1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use base qw/DBIx::Class/;
15 use Data::Dumper; $Data::Dumper::Indent = 1;
17 __PACKAGE__->load_components(qw/AccessorGroup/);
18 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
22 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
26 my $rs = $schema->resultset('User')->search(registered => 1);
27 my @rows = $schema->resultset('CD')->search(year => 2005);
31 The resultset is also known as an iterator. It is responsible for handling
32 queries that may return an arbitrary number of rows, e.g. via L</search>
33 or a C<has_many> relationship.
35 In the examples below, the following table classes are used:
37 package MyApp::Schema::Artist;
38 use base qw/DBIx::Class/;
39 __PACKAGE__->load_components(qw/Core/);
40 __PACKAGE__->table('artist');
41 __PACKAGE__->add_columns(qw/artistid name/);
42 __PACKAGE__->set_primary_key('artistid');
43 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
46 package MyApp::Schema::CD;
47 use base qw/DBIx::Class/;
48 __PACKAGE__->load_components(qw/Core/);
49 __PACKAGE__->table('cd');
50 __PACKAGE__->add_columns(qw/cdid artist title year/);
51 __PACKAGE__->set_primary_key('cdid');
52 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
61 =item Arguments: $source, \%$attrs
63 =item Return Value: $rs
67 The resultset constructor. Takes a source object (usually a
68 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
69 L</ATTRIBUTES> below). Does not perform any queries -- these are
70 executed as needed by the other methods.
72 Generally you won't need to construct a resultset manually. You'll
73 automatically get one from e.g. a L</search> called in scalar context:
75 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
77 IMPORTANT: If called on an object, proxies to new_result instead so
79 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
81 will return a CD object, not a ResultSet.
87 return $class->new_result(@_) if ref $class;
89 my ($source, $attrs) = @_;
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 result_source => $source,
102 result_class => $attrs->{result_class} || $source->result_class,
103 cond => $attrs->{where},
114 =item Arguments: $cond, \%attrs?
116 =item Return Value: $resultset (scalar context), @row_objs (list context)
120 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
121 my $new_rs = $cd_rs->search({ year => 2005 });
123 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
124 # year = 2005 OR year = 2004
126 If you need to pass in additional attributes but no additional condition,
127 call it as C<search(undef, \%attrs)>.
129 # "SELECT name, artistid FROM $artist_table"
130 my @all_artists = $schema->resultset('Artist')->search(undef, {
131 columns => [qw/name artistid/],
138 my $rs = $self->search_rs( @_ );
139 return (wantarray ? $rs->all : $rs);
146 =item Arguments: $cond, \%attrs?
148 =item Return Value: $resultset
152 This method does the same exact thing as search() except it will
153 always return a resultset, even in list context.
162 unless (@_) { # no search, effectively just a clone
163 $rows = $self->get_cache;
167 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
168 my $our_attrs = { %{$self->{attrs}} };
169 my $having = delete $our_attrs->{having};
171 # merge new attrs into inherited
172 foreach my $key (qw/join prefetch/) {
173 next unless exists $attrs->{$key};
174 $our_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, delete $attrs->{$key});
177 my $new_attrs = { %{$our_attrs}, %{$attrs} };
180 (@_ == 1 || ref $_[0] eq "HASH")
184 ? $self->throw_exception("Odd number of arguments to search")
191 if (defined $where) {
192 $new_attrs->{where} = (
193 defined $new_attrs->{where}
196 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
197 } $where, $new_attrs->{where}
203 if (defined $having) {
204 $new_attrs->{having} = (
205 defined $new_attrs->{having}
208 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
209 } $having, $new_attrs->{having}
215 my $rs = (ref $self)->new($self->result_source, $new_attrs);
217 $rs->set_cache($rows);
222 =head2 search_literal
226 =item Arguments: $sql_fragment, @bind_values
228 =item Return Value: $resultset (scalar context), @row_objs (list context)
232 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
233 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
235 Pass a literal chunk of SQL to be added to the conditional part of the
241 my ($self, $cond, @vals) = @_;
242 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
243 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
244 return $self->search(\$cond, $attrs);
251 =item Arguments: @values | \%cols, \%attrs?
253 =item Return Value: $row_object
257 Finds a row based on its primary key or unique constraint. For example, to find
258 a row by its primary key:
260 my $cd = $schema->resultset('CD')->find(5);
262 You can also find a row by a specific unique constraint using the C<key>
263 attribute. For example:
265 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
266 key => 'cd_artist_title'
269 Additionally, you can specify the columns explicitly by name:
271 my $cd = $schema->resultset('CD')->find(
273 artist => 'Massive Attack',
274 title => 'Mezzanine',
276 { key => 'cd_artist_title' }
279 If the C<key> is specified as C<primary>, it searches only on the primary key.
281 If no C<key> is specified, it searches on all unique constraints defined on the
282 source, including the primary key.
