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::Compare (); # no imports!!! guard against insane architecture
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 @{$attrs}{qw(_sqlmaker_select_args _related_results_construction)};
253 if ($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;
418 my $old_attrs = { %{$self->{attrs}} };
419 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
421 my $new_attrs = { %$old_attrs };
423 # take care of call attrs (only if anything is changing)
424 if ($call_attrs and keys %$call_attrs) {
426 # copy for _normalize_selection
427 $call_attrs = { %$call_attrs };
429 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
431 # reset the current selector list if new selectors are supplied
432 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
433 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
436 # Normalize the new selector list (operates on the passed-in attr structure)
437 # Need to do it on every chain instead of only once on _resolved_attrs, in
438 # order to allow detection of empty vs partial 'as'
439 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
440 if $old_attrs->{_dark_selector};
441 $self->_normalize_selection ($call_attrs);
443 # start with blind overwriting merge, exclude selector attrs
444 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
445 delete @{$new_attrs}{@selector_attrs};
447 for (@selector_attrs) {
448 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
449 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
452 # older deprecated name, use only if {columns} is not there
453 if (my $c = delete $new_attrs->{cols}) {
454 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
455 if ($new_attrs->{columns}) {
456 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
459 $new_attrs->{columns} = $c;
464 # join/prefetch use their own crazy merging heuristics
465 foreach my $key (qw/join prefetch/) {
466 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
467 if exists $call_attrs->{$key};
470 # stack binds together
471 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
475 for ($old_where, $call_cond) {
477 $new_attrs->{where} = $self->_stack_cond (
478 $_, $new_attrs->{where}
483 if (defined $old_having) {
484 $new_attrs->{having} = $self->_stack_cond (
485 $old_having, $new_attrs->{having}
489 my $rs = (ref $self)->new($rsrc, $new_attrs);
491 $rs->set_cache($cache) if ($cache);
497 sub _normalize_selection {
498 my ($self, $attrs) = @_;
501 if ( exists $attrs->{include_columns} ) {
502 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
503 $attrs->{'+columns'} = $self->_merge_attr(
504 $attrs->{'+columns'}, delete $attrs->{include_columns}
508 # columns are always placed first, however
510 # Keep the X vs +X separation until _resolved_attrs time - this allows to
511 # delay the decision on whether to use a default select list ($rsrc->columns)
512 # allowing stuff like the remove_columns helper to work
514 # select/as +select/+as pairs need special handling - the amount of select/as
515 # elements in each pair does *not* have to be equal (think multicolumn
516 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
517 # supplied at all) - try to infer the alias, either from the -as parameter
518 # of the selector spec, or use the parameter whole if it looks like a column
519 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
520 # is ok as well), but make sure no more additions to the 'as' chain take place
521 for my $pref ('', '+') {
523 my ($sel, $as) = map {
524 my $key = "${pref}${_}";
526 my $val = [ ref $attrs->{$key} eq 'ARRAY'
528 : $attrs->{$key} || ()
530 delete $attrs->{$key};
534 if (! @$as and ! @$sel ) {
537 elsif (@$as and ! @$sel) {
538 $self->throw_exception(
539 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
543 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
544 # if any @$as has been supplied we assume the user knows what (s)he is doing
545 # and blindly keep stacking up pieces
546 unless ($attrs->{_dark_selector}) {
549 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
550 push @$as, $_->{-as};
552 # assume any plain no-space, no-parenthesis string to be a column spec
553 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
554 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
557 # if all else fails - raise a flag that no more aliasing will be allowed
559 $attrs->{_dark_selector} = {
561 string => ($dark_sel_dumper ||= do {
562 require Data::Dumper::Concise;
563 Data::Dumper::Concise::DumperObject()->Indent(0);
564 })->Values([$_])->Dump
572 elsif (@$as < @$sel) {
573 $self->throw_exception(
574 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
577 elsif ($pref and $attrs->{_dark_selector}) {
578 $self->throw_exception(
579 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
585 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
586 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
591 my ($self, $left, $right) = @_;
593 # collapse single element top-level conditions
594 # (single pass only, unlikely to need recursion)
595 for ($left, $right) {
596 if (ref $_ eq 'ARRAY') {
604 elsif (ref $_ eq 'HASH') {
605 my ($first, $more) = keys %$_;
608 if (! defined $first) {
612 elsif (! defined $more) {
613 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
616 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
623 # merge hashes with weeding out of duplicates (simple cases only)
624 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
626 # shallow copy to destroy
627 $right = { %$right };
628 for (grep { exists $right->{$_} } keys %$left) {
629 # the use of eq_deeply here is justified - the rhs of an
630 # expression can contain a lot of twisted weird stuff
631 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
634 $right = undef unless keys %$right;
638 if (defined $left xor defined $right) {
639 return defined $left ? $left : $right;
641 elsif (! defined $left) {
645 return { -and => [ $left, $right ] };
649 =head2 search_literal
651 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
652 should only be used in that context. C<search_literal> is a convenience
653 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
654 want to ensure columns are bound correctly, use L</search>.
656 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
657 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
658 require C<search_literal>.
662 =item Arguments: $sql_fragment, @standalone_bind_values
664 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
668 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
669 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
671 Pass a literal chunk of SQL to be added to the conditional part of the
674 Example of how to use C<search> instead of C<search_literal>
676 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
677 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
682 my ($self, $sql, @bind) = @_;
684 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
687 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
694 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
696 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
700 Finds and returns a single row based on supplied criteria. Takes either a
701 hashref with the same format as L</create> (including inference of foreign
702 keys from related objects), or a list of primary key values in the same
703 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
704 declaration on the L</result_source>.
706 In either case an attempt is made to combine conditions already existing on
707 the resultset with the condition passed to this method.
709 To aid with preparing the correct query for the storage you may supply the
710 C<key> attribute, which is the name of a
711 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
712 unique constraint corresponding to the
713 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
714 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
715 to construct a query that satisfies the named unique constraint fully (
716 non-NULL values for each column member of the constraint) an exception is
719 If no C<key> is specified, the search is carried over all unique constraints
720 which are fully defined by the available condition.
722 If no such constraint is found, C<find> currently defaults to a simple
723 C<< search->(\%column_values) >> which may or may not do what you expect.
724 Note that this fallback behavior may be deprecated in further versions. If
725 you need to search with arbitrary conditions - use L</search>. If the query
726 resulting from this fallback produces more than one row, a warning to the
727 effect is issued, though only the first row is constructed and returned as
730 In addition to C<key>, L</find> recognizes and applies standard
731 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
733 Note that if you have extra concerns about the correctness of the resulting
734 query you need to specify the C<key> attribute and supply the entire condition
735 as an argument to find (since it is not always possible to perform the
736 combination of the resultset condition with the supplied one, especially if
737 the resultset condition contains literal sql).
739 For example, to find a row by its primary key:
741 my $cd = $schema->resultset('CD')->find(5);
743 You can also find a row by a specific unique constraint:
745 my $cd = $schema->resultset('CD')->find(
747 artist => 'Massive Attack',
748 title => 'Mezzanine',
750 { key => 'cd_artist_title' }
753 See also L</find_or_create> and L</update_or_create>.
759 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
761 my $rsrc = $self->result_source;
764 if (exists $attrs->{key}) {
765 $constraint_name = defined $attrs->{key}
767 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
771 # Parse out the condition from input
774 if (ref $_[0] eq 'HASH') {
775 $call_cond = { %{$_[0]} };
778 # if only values are supplied we need to default to 'primary'
779 $constraint_name = 'primary' unless defined $constraint_name;
781 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
783 $self->throw_exception(
784 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
787 $self->throw_exception (
788 'find() expects either a column/value hashref, or a list of values '
789 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
790 ) unless @c_cols == @_;
793 @{$call_cond}{@c_cols} = @_;
797 for my $key (keys %$call_cond) {
799 my $keyref = ref($call_cond->{$key})
801 my $relinfo = $rsrc->relationship_info($key)
803 my $val = delete $call_cond->{$key};
805 next if $keyref eq 'ARRAY'; # has_many for multi_create
807 my $rel_q = $rsrc->_resolve_condition(
808 $relinfo->{cond}, $val, $key, $key
810 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
811 @related{keys %$rel_q} = values %$rel_q;
815 # relationship conditions take precedence (?)
816 @{$call_cond}{keys %related} = values %related;
818 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
820 if (defined $constraint_name) {
821 $final_cond = $self->_qualify_cond_columns (
823 $self->_build_unique_cond (
831 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
832 # This means that we got here after a merger of relationship conditions
833 # in ::Relationship::Base::search_related (the row method), and furthermore
834 # the relationship is of the 'single' type. This means that the condition
835 # provided by the relationship (already attached to $self) is sufficient,
836 # as there can be only one row in the database that would satisfy the
840 # no key was specified - fall down to heuristics mode:
841 # run through all unique queries registered on the resultset, and
842 # 'OR' all qualifying queries together
843 my (@unique_queries, %seen_column_combinations);
844 for my $c_name ($rsrc->unique_constraint_names) {
845 next if $seen_column_combinations{
846 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
849 push @unique_queries, try {
850 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
854 $final_cond = @unique_queries
855 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
856 : $self->_non_unique_find_fallback ($call_cond, $attrs)
860 # Run the query, passing the result_class since it should propagate for find
861 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
862 if ($rs->_resolved_attrs->{collapse}) {
864 carp "Query returned more than one row" if $rs->next;
872 # This is a stop-gap method as agreed during the discussion on find() cleanup:
873 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
875 # It is invoked when find() is called in legacy-mode with insufficiently-unique
876 # condition. It is provided for overrides until a saner way forward is devised
878 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
879 # the road. Please adjust your tests accordingly to catch this situation early
880 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
882 # The method will not be removed without an adequately complete replacement
883 # for strict-mode enforcement
884 sub _non_unique_find_fallback {
885 my ($self, $cond, $attrs) = @_;
887 return $self->_qualify_cond_columns(
889 exists $attrs->{alias}
891 : $self->{attrs}{alias}
896 sub _qualify_cond_columns {
897 my ($self, $cond, $alias) = @_;
899 my %aliased = %$cond;
900 for (keys %aliased) {
901 $aliased{"$alias.$_"} = delete $aliased{$_}
908 sub _build_unique_cond {
909 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
911 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
913 # combination may fail if $self->{cond} is non-trivial
914 my ($final_cond) = try {
915 $self->_merge_with_rscond ($extra_cond)
920 # trim out everything not in $columns
921 $final_cond = { map {
922 exists $final_cond->{$_}
923 ? ( $_ => $final_cond->{$_} )
927 if (my @missing = grep
928 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
931 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
933 join (', ', map { "'$_'" } @missing),
940 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
942 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
944 carp_unique ( sprintf (
945 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
946 . 'values in column(s): %s). This is almost certainly not what you wanted, '
947 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
949 join (', ', map { "'$_'" } @undefs),
956 =head2 search_related
960 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
962 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
966 $new_rs = $cd_rs->search_related('artist', {
970 Searches the specified relationship, optionally specifying a condition and
971 attributes for matching records. See L</ATTRIBUTES> for more information.
