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 == @_;
824 @{$call_cond}{@c_cols} = @_;
827 # process relationship data if any
828 for my $key (keys %$call_cond) {
830 length ref($call_cond->{$key})
832 my $relinfo = $rsrc->relationship_info($key)
834 # implicitly skip has_many's (likely MC)
835 (ref (my $val = delete $call_cond->{$key}) ne 'ARRAY' )
837 my ($rel_cond, $crosstable) = $rsrc->_resolve_condition(
838 $relinfo->{cond}, $val, $key, $key
841 $self->throw_exception("Complex condition via relationship '$key' is unsupported in find()")
842 if $crosstable or ref($rel_cond) ne 'HASH';
844 # supplement condition
845 # relationship conditions take precedence (?)
846 @{$call_cond}{keys %$rel_cond} = values %$rel_cond;
850 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
852 if (defined $constraint_name) {
853 $final_cond = $self->_qualify_cond_columns (
855 $self->result_source->_minimal_valueset_satisfying_constraint(
856 constraint_name => $constraint_name,
857 values => ($self->_merge_with_rscond($call_cond))[0],
864 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
865 # This means that we got here after a merger of relationship conditions
866 # in ::Relationship::Base::search_related (the row method), and furthermore
867 # the relationship is of the 'single' type. This means that the condition
868 # provided by the relationship (already attached to $self) is sufficient,
869 # as there can be only one row in the database that would satisfy the
873 my (@unique_queries, %seen_column_combinations);
875 # no key was specified - fall down to heuristics mode:
876 # run through all unique queries registered on the resultset, and
877 # 'OR' all qualifying queries together
879 # always start from 'primary' if it exists at all
880 for my $c_name ( sort {
882 : $b eq 'primary' ? 1
884 } $rsrc->unique_constraint_names) {
886 next if $seen_column_combinations{
887 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
890 push @unique_queries, try {
891 $self->result_source->_minimal_valueset_satisfying_constraint(
892 constraint_name => $c_name,
893 values => ($self->_merge_with_rscond($call_cond))[0],
898 $final_cond = @unique_queries
899 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
900 : $self->_non_unique_find_fallback ($call_cond, $attrs)
904 # Run the query, passing the result_class since it should propagate for find
905 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
906 if ($rs->_resolved_attrs->{collapse}) {
908 carp "Query returned more than one row" if $rs->next;
916 # This is a stop-gap method as agreed during the discussion on find() cleanup:
917 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
919 # It is invoked when find() is called in legacy-mode with insufficiently-unique
920 # condition. It is provided for overrides until a saner way forward is devised
922 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
923 # the road. Please adjust your tests accordingly to catch this situation early
924 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
926 # The method will not be removed without an adequately complete replacement
927 # for strict-mode enforcement
928 sub _non_unique_find_fallback {
929 my ($self, $cond, $attrs) = @_;
931 return $self->_qualify_cond_columns(
933 exists $attrs->{alias}
935 : $self->{attrs}{alias}
940 sub _qualify_cond_columns {
941 my ($self, $cond, $alias) = @_;
943 my %aliased = %$cond;
944 for (keys %aliased) {
945 $aliased{"$alias.$_"} = delete $aliased{$_}
952 sub _build_unique_cond {
954 '_build_unique_cond is a private method, and moreover is about to go '
955 . 'away. Please contact the development team at %s if you believe you '
956 . 'have a genuine use for this method, in order to discuss alternatives.',
957 DBIx::Class::_ENV_::HELP_URL,
960 my ($self, $constraint_name, $cond, $croak_on_null) = @_;
962 $self->result_source->_minimal_valueset_satisfying_constraint(
963 constraint_name => $constraint_name,
965 carp_on_nulls => !$croak_on_null
969 =head2 search_related
973 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
975 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
979 $new_rs = $cd_rs->search_related('artist', {
983 Searches the specified relationship, optionally specifying a condition and
984 attributes for matching records. See L</ATTRIBUTES> for more information.