284 See also L</find_or_create> and L</update_or_create>. For information on how to
285 declare unique constraints, see
286 L<DBIx::Class::ResultSource/add_unique_constraint>.
292 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
294 # Default to the primary key, but allow a specific key
295 my @cols = exists $attrs->{key}
296 ? $self->result_source->unique_constraint_columns($attrs->{key})
297 : $self->result_source->primary_columns;
298 $self->throw_exception(
299 "Can't find unless a primary key or unique constraint is defined"
302 # Parse out a hashref from input
304 if (ref $_[0] eq 'HASH') {
305 $input_query = { %{$_[0]} };
307 elsif (@_ == @cols) {
309 @{$input_query}{@cols} = @_;
312 # Compatibility: Allow e.g. find(id => $value)
313 carp "Find by key => value deprecated; please use a hashref instead";
317 my @unique_queries = $self->_unique_queries($input_query, $attrs);
319 # Handle cases where the ResultSet defines the query, or where the user is
321 my $query = @unique_queries ? \@unique_queries : $input_query;
325 my $rs = $self->search($query, $attrs);
326 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
329 return keys %{$self->_resolved_attrs->{collapse}}
330 ? $self->search($query)->next
331 : $self->single($query);
337 # Build a list of queries which satisfy unique constraints.
339 sub _unique_queries {
340 my ($self, $query, $attrs) = @_;
342 my $alias = $self->{attrs}{alias};
343 my @constraint_names = exists $attrs->{key}
345 : $self->result_source->unique_constraint_names;
348 foreach my $name (@constraint_names) {
349 my @unique_cols = $self->result_source->unique_constraint_columns($name);
350 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
352 my $num_query = scalar keys %$unique_query;
353 next unless $num_query;
355 # Add the ResultSet's alias
356 foreach my $col (grep { ! m/\./ } keys %$unique_query) {
357 $unique_query->{"$alias.$col"} = delete $unique_query->{$col};
360 # XXX: Assuming quite a bit about $self->{attrs}{where}
361 my $num_cols = scalar @unique_cols;
362 my $num_where = exists $self->{attrs}{where}
363 ? scalar keys %{ $self->{attrs}{where} }
365 push @unique_queries, $unique_query
366 if $num_query + $num_where == $num_cols;
369 return @unique_queries;
372 # _build_unique_query
374 # Constrain the specified query hash based on the specified column names.
376 sub _build_unique_query {
377 my ($self, $query, $unique_cols) = @_;
380 map { $_ => $query->{$_} }
381 grep { exists $query->{$_} }
386 =head2 search_related
390 =item Arguments: $rel, $cond, \%attrs?
392 =item Return Value: $new_resultset
396 $new_rs = $cd_rs->search_related('artist', {
400 Searches the specified relationship, optionally specifying a condition and
401 attributes for matching records. See L</ATTRIBUTES> for more information.
406 return shift->related_resultset(shift)->search(@_);
413 =item Arguments: none
415 =item Return Value: $cursor
419 Returns a storage-driven cursor to the given resultset. See
420 L<DBIx::Class::Cursor> for more information.
427 my $attrs = { %{$self->_resolved_attrs} };
428 return $self->{cursor}
429 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
430 $attrs->{where},$attrs);
437 =item Arguments: $cond?
439 =item Return Value: $row_object?
443 my $cd = $schema->resultset('CD')->single({ year => 2001 });
445 Inflates the first result without creating a cursor if the resultset has
446 any records in it; if not returns nothing. Used by L</find> as an optimisation.
448 Can optionally take an additional condition *only* - this is a fast-code-path
449 method; if you need to add extra joins or similar call ->search and then
450 ->single without a condition on the $rs returned from that.
455 my ($self, $where) = @_;
456 my $attrs = { %{$self->_resolved_attrs} };
458 if (defined $attrs->{where}) {
461 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
462 $where, delete $attrs->{where} ]
465 $attrs->{where} = $where;
469 unless ($self->_is_unique_query($attrs->{where})) {
470 carp "Query not guaranteed to return a single row"
471 . "; please declare your unique constraints or use search instead";
474 my @data = $self->result_source->storage->select_single(
475 $attrs->{from}, $attrs->{select},
476 $attrs->{where}, $attrs
479 return (@data ? $self->_construct_object(@data) : ());
484 # Try to determine if the specified query is guaranteed to be unique, based on
485 # the declared unique constraints.
487 sub _is_unique_query {
488 my ($self, $query) = @_;
490 my $collapsed = $self->_collapse_query($query);
491 my $alias = $self->{attrs}{alias};
493 foreach my $name ($self->result_source->unique_constraint_names) {
494 my @unique_cols = map {
496 } $self->result_source->unique_constraint_columns($name);
498 # Count the values for each unique column
499 my %seen = map { $_ => 0 } @unique_cols;
501 foreach my $key (keys %$collapsed) {
502 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
503 next unless exists $seen{$aliased}; # Additional constraints are okay
504 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
507 # If we get 0 or more than 1 value for a column, it's not necessarily unique
508 return 1 unless grep { $_ != 1 } values %seen;
516 # Recursively collapse the query, accumulating values for each column.