973 In list context, C<< ->all() >> is called implicitly on the resultset, thus
974 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
976 See also L</search_related_rs>.
981 return shift->related_resultset(shift)->search(@_);
984 =head2 search_related_rs
986 This method works exactly the same as search_related, except that
987 it guarantees a resultset, even in list context.
991 sub search_related_rs {
992 return shift->related_resultset(shift)->search_rs(@_);
999 =item Arguments: none
1001 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1005 Returns a storage-driven cursor to the given resultset. See
1006 L<DBIx::Class::Cursor> for more information.
1013 return $self->{cursor} ||= do {
1014 my $attrs = $self->_resolved_attrs;
1015 $self->result_source->storage->select(
1016 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1025 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1027 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1031 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1033 Inflates the first result without creating a cursor if the resultset has
1034 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1037 While this method can take an optional search condition (just like L</search>)
1038 being a fast-code-path it does not recognize search attributes. If you need to
1039 add extra joins or similar, call L</search> and then chain-call L</single> on the
1040 L<DBIx::Class::ResultSet> returned.
1046 As of 0.08100, this method enforces the assumption that the preceding
1047 query returns only one row. If more than one row is returned, you will receive
1050 Query returned more than one row
1052 In this case, you should be using L</next> or L</find> instead, or if you really
1053 know what you are doing, use the L</rows> attribute to explicitly limit the size
1056 This method will also throw an exception if it is called on a resultset prefetching
1057 has_many, as such a prefetch implies fetching multiple rows from the database in
1058 order to assemble the resulting object.
1065 my ($self, $where) = @_;
1067 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1070 my $attrs = { %{$self->_resolved_attrs} };
1072 $self->throw_exception(
1073 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1074 ) if $attrs->{collapse};
1077 if (defined $attrs->{where}) {
1080 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1081 $where, delete $attrs->{where} ]
1084 $attrs->{where} = $where;
1088 my $data = [ $self->result_source->storage->select_single(
1089 $attrs->{from}, $attrs->{select},
1090 $attrs->{where}, $attrs
1093 return undef unless @$data;
1094 $self->{_stashed_rows} = [ $data ];
1095 $self->_construct_results->[0];
1101 # Recursively collapse the query, accumulating values for each column.
1103 sub _collapse_query {
1104 my ($self, $query, $collapsed) = @_;
1108 if (ref $query eq 'ARRAY') {
1109 foreach my $subquery (@$query) {
1110 next unless ref $subquery; # -or
1111 $collapsed = $self->_collapse_query($subquery, $collapsed);
1114 elsif (ref $query eq 'HASH') {
1115 if (keys %$query and (keys %$query)[0] eq '-and') {
1116 foreach my $subquery (@{$query->{-and}}) {
1117 $collapsed = $self->_collapse_query($subquery, $collapsed);
1121 foreach my $col (keys %$query) {
1122 my $value = $query->{$col};
1123 $collapsed->{$col}{$value}++;
1135 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1137 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1141 my $max_length = $rs->get_column('length')->max;
1143 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1148 my ($self, $column) = @_;
1149 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1157 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1159 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1163 # WHERE title LIKE '%blue%'
1164 $cd_rs = $rs->search_like({ title => '%blue%'});
1166 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1167 that this is simply a convenience method retained for ex Class::DBI users.
1168 You most likely want to use L</search> with specific operators.
1170 For more information, see L<DBIx::Class::Manual::Cookbook>.
1172 This method is deprecated and will be removed in 0.09. Use L</search()>
1173 instead. An example conversion is:
1175 ->search_like({ foo => 'bar' });
1179 ->search({ foo => { like => 'bar' } });
1186 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1187 .' Instead use ->search({ x => { -like => "y%" } })'
1188 .' (note the outer pair of {}s - they are important!)'
1190 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1191 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1192 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1193 return $class->search($query, { %$attrs });
1200 =item Arguments: $first, $last
1202 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1206 Returns a resultset or object list representing a subset of elements from the
1207 resultset slice is called on. Indexes are from 0, i.e., to get the first
1208 three records, call:
1210 my ($one, $two, $three) = $rs->slice(0, 2);
1215 my ($self, $min, $max) = @_;
1216 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1217 $attrs->{offset} = $self->{attrs}{offset} || 0;
1218 $attrs->{offset} += $min;
1219 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1220 return $self->search(undef, $attrs);
1227 =item Arguments: none
1229 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1233 Returns the next element in the resultset (C<undef> is there is none).
1235 Can be used to efficiently iterate over records in the resultset:
1237 my $rs = $schema->resultset('CD')->search;
1238 while (my $cd = $rs->next) {
1242 Note that you need to store the resultset object, and call C<next> on it.
1243 Calling C<< resultset('Table')->next >> repeatedly will always return the
1244 first record from the resultset.
1251 if (my $cache = $self->get_cache) {
1252 $self->{all_cache_position} ||= 0;
1253 return $cache->[$self->{all_cache_position}++];
1256 if ($self->{attrs}{cache}) {
1257 delete $self->{pager};
1258 $self->{all_cache_position} = 1;
1259 return ($self->all)[0];
1262 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1264 $self->{_stashed_results} = $self->_construct_results
1267 return shift @{$self->{_stashed_results}};
1270 # Constructs as many results as it can in one pass while respecting
1271 # cursor laziness. Several modes of operation:
1273 # * Always builds everything present in @{$self->{_stashed_rows}}
1274 # * If called with $fetch_all true - pulls everything off the cursor and
1275 # builds all result structures (or objects) in one pass
1276 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1277 # and if the resultset is ordered properly by the left side:
1278 # * Fetches stuff off the cursor until the "master object" changes,
1279 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1281 # * Just fetches, and collapses/constructs everything as if $fetch_all
1282 # was requested (there is no other way to collapse except for an
1284 # * If no collapse is requested - just get the next row, construct and
1286 sub _construct_results {
1287 my ($self, $fetch_all) = @_;
1289 my $rsrc = $self->result_source;
1290 my $attrs = $self->_resolved_attrs;
1295 ! $attrs->{order_by}
1299 my @pcols = $rsrc->primary_columns
1301 # default order for collapsing unless the user asked for something
1302 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1303 $attrs->{_ordered_for_collapse} = 1;
1304 $attrs->{_order_is_artificial} = 1;
1307 # this will be used as both initial raw-row collector AND as a RV of
1308 # _construct_results. Not regrowing the array twice matters a lot...
1309 # a surprising amount actually
1310 my $rows = delete $self->{_stashed_rows};
1312 my $cursor; # we may not need one at all
1314 my $did_fetch_all = $fetch_all;
1317 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1318 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1320 elsif( $attrs->{collapse} ) {
1322 # a cursor will need to be closed over in case of collapse
1323 $cursor = $self->cursor;
1325 $attrs->{_ordered_for_collapse} = (
1331 ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
1333 ) unless defined $attrs->{_ordered_for_collapse};
1335 if (! $attrs->{_ordered_for_collapse}) {
1338 # instead of looping over ->next, use ->all in stealth mode
1339 # *without* calling a ->reset afterwards
1340 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1341 if (! $cursor->{_done}) {
1342 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1343 $cursor->{_done} = 1;
1348 if (! $did_fetch_all and ! @{$rows||[]} ) {
1349 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1350 $cursor ||= $self->cursor;
1351 if (scalar (my @r = $cursor->next) ) {
1356 return undef unless @{$rows||[]};
1358 # sanity check - people are too clever for their own good
1359 if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
1361 my $multiplied_selectors;
1362 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1364 $aliastypes->{multiplying}{$sel_alias}
1366 $aliastypes->{premultiplied}{$sel_alias}
1368 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1372 for my $i (0 .. $#{$attrs->{as}} ) {
1373 my $sel = $attrs->{select}[$i];
1375 if (ref $sel eq 'SCALAR') {
1378 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1382 $self->throw_exception(
1383 'Result collapse not possible - selection from a has_many source redirected to the main object'
1384 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1388 # hotspot - skip the setter
1389 my $res_class = $self->_result_class;
1391 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1392 $res_class->can ('inflate_result')
1393 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1396 my $infmap = $attrs->{as};
1398 $self->{_result_inflator}{is_core_row} = ( (
1401 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1402 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1404 $self->{_result_inflator}{is_hri} = ( (
1405 ! $self->{_result_inflator}{is_core_row}
1408 require DBIx::Class::ResultClass::HashRefInflator
1410 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1412 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1415 if (! $attrs->{_related_results_construction}) {
1416 # construct a much simpler array->hash folder for the one-table cases right here
1417 if ($self->{_result_inflator}{is_hri}) {
1418 for my $r (@$rows) {
1419 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1422 # FIXME SUBOPTIMAL this is a very very very hot spot
1423 # while rather optimal we can *still* do much better, by
1424 # building a smarter Row::inflate_result(), and
1425 # switch to feeding it data via a much leaner interface
1427 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1428 # this particular resultset size
1429 elsif (@$rows < 60) {
1430 for my $r (@$rows) {
1431 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1436 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1437 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1443 $self->{_result_inflator}{is_hri} ? 'hri'
1444 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1445 : 'classic_nonpruning'
1448 # $args and $attrs to _mk_row_parser are separated to delineate what is
1449 # core collapser stuff and what is dbic $rs specific
1450 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1452 inflate_map => $infmap,
1453 collapse => $attrs->{collapse},
1454 premultiplied => $attrs->{_main_source_premultiplied},
1455 hri_style => $self->{_result_inflator}{is_hri},
1456 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1457 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1459 # column_info metadata historically hasn't been too reliable.
1460 # We need to start fixing this somehow (the collapse resolver
1461 # can't work without it). Add an explicit check for the *main*
1462 # result, hopefully this will gradually weed out such errors
1464 # FIXME - this is a temporary kludge that reduces performance
1465 # It is however necessary for the time being
1466 my ($unrolled_non_null_cols_to_check, $err);
1468 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1471 'Collapse aborted due to invalid ResultSource metadata - the following '
1472 . 'selections are declared non-nullable but NULLs were retrieved: '
1476 COL: for my $i (@$check_non_null_cols) {
1477 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1480 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1483 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1487 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1488 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1490 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1491 my @r = $cursor->next or return;
1492 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1493 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1499 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1500 my @r = $cursor->next or return;
1505 $self->{_row_parser}{$parser_type}{cref}->(
1507 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1510 # Special-case multi-object HRI - there is no $inflator_cref pass
1511 unless ($self->{_result_inflator}{is_hri}) {
1512 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1516 # The @$rows check seems odd at first - why wouldn't we want to warn
1517 # regardless? The issue is things like find() etc, where the user
1518 # *knows* only one result will come back. In these cases the ->all
1519 # is not a pessimization, but rather something we actually want
1521 'Unable to properly collapse has_many results in iterator mode due '
1522 . 'to order criteria - performed an eager cursor slurp underneath. '
1523 . 'Consider using ->all() instead'
1524 ) if ( ! $fetch_all and @$rows > 1 );
1529 =head2 result_source
1533 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1535 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1539 An accessor for the primary ResultSource object from which this ResultSet
1546 =item Arguments: $result_class?
