1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use DBIx::Class::ResultClass::HashRefInflator;
9 use Scalar::Util qw/blessed weaken reftype/;
10 use DBIx::Class::_Util qw(
11 dbic_internal_try dump_value
12 fail_on_internal_wantarray fail_on_internal_call UNRESOLVABLE_CONDITION
16 # not importing first() as it will clash with our own method
20 # De-duplication in _merge_attr() is disabled, but left in for reference
21 # (the merger is used for other things that ought not to be de-duped)
22 *__HM_DEDUP = sub () { 0 };
32 # this is real - CDBICompat overrides it with insanity
33 # yes, prototype won't matter, but that's for now ;)
36 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
40 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
44 my $users_rs = $schema->resultset('User');
45 while( $user = $users_rs->next) {
46 print $user->username;
49 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
50 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
54 A ResultSet is an object which stores a set of conditions representing
55 a query. It is the backbone of DBIx::Class (i.e. the really
56 important/useful bit).
58 No SQL is executed on the database when a ResultSet is created, it
59 just stores all the conditions needed to create the query.
61 A basic ResultSet representing the data of an entire table is returned
62 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
63 L<Source|DBIx::Class::Manual::Glossary/ResultSource> name.
65 my $users_rs = $schema->resultset('User');
67 A new ResultSet is returned from calling L</search> on an existing
68 ResultSet. The new one will contain all the conditions of the
69 original, plus any new conditions added in the C<search> call.
71 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
72 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
75 The query that the ResultSet represents is B<only> executed against
76 the database when these methods are called:
77 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
79 If a resultset is used in a numeric context it returns the L</count>.
80 However, if it is used in a boolean context it is B<always> true. So if
81 you want to check if a resultset has any results, you must use C<if $rs
86 =head2 Chaining resultsets
88 Let's say you've got a query that needs to be run to return some data
89 to the user. But, you have an authorization system in place that
90 prevents certain users from seeing certain information. So, you want
91 to construct the basic query in one method, but add constraints to it in
96 my $request = $self->get_request; # Get a request object somehow.
97 my $schema = $self->result_source->schema;
99 my $cd_rs = $schema->resultset('CD')->search({
100 title => $request->param('title'),
101 year => $request->param('year'),
104 $cd_rs = $self->apply_security_policy( $cd_rs );
106 return $cd_rs->all();
109 sub apply_security_policy {
118 =head3 Resolving conditions and attributes
120 When a resultset is chained from another resultset (e.g.:
121 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
122 and attributes with the same keys need resolving.
124 If any of L</columns>, L</select>, L</as> are present, they reset the
125 original selection, and start the selection "clean".
127 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
128 are merged into the existing ones from the original resultset.
130 The L</where> and L</having> attributes, and any search conditions, are
131 merged with an SQL C<AND> to the existing condition from the original
134 All other attributes are overridden by any new ones supplied in the
137 =head2 Multiple queries
139 Since a resultset just defines a query, you can do all sorts of
140 things with it with the same object.
142 # Don't hit the DB yet.
143 my $cd_rs = $schema->resultset('CD')->search({
144 title => 'something',
148 # Each of these hits the DB individually.
149 my $count = $cd_rs->count;
150 my $most_recent = $cd_rs->get_column('date_released')->max();
151 my @records = $cd_rs->all;
153 And it's not just limited to SELECT statements.
159 $cd_rs->create({ artist => 'Fred' });
161 Which is the same as:
163 $schema->resultset('CD')->create({
164 title => 'something',
169 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
171 =head2 Custom ResultSet classes
173 To add methods to your resultsets, you can subclass L<DBIx::Class::ResultSet>, similar to:
175 package MyApp::Schema::ResultSet::User;
180 use base 'DBIx::Class::ResultSet';
184 $self->search({ $self->current_source_alias . '.active' => 1 });
189 $self->search({ $self->current_source_alias . '.verified' => 0 });
192 sub created_n_days_ago {
193 my ($self, $days_ago) = @_;
195 $self->current_source_alias . '.create_date' => {
197 $self->result_source->schema->storage->datetime_parser->format_datetime(
198 DateTime->now( time_zone => 'UTC' )->subtract( days => $days_ago )
203 sub users_to_warn { shift->active->unverified->created_n_days_ago(7) }
207 See L<DBIx::Class::Schema/load_namespaces> on how DBIC can discover and
208 automatically attach L<Result|DBIx::Class::Manual::ResultClass>-specific
209 L<ResulSet|DBIx::Class::ResultSet> classes.
211 =head3 ResultSet subclassing with Moose and similar constructor-providers
213 Using L<Moose> or L<Moo> in your ResultSet classes is usually overkill, but
214 you may find it useful if your ResultSets contain a lot of business logic
215 (e.g. C<has xml_parser>, C<has json>, etc) or if you just prefer to organize
218 In order to write custom ResultSet classes with L<Moo> you need to use the
219 following template. The L<BUILDARGS|Moo/BUILDARGS> is necessary due to the
220 unusual signature of the L<constructor provided by DBIC
221 |DBIx::Class::ResultSet/new> C<< ->new($source, \%args) >>.
224 extends 'DBIx::Class::ResultSet';
225 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
231 If you want to build your custom ResultSet classes with L<Moose>, you need
232 a similar, though a little more elaborate template in order to interface the
233 inlining of the L<Moose>-provided
234 L<object constructor|Moose::Manual::Construction/WHERE'S THE CONSTRUCTOR?>,
237 package MyApp::Schema::ResultSet::User;
240 use MooseX::NonMoose;
241 extends 'DBIx::Class::ResultSet';
243 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
247 __PACKAGE__->meta->make_immutable;
251 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
252 entirely overwrite the DBIC one (in contrast L<Moo> does this automatically).
253 Alternatively, you can skip L<MooseX::NonMoose> and get by with just L<Moose>
256 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
264 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
266 =item Return Value: L<$resultset|/search>
270 The resultset constructor. Takes a source object (usually a
271 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
272 L</ATTRIBUTES> below). Does not perform any queries -- these are
273 executed as needed by the other methods.
275 Generally you never construct a resultset manually. Instead you get one
277 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
278 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
281 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
287 If called on an object, proxies to L</new_result> instead, so
289 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
291 will return a CD object, not a ResultSet, and is equivalent to:
293 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
295 Please also keep in mind that many internals call L</new_result> directly,
296 so overloading this method with the idea of intercepting new result object
297 creation B<will not work>. See also warning pertaining to L</create>.
307 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
308 return $class->new_result(@_);
311 my ($source, $attrs) = @_;
312 $source = $source->resolve
313 if $source->isa('DBIx::Class::ResultSourceHandle');
315 $attrs = { %{$attrs||{}} };
316 delete @{$attrs}{qw(_last_sqlmaker_alias_map _simple_passthrough_construction)};
318 if ($attrs->{page}) {
319 $attrs->{rows} ||= 10;
322 $attrs->{alias} ||= 'me';
325 result_source => $source,
326 cond => $attrs->{where},
331 # if there is a dark selector, this means we are already in a
332 # chain and the cleanup/sanification was taken care of by
334 $self->_normalize_selection($attrs)
335 unless $attrs->{_dark_selector};
338 $attrs->{result_class} || $source->result_class
348 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
350 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
354 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
355 my $new_rs = $cd_rs->search({ year => 2005 });
357 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
358 # year = 2005 OR year = 2004
360 In list context, C<< ->all() >> is called implicitly on the resultset, thus
361 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
362 To avoid that, use L</search_rs>.
364 If you need to pass in additional attributes but no additional condition,
365 call it as C<search(undef, \%attrs)>.
367 # "SELECT name, artistid FROM $artist_table"
368 my @all_artists = $schema->resultset('Artist')->search(undef, {
369 columns => [qw/name artistid/],
372 For a list of attributes that can be passed to C<search>, see
373 L</ATTRIBUTES>. For more examples of using this function, see
374 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
375 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
376 and its extension L<DBIx::Class::SQLMaker>.
378 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
382 Note that L</search> does not process/deflate any of the values passed in the
383 L<SQL::Abstract>-compatible search condition structure. This is unlike other
384 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
385 manually that any value passed to this method will stringify to something the
386 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
387 objects, for more info see:
388 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
394 my $rs = $self->search_rs( @_ );
397 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray;
400 elsif (defined wantarray) {
404 # we can be called by a relationship helper, which in
405 # turn may be called in void context due to some braindead
406 # overload or whatever else the user decided to be clever
407 # at this particular day. Thus limit the exception to
408 # external code calls only
409 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
410 if (caller)[0] !~ /^\QDBIx::Class::/;
420 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
422 =item Return Value: L<$resultset|/search>
426 This method does the same exact thing as search() except it will
427 always return a resultset, even in list context.
434 my $rsrc = $self->result_source;
435 my ($call_cond, $call_attrs);
437 # Special-case handling for (undef, undef) or (undef)
438 # Note that (foo => undef) is valid deprecated syntax
439 @_ = () if not scalar grep { defined $_ } @_;
445 # fish out attrs in the ($condref, $attr) case
446 elsif (@_ == 2 and ( ! defined $_[0] or length ref $_[0] ) ) {
447 ($call_cond, $call_attrs) = @_;
450 $self->throw_exception('Odd number of arguments to search')
454 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
455 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
457 for my $i (0 .. $#_) {
459 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
460 if (! defined $_[$i] or length ref $_[$i] );
466 # see if we can keep the cache (no $rs changes)
468 my %safe = (alias => 1, cache => 1);
469 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
472 ref $call_cond eq 'HASH' && ! keys %$call_cond
474 ref $call_cond eq 'ARRAY' && ! @$call_cond
476 $cache = $self->get_cache;
479 my $old_attrs = { %{$self->{attrs}} };
480 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
482 my $new_attrs = { %$old_attrs };
484 # take care of call attrs (only if anything is changing)
485 if ($call_attrs and keys %$call_attrs) {
487 # copy for _normalize_selection
488 $call_attrs = { %$call_attrs };
490 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
492 # reset the current selector list if new selectors are supplied
493 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
494 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
497 # Normalize the new selector list (operates on the passed-in attr structure)
498 # Need to do it on every chain instead of only once on _resolved_attrs, in
499 # order to allow detection of empty vs partial 'as'
500 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
501 if $old_attrs->{_dark_selector};
502 $self->_normalize_selection ($call_attrs);
504 # start with blind overwriting merge, exclude selector attrs
505 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
506 delete @{$new_attrs}{@selector_attrs};
508 for (@selector_attrs) {
509 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
510 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
513 # older deprecated name, use only if {columns} is not there
514 if (my $c = delete $new_attrs->{cols}) {
515 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
516 if ($new_attrs->{columns}) {
517 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
520 $new_attrs->{columns} = $c;
525 # join/prefetch use their own crazy merging heuristics
526 foreach my $key (qw/join prefetch/) {
527 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
528 if exists $call_attrs->{$key};
531 # stack binds together
532 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
536 for ($old_where, $call_cond) {
538 $new_attrs->{where} = $self->_stack_cond (
539 $_, $new_attrs->{where}
544 if (defined $old_having) {
545 $new_attrs->{having} = $self->_stack_cond (
546 $old_having, $new_attrs->{having}
550 my $rs = (ref $self)->new($rsrc, $new_attrs);
552 $rs->set_cache($cache) if ($cache);
557 sub _normalize_selection {
558 my ($self, $attrs) = @_;
561 if ( exists $attrs->{include_columns} ) {
562 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
563 $attrs->{'+columns'} = $self->_merge_attr(
564 $attrs->{'+columns'}, delete $attrs->{include_columns}
568 # columns are always placed first, however
570 # Keep the X vs +X separation until _resolved_attrs time - this allows to
571 # delay the decision on whether to use a default select list ($rsrc->columns)
572 # allowing stuff like the remove_columns helper to work
574 # select/as +select/+as pairs need special handling - the amount of select/as
575 # elements in each pair does *not* have to be equal (think multicolumn
576 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
577 # supplied at all) - try to infer the alias, either from the -as parameter
578 # of the selector spec, or use the parameter whole if it looks like a column
579 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
580 # is ok as well), but make sure no more additions to the 'as' chain take place
581 for my $pref ('', '+') {
583 my ($sel, $as) = map {
584 my $key = "${pref}${_}";
586 my $val = [ ref $attrs->{$key} eq 'ARRAY'
588 : $attrs->{$key} || ()
590 delete $attrs->{$key};
594 if (! @$as and ! @$sel ) {
597 elsif (@$as and ! @$sel) {
598 $self->throw_exception(
599 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
603 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
604 # if any @$as has been supplied we assume the user knows what (s)he is doing
605 # and blindly keep stacking up pieces
606 unless ($attrs->{_dark_selector}) {
609 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
610 push @$as, $_->{-as};
612 # assume any plain no-space, no-parenthesis string to be a column spec
613 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
614 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
617 # if all else fails - raise a flag that no more aliasing will be allowed
619 $attrs->{_dark_selector} = {
622 local $Data::Dumper::Indent = 0;
631 elsif (@$as < @$sel) {
632 $self->throw_exception(
633 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
636 elsif ($pref and $attrs->{_dark_selector}) {
637 $self->throw_exception(
638 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
644 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
645 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
650 my ($self, $left, $right) = @_;
653 (ref $_ eq 'ARRAY' and !@$_)
655 (ref $_ eq 'HASH' and ! keys %$_)
656 ) and $_ = undef for ($left, $right);
658 # either one of the two undef
659 if ( (defined $left) xor (defined $right) ) {
660 return defined $left ? $left : $right;
663 elsif ( ! defined $left ) {
667 return $self->result_source->schema->storage->_collapse_cond({ -and => [$left, $right] });
671 =head2 search_literal
673 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
674 should only be used in that context. C<search_literal> is a convenience
675 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
676 want to ensure columns are bound correctly, use L</search>.
