1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use base qw/DBIx::Class/;
15 __PACKAGE__->load_components(qw/AccessorGroup/);
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
91 $attrs->{rows} ||= 10;
92 $attrs->{offset} ||= 0;
93 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
96 $attrs->{alias} ||= 'me';
99 result_source => $source,
100 result_class => $attrs->{result_class} || $source->result_class,
101 cond => $attrs->{where},
112 =item Arguments: $cond, \%attrs?
114 =item Return Value: $resultset (scalar context), @row_objs (list context)
118 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
119 my $new_rs = $cd_rs->search({ year => 2005 });
121 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
122 # year = 2005 OR year = 2004
124 If you need to pass in additional attributes but no additional condition,
125 call it as C<search(undef, \%attrs)>.
127 # "SELECT name, artistid FROM $artist_table"
128 my @all_artists = $schema->resultset('Artist')->search(undef, {
129 columns => [qw/name artistid/],
132 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>.
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} = $where;
469 # XXX: Disabled since it doesn't infer uniqueness in all cases
470 # unless ($self->_is_unique_query($attrs->{where})) {
471 # carp "Query not guaranteed to return a single row"
472 # . "; please declare your unique constraints or use search instead";
475 my @data = $self->result_source->storage->select_single(
476 $attrs->{from}, $attrs->{select},
477 $attrs->{where}, $attrs
480 return (@data ? $self->_construct_object(@data) : ());
485 # Try to determine if the specified query is guaranteed to be unique, based on
486 # the declared unique constraints.
488 sub _is_unique_query {
489 my ($self, $query) = @_;
491 my $collapsed = $self->_collapse_query($query);
492 my $alias = $self->{attrs}{alias};
494 foreach my $name ($self->result_source->unique_constraint_names) {
495 my @unique_cols = map {
497 } $self->result_source->unique_constraint_columns($name);
499 # Count the values for each unique column
500 my %seen = map { $_ => 0 } @unique_cols;
502 foreach my $key (keys %$collapsed) {
503 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
504 next unless exists $seen{$aliased}; # Additional constraints are okay
505 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
508 # If we get 0 or more than 1 value for a column, it's not necessarily unique
509 return 1 unless grep { $_ != 1 } values %seen;
517 # Recursively collapse the query, accumulating values for each column.
519 sub _collapse_query {
520 my ($self, $query, $collapsed) = @_;
524 if (ref $query eq 'ARRAY') {
525 foreach my $subquery (@$query) {
526 next unless ref $subquery; # -or
527 # warn "ARRAY: " . Dumper $subquery;
528 $collapsed = $self->_collapse_query($subquery, $collapsed);
531 elsif (ref $query eq 'HASH') {
532 if (keys %$query and (keys %$query)[0] eq '-and') {
533 foreach my $subquery (@{$query->{-and}}) {
534 # warn "HASH: " . Dumper $subquery;
535 $collapsed = $self->_collapse_query($subquery, $collapsed);
539 # warn "LEAF: " . Dumper $query;
540 foreach my $col (keys %$query) {
541 my $value = $query->{$col};
542 $collapsed->{$col}{$value}++;
554 =item Arguments: $cond?
556 =item Return Value: $resultsetcolumn
560 my $max_length = $rs->get_column('length')->max;
562 Returns a ResultSetColumn instance for $column based on $self
567 my ($self, $column) = @_;
568 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
576 =item Arguments: $cond, \%attrs?
578 =item Return Value: $resultset (scalar context), @row_objs (list context)
582 # WHERE title LIKE '%blue%'
583 $cd_rs = $rs->search_like({ title => '%blue%'});
585 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
586 that this is simply a convenience method. You most likely want to use
587 L</search> with specific operators.
589 For more information, see L<DBIx::Class::Manual::Cookbook>.
595 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
596 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
597 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
598 return $class->search($query, { %$attrs });
605 =item Arguments: $first, $last
607 =item Return Value: $resultset (scalar context), @row_objs (list context)
611 Returns a resultset or object list representing a subset of elements from the
612 resultset slice is called on. Indexes are from 0, i.e., to get the first
615 my ($one, $two, $three) = $rs->slice(0, 2);
620 my ($self, $min, $max) = @_;
621 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
622 $attrs->{offset} = $self->{attrs}{offset} || 0;
623 $attrs->{offset} += $min;
624 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
625 return $self->search(undef(), $attrs);
626 #my $slice = (ref $self)->new($self->result_source, $attrs);
627 #return (wantarray ? $slice->all : $slice);
634 =item Arguments: none
636 =item Return Value: $result?