518 sub _collapse_query {
519 my ($self, $query, $collapsed) = @_;
523 if (ref $query eq 'ARRAY') {
524 foreach my $subquery (@$query) {
525 next unless ref $subquery; # -or
526 # warn "ARRAY: " . Dumper $subquery;
527 $collapsed = $self->_collapse_query($subquery, $collapsed);
530 elsif (ref $query eq 'HASH') {
531 if (keys %$query and (keys %$query)[0] eq '-and') {
532 foreach my $subquery (@{$query->{-and}}) {
533 # warn "HASH: " . Dumper $subquery;
534 $collapsed = $self->_collapse_query($subquery, $collapsed);
538 # warn "LEAF: " . Dumper $query;
539 foreach my $col (keys %$query) {
540 my $value = $query->{$col};
541 $collapsed->{$col}{$value}++;
553 =item Arguments: $cond?
555 =item Return Value: $resultsetcolumn
559 my $max_length = $rs->get_column('length')->max;
561 Returns a ResultSetColumn instance for $column based on $self
566 my ($self, $column) = @_;
567 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
575 =item Arguments: $cond, \%attrs?
577 =item Return Value: $resultset (scalar context), @row_objs (list context)
581 # WHERE title LIKE '%blue%'
582 $cd_rs = $rs->search_like({ title => '%blue%'});
584 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
585 that this is simply a convenience method. You most likely want to use
586 L</search> with specific operators.
588 For more information, see L<DBIx::Class::Manual::Cookbook>.
594 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
595 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
596 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
597 return $class->search($query, { %$attrs });
604 =item Arguments: $first, $last
606 =item Return Value: $resultset (scalar context), @row_objs (list context)
610 Returns a resultset or object list representing a subset of elements from the
611 resultset slice is called on. Indexes are from 0, i.e., to get the first
614 my ($one, $two, $three) = $rs->slice(0, 2);
619 my ($self, $min, $max) = @_;
620 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
621 $attrs->{offset} = $self->{attrs}{offset} || 0;
622 $attrs->{offset} += $min;
623 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
624 return $self->search(undef(), $attrs);
625 #my $slice = (ref $self)->new($self->result_source, $attrs);
626 #return (wantarray ? $slice->all : $slice);
633 =item Arguments: none
635 =item Return Value: $result?
639 Returns the next element in the resultset (C<undef> is there is none).
641 Can be used to efficiently iterate over records in the resultset:
643 my $rs = $schema->resultset('CD')->search;
644 while (my $cd = $rs->next) {
648 Note that you need to store the resultset object, and call C<next> on it.
649 Calling C<< resultset('Table')->next >> repeatedly will always return the
650 first record from the resultset.
656 if (my $cache = $self->get_cache) {
657 $self->{all_cache_position} ||= 0;
658 return $cache->[$self->{all_cache_position}++];
660 if ($self->{attrs}{cache}) {
661 $self->{all_cache_position} = 1;
662 return ($self->all)[0];
665 exists $self->{stashed_row}
666 ? @{delete $self->{stashed_row}}
667 : $self->cursor->next
669 return unless (@row);
670 return $self->_construct_object(@row);
673 sub _construct_object {
674 my ($self, @row) = @_;
675 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
676 my $new = $self->result_class->inflate_result($self->result_source, @$info);
677 $new = $self->{_attrs}{record_filter}->($new)
678 if exists $self->{_attrs}{record_filter};
682 sub _collapse_result {
683 my ($self, $as, $row, $prefix) = @_;
688 foreach my $this_as (@$as) {
689 my $val = shift @copy;
690 if (defined $prefix) {
691 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
693 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
694 $const{$1||''}{$2} = $val;
697 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
698 $const{$1||''}{$2} = $val;
702 my $alias = $self->{attrs}{alias};
703 my $info = [ {}, {} ];
704 foreach my $key (keys %const) {
705 if (length $key && $key ne $alias) {
707 my @parts = split(/\./, $key);
708 foreach my $p (@parts) {
709 $target = $target->[1]->{$p} ||= [];
711 $target->[0] = $const{$key};
713 $info->[0] = $const{$key};
718 if (defined $prefix) {
720 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
721 } keys %{$self->{_attrs}{collapse}}
723 @collapse = keys %{$self->{_attrs}{collapse}};
727 my ($c) = sort { length $a <=> length $b } @collapse;
729 foreach my $p (split(/\./, $c)) {
730 $target = $target->[1]->{$p} ||= [];
732 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
733 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
734 my $tree = $self->_collapse_result($as, $row, $c_prefix);
735 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
741 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
746 last unless (@raw = $self->cursor->next);
747 $row = $self->{stashed_row} = \@raw;
748 $tree = $self->_collapse_result($as, $row, $c_prefix);
750 @$target = (@final ? @final : [ {}, {} ]);
751 # single empty result to indicate an empty prefetched has_many
754 #print "final info: " . Dumper($info);
762 =item Arguments: $result_source?