986 In list context, C<< ->all() >> is called implicitly on the resultset, thus
987 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
989 See also L</search_related_rs>.
994 return shift->related_resultset(shift)->search(@_);
997 =head2 search_related_rs
999 This method works exactly the same as search_related, except that
1000 it guarantees a resultset, even in list context.
1004 sub search_related_rs {
1005 return shift->related_resultset(shift)->search_rs(@_);
1012 =item Arguments: none
1014 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1018 Returns a storage-driven cursor to the given resultset. See
1019 L<DBIx::Class::Cursor> for more information.
1026 return $self->{cursor} ||= do {
1027 my $attrs = $self->_resolved_attrs;
1028 $self->result_source->storage->select(
1029 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1038 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1040 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1044 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1046 Inflates the first result without creating a cursor if the resultset has
1047 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1050 While this method can take an optional search condition (just like L</search>)
1051 being a fast-code-path it does not recognize search attributes. If you need to
1052 add extra joins or similar, call L</search> and then chain-call L</single> on the
1053 L<DBIx::Class::ResultSet> returned.
1059 As of 0.08100, this method enforces the assumption that the preceding
1060 query returns only one row. If more than one row is returned, you will receive
1063 Query returned more than one row
1065 In this case, you should be using L</next> or L</find> instead, or if you really
1066 know what you are doing, use the L</rows> attribute to explicitly limit the size
1069 This method will also throw an exception if it is called on a resultset prefetching
1070 has_many, as such a prefetch implies fetching multiple rows from the database in
1071 order to assemble the resulting object.
1078 my ($self, $where) = @_;
1080 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1083 my $attrs = { %{$self->_resolved_attrs} };
1085 $self->throw_exception(
1086 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1087 ) if $attrs->{collapse};
1090 if (defined $attrs->{where}) {
1093 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1094 $where, delete $attrs->{where} ]
1097 $attrs->{where} = $where;
1101 my $data = [ $self->result_source->storage->select_single(
1102 $attrs->{from}, $attrs->{select},
1103 $attrs->{where}, $attrs
1106 return undef unless @$data;
1107 $self->{_stashed_rows} = [ $data ];
1108 $self->_construct_results->[0];
1115 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1117 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1121 my $max_length = $rs->get_column('length')->max;
1123 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1128 my ($self, $column) = @_;
1129 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1137 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1139 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1143 # WHERE title LIKE '%blue%'
1144 $cd_rs = $rs->search_like({ title => '%blue%'});
1146 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1147 that this is simply a convenience method retained for ex Class::DBI users.
1148 You most likely want to use L</search> with specific operators.
1150 For more information, see L<DBIx::Class::Manual::Cookbook>.
1152 This method is deprecated and will be removed in 0.09. Use L</search()>
1153 instead. An example conversion is:
1155 ->search_like({ foo => 'bar' });
1159 ->search({ foo => { like => 'bar' } });
1166 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1167 .' Instead use ->search({ x => { -like => "y%" } })'
1168 .' (note the outer pair of {}s - they are important!)'
1170 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1171 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1172 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1173 return $class->search($query, { %$attrs });
1180 =item Arguments: $first, $last
1182 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1186 Returns a resultset or object list representing a subset of elements from the
1187 resultset slice is called on. Indexes are from 0, i.e., to get the first
1188 three records, call:
1190 my ($one, $two, $three) = $rs->slice(0, 2);
1195 my ($self, $min, $max) = @_;
1196 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1197 $attrs->{offset} = $self->{attrs}{offset} || 0;
1198 $attrs->{offset} += $min;
1199 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1200 return $self->search(undef, $attrs);
1207 =item Arguments: none
1209 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1213 Returns the next element in the resultset (C<undef> is there is none).
