1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken reftype/;
9 use DBIx::Class::_Util qw(
10 fail_on_internal_wantarray fail_on_internal_call UNRESOLVABLE_CONDITION
13 use Data::Compare (); # no imports!!! guard against insane architecture
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/Source> 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 @{$attrs}{qw(_last_sqlmaker_alias_map _related_results_construction)};
317 if ($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 on of the two undef or both undef
660 if ( ( (defined $left) xor (defined $right) ) or ! defined $left ) {
661 return defined $left ? $left : $right;
664 my $cond = $self->result_source->schema->storage->_collapse_cond({ -and => [$left, $right] });
666 for my $c (grep { ref $cond->{$_} eq 'ARRAY' and ($cond->{$_}[0]||'') eq '-and' } keys %$cond) {
668 my @vals = sort @{$cond->{$c}}[ 1..$#{$cond->{$c}} ];
669 my @fin = shift @vals;
672 push @fin, $v unless Data::Compare::Compare( $fin[-1], $v );
675 $cond->{$c} = (@fin == 1) ? $fin[0] : [-and => @fin ];
681 =head2 search_literal
683 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
684 should only be used in that context. C<search_literal> is a convenience
685 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
686 want to ensure columns are bound correctly, use L</search>.
688 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
689 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
690 require C<search_literal>.
694 =item Arguments: $sql_fragment, @standalone_bind_values
696 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
700 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
701 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
703 Pass a literal chunk of SQL to be added to the conditional part of the
706 Example of how to use C<search> instead of C<search_literal>
708 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
709 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
714 my ($self, $sql, @bind) = @_;
716 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
719 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
726 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
728 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
732 Finds and returns a single row based on supplied criteria. Takes either a
733 hashref with the same format as L</create> (including inference of foreign
734 keys from related objects), or a list of primary key values in the same
735 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
736 declaration on the L</result_source>.
738 In either case an attempt is made to combine conditions already existing on
739 the resultset with the condition passed to this method.
741 To aid with preparing the correct query for the storage you may supply the
742 C<key> attribute, which is the name of a
743 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
744 unique constraint corresponding to the
745 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
746 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
747 to construct a query that satisfies the named unique constraint fully (
748 non-NULL values for each column member of the constraint) an exception is
751 If no C<key> is specified, the search is carried over all unique constraints
752 which are fully defined by the available condition.
754 If no such constraint is found, C<find> currently defaults to a simple
755 C<< search->(\%column_values) >> which may or may not do what you expect.
756 Note that this fallback behavior may be deprecated in further versions. If
757 you need to search with arbitrary conditions - use L</search>. If the query
758 resulting from this fallback produces more than one row, a warning to the
759 effect is issued, though only the first row is constructed and returned as
762 In addition to C<key>, L</find> recognizes and applies standard
763 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
765 Note that if you have extra concerns about the correctness of the resulting
766 query you need to specify the C<key> attribute and supply the entire condition
767 as an argument to find (since it is not always possible to perform the
768 combination of the resultset condition with the supplied one, especially if
769 the resultset condition contains literal sql).
771 For example, to find a row by its primary key:
773 my $cd = $schema->resultset('CD')->find(5);
775 You can also find a row by a specific unique constraint:
777 my $cd = $schema->resultset('CD')->find(
779 artist => 'Massive Attack',
780 title => 'Mezzanine',
782 { key => 'cd_artist_title' }
785 See also L</find_or_create> and L</update_or_create>.
791 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
793 my $rsrc = $self->result_source;
796 if (exists $attrs->{key}) {
797 $constraint_name = defined $attrs->{key}
799 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
803 # Parse out the condition from input
806 if (ref $_[0] eq 'HASH') {
807 $call_cond = { %{$_[0]} };
810 # if only values are supplied we need to default to 'primary'
811 $constraint_name = 'primary' unless defined $constraint_name;
813 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
815 $self->throw_exception(
816 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
819 $self->throw_exception (
820 'find() expects either a column/value hashref, or a list of values '
821 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
822 ) unless @c_cols == @_;
825 @{$call_cond}{@c_cols} = @_;
829 for my $key (keys %$call_cond) {
831 my $keyref = ref($call_cond->{$key})
833 my $relinfo = $rsrc->relationship_info($key)
835 my $val = delete $call_cond->{$key};
837 next if $keyref eq 'ARRAY'; # has_many for multi_create
839 my ($rel_cond, $crosstable) = $rsrc->_resolve_condition(
840 $relinfo->{cond}, $val, $key, $key
843 $self->throw_exception("Complex condition via relationship '$key' is unsupported in find()")
844 if $crosstable or ref($rel_cond) ne 'HASH';
847 @related{keys %$rel_cond} = values %$rel_cond;
851 # relationship conditions take precedence (?)
852 @{$call_cond}{keys %related} = values %related;
854 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
856 if (defined $constraint_name) {
857 $final_cond = $self->_qualify_cond_columns (
859 $self->_build_unique_cond (
867 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
868 # This means that we got here after a merger of relationship conditions
869 # in ::Relationship::Base::search_related (the row method), and furthermore
870 # the relationship is of the 'single' type. This means that the condition
871 # provided by the relationship (already attached to $self) is sufficient,
872 # as there can be only one row in the database that would satisfy the
876 # no key was specified - fall down to heuristics mode:
877 # run through all unique queries registered on the resultset, and
878 # 'OR' all qualifying queries together
879 my (@unique_queries, %seen_column_combinations);
880 for my $c_name ($rsrc->unique_constraint_names) {
881 next if $seen_column_combinations{
882 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
885 push @unique_queries, try {
886 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
890 $final_cond = @unique_queries
891 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
892 : $self->_non_unique_find_fallback ($call_cond, $attrs)
896 # Run the query, passing the result_class since it should propagate for find
897 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
898 if ($rs->_resolved_attrs->{collapse}) {
900 carp "Query returned more than one row" if $rs->next;
908 # This is a stop-gap method as agreed during the discussion on find() cleanup:
909 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
911 # It is invoked when find() is called in legacy-mode with insufficiently-unique
912 # condition. It is provided for overrides until a saner way forward is devised
914 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
915 # the road. Please adjust your tests accordingly to catch this situation early
916 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
918 # The method will not be removed without an adequately complete replacement
919 # for strict-mode enforcement
920 sub _non_unique_find_fallback {
921 my ($self, $cond, $attrs) = @_;
923 return $self->_qualify_cond_columns(
925 exists $attrs->{alias}
927 : $self->{attrs}{alias}
932 sub _qualify_cond_columns {
933 my ($self, $cond, $alias) = @_;
935 my %aliased = %$cond;
936 for (keys %aliased) {
937 $aliased{"$alias.$_"} = delete $aliased{$_}
944 sub _build_unique_cond {
945 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
947 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
949 # combination may fail if $self->{cond} is non-trivial
950 my ($final_cond) = try {
951 $self->_merge_with_rscond ($extra_cond)
956 # trim out everything not in $columns
957 $final_cond = { map {
958 exists $final_cond->{$_}
959 ? ( $_ => $final_cond->{$_} )
963 if (my @missing = grep
964 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
967 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
969 join (', ', map { "'$_'" } @missing),
976 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
978 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
980 carp_unique ( sprintf (
981 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
982 . 'values in column(s): %s). This is almost certainly not what you wanted, '
983 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
985 join (', ', map { "'$_'" } @undefs),
992 =head2 search_related
996 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
998 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1002 $new_rs = $cd_rs->search_related('artist', {
1006 Searches the specified relationship, optionally specifying a condition and
1007 attributes for matching records. See L</ATTRIBUTES> for more information.
1009 In list context, C<< ->all() >> is called implicitly on the resultset, thus
1010 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
1012 See also L</search_related_rs>.
1016 sub search_related {
1017 return shift->related_resultset(shift)->search(@_);
1020 =head2 search_related_rs
1022 This method works exactly the same as search_related, except that
1023 it guarantees a resultset, even in list context.
1027 sub search_related_rs {
1028 return shift->related_resultset(shift)->search_rs(@_);
1035 =item Arguments: none
1037 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1041 Returns a storage-driven cursor to the given resultset. See
1042 L<DBIx::Class::Cursor> for more information.
1049 return $self->{cursor} ||= do {
1050 my $attrs = $self->_resolved_attrs;
1051 $self->result_source->storage->select(
1052 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1061 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1063 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1067 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1069 Inflates the first result without creating a cursor if the resultset has
1070 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1073 While this method can take an optional search condition (just like L</search>)
1074 being a fast-code-path it does not recognize search attributes. If you need to
1075 add extra joins or similar, call L</search> and then chain-call L</single> on the
1076 L<DBIx::Class::ResultSet> returned.
1082 As of 0.08100, this method enforces the assumption that the preceding
1083 query returns only one row. If more than one row is returned, you will receive
1086 Query returned more than one row
1088 In this case, you should be using L</next> or L</find> instead, or if you really
1089 know what you are doing, use the L</rows> attribute to explicitly limit the size
1092 This method will also throw an exception if it is called on a resultset prefetching
1093 has_many, as such a prefetch implies fetching multiple rows from the database in
1094 order to assemble the resulting object.
1101 my ($self, $where) = @_;
1103 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1106 my $attrs = { %{$self->_resolved_attrs} };
1108 $self->throw_exception(
1109 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1110 ) if $attrs->{collapse};
1113 if (defined $attrs->{where}) {
1116 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1117 $where, delete $attrs->{where} ]
1120 $attrs->{where} = $where;
1124 my $data = [ $self->result_source->storage->select_single(
1125 $attrs->{from}, $attrs->{select},
1126 $attrs->{where}, $attrs
1129 return undef unless @$data;
1130 $self->{_stashed_rows} = [ $data ];
1131 $self->_construct_results->[0];
1138 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1140 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1144 my $max_length = $rs->get_column('length')->max;
1146 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1151 my ($self, $column) = @_;
1152 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1160 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1162 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1166 # WHERE title LIKE '%blue%'
1167 $cd_rs = $rs->search_like({ title => '%blue%'});
1169 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1170 that this is simply a convenience method retained for ex Class::DBI users.
1171 You most likely want to use L</search> with specific operators.
1173 For more information, see L<DBIx::Class::Manual::Cookbook>.
1175 This method is deprecated and will be removed in 0.09. Use L</search()>
1176 instead. An example conversion is:
1178 ->search_like({ foo => 'bar' });
1182 ->search({ foo => { like => 'bar' } });
1189 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1190 .' Instead use ->search({ x => { -like => "y%" } })'
1191 .' (note the outer pair of {}s - they are important!)'