640 Returns the next element in the resultset (C<undef> is there is none).
642 Can be used to efficiently iterate over records in the resultset:
644 my $rs = $schema->resultset('CD')->search;
645 while (my $cd = $rs->next) {
649 Note that you need to store the resultset object, and call C<next> on it.
650 Calling C<< resultset('Table')->next >> repeatedly will always return the
651 first record from the resultset.
657 if (my $cache = $self->get_cache) {
658 $self->{all_cache_position} ||= 0;
659 return $cache->[$self->{all_cache_position}++];
661 if ($self->{attrs}{cache}) {
662 $self->{all_cache_position} = 1;
663 return ($self->all)[0];
666 exists $self->{stashed_row}
667 ? @{delete $self->{stashed_row}}
668 : $self->cursor->next
670 return unless (@row);
671 return $self->_construct_object(@row);
674 sub _construct_object {
675 my ($self, @row) = @_;
676 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
677 my $new = $self->result_class->inflate_result($self->result_source, @$info);
678 $new = $self->{_attrs}{record_filter}->($new)
679 if exists $self->{_attrs}{record_filter};
683 sub _collapse_result {
684 my ($self, $as, $row, $prefix) = @_;
689 foreach my $this_as (@$as) {
690 my $val = shift @copy;
691 if (defined $prefix) {
692 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
694 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
695 $const{$1||''}{$2} = $val;
698 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
699 $const{$1||''}{$2} = $val;
703 my $alias = $self->{attrs}{alias};
704 my $info = [ {}, {} ];
705 foreach my $key (keys %const) {
706 if (length $key && $key ne $alias) {
708 my @parts = split(/\./, $key);
709 foreach my $p (@parts) {
710 $target = $target->[1]->{$p} ||= [];
712 $target->[0] = $const{$key};
714 $info->[0] = $const{$key};
719 if (defined $prefix) {
721 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
722 } keys %{$self->{_attrs}{collapse}}
724 @collapse = keys %{$self->{_attrs}{collapse}};
728 my ($c) = sort { length $a <=> length $b } @collapse;
730 foreach my $p (split(/\./, $c)) {
731 $target = $target->[1]->{$p} ||= [];
733 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
734 my @co_key = @{$self->{_attrs}{collapse}{$c_prefix}};
735 my $tree = $self->_collapse_result($as, $row, $c_prefix);
736 my %co_check = map { ($_, $tree->[0]->{$_}); } @co_key;
742 !defined($tree->[0]->{$_}) || $co_check{$_} ne $tree->[0]->{$_}
747 last unless (@raw = $self->cursor->next);
748 $row = $self->{stashed_row} = \@raw;
749 $tree = $self->_collapse_result($as, $row, $c_prefix);
751 @$target = (@final ? @final : [ {}, {} ]);
752 # single empty result to indicate an empty prefetched has_many
755 #print "final info: " . Dumper($info);
763 =item Arguments: $result_source?
765 =item Return Value: $result_source
769 An accessor for the primary ResultSource object from which this ResultSet
776 =item Arguments: $result_class?
778 =item Return Value: $result_class
782 An accessor for the class to use when creating row objects. Defaults to
783 C<< result_source->result_class >> - which in most cases is the name of the
784 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
793 =item Arguments: $cond, \%attrs??
795 =item Return Value: $count
799 Performs an SQL C<COUNT> with the same query as the resultset was built
800 with to find the number of elements. If passed arguments, does a search
801 on the resultset and counts the results of that.