1548 =item Return Value: $result_class
1552 An accessor for the class to use when creating result objects. Defaults to
1553 C<< result_source->result_class >> - which in most cases is the name of the
1554 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1556 Note that changing the result_class will also remove any components
1557 that were originally loaded in the source class via
1558 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1559 in the original source class will not run.
1564 my ($self, $result_class) = @_;
1565 if ($result_class) {
1567 # don't fire this for an object
1568 $self->ensure_class_loaded($result_class)
1569 unless ref($result_class);
1571 if ($self->get_cache) {
1572 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1574 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1575 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1576 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1579 $self->_result_class($result_class);
1581 delete $self->{_result_inflator};
1583 $self->_result_class;
1590 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1592 =item Return Value: $count
1596 Performs an SQL C<COUNT> with the same query as the resultset was built
1597 with to find the number of elements. Passing arguments is equivalent to
1598 C<< $rs->search ($cond, \%attrs)->count >>
1604 return $self->search(@_)->count if @_ and defined $_[0];
1605 return scalar @{ $self->get_cache } if $self->get_cache;
1607 my $attrs = { %{ $self->_resolved_attrs } };
1609 # this is a little optimization - it is faster to do the limit
1610 # adjustments in software, instead of a subquery
1611 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1614 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1615 $crs = $self->_count_subq_rs ($attrs);
1618 $crs = $self->_count_rs ($attrs);
1620 my $count = $crs->next;
1622 $count -= $offset if $offset;
1623 $count = $rows if $rows and $rows < $count;
1624 $count = 0 if ($count < 0);
1633 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1635 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1639 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1640 This can be very handy for subqueries:
1642 ->search( { amount => $some_rs->count_rs->as_query } )
1644 As with regular resultsets the SQL query will be executed only after
1645 the resultset is accessed via L</next> or L</all>. That would return
1646 the same single value obtainable via L</count>.
1652 return $self->search(@_)->count_rs if @_;
1654 # this may look like a lack of abstraction (count() does about the same)
1655 # but in fact an _rs *must* use a subquery for the limits, as the
1656 # software based limiting can not be ported if this $rs is to be used
1657 # in a subquery itself (i.e. ->as_query)
1658 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1659 return $self->_count_subq_rs($self->{_attrs});
1662 return $self->_count_rs($self->{_attrs});
1667 # returns a ResultSetColumn object tied to the count query
1670 my ($self, $attrs) = @_;
1672 my $rsrc = $self->result_source;
1674 my $tmp_attrs = { %$attrs };
1675 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1676 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1678 # overwrite the selector (supplied by the storage)
1679 $rsrc->resultset_class->new($rsrc, {
1681 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1683 })->get_column ('count');
1687 # same as above but uses a subquery
1689 sub _count_subq_rs {
1690 my ($self, $attrs) = @_;
1692 my $rsrc = $self->result_source;
1694 my $sub_attrs = { %$attrs };
1695 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1696 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1698 # if we multi-prefetch we group_by something unique, as this is what we would
1699 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1700 if ( $attrs->{collapse} ) {
1701 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1702 $rsrc->_identifying_column_set || $self->throw_exception(
1703 'Unable to construct a unique group_by criteria properly collapsing the '
1704 . 'has_many prefetch before count()'
1709 # Calculate subquery selector
1710 if (my $g = $sub_attrs->{group_by}) {
1712 my $sql_maker = $rsrc->storage->sql_maker;
1714 # necessary as the group_by may refer to aliased functions
1716 for my $sel (@{$attrs->{select}}) {
1717 $sel_index->{$sel->{-as}} = $sel
1718 if (ref $sel eq 'HASH' and $sel->{-as});
1721 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1722 # also look for named aggregates referred in the having clause
1723 # having often contains scalarrefs - thus parse it out entirely
1725 if ($attrs->{having}) {
1726 local $sql_maker->{having_bind};
1727 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1728 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1729 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1730 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1731 # if we don't unset it we screw up retarded but unfortunately working
1732 # 'MAX(foo.bar)' => { '>', 3 }
1733 $sql_maker->{name_sep} = '';
1736 $sql_maker->clear_renderer;
1737 $sql_maker->clear_converter;
1739 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1741 my $having_sql = $sql_maker->_render_sqla(where => $attrs->{having});
1743 $sql_maker->clear_renderer;
1744 $sql_maker->clear_converter;
1748 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1749 # and if all fails for an utterly naive quoted scalar-with-function
1750 while ($having_sql =~ /
1751 (?: $rquote $sep)? $lquote (.+?) $rquote
1753 [\s,] \w+ \. (\w+) [\s,]
1755 [\s,] $lquote (.+?) $rquote [\s,]
1757 my $part = $1 || $2 || $3; # one of them matched if we got here
1758 unless ($seen_having{$part}++) {
1765 my $colpiece = $sel_index->{$_} || $_;
1767 # unqualify join-based group_by's. Arcane but possible query
1768 # also horrible horrible hack to alias a column (not a func.)
1769 # (probably need to introduce SQLA syntax)
1770 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1773 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1775 push @{$sub_attrs->{select}}, $colpiece;
1779 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1780 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1783 return $rsrc->resultset_class
1784 ->new ($rsrc, $sub_attrs)
1786 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1787 ->get_column ('count');
1791 =head2 count_literal
1793 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1794 should only be used in that context. See L</search_literal> for further info.
1798 =item Arguments: $sql_fragment, @standalone_bind_values
1800 =item Return Value: $count
1804 Counts the results in a literal query. Equivalent to calling L</search_literal>
1805 with the passed arguments, then L</count>.
1809 sub count_literal { shift->search_literal(@_)->count; }
1815 =item Arguments: none
1817 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1821 Returns all elements in the resultset.
1828 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1831 delete @{$self}{qw/_stashed_rows _stashed_results/};
1833 if (my $c = $self->get_cache) {
1837 $self->cursor->reset;
1839 my $objs = $self->_construct_results('fetch_all') || [];
1841 $self->set_cache($objs) if $self->{attrs}{cache};
1850 =item Arguments: none
1852 =item Return Value: $self
1856 Resets the resultset's cursor, so you can iterate through the elements again.
1857 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1865 delete @{$self}{qw/_stashed_rows _stashed_results/};
1866 $self->{all_cache_position} = 0;
1867 $self->cursor->reset;
1875 =item Arguments: none
1877 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1881 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1882 an object for the first result (or C<undef> if the resultset is empty).
1887 return $_[0]->reset->next;
1893 # Determines whether and what type of subquery is required for the $rs operation.
1894 # If grouping is necessary either supplies its own, or verifies the current one
1895 # After all is done delegates to the proper storage method.
1897 sub _rs_update_delete {
1898 my ($self, $op, $values) = @_;
1900 my $rsrc = $self->result_source;
1901 my $storage = $rsrc->schema->storage;
1903 my $attrs = { %{$self->_resolved_attrs} };
1905 my $join_classifications;
1906 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1908 # do we need a subquery for any reason?
1910 defined $existing_group_by
1912 # if {from} is unparseable wrap a subq
1913 ref($attrs->{from}) ne 'ARRAY'
1915 # limits call for a subq
1916 $self->_has_resolved_attr(qw/rows offset/)
1919 # simplify the joinmap, so we can further decide if a subq is necessary
1920 if (!$needs_subq and @{$attrs->{from}} > 1) {
1922 ($attrs->{from}, $join_classifications) =
1923 $storage->_prune_unused_joins ($attrs);
1925 # any non-pruneable non-local restricting joins imply subq
1926 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1929 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1931 (ref $attrs->{from}[0]) ne 'HASH'
1933 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1937 # do we need anything like a subquery?
1938 if (! $needs_subq) {
1939 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1940 # a condition containing 'me' or other table prefixes will not work
1941 # at all - so we convert the WHERE to a dq tree now, dequalify all
1942 # identifiers found therein via a scan across the tree, and then use
1943 # \{} style to pass the result onwards for use in the final query
1944 if ($self->{cond}) {
1946 my $converter = $rsrc->storage->sql_maker->converter;
1948 DQ_IDENTIFIER ,=> sub { $_ = [ $_->[-1] ] for $_[0]->{elements} }
1949 }, my $where_dq = $converter->_where_to_dq($self->{cond}));
1955 # we got this far - means it is time to wrap a subquery
1956 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1958 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1964 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1965 delete $attrs->{$_} for qw/select as collapse/;
1966 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1968 # this will be consumed by the pruner waaaaay down the stack
1969 $attrs->{_force_prune_multiplying_joins} = 1;
1971 my $subrs = (ref $self)->new($rsrc, $attrs);
1973 if (@$idcols == 1) {
1974 $cond = { $idcols->[0] => { -in => \$subrs->_as_select_dq } };
1976 elsif ($storage->_use_multicolumn_in) {
1977 # no syntax for calling this properly yet
1978 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1979 my $left = $storage->sql_maker->_render_sqla(select_select => $idcols);
1980 $left =~ s/^SELECT //i;
1981 my $right = $storage->sql_maker
1983 ->_literal_to_dq(${$subrs->as_query});
1985 { 'SQL.Naive' => 'in' },
1986 [ Literal(SQL => "( $left )"), $right ],
1990 # if all else fails - get all primary keys and operate over a ORed set
1991 # wrap in a transaction for consistency
1992 # this is where the group_by/multiplication starts to matter
1996 # we do not need to check pre-multipliers, since if the premulti is there, its
1997 # parent (who is multi) will be there too
1998 keys %{ $join_classifications->{multiplying} || {} }
2000 # make sure if there is a supplied group_by it matches the columns compiled above
2001 # perfectly. Anything else can not be sanely executed on most databases so croak
2002 # right then and there
2003 if ($existing_group_by) {
2004 my @current_group_by = map
2005 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
2010 join ("\x00", sort @current_group_by)
2012 join ("\x00", sort @{$attrs->{columns}} )
2014 $self->throw_exception (
2015 "You have just attempted a $op operation on a resultset which does group_by"
2016 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2017 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2018 . ' kind of queries. Please retry the operation with a modified group_by or'
2019 . ' without using one at all.'
2024 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2027 $guard = $storage->txn_scope_guard;
2030 for my $row ($subrs->cursor->all) {
2032 { $idcols->[$_] => $row->[$_] }
2039 my $res = $storage->$op (
2041 $op eq 'update' ? $values : (),
2045 $guard->commit if $guard;
2054 =item Arguments: \%values
2056 =item Return Value: $underlying_storage_rv
2060 Sets the specified columns in the resultset to the supplied values in a
2061 single query. Note that this will not run any accessor/set_column/update
2062 triggers, nor will it update any result object instances derived from this
2063 resultset (this includes the contents of the L<resultset cache|/set_cache>
2064 if any). See L</update_all> if you need to execute any on-update
2065 triggers or cascades defined either by you or a
2066 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2068 The return value is a pass through of what the underlying
2069 storage backend returned, and may vary. See L<DBI/execute> for the most
2074 Note that L</update> does not process/deflate any of the values passed in.
2075 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2076 ensure manually that any value passed to this method will stringify to
2077 something the RDBMS knows how to deal with. A notable example is the
2078 handling of L<DateTime> objects, for more info see:
2079 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2084 my ($self, $values) = @_;
2085 $self->throw_exception('Values for update must be a hash')
2086 unless ref $values eq 'HASH';
2088 return $self->_rs_update_delete ('update', $values);
2095 =item Arguments: \%values
2097 =item Return Value: 1
2101 Fetches all objects and updates them one at a time via
2102 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2103 triggers, while L</update> will not.
