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) = @_;
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},
102 # from => $attrs->{from},
103 # collapse => $collapse,
105 page => delete $attrs->{page},
115 =item Arguments: $cond, \%attrs?
117 =item Return Value: $resultset (scalar context), @row_objs (list context)
121 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
122 my $new_rs = $cd_rs->search({ year => 2005 });
124 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
125 # year = 2005 OR year = 2004
127 If you need to pass in additional attributes but no additional condition,
128 call it as C<search(undef, \%attrs)>.
130 # "SELECT name, artistid FROM $artist_table"
131 my @all_artists = $schema->resultset('Artist')->search(undef, {
132 columns => [qw/name artistid/],
140 my $attrs = { %{$self->{attrs}} };
141 my $having = delete $attrs->{having};
142 $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
145 ? ((@_ == 1 || ref $_[0] eq "HASH")
148 ? $self->throw_exception(
149 "Odd number of arguments to search")
152 if (defined $where) {
153 $attrs->{where} = (defined $attrs->{where}
155 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
156 $where, $attrs->{where} ] }
160 if (defined $having) {
161 $attrs->{having} = (defined $attrs->{having}
163 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
164 $having, $attrs->{having} ] }
168 my $rs = (ref $self)->new($self->result_source, $attrs);
169 $rs->{_parent_rs} = $self->{_parent_rs} if ($self->{_parent_rs}); #XXX - hack to pass through parent of related resultsets
171 unless (@_) { # no search, effectively just a clone
172 my $rows = $self->get_cache;
174 $rs->set_cache($rows);
178 return (wantarray ? $rs->all : $rs);
181 =head2 search_literal
185 =item Arguments: $sql_fragment, @bind_values
187 =item Return Value: $resultset (scalar context), @row_objs (list context)
191 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
192 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
194 Pass a literal chunk of SQL to be added to the conditional part of the
201 my ($self, $cond, @vals) = @_;
202 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
203 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
204 return $self->search(\$cond, $attrs);
211 =item Arguments: @values | \%cols, \%attrs?
213 =item Return Value: $row_object
217 Finds a row based on its primary key or unique constraint. For example, to find
218 a row by its primary key:
220 my $cd = $schema->resultset('CD')->find(5);
222 You can also find a row by a specific unique constraint using the C<key>
223 attribute. For example:
225 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'artist_title' });
227 Additionally, you can specify the columns explicitly by name:
229 my $cd = $schema->resultset('CD')->find(
231 artist => 'Massive Attack',
232 title => 'Mezzanine',
234 { key => 'artist_title' }
237 If no C<key> is specified and you explicitly name columns, it searches on all
238 unique constraints defined on the source, including the primary key.
240 If the C<key> is specified as C<primary>, it searches only on the primary key.
242 See also L</find_or_create> and L</update_or_create>. For information on how to
243 declare unique constraints, see
244 L<DBIx::Class::ResultSource/add_unique_constraint>.
250 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
252 # Parse out a hash from input
253 my @cols = exists $attrs->{key}
254 ? $self->result_source->unique_constraint_columns($attrs->{key})
255 : $self->result_source->primary_columns;
258 if (ref $_[0] eq 'HASH') {
259 $hash = { %{$_[0]} };
261 elsif (@_ == @cols) {
263 @{$hash}{@cols} = @_;
266 $self->throw_exception(
267 "Arguments to find must be a hashref or match the number of columns in the "
268 . exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key"
272 # Check the hash we just parsed against our source's unique constraints
273 my @constraint_names = exists $attrs->{key}
275 : $self->result_source->unique_constraint_names;
276 $self->throw_exception(
277 "Can't find unless a primary key or unique constraint is defined"
278 ) unless @constraint_names;
281 foreach my $name (@constraint_names) {
282 my @unique_cols = $self->result_source->unique_constraint_columns($name);
283 my $unique_query = $self->_build_unique_query($hash, \@unique_cols);
285 # Add the ResultSet's alias
286 foreach my $key (grep { ! m/\./ } keys %$unique_query) {
287 my $alias = $self->{attrs}->{alias};
288 $unique_query->{"$alias.$key"} = delete $unique_query->{$key};
291 push @unique_queries, $unique_query if %$unique_query;
294 # Handle cases where the ResultSet already defines the query
295 my $query = @unique_queries ? \@unique_queries : undef;
299 my $rs = $self->search($query, $attrs);
300 return $rs->{attrs}->{prefetch} ? $rs->next : $rs->single;
303 return ($self->{attrs}->{prefetch})
304 ? $self->search($query)->next
305 : $self->single($query);
309 # _build_unique_query
311 # Constrain the specified query hash based on the specified column names.