803 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
804 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
805 not support C<DISTINCT> with multiple columns. If you are using such a
806 database, you should only use columns from the main table in your C<group_by>
813 return $self->search(@_)->count if @_ and defined $_[0];
814 return scalar @{ $self->get_cache } if $self->get_cache;
815 my $count = $self->_count;
816 return 0 unless $count;
818 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
819 $count = $self->{attrs}{rows} if
820 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
824 sub _count { # Separated out so pager can get the full count
826 my $select = { count => '*' };
828 my $attrs = { %{$self->_resolved_attrs} };
829 if (my $group_by = delete $attrs->{group_by}) {
830 delete $attrs->{having};
831 my @distinct = (ref $group_by ? @$group_by : ($group_by));
832 # todo: try CONCAT for multi-column pk
833 my @pk = $self->result_source->primary_columns;
835 my $alias = $attrs->{alias};
836 foreach my $column (@distinct) {
837 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
838 @distinct = ($column);
844 $select = { count => { distinct => \@distinct } };
847 $attrs->{select} = $select;
848 $attrs->{as} = [qw/count/];
850 # offset, order by and page are not needed to count. record_filter is cdbi
851 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
853 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
854 my ($count) = $tmp_rs->cursor->next;
862 =item Arguments: $sql_fragment, @bind_values
864 =item Return Value: $count
868 Counts the results in a literal query. Equivalent to calling L</search_literal>
869 with the passed arguments, then L</count>.
873 sub count_literal { shift->search_literal(@_)->count; }
879 =item Arguments: none
881 =item Return Value: @objects
885 Returns all elements in the resultset. Called implicitly if the resultset
886 is returned in list context.
892 return @{ $self->get_cache } if $self->get_cache;
896 # TODO: don't call resolve here
897 if (keys %{$self->_resolved_attrs->{collapse}}) {
898 # if ($self->{attrs}{prefetch}) {
899 # Using $self->cursor->all is really just an optimisation.
900 # If we're collapsing has_many prefetches it probably makes
901 # very little difference, and this is cleaner than hacking
902 # _construct_object to survive the approach
903 my @row = $self->cursor->next;
905 push(@obj, $self->_construct_object(@row));
906 @row = (exists $self->{stashed_row}
907 ? @{delete $self->{stashed_row}}
908 : $self->cursor->next);
911 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
914 $self->set_cache(\@obj) if $self->{attrs}{cache};
922 =item Arguments: none
924 =item Return Value: $self
928 Resets the resultset's cursor, so you can iterate through the elements again.
934 delete $self->{_attrs} if exists $self->{_attrs};
935 $self->{all_cache_position} = 0;
936 $self->cursor->reset;
944 =item Arguments: none
946 =item Return Value: $object?
950 Resets the resultset and returns an object for the first result (if the
951 resultset returns anything).
956 return $_[0]->reset->next;
959 # _cond_for_update_delete
961 # update/delete require the condition to be modified to handle
962 # the differing SQL syntax available. This transforms the $self->{cond}
963 # appropriately, returning the new condition.
965 sub _cond_for_update_delete {
969 # No-op. No condition, we're updating/deleting everything
970 return $cond unless ref $self->{cond};
972 if (ref $self->{cond} eq 'ARRAY') {
976 foreach my $key (keys %{$_}) {
978 $hash{$1} = $_->{$key};
984 elsif (ref $self->{cond} eq 'HASH') {
985 if ((keys %{$self->{cond}})[0] eq '-and') {
988 my @cond = @{$self->{cond}{-and}};
989 for (my $i = 0; $i < @cond; $i++) {
990 my $entry = $cond[$i];
993 if (ref $entry eq 'HASH') {
994 foreach my $key (keys %{$entry}) {
996 $hash{$1} = $entry->{$key};
1000 $entry =~ /([^.]+)$/;
1001 $hash{$1} = $cond[++$i];
1004 push @{$cond->{-and}}, \%hash;
1008 foreach my $key (keys %{$self->{cond}}) {
1010 $cond->{$1} = $self->{cond}{$key};
1015 $self->throw_exception(
1016 "Can't update/delete on resultset with condition unless hash or array"
1028 =item Arguments: \%values
1030 =item Return Value: $storage_rv
1034 Sets the specified columns in the resultset to the supplied values in a
1035 single query. Return value will be true if the update succeeded or false
1036 if no records were updated; exact type of success value is storage-dependent.
