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 if (ref($related) eq 'REF' and ref($$related) eq 'HASH') {
2342 $related = $self->result_source
2343 ->_extract_fixed_values_for($$related, $rel);
2346 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2347 my @populate = map { {%$_, %$related} } @rows_to_add;
2349 $child->populate( \@populate );
2355 # populate() arguments went over several incarnations
2356 # What we ultimately support is AoH
2357 sub _normalize_populate_args {
2358 my ($self, $arg) = @_;
2360 if (ref $arg eq 'ARRAY') {
2364 elsif (ref $arg->[0] eq 'HASH') {
2367 elsif (ref $arg->[0] eq 'ARRAY') {
2369 my @colnames = @{$arg->[0]};
2370 foreach my $values (@{$arg}[1 .. $#$arg]) {
2371 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2377 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2384 =item Arguments: none
2386 =item Return Value: L<$pager|Data::Page>
2390 Returns a L<Data::Page> object for the current resultset. Only makes
2391 sense for queries with a C<page> attribute.
2393 To get the full count of entries for a paged resultset, call
2394 C<total_entries> on the L<Data::Page> object.
2401 return $self->{pager} if $self->{pager};
2403 my $attrs = $self->{attrs};
2404 if (!defined $attrs->{page}) {
2405 $self->throw_exception("Can't create pager for non-paged rs");
2407 elsif ($attrs->{page} <= 0) {
2408 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2410 $attrs->{rows} ||= 10;
2412 # throw away the paging flags and re-run the count (possibly
2413 # with a subselect) to get the real total count
2414 my $count_attrs = { %$attrs };
2415 delete @{$count_attrs}{qw/rows offset page pager/};
2417 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2419 require DBIx::Class::ResultSet::Pager;
2420 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2421 sub { $total_rs->count }, #lazy-get the total
2423 $self->{attrs}{page},
2431 =item Arguments: $page_number
2433 =item Return Value: L<$resultset|/search>
2437 Returns a resultset for the $page_number page of the resultset on which page
2438 is called, where each page contains a number of rows equal to the 'rows'
2439 attribute set on the resultset (10 by default).
2444 my ($self, $page) = @_;
2445 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2452 =item Arguments: \%col_data
2454 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2458 Creates a new result object in the resultset's result class and returns
2459 it. The row is not inserted into the database at this point, call
2460 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2461 will tell you whether the result object has been inserted or not.
2463 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2468 my ($self, $values) = @_;
2470 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2473 $self->throw_exception( "new_result expects a hashref" )
2474 unless (ref $values eq 'HASH');
2476 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2478 my $new = $self->result_class->new({
2480 ( @$cols_from_relations
2481 ? (-cols_from_relations => $cols_from_relations)
2484 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2488 reftype($new) eq 'HASH'
2494 carp_unique (sprintf (
2495 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2496 $self->result_class,
2503 # _merge_with_rscond
2505 # Takes a simple hash of K/V data and returns its copy merged with the
2506 # condition already present on the resultset. Additionally returns an
2507 # arrayref of value/condition names, which were inferred from related
2508 # objects (this is needed for in-memory related objects)
2509 sub _merge_with_rscond {
2510 my ($self, $data) = @_;
2512 my (%new_data, @cols_from_relations);
2514 my $alias = $self->{attrs}{alias};
2516 if (! defined $self->{cond}) {
2517 # just massage $data below
2519 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2520 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2521 @cols_from_relations = keys %new_data;
2523 elsif (ref $self->{cond} eq 'HASH') {
2524 # precedence must be given to passed values over values inherited from
2525 # the cond, so the order here is important.
2526 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2527 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2529 while ( my($col, $value) = each %implied ) {
2530 my $vref = ref $value;
2536 (keys %$value)[0] eq '='
2538 $new_data{$col} = $value->{'='};
2540 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2541 $new_data{$col} = $value;
2545 elsif (ref $self->{cond} eq 'REF' and ref ${$self->{cond}} eq 'HASH') {
2546 %new_data = %{$self->result_source
2547 ->_extract_fixed_values_for(${$self->{cond}}, $alias)};
2550 $self->throw_exception(
2551 "Can't abstract implicit construct, resultset condition not a hash"
2557 %{ $self->_remove_alias($data, $alias) },
2560 return (\%new_data, \@cols_from_relations);
2563 # _has_resolved_attr
2565 # determines if the resultset defines at least one
2566 # of the attributes supplied
2568 # used to determine if a subquery is necessary
2570 # supports some virtual attributes:
2572 # This will scan for any joins being present on the resultset.
2573 # It is not a mere key-search but a deep inspection of {from}
2576 sub _has_resolved_attr {
2577 my ($self, @attr_names) = @_;
2579 my $attrs = $self->_resolved_attrs;
2583 for my $n (@attr_names) {
2584 if (grep { $n eq $_ } (qw/-join/) ) {
2585 $extra_checks{$n}++;
2589 my $attr = $attrs->{$n};
2591 next if not defined $attr;
2593 if (ref $attr eq 'HASH') {
2594 return 1 if keys %$attr;
2596 elsif (ref $attr eq 'ARRAY') {
2604 # a resolved join is expressed as a multi-level from
2606 $extra_checks{-join}
2608 ref $attrs->{from} eq 'ARRAY'
2610 @{$attrs->{from}} > 1
2618 # Recursively collapse the condition.
2620 sub _collapse_cond {
2621 my ($self, $cond, $collapsed) = @_;
2625 if (ref $cond eq 'ARRAY') {
2626 foreach my $subcond (@$cond) {
2627 next unless ref $subcond; # -or
2628 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2631 elsif (ref $cond eq 'HASH') {
2632 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2633 foreach my $subcond (@{$cond->{-and}}) {
2634 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2638 foreach my $col (keys %$cond) {
2639 my $value = $cond->{$col};
2640 $collapsed->{$col} = $value;
2650 # Remove the specified alias from the specified query hash. A copy is made so
2651 # the original query is not modified.
2654 my ($self, $query, $alias) = @_;
2656 my %orig = %{ $query || {} };
2659 foreach my $key (keys %orig) {
2661 $unaliased{$key} = $orig{$key};
2664 $unaliased{$1} = $orig{$key}
2665 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2675 =item Arguments: none
2677 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2681 Returns the SQL query and bind vars associated with the invocant.