1193 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1194 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1195 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1196 return $class->search($query, { %$attrs });
1203 =item Arguments: $first, $last
1205 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1209 Returns a resultset or object list representing a subset of elements from the
1210 resultset slice is called on. Indexes are from 0, i.e., to get the first
1211 three records, call:
1213 my ($one, $two, $three) = $rs->slice(0, 2);
1218 my ($self, $min, $max) = @_;
1219 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1220 $attrs->{offset} = $self->{attrs}{offset} || 0;
1221 $attrs->{offset} += $min;
1222 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1223 return $self->search(undef, $attrs);
1230 =item Arguments: none
1232 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1236 Returns the next element in the resultset (C<undef> is there is none).
1238 Can be used to efficiently iterate over records in the resultset:
1240 my $rs = $schema->resultset('CD')->search;
1241 while (my $cd = $rs->next) {
1245 Note that you need to store the resultset object, and call C<next> on it.
1246 Calling C<< resultset('Table')->next >> repeatedly will always return the
1247 first record from the resultset.
1254 if (my $cache = $self->get_cache) {
1255 $self->{all_cache_position} ||= 0;
1256 return $cache->[$self->{all_cache_position}++];
1259 if ($self->{attrs}{cache}) {
1260 delete $self->{pager};
1261 $self->{all_cache_position} = 1;
1262 return ($self->all)[0];
1265 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1267 $self->{_stashed_results} = $self->_construct_results
1270 return shift @{$self->{_stashed_results}};
1273 # Constructs as many results as it can in one pass while respecting
1274 # cursor laziness. Several modes of operation:
1276 # * Always builds everything present in @{$self->{_stashed_rows}}
1277 # * If called with $fetch_all true - pulls everything off the cursor and
1278 # builds all result structures (or objects) in one pass
1279 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1280 # and if the resultset is ordered properly by the left side:
1281 # * Fetches stuff off the cursor until the "master object" changes,
1282 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1284 # * Just fetches, and collapses/constructs everything as if $fetch_all
1285 # was requested (there is no other way to collapse except for an
1287 # * If no collapse is requested - just get the next row, construct and
1289 sub _construct_results {
1290 my ($self, $fetch_all) = @_;
1292 my $rsrc = $self->result_source;
1293 my $attrs = $self->_resolved_attrs;
1298 ! $attrs->{order_by}
1302 my @pcols = $rsrc->primary_columns
1304 # default order for collapsing unless the user asked for something
1305 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1306 $attrs->{_ordered_for_collapse} = 1;
1307 $attrs->{_order_is_artificial} = 1;
1310 # this will be used as both initial raw-row collector AND as a RV of
1311 # _construct_results. Not regrowing the array twice matters a lot...
1312 # a surprising amount actually
1313 my $rows = delete $self->{_stashed_rows};
1315 my $cursor; # we may not need one at all
1317 my $did_fetch_all = $fetch_all;
1320 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1321 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1323 elsif( $attrs->{collapse} ) {
1325 # a cursor will need to be closed over in case of collapse
1326 $cursor = $self->cursor;
1328 $attrs->{_ordered_for_collapse} = (
1334 ->_extract_colinfo_of_stable_main_source_order_by_portion($attrs)
1336 ) unless defined $attrs->{_ordered_for_collapse};
1338 if (! $attrs->{_ordered_for_collapse}) {
1341 # instead of looping over ->next, use ->all in stealth mode
1342 # *without* calling a ->reset afterwards
1343 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1344 if (! $cursor->{_done}) {
1345 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1346 $cursor->{_done} = 1;
1351 if (! $did_fetch_all and ! @{$rows||[]} ) {
1352 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1353 $cursor ||= $self->cursor;
1354 if (scalar (my @r = $cursor->next) ) {
1359 return undef unless @{$rows||[]};
1361 # sanity check - people are too clever for their own good
1362 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1364 my $multiplied_selectors;
1365 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1367 $aliastypes->{multiplying}{$sel_alias}
1369 $aliastypes->{premultiplied}{$sel_alias}
1371 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1375 for my $i (0 .. $#{$attrs->{as}} ) {
1376 my $sel = $attrs->{select}[$i];
1378 if (ref $sel eq 'SCALAR') {
1381 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1385 $self->throw_exception(
1386 'Result collapse not possible - selection from a has_many source redirected to the main object'
1387 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1391 # hotspot - skip the setter
1392 my $res_class = $self->_result_class;
1394 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1395 $res_class->can ('inflate_result')
1396 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1399 my $infmap = $attrs->{as};
1401 $self->{_result_inflator}{is_core_row} = ( (
1404 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1405 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1407 $self->{_result_inflator}{is_hri} = ( (
1408 ! $self->{_result_inflator}{is_core_row}
1411 require DBIx::Class::ResultClass::HashRefInflator
1413 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1415 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1418 if (! $attrs->{_related_results_construction}) {
1419 # construct a much simpler array->hash folder for the one-table cases right here
1420 if ($self->{_result_inflator}{is_hri}) {
1421 for my $r (@$rows) {
1422 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1425 # FIXME SUBOPTIMAL this is a very very very hot spot
1426 # while rather optimal we can *still* do much better, by
1427 # building a smarter Row::inflate_result(), and
1428 # switch to feeding it data via a much leaner interface
1430 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1431 # this particular resultset size
1432 elsif (@$rows < 60) {
1433 for my $r (@$rows) {
1434 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1439 '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
1440 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1446 $self->{_result_inflator}{is_hri} ? 'hri'
1447 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1448 : 'classic_nonpruning'
1451 # $args and $attrs to _mk_row_parser are separated to delineate what is
1452 # core collapser stuff and what is dbic $rs specific
1453 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1455 inflate_map => $infmap,
1456 collapse => $attrs->{collapse},
1457 premultiplied => $attrs->{_main_source_premultiplied},
1458 hri_style => $self->{_result_inflator}{is_hri},
1459 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1460 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1462 # column_info metadata historically hasn't been too reliable.
1463 # We need to start fixing this somehow (the collapse resolver
1464 # can't work without it). Add an explicit check for the *main*
1465 # result, hopefully this will gradually weed out such errors
1467 # FIXME - this is a temporary kludge that reduces performance
1468 # It is however necessary for the time being
1469 my ($unrolled_non_null_cols_to_check, $err);
1471 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1474 'Collapse aborted due to invalid ResultSource metadata - the following '
1475 . 'selections are declared non-nullable but NULLs were retrieved: '
1479 COL: for my $i (@$check_non_null_cols) {
1480 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1483 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1486 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1490 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1491 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1493 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1494 my @r = $cursor->next or return;
1495 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1496 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1502 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1503 my @r = $cursor->next or return;
1508 $self->{_row_parser}{$parser_type}{cref}->(
1510 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1513 # Special-case multi-object HRI - there is no $inflator_cref pass
1514 unless ($self->{_result_inflator}{is_hri}) {
1515 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1519 # The @$rows check seems odd at first - why wouldn't we want to warn
1520 # regardless? The issue is things like find() etc, where the user
1521 # *knows* only one result will come back. In these cases the ->all
1522 # is not a pessimization, but rather something we actually want
1524 'Unable to properly collapse has_many results in iterator mode due '
1525 . 'to order criteria - performed an eager cursor slurp underneath. '
1526 . 'Consider using ->all() instead'
1527 ) if ( ! $fetch_all and @$rows > 1 );
1532 =head2 result_source
1536 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1538 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1542 An accessor for the primary ResultSource object from which this ResultSet
1549 =item Arguments: $result_class?
1551 =item Return Value: $result_class
1555 An accessor for the class to use when creating result objects. Defaults to
1556 C<< result_source->result_class >> - which in most cases is the name of the
1557 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1559 Note that changing the result_class will also remove any components
1560 that were originally loaded in the source class via
1561 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1562 in the original source class will not run.
1567 my ($self, $result_class) = @_;
1568 if ($result_class) {
1570 # don't fire this for an object
1571 $self->ensure_class_loaded($result_class)
1572 unless ref($result_class);
1574 if ($self->get_cache) {
1575 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1577 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1578 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1579 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1582 $self->_result_class($result_class);
1584 delete $self->{_result_inflator};
1586 $self->_result_class;
1593 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1595 =item Return Value: $count
1599 Performs an SQL C<COUNT> with the same query as the resultset was built
1600 with to find the number of elements. Passing arguments is equivalent to
1601 C<< $rs->search ($cond, \%attrs)->count >>
1607 return $self->search(@_)->count if @_ and defined $_[0];
1608 return scalar @{ $self->get_cache } if $self->get_cache;
1610 my $attrs = { %{ $self->_resolved_attrs } };
1612 # this is a little optimization - it is faster to do the limit
1613 # adjustments in software, instead of a subquery
1614 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1617 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1618 $crs = $self->_count_subq_rs ($attrs);
1621 $crs = $self->_count_rs ($attrs);
1623 my $count = $crs->next;
1625 $count -= $offset if $offset;
1626 $count = $rows if $rows and $rows < $count;
1627 $count = 0 if ($count < 0);
1636 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1638 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1642 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1643 This can be very handy for subqueries:
1645 ->search( { amount => $some_rs->count_rs->as_query } )
1647 As with regular resultsets the SQL query will be executed only after
1648 the resultset is accessed via L</next> or L</all>. That would return
1649 the same single value obtainable via L</count>.