678 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
679 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
680 require C<search_literal>.
684 =item Arguments: $sql_fragment, @standalone_bind_values
686 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
690 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
691 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
693 Pass a literal chunk of SQL to be added to the conditional part of the
696 Example of how to use C<search> instead of C<search_literal>
698 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
699 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
704 my ($self, $sql, @bind) = @_;
706 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
709 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
716 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
718 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
722 Finds and returns a single row based on supplied criteria. Takes either a
723 hashref with the same format as L</create> (including inference of foreign
724 keys from related objects), or a list of primary key values in the same
725 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
726 declaration on the L</result_source>.
728 In either case an attempt is made to combine conditions already existing on
729 the resultset with the condition passed to this method.
731 To aid with preparing the correct query for the storage you may supply the
732 C<key> attribute, which is the name of a
733 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
734 unique constraint corresponding to the
735 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
736 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
737 to construct a query that satisfies the named unique constraint fully (
738 non-NULL values for each column member of the constraint) an exception is
741 If no C<key> is specified, the search is carried over all unique constraints
742 which are fully defined by the available condition.
744 If no such constraint is found, C<find> currently defaults to a simple
745 C<< search->(\%column_values) >> which may or may not do what you expect.
746 Note that this fallback behavior may be deprecated in further versions. If
747 you need to search with arbitrary conditions - use L</search>. If the query
748 resulting from this fallback produces more than one row, a warning to the
749 effect is issued, though only the first row is constructed and returned as
752 In addition to C<key>, L</find> recognizes and applies standard
753 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
755 Note that if you have extra concerns about the correctness of the resulting
756 query you need to specify the C<key> attribute and supply the entire condition
757 as an argument to find (since it is not always possible to perform the
758 combination of the resultset condition with the supplied one, especially if
759 the resultset condition contains literal sql).
761 For example, to find a row by its primary key:
763 my $cd = $schema->resultset('CD')->find(5);
765 You can also find a row by a specific unique constraint:
767 my $cd = $schema->resultset('CD')->find(
769 artist => 'Massive Attack',
770 title => 'Mezzanine',
772 { key => 'cd_artist_title' }
775 See also L</find_or_create> and L</update_or_create>.
781 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
783 my $rsrc = $self->result_source;
786 if (exists $attrs->{key}) {
787 $constraint_name = defined $attrs->{key}
789 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
793 # Parse out the condition from input
796 if (ref $_[0] eq 'HASH') {
797 $call_cond = { %{$_[0]} };
800 # if only values are supplied we need to default to 'primary'
801 $constraint_name = 'primary' unless defined $constraint_name;
803 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
805 $self->throw_exception(
806 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
809 $self->throw_exception (
810 'find() expects either a column/value hashref, or a list of values '
811 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
812 ) unless @c_cols == @_;
814 @{$call_cond}{@c_cols} = @_;
817 # process relationship data if any
818 for my $key (keys %$call_cond) {
820 length ref($call_cond->{$key})
822 my $relinfo = $rsrc->relationship_info($key)
824 # implicitly skip has_many's (likely MC)
825 (ref (my $val = delete $call_cond->{$key}) ne 'ARRAY' )
827 my ($rel_cond, $crosstable) = $rsrc->_resolve_condition(
828 $relinfo->{cond}, $val, $key, $key
831 $self->throw_exception("Complex condition via relationship '$key' is unsupported in find()")
832 if $crosstable or ref($rel_cond) ne 'HASH';
834 # supplement condition
835 # relationship conditions take precedence (?)
836 @{$call_cond}{keys %$rel_cond} = values %$rel_cond;
840 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
842 if (defined $constraint_name) {
843 $final_cond = $self->_qualify_cond_columns (
845 $self->result_source->_minimal_valueset_satisfying_constraint(
846 constraint_name => $constraint_name,
847 values => ($self->_merge_with_rscond($call_cond))[0],
854 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
855 # This means that we got here after a merger of relationship conditions
856 # in ::Relationship::Base::search_related (the row method), and furthermore
857 # the relationship is of the 'single' type. This means that the condition
858 # provided by the relationship (already attached to $self) is sufficient,
859 # as there can be only one row in the database that would satisfy the
863 my (@unique_queries, %seen_column_combinations, $ci, @fc_exceptions);
865 # no key was specified - fall down to heuristics mode:
866 # run through all unique queries registered on the resultset, and
867 # 'OR' all qualifying queries together
869 # always start from 'primary' if it exists at all
870 for my $c_name ( sort {
872 : $b eq 'primary' ? 1
874 } $rsrc->unique_constraint_names) {
876 next if $seen_column_combinations{
877 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
881 push @unique_queries, $self->_qualify_cond_columns(
882 $self->result_source->_minimal_valueset_satisfying_constraint(
883 constraint_name => $c_name,
884 values => ($self->_merge_with_rscond($call_cond))[0],
885 columns_info => ($ci ||= $self->result_source->columns_info),
891 push @fc_exceptions, $_ if $_ =~ /\bFilterColumn\b/;
896 @unique_queries ? \@unique_queries
897 : @fc_exceptions ? $self->throw_exception(join "; ", map { $_ =~ /(.*) at .+ line \d+$/s } @fc_exceptions )
898 : $self->_non_unique_find_fallback ($call_cond, $attrs)
902 # Run the query, passing the result_class since it should propagate for find
903 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
904 if ($rs->_resolved_attrs->{collapse}) {
906 carp "Query returned more than one row" if $rs->next;
914 # This is a stop-gap method as agreed during the discussion on find() cleanup:
915 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
917 # It is invoked when find() is called in legacy-mode with insufficiently-unique
918 # condition. It is provided for overrides until a saner way forward is devised
920 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
921 # the road. Please adjust your tests accordingly to catch this situation early
922 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
924 # The method will not be removed without an adequately complete replacement
925 # for strict-mode enforcement
926 sub _non_unique_find_fallback {
927 my ($self, $cond, $attrs) = @_;
929 return $self->_qualify_cond_columns(
931 exists $attrs->{alias}
933 : $self->{attrs}{alias}
938 sub _qualify_cond_columns {
939 my ($self, $cond, $alias) = @_;
941 my %aliased = %$cond;
942 for (keys %aliased) {
943 $aliased{"$alias.$_"} = delete $aliased{$_}
950 sub _build_unique_cond {
952 '_build_unique_cond is a private method, and moreover is about to go '
953 . 'away. Please contact the development team at %s if you believe you '
954 . 'have a genuine use for this method, in order to discuss alternatives.',
955 DBIx::Class::_ENV_::HELP_URL,
958 my ($self, $constraint_name, $cond, $croak_on_null) = @_;
960 $self->result_source->_minimal_valueset_satisfying_constraint(
961 constraint_name => $constraint_name,
963 carp_on_nulls => !$croak_on_null
967 =head2 search_related
971 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
973 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
977 $new_rs = $cd_rs->search_related('artist', {
981 Searches the specified relationship, optionally specifying a condition and
982 attributes for matching records. See L</ATTRIBUTES> for more information.
984 In list context, C<< ->all() >> is called implicitly on the resultset, thus
985 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
987 See also L</search_related_rs>.
992 return shift->related_resultset(shift)->search(@_);
995 =head2 search_related_rs
997 This method works exactly the same as search_related, except that
998 it guarantees a resultset, even in list context.
1002 sub search_related_rs {
1003 return shift->related_resultset(shift)->search_rs(@_);
1010 =item Arguments: none
1012 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1016 Returns a storage-driven cursor to the given resultset. See
1017 L<DBIx::Class::Cursor> for more information.
1024 return $self->{cursor} ||= do {
1025 my $attrs = $self->_resolved_attrs;
1026 $self->result_source->storage->select(
1027 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1036 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1038 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1042 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1044 Inflates the first result without creating a cursor if the resultset has
1045 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1048 While this method can take an optional search condition (just like L</search>)
1049 being a fast-code-path it does not recognize search attributes. If you need to
1050 add extra joins or similar, call L</search> and then chain-call L</single> on the
1051 L<DBIx::Class::ResultSet> returned.
1057 As of 0.08100, this method enforces the assumption that the preceding
1058 query returns only one row. If more than one row is returned, you will receive
1061 Query returned more than one row
1063 In this case, you should be using L</next> or L</find> instead, or if you really
1064 know what you are doing, use the L</rows> attribute to explicitly limit the size
1067 This method will also throw an exception if it is called on a resultset prefetching
1068 has_many, as such a prefetch implies fetching multiple rows from the database in
1069 order to assemble the resulting object.
1076 my ($self, $where) = @_;
1078 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1081 my $attrs = { %{$self->_resolved_attrs} };
1083 $self->throw_exception(
1084 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1085 ) if $attrs->{collapse};
1088 if (defined $attrs->{where}) {
1091 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1092 $where, delete $attrs->{where} ]
1095 $attrs->{where} = $where;
1099 my $data = [ $self->result_source->storage->select_single(
1100 $attrs->{from}, $attrs->{select},
1101 $attrs->{where}, $attrs
1104 return undef unless @$data;
1105 $self->{_stashed_rows} = [ $data ];
1106 $self->_construct_results->[0];
1113 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1115 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1119 my $max_length = $rs->get_column('length')->max;
1121 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1126 my ($self, $column) = @_;
1127 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1135 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1137 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1141 # WHERE title LIKE '%blue%'
1142 $cd_rs = $rs->search_like({ title => '%blue%'});
1144 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1145 that this is simply a convenience method retained for ex Class::DBI users.
1146 You most likely want to use L</search> with specific operators.
1148 For more information, see L<DBIx::Class::Manual::Cookbook>.
1150 This method is deprecated and will be removed in 0.09. Use L<search()|/search>
1151 instead. An example conversion is:
1153 ->search_like({ foo => 'bar' });
1157 ->search({ foo => { like => 'bar' } });
1164 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1165 .' Instead use ->search({ x => { -like => "y%" } })'
1166 .' (note the outer pair of {}s - they are important!)'
1168 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1169 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1170 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1171 return $class->search($query, { %$attrs });
1178 =item Arguments: $first, $last
1180 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1184 Returns a resultset or object list representing a subset of elements from the
1185 resultset slice is called on. Indexes are from 0, i.e., to get the first
1186 three records, call:
1188 my ($one, $two, $three) = $rs->slice(0, 2);
1193 my ($self, $min, $max) = @_;
1194 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1195 $attrs->{offset} = $self->{attrs}{offset} || 0;
1196 $attrs->{offset} += $min;
1197 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1198 return $self->search(undef, $attrs);
1205 =item Arguments: none
1207 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1211 Returns the next element in the resultset (C<undef> is there is none).
1213 Can be used to efficiently iterate over records in the resultset:
1215 my $rs = $schema->resultset('CD')->search;
1216 while (my $cd = $rs->next) {
1220 Note that you need to store the resultset object, and call C<next> on it.
1221 Calling C<< resultset('Table')->next >> repeatedly will always return the
1222 first record from the resultset.
1229 if (my $cache = $self->get_cache) {
1230 $self->{all_cache_position} ||= 0;
1231 return $cache->[$self->{all_cache_position}++];
1234 if ($self->{attrs}{cache}) {
1235 delete $self->{pager};
1236 $self->{all_cache_position} = 1;
1237 return ($self->all)[0];
1240 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1242 $self->{_stashed_results} = $self->_construct_results
1245 return shift @{$self->{_stashed_results}};
1248 # Constructs as many results as it can in one pass while respecting
1249 # cursor laziness. Several modes of operation:
1251 # * Always builds everything present in @{$self->{_stashed_rows}}
1252 # * If called with $fetch_all true - pulls everything off the cursor and
1253 # builds all result structures (or objects) in one pass
1254 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1255 # and if the resultset is ordered properly by the left side:
1256 # * Fetches stuff off the cursor until the "master object" changes,
1257 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1259 # * Just fetches, and collapses/constructs everything as if $fetch_all
1260 # was requested (there is no other way to collapse except for an
1262 # * If no collapse is requested - just get the next row, construct and
1264 sub _construct_results {
1265 my ($self, $fetch_all) = @_;
1267 my $rsrc = $self->result_source;
1268 my $attrs = $self->_resolved_attrs;
1273 ! $attrs->{order_by}
1277 my @pcols = $rsrc->primary_columns
1279 # default order for collapsing unless the user asked for something
1280 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1281 $attrs->{_ordered_for_collapse} = 1;
1282 $attrs->{_order_is_artificial} = 1;
1285 # this will be used as both initial raw-row collector AND as a RV of
1286 # _construct_results. Not regrowing the array twice matters a lot...