2683 This is generally used as the RHS for a subquery.
2690 my $attrs = { %{ $self->_resolved_attrs } };
2692 my $aq = $self->result_source->storage->_select_args_to_query (
2693 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2696 $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
2703 my $attrs = { %{ $self->_resolved_attrs } };
2704 my $storage = $self->result_source->storage;
2705 my (undef, $ident, @args) = $storage->_select_args(
2706 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2708 $ident = $ident->from if blessed($ident);
2709 $storage->sql_maker->converter->_select_to_dq(
2718 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2720 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2724 my $artist = $schema->resultset('Artist')->find_or_new(
2725 { artist => 'fred' }, { key => 'artists' });
2727 $cd->cd_to_producer->find_or_new({ producer => $producer },
2728 { key => 'primary' });
2730 Find an existing record from this resultset using L</find>. if none exists,
2731 instantiate a new result object and return it. The object will not be saved
2732 into your storage until you call L<DBIx::Class::Row/insert> on it.
2734 You most likely want this method when looking for existing rows using a unique
2735 constraint that is not the primary key, or looking for related rows.
2737 If you want objects to be saved immediately, use L</find_or_create> instead.
2739 B<Note>: Make sure to read the documentation of L</find> and understand the
2740 significance of the C<key> attribute, as its lack may skew your search, and
2741 subsequently result in spurious new objects.
2743 B<Note>: Take care when using C<find_or_new> with a table having
2744 columns with default values that you intend to be automatically
2745 supplied by the database (e.g. an auto_increment primary key column).
2746 In normal usage, the value of such columns should NOT be included at
2747 all in the call to C<find_or_new>, even when set to C<undef>.
2753 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2754 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2755 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2758 return $self->new_result($hash);
2765 =item Arguments: \%col_data
2767 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2771 Attempt to create a single new row or a row with multiple related rows
2772 in the table represented by the resultset (and related tables). This
2773 will not check for duplicate rows before inserting, use
2774 L</find_or_create> to do that.
2776 To create one row for this resultset, pass a hashref of key/value
2777 pairs representing the columns of the table and the values you wish to
2778 store. If the appropriate relationships are set up, foreign key fields
2779 can also be passed an object representing the foreign row, and the
2780 value will be set to its primary key.
2782 To create related objects, pass a hashref of related-object column values
2783 B<keyed on the relationship name>. If the relationship is of type C<multi>
2784 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2785 The process will correctly identify columns holding foreign keys, and will
2786 transparently populate them from the keys of the corresponding relation.
2787 This can be applied recursively, and will work correctly for a structure
2788 with an arbitrary depth and width, as long as the relationships actually
2789 exists and the correct column data has been supplied.
2791 Instead of hashrefs of plain related data (key/value pairs), you may
2792 also pass new or inserted objects. New objects (not inserted yet, see
2793 L</new_result>), will be inserted into their appropriate tables.
2795 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2797 Example of creating a new row.
2799 $person_rs->create({
2800 name=>"Some Person",
2801 email=>"somebody@someplace.com"
2804 Example of creating a new row and also creating rows in a related C<has_many>
2805 or C<has_one> resultset. Note Arrayref.
2808 { artistid => 4, name => 'Manufactured Crap', cds => [
2809 { title => 'My First CD', year => 2006 },
2810 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2815 Example of creating a new row and also creating a row in a related
2816 C<belongs_to> resultset. Note Hashref.
2819 title=>"Music for Silly Walks",
2822 name=>"Silly Musician",
2830 When subclassing ResultSet never attempt to override this method. Since
2831 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2832 lot of the internals simply never call it, so your override will be
2833 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2834 or L<DBIx::Class::Row/insert> depending on how early in the
2835 L</create> process you need to intervene. See also warning pertaining to
2843 my ($self, $col_data) = @_;
2844 $self->throw_exception( "create needs a hashref" )
2845 unless ref $col_data eq 'HASH';
2846 return $self->new_result($col_data)->insert;
2849 =head2 find_or_create
2853 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2855 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2859 $cd->cd_to_producer->find_or_create({ producer => $producer },
2860 { key => 'primary' });
2862 Tries to find a record based on its primary key or unique constraints; if none
2863 is found, creates one and returns that instead.
2865 my $cd = $schema->resultset('CD')->find_or_create({
2867 artist => 'Massive Attack',
2868 title => 'Mezzanine',
2872 Also takes an optional C<key> attribute, to search by a specific key or unique
2873 constraint. For example:
2875 my $cd = $schema->resultset('CD')->find_or_create(
2877 artist => 'Massive Attack',
2878 title => 'Mezzanine',
2880 { key => 'cd_artist_title' }
2883 B<Note>: Make sure to read the documentation of L</find> and understand the
2884 significance of the C<key> attribute, as its lack may skew your search, and
2885 subsequently result in spurious row creation.
2887 B<Note>: Because find_or_create() reads from the database and then
2888 possibly inserts based on the result, this method is subject to a race
2889 condition. Another process could create a record in the table after
2890 the find has completed and before the create has started. To avoid
2891 this problem, use find_or_create() inside a transaction.
2893 B<Note>: Take care when using C<find_or_create> with a table having
2894 columns with default values that you intend to be automatically
2895 supplied by the database (e.g. an auto_increment primary key column).
2896 In normal usage, the value of such columns should NOT be included at
2897 all in the call to C<find_or_create>, even when set to C<undef>.
2899 See also L</find> and L</update_or_create>. For information on how to declare
2900 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2902 If you need to know if an existing row was found or a new one created use
2903 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2904 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2907 my $cd = $schema->resultset('CD')->find_or_new({
2909 artist => 'Massive Attack',
2910 title => 'Mezzanine',
2914 if( !$cd->in_storage ) {
2921 sub find_or_create {
2923 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2924 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2925 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2928 return $self->create($hash);
2931 =head2 update_or_create
2935 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2937 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2941 $resultset->update_or_create({ col => $val, ... });
2943 Like L</find_or_create>, but if a row is found it is immediately updated via
2944 C<< $found_row->update (\%col_data) >>.
2947 Takes an optional C<key> attribute to search on a specific unique constraint.
2950 # In your application
2951 my $cd = $schema->resultset('CD')->update_or_create(
2953 artist => 'Massive Attack',
2954 title => 'Mezzanine',
2957 { key => 'cd_artist_title' }
2960 $cd->cd_to_producer->update_or_create({
2961 producer => $producer,
2967 B<Note>: Make sure to read the documentation of L</find> and understand the
2968 significance of the C<key> attribute, as its lack may skew your search, and
2969 subsequently result in spurious row creation.