1655 return $self->search(@_)->count_rs if @_;
1657 # this may look like a lack of abstraction (count() does about the same)
1658 # but in fact an _rs *must* use a subquery for the limits, as the
1659 # software based limiting can not be ported if this $rs is to be used
1660 # in a subquery itself (i.e. ->as_query)
1661 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1662 return $self->_count_subq_rs($self->{_attrs});
1665 return $self->_count_rs($self->{_attrs});
1670 # returns a ResultSetColumn object tied to the count query
1673 my ($self, $attrs) = @_;
1675 my $rsrc = $self->result_source;
1677 my $tmp_attrs = { %$attrs };
1678 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1679 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1681 # overwrite the selector (supplied by the storage)
1682 $rsrc->resultset_class->new($rsrc, {
1684 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1686 })->get_column ('count');
1690 # same as above but uses a subquery
1692 sub _count_subq_rs {
1693 my ($self, $attrs) = @_;
1695 my $rsrc = $self->result_source;
1697 my $sub_attrs = { %$attrs };
1698 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1699 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1701 # if we multi-prefetch we group_by something unique, as this is what we would
1702 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1703 if ( $attrs->{collapse} ) {
1704 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1705 $rsrc->_identifying_column_set || $self->throw_exception(
1706 'Unable to construct a unique group_by criteria properly collapsing the '
1707 . 'has_many prefetch before count()'
1712 # Calculate subquery selector
1713 if (my $g = $sub_attrs->{group_by}) {
1715 my $sql_maker = $rsrc->storage->sql_maker;
1717 # necessary as the group_by may refer to aliased functions
1719 for my $sel (@{$attrs->{select}}) {
1720 $sel_index->{$sel->{-as}} = $sel
1721 if (ref $sel eq 'HASH' and $sel->{-as});
1724 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1725 # also look for named aggregates referred in the having clause
1726 # having often contains scalarrefs - thus parse it out entirely
1728 if ($attrs->{having}) {
1729 local $sql_maker->{having_bind};
1730 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1731 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1732 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1733 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1734 # if we don't unset it we screw up retarded but unfortunately working
1735 # 'MAX(foo.bar)' => { '>', 3 }
1736 $sql_maker->{name_sep} = '';
1739 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1741 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1744 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1745 # and if all fails for an utterly naive quoted scalar-with-function
1746 while ($having_sql =~ /
1747 $rquote $sep $lquote (.+?) $rquote
1749 [\s,] \w+ \. (\w+) [\s,]
1751 [\s,] $lquote (.+?) $rquote [\s,]
1753 my $part = $1 || $2 || $3; # one of them matched if we got here
1754 unless ($seen_having{$part}++) {
1761 my $colpiece = $sel_index->{$_} || $_;
1763 # unqualify join-based group_by's. Arcane but possible query
1764 # also horrible horrible hack to alias a column (not a func.)
1765 # (probably need to introduce SQLA syntax)
1766 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1769 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1771 push @{$sub_attrs->{select}}, $colpiece;
1775 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1776 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1779 return $rsrc->resultset_class
1780 ->new ($rsrc, $sub_attrs)
1782 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1783 ->get_column ('count');
1787 =head2 count_literal
1789 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1790 should only be used in that context. See L</search_literal> for further info.
1794 =item Arguments: $sql_fragment, @standalone_bind_values
1796 =item Return Value: $count
1800 Counts the results in a literal query. Equivalent to calling L</search_literal>
1801 with the passed arguments, then L</count>.
1805 sub count_literal { shift->search_literal(@_)->count; }
1811 =item Arguments: none
1813 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1817 Returns all elements in the resultset.
1824 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1827 delete @{$self}{qw/_stashed_rows _stashed_results/};
1829 if (my $c = $self->get_cache) {
1833 $self->cursor->reset;
1835 my $objs = $self->_construct_results('fetch_all') || [];
1837 $self->set_cache($objs) if $self->{attrs}{cache};
1846 =item Arguments: none
1848 =item Return Value: $self
1852 Resets the resultset's cursor, so you can iterate through the elements again.
1853 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1861 delete @{$self}{qw/_stashed_rows _stashed_results/};
1862 $self->{all_cache_position} = 0;
1863 $self->cursor->reset;
1871 =item Arguments: none
1873 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1877 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1878 an object for the first result (or C<undef> if the resultset is empty).
1883 return $_[0]->reset->next;
1889 # Determines whether and what type of subquery is required for the $rs operation.
1890 # If grouping is necessary either supplies its own, or verifies the current one
1891 # After all is done delegates to the proper storage method.
1893 sub _rs_update_delete {
1894 my ($self, $op, $values) = @_;
1896 my $rsrc = $self->result_source;
1897 my $storage = $rsrc->schema->storage;
1899 my $attrs = { %{$self->_resolved_attrs} };
1901 my $join_classifications;
1902 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1904 # do we need a subquery for any reason?
1906 defined $existing_group_by
1908 # if {from} is unparseable wrap a subq
1909 ref($attrs->{from}) ne 'ARRAY'
1911 # limits call for a subq
1912 $self->_has_resolved_attr(qw/rows offset/)
1915 # simplify the joinmap, so we can further decide if a subq is necessary
1916 if (!$needs_subq and @{$attrs->{from}} > 1) {
1918 ($attrs->{from}, $join_classifications) =
1919 $storage->_prune_unused_joins ($attrs);
1921 # any non-pruneable non-local restricting joins imply subq
1922 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1925 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1927 (ref $attrs->{from}[0]) ne 'HASH'
1929 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1933 # do we need anything like a subquery?
1934 if (! $needs_subq) {
1935 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1936 # a condition containing 'me' or other table prefixes will not work
1937 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1939 my $sqla = $rsrc->storage->sql_maker;
1940 local $sqla->{_dequalify_idents} = 1;
1941 \[ $sqla->_recurse_where($self->{cond}) ];
1945 # we got this far - means it is time to wrap a subquery
1946 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1948 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1954 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1955 delete $attrs->{$_} for qw/select as collapse/;
1956 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1958 # this will be consumed by the pruner waaaaay down the stack
1959 $attrs->{_force_prune_multiplying_joins} = 1;
1961 my $subrs = (ref $self)->new($rsrc, $attrs);
1963 if (@$idcols == 1) {
1964 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1966 elsif ($storage->_use_multicolumn_in) {
1967 # no syntax for calling this properly yet
1968 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1969 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1970 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1975 # if all else fails - get all primary keys and operate over a ORed set
1976 # wrap in a transaction for consistency
1977 # this is where the group_by/multiplication starts to matter
1981 # we do not need to check pre-multipliers, since if the premulti is there, its
1982 # parent (who is multi) will be there too
1983 keys %{ $join_classifications->{multiplying} || {} }
1985 # make sure if there is a supplied group_by it matches the columns compiled above
1986 # perfectly. Anything else can not be sanely executed on most databases so croak
1987 # right then and there
1988 if ($existing_group_by) {
1989 my @current_group_by = map
1990 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1995 join ("\x00", sort @current_group_by)
1997 join ("\x00", sort @{$attrs->{columns}} )
1999 $self->throw_exception (
2000 "You have just attempted a $op operation on a resultset which does group_by"
2001 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2002 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2003 . ' kind of queries. Please retry the operation with a modified group_by or'
2004 . ' without using one at all.'
2009 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2012 $guard = $storage->txn_scope_guard;
2014 for my $row ($subrs->cursor->all) {
2016 { $idcols->[$_] => $row->[$_] }
2023 my $res = $cond ? $storage->$op (
2025 $op eq 'update' ? $values : (),
2029 $guard->commit if $guard;
2038 =item Arguments: \%values
2040 =item Return Value: $underlying_storage_rv
2044 Sets the specified columns in the resultset to the supplied values in a
2045 single query. Note that this will not run any accessor/set_column/update
2046 triggers, nor will it update any result object instances derived from this
2047 resultset (this includes the contents of the L<resultset cache|/set_cache>
2048 if any). See L</update_all> if you need to execute any on-update
2049 triggers or cascades defined either by you or a
2050 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2052 The return value is a pass through of what the underlying
2053 storage backend returned, and may vary. See L<DBI/execute> for the most
2058 Note that L</update> does not process/deflate any of the values passed in.
2059 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2060 ensure manually that any value passed to this method will stringify to
2061 something the RDBMS knows how to deal with. A notable example is the
2062 handling of L<DateTime> objects, for more info see:
2063 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2068 my ($self, $values) = @_;
2069 $self->throw_exception('Values for update must be a hash')
2070 unless ref $values eq 'HASH';
2072 return $self->_rs_update_delete ('update', $values);
2079 =item Arguments: \%values
2081 =item Return Value: 1
2085 Fetches all objects and updates them one at a time via
2086 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2087 triggers, while L</update> will not.
2092 my ($self, $values) = @_;
2093 $self->throw_exception('Values for update_all must be a hash')
2094 unless ref $values eq 'HASH';
2096 my $guard = $self->result_source->schema->txn_scope_guard;
2097 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2106 =item Arguments: none
2108 =item Return Value: $underlying_storage_rv
2112 Deletes the rows matching this resultset in a single query. Note that this
2113 will not run any delete triggers, nor will it alter the
2114 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2115 derived from this resultset (this includes the contents of the
2116 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2117 execute any on-delete triggers or cascades defined either by you or a
2118 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2120 The return value is a pass through of what the underlying storage backend
2121 returned, and may vary. See L<DBI/execute> for the most common case.
2127 $self->throw_exception('delete does not accept any arguments')
2130 return $self->_rs_update_delete ('delete');
2137 =item Arguments: none
2139 =item Return Value: 1
2143 Fetches all objects and deletes them one at a time via
2144 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2145 triggers, while L</delete> will not.
2151 $self->throw_exception('delete_all does not accept any arguments')
2154 my $guard = $self->result_source->schema->txn_scope_guard;
2155 $_->delete for $self->all;
2164 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2166 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2170 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2177 The context of this method call has an important effect on what is
2178 submitted to storage. In void context data is fed directly to fastpath
2179 insertion routines provided by the underlying storage (most often
2180 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2181 L<insert|DBIx::Class::Row/insert> calls on the
2182 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2183 augmentation of these methods provided by components. For example if you
2184 are using something like L<DBIx::Class::UUIDColumns> to create primary
2185 keys for you, you will find that your PKs are empty. In this case you
2186 will have to explicitly force scalar or list context in order to create
2191 In non-void (scalar or list) context, this method is simply a wrapper
2192 for L</create>. Depending on list or scalar context either a list of
2193 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2194 containing these objects is returned.
2196 When supplying data in "arrayref of arrayrefs" invocation style, the
2197 first element should be a list of column names and each subsequent
2198 element should be a data value in the earlier specified column order.
2201 $schema->resultset("Artist")->populate([
2202 [ qw( artistid name ) ],
2203 [ 100, 'A Formally Unknown Singer' ],
2204 [ 101, 'A singer that jumped the shark two albums ago' ],
2205 [ 102, 'An actually cool singer' ],
2208 For the arrayref of hashrefs style each hashref should be a structure
2209 suitable for passing to L</create>. Multi-create is also permitted with
2212 $schema->resultset("Artist")->populate([
2213 { artistid => 4, name => 'Manufactured Crap', cds => [
2214 { title => 'My First CD', year => 2006 },
2215 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2218 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2219 { title => 'My parents sold me to a record company', year => 2005 },
2220 { title => 'Why Am I So Ugly?', year => 2006 },
2221 { title => 'I Got Surgery and am now Popular', year => 2007 }
2226 If you attempt a void-context multi-create as in the example above (each
2227 Artist also has the related list of CDs), and B<do not> supply the
2228 necessary autoinc foreign key information, this method will proxy to the
2229 less efficient L</create>, and then throw the Result objects away. In this
2230 case there are obviously no benefits to using this method over L</create>.
