753 See L<DBIx::Class::Schema/throw_exception> for details.
1757 sub throw_exception {
1759 $self->_source_handle->schema->throw_exception(@_);
1762 # XXX: FIXME: Attributes docs need clearing up
1766 The resultset takes various attributes that modify its behavior. Here's an
1773 =item Value: ($order_by | \@order_by)
1777 Which column(s) to order the results by. This is currently passed
1778 through directly to SQL, so you can give e.g. C<year DESC> for a
1779 descending order on the column `year'.
1781 Please note that if you have C<quote_char> enabled (see
1782 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1783 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1784 so you will need to manually quote things as appropriate.)
1790 =item Value: \@columns
1794 Shortcut to request a particular set of columns to be retrieved. Adds
1795 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1796 from that, then auto-populates C<as> from C<select> as normal. (You may also
1797 use the C<cols> attribute, as in earlier versions of DBIC.)
1799 =head2 include_columns
1803 =item Value: \@columns
1807 Shortcut to include additional columns in the returned results - for example
1809 $schema->resultset('CD')->search(undef, {
1810 include_columns => ['artist.name'],
1814 would return all CDs and include a 'name' column to the information
1815 passed to object inflation
1821 =item Value: \@select_columns
1825 Indicates which columns should be selected from the storage. You can use
1826 column names, or in the case of RDBMS back ends, function or stored procedure
1829 $rs = $schema->resultset('Employee')->search(undef, {
1832 { count => 'employeeid' },
1837 When you use function/stored procedure names and do not supply an C<as>
1838 attribute, the column names returned are storage-dependent. E.g. MySQL would
1839 return a column named C<count(employeeid)> in the above example.
1845 Indicates additional columns to be selected from storage. Works the same as
1846 L<select> but adds columns to the selection.
1854 Indicates additional column names for those added via L<+select>.
1862 =item Value: \@inflation_names
1866 Indicates column names for object inflation. This is used in conjunction with
1867 C<select>, usually when C<select> contains one or more function or stored
1870 $rs = $schema->resultset('Employee')->search(undef, {
1873 { count => 'employeeid' }
1875 as => ['name', 'employee_count'],
1878 my $employee = $rs->first(); # get the first Employee
1880 If the object against which the search is performed already has an accessor
1881 matching a column name specified in C<as>, the value can be retrieved using
1882 the accessor as normal:
1884 my $name = $employee->name();
1886 If on the other hand an accessor does not exist in the object, you need to
1887 use C<get_column> instead:
1889 my $employee_count = $employee->get_column('employee_count');
1891 You can create your own accessors if required - see
1892 L<DBIx::Class::Manual::Cookbook> for details.
1894 Please note: This will NOT insert an C<AS employee_count> into the SQL
1895 statement produced, it is used for internal access only. Thus
1896 attempting to use the accessor in an C<order_by> clause or similar
1897 will fail miserably.
1899 To get around this limitation, you can supply literal SQL to your
1900 C<select> attibute that contains the C<AS alias> text, eg:
1902 select => [\'myfield AS alias']
1908 =item Value: ($rel_name | \@rel_names | \%rel_names)
1912 Contains a list of relationships that should be joined for this query. For
1915 # Get CDs by Nine Inch Nails
1916 my $rs = $schema->resultset('CD')->search(
1917 { 'artist.name' => 'Nine Inch Nails' },
1918 { join => 'artist' }
1921 Can also contain a hash reference to refer to the other relation's relations.
1924 package MyApp::Schema::Track;
1925 use base qw/DBIx::Class/;
1926 __PACKAGE__->table('track');
1927 __PACKAGE__->add_columns(qw/trackid cd position title/);
1928 __PACKAGE__->set_primary_key('trackid');
1929 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1932 # In your application
1933 my $rs = $schema->resultset('Artist')->search(
1934 { 'track.title' => 'Teardrop' },
1936 join => { cd => 'track' },
1937 order_by => 'artist.name',
1941 You need to use the relationship (not the table) name in conditions,
1942 because they are aliased as such. The current table is aliased as "me", so
1943 you need to use me.column_name in order to avoid ambiguity. For example:
1945 # Get CDs from 1984 with a 'Foo' track
1946 my $rs = $schema->resultset('CD')->search(
1949 'tracks.name' => 'Foo'
1951 { join => 'tracks' }
1954 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1955 similarly for a third time). For e.g.
1957 my $rs = $schema->resultset('Artist')->search({
1958 'cds.title' => 'Down to Earth',
1959 'cds_2.title' => 'Popular',
1961 join => [ qw/cds cds/ ],
1964 will return a set of all artists that have both a cd with title 'Down
1965 to Earth' and a cd with title 'Popular'.