2971 B<Note>: Take care when using C<update_or_create> with a table having
2972 columns with default values that you intend to be automatically
2973 supplied by the database (e.g. an auto_increment primary key column).
2974 In normal usage, the value of such columns should NOT be included at
2975 all in the call to C<update_or_create>, even when set to C<undef>.
2977 See also L</find> and L</find_or_create>. For information on how to declare
2978 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2980 If you need to know if an existing row was updated or a new one created use
2981 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2982 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2987 sub update_or_create {
2989 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2990 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2992 my $row = $self->find($cond, $attrs);
2994 $row->update($cond);
2998 return $self->create($cond);
3001 =head2 update_or_new
3005 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3007 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3011 $resultset->update_or_new({ col => $val, ... });
3013 Like L</find_or_new> but if a row is found it is immediately updated via
3014 C<< $found_row->update (\%col_data) >>.
3018 # In your application
3019 my $cd = $schema->resultset('CD')->update_or_new(
3021 artist => 'Massive Attack',
3022 title => 'Mezzanine',
3025 { key => 'cd_artist_title' }
3028 if ($cd->in_storage) {
3029 # the cd was updated
3032 # the cd is not yet in the database, let's insert it
3036 B<Note>: Make sure to read the documentation of L</find> and understand the
3037 significance of the C<key> attribute, as its lack may skew your search, and
3038 subsequently result in spurious new objects.
3040 B<Note>: Take care when using C<update_or_new> with a table having
3041 columns with default values that you intend to be automatically
3042 supplied by the database (e.g. an auto_increment primary key column).
3043 In normal usage, the value of such columns should NOT be included at
3044 all in the call to C<update_or_new>, even when set to C<undef>.
3046 See also L</find>, L</find_or_create> and L</find_or_new>.
3052 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3053 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3055 my $row = $self->find( $cond, $attrs );
3056 if ( defined $row ) {
3057 $row->update($cond);
3061 return $self->new_result($cond);
3068 =item Arguments: none
3070 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3074 Gets the contents of the cache for the resultset, if the cache is set.
3076 The cache is populated either by using the L</prefetch> attribute to
3077 L</search> or by calling L</set_cache>.
3089 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3091 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3095 Sets the contents of the cache for the resultset. Expects an arrayref
3096 of objects of the same class as those produced by the resultset. Note that
3097 if the cache is set, the resultset will return the cached objects rather
3098 than re-querying the database even if the cache attr is not set.
3100 The contents of the cache can also be populated by using the
3101 L</prefetch> attribute to L</search>.
3106 my ( $self, $data ) = @_;
3107 $self->throw_exception("set_cache requires an arrayref")
3108 if defined($data) && (ref $data ne 'ARRAY');
3109 $self->{all_cache} = $data;
3116 =item Arguments: none
3118 =item Return Value: undef
3122 Clears the cache for the resultset.
3127 shift->set_cache(undef);
3134 =item Arguments: none
3136 =item Return Value: true, if the resultset has been paginated
3144 return !!$self->{attrs}{page};
3151 =item Arguments: none
3153 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3161 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3164 =head2 related_resultset
3168 =item Arguments: $rel_name
3170 =item Return Value: L<$resultset|/search>
3174 Returns a related resultset for the supplied relationship name.
3176 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3180 sub related_resultset {
3181 my ($self, $rel) = @_;
3183 return $self->{related_resultsets}{$rel}
3184 if defined $self->{related_resultsets}{$rel};
3186 return $self->{related_resultsets}{$rel} = do {
3187 my $rsrc = $self->result_source;
3188 my $rel_info = $rsrc->relationship_info($rel);
3190 $self->throw_exception(
3191 "search_related: result source '" . $rsrc->source_name .
3192 "' has no such relationship $rel")
3195 my $attrs = $self->_chain_relationship($rel);
3197 my $join_count = $attrs->{seen_join}{$rel};
3199 my $alias = $self->result_source->storage
3200 ->relname_to_table_alias($rel, $join_count);
3202 # since this is search_related, and we already slid the select window inwards
3203 # (the select/as attrs were deleted in the beginning), we need to flip all
3204 # left joins to inner, so we get the expected results
3205 # read the comment on top of the actual function to see what this does
3206 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3209 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3210 delete @{$attrs}{qw(result_class alias)};
3212 my $rel_source = $rsrc->related_source($rel);
3216 # The reason we do this now instead of passing the alias to the
3217 # search_rs below is that if you wrap/overload resultset on the
3218 # source you need to know what alias it's -going- to have for things
3219 # to work sanely (e.g. RestrictWithObject wants to be able to add
3220 # extra query restrictions, and these may need to be $alias.)
3222 my $rel_attrs = $rel_source->resultset_attributes;
3223 local $rel_attrs->{alias} = $alias;
3225 $rel_source->resultset
3229 where => $attrs->{where},
3233 if (my $cache = $self->get_cache) {
3234 my @related_cache = map
3235 { @{$_->related_resultset($rel)->get_cache||[]} }
3239 $new->set_cache(\@related_cache) if @related_cache;
3246 =head2 current_source_alias
3250 =item Arguments: none
3252 =item Return Value: $source_alias
3256 Returns the current table alias for the result source this resultset is built
3257 on, that will be used in the SQL query. Usually it is C<me>.
3259 Currently the source alias that refers to the result set returned by a
3260 L</search>/L</find> family method depends on how you got to the resultset: it's
3261 C<me> by default, but eg. L</search_related> aliases it to the related result
3262 source name (and keeps C<me> referring to the original result set). The long
3263 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3264 (and make this method unnecessary).