1215 Can be used to efficiently iterate over records in the resultset:
1217 my $rs = $schema->resultset('CD')->search;
1218 while (my $cd = $rs->next) {
1222 Note that you need to store the resultset object, and call C<next> on it.
1223 Calling C<< resultset('Table')->next >> repeatedly will always return the
1224 first record from the resultset.
1231 if (my $cache = $self->get_cache) {
1232 $self->{all_cache_position} ||= 0;
1233 return $cache->[$self->{all_cache_position}++];
1236 if ($self->{attrs}{cache}) {
1237 delete $self->{pager};
1238 $self->{all_cache_position} = 1;
1239 return ($self->all)[0];
1242 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1244 $self->{_stashed_results} = $self->_construct_results
1247 return shift @{$self->{_stashed_results}};
1250 # Constructs as many results as it can in one pass while respecting
1251 # cursor laziness. Several modes of operation:
1253 # * Always builds everything present in @{$self->{_stashed_rows}}
1254 # * If called with $fetch_all true - pulls everything off the cursor and
1255 # builds all result structures (or objects) in one pass
1256 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1257 # and if the resultset is ordered properly by the left side:
1258 # * Fetches stuff off the cursor until the "master object" changes,
1259 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1261 # * Just fetches, and collapses/constructs everything as if $fetch_all
1262 # was requested (there is no other way to collapse except for an
1264 # * If no collapse is requested - just get the next row, construct and
1266 sub _construct_results {
1267 my ($self, $fetch_all) = @_;
1269 my $rsrc = $self->result_source;
1270 my $attrs = $self->_resolved_attrs;
1275 ! $attrs->{order_by}
1279 my @pcols = $rsrc->primary_columns
1281 # default order for collapsing unless the user asked for something
1282 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1283 $attrs->{_ordered_for_collapse} = 1;
1284 $attrs->{_order_is_artificial} = 1;
1287 # this will be used as both initial raw-row collector AND as a RV of
1288 # _construct_results. Not regrowing the array twice matters a lot...
1289 # a surprising amount actually
1290 my $rows = delete $self->{_stashed_rows};
1292 my $cursor; # we may not need one at all
1294 my $did_fetch_all = $fetch_all;
1297 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1298 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1300 elsif( $attrs->{collapse} ) {
1302 # a cursor will need to be closed over in case of collapse
1303 $cursor = $self->cursor;
1305 $attrs->{_ordered_for_collapse} = (
1311 ->_extract_colinfo_of_stable_main_source_order_by_portion($attrs)
1313 ) unless defined $attrs->{_ordered_for_collapse};
1315 if (! $attrs->{_ordered_for_collapse}) {
1318 # instead of looping over ->next, use ->all in stealth mode
1319 # *without* calling a ->reset afterwards
1320 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1321 if (! $cursor->{_done}) {
1322 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1323 $cursor->{_done} = 1;
1328 if (! $did_fetch_all and ! @{$rows||[]} ) {
1329 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1330 $cursor ||= $self->cursor;
1331 if (scalar (my @r = $cursor->next) ) {
1336 return undef unless @{$rows||[]};
1338 # sanity check - people are too clever for their own good
1339 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1341 my $multiplied_selectors;
1342 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1344 $aliastypes->{multiplying}{$sel_alias}
1346 $aliastypes->{premultiplied}{$sel_alias}
1348 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1352 for my $i (0 .. $#{$attrs->{as}} ) {
1353 my $sel = $attrs->{select}[$i];
1355 if (ref $sel eq 'SCALAR') {
1358 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1362 $self->throw_exception(
1363 'Result collapse not possible - selection from a has_many source redirected to the main object'
1364 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1368 # hotspot - skip the setter
1369 my $res_class = $self->_result_class;
1371 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1372 $res_class->can ('inflate_result')
1373 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1376 my $infmap = $attrs->{as};
1378 $self->{_result_inflator}{is_core_row} = ( (
1381 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1382 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1384 $self->{_result_inflator}{is_hri} = ( (
1385 ! $self->{_result_inflator}{is_core_row}
1388 require DBIx::Class::ResultClass::HashRefInflator
1390 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1392 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1395 if ($attrs->{_simple_passthrough_construction}) {
