1 package DBIx::Class::ResultSet;
11 use Scalar::Util qw/weaken/;
13 use DBIx::Class::ResultSetColumn;
14 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) = @_;
89 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
90 #use Data::Dumper; warn Dumper($attrs);
91 my $alias = ($attrs->{alias} ||= 'me');
93 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
94 delete $attrs->{as} if $attrs->{columns};
95 $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select};
97 map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}}
98 ] if $attrs->{columns};
100 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
102 if (my $include = delete $attrs->{include_columns}) {
103 push(@{$attrs->{select}}, @$include);
104 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
106 #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
108 $attrs->{from} ||= [ { $alias => $source->from } ];
109 $attrs->{seen_join} ||= {};
111 if (my $join = delete $attrs->{join}) {
112 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
113 if (ref $j eq 'HASH') {
114 $seen{$_} = 1 foreach keys %$j;
119 push(@{$attrs->{from}}, $source->resolve_join(
120 $join, $attrs->{alias}, $attrs->{seen_join})
124 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
125 $attrs->{order_by} = [ $attrs->{order_by} ] if
126 $attrs->{order_by} and !ref($attrs->{order_by});
127 $attrs->{order_by} ||= [];
129 my $collapse = $attrs->{collapse} || {};
130 if (my $prefetch = delete $attrs->{prefetch}) {
132 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
133 if ( ref $p eq 'HASH' ) {
134 foreach my $key (keys %$p) {
135 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
139 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
142 my @prefetch = $source->resolve_prefetch(
143 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
144 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
145 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
147 push(@{$attrs->{order_by}}, @pre_order);
149 $attrs->{collapse} = $collapse;
150 # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse};
152 if ($attrs->{page}) {
153 $attrs->{rows} ||= 10;
154 $attrs->{offset} ||= 0;
155 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
159 result_source => $source,
160 result_class => $attrs->{result_class} || $source->result_class,
161 cond => $attrs->{where},
162 from => $attrs->{from},
163 collapse => $collapse,
165 page => delete $attrs->{page},
175 =item Arguments: $cond, \%attrs?
177 =item Return Value: $resultset (scalar context), @row_objs (list context)
181 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
182 my $new_rs = $cd_rs->search({ year => 2005 });
184 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
185 # year = 2005 OR year = 2004
187 If you need to pass in additional attributes but no additional condition,
188 call it as C<search(undef, \%attrs)>.
190 # "SELECT name, artistid FROM $artist_table"
191 my @all_artists = $schema->resultset('Artist')->search(undef, {
192 columns => [qw/name artistid/],
203 my $attrs = { %{$self->{attrs}} };
204 my $having = delete $attrs->{having};
205 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
208 ? ((@_ == 1 || ref $_[0] eq "HASH")
211 ? $self->throw_exception(
212 "Odd number of arguments to search")
215 if (defined $where) {
216 $attrs->{where} = (defined $attrs->{where}
218 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
219 $where, $attrs->{where} ] }
223 if (defined $having) {
224 $attrs->{having} = (defined $attrs->{having}
226 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
227 $having, $attrs->{having} ] }
231 $rs = (ref $self)->new($self->result_source, $attrs);
237 return (wantarray ? $rs->all : $rs);
240 =head2 search_literal
244 =item Arguments: $sql_fragment, @bind_values
246 =item Return Value: $resultset (scalar context), @row_objs (list context)
250 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
251 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
253 Pass a literal chunk of SQL to be added to the conditional part of the
259 my ($self, $cond, @vals) = @_;
260 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
261 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
262 return $self->search(\$cond, $attrs);
269 =item Arguments: @values | \%cols, \%attrs?
271 =item Return Value: $row_object
275 Finds a row based on its primary key or unique constraint. For example:
277 my $cd = $schema->resultset('CD')->find(5);
279 Also takes an optional C<key> attribute, to search by a specific key or unique
280 constraint. For example:
282 my $cd = $schema->resultset('CD')->find(
284 artist => 'Massive Attack',
285 title => 'Mezzanine',
287 { key => 'artist_title' }
290 See also L</find_or_create> and L</update_or_create>.
295 my ($self, @vals) = @_;
296 my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
298 my %unique_constraints = $self->result_source->unique_constraints;
299 $self->throw_exception(
300 "Can't find unless a primary key or unique constraint is defined"
301 ) unless %unique_constraints;
303 my @constraint_names = keys %unique_constraints;
304 if (exists $attrs->{key}) {
305 $self->throw_exception(
306 "Unknown key $attrs->{key} on '" . $self->result_source->name . "'"
307 ) unless exists $unique_constraints{$attrs->{key}};
309 @constraint_names = ($attrs->{key});
313 foreach my $name (@constraint_names) {
314 my @unique_cols = @{ $unique_constraints{$name} };
316 if (ref $vals[0] eq 'HASH') {
318 map { $_ => $vals[0]->{$_} }
319 grep { exists $vals[0]->{$_} }
322 elsif (@unique_cols == @vals) {
323 # Assume the argument order corresponds to the constraint definition
324 @unique_hash{@unique_cols} = @vals;
326 elsif (@vals % 2 == 0) {
327 # Fix for CDBI calling with a hash
328 %unique_hash = @vals;
331 foreach my $key (grep { ! m/\./ } keys %unique_hash) {
332 $unique_hash{"$self->{attrs}{alias}.$key"} = delete $unique_hash{$key};
335 #use Data::Dumper; warn Dumper \@vals, \@unique_cols, \%unique_hash;
336 push @unique_hashes, \%unique_hash if %unique_hash;
339 # Handle cases where the ResultSet already defines the query
340 my $query = @unique_hashes ? \@unique_hashes : undef;
343 my $rs = $self->search($query,$attrs);
344 return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
346 return keys %{$self->{collapse}}
347 ? $self->search($query)->next
348 : $self->single($query);
352 =head2 search_related
356 =item Arguments: $cond, \%attrs?
358 =item Return Value: $new_resultset
362 $new_rs = $cd_rs->search_related('artist', {
366 Searches the specified relationship, optionally specifying a condition and
367 attributes for matching records. See L</ATTRIBUTES> for more information.
372 return shift->related_resultset(shift)->search(@_);
379 =item Arguments: none
381 =item Return Value: $cursor
385 Returns a storage-driven cursor to the given resultset. See
386 L<DBIx::Class::Cursor> for more information.
392 my $attrs = { %{$self->{attrs}} };
393 return $self->{cursor}
394 ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
395 $attrs->{where},$attrs);
402 =item Arguments: $cond?
404 =item Return Value: $row_object?
408 my $cd = $schema->resultset('CD')->single({ year => 2001 });
410 Inflates the first result without creating a cursor if the resultset has
411 any records in it; if not returns nothing. Used by find() as an optimisation.
416 my ($self, $where) = @_;
417 my $attrs = { %{$self->{attrs}} };
419 if (defined $attrs->{where}) {
422 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
423 $where, delete $attrs->{where} ]
426 $attrs->{where} = $where;
429 my @data = $self->result_source->storage->select_single(
430 $self->{from}, $attrs->{select},
431 $attrs->{where},$attrs);
432 return (@data ? $self->_construct_object(@data) : ());
439 =item Arguments: $cond?
441 =item Return Value: $resultsetcolumn
445 my $max_length = $rs->get_column('length')->max;
447 Returns a ResultSetColumn instance for $column based on $self
452 my ($self, $column) = @_;
454 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
462 =item Arguments: $cond, \%attrs?
464 =item Return Value: $resultset (scalar context), @row_objs (list context)
468 # WHERE title LIKE '%blue%'
469 $cd_rs = $rs->search_like({ title => '%blue%'});
471 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
472 that this is simply a convenience method. You most likely want to use
473 L</search> with specific operators.
475 For more information, see L<DBIx::Class::Manual::Cookbook>.
481 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
482 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
483 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
484 return $class->search($query, { %$attrs });
491 =item Arguments: $first, $last
493 =item Return Value: $resultset (scalar context), @row_objs (list context)
497 Returns a resultset or object list representing a subset of elements from the
498 resultset slice is called on. Indexes are from 0, i.e., to get the first
501 my ($one, $two, $three) = $rs->slice(0, 2);
506 my ($self, $min, $max) = @_;
507 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
508 $attrs->{offset} = $self->{attrs}{offset} || 0;
509 $attrs->{offset} += $min;
510 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
511 return $self->search(undef(), $attrs);
512 #my $slice = (ref $self)->new($self->result_source, $attrs);
513 #return (wantarray ? $slice->all : $slice);
520 =item Arguments: none
522 =item Return Value: $result?