3266 Thus it's currently necessary to use this method in predefined queries (see
3267 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3268 source alias of the current result set:
3270 # in a result set class
3272 my ($self, $user) = @_;
3274 my $me = $self->current_source_alias;
3276 return $self->search({
3277 "$me.modified" => $user->id,
3283 sub current_source_alias {
3284 return (shift->{attrs} || {})->{alias} || 'me';
3287 =head2 as_subselect_rs
3291 =item Arguments: none
3293 =item Return Value: L<$resultset|/search>
3297 Act as a barrier to SQL symbols. The resultset provided will be made into a
3298 "virtual view" by including it as a subquery within the from clause. From this
3299 point on, any joined tables are inaccessible to ->search on the resultset (as if
3300 it were simply where-filtered without joins). For example:
3302 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3304 # 'x' now pollutes the query namespace
3306 # So the following works as expected
3307 my $ok_rs = $rs->search({'x.other' => 1});
3309 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3310 # def) we look for one row with contradictory terms and join in another table
3311 # (aliased 'x_2') which we never use
3312 my $broken_rs = $rs->search({'x.name' => 'def'});
3314 my $rs2 = $rs->as_subselect_rs;
3316 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3317 my $not_joined_rs = $rs2->search({'x.other' => 1});
3319 # works as expected: finds a 'table' row related to two x rows (abc and def)
3320 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3322 Another example of when one might use this would be to select a subset of
3323 columns in a group by clause:
3325 my $rs = $schema->resultset('Bar')->search(undef, {
3326 group_by => [qw{ id foo_id baz_id }],
3327 })->as_subselect_rs->search(undef, {
3328 columns => [qw{ id foo_id }]
3331 In the above example normally columns would have to be equal to the group by,
3332 but because we isolated the group by into a subselect the above works.
3336 sub as_subselect_rs {
3339 my $attrs = $self->_resolved_attrs;
3341 my $fresh_rs = (ref $self)->new (
3342 $self->result_source
3345 # these pieces will be locked in the subquery
3346 delete $fresh_rs->{cond};
3347 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3349 return $fresh_rs->search( {}, {
3351 $attrs->{alias} => $self->as_query,
3352 -alias => $attrs->{alias},
3353 -rsrc => $self->result_source,
3355 alias => $attrs->{alias},
3359 # This code is called by search_related, and makes sure there
3360 # is clear separation between the joins before, during, and
3361 # after the relationship. This information is needed later
3362 # in order to properly resolve prefetch aliases (any alias
3363 # with a relation_chain_depth less than the depth of the
3364 # current prefetch is not considered)
3366 # The increments happen twice per join. An even number means a
3367 # relationship specified via a search_related, whereas an odd
3368 # number indicates a join/prefetch added via attributes
3370 # Also this code will wrap the current resultset (the one we
3371 # chain to) in a subselect IFF it contains limiting attributes
3372 sub _chain_relationship {
3373 my ($self, $rel) = @_;
3374 my $source = $self->result_source;
3375 my $attrs = { %{$self->{attrs}||{}} };
3377 # we need to take the prefetch the attrs into account before we
3378 # ->_resolve_join as otherwise they get lost - captainL
3379 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3381 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3383 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3386 my @force_subq_attrs = qw/offset rows group_by having/;
3389 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3391 $self->_has_resolved_attr (@force_subq_attrs)
3393 # Nuke the prefetch (if any) before the new $rs attrs
3394 # are resolved (prefetch is useless - we are wrapping
3395 # a subquery anyway).
3396 my $rs_copy = $self->search;
3397 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3398 $rs_copy->{attrs}{join},
3399 delete $rs_copy->{attrs}{prefetch},
3404 -alias => $attrs->{alias},
3405 $attrs->{alias} => $rs_copy->as_query,
3407 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3408 $seen->{-relation_chain_depth} = 0;
3410 elsif ($attrs->{from}) { #shallow copy suffices
3411 $from = [ @{$attrs->{from}} ];
3416 -alias => $attrs->{alias},
3417 $attrs->{alias} => $source->from,
3421 my $jpath = ($seen->{-relation_chain_depth})
3422 ? $from->[-1][0]{-join_path}
3425 my @requested_joins = $source->_resolve_join(
3432 push @$from, @requested_joins;
3434 $seen->{-relation_chain_depth}++;
3436 # if $self already had a join/prefetch specified on it, the requested
3437 # $rel might very well be already included. What we do in this case
3438 # is effectively a no-op (except that we bump up the chain_depth on
3439 # the join in question so we could tell it *is* the search_related)
3442 # we consider the last one thus reverse
3443 for my $j (reverse @requested_joins) {
3444 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3445 if ($rel eq $last_j) {
3446 $j->[0]{-relation_chain_depth}++;
3452 unless ($already_joined) {
3453 push @$from, $source->_resolve_join(
3461 $seen->{-relation_chain_depth}++;
3463 return {%$attrs, from => $from, seen_join => $seen};
3466 sub _resolved_attrs {
3468 return $self->{_attrs} if $self->{_attrs};
3470 my $attrs = { %{ $self->{attrs} || {} } };
3471 my $source = $self->result_source;
3472 my $alias = $attrs->{alias};
3474 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3475 if $attrs->{collapse} and $attrs->{distinct};
3477 # default selection list
3478 $attrs->{columns} = [ $source->columns ]
3479 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3481 # merge selectors together
3482 for (qw/columns select as/) {
3483 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3484 if $attrs->{$_} or $attrs->{"+$_"};
3487 # disassemble columns
3489 if (my $cols = delete $attrs->{columns}) {
3490 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3491 if (ref $c eq 'HASH') {
3492 for my $as (sort keys %$c) {
3493 push @sel, $c->{$as};
3504 # when trying to weed off duplicates later do not go past this point -
3505 # everything added from here on is unbalanced "anyone's guess" stuff
3506 my $dedup_stop_idx = $#as;
3508 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3510 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3511 if $attrs->{select};
3513 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3514 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3516 # disqualify all $alias.col as-bits (inflate-map mandated)
3517 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3519 # de-duplicate the result (remove *identical* select/as pairs)
3520 # and also die on duplicate {as} pointing to different {select}s
3521 # not using a c-style for as the condition is prone to shrinkage
3524 while ($i <= $dedup_stop_idx) {
3525 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3530 elsif ($seen->{$as[$i]}++) {