1287 # a surprising amount actually
1288 my $rows = delete $self->{_stashed_rows};
1290 my $cursor; # we may not need one at all
1292 my $did_fetch_all = $fetch_all;
1295 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1296 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1298 elsif( $attrs->{collapse} ) {
1300 # a cursor will need to be closed over in case of collapse
1301 $cursor = $self->cursor;
1303 $attrs->{_ordered_for_collapse} = (
1309 ->_extract_colinfo_of_stable_main_source_order_by_portion($attrs)
1311 ) unless defined $attrs->{_ordered_for_collapse};
1313 if (! $attrs->{_ordered_for_collapse}) {
1316 # instead of looping over ->next, use ->all in stealth mode
1317 # *without* calling a ->reset afterwards
1318 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1319 if (! $cursor->{_done}) {
1320 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1321 $cursor->{_done} = 1;
1326 if (! $did_fetch_all and ! @{$rows||[]} ) {
1327 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1328 $cursor ||= $self->cursor;
1329 if (scalar (my @r = $cursor->next) ) {
1334 return undef unless @{$rows||[]};
1336 # sanity check - people are too clever for their own good
1337 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1339 my $multiplied_selectors;
1340 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1342 $aliastypes->{multiplying}{$sel_alias}
1344 $aliastypes->{premultiplied}{$sel_alias}
1346 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1350 for my $i (0 .. $#{$attrs->{as}} ) {
1351 my $sel = $attrs->{select}[$i];
1353 if (ref $sel eq 'SCALAR') {
1356 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1360 $self->throw_exception(
1361 'Result collapse not possible - selection from a has_many source redirected to the main object'
1362 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1366 # hotspot - skip the setter
1367 my $res_class = $self->_result_class;
1369 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1370 $res_class->can ('inflate_result')
1371 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1374 my $infmap = $attrs->{as};
1376 $self->{_result_inflator}{is_core_row} = ( (
1379 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1380 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1382 $self->{_result_inflator}{is_hri} = ( (
1383 ! $self->{_result_inflator}{is_core_row}
1385 $inflator_cref == \&DBIx::Class::ResultClass::HashRefInflator::inflate_result
1386 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1389 if ($attrs->{_simple_passthrough_construction}) {
1390 # construct a much simpler array->hash folder for the one-table HRI cases right here
1391 if ($self->{_result_inflator}{is_hri}) {
1392 for my $r (@$rows) {
1393 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1396 # FIXME SUBOPTIMAL this is a very very very hot spot
1397 # while rather optimal we can *still* do much better, by
1398 # building a smarter Row::inflate_result(), and
1399 # switch to feeding it data via a much leaner interface
1401 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1402 # this particular resultset size
1403 elsif ( $self->{_result_inflator}{is_core_row} and @$rows < 60 ) {
1404 for my $r (@$rows) {
1405 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1410 ( $self->{_result_inflator}{is_core_row}
1411 ? '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows'
1412 # a custom inflator may be a multiplier/reductor - put it in direct list ctx
1413 : '@$rows = map { $inflator_cref->($res_class, $rsrc, { %s } ) } @$rows'
1415 ( join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) )
1421 $self->{_result_inflator}{is_hri} ? 'hri'
1422 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1423 : 'classic_nonpruning'
1426 unless( $self->{_row_parser}{$parser_type}{cref} ) {
1428 # $args and $attrs to _mk_row_parser are separated to delineate what is
1429 # core collapser stuff and what is dbic $rs specific
1430 $self->{_row_parser}{$parser_type}{src} = $rsrc->_mk_row_parser({
1431 inflate_map => $infmap,
1432 collapse => $attrs->{collapse},
1433 premultiplied => $attrs->{_main_source_premultiplied},
1434 hri_style => $self->{_result_inflator}{is_hri},
1435 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1438 $self->{_row_parser}{$parser_type}{cref} = do {
1439 package # hide form PAUSE
1440 DBIx::Class::__GENERATED_ROW_PARSER__;
1442 eval $self->{_row_parser}{$parser_type}{src};
1446 # this needs to close over the *current* cursor, hence why it is not cached above
1447 my $next_cref = ($did_fetch_all or ! $attrs->{collapse})
1450 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1451 my @r = $cursor->next or return;
1456 $self->{_row_parser}{$parser_type}{cref}->(
1459 ( $self->{_stashed_rows} = [] ),
1460 ( my $null_violations = {} ),
1463 $self->throw_exception(
1464 'Collapse aborted - the following columns are declared (or defaulted to) '
1465 . 'non-nullable within DBIC but NULLs were retrieved from storage: '
1466 . join( ', ', map { "'$infmap->[$_]'" } sort { $a <=> $b } keys %$null_violations )
1467 . ' within data row ' . dump_value({
1470 ( ! defined $self->{_stashed_rows}[0][$_] or length $self->{_stashed_rows}[0][$_] < 50 )
1471 ? $self->{_stashed_rows}[0][$_]
1472 : substr( $self->{_stashed_rows}[0][$_], 0, 50 ) . '...'
1473 } 0 .. $#{$self->{_stashed_rows}[0]}
1475 ) if keys %$null_violations;
1477 # simple in-place substitution, does not regrow $rows
1478 if ($self->{_result_inflator}{is_core_row}) {
1479 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1481 # Special-case multi-object HRI - there is no $inflator_cref pass at all
1482 elsif ( ! $self->{_result_inflator}{is_hri} ) {
1483 # the inflator may be a multiplier/reductor - put it in list ctx
1484 @$rows = map { $inflator_cref->($res_class, $rsrc, @$_) } @$rows;
1488 # The @$rows check seems odd at first - why wouldn't we want to warn
1489 # regardless? The issue is things like find() etc, where the user
1490 # *knows* only one result will come back. In these cases the ->all
1491 # is not a pessimization, but rather something we actually want
1493 'Unable to properly collapse has_many results in iterator mode due '
1494 . 'to order criteria - performed an eager cursor slurp underneath. '
1495 . 'Consider using ->all() instead'
1496 ) if ( ! $fetch_all and @$rows > 1 );
1501 =head2 result_source
1505 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1507 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1511 An accessor for the primary ResultSource object from which this ResultSet
1518 =item Arguments: $result_class?
1520 =item Return Value: $result_class
1524 An accessor for the class to use when creating result objects. Defaults to
1525 C<< result_source->result_class >> - which in most cases is the name of the
1526 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1528 Note that changing the result_class will also remove any components
1529 that were originally loaded in the source class via
1530 L<load_components|Class::C3::Componentised/load_components( @comps )>.
1531 Any overloaded methods in the original source class will not run.
1536 my ($self, $result_class) = @_;
1537 if ($result_class) {
1539 # don't fire this for an object
1540 $self->ensure_class_loaded($result_class)
1541 unless ref($result_class);
1543 if ($self->get_cache) {
1544 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1546 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1547 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1548 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1551 $self->_result_class($result_class);
1553 delete $self->{_result_inflator};
1555 $self->_result_class;
1562 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1564 =item Return Value: $count
1568 Performs an SQL C<COUNT> with the same query as the resultset was built
1569 with to find the number of elements. Passing arguments is equivalent to
1570 C<< $rs->search ($cond, \%attrs)->count >>
1576 return $self->search(@_)->count if @_ and defined $_[0];
1577 return scalar @{ $self->get_cache } if $self->get_cache;
1579 my $attrs = { %{ $self->_resolved_attrs } };
1581 # this is a little optimization - it is faster to do the limit
1582 # adjustments in software, instead of a subquery
1583 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1586 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1587 $crs = $self->_count_subq_rs ($attrs);
1590 $crs = $self->_count_rs ($attrs);
1592 my $count = $crs->next;
1594 $count -= $offset if $offset;
1595 $count = $rows if $rows and $rows < $count;
1596 $count = 0 if ($count < 0);
1605 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1607 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1611 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1612 This can be very handy for subqueries:
1614 ->search( { amount => $some_rs->count_rs->as_query } )
1616 As with regular resultsets the SQL query will be executed only after
1617 the resultset is accessed via L</next> or L</all>. That would return
1618 the same single value obtainable via L</count>.
1624 return $self->search(@_)->count_rs if @_;
1626 # this may look like a lack of abstraction (count() does about the same)
1627 # but in fact an _rs *must* use a subquery for the limits, as the
1628 # software based limiting can not be ported if this $rs is to be used
1629 # in a subquery itself (i.e. ->as_query)
1630 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1631 return $self->_count_subq_rs($self->{_attrs});
1634 return $self->_count_rs($self->{_attrs});
1639 # returns a ResultSetColumn object tied to the count query
1642 my ($self, $attrs) = @_;
1644 my $rsrc = $self->result_source;
1646 my $tmp_attrs = { %$attrs };
1647 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1648 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1650 # overwrite the selector (supplied by the storage)
1651 $rsrc->resultset_class->new($rsrc, {
1653 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1655 })->get_column ('count');
1659 # same as above but uses a subquery
1661 sub _count_subq_rs {
1662 my ($self, $attrs) = @_;
1664 my $rsrc = $self->result_source;
1666 my $sub_attrs = { %$attrs };
1667 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1668 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1670 # if we multi-prefetch we group_by something unique, as this is what we would
1671 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1672 if ( $attrs->{collapse} ) {
1673 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1674 $rsrc->_identifying_column_set || $self->throw_exception(
1675 'Unable to construct a unique group_by criteria properly collapsing the '
1676 . 'has_many prefetch before count()'
1681 # Calculate subquery selector
1682 if (my $g = $sub_attrs->{group_by}) {
1684 my $sql_maker = $rsrc->storage->sql_maker;
1686 # necessary as the group_by may refer to aliased functions
1688 for my $sel (@{$attrs->{select}}) {
1689 $sel_index->{$sel->{-as}} = $sel
1690 if (ref $sel eq 'HASH' and $sel->{-as});
1693 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1694 # also look for named aggregates referred in the having clause
1695 # having often contains scalarrefs - thus parse it out entirely
1697 if ($attrs->{having}) {
1698 local $sql_maker->{having_bind};
1699 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1700 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1701 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1702 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1703 # if we don't unset it we screw up retarded but unfortunately working
1704 # 'MAX(foo.bar)' => { '>', 3 }
1705 $sql_maker->{name_sep} = '';
1708 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1710 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1713 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1714 # and if all fails for an utterly naive quoted scalar-with-function
1715 while ($having_sql =~ /
1716 $rquote $sep $lquote (.+?) $rquote
1718 [\s,] \w+ \. (\w+) [\s,]
1720 [\s,] $lquote (.+?) $rquote [\s,]
1722 my $part = $1 || $2 || $3; # one of them matched if we got here
1723 unless ($seen_having{$part}++) {
1730 my $colpiece = $sel_index->{$_} || $_;
1732 # unqualify join-based group_by's. Arcane but possible query
1733 # also horrible horrible hack to alias a column (not a func.)
1734 # (probably need to introduce SQLA syntax)
1735 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1738 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1740 push @{$sub_attrs->{select}}, $colpiece;
1744 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1745 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1748 return $rsrc->resultset_class
1749 ->new ($rsrc, $sub_attrs)
1751 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1752 ->get_column ('count');
1756 =head2 count_literal
1758 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1759 should only be used in that context. See L</search_literal> for further info.
1763 =item Arguments: $sql_fragment, @standalone_bind_values
1765 =item Return Value: $count
1769 Counts the results in a literal query. Equivalent to calling L</search_literal>
1770 with the passed arguments, then L</count>.
1774 sub count_literal { shift->search_literal(@_)->count; }
1780 =item Arguments: none
1782 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1786 Returns all elements in the resultset.
1793 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1796 delete @{$self}{qw/_stashed_rows _stashed_results/};
1798 if (my $c = $self->get_cache) {
1802 $self->cursor->reset;
1804 my $objs = $self->_construct_results('fetch_all') || [];
1806 $self->set_cache($objs) if $self->{attrs}{cache};
1815 =item Arguments: none
1817 =item Return Value: $self
1821 Resets the resultset's cursor, so you can iterate through the elements again.
1822 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1830 delete @{$self}{qw/_stashed_rows _stashed_results/};
1831 $self->{all_cache_position} = 0;
1832 $self->cursor->reset;
1840 =item Arguments: none
1842 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1846 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1847 an object for the first result (or C<undef> if the resultset is empty).
1852 return $_[0]->reset->next;
1858 # Determines whether and what type of subquery is required for the $rs operation.
1859 # If grouping is necessary either supplies its own, or verifies the current one
1860 # After all is done delegates to the proper storage method.
1862 sub _rs_update_delete {
1863 my ($self, $op, $values) = @_;
1865 my $rsrc = $self->result_source;
1866 my $storage = $rsrc->schema->storage;
1868 my $attrs = { %{$self->_resolved_attrs} };
1870 my $join_classifications;
1871 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1873 # do we need a subquery for any reason?
1875 defined $existing_group_by
1877 # if {from} is unparseable wrap a subq
1878 ref($attrs->{from}) ne 'ARRAY'
1880 # limits call for a subq
1881 $self->_has_resolved_attr(qw/rows offset/)
1884 # simplify the joinmap, so we can further decide if a subq is necessary
1885 if (!$needs_subq and @{$attrs->{from}} > 1) {
1887 ($attrs->{from}, $join_classifications) =
1888 $storage->_prune_unused_joins ($attrs);
1890 # any non-pruneable non-local restricting joins imply subq
1891 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1894 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1896 (ref $attrs->{from}[0]) ne 'HASH'
1898 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1902 # do we need anything like a subquery?
