1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken reftype/;
9 use DBIx::Class::_Util 'fail_on_internal_wantarray';
11 use Data::Dumper::Concise ();
12 use Data::Query::Constants;
13 use Data::Query::ExprHelpers;
14 # not importing first() as it will clash with our own method
18 # De-duplication in _merge_attr() is disabled, but left in for reference
19 # (the merger is used for other things that ought not to be de-duped)
20 *__HM_DEDUP = sub () { 0 };
30 # this is real - CDBICompat overrides it with insanity
31 # yes, prototype won't matter, but that's for now ;)
34 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
38 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
42 my $users_rs = $schema->resultset('User');
43 while( $user = $users_rs->next) {
44 print $user->username;
47 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
48 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
52 A ResultSet is an object which stores a set of conditions representing
53 a query. It is the backbone of DBIx::Class (i.e. the really
54 important/useful bit).
56 No SQL is executed on the database when a ResultSet is created, it
57 just stores all the conditions needed to create the query.
59 A basic ResultSet representing the data of an entire table is returned
60 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
61 L<Source|DBIx::Class::Manual::Glossary/Source> name.
63 my $users_rs = $schema->resultset('User');
65 A new ResultSet is returned from calling L</search> on an existing
66 ResultSet. The new one will contain all the conditions of the
67 original, plus any new conditions added in the C<search> call.
69 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
70 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
73 The query that the ResultSet represents is B<only> executed against
74 the database when these methods are called:
75 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
77 If a resultset is used in a numeric context it returns the L</count>.
78 However, if it is used in a boolean context it is B<always> true. So if
79 you want to check if a resultset has any results, you must use C<if $rs
82 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
84 If you want to make your custom ResultSet classes with L<Moose>, use a template
87 package MyApp::Schema::ResultSet::User;
90 use namespace::autoclean;
92 extends 'DBIx::Class::ResultSet';
94 sub BUILDARGS { $_[2] }
98 __PACKAGE__->meta->make_immutable;
102 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
103 clash with the regular ResultSet constructor. Alternatively, you can use:
105 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
107 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
108 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
112 =head2 Chaining resultsets
114 Let's say you've got a query that needs to be run to return some data
115 to the user. But, you have an authorization system in place that
116 prevents certain users from seeing certain information. So, you want
117 to construct the basic query in one method, but add constraints to it in
122 my $request = $self->get_request; # Get a request object somehow.
123 my $schema = $self->result_source->schema;
125 my $cd_rs = $schema->resultset('CD')->search({
126 title => $request->param('title'),
127 year => $request->param('year'),
130 $cd_rs = $self->apply_security_policy( $cd_rs );
132 return $cd_rs->all();
135 sub apply_security_policy {
144 =head3 Resolving conditions and attributes
146 When a resultset is chained from another resultset (e.g.:
147 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
148 and attributes with the same keys need resolving.
150 If any of L</columns>, L</select>, L</as> are present, they reset the
151 original selection, and start the selection "clean".
153 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
154 are merged into the existing ones from the original resultset.
156 The L</where> and L</having> attributes, and any search conditions, are
157 merged with an SQL C<AND> to the existing condition from the original
160 All other attributes are overridden by any new ones supplied in the
163 =head2 Multiple queries
165 Since a resultset just defines a query, you can do all sorts of
166 things with it with the same object.
168 # Don't hit the DB yet.
169 my $cd_rs = $schema->resultset('CD')->search({
170 title => 'something',
174 # Each of these hits the DB individually.
175 my $count = $cd_rs->count;
176 my $most_recent = $cd_rs->get_column('date_released')->max();
177 my @records = $cd_rs->all;
179 And it's not just limited to SELECT statements.
185 $cd_rs->create({ artist => 'Fred' });
187 Which is the same as:
189 $schema->resultset('CD')->create({
190 title => 'something',
195 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
203 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
205 =item Return Value: L<$resultset|/search>
209 The resultset constructor. Takes a source object (usually a
210 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
211 L</ATTRIBUTES> below). Does not perform any queries -- these are
212 executed as needed by the other methods.
214 Generally you never construct a resultset manually. Instead you get one
216 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
217 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
220 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
226 If called on an object, proxies to L</new_result> instead, so
228 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
230 will return a CD object, not a ResultSet, and is equivalent to:
232 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
234 Please also keep in mind that many internals call L</new_result> directly,
235 so overloading this method with the idea of intercepting new result object
236 creation B<will not work>. See also warning pertaining to L</create>.
244 return $class->new_result(@_) if ref $class;
246 my ($source, $attrs) = @_;
247 $source = $source->resolve
248 if $source->isa('DBIx::Class::ResultSourceHandle');
250 $attrs = { %{$attrs||{}} };
251 delete @{$attrs}{qw(_last_sqlmaker_alias_map _related_results_construction)};
253 if ($attrs->{page}) {
254 $attrs->{rows} ||= 10;
257 $attrs->{alias} ||= 'me';
260 result_source => $source,
261 cond => $attrs->{where},
266 # if there is a dark selector, this means we are already in a
267 # chain and the cleanup/sanification was taken care of by
269 $self->_normalize_selection($attrs)
270 unless $attrs->{_dark_selector};
273 $attrs->{result_class} || $source->result_class
283 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
285 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
289 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
290 my $new_rs = $cd_rs->search({ year => 2005 });
292 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
293 # year = 2005 OR year = 2004
295 In list context, C<< ->all() >> is called implicitly on the resultset, thus
296 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
297 To avoid that, use L</search_rs>.
299 If you need to pass in additional attributes but no additional condition,
300 call it as C<search(undef, \%attrs)>.
302 # "SELECT name, artistid FROM $artist_table"
303 my @all_artists = $schema->resultset('Artist')->search(undef, {
304 columns => [qw/name artistid/],
307 For a list of attributes that can be passed to C<search>, see
308 L</ATTRIBUTES>. For more examples of using this function, see
309 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
310 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
311 and its extension L<DBIx::Class::SQLMaker>.
313 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
317 Note that L</search> does not process/deflate any of the values passed in the
318 L<SQL::Abstract>-compatible search condition structure. This is unlike other
319 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
320 manually that any value passed to this method will stringify to something the
321 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
322 objects, for more info see:
323 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
329 my $rs = $self->search_rs( @_ );
332 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray($rs);
335 elsif (defined wantarray) {
339 # we can be called by a relationship helper, which in
340 # turn may be called in void context due to some braindead
341 # overload or whatever else the user decided to be clever
342 # at this particular day. Thus limit the exception to
343 # external code calls only
344 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
345 if (caller)[0] !~ /^\QDBIx::Class::/;
355 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
357 =item Return Value: L<$resultset|/search>
361 This method does the same exact thing as search() except it will
362 always return a resultset, even in list context.
369 my $rsrc = $self->result_source;
370 my ($call_cond, $call_attrs);
372 # Special-case handling for (undef, undef) or (undef)
373 # Note that (foo => undef) is valid deprecated syntax
374 @_ = () if not scalar grep { defined $_ } @_;
380 # fish out attrs in the ($condref, $attr) case
381 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
382 ($call_cond, $call_attrs) = @_;
385 $self->throw_exception('Odd number of arguments to search')
389 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
390 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
392 for my $i (0 .. $#_) {
394 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
395 if (! defined $_[$i] or ref $_[$i] ne '');
401 if (blessed($call_cond) and $call_cond->isa('Data::Query::ExprBuilder')) {
402 $call_cond = \$call_cond->{expr};
405 # see if we can keep the cache (no $rs changes)
407 my %safe = (alias => 1, cache => 1);
408 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
411 ref $call_cond eq 'HASH' && ! keys %$call_cond
413 ref $call_cond eq 'ARRAY' && ! @$call_cond
415 $cache = $self->get_cache;
417 $self->{attrs}{cache} and
418 ($self->{attrs}{grep_cache} or $call_attrs->{grep_cache})
422 and not (exists $call_attrs->{grep_cache} and !$call_attrs->{grep_cache})
424 die "Can't do complex search on resultset with grep_cache set";
426 my $grep_one = $self->_construct_perl_predicate($call_cond);
427 $cache = [ grep $grep_one->($_), $self->all ];
430 my $old_attrs = { %{$self->{attrs}} };
431 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
433 my $new_attrs = { %$old_attrs };
435 # take care of call attrs (only if anything is changing)
436 if ($call_attrs and keys %$call_attrs) {
438 # copy for _normalize_selection
439 $call_attrs = { %$call_attrs };
441 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
443 # reset the current selector list if new selectors are supplied
444 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
445 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
448 # Normalize the new selector list (operates on the passed-in attr structure)
449 # Need to do it on every chain instead of only once on _resolved_attrs, in
450 # order to allow detection of empty vs partial 'as'
451 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
452 if $old_attrs->{_dark_selector};
453 $self->_normalize_selection ($call_attrs);
455 # start with blind overwriting merge, exclude selector attrs
456 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
457 delete @{$new_attrs}{@selector_attrs};
459 for (@selector_attrs) {
460 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
461 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
464 # older deprecated name, use only if {columns} is not there
465 if (my $c = delete $new_attrs->{cols}) {
466 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
467 if ($new_attrs->{columns}) {
468 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
471 $new_attrs->{columns} = $c;
476 # join/prefetch use their own crazy merging heuristics
477 foreach my $key (qw/join prefetch/) {
478 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
479 if exists $call_attrs->{$key};
482 # stack binds together
483 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
487 for ($old_where, $call_cond) {
489 $new_attrs->{where} = $self->_stack_cond (
490 $_, $new_attrs->{where}
495 if (defined $old_having) {
496 $new_attrs->{having} = $self->_stack_cond (
497 $old_having, $new_attrs->{having}
501 my $rs = (ref $self)->new($rsrc, $new_attrs);
503 $rs->set_cache($cache) if ($cache);
509 sub _normalize_selection {
510 my ($self, $attrs) = @_;
513 if ( exists $attrs->{include_columns} ) {
514 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
515 $attrs->{'+columns'} = $self->_merge_attr(
516 $attrs->{'+columns'}, delete $attrs->{include_columns}
520 # columns are always placed first, however
522 # Keep the X vs +X separation until _resolved_attrs time - this allows to
523 # delay the decision on whether to use a default select list ($rsrc->columns)
524 # allowing stuff like the remove_columns helper to work
526 # select/as +select/+as pairs need special handling - the amount of select/as
527 # elements in each pair does *not* have to be equal (think multicolumn
528 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
529 # supplied at all) - try to infer the alias, either from the -as parameter
530 # of the selector spec, or use the parameter whole if it looks like a column
531 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
532 # is ok as well), but make sure no more additions to the 'as' chain take place
533 for my $pref ('', '+') {
535 my ($sel, $as) = map {
536 my $key = "${pref}${_}";
538 my $val = [ ref $attrs->{$key} eq 'ARRAY'
540 : $attrs->{$key} || ()
542 delete $attrs->{$key};
546 if (! @$as and ! @$sel ) {
549 elsif (@$as and ! @$sel) {
550 $self->throw_exception(
551 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
555 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
556 # if any @$as has been supplied we assume the user knows what (s)he is doing
557 # and blindly keep stacking up pieces
558 unless ($attrs->{_dark_selector}) {
561 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
562 push @$as, $_->{-as};
564 # assume any plain no-space, no-parenthesis string to be a column spec
565 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
566 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
569 # if all else fails - raise a flag that no more aliasing will be allowed
571 $attrs->{_dark_selector} = {
573 string => ($dark_sel_dumper ||= do {
574 require Data::Dumper::Concise;
575 Data::Dumper::Concise::DumperObject()->Indent(0);
576 })->Values([$_])->Dump
584 elsif (@$as < @$sel) {
585 $self->throw_exception(
586 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
589 elsif ($pref and $attrs->{_dark_selector}) {
590 $self->throw_exception(
591 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
597 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
598 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
603 my ($self, $left, $right) = @_;
605 my $source = $self->result_source;
607 my $converter = $source->schema->storage->sql_maker->converter;
609 my @top = map $source->_extract_top_level_conditions(
610 $converter->_expr_to_dq($_)
611 ), grep defined, $left, $right;
613 return undef unless @top;
617 my @uniq = grep { !$seen{Data::Dumper::Concise::Dumper($_)}++ } @top;
619 return \$uniq[0] if @uniq == 1;
621 return \Operator({ 'SQL.Naive' => 'AND' }, \@uniq);
625 '=' => { numeric => '==', string => 'eq' },
628 sub _construct_perl_predicate {
629 my ($self, $cond) = @_;
631 # This shouldn't really live here but it'll do for the moment.
