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 fail_on_internal_wantarray fail_on_internal_call UNRESOLVABLE_CONDITION
15 # not importing first() as it will clash with our own method
19 # De-duplication in _merge_attr() is disabled, but left in for reference
20 # (the merger is used for other things that ought not to be de-duped)
21 *__HM_DEDUP = sub () { 0 };
31 # this is real - CDBICompat overrides it with insanity
32 # yes, prototype won't matter, but that's for now ;)
35 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
39 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
43 my $users_rs = $schema->resultset('User');
44 while( $user = $users_rs->next) {
45 print $user->username;
48 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
49 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
53 A ResultSet is an object which stores a set of conditions representing
54 a query. It is the backbone of DBIx::Class (i.e. the really
55 important/useful bit).
57 No SQL is executed on the database when a ResultSet is created, it
58 just stores all the conditions needed to create the query.
60 A basic ResultSet representing the data of an entire table is returned
61 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
62 L<Source|DBIx::Class::Manual::Glossary/ResultSource> name.
64 my $users_rs = $schema->resultset('User');
66 A new ResultSet is returned from calling L</search> on an existing
67 ResultSet. The new one will contain all the conditions of the
68 original, plus any new conditions added in the C<search> call.
70 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
71 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
74 The query that the ResultSet represents is B<only> executed against
75 the database when these methods are called:
76 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
78 If a resultset is used in a numeric context it returns the L</count>.
79 However, if it is used in a boolean context it is B<always> true. So if
80 you want to check if a resultset has any results, you must use C<if $rs
85 =head2 Chaining resultsets
87 Let's say you've got a query that needs to be run to return some data
88 to the user. But, you have an authorization system in place that
89 prevents certain users from seeing certain information. So, you want
90 to construct the basic query in one method, but add constraints to it in
95 my $request = $self->get_request; # Get a request object somehow.
96 my $schema = $self->result_source->schema;
98 my $cd_rs = $schema->resultset('CD')->search({
99 title => $request->param('title'),
100 year => $request->param('year'),
103 $cd_rs = $self->apply_security_policy( $cd_rs );
105 return $cd_rs->all();
108 sub apply_security_policy {
117 =head3 Resolving conditions and attributes
119 When a resultset is chained from another resultset (e.g.:
120 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
121 and attributes with the same keys need resolving.
123 If any of L</columns>, L</select>, L</as> are present, they reset the
124 original selection, and start the selection "clean".
126 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
127 are merged into the existing ones from the original resultset.
129 The L</where> and L</having> attributes, and any search conditions, are
130 merged with an SQL C<AND> to the existing condition from the original
133 All other attributes are overridden by any new ones supplied in the
136 =head2 Multiple queries
138 Since a resultset just defines a query, you can do all sorts of
139 things with it with the same object.
141 # Don't hit the DB yet.
142 my $cd_rs = $schema->resultset('CD')->search({
143 title => 'something',
147 # Each of these hits the DB individually.
148 my $count = $cd_rs->count;
149 my $most_recent = $cd_rs->get_column('date_released')->max();
150 my @records = $cd_rs->all;
152 And it's not just limited to SELECT statements.
158 $cd_rs->create({ artist => 'Fred' });
160 Which is the same as:
162 $schema->resultset('CD')->create({
163 title => 'something',
168 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
170 =head2 Custom ResultSet classes
172 To add methods to your resultsets, you can subclass L<DBIx::Class::ResultSet>, similar to:
174 package MyApp::Schema::ResultSet::User;
179 use base 'DBIx::Class::ResultSet';
183 $self->search({ $self->current_source_alias . '.active' => 1 });
188 $self->search({ $self->current_source_alias . '.verified' => 0 });
191 sub created_n_days_ago {
192 my ($self, $days_ago) = @_;
194 $self->current_source_alias . '.create_date' => {
196 $self->result_source->schema->storage->datetime_parser->format_datetime(
197 DateTime->now( time_zone => 'UTC' )->subtract( days => $days_ago )
202 sub users_to_warn { shift->active->unverified->created_n_days_ago(7) }
206 See L<DBIx::Class::Schema/load_namespaces> on how DBIC can discover and
207 automatically attach L<Result|DBIx::Class::Manual::ResultClass>-specific
208 L<ResulSet|DBIx::Class::ResultSet> classes.
210 =head3 ResultSet subclassing with Moose and similar constructor-providers
212 Using L<Moose> or L<Moo> in your ResultSet classes is usually overkill, but
213 you may find it useful if your ResultSets contain a lot of business logic
214 (e.g. C<has xml_parser>, C<has json>, etc) or if you just prefer to organize
217 In order to write custom ResultSet classes with L<Moo> you need to use the
218 following template. The L<BUILDARGS|Moo/BUILDARGS> is necessary due to the
219 unusual signature of the L<constructor provided by DBIC
220 |DBIx::Class::ResultSet/new> C<< ->new($source, \%args) >>.
223 extends 'DBIx::Class::ResultSet';
224 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
230 If you want to build your custom ResultSet classes with L<Moose>, you need
231 a similar, though a little more elaborate template in order to interface the
232 inlining of the L<Moose>-provided
233 L<object constructor|Moose::Manual::Construction/WHERE'S THE CONSTRUCTOR?>,
236 package MyApp::Schema::ResultSet::User;
239 use MooseX::NonMoose;
240 extends 'DBIx::Class::ResultSet';
242 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
246 __PACKAGE__->meta->make_immutable;
250 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
251 entirely overwrite the DBIC one (in contrast L<Moo> does this automatically).
252 Alternatively, you can skip L<MooseX::NonMoose> and get by with just L<Moose>
255 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
263 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
265 =item Return Value: L<$resultset|/search>
269 The resultset constructor. Takes a source object (usually a
270 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
271 L</ATTRIBUTES> below). Does not perform any queries -- these are
272 executed as needed by the other methods.
274 Generally you never construct a resultset manually. Instead you get one
276 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
277 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
280 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
286 If called on an object, proxies to L</new_result> instead, so
288 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
290 will return a CD object, not a ResultSet, and is equivalent to:
292 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
294 Please also keep in mind that many internals call L</new_result> directly,
295 so overloading this method with the idea of intercepting new result object
296 creation B<will not work>. See also warning pertaining to L</create>.
306 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
307 return $class->new_result(@_);
310 my ($source, $attrs) = @_;
311 $source = $source->resolve
312 if $source->isa('DBIx::Class::ResultSourceHandle');
314 $attrs = { %{$attrs||{}} };
315 delete @{$attrs}{qw(_last_sqlmaker_alias_map _simple_passthrough_construction)};
317 if ($attrs->{page}) {
318 $attrs->{rows} ||= 10;
321 $attrs->{alias} ||= 'me';
324 result_source => $source,
325 cond => $attrs->{where},
330 # if there is a dark selector, this means we are already in a
331 # chain and the cleanup/sanification was taken care of by
333 $self->_normalize_selection($attrs)
334 unless $attrs->{_dark_selector};
337 $attrs->{result_class} || $source->result_class
347 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
349 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
353 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
354 my $new_rs = $cd_rs->search({ year => 2005 });
356 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
357 # year = 2005 OR year = 2004
359 In list context, C<< ->all() >> is called implicitly on the resultset, thus
360 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
361 To avoid that, use L</search_rs>.
363 If you need to pass in additional attributes but no additional condition,
364 call it as C<search(undef, \%attrs)>.
366 # "SELECT name, artistid FROM $artist_table"
367 my @all_artists = $schema->resultset('Artist')->search(undef, {
368 columns => [qw/name artistid/],
371 For a list of attributes that can be passed to C<search>, see
372 L</ATTRIBUTES>. For more examples of using this function, see
373 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
374 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
375 and its extension L<DBIx::Class::SQLMaker>.
377 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
381 Note that L</search> does not process/deflate any of the values passed in the
382 L<SQL::Abstract>-compatible search condition structure. This is unlike other
383 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
384 manually that any value passed to this method will stringify to something the
385 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
386 objects, for more info see:
387 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
393 my $rs = $self->search_rs( @_ );
396 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray;
399 elsif (defined wantarray) {
403 # we can be called by a relationship helper, which in
404 # turn may be called in void context due to some braindead
405 # overload or whatever else the user decided to be clever
406 # at this particular day. Thus limit the exception to
407 # external code calls only
408 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
409 if (caller)[0] !~ /^\QDBIx::Class::/;
419 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
421 =item Return Value: L<$resultset|/search>
425 This method does the same exact thing as search() except it will
426 always return a resultset, even in list context.
433 my $rsrc = $self->result_source;
434 my ($call_cond, $call_attrs);
436 # Special-case handling for (undef, undef) or (undef)
437 # Note that (foo => undef) is valid deprecated syntax
438 @_ = () if not scalar grep { defined $_ } @_;
444 # fish out attrs in the ($condref, $attr) case
445 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
446 ($call_cond, $call_attrs) = @_;
449 $self->throw_exception('Odd number of arguments to search')
453 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
454 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
456 for my $i (0 .. $#_) {
458 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
459 if (! defined $_[$i] or ref $_[$i] ne '');
465 # see if we can keep the cache (no $rs changes)
467 my %safe = (alias => 1, cache => 1);
468 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
471 ref $call_cond eq 'HASH' && ! keys %$call_cond
473 ref $call_cond eq 'ARRAY' && ! @$call_cond
475 $cache = $self->get_cache;
478 my $old_attrs = { %{$self->{attrs}} };
479 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
481 my $new_attrs = { %$old_attrs };
483 # take care of call attrs (only if anything is changing)
484 if ($call_attrs and keys %$call_attrs) {
486 # copy for _normalize_selection
487 $call_attrs = { %$call_attrs };
489 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
491 # reset the current selector list if new selectors are supplied
492 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
493 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
496 # Normalize the new selector list (operates on the passed-in attr structure)
497 # Need to do it on every chain instead of only once on _resolved_attrs, in
498 # order to allow detection of empty vs partial 'as'
499 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
500 if $old_attrs->{_dark_selector};
501 $self->_normalize_selection ($call_attrs);
503 # start with blind overwriting merge, exclude selector attrs
504 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
505 delete @{$new_attrs}{@selector_attrs};
507 for (@selector_attrs) {
508 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
509 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
512 # older deprecated name, use only if {columns} is not there
513 if (my $c = delete $new_attrs->{cols}) {
514 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
515 if ($new_attrs->{columns}) {
516 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
519 $new_attrs->{columns} = $c;
524 # join/prefetch use their own crazy merging heuristics
525 foreach my $key (qw/join prefetch/) {
526 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
527 if exists $call_attrs->{$key};
530 # stack binds together
531 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
535 for ($old_where, $call_cond) {
537 $new_attrs->{where} = $self->_stack_cond (
538 $_, $new_attrs->{where}
543 if (defined $old_having) {
544 $new_attrs->{having} = $self->_stack_cond (
545 $old_having, $new_attrs->{having}
549 my $rs = (ref $self)->new($rsrc, $new_attrs);
551 $rs->set_cache($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 $attrs->{_dark_selector} = {
621 string => ($dark_sel_dumper ||= do {
622 require Data::Dumper::Concise;
623 Data::Dumper::Concise::DumperObject()->Indent(0);
624 })->Values([$_])->Dump
632 elsif (@$as < @$sel) {
633 $self->throw_exception(
634 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
637 elsif ($pref and $attrs->{_dark_selector}) {
638 $self->throw_exception(
639 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
645 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
646 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
651 my ($self, $left, $right) = @_;
654 (ref $_ eq 'ARRAY' and !@$_)
656 (ref $_ eq 'HASH' and ! keys %$_)
657 ) and $_ = undef for ($left, $right);
659 # either one of the two undef
660 if ( (defined $left) xor (defined $right) ) {
661 return defined $left ? $left : $right;
664 elsif ( ! defined $left ) {
668 return $self->result_source->schema->storage->_collapse_cond({ -and => [$left, $right] });
672 =head2 search_literal
674 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
675 should only be used in that context. C<search_literal> is a convenience
676 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
677 want to ensure columns are bound correctly, use L</search>.
679 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
680 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
681 require C<search_literal>.
685 =item Arguments: $sql_fragment, @standalone_bind_values
687 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
691 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
692 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
694 Pass a literal chunk of SQL to be added to the conditional part of the
697 Example of how to use C<search> instead of C<search_literal>
699 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
700 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
705 my ($self, $sql, @bind) = @_;
707 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
710 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
717 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
719 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
723 Finds and returns a single row based on supplied criteria. Takes either a
724 hashref with the same format as L</create> (including inference of foreign
725 keys from related objects), or a list of primary key values in the same
726 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
727 declaration on the L</result_source>.