313 sub _build_unique_query {
314 my ($self, $query, $unique_cols) = @_;
317 map { $_ => $query->{$_} }
318 grep { exists $query->{$_} }
321 return \%unique_query;
324 =head2 search_related
328 =item Arguments: $cond, \%attrs?
330 =item Return Value: $new_resultset
334 $new_rs = $cd_rs->search_related('artist', {
338 Searches the specified relationship, optionally specifying a condition and
339 attributes for matching records. See L</ATTRIBUTES> for more information.
344 return shift->related_resultset(shift)->search(@_);
351 =item Arguments: none
353 =item Return Value: $cursor
357 Returns a storage-driven cursor to the given resultset. See
358 L<DBIx::Class::Cursor> for more information.
366 my $attrs = { %{$self->{_attrs}} };
367 return $self->{cursor}
368 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
369 $attrs->{where},$attrs);
376 =item Arguments: $cond?
378 =item Return Value: $row_object?
382 my $cd = $schema->resultset('CD')->single({ year => 2001 });
384 Inflates the first result without creating a cursor if the resultset has
385 any records in it; if not returns nothing. Used by L</find> as an optimisation.
390 my ($self, $where) = @_;
392 my $attrs = { %{$self->{_attrs}} };
394 if (defined $attrs->{where}) {
397 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
398 $where, delete $attrs->{where} ]
401 $attrs->{where} = $where;
405 my @data = $self->result_source->storage->select_single(
406 $attrs->{from}, $attrs->{select},
407 $attrs->{where},$attrs);
408 return (@data ? $self->_construct_object(@data) : ());
415 =item Arguments: $cond?
417 =item Return Value: $resultsetcolumn
421 my $max_length = $rs->get_column('length')->max;
423 Returns a ResultSetColumn instance for $column based on $self
428 my ($self, $column) = @_;
430 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
438 =item Arguments: $cond, \%attrs?
440 =item Return Value: $resultset (scalar context), @row_objs (list context)
444 # WHERE title LIKE '%blue%'
445 $cd_rs = $rs->search_like({ title => '%blue%'});
447 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
448 that this is simply a convenience method. You most likely want to use
449 L</search> with specific operators.
451 For more information, see L<DBIx::Class::Manual::Cookbook>.
457 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
458 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
459 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
460 return $class->search($query, { %$attrs });
467 =item Arguments: $first, $last
469 =item Return Value: $resultset (scalar context), @row_objs (list context)
473 Returns a resultset or object list representing a subset of elements from the
474 resultset slice is called on. Indexes are from 0, i.e., to get the first
477 my ($one, $two, $three) = $rs->slice(0, 2);
482 my ($self, $min, $max) = @_;
483 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
484 $attrs->{offset} = $self->{attrs}{offset} || 0;
485 $attrs->{offset} += $min;
486 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
487 return $self->search(undef(), $attrs);
488 #my $slice = (ref $self)->new($self->result_source, $attrs);
489 #return (wantarray ? $slice->all : $slice);
496 =item Arguments: none
498 =item Return Value: $result?
502 Returns the next element in the resultset (C<undef> is there is none).
504 Can be used to efficiently iterate over records in the resultset:
506 my $rs = $schema->resultset('CD')->search;
507 while (my $cd = $rs->next) {
511 Note that you need to store the resultset object, and call C<next> on it.
512 Calling C<< resultset('Table')->next >> repeatedly will always return the
513 first record from the resultset.
519 if (@{$self->{all_cache} || []}) {
520 $self->{all_cache_position} ||= 0;
521 return $self->{all_cache}->[$self->{all_cache_position}++];
523 if ($self->{attrs}{cache}) {
524 $self->{all_cache_position} = 1;
525 return ($self->all)[0];
527 my @row = (exists $self->{stashed_row} ?
