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 @{$attrs}{qw(_last_sqlmaker_alias_map _simple_passthrough_construction)};
317 if ($attrs->{page}) {
318 $attrs->{rows} ||= 10;
321 $attrs->{alias} ||= 'me';
324 result_source => $source,
325 cond => $attrs->{where},
330 # if there is a dark selector, this means we are already in a
331 # chain and the cleanup/sanification was taken care of by
333 $self->_normalize_selection($attrs)
334 unless $attrs->{_dark_selector};
337 $attrs->{result_class} || $source->result_class
347 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
349 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
353 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
354 my $new_rs = $cd_rs->search({ year => 2005 });
356 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
357 # year = 2005 OR year = 2004
359 In list context, C<< ->all() >> is called implicitly on the resultset, thus
360 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
361 To avoid that, use L</search_rs>.
363 If you need to pass in additional attributes but no additional condition,
364 call it as C<search(undef, \%attrs)>.
366 # "SELECT name, artistid FROM $artist_table"
367 my @all_artists = $schema->resultset('Artist')->search(undef, {
368 columns => [qw/name artistid/],
371 For a list of attributes that can be passed to C<search>, see
372 L</ATTRIBUTES>. For more examples of using this function, see
373 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
374 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
375 and its extension L<DBIx::Class::SQLMaker>.
377 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
381 Note that L</search> does not process/deflate any of the values passed in the
382 L<SQL::Abstract>-compatible search condition structure. This is unlike other
383 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
384 manually that any value passed to this method will stringify to something the
385 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
386 objects, for more info see:
387 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
393 my $rs = $self->search_rs( @_ );
396 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray;
399 elsif (defined wantarray) {
403 # we can be called by a relationship helper, which in
404 # turn may be called in void context due to some braindead
405 # overload or whatever else the user decided to be clever
406 # at this particular day. Thus limit the exception to
407 # external code calls only
408 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
409 if (caller)[0] !~ /^\QDBIx::Class::/;
419 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
421 =item Return Value: L<$resultset|/search>
425 This method does the same exact thing as search() except it will
426 always return a resultset, even in list context.
433 my $rsrc = $self->result_source;
434 my ($call_cond, $call_attrs);
436 # Special-case handling for (undef, undef) or (undef)
437 # Note that (foo => undef) is valid deprecated syntax
438 @_ = () if not scalar grep { defined $_ } @_;
444 # fish out attrs in the ($condref, $attr) case
445 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
446 ($call_cond, $call_attrs) = @_;
449 $self->throw_exception('Odd number of arguments to search')
453 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
454 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
456 for my $i (0 .. $#_) {
458 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
459 if (! defined $_[$i] or ref $_[$i] ne '');
465 # see if we can keep the cache (no $rs changes)
467 my %safe = (alias => 1, cache => 1);
468 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
471 ref $call_cond eq 'HASH' && ! keys %$call_cond
473 ref $call_cond eq 'ARRAY' && ! @$call_cond
475 $cache = $self->get_cache;
478 my $old_attrs = { %{$self->{attrs}} };
479 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
481 my $new_attrs = { %$old_attrs };
483 # take care of call attrs (only if anything is changing)
484 if ($call_attrs and keys %$call_attrs) {
486 # copy for _normalize_selection
487 $call_attrs = { %$call_attrs };
489 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
491 # reset the current selector list if new selectors are supplied
492 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
493 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
496 # Normalize the new selector list (operates on the passed-in attr structure)
497 # Need to do it on every chain instead of only once on _resolved_attrs, in
498 # order to allow detection of empty vs partial 'as'
499 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
500 if $old_attrs->{_dark_selector};
501 $self->_normalize_selection ($call_attrs);
503 # start with blind overwriting merge, exclude selector attrs
504 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
505 delete @{$new_attrs}{@selector_attrs};
507 for (@selector_attrs) {
508 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
509 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
512 # older deprecated name, use only if {columns} is not there
513 if (my $c = delete $new_attrs->{cols}) {
514 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
515 if ($new_attrs->{columns}) {
516 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
519 $new_attrs->{columns} = $c;
524 # join/prefetch use their own crazy merging heuristics
525 foreach my $key (qw/join prefetch/) {
526 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
527 if exists $call_attrs->{$key};
530 # stack binds together
531 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
535 for ($old_where, $call_cond) {
537 $new_attrs->{where} = $self->_stack_cond (
538 $_, $new_attrs->{where}
543 if (defined $old_having) {
544 $new_attrs->{having} = $self->_stack_cond (
545 $old_having, $new_attrs->{having}
549 my $rs = (ref $self)->new($rsrc, $new_attrs);
551 $rs->set_cache($cache) if ($cache);
557 sub _normalize_selection {
558 my ($self, $attrs) = @_;
561 if ( exists $attrs->{include_columns} ) {
562 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
563 $attrs->{'+columns'} = $self->_merge_attr(
564 $attrs->{'+columns'}, delete $attrs->{include_columns}
568 # columns are always placed first, however
570 # Keep the X vs +X separation until _resolved_attrs time - this allows to
571 # delay the decision on whether to use a default select list ($rsrc->columns)
572 # allowing stuff like the remove_columns helper to work
574 # select/as +select/+as pairs need special handling - the amount of select/as
575 # elements in each pair does *not* have to be equal (think multicolumn
576 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
577 # supplied at all) - try to infer the alias, either from the -as parameter
578 # of the selector spec, or use the parameter whole if it looks like a column
579 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
580 # is ok as well), but make sure no more additions to the 'as' chain take place
581 for my $pref ('', '+') {
583 my ($sel, $as) = map {
584 my $key = "${pref}${_}";
586 my $val = [ ref $attrs->{$key} eq 'ARRAY'
588 : $attrs->{$key} || ()
590 delete $attrs->{$key};
594 if (! @$as and ! @$sel ) {
597 elsif (@$as and ! @$sel) {
598 $self->throw_exception(
599 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
603 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
604 # if any @$as has been supplied we assume the user knows what (s)he is doing
605 # and blindly keep stacking up pieces
606 unless ($attrs->{_dark_selector}) {
609 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
610 push @$as, $_->{-as};
612 # assume any plain no-space, no-parenthesis string to be a column spec
613 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
614 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
617 # if all else fails - raise a flag that no more aliasing will be allowed
619 $attrs->{_dark_selector} = {
621 string => ($dark_sel_dumper ||= do {
622 require Data::Dumper::Concise;
623 Data::Dumper::Concise::DumperObject()->Indent(0);
624 })->Values([$_])->Dump
632 elsif (@$as < @$sel) {
633 $self->throw_exception(
634 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
637 elsif ($pref and $attrs->{_dark_selector}) {
638 $self->throw_exception(
639 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
645 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
646 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
651 my ($self, $left, $right) = @_;
654 (ref $_ eq 'ARRAY' and !@$_)
656 (ref $_ eq 'HASH' and ! keys %$_)
657 ) and $_ = undef for ($left, $right);
659 # either 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->{_simple_passthrough_construction}) {
1419 # construct a much simpler array->hash folder for the one-table HRI 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 ( $self->{_result_inflator}{is_core_row} and @$rows < 60 ) {
1433 for my $r (@$rows) {
1434 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1439 ( $self->{_result_inflator}{is_core_row}
1440 ? '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows'
1441 # a custom inflator may be a multiplier/reductor - put it in direct list ctx
1442 : '@$rows = map { $inflator_cref->($res_class, $rsrc, { %s } ) } @$rows'
1444 ( join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) )
1450 $self->{_result_inflator}{is_hri} ? 'hri'
1451 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1452 : 'classic_nonpruning'
1455 # $args and $attrs to _mk_row_parser are separated to delineate what is
1456 # core collapser stuff and what is dbic $rs specific
1457 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1459 inflate_map => $infmap,
1460 collapse => $attrs->{collapse},
1461 premultiplied => $attrs->{_main_source_premultiplied},
1462 hri_style => $self->{_result_inflator}{is_hri},
1463 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1464 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1466 # column_info metadata historically hasn't been too reliable.
1467 # We need to start fixing this somehow (the collapse resolver
1468 # can't work without it). Add an explicit check for the *main*
1469 # result, hopefully this will gradually weed out such errors
1471 # FIXME - this is a temporary kludge that reduces performance
1472 # It is however necessary for the time being
1473 my ($unrolled_non_null_cols_to_check, $err);
1475 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1478 'Collapse aborted due to invalid ResultSource metadata - the following '
1479 . 'selections are declared non-nullable but NULLs were retrieved: '
1483 COL: for my $i (@$check_non_null_cols) {
1484 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1487 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1490 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1494 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1495 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1497 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1498 my @r = $cursor->next or return;
1499 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1500 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1506 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1507 my @r = $cursor->next or return;
1512 $self->{_row_parser}{$parser_type}{cref}->(
1514 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1517 # simple in-place substitution, does not regrow $rows
1518 if ($self->{_result_inflator}{is_core_row}) {
1519 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1521 # Special-case multi-object HRI - there is no $inflator_cref pass at all
1522 elsif ( ! $self->{_result_inflator}{is_hri} ) {
1523 # the inflator may be a multiplier/reductor - put it in list ctx
1524 @$rows = map { $inflator_cref->($res_class, $rsrc, @$_) } @$rows;
1528 # The @$rows check seems odd at first - why wouldn't we want to warn
1529 # regardless? The issue is things like find() etc, where the user
1530 # *knows* only one result will come back. In these cases the ->all
1531 # is not a pessimization, but rather something we actually want
1533 'Unable to properly collapse has_many results in iterator mode due '
1534 . 'to order criteria - performed an eager cursor slurp underneath. '
1535 . 'Consider using ->all() instead'
1536 ) if ( ! $fetch_all and @$rows > 1 );
1541 =head2 result_source
1545 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1547 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1551 An accessor for the primary ResultSource object from which this ResultSet
1558 =item Arguments: $result_class?
1560 =item Return Value: $result_class
1564 An accessor for the class to use when creating result objects. Defaults to
1565 C<< result_source->result_class >> - which in most cases is the name of the
1566 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1568 Note that changing the result_class will also remove any components
1569 that were originally loaded in the source class via
1570 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1571 in the original source class will not run.