764 =item Return Value: $result_source
768 An accessor for the primary ResultSource object from which this ResultSet
778 =item Arguments: $cond, \%attrs??
780 =item Return Value: $count
784 Performs an SQL C<COUNT> with the same query as the resultset was built
785 with to find the number of elements. If passed arguments, does a search
786 on the resultset and counts the results of that.
788 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
789 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
790 not support C<DISTINCT> with multiple columns. If you are using such a
791 database, you should only use columns from the main table in your C<group_by>
798 return $self->search(@_)->count if @_ and defined $_[0];
799 return scalar @{ $self->get_cache } if $self->get_cache;
800 my $count = $self->_count;
801 return 0 unless $count;
803 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
804 $count = $self->{attrs}{rows} if
805 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
809 sub _count { # Separated out so pager can get the full count
811 my $select = { count => '*' };
813 my $attrs = { %{$self->_resolved_attrs} };
814 if (my $group_by = delete $attrs->{group_by}) {
815 delete $attrs->{having};
816 my @distinct = (ref $group_by ? @$group_by : ($group_by));
817 # todo: try CONCAT for multi-column pk
818 my @pk = $self->result_source->primary_columns;
820 my $alias = $attrs->{alias};
821 foreach my $column (@distinct) {
822 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
823 @distinct = ($column);
829 $select = { count => { distinct => \@distinct } };
832 $attrs->{select} = $select;
833 $attrs->{as} = [qw/count/];
835 # offset, order by and page are not needed to count. record_filter is cdbi
836 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
838 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
839 my ($count) = $tmp_rs->cursor->next;
847 =item Arguments: $sql_fragment, @bind_values
849 =item Return Value: $count
853 Counts the results in a literal query. Equivalent to calling L</search_literal>
854 with the passed arguments, then L</count>.
858 sub count_literal { shift->search_literal(@_)->count; }
864 =item Arguments: none
866 =item Return Value: @objects
870 Returns all elements in the resultset. Called implicitly if the resultset
871 is returned in list context.
877 return @{ $self->get_cache } if $self->get_cache;
881 # TODO: don't call resolve here
882 if (keys %{$self->_resolved_attrs->{collapse}}) {
883 # if ($self->{attrs}{prefetch}) {
884 # Using $self->cursor->all is really just an optimisation.
885 # If we're collapsing has_many prefetches it probably makes
886 # very little difference, and this is cleaner than hacking
887 # _construct_object to survive the approach
888 my @row = $self->cursor->next;
890 push(@obj, $self->_construct_object(@row));
891 @row = (exists $self->{stashed_row}
892 ? @{delete $self->{stashed_row}}
893 : $self->cursor->next);
896 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
899 $self->set_cache(\@obj) if $self->{attrs}{cache};
907 =item Arguments: none
909 =item Return Value: $self
913 Resets the resultset's cursor, so you can iterate through the elements again.
919 delete $self->{_attrs} if exists $self->{_attrs};
920 $self->{all_cache_position} = 0;
921 $self->cursor->reset;
929 =item Arguments: none
931 =item Return Value: $object?
935 Resets the resultset and returns an object for the first result (if the
936 resultset returns anything).
941 return $_[0]->reset->next;
944 # _cond_for_update_delete
946 # update/delete require the condition to be modified to handle
947 # the differing SQL syntax available. This transforms the $self->{cond}
948 # appropriately, returning the new condition.
950 sub _cond_for_update_delete {
954 # No-op. No condition, we're updating/deleting everything
955 return $cond unless ref $self->{cond};
957 if (ref $self->{cond} eq 'ARRAY') {
961 foreach my $key (keys %{$_}) {
963 $hash{$1} = $_->{$key};
969 elsif (ref $self->{cond} eq 'HASH') {
970 if ((keys %{$self->{cond}})[0] eq '-and') {
973 my @cond = @{$self->{cond}{-and}};
974 for (my $i = 0; $i < @cond; $i++) {
975 my $entry = $cond[$i];
978 if (ref $entry eq 'HASH') {
979 foreach my $key (keys %{$entry}) {
981 $hash{$1} = $entry->{$key};
985 $entry =~ /([^.]+)$/;
986 $hash{$1} = $cond[++$i];
989 push @{$cond->{-and}}, \%hash;
993 foreach my $key (keys %{$self->{cond}}) {
995 $cond->{$1} = $self->{cond}{$key};
1000 $self->throw_exception(
1001 "Can't update/delete on resultset with condition unless hash or array"
1013 =item Arguments: \%values
1015 =item Return Value: $storage_rv
1019 Sets the specified columns in the resultset to the supplied values in a
1020 single query. Return value will be true if the update succeeded or false
1021 if no records were updated; exact type of success value is storage-dependent.