1903 if (! $needs_subq) {
1904 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1905 # a condition containing 'me' or other table prefixes will not work
1906 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1908 my $sqla = $rsrc->storage->sql_maker;
1909 local $sqla->{_dequalify_idents} = 1;
1910 \[ $sqla->_recurse_where($self->{cond}) ];
1914 # we got this far - means it is time to wrap a subquery
1915 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1917 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1923 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1924 delete $attrs->{$_} for qw/select as collapse/;
1925 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1927 # this will be consumed by the pruner waaaaay down the stack
1928 $attrs->{_force_prune_multiplying_joins} = 1;
1930 my $subrs = (ref $self)->new($rsrc, $attrs);
1932 if (@$idcols == 1) {
1933 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1935 elsif ($storage->_use_multicolumn_in) {
1936 # no syntax for calling this properly yet
1937 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1938 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1939 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1944 # if all else fails - get all primary keys and operate over a ORed set
1945 # wrap in a transaction for consistency
1946 # this is where the group_by/multiplication starts to matter
1950 # we do not need to check pre-multipliers, since if the premulti is there, its
1951 # parent (who is multi) will be there too
1952 keys %{ $join_classifications->{multiplying} || {} }
1954 # make sure if there is a supplied group_by it matches the columns compiled above
1955 # perfectly. Anything else can not be sanely executed on most databases so croak
1956 # right then and there
1957 if ($existing_group_by) {
1958 my @current_group_by = map
1959 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1964 join ("\x00", sort @current_group_by)
1966 join ("\x00", sort @{$attrs->{columns}} )
1968 $self->throw_exception (
1969 "You have just attempted a $op operation on a resultset which does group_by"
1970 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1971 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1972 . ' kind of queries. Please retry the operation with a modified group_by or'
1973 . ' without using one at all.'
1978 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1981 $guard = $storage->txn_scope_guard;
1983 for my $row ($subrs->cursor->all) {
1985 { $idcols->[$_] => $row->[$_] }
1992 my $res = $cond ? $storage->$op (
1994 $op eq 'update' ? $values : (),
1998 $guard->commit if $guard;
2007 =item Arguments: \%values
2009 =item Return Value: $underlying_storage_rv
2013 Sets the specified columns in the resultset to the supplied values in a
2014 single query. Note that this will not run any accessor/set_column/update
2015 triggers, nor will it update any result object instances derived from this
2016 resultset (this includes the contents of the L<resultset cache|/set_cache>
2017 if any). See L</update_all> if you need to execute any on-update
2018 triggers or cascades defined either by you or a
2019 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2021 The return value is a pass through of what the underlying
2022 storage backend returned, and may vary. See L<DBI/execute> for the most
2027 Note that L</update> does not process/deflate any of the values passed in.
2028 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2029 ensure manually that any value passed to this method will stringify to
2030 something the RDBMS knows how to deal with. A notable example is the
2031 handling of L<DateTime> objects, for more info see:
2032 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2037 my ($self, $values) = @_;
2038 $self->throw_exception('Values for update must be a hash')
2039 unless ref $values eq 'HASH';
2041 return $self->_rs_update_delete ('update', $values);
2048 =item Arguments: \%values
2050 =item Return Value: 1
2054 Fetches all objects and updates them one at a time via
2055 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2056 triggers, while L</update> will not.
2061 my ($self, $values) = @_;
2062 $self->throw_exception('Values for update_all must be a hash')
2063 unless ref $values eq 'HASH';
2065 my $guard = $self->result_source->schema->txn_scope_guard;
2066 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2075 =item Arguments: none
2077 =item Return Value: $underlying_storage_rv
2081 Deletes the rows matching this resultset in a single query. Note that this
2082 will not run any delete triggers, nor will it alter the
2083 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2084 derived from this resultset (this includes the contents of the
2085 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2086 execute any on-delete triggers or cascades defined either by you or a
2087 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2089 The return value is a pass through of what the underlying storage backend
2090 returned, and may vary. See L<DBI/execute> for the most common case.
2096 $self->throw_exception('delete does not accept any arguments')
2099 return $self->_rs_update_delete ('delete');
2106 =item Arguments: none
2108 =item Return Value: 1
2112 Fetches all objects and deletes them one at a time via
2113 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2114 triggers, while L</delete> will not.
2120 $self->throw_exception('delete_all does not accept any arguments')
2123 my $guard = $self->result_source->schema->txn_scope_guard;
2124 $_->delete for $self->all;
2133 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2135 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2139 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2146 The context of this method call has an important effect on what is
2147 submitted to storage. In void context data is fed directly to fastpath
2148 insertion routines provided by the underlying storage (most often
2149 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2150 L<insert|DBIx::Class::Row/insert> calls on the
2151 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2152 augmentation of these methods provided by components. For example if you
2153 are using something like L<DBIx::Class::UUIDColumns> to create primary
2154 keys for you, you will find that your PKs are empty. In this case you
2155 will have to explicitly force scalar or list context in order to create
2160 In non-void (scalar or list) context, this method is simply a wrapper
2161 for L</create>. Depending on list or scalar context either a list of
2162 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2163 containing these objects is returned.
2165 When supplying data in "arrayref of arrayrefs" invocation style, the
2166 first element should be a list of column names and each subsequent
2167 element should be a data value in the earlier specified column order.
2170 $schema->resultset("Artist")->populate([
2171 [ qw( artistid name ) ],
2172 [ 100, 'A Formally Unknown Singer' ],
2173 [ 101, 'A singer that jumped the shark two albums ago' ],
2174 [ 102, 'An actually cool singer' ],
2177 For the arrayref of hashrefs style each hashref should be a structure
2178 suitable for passing to L</create>. Multi-create is also permitted with
2181 $schema->resultset("Artist")->populate([
2182 { artistid => 4, name => 'Manufactured Crap', cds => [
2183 { title => 'My First CD', year => 2006 },
2184 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2187 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2188 { title => 'My parents sold me to a record company', year => 2005 },
2189 { title => 'Why Am I So Ugly?', year => 2006 },
2190 { title => 'I Got Surgery and am now Popular', year => 2007 }
2195 If you attempt a void-context multi-create as in the example above (each
2196 Artist also has the related list of CDs), and B<do not> supply the
2197 necessary autoinc foreign key information, this method will proxy to the
2198 less efficient L</create>, and then throw the Result objects away. In this
2199 case there are obviously no benefits to using this method over L</create>.
2206 # this is naive and just a quick check
2207 # the types will need to be checked more thoroughly when the
2208 # multi-source populate gets added
2210 ref $_[0] eq 'ARRAY'
2212 ( @{$_[0]} or return )
2214 ( ref $_[0][0] eq 'HASH' or ref $_[0][0] eq 'ARRAY' )
2217 ) or $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2219 # FIXME - no cref handling
2220 # At this point assume either hashes or arrays
2222 if(defined wantarray) {
2223 my (@results, $guard);
2225 if (ref $data->[0] eq 'ARRAY') {
2226 # column names only, nothing to do
2227 return if @$data == 1;
2229 $guard = $self->result_source->schema->storage->txn_scope_guard
2233 { my $vals = $_; $self->new_result({ map { $data->[0][$_] => $vals->[$_] } 0..$#{$data->[0]} })->insert }
2234 @{$data}[1 .. $#$data]
2239 $guard = $self->result_source->schema->storage->txn_scope_guard
2242 @results = map { $self->new_result($_)->insert } @$data;
2245 $guard->commit if $guard;
2246 return wantarray ? @results : \@results;
2249 # we have to deal with *possibly incomplete* related data
2250 # this means we have to walk the data structure twice
2251 # whether we want this or not
2252 # jnap, I hate you ;)
2253 my $rsrc = $self->result_source;
2254 my $rel_info = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2256 my ($colinfo, $colnames, $slices_with_rels);
2260 for my $i (0 .. $#$data) {
2262 my $current_slice_seen_rel_infos;
2264 ### Determine/Supplement collists
2265 ### BEWARE - This is a hot piece of code, a lot of weird idioms were used
2266 if( ref $data->[$i] eq 'ARRAY' ) {
2268 # positional(!) explicit column list
2270 # column names only, nothing to do
2271 return if @$data == 1;
2273 $colinfo->{$data->[0][$_]} = { pos => $_, name => $data->[0][$_] } and push @$colnames, $data->[0][$_]
2274 for 0 .. $#{$data->[0]};
2281 for (values %$colinfo) {
2282 if ($_->{is_rel} ||= (
2283 $rel_info->{$_->{name}}
2286 ref $data->[$i][$_->{pos}] eq 'ARRAY'
2288 ref $data->[$i][$_->{pos}] eq 'HASH'
2290 ( defined blessed $data->[$i][$_->{pos}] and $data->[$i][$_->{pos}]->isa('DBIx::Class::Row') )
2296 # moar sanity check... sigh
2297 for ( ref $data->[$i][$_->{pos}] eq 'ARRAY' ? @{$data->[$i][$_->{pos}]} : $data->[$i][$_->{pos}] ) {
2298 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2299 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2300 return my $throwaway = $self->populate(@_);
2304 push @$current_slice_seen_rel_infos, $rel_info->{$_->{name}};
2309 if ($current_slice_seen_rel_infos) {
2310 push @$slices_with_rels, { map { $colnames->[$_] => $data->[$i][$_] } 0 .. $#$colnames };
2312 # this is needed further down to decide whether or not to fallback to create()
2313 $colinfo->{$colnames->[$_]}{seen_null} ||= ! defined $data->[$i][$_]
2314 for 0 .. $#$colnames;
2317 elsif( ref $data->[$i] eq 'HASH' ) {
2319 for ( sort keys %{$data->[$i]} ) {
2321 $colinfo->{$_} ||= do {
2323 $self->throw_exception("Column '$_' must be present in supplied explicit column list")
2324 if $data_start; # it will be 0 on AoH, 1 on AoA
2326 push @$colnames, $_;
2329 { pos => $#$colnames, name => $_ }
2332 if ($colinfo->{$_}{is_rel} ||= (
2336 ref $data->[$i]{$_} eq 'ARRAY'
2338 ref $data->[$i]{$_} eq 'HASH'
2340 ( defined blessed $data->[$i]{$_} and $data->[$i]{$_}->isa('DBIx::Class::Row') )
2346 # moar sanity check... sigh
2347 for ( ref $data->[$i]{$_} eq 'ARRAY' ? @{$data->[$i]{$_}} : $data->[$i]{$_} ) {
2348 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2349 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2350 return my $throwaway = $self->populate(@_);
2354 push @$current_slice_seen_rel_infos, $rel_info->{$_};
2358 if ($current_slice_seen_rel_infos) {
2359 push @$slices_with_rels, $data->[$i];
2361 # this is needed further down to decide whether or not to fallback to create()
2362 $colinfo->{$_}{seen_null} ||= ! defined $data->[$i]{$_}
2363 for keys %{$data->[$i]};
2367 $self->throw_exception('Unexpected populate() data structure member type: ' . ref $data->[$i] );
2371 { $_->{attrs}{is_depends_on} }
2372 @{ $current_slice_seen_rel_infos || [] }
2374 carp_unique("Fast-path populate() of belongs_to relationship data is not possible - falling back to regular create()");
2375 return my $throwaway = $self->populate(@_);
2379 if( $slices_with_rels ) {
2381 # need to exclude the rel "columns"
2382 $colnames = [ grep { ! $colinfo->{$_}{is_rel} } @$colnames ];
2384 # extra sanity check - ensure the main source is in fact identifiable
2385 # the localizing of nullability is insane, but oh well... the use-case is legit
2386 my $ci = $rsrc->columns_info($colnames);
2388 $ci->{$_} = { %{$ci->{$_}}, is_nullable => 0 }
2389 for grep { ! $colinfo->{$_}{seen_null} } keys %$ci;
2391 unless( $rsrc->_identifying_column_set($ci) ) {
2392 carp_unique("Fast-path populate() of non-uniquely identifiable rows with related data is not possible - falling back to regular create()");
2393 return my $throwaway = $self->populate(@_);
2397 ### inherit the data locked in the conditions of the resultset
2398 my ($rs_data) = $self->_merge_with_rscond({});
2399 delete @{$rs_data}{@$colnames}; # passed-in stuff takes precedence
2401 # if anything left - decompose rs_data
2403 if (keys %$rs_data) {
2404 push @$rs_data_vals, $rs_data->{$_}
2405 for sort keys %$rs_data;
2410 $guard = $rsrc->schema->storage->txn_scope_guard
2411 if $slices_with_rels;
2413 ### main source data
2414 # FIXME - need to switch entirely to a coderef-based thing,
2415 # so that large sets aren't copied several times... I think
2416 $rsrc->storage->_insert_bulk(
2418 [ @$colnames, sort keys %$rs_data ],
2420 ref $data->[$_] eq 'ARRAY'
2422 $slices_with_rels ? [ @{$data->[$_]}[0..$#$colnames], @{$rs_data_vals||[]} ] # the collist changed
2423 : $rs_data_vals ? [ @{$data->[$_]}, @$rs_data_vals ]
2426 : [ @{$data->[$_]}{@$colnames}, @{$rs_data_vals||[]} ]
2427 } $data_start .. $#$data ],
2430 ### do the children relationships
2431 if ( $slices_with_rels ) {
2432 my @rels = grep { $colinfo->{$_}{is_rel} } keys %$colinfo
2433 or die 'wtf... please report a bug with DBIC_TRACE=1 output (stacktrace)';
2435 for my $sl (@$slices_with_rels) {
2437 my ($main_proto, $main_proto_rs);
2438 for my $rel (@rels) {
2439 next unless defined $sl->{$rel};
2443 (map { $_ => $sl->{$_} } @$colnames),
2446 unless (defined $colinfo->{$rel}{rs}) {
2448 $colinfo->{$rel}{rs} = $rsrc->related_source($rel)->resultset;
2450 $colinfo->{$rel}{fk_map} = { reverse %{ $rsrc->_resolve_relationship_condition(
2452 self_alias => "\xFE", # irrelevant
2453 foreign_alias => "\xFF", # irrelevant
2454 )->{identity_map} || {} } };
2458 $colinfo->{$rel}{rs}->search({ map # only so that we inherit them values properly, no actual search
2461 ( $main_proto_rs ||= $rsrc->resultset->search($main_proto) )
2462 ->get_column( $colinfo->{$rel}{fk_map}{$_} )
2466 keys %{$colinfo->{$rel}{fk_map}}
2467 })->populate( ref $sl->{$rel} eq 'ARRAY' ? $sl->{$rel} : [ $sl->{$rel} ] );
2474 $guard->commit if $guard;
2481 =item Arguments: none
2483 =item Return Value: L<$pager|Data::Page>
2487 Returns a L<Data::Page> object for the current resultset. Only makes
2488 sense for queries with a C<page> attribute.