1396 # construct a much simpler array->hash folder for the one-table HRI cases right here
1397 if ($self->{_result_inflator}{is_hri}) {
1398 for my $r (@$rows) {
1399 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1402 # FIXME SUBOPTIMAL this is a very very very hot spot
1403 # while rather optimal we can *still* do much better, by
1404 # building a smarter Row::inflate_result(), and
1405 # switch to feeding it data via a much leaner interface
1407 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1408 # this particular resultset size
1409 elsif ( $self->{_result_inflator}{is_core_row} and @$rows < 60 ) {
1410 for my $r (@$rows) {
1411 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1416 ( $self->{_result_inflator}{is_core_row}
1417 ? '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows'
1418 # a custom inflator may be a multiplier/reductor - put it in direct list ctx
1419 : '@$rows = map { $inflator_cref->($res_class, $rsrc, { %s } ) } @$rows'
1421 ( join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) )
1427 $self->{_result_inflator}{is_hri} ? 'hri'
1428 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1429 : 'classic_nonpruning'
1432 # $args and $attrs to _mk_row_parser are separated to delineate what is
1433 # core collapser stuff and what is dbic $rs specific
1434 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1436 inflate_map => $infmap,
1437 collapse => $attrs->{collapse},
1438 premultiplied => $attrs->{_main_source_premultiplied},
1439 hri_style => $self->{_result_inflator}{is_hri},
1440 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1441 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1443 # column_info metadata historically hasn't been too reliable.
1444 # We need to start fixing this somehow (the collapse resolver
1445 # can't work without it). Add an explicit check for the *main*
1446 # result, hopefully this will gradually weed out such errors
1448 # FIXME - this is a temporary kludge that reduces performance
1449 # It is however necessary for the time being
1450 my ($unrolled_non_null_cols_to_check, $err);
1452 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1455 'Collapse aborted due to invalid ResultSource metadata - the following '
1456 . 'selections are declared non-nullable but NULLs were retrieved: '
1460 COL: for my $i (@$check_non_null_cols) {
1461 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1464 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1467 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1471 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1472 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1474 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1475 my @r = $cursor->next or return;
1476 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1477 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1483 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1484 my @r = $cursor->next or return;
1489 $self->{_row_parser}{$parser_type}{cref}->(
1491 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1494 # simple in-place substitution, does not regrow $rows
1495 if ($self->{_result_inflator}{is_core_row}) {
1496 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1498 # Special-case multi-object HRI - there is no $inflator_cref pass at all
1499 elsif ( ! $self->{_result_inflator}{is_hri} ) {
1500 # the inflator may be a multiplier/reductor - put it in list ctx
1501 @$rows = map { $inflator_cref->($res_class, $rsrc, @$_) } @$rows;
1505 # The @$rows check seems odd at first - why wouldn't we want to warn
1506 # regardless? The issue is things like find() etc, where the user
1507 # *knows* only one result will come back. In these cases the ->all
1508 # is not a pessimization, but rather something we actually want
1510 'Unable to properly collapse has_many results in iterator mode due '
1511 . 'to order criteria - performed an eager cursor slurp underneath. '
1512 . 'Consider using ->all() instead'
1513 ) if ( ! $fetch_all and @$rows > 1 );
1518 =head2 result_source
1522 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1524 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1528 An accessor for the primary ResultSource object from which this ResultSet
1535 =item Arguments: $result_class?
1537 =item Return Value: $result_class
1541 An accessor for the class to use when creating result objects. Defaults to
1542 C<< result_source->result_class >> - which in most cases is the name of the
1543 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1545 Note that changing the result_class will also remove any components
1546 that were originally loaded in the source class via
1547 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1548 in the original source class will not run.