1041 my ($self, $values) = @_;
1042 $self->throw_exception("Values for update must be a hash")
1043 unless ref $values eq 'HASH';
1045 my $cond = $self->_cond_for_update_delete;
1047 return $self->result_source->storage->update(
1048 $self->result_source->from, $values, $cond
1056 =item Arguments: \%values
1058 =item Return Value: 1
1062 Fetches all objects and updates them one at a time. Note that C<update_all>
1063 will run DBIC cascade triggers, while L</update> will not.
1068 my ($self, $values) = @_;
1069 $self->throw_exception("Values for update must be a hash")
1070 unless ref $values eq 'HASH';
1071 foreach my $obj ($self->all) {
1072 $obj->set_columns($values)->update;
1081 =item Arguments: none
1083 =item Return Value: 1
1087 Deletes the contents of the resultset from its result source. Note that this
1088 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1096 my $cond = $self->_cond_for_update_delete;
1098 $self->result_source->storage->delete($self->result_source->from, $cond);
1106 =item Arguments: none
1108 =item Return Value: 1
1112 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1113 will run DBIC cascade triggers, while L</delete> will not.
1119 $_->delete for $self->all;
1127 =item Arguments: none
1129 =item Return Value: $pager
1133 Return Value a L<Data::Page> object for the current resultset. Only makes
1134 sense for queries with a C<page> attribute.
1140 my $attrs = $self->{attrs};
1141 $self->throw_exception("Can't create pager for non-paged rs")
1142 unless $self->{attrs}{page};
1143 $attrs->{rows} ||= 10;
1144 return $self->{pager} ||= Data::Page->new(
1145 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1152 =item Arguments: $page_number
1154 =item Return Value: $rs
1158 Returns a resultset for the $page_number page of the resultset on which page
1159 is called, where each page contains a number of rows equal to the 'rows'
1160 attribute set on the resultset (10 by default).
1165 my ($self, $page) = @_;
1166 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1173 =item Arguments: \%vals
1175 =item Return Value: $object
1179 Creates an object in the resultset's result class and returns it.
1184 my ($self, $values) = @_;
1185 $self->throw_exception( "new_result needs a hash" )
1186 unless (ref $values eq 'HASH');
1187 $self->throw_exception(
1188 "Can't abstract implicit construct, condition not a hash"
1189 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1191 my $alias = $self->{attrs}{alias};
1192 foreach my $key (keys %{$self->{cond}||{}}) {
1193 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1195 my $obj = $self->result_class->new(\%new);
1196 $obj->result_source($self->result_source) if $obj->can('result_source');
1204 =item Arguments: \%vals, \%attrs?
1206 =item Return Value: $object
1210 Find an existing record from this resultset. If none exists, instantiate a new
1211 result object and return it. The object will not be saved into your storage
1212 until you call L<DBIx::Class::Row/insert> on it.
1214 If you want objects to be saved immediately, use L</find_or_create> instead.
1220 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1221 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1222 my $exists = $self->find($hash, $attrs);
1223 return defined $exists ? $exists : $self->new_result($hash);
1230 =item Arguments: \%vals
1232 =item Return Value: $object
1236 Inserts a record into the resultset and returns the object representing it.
1238 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1243 my ($self, $attrs) = @_;
1244 $self->throw_exception( "create needs a hashref" )
1245 unless ref $attrs eq 'HASH';
1246 return $self->new_result($attrs)->insert;
1249 =head2 find_or_create
1253 =item Arguments: \%vals, \%attrs?
1255 =item Return Value: $object
1259 $class->find_or_create({ key => $val, ... });
1261 Tries to find a record based on its primary key or unique constraint; if none
1262 is found, creates one and returns that instead.