729 In either case an attempt is made to combine conditions already existing on
730 the resultset with the condition passed to this method.
732 To aid with preparing the correct query for the storage you may supply the
733 C<key> attribute, which is the name of a
734 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
735 unique constraint corresponding to the
736 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
737 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
738 to construct a query that satisfies the named unique constraint fully (
739 non-NULL values for each column member of the constraint) an exception is
742 If no C<key> is specified, the search is carried over all unique constraints
743 which are fully defined by the available condition.
745 If no such constraint is found, C<find> currently defaults to a simple
746 C<< search->(\%column_values) >> which may or may not do what you expect.
747 Note that this fallback behavior may be deprecated in further versions. If
748 you need to search with arbitrary conditions - use L</search>. If the query
749 resulting from this fallback produces more than one row, a warning to the
750 effect is issued, though only the first row is constructed and returned as
753 In addition to C<key>, L</find> recognizes and applies standard
754 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
756 Note that if you have extra concerns about the correctness of the resulting
757 query you need to specify the C<key> attribute and supply the entire condition
758 as an argument to find (since it is not always possible to perform the
759 combination of the resultset condition with the supplied one, especially if
760 the resultset condition contains literal sql).
762 For example, to find a row by its primary key:
764 my $cd = $schema->resultset('CD')->find(5);
766 You can also find a row by a specific unique constraint:
768 my $cd = $schema->resultset('CD')->find(
770 artist => 'Massive Attack',
771 title => 'Mezzanine',
773 { key => 'cd_artist_title' }
776 See also L</find_or_create> and L</update_or_create>.
782 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
784 my $rsrc = $self->result_source;
787 if (exists $attrs->{key}) {
788 $constraint_name = defined $attrs->{key}
790 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
794 # Parse out the condition from input
797 if (ref $_[0] eq 'HASH') {
798 $call_cond = { %{$_[0]} };
801 # if only values are supplied we need to default to 'primary'
802 $constraint_name = 'primary' unless defined $constraint_name;
804 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
806 $self->throw_exception(
807 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
810 $self->throw_exception (
811 'find() expects either a column/value hashref, or a list of values '
812 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
813 ) unless @c_cols == @_;
815 @{$call_cond}{@c_cols} = @_;
818 # process relationship data if any
819 for my $key (keys %$call_cond) {
821 length ref($call_cond->{$key})
823 my $relinfo = $rsrc->relationship_info($key)
825 # implicitly skip has_many's (likely MC)
826 (ref (my $val = delete $call_cond->{$key}) ne 'ARRAY' )
828 my ($rel_cond, $crosstable) = $rsrc->_resolve_condition(
829 $relinfo->{cond}, $val, $key, $key
832 $self->throw_exception("Complex condition via relationship '$key' is unsupported in find()")
833 if $crosstable or ref($rel_cond) ne 'HASH';
835 # supplement condition
836 # relationship conditions take precedence (?)
837 @{$call_cond}{keys %$rel_cond} = values %$rel_cond;
841 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
843 if (defined $constraint_name) {
844 $final_cond = $self->_qualify_cond_columns (
846 $self->result_source->_minimal_valueset_satisfying_constraint(
847 constraint_name => $constraint_name,
848 values => ($self->_merge_with_rscond($call_cond))[0],
855 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
856 # This means that we got here after a merger of relationship conditions
857 # in ::Relationship::Base::search_related (the row method), and furthermore
858 # the relationship is of the 'single' type. This means that the condition
859 # provided by the relationship (already attached to $self) is sufficient,
860 # as there can be only one row in the database that would satisfy the
864 my (@unique_queries, %seen_column_combinations, $ci, @fc_exceptions);
866 # no key was specified - fall down to heuristics mode:
867 # run through all unique queries registered on the resultset, and
868 # 'OR' all qualifying queries together
870 # always start from 'primary' if it exists at all
871 for my $c_name ( sort {
873 : $b eq 'primary' ? 1
875 } $rsrc->unique_constraint_names) {
877 next if $seen_column_combinations{
878 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
882 push @unique_queries, $self->_qualify_cond_columns(
883 $self->result_source->_minimal_valueset_satisfying_constraint(
884 constraint_name => $c_name,
885 values => ($self->_merge_with_rscond($call_cond))[0],
886 columns_info => ($ci ||= $self->result_source->columns_info),
892 push @fc_exceptions, $_ if $_ =~ /\bFilterColumn\b/;
897 @unique_queries ? \@unique_queries
898 : @fc_exceptions ? $self->throw_exception(join "; ", map { $_ =~ /(.*) at .+ line \d+$/s } @fc_exceptions )
899 : $self->_non_unique_find_fallback ($call_cond, $attrs)
903 # Run the query, passing the result_class since it should propagate for find
904 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
905 if ($rs->_resolved_attrs->{collapse}) {
907 carp "Query returned more than one row" if $rs->next;
915 # This is a stop-gap method as agreed during the discussion on find() cleanup:
916 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
918 # It is invoked when find() is called in legacy-mode with insufficiently-unique
919 # condition. It is provided for overrides until a saner way forward is devised
921 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
922 # the road. Please adjust your tests accordingly to catch this situation early
923 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
925 # The method will not be removed without an adequately complete replacement
926 # for strict-mode enforcement
927 sub _non_unique_find_fallback {
928 my ($self, $cond, $attrs) = @_;
930 return $self->_qualify_cond_columns(
932 exists $attrs->{alias}
934 : $self->{attrs}{alias}
939 sub _qualify_cond_columns {
940 my ($self, $cond, $alias) = @_;
942 my %aliased = %$cond;
943 for (keys %aliased) {
944 $aliased{"$alias.$_"} = delete $aliased{$_}
951 sub _build_unique_cond {
953 '_build_unique_cond is a private method, and moreover is about to go '
954 . 'away. Please contact the development team at %s if you believe you '
955 . 'have a genuine use for this method, in order to discuss alternatives.',
956 DBIx::Class::_ENV_::HELP_URL,
959 my ($self, $constraint_name, $cond, $croak_on_null) = @_;
961 $self->result_source->_minimal_valueset_satisfying_constraint(
962 constraint_name => $constraint_name,
964 carp_on_nulls => !$croak_on_null
968 =head2 search_related
972 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
974 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
978 $new_rs = $cd_rs->search_related('artist', {
982 Searches the specified relationship, optionally specifying a condition and
983 attributes for matching records. See L</ATTRIBUTES> for more information.
985 In list context, C<< ->all() >> is called implicitly on the resultset, thus
986 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
988 See also L</search_related_rs>.
993 return shift->related_resultset(shift)->search(@_);
996 =head2 search_related_rs
998 This method works exactly the same as search_related, except that
999 it guarantees a resultset, even in list context.
1003 sub search_related_rs {
1004 return shift->related_resultset(shift)->search_rs(@_);
1011 =item Arguments: none
1013 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1017 Returns a storage-driven cursor to the given resultset. See
1018 L<DBIx::Class::Cursor> for more information.
1025 return $self->{cursor} ||= do {
1026 my $attrs = $self->_resolved_attrs;
1027 $self->result_source->storage->select(
1028 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1037 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1039 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1043 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1045 Inflates the first result without creating a cursor if the resultset has
1046 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1049 While this method can take an optional search condition (just like L</search>)
1050 being a fast-code-path it does not recognize search attributes. If you need to
1051 add extra joins or similar, call L</search> and then chain-call L</single> on the
1052 L<DBIx::Class::ResultSet> returned.
1058 As of 0.08100, this method enforces the assumption that the preceding
1059 query returns only one row. If more than one row is returned, you will receive
1062 Query returned more than one row
1064 In this case, you should be using L</next> or L</find> instead, or if you really
1065 know what you are doing, use the L</rows> attribute to explicitly limit the size
1068 This method will also throw an exception if it is called on a resultset prefetching
1069 has_many, as such a prefetch implies fetching multiple rows from the database in
1070 order to assemble the resulting object.
1077 my ($self, $where) = @_;
1079 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1082 my $attrs = { %{$self->_resolved_attrs} };
1084 $self->throw_exception(
1085 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1086 ) if $attrs->{collapse};
1089 if (defined $attrs->{where}) {
1092 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1093 $where, delete $attrs->{where} ]
1096 $attrs->{where} = $where;
1100 my $data = [ $self->result_source->storage->select_single(
1101 $attrs->{from}, $attrs->{select},
1102 $attrs->{where}, $attrs
1105 return undef unless @$data;
1106 $self->{_stashed_rows} = [ $data ];
1107 $self->_construct_results->[0];
1114 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1116 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1120 my $max_length = $rs->get_column('length')->max;
1122 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1127 my ($self, $column) = @_;
1128 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1136 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1138 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1142 # WHERE title LIKE '%blue%'
1143 $cd_rs = $rs->search_like({ title => '%blue%'});
1145 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1146 that this is simply a convenience method retained for ex Class::DBI users.
1147 You most likely want to use L</search> with specific operators.
1149 For more information, see L<DBIx::Class::Manual::Cookbook>.
1151 This method is deprecated and will be removed in 0.09. Use L<search()|/search>
1152 instead. An example conversion is:
1154 ->search_like({ foo => 'bar' });
1158 ->search({ foo => { like => 'bar' } });
1165 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1166 .' Instead use ->search({ x => { -like => "y%" } })'
1167 .' (note the outer pair of {}s - they are important!)'
1169 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1170 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1171 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1172 return $class->search($query, { %$attrs });
1179 =item Arguments: $first, $last
1181 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1185 Returns a resultset or object list representing a subset of elements from the
1186 resultset slice is called on. Indexes are from 0, i.e., to get the first
1187 three records, call:
1189 my ($one, $two, $three) = $rs->slice(0, 2);
1194 my ($self, $min, $max) = @_;
1195 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1196 $attrs->{offset} = $self->{attrs}{offset} || 0;
1197 $attrs->{offset} += $min;
1198 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1199 return $self->search(undef, $attrs);
1206 =item Arguments: none
1208 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1212 Returns the next element in the resultset (C<undef> is there is none).
1214 Can be used to efficiently iterate over records in the resultset:
1216 my $rs = $schema->resultset('CD')->search;
1217 while (my $cd = $rs->next) {
1221 Note that you need to store the resultset object, and call C<next> on it.
1222 Calling C<< resultset('Table')->next >> repeatedly will always return the
1223 first record from the resultset.
1230 if (my $cache = $self->get_cache) {
1231 $self->{all_cache_position} ||= 0;
1232 return $cache->[$self->{all_cache_position}++];
1235 if ($self->{attrs}{cache}) {
1236 delete $self->{pager};
1237 $self->{all_cache_position} = 1;
1238 return ($self->all)[0];
1241 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1243 $self->{_stashed_results} = $self->_construct_results
1246 return shift @{$self->{_stashed_results}};
1249 # Constructs as many results as it can in one pass while respecting
1250 # cursor laziness. Several modes of operation:
1252 # * Always builds everything present in @{$self->{_stashed_rows}}
1253 # * If called with $fetch_all true - pulls everything off the cursor and
1254 # builds all result structures (or objects) in one pass
1255 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1256 # and if the resultset is ordered properly by the left side:
1257 # * Fetches stuff off the cursor until the "master object" changes,
1258 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1260 # * Just fetches, and collapses/constructs everything as if $fetch_all
1261 # was requested (there is no other way to collapse except for an
1263 # * If no collapse is requested - just get the next row, construct and
1265 sub _construct_results {
1266 my ($self, $fetch_all) = @_;
1268 my $rsrc = $self->result_source;
1269 my $attrs = $self->_resolved_attrs;
1274 ! $attrs->{order_by}
1278 my @pcols = $rsrc->primary_columns
1280 # default order for collapsing unless the user asked for something
1281 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1282 $attrs->{_ordered_for_collapse} = 1;
1283 $attrs->{_order_is_artificial} = 1;
1286 # this will be used as both initial raw-row collector AND as a RV of
1287 # _construct_results. Not regrowing the array twice matters a lot...