3531 $self->throw_exception(
3532 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3540 $attrs->{select} = \@sel;
3541 $attrs->{as} = \@as;
3543 $attrs->{from} ||= [{
3545 -alias => $self->{attrs}{alias},
3546 $self->{attrs}{alias} => $source->from,
3549 if ( $attrs->{join} || $attrs->{prefetch} ) {
3551 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3552 if ref $attrs->{from} ne 'ARRAY';
3554 my $join = (delete $attrs->{join}) || {};
3556 if ( defined $attrs->{prefetch} ) {
3557 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3560 $attrs->{from} = # have to copy here to avoid corrupting the original
3562 @{ $attrs->{from} },
3563 $source->_resolve_join(
3566 { %{ $attrs->{seen_join} || {} } },
3567 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3568 ? $attrs->{from}[-1][0]{-join_path}
3575 if ( defined $attrs->{order_by} ) {
3576 $attrs->{order_by} = (
3577 ref( $attrs->{order_by} ) eq 'ARRAY'
3578 ? [ @{ $attrs->{order_by} } ]
3579 : [ $attrs->{order_by} || () ]
3583 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3584 $attrs->{group_by} = [ $attrs->{group_by} ];
3588 # generate selections based on the prefetch helper
3589 my ($prefetch, @prefetch_select, @prefetch_as);
3590 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3591 if defined $attrs->{prefetch};
3595 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3596 if $attrs->{_dark_selector};
3598 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3599 if defined $attrs->{collapse} and ! $attrs->{collapse};
3601 $attrs->{collapse} = 1;
3603 # this is a separate structure (we don't look in {from} directly)
3604 # as the resolver needs to shift things off the lists to work
3605 # properly (identical-prefetches on different branches)
3607 if (ref $attrs->{from} eq 'ARRAY') {
3609 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3611 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3612 next unless $j->[0]{-alias};
3613 next unless $j->[0]{-join_path};
3614 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3616 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3619 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3620 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3624 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3626 # save these for after distinct resolution
3627 @prefetch_select = map { $_->[0] } @prefetch;
3628 @prefetch_as = map { $_->[1] } @prefetch;
3631 # run through the resulting joinstructure (starting from our current slot)
3632 # and unset collapse if proven unnecessary
3634 # also while we are at it find out if the current root source has
3635 # been premultiplied by previous related_source chaining
3637 # this allows to predict whether a root object with all other relation
3638 # data set to NULL is in fact unique
3639 if ($attrs->{collapse}) {
3641 if (ref $attrs->{from} eq 'ARRAY') {
3643 if (@{$attrs->{from}} == 1) {
3644 # no joins - no collapse
3645 $attrs->{collapse} = 0;
3648 # find where our table-spec starts
3649 my @fromlist = @{$attrs->{from}};
3651 my $t = shift @fromlist;
3654 # me vs join from-spec distinction - a ref means non-root
3655 if (ref $t eq 'ARRAY') {
3657 $is_multi ||= ! $t->{-is_single};
3659 last if ($t->{-alias} && $t->{-alias} eq $alias);
3660 $attrs->{_main_source_premultiplied} ||= $is_multi;
3663 # no non-singles remaining, nor any premultiplication - nothing to collapse
3665 ! $attrs->{_main_source_premultiplied}
3667 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3669 $attrs->{collapse} = 0;
3675 # if we can not analyze the from - err on the side of safety
3676 $attrs->{_main_source_premultiplied} = 1;
3680 # generate the distinct induced group_by before injecting the prefetched select/as parts
3681 if (delete $attrs->{distinct}) {
3682 if ($attrs->{group_by}) {
3683 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3686 $attrs->{_grouped_by_distinct} = 1;
3687 # distinct affects only the main selection part, not what prefetch may add below
3688 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3690 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3691 # The thinking is: if we are collapsing the subquerying prefetch engine will
3692 # rip stuff apart for us anyway, and we do not want to have a potentially
3693 # function-converted external order_by
3694 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3695 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3699 # inject prefetch-bound selection (if any)
3700 push @{$attrs->{select}}, @prefetch_select;
3701 push @{$attrs->{as}}, @prefetch_as;
3703 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3704 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3705 $attrs->{_related_results_construction} = 1;
3708 # if both page and offset are specified, produce a combined offset
3709 # even though it doesn't make much sense, this is what pre 081xx has
3711 if (my $page = delete $attrs->{page}) {
3713 ($attrs->{rows} * ($page - 1))
3715 ($attrs->{offset} || 0)
3719 return $self->{_attrs} = $attrs;
3723 my ($self, $attr) = @_;
3725 if (ref $attr eq 'HASH') {
3726 return $self->_rollout_hash($attr);
3727 } elsif (ref $attr eq 'ARRAY') {
3728 return $self->_rollout_array($attr);
3734 sub _rollout_array {
3735 my ($self, $attr) = @_;
3738 foreach my $element (@{$attr}) {
3739 if (ref $element eq 'HASH') {
3740 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3741 } elsif (ref $element eq 'ARRAY') {
3742 # XXX - should probably recurse here
3743 push( @rolled_array, @{$self->_rollout_array($element)} );
3745 push( @rolled_array, $element );
3748 return \@rolled_array;
3752 my ($self, $attr) = @_;
3755 foreach my $key (keys %{$attr}) {
3756 push( @rolled_array, { $key => $attr->{$key} } );
3758 return \@rolled_array;
3761 sub _calculate_score {
3762 my ($self, $a, $b) = @_;
3764 if (defined $a xor defined $b) {
3767 elsif (not defined $a) {
3771 if (ref $b eq 'HASH') {
3772 my ($b_key) = keys %{$b};
3773 if (ref $a eq 'HASH') {
3774 my ($a_key) = keys %{$a};
3775 if ($a_key eq $b_key) {
3776 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3781 return ($a eq $b_key) ? 1 : 0;
3784 if (ref $a eq 'HASH') {
3785 my ($a_key) = keys %{$a};
3786 return ($b eq $a_key) ? 1 : 0;
3788 return ($b eq $a) ? 1 : 0;
3793 sub _merge_joinpref_attr {
3794 my ($self, $orig, $import) = @_;
3796 return $import unless defined($orig);
3797 return $orig unless defined($import);
3799 $orig = $self->_rollout_attr($orig);
3800 $import = $self->_rollout_attr($import);
3803 foreach my $import_element ( @{$import} ) {
3804 # find best candidate from $orig to merge $b_element into
3805 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3806 foreach my $orig_element ( @{$orig} ) {
3807 my $score = $self->_calculate_score( $orig_element, $import_element );
3808 if ($score > $best_candidate->{score}) {
3809 $best_candidate->{position} = $position;
3810 $best_candidate->{score} = $score;