1576 my ($self, $result_class) = @_;
1577 if ($result_class) {
1579 # don't fire this for an object
1580 $self->ensure_class_loaded($result_class)
1581 unless ref($result_class);
1583 if ($self->get_cache) {
1584 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1586 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1587 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1588 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1591 $self->_result_class($result_class);
1593 delete $self->{_result_inflator};
1595 $self->_result_class;
1602 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1604 =item Return Value: $count
1608 Performs an SQL C<COUNT> with the same query as the resultset was built
1609 with to find the number of elements. Passing arguments is equivalent to
1610 C<< $rs->search ($cond, \%attrs)->count >>
1616 return $self->search(@_)->count if @_ and defined $_[0];
1617 return scalar @{ $self->get_cache } if $self->get_cache;
1619 my $attrs = { %{ $self->_resolved_attrs } };
1621 # this is a little optimization - it is faster to do the limit
1622 # adjustments in software, instead of a subquery
1623 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1626 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1627 $crs = $self->_count_subq_rs ($attrs);
1630 $crs = $self->_count_rs ($attrs);
1632 my $count = $crs->next;
1634 $count -= $offset if $offset;
1635 $count = $rows if $rows and $rows < $count;
1636 $count = 0 if ($count < 0);
1645 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1647 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1651 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1652 This can be very handy for subqueries:
1654 ->search( { amount => $some_rs->count_rs->as_query } )
1656 As with regular resultsets the SQL query will be executed only after
1657 the resultset is accessed via L</next> or L</all>. That would return
1658 the same single value obtainable via L</count>.
1664 return $self->search(@_)->count_rs if @_;
1666 # this may look like a lack of abstraction (count() does about the same)
1667 # but in fact an _rs *must* use a subquery for the limits, as the
1668 # software based limiting can not be ported if this $rs is to be used
1669 # in a subquery itself (i.e. ->as_query)
1670 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1671 return $self->_count_subq_rs($self->{_attrs});
1674 return $self->_count_rs($self->{_attrs});
1679 # returns a ResultSetColumn object tied to the count query
1682 my ($self, $attrs) = @_;
1684 my $rsrc = $self->result_source;
1686 my $tmp_attrs = { %$attrs };
1687 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1688 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1690 # overwrite the selector (supplied by the storage)
1691 $rsrc->resultset_class->new($rsrc, {
1693 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1695 })->get_column ('count');
1699 # same as above but uses a subquery
1701 sub _count_subq_rs {
1702 my ($self, $attrs) = @_;
1704 my $rsrc = $self->result_source;
1706 my $sub_attrs = { %$attrs };
1707 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1708 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1710 # if we multi-prefetch we group_by something unique, as this is what we would
1711 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1712 if ( $attrs->{collapse} ) {
1713 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1714 $rsrc->_identifying_column_set || $self->throw_exception(
1715 'Unable to construct a unique group_by criteria properly collapsing the '
1716 . 'has_many prefetch before count()'
1721 # Calculate subquery selector
1722 if (my $g = $sub_attrs->{group_by}) {
1724 my $sql_maker = $rsrc->storage->sql_maker;
1726 # necessary as the group_by may refer to aliased functions
1728 for my $sel (@{$attrs->{select}}) {
1729 $sel_index->{$sel->{-as}} = $sel
1730 if (ref $sel eq 'HASH' and $sel->{-as});
1733 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1734 # also look for named aggregates referred in the having clause
1735 # having often contains scalarrefs - thus parse it out entirely
1737 if ($attrs->{having}) {
1738 local $sql_maker->{having_bind};
1739 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1740 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1741 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1742 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1743 # if we don't unset it we screw up retarded but unfortunately working
1744 # 'MAX(foo.bar)' => { '>', 3 }
1745 $sql_maker->{name_sep} = '';
1748 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1750 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1753 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1754 # and if all fails for an utterly naive quoted scalar-with-function
1755 while ($having_sql =~ /
1756 $rquote $sep $lquote (.+?) $rquote
1758 [\s,] \w+ \. (\w+) [\s,]
1760 [\s,] $lquote (.+?) $rquote [\s,]
1762 my $part = $1 || $2 || $3; # one of them matched if we got here
1763 unless ($seen_having{$part}++) {
1770 my $colpiece = $sel_index->{$_} || $_;
1772 # unqualify join-based group_by's. Arcane but possible query
1773 # also horrible horrible hack to alias a column (not a func.)
1774 # (probably need to introduce SQLA syntax)
1775 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1778 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1780 push @{$sub_attrs->{select}}, $colpiece;
1784 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1785 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1788 return $rsrc->resultset_class
1789 ->new ($rsrc, $sub_attrs)
1791 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1792 ->get_column ('count');
1796 =head2 count_literal
1798 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1799 should only be used in that context. See L</search_literal> for further info.
1803 =item Arguments: $sql_fragment, @standalone_bind_values
1805 =item Return Value: $count
1809 Counts the results in a literal query. Equivalent to calling L</search_literal>
1810 with the passed arguments, then L</count>.
1814 sub count_literal { shift->search_literal(@_)->count; }
1820 =item Arguments: none
1822 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1826 Returns all elements in the resultset.
1833 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1836 delete @{$self}{qw/_stashed_rows _stashed_results/};
1838 if (my $c = $self->get_cache) {
1842 $self->cursor->reset;
1844 my $objs = $self->_construct_results('fetch_all') || [];
1846 $self->set_cache($objs) if $self->{attrs}{cache};
1855 =item Arguments: none
1857 =item Return Value: $self
1861 Resets the resultset's cursor, so you can iterate through the elements again.
1862 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1870 delete @{$self}{qw/_stashed_rows _stashed_results/};
1871 $self->{all_cache_position} = 0;
1872 $self->cursor->reset;
1880 =item Arguments: none
1882 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1886 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1887 an object for the first result (or C<undef> if the resultset is empty).
1892 return $_[0]->reset->next;
1898 # Determines whether and what type of subquery is required for the $rs operation.
1899 # If grouping is necessary either supplies its own, or verifies the current one
1900 # After all is done delegates to the proper storage method.
1902 sub _rs_update_delete {
1903 my ($self, $op, $values) = @_;
1905 my $rsrc = $self->result_source;
1906 my $storage = $rsrc->schema->storage;
1908 my $attrs = { %{$self->_resolved_attrs} };
1910 my $join_classifications;
1911 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1913 # do we need a subquery for any reason?
1915 defined $existing_group_by
1917 # if {from} is unparseable wrap a subq
1918 ref($attrs->{from}) ne 'ARRAY'
1920 # limits call for a subq
1921 $self->_has_resolved_attr(qw/rows offset/)
1924 # simplify the joinmap, so we can further decide if a subq is necessary
1925 if (!$needs_subq and @{$attrs->{from}} > 1) {
1927 ($attrs->{from}, $join_classifications) =
1928 $storage->_prune_unused_joins ($attrs);
1930 # any non-pruneable non-local restricting joins imply subq
1931 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1934 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1936 (ref $attrs->{from}[0]) ne 'HASH'
1938 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1942 # do we need anything like a subquery?
1943 if (! $needs_subq) {
1944 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1945 # a condition containing 'me' or other table prefixes will not work
1946 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1948 my $sqla = $rsrc->storage->sql_maker;
1949 local $sqla->{_dequalify_idents} = 1;
1950 \[ $sqla->_recurse_where($self->{cond}) ];
1954 # we got this far - means it is time to wrap a subquery
1955 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1957 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1963 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1964 delete $attrs->{$_} for qw/select as collapse/;
1965 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1967 # this will be consumed by the pruner waaaaay down the stack
1968 $attrs->{_force_prune_multiplying_joins} = 1;
1970 my $subrs = (ref $self)->new($rsrc, $attrs);
1972 if (@$idcols == 1) {
1973 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1975 elsif ($storage->_use_multicolumn_in) {
1976 # no syntax for calling this properly yet
1977 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1978 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1979 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1984 # if all else fails - get all primary keys and operate over a ORed set
1985 # wrap in a transaction for consistency
1986 # this is where the group_by/multiplication starts to matter
1990 # we do not need to check pre-multipliers, since if the premulti is there, its
1991 # parent (who is multi) will be there too
1992 keys %{ $join_classifications->{multiplying} || {} }
1994 # make sure if there is a supplied group_by it matches the columns compiled above
1995 # perfectly. Anything else can not be sanely executed on most databases so croak
1996 # right then and there
1997 if ($existing_group_by) {
1998 my @current_group_by = map
1999 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
2004 join ("\x00", sort @current_group_by)
2006 join ("\x00", sort @{$attrs->{columns}} )
2008 $self->throw_exception (
2009 "You have just attempted a $op operation on a resultset which does group_by"
2010 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2011 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2012 . ' kind of queries. Please retry the operation with a modified group_by or'
2013 . ' without using one at all.'
2018 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2021 $guard = $storage->txn_scope_guard;
2023 for my $row ($subrs->cursor->all) {
2025 { $idcols->[$_] => $row->[$_] }
2032 my $res = $cond ? $storage->$op (
2034 $op eq 'update' ? $values : (),
2038 $guard->commit if $guard;
2047 =item Arguments: \%values
2049 =item Return Value: $underlying_storage_rv
2053 Sets the specified columns in the resultset to the supplied values in a
2054 single query. Note that this will not run any accessor/set_column/update
2055 triggers, nor will it update any result object instances derived from this
2056 resultset (this includes the contents of the L<resultset cache|/set_cache>
2057 if any). See L</update_all> if you need to execute any on-update
2058 triggers or cascades defined either by you or a
2059 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2061 The return value is a pass through of what the underlying
2062 storage backend returned, and may vary. See L<DBI/execute> for the most
2067 Note that L</update> does not process/deflate any of the values passed in.
2068 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2069 ensure manually that any value passed to this method will stringify to
2070 something the RDBMS knows how to deal with. A notable example is the
2071 handling of L<DateTime> objects, for more info see:
2072 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2077 my ($self, $values) = @_;
2078 $self->throw_exception('Values for update must be a hash')
2079 unless ref $values eq 'HASH';
2081 return $self->_rs_update_delete ('update', $values);
2088 =item Arguments: \%values
2090 =item Return Value: 1
2094 Fetches all objects and updates them one at a time via
2095 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2096 triggers, while L</update> will not.