1288 # a surprising amount actually
1289 my $rows = delete $self->{_stashed_rows};
1291 my $cursor; # we may not need one at all
1293 my $did_fetch_all = $fetch_all;
1296 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1297 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1299 elsif( $attrs->{collapse} ) {
1301 # a cursor will need to be closed over in case of collapse
1302 $cursor = $self->cursor;
1304 $attrs->{_ordered_for_collapse} = (
1310 ->_extract_colinfo_of_stable_main_source_order_by_portion($attrs)
1312 ) unless defined $attrs->{_ordered_for_collapse};
1314 if (! $attrs->{_ordered_for_collapse}) {
1317 # instead of looping over ->next, use ->all in stealth mode
1318 # *without* calling a ->reset afterwards
1319 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1320 if (! $cursor->{_done}) {
1321 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1322 $cursor->{_done} = 1;
1327 if (! $did_fetch_all and ! @{$rows||[]} ) {
1328 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1329 $cursor ||= $self->cursor;
1330 if (scalar (my @r = $cursor->next) ) {
1335 return undef unless @{$rows||[]};
1337 # sanity check - people are too clever for their own good
1338 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1340 my $multiplied_selectors;
1341 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1343 $aliastypes->{multiplying}{$sel_alias}
1345 $aliastypes->{premultiplied}{$sel_alias}
1347 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1351 for my $i (0 .. $#{$attrs->{as}} ) {
1352 my $sel = $attrs->{select}[$i];
1354 if (ref $sel eq 'SCALAR') {
1357 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1361 $self->throw_exception(
1362 'Result collapse not possible - selection from a has_many source redirected to the main object'
1363 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1367 # hotspot - skip the setter
1368 my $res_class = $self->_result_class;
1370 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1371 $res_class->can ('inflate_result')
1372 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1375 my $infmap = $attrs->{as};
1377 $self->{_result_inflator}{is_core_row} = ( (
1380 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1381 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1383 $self->{_result_inflator}{is_hri} = ( (
1384 ! $self->{_result_inflator}{is_core_row}
1386 $inflator_cref == \&DBIx::Class::ResultClass::HashRefInflator::inflate_result
1387 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1390 if ($attrs->{_simple_passthrough_construction}) {
1391 # construct a much simpler array->hash folder for the one-table HRI cases right here
1392 if ($self->{_result_inflator}{is_hri}) {
1393 for my $r (@$rows) {
1394 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1397 # FIXME SUBOPTIMAL this is a very very very hot spot
1398 # while rather optimal we can *still* do much better, by
1399 # building a smarter Row::inflate_result(), and
1400 # switch to feeding it data via a much leaner interface
1402 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1403 # this particular resultset size
1404 elsif ( $self->{_result_inflator}{is_core_row} and @$rows < 60 ) {
1405 for my $r (@$rows) {
1406 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1411 ( $self->{_result_inflator}{is_core_row}
1412 ? '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows'
1413 # a custom inflator may be a multiplier/reductor - put it in direct list ctx
1414 : '@$rows = map { $inflator_cref->($res_class, $rsrc, { %s } ) } @$rows'
1416 ( join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) )
1422 $self->{_result_inflator}{is_hri} ? 'hri'
1423 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1424 : 'classic_nonpruning'
1427 # $args and $attrs to _mk_row_parser are separated to delineate what is
1428 # core collapser stuff and what is dbic $rs specific
1429 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $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},
1436 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1438 # column_info metadata historically hasn't been too reliable.
1439 # We need to start fixing this somehow (the collapse resolver
1440 # can't work without it). Add an explicit check for the *main*
1441 # result, hopefully this will gradually weed out such errors
1443 # FIXME - this is a temporary kludge that reduces performance
1444 # It is however necessary for the time being
1445 my ($unrolled_non_null_cols_to_check, $err);
1447 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1450 'Collapse aborted due to invalid ResultSource metadata - the following '
1451 . 'selections are declared non-nullable but NULLs were retrieved: '
1455 COL: for my $i (@$check_non_null_cols) {
1456 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1459 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1462 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1466 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1467 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1469 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1470 my @r = $cursor->next or return;
1471 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1472 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1478 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1479 my @r = $cursor->next or return;
1484 $self->{_row_parser}{$parser_type}{cref}->(
1486 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1489 # simple in-place substitution, does not regrow $rows
1490 if ($self->{_result_inflator}{is_core_row}) {
1491 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1493 # Special-case multi-object HRI - there is no $inflator_cref pass at all
1494 elsif ( ! $self->{_result_inflator}{is_hri} ) {
1495 # the inflator may be a multiplier/reductor - put it in list ctx
1496 @$rows = map { $inflator_cref->($res_class, $rsrc, @$_) } @$rows;
1500 # The @$rows check seems odd at first - why wouldn't we want to warn
1501 # regardless? The issue is things like find() etc, where the user
1502 # *knows* only one result will come back. In these cases the ->all
1503 # is not a pessimization, but rather something we actually want
1505 'Unable to properly collapse has_many results in iterator mode due '
1506 . 'to order criteria - performed an eager cursor slurp underneath. '
1507 . 'Consider using ->all() instead'
1508 ) if ( ! $fetch_all and @$rows > 1 );
1513 =head2 result_source
1517 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1519 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1523 An accessor for the primary ResultSource object from which this ResultSet
1530 =item Arguments: $result_class?
1532 =item Return Value: $result_class
1536 An accessor for the class to use when creating result objects. Defaults to
1537 C<< result_source->result_class >> - which in most cases is the name of the
1538 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1540 Note that changing the result_class will also remove any components
1541 that were originally loaded in the source class via
1542 L<load_components|Class::C3::Componentised/load_components( @comps )>.
1543 Any overloaded methods in the original source class will not run.
1548 my ($self, $result_class) = @_;
1549 if ($result_class) {
1551 # don't fire this for an object
1552 $self->ensure_class_loaded($result_class)
1553 unless ref($result_class);
1555 if ($self->get_cache) {
1556 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1558 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1559 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1560 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1563 $self->_result_class($result_class);
1565 delete $self->{_result_inflator};
1567 $self->_result_class;
1574 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1576 =item Return Value: $count
1580 Performs an SQL C<COUNT> with the same query as the resultset was built
1581 with to find the number of elements. Passing arguments is equivalent to
1582 C<< $rs->search ($cond, \%attrs)->count >>
1588 return $self->search(@_)->count if @_ and defined $_[0];
1589 return scalar @{ $self->get_cache } if $self->get_cache;
1591 my $attrs = { %{ $self->_resolved_attrs } };
1593 # this is a little optimization - it is faster to do the limit
1594 # adjustments in software, instead of a subquery
1595 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1598 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1599 $crs = $self->_count_subq_rs ($attrs);
1602 $crs = $self->_count_rs ($attrs);
1604 my $count = $crs->next;
1606 $count -= $offset if $offset;
1607 $count = $rows if $rows and $rows < $count;
1608 $count = 0 if ($count < 0);
1617 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1619 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1623 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1624 This can be very handy for subqueries:
1626 ->search( { amount => $some_rs->count_rs->as_query } )
1628 As with regular resultsets the SQL query will be executed only after
1629 the resultset is accessed via L</next> or L</all>. That would return
1630 the same single value obtainable via L</count>.
1636 return $self->search(@_)->count_rs if @_;
1638 # this may look like a lack of abstraction (count() does about the same)
1639 # but in fact an _rs *must* use a subquery for the limits, as the
1640 # software based limiting can not be ported if this $rs is to be used
1641 # in a subquery itself (i.e. ->as_query)
1642 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1643 return $self->_count_subq_rs($self->{_attrs});
1646 return $self->_count_rs($self->{_attrs});
1651 # returns a ResultSetColumn object tied to the count query
1654 my ($self, $attrs) = @_;
1656 my $rsrc = $self->result_source;
1658 my $tmp_attrs = { %$attrs };
1659 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1660 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1662 # overwrite the selector (supplied by the storage)
1663 $rsrc->resultset_class->new($rsrc, {
1665 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1667 })->get_column ('count');
1671 # same as above but uses a subquery
1673 sub _count_subq_rs {
1674 my ($self, $attrs) = @_;
1676 my $rsrc = $self->result_source;
1678 my $sub_attrs = { %$attrs };
1679 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1680 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1682 # if we multi-prefetch we group_by something unique, as this is what we would
1683 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1684 if ( $attrs->{collapse} ) {
1685 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1686 $rsrc->_identifying_column_set || $self->throw_exception(
1687 'Unable to construct a unique group_by criteria properly collapsing the '
1688 . 'has_many prefetch before count()'
1693 # Calculate subquery selector
1694 if (my $g = $sub_attrs->{group_by}) {
1696 my $sql_maker = $rsrc->storage->sql_maker;
1698 # necessary as the group_by may refer to aliased functions
1700 for my $sel (@{$attrs->{select}}) {
1701 $sel_index->{$sel->{-as}} = $sel
1702 if (ref $sel eq 'HASH' and $sel->{-as});
1705 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1706 # also look for named aggregates referred in the having clause
1707 # having often contains scalarrefs - thus parse it out entirely
1709 if ($attrs->{having}) {
1710 local $sql_maker->{having_bind};
1711 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1712 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1713 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1714 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1715 # if we don't unset it we screw up retarded but unfortunately working
1716 # 'MAX(foo.bar)' => { '>', 3 }
1717 $sql_maker->{name_sep} = '';
1720 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1722 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1725 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1726 # and if all fails for an utterly naive quoted scalar-with-function
1727 while ($having_sql =~ /
1728 $rquote $sep $lquote (.+?) $rquote
1730 [\s,] \w+ \. (\w+) [\s,]
1732 [\s,] $lquote (.+?) $rquote [\s,]
1734 my $part = $1 || $2 || $3; # one of them matched if we got here
1735 unless ($seen_having{$part}++) {
1742 my $colpiece = $sel_index->{$_} || $_;
1744 # unqualify join-based group_by's. Arcane but possible query
1745 # also horrible horrible hack to alias a column (not a func.)
1746 # (probably need to introduce SQLA syntax)
1747 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1750 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1752 push @{$sub_attrs->{select}}, $colpiece;
1756 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1757 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1760 return $rsrc->resultset_class
1761 ->new ($rsrc, $sub_attrs)
1763 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1764 ->get_column ('count');
1768 =head2 count_literal
1770 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1771 should only be used in that context. See L</search_literal> for further info.
1775 =item Arguments: $sql_fragment, @standalone_bind_values
1777 =item Return Value: $count
1781 Counts the results in a literal query. Equivalent to calling L</search_literal>
1782 with the passed arguments, then L</count>.
1786 sub count_literal { shift->search_literal(@_)->count; }
1792 =item Arguments: none
1794 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1798 Returns all elements in the resultset.
1805 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1808 delete @{$self}{qw/_stashed_rows _stashed_results/};
1810 if (my $c = $self->get_cache) {
1814 $self->cursor->reset;
1816 my $objs = $self->_construct_results('fetch_all') || [];
1818 $self->set_cache($objs) if $self->{attrs}{cache};
1827 =item Arguments: none
1829 =item Return Value: $self
1833 Resets the resultset's cursor, so you can iterate through the elements again.
1834 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1842 delete @{$self}{qw/_stashed_rows _stashed_results/};
1843 $self->{all_cache_position} = 0;
1844 $self->cursor->reset;
1852 =item Arguments: none
1854 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1858 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1859 an object for the first result (or C<undef> if the resultset is empty).
1864 return $_[0]->reset->next;
1870 # Determines whether and what type of subquery is required for the $rs operation.
1871 # If grouping is necessary either supplies its own, or verifies the current one
1872 # After all is done delegates to the proper storage method.
1874 sub _rs_update_delete {
1875 my ($self, $op, $values) = @_;
1877 my $rsrc = $self->result_source;
1878 my $storage = $rsrc->schema->storage;
1880 my $attrs = { %{$self->_resolved_attrs} };
1882 my $join_classifications;
1883 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1885 # do we need a subquery for any reason?
1887 defined $existing_group_by
1889 # if {from} is unparseable wrap a subq
1890 ref($attrs->{from}) ne 'ARRAY'
1892 # limits call for a subq
1893 $self->_has_resolved_attr(qw/rows offset/)
1896 # simplify the joinmap, so we can further decide if a subq is necessary
1897 if (!$needs_subq and @{$attrs->{from}} > 1) {
1899 ($attrs->{from}, $join_classifications) =
1900 $storage->_prune_unused_joins ($attrs);
1902 # any non-pruneable non-local restricting joins imply subq
1903 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1906 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1908 (ref $attrs->{from}[0]) ne 'HASH'
1910 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1914 # do we need anything like a subquery?