3814 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3815 $import_key = '' if not defined $import_key;
3817 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3818 push( @{$orig}, $import_element );
3820 my $orig_best = $orig->[$best_candidate->{position}];
3821 # merge orig_best and b_element together and replace original with merged
3822 if (ref $orig_best ne 'HASH') {
3823 $orig->[$best_candidate->{position}] = $import_element;
3824 } elsif (ref $import_element eq 'HASH') {
3825 my ($key) = keys %{$orig_best};
3826 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3829 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3832 return @$orig ? $orig : ();
3840 require Hash::Merge;
3841 my $hm = Hash::Merge->new;
3843 $hm->specify_behavior({
3846 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3848 if ($defl xor $defr) {
3849 return [ $defl ? $_[0] : $_[1] ];
3854 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3858 return [$_[0], $_[1]];
3862 return $_[1] if !defined $_[0];
3863 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3864 return [$_[0], @{$_[1]}]
3867 return [] if !defined $_[0] and !keys %{$_[1]};
3868 return [ $_[1] ] if !defined $_[0];
3869 return [ $_[0] ] if !keys %{$_[1]};
3870 return [$_[0], $_[1]]
3875 return $_[0] if !defined $_[1];
3876 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3877 return [@{$_[0]}, $_[1]]
3880 my @ret = @{$_[0]} or return $_[1];
3881 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3882 my %idx = map { $_ => 1 } @ret;
3883 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3887 return [ $_[1] ] if ! @{$_[0]};
3888 return $_[0] if !keys %{$_[1]};
3889 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3890 return [ @{$_[0]}, $_[1] ];
3895 return [] if !keys %{$_[0]} and !defined $_[1];
3896 return [ $_[0] ] if !defined $_[1];
3897 return [ $_[1] ] if !keys %{$_[0]};
3898 return [$_[0], $_[1]]
3901 return [] if !keys %{$_[0]} and !@{$_[1]};
3902 return [ $_[0] ] if !@{$_[1]};
3903 return $_[1] if !keys %{$_[0]};
3904 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3905 return [ $_[0], @{$_[1]} ];
3908 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3909 return [ $_[0] ] if !keys %{$_[1]};
3910 return [ $_[1] ] if !keys %{$_[0]};
3911 return [ $_[0] ] if $_[0] eq $_[1];
3912 return [ $_[0], $_[1] ];
3915 } => 'DBIC_RS_ATTR_MERGER');
3919 return $hm->merge ($_[1], $_[2]);
3923 sub STORABLE_freeze {
3924 my ($self, $cloning) = @_;
3925 my $to_serialize = { %$self };
3927 # A cursor in progress can't be serialized (and would make little sense anyway)
3928 # the parser can be regenerated (and can't be serialized)
3929 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3931 # nor is it sensical to store a not-yet-fired-count pager
3932 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3933 delete $to_serialize->{pager};
3936 Storable::nfreeze($to_serialize);
3939 # need this hook for symmetry
3941 my ($self, $cloning, $serialized) = @_;
3943 %$self = %{ Storable::thaw($serialized) };
3949 =head2 throw_exception
3951 See L<DBIx::Class::Schema/throw_exception> for details.
3955 sub throw_exception {
3958 if (ref $self and my $rsrc = $self->result_source) {
3959 $rsrc->throw_exception(@_)
3962 DBIx::Class::Exception->throw(@_);
3970 # XXX: FIXME: Attributes docs need clearing up
3974 Attributes are used to refine a ResultSet in various ways when
3975 searching for data. They can be passed to any method which takes an
3976 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3979 Default attributes can be set on the result class using
3980 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3981 the CAVEATS on that feature before using it!)
3983 These are in no particular order:
3989 =item Value: ( $order_by | \@order_by | \%order_by )
3993 Which column(s) to order the results by.
3995 [The full list of suitable values is documented in
3996 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3999 If a single column name, or an arrayref of names is supplied, the
4000 argument is passed through directly to SQL. The hashref syntax allows
4001 for connection-agnostic specification of ordering direction:
4003 For descending order:
4005 order_by => { -desc => [qw/col1 col2 col3/] }
4007 For explicit ascending order:
4009 order_by => { -asc => 'col' }
4011 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4012 supported, although you are strongly encouraged to use the hashref
4013 syntax as outlined above.
4019 =item Value: \@columns | \%columns | $column
4023 Shortcut to request a particular set of columns to be retrieved. Each
4024 column spec may be a string (a table column name), or a hash (in which
4025 case the key is the C<as> value, and the value is used as the C<select>
4026 expression). Adds C<me.> onto the start of any column without a C<.> in
4027 it and sets C<select> from that, then auto-populates C<as> from
4028 C<select> as normal. (You may also use the C<cols> attribute, as in
4029 earlier versions of DBIC, but this is deprecated.)
4031 Essentially C<columns> does the same as L</select> and L</as>.
4033 columns => [ 'foo', { bar => 'baz' } ]
4037 select => [qw/foo baz/],
4044 =item Value: \@columns
4048 Indicates additional columns to be selected from storage. Works the same as
4049 L</columns> but adds columns to the selection. (You may also use the
4050 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4051 deprecated). For example:-
4053 $schema->resultset('CD')->search(undef, {
4054 '+columns' => ['artist.name'],
4058 would return all CDs and include a 'name' column to the information
4059 passed to object inflation. Note that the 'artist' is the name of the
4060 column (or relationship) accessor, and 'name' is the name of the column
4061 accessor in the related table.
4063 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
4064 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
4065 unary plus operator before it.
4067 =head2 include_columns
4071 =item Value: \@columns
4075 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
4081 =item Value: \@select_columns
4085 Indicates which columns should be selected from the storage. You can use
4086 column names, or in the case of RDBMS back ends, function or stored procedure
4089 $rs = $schema->resultset('Employee')->search(undef, {
4092 { count => 'employeeid' },
4093 { max => { length => 'name' }, -as => 'longest_name' }
4098 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4100 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4101 use L</select>, to instruct DBIx::Class how to store the result of the column.
4102 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4103 identifier aliasing. You can however alias a function, so you can use it in
4104 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4105 attribute> supplied as shown in the example above.
4107 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
4108 Not doing so causes Perl to incorrectly interpret them as a bareword with a
4109 unary plus operator before it.