2101 my ($self, $values) = @_;
2102 $self->throw_exception('Values for update_all must be a hash')
2103 unless ref $values eq 'HASH';
2105 my $guard = $self->result_source->schema->txn_scope_guard;
2106 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2115 =item Arguments: none
2117 =item Return Value: $underlying_storage_rv
2121 Deletes the rows matching this resultset in a single query. Note that this
2122 will not run any delete triggers, nor will it alter the
2123 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2124 derived from this resultset (this includes the contents of the
2125 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2126 execute any on-delete triggers or cascades defined either by you or a
2127 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2129 The return value is a pass through of what the underlying storage backend
2130 returned, and may vary. See L<DBI/execute> for the most common case.
2136 $self->throw_exception('delete does not accept any arguments')
2139 return $self->_rs_update_delete ('delete');
2146 =item Arguments: none
2148 =item Return Value: 1
2152 Fetches all objects and deletes them one at a time via
2153 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2154 triggers, while L</delete> will not.
2160 $self->throw_exception('delete_all does not accept any arguments')
2163 my $guard = $self->result_source->schema->txn_scope_guard;
2164 $_->delete for $self->all;
2173 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2175 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2179 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2186 The context of this method call has an important effect on what is
2187 submitted to storage. In void context data is fed directly to fastpath
2188 insertion routines provided by the underlying storage (most often
2189 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2190 L<insert|DBIx::Class::Row/insert> calls on the
2191 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2192 augmentation of these methods provided by components. For example if you
2193 are using something like L<DBIx::Class::UUIDColumns> to create primary
2194 keys for you, you will find that your PKs are empty. In this case you
2195 will have to explicitly force scalar or list context in order to create
2200 In non-void (scalar or list) context, this method is simply a wrapper
2201 for L</create>. Depending on list or scalar context either a list of
2202 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2203 containing these objects is returned.
2205 When supplying data in "arrayref of arrayrefs" invocation style, the
2206 first element should be a list of column names and each subsequent
2207 element should be a data value in the earlier specified column order.
2210 $schema->resultset("Artist")->populate([
2211 [ qw( artistid name ) ],
2212 [ 100, 'A Formally Unknown Singer' ],
2213 [ 101, 'A singer that jumped the shark two albums ago' ],
2214 [ 102, 'An actually cool singer' ],
2217 For the arrayref of hashrefs style each hashref should be a structure
2218 suitable for passing to L</create>. Multi-create is also permitted with
2221 $schema->resultset("Artist")->populate([
2222 { artistid => 4, name => 'Manufactured Crap', cds => [
2223 { title => 'My First CD', year => 2006 },
2224 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2227 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2228 { title => 'My parents sold me to a record company', year => 2005 },
2229 { title => 'Why Am I So Ugly?', year => 2006 },
2230 { title => 'I Got Surgery and am now Popular', year => 2007 }
2235 If you attempt a void-context multi-create as in the example above (each
2236 Artist also has the related list of CDs), and B<do not> supply the
2237 necessary autoinc foreign key information, this method will proxy to the
2238 less efficient L</create>, and then throw the Result objects away. In this
2239 case there are obviously no benefits to using this method over L</create>.
2248 # this is naive and just a quick check
2249 # the types will need to be checked more thoroughly when the
2250 # multi-source populate gets added
2251 if (ref $_[0] eq 'ARRAY') {
2252 return unless @{$_[0]};
2254 $data = $_[0] if (ref $_[0][0] eq 'HASH' or ref $_[0][0] eq 'ARRAY');
2257 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs')
2260 # FIXME - no cref handling
2261 # At this point assume either hashes or arrays
2263 if(defined wantarray) {
2266 $guard = $self->result_source->schema->storage->txn_scope_guard
2267 if ( @$data > 2 or ( @$data == 2 and ref $data->[0] eq 'ARRAY' ) );
2269 if (ref $data->[0] eq 'ARRAY') {
2271 { my $vals = $_; $self->new_result({ map { $data->[0][$_] => $vals->[$_] } 0..$#{$data->[0]} })->insert }
2272 @{$data}[1 .. $#$data]
2276 @results = map { $self->new_result($_)->insert } @$data;
2279 $guard->commit if $guard;
2280 return wantarray ? @results : \@results;
2283 # we have to deal with *possibly incomplete* related data
2284 # this means we have to walk the data structure twice
2285 # whether we want this or not
2286 # jnap, I hate you ;)
2287 my $rsrc = $self->result_source;
2288 my $rel_info = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2290 my ($colinfo, $colnames, $slices_with_rels);
2294 for my $i (0 .. $#$data) {
2296 my $current_slice_seen_rel_infos;
2298 ### Determine/Supplement collists
2299 ### BEWARE - This is a hot piece of code, a lot of weird idioms were used
2300 if( ref $data->[$i] eq 'ARRAY' ) {
2302 # positional(!) explicit column list
2305 $colinfo->{$data->[0][$_]} = { pos => $_, name => $data->[0][$_] } and push @$colnames, $data->[0][$_]
2306 for 0 .. $#{$data->[0]};
2313 for (values %$colinfo) {
2314 if ($_->{is_rel} ||= (
2315 $rel_info->{$_->{name}}
2318 ref $data->[$i][$_->{pos}] eq 'ARRAY'
2320 ref $data->[$i][$_->{pos}] eq 'HASH'
2322 ( defined blessed $data->[$i][$_->{pos}] and $data->[$i][$_->{pos}]->isa('DBIx::Class::Row') )
2328 # moar sanity check... sigh
2329 for ( ref $data->[$i][$_->{pos}] eq 'ARRAY' ? @{$data->[$i][$_->{pos}]} : $data->[$i][$_->{pos}] ) {
2330 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2331 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2332 return my $throwaway = $self->populate(@_);
2336 push @$current_slice_seen_rel_infos, $rel_info->{$_->{name}};
2341 if ($current_slice_seen_rel_infos) {
2342 push @$slices_with_rels, { map { $colnames->[$_] => $data->[$i][$_] } 0 .. $#$colnames };
2344 # this is needed further down to decide whether or not to fallback to create()
2345 $colinfo->{$colnames->[$_]}{seen_null} ||= ! defined $data->[$i][$_]
2346 for 0 .. $#$colnames;
2349 elsif( ref $data->[$i] eq 'HASH' ) {
2351 for ( sort keys %{$data->[$i]} ) {
2353 $colinfo->{$_} ||= do {
2355 $self->throw_exception("Column '$_' must be present in supplied explicit column list")
2356 if $data_start; # it will be 0 on AoH, 1 on AoA
2358 push @$colnames, $_;
2361 { pos => $#$colnames, name => $_ }
2364 if ($colinfo->{$_}{is_rel} ||= (
2368 ref $data->[$i]{$_} eq 'ARRAY'
2370 ref $data->[$i]{$_} eq 'HASH'
2372 ( defined blessed $data->[$i]{$_} and $data->[$i]{$_}->isa('DBIx::Class::Row') )
2378 # moar sanity check... sigh
2379 for ( ref $data->[$i]{$_} eq 'ARRAY' ? @{$data->[$i]{$_}} : $data->[$i]{$_} ) {
2380 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2381 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2382 return my $throwaway = $self->populate(@_);
2386 push @$current_slice_seen_rel_infos, $rel_info->{$_};
2390 if ($current_slice_seen_rel_infos) {
2391 push @$slices_with_rels, $data->[$i];
2393 # this is needed further down to decide whether or not to fallback to create()
2394 $colinfo->{$_}{seen_null} ||= ! defined $data->[$i]{$_}
2395 for keys %{$data->[$i]};
2399 $self->throw_exception('Unexpected populate() data structure member type: ' . ref $data->[$i] );
2403 { $_->{attrs}{is_depends_on} }
2404 @{ $current_slice_seen_rel_infos || [] }
2406 carp_unique("Fast-path populate() of belongs_to relationship data is not possible - falling back to regular create()");
2407 return my $throwaway = $self->populate(@_);
2411 if( $slices_with_rels ) {
2413 # need to exclude the rel "columns"
2414 $colnames = [ grep { ! $colinfo->{$_}{is_rel} } @$colnames ];
2416 # extra sanity check - ensure the main source is in fact identifiable
2417 # the localizing of nullability is insane, but oh well... the use-case is legit
2418 my $ci = $rsrc->columns_info($colnames);
2420 $ci->{$_} = { %{$ci->{$_}}, is_nullable => 0 }
2421 for grep { ! $colinfo->{$_}{seen_null} } keys %$ci;
2423 unless( $rsrc->_identifying_column_set($ci) ) {
2424 carp_unique("Fast-path populate() of non-uniquely identifiable rows with related data is not possible - falling back to regular create()");
2425 return my $throwaway = $self->populate(@_);
2429 ### inherit the data locked in the conditions of the resultset
2430 my ($rs_data) = $self->_merge_with_rscond({});
2431 delete @{$rs_data}{@$colnames}; # passed-in stuff takes precedence
2433 # if anything left - decompose rs_data
2435 if (keys %$rs_data) {
2436 push @$rs_data_vals, $rs_data->{$_}
2437 for sort keys %$rs_data;
2441 $guard = $rsrc->schema->storage->txn_scope_guard
2442 if $slices_with_rels;
2444 ### main source data
2445 # FIXME - need to switch entirely to a coderef-based thing,
2446 # so that large sets aren't copied several times... I think
2447 $rsrc->storage->insert_bulk(
2449 [ @$colnames, sort keys %$rs_data ],
2451 ref $data->[$_] eq 'ARRAY'
2453 $slices_with_rels ? [ @{$data->[$_]}[0..$#$colnames], @{$rs_data_vals||[]} ] # the collist changed
2454 : $rs_data_vals ? [ @{$data->[$_]}, @$rs_data_vals ]
2457 : [ @{$data->[$_]}{@$colnames}, @{$rs_data_vals||[]} ]
2458 } $data_start .. $#$data ],
2461 ### do the children relationships
2462 if ( $slices_with_rels ) {
2463 my @rels = grep { $colinfo->{$_}{is_rel} } keys %$colinfo
2464 or die 'wtf... please report a bug with DBIC_TRACE=1 output (stacktrace)';
2466 for my $sl (@$slices_with_rels) {
2468 my ($main_proto, $main_proto_rs);
2469 for my $rel (@rels) {
2470 next unless defined $sl->{$rel};
2474 (map { $_ => $sl->{$_} } @$colnames),
2477 unless (defined $colinfo->{$rel}{rs}) {
2479 $colinfo->{$rel}{rs} = $rsrc->related_source($rel)->resultset;
2481 $colinfo->{$rel}{fk_map} = { reverse %{ $rsrc->_resolve_relationship_condition(
2483 self_alias => "\xFE", # irrelevant
2484 foreign_alias => "\xFF", # irrelevant
2485 )->{identity_map} || {} } };
2489 $colinfo->{$rel}{rs}->search({ map # only so that we inherit them values properly, no actual search
2492 ( $main_proto_rs ||= $rsrc->resultset->search($main_proto) )
2493 ->get_column( $colinfo->{$rel}{fk_map}{$_} )
2497 keys %{$colinfo->{$rel}{fk_map}}
2498 })->populate( ref $sl->{$rel} eq 'ARRAY' ? $sl->{$rel} : [ $sl->{$rel} ] );
2505 $guard->commit if $guard;
2512 =item Arguments: none
2514 =item Return Value: L<$pager|Data::Page>
2518 Returns a L<Data::Page> object for the current resultset. Only makes
2519 sense for queries with a C<page> attribute.