1915 if (! $needs_subq) {
1916 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1917 # a condition containing 'me' or other table prefixes will not work
1918 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1920 my $sqla = $rsrc->storage->sql_maker;
1921 local $sqla->{_dequalify_idents} = 1;
1922 \[ $sqla->_recurse_where($self->{cond}) ];
1926 # we got this far - means it is time to wrap a subquery
1927 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1929 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1935 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1936 delete $attrs->{$_} for qw/select as collapse/;
1937 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1939 # this will be consumed by the pruner waaaaay down the stack
1940 $attrs->{_force_prune_multiplying_joins} = 1;
1942 my $subrs = (ref $self)->new($rsrc, $attrs);
1944 if (@$idcols == 1) {
1945 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1947 elsif ($storage->_use_multicolumn_in) {
1948 # no syntax for calling this properly yet
1949 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1950 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1951 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1956 # if all else fails - get all primary keys and operate over a ORed set
1957 # wrap in a transaction for consistency
1958 # this is where the group_by/multiplication starts to matter
1962 # we do not need to check pre-multipliers, since if the premulti is there, its
1963 # parent (who is multi) will be there too
1964 keys %{ $join_classifications->{multiplying} || {} }
1966 # make sure if there is a supplied group_by it matches the columns compiled above
1967 # perfectly. Anything else can not be sanely executed on most databases so croak
1968 # right then and there
1969 if ($existing_group_by) {
1970 my @current_group_by = map
1971 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1976 join ("\x00", sort @current_group_by)
1978 join ("\x00", sort @{$attrs->{columns}} )
1980 $self->throw_exception (
1981 "You have just attempted a $op operation on a resultset which does group_by"
1982 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1983 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1984 . ' kind of queries. Please retry the operation with a modified group_by or'
1985 . ' without using one at all.'
1990 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1993 $guard = $storage->txn_scope_guard;
1995 for my $row ($subrs->cursor->all) {
1997 { $idcols->[$_] => $row->[$_] }
2004 my $res = $cond ? $storage->$op (
2006 $op eq 'update' ? $values : (),
2010 $guard->commit if $guard;
2019 =item Arguments: \%values
2021 =item Return Value: $underlying_storage_rv
2025 Sets the specified columns in the resultset to the supplied values in a
2026 single query. Note that this will not run any accessor/set_column/update
2027 triggers, nor will it update any result object instances derived from this
2028 resultset (this includes the contents of the L<resultset cache|/set_cache>
2029 if any). See L</update_all> if you need to execute any on-update
2030 triggers or cascades defined either by you or a
2031 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2033 The return value is a pass through of what the underlying
2034 storage backend returned, and may vary. See L<DBI/execute> for the most
2039 Note that L</update> does not process/deflate any of the values passed in.
2040 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2041 ensure manually that any value passed to this method will stringify to
2042 something the RDBMS knows how to deal with. A notable example is the
2043 handling of L<DateTime> objects, for more info see:
2044 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2049 my ($self, $values) = @_;
2050 $self->throw_exception('Values for update must be a hash')
2051 unless ref $values eq 'HASH';
2053 return $self->_rs_update_delete ('update', $values);
2060 =item Arguments: \%values
2062 =item Return Value: 1
2066 Fetches all objects and updates them one at a time via
2067 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2068 triggers, while L</update> will not.
2073 my ($self, $values) = @_;
2074 $self->throw_exception('Values for update_all must be a hash')
2075 unless ref $values eq 'HASH';
2077 my $guard = $self->result_source->schema->txn_scope_guard;
2078 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2087 =item Arguments: none
2089 =item Return Value: $underlying_storage_rv
2093 Deletes the rows matching this resultset in a single query. Note that this
2094 will not run any delete triggers, nor will it alter the
2095 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2096 derived from this resultset (this includes the contents of the
2097 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2098 execute any on-delete triggers or cascades defined either by you or a
2099 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2101 The return value is a pass through of what the underlying storage backend
2102 returned, and may vary. See L<DBI/execute> for the most common case.
2108 $self->throw_exception('delete does not accept any arguments')
2111 return $self->_rs_update_delete ('delete');
2118 =item Arguments: none
2120 =item Return Value: 1
2124 Fetches all objects and deletes them one at a time via
2125 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2126 triggers, while L</delete> will not.
2132 $self->throw_exception('delete_all does not accept any arguments')
2135 my $guard = $self->result_source->schema->txn_scope_guard;
2136 $_->delete for $self->all;
2145 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2147 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2151 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2158 The context of this method call has an important effect on what is
2159 submitted to storage. In void context data is fed directly to fastpath
2160 insertion routines provided by the underlying storage (most often
2161 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2162 L<insert|DBIx::Class::Row/insert> calls on the
2163 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2164 augmentation of these methods provided by components. For example if you
2165 are using something like L<DBIx::Class::UUIDColumns> to create primary
2166 keys for you, you will find that your PKs are empty. In this case you
2167 will have to explicitly force scalar or list context in order to create
2172 In non-void (scalar or list) context, this method is simply a wrapper
2173 for L</create>. Depending on list or scalar context either a list of
2174 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2175 containing these objects is returned.
2177 When supplying data in "arrayref of arrayrefs" invocation style, the
2178 first element should be a list of column names and each subsequent
2179 element should be a data value in the earlier specified column order.
2182 $schema->resultset("Artist")->populate([
2183 [ qw( artistid name ) ],
2184 [ 100, 'A Formally Unknown Singer' ],
2185 [ 101, 'A singer that jumped the shark two albums ago' ],
2186 [ 102, 'An actually cool singer' ],
2189 For the arrayref of hashrefs style each hashref should be a structure
2190 suitable for passing to L</create>. Multi-create is also permitted with
2193 $schema->resultset("Artist")->populate([
2194 { artistid => 4, name => 'Manufactured Crap', cds => [
2195 { title => 'My First CD', year => 2006 },
2196 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2199 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2200 { title => 'My parents sold me to a record company', year => 2005 },
2201 { title => 'Why Am I So Ugly?', year => 2006 },
2202 { title => 'I Got Surgery and am now Popular', year => 2007 }
2207 If you attempt a void-context multi-create as in the example above (each
2208 Artist also has the related list of CDs), and B<do not> supply the
2209 necessary autoinc foreign key information, this method will proxy to the
2210 less efficient L</create>, and then throw the Result objects away. In this
2211 case there are obviously no benefits to using this method over L</create>.
2218 # this is naive and just a quick check
2219 # the types will need to be checked more thoroughly when the
2220 # multi-source populate gets added
2222 ref $_[0] eq 'ARRAY'
2224 ( @{$_[0]} or return )
2226 ( ref $_[0][0] eq 'HASH' or ref $_[0][0] eq 'ARRAY' )
2229 ) or $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2231 # FIXME - no cref handling
2232 # At this point assume either hashes or arrays
2234 if(defined wantarray) {
2235 my (@results, $guard);
2237 if (ref $data->[0] eq 'ARRAY') {
2238 # column names only, nothing to do
2239 return if @$data == 1;
2241 $guard = $self->result_source->schema->storage->txn_scope_guard
2245 { my $vals = $_; $self->new_result({ map { $data->[0][$_] => $vals->[$_] } 0..$#{$data->[0]} })->insert }
2246 @{$data}[1 .. $#$data]
2251 $guard = $self->result_source->schema->storage->txn_scope_guard
2254 @results = map { $self->new_result($_)->insert } @$data;
2257 $guard->commit if $guard;
2258 return wantarray ? @results : \@results;
2261 # we have to deal with *possibly incomplete* related data
2262 # this means we have to walk the data structure twice
2263 # whether we want this or not
2264 # jnap, I hate you ;)
2265 my $rsrc = $self->result_source;
2266 my $rel_info = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2268 my ($colinfo, $colnames, $slices_with_rels);
2272 for my $i (0 .. $#$data) {
2274 my $current_slice_seen_rel_infos;
2276 ### Determine/Supplement collists
2277 ### BEWARE - This is a hot piece of code, a lot of weird idioms were used
2278 if( ref $data->[$i] eq 'ARRAY' ) {
2280 # positional(!) explicit column list
2282 # column names only, nothing to do
2283 return if @$data == 1;
2285 $colinfo->{$data->[0][$_]} = { pos => $_, name => $data->[0][$_] } and push @$colnames, $data->[0][$_]
2286 for 0 .. $#{$data->[0]};
2293 for (values %$colinfo) {
2294 if ($_->{is_rel} ||= (
2295 $rel_info->{$_->{name}}
2298 ref $data->[$i][$_->{pos}] eq 'ARRAY'
2300 ref $data->[$i][$_->{pos}] eq 'HASH'
2302 ( defined blessed $data->[$i][$_->{pos}] and $data->[$i][$_->{pos}]->isa('DBIx::Class::Row') )
2308 # moar sanity check... sigh
2309 for ( ref $data->[$i][$_->{pos}] eq 'ARRAY' ? @{$data->[$i][$_->{pos}]} : $data->[$i][$_->{pos}] ) {
2310 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2311 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2312 return my $throwaway = $self->populate(@_);
2316 push @$current_slice_seen_rel_infos, $rel_info->{$_->{name}};
2321 if ($current_slice_seen_rel_infos) {
2322 push @$slices_with_rels, { map { $colnames->[$_] => $data->[$i][$_] } 0 .. $#$colnames };
2324 # this is needed further down to decide whether or not to fallback to create()
2325 $colinfo->{$colnames->[$_]}{seen_null} ||= ! defined $data->[$i][$_]
2326 for 0 .. $#$colnames;
2329 elsif( ref $data->[$i] eq 'HASH' ) {
2331 for ( sort keys %{$data->[$i]} ) {
2333 $colinfo->{$_} ||= do {
2335 $self->throw_exception("Column '$_' must be present in supplied explicit column list")
2336 if $data_start; # it will be 0 on AoH, 1 on AoA
2338 push @$colnames, $_;
2341 { pos => $#$colnames, name => $_ }
2344 if ($colinfo->{$_}{is_rel} ||= (
2348 ref $data->[$i]{$_} eq 'ARRAY'
2350 ref $data->[$i]{$_} eq 'HASH'
2352 ( defined blessed $data->[$i]{$_} and $data->[$i]{$_}->isa('DBIx::Class::Row') )
2358 # moar sanity check... sigh
2359 for ( ref $data->[$i]{$_} eq 'ARRAY' ? @{$data->[$i]{$_}} : $data->[$i]{$_} ) {
2360 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2361 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2362 return my $throwaway = $self->populate(@_);
2366 push @$current_slice_seen_rel_infos, $rel_info->{$_};
2370 if ($current_slice_seen_rel_infos) {
2371 push @$slices_with_rels, $data->[$i];
2373 # this is needed further down to decide whether or not to fallback to create()
2374 $colinfo->{$_}{seen_null} ||= ! defined $data->[$i]{$_}
2375 for keys %{$data->[$i]};
2379 $self->throw_exception('Unexpected populate() data structure member type: ' . ref $data->[$i] );
2383 { $_->{attrs}{is_depends_on} }
2384 @{ $current_slice_seen_rel_infos || [] }
2386 carp_unique("Fast-path populate() of belongs_to relationship data is not possible - falling back to regular create()");
2387 return my $throwaway = $self->populate(@_);
2391 if( $slices_with_rels ) {
2393 # need to exclude the rel "columns"
2394 $colnames = [ grep { ! $colinfo->{$_}{is_rel} } @$colnames ];
2396 # extra sanity check - ensure the main source is in fact identifiable
2397 # the localizing of nullability is insane, but oh well... the use-case is legit
2398 my $ci = $rsrc->columns_info($colnames);
2400 $ci->{$_} = { %{$ci->{$_}}, is_nullable => 0 }
2401 for grep { ! $colinfo->{$_}{seen_null} } keys %$ci;
2403 unless( $rsrc->_identifying_column_set($ci) ) {
2404 carp_unique("Fast-path populate() of non-uniquely identifiable rows with related data is not possible - falling back to regular create()");
2405 return my $throwaway = $self->populate(@_);
2409 ### inherit the data locked in the conditions of the resultset
2410 my ($rs_data) = $self->_merge_with_rscond({});
2411 delete @{$rs_data}{@$colnames}; # passed-in stuff takes precedence
2413 # if anything left - decompose rs_data
2415 if (keys %$rs_data) {
2416 push @$rs_data_vals, $rs_data->{$_}
2417 for sort keys %$rs_data;
2422 $guard = $rsrc->schema->storage->txn_scope_guard
2423 if $slices_with_rels;
2425 ### main source data
2426 # FIXME - need to switch entirely to a coderef-based thing,
2427 # so that large sets aren't copied several times... I think
2428 $rsrc->storage->_insert_bulk(
2430 [ @$colnames, sort keys %$rs_data ],
2432 ref $data->[$_] eq 'ARRAY'
2434 $slices_with_rels ? [ @{$data->[$_]}[0..$#$colnames], @{$rs_data_vals||[]} ] # the collist changed
2435 : $rs_data_vals ? [ @{$data->[$_]}, @$rs_data_vals ]
2438 : [ @{$data->[$_]}{@$colnames}, @{$rs_data_vals||[]} ]
2439 } $data_start .. $#$data ],
2442 ### do the children relationships
2443 if ( $slices_with_rels ) {
2444 my @rels = grep { $colinfo->{$_}{is_rel} } keys %$colinfo
2445 or die 'wtf... please report a bug with DBIC_TRACE=1 output (stacktrace)';
2447 for my $sl (@$slices_with_rels) {
2449 my ($main_proto, $main_proto_rs);
2450 for my $rel (@rels) {
2451 next unless defined $sl->{$rel};
2455 (map { $_ => $sl->{$_} } @$colnames),
2458 unless (defined $colinfo->{$rel}{rs}) {
2460 $colinfo->{$rel}{rs} = $rsrc->related_source($rel)->resultset;
2462 $colinfo->{$rel}{fk_map} = { reverse %{ $rsrc->_resolve_relationship_condition(
2464 self_alias => "\xFE", # irrelevant
2465 foreign_alias => "\xFF", # irrelevant
2466 )->{identity_map} || {} } };
2470 $colinfo->{$rel}{rs}->search({ map # only so that we inherit them values properly, no actual search
2473 ( $main_proto_rs ||= $rsrc->resultset->search($main_proto) )
2474 ->get_column( $colinfo->{$rel}{fk_map}{$_} )
2478 keys %{$colinfo->{$rel}{fk_map}}
2479 })->populate( ref $sl->{$rel} eq 'ARRAY' ? $sl->{$rel} : [ $sl->{$rel} ] );
2486 $guard->commit if $guard;
2493 =item Arguments: none
2495 =item Return Value: L<$pager|Data::Page>
2499 Returns a L<Data::Page> object for the current resultset. Only makes
2500 sense for queries with a C<page> attribute.