1553 my ($self, $result_class) = @_;
1554 if ($result_class) {
1556 # don't fire this for an object
1557 $self->ensure_class_loaded($result_class)
1558 unless ref($result_class);
1560 if ($self->get_cache) {
1561 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1563 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1564 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1565 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1568 $self->_result_class($result_class);
1570 delete $self->{_result_inflator};
1572 $self->_result_class;
1579 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1581 =item Return Value: $count
1585 Performs an SQL C<COUNT> with the same query as the resultset was built
1586 with to find the number of elements. Passing arguments is equivalent to
1587 C<< $rs->search ($cond, \%attrs)->count >>
1593 return $self->search(@_)->count if @_ and defined $_[0];
1594 return scalar @{ $self->get_cache } if $self->get_cache;
1596 my $attrs = { %{ $self->_resolved_attrs } };
1598 # this is a little optimization - it is faster to do the limit
1599 # adjustments in software, instead of a subquery
1600 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1603 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1604 $crs = $self->_count_subq_rs ($attrs);
1607 $crs = $self->_count_rs ($attrs);
1609 my $count = $crs->next;
1611 $count -= $offset if $offset;
1612 $count = $rows if $rows and $rows < $count;
1613 $count = 0 if ($count < 0);
1622 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1624 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1628 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1629 This can be very handy for subqueries:
1631 ->search( { amount => $some_rs->count_rs->as_query } )
1633 As with regular resultsets the SQL query will be executed only after
1634 the resultset is accessed via L</next> or L</all>. That would return
1635 the same single value obtainable via L</count>.
1641 return $self->search(@_)->count_rs if @_;
1643 # this may look like a lack of abstraction (count() does about the same)
1644 # but in fact an _rs *must* use a subquery for the limits, as the
1645 # software based limiting can not be ported if this $rs is to be used
1646 # in a subquery itself (i.e. ->as_query)
1647 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1648 return $self->_count_subq_rs($self->{_attrs});
1651 return $self->_count_rs($self->{_attrs});
1656 # returns a ResultSetColumn object tied to the count query
1659 my ($self, $attrs) = @_;
1661 my $rsrc = $self->result_source;
1663 my $tmp_attrs = { %$attrs };
1664 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1665 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1667 # overwrite the selector (supplied by the storage)
1668 $rsrc->resultset_class->new($rsrc, {
1670 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1672 })->get_column ('count');
1676 # same as above but uses a subquery
1678 sub _count_subq_rs {
1679 my ($self, $attrs) = @_;
1681 my $rsrc = $self->result_source;
1683 my $sub_attrs = { %$attrs };
1684 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1685 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1687 # if we multi-prefetch we group_by something unique, as this is what we would
1688 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1689 if ( $attrs->{collapse} ) {
1690 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1691 $rsrc->_identifying_column_set || $self->throw_exception(
1692 'Unable to construct a unique group_by criteria properly collapsing the '
1693 . 'has_many prefetch before count()'
1698 # Calculate subquery selector
1699 if (my $g = $sub_attrs->{group_by}) {
1701 my $sql_maker = $rsrc->storage->sql_maker;
1703 # necessary as the group_by may refer to aliased functions
1705 for my $sel (@{$attrs->{select}}) {
1706 $sel_index->{$sel->{-as}} = $sel
1707 if (ref $sel eq 'HASH' and $sel->{-as});
1710 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1711 # also look for named aggregates referred in the having clause
1712 # having often contains scalarrefs - thus parse it out entirely
1714 if ($attrs->{having}) {
1715 local $sql_maker->{having_bind};
1716 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1717 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1718 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1719 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1720 # if we don't unset it we screw up retarded but unfortunately working
1721 # 'MAX(foo.bar)' => { '>', 3 }
1722 $sql_maker->{name_sep} = '';
1725 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1727 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1730 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1731 # and if all fails for an utterly naive quoted scalar-with-function
1732 while ($having_sql =~ /
1733 $rquote $sep $lquote (.+?) $rquote
1735 [\s,] \w+ \. (\w+) [\s,]
1737 [\s,] $lquote (.+?) $rquote [\s,]
1739 my $part = $1 || $2 || $3; # one of them matched if we got here
1740 unless ($seen_having{$part}++) {
1747 my $colpiece = $sel_index->{$_} || $_;
1749 # unqualify join-based group_by's. Arcane but possible query
1750 # also horrible horrible hack to alias a column (not a func.)