1264 my $cd = $schema->resultset('CD')->find_or_create({
1266 artist => 'Massive Attack',
1267 title => 'Mezzanine',
1271 Also takes an optional C<key> attribute, to search by a specific key or unique
1272 constraint. For example:
1274 my $cd = $schema->resultset('CD')->find_or_create(
1276 artist => 'Massive Attack',
1277 title => 'Mezzanine',
1279 { key => 'cd_artist_title' }
1282 See also L</find> and L</update_or_create>. For information on how to declare
1283 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1287 sub find_or_create {
1289 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1290 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1291 my $exists = $self->find($hash, $attrs);
1292 return defined $exists ? $exists : $self->create($hash);
1295 =head2 update_or_create
1299 =item Arguments: \%col_values, { key => $unique_constraint }?
1301 =item Return Value: $object
1305 $class->update_or_create({ col => $val, ... });
1307 First, searches for an existing row matching one of the unique constraints
1308 (including the primary key) on the source of this resultset. If a row is
1309 found, updates it with the other given column values. Otherwise, creates a new
1312 Takes an optional C<key> attribute to search on a specific unique constraint.
1315 # In your application
1316 my $cd = $schema->resultset('CD')->update_or_create(
1318 artist => 'Massive Attack',
1319 title => 'Mezzanine',
1322 { key => 'cd_artist_title' }
1325 If no C<key> is specified, it searches on all unique constraints defined on the
1326 source, including the primary key.
1328 If the C<key> is specified as C<primary>, it searches only on the primary key.
1330 See also L</find> and L</find_or_create>. For information on how to declare
1331 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1335 sub update_or_create {
1337 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1338 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1340 my $row = $self->find($cond);
1342 $row->update($cond);
1346 return $self->create($cond);
1353 =item Arguments: none
1355 =item Return Value: \@cache_objects?
1359 Gets the contents of the cache for the resultset, if the cache is set.
1371 =item Arguments: \@cache_objects
1373 =item Return Value: \@cache_objects
1377 Sets the contents of the cache for the resultset. Expects an arrayref
1378 of objects of the same class as those produced by the resultset. Note that
1379 if the cache is set the resultset will return the cached objects rather
1380 than re-querying the database even if the cache attr is not set.
1385 my ( $self, $data ) = @_;
1386 $self->throw_exception("set_cache requires an arrayref")
1387 if defined($data) && (ref $data ne 'ARRAY');
1388 $self->{all_cache} = $data;
1395 =item Arguments: none
1397 =item Return Value: []
1401 Clears the cache for the resultset.
1406 shift->set_cache(undef);
1409 =head2 related_resultset
1413 =item Arguments: $relationship_name
1415 =item Return Value: $resultset
1419 Returns a related resultset for the supplied relationship name.
1421 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1425 sub related_resultset {
1426 my ($self, $rel) = @_;
1428 $self->{related_resultsets} ||= {};
1429 return $self->{related_resultsets}{$rel} ||= do {
1430 my $rel_obj = $self->result_source->relationship_info($rel);
1432 $self->throw_exception(
1433 "search_related: result source '" . $self->result_source->name .