1026 my ($self, $values) = @_;
1027 $self->throw_exception("Values for update must be a hash")
1028 unless ref $values eq 'HASH';
1030 my $cond = $self->_cond_for_update_delete;
1032 return $self->result_source->storage->update(
1033 $self->result_source->from, $values, $cond
1041 =item Arguments: \%values
1043 =item Return Value: 1
1047 Fetches all objects and updates them one at a time. Note that C<update_all>
1048 will run DBIC cascade triggers, while L</update> will not.
1053 my ($self, $values) = @_;
1054 $self->throw_exception("Values for update must be a hash")
1055 unless ref $values eq 'HASH';
1056 foreach my $obj ($self->all) {
1057 $obj->set_columns($values)->update;
1066 =item Arguments: none
1068 =item Return Value: 1
1072 Deletes the contents of the resultset from its result source. Note that this
1073 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1081 my $cond = $self->_cond_for_update_delete;
1083 $self->result_source->storage->delete($self->result_source->from, $cond);
1091 =item Arguments: none
1093 =item Return Value: 1
1097 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1098 will run DBIC cascade triggers, while L</delete> will not.
1104 $_->delete for $self->all;
1112 =item Arguments: none
1114 =item Return Value: $pager
1118 Return Value a L<Data::Page> object for the current resultset. Only makes
1119 sense for queries with a C<page> attribute.
1125 my $attrs = $self->{attrs};
1126 $self->throw_exception("Can't create pager for non-paged rs")
1127 unless $self->{attrs}{page};
1128 $attrs->{rows} ||= 10;
1129 return $self->{pager} ||= Data::Page->new(
1130 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1137 =item Arguments: $page_number
1139 =item Return Value: $rs
1143 Returns a resultset for the $page_number page of the resultset on which page
1144 is called, where each page contains a number of rows equal to the 'rows'
1145 attribute set on the resultset (10 by default).
1150 my ($self, $page) = @_;
1151 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1158 =item Arguments: \%vals
1160 =item Return Value: $object
1164 Creates an object in the resultset's result class and returns it.
1169 my ($self, $values) = @_;
1170 $self->throw_exception( "new_result needs a hash" )
1171 unless (ref $values eq 'HASH');
1172 $self->throw_exception(
1173 "Can't abstract implicit construct, condition not a hash"
1174 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1176 my $alias = $self->{attrs}{alias};
1177 foreach my $key (keys %{$self->{cond}||{}}) {
1178 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1180 my $obj = $self->result_class->new(\%new);
1181 $obj->result_source($self->result_source) if $obj->can('result_source');
1189 =item Arguments: \%vals, \%attrs?
1191 =item Return Value: $object
1195 Find an existing record from this resultset. If none exists, instantiate a new
1196 result object and return it. The object will not be saved into your storage
1197 until you call L<DBIx::Class::Row/insert> on it.
1199 If you want objects to be saved immediately, use L</find_or_create> instead.
1205 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1206 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1207 my $exists = $self->find($hash, $attrs);
1208 return defined $exists ? $exists : $self->new_result($hash);
1215 =item Arguments: \%vals
1217 =item Return Value: $object
1221 Inserts a record into the resultset and returns the object representing it.
1223 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1228 my ($self, $attrs) = @_;
1229 $self->throw_exception( "create needs a hashref" )
1230 unless ref $attrs eq 'HASH';
1231 return $self->new_result($attrs)->insert;
1234 =head2 find_or_create
1238 =item Arguments: \%vals, \%attrs?
1240 =item Return Value: $object
1244 $class->find_or_create({ key => $val, ... });
1246 Tries to find a record based on its primary key or unique constraint; if none
1247 is found, creates one and returns that instead.
1249 my $cd = $schema->resultset('CD')->find_or_create({
1251 artist => 'Massive Attack',
1252 title => 'Mezzanine',
1256 Also takes an optional C<key> attribute, to search by a specific key or unique
1257 constraint. For example:
1259 my $cd = $schema->resultset('CD')->find_or_create(
1261 artist => 'Massive Attack',
1262 title => 'Mezzanine',
1264 { key => 'cd_artist_title' }
1267 See also L</find> and L</update_or_create>. For information on how to declare
1268 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1272 sub find_or_create {
1274 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1275 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1276 my $exists = $self->find($hash, $attrs);
1277 return defined $exists ? $exists : $self->create($hash);
1280 =head2 update_or_create
1284 =item Arguments: \%col_values, { key => $unique_constraint }?
1286 =item Return Value: $object
1290 $class->update_or_create({ col => $val, ... });
1292 First, searches for an existing row matching one of the unique constraints
1293 (including the primary key) on the source of this resultset. If a row is
1294 found, updates it with the other given column values. Otherwise, creates a new
1297 Takes an optional C<key> attribute to search on a specific unique constraint.
1300 # In your application
1301 my $cd = $schema->resultset('CD')->update_or_create(
1303 artist => 'Massive Attack',
1304 title => 'Mezzanine',
1307 { key => 'cd_artist_title' }
1310 If no C<key> is specified, it searches on all unique constraints defined on the
1311 source, including the primary key.