528 @{delete $self->{stashed_row}} :
531 return unless (@row);
532 return $self->_construct_object(@row);
535 # XXX - this is essentially just the old new(). rewrite / tidy up?
539 return if(exists $self->{_attrs}); #return if _resolve has already been called
541 my $attrs = $self->{attrs};
542 my $source = ($self->{_parent_rs}) ? $self->{_parent_rs} : $self->{result_source};
544 # XXX - this is a hack to prevent dclone dieing because of the code ref, get's put back in $attrs afterwards
545 my $record_filter = delete $attrs->{record_filter} if (defined $attrs->{record_filter});
546 $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
547 my $alias = $attrs->{alias};
549 $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
550 delete $attrs->{as} if $attrs->{columns};
551 $attrs->{columns} ||= [ $self->{result_source}->columns ] unless $attrs->{select};
552 my $select_alias = ($self->{_parent_rs}) ? $self->{attrs}->{_live_join} : $alias;
554 map { m/\./ ? $_ : "${select_alias}.$_" } @{delete $attrs->{columns}}
555 ] if $attrs->{columns};
557 map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}}
559 if (my $include = delete $attrs->{include_columns}) {
560 push(@{$attrs->{select}}, @$include);
561 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
563 #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
565 $attrs->{from} ||= [ { $alias => $source->from } ];
566 $attrs->{seen_join} ||= {};
568 if (my $join = delete $attrs->{join}) {
569 foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
570 if (ref $j eq 'HASH') {
571 $seen{$_} = 1 foreach keys %$j;
577 push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
580 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
581 $attrs->{order_by} = [ $attrs->{order_by} ] if
582 $attrs->{order_by} and !ref($attrs->{order_by});
583 $attrs->{order_by} ||= [];
585 my $collapse = $attrs->{collapse} || {};
586 if (my $prefetch = delete $attrs->{prefetch}) {
588 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
589 if ( ref $p eq 'HASH' ) {
590 foreach my $key (keys %$p) {
591 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
595 push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
598 my @prefetch = $source->resolve_prefetch(
599 $p, $attrs->{alias}, {}, \@pre_order, $collapse);
600 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
601 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
603 push(@{$attrs->{order_by}}, @pre_order);
605 $attrs->{collapse} = $collapse;
606 $attrs->{record_filter} = $record_filter if ($record_filter);
607 $self->{_attrs} = $attrs;
610 sub _construct_object {
611 my ($self, @row) = @_;
612 my @as = @{ $self->{_attrs}{as} };
614 my $info = $self->_collapse_result(\@as, \@row);
615 my $new = $self->result_class->inflate_result($self->result_source, @$info, $self->{_parent_rs});
616 $new = $self->{_attrs}{record_filter}->($new)
617 if exists $self->{_attrs}{record_filter};
621 sub _collapse_result {
622 my ($self, $as, $row, $prefix) = @_;
624 my $live_join = $self->{attrs}->{_live_join} ||="";
628 foreach my $this_as (@$as) {
629 my $val = shift @copy;
630 if (defined $prefix) {
631 if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
633 $remain =~ /^(?:(.*)\.)?([^.]+)$/;
634 $const{$1||''}{$2} = $val;
637 $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
638 $const{$1||''}{$2} = $val;
642 my $info = [ {}, {} ];
643 foreach my $key (keys %const) {
644 if (length $key && $key ne $live_join) {
646 my @parts = split(/\./, $key);
647 foreach my $p (@parts) {
648 $target = $target->[1]->{$p} ||= [];
650 $target->[0] = $const{$key};
652 $info->[0] = $const{$key};
657 if (defined $prefix) {
659 m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()
660 } keys %{$self->{_attrs}->{collapse}}
662 @collapse = keys %{$self->{_attrs}->{collapse}};
666 my ($c) = sort { length $a <=> length $b } @collapse;
668 foreach my $p (split(/\./, $c)) {
669 $target = $target->[1]->{$p} ||= [];
671 my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
672 my @co_key = @{$self->{_attrs}->{collapse}{$c_prefix}};
673 my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
674 my $tree = $self->_collapse_result($as, $row, $c_prefix);
677 !defined($tree->[0]->{$_}) ||
678 $co_check{$_} ne $tree->[0]->{$_}
681 last unless (@raw = $self->cursor->next);
682 $row = $self->{stashed_row} = \@raw;
683 $tree = $self->_collapse_result($as, $row, $c_prefix);
694 =item Arguments: $result_source?