634 $self->current_source_alias => {
636 source => $self->result_source,
637 columns_info => $self->result_source->columns_info,
641 my $attrs = $self->_resolved_attrs;
642 foreach my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
643 next unless $j->[0]{-alias};
644 next unless $j->[0]{-join_path};
645 $alias_map{$j->[0]{-alias}} = {
646 join_path => [ map { keys %$_ } @{$j->[0]{-join_path}} ],
647 source => $j->[0]{-rsrc},
648 columns_info => $j->[0]{-rsrc}->columns_info,
652 my %as_map = map +($attrs->{select}[$_] => $attrs->{as}[$_]),
653 grep !ref($attrs->{select}[$_]), 0..$#{$attrs->{select}};
655 my $storage = $self->result_source->schema->storage;
656 my $sql_maker = $storage->sql_maker;
657 my $tree = map_dq_tree {
659 my $op = $_->{operator}{'SQL.Naive'} or die "No operator";
660 if (lc($op) =~ /^(?:and|or|not)$/i) {
661 return Operator({ 'Perl' => lc($op) }, $op->{args});
663 if (my $op_map = $perl_op_map{$op}) {
664 die "Binop doesn't have two args - wtf?"
665 unless @{$_->{args}} == 2;
667 my @mapped_args = map {
669 die "Identifier not alias.colname"
670 unless @{$_->{elements}} == 2;
671 my ($alias, $col) = @{$_->{elements}};
672 die "${alias}.${col} not selected"
673 unless $as_map{"${alias}.${col}"};
674 unless ($data_type) {
675 my $colinfo = $alias_map{$alias}{columns_info}{$col};
676 unless (defined $colinfo->{is_numeric}) {
677 $colinfo->{is_numeric} = (
678 $storage->is_datatype_numeric($colinfo->{data_type})
683 $data_type = $colinfo->{is_numeric} ? 'numeric' : 'string';
685 Identifier(@{$alias_map{$alias}{join_path}}, $col);
689 die "Argument to operator neither identifier nor value";
692 die "Couldn't determine numeric versus string" unless $data_type;
693 return \Operator({ Perl => $op_map->{$data_type} }, \@mapped_args);
696 die "Unable to map node to perl";
697 } $sql_maker->converter->_where_to_dq($cond);
698 my ($code, @values) = @{$storage->perl_renderer->render($tree)};
699 my $sub = eval q!sub { !.$code.q! }!
700 or die "Failed to build sub: $@";
701 my @args = map $_->{value}, @values;
702 return sub { local $_ = $_[0]; $sub->(@args) };
705 =head2 search_literal
707 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
708 should only be used in that context. C<search_literal> is a convenience
709 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
710 want to ensure columns are bound correctly, use L</search>.
712 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
713 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
714 require C<search_literal>.
718 =item Arguments: $sql_fragment, @standalone_bind_values
720 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
724 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
725 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
727 Pass a literal chunk of SQL to be added to the conditional part of the
730 Example of how to use C<search> instead of C<search_literal>
732 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
733 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
738 my ($self, $sql, @bind) = @_;
740 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
743 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
750 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
752 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
756 Finds and returns a single row based on supplied criteria. Takes either a
757 hashref with the same format as L</create> (including inference of foreign
758 keys from related objects), or a list of primary key values in the same
759 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
760 declaration on the L</result_source>.
762 In either case an attempt is made to combine conditions already existing on
763 the resultset with the condition passed to this method.
765 To aid with preparing the correct query for the storage you may supply the
766 C<key> attribute, which is the name of a
767 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
768 unique constraint corresponding to the
769 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
770 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
771 to construct a query that satisfies the named unique constraint fully (
772 non-NULL values for each column member of the constraint) an exception is
775 If no C<key> is specified, the search is carried over all unique constraints
776 which are fully defined by the available condition.
778 If no such constraint is found, C<find> currently defaults to a simple
779 C<< search->(\%column_values) >> which may or may not do what you expect.
780 Note that this fallback behavior may be deprecated in further versions. If
781 you need to search with arbitrary conditions - use L</search>. If the query
782 resulting from this fallback produces more than one row, a warning to the
783 effect is issued, though only the first row is constructed and returned as
786 In addition to C<key>, L</find> recognizes and applies standard
787 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
789 Note that if you have extra concerns about the correctness of the resulting
790 query you need to specify the C<key> attribute and supply the entire condition
791 as an argument to find (since it is not always possible to perform the
792 combination of the resultset condition with the supplied one, especially if
793 the resultset condition contains literal sql).
795 For example, to find a row by its primary key:
797 my $cd = $schema->resultset('CD')->find(5);
799 You can also find a row by a specific unique constraint:
801 my $cd = $schema->resultset('CD')->find(
803 artist => 'Massive Attack',
804 title => 'Mezzanine',
806 { key => 'cd_artist_title' }
809 See also L</find_or_create> and L</update_or_create>.
815 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
817 my $rsrc = $self->result_source;
820 if (exists $attrs->{key}) {
821 $constraint_name = defined $attrs->{key}
823 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
827 # Parse out the condition from input
830 if (ref $_[0] eq 'HASH') {
831 $call_cond = { %{$_[0]} };
834 # if only values are supplied we need to default to 'primary'
835 $constraint_name = 'primary' unless defined $constraint_name;
837 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
839 $self->throw_exception(
840 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
843 $self->throw_exception (
844 'find() expects either a column/value hashref, or a list of values '
845 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
846 ) unless @c_cols == @_;
849 @{$call_cond}{@c_cols} = @_;
853 for my $key (keys %$call_cond) {
855 my $keyref = ref($call_cond->{$key})
857 my $relinfo = $rsrc->relationship_info($key)
859 my $val = delete $call_cond->{$key};
861 next if $keyref eq 'ARRAY'; # has_many for multi_create
863 my $rel_q = $rsrc->_resolve_condition(
864 $relinfo->{cond}, $val, $key, $key
866 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
867 @related{keys %$rel_q} = values %$rel_q;
871 # relationship conditions take precedence (?)
872 @{$call_cond}{keys %related} = values %related;
874 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
876 if (defined $constraint_name) {
877 $final_cond = $self->_qualify_cond_columns (
879 $self->_build_unique_cond (
887 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
888 # This means that we got here after a merger of relationship conditions
889 # in ::Relationship::Base::search_related (the row method), and furthermore
890 # the relationship is of the 'single' type. This means that the condition
891 # provided by the relationship (already attached to $self) is sufficient,
892 # as there can be only one row in the database that would satisfy the
896 # no key was specified - fall down to heuristics mode:
897 # run through all unique queries registered on the resultset, and
898 # 'OR' all qualifying queries together
899 my (@unique_queries, %seen_column_combinations);
900 for my $c_name ($rsrc->unique_constraint_names) {
901 next if $seen_column_combinations{
902 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
905 push @unique_queries, try {
906 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
910 $final_cond = @unique_queries
911 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
912 : $self->_non_unique_find_fallback ($call_cond, $attrs)
916 # Run the query, passing the result_class since it should propagate for find
917 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
918 if ($rs->_resolved_attrs->{collapse}) {
920 carp "Query returned more than one row" if $rs->next;
928 # This is a stop-gap method as agreed during the discussion on find() cleanup:
929 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
931 # It is invoked when find() is called in legacy-mode with insufficiently-unique
932 # condition. It is provided for overrides until a saner way forward is devised
934 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
935 # the road. Please adjust your tests accordingly to catch this situation early
936 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
938 # The method will not be removed without an adequately complete replacement
939 # for strict-mode enforcement
940 sub _non_unique_find_fallback {
941 my ($self, $cond, $attrs) = @_;
943 return $self->_qualify_cond_columns(
945 exists $attrs->{alias}
947 : $self->{attrs}{alias}
952 sub _qualify_cond_columns {
953 my ($self, $cond, $alias) = @_;
955 my %aliased = %$cond;
956 for (keys %aliased) {
957 $aliased{"$alias.$_"} = delete $aliased{$_}
964 sub _build_unique_cond {
965 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
967 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
969 # combination may fail if $self->{cond} is non-trivial
970 my ($final_cond) = try {
971 $self->_merge_with_rscond ($extra_cond)
976 # trim out everything not in $columns
977 $final_cond = { map {
978 exists $final_cond->{$_}
979 ? ( $_ => $final_cond->{$_} )
983 if (my @missing = grep
984 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
987 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
989 join (', ', map { "'$_'" } @missing),
996 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
998 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
1000 carp_unique ( sprintf (
1001 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
1002 . 'values in column(s): %s). This is almost certainly not what you wanted, '
1003 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
1005 join (', ', map { "'$_'" } @undefs),
1012 =head2 search_related
1016 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
1018 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1022 $new_rs = $cd_rs->search_related('artist', {
1026 Searches the specified relationship, optionally specifying a condition and
1027 attributes for matching records. See L</ATTRIBUTES> for more information.
1029 In list context, C<< ->all() >> is called implicitly on the resultset, thus
1030 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
1032 See also L</search_related_rs>.
1036 sub search_related {
1037 return shift->related_resultset(shift)->search(@_);
1040 =head2 search_related_rs
1042 This method works exactly the same as search_related, except that
1043 it guarantees a resultset, even in list context.
1047 sub search_related_rs {
1048 return shift->related_resultset(shift)->search_rs(@_);
1055 =item Arguments: none
1057 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1061 Returns a storage-driven cursor to the given resultset. See
1062 L<DBIx::Class::Cursor> for more information.
1069 return $self->{cursor} ||= do {
1070 my $attrs = $self->_resolved_attrs;
1071 $self->result_source->storage->select(
1072 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1081 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1083 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1087 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1089 Inflates the first result without creating a cursor if the resultset has
1090 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1093 While this method can take an optional search condition (just like L</search>)
1094 being a fast-code-path it does not recognize search attributes. If you need to
1095 add extra joins or similar, call L</search> and then chain-call L</single> on the
1096 L<DBIx::Class::ResultSet> returned.
1102 As of 0.08100, this method enforces the assumption that the preceding
1103 query returns only one row. If more than one row is returned, you will receive
1106 Query returned more than one row
1108 In this case, you should be using L</next> or L</find> instead, or if you really
1109 know what you are doing, use the L</rows> attribute to explicitly limit the size
1112 This method will also throw an exception if it is called on a resultset prefetching
1113 has_many, as such a prefetch implies fetching multiple rows from the database in
1114 order to assemble the resulting object.
1121 my ($self, $where) = @_;
1123 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1126 my $attrs = { %{$self->_resolved_attrs} };
1128 $self->throw_exception(
1129 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1130 ) if $attrs->{collapse};
1133 if (defined $attrs->{where}) {
1136 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1137 $where, delete $attrs->{where} ]
1140 $attrs->{where} = $where;
1144 my $data = [ $self->result_source->storage->select_single(
1145 $attrs->{from}, $attrs->{select},
1146 $attrs->{where}, $attrs
1149 return undef unless @$data;
1150 $self->{_stashed_rows} = [ $data ];
1151 $self->_construct_results->[0];
1157 # Recursively collapse the query, accumulating values for each column.
1159 sub _collapse_query {
1160 my ($self, $query, $collapsed) = @_;
1164 if (ref $query eq 'ARRAY') {
1165 foreach my $subquery (@$query) {
1166 next unless ref $subquery; # -or
1167 $collapsed = $self->_collapse_query($subquery, $collapsed);
1170 elsif (ref $query eq 'HASH') {
1171 if (keys %$query and (keys %$query)[0] eq '-and') {
1172 foreach my $subquery (@{$query->{-and}}) {
1173 $collapsed = $self->_collapse_query($subquery, $collapsed);
1177 foreach my $col (keys %$query) {
1178 my $value = $query->{$col};
1179 $collapsed->{$col}{$value}++;
1191 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1193 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1197 my $max_length = $rs->get_column('length')->max;
1199 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1204 my ($self, $column) = @_;
1205 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1213 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1215 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1219 # WHERE title LIKE '%blue%'
1220 $cd_rs = $rs->search_like({ title => '%blue%'});
1222 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1223 that this is simply a convenience method retained for ex Class::DBI users.
1224 You most likely want to use L</search> with specific operators.
1226 For more information, see L<DBIx::Class::Manual::Cookbook>.
1228 This method is deprecated and will be removed in 0.09. Use L</search()>
1229 instead. An example conversion is:
1231 ->search_like({ foo => 'bar' });
1235 ->search({ foo => { like => 'bar' } });
1242 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1243 .' Instead use ->search({ x => { -like => "y%" } })'
1244 .' (note the outer pair of {}s - they are important!)'