2521 To get the full count of entries for a paged resultset, call
2522 C<total_entries> on the L<Data::Page> object.
2529 return $self->{pager} if $self->{pager};
2531 my $attrs = $self->{attrs};
2532 if (!defined $attrs->{page}) {
2533 $self->throw_exception("Can't create pager for non-paged rs");
2535 elsif ($attrs->{page} <= 0) {
2536 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2538 $attrs->{rows} ||= 10;
2540 # throw away the paging flags and re-run the count (possibly
2541 # with a subselect) to get the real total count
2542 my $count_attrs = { %$attrs };
2543 delete @{$count_attrs}{qw/rows offset page pager/};
2545 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2547 require DBIx::Class::ResultSet::Pager;
2548 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2549 sub { $total_rs->count }, #lazy-get the total
2551 $self->{attrs}{page},
2559 =item Arguments: $page_number
2561 =item Return Value: L<$resultset|/search>
2565 Returns a resultset for the $page_number page of the resultset on which page
2566 is called, where each page contains a number of rows equal to the 'rows'
2567 attribute set on the resultset (10 by default).
2572 my ($self, $page) = @_;
2573 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2580 =item Arguments: \%col_data
2582 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2586 Creates a new result object in the resultset's result class and returns
2587 it. The row is not inserted into the database at this point, call
2588 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2589 will tell you whether the result object has been inserted or not.
2591 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2596 my ($self, $values) = @_;
2598 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2601 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2602 unless (ref $values eq 'HASH');
2604 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2606 my $new = $self->result_class->new({
2608 ( @$cols_from_relations
2609 ? (-cols_from_relations => $cols_from_relations)
2612 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2616 reftype($new) eq 'HASH'
2622 carp_unique (sprintf (
2623 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2624 $self->result_class,
2631 # _merge_with_rscond
2633 # Takes a simple hash of K/V data and returns its copy merged with the
2634 # condition already present on the resultset. Additionally returns an
2635 # arrayref of value/condition names, which were inferred from related
2636 # objects (this is needed for in-memory related objects)
2637 sub _merge_with_rscond {
2638 my ($self, $data) = @_;
2640 my ($implied_data, @cols_from_relations);
2642 my $alias = $self->{attrs}{alias};
2644 if (! defined $self->{cond}) {
2645 # just massage $data below
2647 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2648 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2649 @cols_from_relations = keys %{ $implied_data || {} };
2652 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2653 $implied_data = { map {
2654 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2660 { %{ $self->_remove_alias($_, $alias) } }
2661 # precedence must be given to passed values over values inherited from
2662 # the cond, so the order here is important.
2663 ( $implied_data||(), $data)
2665 \@cols_from_relations
2669 # _has_resolved_attr
2671 # determines if the resultset defines at least one
2672 # of the attributes supplied
2674 # used to determine if a subquery is necessary
2676 # supports some virtual attributes:
2678 # This will scan for any joins being present on the resultset.
2679 # It is not a mere key-search but a deep inspection of {from}
2682 sub _has_resolved_attr {
2683 my ($self, @attr_names) = @_;
2685 my $attrs = $self->_resolved_attrs;
2689 for my $n (@attr_names) {
2690 if (grep { $n eq $_ } (qw/-join/) ) {
2691 $extra_checks{$n}++;
2695 my $attr = $attrs->{$n};
2697 next if not defined $attr;
2699 if (ref $attr eq 'HASH') {
2700 return 1 if keys %$attr;
2702 elsif (ref $attr eq 'ARRAY') {
2710 # a resolved join is expressed as a multi-level from
2712 $extra_checks{-join}
2714 ref $attrs->{from} eq 'ARRAY'
2716 @{$attrs->{from}} > 1
2724 # Remove the specified alias from the specified query hash. A copy is made so
2725 # the original query is not modified.
2728 my ($self, $query, $alias) = @_;
2730 my %orig = %{ $query || {} };
2733 foreach my $key (keys %orig) {
2735 $unaliased{$key} = $orig{$key};
2738 $unaliased{$1} = $orig{$key}
2739 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2749 =item Arguments: none
2751 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2755 Returns the SQL query and bind vars associated with the invocant.
2757 This is generally used as the RHS for a subquery.
2764 my $attrs = { %{ $self->_resolved_attrs } };
2766 my $aq = $self->result_source->storage->_select_args_to_query (
2767 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2777 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2779 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2783 my $artist = $schema->resultset('Artist')->find_or_new(
2784 { artist => 'fred' }, { key => 'artists' });
2786 $cd->cd_to_producer->find_or_new({ producer => $producer },
2787 { key => 'primary' });
2789 Find an existing record from this resultset using L</find>. if none exists,
2790 instantiate a new result object and return it. The object will not be saved
2791 into your storage until you call L<DBIx::Class::Row/insert> on it.
2793 You most likely want this method when looking for existing rows using a unique
2794 constraint that is not the primary key, or looking for related rows.
2796 If you want objects to be saved immediately, use L</find_or_create> instead.
2798 B<Note>: Make sure to read the documentation of L</find> and understand the
2799 significance of the C<key> attribute, as its lack may skew your search, and
2800 subsequently result in spurious new objects.
2802 B<Note>: Take care when using C<find_or_new> with a table having
2803 columns with default values that you intend to be automatically
2804 supplied by the database (e.g. an auto_increment primary key column).
2805 In normal usage, the value of such columns should NOT be included at
2806 all in the call to C<find_or_new>, even when set to C<undef>.
2812 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2813 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2814 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2817 return $self->new_result($hash);
2824 =item Arguments: \%col_data
2826 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2830 Attempt to create a single new row or a row with multiple related rows
2831 in the table represented by the resultset (and related tables). This
2832 will not check for duplicate rows before inserting, use
2833 L</find_or_create> to do that.
2835 To create one row for this resultset, pass a hashref of key/value
2836 pairs representing the columns of the table and the values you wish to
2837 store. If the appropriate relationships are set up, foreign key fields
2838 can also be passed an object representing the foreign row, and the
2839 value will be set to its primary key.
2841 To create related objects, pass a hashref of related-object column values
2842 B<keyed on the relationship name>. If the relationship is of type C<multi>
2843 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2844 The process will correctly identify columns holding foreign keys, and will
2845 transparently populate them from the keys of the corresponding relation.
2846 This can be applied recursively, and will work correctly for a structure
2847 with an arbitrary depth and width, as long as the relationships actually
2848 exists and the correct column data has been supplied.
2850 Instead of hashrefs of plain related data (key/value pairs), you may
2851 also pass new or inserted objects. New objects (not inserted yet, see
2852 L</new_result>), will be inserted into their appropriate tables.
2854 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2856 Example of creating a new row.
2858 $person_rs->create({
2859 name=>"Some Person",
2860 email=>"somebody@someplace.com"
2863 Example of creating a new row and also creating rows in a related C<has_many>
2864 or C<has_one> resultset. Note Arrayref.
2867 { artistid => 4, name => 'Manufactured Crap', cds => [
2868 { title => 'My First CD', year => 2006 },
2869 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2874 Example of creating a new row and also creating a row in a related
2875 C<belongs_to> resultset. Note Hashref.
2878 title=>"Music for Silly Walks",
2881 name=>"Silly Musician",
2889 When subclassing ResultSet never attempt to override this method. Since
2890 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2891 lot of the internals simply never call it, so your override will be
2892 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2893 or L<DBIx::Class::Row/insert> depending on how early in the
2894 L</create> process you need to intervene. See also warning pertaining to
2902 #my ($self, $col_data) = @_;
2903 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2904 return shift->new_result(shift)->insert;
2907 =head2 find_or_create
2911 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2913 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2917 $cd->cd_to_producer->find_or_create({ producer => $producer },
2918 { key => 'primary' });
2920 Tries to find a record based on its primary key or unique constraints; if none
2921 is found, creates one and returns that instead.
2923 my $cd = $schema->resultset('CD')->find_or_create({
2925 artist => 'Massive Attack',
2926 title => 'Mezzanine',
2930 Also takes an optional C<key> attribute, to search by a specific key or unique
2931 constraint. For example:
2933 my $cd = $schema->resultset('CD')->find_or_create(
2935 artist => 'Massive Attack',
2936 title => 'Mezzanine',
2938 { key => 'cd_artist_title' }
2941 B<Note>: Make sure to read the documentation of L</find> and understand the
2942 significance of the C<key> attribute, as its lack may skew your search, and
2943 subsequently result in spurious row creation.