1313 If the C<key> is specified as C<primary>, it searches only on the primary key.
1315 See also L</find> and L</find_or_create>. For information on how to declare
1316 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1320 sub update_or_create {
1322 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1323 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1325 my $row = $self->find($cond);
1327 $row->update($cond);
1331 return $self->create($cond);
1338 =item Arguments: none
1340 =item Return Value: \@cache_objects?
1344 Gets the contents of the cache for the resultset, if the cache is set.
1356 =item Arguments: \@cache_objects
1358 =item Return Value: \@cache_objects
1362 Sets the contents of the cache for the resultset. Expects an arrayref
1363 of objects of the same class as those produced by the resultset. Note that
1364 if the cache is set the resultset will return the cached objects rather
1365 than re-querying the database even if the cache attr is not set.
1370 my ( $self, $data ) = @_;
1371 $self->throw_exception("set_cache requires an arrayref")
1372 if defined($data) && (ref $data ne 'ARRAY');
1373 $self->{all_cache} = $data;
1380 =item Arguments: none
1382 =item Return Value: []
1386 Clears the cache for the resultset.
1391 shift->set_cache(undef);
1394 =head2 related_resultset
1398 =item Arguments: $relationship_name
1400 =item Return Value: $resultset
1404 Returns a related resultset for the supplied relationship name.
1406 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1410 sub related_resultset {
1411 my ($self, $rel) = @_;
1413 $self->{related_resultsets} ||= {};
1414 return $self->{related_resultsets}{$rel} ||= do {
1415 my $rel_obj = $self->result_source->relationship_info($rel);
1417 $self->throw_exception(
1418 "search_related: result source '" . $self->result_source->name .
1419 "' has no such relationship $rel")
1422 my ($from,$seen) = $self->search(undef, { join => $rel })->_resolve_from;
1424 my $join_count = $self->{attrs}{seen_join}{$rel};
1425 my $alias = $join_count ? join('_', $rel, $join_count+1) : $rel;
1427 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1429 %{$self->{attrs}||{}},
1435 where => $self->{cond},
1437 _parent_from => $from,
1444 my $source = $self->result_source;
1445 my $attrs = $self->{attrs};
1447 my $from = $attrs->{_parent_from}
1448 || [ { $attrs->{alias} => $source->from } ];
1450 my $seen = { %{$attrs->{seen_join}||{}} };
1452 if ($attrs->{join}) {
1454 $source->resolve_join($attrs->{join}, $attrs->{alias}, $seen)
1458 return ($from,$seen);
1461 sub _resolved_attrs {
1463 return $self->{_attrs} if $self->{_attrs};
1465 my $attrs = { %{$self->{attrs}||{}} };
1466 my $source = $self->{result_source};
1467 my $alias = $attrs->{alias};
1469 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1470 if ($attrs->{columns}) {
1471 delete $attrs->{as};
1472 } elsif (!$attrs->{select}) {
1473 $attrs->{columns} = [ $source->columns ];
1476 $attrs->{select} ||= [
1477 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
1480 map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
1484 if ($adds = delete $attrs->{include_columns}) {
1485 $adds = [$adds] unless ref $adds eq 'ARRAY';
1486 push(@{$attrs->{select}}, @$adds);
1487 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1489 if ($adds = delete $attrs->{'+select'}) {
1490 $adds = [$adds] unless ref $adds eq 'ARRAY';
1491 push(@{$attrs->{select}}, map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1493 if (my $adds = delete $attrs->{'+as'}) {
1494 $adds = [$adds] unless ref $adds eq 'ARRAY';
1495 push(@{$attrs->{as}}, @$adds);
1498 $attrs->{from} ||= delete $attrs->{_parent_from}
1499 || [ { 'me' => $source->from } ];
1501 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1502 my $join = delete $attrs->{join} || {};
1504 if (defined $attrs->{prefetch}) {
1505 $join = $self->_merge_attr(
1506 $join, $attrs->{prefetch}
1510 push(@{$attrs->{from}},
1511 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1515 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1516 if ($attrs->{order_by}) {
1517 $attrs->{order_by} = [ $attrs->{order_by} ] unless ref $attrs->{order_by};
1519 $attrs->{order_by} ||= [];
1522 my $collapse = $attrs->{collapse} || {};
1523 if (my $prefetch = delete $attrs->{prefetch}) {
1525 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1526 # bring joins back to level of current class
1527 my @prefetch = $source->resolve_prefetch(
1528 $p, $alias, { %{$attrs->{seen_join}||{}} }, \@pre_order, $collapse
1530 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1531 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1533 push(@{$attrs->{order_by}}, @pre_order);
1535 $attrs->{collapse} = $collapse;
1537 return $self->{_attrs} = $attrs;
1541 my ($self, $a, $b) = @_;
1542 return $b unless $a;
1544 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1545 foreach my $key (keys %{$b}) {
1546 if (exists $a->{$key}) {
1547 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1549 $a->{$key} = $b->{$key};
1554 $a = [$a] unless ref $a eq 'ARRAY';
1555 $b = [$b] unless ref $b eq 'ARRAY';
1559 foreach my $x ($a, $b) {
1560 foreach my $element (@{$x}) {
1561 if (ref $element eq 'HASH') {
1562 $hash = $self->_merge_attr($hash, $element);
1563 } elsif (ref $element eq 'ARRAY') {
1564 push(@array, @{$element});
1566 push(@array, $element) unless $b == $x
1567 && grep { $_ eq $element } @array;
1572 @array = grep { !exists $hash->{$_} } @array;