1246 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1247 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1248 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1249 return $class->search($query, { %$attrs });
1256 =item Arguments: $first, $last
1258 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1262 Returns a resultset or object list representing a subset of elements from the
1263 resultset slice is called on. Indexes are from 0, i.e., to get the first
1264 three records, call:
1266 my ($one, $two, $three) = $rs->slice(0, 2);
1271 my ($self, $min, $max) = @_;
1272 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1273 $attrs->{offset} = $self->{attrs}{offset} || 0;
1274 $attrs->{offset} += $min;
1275 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1276 return $self->search(undef, $attrs);
1283 =item Arguments: none
1285 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1289 Returns the next element in the resultset (C<undef> is there is none).
1291 Can be used to efficiently iterate over records in the resultset:
1293 my $rs = $schema->resultset('CD')->search;
1294 while (my $cd = $rs->next) {
1298 Note that you need to store the resultset object, and call C<next> on it.
1299 Calling C<< resultset('Table')->next >> repeatedly will always return the
1300 first record from the resultset.
1307 if (my $cache = $self->get_cache) {
1308 $self->{all_cache_position} ||= 0;
1309 return $cache->[$self->{all_cache_position}++];
1312 if ($self->{attrs}{cache}) {
1313 delete $self->{pager};
1314 $self->{all_cache_position} = 1;
1315 return ($self->all)[0];
1318 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1320 $self->{_stashed_results} = $self->_construct_results
1323 return shift @{$self->{_stashed_results}};
1326 # Constructs as many results as it can in one pass while respecting
1327 # cursor laziness. Several modes of operation:
1329 # * Always builds everything present in @{$self->{_stashed_rows}}
1330 # * If called with $fetch_all true - pulls everything off the cursor and
1331 # builds all result structures (or objects) in one pass
1332 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1333 # and if the resultset is ordered properly by the left side:
1334 # * Fetches stuff off the cursor until the "master object" changes,
1335 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1337 # * Just fetches, and collapses/constructs everything as if $fetch_all
1338 # was requested (there is no other way to collapse except for an
1340 # * If no collapse is requested - just get the next row, construct and
1342 sub _construct_results {
1343 my ($self, $fetch_all) = @_;
1345 my $rsrc = $self->result_source;
1346 my $attrs = $self->_resolved_attrs;
1351 ! $attrs->{order_by}
1355 my @pcols = $rsrc->primary_columns
1357 # default order for collapsing unless the user asked for something
1358 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1359 $attrs->{_ordered_for_collapse} = 1;
1360 $attrs->{_order_is_artificial} = 1;
1363 # this will be used as both initial raw-row collector AND as a RV of
1364 # _construct_results. Not regrowing the array twice matters a lot...
1365 # a surprising amount actually
1366 my $rows = delete $self->{_stashed_rows};
1368 my $cursor; # we may not need one at all
1370 my $did_fetch_all = $fetch_all;
1373 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1374 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1376 elsif( $attrs->{collapse} ) {
1378 # a cursor will need to be closed over in case of collapse
1379 $cursor = $self->cursor;
1381 $attrs->{_ordered_for_collapse} = (
1387 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1389 ) unless defined $attrs->{_ordered_for_collapse};
1391 if (! $attrs->{_ordered_for_collapse}) {
1394 # instead of looping over ->next, use ->all in stealth mode
1395 # *without* calling a ->reset afterwards
1396 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1397 if (! $cursor->{_done}) {
1398 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1399 $cursor->{_done} = 1;
1404 if (! $did_fetch_all and ! @{$rows||[]} ) {
1405 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1406 $cursor ||= $self->cursor;
1407 if (scalar (my @r = $cursor->next) ) {
1412 return undef unless @{$rows||[]};
1414 # sanity check - people are too clever for their own good
1415 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1417 my $multiplied_selectors;
1418 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1420 $aliastypes->{multiplying}{$sel_alias}
1422 $aliastypes->{premultiplied}{$sel_alias}
1424 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1428 for my $i (0 .. $#{$attrs->{as}} ) {
1429 my $sel = $attrs->{select}[$i];
1431 if (ref $sel eq 'SCALAR') {
1434 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1438 $self->throw_exception(
1439 'Result collapse not possible - selection from a has_many source redirected to the main object'
1440 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1444 # hotspot - skip the setter
1445 my $res_class = $self->_result_class;
1447 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1448 $res_class->can ('inflate_result')
1449 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1452 my $infmap = $attrs->{as};
1454 $self->{_result_inflator}{is_core_row} = ( (
1457 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1458 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1460 $self->{_result_inflator}{is_hri} = ( (
1461 ! $self->{_result_inflator}{is_core_row}
1464 require DBIx::Class::ResultClass::HashRefInflator
1466 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1468 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1471 if (! $attrs->{_related_results_construction}) {
1472 # construct a much simpler array->hash folder for the one-table cases right here
1473 if ($self->{_result_inflator}{is_hri}) {
1474 for my $r (@$rows) {
1475 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1478 # FIXME SUBOPTIMAL this is a very very very hot spot
1479 # while rather optimal we can *still* do much better, by
1480 # building a smarter Row::inflate_result(), and
1481 # switch to feeding it data via a much leaner interface
1483 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1484 # this particular resultset size
1485 elsif (@$rows < 60) {
1486 for my $r (@$rows) {
1487 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1492 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1493 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1499 $self->{_result_inflator}{is_hri} ? 'hri'
1500 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1501 : 'classic_nonpruning'
1504 # $args and $attrs to _mk_row_parser are separated to delineate what is
1505 # core collapser stuff and what is dbic $rs specific
1506 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1508 inflate_map => $infmap,
1509 collapse => $attrs->{collapse},
1510 premultiplied => $attrs->{_main_source_premultiplied},
1511 hri_style => $self->{_result_inflator}{is_hri},
1512 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1513 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1515 # column_info metadata historically hasn't been too reliable.
1516 # We need to start fixing this somehow (the collapse resolver
1517 # can't work without it). Add an explicit check for the *main*
1518 # result, hopefully this will gradually weed out such errors
1520 # FIXME - this is a temporary kludge that reduces performance
1521 # It is however necessary for the time being
1522 my ($unrolled_non_null_cols_to_check, $err);
1524 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1527 'Collapse aborted due to invalid ResultSource metadata - the following '
1528 . 'selections are declared non-nullable but NULLs were retrieved: '
1532 COL: for my $i (@$check_non_null_cols) {
1533 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1536 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1539 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1543 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1544 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1546 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1547 my @r = $cursor->next or return;
1548 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1549 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1555 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1556 my @r = $cursor->next or return;
1561 $self->{_row_parser}{$parser_type}{cref}->(
1563 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1566 # Special-case multi-object HRI - there is no $inflator_cref pass
1567 unless ($self->{_result_inflator}{is_hri}) {
1568 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1572 # The @$rows check seems odd at first - why wouldn't we want to warn
1573 # regardless? The issue is things like find() etc, where the user
1574 # *knows* only one result will come back. In these cases the ->all
1575 # is not a pessimization, but rather something we actually want
1577 'Unable to properly collapse has_many results in iterator mode due '
1578 . 'to order criteria - performed an eager cursor slurp underneath. '
1579 . 'Consider using ->all() instead'
1580 ) if ( ! $fetch_all and @$rows > 1 );
1585 =head2 result_source
1589 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1591 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1595 An accessor for the primary ResultSource object from which this ResultSet
1602 =item Arguments: $result_class?
1604 =item Return Value: $result_class
1608 An accessor for the class to use when creating result objects. Defaults to
1609 C<< result_source->result_class >> - which in most cases is the name of the
1610 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1612 Note that changing the result_class will also remove any components
1613 that were originally loaded in the source class via
1614 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1615 in the original source class will not run.
1620 my ($self, $result_class) = @_;
1621 if ($result_class) {
1623 # don't fire this for an object
1624 $self->ensure_class_loaded($result_class)
1625 unless ref($result_class);
1627 if ($self->get_cache) {
1628 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1630 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1631 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1632 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1635 $self->_result_class($result_class);
1637 delete $self->{_result_inflator};
1639 $self->_result_class;
1646 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1648 =item Return Value: $count
1652 Performs an SQL C<COUNT> with the same query as the resultset was built
1653 with to find the number of elements. Passing arguments is equivalent to
1654 C<< $rs->search ($cond, \%attrs)->count >>
1660 return $self->search(@_)->count if @_ and defined $_[0];
1661 return scalar @{ $self->get_cache } if $self->get_cache;
1663 my $attrs = { %{ $self->_resolved_attrs } };
1665 # this is a little optimization - it is faster to do the limit
1666 # adjustments in software, instead of a subquery
1667 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1670 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1671 $crs = $self->_count_subq_rs ($attrs);
1674 $crs = $self->_count_rs ($attrs);
1676 my $count = $crs->next;
1678 $count -= $offset if $offset;
1679 $count = $rows if $rows and $rows < $count;
1680 $count = 0 if ($count < 0);
1689 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1691 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1695 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1696 This can be very handy for subqueries:
1698 ->search( { amount => $some_rs->count_rs->as_query } )
1700 As with regular resultsets the SQL query will be executed only after
1701 the resultset is accessed via L</next> or L</all>. That would return
1702 the same single value obtainable via L</count>.
1708 return $self->search(@_)->count_rs if @_;
1710 # this may look like a lack of abstraction (count() does about the same)
1711 # but in fact an _rs *must* use a subquery for the limits, as the
1712 # software based limiting can not be ported if this $rs is to be used
1713 # in a subquery itself (i.e. ->as_query)
1714 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1715 return $self->_count_subq_rs($self->{_attrs});
1718 return $self->_count_rs($self->{_attrs});
1723 # returns a ResultSetColumn object tied to the count query
1726 my ($self, $attrs) = @_;
1728 my $rsrc = $self->result_source;
1730 my $tmp_attrs = { %$attrs };
1731 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1732 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1734 # overwrite the selector (supplied by the storage)
1735 $rsrc->resultset_class->new($rsrc, {
1737 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1739 })->get_column ('count');
1743 # same as above but uses a subquery
1745 sub _count_subq_rs {
1746 my ($self, $attrs) = @_;
1748 my $rsrc = $self->result_source;
1750 my $sub_attrs = { %$attrs };
1751 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1752 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1754 # if we multi-prefetch we group_by something unique, as this is what we would
1755 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1756 if ( $attrs->{collapse} ) {
1757 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1758 $rsrc->_identifying_column_set || $self->throw_exception(
1759 'Unable to construct a unique group_by criteria properly collapsing the '
1760 . 'has_many prefetch before count()'
1765 # Calculate subquery selector
1766 if (my $g = $sub_attrs->{group_by}) {
1768 my $sql_maker = $rsrc->storage->sql_maker;
1770 # necessary as the group_by may refer to aliased functions
1772 for my $sel (@{$attrs->{select}}) {
1773 $sel_index->{$sel->{-as}} = $sel
1774 if (ref $sel eq 'HASH' and $sel->{-as});
1777 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1778 # also look for named aggregates referred in the having clause
1779 # having often contains scalarrefs - thus parse it out entirely
1781 if ($attrs->{having}) {
1782 local $sql_maker->{having_bind};
1783 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1784 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1785 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1786 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1787 # if we don't unset it we screw up retarded but unfortunately working
1788 # 'MAX(foo.bar)' => { '>', 3 }
1789 $sql_maker->{name_sep} = '';
1792 # delete local is 5.12+
1793 local @{$sql_maker}{qw(renderer converter)};
1794 delete @{$sql_maker}{qw(renderer converter)};
1796 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1798 my $having_sql = $sql_maker->_render_sqla(where => $attrs->{having});
1802 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1803 # and if all fails for an utterly naive quoted scalar-with-function
1804 while ($having_sql =~ /
1805 (?: $rquote $sep)? $lquote (.+?) $rquote
1807 [\s,] \w+ \. (\w+) [\s,]
1809 [\s,] $lquote (.+?) $rquote [\s,]
1811 my $part = $1 || $2 || $3; # one of them matched if we got here
1812 unless ($seen_having{$part}++) {
1819 my $colpiece = $sel_index->{$_} || $_;
1821 # unqualify join-based group_by's. Arcane but possible query
1822 # also horrible horrible hack to alias a column (not a func.)