2502 To get the full count of entries for a paged resultset, call
2503 C<total_entries> on the L<Data::Page> object.
2510 return $self->{pager} if $self->{pager};
2512 my $attrs = $self->{attrs};
2513 if (!defined $attrs->{page}) {
2514 $self->throw_exception("Can't create pager for non-paged rs");
2516 elsif ($attrs->{page} <= 0) {
2517 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2519 $attrs->{rows} ||= 10;
2521 # throw away the paging flags and re-run the count (possibly
2522 # with a subselect) to get the real total count
2523 my $count_attrs = { %$attrs };
2524 delete @{$count_attrs}{qw/rows offset page pager/};
2526 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2528 require DBIx::Class::ResultSet::Pager;
2529 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2530 sub { $total_rs->count }, #lazy-get the total
2532 $self->{attrs}{page},
2540 =item Arguments: $page_number
2542 =item Return Value: L<$resultset|/search>
2546 Returns a resultset for the $page_number page of the resultset on which page
2547 is called, where each page contains a number of rows equal to the 'rows'
2548 attribute set on the resultset (10 by default).
2553 my ($self, $page) = @_;
2554 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2561 =item Arguments: \%col_data
2563 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2567 Creates a new result object in the resultset's result class and returns
2568 it. The row is not inserted into the database at this point, call
2569 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2570 will tell you whether the result object has been inserted or not.
2572 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2577 my ($self, $values) = @_;
2579 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2582 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2583 unless (ref $values eq 'HASH');
2585 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2587 my $new = $self->result_class->new({
2589 ( @$cols_from_relations
2590 ? (-cols_from_relations => $cols_from_relations)
2593 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2597 reftype($new) eq 'HASH'
2603 carp_unique (sprintf (
2604 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2605 $self->result_class,
2612 # _merge_with_rscond
2614 # Takes a simple hash of K/V data and returns its copy merged with the
2615 # condition already present on the resultset. Additionally returns an
2616 # arrayref of value/condition names, which were inferred from related
2617 # objects (this is needed for in-memory related objects)
2618 sub _merge_with_rscond {
2619 my ($self, $data) = @_;
2621 my ($implied_data, @cols_from_relations);
2623 my $alias = $self->{attrs}{alias};
2625 if (! defined $self->{cond}) {
2626 # just massage $data below
2628 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2629 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2630 @cols_from_relations = keys %{ $implied_data || {} };
2633 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2634 $implied_data = { map {
2635 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2641 { %{ $self->_remove_alias($_, $alias) } }
2642 # precedence must be given to passed values over values inherited from
2643 # the cond, so the order here is important.
2644 ( $implied_data||(), $data)
2646 \@cols_from_relations
2650 # _has_resolved_attr
2652 # determines if the resultset defines at least one
2653 # of the attributes supplied
2655 # used to determine if a subquery is necessary
2657 # supports some virtual attributes:
2659 # This will scan for any joins being present on the resultset.
2660 # It is not a mere key-search but a deep inspection of {from}
2663 sub _has_resolved_attr {
2664 my ($self, @attr_names) = @_;
2666 my $attrs = $self->_resolved_attrs;
2670 for my $n (@attr_names) {
2671 if (grep { $n eq $_ } (qw/-join/) ) {
2672 $extra_checks{$n}++;
2676 my $attr = $attrs->{$n};
2678 next if not defined $attr;
2680 if (ref $attr eq 'HASH') {
2681 return 1 if keys %$attr;
2683 elsif (ref $attr eq 'ARRAY') {
2691 # a resolved join is expressed as a multi-level from
2693 $extra_checks{-join}
2695 ref $attrs->{from} eq 'ARRAY'
2697 @{$attrs->{from}} > 1
2705 # Remove the specified alias from the specified query hash. A copy is made so
2706 # the original query is not modified.
2709 my ($self, $query, $alias) = @_;
2711 my %orig = %{ $query || {} };
2714 foreach my $key (keys %orig) {
2716 $unaliased{$key} = $orig{$key};
2719 $unaliased{$1} = $orig{$key}
2720 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2730 =item Arguments: none
2732 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2736 Returns the SQL query and bind vars associated with the invocant.
2738 This is generally used as the RHS for a subquery.
2745 my $attrs = { %{ $self->_resolved_attrs } };
2747 my $aq = $self->result_source->storage->_select_args_to_query (
2748 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2758 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2760 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2764 my $artist = $schema->resultset('Artist')->find_or_new(
2765 { artist => 'fred' }, { key => 'artists' });
2767 $cd->cd_to_producer->find_or_new({ producer => $producer },
2768 { key => 'primary' });
2770 Find an existing record from this resultset using L</find>. if none exists,
2771 instantiate a new result object and return it. The object will not be saved
2772 into your storage until you call L<DBIx::Class::Row/insert> on it.
2774 You most likely want this method when looking for existing rows using a unique
2775 constraint that is not the primary key, or looking for related rows.
2777 If you want objects to be saved immediately, use L</find_or_create> instead.
2779 B<Note>: Make sure to read the documentation of L</find> and understand the
2780 significance of the C<key> attribute, as its lack may skew your search, and
2781 subsequently result in spurious new objects.
2783 B<Note>: Take care when using C<find_or_new> with a table having
2784 columns with default values that you intend to be automatically
2785 supplied by the database (e.g. an auto_increment primary key column).
2786 In normal usage, the value of such columns should NOT be included at
2787 all in the call to C<find_or_new>, even when set to C<undef>.
2793 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2794 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2795 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2798 return $self->new_result($hash);
2805 =item Arguments: \%col_data
2807 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2811 Attempt to create a single new row or a row with multiple related rows
2812 in the table represented by the resultset (and related tables). This
2813 will not check for duplicate rows before inserting, use
2814 L</find_or_create> to do that.
2816 To create one row for this resultset, pass a hashref of key/value
2817 pairs representing the columns of the table and the values you wish to
2818 store. If the appropriate relationships are set up, foreign key fields
2819 can also be passed an object representing the foreign row, and the
2820 value will be set to its primary key.
2822 To create related objects, pass a hashref of related-object column values
2823 B<keyed on the relationship name>. If the relationship is of type C<multi>
2824 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2825 The process will correctly identify columns holding foreign keys, and will
2826 transparently populate them from the keys of the corresponding relation.
2827 This can be applied recursively, and will work correctly for a structure
2828 with an arbitrary depth and width, as long as the relationships actually
2829 exists and the correct column data has been supplied.
2831 Instead of hashrefs of plain related data (key/value pairs), you may
2832 also pass new or inserted objects. New objects (not inserted yet, see
2833 L</new_result>), will be inserted into their appropriate tables.
2835 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2837 Example of creating a new row.
2839 $person_rs->create({
2840 name=>"Some Person",
2841 email=>"somebody@someplace.com"
2844 Example of creating a new row and also creating rows in a related C<has_many>
2845 or C<has_one> resultset. Note Arrayref.
2848 { artistid => 4, name => 'Manufactured Crap', cds => [
2849 { title => 'My First CD', year => 2006 },
2850 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2855 Example of creating a new row and also creating a row in a related
2856 C<belongs_to> resultset. Note Hashref.
2859 title=>"Music for Silly Walks",
2862 name=>"Silly Musician",
2870 When subclassing ResultSet never attempt to override this method. Since
2871 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2872 lot of the internals simply never call it, so your override will be
2873 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2874 or L<DBIx::Class::Row/insert> depending on how early in the
2875 L</create> process you need to intervene. See also warning pertaining to
2883 #my ($self, $col_data) = @_;
2884 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2885 return shift->new_result(shift)->insert;
2888 =head2 find_or_create
2892 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2894 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2898 $cd->cd_to_producer->find_or_create({ producer => $producer },
2899 { key => 'primary' });
2901 Tries to find a record based on its primary key or unique constraints; if none
2902 is found, creates one and returns that instead.
2904 my $cd = $schema->resultset('CD')->find_or_create({
2906 artist => 'Massive Attack',
2907 title => 'Mezzanine',
2911 Also takes an optional C<key> attribute, to search by a specific key or unique
2912 constraint. For example:
2914 my $cd = $schema->resultset('CD')->find_or_create(
2916 artist => 'Massive Attack',
2917 title => 'Mezzanine',
2919 { key => 'cd_artist_title' }
2922 B<Note>: Make sure to read the documentation of L</find> and understand the
2923 significance of the C<key> attribute, as its lack may skew your search, and
2924 subsequently result in spurious row creation.
2926 B<Note>: Because find_or_create() reads from the database and then
2927 possibly inserts based on the result, this method is subject to a race
2928 condition. Another process could create a record in the table after
2929 the find has completed and before the create has started. To avoid
2930 this problem, use find_or_create() inside a transaction.
2932 B<Note>: Take care when using C<find_or_create> with a table having
2933 columns with default values that you intend to be automatically
2934 supplied by the database (e.g. an auto_increment primary key column).
2935 In normal usage, the value of such columns should NOT be included at
2936 all in the call to C<find_or_create>, even when set to C<undef>.
2938 See also L</find> and L</update_or_create>. For information on how to declare
2939 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2941 If you need to know if an existing row was found or a new one created use
2942 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2943 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2946 my $cd = $schema->resultset('CD')->find_or_new({
2948 artist => 'Massive Attack',
2949 title => 'Mezzanine',
2953 if( !$cd->in_storage ) {
2960 sub find_or_create {
2962 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2963 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2964 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2967 return $self->new_result($hash)->insert;
2970 =head2 update_or_create
2974 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2976 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2980 $resultset->update_or_create({ col => $val, ... });
2982 Like L</find_or_create>, but if a row is found it is immediately updated via
2983 C<< $found_row->update (\%col_data) >>.
2986 Takes an optional C<key> attribute to search on a specific unique constraint.
2989 # In your application
2990 my $cd = $schema->resultset('CD')->update_or_create(
2992 artist => 'Massive Attack',
2993 title => 'Mezzanine',
2996 { key => 'cd_artist_title' }
2999 $cd->cd_to_producer->update_or_create({
3000 producer => $producer,
3006 B<Note>: Make sure to read the documentation of L</find> and understand the
3007 significance of the C<key> attribute, as its lack may skew your search, and
3008 subsequently result in spurious row creation.
3010 B<Note>: Take care when using C<update_or_create> with a table having
3011 columns with default values that you intend to be automatically
3012 supplied by the database (e.g. an auto_increment primary key column).
3013 In normal usage, the value of such columns should NOT be included at
3014 all in the call to C<update_or_create>, even when set to C<undef>.
3016 See also L</find> and L</find_or_create>. For information on how to declare
3017 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3019 If you need to know if an existing row was updated or a new one created use
3020 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3021 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3026 sub update_or_create {
3028 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3029 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3031 my $row = $self->find($cond, $attrs);
3033 $row->update($cond);
3037 return $self->new_result($cond)->insert;
3040 =head2 update_or_new
3044 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3046 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3050 $resultset->update_or_new({ col => $val, ... });
3052 Like L</find_or_new> but if a row is found it is immediately updated via
3053 C<< $found_row->update (\%col_data) >>.
3057 # In your application
3058 my $cd = $schema->resultset('CD')->update_or_new(
3060 artist => 'Massive Attack',
3061 title => 'Mezzanine',
3064 { key => 'cd_artist_title' }
3067 if ($cd->in_storage) {
3068 # the cd was updated
3071 # the cd is not yet in the database, let's insert it
3075 B<Note>: Make sure to read the documentation of L</find> and understand the
3076 significance of the C<key> attribute, as its lack may skew your search, and
3077 subsequently result in spurious new objects.