2237 # cruft placed in standalone method
2238 my $data = $self->_normalize_populate_args(@_);
2240 return unless @$data;
2242 if(defined wantarray) {
2243 my @created = map { $self->new_result($_)->insert } @$data;
2244 return wantarray ? @created : \@created;
2247 my $first = $data->[0];
2249 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2250 # it relationship data
2251 my (@rels, @columns);
2252 my $rsrc = $self->result_source;
2253 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2254 for (keys %$first) {
2255 my $ref = ref $first->{$_};
2256 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2262 my @pks = $rsrc->primary_columns;
2264 ## do the belongs_to relationships
2265 foreach my $index (0..$#$data) {
2267 # delegate to create() for any dataset without primary keys with specified relationships
2268 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2270 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2271 my @ret = $self->populate($data);
2277 foreach my $rel (@rels) {
2278 next unless ref $data->[$index]->{$rel} eq "HASH";
2279 my $result = $self->related_resultset($rel)->new_result($data->[$index]->{$rel})->insert;
2280 my (undef, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2281 my $related = $result->result_source->_resolve_condition(
2282 $reverse_relinfo->{cond},
2288 delete $data->[$index]->{$rel};
2289 $data->[$index] = {%{$data->[$index]}, %$related};
2291 push @columns, keys %$related if $index == 0;
2295 ## inherit the data locked in the conditions of the resultset
2296 my ($rs_data) = $self->_merge_with_rscond({});
2297 delete @{$rs_data}{@columns};
2299 ## do bulk insert on current row
2300 $rsrc->storage->insert_bulk(
2302 [@columns, keys %$rs_data],
2303 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2306 ## do the has_many relationships
2307 foreach my $item (@$data) {
2311 foreach my $rel (@rels) {
2312 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2314 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2316 my $child = $main_row->$rel;
2318 my $related = $child->result_source->_resolve_condition(
2319 $rels->{$rel}{cond},
2325 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2326 my @populate = map { {%$_, %$related} } @rows_to_add;
2328 $child->populate( \@populate );
2335 # populate() arguments went over several incarnations
2336 # What we ultimately support is AoH
2337 sub _normalize_populate_args {
2338 my ($self, $arg) = @_;
2340 if (ref $arg eq 'ARRAY') {
2344 elsif (ref $arg->[0] eq 'HASH') {
2347 elsif (ref $arg->[0] eq 'ARRAY') {
2349 my @colnames = @{$arg->[0]};
2350 foreach my $values (@{$arg}[1 .. $#$arg]) {
2351 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2357 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2364 =item Arguments: none
2366 =item Return Value: L<$pager|Data::Page>
2370 Returns a L<Data::Page> object for the current resultset. Only makes
2371 sense for queries with a C<page> attribute.
2373 To get the full count of entries for a paged resultset, call
2374 C<total_entries> on the L<Data::Page> object.
2381 return $self->{pager} if $self->{pager};
2383 my $attrs = $self->{attrs};
2384 if (!defined $attrs->{page}) {
2385 $self->throw_exception("Can't create pager for non-paged rs");
2387 elsif ($attrs->{page} <= 0) {
2388 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2390 $attrs->{rows} ||= 10;
2392 # throw away the paging flags and re-run the count (possibly
2393 # with a subselect) to get the real total count
2394 my $count_attrs = { %$attrs };
2395 delete @{$count_attrs}{qw/rows offset page pager/};
2397 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2399 require DBIx::Class::ResultSet::Pager;
2400 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2401 sub { $total_rs->count }, #lazy-get the total
2403 $self->{attrs}{page},
2411 =item Arguments: $page_number
2413 =item Return Value: L<$resultset|/search>
2417 Returns a resultset for the $page_number page of the resultset on which page
2418 is called, where each page contains a number of rows equal to the 'rows'
2419 attribute set on the resultset (10 by default).
2424 my ($self, $page) = @_;
2425 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2432 =item Arguments: \%col_data
2434 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2438 Creates a new result object in the resultset's result class and returns
2439 it. The row is not inserted into the database at this point, call
2440 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2441 will tell you whether the result object has been inserted or not.
2443 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2448 my ($self, $values) = @_;
2450 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2453 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2454 unless (ref $values eq 'HASH');
2456 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2458 my $new = $self->result_class->new({
2460 ( @$cols_from_relations
2461 ? (-cols_from_relations => $cols_from_relations)
2464 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2468 reftype($new) eq 'HASH'
2474 carp_unique (sprintf (
2475 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2476 $self->result_class,
2483 # _merge_with_rscond
2485 # Takes a simple hash of K/V data and returns its copy merged with the
2486 # condition already present on the resultset. Additionally returns an
2487 # arrayref of value/condition names, which were inferred from related
2488 # objects (this is needed for in-memory related objects)
2489 sub _merge_with_rscond {
2490 my ($self, $data) = @_;
2492 my ($implied_data, @cols_from_relations);
2494 my $alias = $self->{attrs}{alias};
2496 if (! defined $self->{cond}) {
2497 # just massage $data below
2499 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2500 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2501 @cols_from_relations = keys %{ $implied_data || {} };
2504 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2505 $implied_data = { map {
2506 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2512 { %{ $self->_remove_alias($_, $alias) } }
2513 # precedence must be given to passed values over values inherited from
2514 # the cond, so the order here is important.
2515 ( $implied_data||(), $data)
2517 \@cols_from_relations
2521 # _has_resolved_attr
2523 # determines if the resultset defines at least one
2524 # of the attributes supplied
2526 # used to determine if a subquery is necessary
2528 # supports some virtual attributes:
2530 # This will scan for any joins being present on the resultset.
2531 # It is not a mere key-search but a deep inspection of {from}
2534 sub _has_resolved_attr {
2535 my ($self, @attr_names) = @_;
2537 my $attrs = $self->_resolved_attrs;
2541 for my $n (@attr_names) {
2542 if (grep { $n eq $_ } (qw/-join/) ) {
2543 $extra_checks{$n}++;
2547 my $attr = $attrs->{$n};
2549 next if not defined $attr;
2551 if (ref $attr eq 'HASH') {
2552 return 1 if keys %$attr;
2554 elsif (ref $attr eq 'ARRAY') {
2562 # a resolved join is expressed as a multi-level from
2564 $extra_checks{-join}
2566 ref $attrs->{from} eq 'ARRAY'
2568 @{$attrs->{from}} > 1
2576 # Remove the specified alias from the specified query hash. A copy is made so
2577 # the original query is not modified.
2580 my ($self, $query, $alias) = @_;
2582 my %orig = %{ $query || {} };
2585 foreach my $key (keys %orig) {
2587 $unaliased{$key} = $orig{$key};
2590 $unaliased{$1} = $orig{$key}
2591 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2601 =item Arguments: none
2603 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2607 Returns the SQL query and bind vars associated with the invocant.
2609 This is generally used as the RHS for a subquery.
2616 my $attrs = { %{ $self->_resolved_attrs } };
2618 my $aq = $self->result_source->storage->_select_args_to_query (
2619 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2629 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2631 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2635 my $artist = $schema->resultset('Artist')->find_or_new(
2636 { artist => 'fred' }, { key => 'artists' });
2638 $cd->cd_to_producer->find_or_new({ producer => $producer },
2639 { key => 'primary' });
2641 Find an existing record from this resultset using L</find>. if none exists,
2642 instantiate a new result object and return it. The object will not be saved
2643 into your storage until you call L<DBIx::Class::Row/insert> on it.
2645 You most likely want this method when looking for existing rows using a unique
2646 constraint that is not the primary key, or looking for related rows.
2648 If you want objects to be saved immediately, use L</find_or_create> instead.
2650 B<Note>: Make sure to read the documentation of L</find> and understand the
2651 significance of the C<key> attribute, as its lack may skew your search, and
2652 subsequently result in spurious new objects.
2654 B<Note>: Take care when using C<find_or_new> with a table having
2655 columns with default values that you intend to be automatically
2656 supplied by the database (e.g. an auto_increment primary key column).
2657 In normal usage, the value of such columns should NOT be included at
2658 all in the call to C<find_or_new>, even when set to C<undef>.
2664 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2665 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2666 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2669 return $self->new_result($hash);
2676 =item Arguments: \%col_data
2678 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2682 Attempt to create a single new row or a row with multiple related rows
2683 in the table represented by the resultset (and related tables). This
2684 will not check for duplicate rows before inserting, use
2685 L</find_or_create> to do that.
2687 To create one row for this resultset, pass a hashref of key/value
2688 pairs representing the columns of the table and the values you wish to
2689 store. If the appropriate relationships are set up, foreign key fields
2690 can also be passed an object representing the foreign row, and the
2691 value will be set to its primary key.
2693 To create related objects, pass a hashref of related-object column values
2694 B<keyed on the relationship name>. If the relationship is of type C<multi>
2695 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2696 The process will correctly identify columns holding foreign keys, and will
2697 transparently populate them from the keys of the corresponding relation.
2698 This can be applied recursively, and will work correctly for a structure
2699 with an arbitrary depth and width, as long as the relationships actually
2700 exists and the correct column data has been supplied.
2702 Instead of hashrefs of plain related data (key/value pairs), you may
2703 also pass new or inserted objects. New objects (not inserted yet, see
2704 L</new_result>), will be inserted into their appropriate tables.
2706 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2708 Example of creating a new row.
2710 $person_rs->create({
2711 name=>"Some Person",
2712 email=>"somebody@someplace.com"
2715 Example of creating a new row and also creating rows in a related C<has_many>
2716 or C<has_one> resultset. Note Arrayref.