2108 my ($self, $values) = @_;
2109 $self->throw_exception('Values for update_all must be a hash')
2110 unless ref $values eq 'HASH';
2112 my $guard = $self->result_source->schema->txn_scope_guard;
2113 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2122 =item Arguments: none
2124 =item Return Value: $underlying_storage_rv
2128 Deletes the rows matching this resultset in a single query. Note that this
2129 will not run any delete triggers, nor will it alter the
2130 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2131 derived from this resultset (this includes the contents of the
2132 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2133 execute any on-delete triggers or cascades defined either by you or a
2134 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2136 The return value is a pass through of what the underlying storage backend
2137 returned, and may vary. See L<DBI/execute> for the most common case.
2143 $self->throw_exception('delete does not accept any arguments')
2146 return $self->_rs_update_delete ('delete');
2153 =item Arguments: none
2155 =item Return Value: 1
2159 Fetches all objects and deletes them one at a time via
2160 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2161 triggers, while L</delete> will not.
2167 $self->throw_exception('delete_all does not accept any arguments')
2170 my $guard = $self->result_source->schema->txn_scope_guard;
2171 $_->delete for $self->all;
2180 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2182 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2186 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2193 The context of this method call has an important effect on what is
2194 submitted to storage. In void context data is fed directly to fastpath
2195 insertion routines provided by the underlying storage (most often
2196 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2197 L<insert|DBIx::Class::Row/insert> calls on the
2198 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2199 augmentation of these methods provided by components. For example if you
2200 are using something like L<DBIx::Class::UUIDColumns> to create primary
2201 keys for you, you will find that your PKs are empty. In this case you
2202 will have to explicitly force scalar or list context in order to create
2207 In non-void (scalar or list) context, this method is simply a wrapper
2208 for L</create>. Depending on list or scalar context either a list of
2209 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2210 containing these objects is returned.
2212 When supplying data in "arrayref of arrayrefs" invocation style, the
2213 first element should be a list of column names and each subsequent
2214 element should be a data value in the earlier specified column order.
2217 $schema->resultset("Artist")->populate([
2218 [ qw( artistid name ) ],
2219 [ 100, 'A Formally Unknown Singer' ],
2220 [ 101, 'A singer that jumped the shark two albums ago' ],
2221 [ 102, 'An actually cool singer' ],
2224 For the arrayref of hashrefs style each hashref should be a structure
2225 suitable for passing to L</create>. Multi-create is also permitted with
2228 $schema->resultset("Artist")->populate([
2229 { artistid => 4, name => 'Manufactured Crap', cds => [
2230 { title => 'My First CD', year => 2006 },
2231 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2234 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2235 { title => 'My parents sold me to a record company', year => 2005 },
2236 { title => 'Why Am I So Ugly?', year => 2006 },
2237 { title => 'I Got Surgery and am now Popular', year => 2007 }
2242 If you attempt a void-context multi-create as in the example above (each
2243 Artist also has the related list of CDs), and B<do not> supply the
2244 necessary autoinc foreign key information, this method will proxy to the
2245 less efficient L</create>, and then throw the Result objects away. In this
2246 case there are obviously no benefits to using this method over L</create>.
2253 # cruft placed in standalone method
2254 my $data = $self->_normalize_populate_args(@_);
2256 return unless @$data;
2258 if(defined wantarray) {
2259 my @created = map { $self->create($_) } @$data;
2260 return wantarray ? @created : \@created;
2263 my $first = $data->[0];
2265 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2266 # it relationship data
2267 my (@rels, @columns);
2268 my $rsrc = $self->result_source;
2269 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2270 for (keys %$first) {
2271 my $ref = ref $first->{$_};
2272 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2278 my @pks = $rsrc->primary_columns;
2280 ## do the belongs_to relationships
2281 foreach my $index (0..$#$data) {
2283 # delegate to create() for any dataset without primary keys with specified relationships
2284 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2286 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2287 my @ret = $self->populate($data);
2293 foreach my $rel (@rels) {
2294 next unless ref $data->[$index]->{$rel} eq "HASH";
2295 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2296 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2297 my $related = $result->result_source->_resolve_condition(
2298 $reverse_relinfo->{cond},
2304 delete $data->[$index]->{$rel};
2305 $data->[$index] = {%{$data->[$index]}, %$related};
2307 push @columns, keys %$related if $index == 0;
2311 ## inherit the data locked in the conditions of the resultset
2312 my ($rs_data) = $self->_merge_with_rscond({});
2313 delete @{$rs_data}{@columns};
2315 ## do bulk insert on current row
2316 $rsrc->storage->insert_bulk(
2318 [@columns, keys %$rs_data],
2319 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2322 ## do the has_many relationships
2323 foreach my $item (@$data) {
2327 foreach my $rel (@rels) {
2328 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2330 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2332 my $child = $main_row->$rel;
2334 my $related = $child->result_source->_resolve_condition(
2335 $rels->{$rel}{cond},
2341 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2342 my @populate = map { {%$_, %$related} } @rows_to_add;
2344 $child->populate( \@populate );
2351 # populate() arguments went over several incarnations
2352 # What we ultimately support is AoH
2353 sub _normalize_populate_args {
2354 my ($self, $arg) = @_;
2356 if (ref $arg eq 'ARRAY') {
2360 elsif (ref $arg->[0] eq 'HASH') {
2363 elsif (ref $arg->[0] eq 'ARRAY') {
2365 my @colnames = @{$arg->[0]};
2366 foreach my $values (@{$arg}[1 .. $#$arg]) {
2367 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2373 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2380 =item Arguments: none
2382 =item Return Value: L<$pager|Data::Page>
2386 Returns a L<Data::Page> object for the current resultset. Only makes
2387 sense for queries with a C<page> attribute.
2389 To get the full count of entries for a paged resultset, call
2390 C<total_entries> on the L<Data::Page> object.
2397 return $self->{pager} if $self->{pager};
2399 my $attrs = $self->{attrs};
2400 if (!defined $attrs->{page}) {
2401 $self->throw_exception("Can't create pager for non-paged rs");
2403 elsif ($attrs->{page} <= 0) {
2404 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2406 $attrs->{rows} ||= 10;
2408 # throw away the paging flags and re-run the count (possibly
2409 # with a subselect) to get the real total count
2410 my $count_attrs = { %$attrs };
2411 delete @{$count_attrs}{qw/rows offset page pager/};
2413 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2415 require DBIx::Class::ResultSet::Pager;
2416 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2417 sub { $total_rs->count }, #lazy-get the total
2419 $self->{attrs}{page},
2427 =item Arguments: $page_number
2429 =item Return Value: L<$resultset|/search>
2433 Returns a resultset for the $page_number page of the resultset on which page
2434 is called, where each page contains a number of rows equal to the 'rows'
2435 attribute set on the resultset (10 by default).
2440 my ($self, $page) = @_;
2441 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2448 =item Arguments: \%col_data
2450 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2454 Creates a new result object in the resultset's result class and returns
2455 it. The row is not inserted into the database at this point, call
2456 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2457 will tell you whether the result object has been inserted or not.
2459 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2464 my ($self, $values) = @_;
2466 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2469 $self->throw_exception( "new_result expects a hashref" )
2470 unless (ref $values eq 'HASH');
2472 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2474 my $new = $self->result_class->new({
2476 ( @$cols_from_relations
2477 ? (-cols_from_relations => $cols_from_relations)
2480 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2484 reftype($new) eq 'HASH'
2490 carp_unique (sprintf (
2491 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2492 $self->result_class,
2499 # _merge_with_rscond
2501 # Takes a simple hash of K/V data and returns its copy merged with the
2502 # condition already present on the resultset. Additionally returns an
2503 # arrayref of value/condition names, which were inferred from related
2504 # objects (this is needed for in-memory related objects)
2505 sub _merge_with_rscond {
2506 my ($self, $data) = @_;
2508 my (%new_data, @cols_from_relations);
2510 my $alias = $self->{attrs}{alias};
2512 if (! defined $self->{cond}) {
2513 # just massage $data below
2515 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2516 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2517 @cols_from_relations = keys %new_data;
2519 elsif (ref $self->{cond} ne 'HASH') {
2520 $self->throw_exception(
2521 "Can't abstract implicit construct, resultset condition not a hash"
2525 # precedence must be given to passed values over values inherited from
2526 # the cond, so the order here is important.
2527 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2528 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2530 while ( my($col, $value) = each %implied ) {
2531 my $vref = ref $value;
2537 (keys %$value)[0] eq '='
2539 $new_data{$col} = $value->{'='};
2541 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2542 $new_data{$col} = $value;
2549 %{ $self->_remove_alias($data, $alias) },
2552 return (\%new_data, \@cols_from_relations);
2555 # _has_resolved_attr
2557 # determines if the resultset defines at least one
2558 # of the attributes supplied
2560 # used to determine if a subquery is necessary
2562 # supports some virtual attributes:
2564 # This will scan for any joins being present on the resultset.
2565 # It is not a mere key-search but a deep inspection of {from}
2568 sub _has_resolved_attr {
2569 my ($self, @attr_names) = @_;
2571 my $attrs = $self->_resolved_attrs;
2575 for my $n (@attr_names) {
2576 if (grep { $n eq $_ } (qw/-join/) ) {
2577 $extra_checks{$n}++;
2581 my $attr = $attrs->{$n};
2583 next if not defined $attr;
2585 if (ref $attr eq 'HASH') {
2586 return 1 if keys %$attr;
2588 elsif (ref $attr eq 'ARRAY') {
2596 # a resolved join is expressed as a multi-level from
2598 $extra_checks{-join}
2600 ref $attrs->{from} eq 'ARRAY'
2602 @{$attrs->{from}} > 1
2610 # Recursively collapse the condition.
2612 sub _collapse_cond {
2613 my ($self, $cond, $collapsed) = @_;
2617 if (ref $cond eq 'ARRAY') {
2618 foreach my $subcond (@$cond) {
2619 next unless ref $subcond; # -or
2620 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2623 elsif (ref $cond eq 'HASH') {
2624 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2625 foreach my $subcond (@{$cond->{-and}}) {
2626 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2630 foreach my $col (keys %$cond) {
2631 my $value = $cond->{$col};
2632 $collapsed->{$col} = $value;
2642 # Remove the specified alias from the specified query hash. A copy is made so
2643 # the original query is not modified.
2646 my ($self, $query, $alias) = @_;
2648 my %orig = %{ $query || {} };
2651 foreach my $key (keys %orig) {
2653 $unaliased{$key} = $orig{$key};
2656 $unaliased{$1} = $orig{$key}
2657 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2667 =item Arguments: none
2669 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2673 Returns the SQL query and bind vars associated with the invocant.