2490 To get the full count of entries for a paged resultset, call
2491 C<total_entries> on the L<Data::Page> object.
2498 return $self->{pager} if $self->{pager};
2500 my $attrs = $self->{attrs};
2501 if (!defined $attrs->{page}) {
2502 $self->throw_exception("Can't create pager for non-paged rs");
2504 elsif ($attrs->{page} <= 0) {
2505 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2507 $attrs->{rows} ||= 10;
2509 # throw away the paging flags and re-run the count (possibly
2510 # with a subselect) to get the real total count
2511 my $count_attrs = { %$attrs };
2512 delete @{$count_attrs}{qw/rows offset page pager/};
2514 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2516 require DBIx::Class::ResultSet::Pager;
2517 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2518 sub { $total_rs->count }, #lazy-get the total
2520 $self->{attrs}{page},
2528 =item Arguments: $page_number
2530 =item Return Value: L<$resultset|/search>
2534 Returns a resultset for the $page_number page of the resultset on which page
2535 is called, where each page contains a number of rows equal to the 'rows'
2536 attribute set on the resultset (10 by default).
2541 my ($self, $page) = @_;
2542 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2549 =item Arguments: \%col_data
2551 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2555 Creates a new result object in the resultset's result class and returns
2556 it. The row is not inserted into the database at this point, call
2557 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2558 will tell you whether the result object has been inserted or not.
2560 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2565 my ($self, $values) = @_;
2567 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2570 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2571 unless (ref $values eq 'HASH');
2573 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2575 my $new = $self->result_class->new({
2577 ( @$cols_from_relations
2578 ? (-cols_from_relations => $cols_from_relations)
2581 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2585 reftype($new) eq 'HASH'
2591 carp_unique (sprintf (
2592 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2593 $self->result_class,
2600 # _merge_with_rscond
2602 # Takes a simple hash of K/V data and returns its copy merged with the
2603 # condition already present on the resultset. Additionally returns an
2604 # arrayref of value/condition names, which were inferred from related
2605 # objects (this is needed for in-memory related objects)
2606 sub _merge_with_rscond {
2607 my ($self, $data) = @_;
2609 my ($implied_data, @cols_from_relations);
2611 my $alias = $self->{attrs}{alias};
2613 if (! defined $self->{cond}) {
2614 # just massage $data below
2616 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2617 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2618 @cols_from_relations = keys %{ $implied_data || {} };
2621 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2622 $implied_data = { map {
2623 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2629 { %{ $self->_remove_alias($_, $alias) } }
2630 # precedence must be given to passed values over values inherited from
2631 # the cond, so the order here is important.
2632 ( $implied_data||(), $data)
2634 \@cols_from_relations
2638 # _has_resolved_attr
2640 # determines if the resultset defines at least one
2641 # of the attributes supplied
2643 # used to determine if a subquery is necessary
2645 # supports some virtual attributes:
2647 # This will scan for any joins being present on the resultset.
2648 # It is not a mere key-search but a deep inspection of {from}
2651 sub _has_resolved_attr {
2652 my ($self, @attr_names) = @_;
2654 my $attrs = $self->_resolved_attrs;
2658 for my $n (@attr_names) {
2659 if (grep { $n eq $_ } (qw/-join/) ) {
2660 $extra_checks{$n}++;
2664 my $attr = $attrs->{$n};
2666 next if not defined $attr;
2668 if (ref $attr eq 'HASH') {
2669 return 1 if keys %$attr;
2671 elsif (ref $attr eq 'ARRAY') {
2679 # a resolved join is expressed as a multi-level from
2681 $extra_checks{-join}
2683 ref $attrs->{from} eq 'ARRAY'
2685 @{$attrs->{from}} > 1
2693 # Remove the specified alias from the specified query hash. A copy is made so
2694 # the original query is not modified.
2697 my ($self, $query, $alias) = @_;
2699 my %orig = %{ $query || {} };
2702 foreach my $key (keys %orig) {
2704 $unaliased{$key} = $orig{$key};
2707 $unaliased{$1} = $orig{$key}
2708 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2718 =item Arguments: none
2720 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2724 Returns the SQL query and bind vars associated with the invocant.
2726 This is generally used as the RHS for a subquery.
2733 my $attrs = { %{ $self->_resolved_attrs } };
2735 my $aq = $self->result_source->storage->_select_args_to_query (
2736 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2746 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2748 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2752 my $artist = $schema->resultset('Artist')->find_or_new(
2753 { artist => 'fred' }, { key => 'artists' });
2755 $cd->cd_to_producer->find_or_new({ producer => $producer },
2756 { key => 'primary' });
2758 Find an existing record from this resultset using L</find>. if none exists,
2759 instantiate a new result object and return it. The object will not be saved
2760 into your storage until you call L<DBIx::Class::Row/insert> on it.
2762 You most likely want this method when looking for existing rows using a unique
2763 constraint that is not the primary key, or looking for related rows.
2765 If you want objects to be saved immediately, use L</find_or_create> instead.
2767 B<Note>: Make sure to read the documentation of L</find> and understand the
2768 significance of the C<key> attribute, as its lack may skew your search, and
2769 subsequently result in spurious new objects.
2771 B<Note>: Take care when using C<find_or_new> with a table having
2772 columns with default values that you intend to be automatically
2773 supplied by the database (e.g. an auto_increment primary key column).
2774 In normal usage, the value of such columns should NOT be included at
2775 all in the call to C<find_or_new>, even when set to C<undef>.
2781 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2782 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2783 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2786 return $self->new_result($hash);
2793 =item Arguments: \%col_data
2795 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2799 Attempt to create a single new row or a row with multiple related rows
2800 in the table represented by the resultset (and related tables). This
2801 will not check for duplicate rows before inserting, use
2802 L</find_or_create> to do that.
2804 To create one row for this resultset, pass a hashref of key/value
2805 pairs representing the columns of the table and the values you wish to
2806 store. If the appropriate relationships are set up, foreign key fields
2807 can also be passed an object representing the foreign row, and the
2808 value will be set to its primary key.
2810 To create related objects, pass a hashref of related-object column values
2811 B<keyed on the relationship name>. If the relationship is of type C<multi>
2812 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2813 The process will correctly identify columns holding foreign keys, and will
2814 transparently populate them from the keys of the corresponding relation.
2815 This can be applied recursively, and will work correctly for a structure
2816 with an arbitrary depth and width, as long as the relationships actually
2817 exists and the correct column data has been supplied.
2819 Instead of hashrefs of plain related data (key/value pairs), you may
2820 also pass new or inserted objects. New objects (not inserted yet, see
2821 L</new_result>), will be inserted into their appropriate tables.
2823 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2825 Example of creating a new row.
2827 $person_rs->create({
2828 name=>"Some Person",
2829 email=>"somebody@someplace.com"
2832 Example of creating a new row and also creating rows in a related C<has_many>
2833 or C<has_one> resultset. Note Arrayref.
2836 { artistid => 4, name => 'Manufactured Crap', cds => [
2837 { title => 'My First CD', year => 2006 },
2838 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2843 Example of creating a new row and also creating a row in a related
2844 C<belongs_to> resultset. Note Hashref.
2847 title=>"Music for Silly Walks",
2850 name=>"Silly Musician",
2858 When subclassing ResultSet never attempt to override this method. Since
2859 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2860 lot of the internals simply never call it, so your override will be
2861 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2862 or L<DBIx::Class::Row/insert> depending on how early in the
2863 L</create> process you need to intervene. See also warning pertaining to
2871 #my ($self, $col_data) = @_;
2872 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2873 return shift->new_result(shift)->insert;
2876 =head2 find_or_create
2880 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2882 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2886 $cd->cd_to_producer->find_or_create({ producer => $producer },
2887 { key => 'primary' });
2889 Tries to find a record based on its primary key or unique constraints; if none
2890 is found, creates one and returns that instead.
2892 my $cd = $schema->resultset('CD')->find_or_create({
2894 artist => 'Massive Attack',
2895 title => 'Mezzanine',
2899 Also takes an optional C<key> attribute, to search by a specific key or unique
2900 constraint. For example:
2902 my $cd = $schema->resultset('CD')->find_or_create(
2904 artist => 'Massive Attack',
2905 title => 'Mezzanine',
2907 { key => 'cd_artist_title' }
2910 B<Note>: Make sure to read the documentation of L</find> and understand the
2911 significance of the C<key> attribute, as its lack may skew your search, and
2912 subsequently result in spurious row creation.
2914 B<Note>: Because find_or_create() reads from the database and then
2915 possibly inserts based on the result, this method is subject to a race
2916 condition. Another process could create a record in the table after
2917 the find has completed and before the create has started. To avoid
2918 this problem, use find_or_create() inside a transaction.
2920 B<Note>: Take care when using C<find_or_create> with a table having
2921 columns with default values that you intend to be automatically
2922 supplied by the database (e.g. an auto_increment primary key column).
2923 In normal usage, the value of such columns should NOT be included at
2924 all in the call to C<find_or_create>, even when set to C<undef>.
2926 See also L</find> and L</update_or_create>. For information on how to declare
2927 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2929 If you need to know if an existing row was found or a new one created use
2930 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2931 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2934 my $cd = $schema->resultset('CD')->find_or_new({
2936 artist => 'Massive Attack',
2937 title => 'Mezzanine',
2941 if( !$cd->in_storage ) {
2948 sub find_or_create {
2950 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2951 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2952 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2955 return $self->new_result($hash)->insert;
2958 =head2 update_or_create
2962 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2964 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2968 $resultset->update_or_create({ col => $val, ... });
2970 Like L</find_or_create>, but if a row is found it is immediately updated via
2971 C<< $found_row->update (\%col_data) >>.
2974 Takes an optional C<key> attribute to search on a specific unique constraint.
2977 # In your application
2978 my $cd = $schema->resultset('CD')->update_or_create(
2980 artist => 'Massive Attack',
2981 title => 'Mezzanine',
2984 { key => 'cd_artist_title' }
2987 $cd->cd_to_producer->update_or_create({
2988 producer => $producer,
2994 B<Note>: Make sure to read the documentation of L</find> and understand the
2995 significance of the C<key> attribute, as its lack may skew your search, and
2996 subsequently result in spurious row creation.
2998 B<Note>: Take care when using C<update_or_create> with a table having
2999 columns with default values that you intend to be automatically
3000 supplied by the database (e.g. an auto_increment primary key column).
3001 In normal usage, the value of such columns should NOT be included at
3002 all in the call to C<update_or_create>, even when set to C<undef>.
3004 See also L</find> and L</find_or_create>. For information on how to declare
3005 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3007 If you need to know if an existing row was updated or a new one created use
3008 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3009 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3014 sub update_or_create {
3016 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3017 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3019 my $row = $self->find($cond, $attrs);
3021 $row->update($cond);
3025 return $self->new_result($cond)->insert;
3028 =head2 update_or_new
3032 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3034 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3038 $resultset->update_or_new({ col => $val, ... });
3040 Like L</find_or_new> but if a row is found it is immediately updated via
3041 C<< $found_row->update (\%col_data) >>.
3045 # In your application
3046 my $cd = $schema->resultset('CD')->update_or_new(
3048 artist => 'Massive Attack',
3049 title => 'Mezzanine',
3052 { key => 'cd_artist_title' }
3055 if ($cd->in_storage) {
3056 # the cd was updated
3059 # the cd is not yet in the database, let's insert it
3063 B<Note>: Make sure to read the documentation of L</find> and understand the
3064 significance of the C<key> attribute, as its lack may skew your search, and
3065 subsequently result in spurious new objects.
3067 B<Note>: Take care when using C<update_or_new> with a table having
3068 columns with default values that you intend to be automatically
3069 supplied by the database (e.g. an auto_increment primary key column).
3070 In normal usage, the value of such columns should NOT be included at
3071 all in the call to C<update_or_new>, even when set to C<undef>.