696 =item Return Value: $result_source
700 An accessor for the primary ResultSource object from which this ResultSet
710 =item Arguments: $cond, \%attrs??
712 =item Return Value: $count
716 Performs an SQL C<COUNT> with the same query as the resultset was built
717 with to find the number of elements. If passed arguments, does a search
718 on the resultset and counts the results of that.
720 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
721 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
722 not support C<DISTINCT> with multiple columns. If you are using such a
723 database, you should only use columns from the main table in your C<group_by>
730 return $self->search(@_)->count if @_ and defined $_[0];
731 return scalar @{ $self->get_cache } if @{ $self->get_cache };
733 my $count = $self->_count;
734 return 0 unless $count;
736 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
737 $count = $self->{attrs}{rows} if
738 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
742 sub _count { # Separated out so pager can get the full count
744 my $select = { count => '*' };
747 my $attrs = { %{ $self->{_attrs} } };
748 if (my $group_by = delete $attrs->{group_by}) {
749 delete $attrs->{having};
750 my @distinct = (ref $group_by ? @$group_by : ($group_by));
751 # todo: try CONCAT for multi-column pk
752 my @pk = $self->result_source->primary_columns;
754 foreach my $column (@distinct) {
755 if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
756 @distinct = ($column);
762 $select = { count => { distinct => \@distinct } };
763 #use Data::Dumper; die Dumper $select;
766 $attrs->{select} = $select;
767 $attrs->{as} = [qw/count/];
769 # offset, order by and page are not needed to count. record_filter is cdbi
770 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
772 my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
780 =item Arguments: $sql_fragment, @bind_values
782 =item Return Value: $count
786 Counts the results in a literal query. Equivalent to calling L</search_literal>
787 with the passed arguments, then L</count>.
791 sub count_literal { shift->search_literal(@_)->count; }
797 =item Arguments: none
799 =item Return Value: @objects
803 Returns all elements in the resultset. Called implicitly if the resultset
804 is returned in list context.
810 return @{ $self->get_cache } if @{ $self->get_cache };
814 # XXX used to be 'if (keys %{$self->{collapse}})'
815 # XXX replaced by this as it seemed to do roughly the same thing
816 # XXX could be bad as never really understood exactly what collapse did
817 if ($self->{attrs}->{prefetch}) {
818 # Using $self->cursor->all is really just an optimisation.
819 # If we're collapsing has_many prefetches it probably makes
820 # very little difference, and this is cleaner than hacking
821 # _construct_object to survive the approach
822 my @row = $self->cursor->next;
824 push(@obj, $self->_construct_object(@row));
825 @row = (exists $self->{stashed_row}
826 ? @{delete $self->{stashed_row}}
827 : $self->cursor->next);
830 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
833 $self->set_cache(\@obj) if $self->{attrs}{cache};
841 =item Arguments: none
843 =item Return Value: $self
847 Resets the resultset's cursor, so you can iterate through the elements again.
853 delete $self->{_attrs} if (exists $self->{_attrs});
855 $self->{all_cache_position} = 0;
856 $self->cursor->reset;
864 =item Arguments: none
866 =item Return Value: $object?
870 Resets the resultset and returns an object for the first result (if the
871 resultset returns anything).
876 return $_[0]->reset->next;
879 # _cond_for_update_delete
881 # update/delete require the condition to be modified to handle
882 # the differing SQL syntax available. This transforms the $self->{cond}
883 # appropriately, returning the new condition.