2675 This is generally used as the RHS for a subquery.
2682 my $attrs = { %{ $self->_resolved_attrs } };
2684 my $aq = $self->result_source->storage->_select_args_to_query (
2685 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2688 $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
2695 my $attrs = { %{ $self->_resolved_attrs } };
2696 my $storage = $self->result_source->storage;
2697 my (undef, $ident, @args) = $storage->_select_args(
2698 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2700 $ident = $ident->from if blessed($ident);
2701 $storage->sql_maker->converter->_select_to_dq(
2710 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2712 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2716 my $artist = $schema->resultset('Artist')->find_or_new(
2717 { artist => 'fred' }, { key => 'artists' });
2719 $cd->cd_to_producer->find_or_new({ producer => $producer },
2720 { key => 'primary' });
2722 Find an existing record from this resultset using L</find>. if none exists,
2723 instantiate a new result object and return it. The object will not be saved
2724 into your storage until you call L<DBIx::Class::Row/insert> on it.
2726 You most likely want this method when looking for existing rows using a unique
2727 constraint that is not the primary key, or looking for related rows.
2729 If you want objects to be saved immediately, use L</find_or_create> instead.
2731 B<Note>: Make sure to read the documentation of L</find> and understand the
2732 significance of the C<key> attribute, as its lack may skew your search, and
2733 subsequently result in spurious new objects.
2735 B<Note>: Take care when using C<find_or_new> with a table having
2736 columns with default values that you intend to be automatically
2737 supplied by the database (e.g. an auto_increment primary key column).
2738 In normal usage, the value of such columns should NOT be included at
2739 all in the call to C<find_or_new>, even when set to C<undef>.
2745 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2746 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2747 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2750 return $self->new_result($hash);
2757 =item Arguments: \%col_data
2759 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2763 Attempt to create a single new row or a row with multiple related rows
2764 in the table represented by the resultset (and related tables). This
2765 will not check for duplicate rows before inserting, use
2766 L</find_or_create> to do that.
2768 To create one row for this resultset, pass a hashref of key/value
2769 pairs representing the columns of the table and the values you wish to
2770 store. If the appropriate relationships are set up, foreign key fields
2771 can also be passed an object representing the foreign row, and the
2772 value will be set to its primary key.
2774 To create related objects, pass a hashref of related-object column values
2775 B<keyed on the relationship name>. If the relationship is of type C<multi>
2776 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2777 The process will correctly identify columns holding foreign keys, and will
2778 transparently populate them from the keys of the corresponding relation.
2779 This can be applied recursively, and will work correctly for a structure
2780 with an arbitrary depth and width, as long as the relationships actually
2781 exists and the correct column data has been supplied.
2783 Instead of hashrefs of plain related data (key/value pairs), you may
2784 also pass new or inserted objects. New objects (not inserted yet, see
2785 L</new_result>), will be inserted into their appropriate tables.
2787 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2789 Example of creating a new row.
2791 $person_rs->create({
2792 name=>"Some Person",
2793 email=>"somebody@someplace.com"
2796 Example of creating a new row and also creating rows in a related C<has_many>
2797 or C<has_one> resultset. Note Arrayref.
2800 { artistid => 4, name => 'Manufactured Crap', cds => [
2801 { title => 'My First CD', year => 2006 },
2802 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2807 Example of creating a new row and also creating a row in a related
2808 C<belongs_to> resultset. Note Hashref.
2811 title=>"Music for Silly Walks",
2814 name=>"Silly Musician",
2822 When subclassing ResultSet never attempt to override this method. Since
2823 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2824 lot of the internals simply never call it, so your override will be
2825 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2826 or L<DBIx::Class::Row/insert> depending on how early in the
2827 L</create> process you need to intervene. See also warning pertaining to
2835 my ($self, $col_data) = @_;
2836 $self->throw_exception( "create needs a hashref" )
2837 unless ref $col_data eq 'HASH';
2838 return $self->new_result($col_data)->insert;
2841 =head2 find_or_create
2845 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2847 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2851 $cd->cd_to_producer->find_or_create({ producer => $producer },
2852 { key => 'primary' });
2854 Tries to find a record based on its primary key or unique constraints; if none
2855 is found, creates one and returns that instead.
2857 my $cd = $schema->resultset('CD')->find_or_create({
2859 artist => 'Massive Attack',
2860 title => 'Mezzanine',
2864 Also takes an optional C<key> attribute, to search by a specific key or unique
2865 constraint. For example:
2867 my $cd = $schema->resultset('CD')->find_or_create(
2869 artist => 'Massive Attack',
2870 title => 'Mezzanine',
2872 { key => 'cd_artist_title' }
2875 B<Note>: Make sure to read the documentation of L</find> and understand the
2876 significance of the C<key> attribute, as its lack may skew your search, and
2877 subsequently result in spurious row creation.
2879 B<Note>: Because find_or_create() reads from the database and then
2880 possibly inserts based on the result, this method is subject to a race
2881 condition. Another process could create a record in the table after
2882 the find has completed and before the create has started. To avoid
2883 this problem, use find_or_create() inside a transaction.
2885 B<Note>: Take care when using C<find_or_create> with a table having
2886 columns with default values that you intend to be automatically
2887 supplied by the database (e.g. an auto_increment primary key column).
2888 In normal usage, the value of such columns should NOT be included at
2889 all in the call to C<find_or_create>, even when set to C<undef>.
2891 See also L</find> and L</update_or_create>. For information on how to declare
2892 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2894 If you need to know if an existing row was found or a new one created use
2895 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2896 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2899 my $cd = $schema->resultset('CD')->find_or_new({
2901 artist => 'Massive Attack',
2902 title => 'Mezzanine',
2906 if( !$cd->in_storage ) {
2913 sub find_or_create {
2915 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2916 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2917 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2920 return $self->create($hash);
2923 =head2 update_or_create
2927 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2929 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2933 $resultset->update_or_create({ col => $val, ... });
2935 Like L</find_or_create>, but if a row is found it is immediately updated via
2936 C<< $found_row->update (\%col_data) >>.
2939 Takes an optional C<key> attribute to search on a specific unique constraint.
2942 # In your application
2943 my $cd = $schema->resultset('CD')->update_or_create(
2945 artist => 'Massive Attack',
2946 title => 'Mezzanine',
2949 { key => 'cd_artist_title' }
2952 $cd->cd_to_producer->update_or_create({
2953 producer => $producer,
2959 B<Note>: Make sure to read the documentation of L</find> and understand the
2960 significance of the C<key> attribute, as its lack may skew your search, and
2961 subsequently result in spurious row creation.
2963 B<Note>: Take care when using C<update_or_create> with a table having
2964 columns with default values that you intend to be automatically
2965 supplied by the database (e.g. an auto_increment primary key column).
2966 In normal usage, the value of such columns should NOT be included at
2967 all in the call to C<update_or_create>, even when set to C<undef>.
2969 See also L</find> and L</find_or_create>. For information on how to declare
2970 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2972 If you need to know if an existing row was updated or a new one created use
2973 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2974 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2979 sub update_or_create {
2981 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2982 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2984 my $row = $self->find($cond, $attrs);
2986 $row->update($cond);
2990 return $self->create($cond);
2993 =head2 update_or_new
2997 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2999 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3003 $resultset->update_or_new({ col => $val, ... });
3005 Like L</find_or_new> but if a row is found it is immediately updated via
3006 C<< $found_row->update (\%col_data) >>.
3010 # In your application
3011 my $cd = $schema->resultset('CD')->update_or_new(
3013 artist => 'Massive Attack',
3014 title => 'Mezzanine',
3017 { key => 'cd_artist_title' }
3020 if ($cd->in_storage) {
3021 # the cd was updated
3024 # the cd is not yet in the database, let's insert it
3028 B<Note>: Make sure to read the documentation of L</find> and understand the
3029 significance of the C<key> attribute, as its lack may skew your search, and
3030 subsequently result in spurious new objects.
3032 B<Note>: Take care when using C<update_or_new> with a table having
3033 columns with default values that you intend to be automatically
3034 supplied by the database (e.g. an auto_increment primary key column).
3035 In normal usage, the value of such columns should NOT be included at
3036 all in the call to C<update_or_new>, even when set to C<undef>.
3038 See also L</find>, L</find_or_create> and L</find_or_new>.
3044 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3045 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3047 my $row = $self->find( $cond, $attrs );
3048 if ( defined $row ) {
3049 $row->update($cond);
3053 return $self->new_result($cond);
3060 =item Arguments: none
3062 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3066 Gets the contents of the cache for the resultset, if the cache is set.
3068 The cache is populated either by using the L</prefetch> attribute to
3069 L</search> or by calling L</set_cache>.
3081 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3083 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3087 Sets the contents of the cache for the resultset. Expects an arrayref
3088 of objects of the same class as those produced by the resultset. Note that
3089 if the cache is set, the resultset will return the cached objects rather
3090 than re-querying the database even if the cache attr is not set.
3092 The contents of the cache can also be populated by using the
3093 L</prefetch> attribute to L</search>.
3098 my ( $self, $data ) = @_;
3099 $self->throw_exception("set_cache requires an arrayref")
3100 if defined($data) && (ref $data ne 'ARRAY');
3101 $self->{all_cache} = $data;
3108 =item Arguments: none
3110 =item Return Value: undef
3114 Clears the cache for the resultset.
3119 shift->set_cache(undef);
3126 =item Arguments: none
3128 =item Return Value: true, if the resultset has been paginated
3136 return !!$self->{attrs}{page};
3143 =item Arguments: none
3145 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3153 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3156 =head2 related_resultset
3160 =item Arguments: $rel_name
3162 =item Return Value: L<$resultset|/search>
3166 Returns a related resultset for the supplied relationship name.
3168 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3172 sub related_resultset {
3173 my ($self, $rel) = @_;
3175 return $self->{related_resultsets}{$rel}
3176 if defined $self->{related_resultsets}{$rel};
3178 return $self->{related_resultsets}{$rel} = do {
3179 my $rsrc = $self->result_source;
3180 my $rel_info = $rsrc->relationship_info($rel);
3182 $self->throw_exception(
3183 "search_related: result source '" . $rsrc->source_name .
3184 "' has no such relationship $rel")
3187 my $attrs = $self->_chain_relationship($rel);
3189 my $join_count = $attrs->{seen_join}{$rel};
3191 my $alias = $self->result_source->storage
3192 ->relname_to_table_alias($rel, $join_count);
3194 # since this is search_related, and we already slid the select window inwards
3195 # (the select/as attrs were deleted in the beginning), we need to flip all
3196 # left joins to inner, so we get the expected results
3197 # read the comment on top of the actual function to see what this does
3198 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3201 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3202 delete @{$attrs}{qw(result_class alias)};
3204 my $rel_source = $rsrc->related_source($rel);
3208 # The reason we do this now instead of passing the alias to the
3209 # search_rs below is that if you wrap/overload resultset on the
3210 # source you need to know what alias it's -going- to have for things
3211 # to work sanely (e.g. RestrictWithObject wants to be able to add
3212 # extra query restrictions, and these may need to be $alias.)