526 Returns the next element in the resultset (C<undef> is there is none).
528 Can be used to efficiently iterate over records in the resultset:
530 my $rs = $schema->resultset('CD')->search;
531 while (my $cd = $rs->next) {
535 Note that you need to store the resultset object, and call C<next> on it.
536 Calling C<< resultset('Table')->next >> repeatedly will always return the
537 first record from the resultset.
543 if (@{$self->{all_cache} || []}) {
544 $self->{all_cache_position} ||= 0;
545 return $self->{all_cache}->[$self->{all_cache_position}++];
547 if ($self->{attrs}{cache}) {
548 $self->{all_cache_position} = 1;
549 return ($self->all)[0];
551 my @row = (exists $self->{stashed_row} ?
552 @{delete $self->{stashed_row}} :
555 # warn Dumper(\@row); use Data::Dumper;
556 return unless (@row);
557 return $self->_construct_object(@row);
560 sub _construct_object {
561 my ($self, @row) = @_;
562 my @as = @{ $self->{attrs}{as} };
564 my $info = $self->_collapse_result(\@as, \@row);
566 my $new = $self->result_class->inflate_result($self->result_source, @$info);
568 $new = $self->{attrs}{record_filter}->($new)
569 if exists $self->{attrs}{record_filter};
573 sub _collapse_result {
574 my ($self, $as, $row, $prefix) = @_;
579 foreach my $this_as (@$as) {
580 my $val = shift @copy;
581 if (defined $prefix) {
582 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
584 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
585 $const{$1||''}{$2} = $val;
588 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
589 $const{$1||''}{$2} = $val;
593 my $info = [ {}, {} ];
594 foreach my $key (keys %const) {
597 my @parts = split(/\./, $key);
598 foreach my $p (@parts) {
599 $target = $target->[1]->{$p} ||= [];
601 $target->[0] = $const{$key};
603 $info->[0] = $const{$key};
608 if (defined $prefix) {
610 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
611 } keys %{$self->{collapse}}
613 @collapse = keys %{$self->{collapse}};
617 my ($c) = sort { length $a <=> length $b } @collapse;
619 foreach my $p (split(/\./, $c)) {
620 $target = $target->[1]->{$p} ||= [];
622 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
623 my @co_key = @{$self->{collapse}{$c_prefix}};
624 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
625 my $tree = $self->_collapse_result($as, $row, $c_prefix);
628 !defined($tree->[0]->{$_}) ||
629 $co_check{$_} ne $tree->[0]->{$_}
632 last unless (@raw = $self->cursor->next);
633 $row = $self->{stashed_row} = \@raw;
634 $tree = $self->_collapse_result($as, $row, $c_prefix);
635 #warn Data::Dumper::Dumper($tree, $row);
647 =item Arguments: $result_source?
649 =item Return Value: $result_source
653 An accessor for the primary ResultSource object from which this ResultSet
663 =item Arguments: $cond, \%attrs??
665 =item Return Value: $count
669 Performs an SQL C<COUNT> with the same query as the resultset was built
670 with to find the number of elements. If passed arguments, does a search
671 on the resultset and counts the results of that.
673 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
674 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
675 not support C<DISTINCT> with multiple columns. If you are using such a
676 database, you should only use columns from the main table in your C<group_by>
683 return $self->search(@_)->count if @_ and defined $_[0];
684 return scalar @{ $self->get_cache } if @{ $self->get_cache };
686 my $count = $self->_count;
687 return 0 unless $count;
689 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
690 $count = $self->{attrs}{rows} if
691 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
695 sub _count { # Separated out so pager can get the full count
697 my $select = { count => '*' };
698 my $attrs = { %{ $self->{attrs} } };
699 if (my $group_by = delete $attrs->{group_by}) {
700 delete $attrs->{having};
701 my @distinct = (ref $group_by ? @$group_by : ($group_by));
702 # todo: try CONCAT for multi-column pk
703 my @pk = $self->result_source->primary_columns;
705 foreach my $column (@distinct) {
706 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
707 @distinct = ($column);
713 $select = { count => { distinct => \@distinct } };
714 #use Data::Dumper; die Dumper $select;
717 $attrs->{select} = $select;
718 $attrs->{as} = [qw/count/];
720 # offset, order by and page are not needed to count. record_filter is cdbi
721 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
723 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
731 =item Arguments: $sql_fragment, @bind_values
733 =item Return Value: $count
737 Counts the results in a literal query. Equivalent to calling L</search_literal>
738 with the passed arguments, then L</count>.