1574 return keys %{$hash}
1583 =head2 throw_exception
1585 See L<DBIx::Class::Schema/throw_exception> for details.
1589 sub throw_exception {
1591 $self->result_source->schema->throw_exception(@_);
1594 # XXX: FIXME: Attributes docs need clearing up
1598 The resultset takes various attributes that modify its behavior. Here's an
1605 =item Value: ($order_by | \@order_by)
1609 Which column(s) to order the results by. This is currently passed
1610 through directly to SQL, so you can give e.g. C<year DESC> for a
1611 descending order on the column `year'.
1613 Please note that if you have quoting enabled (see
1614 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1615 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1616 so you will need to manually quote things as appropriate.)
1622 =item Value: \@columns
1626 Shortcut to request a particular set of columns to be retrieved. Adds
1627 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1628 from that, then auto-populates C<as> from C<select> as normal. (You may also
1629 use the C<cols> attribute, as in earlier versions of DBIC.)
1631 =head2 include_columns
1635 =item Value: \@columns
1639 Shortcut to include additional columns in the returned results - for example
1641 $schema->resultset('CD')->search(undef, {
1642 include_columns => ['artist.name'],
1646 would return all CDs and include a 'name' column to the information
1647 passed to object inflation
1653 =item Value: \@select_columns
1657 Indicates which columns should be selected from the storage. You can use
1658 column names, or in the case of RDBMS back ends, function or stored procedure
1661 $rs = $schema->resultset('Employee')->search(undef, {
1664 { count => 'employeeid' },
1669 When you use function/stored procedure names and do not supply an C<as>
1670 attribute, the column names returned are storage-dependent. E.g. MySQL would
1671 return a column named C<count(employeeid)> in the above example.
1677 Indicates additional columns to be selected from storage. Works the same as
1678 L<select> but adds columns to the selection.
1686 Indicates additional column names for those added via L<+select>.
1694 =item Value: \@inflation_names
1698 Indicates column names for object inflation. This is used in conjunction with
1699 C<select>, usually when C<select> contains one or more function or stored
1702 $rs = $schema->resultset('Employee')->search(undef, {
1705 { count => 'employeeid' }
1707 as => ['name', 'employee_count'],
1710 my $employee = $rs->first(); # get the first Employee
1712 If the object against which the search is performed already has an accessor
1713 matching a column name specified in C<as>, the value can be retrieved using
1714 the accessor as normal:
1716 my $name = $employee->name();
1718 If on the other hand an accessor does not exist in the object, you need to
1719 use C<get_column> instead:
1721 my $employee_count = $employee->get_column('employee_count');
1723 You can create your own accessors if required - see
1724 L<DBIx::Class::Manual::Cookbook> for details.
1726 Please note: This will NOT insert an C<AS employee_count> into the SQL statement
1727 produced, it is used for internal access only. Thus attempting to use the accessor
1728 in an C<order_by> clause or similar will fail misrably.
1734 =item Value: ($rel_name | \@rel_names | \%rel_names)
1738 Contains a list of relationships that should be joined for this query. For
1741 # Get CDs by Nine Inch Nails
1742 my $rs = $schema->resultset('CD')->search(
1743 { 'artist.name' => 'Nine Inch Nails' },
1744 { join => 'artist' }
1747 Can also contain a hash reference to refer to the other relation's relations.
1750 package MyApp::Schema::Track;
1751 use base qw/DBIx::Class/;
1752 __PACKAGE__->table('track');
1753 __PACKAGE__->add_columns(qw/trackid cd position title/);
1754 __PACKAGE__->set_primary_key('trackid');
1755 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1758 # In your application
1759 my $rs = $schema->resultset('Artist')->search(
1760 { 'track.title' => 'Teardrop' },
1762 join => { cd => 'track' },
1763 order_by => 'artist.name',
1767 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1768 similarly for a third time). For e.g.
1770 my $rs = $schema->resultset('Artist')->search({
1771 'cds.title' => 'Down to Earth',
1772 'cds_2.title' => 'Popular',
1774 join => [ qw/cds cds/ ],
1777 will return a set of all artists that have both a cd with title 'Down
1778 to Earth' and a cd with title 'Popular'.