3214 my $rel_attrs = $rel_source->resultset_attributes;
3215 local $rel_attrs->{alias} = $alias;
3217 $rel_source->resultset
3221 where => $attrs->{where},
3225 if (my $cache = $self->get_cache) {
3226 my @related_cache = map
3227 { @{$_->related_resultset($rel)->get_cache||[]} }
3231 $new->set_cache(\@related_cache) if @related_cache;
3238 =head2 current_source_alias
3242 =item Arguments: none
3244 =item Return Value: $source_alias
3248 Returns the current table alias for the result source this resultset is built
3249 on, that will be used in the SQL query. Usually it is C<me>.
3251 Currently the source alias that refers to the result set returned by a
3252 L</search>/L</find> family method depends on how you got to the resultset: it's
3253 C<me> by default, but eg. L</search_related> aliases it to the related result
3254 source name (and keeps C<me> referring to the original result set). The long
3255 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3256 (and make this method unnecessary).
3258 Thus it's currently necessary to use this method in predefined queries (see
3259 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3260 source alias of the current result set:
3262 # in a result set class
3264 my ($self, $user) = @_;
3266 my $me = $self->current_source_alias;
3268 return $self->search({
3269 "$me.modified" => $user->id,
3275 sub current_source_alias {
3276 return (shift->{attrs} || {})->{alias} || 'me';
3279 =head2 as_subselect_rs
3283 =item Arguments: none
3285 =item Return Value: L<$resultset|/search>
3289 Act as a barrier to SQL symbols. The resultset provided will be made into a
3290 "virtual view" by including it as a subquery within the from clause. From this
3291 point on, any joined tables are inaccessible to ->search on the resultset (as if
3292 it were simply where-filtered without joins). For example:
3294 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3296 # 'x' now pollutes the query namespace
3298 # So the following works as expected
3299 my $ok_rs = $rs->search({'x.other' => 1});
3301 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3302 # def) we look for one row with contradictory terms and join in another table
3303 # (aliased 'x_2') which we never use
3304 my $broken_rs = $rs->search({'x.name' => 'def'});
3306 my $rs2 = $rs->as_subselect_rs;
3308 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3309 my $not_joined_rs = $rs2->search({'x.other' => 1});
3311 # works as expected: finds a 'table' row related to two x rows (abc and def)
3312 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3314 Another example of when one might use this would be to select a subset of
3315 columns in a group by clause:
3317 my $rs = $schema->resultset('Bar')->search(undef, {
3318 group_by => [qw{ id foo_id baz_id }],
3319 })->as_subselect_rs->search(undef, {
3320 columns => [qw{ id foo_id }]
3323 In the above example normally columns would have to be equal to the group by,
3324 but because we isolated the group by into a subselect the above works.
3328 sub as_subselect_rs {
3331 my $attrs = $self->_resolved_attrs;
3333 my $fresh_rs = (ref $self)->new (
3334 $self->result_source
3337 # these pieces will be locked in the subquery
3338 delete $fresh_rs->{cond};
3339 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3341 return $fresh_rs->search( {}, {
3343 $attrs->{alias} => $self->as_query,
3344 -alias => $attrs->{alias},
3345 -rsrc => $self->result_source,
3347 alias => $attrs->{alias},
3351 # This code is called by search_related, and makes sure there
3352 # is clear separation between the joins before, during, and
3353 # after the relationship. This information is needed later
3354 # in order to properly resolve prefetch aliases (any alias
3355 # with a relation_chain_depth less than the depth of the
3356 # current prefetch is not considered)
3358 # The increments happen twice per join. An even number means a
3359 # relationship specified via a search_related, whereas an odd
3360 # number indicates a join/prefetch added via attributes
3362 # Also this code will wrap the current resultset (the one we
3363 # chain to) in a subselect IFF it contains limiting attributes
3364 sub _chain_relationship {
3365 my ($self, $rel) = @_;
3366 my $source = $self->result_source;
3367 my $attrs = { %{$self->{attrs}||{}} };
3369 # we need to take the prefetch the attrs into account before we
3370 # ->_resolve_join as otherwise they get lost - captainL
3371 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3373 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3375 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3378 my @force_subq_attrs = qw/offset rows group_by having/;
3381 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3383 $self->_has_resolved_attr (@force_subq_attrs)
3385 # Nuke the prefetch (if any) before the new $rs attrs
3386 # are resolved (prefetch is useless - we are wrapping
3387 # a subquery anyway).
3388 my $rs_copy = $self->search;
3389 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3390 $rs_copy->{attrs}{join},
3391 delete $rs_copy->{attrs}{prefetch},
3396 -alias => $attrs->{alias},
3397 $attrs->{alias} => $rs_copy->as_query,
3399 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3400 $seen->{-relation_chain_depth} = 0;
3402 elsif ($attrs->{from}) { #shallow copy suffices
3403 $from = [ @{$attrs->{from}} ];
3408 -alias => $attrs->{alias},
3409 $attrs->{alias} => $source->from,
3413 my $jpath = ($seen->{-relation_chain_depth})
3414 ? $from->[-1][0]{-join_path}
3417 my @requested_joins = $source->_resolve_join(
3424 push @$from, @requested_joins;
3426 $seen->{-relation_chain_depth}++;
3428 # if $self already had a join/prefetch specified on it, the requested
3429 # $rel might very well be already included. What we do in this case
3430 # is effectively a no-op (except that we bump up the chain_depth on
3431 # the join in question so we could tell it *is* the search_related)
3434 # we consider the last one thus reverse
3435 for my $j (reverse @requested_joins) {
3436 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3437 if ($rel eq $last_j) {
3438 $j->[0]{-relation_chain_depth}++;
3444 unless ($already_joined) {
3445 push @$from, $source->_resolve_join(
3453 $seen->{-relation_chain_depth}++;
3455 return {%$attrs, from => $from, seen_join => $seen};
3458 sub _resolved_attrs {
3460 return $self->{_attrs} if $self->{_attrs};
3462 my $attrs = { %{ $self->{attrs} || {} } };
3463 my $source = $self->result_source;
3464 my $alias = $attrs->{alias};
3466 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3467 if $attrs->{collapse} and $attrs->{distinct};
3469 # default selection list
3470 $attrs->{columns} = [ $source->columns ]
3471 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3473 # merge selectors together
3474 for (qw/columns select as/) {
3475 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3476 if $attrs->{$_} or $attrs->{"+$_"};
3479 # disassemble columns
3481 if (my $cols = delete $attrs->{columns}) {
3482 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3483 if (ref $c eq 'HASH') {
3484 for my $as (sort keys %$c) {
3485 push @sel, $c->{$as};
3496 # when trying to weed off duplicates later do not go past this point -
3497 # everything added from here on is unbalanced "anyone's guess" stuff
3498 my $dedup_stop_idx = $#as;
3500 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3502 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3503 if $attrs->{select};
3505 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3506 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3508 # disqualify all $alias.col as-bits (inflate-map mandated)
3509 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3511 # de-duplicate the result (remove *identical* select/as pairs)
3512 # and also die on duplicate {as} pointing to different {select}s
3513 # not using a c-style for as the condition is prone to shrinkage
3516 while ($i <= $dedup_stop_idx) {
3517 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3522 elsif ($seen->{$as[$i]}++) {
3523 $self->throw_exception(
3524 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3532 $attrs->{select} = \@sel;
3533 $attrs->{as} = \@as;
3535 $attrs->{from} ||= [{
3537 -alias => $self->{attrs}{alias},
3538 $self->{attrs}{alias} => $source->from,
3541 if ( $attrs->{join} || $attrs->{prefetch} ) {
3543 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3544 if ref $attrs->{from} ne 'ARRAY';
3546 my $join = (delete $attrs->{join}) || {};
3548 if ( defined $attrs->{prefetch} ) {
3549 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3552 $attrs->{from} = # have to copy here to avoid corrupting the original
3554 @{ $attrs->{from} },
3555 $source->_resolve_join(
3558 { %{ $attrs->{seen_join} || {} } },
3559 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3560 ? $attrs->{from}[-1][0]{-join_path}
3567 if ( defined $attrs->{order_by} ) {
3568 $attrs->{order_by} = (
3569 ref( $attrs->{order_by} ) eq 'ARRAY'
3570 ? [ @{ $attrs->{order_by} } ]
3571 : [ $attrs->{order_by} || () ]
3575 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3576 $attrs->{group_by} = [ $attrs->{group_by} ];
3580 # generate selections based on the prefetch helper
3581 my ($prefetch, @prefetch_select, @prefetch_as);
3582 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3583 if defined $attrs->{prefetch};
3587 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3588 if $attrs->{_dark_selector};
3590 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3591 if defined $attrs->{collapse} and ! $attrs->{collapse};
3593 $attrs->{collapse} = 1;
3595 # this is a separate structure (we don't look in {from} directly)
3596 # as the resolver needs to shift things off the lists to work
3597 # properly (identical-prefetches on different branches)
3599 if (ref $attrs->{from} eq 'ARRAY') {
3601 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3603 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3604 next unless $j->[0]{-alias};
3605 next unless $j->[0]{-join_path};
3606 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3608 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3611 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3612 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3616 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3618 # save these for after distinct resolution
3619 @prefetch_select = map { $_->[0] } @prefetch;
3620 @prefetch_as = map { $_->[1] } @prefetch;
3623 # run through the resulting joinstructure (starting from our current slot)
3624 # and unset collapse if proven unnecessary
3626 # also while we are at it find out if the current root source has
3627 # been premultiplied by previous related_source chaining
3629 # this allows to predict whether a root object with all other relation
3630 # data set to NULL is in fact unique
3631 if ($attrs->{collapse}) {
3633 if (ref $attrs->{from} eq 'ARRAY') {
3635 if (@{$attrs->{from}} == 1) {
3636 # no joins - no collapse
3637 $attrs->{collapse} = 0;
3640 # find where our table-spec starts
3641 my @fromlist = @{$attrs->{from}};
3643 my $t = shift @fromlist;
3646 # me vs join from-spec distinction - a ref means non-root
3647 if (ref $t eq 'ARRAY') {
3649 $is_multi ||= ! $t->{-is_single};
3651 last if ($t->{-alias} && $t->{-alias} eq $alias);
3652 $attrs->{_main_source_premultiplied} ||= $is_multi;
3655 # no non-singles remaining, nor any premultiplication - nothing to collapse
3657 ! $attrs->{_main_source_premultiplied}
3659 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3661 $attrs->{collapse} = 0;
3667 # if we can not analyze the from - err on the side of safety
3668 $attrs->{_main_source_premultiplied} = 1;
3672 # generate the distinct induced group_by before injecting the prefetched select/as parts
3673 if (delete $attrs->{distinct}) {
3674 if ($attrs->{group_by}) {
3675 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3678 $attrs->{_grouped_by_distinct} = 1;
3679 # distinct affects only the main selection part, not what prefetch may add below
3680 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3682 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3683 # The thinking is: if we are collapsing the subquerying prefetch engine will
3684 # rip stuff apart for us anyway, and we do not want to have a potentially