742 sub count_literal { shift->search_literal(@_)->count; }
748 =item Arguments: none
750 =item Return Value: @objects
754 Returns all elements in the resultset. Called implicitly if the resultset
755 is returned in list context.
761 return @{ $self->get_cache } if @{ $self->get_cache };
765 if (keys %{$self->{collapse}}) {
766 # Using $self->cursor->all is really just an optimisation.
767 # If we're collapsing has_many prefetches it probably makes
768 # very little difference, and this is cleaner than hacking
769 # _construct_object to survive the approach
770 $self->cursor->reset;
771 my @row = $self->cursor->next;
773 push(@obj, $self->_construct_object(@row));
774 @row = (exists $self->{stashed_row}
775 ? @{delete $self->{stashed_row}}
776 : $self->cursor->next);
779 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
782 $self->set_cache(\@obj) if $self->{attrs}{cache};
790 =item Arguments: none
792 =item Return Value: $self
796 Resets the resultset's cursor, so you can iterate through the elements again.
802 $self->{all_cache_position} = 0;
803 $self->cursor->reset;
811 =item Arguments: none
813 =item Return Value: $object?
817 Resets the resultset and returns an object for the first result (if the
818 resultset returns anything).
823 return $_[0]->reset->next;
826 # _cond_for_update_delete
828 # update/delete require the condition to be modified to handle
829 # the differing SQL syntax available. This transforms the $self->{cond}
830 # appropriately, returning the new condition.
832 sub _cond_for_update_delete {
836 if (!ref($self->{cond})) {
837 # No-op. No condition, we're updating/deleting everything
839 elsif (ref $self->{cond} eq 'ARRAY') {
843 foreach my $key (keys %{$_}) {
845 $hash{$1} = $_->{$key};
851 elsif (ref $self->{cond} eq 'HASH') {
852 if ((keys %{$self->{cond}})[0] eq '-and') {
855 my @cond = @{$self->{cond}{-and}};
856 for (my $i = 0; $i < @cond - 1; $i++) {
857 my $entry = $cond[$i];
860 if (ref $entry eq 'HASH') {
861 foreach my $key (keys %{$entry}) {
863 $hash{$1} = $entry->{$key};
867 $entry =~ /([^.]+)$/;
868 $hash{$entry} = $cond[++$i];
871 push @{$cond->{-and}}, \%hash;
875 foreach my $key (keys %{$self->{cond}}) {
877 $cond->{$1} = $self->{cond}{$key};
882 $self->throw_exception(
883 "Can't update/delete on resultset with condition unless hash or array"
895 =item Arguments: \%values
897 =item Return Value: $storage_rv
901 Sets the specified columns in the resultset to the supplied values in a
902 single query. Return value will be true if the update succeeded or false
903 if no records were updated; exact type of success value is storage-dependent.
908 my ($self, $values) = @_;
909 $self->throw_exception("Values for update must be a hash")
910 unless ref $values eq 'HASH';
912 my $cond = $self->_cond_for_update_delete;
914 return $self->result_source->storage->update(
915 $self->result_source->from, $values, $cond
923 =item Arguments: \%values
925 =item Return Value: 1
929 Fetches all objects and updates them one at a time. Note that C<update_all>
930 will run DBIC cascade triggers, while L</update> will not.
935 my ($self, $values) = @_;
936 $self->throw_exception("Values for update must be a hash")
937 unless ref $values eq 'HASH';
938 foreach my $obj ($self->all) {
939 $obj->set_columns($values)->update;
948 =item Arguments: none
950 =item Return Value: 1
954 Deletes the contents of the resultset from its result source. Note that this
955 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
964 my $cond = $self->_cond_for_update_delete;
966 $self->result_source->storage->delete($self->result_source->from, $cond);
974 =item Arguments: none
976 =item Return Value: 1
980 Fetches all objects and deletes them one at a time. Note that C<delete_all>
981 will run DBIC cascade triggers, while L</delete> will not.
987 $_->delete for $self->all;
995 =item Arguments: none
997 =item Return Value: $pager
1001 Return Value a L<Data::Page> object for the current resultset. Only makes
1002 sense for queries with a C<page> attribute.