1823 # (probably need to introduce SQLA syntax)
1824 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1827 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1829 push @{$sub_attrs->{select}}, $colpiece;
1833 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1834 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1837 return $rsrc->resultset_class
1838 ->new ($rsrc, $sub_attrs)
1840 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1841 ->get_column ('count');
1845 =head2 count_literal
1847 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1848 should only be used in that context. See L</search_literal> for further info.
1852 =item Arguments: $sql_fragment, @standalone_bind_values
1854 =item Return Value: $count
1858 Counts the results in a literal query. Equivalent to calling L</search_literal>
1859 with the passed arguments, then L</count>.
1863 sub count_literal { shift->search_literal(@_)->count; }
1869 =item Arguments: none
1871 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1875 Returns all elements in the resultset.
1882 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1885 delete @{$self}{qw/_stashed_rows _stashed_results/};
1887 if (my $c = $self->get_cache) {
1891 $self->cursor->reset;
1893 my $objs = $self->_construct_results('fetch_all') || [];
1895 $self->set_cache($objs) if $self->{attrs}{cache};
1904 =item Arguments: none
1906 =item Return Value: $self
1910 Resets the resultset's cursor, so you can iterate through the elements again.
1911 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1919 delete @{$self}{qw/_stashed_rows _stashed_results/};
1920 $self->{all_cache_position} = 0;
1921 $self->cursor->reset;
1929 =item Arguments: none
1931 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1935 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1936 an object for the first result (or C<undef> if the resultset is empty).
1941 return $_[0]->reset->next;
1947 # Determines whether and what type of subquery is required for the $rs operation.
1948 # If grouping is necessary either supplies its own, or verifies the current one
1949 # After all is done delegates to the proper storage method.
1951 sub _rs_update_delete {
1952 my ($self, $op, $values) = @_;
1954 my $rsrc = $self->result_source;
1955 my $storage = $rsrc->schema->storage;
1957 my $attrs = { %{$self->_resolved_attrs} };
1959 my $join_classifications;
1960 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1962 # do we need a subquery for any reason?
1964 defined $existing_group_by
1966 # if {from} is unparseable wrap a subq
1967 ref($attrs->{from}) ne 'ARRAY'
1969 # limits call for a subq
1970 $self->_has_resolved_attr(qw/rows offset/)
1973 # simplify the joinmap, so we can further decide if a subq is necessary
1974 if (!$needs_subq and @{$attrs->{from}} > 1) {
1976 ($attrs->{from}, $join_classifications) =
1977 $storage->_prune_unused_joins ($attrs);
1979 # any non-pruneable non-local restricting joins imply subq
1980 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1983 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1985 (ref $attrs->{from}[0]) ne 'HASH'
1987 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1991 # do we need anything like a subquery?
1992 if (! $needs_subq) {
1993 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1994 # a condition containing 'me' or other table prefixes will not work
1995 # at all - so we convert the WHERE to a dq tree now, dequalify all
1996 # identifiers found therein via a scan across the tree, and then use
1997 # \{} style to pass the result onwards for use in the final query
1998 if ($self->{cond}) {
2000 my $converter = $rsrc->storage->sql_maker->converter;
2002 DQ_IDENTIFIER ,=> sub { $_ = [ $_->[-1] ] for $_[0]->{elements} }
2003 }, my $where_dq = $converter->_where_to_dq($self->{cond}));
2009 # we got this far - means it is time to wrap a subquery
2010 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
2012 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
2018 # make a new $rs selecting only the PKs (that's all we really need for the subq)
2019 delete $attrs->{$_} for qw/select as collapse/;
2020 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
2022 # this will be consumed by the pruner waaaaay down the stack
2023 $attrs->{_force_prune_multiplying_joins} = 1;
2025 my $subrs = (ref $self)->new($rsrc, $attrs);
2027 if (@$idcols == 1) {
2028 $cond = { $idcols->[0] => { -in => \$subrs->_as_select_dq } };
2030 elsif ($storage->_use_multicolumn_in) {
2031 # no syntax for calling this properly yet
2032 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
2033 my $left = $storage->sql_maker->_render_sqla(select_select => $idcols);
2034 $left =~ s/^SELECT //i;
2035 my $right = $storage->sql_maker
2037 ->_literal_to_dq(${$subrs->as_query});
2039 { 'SQL.Naive' => 'in' },
2040 [ Literal(SQL => "( $left )"), $right ],
2044 # if all else fails - get all primary keys and operate over a ORed set
2045 # wrap in a transaction for consistency
2046 # this is where the group_by/multiplication starts to matter
2050 # we do not need to check pre-multipliers, since if the premulti is there, its
2051 # parent (who is multi) will be there too
2052 keys %{ $join_classifications->{multiplying} || {} }
2054 # make sure if there is a supplied group_by it matches the columns compiled above
2055 # perfectly. Anything else can not be sanely executed on most databases so croak
2056 # right then and there
2057 if ($existing_group_by) {
2058 my @current_group_by = map
2059 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
2064 join ("\x00", sort @current_group_by)
2066 join ("\x00", sort @{$attrs->{columns}} )
2068 $self->throw_exception (
2069 "You have just attempted a $op operation on a resultset which does group_by"
2070 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2071 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2072 . ' kind of queries. Please retry the operation with a modified group_by or'
2073 . ' without using one at all.'
2078 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2081 $guard = $storage->txn_scope_guard;
2084 for my $row ($subrs->cursor->all) {
2086 { $idcols->[$_] => $row->[$_] }
2093 my $res = $storage->$op (
2095 $op eq 'update' ? $values : (),
2099 $guard->commit if $guard;
2108 =item Arguments: \%values
2110 =item Return Value: $underlying_storage_rv
2114 Sets the specified columns in the resultset to the supplied values in a
2115 single query. Note that this will not run any accessor/set_column/update
2116 triggers, nor will it update any result object instances derived from this
2117 resultset (this includes the contents of the L<resultset cache|/set_cache>
2118 if any). See L</update_all> if you need to execute any on-update
2119 triggers or cascades defined either by you or a
2120 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2122 The return value is a pass through of what the underlying
2123 storage backend returned, and may vary. See L<DBI/execute> for the most
2128 Note that L</update> does not process/deflate any of the values passed in.
2129 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2130 ensure manually that any value passed to this method will stringify to
2131 something the RDBMS knows how to deal with. A notable example is the
2132 handling of L<DateTime> objects, for more info see:
2133 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2138 my ($self, $values) = @_;
2139 $self->throw_exception('Values for update must be a hash')
2140 unless ref $values eq 'HASH';
2142 return $self->_rs_update_delete ('update', $values);
2149 =item Arguments: \%values
2151 =item Return Value: 1
2155 Fetches all objects and updates them one at a time via
2156 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2157 triggers, while L</update> will not.
2162 my ($self, $values) = @_;
2163 $self->throw_exception('Values for update_all must be a hash')
2164 unless ref $values eq 'HASH';
2166 my $guard = $self->result_source->schema->txn_scope_guard;
2167 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2176 =item Arguments: none
2178 =item Return Value: $underlying_storage_rv
2182 Deletes the rows matching this resultset in a single query. Note that this
2183 will not run any delete triggers, nor will it alter the
2184 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2185 derived from this resultset (this includes the contents of the
2186 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2187 execute any on-delete triggers or cascades defined either by you or a
2188 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2190 The return value is a pass through of what the underlying storage backend
2191 returned, and may vary. See L<DBI/execute> for the most common case.
2197 $self->throw_exception('delete does not accept any arguments')
2200 return $self->_rs_update_delete ('delete');
2207 =item Arguments: none
2209 =item Return Value: 1
2213 Fetches all objects and deletes them one at a time via
2214 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2215 triggers, while L</delete> will not.
2221 $self->throw_exception('delete_all does not accept any arguments')
2224 my $guard = $self->result_source->schema->txn_scope_guard;
2225 $_->delete for $self->all;
2234 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2236 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2240 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2247 The context of this method call has an important effect on what is
2248 submitted to storage. In void context data is fed directly to fastpath
2249 insertion routines provided by the underlying storage (most often
2250 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2251 L<insert|DBIx::Class::Row/insert> calls on the
2252 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2253 augmentation of these methods provided by components. For example if you
2254 are using something like L<DBIx::Class::UUIDColumns> to create primary
2255 keys for you, you will find that your PKs are empty. In this case you
2256 will have to explicitly force scalar or list context in order to create
2261 In non-void (scalar or list) context, this method is simply a wrapper
2262 for L</create>. Depending on list or scalar context either a list of
2263 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2264 containing these objects is returned.
2266 When supplying data in "arrayref of arrayrefs" invocation style, the
2267 first element should be a list of column names and each subsequent
2268 element should be a data value in the earlier specified column order.
2271 $schema->resultset("Artist")->populate([
2272 [ qw( artistid name ) ],
2273 [ 100, 'A Formally Unknown Singer' ],
2274 [ 101, 'A singer that jumped the shark two albums ago' ],
2275 [ 102, 'An actually cool singer' ],
2278 For the arrayref of hashrefs style each hashref should be a structure
2279 suitable for passing to L</create>. Multi-create is also permitted with
2282 $schema->resultset("Artist")->populate([
2283 { artistid => 4, name => 'Manufactured Crap', cds => [
2284 { title => 'My First CD', year => 2006 },
2285 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2288 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2289 { title => 'My parents sold me to a record company', year => 2005 },
2290 { title => 'Why Am I So Ugly?', year => 2006 },
2291 { title => 'I Got Surgery and am now Popular', year => 2007 }
2296 If you attempt a void-context multi-create as in the example above (each
2297 Artist also has the related list of CDs), and B<do not> supply the
2298 necessary autoinc foreign key information, this method will proxy to the
2299 less efficient L</create>, and then throw the Result objects away. In this
2300 case there are obviously no benefits to using this method over L</create>.
2307 # cruft placed in standalone method
2308 my $data = $self->_normalize_populate_args(@_);
2310 return unless @$data;
2312 if(defined wantarray) {
2313 my @created = map { $self->create($_) } @$data;
2314 return wantarray ? @created : \@created;
2317 my $first = $data->[0];
2319 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2320 # it relationship data
2321 my (@rels, @columns);
2322 my $rsrc = $self->result_source;
2323 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2324 for (keys %$first) {
2325 my $ref = ref $first->{$_};
2326 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2332 my @pks = $rsrc->primary_columns;
2334 ## do the belongs_to relationships
2335 foreach my $index (0..$#$data) {
2337 # delegate to create() for any dataset without primary keys with specified relationships
2338 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2340 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2341 my @ret = $self->populate($data);
2347 foreach my $rel (@rels) {
2348 next unless ref $data->[$index]->{$rel} eq "HASH";
2349 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2350 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2351 my $related = $result->result_source->_resolve_condition(
2352 $reverse_relinfo->{cond},
2358 delete $data->[$index]->{$rel};
2359 $data->[$index] = {%{$data->[$index]}, %$related};
2361 push @columns, keys %$related if $index == 0;
2365 ## inherit the data locked in the conditions of the resultset
2366 my ($rs_data) = $self->_merge_with_rscond({});
2367 delete @{$rs_data}{@columns};
2369 ## do bulk insert on current row
2370 $rsrc->storage->insert_bulk(
2372 [@columns, keys %$rs_data],
2373 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2376 ## do the has_many relationships
2377 foreach my $item (@$data) {
2381 foreach my $rel (@rels) {
2382 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2384 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2386 my $child = $main_row->$rel;
2388 my $related = $child->result_source->_resolve_condition(
2389 $rels->{$rel}{cond},
2395 if (ref($related) eq 'REF' and ref($$related) eq 'HASH') {
2396 $related = $self->result_source
2397 ->_extract_fixed_values_for($$related, $rel);
2400 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2401 my @populate = map { {%$_, %$related} } @rows_to_add;
2403 $child->populate( \@populate );
2409 # populate() arguments went over several incarnations
2410 # What we ultimately support is AoH
2411 sub _normalize_populate_args {
2412 my ($self, $arg) = @_;
2414 if (ref $arg eq 'ARRAY') {
2418 elsif (ref $arg->[0] eq 'HASH') {
2421 elsif (ref $arg->[0] eq 'ARRAY') {
2423 my @colnames = @{$arg->[0]};
2424 foreach my $values (@{$arg}[1 .. $#$arg]) {
2425 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2431 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2438 =item Arguments: none
2440 =item Return Value: L<$pager|Data::Page>
2444 Returns a L<Data::Page> object for the current resultset. Only makes
2445 sense for queries with a C<page> attribute.