3685 # function-converted external order_by
3686 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3687 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3691 # inject prefetch-bound selection (if any)
3692 push @{$attrs->{select}}, @prefetch_select;
3693 push @{$attrs->{as}}, @prefetch_as;
3695 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3696 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3697 $attrs->{_related_results_construction} = 1;
3700 # if both page and offset are specified, produce a combined offset
3701 # even though it doesn't make much sense, this is what pre 081xx has
3703 if (my $page = delete $attrs->{page}) {
3705 ($attrs->{rows} * ($page - 1))
3707 ($attrs->{offset} || 0)
3711 return $self->{_attrs} = $attrs;
3715 my ($self, $attr) = @_;
3717 if (ref $attr eq 'HASH') {
3718 return $self->_rollout_hash($attr);
3719 } elsif (ref $attr eq 'ARRAY') {
3720 return $self->_rollout_array($attr);
3726 sub _rollout_array {
3727 my ($self, $attr) = @_;
3730 foreach my $element (@{$attr}) {
3731 if (ref $element eq 'HASH') {
3732 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3733 } elsif (ref $element eq 'ARRAY') {
3734 # XXX - should probably recurse here
3735 push( @rolled_array, @{$self->_rollout_array($element)} );
3737 push( @rolled_array, $element );
3740 return \@rolled_array;
3744 my ($self, $attr) = @_;
3747 foreach my $key (keys %{$attr}) {
3748 push( @rolled_array, { $key => $attr->{$key} } );
3750 return \@rolled_array;
3753 sub _calculate_score {
3754 my ($self, $a, $b) = @_;
3756 if (defined $a xor defined $b) {
3759 elsif (not defined $a) {
3763 if (ref $b eq 'HASH') {
3764 my ($b_key) = keys %{$b};
3765 if (ref $a eq 'HASH') {
3766 my ($a_key) = keys %{$a};
3767 if ($a_key eq $b_key) {
3768 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3773 return ($a eq $b_key) ? 1 : 0;
3776 if (ref $a eq 'HASH') {
3777 my ($a_key) = keys %{$a};
3778 return ($b eq $a_key) ? 1 : 0;
3780 return ($b eq $a) ? 1 : 0;
3785 sub _merge_joinpref_attr {
3786 my ($self, $orig, $import) = @_;
3788 return $import unless defined($orig);
3789 return $orig unless defined($import);
3791 $orig = $self->_rollout_attr($orig);
3792 $import = $self->_rollout_attr($import);
3795 foreach my $import_element ( @{$import} ) {
3796 # find best candidate from $orig to merge $b_element into
3797 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3798 foreach my $orig_element ( @{$orig} ) {
3799 my $score = $self->_calculate_score( $orig_element, $import_element );
3800 if ($score > $best_candidate->{score}) {
3801 $best_candidate->{position} = $position;
3802 $best_candidate->{score} = $score;
3806 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3807 $import_key = '' if not defined $import_key;
3809 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3810 push( @{$orig}, $import_element );
3812 my $orig_best = $orig->[$best_candidate->{position}];
3813 # merge orig_best and b_element together and replace original with merged
3814 if (ref $orig_best ne 'HASH') {
3815 $orig->[$best_candidate->{position}] = $import_element;
3816 } elsif (ref $import_element eq 'HASH') {
3817 my ($key) = keys %{$orig_best};
3818 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3821 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3824 return @$orig ? $orig : ();
3832 require Hash::Merge;
3833 my $hm = Hash::Merge->new;
3835 $hm->specify_behavior({
3838 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3840 if ($defl xor $defr) {
3841 return [ $defl ? $_[0] : $_[1] ];
3846 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3850 return [$_[0], $_[1]];
3854 return $_[1] if !defined $_[0];
3855 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3856 return [$_[0], @{$_[1]}]
3859 return [] if !defined $_[0] and !keys %{$_[1]};
3860 return [ $_[1] ] if !defined $_[0];
3861 return [ $_[0] ] if !keys %{$_[1]};
3862 return [$_[0], $_[1]]
3867 return $_[0] if !defined $_[1];
3868 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3869 return [@{$_[0]}, $_[1]]
3872 my @ret = @{$_[0]} or return $_[1];
3873 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3874 my %idx = map { $_ => 1 } @ret;
3875 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3879 return [ $_[1] ] if ! @{$_[0]};
3880 return $_[0] if !keys %{$_[1]};
3881 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3882 return [ @{$_[0]}, $_[1] ];
3887 return [] if !keys %{$_[0]} and !defined $_[1];
3888 return [ $_[0] ] if !defined $_[1];
3889 return [ $_[1] ] if !keys %{$_[0]};
3890 return [$_[0], $_[1]]
3893 return [] if !keys %{$_[0]} and !@{$_[1]};
3894 return [ $_[0] ] if !@{$_[1]};
3895 return $_[1] if !keys %{$_[0]};
3896 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3897 return [ $_[0], @{$_[1]} ];
3900 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3901 return [ $_[0] ] if !keys %{$_[1]};
3902 return [ $_[1] ] if !keys %{$_[0]};
3903 return [ $_[0] ] if $_[0] eq $_[1];
3904 return [ $_[0], $_[1] ];
3907 } => 'DBIC_RS_ATTR_MERGER');
3911 return $hm->merge ($_[1], $_[2]);
3915 sub STORABLE_freeze {
3916 my ($self, $cloning) = @_;
3917 my $to_serialize = { %$self };
3919 # A cursor in progress can't be serialized (and would make little sense anyway)
3920 # the parser can be regenerated (and can't be serialized)
3921 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3923 # nor is it sensical to store a not-yet-fired-count pager
3924 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3925 delete $to_serialize->{pager};
3928 Storable::nfreeze($to_serialize);
3931 # need this hook for symmetry
3933 my ($self, $cloning, $serialized) = @_;
3935 %$self = %{ Storable::thaw($serialized) };
3941 =head2 throw_exception
3943 See L<DBIx::Class::Schema/throw_exception> for details.
3947 sub throw_exception {
3950 if (ref $self and my $rsrc = $self->result_source) {
3951 $rsrc->throw_exception(@_)
3954 DBIx::Class::Exception->throw(@_);
3962 # XXX: FIXME: Attributes docs need clearing up
3966 Attributes are used to refine a ResultSet in various ways when
3967 searching for data. They can be passed to any method which takes an
3968 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3971 Default attributes can be set on the result class using
3972 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3973 the CAVEATS on that feature before using it!)
3975 These are in no particular order:
3981 =item Value: ( $order_by | \@order_by | \%order_by )
3985 Which column(s) to order the results by.
3987 [The full list of suitable values is documented in
3988 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3991 If a single column name, or an arrayref of names is supplied, the
3992 argument is passed through directly to SQL. The hashref syntax allows
3993 for connection-agnostic specification of ordering direction:
3995 For descending order:
3997 order_by => { -desc => [qw/col1 col2 col3/] }
3999 For explicit ascending order:
4001 order_by => { -asc => 'col' }
4003 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4004 supported, although you are strongly encouraged to use the hashref
4005 syntax as outlined above.
4011 =item Value: \@columns | \%columns | $column
4015 Shortcut to request a particular set of columns to be retrieved. Each
4016 column spec may be a string (a table column name), or a hash (in which
4017 case the key is the C<as> value, and the value is used as the C<select>
4018 expression). Adds C<me.> onto the start of any column without a C<.> in
4019 it and sets C<select> from that, then auto-populates C<as> from
4020 C<select> as normal. (You may also use the C<cols> attribute, as in
4021 earlier versions of DBIC, but this is deprecated.)
4023 Essentially C<columns> does the same as L</select> and L</as>.
4025 columns => [ 'foo', { bar => 'baz' } ]
4029 select => [qw/foo baz/],
4036 =item Value: \@columns
4040 Indicates additional columns to be selected from storage. Works the same as
4041 L</columns> but adds columns to the selection. (You may also use the
4042 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4043 deprecated). For example:-
4045 $schema->resultset('CD')->search(undef, {
4046 '+columns' => ['artist.name'],
4050 would return all CDs and include a 'name' column to the information
4051 passed to object inflation. Note that the 'artist' is the name of the
4052 column (or relationship) accessor, and 'name' is the name of the column
4053 accessor in the related table.
4055 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4056 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4057 unary plus operator before it.
4059 =head2 include_columns
4063 =item Value: \@columns
4067 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4073 =item Value: \@select_columns
4077 Indicates which columns should be selected from the storage. You can use
4078 column names, or in the case of RDBMS back ends, function or stored procedure
4081 $rs = $schema->resultset('Employee')->search(undef, {
4084 { count => 'employeeid' },
4085 { max => { length => 'name' }, -as => 'longest_name' }
4090 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4092 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4093 use L</select>, to instruct DBIx::Class how to store the result of the column.
4094 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4095 identifier aliasing. You can however alias a function, so you can use it in
4096 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4097 attribute> supplied as shown in the example above.
4099 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4100 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4101 unary plus operator before it.
4107 Indicates additional columns to be selected from storage. Works the same as
4108 L</select> but adds columns to the default selection, instead of specifying
4117 =item Value: \@inflation_names
4121 Indicates column names for object inflation. That is L</as> indicates the
4122 slot name in which the column value will be stored within the
4123 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4124 identifier by the C<get_column> method (or via the object accessor B<if one
4125 with the same name already exists>) as shown below. The L</as> attribute has
4126 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4128 $rs = $schema->resultset('Employee')->search(undef, {
4131 { count => 'employeeid' },
4132 { max => { length => 'name' }, -as => 'longest_name' }
4141 If the object against which the search is performed already has an accessor
4142 matching a column name specified in C<as>, the value can be retrieved using
4143 the accessor as normal:
4145 my $name = $employee->name();
4147 If on the other hand an accessor does not exist in the object, you need to
4148 use C<get_column> instead:
4150 my $employee_count = $employee->get_column('employee_count');
4152 You can create your own accessors if required - see
4153 L<DBIx::Class::Manual::Cookbook> for details.
4159 Indicates additional column names for those added via L</+select>. See L</as>.
4167 =item Value: ($rel_name | \@rel_names | \%rel_names)
4171 Contains a list of relationships that should be joined for this query. For
4174 # Get CDs by Nine Inch Nails
4175 my $rs = $schema->resultset('CD')->search(
4176 { 'artist.name' => 'Nine Inch Nails' },
4177 { join => 'artist' }
4180 Can also contain a hash reference to refer to the other relation's relations.
4183 package MyApp::Schema::Track;
4184 use base qw/DBIx::Class/;
4185 __PACKAGE__->table('track');
4186 __PACKAGE__->add_columns(qw/trackid cd position title/);
4187 __PACKAGE__->set_primary_key('trackid');
4188 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4191 # In your application
4192 my $rs = $schema->resultset('Artist')->search(
4193 { 'track.title' => 'Teardrop' },
4195 join => { cd => 'track' },
4196 order_by => 'artist.name',
4200 You need to use the relationship (not the table) name in conditions,
4201 because they are aliased as such. The current table is aliased as "me", so
4202 you need to use me.column_name in order to avoid ambiguity. For example:
4204 # Get CDs from 1984 with a 'Foo' track
4205 my $rs = $schema->resultset('CD')->search(
4208 'tracks.name' => 'Foo'
4210 { join => 'tracks' }
4213 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4214 similarly for a third time). For e.g.