1434 "' has no such relationship $rel")
1437 my ($from,$seen) = $self->_resolve_from($rel);
1439 my $join_count = $seen->{$rel};
1440 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1442 $self->result_source->schema->resultset($rel_obj->{class})->search_rs(
1444 %{$self->{attrs}||{}},
1450 where => $self->{cond},
1458 my ($self, $extra_join) = @_;
1459 my $source = $self->result_source;
1460 my $attrs = $self->{attrs};
1462 my $from = $attrs->{from}
1463 || [ { $attrs->{alias} => $source->from } ];
1465 my $seen = { %{$attrs->{seen_join}||{}} };
1467 my $join = ($attrs->{join}
1468 ? [ $attrs->{join}, $extra_join ]
1472 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1475 return ($from,$seen);
1478 sub _resolved_attrs {
1480 return $self->{_attrs} if $self->{_attrs};
1482 my $attrs = { %{$self->{attrs}||{}} };
1483 my $source = $self->{result_source};
1484 my $alias = $attrs->{alias};
1486 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1487 if ($attrs->{columns}) {
1488 delete $attrs->{as};
1489 } elsif (!$attrs->{select}) {
1490 $attrs->{columns} = [ $source->columns ];
1495 ? (ref $attrs->{select} eq 'ARRAY'
1496 ? [ @{$attrs->{select}} ]
1497 : [ $attrs->{select} ])
1498 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1502 ? (ref $attrs->{as} eq 'ARRAY'
1503 ? [ @{$attrs->{as}} ]
1505 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1509 if ($adds = delete $attrs->{include_columns}) {
1510 $adds = [$adds] unless ref $adds eq 'ARRAY';
1511 push(@{$attrs->{select}}, @$adds);
1512 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1514 if ($adds = delete $attrs->{'+select'}) {
1515 $adds = [$adds] unless ref $adds eq 'ARRAY';
1516 push(@{$attrs->{select}},
1517 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1519 if (my $adds = delete $attrs->{'+as'}) {
1520 $adds = [$adds] unless ref $adds eq 'ARRAY';
1521 push(@{$attrs->{as}}, @$adds);
1524 $attrs->{from} ||= [ { 'me' => $source->from } ];
1526 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1527 my $join = delete $attrs->{join} || {};
1529 if (defined $attrs->{prefetch}) {
1530 $join = $self->_merge_attr(
1531 $join, $attrs->{prefetch}
1535 $attrs->{from} = # have to copy here to avoid corrupting the original
1538 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1542 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1543 if ($attrs->{order_by}) {
1544 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1545 ? [ @{$attrs->{order_by}} ]
1546 : [ $attrs->{order_by} ]);
1548 $attrs->{order_by} = [];
1551 my $collapse = $attrs->{collapse} || {};
1552 if (my $prefetch = delete $attrs->{prefetch}) {
1554 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1555 # bring joins back to level of current class
1556 my @prefetch = $source->resolve_prefetch(
1557 $p, $alias, { %{$attrs->{seen_join}||{}} }, \@pre_order, $collapse
1559 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1560 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1562 push(@{$attrs->{order_by}}, @pre_order);
1564 $attrs->{collapse} = $collapse;
1566 return $self->{_attrs} = $attrs;
1570 my ($self, $a, $b) = @_;
1571 return $b unless defined($a);
1572 return $a unless defined($b);
1574 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1575 foreach my $key (keys %{$b}) {
1576 if (exists $a->{$key}) {
1577 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1579 $a->{$key} = $b->{$key};
1584 $a = [$a] unless ref $a eq 'ARRAY';
1585 $b = [$b] unless ref $b eq 'ARRAY';
1589 foreach my $x ($a, $b) {
1590 foreach my $element (@{$x}) {
1591 if (ref $element eq 'HASH') {
1592 $hash = $self->_merge_attr($hash, $element);
1593 } elsif (ref $element eq 'ARRAY') {
1594 push(@array, @{$element});
1596 push(@array, $element) unless $b == $x
1597 && grep { $_ eq $element } @array;
1602 @array = grep { !exists $hash->{$_} } @array;
1604 return keys %{$hash}
1613 =head2 throw_exception
1615 See L<DBIx::Class::Schema/throw_exception> for details.
1619 sub throw_exception {
1621 $self->result_source->schema->throw_exception(@_);
1624 # XXX: FIXME: Attributes docs need clearing up
1628 The resultset takes various attributes that modify its behavior. Here's an
1635 =item Value: ($order_by | \@order_by)
1639 Which column(s) to order the results by. This is currently passed
1640 through directly to SQL, so you can give e.g. C<year DESC> for a
1641 descending order on the column `year'.
1643 Please note that if you have quoting enabled (see
1644 L<DBIx::Class::Storage/quote_char>) you will need to do C<\'year DESC' > to
1645 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1646 so you will need to manually quote things as appropriate.)
1652 =item Value: \@columns
1656 Shortcut to request a particular set of columns to be retrieved. Adds
1657 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1658 from that, then auto-populates C<as> from C<select> as normal. (You may also
1659 use the C<cols> attribute, as in earlier versions of DBIC.)