1008 my $attrs = $self->{attrs};
1009 $self->throw_exception("Can't create pager for non-paged rs")
1010 unless $self->{page};
1011 $attrs->{rows} ||= 10;
1012 return $self->{pager} ||= Data::Page->new(
1013 $self->_count, $attrs->{rows}, $self->{page});
1020 =item Arguments: $page_number
1022 =item Return Value: $rs
1026 Returns a resultset for the $page_number page of the resultset on which page
1027 is called, where each page contains a number of rows equal to the 'rows'
1028 attribute set on the resultset (10 by default).
1033 my ($self, $page) = @_;
1034 my $attrs = { %{$self->{attrs}} };
1035 $attrs->{page} = $page;
1036 return (ref $self)->new($self->result_source, $attrs);
1043 =item Arguments: \%vals
1045 =item Return Value: $object
1049 Creates an object in the resultset's result class and returns it.
1054 my ($self, $values) = @_;
1055 $self->throw_exception( "new_result needs a hash" )
1056 unless (ref $values eq 'HASH');
1057 $self->throw_exception(
1058 "Can't abstract implicit construct, condition not a hash"
1059 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1061 my $alias = $self->{attrs}{alias};
1062 foreach my $key (keys %{$self->{cond}||{}}) {
1063 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1065 my $obj = $self->result_class->new(\%new);
1066 $obj->result_source($self->result_source) if $obj->can('result_source');
1074 =item Arguments: \%vals
1076 =item Return Value: $object
1080 Inserts a record into the resultset and returns the object representing it.
1082 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1087 my ($self, $attrs) = @_;
1088 $self->throw_exception( "create needs a hashref" )
1089 unless ref $attrs eq 'HASH';
1090 return $self->new_result($attrs)->insert;
1093 =head2 find_or_create
1097 =item Arguments: \%vals, \%attrs?
1099 =item Return Value: $object
1103 $class->find_or_create({ key => $val, ... });
1105 Searches for a record matching the search condition; if it doesn't find one,
1106 creates one and returns that instead.
1108 my $cd = $schema->resultset('CD')->find_or_create({
1110 artist => 'Massive Attack',
1111 title => 'Mezzanine',
1115 Also takes an optional C<key> attribute, to search by a specific key or unique
1116 constraint. For example:
1118 my $cd = $schema->resultset('CD')->find_or_create(
1120 artist => 'Massive Attack',
1121 title => 'Mezzanine',
1123 { key => 'artist_title' }
1126 See also L</find> and L</update_or_create>.
1130 sub find_or_create {
1132 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1133 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1134 my $exists = $self->find($hash, $attrs);
1135 return defined $exists ? $exists : $self->create($hash);
1138 =head2 update_or_create
1142 =item Arguments: \%col_values, { key => $unique_constraint }?
1144 =item Return Value: $object
1148 $class->update_or_create({ col => $val, ... });
1150 First, searches for an existing row matching one of the unique constraints
1151 (including the primary key) on the source of this resultset. If a row is
1152 found, updates it with the other given column values. Otherwise, creates a new
1155 Takes an optional C<key> attribute to search on a specific unique constraint.
1158 # In your application
1159 my $cd = $schema->resultset('CD')->update_or_create(
1161 artist => 'Massive Attack',
1162 title => 'Mezzanine',
1165 { key => 'artist_title' }
1168 If no C<key> is specified, it searches on all unique constraints defined on the
1169 source, including the primary key.
1171 If the C<key> is specified as C<primary>, it searches only on the primary key.
1173 See also L</find> and L</find_or_create>.
1177 sub update_or_create {
1179 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1180 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1182 my $row = $self->find($hash, $attrs);
1184 $row->set_columns($hash);
1189 return $self->create($hash);
1196 =item Arguments: none
1198 =item Return Value: \@cache_objects?
1202 Gets the contents of the cache for the resultset, if the cache is set.
1207 shift->{all_cache} || [];
1214 =item Arguments: \@cache_objects
1216 =item Return Value: \@cache_objects
1220 Sets the contents of the cache for the resultset. Expects an arrayref
1221 of objects of the same class as those produced by the resultset. Note that
1222 if the cache is set the resultset will return the cached objects rather
1223 than re-querying the database even if the cache attr is not set.