885 sub _cond_for_update_delete {
889 if (!ref($self->{cond})) {
890 # No-op. No condition, we're updating/deleting everything
892 elsif (ref $self->{cond} eq 'ARRAY') {
896 foreach my $key (keys %{$_}) {
898 $hash{$1} = $_->{$key};
904 elsif (ref $self->{cond} eq 'HASH') {
905 if ((keys %{$self->{cond}})[0] eq '-and') {
908 my @cond = @{$self->{cond}{-and}};
909 for (my $i = 0; $i < @cond - 1; $i++) {
910 my $entry = $cond[$i];
913 if (ref $entry eq 'HASH') {
914 foreach my $key (keys %{$entry}) {
916 $hash{$1} = $entry->{$key};
920 $entry =~ /([^.]+)$/;
921 $hash{$entry} = $cond[++$i];
924 push @{$cond->{-and}}, \%hash;
928 foreach my $key (keys %{$self->{cond}}) {
930 $cond->{$1} = $self->{cond}{$key};
935 $self->throw_exception(
936 "Can't update/delete on resultset with condition unless hash or array"
948 =item Arguments: \%values
950 =item Return Value: $storage_rv
954 Sets the specified columns in the resultset to the supplied values in a
955 single query. Return value will be true if the update succeeded or false
956 if no records were updated; exact type of success value is storage-dependent.
961 my ($self, $values) = @_;
962 $self->throw_exception("Values for update must be a hash")
963 unless ref $values eq 'HASH';
965 my $cond = $self->_cond_for_update_delete;
967 return $self->result_source->storage->update(
968 $self->result_source->from, $values, $cond
976 =item Arguments: \%values
978 =item Return Value: 1
982 Fetches all objects and updates them one at a time. Note that C<update_all>
983 will run DBIC cascade triggers, while L</update> will not.
988 my ($self, $values) = @_;
989 $self->throw_exception("Values for update must be a hash")
990 unless ref $values eq 'HASH';
991 foreach my $obj ($self->all) {
992 $obj->set_columns($values)->update;
1001 =item Arguments: none
1003 =item Return Value: 1
1007 Deletes the contents of the resultset from its result source. Note that this
1008 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1017 my $cond = $self->_cond_for_update_delete;
1019 $self->result_source->storage->delete($self->result_source->from, $cond);
1027 =item Arguments: none
1029 =item Return Value: 1
1033 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1034 will run DBIC cascade triggers, while L</delete> will not.
1040 $_->delete for $self->all;
1048 =item Arguments: none
1050 =item Return Value: $pager
1054 Return Value a L<Data::Page> object for the current resultset. Only makes
1055 sense for queries with a C<page> attribute.
1061 my $attrs = $self->{attrs};
1062 $self->throw_exception("Can't create pager for non-paged rs")
1063 unless $self->{page};
1064 $attrs->{rows} ||= 10;
1065 return $self->{pager} ||= Data::Page->new(
1066 $self->_count, $attrs->{rows}, $self->{page});
1073 =item Arguments: $page_number
1075 =item Return Value: $rs
1079 Returns a resultset for the $page_number page of the resultset on which page
1080 is called, where each page contains a number of rows equal to the 'rows'
1081 attribute set on the resultset (10 by default).
1086 my ($self, $page) = @_;
1087 my $attrs = { %{$self->{attrs}} };
1088 $attrs->{page} = $page;
1089 return (ref $self)->new($self->result_source, $attrs);
1096 =item Arguments: \%vals
1098 =item Return Value: $object
1102 Creates an object in the resultset's result class and returns it.
1107 my ($self, $values) = @_;
1108 $self->throw_exception( "new_result needs a hash" )
1109 unless (ref $values eq 'HASH');
1110 $self->throw_exception(
1111 "Can't abstract implicit construct, condition not a hash"
1112 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1114 my $alias = $self->{attrs}{alias};
1115 foreach my $key (keys %{$self->{cond}||{}}) {
1116 $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
1118 my $obj = $self->result_class->new(\%new);
1119 $obj->result_source($self->result_source) if $obj->can('result_source');
1127 =item Arguments: \%vals, \%attrs?
1129 =item Return Value: $object
1133 Find an existing record from this resultset. If none exists, instantiate a new
1134 result object and return it. The object will not be saved into your storage
1135 until you call L<DBIx::Class::Row/insert> on it.