1751 # (probably need to introduce SQLA syntax)
1752 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1755 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1757 push @{$sub_attrs->{select}}, $colpiece;
1761 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1762 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1765 return $rsrc->resultset_class
1766 ->new ($rsrc, $sub_attrs)
1768 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1769 ->get_column ('count');
1773 =head2 count_literal
1775 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1776 should only be used in that context. See L</search_literal> for further info.
1780 =item Arguments: $sql_fragment, @standalone_bind_values
1782 =item Return Value: $count
1786 Counts the results in a literal query. Equivalent to calling L</search_literal>
1787 with the passed arguments, then L</count>.
1791 sub count_literal { shift->search_literal(@_)->count; }
1797 =item Arguments: none
1799 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1803 Returns all elements in the resultset.
1810 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1813 delete @{$self}{qw/_stashed_rows _stashed_results/};
1815 if (my $c = $self->get_cache) {
1819 $self->cursor->reset;
1821 my $objs = $self->_construct_results('fetch_all') || [];
1823 $self->set_cache($objs) if $self->{attrs}{cache};
1832 =item Arguments: none
1834 =item Return Value: $self
1838 Resets the resultset's cursor, so you can iterate through the elements again.
1839 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1847 delete @{$self}{qw/_stashed_rows _stashed_results/};
1848 $self->{all_cache_position} = 0;
1849 $self->cursor->reset;
1857 =item Arguments: none
1859 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1863 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1864 an object for the first result (or C<undef> if the resultset is empty).
1869 return $_[0]->reset->next;
1875 # Determines whether and what type of subquery is required for the $rs operation.
1876 # If grouping is necessary either supplies its own, or verifies the current one
1877 # After all is done delegates to the proper storage method.
1879 sub _rs_update_delete {
1880 my ($self, $op, $values) = @_;
1882 my $rsrc = $self->result_source;
1883 my $storage = $rsrc->schema->storage;
1885 my $attrs = { %{$self->_resolved_attrs} };
1887 my $join_classifications;
1888 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1890 # do we need a subquery for any reason?
1892 defined $existing_group_by
1894 # if {from} is unparseable wrap a subq
1895 ref($attrs->{from}) ne 'ARRAY'
1897 # limits call for a subq
1898 $self->_has_resolved_attr(qw/rows offset/)
1901 # simplify the joinmap, so we can further decide if a subq is necessary
1902 if (!$needs_subq and @{$attrs->{from}} > 1) {
1904 ($attrs->{from}, $join_classifications) =
1905 $storage->_prune_unused_joins ($attrs);
1907 # any non-pruneable non-local restricting joins imply subq
1908 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1911 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1913 (ref $attrs->{from}[0]) ne 'HASH'
1915 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1919 # do we need anything like a subquery?