1228 my ( $self, $data ) = @_;
1229 $self->throw_exception("set_cache requires an arrayref")
1230 if ref $data ne 'ARRAY';
1231 my $result_class = $self->result_class;
1233 $self->throw_exception(
1234 "cannot cache object of type '$_', expected '$result_class'"
1235 ) if ref $_ ne $result_class;
1237 $self->{all_cache} = $data;
1244 =item Arguments: none
1246 =item Return Value: []
1250 Clears the cache for the resultset.
1255 shift->set_cache([]);
1258 =head2 related_resultset
1262 =item Arguments: $relationship_name
1264 =item Return Value: $resultset
1268 Returns a related resultset for the supplied relationship name.
1270 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1274 sub related_resultset {
1275 my ( $self, $rel ) = @_;
1276 $self->{related_resultsets} ||= {};
1277 return $self->{related_resultsets}{$rel} ||= do {
1278 #warn "fetching related resultset for rel '$rel'";
1279 my $rel_obj = $self->result_source->relationship_info($rel);
1280 $self->throw_exception(
1281 "search_related: result source '" . $self->result_source->name .
1282 "' has no such relationship ${rel}")
1283 unless $rel_obj; #die Dumper $self->{attrs};
1285 my $rs = $self->search(undef, { join => $rel });
1286 my $alias = defined $rs->{attrs}{seen_join}{$rel}
1287 && $rs->{attrs}{seen_join}{$rel} > 1
1288 ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
1291 $self->result_source->schema->resultset($rel_obj->{class}
1301 =head2 throw_exception
1303 See L<DBIx::Class::Schema/throw_exception> for details.
1307 sub throw_exception {
1309 $self->result_source->schema->throw_exception(@_);
1312 # XXX: FIXME: Attributes docs need clearing up
1316 The resultset takes various attributes that modify its behavior. Here's an
1323 =item Value: ($order_by | \@order_by)
1327 Which column(s) to order the results by. This is currently passed
1328 through directly to SQL, so you can give e.g. C<year DESC> for a
1329 descending order on the column `year'.
1335 =item Value: \@columns
1339 Shortcut to request a particular set of columns to be retrieved. Adds
1340 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1341 from that, then auto-populates C<as> from C<select> as normal. (You may also
1342 use the C<cols> attribute, as in earlier versions of DBIC.)
1344 =head2 include_columns
1348 =item Value: \@columns
1352 Shortcut to include additional columns in the returned results - for example
1354 $schema->resultset('CD')->search(undef, {
1355 include_columns => ['artist.name'],
1359 would return all CDs and include a 'name' column to the information
1360 passed to object inflation
1366 =item Value: \@select_columns
1370 Indicates which columns should be selected from the storage. You can use
1371 column names, or in the case of RDBMS back ends, function or stored procedure
1374 $rs = $schema->resultset('Employee')->search(undef, {
1377 { count => 'employeeid' },
1382 When you use function/stored procedure names and do not supply an C<as>
1383 attribute, the column names returned are storage-dependent. E.g. MySQL would
1384 return a column named C<count(employeeid)> in the above example.
1390 =item Value: \@inflation_names
1394 Indicates column names for object inflation. This is used in conjunction with
1395 C<select>, usually when C<select> contains one or more function or stored
1398 $rs = $schema->resultset('Employee')->search(undef, {
1401 { count => 'employeeid' }
1403 as => ['name', 'employee_count'],
1406 my $employee = $rs->first(); # get the first Employee
1408 If the object against which the search is performed already has an accessor
1409 matching a column name specified in C<as>, the value can be retrieved using
1410 the accessor as normal:
1412 my $name = $employee->name();
1414 If on the other hand an accessor does not exist in the object, you need to
1415 use C<get_column> instead:
1417 my $employee_count = $employee->get_column('employee_count');
1419 You can create your own accessors if required - see
1420 L<DBIx::Class::Manual::Cookbook> for details.
1426 =item Value: ($rel_name | \@rel_names | \%rel_names)
1430 Contains a list of relationships that should be joined for this query. For
1433 # Get CDs by Nine Inch Nails
1434 my $rs = $schema->resultset('CD')->search(
1435 { 'artist.name' => 'Nine Inch Nails' },
1436 { join => 'artist' }
1439 Can also contain a hash reference to refer to the other relation's relations.
1442 package MyApp::Schema::Track;
1443 use base qw/DBIx::Class/;
1444 __PACKAGE__->table('track');
1445 __PACKAGE__->add_columns(qw/trackid cd position title/);
1446 __PACKAGE__->set_primary_key('trackid');
1447 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1450 # In your application
1451 my $rs = $schema->resultset('Artist')->search(
1452 { 'track.title' => 'Teardrop' },
1454 join => { cd => 'track' },
1455 order_by => 'artist.name',
1459 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1460 similarly for a third time). For e.g.