1780 If you want to fetch related objects from other tables as well, see C<prefetch>
1787 =item Value: ($rel_name | \@rel_names | \%rel_names)
1791 Contains one or more relationships that should be fetched along with the main
1792 query (when they are accessed afterwards they will have already been
1793 "prefetched"). This is useful for when you know you will need the related
1794 objects, because it saves at least one query:
1796 my $rs = $schema->resultset('Tag')->search(
1805 The initial search results in SQL like the following:
1807 SELECT tag.*, cd.*, artist.* FROM tag
1808 JOIN cd ON tag.cd = cd.cdid
1809 JOIN artist ON cd.artist = artist.artistid
1811 L<DBIx::Class> has no need to go back to the database when we access the
1812 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1815 Simple prefetches will be joined automatically, so there is no need
1816 for a C<join> attribute in the above search. If you're prefetching to
1817 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1818 specify the join as well.
1820 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1821 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1822 with an accessor type of 'single' or 'filter').
1832 Makes the resultset paged and specifies the page to retrieve. Effectively
1833 identical to creating a non-pages resultset and then calling ->page($page)
1836 If L<rows> attribute is not specified it defualts to 10 rows per page.
1846 Specifes the maximum number of rows for direct retrieval or the number of
1847 rows per page if the page attribute or method is used.
1853 =item Value: $offset
1857 Specifies the (zero-based) row number for the first row to be returned, or the
1858 of the first row of the first page if paging is used.
1864 =item Value: \@columns
1868 A arrayref of columns to group by. Can include columns of joined tables.
1870 group_by => [qw/ column1 column2 ... /]
1876 =item Value: $condition
1880 HAVING is a select statement attribute that is applied between GROUP BY and
1881 ORDER BY. It is applied to the after the grouping calculations have been
1884 having => { 'count(employee)' => { '>=', 100 } }
1890 =item Value: (0 | 1)
1894 Set to 1 to group by all columns.
1900 Adds to the WHERE clause.
1902 # only return rows WHERE deleted IS NULL for all searches
1903 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
1905 Can be overridden by passing C<{ where => undef }> as an attribute
1912 Set to 1 to cache search results. This prevents extra SQL queries if you
1913 revisit rows in your ResultSet:
1915 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1917 while( my $artist = $resultset->next ) {
1921 $rs->first; # without cache, this would issue a query
1923 By default, searches are not cached.
1925 For more examples of using these attributes, see
1926 L<DBIx::Class::Manual::Cookbook>.
1932 =item Value: \@from_clause
1936 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1937 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1940 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1942 C<join> will usually do what you need and it is strongly recommended that you
1943 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1944 And we really do mean "cannot", not just tried and failed. Attempting to use
1945 this because you're having problems with C<join> is like trying to use x86
1946 ASM because you've got a syntax error in your C. Trust us on this.
1948 Now, if you're still really, really sure you need to use this (and if you're
1949 not 100% sure, ask the mailing list first), here's an explanation of how this
1952 The syntax is as follows -
1955 { <alias1> => <table1> },
1957 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1958 [], # nested JOIN (optional)
1959 { <table1.column1> => <table2.column2>, ... (more conditions) },
1961 # More of the above [ ] may follow for additional joins
1968 ON <table1.column1> = <table2.column2>
1969 <more joins may follow>
1971 An easy way to follow the examples below is to remember the following:
1973 Anything inside "[]" is a JOIN
1974 Anything inside "{}" is a condition for the enclosing JOIN
1976 The following examples utilize a "person" table in a family tree application.
1977 In order to express parent->child relationships, this table is self-joined:
1979 # Person->belongs_to('father' => 'Person');
1980 # Person->belongs_to('mother' => 'Person');
1982 C<from> can be used to nest joins. Here we return all children with a father,
1983 then search against all mothers of those children:
1985 $rs = $schema->resultset('Person')->search(
1988 alias => 'mother', # alias columns in accordance with "from"
1990 { mother => 'person' },
1993 { child => 'person' },
1995 { father => 'person' },
1996 { 'father.person_id' => 'child.father_id' }
1999 { 'mother.person_id' => 'child.mother_id' }
2006 # SELECT mother.* FROM person mother
2009 # JOIN person father
2010 # ON ( father.person_id = child.father_id )
2012 # ON ( mother.person_id = child.mother_id )
2014 The type of any join can be controlled manually. To search against only people
2015 with a father in the person table, we could explicitly use C<INNER JOIN>:
2017 $rs = $schema->resultset('Person')->search(
2020 alias => 'child', # alias columns in accordance with "from"
2022 { child => 'person' },
2024 { father => 'person', -join_type => 'inner' },
2025 { 'father.id' => 'child.father_id' }
2032 # SELECT child.* FROM person child
2033 # INNER JOIN person father ON child.father_id = father.id