3073 See also L</find>, L</find_or_create> and L</find_or_new>.
3079 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3080 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3082 my $row = $self->find( $cond, $attrs );
3083 if ( defined $row ) {
3084 $row->update($cond);
3088 return $self->new_result($cond);
3095 =item Arguments: none
3097 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3101 Gets the contents of the cache for the resultset, if the cache is set.
3103 The cache is populated either by using the L</prefetch> attribute to
3104 L</search> or by calling L</set_cache>.
3116 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3118 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3122 Sets the contents of the cache for the resultset. Expects an arrayref
3123 of objects of the same class as those produced by the resultset. Note that
3124 if the cache is set, the resultset will return the cached objects rather
3125 than re-querying the database even if the cache attr is not set.
3127 The contents of the cache can also be populated by using the
3128 L</prefetch> attribute to L</search>.
3133 my ( $self, $data ) = @_;
3134 $self->throw_exception("set_cache requires an arrayref")
3135 if defined($data) && (ref $data ne 'ARRAY');
3136 $self->{all_cache} = $data;
3143 =item Arguments: none
3145 =item Return Value: undef
3149 Clears the cache for the resultset.
3154 shift->set_cache(undef);
3161 =item Arguments: none
3163 =item Return Value: true, if the resultset has been paginated
3171 return !!$self->{attrs}{page};
3178 =item Arguments: none
3180 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3188 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3191 =head2 related_resultset
3195 =item Arguments: $rel_name
3197 =item Return Value: L<$resultset|/search>
3201 Returns a related resultset for the supplied relationship name.
3203 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3207 sub related_resultset {
3208 $_[0]->throw_exception(
3209 'Extra arguments to $rs->related_resultset() were always quietly '
3210 . 'discarded without consideration, you need to switch to '
3211 . '...->related_resultset( $relname )->search_rs( $search, $args ) instead.'
3214 return $_[0]->{related_resultsets}{$_[1]}
3215 if defined $_[0]->{related_resultsets}{$_[1]};
3217 my ($self, $rel) = @_;
3219 return $self->{related_resultsets}{$rel} = do {
3220 my $rsrc = $self->result_source;
3221 my $rel_info = $rsrc->relationship_info($rel);
3223 $self->throw_exception(
3224 "search_related: result source '" . $rsrc->source_name .
3225 "' has no such relationship $rel")
3228 my $attrs = $self->_chain_relationship($rel);
3230 my $storage = $rsrc->schema->storage;
3232 # Previously this atribute was deleted (instead of being set as it is now)
3233 # Doing so seems to be harmless in all available test permutations
3234 # See also 01d59a6a6 and mst's comment below
3236 $attrs->{alias} = $storage->relname_to_table_alias(
3238 $attrs->{seen_join}{$rel}
3241 # since this is search_related, and we already slid the select window inwards
3242 # (the select/as attrs were deleted in the beginning), we need to flip all
3243 # left joins to inner, so we get the expected results
3244 # read the comment on top of the actual function to see what this does
3245 $attrs->{from} = $storage->_inner_join_to_node( $attrs->{from}, $attrs->{alias} );
3247 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3248 delete $attrs->{result_class};
3252 # The reason we do this now instead of passing the alias to the
3253 # search_rs below is that if you wrap/overload resultset on the
3254 # source you need to know what alias it's -going- to have for things
3255 # to work sanely (e.g. RestrictWithObject wants to be able to add
3256 # extra query restrictions, and these may need to be $alias.)
3257 # -- mst ~ 2007 (01d59a6a6)
3259 # FIXME - this seems to be no longer neccessary (perhaps due to the
3260 # advances in relcond resolution. Testing DBIC::S::RWO and its only
3261 # dependent (as of Jun 2015 ) does not yield any difference with or
3262 # without this line. Nevertheless keep it as is for now, to minimize
3263 # churn, there is enough potential for breakage in 0.0829xx as it is
3264 # -- ribasushi Jun 2015
3266 my $rel_source = $rsrc->related_source($rel);
3267 local $rel_source->resultset_attributes->{alias} = $attrs->{alias};
3269 $rel_source->resultset->search_rs( undef, $attrs );
3272 if (my $cache = $self->get_cache) {
3273 my @related_cache = map
3274 { $_->related_resultset($rel)->get_cache || () }
3278 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3285 =head2 current_source_alias
3289 =item Arguments: none
3291 =item Return Value: $source_alias
3295 Returns the current table alias for the result source this resultset is built
3296 on, that will be used in the SQL query. Usually it is C<me>.
3298 Currently the source alias that refers to the result set returned by a
3299 L</search>/L</find> family method depends on how you got to the resultset: it's
3300 C<me> by default, but eg. L</search_related> aliases it to the related result
3301 source name (and keeps C<me> referring to the original result set). The long
3302 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3303 (and make this method unnecessary).
3305 Thus it's currently necessary to use this method in predefined queries (see
3306 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3307 source alias of the current result set:
3309 # in a result set class
3311 my ($self, $user) = @_;
3313 my $me = $self->current_source_alias;
3315 return $self->search({
3316 "$me.modified" => $user->id,
3320 The alias of L<newly created resultsets|/search> can be altered by the
3321 L<alias attribute|/alias>.
3325 sub current_source_alias {
3326 return (shift->{attrs} || {})->{alias} || 'me';
3329 =head2 as_subselect_rs
3333 =item Arguments: none
3335 =item Return Value: L<$resultset|/search>
3339 Act as a barrier to SQL symbols. The resultset provided will be made into a
3340 "virtual view" by including it as a subquery within the from clause. From this
3341 point on, any joined tables are inaccessible to ->search on the resultset (as if
3342 it were simply where-filtered without joins). For example:
3344 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3346 # 'x' now pollutes the query namespace
3348 # So the following works as expected
3349 my $ok_rs = $rs->search({'x.other' => 1});
3351 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3352 # def) we look for one row with contradictory terms and join in another table
3353 # (aliased 'x_2') which we never use
3354 my $broken_rs = $rs->search({'x.name' => 'def'});
3356 my $rs2 = $rs->as_subselect_rs;
3358 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3359 my $not_joined_rs = $rs2->search({'x.other' => 1});
3361 # works as expected: finds a 'table' row related to two x rows (abc and def)
3362 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3364 Another example of when one might use this would be to select a subset of
3365 columns in a group by clause:
3367 my $rs = $schema->resultset('Bar')->search(undef, {
3368 group_by => [qw{ id foo_id baz_id }],
3369 })->as_subselect_rs->search(undef, {
3370 columns => [qw{ id foo_id }]
3373 In the above example normally columns would have to be equal to the group by,
3374 but because we isolated the group by into a subselect the above works.
3378 sub as_subselect_rs {
3381 my $attrs = $self->_resolved_attrs;
3383 my $fresh_rs = (ref $self)->new (
3384 $self->result_source
3387 # these pieces will be locked in the subquery
3388 delete $fresh_rs->{cond};
3389 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3391 return $fresh_rs->search( {}, {
3393 $attrs->{alias} => $self->as_query,
3394 -alias => $attrs->{alias},
3395 -rsrc => $self->result_source,
3397 alias => $attrs->{alias},
3401 # This code is called by search_related, and makes sure there
3402 # is clear separation between the joins before, during, and
3403 # after the relationship. This information is needed later
3404 # in order to properly resolve prefetch aliases (any alias
3405 # with a relation_chain_depth less than the depth of the
3406 # current prefetch is not considered)
3408 # The increments happen twice per join. An even number means a
3409 # relationship specified via a search_related, whereas an odd
3410 # number indicates a join/prefetch added via attributes
3412 # Also this code will wrap the current resultset (the one we
3413 # chain to) in a subselect IFF it contains limiting attributes
3414 sub _chain_relationship {
3415 my ($self, $rel) = @_;
3416 my $source = $self->result_source;
3417 my $attrs = { %{$self->{attrs}||{}} };
3419 # we need to take the prefetch the attrs into account before we
3420 # ->_resolve_join as otherwise they get lost - captainL
3421 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3423 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3425 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3428 my @force_subq_attrs = qw/offset rows group_by having/;
3431 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3433 $self->_has_resolved_attr (@force_subq_attrs)
3435 # Nuke the prefetch (if any) before the new $rs attrs
3436 # are resolved (prefetch is useless - we are wrapping
3437 # a subquery anyway).
3438 my $rs_copy = $self->search;
3439 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3440 $rs_copy->{attrs}{join},
3441 delete $rs_copy->{attrs}{prefetch},
3446 -alias => $attrs->{alias},
3447 $attrs->{alias} => $rs_copy->as_query,
3449 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3450 $seen->{-relation_chain_depth} = 0;
3452 elsif ($attrs->{from}) { #shallow copy suffices
3453 $from = [ @{$attrs->{from}} ];
3458 -alias => $attrs->{alias},
3459 $attrs->{alias} => $source->from,
3463 my $jpath = ($seen->{-relation_chain_depth})
3464 ? $from->[-1][0]{-join_path}
3467 my @requested_joins = $source->_resolve_join(
3474 push @$from, @requested_joins;
3476 $seen->{-relation_chain_depth}++;
3478 # if $self already had a join/prefetch specified on it, the requested
3479 # $rel might very well be already included. What we do in this case
3480 # is effectively a no-op (except that we bump up the chain_depth on
3481 # the join in question so we could tell it *is* the search_related)
3484 # we consider the last one thus reverse
3485 for my $j (reverse @requested_joins) {
3486 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3487 if ($rel eq $last_j) {
3488 $j->[0]{-relation_chain_depth}++;
3494 unless ($already_joined) {
3495 push @$from, $source->_resolve_join(
3503 $seen->{-relation_chain_depth}++;
3505 return {%$attrs, from => $from, seen_join => $seen};
3508 sub _resolved_attrs {
3510 return $self->{_attrs} if $self->{_attrs};
3512 my $attrs = { %{ $self->{attrs} || {} } };
3513 my $source = $attrs->{result_source} = $self->result_source;
3514 my $alias = $attrs->{alias};
3516 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3517 if $attrs->{collapse} and $attrs->{distinct};
3520 # Sanity check the paging attributes
3521 # SQLMaker does it too, but in case of a software_limit we'll never get there
3522 if (defined $attrs->{offset}) {
3523 $self->throw_exception('A supplied offset attribute must be a non-negative integer')
3524 if ( $attrs->{offset} =~ /[^0-9]/ or $attrs->{offset} < 0 );
3526 if (defined $attrs->{rows}) {
3527 $self->throw_exception("The rows attribute must be a positive integer if present")
3528 if ( $attrs->{rows} =~ /[^0-9]/ or $attrs->{rows} <= 0 );
3532 # default selection list
3533 $attrs->{columns} = [ $source->columns ]
3534 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3536 # merge selectors together
3537 for (qw/columns select as/) {
3538 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3539 if $attrs->{$_} or $attrs->{"+$_"};
3542 # disassemble columns
3544 if (my $cols = delete $attrs->{columns}) {
3545 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3546 if (ref $c eq 'HASH') {
3547 for my $as (sort keys %$c) {
3548 push @sel, $c->{$as};
3559 # when trying to weed off duplicates later do not go past this point -
3560 # everything added from here on is unbalanced "anyone's guess" stuff
3561 my $dedup_stop_idx = $#as;
3563 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3565 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3566 if $attrs->{select};
3568 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3569 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3571 # disqualify all $alias.col as-bits (inflate-map mandated)
3572 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3574 # de-duplicate the result (remove *identical* select/as pairs)
3575 # and also die on duplicate {as} pointing to different {select}s
3576 # not using a c-style for as the condition is prone to shrinkage
3579 while ($i <= $dedup_stop_idx) {
3580 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3585 elsif ($seen->{$as[$i]}++) {
3586 $self->throw_exception(
3587 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3595 $attrs->{select} = \@sel;
3596 $attrs->{as} = \@as;
3598 $attrs->{from} ||= [{
3600 -alias => $self->{attrs}{alias},
3601 $self->{attrs}{alias} => $source->from,
3604 if ( $attrs->{join} || $attrs->{prefetch} ) {
3606 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3607 if ref $attrs->{from} ne 'ARRAY';
3609 my $join = (delete $attrs->{join}) || {};
3611 if ( defined $attrs->{prefetch} ) {
3612 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3615 $attrs->{from} = # have to copy here to avoid corrupting the original
3617 @{ $attrs->{from} },
3618 $source->_resolve_join(
3621 { %{ $attrs->{seen_join} || {} } },
3622 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3623 ? $attrs->{from}[-1][0]{-join_path}
3631 for my $attr (qw(order_by group_by)) {
3633 if ( defined $attrs->{$attr} ) {
3635 ref( $attrs->{$attr} ) eq 'ARRAY'
3636 ? [ @{ $attrs->{$attr} } ]
3637 : [ $attrs->{$attr} || () ]
3640 delete $attrs->{$attr} unless @{$attrs->{$attr}};
3645 # set collapse default based on presence of prefetch
3648 defined $attrs->{prefetch}
3650 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3652 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3653 if defined $attrs->{collapse} and ! $attrs->{collapse};
3655 $attrs->{collapse} = 1;
3659 # run through the resulting joinstructure (starting from our current slot)
3660 # and unset collapse if proven unnecessary
3662 # also while we are at it find out if the current root source has
3663 # been premultiplied by previous related_source chaining
3665 # this allows to predict whether a root object with all other relation