1137 If you want objects to be saved immediately, use L</find_or_create> instead.
1143 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1144 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1145 my $exists = $self->find($hash, $attrs);
1146 return defined $exists ? $exists : $self->new_result($hash);
1153 =item Arguments: \%vals
1155 =item Return Value: $object
1159 Inserts a record into the resultset and returns the object representing it.
1161 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1166 my ($self, $attrs) = @_;
1167 $self->throw_exception( "create needs a hashref" )
1168 unless ref $attrs eq 'HASH';
1169 return $self->new_result($attrs)->insert;
1172 =head2 find_or_create
1176 =item Arguments: \%vals, \%attrs?
1178 =item Return Value: $object
1182 $class->find_or_create({ key => $val, ... });
1184 Searches for a record matching the search condition; if it doesn't find one,
1185 creates one and returns that instead.
1187 my $cd = $schema->resultset('CD')->find_or_create({
1189 artist => 'Massive Attack',
1190 title => 'Mezzanine',
1194 Also takes an optional C<key> attribute, to search by a specific key or unique
1195 constraint. For example:
1197 my $cd = $schema->resultset('CD')->find_or_create(
1199 artist => 'Massive Attack',
1200 title => 'Mezzanine',
1202 { key => 'artist_title' }
1205 See also L</find> and L</update_or_create>. For information on how to declare
1206 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1210 sub find_or_create {
1212 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1213 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1214 my $exists = $self->find($hash, $attrs);
1215 return defined $exists ? $exists : $self->create($hash);
1218 =head2 update_or_create
1222 =item Arguments: \%col_values, { key => $unique_constraint }?
1224 =item Return Value: $object
1228 $class->update_or_create({ col => $val, ... });
1230 First, searches for an existing row matching one of the unique constraints
1231 (including the primary key) on the source of this resultset. If a row is
1232 found, updates it with the other given column values. Otherwise, creates a new
1235 Takes an optional C<key> attribute to search on a specific unique constraint.
1238 # In your application
1239 my $cd = $schema->resultset('CD')->update_or_create(
1241 artist => 'Massive Attack',
1242 title => 'Mezzanine',
1245 { key => 'artist_title' }
1248 If no C<key> is specified, it searches on all unique constraints defined on the
1249 source, including the primary key.
1251 If the C<key> is specified as C<primary>, it searches only on the primary key.
1253 See also L</find> and L</find_or_create>. For information on how to declare
1254 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1258 sub update_or_create {
1260 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1261 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1263 my $row = $self->find($hash, $attrs);
1265 $row->set_columns($hash);
1270 return $self->create($hash);
1277 =item Arguments: none
1279 =item Return Value: \@cache_objects?
1283 Gets the contents of the cache for the resultset, if the cache is set.
1288 shift->{all_cache} || [];
1295 =item Arguments: \@cache_objects
1297 =item Return Value: \@cache_objects
1301 Sets the contents of the cache for the resultset. Expects an arrayref
1302 of objects of the same class as those produced by the resultset. Note that
1303 if the cache is set the resultset will return the cached objects rather
1304 than re-querying the database even if the cache attr is not set.
1309 my ( $self, $data ) = @_;
1310 $self->throw_exception("set_cache requires an arrayref")
1311 if ref $data ne 'ARRAY';
1312 my $result_class = $self->result_class;
1314 $self->throw_exception(
1315 "cannot cache object of type '$_', expected '$result_class'"
1316 ) if ref $_ ne $result_class;
1318 $self->{all_cache} = $data;
1325 =item Arguments: none
1327 =item Return Value: []
1331 Clears the cache for the resultset.
1336 shift->set_cache([]);
1339 =head2 related_resultset
1343 =item Arguments: $relationship_name
1345 =item Return Value: $resultset
1349 Returns a related resultset for the supplied relationship name.
1351 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1355 sub related_resultset {
1356 my ( $self, $rel ) = @_;
1358 $self->{related_resultsets} ||= {};
1359 return $self->{related_resultsets}{$rel} ||= do {
1360 #warn "fetching related resultset for rel '$rel' " . $self->result_source->{name};
1361 my $rel_obj = $self->result_source->relationship_info($rel);
1362 $self->throw_exception(
1363 "search_related: result source '" . $self->result_source->name .