2447 To get the full count of entries for a paged resultset, call
2448 C<total_entries> on the L<Data::Page> object.
2455 return $self->{pager} if $self->{pager};
2457 my $attrs = $self->{attrs};
2458 if (!defined $attrs->{page}) {
2459 $self->throw_exception("Can't create pager for non-paged rs");
2461 elsif ($attrs->{page} <= 0) {
2462 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2464 $attrs->{rows} ||= 10;
2466 # throw away the paging flags and re-run the count (possibly
2467 # with a subselect) to get the real total count
2468 my $count_attrs = { %$attrs };
2469 delete @{$count_attrs}{qw/rows offset page pager/};
2471 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2473 require DBIx::Class::ResultSet::Pager;
2474 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2475 sub { $total_rs->count }, #lazy-get the total
2477 $self->{attrs}{page},
2485 =item Arguments: $page_number
2487 =item Return Value: L<$resultset|/search>
2491 Returns a resultset for the $page_number page of the resultset on which page
2492 is called, where each page contains a number of rows equal to the 'rows'
2493 attribute set on the resultset (10 by default).
2498 my ($self, $page) = @_;
2499 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2506 =item Arguments: \%col_data
2508 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2512 Creates a new result object in the resultset's result class and returns
2513 it. The row is not inserted into the database at this point, call
2514 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2515 will tell you whether the result object has been inserted or not.
2517 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2522 my ($self, $values) = @_;
2524 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2527 $self->throw_exception( "new_result expects a hashref" )
2528 unless (ref $values eq 'HASH');
2530 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2532 my $new = $self->result_class->new({
2534 ( @$cols_from_relations
2535 ? (-cols_from_relations => $cols_from_relations)
2538 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2542 reftype($new) eq 'HASH'
2548 carp_unique (sprintf (
2549 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2550 $self->result_class,
2557 # _merge_with_rscond
2559 # Takes a simple hash of K/V data and returns its copy merged with the
2560 # condition already present on the resultset. Additionally returns an
2561 # arrayref of value/condition names, which were inferred from related
2562 # objects (this is needed for in-memory related objects)
2563 sub _merge_with_rscond {
2564 my ($self, $data) = @_;
2566 my (%new_data, @cols_from_relations);
2568 my $alias = $self->{attrs}{alias};
2570 if (! defined $self->{cond}) {
2571 # just massage $data below
2573 elsif (ref $self->{cond} eq 'HASH') {
2574 # precedence must be given to passed values over values inherited from
2575 # the cond, so the order here is important.
2576 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2577 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2579 while ( my($col, $value) = each %implied ) {
2580 my $vref = ref $value;
2586 (keys %$value)[0] eq '='
2588 $new_data{$col} = $value->{'='};
2590 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2591 $new_data{$col} = $value;
2595 elsif (ref $self->{cond} eq 'REF' and ref ${$self->{cond}} eq 'HASH') {
2596 if ((${$self->{cond}})->{'DBIx::Class::ResultSource.UNRESOLVABLE'}) {
2597 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2598 @cols_from_relations = keys %new_data;
2600 %new_data = %{$self->_remove_alias(
2601 $self->result_source
2602 ->_extract_fixed_values_for(${$self->{cond}}),
2608 $self->throw_exception(
2609 "Can't abstract implicit construct, resultset condition not a hash"
2615 %{ $self->_remove_alias($data, $alias) },
2618 return (\%new_data, \@cols_from_relations);
2621 # _has_resolved_attr
2623 # determines if the resultset defines at least one
2624 # of the attributes supplied
2626 # used to determine if a subquery is necessary
2628 # supports some virtual attributes:
2630 # This will scan for any joins being present on the resultset.
2631 # It is not a mere key-search but a deep inspection of {from}
2634 sub _has_resolved_attr {
2635 my ($self, @attr_names) = @_;
2637 my $attrs = $self->_resolved_attrs;
2641 for my $n (@attr_names) {
2642 if (grep { $n eq $_ } (qw/-join/) ) {
2643 $extra_checks{$n}++;
2647 my $attr = $attrs->{$n};
2649 next if not defined $attr;
2651 if (ref $attr eq 'HASH') {
2652 return 1 if keys %$attr;
2654 elsif (ref $attr eq 'ARRAY') {
2662 # a resolved join is expressed as a multi-level from
2664 $extra_checks{-join}
2666 ref $attrs->{from} eq 'ARRAY'
2668 @{$attrs->{from}} > 1
2676 # Recursively collapse the condition.
2678 sub _collapse_cond {
2679 my ($self, $cond, $collapsed) = @_;
2683 if (ref $cond eq 'ARRAY') {
2684 foreach my $subcond (@$cond) {
2685 next unless ref $subcond; # -or
2686 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2689 elsif (ref $cond eq 'HASH') {
2690 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2691 foreach my $subcond (@{$cond->{-and}}) {
2692 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2696 foreach my $col (keys %$cond) {
2697 my $value = $cond->{$col};
2698 $collapsed->{$col} = $value;
2708 # Remove the specified alias from the specified query hash. A copy is made so
2709 # the original query is not modified.
2712 my ($self, $query, $alias) = @_;
2714 my %orig = %{ $query || {} };
2717 foreach my $key (keys %orig) {
2719 $unaliased{$key} = $orig{$key};
2722 $unaliased{$1} = $orig{$key}
2723 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2733 =item Arguments: none
2735 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2739 Returns the SQL query and bind vars associated with the invocant.
2741 This is generally used as the RHS for a subquery.
2748 my $attrs = { %{ $self->_resolved_attrs } };
2750 my $aq = $self->result_source->storage->_select_args_to_query (
2751 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2759 my $attrs = { %{ $self->_resolved_attrs } };
2760 my $storage = $self->result_source->storage;
2761 my (undef, $ident, @args) = $storage->_select_args(
2762 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2764 $ident = $ident->from if blessed($ident);
2765 $storage->sql_maker->converter->_select_to_dq(
2774 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2776 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2780 my $artist = $schema->resultset('Artist')->find_or_new(
2781 { artist => 'fred' }, { key => 'artists' });
2783 $cd->cd_to_producer->find_or_new({ producer => $producer },
2784 { key => 'primary' });
2786 Find an existing record from this resultset using L</find>. if none exists,
2787 instantiate a new result object and return it. The object will not be saved
2788 into your storage until you call L<DBIx::Class::Row/insert> on it.
2790 You most likely want this method when looking for existing rows using a unique
2791 constraint that is not the primary key, or looking for related rows.
2793 If you want objects to be saved immediately, use L</find_or_create> instead.
2795 B<Note>: Make sure to read the documentation of L</find> and understand the
2796 significance of the C<key> attribute, as its lack may skew your search, and
2797 subsequently result in spurious new objects.
2799 B<Note>: Take care when using C<find_or_new> with a table having
2800 columns with default values that you intend to be automatically
2801 supplied by the database (e.g. an auto_increment primary key column).
2802 In normal usage, the value of such columns should NOT be included at
2803 all in the call to C<find_or_new>, even when set to C<undef>.
2809 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2810 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2811 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2814 return $self->new_result($hash);
2821 =item Arguments: \%col_data
2823 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2827 Attempt to create a single new row or a row with multiple related rows
2828 in the table represented by the resultset (and related tables). This
2829 will not check for duplicate rows before inserting, use
2830 L</find_or_create> to do that.
2832 To create one row for this resultset, pass a hashref of key/value
2833 pairs representing the columns of the table and the values you wish to
2834 store. If the appropriate relationships are set up, foreign key fields
2835 can also be passed an object representing the foreign row, and the
2836 value will be set to its primary key.
2838 To create related objects, pass a hashref of related-object column values
2839 B<keyed on the relationship name>. If the relationship is of type C<multi>
2840 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2841 The process will correctly identify columns holding foreign keys, and will
2842 transparently populate them from the keys of the corresponding relation.
2843 This can be applied recursively, and will work correctly for a structure
2844 with an arbitrary depth and width, as long as the relationships actually
2845 exists and the correct column data has been supplied.
2847 Instead of hashrefs of plain related data (key/value pairs), you may
2848 also pass new or inserted objects. New objects (not inserted yet, see
2849 L</new_result>), will be inserted into their appropriate tables.
2851 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2853 Example of creating a new row.
2855 $person_rs->create({
2856 name=>"Some Person",
2857 email=>"somebody@someplace.com"
2860 Example of creating a new row and also creating rows in a related C<has_many>
2861 or C<has_one> resultset. Note Arrayref.
2864 { artistid => 4, name => 'Manufactured Crap', cds => [
2865 { title => 'My First CD', year => 2006 },
2866 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2871 Example of creating a new row and also creating a row in a related
2872 C<belongs_to> resultset. Note Hashref.
2875 title=>"Music for Silly Walks",
2878 name=>"Silly Musician",
2886 When subclassing ResultSet never attempt to override this method. Since
2887 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2888 lot of the internals simply never call it, so your override will be
2889 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2890 or L<DBIx::Class::Row/insert> depending on how early in the
2891 L</create> process you need to intervene. See also warning pertaining to
2899 my ($self, $col_data) = @_;
2900 $self->throw_exception( "create needs a hashref" )
2901 unless ref $col_data eq 'HASH';
2902 return $self->new_result($col_data)->insert;
2905 =head2 find_or_create
2909 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2911 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2915 $cd->cd_to_producer->find_or_create({ producer => $producer },
2916 { key => 'primary' });
2918 Tries to find a record based on its primary key or unique constraints; if none
2919 is found, creates one and returns that instead.
2921 my $cd = $schema->resultset('CD')->find_or_create({
2923 artist => 'Massive Attack',
2924 title => 'Mezzanine',
2928 Also takes an optional C<key> attribute, to search by a specific key or unique
2929 constraint. For example:
2931 my $cd = $schema->resultset('CD')->find_or_create(
2933 artist => 'Massive Attack',
2934 title => 'Mezzanine',
2936 { key => 'cd_artist_title' }
2939 B<Note>: Make sure to read the documentation of L</find> and understand the
2940 significance of the C<key> attribute, as its lack may skew your search, and
2941 subsequently result in spurious row creation.
2943 B<Note>: Because find_or_create() reads from the database and then
2944 possibly inserts based on the result, this method is subject to a race
2945 condition. Another process could create a record in the table after
2946 the find has completed and before the create has started. To avoid
2947 this problem, use find_or_create() inside a transaction.
2949 B<Note>: Take care when using C<find_or_create> with a table having
2950 columns with default values that you intend to be automatically
2951 supplied by the database (e.g. an auto_increment primary key column).
2952 In normal usage, the value of such columns should NOT be included at
2953 all in the call to C<find_or_create>, even when set to C<undef>.
2955 See also L</find> and L</update_or_create>. For information on how to declare
2956 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2958 If you need to know if an existing row was found or a new one created use
2959 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2960 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2963 my $cd = $schema->resultset('CD')->find_or_new({
2965 artist => 'Massive Attack',
2966 title => 'Mezzanine',
2970 if( !$cd->in_storage ) {
2977 sub find_or_create {
2979 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2980 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2981 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2984 return $self->create($hash);
2987 =head2 update_or_create
2991 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2993 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2997 $resultset->update_or_create({ col => $val, ... });
2999 Like L</find_or_create>, but if a row is found it is immediately updated via
3000 C<< $found_row->update (\%col_data) >>.
3003 Takes an optional C<key> attribute to search on a specific unique constraint.
3006 # In your application
3007 my $cd = $schema->resultset('CD')->update_or_create(
3009 artist => 'Massive Attack',
3010 title => 'Mezzanine',
3013 { key => 'cd_artist_title' }
3016 $cd->cd_to_producer->update_or_create({
3017 producer => $producer,
3023 B<Note>: Make sure to read the documentation of L</find> and understand the
3024 significance of the C<key> attribute, as its lack may skew your search, and
3025 subsequently result in spurious row creation.
3027 B<Note>: Take care when using C<update_or_create> with a table having
3028 columns with default values that you intend to be automatically
3029 supplied by the database (e.g. an auto_increment primary key column).
3030 In normal usage, the value of such columns should NOT be included at
3031 all in the call to C<update_or_create>, even when set to C<undef>.