3666 # data set to NULL is in fact unique
3667 if ($attrs->{collapse}) {
3669 if (ref $attrs->{from} eq 'ARRAY') {
3671 if (@{$attrs->{from}} == 1) {
3672 # no joins - no collapse
3673 $attrs->{collapse} = 0;
3676 # find where our table-spec starts
3677 my @fromlist = @{$attrs->{from}};
3679 my $t = shift @fromlist;
3682 # me vs join from-spec distinction - a ref means non-root
3683 if (ref $t eq 'ARRAY') {
3685 $is_multi ||= ! $t->{-is_single};
3687 last if ($t->{-alias} && $t->{-alias} eq $alias);
3688 $attrs->{_main_source_premultiplied} ||= $is_multi;
3691 # no non-singles remaining, nor any premultiplication - nothing to collapse
3693 ! $attrs->{_main_source_premultiplied}
3695 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3697 $attrs->{collapse} = 0;
3703 # if we can not analyze the from - err on the side of safety
3704 $attrs->{_main_source_premultiplied} = 1;
3709 # generate the distinct induced group_by before injecting the prefetched select/as parts
3710 if (delete $attrs->{distinct}) {
3711 if ($attrs->{group_by}) {
3712 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3715 $attrs->{_grouped_by_distinct} = 1;
3716 # distinct affects only the main selection part, not what prefetch may add below
3717 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3719 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3720 # The thinking is: if we are collapsing the subquerying prefetch engine will
3721 # rip stuff apart for us anyway, and we do not want to have a potentially
3722 # function-converted external order_by
3723 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3724 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3729 # generate selections based on the prefetch helper
3732 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3733 if $attrs->{_dark_selector};
3735 # this is a separate structure (we don't look in {from} directly)
3736 # as the resolver needs to shift things off the lists to work
3737 # properly (identical-prefetches on different branches)
3738 my $joined_node_aliases_map = {};
3739 if (ref $attrs->{from} eq 'ARRAY') {
3741 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3743 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3744 next unless $j->[0]{-alias};
3745 next unless $j->[0]{-join_path};
3746 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3748 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3750 my $p = $joined_node_aliases_map;
3751 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3752 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3756 ( push @{$attrs->{select}}, $_->[0] ) and ( push @{$attrs->{as}}, $_->[1] )
3757 for $source->_resolve_selection_from_prefetch( $prefetch, $joined_node_aliases_map );
3761 $attrs->{_simple_passthrough_construction} = !(
3764 grep { $_ =~ /\./ } @{$attrs->{as}}
3768 # if both page and offset are specified, produce a combined offset
3769 # even though it doesn't make much sense, this is what pre 081xx has
3771 if (my $page = delete $attrs->{page}) {
3773 ($attrs->{rows} * ($page - 1))
3775 ($attrs->{offset} || 0)
3779 return $self->{_attrs} = $attrs;
3783 my ($self, $attr) = @_;
3785 if (ref $attr eq 'HASH') {
3786 return $self->_rollout_hash($attr);
3787 } elsif (ref $attr eq 'ARRAY') {
3788 return $self->_rollout_array($attr);
3794 sub _rollout_array {
3795 my ($self, $attr) = @_;
3798 foreach my $element (@{$attr}) {
3799 if (ref $element eq 'HASH') {
3800 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3801 } elsif (ref $element eq 'ARRAY') {
3802 # XXX - should probably recurse here
3803 push( @rolled_array, @{$self->_rollout_array($element)} );
3805 push( @rolled_array, $element );
3808 return \@rolled_array;
3812 my ($self, $attr) = @_;
3815 foreach my $key (keys %{$attr}) {
3816 push( @rolled_array, { $key => $attr->{$key} } );
3818 return \@rolled_array;
3821 sub _calculate_score {
3822 my ($self, $a, $b) = @_;
3824 if (defined $a xor defined $b) {
3827 elsif (not defined $a) {
3831 if (ref $b eq 'HASH') {
3832 my ($b_key) = keys %{$b};
3833 $b_key = '' if ! defined $b_key;
3834 if (ref $a eq 'HASH') {
3835 my ($a_key) = keys %{$a};
3836 $a_key = '' if ! defined $a_key;
3837 if ($a_key eq $b_key) {
3838 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3843 return ($a eq $b_key) ? 1 : 0;
3846 if (ref $a eq 'HASH') {
3847 my ($a_key) = keys %{$a};
3848 return ($b eq $a_key) ? 1 : 0;
3850 return ($b eq $a) ? 1 : 0;
3855 sub _merge_joinpref_attr {
3856 my ($self, $orig, $import) = @_;
3858 return $import unless defined($orig);
3859 return $orig unless defined($import);
3861 $orig = $self->_rollout_attr($orig);
3862 $import = $self->_rollout_attr($import);
3865 foreach my $import_element ( @{$import} ) {
3866 # find best candidate from $orig to merge $b_element into
3867 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3868 foreach my $orig_element ( @{$orig} ) {
3869 my $score = $self->_calculate_score( $orig_element, $import_element );
3870 if ($score > $best_candidate->{score}) {
3871 $best_candidate->{position} = $position;
3872 $best_candidate->{score} = $score;
3876 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3877 $import_key = '' if not defined $import_key;
3879 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3880 push( @{$orig}, $import_element );
3882 my $orig_best = $orig->[$best_candidate->{position}];
3883 # merge orig_best and b_element together and replace original with merged
3884 if (ref $orig_best ne 'HASH') {
3885 $orig->[$best_candidate->{position}] = $import_element;
3886 } elsif (ref $import_element eq 'HASH') {
3887 my ($key) = keys %{$orig_best};
3888 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3891 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3894 return @$orig ? $orig : ();
3902 require Hash::Merge;
3903 my $hm = Hash::Merge->new;
3905 $hm->specify_behavior({
3908 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3910 if ($defl xor $defr) {
3911 return [ $defl ? $_[0] : $_[1] ];
3916 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3920 return [$_[0], $_[1]];
3924 return $_[1] if !defined $_[0];
3925 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3926 return [$_[0], @{$_[1]}]
3929 return [] if !defined $_[0] and !keys %{$_[1]};
3930 return [ $_[1] ] if !defined $_[0];
3931 return [ $_[0] ] if !keys %{$_[1]};
3932 return [$_[0], $_[1]]
3937 return $_[0] if !defined $_[1];
3938 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3939 return [@{$_[0]}, $_[1]]
3942 my @ret = @{$_[0]} or return $_[1];
3943 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3944 my %idx = map { $_ => 1 } @ret;
3945 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3949 return [ $_[1] ] if ! @{$_[0]};
3950 return $_[0] if !keys %{$_[1]};
3951 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3952 return [ @{$_[0]}, $_[1] ];
3957 return [] if !keys %{$_[0]} and !defined $_[1];
3958 return [ $_[0] ] if !defined $_[1];
3959 return [ $_[1] ] if !keys %{$_[0]};
3960 return [$_[0], $_[1]]
3963 return [] if !keys %{$_[0]} and !@{$_[1]};
3964 return [ $_[0] ] if !@{$_[1]};
3965 return $_[1] if !keys %{$_[0]};
3966 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3967 return [ $_[0], @{$_[1]} ];
3970 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3971 return [ $_[0] ] if !keys %{$_[1]};
3972 return [ $_[1] ] if !keys %{$_[0]};
3973 return [ $_[0] ] if $_[0] eq $_[1];
3974 return [ $_[0], $_[1] ];
3977 } => 'DBIC_RS_ATTR_MERGER');
3981 return $hm->merge ($_[1], $_[2]);
3985 sub STORABLE_freeze {
3986 my ($self, $cloning) = @_;
3987 my $to_serialize = { %$self };
3989 # A cursor in progress can't be serialized (and would make little sense anyway)
3990 # the parser can be regenerated (and can't be serialized)
3991 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3993 # nor is it sensical to store a not-yet-fired-count pager
3994 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3995 delete $to_serialize->{pager};
3998 Storable::nfreeze($to_serialize);
4001 # need this hook for symmetry
4003 my ($self, $cloning, $serialized) = @_;
4005 %$self = %{ Storable::thaw($serialized) };
4011 =head2 throw_exception
4013 See L<DBIx::Class::Schema/throw_exception> for details.
4017 sub throw_exception {
4020 if (ref $self and my $rsrc = $self->result_source) {
4021 $rsrc->throw_exception(@_)
4024 DBIx::Class::Exception->throw(@_);
4032 # XXX: FIXME: Attributes docs need clearing up
4036 Attributes are used to refine a ResultSet in various ways when
4037 searching for data. They can be passed to any method which takes an
4038 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4041 Default attributes can be set on the result class using
4042 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4043 the CAVEATS on that feature before using it!)
4045 These are in no particular order:
4051 =item Value: ( $order_by | \@order_by | \%order_by )
4055 Which column(s) to order the results by.
4057 [The full list of suitable values is documented in
4058 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4061 If a single column name, or an arrayref of names is supplied, the
4062 argument is passed through directly to SQL. The hashref syntax allows
4063 for connection-agnostic specification of ordering direction:
4065 For descending order:
4067 order_by => { -desc => [qw/col1 col2 col3/] }
4069 For explicit ascending order:
4071 order_by => { -asc => 'col' }
4073 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4074 supported, although you are strongly encouraged to use the hashref
4075 syntax as outlined above.
4081 =item Value: \@columns | \%columns | $column
4085 Shortcut to request a particular set of columns to be retrieved. Each
4086 column spec may be a string (a table column name), or a hash (in which
4087 case the key is the C<as> value, and the value is used as the C<select>
4088 expression). Adds the L</current_source_alias> onto the start of any column without a C<.> in
4089 it and sets C<select> from that, then auto-populates C<as> from
4090 C<select> as normal. (You may also use the C<cols> attribute, as in
4091 earlier versions of DBIC, but this is deprecated)
4093 Essentially C<columns> does the same as L</select> and L</as>.
4095 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
4099 select => [qw(some_column another_column)],
4100 as => [qw(some_column dbic_slot)]
4102 If you want to individually retrieve related columns (in essence perform
4103 manual L</prefetch>) you have to make sure to specify the correct inflation slot
4104 chain such that it matches existing relationships:
4106 my $rs = $schema->resultset('Artist')->search({}, {
4107 # required to tell DBIC to collapse has_many relationships
4109 join => { cds => 'tracks' },
4111 'cds.cdid' => 'cds.cdid',
4112 'cds.tracks.title' => 'tracks.title',
4116 Like elsewhere, literal SQL or literal values can be included by using a
4117 scalar reference or a literal bind value, and these values will be available
4118 in the result with C<get_column> (see also
4119 L<SQL::Abstract/Literal SQL and value type operators>):
4121 # equivalent SQL: SELECT 1, 'a string', IF(my_column,?,?) ...
4122 # bind values: $true_value, $false_value
4126 bar => \q{'a string'},
4127 baz => \[ 'IF(my_column,?,?)', $true_value, $false_value ],
4133 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
4134 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
4135 with a unary plus operator before it, which is the same as simply C<columns>.
4139 =item Value: \@extra_columns
4143 Indicates additional columns to be selected from storage. Works the same as
4144 L</columns> but adds columns to the current selection. (You may also use the
4145 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4148 $schema->resultset('CD')->search(undef, {
4149 '+columns' => ['artist.name'],
4153 would return all CDs and include a 'name' column to the information
4154 passed to object inflation. Note that the 'artist' is the name of the
4155 column (or relationship) accessor, and 'name' is the name of the column
4156 accessor in the related table.
4162 =item Value: \@select_columns
4166 Indicates which columns should be selected from the storage. You can use
4167 column names, or in the case of RDBMS back ends, function or stored procedure
4170 $rs = $schema->resultset('Employee')->search(undef, {
4173 { count => 'employeeid' },
4174 { max => { length => 'name' }, -as => 'longest_name' }
4179 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4181 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4182 use L</select>, to instruct DBIx::Class how to store the result of the column.
4184 Also note that the L</as> attribute has B<nothing to do> with the SQL-side
4185 C<AS> identifier aliasing. You B<can> alias a function (so you can use it e.g.
4186 in an C<ORDER BY> clause), however this is done via the C<-as> B<select
4187 function attribute> supplied as shown in the example above.
4191 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4192 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4193 with a unary plus operator before it, which is the same as simply C<select>.
4197 =item Value: \@extra_select_columns
4201 Indicates additional columns to be selected from storage. Works the same as
4202 L</select> but adds columns to the current selection, instead of specifying
4203 a new explicit list.
4209 =item Value: \@inflation_names
4213 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4214 slot name in which the column value will be stored within the
4215 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4216 identifier by the C<get_column> method (or via the object accessor B<if one
4217 with the same name already exists>) as shown below.
4219 The L</as> attribute has B<nothing to do> with the SQL-side identifier
4220 aliasing C<AS>. See L</select> for details.
4222 $rs = $schema->resultset('Employee')->search(undef, {
4225 { count => 'employeeid' },
4226 { max => { length => 'name' }, -as => 'longest_name' }
4235 If the object against which the search is performed already has an accessor
4236 matching a column name specified in C<as>, the value can be retrieved using
4237 the accessor as normal:
4239 my $name = $employee->name();
4241 If on the other hand an accessor does not exist in the object, you need to
4242 use C<get_column> instead:
4244 my $employee_count = $employee->get_column('employee_count');
4246 You can create your own accessors if required - see
4247 L<DBIx::Class::Manual::Cookbook> for details.
4251 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4252 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4253 with a unary plus operator before it, which is the same as simply C<as>.