1364 "' has no such relationship ${rel}")
1365 unless $rel_obj; #die Dumper $self->{attrs};
1367 my $rs = $self->result_source->schema->resultset($rel_obj->{class}
1369 { %{$self->{attrs}},
1373 _live_join => $rel }
1376 # keep reference of the original resultset
1377 $rs->{_parent_rs} = $self->result_source;
1382 =head2 throw_exception
1384 See L<DBIx::Class::Schema/throw_exception> for details.
1388 sub throw_exception {
1390 $self->result_source->schema->throw_exception(@_);
1393 # XXX: FIXME: Attributes docs need clearing up
1397 The resultset takes various attributes that modify its behavior. Here's an
1404 =item Value: ($order_by | \@order_by)
1408 Which column(s) to order the results by. This is currently passed
1409 through directly to SQL, so you can give e.g. C<year DESC> for a
1410 descending order on the column `year'.
1416 =item Value: \@columns
1420 Shortcut to request a particular set of columns to be retrieved. Adds
1421 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1422 from that, then auto-populates C<as> from C<select> as normal. (You may also
1423 use the C<cols> attribute, as in earlier versions of DBIC.)
1425 =head2 include_columns
1429 =item Value: \@columns
1433 Shortcut to include additional columns in the returned results - for example
1435 $schema->resultset('CD')->search(undef, {
1436 include_columns => ['artist.name'],
1440 would return all CDs and include a 'name' column to the information
1441 passed to object inflation
1447 =item Value: \@select_columns
1451 Indicates which columns should be selected from the storage. You can use
1452 column names, or in the case of RDBMS back ends, function or stored procedure
1455 $rs = $schema->resultset('Employee')->search(undef, {
1458 { count => 'employeeid' },
1463 When you use function/stored procedure names and do not supply an C<as>
1464 attribute, the column names returned are storage-dependent. E.g. MySQL would
1465 return a column named C<count(employeeid)> in the above example.
1471 =item Value: \@inflation_names
1475 Indicates column names for object inflation. This is used in conjunction with
1476 C<select>, usually when C<select> contains one or more function or stored
1479 $rs = $schema->resultset('Employee')->search(undef, {
1482 { count => 'employeeid' }
1484 as => ['name', 'employee_count'],
1487 my $employee = $rs->first(); # get the first Employee
1489 If the object against which the search is performed already has an accessor
1490 matching a column name specified in C<as>, the value can be retrieved using
1491 the accessor as normal:
1493 my $name = $employee->name();
1495 If on the other hand an accessor does not exist in the object, you need to
1496 use C<get_column> instead:
1498 my $employee_count = $employee->get_column('employee_count');
1500 You can create your own accessors if required - see
1501 L<DBIx::Class::Manual::Cookbook> for details.
1507 =item Value: ($rel_name | \@rel_names | \%rel_names)
1511 Contains a list of relationships that should be joined for this query. For
1514 # Get CDs by Nine Inch Nails
1515 my $rs = $schema->resultset('CD')->search(
1516 { 'artist.name' => 'Nine Inch Nails' },
1517 { join => 'artist' }
1520 Can also contain a hash reference to refer to the other relation's relations.
1523 package MyApp::Schema::Track;
1524 use base qw/DBIx::Class/;
1525 __PACKAGE__->table('track');
1526 __PACKAGE__->add_columns(qw/trackid cd position title/);
1527 __PACKAGE__->set_primary_key('trackid');
1528 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1531 # In your application
1532 my $rs = $schema->resultset('Artist')->search(
1533 { 'track.title' => 'Teardrop' },
1535 join => { cd => 'track' },
1536 order_by => 'artist.name',
1540 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1541 similarly for a third time). For e.g.
1543 my $rs = $schema->resultset('Artist')->search({
1544 'cds.title' => 'Down to Earth',
1545 'cds_2.title' => 'Popular',
1547 join => [ qw/cds cds/ ],
1550 will return a set of all artists that have both a cd with title 'Down
1551 to Earth' and a cd with title 'Popular'.