2719 { artistid => 4, name => 'Manufactured Crap', cds => [
2720 { title => 'My First CD', year => 2006 },
2721 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2726 Example of creating a new row and also creating a row in a related
2727 C<belongs_to> resultset. Note Hashref.
2730 title=>"Music for Silly Walks",
2733 name=>"Silly Musician",
2741 When subclassing ResultSet never attempt to override this method. Since
2742 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2743 lot of the internals simply never call it, so your override will be
2744 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2745 or L<DBIx::Class::Row/insert> depending on how early in the
2746 L</create> process you need to intervene. See also warning pertaining to
2754 #my ($self, $col_data) = @_;
2755 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2756 return shift->new_result(shift)->insert;
2759 =head2 find_or_create
2763 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2765 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2769 $cd->cd_to_producer->find_or_create({ producer => $producer },
2770 { key => 'primary' });
2772 Tries to find a record based on its primary key or unique constraints; if none
2773 is found, creates one and returns that instead.
2775 my $cd = $schema->resultset('CD')->find_or_create({
2777 artist => 'Massive Attack',
2778 title => 'Mezzanine',
2782 Also takes an optional C<key> attribute, to search by a specific key or unique
2783 constraint. For example:
2785 my $cd = $schema->resultset('CD')->find_or_create(
2787 artist => 'Massive Attack',
2788 title => 'Mezzanine',
2790 { key => 'cd_artist_title' }
2793 B<Note>: Make sure to read the documentation of L</find> and understand the
2794 significance of the C<key> attribute, as its lack may skew your search, and
2795 subsequently result in spurious row creation.
2797 B<Note>: Because find_or_create() reads from the database and then
2798 possibly inserts based on the result, this method is subject to a race
2799 condition. Another process could create a record in the table after
2800 the find has completed and before the create has started. To avoid
2801 this problem, use find_or_create() inside a transaction.
2803 B<Note>: Take care when using C<find_or_create> with a table having
2804 columns with default values that you intend to be automatically
2805 supplied by the database (e.g. an auto_increment primary key column).
2806 In normal usage, the value of such columns should NOT be included at
2807 all in the call to C<find_or_create>, even when set to C<undef>.
2809 See also L</find> and L</update_or_create>. For information on how to declare
2810 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2812 If you need to know if an existing row was found or a new one created use
2813 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2814 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2817 my $cd = $schema->resultset('CD')->find_or_new({
2819 artist => 'Massive Attack',
2820 title => 'Mezzanine',
2824 if( !$cd->in_storage ) {
2831 sub find_or_create {
2833 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2834 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2835 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2838 return $self->new_result($hash)->insert;
2841 =head2 update_or_create
2845 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2847 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2851 $resultset->update_or_create({ col => $val, ... });
2853 Like L</find_or_create>, but if a row is found it is immediately updated via
2854 C<< $found_row->update (\%col_data) >>.
2857 Takes an optional C<key> attribute to search on a specific unique constraint.
2860 # In your application
2861 my $cd = $schema->resultset('CD')->update_or_create(
2863 artist => 'Massive Attack',
2864 title => 'Mezzanine',
2867 { key => 'cd_artist_title' }
2870 $cd->cd_to_producer->update_or_create({
2871 producer => $producer,
2877 B<Note>: Make sure to read the documentation of L</find> and understand the
2878 significance of the C<key> attribute, as its lack may skew your search, and
2879 subsequently result in spurious row creation.
2881 B<Note>: Take care when using C<update_or_create> with a table having
2882 columns with default values that you intend to be automatically
2883 supplied by the database (e.g. an auto_increment primary key column).
2884 In normal usage, the value of such columns should NOT be included at
2885 all in the call to C<update_or_create>, even when set to C<undef>.
2887 See also L</find> and L</find_or_create>. For information on how to declare
2888 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2890 If you need to know if an existing row was updated or a new one created use
2891 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2892 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2897 sub update_or_create {
2899 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2900 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2902 my $row = $self->find($cond, $attrs);
2904 $row->update($cond);
2908 return $self->new_result($cond)->insert;
2911 =head2 update_or_new
2915 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2917 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2921 $resultset->update_or_new({ col => $val, ... });
2923 Like L</find_or_new> but if a row is found it is immediately updated via
2924 C<< $found_row->update (\%col_data) >>.
2928 # In your application
2929 my $cd = $schema->resultset('CD')->update_or_new(
2931 artist => 'Massive Attack',
2932 title => 'Mezzanine',
2935 { key => 'cd_artist_title' }
2938 if ($cd->in_storage) {
2939 # the cd was updated
2942 # the cd is not yet in the database, let's insert it
2946 B<Note>: Make sure to read the documentation of L</find> and understand the
2947 significance of the C<key> attribute, as its lack may skew your search, and
2948 subsequently result in spurious new objects.
2950 B<Note>: Take care when using C<update_or_new> with a table having
2951 columns with default values that you intend to be automatically
2952 supplied by the database (e.g. an auto_increment primary key column).
2953 In normal usage, the value of such columns should NOT be included at
2954 all in the call to C<update_or_new>, even when set to C<undef>.
2956 See also L</find>, L</find_or_create> and L</find_or_new>.
2962 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2963 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2965 my $row = $self->find( $cond, $attrs );
2966 if ( defined $row ) {
2967 $row->update($cond);
2971 return $self->new_result($cond);
2978 =item Arguments: none
2980 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
2984 Gets the contents of the cache for the resultset, if the cache is set.
2986 The cache is populated either by using the L</prefetch> attribute to
2987 L</search> or by calling L</set_cache>.
2999 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3001 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3005 Sets the contents of the cache for the resultset. Expects an arrayref
3006 of objects of the same class as those produced by the resultset. Note that
3007 if the cache is set, the resultset will return the cached objects rather
3008 than re-querying the database even if the cache attr is not set.
3010 The contents of the cache can also be populated by using the
3011 L</prefetch> attribute to L</search>.
3016 my ( $self, $data ) = @_;
3017 $self->throw_exception("set_cache requires an arrayref")
3018 if defined($data) && (ref $data ne 'ARRAY');
3019 $self->{all_cache} = $data;
3026 =item Arguments: none
3028 =item Return Value: undef
3032 Clears the cache for the resultset.
3037 shift->set_cache(undef);
3044 =item Arguments: none
3046 =item Return Value: true, if the resultset has been paginated
3054 return !!$self->{attrs}{page};
3061 =item Arguments: none
3063 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3071 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3074 =head2 related_resultset
3078 =item Arguments: $rel_name
3080 =item Return Value: L<$resultset|/search>
3084 Returns a related resultset for the supplied relationship name.
3086 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3090 sub related_resultset {
3091 my ($self, $rel) = @_;
3093 return $self->{related_resultsets}{$rel}
3094 if defined $self->{related_resultsets}{$rel};
3096 return $self->{related_resultsets}{$rel} = do {
3097 my $rsrc = $self->result_source;
3098 my $rel_info = $rsrc->relationship_info($rel);
3100 $self->throw_exception(
3101 "search_related: result source '" . $rsrc->source_name .
3102 "' has no such relationship $rel")
3105 my $attrs = $self->_chain_relationship($rel);
3107 my $join_count = $attrs->{seen_join}{$rel};
3109 my $alias = $self->result_source->storage
3110 ->relname_to_table_alias($rel, $join_count);
3112 # since this is search_related, and we already slid the select window inwards
3113 # (the select/as attrs were deleted in the beginning), we need to flip all
3114 # left joins to inner, so we get the expected results
3115 # read the comment on top of the actual function to see what this does
3116 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3119 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3120 delete @{$attrs}{qw(result_class alias)};
3122 my $rel_source = $rsrc->related_source($rel);
3126 # The reason we do this now instead of passing the alias to the
3127 # search_rs below is that if you wrap/overload resultset on the
3128 # source you need to know what alias it's -going- to have for things
3129 # to work sanely (e.g. RestrictWithObject wants to be able to add
3130 # extra query restrictions, and these may need to be $alias.)
3132 my $rel_attrs = $rel_source->resultset_attributes;
3133 local $rel_attrs->{alias} = $alias;
3135 $rel_source->resultset
3139 where => $attrs->{where},
3143 if (my $cache = $self->get_cache) {
3144 my @related_cache = map
3145 { $_->related_resultset($rel)->get_cache || () }
3149 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3156 =head2 current_source_alias
3160 =item Arguments: none
3162 =item Return Value: $source_alias
3166 Returns the current table alias for the result source this resultset is built
3167 on, that will be used in the SQL query. Usually it is C<me>.
3169 Currently the source alias that refers to the result set returned by a
3170 L</search>/L</find> family method depends on how you got to the resultset: it's
3171 C<me> by default, but eg. L</search_related> aliases it to the related result
3172 source name (and keeps C<me> referring to the original result set). The long
3173 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3174 (and make this method unnecessary).
3176 Thus it's currently necessary to use this method in predefined queries (see
3177 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3178 source alias of the current result set:
3180 # in a result set class
3182 my ($self, $user) = @_;
3184 my $me = $self->current_source_alias;
3186 return $self->search({
3187 "$me.modified" => $user->id,
3193 sub current_source_alias {
3194 return (shift->{attrs} || {})->{alias} || 'me';
3197 =head2 as_subselect_rs
3201 =item Arguments: none
3203 =item Return Value: L<$resultset|/search>
3207 Act as a barrier to SQL symbols. The resultset provided will be made into a
3208 "virtual view" by including it as a subquery within the from clause. From this
3209 point on, any joined tables are inaccessible to ->search on the resultset (as if
3210 it were simply where-filtered without joins). For example:
3212 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3214 # 'x' now pollutes the query namespace
3216 # So the following works as expected
3217 my $ok_rs = $rs->search({'x.other' => 1});
3219 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3220 # def) we look for one row with contradictory terms and join in another table
3221 # (aliased 'x_2') which we never use
3222 my $broken_rs = $rs->search({'x.name' => 'def'});
3224 my $rs2 = $rs->as_subselect_rs;
3226 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3227 my $not_joined_rs = $rs2->search({'x.other' => 1});
3229 # works as expected: finds a 'table' row related to two x rows (abc and def)
3230 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3232 Another example of when one might use this would be to select a subset of
3233 columns in a group by clause:
3235 my $rs = $schema->resultset('Bar')->search(undef, {
3236 group_by => [qw{ id foo_id baz_id }],
3237 })->as_subselect_rs->search(undef, {
3238 columns => [qw{ id foo_id }]
3241 In the above example normally columns would have to be equal to the group by,
3242 but because we isolated the group by into a subselect the above works.