1462 my $rs = $schema->resultset('Artist')->search({
1463 'cds.title' => 'Down to Earth',
1464 'cds_2.title' => 'Popular',
1466 join => [ qw/cds cds/ ],
1469 will return a set of all artists that have both a cd with title 'Down
1470 to Earth' and a cd with title 'Popular'.
1472 If you want to fetch related objects from other tables as well, see C<prefetch>
1479 =item Value: ($rel_name | \@rel_names | \%rel_names)
1483 Contains one or more relationships that should be fetched along with the main
1484 query (when they are accessed afterwards they will have already been
1485 "prefetched"). This is useful for when you know you will need the related
1486 objects, because it saves at least one query:
1488 my $rs = $schema->resultset('Tag')->search(
1497 The initial search results in SQL like the following:
1499 SELECT tag.*, cd.*, artist.* FROM tag
1500 JOIN cd ON tag.cd = cd.cdid
1501 JOIN artist ON cd.artist = artist.artistid
1503 L<DBIx::Class> has no need to go back to the database when we access the
1504 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1507 Simple prefetches will be joined automatically, so there is no need
1508 for a C<join> attribute in the above search. If you're prefetching to
1509 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1510 specify the join as well.
1512 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1513 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1514 with an accessor type of 'single' or 'filter').
1520 =item Value: \@from_clause
1524 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1525 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1528 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1529 C<join> will usually do what you need and it is strongly recommended that you
1530 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1532 In simple terms, C<from> works as follows:
1535 { <alias> => <table>, -join_type => 'inner|left|right' }
1536 [] # nested JOIN (optional)
1537 { <table.column> => <foreign_table.foreign_key> }
1543 ON <table.column> = <foreign_table.foreign_key>
1545 An easy way to follow the examples below is to remember the following:
1547 Anything inside "[]" is a JOIN
1548 Anything inside "{}" is a condition for the enclosing JOIN
1550 The following examples utilize a "person" table in a family tree application.
1551 In order to express parent->child relationships, this table is self-joined:
1553 # Person->belongs_to('father' => 'Person');
1554 # Person->belongs_to('mother' => 'Person');
1556 C<from> can be used to nest joins. Here we return all children with a father,
1557 then search against all mothers of those children:
1559 $rs = $schema->resultset('Person')->search(
1562 alias => 'mother', # alias columns in accordance with "from"
1564 { mother => 'person' },
1567 { child => 'person' },
1569 { father => 'person' },
1570 { 'father.person_id' => 'child.father_id' }
1573 { 'mother.person_id' => 'child.mother_id' }
1580 # SELECT mother.* FROM person mother
1583 # JOIN person father
1584 # ON ( father.person_id = child.father_id )
1586 # ON ( mother.person_id = child.mother_id )
1588 The type of any join can be controlled manually. To search against only people
1589 with a father in the person table, we could explicitly use C<INNER JOIN>:
1591 $rs = $schema->resultset('Person')->search(
1594 alias => 'child', # alias columns in accordance with "from"
1596 { child => 'person' },
1598 { father => 'person', -join_type => 'inner' },
1599 { 'father.id' => 'child.father_id' }
1606 # SELECT child.* FROM person child
1607 # INNER JOIN person father ON child.father_id = father.id
1617 Makes the resultset paged and specifies the page to retrieve. Effectively
1618 identical to creating a non-pages resultset and then calling ->page($page)
1629 Specifes the maximum number of rows for direct retrieval or the number of
1630 rows per page if the page attribute or method is used.
1636 =item Value: \@columns
1640 A arrayref of columns to group by. Can include columns of joined tables.
1642 group_by => [qw/ column1 column2 ... /]
1648 =item Value: $condition
1652 HAVING is a select statement attribute that is applied between GROUP BY and
1653 ORDER BY. It is applied to the after the grouping calculations have been
1656 having => { 'count(employee)' => { '>=', 100 } }
1662 =item Value: (0 | 1)
1666 Set to 1 to group by all columns.
1670 Set to 1 to cache search results. This prevents extra SQL queries if you
1671 revisit rows in your ResultSet:
1673 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1675 while( my $artist = $resultset->next ) {
1679 $rs->first; # without cache, this would issue a query
1681 By default, searches are not cached.
1683 For more examples of using these attributes, see
1684 L<DBIx::Class::Manual::Cookbook>.