1553 If you want to fetch related objects from other tables as well, see C<prefetch>
1560 =item Value: ($rel_name | \@rel_names | \%rel_names)
1564 Contains one or more relationships that should be fetched along with the main
1565 query (when they are accessed afterwards they will have already been
1566 "prefetched"). This is useful for when you know you will need the related
1567 objects, because it saves at least one query:
1569 my $rs = $schema->resultset('Tag')->search(
1578 The initial search results in SQL like the following:
1580 SELECT tag.*, cd.*, artist.* FROM tag
1581 JOIN cd ON tag.cd = cd.cdid
1582 JOIN artist ON cd.artist = artist.artistid
1584 L<DBIx::Class> has no need to go back to the database when we access the
1585 C<cd> or C<artist> relationships, which saves us two SQL statements in this
1588 Simple prefetches will be joined automatically, so there is no need
1589 for a C<join> attribute in the above search. If you're prefetching to
1590 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
1591 specify the join as well.
1593 C<prefetch> can be used with the following relationship types: C<belongs_to>,
1594 C<has_one> (or if you're using C<add_relationship>, any relationship declared
1595 with an accessor type of 'single' or 'filter').
1601 =item Value: \@from_clause
1605 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
1606 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
1609 NOTE: Use this on your own risk. This allows you to shoot off your foot!
1610 C<join> will usually do what you need and it is strongly recommended that you
1611 avoid using C<from> unless you cannot achieve the desired result using C<join>.
1613 In simple terms, C<from> works as follows:
1616 { <alias> => <table>, -join_type => 'inner|left|right' }
1617 [] # nested JOIN (optional)
1618 { <table.column> => <foreign_table.foreign_key> }
1624 ON <table.column> = <foreign_table.foreign_key>
1626 An easy way to follow the examples below is to remember the following:
1628 Anything inside "[]" is a JOIN
1629 Anything inside "{}" is a condition for the enclosing JOIN
1631 The following examples utilize a "person" table in a family tree application.
1632 In order to express parent->child relationships, this table is self-joined:
1634 # Person->belongs_to('father' => 'Person');
1635 # Person->belongs_to('mother' => 'Person');
1637 C<from> can be used to nest joins. Here we return all children with a father,
1638 then search against all mothers of those children:
1640 $rs = $schema->resultset('Person')->search(
1643 alias => 'mother', # alias columns in accordance with "from"
1645 { mother => 'person' },
1648 { child => 'person' },
1650 { father => 'person' },
1651 { 'father.person_id' => 'child.father_id' }
1654 { 'mother.person_id' => 'child.mother_id' }
1661 # SELECT mother.* FROM person mother
1664 # JOIN person father
1665 # ON ( father.person_id = child.father_id )
1667 # ON ( mother.person_id = child.mother_id )
1669 The type of any join can be controlled manually. To search against only people
1670 with a father in the person table, we could explicitly use C<INNER JOIN>:
1672 $rs = $schema->resultset('Person')->search(
1675 alias => 'child', # alias columns in accordance with "from"
1677 { child => 'person' },
1679 { father => 'person', -join_type => 'inner' },
1680 { 'father.id' => 'child.father_id' }
1687 # SELECT child.* FROM person child
1688 # INNER JOIN person father ON child.father_id = father.id
1698 Makes the resultset paged and specifies the page to retrieve. Effectively
1699 identical to creating a non-pages resultset and then calling ->page($page)
1710 Specifes the maximum number of rows for direct retrieval or the number of
1711 rows per page if the page attribute or method is used.
1717 =item Value: \@columns
1721 A arrayref of columns to group by. Can include columns of joined tables.
1723 group_by => [qw/ column1 column2 ... /]
1729 =item Value: $condition
1733 HAVING is a select statement attribute that is applied between GROUP BY and
1734 ORDER BY. It is applied to the after the grouping calculations have been
1737 having => { 'count(employee)' => { '>=', 100 } }
1743 =item Value: (0 | 1)
1747 Set to 1 to group by all columns.
1751 Set to 1 to cache search results. This prevents extra SQL queries if you
1752 revisit rows in your ResultSet:
1754 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
1756 while( my $artist = $resultset->next ) {
1760 $rs->first; # without cache, this would issue a query
1762 By default, searches are not cached.
1764 For more examples of using these attributes, see
1765 L<DBIx::Class::Manual::Cookbook>.