3246 sub as_subselect_rs {
3249 my $attrs = $self->_resolved_attrs;
3251 my $fresh_rs = (ref $self)->new (
3252 $self->result_source
3255 # these pieces will be locked in the subquery
3256 delete $fresh_rs->{cond};
3257 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3259 return $fresh_rs->search( {}, {
3261 $attrs->{alias} => $self->as_query,
3262 -alias => $attrs->{alias},
3263 -rsrc => $self->result_source,
3265 alias => $attrs->{alias},
3269 # This code is called by search_related, and makes sure there
3270 # is clear separation between the joins before, during, and
3271 # after the relationship. This information is needed later
3272 # in order to properly resolve prefetch aliases (any alias
3273 # with a relation_chain_depth less than the depth of the
3274 # current prefetch is not considered)
3276 # The increments happen twice per join. An even number means a
3277 # relationship specified via a search_related, whereas an odd
3278 # number indicates a join/prefetch added via attributes
3280 # Also this code will wrap the current resultset (the one we
3281 # chain to) in a subselect IFF it contains limiting attributes
3282 sub _chain_relationship {
3283 my ($self, $rel) = @_;
3284 my $source = $self->result_source;
3285 my $attrs = { %{$self->{attrs}||{}} };
3287 # we need to take the prefetch the attrs into account before we
3288 # ->_resolve_join as otherwise they get lost - captainL
3289 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3291 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3293 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3296 my @force_subq_attrs = qw/offset rows group_by having/;
3299 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3301 $self->_has_resolved_attr (@force_subq_attrs)
3303 # Nuke the prefetch (if any) before the new $rs attrs
3304 # are resolved (prefetch is useless - we are wrapping
3305 # a subquery anyway).
3306 my $rs_copy = $self->search;
3307 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3308 $rs_copy->{attrs}{join},
3309 delete $rs_copy->{attrs}{prefetch},
3314 -alias => $attrs->{alias},
3315 $attrs->{alias} => $rs_copy->as_query,
3317 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3318 $seen->{-relation_chain_depth} = 0;
3320 elsif ($attrs->{from}) { #shallow copy suffices
3321 $from = [ @{$attrs->{from}} ];
3326 -alias => $attrs->{alias},
3327 $attrs->{alias} => $source->from,
3331 my $jpath = ($seen->{-relation_chain_depth})
3332 ? $from->[-1][0]{-join_path}
3335 my @requested_joins = $source->_resolve_join(
3342 push @$from, @requested_joins;
3344 $seen->{-relation_chain_depth}++;
3346 # if $self already had a join/prefetch specified on it, the requested
3347 # $rel might very well be already included. What we do in this case
3348 # is effectively a no-op (except that we bump up the chain_depth on
3349 # the join in question so we could tell it *is* the search_related)
3352 # we consider the last one thus reverse
3353 for my $j (reverse @requested_joins) {
3354 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3355 if ($rel eq $last_j) {
3356 $j->[0]{-relation_chain_depth}++;
3362 unless ($already_joined) {
3363 push @$from, $source->_resolve_join(
3371 $seen->{-relation_chain_depth}++;
3373 return {%$attrs, from => $from, seen_join => $seen};
3376 sub _resolved_attrs {
3378 return $self->{_attrs} if $self->{_attrs};
3380 my $attrs = { %{ $self->{attrs} || {} } };
3381 my $source = $attrs->{result_source} = $self->result_source;
3382 my $alias = $attrs->{alias};
3384 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3385 if $attrs->{collapse} and $attrs->{distinct};
3387 # default selection list
3388 $attrs->{columns} = [ $source->columns ]
3389 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3391 # merge selectors together
3392 for (qw/columns select as/) {
3393 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3394 if $attrs->{$_} or $attrs->{"+$_"};
3397 # disassemble columns
3399 if (my $cols = delete $attrs->{columns}) {
3400 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3401 if (ref $c eq 'HASH') {
3402 for my $as (sort keys %$c) {
3403 push @sel, $c->{$as};
3414 # when trying to weed off duplicates later do not go past this point -
3415 # everything added from here on is unbalanced "anyone's guess" stuff
3416 my $dedup_stop_idx = $#as;
3418 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3420 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3421 if $attrs->{select};
3423 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3424 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3426 # disqualify all $alias.col as-bits (inflate-map mandated)
3427 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3429 # de-duplicate the result (remove *identical* select/as pairs)
3430 # and also die on duplicate {as} pointing to different {select}s
3431 # not using a c-style for as the condition is prone to shrinkage
3434 while ($i <= $dedup_stop_idx) {
3435 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3440 elsif ($seen->{$as[$i]}++) {
3441 $self->throw_exception(
3442 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3450 $attrs->{select} = \@sel;
3451 $attrs->{as} = \@as;
3453 $attrs->{from} ||= [{
3455 -alias => $self->{attrs}{alias},
3456 $self->{attrs}{alias} => $source->from,
3459 if ( $attrs->{join} || $attrs->{prefetch} ) {
3461 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3462 if ref $attrs->{from} ne 'ARRAY';
3464 my $join = (delete $attrs->{join}) || {};
3466 if ( defined $attrs->{prefetch} ) {
3467 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3470 $attrs->{from} = # have to copy here to avoid corrupting the original
3472 @{ $attrs->{from} },
3473 $source->_resolve_join(
3476 { %{ $attrs->{seen_join} || {} } },
3477 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3478 ? $attrs->{from}[-1][0]{-join_path}
3485 if ( defined $attrs->{order_by} ) {
3486 $attrs->{order_by} = (
3487 ref( $attrs->{order_by} ) eq 'ARRAY'
3488 ? [ @{ $attrs->{order_by} } ]
3489 : [ $attrs->{order_by} || () ]
3493 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3494 $attrs->{group_by} = [ $attrs->{group_by} ];
3498 # generate selections based on the prefetch helper
3499 my ($prefetch, @prefetch_select, @prefetch_as);
3500 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3501 if defined $attrs->{prefetch};
3505 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3506 if $attrs->{_dark_selector};
3508 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3509 if defined $attrs->{collapse} and ! $attrs->{collapse};
3511 $attrs->{collapse} = 1;
3513 # this is a separate structure (we don't look in {from} directly)
3514 # as the resolver needs to shift things off the lists to work
3515 # properly (identical-prefetches on different branches)
3517 if (ref $attrs->{from} eq 'ARRAY') {
3519 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3521 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3522 next unless $j->[0]{-alias};
3523 next unless $j->[0]{-join_path};
3524 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3526 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3529 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3530 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3534 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3536 # save these for after distinct resolution
3537 @prefetch_select = map { $_->[0] } @prefetch;
3538 @prefetch_as = map { $_->[1] } @prefetch;
3541 # run through the resulting joinstructure (starting from our current slot)
3542 # and unset collapse if proven unnecessary
3544 # also while we are at it find out if the current root source has
3545 # been premultiplied by previous related_source chaining
3547 # this allows to predict whether a root object with all other relation
3548 # data set to NULL is in fact unique
3549 if ($attrs->{collapse}) {
3551 if (ref $attrs->{from} eq 'ARRAY') {
3553 if (@{$attrs->{from}} == 1) {
3554 # no joins - no collapse
3555 $attrs->{collapse} = 0;
3558 # find where our table-spec starts
3559 my @fromlist = @{$attrs->{from}};
3561 my $t = shift @fromlist;
3564 # me vs join from-spec distinction - a ref means non-root
3565 if (ref $t eq 'ARRAY') {
3567 $is_multi ||= ! $t->{-is_single};
3569 last if ($t->{-alias} && $t->{-alias} eq $alias);
3570 $attrs->{_main_source_premultiplied} ||= $is_multi;
3573 # no non-singles remaining, nor any premultiplication - nothing to collapse
3575 ! $attrs->{_main_source_premultiplied}
3577 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3579 $attrs->{collapse} = 0;
3585 # if we can not analyze the from - err on the side of safety
3586 $attrs->{_main_source_premultiplied} = 1;
3590 # generate the distinct induced group_by before injecting the prefetched select/as parts
3591 if (delete $attrs->{distinct}) {
3592 if ($attrs->{group_by}) {
3593 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3596 $attrs->{_grouped_by_distinct} = 1;
3597 # distinct affects only the main selection part, not what prefetch may add below
3598 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3600 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3601 # The thinking is: if we are collapsing the subquerying prefetch engine will
3602 # rip stuff apart for us anyway, and we do not want to have a potentially
3603 # function-converted external order_by
3604 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3605 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3609 # inject prefetch-bound selection (if any)
3610 push @{$attrs->{select}}, @prefetch_select;
3611 push @{$attrs->{as}}, @prefetch_as;
3613 # whether we can get away with the dumbest (possibly DBI-internal) collapser
3614 if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3615 $attrs->{_related_results_construction} = 1;
3618 # if both page and offset are specified, produce a combined offset
3619 # even though it doesn't make much sense, this is what pre 081xx has
3621 if (my $page = delete $attrs->{page}) {
3623 ($attrs->{rows} * ($page - 1))
3625 ($attrs->{offset} || 0)
3629 return $self->{_attrs} = $attrs;
3633 my ($self, $attr) = @_;
3635 if (ref $attr eq 'HASH') {
3636 return $self->_rollout_hash($attr);
3637 } elsif (ref $attr eq 'ARRAY') {
3638 return $self->_rollout_array($attr);
3644 sub _rollout_array {
3645 my ($self, $attr) = @_;
3648 foreach my $element (@{$attr}) {
3649 if (ref $element eq 'HASH') {
3650 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3651 } elsif (ref $element eq 'ARRAY') {
3652 # XXX - should probably recurse here
3653 push( @rolled_array, @{$self->_rollout_array($element)} );
3655 push( @rolled_array, $element );
3658 return \@rolled_array;
3662 my ($self, $attr) = @_;
3665 foreach my $key (keys %{$attr}) {
3666 push( @rolled_array, { $key => $attr->{$key} } );
3668 return \@rolled_array;
3671 sub _calculate_score {
3672 my ($self, $a, $b) = @_;
3674 if (defined $a xor defined $b) {
3677 elsif (not defined $a) {
3681 if (ref $b eq 'HASH') {
3682 my ($b_key) = keys %{$b};
3683 if (ref $a eq 'HASH') {
3684 my ($a_key) = keys %{$a};
3685 if ($a_key eq $b_key) {
3686 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3691 return ($a eq $b_key) ? 1 : 0;
3694 if (ref $a eq 'HASH') {
3695 my ($a_key) = keys %{$a};
3696 return ($b eq $a_key) ? 1 : 0;
3698 return ($b eq $a) ? 1 : 0;
3703 sub _merge_joinpref_attr {
3704 my ($self, $orig, $import) = @_;
3706 return $import unless defined($orig);
3707 return $orig unless defined($import);
3709 $orig = $self->_rollout_attr($orig);
3710 $import = $self->_rollout_attr($import);