4115 Indicates additional columns to be selected from storage. Works the same as
4116 L</select> but adds columns to the default selection, instead of specifying
4125 =item Value: \@inflation_names
4129 Indicates column names for object inflation. That is L</as> indicates the
4130 slot name in which the column value will be stored within the
4131 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4132 identifier by the C<get_column> method (or via the object accessor B<if one
4133 with the same name already exists>) as shown below. The L</as> attribute has
4134 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4136 $rs = $schema->resultset('Employee')->search(undef, {
4139 { count => 'employeeid' },
4140 { max => { length => 'name' }, -as => 'longest_name' }
4149 If the object against which the search is performed already has an accessor
4150 matching a column name specified in C<as>, the value can be retrieved using
4151 the accessor as normal:
4153 my $name = $employee->name();
4155 If on the other hand an accessor does not exist in the object, you need to
4156 use C<get_column> instead:
4158 my $employee_count = $employee->get_column('employee_count');
4160 You can create your own accessors if required - see
4161 L<DBIx::Class::Manual::Cookbook> for details.
4167 Indicates additional column names for those added via L</+select>. See L</as>.
4175 =item Value: ($rel_name | \@rel_names | \%rel_names)
4179 Contains a list of relationships that should be joined for this query. For
4182 # Get CDs by Nine Inch Nails
4183 my $rs = $schema->resultset('CD')->search(
4184 { 'artist.name' => 'Nine Inch Nails' },
4185 { join => 'artist' }
4188 Can also contain a hash reference to refer to the other relation's relations.
4191 package MyApp::Schema::Track;
4192 use base qw/DBIx::Class/;
4193 __PACKAGE__->table('track');
4194 __PACKAGE__->add_columns(qw/trackid cd position title/);
4195 __PACKAGE__->set_primary_key('trackid');
4196 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4199 # In your application
4200 my $rs = $schema->resultset('Artist')->search(
4201 { 'track.title' => 'Teardrop' },
4203 join => { cd => 'track' },
4204 order_by => 'artist.name',
4208 You need to use the relationship (not the table) name in conditions,
4209 because they are aliased as such. The current table is aliased as "me", so
4210 you need to use me.column_name in order to avoid ambiguity. For example:
4212 # Get CDs from 1984 with a 'Foo' track
4213 my $rs = $schema->resultset('CD')->search(
4216 'tracks.name' => 'Foo'
4218 { join => 'tracks' }
4221 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4222 similarly for a third time). For e.g.
4224 my $rs = $schema->resultset('Artist')->search({
4225 'cds.title' => 'Down to Earth',
4226 'cds_2.title' => 'Popular',
4228 join => [ qw/cds cds/ ],
4231 will return a set of all artists that have both a cd with title 'Down
4232 to Earth' and a cd with title 'Popular'.
4234 If you want to fetch related objects from other tables as well, see L</prefetch>
4237 NOTE: An internal join-chain pruner will discard certain joins while
4238 constructing the actual SQL query, as long as the joins in question do not
4239 affect the retrieved result. This for example includes 1:1 left joins
4240 that are not part of the restriction specification (WHERE/HAVING) nor are
4241 a part of the query selection.
4243 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4249 =item Value: (0 | 1)
4253 When set to a true value, indicates that any rows fetched from joined has_many
4254 relationships are to be aggregated into the corresponding "parent" object. For
4255 example, the resultset:
4257 my $rs = $schema->resultset('CD')->search({}, {
4258 '+columns' => [ qw/ tracks.title tracks.position / ],
4263 While executing the following query:
4265 SELECT me.*, tracks.title, tracks.position
4267 LEFT JOIN track tracks
4268 ON tracks.cdid = me.cdid
4270 Will return only as many objects as there are rows in the CD source, even
4271 though the result of the query may span many rows. Each of these CD objects
4272 will in turn have multiple "Track" objects hidden behind the has_many
4273 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4274 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4275 product"), with each CD object containing exactly one of all fetched Track data.
4277 When a collapse is requested on a non-ordered resultset, an order by some
4278 unique part of the main source (the left-most table) is inserted automatically.
4279 This is done so that the resultset is allowed to be "lazy" - calling
4280 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4281 object with all of its related data.
4283 If an L</order_by> is already declared, and orders the resultset in a way that
4284 makes collapsing as described above impossible (e.g. C<< ORDER BY
4285 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4286 switch to "eager" mode and slurp the entire resultset before constructing the
4287 first object returned by L</next>.
4289 Setting this attribute on a resultset that does not join any has_many
4290 relations is a no-op.
4292 For a more in-depth discussion, see L</PREFETCHING>.
4298 =item Value: ($rel_name | \@rel_names | \%rel_names)
4302 This attribute is a shorthand for specifying a L</join> spec, adding all
4303 columns from the joined related sources as L</+columns> and setting
4304 L</collapse> to a true value. For example, the following two queries are
4307 my $rs = $schema->resultset('Artist')->search({}, {
4308 prefetch => { cds => ['genre', 'tracks' ] },
4313 my $rs = $schema->resultset('Artist')->search({}, {
4314 join => { cds => ['genre', 'tracks' ] },
4318 { +{ "cds.$_" => "cds.$_" } }
4319 $schema->source('Artist')->related_source('cds')->columns
4322 { +{ "cds.genre.$_" => "genre.$_" } }
4323 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4326 { +{ "cds.tracks.$_" => "tracks.$_" } }
4327 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4332 Both producing the following SQL:
4334 SELECT me.artistid, me.name, me.rank, me.charfield,
4335 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4336 genre.genreid, genre.name,
4337 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4340 ON cds.artist = me.artistid
4341 LEFT JOIN genre genre
4342 ON genre.genreid = cds.genreid
4343 LEFT JOIN track tracks
4344 ON tracks.cd = cds.cdid
4345 ORDER BY me.artistid
4347 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4348 the arguments are properly merged and generally do the right thing. For
4349 example, you may want to do the following:
4351 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4352 { 'genre.genreid' => undef },
4354 join => { cds => 'genre' },
4359 Which generates the following SQL:
4361 SELECT me.artistid, me.name, me.rank, me.charfield,
4362 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4365 ON cds.artist = me.artistid
4366 LEFT JOIN genre genre
4367 ON genre.genreid = cds.genreid
4368 WHERE genre.genreid IS NULL
4369 ORDER BY me.artistid
4371 For a more in-depth discussion, see L</PREFETCHING>.
4377 =item Value: $source_alias
4381 Sets the source alias for the query. Normally, this defaults to C<me>, but
4382 nested search queries (sub-SELECTs) might need specific aliases set to
4383 reference inner queries. For example:
4386 ->related_resultset('CDs')
4387 ->related_resultset('Tracks')
4389 'track.id' => { -ident => 'none_search.id' },
4393 my $ids = $self->search({
4396 alias => 'none_search',
4397 group_by => 'none_search.id',
4398 })->get_column('id')->as_query;
4400 $self->search({ id => { -in => $ids } })
4402 This attribute is directly tied to L</current_source_alias>.
4412 Makes the resultset paged and specifies the page to retrieve. Effectively
4413 identical to creating a non-pages resultset and then calling ->page($page)
4416 If L</rows> attribute is not specified it defaults to 10 rows per page.
4418 When you have a paged resultset, L</count> will only return the number
4419 of rows in the page. To get the total, use the L</pager> and call
4420 C<total_entries> on it.
4430 Specifies the maximum number of rows for direct retrieval or the number of
4431 rows per page if the page attribute or method is used.