2945 B<Note>: Because find_or_create() reads from the database and then
2946 possibly inserts based on the result, this method is subject to a race
2947 condition. Another process could create a record in the table after
2948 the find has completed and before the create has started. To avoid
2949 this problem, use find_or_create() inside a transaction.
2951 B<Note>: Take care when using C<find_or_create> with a table having
2952 columns with default values that you intend to be automatically
2953 supplied by the database (e.g. an auto_increment primary key column).
2954 In normal usage, the value of such columns should NOT be included at
2955 all in the call to C<find_or_create>, even when set to C<undef>.
2957 See also L</find> and L</update_or_create>. For information on how to declare
2958 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2960 If you need to know if an existing row was found or a new one created use
2961 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2962 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2965 my $cd = $schema->resultset('CD')->find_or_new({
2967 artist => 'Massive Attack',
2968 title => 'Mezzanine',
2972 if( !$cd->in_storage ) {
2979 sub find_or_create {
2981 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2982 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2983 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2986 return $self->new_result($hash)->insert;
2989 =head2 update_or_create
2993 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2995 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2999 $resultset->update_or_create({ col => $val, ... });
3001 Like L</find_or_create>, but if a row is found it is immediately updated via
3002 C<< $found_row->update (\%col_data) >>.
3005 Takes an optional C<key> attribute to search on a specific unique constraint.
3008 # In your application
3009 my $cd = $schema->resultset('CD')->update_or_create(
3011 artist => 'Massive Attack',
3012 title => 'Mezzanine',
3015 { key => 'cd_artist_title' }
3018 $cd->cd_to_producer->update_or_create({
3019 producer => $producer,
3025 B<Note>: Make sure to read the documentation of L</find> and understand the
3026 significance of the C<key> attribute, as its lack may skew your search, and
3027 subsequently result in spurious row creation.
3029 B<Note>: Take care when using C<update_or_create> with a table having
3030 columns with default values that you intend to be automatically
3031 supplied by the database (e.g. an auto_increment primary key column).
3032 In normal usage, the value of such columns should NOT be included at
3033 all in the call to C<update_or_create>, even when set to C<undef>.
3035 See also L</find> and L</find_or_create>. For information on how to declare
3036 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3038 If you need to know if an existing row was updated or a new one created use
3039 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3040 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3045 sub update_or_create {
3047 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3048 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3050 my $row = $self->find($cond, $attrs);
3052 $row->update($cond);
3056 return $self->new_result($cond)->insert;
3059 =head2 update_or_new
3063 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3065 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3069 $resultset->update_or_new({ col => $val, ... });
3071 Like L</find_or_new> but if a row is found it is immediately updated via
3072 C<< $found_row->update (\%col_data) >>.
3076 # In your application
3077 my $cd = $schema->resultset('CD')->update_or_new(
3079 artist => 'Massive Attack',
3080 title => 'Mezzanine',
3083 { key => 'cd_artist_title' }
3086 if ($cd->in_storage) {
3087 # the cd was updated
3090 # the cd is not yet in the database, let's insert it
3094 B<Note>: Make sure to read the documentation of L</find> and understand the
3095 significance of the C<key> attribute, as its lack may skew your search, and
3096 subsequently result in spurious new objects.
3098 B<Note>: Take care when using C<update_or_new> with a table having
3099 columns with default values that you intend to be automatically
3100 supplied by the database (e.g. an auto_increment primary key column).
3101 In normal usage, the value of such columns should NOT be included at
3102 all in the call to C<update_or_new>, even when set to C<undef>.
3104 See also L</find>, L</find_or_create> and L</find_or_new>.
3110 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3111 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3113 my $row = $self->find( $cond, $attrs );
3114 if ( defined $row ) {
3115 $row->update($cond);
3119 return $self->new_result($cond);
3126 =item Arguments: none
3128 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3132 Gets the contents of the cache for the resultset, if the cache is set.
3134 The cache is populated either by using the L</prefetch> attribute to
3135 L</search> or by calling L</set_cache>.
3147 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3149 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3153 Sets the contents of the cache for the resultset. Expects an arrayref
3154 of objects of the same class as those produced by the resultset. Note that
3155 if the cache is set, the resultset will return the cached objects rather
3156 than re-querying the database even if the cache attr is not set.
3158 The contents of the cache can also be populated by using the
3159 L</prefetch> attribute to L</search>.
3164 my ( $self, $data ) = @_;
3165 $self->throw_exception("set_cache requires an arrayref")
3166 if defined($data) && (ref $data ne 'ARRAY');
3167 $self->{all_cache} = $data;
3174 =item Arguments: none
3176 =item Return Value: undef
3180 Clears the cache for the resultset.
3185 shift->set_cache(undef);
3192 =item Arguments: none
3194 =item Return Value: true, if the resultset has been paginated
3202 return !!$self->{attrs}{page};
3209 =item Arguments: none
3211 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3219 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3222 =head2 related_resultset
3226 =item Arguments: $rel_name
3228 =item Return Value: L<$resultset|/search>
3232 Returns a related resultset for the supplied relationship name.
3234 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3238 sub related_resultset {
3239 my ($self, $rel) = @_;
3241 return $self->{related_resultsets}{$rel}
3242 if defined $self->{related_resultsets}{$rel};
3244 return $self->{related_resultsets}{$rel} = do {
3245 my $rsrc = $self->result_source;
3246 my $rel_info = $rsrc->relationship_info($rel);
3248 $self->throw_exception(
3249 "search_related: result source '" . $rsrc->source_name .
3250 "' has no such relationship $rel")
3253 my $attrs = $self->_chain_relationship($rel);
3255 my $join_count = $attrs->{seen_join}{$rel};
3257 my $alias = $self->result_source->storage
3258 ->relname_to_table_alias($rel, $join_count);
3260 # since this is search_related, and we already slid the select window inwards
3261 # (the select/as attrs were deleted in the beginning), we need to flip all
3262 # left joins to inner, so we get the expected results
3263 # read the comment on top of the actual function to see what this does
3264 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3267 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3268 delete @{$attrs}{qw(result_class alias)};
3270 my $rel_source = $rsrc->related_source($rel);
3274 # The reason we do this now instead of passing the alias to the
3275 # search_rs below is that if you wrap/overload resultset on the
3276 # source you need to know what alias it's -going- to have for things
3277 # to work sanely (e.g. RestrictWithObject wants to be able to add
3278 # extra query restrictions, and these may need to be $alias.)
3280 my $rel_attrs = $rel_source->resultset_attributes;
3281 local $rel_attrs->{alias} = $alias;
3283 $rel_source->resultset
3287 where => $attrs->{where},
3291 if (my $cache = $self->get_cache) {
3292 my @related_cache = map
3293 { $_->related_resultset($rel)->get_cache || () }
3297 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3304 =head2 current_source_alias
3308 =item Arguments: none
3310 =item Return Value: $source_alias
3314 Returns the current table alias for the result source this resultset is built
3315 on, that will be used in the SQL query. Usually it is C<me>.
3317 Currently the source alias that refers to the result set returned by a
3318 L</search>/L</find> family method depends on how you got to the resultset: it's
3319 C<me> by default, but eg. L</search_related> aliases it to the related result
3320 source name (and keeps C<me> referring to the original result set). The long
3321 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3322 (and make this method unnecessary).
3324 Thus it's currently necessary to use this method in predefined queries (see
3325 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3326 source alias of the current result set:
3328 # in a result set class
3330 my ($self, $user) = @_;
3332 my $me = $self->current_source_alias;
3334 return $self->search({
3335 "$me.modified" => $user->id,
3341 sub current_source_alias {
3342 return (shift->{attrs} || {})->{alias} || 'me';
3345 =head2 as_subselect_rs
3349 =item Arguments: none
3351 =item Return Value: L<$resultset|/search>
3355 Act as a barrier to SQL symbols. The resultset provided will be made into a
3356 "virtual view" by including it as a subquery within the from clause. From this
3357 point on, any joined tables are inaccessible to ->search on the resultset (as if
3358 it were simply where-filtered without joins). For example:
3360 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3362 # 'x' now pollutes the query namespace
3364 # So the following works as expected
3365 my $ok_rs = $rs->search({'x.other' => 1});
3367 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3368 # def) we look for one row with contradictory terms and join in another table
3369 # (aliased 'x_2') which we never use
3370 my $broken_rs = $rs->search({'x.name' => 'def'});
3372 my $rs2 = $rs->as_subselect_rs;
3374 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3375 my $not_joined_rs = $rs2->search({'x.other' => 1});
3377 # works as expected: finds a 'table' row related to two x rows (abc and def)
3378 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3380 Another example of when one might use this would be to select a subset of
3381 columns in a group by clause:
3383 my $rs = $schema->resultset('Bar')->search(undef, {
3384 group_by => [qw{ id foo_id baz_id }],
3385 })->as_subselect_rs->search(undef, {
3386 columns => [qw{ id foo_id }]
3389 In the above example normally columns would have to be equal to the group by,
3390 but because we isolated the group by into a subselect the above works.
3394 sub as_subselect_rs {
3397 my $attrs = $self->_resolved_attrs;
3399 my $fresh_rs = (ref $self)->new (
3400 $self->result_source
3403 # these pieces will be locked in the subquery
3404 delete $fresh_rs->{cond};
3405 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3407 return $fresh_rs->search( {}, {
3409 $attrs->{alias} => $self->as_query,
3410 -alias => $attrs->{alias},
3411 -rsrc => $self->result_source,
3413 alias => $attrs->{alias},
3417 # This code is called by search_related, and makes sure there
3418 # is clear separation between the joins before, during, and
3419 # after the relationship. This information is needed later
3420 # in order to properly resolve prefetch aliases (any alias
3421 # with a relation_chain_depth less than the depth of the
3422 # current prefetch is not considered)
3424 # The increments happen twice per join. An even number means a
3425 # relationship specified via a search_related, whereas an odd
3426 # number indicates a join/prefetch added via attributes
3428 # Also this code will wrap the current resultset (the one we
3429 # chain to) in a subselect IFF it contains limiting attributes
3430 sub _chain_relationship {
3431 my ($self, $rel) = @_;
3432 my $source = $self->result_source;
3433 my $attrs = { %{$self->{attrs}||{}} };
3435 # we need to take the prefetch the attrs into account before we
3436 # ->_resolve_join as otherwise they get lost - captainL
3437 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3439 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3441 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3444 my @force_subq_attrs = qw/offset rows group_by having/;
3447 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3449 $self->_has_resolved_attr (@force_subq_attrs)
3451 # Nuke the prefetch (if any) before the new $rs attrs
3452 # are resolved (prefetch is useless - we are wrapping
3453 # a subquery anyway).