4216 my $rs = $schema->resultset('Artist')->search({
4217 'cds.title' => 'Down to Earth',
4218 'cds_2.title' => 'Popular',
4220 join => [ qw/cds cds/ ],
4223 will return a set of all artists that have both a cd with title 'Down
4224 to Earth' and a cd with title 'Popular'.
4226 If you want to fetch related objects from other tables as well, see L</prefetch>
4229 NOTE: An internal join-chain pruner will discard certain joins while
4230 constructing the actual SQL query, as long as the joins in question do not
4231 affect the retrieved result. This for example includes 1:1 left joins
4232 that are not part of the restriction specification (WHERE/HAVING) nor are
4233 a part of the query selection.
4235 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4241 =item Value: (0 | 1)
4245 When set to a true value, indicates that any rows fetched from joined has_many
4246 relationships are to be aggregated into the corresponding "parent" object. For
4247 example, the resultset:
4249 my $rs = $schema->resultset('CD')->search({}, {
4250 '+columns' => [ qw/ tracks.title tracks.position / ],
4255 While executing the following query:
4257 SELECT me.*, tracks.title, tracks.position
4259 LEFT JOIN track tracks
4260 ON tracks.cdid = me.cdid
4262 Will return only as many objects as there are rows in the CD source, even
4263 though the result of the query may span many rows. Each of these CD objects
4264 will in turn have multiple "Track" objects hidden behind the has_many
4265 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4266 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4267 product"), with each CD object containing exactly one of all fetched Track data.
4269 When a collapse is requested on a non-ordered resultset, an order by some
4270 unique part of the main source (the left-most table) is inserted automatically.
4271 This is done so that the resultset is allowed to be "lazy" - calling
4272 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4273 object with all of its related data.
4275 If an L</order_by> is already declared, and orders the resultset in a way that
4276 makes collapsing as described above impossible (e.g. C<< ORDER BY
4277 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4278 switch to "eager" mode and slurp the entire resultset before constructing the
4279 first object returned by L</next>.
4281 Setting this attribute on a resultset that does not join any has_many
4282 relations is a no-op.
4284 For a more in-depth discussion, see L</PREFETCHING>.
4290 =item Value: ($rel_name | \@rel_names | \%rel_names)
4294 This attribute is a shorthand for specifying a L</join> spec, adding all
4295 columns from the joined related sources as L</+columns> and setting
4296 L</collapse> to a true value. For example, the following two queries are
4299 my $rs = $schema->resultset('Artist')->search({}, {
4300 prefetch => { cds => ['genre', 'tracks' ] },
4305 my $rs = $schema->resultset('Artist')->search({}, {
4306 join => { cds => ['genre', 'tracks' ] },
4310 { +{ "cds.$_" => "cds.$_" } }
4311 $schema->source('Artist')->related_source('cds')->columns
4314 { +{ "cds.genre.$_" => "genre.$_" } }
4315 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4318 { +{ "cds.tracks.$_" => "tracks.$_" } }
4319 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4324 Both producing the following SQL:
4326 SELECT me.artistid, me.name, me.rank, me.charfield,
4327 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4328 genre.genreid, genre.name,
4329 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4332 ON cds.artist = me.artistid
4333 LEFT JOIN genre genre
4334 ON genre.genreid = cds.genreid
4335 LEFT JOIN track tracks
4336 ON tracks.cd = cds.cdid
4337 ORDER BY me.artistid
4339 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4340 the arguments are properly merged and generally do the right thing. For
4341 example, you may want to do the following:
4343 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4344 { 'genre.genreid' => undef },
4346 join => { cds => 'genre' },
4351 Which generates the following SQL:
4353 SELECT me.artistid, me.name, me.rank, me.charfield,
4354 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4357 ON cds.artist = me.artistid
4358 LEFT JOIN genre genre
4359 ON genre.genreid = cds.genreid
4360 WHERE genre.genreid IS NULL
4361 ORDER BY me.artistid
4363 For a more in-depth discussion, see L</PREFETCHING>.
4369 =item Value: $source_alias
4373 Sets the source alias for the query. Normally, this defaults to C<me>, but
4374 nested search queries (sub-SELECTs) might need specific aliases set to
4375 reference inner queries. For example:
4378 ->related_resultset('CDs')
4379 ->related_resultset('Tracks')
4381 'track.id' => { -ident => 'none_search.id' },
4385 my $ids = $self->search({
4388 alias => 'none_search',
4389 group_by => 'none_search.id',
4390 })->get_column('id')->as_query;
4392 $self->search({ id => { -in => $ids } })
4394 This attribute is directly tied to L</current_source_alias>.
4404 Makes the resultset paged and specifies the page to retrieve. Effectively
4405 identical to creating a non-pages resultset and then calling ->page($page)
4408 If L</rows> attribute is not specified it defaults to 10 rows per page.
4410 When you have a paged resultset, L</count> will only return the number
4411 of rows in the page. To get the total, use the L</pager> and call
4412 C<total_entries> on it.
4422 Specifies the maximum number of rows for direct retrieval or the number of
4423 rows per page if the page attribute or method is used.
4429 =item Value: $offset
4433 Specifies the (zero-based) row number for the first row to be returned, or the
4434 of the first row of the first page if paging is used.
4436 =head2 software_limit
4440 =item Value: (0 | 1)
4444 When combined with L</rows> and/or L</offset> the generated SQL will not
4445 include any limit dialect stanzas. Instead the entire result will be selected
4446 as if no limits were specified, and DBIC will perform the limit locally, by
4447 artificially advancing and finishing the resulting L</cursor>.
4449 This is the recommended way of performing resultset limiting when no sane RDBMS
4450 implementation is available (e.g.
4451 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4452 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4458 =item Value: \@columns
4462 A arrayref of columns to group by. Can include columns of joined tables.
4464 group_by => [qw/ column1 column2 ... /]
4470 =item Value: $condition
4474 HAVING is a select statement attribute that is applied between GROUP BY and
4475 ORDER BY. It is applied to the after the grouping calculations have been
4478 having => { 'count_employee' => { '>=', 100 } }
4480 or with an in-place function in which case literal SQL is required:
4482 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4488 =item Value: (0 | 1)
4492 Set to 1 to automatically generate a L</group_by> clause based on the selection
4493 (including intelligent handling of L</order_by> contents). Note that the group
4494 criteria calculation takes place over the B<final> selection. This includes
4495 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4496 L</search> calls, and standalone columns selected via
4497 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4498 extra selections specified via L</prefetch> - such selections are explicitly
4499 excluded from group criteria calculations.
4501 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4502 setting is ignored and an appropriate warning is issued.
4508 Adds to the WHERE clause.
4510 # only return rows WHERE deleted IS NULL for all searches
4511 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4513 Can be overridden by passing C<< { where => undef } >> as an attribute
4516 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4522 Set to 1 to cache search results. This prevents extra SQL queries if you
4523 revisit rows in your ResultSet:
4525 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4527 while( my $artist = $resultset->next ) {
4531 $rs->first; # without cache, this would issue a query
4533 By default, searches are not cached.
4535 For more examples of using these attributes, see
4536 L<DBIx::Class::Manual::Cookbook>.
4542 =item Value: ( 'update' | 'shared' | \$scalar )
4546 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4547 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4552 DBIx::Class supports arbitrary related data prefetching from multiple related
4553 sources. Any combination of relationship types and column sets are supported.
4554 If L<collapsing|/collapse> is requested, there is an additional requirement of
4555 selecting enough data to make every individual object uniquely identifiable.
4557 Here are some more involved examples, based on the following relationship map:
4560 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4561 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4562 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4564 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4566 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4570 my $rs = $schema->resultset('Tag')->search(
4579 The initial search results in SQL like the following:
4581 SELECT tag.*, cd.*, artist.* FROM tag
4582 JOIN cd ON tag.cd = cd.cdid
4583 JOIN artist ON cd.artist = artist.artistid
4585 L<DBIx::Class> has no need to go back to the database when we access the
4586 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4589 Simple prefetches will be joined automatically, so there is no need
4590 for a C<join> attribute in the above search.
4592 The L</prefetch> attribute can be used with any of the relationship types
4593 and multiple prefetches can be specified together. Below is a more complex
4594 example that prefetches a CD's artist, its liner notes (if present),
4595 the cover image, the tracks on that CD, and the guests on those
4598 my $rs = $schema->resultset('CD')->search(
4602 { artist => 'record_label'}, # belongs_to => belongs_to
4603 'liner_note', # might_have
4604 'cover_image', # has_one
4605 { tracks => 'guests' }, # has_many => has_many
4610 This will produce SQL like the following:
4612 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4616 ON artist.artistid = me.artistid
4617 JOIN record_label record_label
4618 ON record_label.labelid = artist.labelid
4619 LEFT JOIN track tracks
4620 ON tracks.cdid = me.cdid
4621 LEFT JOIN guest guests
4622 ON guests.trackid = track.trackid
4623 LEFT JOIN liner_notes liner_note
4624 ON liner_note.cdid = me.cdid
4625 JOIN cd_artwork cover_image
4626 ON cover_image.cdid = me.cdid
4629 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4630 C<tracks>, and C<guests> of the CD will all be available through the
4631 relationship accessors without the need for additional queries to the
4636 Prefetch does a lot of deep magic. As such, it may not behave exactly
4637 as you might expect.
4643 Prefetch uses the L</cache> to populate the prefetched relationships. This
4644 may or may not be what you want.
4648 If you specify a condition on a prefetched relationship, ONLY those
4649 rows that match the prefetched condition will be fetched into that relationship.
4650 This means that adding prefetch to a search() B<may alter> what is returned by
4651 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4653 my $artist_rs = $schema->resultset('Artist')->search({
4659 my $count = $artist_rs->first->cds->count;
4661 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4663 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4665 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4667 That cmp_ok() may or may not pass depending on the datasets involved. In other
4668 words the C<WHERE> condition would apply to the entire dataset, just like
4669 it would in regular SQL. If you want to add a condition only to the "right side"
4670 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4671 condition|DBIx::Class::Relationship::Base/condition>
4675 =head1 DBIC BIND VALUES
4677 Because DBIC may need more information to bind values than just the column name
4678 and value itself, it uses a special format for both passing and receiving bind
4679 values. Each bind value should be composed of an arrayref of
4680 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4686 If present (in any form), this is what is being passed directly to bind_param.
4687 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4688 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4690 If this is specified, all other bind options described below are ignored.
4694 If present, this is used to infer the actual bind attribute by passing to
4695 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4696 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4698 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4699 currently drivers are expected to "Do the Right Thing" when given a common
4700 datatype name. (Not ideal, but that's what we got at this point.)
4704 Currently used to correctly allocate buffers for bind_param_inout().
4705 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4706 or to a sensible value based on the "data_type".
4710 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4711 explicitly specified they are never overridden). Also used by some weird DBDs,
4712 where the column name should be available at bind_param time (e.g. Oracle).
4716 For backwards compatibility and convenience, the following shortcuts are
4719 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4720 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4721 [ undef, $val ] === [ {}, $val ]
4722 $val === [ {}, $val ]
4724 =head1 AUTHOR AND CONTRIBUTORS
4726 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4730 You may distribute this code under the same terms as Perl itself.