3033 See also L</find> and L</find_or_create>. For information on how to declare
3034 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3036 If you need to know if an existing row was updated or a new one created use
3037 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3038 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3043 sub update_or_create {
3045 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3046 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3048 my $row = $self->find($cond, $attrs);
3050 $row->update($cond);
3054 return $self->create($cond);
3057 =head2 update_or_new
3061 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3063 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3067 $resultset->update_or_new({ col => $val, ... });
3069 Like L</find_or_new> but if a row is found it is immediately updated via
3070 C<< $found_row->update (\%col_data) >>.
3074 # In your application
3075 my $cd = $schema->resultset('CD')->update_or_new(
3077 artist => 'Massive Attack',
3078 title => 'Mezzanine',
3081 { key => 'cd_artist_title' }
3084 if ($cd->in_storage) {
3085 # the cd was updated
3088 # the cd is not yet in the database, let's insert it
3092 B<Note>: Make sure to read the documentation of L</find> and understand the
3093 significance of the C<key> attribute, as its lack may skew your search, and
3094 subsequently result in spurious new objects.
3096 B<Note>: Take care when using C<update_or_new> with a table having
3097 columns with default values that you intend to be automatically
3098 supplied by the database (e.g. an auto_increment primary key column).
3099 In normal usage, the value of such columns should NOT be included at
3100 all in the call to C<update_or_new>, even when set to C<undef>.
3102 See also L</find>, L</find_or_create> and L</find_or_new>.
3108 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3109 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3111 my $row = $self->find( $cond, $attrs );
3112 if ( defined $row ) {
3113 $row->update($cond);
3117 return $self->new_result($cond);
3124 =item Arguments: none
3126 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3130 Gets the contents of the cache for the resultset, if the cache is set.
3132 The cache is populated either by using the L</prefetch> attribute to
3133 L</search> or by calling L</set_cache>.
3145 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3147 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3151 Sets the contents of the cache for the resultset. Expects an arrayref
3152 of objects of the same class as those produced by the resultset. Note that
3153 if the cache is set, the resultset will return the cached objects rather
3154 than re-querying the database even if the cache attr is not set.
3156 The contents of the cache can also be populated by using the
3157 L</prefetch> attribute to L</search>.
3162 my ( $self, $data ) = @_;
3163 $self->throw_exception("set_cache requires an arrayref")
3164 if defined($data) && (ref $data ne 'ARRAY');
3165 $self->{all_cache} = $data;
3172 =item Arguments: none
3174 =item Return Value: undef
3178 Clears the cache for the resultset.
3183 shift->set_cache(undef);
3190 =item Arguments: none
3192 =item Return Value: true, if the resultset has been paginated
3200 return !!$self->{attrs}{page};
3207 =item Arguments: none
3209 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3217 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3220 =head2 related_resultset
3224 =item Arguments: $rel_name
3226 =item Return Value: L<$resultset|/search>
3230 Returns a related resultset for the supplied relationship name.
3232 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3236 sub related_resultset {
3237 my ($self, $rel) = @_;
3239 return $self->{related_resultsets}{$rel}
3240 if defined $self->{related_resultsets}{$rel};
3242 return $self->{related_resultsets}{$rel} = do {
3243 my $rsrc = $self->result_source;
3244 my $rel_info = $rsrc->relationship_info($rel);
3246 $self->throw_exception(
3247 "search_related: result source '" . $rsrc->source_name .
3248 "' has no such relationship $rel")
3251 my $attrs = $self->_chain_relationship($rel);
3253 my $join_count = $attrs->{seen_join}{$rel};
3255 my $alias = $self->result_source->storage
3256 ->relname_to_table_alias($rel, $join_count);
3258 # since this is search_related, and we already slid the select window inwards
3259 # (the select/as attrs were deleted in the beginning), we need to flip all
3260 # left joins to inner, so we get the expected results
3261 # read the comment on top of the actual function to see what this does
3262 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3265 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3266 delete @{$attrs}{qw(result_class alias)};
3268 my $rel_source = $rsrc->related_source($rel);
3272 # The reason we do this now instead of passing the alias to the
3273 # search_rs below is that if you wrap/overload resultset on the
3274 # source you need to know what alias it's -going- to have for things
3275 # to work sanely (e.g. RestrictWithObject wants to be able to add
3276 # extra query restrictions, and these may need to be $alias.)
3278 my $rel_attrs = $rel_source->resultset_attributes;
3279 local $rel_attrs->{alias} = $alias;
3281 $rel_source->resultset
3285 where => $attrs->{where},
3289 if (my $cache = $self->get_cache) {
3290 my @related_cache = map
3291 { @{$_->related_resultset($rel)->get_cache||[]} }
3295 $new->set_cache(\@related_cache) if @related_cache;
3302 =head2 current_source_alias
3306 =item Arguments: none
3308 =item Return Value: $source_alias
3312 Returns the current table alias for the result source this resultset is built
3313 on, that will be used in the SQL query. Usually it is C<me>.
3315 Currently the source alias that refers to the result set returned by a
3316 L</search>/L</find> family method depends on how you got to the resultset: it's
3317 C<me> by default, but eg. L</search_related> aliases it to the related result
3318 source name (and keeps C<me> referring to the original result set). The long
3319 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3320 (and make this method unnecessary).
3322 Thus it's currently necessary to use this method in predefined queries (see
3323 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3324 source alias of the current result set:
3326 # in a result set class
3328 my ($self, $user) = @_;
3330 my $me = $self->current_source_alias;
3332 return $self->search({
3333 "$me.modified" => $user->id,
3339 sub current_source_alias {
3340 return (shift->{attrs} || {})->{alias} || 'me';
3343 =head2 as_subselect_rs
3347 =item Arguments: none
3349 =item Return Value: L<$resultset|/search>
3353 Act as a barrier to SQL symbols. The resultset provided will be made into a
3354 "virtual view" by including it as a subquery within the from clause. From this
3355 point on, any joined tables are inaccessible to ->search on the resultset (as if
3356 it were simply where-filtered without joins). For example:
3358 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3360 # 'x' now pollutes the query namespace
3362 # So the following works as expected
3363 my $ok_rs = $rs->search({'x.other' => 1});
3365 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3366 # def) we look for one row with contradictory terms and join in another table
3367 # (aliased 'x_2') which we never use
3368 my $broken_rs = $rs->search({'x.name' => 'def'});
3370 my $rs2 = $rs->as_subselect_rs;
3372 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3373 my $not_joined_rs = $rs2->search({'x.other' => 1});
3375 # works as expected: finds a 'table' row related to two x rows (abc and def)
3376 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3378 Another example of when one might use this would be to select a subset of
3379 columns in a group by clause:
3381 my $rs = $schema->resultset('Bar')->search(undef, {
3382 group_by => [qw{ id foo_id baz_id }],
3383 })->as_subselect_rs->search(undef, {
3384 columns => [qw{ id foo_id }]
3387 In the above example normally columns would have to be equal to the group by,
3388 but because we isolated the group by into a subselect the above works.
3392 sub as_subselect_rs {
3395 my $attrs = $self->_resolved_attrs;
3397 my $fresh_rs = (ref $self)->new (
3398 $self->result_source
3401 # these pieces will be locked in the subquery
3402 delete $fresh_rs->{cond};
3403 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3405 return $fresh_rs->search( {}, {
3407 $attrs->{alias} => $self->as_query,
3408 -alias => $attrs->{alias},
3409 -rsrc => $self->result_source,
3411 alias => $attrs->{alias},
3415 # This code is called by search_related, and makes sure there
3416 # is clear separation between the joins before, during, and
3417 # after the relationship. This information is needed later
3418 # in order to properly resolve prefetch aliases (any alias
3419 # with a relation_chain_depth less than the depth of the
3420 # current prefetch is not considered)
3422 # The increments happen twice per join. An even number means a
3423 # relationship specified via a search_related, whereas an odd
3424 # number indicates a join/prefetch added via attributes
3426 # Also this code will wrap the current resultset (the one we
3427 # chain to) in a subselect IFF it contains limiting attributes
3428 sub _chain_relationship {
3429 my ($self, $rel) = @_;
3430 my $source = $self->result_source;
3431 my $attrs = { %{$self->{attrs}||{}} };
3433 # we need to take the prefetch the attrs into account before we
3434 # ->_resolve_join as otherwise they get lost - captainL
3435 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3437 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3439 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3442 my @force_subq_attrs = qw/offset rows group_by having/;
3445 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3447 $self->_has_resolved_attr (@force_subq_attrs)
3449 # Nuke the prefetch (if any) before the new $rs attrs
3450 # are resolved (prefetch is useless - we are wrapping
3451 # a subquery anyway).
3452 my $rs_copy = $self->search;
3453 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3454 $rs_copy->{attrs}{join},
3455 delete $rs_copy->{attrs}{prefetch},
3460 -alias => $attrs->{alias},
3461 $attrs->{alias} => $rs_copy->as_query,
3463 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3464 $seen->{-relation_chain_depth} = 0;
3466 elsif ($attrs->{from}) { #shallow copy suffices
3467 $from = [ @{$attrs->{from}} ];
3472 -alias => $attrs->{alias},
3473 $attrs->{alias} => $source->from,
3477 my $jpath = ($seen->{-relation_chain_depth})
3478 ? $from->[-1][0]{-join_path}
3481 my @requested_joins = $source->_resolve_join(
3488 push @$from, @requested_joins;
3490 $seen->{-relation_chain_depth}++;
3492 # if $self already had a join/prefetch specified on it, the requested
3493 # $rel might very well be already included. What we do in this case
3494 # is effectively a no-op (except that we bump up the chain_depth on
3495 # the join in question so we could tell it *is* the search_related)
3498 # we consider the last one thus reverse
3499 for my $j (reverse @requested_joins) {
3500 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3501 if ($rel eq $last_j) {
3502 $j->[0]{-relation_chain_depth}++;
3508 unless ($already_joined) {
3509 push @$from, $source->_resolve_join(
3517 $seen->{-relation_chain_depth}++;
3519 return {%$attrs, from => $from, seen_join => $seen};
3522 sub _resolved_attrs {
3524 return $self->{_attrs} if $self->{_attrs};
3526 my $attrs = { %{ $self->{attrs} || {} } };
3527 my $source = $self->result_source;
3528 my $alias = $attrs->{alias};
3530 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3531 if $attrs->{collapse} and $attrs->{distinct};
3533 # default selection list
3534 $attrs->{columns} = [ $source->columns ]
3535 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3537 # merge selectors together
3538 for (qw/columns select as/) {
3539 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3540 if $attrs->{$_} or $attrs->{"+$_"};
3543 # disassemble columns
3545 if (my $cols = delete $attrs->{columns}) {
3546 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3547 if (ref $c eq 'HASH') {
3548 for my $as (sort keys %$c) {
3549 push @sel, $c->{$as};
3560 # when trying to weed off duplicates later do not go past this point -
3561 # everything added from here on is unbalanced "anyone's guess" stuff
3562 my $dedup_stop_idx = $#as;
3564 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3566 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3567 if $attrs->{select};
3569 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3570 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3572 # disqualify all $alias.col as-bits (inflate-map mandated)
3573 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3575 # de-duplicate the result (remove *identical* select/as pairs)
3576 # and also die on duplicate {as} pointing to different {select}s
3577 # not using a c-style for as the condition is prone to shrinkage
3580 while ($i <= $dedup_stop_idx) {
3581 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3586 elsif ($seen->{$as[$i]}++) {
3587 $self->throw_exception(
3588 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3596 $attrs->{select} = \@sel;
3597 $attrs->{as} = \@as;
3599 $attrs->{from} ||= [{
3601 -alias => $self->{attrs}{alias},
3602 $self->{attrs}{alias} => $source->from,
3605 if ( $attrs->{join} || $attrs->{prefetch} ) {