3454 my $rs_copy = $self->search;
3455 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3456 $rs_copy->{attrs}{join},
3457 delete $rs_copy->{attrs}{prefetch},
3462 -alias => $attrs->{alias},
3463 $attrs->{alias} => $rs_copy->as_query,
3465 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3466 $seen->{-relation_chain_depth} = 0;
3468 elsif ($attrs->{from}) { #shallow copy suffices
3469 $from = [ @{$attrs->{from}} ];
3474 -alias => $attrs->{alias},
3475 $attrs->{alias} => $source->from,
3479 my $jpath = ($seen->{-relation_chain_depth})
3480 ? $from->[-1][0]{-join_path}
3483 my @requested_joins = $source->_resolve_join(
3490 push @$from, @requested_joins;
3492 $seen->{-relation_chain_depth}++;
3494 # if $self already had a join/prefetch specified on it, the requested
3495 # $rel might very well be already included. What we do in this case
3496 # is effectively a no-op (except that we bump up the chain_depth on
3497 # the join in question so we could tell it *is* the search_related)
3500 # we consider the last one thus reverse
3501 for my $j (reverse @requested_joins) {
3502 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3503 if ($rel eq $last_j) {
3504 $j->[0]{-relation_chain_depth}++;
3510 unless ($already_joined) {
3511 push @$from, $source->_resolve_join(
3519 $seen->{-relation_chain_depth}++;
3521 return {%$attrs, from => $from, seen_join => $seen};
3524 sub _resolved_attrs {
3526 return $self->{_attrs} if $self->{_attrs};
3528 my $attrs = { %{ $self->{attrs} || {} } };
3529 my $source = $attrs->{result_source} = $self->result_source;
3530 my $alias = $attrs->{alias};
3532 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3533 if $attrs->{collapse} and $attrs->{distinct};
3535 # default selection list
3536 $attrs->{columns} = [ $source->columns ]
3537 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3539 # merge selectors together
3540 for (qw/columns select as/) {
3541 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3542 if $attrs->{$_} or $attrs->{"+$_"};
3545 # disassemble columns
3547 if (my $cols = delete $attrs->{columns}) {
3548 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3549 if (ref $c eq 'HASH') {
3550 for my $as (sort keys %$c) {
3551 push @sel, $c->{$as};
3562 # when trying to weed off duplicates later do not go past this point -
3563 # everything added from here on is unbalanced "anyone's guess" stuff
3564 my $dedup_stop_idx = $#as;
3566 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3568 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3569 if $attrs->{select};
3571 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3572 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3574 # disqualify all $alias.col as-bits (inflate-map mandated)
3575 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3577 # de-duplicate the result (remove *identical* select/as pairs)
3578 # and also die on duplicate {as} pointing to different {select}s
3579 # not using a c-style for as the condition is prone to shrinkage
3582 while ($i <= $dedup_stop_idx) {
3583 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3588 elsif ($seen->{$as[$i]}++) {
3589 $self->throw_exception(
3590 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3598 $attrs->{select} = \@sel;
3599 $attrs->{as} = \@as;
3601 $attrs->{from} ||= [{
3603 -alias => $self->{attrs}{alias},
3604 $self->{attrs}{alias} => $source->from,
3607 if ( $attrs->{join} || $attrs->{prefetch} ) {
3609 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3610 if ref $attrs->{from} ne 'ARRAY';
3612 my $join = (delete $attrs->{join}) || {};
3614 if ( defined $attrs->{prefetch} ) {
3615 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3618 $attrs->{from} = # have to copy here to avoid corrupting the original
3620 @{ $attrs->{from} },
3621 $source->_resolve_join(
3624 { %{ $attrs->{seen_join} || {} } },
3625 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3626 ? $attrs->{from}[-1][0]{-join_path}
3633 if ( defined $attrs->{order_by} ) {
3634 $attrs->{order_by} = (
3635 ref( $attrs->{order_by} ) eq 'ARRAY'
3636 ? [ @{ $attrs->{order_by} } ]
3637 : [ $attrs->{order_by} || () ]
3641 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3642 $attrs->{group_by} = [ $attrs->{group_by} ];
3646 # generate selections based on the prefetch helper
3647 my ($prefetch, @prefetch_select, @prefetch_as);
3648 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3649 if defined $attrs->{prefetch};
3653 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3654 if $attrs->{_dark_selector};
3656 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3657 if defined $attrs->{collapse} and ! $attrs->{collapse};
3659 $attrs->{collapse} = 1;
3661 # this is a separate structure (we don't look in {from} directly)
3662 # as the resolver needs to shift things off the lists to work
3663 # properly (identical-prefetches on different branches)
3665 if (ref $attrs->{from} eq 'ARRAY') {
3667 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3669 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3670 next unless $j->[0]{-alias};
3671 next unless $j->[0]{-join_path};
3672 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3674 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3677 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3678 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3682 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3684 # save these for after distinct resolution
3685 @prefetch_select = map { $_->[0] } @prefetch;
3686 @prefetch_as = map { $_->[1] } @prefetch;
3689 # run through the resulting joinstructure (starting from our current slot)
3690 # and unset collapse if proven unnecessary
3692 # also while we are at it find out if the current root source has
3693 # been premultiplied by previous related_source chaining
3695 # this allows to predict whether a root object with all other relation
3696 # data set to NULL is in fact unique
3697 if ($attrs->{collapse}) {
3699 if (ref $attrs->{from} eq 'ARRAY') {
3701 if (@{$attrs->{from}} == 1) {
3702 # no joins - no collapse
3703 $attrs->{collapse} = 0;
3706 # find where our table-spec starts
3707 my @fromlist = @{$attrs->{from}};
3709 my $t = shift @fromlist;
3712 # me vs join from-spec distinction - a ref means non-root
3713 if (ref $t eq 'ARRAY') {
3715 $is_multi ||= ! $t->{-is_single};
3717 last if ($t->{-alias} && $t->{-alias} eq $alias);
3718 $attrs->{_main_source_premultiplied} ||= $is_multi;
3721 # no non-singles remaining, nor any premultiplication - nothing to collapse
3723 ! $attrs->{_main_source_premultiplied}
3725 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3727 $attrs->{collapse} = 0;
3733 # if we can not analyze the from - err on the side of safety
3734 $attrs->{_main_source_premultiplied} = 1;
3738 # generate the distinct induced group_by before injecting the prefetched select/as parts
3739 if (delete $attrs->{distinct}) {
3740 if ($attrs->{group_by}) {
3741 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3744 $attrs->{_grouped_by_distinct} = 1;
3745 # distinct affects only the main selection part, not what prefetch may add below
3746 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3748 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3749 # The thinking is: if we are collapsing the subquerying prefetch engine will
3750 # rip stuff apart for us anyway, and we do not want to have a potentially
3751 # function-converted external order_by
3752 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3753 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3757 # inject prefetch-bound selection (if any)
3758 push @{$attrs->{select}}, @prefetch_select;
3759 push @{$attrs->{as}}, @prefetch_as;
3761 $attrs->{_simple_passthrough_construction} = !(
3764 grep { $_ =~ /\./ } @{$attrs->{as}}
3767 # if both page and offset are specified, produce a combined offset
3768 # even though it doesn't make much sense, this is what pre 081xx has
3770 if (my $page = delete $attrs->{page}) {
3772 ($attrs->{rows} * ($page - 1))
3774 ($attrs->{offset} || 0)
3778 return $self->{_attrs} = $attrs;
3782 my ($self, $attr) = @_;
3784 if (ref $attr eq 'HASH') {
3785 return $self->_rollout_hash($attr);
3786 } elsif (ref $attr eq 'ARRAY') {
3787 return $self->_rollout_array($attr);
3793 sub _rollout_array {
3794 my ($self, $attr) = @_;
3797 foreach my $element (@{$attr}) {
3798 if (ref $element eq 'HASH') {
3799 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3800 } elsif (ref $element eq 'ARRAY') {
3801 # XXX - should probably recurse here
3802 push( @rolled_array, @{$self->_rollout_array($element)} );
3804 push( @rolled_array, $element );
3807 return \@rolled_array;
3811 my ($self, $attr) = @_;
3814 foreach my $key (keys %{$attr}) {
3815 push( @rolled_array, { $key => $attr->{$key} } );
3817 return \@rolled_array;
3820 sub _calculate_score {
3821 my ($self, $a, $b) = @_;
3823 if (defined $a xor defined $b) {
3826 elsif (not defined $a) {
3830 if (ref $b eq 'HASH') {
3831 my ($b_key) = keys %{$b};
3832 if (ref $a eq 'HASH') {
3833 my ($a_key) = keys %{$a};
3834 if ($a_key eq $b_key) {
3835 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3840 return ($a eq $b_key) ? 1 : 0;
3843 if (ref $a eq 'HASH') {
3844 my ($a_key) = keys %{$a};
3845 return ($b eq $a_key) ? 1 : 0;
3847 return ($b eq $a) ? 1 : 0;
3852 sub _merge_joinpref_attr {
3853 my ($self, $orig, $import) = @_;
3855 return $import unless defined($orig);
3856 return $orig unless defined($import);
3858 $orig = $self->_rollout_attr($orig);
3859 $import = $self->_rollout_attr($import);
3862 foreach my $import_element ( @{$import} ) {
3863 # find best candidate from $orig to merge $b_element into
3864 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3865 foreach my $orig_element ( @{$orig} ) {
3866 my $score = $self->_calculate_score( $orig_element, $import_element );
3867 if ($score > $best_candidate->{score}) {
3868 $best_candidate->{position} = $position;
3869 $best_candidate->{score} = $score;
3873 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3874 $import_key = '' if not defined $import_key;
3876 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3877 push( @{$orig}, $import_element );
3879 my $orig_best = $orig->[$best_candidate->{position}];
3880 # merge orig_best and b_element together and replace original with merged
3881 if (ref $orig_best ne 'HASH') {
3882 $orig->[$best_candidate->{position}] = $import_element;
3883 } elsif (ref $import_element eq 'HASH') {
3884 my ($key) = keys %{$orig_best};
3885 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3888 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3891 return @$orig ? $orig : ();
3899 require Hash::Merge;
3900 my $hm = Hash::Merge->new;
3902 $hm->specify_behavior({
3905 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3907 if ($defl xor $defr) {
3908 return [ $defl ? $_[0] : $_[1] ];
3913 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3917 return [$_[0], $_[1]];
3921 return $_[1] if !defined $_[0];
3922 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3923 return [$_[0], @{$_[1]}]