1661 =head2 include_columns
1665 =item Value: \@columns
1669 Shortcut to include additional columns in the returned results - for example
1671 $schema->resultset('CD')->search(undef, {
1672 include_columns => ['artist.name'],
1676 would return all CDs and include a 'name' column to the information
1677 passed to object inflation
1683 =item Value: \@select_columns
1687 Indicates which columns should be selected from the storage. You can use
1688 column names, or in the case of RDBMS back ends, function or stored procedure
1691 $rs = $schema->resultset('Employee')->search(undef, {
1694 { count => 'employeeid' },
1699 When you use function/stored procedure names and do not supply an C<as>
1700 attribute, the column names returned are storage-dependent. E.g. MySQL would
1701 return a column named C<count(employeeid)> in the above example.
1707 Indicates additional columns to be selected from storage. Works the same as
1708 L<select> but adds columns to the selection.
1716 Indicates additional column names for those added via L<+select>.
1724 =item Value: \@inflation_names
1728 Indicates column names for object inflation. This is used in conjunction with
1729 C<select>, usually when C<select> contains one or more function or stored
1732 $rs = $schema->resultset('Employee')->search(undef, {
1735 { count => 'employeeid' }
1737 as => ['name', 'employee_count'],
1740 my $employee = $rs->first(); # get the first Employee
1742 If the object against which the search is performed already has an accessor
1743 matching a column name specified in C<as>, the value can be retrieved using
1744 the accessor as normal:
1746 my $name = $employee->name();
1748 If on the other hand an accessor does not exist in the object, you need to
1749 use C<get_column> instead:
1751 my $employee_count = $employee->get_column('employee_count');
1753 You can create your own accessors if required - see
1754 L<DBIx::Class::Manual::Cookbook> for details.
1756 Please note: This will NOT insert an C<AS employee_count> into the SQL
1757 statement produced, it is used for internal access only. Thus
1758 attempting to use the accessor in an C<order_by> clause or similar
1759 will fail miserably.
1761 To get around this limitation, you can supply literal SQL to your
1762 C<select> attibute that contains the C<AS alias> text, eg:
1764 select => [\'myfield AS alias']
1770 =item Value: ($rel_name | \@rel_names | \%rel_names)
1774 Contains a list of relationships that should be joined for this query. For
1777 # Get CDs by Nine Inch Nails
1778 my $rs = $schema->resultset('CD')->search(
1779 { 'artist.name' => 'Nine Inch Nails' },
1780 { join => 'artist' }
1783 Can also contain a hash reference to refer to the other relation's relations.
1786 package MyApp::Schema::Track;
1787 use base qw/DBIx::Class/;
1788 __PACKAGE__->table('track');
1789 __PACKAGE__->add_columns(qw/trackid cd position title/);
1790 __PACKAGE__->set_primary_key('trackid');
1791 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1794 # In your application
1795 my $rs = $schema->resultset('Artist')->search(
1796 { 'track.title' => 'Teardrop' },
1798 join => { cd => 'track' },
1799 order_by => 'artist.name',
1803 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1804 similarly for a third time). For e.g.
1806 my $rs = $schema->resultset('Artist')->search({
1807 'cds.title' => 'Down to Earth',
1808 'cds_2.title' => 'Popular',
1810 join => [ qw/cds cds/ ],
1813 will return a set of all artists that have both a cd with title 'Down
1814 to Earth' and a cd with title 'Popular'.
1816 If you want to fetch related objects from other tables as well, see C<prefetch>
1823 =item Value: ($rel_name | \@rel_names | \%rel_names)
1827 Contains one or more relationships that should be fetched along with the main
1828 query (when they are accessed afterwards they will have already been
1829 "prefetched"). This is useful for when you know you will need the related
1830 objects, because it saves at least one query:
1832 my $rs = $schema->resultset('Tag')->search(
1841 The initial search results in SQL like the following:
1843 SELECT tag.*, cd.*, artist.* FROM tag
1844 JOIN cd ON tag.cd = cd.cdid
1845 JOIN artist ON cd.artist = artist.artistid
1847 L<DBIx::Class> has no need to go back to the database when we access the
1848 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1851 Simple prefetches will be joined automatically, so there is no need
1852 for a C<join> attribute in the above search. If you're prefetching to
1853 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1854 specify the join as well.