3607 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3608 if ref $attrs->{from} ne 'ARRAY';
3610 my $join = (delete $attrs->{join}) || {};
3612 if ( defined $attrs->{prefetch} ) {
3613 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3616 $attrs->{from} = # have to copy here to avoid corrupting the original
3618 @{ $attrs->{from} },
3619 $source->_resolve_join(
3622 ($attrs->{seen_join} = { %{ $attrs->{seen_join} || {} } }),
3623 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3624 ? $attrs->{from}[-1][0]{-join_path}
3631 if ( defined $attrs->{order_by} ) {
3632 $attrs->{order_by} = (
3633 ref( $attrs->{order_by} ) eq 'ARRAY'
3634 ? [ @{ $attrs->{order_by} } ]
3635 : [ $attrs->{order_by} || () ]
3639 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3640 $attrs->{group_by} = [ $attrs->{group_by} ];
3644 # generate selections based on the prefetch helper
3645 my ($prefetch, @prefetch_select, @prefetch_as);
3646 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3647 if defined $attrs->{prefetch};
3651 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3652 if $attrs->{_dark_selector};
3654 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3655 if defined $attrs->{collapse} and ! $attrs->{collapse};
3657 $attrs->{collapse} = 1;
3659 # this is a separate structure (we don't look in {from} directly)
3660 # as the resolver needs to shift things off the lists to work
3661 # properly (identical-prefetches on different branches)
3663 if (ref $attrs->{from} eq 'ARRAY') {
3665 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3667 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3668 next unless $j->[0]{-alias};
3669 next unless $j->[0]{-join_path};
3670 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3672 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3675 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3676 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3680 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3682 # save these for after distinct resolution
3683 @prefetch_select = map { $_->[0] } @prefetch;
3684 @prefetch_as = map { $_->[1] } @prefetch;
3687 # run through the resulting joinstructure (starting from our current slot)
3688 # and unset collapse if proven unnecessary
3690 # also while we are at it find out if the current root source has
3691 # been premultiplied by previous related_source chaining
3693 # this allows to predict whether a root object with all other relation
3694 # data set to NULL is in fact unique
3695 if ($attrs->{collapse}) {
3697 if (ref $attrs->{from} eq 'ARRAY') {
3699 if (@{$attrs->{from}} == 1) {
3700 # no joins - no collapse
3701 $attrs->{collapse} = 0;
3704 # find where our table-spec starts
3705 my @fromlist = @{$attrs->{from}};
3707 my $t = shift @fromlist;
3710 # me vs join from-spec distinction - a ref means non-root
3711 if (ref $t eq 'ARRAY') {
3713 $is_multi ||= ! $t->{-is_single};
3715 last if ($t->{-alias} && $t->{-alias} eq $alias);
3716 $attrs->{_main_source_premultiplied} ||= $is_multi;
3719 # no non-singles remaining, nor any premultiplication - nothing to collapse
3721 ! $attrs->{_main_source_premultiplied}
3723 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3725 $attrs->{collapse} = 0;
3731 # if we can not analyze the from - err on the side of safety
3732 $attrs->{_main_source_premultiplied} = 1;
3736 # generate the distinct induced group_by before injecting the prefetched select/as parts
3737 if (delete $attrs->{distinct}) {
3738 if ($attrs->{group_by}) {
3739 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3742 $attrs->{_grouped_by_distinct} = 1;
3743 # distinct affects only the main selection part, not what prefetch may add below
3744 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3746 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3747 # The thinking is: if we are collapsing the subquerying prefetch engine will
3748 # rip stuff apart for us anyway, and we do not want to have a potentially
3749 # function-converted external order_by
3750 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3751 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3755 # inject prefetch-bound selection (if any)
3756 push @{$attrs->{select}}, @prefetch_select;
3757 push @{$attrs->{as}}, @prefetch_as;
3759 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3760 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3761 $attrs->{_related_results_construction} = 1;
3764 # if both page and offset are specified, produce a combined offset
3765 # even though it doesn't make much sense, this is what pre 081xx has
3767 if (my $page = delete $attrs->{page}) {
3769 ($attrs->{rows} * ($page - 1))
3771 ($attrs->{offset} || 0)
3775 return $self->{_attrs} = $attrs;
3779 my ($self, $attr) = @_;
3781 if (ref $attr eq 'HASH') {
3782 return $self->_rollout_hash($attr);
3783 } elsif (ref $attr eq 'ARRAY') {
3784 return $self->_rollout_array($attr);
3790 sub _rollout_array {
3791 my ($self, $attr) = @_;
3794 foreach my $element (@{$attr}) {
3795 if (ref $element eq 'HASH') {
3796 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3797 } elsif (ref $element eq 'ARRAY') {
3798 # XXX - should probably recurse here
3799 push( @rolled_array, @{$self->_rollout_array($element)} );
3801 push( @rolled_array, $element );
3804 return \@rolled_array;
3808 my ($self, $attr) = @_;
3811 foreach my $key (keys %{$attr}) {
3812 push( @rolled_array, { $key => $attr->{$key} } );
3814 return \@rolled_array;
3817 sub _calculate_score {
3818 my ($self, $a, $b) = @_;
3820 if (defined $a xor defined $b) {
3823 elsif (not defined $a) {
3827 if (ref $b eq 'HASH') {
3828 my ($b_key) = keys %{$b};
3829 if (ref $a eq 'HASH') {
3830 my ($a_key) = keys %{$a};
3831 if ($a_key eq $b_key) {
3832 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3837 return ($a eq $b_key) ? 1 : 0;
3840 if (ref $a eq 'HASH') {
3841 my ($a_key) = keys %{$a};
3842 return ($b eq $a_key) ? 1 : 0;
3844 return ($b eq $a) ? 1 : 0;
3849 sub _merge_joinpref_attr {
3850 my ($self, $orig, $import) = @_;
3852 return $import unless defined($orig);
3853 return $orig unless defined($import);
3855 $orig = $self->_rollout_attr($orig);
3856 $import = $self->_rollout_attr($import);
3859 foreach my $import_element ( @{$import} ) {
3860 # find best candidate from $orig to merge $b_element into
3861 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3862 foreach my $orig_element ( @{$orig} ) {
3863 my $score = $self->_calculate_score( $orig_element, $import_element );
3864 if ($score > $best_candidate->{score}) {
3865 $best_candidate->{position} = $position;
3866 $best_candidate->{score} = $score;
3870 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3871 $import_key = '' if not defined $import_key;
3873 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3874 push( @{$orig}, $import_element );
3876 my $orig_best = $orig->[$best_candidate->{position}];
3877 # merge orig_best and b_element together and replace original with merged
3878 if (ref $orig_best ne 'HASH') {
3879 $orig->[$best_candidate->{position}] = $import_element;
3880 } elsif (ref $import_element eq 'HASH') {
3881 my ($key) = keys %{$orig_best};
3882 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3885 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3888 return @$orig ? $orig : ();
3896 require Hash::Merge;
3897 my $hm = Hash::Merge->new;
3899 $hm->specify_behavior({
3902 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3904 if ($defl xor $defr) {
3905 return [ $defl ? $_[0] : $_[1] ];
3910 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3914 return [$_[0], $_[1]];
3918 return $_[1] if !defined $_[0];
3919 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3920 return [$_[0], @{$_[1]}]
3923 return [] if !defined $_[0] and !keys %{$_[1]};
3924 return [ $_[1] ] if !defined $_[0];
3925 return [ $_[0] ] if !keys %{$_[1]};
3926 return [$_[0], $_[1]]
3931 return $_[0] if !defined $_[1];
3932 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3933 return [@{$_[0]}, $_[1]]
3936 my @ret = @{$_[0]} or return $_[1];
3937 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3938 my %idx = map { $_ => 1 } @ret;
3939 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3943 return [ $_[1] ] if ! @{$_[0]};
3944 return $_[0] if !keys %{$_[1]};
3945 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3946 return [ @{$_[0]}, $_[1] ];
3951 return [] if !keys %{$_[0]} and !defined $_[1];
3952 return [ $_[0] ] if !defined $_[1];
3953 return [ $_[1] ] if !keys %{$_[0]};
3954 return [$_[0], $_[1]]
3957 return [] if !keys %{$_[0]} and !@{$_[1]};
3958 return [ $_[0] ] if !@{$_[1]};
3959 return $_[1] if !keys %{$_[0]};
3960 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3961 return [ $_[0], @{$_[1]} ];
3964 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3965 return [ $_[0] ] if !keys %{$_[1]};
3966 return [ $_[1] ] if !keys %{$_[0]};
3967 return [ $_[0] ] if $_[0] eq $_[1];
3968 return [ $_[0], $_[1] ];
3971 } => 'DBIC_RS_ATTR_MERGER');
3975 return $hm->merge ($_[1], $_[2]);
3979 sub STORABLE_freeze {
3980 my ($self, $cloning) = @_;
3981 my $to_serialize = { %$self };
3983 # A cursor in progress can't be serialized (and would make little sense anyway)
3984 # the parser can be regenerated (and can't be serialized)
3985 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3987 # nor is it sensical to store a not-yet-fired-count pager
3988 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3989 delete $to_serialize->{pager};
3992 Storable::nfreeze($to_serialize);
3995 # need this hook for symmetry
3997 my ($self, $cloning, $serialized) = @_;
3999 %$self = %{ Storable::thaw($serialized) };
4005 =head2 throw_exception
4007 See L<DBIx::Class::Schema/throw_exception> for details.
4011 sub throw_exception {
4014 if (ref $self and my $rsrc = $self->result_source) {
4015 $rsrc->throw_exception(@_)
4018 DBIx::Class::Exception->throw(@_);
4026 # XXX: FIXME: Attributes docs need clearing up
4030 Attributes are used to refine a ResultSet in various ways when
4031 searching for data. They can be passed to any method which takes an
4032 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4035 Default attributes can be set on the result class using
4036 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4037 the CAVEATS on that feature before using it!)
4039 These are in no particular order:
4045 =item Value: ( $order_by | \@order_by | \%order_by )
4049 Which column(s) to order the results by.
4051 [The full list of suitable values is documented in
4052 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4055 If a single column name, or an arrayref of names is supplied, the
4056 argument is passed through directly to SQL. The hashref syntax allows
4057 for connection-agnostic specification of ordering direction:
4059 For descending order:
4061 order_by => { -desc => [qw/col1 col2 col3/] }
4063 For explicit ascending order:
4065 order_by => { -asc => 'col' }
4067 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4068 supported, although you are strongly encouraged to use the hashref
4069 syntax as outlined above.
4075 =item Value: \@columns | \%columns | $column
4079 Shortcut to request a particular set of columns to be retrieved. Each
4080 column spec may be a string (a table column name), or a hash (in which
4081 case the key is the C<as> value, and the value is used as the C<select>
4082 expression). Adds C<me.> onto the start of any column without a C<.> in
4083 it and sets C<select> from that, then auto-populates C<as> from
4084 C<select> as normal. (You may also use the C<cols> attribute, as in
4085 earlier versions of DBIC, but this is deprecated.)
4087 Essentially C<columns> does the same as L</select> and L</as>.
4089 columns => [ 'foo', { bar => 'baz' } ]
4093 select => [qw/foo baz/],
4100 =item Value: \@columns
4104 Indicates additional columns to be selected from storage. Works the same as
4105 L</columns> but adds columns to the selection. (You may also use the
4106 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4107 deprecated). For example:-
4109 $schema->resultset('CD')->search(undef, {
4110 '+columns' => ['artist.name'],
4114 would return all CDs and include a 'name' column to the information
4115 passed to object inflation. Note that the 'artist' is the name of the
4116 column (or relationship) accessor, and 'name' is the name of the column
4117 accessor in the related table.
4119 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4120 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4121 unary plus operator before it.
4123 =head2 include_columns
4127 =item Value: \@columns
4131 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4137 =item Value: \@select_columns
4141 Indicates which columns should be selected from the storage. You can use
4142 column names, or in the case of RDBMS back ends, function or stored procedure
4145 $rs = $schema->resultset('Employee')->search(undef, {
4148 { count => 'employeeid' },
4149 { max => { length => 'name' }, -as => 'longest_name' }
4154 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4156 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4157 use L</select>, to instruct DBIx::Class how to store the result of the column.
4158 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4159 identifier aliasing. You can however alias a function, so you can use it in
4160 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4161 attribute> supplied as shown in the example above.
4163 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4164 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4165 unary plus operator before it.