3926 return [] if !defined $_[0] and !keys %{$_[1]};
3927 return [ $_[1] ] if !defined $_[0];
3928 return [ $_[0] ] if !keys %{$_[1]};
3929 return [$_[0], $_[1]]
3934 return $_[0] if !defined $_[1];
3935 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3936 return [@{$_[0]}, $_[1]]
3939 my @ret = @{$_[0]} or return $_[1];
3940 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3941 my %idx = map { $_ => 1 } @ret;
3942 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3946 return [ $_[1] ] if ! @{$_[0]};
3947 return $_[0] if !keys %{$_[1]};
3948 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3949 return [ @{$_[0]}, $_[1] ];
3954 return [] if !keys %{$_[0]} and !defined $_[1];
3955 return [ $_[0] ] if !defined $_[1];
3956 return [ $_[1] ] if !keys %{$_[0]};
3957 return [$_[0], $_[1]]
3960 return [] if !keys %{$_[0]} and !@{$_[1]};
3961 return [ $_[0] ] if !@{$_[1]};
3962 return $_[1] if !keys %{$_[0]};
3963 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3964 return [ $_[0], @{$_[1]} ];
3967 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3968 return [ $_[0] ] if !keys %{$_[1]};
3969 return [ $_[1] ] if !keys %{$_[0]};
3970 return [ $_[0] ] if $_[0] eq $_[1];
3971 return [ $_[0], $_[1] ];
3974 } => 'DBIC_RS_ATTR_MERGER');
3978 return $hm->merge ($_[1], $_[2]);
3982 sub STORABLE_freeze {
3983 my ($self, $cloning) = @_;
3984 my $to_serialize = { %$self };
3986 # A cursor in progress can't be serialized (and would make little sense anyway)
3987 # the parser can be regenerated (and can't be serialized)
3988 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3990 # nor is it sensical to store a not-yet-fired-count pager
3991 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3992 delete $to_serialize->{pager};
3995 Storable::nfreeze($to_serialize);
3998 # need this hook for symmetry
4000 my ($self, $cloning, $serialized) = @_;
4002 %$self = %{ Storable::thaw($serialized) };
4008 =head2 throw_exception
4010 See L<DBIx::Class::Schema/throw_exception> for details.
4014 sub throw_exception {
4017 if (ref $self and my $rsrc = $self->result_source) {
4018 $rsrc->throw_exception(@_)
4021 DBIx::Class::Exception->throw(@_);
4029 # XXX: FIXME: Attributes docs need clearing up
4033 Attributes are used to refine a ResultSet in various ways when
4034 searching for data. They can be passed to any method which takes an
4035 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4038 Default attributes can be set on the result class using
4039 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4040 the CAVEATS on that feature before using it!)
4042 These are in no particular order:
4048 =item Value: ( $order_by | \@order_by | \%order_by )
4052 Which column(s) to order the results by.
4054 [The full list of suitable values is documented in
4055 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4058 If a single column name, or an arrayref of names is supplied, the
4059 argument is passed through directly to SQL. The hashref syntax allows
4060 for connection-agnostic specification of ordering direction:
4062 For descending order:
4064 order_by => { -desc => [qw/col1 col2 col3/] }
4066 For explicit ascending order:
4068 order_by => { -asc => 'col' }
4070 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4071 supported, although you are strongly encouraged to use the hashref
4072 syntax as outlined above.
4078 =item Value: \@columns | \%columns | $column
4082 Shortcut to request a particular set of columns to be retrieved. Each
4083 column spec may be a string (a table column name), or a hash (in which
4084 case the key is the C<as> value, and the value is used as the C<select>
4085 expression). Adds the L</current_source_alias> onto the start of any column without a C<.> in
4086 it and sets C<select> from that, then auto-populates C<as> from
4087 C<select> as normal. (You may also use the C<cols> attribute, as in
4088 earlier versions of DBIC, but this is deprecated)
4090 Essentially C<columns> does the same as L</select> and L</as>.
4092 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
4096 select => [qw(some_column another_column)],
4097 as => [qw(some_column dbic_slot)]
4099 If you want to individually retrieve related columns (in essence perform
4100 manual prefetch) you have to make sure to specify the correct inflation slot
4101 chain such that it matches existing relationships:
4103 my $rs = $schema->resultset('Artist')->search({}, {
4104 # required to tell DBIC to collapse has_many relationships
4106 join => { cds => 'tracks'},
4108 'cds.cdid' => 'cds.cdid',
4109 'cds.tracks.title' => 'tracks.title',
4115 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
4116 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
4117 with a unary plus operator before it, which is the same as simply C<columns>.
4121 =item Value: \@extra_columns
4125 Indicates additional columns to be selected from storage. Works the same as
4126 L</columns> but adds columns to the current selection. (You may also use the
4127 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4130 $schema->resultset('CD')->search(undef, {
4131 '+columns' => ['artist.name'],
4135 would return all CDs and include a 'name' column to the information
4136 passed to object inflation. Note that the 'artist' is the name of the
4137 column (or relationship) accessor, and 'name' is the name of the column
4138 accessor in the related table.
4144 =item Value: \@select_columns
4148 Indicates which columns should be selected from the storage. You can use
4149 column names, or in the case of RDBMS back ends, function or stored procedure
4152 $rs = $schema->resultset('Employee')->search(undef, {
4155 { count => 'employeeid' },
4156 { max => { length => 'name' }, -as => 'longest_name' }
4161 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4163 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4164 use L</select>, to instruct DBIx::Class how to store the result of the column.
4165 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4166 identifier aliasing. You can however alias a function, so you can use it in
4167 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4168 attribute> supplied as shown in the example above.
4172 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4173 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4174 with a unary plus operator before it, which is the same as simply C<select>.
4178 =item Value: \@extra_select_columns
4182 Indicates additional columns to be selected from storage. Works the same as
4183 L</select> but adds columns to the current selection, instead of specifying
4184 a new explicit list.
4190 =item Value: \@inflation_names
4194 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4195 slot name in which the column value will be stored within the
4196 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4197 identifier by the C<get_column> method (or via the object accessor B<if one
4198 with the same name already exists>) as shown below. The L</as> attribute has
4199 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4201 $rs = $schema->resultset('Employee')->search(undef, {
4204 { count => 'employeeid' },
4205 { max => { length => 'name' }, -as => 'longest_name' }
4214 If the object against which the search is performed already has an accessor
4215 matching a column name specified in C<as>, the value can be retrieved using
4216 the accessor as normal:
4218 my $name = $employee->name();
4220 If on the other hand an accessor does not exist in the object, you need to
4221 use C<get_column> instead:
4223 my $employee_count = $employee->get_column('employee_count');
4225 You can create your own accessors if required - see
4226 L<DBIx::Class::Manual::Cookbook> for details.
4230 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4231 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4232 with a unary plus operator before it, which is the same as simply C<as>.
4236 =item Value: \@extra_inflation_names
4240 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4246 =item Value: ($rel_name | \@rel_names | \%rel_names)
4250 Contains a list of relationships that should be joined for this query. For
4253 # Get CDs by Nine Inch Nails
4254 my $rs = $schema->resultset('CD')->search(
4255 { 'artist.name' => 'Nine Inch Nails' },
4256 { join => 'artist' }
4259 Can also contain a hash reference to refer to the other relation's relations.
4262 package MyApp::Schema::Track;
4263 use base qw/DBIx::Class/;
4264 __PACKAGE__->table('track');
4265 __PACKAGE__->add_columns(qw/trackid cd position title/);
4266 __PACKAGE__->set_primary_key('trackid');
4267 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4270 # In your application
4271 my $rs = $schema->resultset('Artist')->search(
4272 { 'track.title' => 'Teardrop' },
4274 join => { cd => 'track' },
4275 order_by => 'artist.name',
4279 You need to use the relationship (not the table) name in conditions,
4280 because they are aliased as such. The current table is aliased as "me", so
4281 you need to use me.column_name in order to avoid ambiguity. For example:
4283 # Get CDs from 1984 with a 'Foo' track
4284 my $rs = $schema->resultset('CD')->search(
4287 'tracks.name' => 'Foo'
4289 { join => 'tracks' }
4292 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4293 similarly for a third time). For e.g.
4295 my $rs = $schema->resultset('Artist')->search({
4296 'cds.title' => 'Down to Earth',
4297 'cds_2.title' => 'Popular',
4299 join => [ qw/cds cds/ ],
4302 will return a set of all artists that have both a cd with title 'Down
4303 to Earth' and a cd with title 'Popular'.
4305 If you want to fetch related objects from other tables as well, see L</prefetch>
4308 NOTE: An internal join-chain pruner will discard certain joins while
4309 constructing the actual SQL query, as long as the joins in question do not
4310 affect the retrieved result. This for example includes 1:1 left joins
4311 that are not part of the restriction specification (WHERE/HAVING) nor are
4312 a part of the query selection.
4314 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4320 =item Value: (0 | 1)
4324 When set to a true value, indicates that any rows fetched from joined has_many
4325 relationships are to be aggregated into the corresponding "parent" object. For
4326 example, the resultset:
4328 my $rs = $schema->resultset('CD')->search({}, {
4329 '+columns' => [ qw/ tracks.title tracks.position / ],
4334 While executing the following query:
4336 SELECT me.*, tracks.title, tracks.position
4338 LEFT JOIN track tracks
4339 ON tracks.cdid = me.cdid
4341 Will return only as many objects as there are rows in the CD source, even
4342 though the result of the query may span many rows. Each of these CD objects
4343 will in turn have multiple "Track" objects hidden behind the has_many
4344 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4345 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4346 product"), with each CD object containing exactly one of all fetched Track data.