1967 If you want to fetch related objects from other tables as well, see C<prefetch>
1974 =item Value: ($rel_name | \@rel_names | \%rel_names)
1978 Contains one or more relationships that should be fetched along with the main
1979 query (when they are accessed afterwards they will have already been
1980 "prefetched"). This is useful for when you know you will need the related
1981 objects, because it saves at least one query:
1983 my $rs = $schema->resultset('Tag')->search(
1992 The initial search results in SQL like the following:
1994 SELECT tag.*, cd.*, artist.* FROM tag
1995 JOIN cd ON tag.cd = cd.cdid
1996 JOIN artist ON cd.artist = artist.artistid
1998 L<DBIx::Class> has no need to go back to the database when we access the
1999 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2002 Simple prefetches will be joined automatically, so there is no need
2003 for a C<join> attribute in the above search. If you're prefetching to
2004 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2005 specify the join as well.
2007 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2008 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2009 with an accessor type of 'single' or 'filter').
2019 Makes the resultset paged and specifies the page to retrieve. Effectively
2020 identical to creating a non-pages resultset and then calling ->page($page)
2023 If L<rows> attribute is not specified it defualts to 10 rows per page.
2033 Specifes the maximum number of rows for direct retrieval or the number of
2034 rows per page if the page attribute or method is used.
2040 =item Value: $offset
2044 Specifies the (zero-based) row number for the first row to be returned, or the
2045 of the first row of the first page if paging is used.
2051 =item Value: \@columns
2055 A arrayref of columns to group by. Can include columns of joined tables.
2057 group_by => [qw/ column1 column2 ... /]
2063 =item Value: $condition
2067 HAVING is a select statement attribute that is applied between GROUP BY and
2068 ORDER BY. It is applied to the after the grouping calculations have been
2071 having => { 'count(employee)' => { '>=', 100 } }
2077 =item Value: (0 | 1)
2081 Set to 1 to group by all columns.
2087 Adds to the WHERE clause.
2089 # only return rows WHERE deleted IS NULL for all searches
2090 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2092 Can be overridden by passing C<{ where => undef }> as an attribute
2099 Set to 1 to cache search results. This prevents extra SQL queries if you
2100 revisit rows in your ResultSet:
2102 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2104 while( my $artist = $resultset->next ) {
2108 $rs->first; # without cache, this would issue a query
2110 By default, searches are not cached.
2112 For more examples of using these attributes, see
2113 L<DBIx::Class::Manual::Cookbook>.
2119 =item Value: \@from_clause
2123 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2124 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2127 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2129 C<join> will usually do what you need and it is strongly recommended that you
2130 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2131 And we really do mean "cannot", not just tried and failed. Attempting to use
2132 this because you're having problems with C<join> is like trying to use x86
2133 ASM because you've got a syntax error in your C. Trust us on this.
2135 Now, if you're still really, really sure you need to use this (and if you're
2136 not 100% sure, ask the mailing list first), here's an explanation of how this
2139 The syntax is as follows -
2142 { <alias1> => <table1> },
2144 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2145 [], # nested JOIN (optional)
2146 { <table1.column1> => <table2.column2>, ... (more conditions) },
2148 # More of the above [ ] may follow for additional joins
2155 ON <table1.column1> = <table2.column2>
2156 <more joins may follow>
2158 An easy way to follow the examples below is to remember the following:
2160 Anything inside "[]" is a JOIN
2161 Anything inside "{}" is a condition for the enclosing JOIN
2163 The following examples utilize a "person" table in a family tree application.
2164 In order to express parent->child relationships, this table is self-joined:
2166 # Person->belongs_to('father' => 'Person');
2167 # Person->belongs_to('mother' => 'Person');
2169 C<from> can be used to nest joins. Here we return all children with a father,
2170 then search against all mothers of those children:
2172 $rs = $schema->resultset('Person')->search(
2175 alias => 'mother', # alias columns in accordance with "from"
2177 { mother => 'person' },
2180 { child => 'person' },
2182 { father => 'person' },
2183 { 'father.person_id' => 'child.father_id' }
2186 { 'mother.person_id' => 'child.mother_id' }
2193 # SELECT mother.* FROM person mother
2196 # JOIN person father
2197 # ON ( father.person_id = child.father_id )
2199 # ON ( mother.person_id = child.mother_id )
2201 The type of any join can be controlled manually. To search against only people
2202 with a father in the person table, we could explicitly use C<INNER JOIN>:
2204 $rs = $schema->resultset('Person')->search(
2207 alias => 'child', # alias columns in accordance with "from"
2209 { child => 'person' },
2211 { father => 'person', -join_type => 'inner' },
2212 { 'father.id' => 'child.father_id' }
2219 # SELECT child.* FROM person child
2220 # INNER JOIN person father ON child.father_id = father.id