3079 B<Note>: Take care when using C<update_or_new> with a table having
3080 columns with default values that you intend to be automatically
3081 supplied by the database (e.g. an auto_increment primary key column).
3082 In normal usage, the value of such columns should NOT be included at
3083 all in the call to C<update_or_new>, even when set to C<undef>.
3085 See also L</find>, L</find_or_create> and L</find_or_new>.
3091 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3092 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3094 my $row = $self->find( $cond, $attrs );
3095 if ( defined $row ) {
3096 $row->update($cond);
3100 return $self->new_result($cond);
3107 =item Arguments: none
3109 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3113 Gets the contents of the cache for the resultset, if the cache is set.
3115 The cache is populated either by using the L</prefetch> attribute to
3116 L</search> or by calling L</set_cache>.
3128 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3130 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3134 Sets the contents of the cache for the resultset. Expects an arrayref
3135 of objects of the same class as those produced by the resultset. Note that
3136 if the cache is set, the resultset will return the cached objects rather
3137 than re-querying the database even if the cache attr is not set.
3139 The contents of the cache can also be populated by using the
3140 L</prefetch> attribute to L</search>.
3145 my ( $self, $data ) = @_;
3146 $self->throw_exception("set_cache requires an arrayref")
3147 if defined($data) && (ref $data ne 'ARRAY');
3148 $self->{all_cache} = $data;
3155 =item Arguments: none
3157 =item Return Value: undef
3161 Clears the cache for the resultset.
3166 shift->set_cache(undef);
3173 =item Arguments: none
3175 =item Return Value: true, if the resultset has been paginated
3183 return !!$self->{attrs}{page};
3190 =item Arguments: none
3192 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3200 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3203 =head2 related_resultset
3207 =item Arguments: $rel_name
3209 =item Return Value: L<$resultset|/search>
3213 Returns a related resultset for the supplied relationship name.
3215 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3219 sub related_resultset {
3220 my ($self, $rel) = @_;
3222 return $self->{related_resultsets}{$rel}
3223 if defined $self->{related_resultsets}{$rel};
3225 return $self->{related_resultsets}{$rel} = do {
3226 my $rsrc = $self->result_source;
3227 my $rel_info = $rsrc->relationship_info($rel);
3229 $self->throw_exception(
3230 "search_related: result source '" . $rsrc->source_name .
3231 "' has no such relationship $rel")
3234 my $attrs = $self->_chain_relationship($rel);
3236 my $join_count = $attrs->{seen_join}{$rel};
3238 my $alias = $self->result_source->storage
3239 ->relname_to_table_alias($rel, $join_count);
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} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3248 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3249 delete @{$attrs}{qw(result_class alias)};
3251 my $rel_source = $rsrc->related_source($rel);
3255 # The reason we do this now instead of passing the alias to the
3256 # search_rs below is that if you wrap/overload resultset on the
3257 # source you need to know what alias it's -going- to have for things
3258 # to work sanely (e.g. RestrictWithObject wants to be able to add
3259 # extra query restrictions, and these may need to be $alias.)
3261 my $rel_attrs = $rel_source->resultset_attributes;
3262 local $rel_attrs->{alias} = $alias;
3264 $rel_source->resultset
3268 where => $attrs->{where},
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" => $user->id,
3322 sub current_source_alias {
3323 return (shift->{attrs} || {})->{alias} || 'me';
3326 =head2 as_subselect_rs
3330 =item Arguments: none
3332 =item Return Value: L<$resultset|/search>
3336 Act as a barrier to SQL symbols. The resultset provided will be made into a
3337 "virtual view" by including it as a subquery within the from clause. From this
3338 point on, any joined tables are inaccessible to ->search on the resultset (as if
3339 it were simply where-filtered without joins). For example:
3341 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3343 # 'x' now pollutes the query namespace
3345 # So the following works as expected
3346 my $ok_rs = $rs->search({'x.other' => 1});
3348 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3349 # def) we look for one row with contradictory terms and join in another table
3350 # (aliased 'x_2') which we never use
3351 my $broken_rs = $rs->search({'x.name' => 'def'});
3353 my $rs2 = $rs->as_subselect_rs;
3355 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3356 my $not_joined_rs = $rs2->search({'x.other' => 1});
3358 # works as expected: finds a 'table' row related to two x rows (abc and def)
3359 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3361 Another example of when one might use this would be to select a subset of
3362 columns in a group by clause:
3364 my $rs = $schema->resultset('Bar')->search(undef, {
3365 group_by => [qw{ id foo_id baz_id }],
3366 })->as_subselect_rs->search(undef, {
3367 columns => [qw{ id foo_id }]
3370 In the above example normally columns would have to be equal to the group by,
3371 but because we isolated the group by into a subselect the above works.
3375 sub as_subselect_rs {
3378 my $attrs = $self->_resolved_attrs;
3380 my $fresh_rs = (ref $self)->new (
3381 $self->result_source
3384 # these pieces will be locked in the subquery
3385 delete $fresh_rs->{cond};
3386 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3388 return $fresh_rs->search( {}, {
3390 $attrs->{alias} => $self->as_query,
3391 -alias => $attrs->{alias},
3392 -rsrc => $self->result_source,
3394 alias => $attrs->{alias},
3398 # This code is called by search_related, and makes sure there
3399 # is clear separation between the joins before, during, and
3400 # after the relationship. This information is needed later
3401 # in order to properly resolve prefetch aliases (any alias
3402 # with a relation_chain_depth less than the depth of the
3403 # current prefetch is not considered)
3405 # The increments happen twice per join. An even number means a
3406 # relationship specified via a search_related, whereas an odd
3407 # number indicates a join/prefetch added via attributes
3409 # Also this code will wrap the current resultset (the one we
3410 # chain to) in a subselect IFF it contains limiting attributes
3411 sub _chain_relationship {
3412 my ($self, $rel) = @_;
3413 my $source = $self->result_source;
3414 my $attrs = { %{$self->{attrs}||{}} };
3416 # we need to take the prefetch the attrs into account before we
3417 # ->_resolve_join as otherwise they get lost - captainL
3418 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3420 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3422 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3425 my @force_subq_attrs = qw/offset rows group_by having/;
3428 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3430 $self->_has_resolved_attr (@force_subq_attrs)
3432 # Nuke the prefetch (if any) before the new $rs attrs
3433 # are resolved (prefetch is useless - we are wrapping
3434 # a subquery anyway).
3435 my $rs_copy = $self->search;
3436 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3437 $rs_copy->{attrs}{join},
3438 delete $rs_copy->{attrs}{prefetch},
3443 -alias => $attrs->{alias},
3444 $attrs->{alias} => $rs_copy->as_query,
3446 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3447 $seen->{-relation_chain_depth} = 0;
3449 elsif ($attrs->{from}) { #shallow copy suffices
3450 $from = [ @{$attrs->{from}} ];
3455 -alias => $attrs->{alias},
3456 $attrs->{alias} => $source->from,
3460 my $jpath = ($seen->{-relation_chain_depth})
3461 ? $from->[-1][0]{-join_path}
3464 my @requested_joins = $source->_resolve_join(
3471 push @$from, @requested_joins;
3473 $seen->{-relation_chain_depth}++;
3475 # if $self already had a join/prefetch specified on it, the requested
3476 # $rel might very well be already included. What we do in this case
3477 # is effectively a no-op (except that we bump up the chain_depth on
3478 # the join in question so we could tell it *is* the search_related)
3481 # we consider the last one thus reverse
3482 for my $j (reverse @requested_joins) {
3483 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3484 if ($rel eq $last_j) {
3485 $j->[0]{-relation_chain_depth}++;
3491 unless ($already_joined) {
3492 push @$from, $source->_resolve_join(
3500 $seen->{-relation_chain_depth}++;
3502 return {%$attrs, from => $from, seen_join => $seen};
3505 sub _resolved_attrs {
3507 return $self->{_attrs} if $self->{_attrs};
3509 my $attrs = { %{ $self->{attrs} || {} } };
3510 my $source = $attrs->{result_source} = $self->result_source;
3511 my $alias = $attrs->{alias};
3513 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3514 if $attrs->{collapse} and $attrs->{distinct};
3516 # default selection list
3517 $attrs->{columns} = [ $source->columns ]
3518 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3520 # merge selectors together
3521 for (qw/columns select as/) {
3522 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3523 if $attrs->{$_} or $attrs->{"+$_"};
3526 # disassemble columns
3528 if (my $cols = delete $attrs->{columns}) {
3529 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3530 if (ref $c eq 'HASH') {
3531 for my $as (sort keys %$c) {
3532 push @sel, $c->{$as};
3543 # when trying to weed off duplicates later do not go past this point -
3544 # everything added from here on is unbalanced "anyone's guess" stuff
3545 my $dedup_stop_idx = $#as;
3547 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3549 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3550 if $attrs->{select};
3552 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3553 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3555 # disqualify all $alias.col as-bits (inflate-map mandated)
3556 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3558 # de-duplicate the result (remove *identical* select/as pairs)
3559 # and also die on duplicate {as} pointing to different {select}s
3560 # not using a c-style for as the condition is prone to shrinkage
3563 while ($i <= $dedup_stop_idx) {
3564 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3569 elsif ($seen->{$as[$i]}++) {
3570 $self->throw_exception(
3571 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3579 $attrs->{select} = \@sel;
3580 $attrs->{as} = \@as;
3582 $attrs->{from} ||= [{
3584 -alias => $self->{attrs}{alias},
3585 $self->{attrs}{alias} => $source->from,
3588 if ( $attrs->{join} || $attrs->{prefetch} ) {
3590 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3591 if ref $attrs->{from} ne 'ARRAY';
3593 my $join = (delete $attrs->{join}) || {};
3595 if ( defined $attrs->{prefetch} ) {
3596 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3599 $attrs->{from} = # have to copy here to avoid corrupting the original
3601 @{ $attrs->{from} },
3602 $source->_resolve_join(
3605 { %{ $attrs->{seen_join} || {} } },
3606 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3607 ? $attrs->{from}[-1][0]{-join_path}
3614 for my $attr (qw(order_by group_by)) {
3616 if ( defined $attrs->{$attr} ) {
3618 ref( $attrs->{$attr} ) eq 'ARRAY'
3619 ? [ @{ $attrs->{$attr} } ]
3620 : [ $attrs->{$attr} || () ]
3623 delete $attrs->{$attr} unless @{$attrs->{$attr}};
3627 # generate selections based on the prefetch helper
3628 my ($prefetch, @prefetch_select, @prefetch_as);
3629 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3630 if defined $attrs->{prefetch};
3634 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3635 if $attrs->{_dark_selector};
3637 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3638 if defined $attrs->{collapse} and ! $attrs->{collapse};
3640 $attrs->{collapse} = 1;
3642 # this is a separate structure (we don't look in {from} directly)
3643 # as the resolver needs to shift things off the lists to work
3644 # properly (identical-prefetches on different branches)
3646 if (ref $attrs->{from} eq 'ARRAY') {
3648 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3650 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3651 next unless $j->[0]{-alias};
3652 next unless $j->[0]{-join_path};
3653 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3655 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3658 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3659 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3663 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3665 # save these for after distinct resolution
3666 @prefetch_select = map { $_->[0] } @prefetch;
3667 @prefetch_as = map { $_->[1] } @prefetch;
3670 # run through the resulting joinstructure (starting from our current slot)
3671 # and unset collapse if proven unnecessary
3673 # also while we are at it find out if the current root source has
3674 # been premultiplied by previous related_source chaining
3676 # this allows to predict whether a root object with all other relation
3677 # data set to NULL is in fact unique
3678 if ($attrs->{collapse}) {
3680 if (ref $attrs->{from} eq 'ARRAY') {
3682 if (@{$attrs->{from}} == 1) {
3683 # no joins - no collapse
3684 $attrs->{collapse} = 0;
3687 # find where our table-spec starts