4348 When a collapse is requested on a non-ordered resultset, an order by some
4349 unique part of the main source (the left-most table) is inserted automatically.
4350 This is done so that the resultset is allowed to be "lazy" - calling
4351 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4352 object with all of its related data.
4354 If an L</order_by> is already declared, and orders the resultset in a way that
4355 makes collapsing as described above impossible (e.g. C<< ORDER BY
4356 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4357 switch to "eager" mode and slurp the entire resultset before constructing the
4358 first object returned by L</next>.
4360 Setting this attribute on a resultset that does not join any has_many
4361 relations is a no-op.
4363 For a more in-depth discussion, see L</PREFETCHING>.
4369 =item Value: ($rel_name | \@rel_names | \%rel_names)
4373 This attribute is a shorthand for specifying a L</join> spec, adding all
4374 columns from the joined related sources as L</+columns> and setting
4375 L</collapse> to a true value. For example, the following two queries are
4378 my $rs = $schema->resultset('Artist')->search({}, {
4379 prefetch => { cds => ['genre', 'tracks' ] },
4384 my $rs = $schema->resultset('Artist')->search({}, {
4385 join => { cds => ['genre', 'tracks' ] },
4389 { +{ "cds.$_" => "cds.$_" } }
4390 $schema->source('Artist')->related_source('cds')->columns
4393 { +{ "cds.genre.$_" => "genre.$_" } }
4394 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4397 { +{ "cds.tracks.$_" => "tracks.$_" } }
4398 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4403 Both producing the following SQL:
4405 SELECT me.artistid, me.name, me.rank, me.charfield,
4406 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4407 genre.genreid, genre.name,
4408 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4411 ON cds.artist = me.artistid
4412 LEFT JOIN genre genre
4413 ON genre.genreid = cds.genreid
4414 LEFT JOIN track tracks
4415 ON tracks.cd = cds.cdid
4416 ORDER BY me.artistid
4418 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4419 the arguments are properly merged and generally do the right thing. For
4420 example, you may want to do the following:
4422 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4423 { 'genre.genreid' => undef },
4425 join => { cds => 'genre' },
4430 Which generates the following SQL:
4432 SELECT me.artistid, me.name, me.rank, me.charfield,
4433 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4436 ON cds.artist = me.artistid
4437 LEFT JOIN genre genre
4438 ON genre.genreid = cds.genreid
4439 WHERE genre.genreid IS NULL
4440 ORDER BY me.artistid
4442 For a more in-depth discussion, see L</PREFETCHING>.
4448 =item Value: $source_alias
4452 Sets the source alias for the query. Normally, this defaults to C<me>, but
4453 nested search queries (sub-SELECTs) might need specific aliases set to
4454 reference inner queries. For example:
4457 ->related_resultset('CDs')
4458 ->related_resultset('Tracks')
4460 'track.id' => { -ident => 'none_search.id' },
4464 my $ids = $self->search({
4467 alias => 'none_search',
4468 group_by => 'none_search.id',
4469 })->get_column('id')->as_query;
4471 $self->search({ id => { -in => $ids } })
4473 This attribute is directly tied to L</current_source_alias>.
4483 Makes the resultset paged and specifies the page to retrieve. Effectively
4484 identical to creating a non-pages resultset and then calling ->page($page)
4487 If L</rows> attribute is not specified it defaults to 10 rows per page.
4489 When you have a paged resultset, L</count> will only return the number
4490 of rows in the page. To get the total, use the L</pager> and call
4491 C<total_entries> on it.
4501 Specifies the maximum number of rows for direct retrieval or the number of
4502 rows per page if the page attribute or method is used.
4508 =item Value: $offset
4512 Specifies the (zero-based) row number for the first row to be returned, or the
4513 of the first row of the first page if paging is used.
4515 =head2 software_limit
4519 =item Value: (0 | 1)
4523 When combined with L</rows> and/or L</offset> the generated SQL will not
4524 include any limit dialect stanzas. Instead the entire result will be selected
4525 as if no limits were specified, and DBIC will perform the limit locally, by
4526 artificially advancing and finishing the resulting L</cursor>.
4528 This is the recommended way of performing resultset limiting when no sane RDBMS
4529 implementation is available (e.g.
4530 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4531 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4537 =item Value: \@columns
4541 A arrayref of columns to group by. Can include columns of joined tables.
4543 group_by => [qw/ column1 column2 ... /]
4549 =item Value: $condition
4553 HAVING is a select statement attribute that is applied between GROUP BY and
4554 ORDER BY. It is applied to the after the grouping calculations have been
4557 having => { 'count_employee' => { '>=', 100 } }
4559 or with an in-place function in which case literal SQL is required:
4561 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4567 =item Value: (0 | 1)
4571 Set to 1 to automatically generate a L</group_by> clause based on the selection
4572 (including intelligent handling of L</order_by> contents). Note that the group
4573 criteria calculation takes place over the B<final> selection. This includes
4574 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4575 L</search> calls, and standalone columns selected via
4576 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4577 extra selections specified via L</prefetch> - such selections are explicitly
4578 excluded from group criteria calculations.
4580 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4581 setting is ignored and an appropriate warning is issued.
4587 Adds to the WHERE clause.
4589 # only return rows WHERE deleted IS NULL for all searches
4590 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4592 Can be overridden by passing C<< { where => undef } >> as an attribute
4595 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4601 Set to 1 to cache search results. This prevents extra SQL queries if you
4602 revisit rows in your ResultSet:
4604 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4606 while( my $artist = $resultset->next ) {
4610 $rs->first; # without cache, this would issue a query
4612 By default, searches are not cached.
4614 For more examples of using these attributes, see
4615 L<DBIx::Class::Manual::Cookbook>.
4621 =item Value: ( 'update' | 'shared' | \$scalar )
4625 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4626 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4631 DBIx::Class supports arbitrary related data prefetching from multiple related
4632 sources. Any combination of relationship types and column sets are supported.
4633 If L<collapsing|/collapse> is requested, there is an additional requirement of
4634 selecting enough data to make every individual object uniquely identifiable.
4636 Here are some more involved examples, based on the following relationship map:
4639 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4640 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4641 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4643 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4645 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4649 my $rs = $schema->resultset('Tag')->search(
4658 The initial search results in SQL like the following:
4660 SELECT tag.*, cd.*, artist.* FROM tag
4661 JOIN cd ON tag.cd = cd.cdid
4662 JOIN artist ON cd.artist = artist.artistid
4664 L<DBIx::Class> has no need to go back to the database when we access the
4665 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4668 Simple prefetches will be joined automatically, so there is no need
4669 for a C<join> attribute in the above search.
4671 The L</prefetch> attribute can be used with any of the relationship types
4672 and multiple prefetches can be specified together. Below is a more complex
4673 example that prefetches a CD's artist, its liner notes (if present),
4674 the cover image, the tracks on that CD, and the guests on those
4677 my $rs = $schema->resultset('CD')->search(
4681 { artist => 'record_label'}, # belongs_to => belongs_to
4682 'liner_note', # might_have
4683 'cover_image', # has_one
4684 { tracks => 'guests' }, # has_many => has_many
4689 This will produce SQL like the following:
4691 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4695 ON artist.artistid = me.artistid
4696 JOIN record_label record_label
4697 ON record_label.labelid = artist.labelid
4698 LEFT JOIN track tracks
4699 ON tracks.cdid = me.cdid
4700 LEFT JOIN guest guests
4701 ON guests.trackid = track.trackid
4702 LEFT JOIN liner_notes liner_note
4703 ON liner_note.cdid = me.cdid
4704 JOIN cd_artwork cover_image
4705 ON cover_image.cdid = me.cdid
4708 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4709 C<tracks>, and C<guests> of the CD will all be available through the
4710 relationship accessors without the need for additional queries to the
4715 Prefetch does a lot of deep magic. As such, it may not behave exactly
4716 as you might expect.
4722 Prefetch uses the L</cache> to populate the prefetched relationships. This
4723 may or may not be what you want.
4727 If you specify a condition on a prefetched relationship, ONLY those
4728 rows that match the prefetched condition will be fetched into that relationship.
4729 This means that adding prefetch to a search() B<may alter> what is returned by
4730 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4732 my $artist_rs = $schema->resultset('Artist')->search({
4738 my $count = $artist_rs->first->cds->count;
4740 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4742 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4744 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4746 That cmp_ok() may or may not pass depending on the datasets involved. In other
4747 words the C<WHERE> condition would apply to the entire dataset, just like
4748 it would in regular SQL. If you want to add a condition only to the "right side"
4749 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4750 condition|DBIx::Class::Relationship::Base/condition>
4754 =head1 DBIC BIND VALUES
4756 Because DBIC may need more information to bind values than just the column name
4757 and value itself, it uses a special format for both passing and receiving bind
4758 values. Each bind value should be composed of an arrayref of
4759 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4765 If present (in any form), this is what is being passed directly to bind_param.
4766 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4767 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4769 If this is specified, all other bind options described below are ignored.
4773 If present, this is used to infer the actual bind attribute by passing to
4774 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4775 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4777 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4778 currently drivers are expected to "Do the Right Thing" when given a common
4779 datatype name. (Not ideal, but that's what we got at this point.)
4783 Currently used to correctly allocate buffers for bind_param_inout().
4784 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4785 or to a sensible value based on the "data_type".
4789 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4790 explicitly specified they are never overridden). Also used by some weird DBDs,
4791 where the column name should be available at bind_param time (e.g. Oracle).
4795 For backwards compatibility and convenience, the following shortcuts are
4798 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4799 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4800 [ undef, $val ] === [ {}, $val ]
4801 $val === [ {}, $val ]
4803 =head1 AUTHOR AND CONTRIBUTORS
4805 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4809 You may distribute this code under the same terms as Perl itself.