4257 =item Value: \@extra_inflation_names
4261 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4267 =item Value: ($rel_name | \@rel_names | \%rel_names)
4271 Contains a list of relationships that should be joined for this query. For
4274 # Get CDs by Nine Inch Nails
4275 my $rs = $schema->resultset('CD')->search(
4276 { 'artist.name' => 'Nine Inch Nails' },
4277 { join => 'artist' }
4280 Can also contain a hash reference to refer to the other relation's relations.
4283 package MyApp::Schema::Track;
4284 use base qw/DBIx::Class/;
4285 __PACKAGE__->table('track');
4286 __PACKAGE__->add_columns(qw/trackid cd position title/);
4287 __PACKAGE__->set_primary_key('trackid');
4288 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4291 # In your application
4292 my $rs = $schema->resultset('Artist')->search(
4293 { 'track.title' => 'Teardrop' },
4295 join => { cd => 'track' },
4296 order_by => 'artist.name',
4300 You need to use the relationship (not the table) name in conditions,
4301 because they are aliased as such. The current table is aliased as "me", so
4302 you need to use me.column_name in order to avoid ambiguity. For example:
4304 # Get CDs from 1984 with a 'Foo' track
4305 my $rs = $schema->resultset('CD')->search(
4308 'tracks.name' => 'Foo'
4310 { join => 'tracks' }
4313 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4314 similarly for a third time). For e.g.
4316 my $rs = $schema->resultset('Artist')->search({
4317 'cds.title' => 'Down to Earth',
4318 'cds_2.title' => 'Popular',
4320 join => [ qw/cds cds/ ],
4323 will return a set of all artists that have both a cd with title 'Down
4324 to Earth' and a cd with title 'Popular'.
4326 If you want to fetch related objects from other tables as well, see L</prefetch>
4329 NOTE: An internal join-chain pruner will discard certain joins while
4330 constructing the actual SQL query, as long as the joins in question do not
4331 affect the retrieved result. This for example includes 1:1 left joins
4332 that are not part of the restriction specification (WHERE/HAVING) nor are
4333 a part of the query selection.
4335 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4341 =item Value: (0 | 1)
4345 When set to a true value, indicates that any rows fetched from joined has_many
4346 relationships are to be aggregated into the corresponding "parent" object. For
4347 example, the resultset:
4349 my $rs = $schema->resultset('CD')->search({}, {
4350 '+columns' => [ qw/ tracks.title tracks.position / ],
4355 While executing the following query:
4357 SELECT me.*, tracks.title, tracks.position
4359 LEFT JOIN track tracks
4360 ON tracks.cdid = me.cdid
4362 Will return only as many objects as there are rows in the CD source, even
4363 though the result of the query may span many rows. Each of these CD objects
4364 will in turn have multiple "Track" objects hidden behind the has_many
4365 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4366 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4367 product"), with each CD object containing exactly one of all fetched Track data.
4369 When a collapse is requested on a non-ordered resultset, an order by some
4370 unique part of the main source (the left-most table) is inserted automatically.
4371 This is done so that the resultset is allowed to be "lazy" - calling
4372 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4373 object with all of its related data.
4375 If an L</order_by> is already declared, and orders the resultset in a way that
4376 makes collapsing as described above impossible (e.g. C<< ORDER BY
4377 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4378 switch to "eager" mode and slurp the entire resultset before constructing the
4379 first object returned by L</next>.
4381 Setting this attribute on a resultset that does not join any has_many
4382 relations is a no-op.
4384 For a more in-depth discussion, see L</PREFETCHING>.
4390 =item Value: ($rel_name | \@rel_names | \%rel_names)
4394 This attribute is a shorthand for specifying a L</join> spec, adding all
4395 columns from the joined related sources as L</+columns> and setting
4396 L</collapse> to a true value. It can be thought of as a rough B<superset>
4397 of the L</join> attribute.
4399 For example, the following two queries are equivalent:
4401 my $rs = $schema->resultset('Artist')->search({}, {
4402 prefetch => { cds => ['genre', 'tracks' ] },
4407 my $rs = $schema->resultset('Artist')->search({}, {
4408 join => { cds => ['genre', 'tracks' ] },
4412 { +{ "cds.$_" => "cds.$_" } }
4413 $schema->source('Artist')->related_source('cds')->columns
4416 { +{ "cds.genre.$_" => "genre.$_" } }
4417 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4420 { +{ "cds.tracks.$_" => "tracks.$_" } }
4421 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4426 Both producing the following SQL:
4428 SELECT me.artistid, me.name, me.rank, me.charfield,
4429 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4430 genre.genreid, genre.name,
4431 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4434 ON cds.artist = me.artistid
4435 LEFT JOIN genre genre
4436 ON genre.genreid = cds.genreid
4437 LEFT JOIN track tracks
4438 ON tracks.cd = cds.cdid
4439 ORDER BY me.artistid
4441 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4442 the arguments are properly merged and generally do the right thing. For
4443 example, you may want to do the following:
4445 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4446 { 'genre.genreid' => undef },
4448 join => { cds => 'genre' },
4453 Which generates the following SQL:
4455 SELECT me.artistid, me.name, me.rank, me.charfield,
4456 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4459 ON cds.artist = me.artistid
4460 LEFT JOIN genre genre
4461 ON genre.genreid = cds.genreid
4462 WHERE genre.genreid IS NULL
4463 ORDER BY me.artistid
4465 For a more in-depth discussion, see L</PREFETCHING>.
4471 =item Value: $source_alias
4475 Sets the source alias for the query. Normally, this defaults to C<me>, but
4476 nested search queries (sub-SELECTs) might need specific aliases set to
4477 reference inner queries. For example:
4480 ->related_resultset('CDs')
4481 ->related_resultset('Tracks')
4483 'track.id' => { -ident => 'none_search.id' },
4487 my $ids = $self->search({
4490 alias => 'none_search',
4491 group_by => 'none_search.id',
4492 })->get_column('id')->as_query;
4494 $self->search({ id => { -in => $ids } })
4496 This attribute is directly tied to L</current_source_alias>.
4506 Makes the resultset paged and specifies the page to retrieve. Effectively
4507 identical to creating a non-pages resultset and then calling ->page($page)
4510 If L</rows> attribute is not specified it defaults to 10 rows per page.
4512 When you have a paged resultset, L</count> will only return the number
4513 of rows in the page. To get the total, use the L</pager> and call
4514 C<total_entries> on it.
4524 Specifies the maximum number of rows for direct retrieval or the number of
4525 rows per page if the page attribute or method is used.
4531 =item Value: $offset
4535 Specifies the (zero-based) row number for the first row to be returned, or the
4536 of the first row of the first page if paging is used.
4538 =head2 software_limit
4542 =item Value: (0 | 1)
4546 When combined with L</rows> and/or L</offset> the generated SQL will not
4547 include any limit dialect stanzas. Instead the entire result will be selected
4548 as if no limits were specified, and DBIC will perform the limit locally, by
4549 artificially advancing and finishing the resulting L</cursor>.
4551 This is the recommended way of performing resultset limiting when no sane RDBMS
4552 implementation is available (e.g.
4553 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4554 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4560 =item Value: \@columns
4564 A arrayref of columns to group by. Can include columns of joined tables.
4566 group_by => [qw/ column1 column2 ... /]
4572 =item Value: $condition
4576 The HAVING operator specifies a B<secondary> condition applied to the set
4577 after the grouping calculations have been done. In other words it is a
4578 constraint just like L</where> (and accepting the same
4579 L<SQL::Abstract syntax|SQL::Abstract/WHERE CLAUSES>) applied to the data
4580 as it exists after GROUP BY has taken place. Specifying L</having> without
4581 L</group_by> is a logical mistake, and a fatal error on most RDBMS engines.
4585 having => { 'count_employee' => { '>=', 100 } }
4587 or with an in-place function in which case literal SQL is required:
4589 having => \[ 'count(employee) >= ?', 100 ]
4595 =item Value: (0 | 1)
4599 Set to 1 to automatically generate a L</group_by> clause based on the selection
4600 (including intelligent handling of L</order_by> contents). Note that the group
4601 criteria calculation takes place over the B<final> selection. This includes
4602 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4603 L</search> calls, and standalone columns selected via
4604 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4605 extra selections specified via L</prefetch> - such selections are explicitly
4606 excluded from group criteria calculations.
4608 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4609 setting is ignored and an appropriate warning is issued.
4613 Adds extra conditions to the resultset, combined with the preexisting C<WHERE>
4614 conditions, same as the B<first> argument to the L<search operator|/search>
4616 # only return rows WHERE deleted IS NULL for all searches
4617 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4619 Note that the above example is
4620 L<strongly discouraged|DBIx::Class::ResultSource/resultset_attributes>.
4624 Set to 1 to cache search results. This prevents extra SQL queries if you
4625 revisit rows in your ResultSet:
4627 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4629 while( my $artist = $resultset->next ) {
4633 $resultset->first; # without cache, this would issue a query
4635 By default, searches are not cached.
4637 For more examples of using these attributes, see
4638 L<DBIx::Class::Manual::Cookbook>.
4644 =item Value: ( 'update' | 'shared' | \$scalar )
4648 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4649 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4654 DBIx::Class supports arbitrary related data prefetching from multiple related
4655 sources. Any combination of relationship types and column sets are supported.
4656 If L<collapsing|/collapse> is requested, there is an additional requirement of
4657 selecting enough data to make every individual object uniquely identifiable.
4659 Here are some more involved examples, based on the following relationship map:
4662 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4663 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4664 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4666 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4668 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4672 my $rs = $schema->resultset('Tag')->search(
4681 The initial search results in SQL like the following:
4683 SELECT tag.*, cd.*, artist.* FROM tag
4684 JOIN cd ON tag.cd = cd.cdid
4685 JOIN artist ON cd.artist = artist.artistid
4687 L<DBIx::Class> has no need to go back to the database when we access the
4688 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4691 Simple prefetches will be joined automatically, so there is no need
4692 for a C<join> attribute in the above search.
4694 The L</prefetch> attribute can be used with any of the relationship types
4695 and multiple prefetches can be specified together. Below is a more complex
4696 example that prefetches a CD's artist, its liner notes (if present),
4697 the cover image, the tracks on that CD, and the guests on those
4700 my $rs = $schema->resultset('CD')->search(
4704 { artist => 'record_label'}, # belongs_to => belongs_to
4705 'liner_note', # might_have
4706 'cover_image', # has_one
4707 { tracks => 'guests' }, # has_many => has_many
4712 This will produce SQL like the following:
4714 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4718 ON artist.artistid = me.artistid
4719 JOIN record_label record_label
4720 ON record_label.labelid = artist.labelid
4721 LEFT JOIN track tracks
4722 ON tracks.cdid = me.cdid
4723 LEFT JOIN guest guests
4724 ON guests.trackid = track.trackid
4725 LEFT JOIN liner_notes liner_note
4726 ON liner_note.cdid = me.cdid
4727 JOIN cd_artwork cover_image
4728 ON cover_image.cdid = me.cdid
4731 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4732 C<tracks>, and C<guests> of the CD will all be available through the
4733 relationship accessors without the need for additional queries to the
4738 Prefetch does a lot of deep magic. As such, it may not behave exactly
4739 as you might expect.
4745 Prefetch uses the L</cache> to populate the prefetched relationships. This
4746 may or may not be what you want.
4750 If you specify a condition on a prefetched relationship, ONLY those
4751 rows that match the prefetched condition will be fetched into that relationship.
4752 This means that adding prefetch to a search() B<may alter> what is returned by
4753 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4755 my $artist_rs = $schema->resultset('Artist')->search({
4761 my $count = $artist_rs->first->cds->count;
4763 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4765 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4767 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4769 That cmp_ok() may or may not pass depending on the datasets involved. In other
4770 words the C<WHERE> condition would apply to the entire dataset, just like
4771 it would in regular SQL. If you want to add a condition only to the "right side"
4772 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4773 condition|DBIx::Class::Relationship::Base/condition>
4777 =head1 DBIC BIND VALUES
4779 Because DBIC may need more information to bind values than just the column name
4780 and value itself, it uses a special format for both passing and receiving bind
4781 values. Each bind value should be composed of an arrayref of
4782 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4788 If present (in any form), this is what is being passed directly to bind_param.
4789 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4790 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4792 If this is specified, all other bind options described below are ignored.
4796 If present, this is used to infer the actual bind attribute by passing to
4797 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4798 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4800 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4801 currently drivers are expected to "Do the Right Thing" when given a common
4802 datatype name. (Not ideal, but that's what we got at this point.)
4806 Currently used to correctly allocate buffers for bind_param_inout().
4807 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4808 or to a sensible value based on the "data_type".
4812 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4813 explicitly specified they are never overridden). Also used by some weird DBDs,
4814 where the column name should be available at bind_param time (e.g. Oracle).
4818 For backwards compatibility and convenience, the following shortcuts are
4821 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4822 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4823 [ undef, $val ] === [ {}, $val ]
4824 $val === [ {}, $val ]
4826 =head1 FURTHER QUESTIONS?
4828 Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
4830 =head1 COPYRIGHT AND LICENSE
4832 This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
4833 by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
4834 redistribute it and/or modify it under the same terms as the
4835 L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.