3688 my @fromlist = @{$attrs->{from}};
3690 my $t = shift @fromlist;
3693 # me vs join from-spec distinction - a ref means non-root
3694 if (ref $t eq 'ARRAY') {
3696 $is_multi ||= ! $t->{-is_single};
3698 last if ($t->{-alias} && $t->{-alias} eq $alias);
3699 $attrs->{_main_source_premultiplied} ||= $is_multi;
3702 # no non-singles remaining, nor any premultiplication - nothing to collapse
3704 ! $attrs->{_main_source_premultiplied}
3706 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3708 $attrs->{collapse} = 0;
3714 # if we can not analyze the from - err on the side of safety
3715 $attrs->{_main_source_premultiplied} = 1;
3719 # generate the distinct induced group_by before injecting the prefetched select/as parts
3720 if (delete $attrs->{distinct}) {
3721 if ($attrs->{group_by}) {
3722 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3725 $attrs->{_grouped_by_distinct} = 1;
3726 # distinct affects only the main selection part, not what prefetch may add below
3727 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3729 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3730 # The thinking is: if we are collapsing the subquerying prefetch engine will
3731 # rip stuff apart for us anyway, and we do not want to have a potentially
3732 # function-converted external order_by
3733 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3734 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3738 # inject prefetch-bound selection (if any)
3739 push @{$attrs->{select}}, @prefetch_select;
3740 push @{$attrs->{as}}, @prefetch_as;
3742 $attrs->{_simple_passthrough_construction} = !(
3745 grep { $_ =~ /\./ } @{$attrs->{as}}
3748 # if both page and offset are specified, produce a combined offset
3749 # even though it doesn't make much sense, this is what pre 081xx has
3751 if (my $page = delete $attrs->{page}) {
3753 ($attrs->{rows} * ($page - 1))
3755 ($attrs->{offset} || 0)
3759 return $self->{_attrs} = $attrs;
3763 my ($self, $attr) = @_;
3765 if (ref $attr eq 'HASH') {
3766 return $self->_rollout_hash($attr);
3767 } elsif (ref $attr eq 'ARRAY') {
3768 return $self->_rollout_array($attr);
3774 sub _rollout_array {
3775 my ($self, $attr) = @_;
3778 foreach my $element (@{$attr}) {
3779 if (ref $element eq 'HASH') {
3780 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3781 } elsif (ref $element eq 'ARRAY') {
3782 # XXX - should probably recurse here
3783 push( @rolled_array, @{$self->_rollout_array($element)} );
3785 push( @rolled_array, $element );
3788 return \@rolled_array;
3792 my ($self, $attr) = @_;
3795 foreach my $key (keys %{$attr}) {
3796 push( @rolled_array, { $key => $attr->{$key} } );
3798 return \@rolled_array;
3801 sub _calculate_score {
3802 my ($self, $a, $b) = @_;
3804 if (defined $a xor defined $b) {
3807 elsif (not defined $a) {
3811 if (ref $b eq 'HASH') {
3812 my ($b_key) = keys %{$b};
3813 if (ref $a eq 'HASH') {
3814 my ($a_key) = keys %{$a};
3815 if ($a_key eq $b_key) {
3816 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3821 return ($a eq $b_key) ? 1 : 0;
3824 if (ref $a eq 'HASH') {
3825 my ($a_key) = keys %{$a};
3826 return ($b eq $a_key) ? 1 : 0;
3828 return ($b eq $a) ? 1 : 0;
3833 sub _merge_joinpref_attr {
3834 my ($self, $orig, $import) = @_;
3836 return $import unless defined($orig);
3837 return $orig unless defined($import);
3839 $orig = $self->_rollout_attr($orig);
3840 $import = $self->_rollout_attr($import);
3843 foreach my $import_element ( @{$import} ) {
3844 # find best candidate from $orig to merge $b_element into
3845 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3846 foreach my $orig_element ( @{$orig} ) {
3847 my $score = $self->_calculate_score( $orig_element, $import_element );
3848 if ($score > $best_candidate->{score}) {
3849 $best_candidate->{position} = $position;
3850 $best_candidate->{score} = $score;
3854 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3855 $import_key = '' if not defined $import_key;
3857 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3858 push( @{$orig}, $import_element );
3860 my $orig_best = $orig->[$best_candidate->{position}];
3861 # merge orig_best and b_element together and replace original with merged
3862 if (ref $orig_best ne 'HASH') {
3863 $orig->[$best_candidate->{position}] = $import_element;
3864 } elsif (ref $import_element eq 'HASH') {
3865 my ($key) = keys %{$orig_best};
3866 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3869 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3872 return @$orig ? $orig : ();
3880 require Hash::Merge;
3881 my $hm = Hash::Merge->new;
3883 $hm->specify_behavior({
3886 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3888 if ($defl xor $defr) {
3889 return [ $defl ? $_[0] : $_[1] ];
3894 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3898 return [$_[0], $_[1]];
3902 return $_[1] if !defined $_[0];
3903 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3904 return [$_[0], @{$_[1]}]
3907 return [] if !defined $_[0] and !keys %{$_[1]};
3908 return [ $_[1] ] if !defined $_[0];
3909 return [ $_[0] ] if !keys %{$_[1]};
3910 return [$_[0], $_[1]]
3915 return $_[0] if !defined $_[1];
3916 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3917 return [@{$_[0]}, $_[1]]
3920 my @ret = @{$_[0]} or return $_[1];
3921 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3922 my %idx = map { $_ => 1 } @ret;
3923 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3927 return [ $_[1] ] if ! @{$_[0]};
3928 return $_[0] if !keys %{$_[1]};
3929 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3930 return [ @{$_[0]}, $_[1] ];
3935 return [] if !keys %{$_[0]} and !defined $_[1];
3936 return [ $_[0] ] if !defined $_[1];
3937 return [ $_[1] ] if !keys %{$_[0]};
3938 return [$_[0], $_[1]]
3941 return [] if !keys %{$_[0]} and !@{$_[1]};
3942 return [ $_[0] ] if !@{$_[1]};
3943 return $_[1] if !keys %{$_[0]};
3944 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3945 return [ $_[0], @{$_[1]} ];
3948 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3949 return [ $_[0] ] if !keys %{$_[1]};
3950 return [ $_[1] ] if !keys %{$_[0]};
3951 return [ $_[0] ] if $_[0] eq $_[1];
3952 return [ $_[0], $_[1] ];
3955 } => 'DBIC_RS_ATTR_MERGER');
3959 return $hm->merge ($_[1], $_[2]);
3963 sub STORABLE_freeze {
3964 my ($self, $cloning) = @_;
3965 my $to_serialize = { %$self };
3967 # A cursor in progress can't be serialized (and would make little sense anyway)
3968 # the parser can be regenerated (and can't be serialized)
3969 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3971 # nor is it sensical to store a not-yet-fired-count pager
3972 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3973 delete $to_serialize->{pager};
3976 Storable::nfreeze($to_serialize);
3979 # need this hook for symmetry
3981 my ($self, $cloning, $serialized) = @_;
3983 %$self = %{ Storable::thaw($serialized) };
3989 =head2 throw_exception
3991 See L<DBIx::Class::Schema/throw_exception> for details.
3995 sub throw_exception {
3998 if (ref $self and my $rsrc = $self->result_source) {
3999 $rsrc->throw_exception(@_)
4002 DBIx::Class::Exception->throw(@_);
4010 # XXX: FIXME: Attributes docs need clearing up
4014 Attributes are used to refine a ResultSet in various ways when
4015 searching for data. They can be passed to any method which takes an
4016 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4019 Default attributes can be set on the result class using
4020 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4021 the CAVEATS on that feature before using it!)
4023 These are in no particular order:
4029 =item Value: ( $order_by | \@order_by | \%order_by )
4033 Which column(s) to order the results by.
4035 [The full list of suitable values is documented in
4036 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4039 If a single column name, or an arrayref of names is supplied, the
4040 argument is passed through directly to SQL. The hashref syntax allows
4041 for connection-agnostic specification of ordering direction:
4043 For descending order:
4045 order_by => { -desc => [qw/col1 col2 col3/] }
4047 For explicit ascending order:
4049 order_by => { -asc => 'col' }
4051 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4052 supported, although you are strongly encouraged to use the hashref
4053 syntax as outlined above.
4059 =item Value: \@columns | \%columns | $column
4063 Shortcut to request a particular set of columns to be retrieved. Each
4064 column spec may be a string (a table column name), or a hash (in which
4065 case the key is the C<as> value, and the value is used as the C<select>
4066 expression). Adds the L</current_source_alias> onto the start of any column without a C<.> in
4067 it and sets C<select> from that, then auto-populates C<as> from
4068 C<select> as normal. (You may also use the C<cols> attribute, as in
4069 earlier versions of DBIC, but this is deprecated)
4071 Essentially C<columns> does the same as L</select> and L</as>.
4073 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
4077 select => [qw(some_column another_column)],
4078 as => [qw(some_column dbic_slot)]
4080 If you want to individually retrieve related columns (in essence perform
4081 manual prefetch) you have to make sure to specify the correct inflation slot
4082 chain such that it matches existing relationships:
4084 my $rs = $schema->resultset('Artist')->search({}, {
4085 # required to tell DBIC to collapse has_many relationships
4087 join => { cds => 'tracks'},
4089 'cds.cdid' => 'cds.cdid',
4090 'cds.tracks.title' => 'tracks.title',
4094 Like elsewhere, literal SQL or literal values can be included by using a
4095 scalar reference or a literal bind value, and these values will be available
4096 in the result with C<get_column> (see also
4097 L<SQL::Abstract/Literal SQL and value type operators>):
4099 # equivalent SQL: SELECT 1, 'a string', IF(my_column,?,?) ...
4100 # bind values: $true_value, $false_value
4104 bar => \q{'a string'},
4105 baz => \[ 'IF(my_column,?,?)', $true_value, $false_value ],
4111 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
4112 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
4113 with a unary plus operator before it, which is the same as simply C<columns>.
4117 =item Value: \@extra_columns
4121 Indicates additional columns to be selected from storage. Works the same as
4122 L</columns> but adds columns to the current selection. (You may also use the
4123 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4126 $schema->resultset('CD')->search(undef, {
4127 '+columns' => ['artist.name'],
4131 would return all CDs and include a 'name' column to the information
4132 passed to object inflation. Note that the 'artist' is the name of the
4133 column (or relationship) accessor, and 'name' is the name of the column
4134 accessor in the related table.
4140 =item Value: \@select_columns
4144 Indicates which columns should be selected from the storage. You can use
4145 column names, or in the case of RDBMS back ends, function or stored procedure
4148 $rs = $schema->resultset('Employee')->search(undef, {
4151 { count => 'employeeid' },
4152 { max => { length => 'name' }, -as => 'longest_name' }
4157 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4159 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4160 use L</select>, to instruct DBIx::Class how to store the result of the column.
4162 Also note that the L</as> attribute has B<nothing to do> with the SQL-side
4163 C<AS> identifier aliasing. You B<can> alias a function (so you can use it e.g.
4164 in an C<ORDER BY> clause), however this is done via the C<-as> B<select
4165 function attribute> supplied as shown in the example above.
4169 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4170 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4171 with a unary plus operator before it, which is the same as simply C<select>.
4175 =item Value: \@extra_select_columns
4179 Indicates additional columns to be selected from storage. Works the same as
4180 L</select> but adds columns to the current selection, instead of specifying
4181 a new explicit list.
4187 =item Value: \@inflation_names
4191 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4192 slot name in which the column value will be stored within the
4193 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4194 identifier by the C<get_column> method (or via the object accessor B<if one
4195 with the same name already exists>) as shown below.
4197 The L</as> attribute has B<nothing to do> with the SQL-side identifier
4198 aliasing C<AS>. See L</select> for details.
4200 $rs = $schema->resultset('Employee')->search(undef, {
4203 { count => 'employeeid' },
4204 { max => { length => 'name' }, -as => 'longest_name' }
4213 If the object against which the search is performed already has an accessor
4214 matching a column name specified in C<as>, the value can be retrieved using
4215 the accessor as normal:
4217 my $name = $employee->name();
4219 If on the other hand an accessor does not exist in the object, you need to
4220 use C<get_column> instead:
4222 my $employee_count = $employee->get_column('employee_count');
4224 You can create your own accessors if required - see
4225 L<DBIx::Class::Manual::Cookbook> for details.
4229 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4230 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4231 with a unary plus operator before it, which is the same as simply C<as>.