4171 Indicates additional columns to be selected from storage. Works the same as
4172 L</select> but adds columns to the default selection, instead of specifying
4181 =item Value: \@inflation_names
4185 Indicates column names for object inflation. That is L</as> indicates the
4186 slot name in which the column value will be stored within the
4187 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4188 identifier by the C<get_column> method (or via the object accessor B<if one
4189 with the same name already exists>) as shown below. The L</as> attribute has
4190 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4192 $rs = $schema->resultset('Employee')->search(undef, {
4195 { count => 'employeeid' },
4196 { max => { length => 'name' }, -as => 'longest_name' }
4205 If the object against which the search is performed already has an accessor
4206 matching a column name specified in C<as>, the value can be retrieved using
4207 the accessor as normal:
4209 my $name = $employee->name();
4211 If on the other hand an accessor does not exist in the object, you need to
4212 use C<get_column> instead:
4214 my $employee_count = $employee->get_column('employee_count');
4216 You can create your own accessors if required - see
4217 L<DBIx::Class::Manual::Cookbook> for details.
4223 Indicates additional column names for those added via L</+select>. See L</as>.
4231 =item Value: ($rel_name | \@rel_names | \%rel_names)
4235 Contains a list of relationships that should be joined for this query. For
4238 # Get CDs by Nine Inch Nails
4239 my $rs = $schema->resultset('CD')->search(
4240 { 'artist.name' => 'Nine Inch Nails' },
4241 { join => 'artist' }
4244 Can also contain a hash reference to refer to the other relation's relations.
4247 package MyApp::Schema::Track;
4248 use base qw/DBIx::Class/;
4249 __PACKAGE__->table('track');
4250 __PACKAGE__->add_columns(qw/trackid cd position title/);
4251 __PACKAGE__->set_primary_key('trackid');
4252 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4255 # In your application
4256 my $rs = $schema->resultset('Artist')->search(
4257 { 'track.title' => 'Teardrop' },
4259 join => { cd => 'track' },
4260 order_by => 'artist.name',
4264 You need to use the relationship (not the table) name in conditions,
4265 because they are aliased as such. The current table is aliased as "me", so
4266 you need to use me.column_name in order to avoid ambiguity. For example:
4268 # Get CDs from 1984 with a 'Foo' track
4269 my $rs = $schema->resultset('CD')->search(
4272 'tracks.name' => 'Foo'
4274 { join => 'tracks' }
4277 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4278 similarly for a third time). For e.g.
4280 my $rs = $schema->resultset('Artist')->search({
4281 'cds.title' => 'Down to Earth',
4282 'cds_2.title' => 'Popular',
4284 join => [ qw/cds cds/ ],
4287 will return a set of all artists that have both a cd with title 'Down
4288 to Earth' and a cd with title 'Popular'.
4290 If you want to fetch related objects from other tables as well, see L</prefetch>
4293 NOTE: An internal join-chain pruner will discard certain joins while
4294 constructing the actual SQL query, as long as the joins in question do not
4295 affect the retrieved result. This for example includes 1:1 left joins
4296 that are not part of the restriction specification (WHERE/HAVING) nor are
4297 a part of the query selection.
4299 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4305 =item Value: (0 | 1)
4309 When set to a true value, indicates that any rows fetched from joined has_many
4310 relationships are to be aggregated into the corresponding "parent" object. For
4311 example, the resultset:
4313 my $rs = $schema->resultset('CD')->search({}, {
4314 '+columns' => [ qw/ tracks.title tracks.position / ],
4319 While executing the following query:
4321 SELECT me.*, tracks.title, tracks.position
4323 LEFT JOIN track tracks
4324 ON tracks.cdid = me.cdid
4326 Will return only as many objects as there are rows in the CD source, even
4327 though the result of the query may span many rows. Each of these CD objects
4328 will in turn have multiple "Track" objects hidden behind the has_many
4329 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4330 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4331 product"), with each CD object containing exactly one of all fetched Track data.
4333 When a collapse is requested on a non-ordered resultset, an order by some
4334 unique part of the main source (the left-most table) is inserted automatically.
4335 This is done so that the resultset is allowed to be "lazy" - calling
4336 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4337 object with all of its related data.
4339 If an L</order_by> is already declared, and orders the resultset in a way that
4340 makes collapsing as described above impossible (e.g. C<< ORDER BY
4341 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4342 switch to "eager" mode and slurp the entire resultset before constructing the
4343 first object returned by L</next>.
4345 Setting this attribute on a resultset that does not join any has_many
4346 relations is a no-op.
4348 For a more in-depth discussion, see L</PREFETCHING>.
4354 =item Value: ($rel_name | \@rel_names | \%rel_names)
4358 This attribute is a shorthand for specifying a L</join> spec, adding all
4359 columns from the joined related sources as L</+columns> and setting
4360 L</collapse> to a true value. For example, the following two queries are
4363 my $rs = $schema->resultset('Artist')->search({}, {
4364 prefetch => { cds => ['genre', 'tracks' ] },
4369 my $rs = $schema->resultset('Artist')->search({}, {
4370 join => { cds => ['genre', 'tracks' ] },
4374 { +{ "cds.$_" => "cds.$_" } }
4375 $schema->source('Artist')->related_source('cds')->columns
4378 { +{ "cds.genre.$_" => "genre.$_" } }
4379 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4382 { +{ "cds.tracks.$_" => "tracks.$_" } }
4383 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4388 Both producing the following SQL:
4390 SELECT me.artistid, me.name, me.rank, me.charfield,
4391 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4392 genre.genreid, genre.name,
4393 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4396 ON cds.artist = me.artistid
4397 LEFT JOIN genre genre
4398 ON genre.genreid = cds.genreid
4399 LEFT JOIN track tracks
4400 ON tracks.cd = cds.cdid
4401 ORDER BY me.artistid
4403 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4404 the arguments are properly merged and generally do the right thing. For
4405 example, you may want to do the following:
4407 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4408 { 'genre.genreid' => undef },
4410 join => { cds => 'genre' },
4415 Which generates the following SQL:
4417 SELECT me.artistid, me.name, me.rank, me.charfield,
4418 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4421 ON cds.artist = me.artistid
4422 LEFT JOIN genre genre
4423 ON genre.genreid = cds.genreid
4424 WHERE genre.genreid IS NULL
4425 ORDER BY me.artistid
4427 For a more in-depth discussion, see L</PREFETCHING>.
4433 =item Value: $source_alias
4437 Sets the source alias for the query. Normally, this defaults to C<me>, but
4438 nested search queries (sub-SELECTs) might need specific aliases set to
4439 reference inner queries. For example:
4442 ->related_resultset('CDs')
4443 ->related_resultset('Tracks')
4445 'track.id' => { -ident => 'none_search.id' },
4449 my $ids = $self->search({
4452 alias => 'none_search',
4453 group_by => 'none_search.id',
4454 })->get_column('id')->as_query;
4456 $self->search({ id => { -in => $ids } })
4458 This attribute is directly tied to L</current_source_alias>.
4468 Makes the resultset paged and specifies the page to retrieve. Effectively
4469 identical to creating a non-pages resultset and then calling ->page($page)
4472 If L</rows> attribute is not specified it defaults to 10 rows per page.
4474 When you have a paged resultset, L</count> will only return the number
4475 of rows in the page. To get the total, use the L</pager> and call
4476 C<total_entries> on it.
4486 Specifies the maximum number of rows for direct retrieval or the number of
4487 rows per page if the page attribute or method is used.
4493 =item Value: $offset
4497 Specifies the (zero-based) row number for the first row to be returned, or the
4498 of the first row of the first page if paging is used.
4500 =head2 software_limit
4504 =item Value: (0 | 1)
4508 When combined with L</rows> and/or L</offset> the generated SQL will not
4509 include any limit dialect stanzas. Instead the entire result will be selected
4510 as if no limits were specified, and DBIC will perform the limit locally, by
4511 artificially advancing and finishing the resulting L</cursor>.
4513 This is the recommended way of performing resultset limiting when no sane RDBMS
4514 implementation is available (e.g.
4515 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4516 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4522 =item Value: \@columns
4526 A arrayref of columns to group by. Can include columns of joined tables.
4528 group_by => [qw/ column1 column2 ... /]
4534 =item Value: $condition
4538 HAVING is a select statement attribute that is applied between GROUP BY and
4539 ORDER BY. It is applied to the after the grouping calculations have been
4542 having => { 'count_employee' => { '>=', 100 } }
4544 or with an in-place function in which case literal SQL is required:
4546 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4552 =item Value: (0 | 1)
4556 Set to 1 to automatically generate a L</group_by> clause based on the selection
4557 (including intelligent handling of L</order_by> contents). Note that the group
4558 criteria calculation takes place over the B<final> selection. This includes
4559 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4560 L</search> calls, and standalone columns selected via
4561 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4562 extra selections specified via L</prefetch> - such selections are explicitly
4563 excluded from group criteria calculations.
4565 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4566 setting is ignored and an appropriate warning is issued.
4572 Adds to the WHERE clause.
4574 # only return rows WHERE deleted IS NULL for all searches
4575 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4577 Can be overridden by passing C<< { where => undef } >> as an attribute
4580 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4586 Set to 1 to cache search results. This prevents extra SQL queries if you
4587 revisit rows in your ResultSet:
4589 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4591 while( my $artist = $resultset->next ) {
4595 $rs->first; # without cache, this would issue a query
4597 By default, searches are not cached.
4599 For more examples of using these attributes, see
4600 L<DBIx::Class::Manual::Cookbook>.
4606 =item Value: ( 'update' | 'shared' | \$scalar )
4610 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4611 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4616 DBIx::Class supports arbitrary related data prefetching from multiple related
4617 sources. Any combination of relationship types and column sets are supported.
4618 If L<collapsing|/collapse> is requested, there is an additional requirement of
4619 selecting enough data to make every individual object uniquely identifiable.
4621 Here are some more involved examples, based on the following relationship map:
4624 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4625 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4626 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4628 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4630 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4634 my $rs = $schema->resultset('Tag')->search(
4643 The initial search results in SQL like the following:
4645 SELECT tag.*, cd.*, artist.* FROM tag
4646 JOIN cd ON tag.cd = cd.cdid
4647 JOIN artist ON cd.artist = artist.artistid
4649 L<DBIx::Class> has no need to go back to the database when we access the
4650 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4653 Simple prefetches will be joined automatically, so there is no need
4654 for a C<join> attribute in the above search.
4656 The L</prefetch> attribute can be used with any of the relationship types
4657 and multiple prefetches can be specified together. Below is a more complex
4658 example that prefetches a CD's artist, its liner notes (if present),
4659 the cover image, the tracks on that CD, and the guests on those
4662 my $rs = $schema->resultset('CD')->search(
4666 { artist => 'record_label'}, # belongs_to => belongs_to
4667 'liner_note', # might_have
4668 'cover_image', # has_one
4669 { tracks => 'guests' }, # has_many => has_many
4674 This will produce SQL like the following:
4676 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4680 ON artist.artistid = me.artistid
4681 JOIN record_label record_label
4682 ON record_label.labelid = artist.labelid
4683 LEFT JOIN track tracks
4684 ON tracks.cdid = me.cdid
4685 LEFT JOIN guest guests
4686 ON guests.trackid = track.trackid
4687 LEFT JOIN liner_notes liner_note
4688 ON liner_note.cdid = me.cdid
4689 JOIN cd_artwork cover_image
4690 ON cover_image.cdid = me.cdid
4693 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4694 C<tracks>, and C<guests> of the CD will all be available through the
4695 relationship accessors without the need for additional queries to the
4700 Prefetch does a lot of deep magic. As such, it may not behave exactly
4701 as you might expect.
4707 Prefetch uses the L</cache> to populate the prefetched relationships. This
4708 may or may not be what you want.
4712 If you specify a condition on a prefetched relationship, ONLY those
4713 rows that match the prefetched condition will be fetched into that relationship.
4714 This means that adding prefetch to a search() B<may alter> what is returned by
4715 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4717 my $artist_rs = $schema->resultset('Artist')->search({
4723 my $count = $artist_rs->first->cds->count;
4725 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4727 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4729 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4731 That cmp_ok() may or may not pass depending on the datasets involved. In other
4732 words the C<WHERE> condition would apply to the entire dataset, just like
4733 it would in regular SQL. If you want to add a condition only to the "right side"
4734 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4735 condition|DBIx::Class::Relationship::Base/condition>
4739 =head1 DBIC BIND VALUES
4741 Because DBIC may need more information to bind values than just the column name
4742 and value itself, it uses a special format for both passing and receiving bind
4743 values. Each bind value should be composed of an arrayref of
4744 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4750 If present (in any form), this is what is being passed directly to bind_param.
4751 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4752 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4754 If this is specified, all other bind options described below are ignored.
4758 If present, this is used to infer the actual bind attribute by passing to
4759 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4760 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4762 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4763 currently drivers are expected to "Do the Right Thing" when given a common
4764 datatype name. (Not ideal, but that's what we got at this point.)
4768 Currently used to correctly allocate buffers for bind_param_inout().
4769 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4770 or to a sensible value based on the "data_type".
4774 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4775 explicitly specified they are never overridden). Also used by some weird DBDs,
4776 where the column name should be available at bind_param time (e.g. Oracle).
4780 For backwards compatibility and convenience, the following shortcuts are
4783 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4784 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4785 [ undef, $val ] === [ {}, $val ]
4786 $val === [ {}, $val ]
4788 =head1 AUTHOR AND CONTRIBUTORS
4790 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4794 You may distribute this code under the same terms as Perl itself.