3713 foreach my $import_element ( @{$import} ) {
3714 # find best candidate from $orig to merge $b_element into
3715 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3716 foreach my $orig_element ( @{$orig} ) {
3717 my $score = $self->_calculate_score( $orig_element, $import_element );
3718 if ($score > $best_candidate->{score}) {
3719 $best_candidate->{position} = $position;
3720 $best_candidate->{score} = $score;
3724 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3725 $import_key = '' if not defined $import_key;
3727 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3728 push( @{$orig}, $import_element );
3730 my $orig_best = $orig->[$best_candidate->{position}];
3731 # merge orig_best and b_element together and replace original with merged
3732 if (ref $orig_best ne 'HASH') {
3733 $orig->[$best_candidate->{position}] = $import_element;
3734 } elsif (ref $import_element eq 'HASH') {
3735 my ($key) = keys %{$orig_best};
3736 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3739 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3742 return @$orig ? $orig : ();
3750 require Hash::Merge;
3751 my $hm = Hash::Merge->new;
3753 $hm->specify_behavior({
3756 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3758 if ($defl xor $defr) {
3759 return [ $defl ? $_[0] : $_[1] ];
3764 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3768 return [$_[0], $_[1]];
3772 return $_[1] if !defined $_[0];
3773 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3774 return [$_[0], @{$_[1]}]
3777 return [] if !defined $_[0] and !keys %{$_[1]};
3778 return [ $_[1] ] if !defined $_[0];
3779 return [ $_[0] ] if !keys %{$_[1]};
3780 return [$_[0], $_[1]]
3785 return $_[0] if !defined $_[1];
3786 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3787 return [@{$_[0]}, $_[1]]
3790 my @ret = @{$_[0]} or return $_[1];
3791 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3792 my %idx = map { $_ => 1 } @ret;
3793 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3797 return [ $_[1] ] if ! @{$_[0]};
3798 return $_[0] if !keys %{$_[1]};
3799 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3800 return [ @{$_[0]}, $_[1] ];
3805 return [] if !keys %{$_[0]} and !defined $_[1];
3806 return [ $_[0] ] if !defined $_[1];
3807 return [ $_[1] ] if !keys %{$_[0]};
3808 return [$_[0], $_[1]]
3811 return [] if !keys %{$_[0]} and !@{$_[1]};
3812 return [ $_[0] ] if !@{$_[1]};
3813 return $_[1] if !keys %{$_[0]};
3814 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3815 return [ $_[0], @{$_[1]} ];
3818 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3819 return [ $_[0] ] if !keys %{$_[1]};
3820 return [ $_[1] ] if !keys %{$_[0]};
3821 return [ $_[0] ] if $_[0] eq $_[1];
3822 return [ $_[0], $_[1] ];
3825 } => 'DBIC_RS_ATTR_MERGER');
3829 return $hm->merge ($_[1], $_[2]);
3833 sub STORABLE_freeze {
3834 my ($self, $cloning) = @_;
3835 my $to_serialize = { %$self };
3837 # A cursor in progress can't be serialized (and would make little sense anyway)
3838 # the parser can be regenerated (and can't be serialized)
3839 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3841 # nor is it sensical to store a not-yet-fired-count pager
3842 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3843 delete $to_serialize->{pager};
3846 Storable::nfreeze($to_serialize);
3849 # need this hook for symmetry
3851 my ($self, $cloning, $serialized) = @_;
3853 %$self = %{ Storable::thaw($serialized) };
3859 =head2 throw_exception
3861 See L<DBIx::Class::Schema/throw_exception> for details.
3865 sub throw_exception {
3868 if (ref $self and my $rsrc = $self->result_source) {
3869 $rsrc->throw_exception(@_)
3872 DBIx::Class::Exception->throw(@_);
3880 # XXX: FIXME: Attributes docs need clearing up
3884 Attributes are used to refine a ResultSet in various ways when
3885 searching for data. They can be passed to any method which takes an
3886 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3889 Default attributes can be set on the result class using
3890 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3891 the CAVEATS on that feature before using it!)
3893 These are in no particular order:
3899 =item Value: ( $order_by | \@order_by | \%order_by )
3903 Which column(s) to order the results by.
3905 [The full list of suitable values is documented in
3906 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3909 If a single column name, or an arrayref of names is supplied, the
3910 argument is passed through directly to SQL. The hashref syntax allows
3911 for connection-agnostic specification of ordering direction:
3913 For descending order:
3915 order_by => { -desc => [qw/col1 col2 col3/] }
3917 For explicit ascending order:
3919 order_by => { -asc => 'col' }
3921 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3922 supported, although you are strongly encouraged to use the hashref
3923 syntax as outlined above.
3929 =item Value: \@columns | \%columns | $column
3933 Shortcut to request a particular set of columns to be retrieved. Each
3934 column spec may be a string (a table column name), or a hash (in which
3935 case the key is the C<as> value, and the value is used as the C<select>
3936 expression). Adds C<me.> onto the start of any column without a C<.> in
3937 it and sets C<select> from that, then auto-populates C<as> from
3938 C<select> as normal. (You may also use the C<cols> attribute, as in
3939 earlier versions of DBIC, but this is deprecated)
3941 Essentially C<columns> does the same as L</select> and L</as>.
3943 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
3947 select => [qw(some_column another_column)],
3948 as => [qw(some_column dbic_slot)]
3950 If you want to individually retrieve related columns (in essence perform
3951 manual prefetch) you have to make sure to specify the correct inflation slot
3952 chain such that it matches existing relationships:
3954 my $rs = $schema->resultset('Artist')->search({}, {
3955 # required to tell DBIC to collapse has_many relationships
3957 join => { cds => 'tracks'},
3959 'cds.cdid' => 'cds.cdid',
3960 'cds.tracks.title' => 'tracks.title',
3966 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
3967 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
3968 with a unary plus operator before it, which is the same as simply C<columns>.
3972 =item Value: \@extra_columns
3976 Indicates additional columns to be selected from storage. Works the same as
3977 L</columns> but adds columns to the current selection. (You may also use the
3978 C<include_columns> attribute, as in earlier versions of DBIC, but this is
3981 $schema->resultset('CD')->search(undef, {
3982 '+columns' => ['artist.name'],
3986 would return all CDs and include a 'name' column to the information
3987 passed to object inflation. Note that the 'artist' is the name of the
3988 column (or relationship) accessor, and 'name' is the name of the column
3989 accessor in the related table.
3995 =item Value: \@select_columns
3999 Indicates which columns should be selected from the storage. You can use
4000 column names, or in the case of RDBMS back ends, function or stored procedure
4003 $rs = $schema->resultset('Employee')->search(undef, {
4006 { count => 'employeeid' },
4007 { max => { length => 'name' }, -as => 'longest_name' }
4012 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4014 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4015 use L</select>, to instruct DBIx::Class how to store the result of the column.
4016 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4017 identifier aliasing. You can however alias a function, so you can use it in
4018 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4019 attribute> supplied as shown in the example above.
4023 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4024 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4025 with a unary plus operator before it, which is the same as simply C<select>.
4029 =item Value: \@extra_select_columns
4033 Indicates additional columns to be selected from storage. Works the same as
4034 L</select> but adds columns to the current selection, instead of specifying
4035 a new explicit list.
4041 =item Value: \@inflation_names
4045 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4046 slot name in which the column value will be stored within the
4047 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4048 identifier by the C<get_column> method (or via the object accessor B<if one
4049 with the same name already exists>) as shown below. The L</as> attribute has
4050 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4052 $rs = $schema->resultset('Employee')->search(undef, {
4055 { count => 'employeeid' },
4056 { max => { length => 'name' }, -as => 'longest_name' }
4065 If the object against which the search is performed already has an accessor
4066 matching a column name specified in C<as>, the value can be retrieved using
4067 the accessor as normal:
4069 my $name = $employee->name();
4071 If on the other hand an accessor does not exist in the object, you need to
4072 use C<get_column> instead:
4074 my $employee_count = $employee->get_column('employee_count');
4076 You can create your own accessors if required - see
4077 L<DBIx::Class::Manual::Cookbook> for details.
4081 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4082 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4083 with a unary plus operator before it, which is the same as simply C<as>.
4087 =item Value: \@extra_inflation_names
4091 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4097 =item Value: ($rel_name | \@rel_names | \%rel_names)
4101 Contains a list of relationships that should be joined for this query. For
4104 # Get CDs by Nine Inch Nails
4105 my $rs = $schema->resultset('CD')->search(
4106 { 'artist.name' => 'Nine Inch Nails' },
4107 { join => 'artist' }
4110 Can also contain a hash reference to refer to the other relation's relations.
4113 package MyApp::Schema::Track;
4114 use base qw/DBIx::Class/;
4115 __PACKAGE__->table('track');
4116 __PACKAGE__->add_columns(qw/trackid cd position title/);
4117 __PACKAGE__->set_primary_key('trackid');
4118 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4121 # In your application
4122 my $rs = $schema->resultset('Artist')->search(
4123 { 'track.title' => 'Teardrop' },
4125 join => { cd => 'track' },
4126 order_by => 'artist.name',
4130 You need to use the relationship (not the table) name in conditions,
4131 because they are aliased as such. The current table is aliased as "me", so
4132 you need to use me.column_name in order to avoid ambiguity. For example:
4134 # Get CDs from 1984 with a 'Foo' track
4135 my $rs = $schema->resultset('CD')->search(
4138 'tracks.name' => 'Foo'
4140 { join => 'tracks' }
4143 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4144 similarly for a third time). For e.g.
4146 my $rs = $schema->resultset('Artist')->search({
4147 'cds.title' => 'Down to Earth',
4148 'cds_2.title' => 'Popular',
4150 join => [ qw/cds cds/ ],
4153 will return a set of all artists that have both a cd with title 'Down
4154 to Earth' and a cd with title 'Popular'.
4156 If you want to fetch related objects from other tables as well, see L</prefetch>
4159 NOTE: An internal join-chain pruner will discard certain joins while
4160 constructing the actual SQL query, as long as the joins in question do not
4161 affect the retrieved result. This for example includes 1:1 left joins
4162 that are not part of the restriction specification (WHERE/HAVING) nor are
4163 a part of the query selection.