4235 =item Value: \@extra_inflation_names
4239 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4245 =item Value: ($rel_name | \@rel_names | \%rel_names)
4249 Contains a list of relationships that should be joined for this query. For
4252 # Get CDs by Nine Inch Nails
4253 my $rs = $schema->resultset('CD')->search(
4254 { 'artist.name' => 'Nine Inch Nails' },
4255 { join => 'artist' }
4258 Can also contain a hash reference to refer to the other relation's relations.
4261 package MyApp::Schema::Track;
4262 use base qw/DBIx::Class/;
4263 __PACKAGE__->table('track');
4264 __PACKAGE__->add_columns(qw/trackid cd position title/);
4265 __PACKAGE__->set_primary_key('trackid');
4266 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4269 # In your application
4270 my $rs = $schema->resultset('Artist')->search(
4271 { 'track.title' => 'Teardrop' },
4273 join => { cd => 'track' },
4274 order_by => 'artist.name',
4278 You need to use the relationship (not the table) name in conditions,
4279 because they are aliased as such. The current table is aliased as "me", so
4280 you need to use me.column_name in order to avoid ambiguity. For example:
4282 # Get CDs from 1984 with a 'Foo' track
4283 my $rs = $schema->resultset('CD')->search(
4286 'tracks.name' => 'Foo'
4288 { join => 'tracks' }
4291 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4292 similarly for a third time). For e.g.
4294 my $rs = $schema->resultset('Artist')->search({
4295 'cds.title' => 'Down to Earth',
4296 'cds_2.title' => 'Popular',
4298 join => [ qw/cds cds/ ],
4301 will return a set of all artists that have both a cd with title 'Down
4302 to Earth' and a cd with title 'Popular'.
4304 If you want to fetch related objects from other tables as well, see L</prefetch>
4307 NOTE: An internal join-chain pruner will discard certain joins while
4308 constructing the actual SQL query, as long as the joins in question do not
4309 affect the retrieved result. This for example includes 1:1 left joins
4310 that are not part of the restriction specification (WHERE/HAVING) nor are
4311 a part of the query selection.
4313 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4319 =item Value: (0 | 1)
4323 When set to a true value, indicates that any rows fetched from joined has_many
4324 relationships are to be aggregated into the corresponding "parent" object. For
4325 example, the resultset:
4327 my $rs = $schema->resultset('CD')->search({}, {
4328 '+columns' => [ qw/ tracks.title tracks.position / ],
4333 While executing the following query:
4335 SELECT me.*, tracks.title, tracks.position
4337 LEFT JOIN track tracks
4338 ON tracks.cdid = me.cdid
4340 Will return only as many objects as there are rows in the CD source, even
4341 though the result of the query may span many rows. Each of these CD objects
4342 will in turn have multiple "Track" objects hidden behind the has_many
4343 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4344 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4345 product"), with each CD object containing exactly one of all fetched Track data.
4347 When a collapse is requested on a non-ordered resultset, an order by some
4348 unique part of the main source (the left-most table) is inserted automatically.
4349 This is done so that the resultset is allowed to be "lazy" - calling
4350 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4351 object with all of its related data.
4353 If an L</order_by> is already declared, and orders the resultset in a way that
4354 makes collapsing as described above impossible (e.g. C<< ORDER BY
4355 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4356 switch to "eager" mode and slurp the entire resultset before constructing the
4357 first object returned by L</next>.
4359 Setting this attribute on a resultset that does not join any has_many
4360 relations is a no-op.
4362 For a more in-depth discussion, see L</PREFETCHING>.
4368 =item Value: ($rel_name | \@rel_names | \%rel_names)
4372 This attribute is a shorthand for specifying a L</join> spec, adding all
4373 columns from the joined related sources as L</+columns> and setting
4374 L</collapse> to a true value. It can be thought of as a rough B<superset>
4375 of the L</join> attribute.
4377 For example, the following two queries are equivalent:
4379 my $rs = $schema->resultset('Artist')->search({}, {
4380 prefetch => { cds => ['genre', 'tracks' ] },
4385 my $rs = $schema->resultset('Artist')->search({}, {
4386 join => { cds => ['genre', 'tracks' ] },
4390 { +{ "cds.$_" => "cds.$_" } }
4391 $schema->source('Artist')->related_source('cds')->columns
4394 { +{ "cds.genre.$_" => "genre.$_" } }
4395 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4398 { +{ "cds.tracks.$_" => "tracks.$_" } }
4399 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4404 Both producing the following SQL:
4406 SELECT me.artistid, me.name, me.rank, me.charfield,
4407 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4408 genre.genreid, genre.name,
4409 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4412 ON cds.artist = me.artistid
4413 LEFT JOIN genre genre
4414 ON genre.genreid = cds.genreid
4415 LEFT JOIN track tracks
4416 ON tracks.cd = cds.cdid
4417 ORDER BY me.artistid
4419 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4420 the arguments are properly merged and generally do the right thing. For
4421 example, you may want to do the following:
4423 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4424 { 'genre.genreid' => undef },
4426 join => { cds => 'genre' },
4431 Which generates the following SQL:
4433 SELECT me.artistid, me.name, me.rank, me.charfield,
4434 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4437 ON cds.artist = me.artistid
4438 LEFT JOIN genre genre
4439 ON genre.genreid = cds.genreid
4440 WHERE genre.genreid IS NULL
4441 ORDER BY me.artistid
4443 For a more in-depth discussion, see L</PREFETCHING>.
4449 =item Value: $source_alias
4453 Sets the source alias for the query. Normally, this defaults to C<me>, but
4454 nested search queries (sub-SELECTs) might need specific aliases set to
4455 reference inner queries. For example:
4458 ->related_resultset('CDs')
4459 ->related_resultset('Tracks')
4461 'track.id' => { -ident => 'none_search.id' },
4465 my $ids = $self->search({
4468 alias => 'none_search',
4469 group_by => 'none_search.id',
4470 })->get_column('id')->as_query;
4472 $self->search({ id => { -in => $ids } })
4474 This attribute is directly tied to L</current_source_alias>.
4484 Makes the resultset paged and specifies the page to retrieve. Effectively
4485 identical to creating a non-pages resultset and then calling ->page($page)
4488 If L</rows> attribute is not specified it defaults to 10 rows per page.
4490 When you have a paged resultset, L</count> will only return the number
4491 of rows in the page. To get the total, use the L</pager> and call
4492 C<total_entries> on it.
4502 Specifies the maximum number of rows for direct retrieval or the number of
4503 rows per page if the page attribute or method is used.
4509 =item Value: $offset
4513 Specifies the (zero-based) row number for the first row to be returned, or the
4514 of the first row of the first page if paging is used.
4516 =head2 software_limit
4520 =item Value: (0 | 1)
4524 When combined with L</rows> and/or L</offset> the generated SQL will not
4525 include any limit dialect stanzas. Instead the entire result will be selected
4526 as if no limits were specified, and DBIC will perform the limit locally, by
4527 artificially advancing and finishing the resulting L</cursor>.
4529 This is the recommended way of performing resultset limiting when no sane RDBMS
4530 implementation is available (e.g.
4531 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4532 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4538 =item Value: \@columns
4542 A arrayref of columns to group by. Can include columns of joined tables.
4544 group_by => [qw/ column1 column2 ... /]
4550 =item Value: $condition
4554 The HAVING operator specifies a B<secondary> condition applied to the set
4555 after the grouping calculations have been done. In other words it is a
4556 constraint just like L</where> (and accepting the same
4557 L<SQL::Abstract syntax|SQL::Abstract/WHERE CLAUSES>) applied to the data
4558 as it exists after GROUP BY has taken place. Specifying L</having> without
4559 L</group_by> is a logical mistake, and a fatal error on most RDBMS engines.
4563 having => { 'count_employee' => { '>=', 100 } }
4565 or with an in-place function in which case literal SQL is required:
4567 having => \[ 'count(employee) >= ?', 100 ]
4573 =item Value: (0 | 1)
4577 Set to 1 to automatically generate a L</group_by> clause based on the selection
4578 (including intelligent handling of L</order_by> contents). Note that the group
4579 criteria calculation takes place over the B<final> selection. This includes
4580 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4581 L</search> calls, and standalone columns selected via
4582 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4583 extra selections specified via L</prefetch> - such selections are explicitly
4584 excluded from group criteria calculations.
4586 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4587 setting is ignored and an appropriate warning is issued.
4593 Adds to the WHERE clause.
4595 # only return rows WHERE deleted IS NULL for all searches
4596 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4598 Can be overridden by passing C<< { where => undef } >> as an attribute
4601 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4607 Set to 1 to cache search results. This prevents extra SQL queries if you
4608 revisit rows in your ResultSet:
4610 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4612 while( my $artist = $resultset->next ) {
4616 $rs->first; # without cache, this would issue a query
4618 By default, searches are not cached.
4620 For more examples of using these attributes, see
4621 L<DBIx::Class::Manual::Cookbook>.
4627 =item Value: ( 'update' | 'shared' | \$scalar )
4631 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4632 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4637 DBIx::Class supports arbitrary related data prefetching from multiple related
4638 sources. Any combination of relationship types and column sets are supported.
4639 If L<collapsing|/collapse> is requested, there is an additional requirement of
4640 selecting enough data to make every individual object uniquely identifiable.
4642 Here are some more involved examples, based on the following relationship map:
4645 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4646 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4647 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4649 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4651 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4655 my $rs = $schema->resultset('Tag')->search(
4664 The initial search results in SQL like the following:
4666 SELECT tag.*, cd.*, artist.* FROM tag
4667 JOIN cd ON tag.cd = cd.cdid
4668 JOIN artist ON cd.artist = artist.artistid
4670 L<DBIx::Class> has no need to go back to the database when we access the
4671 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4674 Simple prefetches will be joined automatically, so there is no need
4675 for a C<join> attribute in the above search.
4677 The L</prefetch> attribute can be used with any of the relationship types
4678 and multiple prefetches can be specified together. Below is a more complex
4679 example that prefetches a CD's artist, its liner notes (if present),
4680 the cover image, the tracks on that CD, and the guests on those
4683 my $rs = $schema->resultset('CD')->search(
4687 { artist => 'record_label'}, # belongs_to => belongs_to
4688 'liner_note', # might_have
4689 'cover_image', # has_one
4690 { tracks => 'guests' }, # has_many => has_many
4695 This will produce SQL like the following:
4697 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4701 ON artist.artistid = me.artistid
4702 JOIN record_label record_label
4703 ON record_label.labelid = artist.labelid
4704 LEFT JOIN track tracks
4705 ON tracks.cdid = me.cdid
4706 LEFT JOIN guest guests
4707 ON guests.trackid = track.trackid
4708 LEFT JOIN liner_notes liner_note
4709 ON liner_note.cdid = me.cdid
4710 JOIN cd_artwork cover_image
4711 ON cover_image.cdid = me.cdid
4714 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4715 C<tracks>, and C<guests> of the CD will all be available through the
4716 relationship accessors without the need for additional queries to the
4721 Prefetch does a lot of deep magic. As such, it may not behave exactly
4722 as you might expect.
4728 Prefetch uses the L</cache> to populate the prefetched relationships. This
4729 may or may not be what you want.
4733 If you specify a condition on a prefetched relationship, ONLY those
4734 rows that match the prefetched condition will be fetched into that relationship.
4735 This means that adding prefetch to a search() B<may alter> what is returned by
4736 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4738 my $artist_rs = $schema->resultset('Artist')->search({
4744 my $count = $artist_rs->first->cds->count;
4746 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4748 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4750 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4752 That cmp_ok() may or may not pass depending on the datasets involved. In other
4753 words the C<WHERE> condition would apply to the entire dataset, just like
4754 it would in regular SQL. If you want to add a condition only to the "right side"
4755 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4756 condition|DBIx::Class::Relationship::Base/condition>
4760 =head1 DBIC BIND VALUES
4762 Because DBIC may need more information to bind values than just the column name
4763 and value itself, it uses a special format for both passing and receiving bind
4764 values. Each bind value should be composed of an arrayref of
4765 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4771 If present (in any form), this is what is being passed directly to bind_param.
4772 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4773 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4775 If this is specified, all other bind options described below are ignored.
4779 If present, this is used to infer the actual bind attribute by passing to
4780 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4781 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4783 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4784 currently drivers are expected to "Do the Right Thing" when given a common
4785 datatype name. (Not ideal, but that's what we got at this point.)
4789 Currently used to correctly allocate buffers for bind_param_inout().
4790 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4791 or to a sensible value based on the "data_type".
4795 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4796 explicitly specified they are never overridden). Also used by some weird DBDs,
4797 where the column name should be available at bind_param time (e.g. Oracle).
4801 For backwards compatibility and convenience, the following shortcuts are
4804 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4805 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4806 [ undef, $val ] === [ {}, $val ]
4807 $val === [ {}, $val ]
4809 =head1 FURTHER QUESTIONS?
4811 Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
4813 =head1 COPYRIGHT AND LICENSE
4815 This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
4816 by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
4817 redistribute it and/or modify it under the same terms as the
4818 L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.