4437 =item Value: $offset
4441 Specifies the (zero-based) row number for the first row to be returned, or the
4442 of the first row of the first page if paging is used.
4444 =head2 software_limit
4448 =item Value: (0 | 1)
4452 When combined with L</rows> and/or L</offset> the generated SQL will not
4453 include any limit dialect stanzas. Instead the entire result will be selected
4454 as if no limits were specified, and DBIC will perform the limit locally, by
4455 artificially advancing and finishing the resulting L</cursor>.
4457 This is the recommended way of performing resultset limiting when no sane RDBMS
4458 implementation is available (e.g.
4459 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4460 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4466 =item Value: \@columns
4470 A arrayref of columns to group by. Can include columns of joined tables.
4472 group_by => [qw/ column1 column2 ... /]
4478 =item Value: $condition
4482 HAVING is a select statement attribute that is applied between GROUP BY and
4483 ORDER BY. It is applied to the after the grouping calculations have been
4486 having => { 'count_employee' => { '>=', 100 } }
4488 or with an in-place function in which case literal SQL is required:
4490 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4496 =item Value: (0 | 1)
4500 Set to 1 to automatically generate a L</group_by> clause based on the selection
4501 (including intelligent handling of L</order_by> contents). Note that the group
4502 criteria calculation takes place over the B<final> selection. This includes
4503 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4504 L</search> calls, and standalone columns selected via
4505 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4506 extra selections specified via L</prefetch> - such selections are explicitly
4507 excluded from group criteria calculations.
4509 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4510 setting is ignored and an appropriate warning is issued.
4516 Adds to the WHERE clause.
4518 # only return rows WHERE deleted IS NULL for all searches
4519 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4521 Can be overridden by passing C<< { where => undef } >> as an attribute
4524 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4530 Set to 1 to cache search results. This prevents extra SQL queries if you
4531 revisit rows in your ResultSet:
4533 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4535 while( my $artist = $resultset->next ) {
4539 $rs->first; # without cache, this would issue a query
4541 By default, searches are not cached.
4543 For more examples of using these attributes, see
4544 L<DBIx::Class::Manual::Cookbook>.
4550 =item Value: ( 'update' | 'shared' | \$scalar )
4554 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4555 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4560 DBIx::Class supports arbitrary related data prefetching from multiple related
4561 sources. Any combination of relationship types and column sets are supported.
4562 If L<collapsing|/collapse> is requested, there is an additional requirement of
4563 selecting enough data to make every individual object uniquely identifiable.
4565 Here are some more involved examples, based on the following relationship map:
4568 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4569 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4570 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4572 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4574 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4578 my $rs = $schema->resultset('Tag')->search(
4587 The initial search results in SQL like the following:
4589 SELECT tag.*, cd.*, artist.* FROM tag
4590 JOIN cd ON tag.cd = cd.cdid
4591 JOIN artist ON cd.artist = artist.artistid
4593 L<DBIx::Class> has no need to go back to the database when we access the
4594 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4597 Simple prefetches will be joined automatically, so there is no need
4598 for a C<join> attribute in the above search.
4600 The L</prefetch> attribute can be used with any of the relationship types
4601 and multiple prefetches can be specified together. Below is a more complex
4602 example that prefetches a CD's artist, its liner notes (if present),
4603 the cover image, the tracks on that CD, and the guests on those
4606 my $rs = $schema->resultset('CD')->search(
4610 { artist => 'record_label'}, # belongs_to => belongs_to
4611 'liner_note', # might_have
4612 'cover_image', # has_one
4613 { tracks => 'guests' }, # has_many => has_many
4618 This will produce SQL like the following:
4620 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4624 ON artist.artistid = me.artistid
4625 JOIN record_label record_label
4626 ON record_label.labelid = artist.labelid
4627 LEFT JOIN track tracks
4628 ON tracks.cdid = me.cdid
4629 LEFT JOIN guest guests
4630 ON guests.trackid = track.trackid
4631 LEFT JOIN liner_notes liner_note
4632 ON liner_note.cdid = me.cdid
4633 JOIN cd_artwork cover_image
4634 ON cover_image.cdid = me.cdid
4637 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4638 C<tracks>, and C<guests> of the CD will all be available through the
4639 relationship accessors without the need for additional queries to the
4644 Prefetch does a lot of deep magic. As such, it may not behave exactly
4645 as you might expect.
4651 Prefetch uses the L</cache> to populate the prefetched relationships. This
4652 may or may not be what you want.
4656 If you specify a condition on a prefetched relationship, ONLY those
4657 rows that match the prefetched condition will be fetched into that relationship.
4658 This means that adding prefetch to a search() B<may alter> what is returned by
4659 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4661 my $artist_rs = $schema->resultset('Artist')->search({
4667 my $count = $artist_rs->first->cds->count;
4669 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4671 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4673 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4675 That cmp_ok() may or may not pass depending on the datasets involved. In other
4676 words the C<WHERE> condition would apply to the entire dataset, just like
4677 it would in regular SQL. If you want to add a condition only to the "right side"
4678 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4679 condition|DBIx::Class::Relationship::Base/condition>
4683 =head1 DBIC BIND VALUES
4685 Because DBIC may need more information to bind values than just the column name
4686 and value itself, it uses a special format for both passing and receiving bind
4687 values. Each bind value should be composed of an arrayref of
4688 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4694 If present (in any form), this is what is being passed directly to bind_param.
4695 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4696 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4698 If this is specified, all other bind options described below are ignored.
4702 If present, this is used to infer the actual bind attribute by passing to
4703 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4704 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4706 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4707 currently drivers are expected to "Do the Right Thing" when given a common
4708 datatype name. (Not ideal, but that's what we got at this point.)
4712 Currently used to correctly allocate buffers for bind_param_inout().
4713 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4714 or to a sensible value based on the "data_type".
4718 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4719 explicitly specified they are never overridden). Also used by some weird DBDs,
4720 where the column name should be available at bind_param time (e.g. Oracle).
4724 For backwards compatibility and convenience, the following shortcuts are
4727 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4728 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4729 [ undef, $val ] === [ {}, $val ]
4730 $val === [ {}, $val ]
4732 =head1 AUTHOR AND CONTRIBUTORS
4734 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4738 You may distribute this code under the same terms as Perl itself.