4165 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4171 =item Value: (0 | 1)
4175 When set to a true value, indicates that any rows fetched from joined has_many
4176 relationships are to be aggregated into the corresponding "parent" object. For
4177 example, the resultset:
4179 my $rs = $schema->resultset('CD')->search({}, {
4180 '+columns' => [ qw/ tracks.title tracks.position / ],
4185 While executing the following query:
4187 SELECT me.*, tracks.title, tracks.position
4189 LEFT JOIN track tracks
4190 ON tracks.cdid = me.cdid
4192 Will return only as many objects as there are rows in the CD source, even
4193 though the result of the query may span many rows. Each of these CD objects
4194 will in turn have multiple "Track" objects hidden behind the has_many
4195 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4196 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4197 product"), with each CD object containing exactly one of all fetched Track data.
4199 When a collapse is requested on a non-ordered resultset, an order by some
4200 unique part of the main source (the left-most table) is inserted automatically.
4201 This is done so that the resultset is allowed to be "lazy" - calling
4202 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4203 object with all of its related data.
4205 If an L</order_by> is already declared, and orders the resultset in a way that
4206 makes collapsing as described above impossible (e.g. C<< ORDER BY
4207 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4208 switch to "eager" mode and slurp the entire resultset before constructing the
4209 first object returned by L</next>.
4211 Setting this attribute on a resultset that does not join any has_many
4212 relations is a no-op.
4214 For a more in-depth discussion, see L</PREFETCHING>.
4220 =item Value: ($rel_name | \@rel_names | \%rel_names)
4224 This attribute is a shorthand for specifying a L</join> spec, adding all
4225 columns from the joined related sources as L</+columns> and setting
4226 L</collapse> to a true value. For example, the following two queries are
4229 my $rs = $schema->resultset('Artist')->search({}, {
4230 prefetch => { cds => ['genre', 'tracks' ] },
4235 my $rs = $schema->resultset('Artist')->search({}, {
4236 join => { cds => ['genre', 'tracks' ] },
4240 { +{ "cds.$_" => "cds.$_" } }
4241 $schema->source('Artist')->related_source('cds')->columns
4244 { +{ "cds.genre.$_" => "genre.$_" } }
4245 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4248 { +{ "cds.tracks.$_" => "tracks.$_" } }
4249 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4254 Both producing the following SQL:
4256 SELECT me.artistid, me.name, me.rank, me.charfield,
4257 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4258 genre.genreid, genre.name,
4259 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4262 ON cds.artist = me.artistid
4263 LEFT JOIN genre genre
4264 ON genre.genreid = cds.genreid
4265 LEFT JOIN track tracks
4266 ON tracks.cd = cds.cdid
4267 ORDER BY me.artistid
4269 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4270 the arguments are properly merged and generally do the right thing. For
4271 example, you may want to do the following:
4273 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4274 { 'genre.genreid' => undef },
4276 join => { cds => 'genre' },
4281 Which generates the following SQL:
4283 SELECT me.artistid, me.name, me.rank, me.charfield,
4284 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4287 ON cds.artist = me.artistid
4288 LEFT JOIN genre genre
4289 ON genre.genreid = cds.genreid
4290 WHERE genre.genreid IS NULL
4291 ORDER BY me.artistid
4293 For a more in-depth discussion, see L</PREFETCHING>.
4299 =item Value: $source_alias
4303 Sets the source alias for the query. Normally, this defaults to C<me>, but
4304 nested search queries (sub-SELECTs) might need specific aliases set to
4305 reference inner queries. For example:
4308 ->related_resultset('CDs')
4309 ->related_resultset('Tracks')
4311 'track.id' => { -ident => 'none_search.id' },
4315 my $ids = $self->search({
4318 alias => 'none_search',
4319 group_by => 'none_search.id',
4320 })->get_column('id')->as_query;
4322 $self->search({ id => { -in => $ids } })
4324 This attribute is directly tied to L</current_source_alias>.
4334 Makes the resultset paged and specifies the page to retrieve. Effectively
4335 identical to creating a non-pages resultset and then calling ->page($page)
4338 If L</rows> attribute is not specified it defaults to 10 rows per page.
4340 When you have a paged resultset, L</count> will only return the number
4341 of rows in the page. To get the total, use the L</pager> and call
4342 C<total_entries> on it.
4352 Specifies the maximum number of rows for direct retrieval or the number of
4353 rows per page if the page attribute or method is used.
4359 =item Value: $offset
4363 Specifies the (zero-based) row number for the first row to be returned, or the
4364 of the first row of the first page if paging is used.
4366 =head2 software_limit
4370 =item Value: (0 | 1)
4374 When combined with L</rows> and/or L</offset> the generated SQL will not
4375 include any limit dialect stanzas. Instead the entire result will be selected
4376 as if no limits were specified, and DBIC will perform the limit locally, by
4377 artificially advancing and finishing the resulting L</cursor>.
4379 This is the recommended way of performing resultset limiting when no sane RDBMS
4380 implementation is available (e.g.
4381 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4382 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4388 =item Value: \@columns
4392 A arrayref of columns to group by. Can include columns of joined tables.
4394 group_by => [qw/ column1 column2 ... /]
4400 =item Value: $condition
4404 HAVING is a select statement attribute that is applied between GROUP BY and
4405 ORDER BY. It is applied to the after the grouping calculations have been
4408 having => { 'count_employee' => { '>=', 100 } }
4410 or with an in-place function in which case literal SQL is required:
4412 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4418 =item Value: (0 | 1)
4422 Set to 1 to automatically generate a L</group_by> clause based on the selection
4423 (including intelligent handling of L</order_by> contents). Note that the group
4424 criteria calculation takes place over the B<final> selection. This includes
4425 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4426 L</search> calls, and standalone columns selected via
4427 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4428 extra selections specified via L</prefetch> - such selections are explicitly
4429 excluded from group criteria calculations.
4431 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4432 setting is ignored and an appropriate warning is issued.
4438 Adds to the WHERE clause.
4440 # only return rows WHERE deleted IS NULL for all searches
4441 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4443 Can be overridden by passing C<< { where => undef } >> as an attribute
4446 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4452 Set to 1 to cache search results. This prevents extra SQL queries if you
4453 revisit rows in your ResultSet:
4455 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4457 while( my $artist = $resultset->next ) {
4461 $rs->first; # without cache, this would issue a query
4463 By default, searches are not cached.
4465 For more examples of using these attributes, see
4466 L<DBIx::Class::Manual::Cookbook>.
4472 =item Value: ( 'update' | 'shared' | \$scalar )
4476 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4477 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4482 DBIx::Class supports arbitrary related data prefetching from multiple related
4483 sources. Any combination of relationship types and column sets are supported.
4484 If L<collapsing|/collapse> is requested, there is an additional requirement of
4485 selecting enough data to make every individual object uniquely identifiable.
4487 Here are some more involved examples, based on the following relationship map:
4490 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4491 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4492 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4494 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4496 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4500 my $rs = $schema->resultset('Tag')->search(
4509 The initial search results in SQL like the following:
4511 SELECT tag.*, cd.*, artist.* FROM tag
4512 JOIN cd ON tag.cd = cd.cdid
4513 JOIN artist ON cd.artist = artist.artistid
4515 L<DBIx::Class> has no need to go back to the database when we access the
4516 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4519 Simple prefetches will be joined automatically, so there is no need
4520 for a C<join> attribute in the above search.
4522 The L</prefetch> attribute can be used with any of the relationship types
4523 and multiple prefetches can be specified together. Below is a more complex
4524 example that prefetches a CD's artist, its liner notes (if present),
4525 the cover image, the tracks on that CD, and the guests on those
4528 my $rs = $schema->resultset('CD')->search(
4532 { artist => 'record_label'}, # belongs_to => belongs_to
4533 'liner_note', # might_have
4534 'cover_image', # has_one
4535 { tracks => 'guests' }, # has_many => has_many
4540 This will produce SQL like the following:
4542 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4546 ON artist.artistid = me.artistid
4547 JOIN record_label record_label
4548 ON record_label.labelid = artist.labelid
4549 LEFT JOIN track tracks
4550 ON tracks.cdid = me.cdid
4551 LEFT JOIN guest guests
4552 ON guests.trackid = track.trackid
4553 LEFT JOIN liner_notes liner_note
4554 ON liner_note.cdid = me.cdid
4555 JOIN cd_artwork cover_image
4556 ON cover_image.cdid = me.cdid
4559 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4560 C<tracks>, and C<guests> of the CD will all be available through the
4561 relationship accessors without the need for additional queries to the
4566 Prefetch does a lot of deep magic. As such, it may not behave exactly
4567 as you might expect.
4573 Prefetch uses the L</cache> to populate the prefetched relationships. This
4574 may or may not be what you want.
4578 If you specify a condition on a prefetched relationship, ONLY those
4579 rows that match the prefetched condition will be fetched into that relationship.
4580 This means that adding prefetch to a search() B<may alter> what is returned by
4581 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4583 my $artist_rs = $schema->resultset('Artist')->search({
4589 my $count = $artist_rs->first->cds->count;
4591 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4593 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4595 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4597 That cmp_ok() may or may not pass depending on the datasets involved. In other
4598 words the C<WHERE> condition would apply to the entire dataset, just like
4599 it would in regular SQL. If you want to add a condition only to the "right side"
4600 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4601 condition|DBIx::Class::Relationship::Base/condition>
4605 =head1 DBIC BIND VALUES
4607 Because DBIC may need more information to bind values than just the column name
4608 and value itself, it uses a special format for both passing and receiving bind
4609 values. Each bind value should be composed of an arrayref of
4610 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4616 If present (in any form), this is what is being passed directly to bind_param.
4617 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4618 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4620 If this is specified, all other bind options described below are ignored.
4624 If present, this is used to infer the actual bind attribute by passing to
4625 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4626 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4628 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4629 currently drivers are expected to "Do the Right Thing" when given a common
4630 datatype name. (Not ideal, but that's what we got at this point.)
4634 Currently used to correctly allocate buffers for bind_param_inout().
4635 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4636 or to a sensible value based on the "data_type".
4640 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4641 explicitly specified they are never overridden). Also used by some weird DBDs,
4642 where the column name should be available at bind_param time (e.g. Oracle).
4646 For backwards compatibility and convenience, the following shortcuts are
4649 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4650 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4651 [ undef, $val ] === [ {}, $val ]
4652 $val === [ {}, $val ]
4654 =head1 AUTHOR AND CONTRIBUTORS
4656 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4660 You may distribute this code under the same terms as Perl itself.