1856 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1857 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1858 with an accessor type of 'single' or 'filter').
1868 Makes the resultset paged and specifies the page to retrieve. Effectively
1869 identical to creating a non-pages resultset and then calling ->page($page)
1872 If L<rows> attribute is not specified it defualts to 10 rows per page.
1882 Specifes the maximum number of rows for direct retrieval or the number of
1883 rows per page if the page attribute or method is used.
1889 =item Value: $offset
1893 Specifies the (zero-based) row number for the first row to be returned, or the
1894 of the first row of the first page if paging is used.
1900 =item Value: \@columns
1904 A arrayref of columns to group by. Can include columns of joined tables.
1906 group_by => [qw/ column1 column2 ... /]
1912 =item Value: $condition
1916 HAVING is a select statement attribute that is applied between GROUP BY and
1917 ORDER BY. It is applied to the after the grouping calculations have been
1920 having => { 'count(employee)' => { '>=', 100 } }
1926 =item Value: (0 | 1)
1930 Set to 1 to group by all columns.
1936 Adds to the WHERE clause.
1938 # only return rows WHERE deleted IS NULL for all searches
1939 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
1941 Can be overridden by passing C<{ where => undef }> as an attribute
1948 Set to 1 to cache search results. This prevents extra SQL queries if you
1949 revisit rows in your ResultSet:
1951 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1953 while( my $artist = $resultset->next ) {
1957 $rs->first; # without cache, this would issue a query
1959 By default, searches are not cached.
1961 For more examples of using these attributes, see
1962 L<DBIx::Class::Manual::Cookbook>.
1968 =item Value: \@from_clause
1972 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1973 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1976 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1978 C<join> will usually do what you need and it is strongly recommended that you
1979 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1980 And we really do mean "cannot", not just tried and failed. Attempting to use
1981 this because you're having problems with C<join> is like trying to use x86
1982 ASM because you've got a syntax error in your C. Trust us on this.
1984 Now, if you're still really, really sure you need to use this (and if you're
1985 not 100% sure, ask the mailing list first), here's an explanation of how this
1988 The syntax is as follows -
1991 { <alias1> => <table1> },
1993 { <alias2> => <table2>, -join_type => 'inner|left|right' },
1994 [], # nested JOIN (optional)
1995 { <table1.column1> => <table2.column2>, ... (more conditions) },
1997 # More of the above [ ] may follow for additional joins
2004 ON <table1.column1> = <table2.column2>
2005 <more joins may follow>
2007 An easy way to follow the examples below is to remember the following:
2009 Anything inside "[]" is a JOIN
2010 Anything inside "{}" is a condition for the enclosing JOIN
2012 The following examples utilize a "person" table in a family tree application.
2013 In order to express parent->child relationships, this table is self-joined:
2015 # Person->belongs_to('father' => 'Person');
2016 # Person->belongs_to('mother' => 'Person');
2018 C<from> can be used to nest joins. Here we return all children with a father,
2019 then search against all mothers of those children:
2021 $rs = $schema->resultset('Person')->search(
2024 alias => 'mother', # alias columns in accordance with "from"
2026 { mother => 'person' },
2029 { child => 'person' },
2031 { father => 'person' },
2032 { 'father.person_id' => 'child.father_id' }
2035 { 'mother.person_id' => 'child.mother_id' }
2042 # SELECT mother.* FROM person mother
2045 # JOIN person father
2046 # ON ( father.person_id = child.father_id )
2048 # ON ( mother.person_id = child.mother_id )
2050 The type of any join can be controlled manually. To search against only people
2051 with a father in the person table, we could explicitly use C<INNER JOIN>:
2053 $rs = $schema->resultset('Person')->search(
2056 alias => 'child', # alias columns in accordance with "from"
2058 { child => 'person' },
2060 { father => 'person', -join_type => 'inner' },
2061 { 'father.id' => 'child.father_id' }
2068 # SELECT child.* FROM person child
2069 # INNER JOIN person father ON child.father_id = father.id