1920 if (! $needs_subq) {
1921 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1922 # a condition containing 'me' or other table prefixes will not work
1923 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1925 my $sqla = $rsrc->storage->sql_maker;
1926 local $sqla->{_dequalify_idents} = 1;
1927 \[ $sqla->_recurse_where($self->{cond}) ];
1931 # we got this far - means it is time to wrap a subquery
1932 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1934 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1940 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1941 delete $attrs->{$_} for qw/select as collapse/;
1942 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1944 # this will be consumed by the pruner waaaaay down the stack
1945 $attrs->{_force_prune_multiplying_joins} = 1;
1947 my $subrs = (ref $self)->new($rsrc, $attrs);
1949 if (@$idcols == 1) {
1950 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1952 elsif ($storage->_use_multicolumn_in) {
1953 # no syntax for calling this properly yet
1954 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1955 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1956 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1961 # if all else fails - get all primary keys and operate over a ORed set
1962 # wrap in a transaction for consistency
1963 # this is where the group_by/multiplication starts to matter
1967 # we do not need to check pre-multipliers, since if the premulti is there, its
1968 # parent (who is multi) will be there too
1969 keys %{ $join_classifications->{multiplying} || {} }
1971 # make sure if there is a supplied group_by it matches the columns compiled above
1972 # perfectly. Anything else can not be sanely executed on most databases so croak
1973 # right then and there
1974 if ($existing_group_by) {
1975 my @current_group_by = map
1976 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1981 join ("\x00", sort @current_group_by)
1983 join ("\x00", sort @{$attrs->{columns}} )
1985 $self->throw_exception (
1986 "You have just attempted a $op operation on a resultset which does group_by"
1987 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1988 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1989 . ' kind of queries. Please retry the operation with a modified group_by or'
1990 . ' without using one at all.'
1995 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1998 $guard = $storage->txn_scope_guard;
2000 for my $row ($subrs->cursor->all) {
2002 { $idcols->[$_] => $row->[$_] }
2009 my $res = $cond ? $storage->$op (
2011 $op eq 'update' ? $values : (),
2015 $guard->commit if $guard;
2024 =item Arguments: \%values
2026 =item Return Value: $underlying_storage_rv
2030 Sets the specified columns in the resultset to the supplied values in a
2031 single query. Note that this will not run any accessor/set_column/update
2032 triggers, nor will it update any result object instances derived from this
2033 resultset (this includes the contents of the L<resultset cache|/set_cache>
2034 if any). See L</update_all> if you need to execute any on-update
2035 triggers or cascades defined either by you or a
2036 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2038 The return value is a pass through of what the underlying
2039 storage backend returned, and may vary. See L<DBI/execute> for the most
2044 Note that L</update> does not process/deflate any of the values passed in.
2045 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2046 ensure manually that any value passed to this method will stringify to
2047 something the RDBMS knows how to deal with. A notable example is the
2048 handling of L<DateTime> objects, for more info see:
2049 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2054 my ($self, $values) = @_;
2055 $self->throw_exception('Values for update must be a hash')
2056 unless ref $values eq 'HASH';
2058 return $self->_rs_update_delete ('update', $values);
2065 =item Arguments: \%values
2067 =item Return Value: 1
2071 Fetches all objects and updates them one at a time via
2072 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2073 triggers, while L</update> will not.
2078 my ($self, $values) = @_;
2079 $self->throw_exception('Values for update_all must be a hash')
2080 unless ref $values eq 'HASH';
2082 my $guard = $self->result_source->schema->txn_scope_guard;
2083 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2092 =item Arguments: none
2094 =item Return Value: $underlying_storage_rv
2098 Deletes the rows matching this resultset in a single query. Note that this
2099 will not run any delete triggers, nor will it alter the
2100 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2101 derived from this resultset (this includes the contents of the
2102 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2103 execute any on-delete triggers or cascades defined either by you or a
2104 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2106 The return value is a pass through of what the underlying storage backend
2107 returned, and may vary. See L<DBI/execute> for the most common case.
2113 $self->throw_exception('delete does not accept any arguments')
2116 return $self->_rs_update_delete ('delete');
2123 =item Arguments: none
2125 =item Return Value: 1
2129 Fetches all objects and deletes them one at a time via
2130 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2131 triggers, while L</delete> will not.
2137 $self->throw_exception('delete_all does not accept any arguments')
2140 my $guard = $self->result_source->schema->txn_scope_guard;
2141 $_->delete for $self->all;
2150 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2152 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2156 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2163 The context of this method call has an important effect on what is
2164 submitted to storage. In void context data is fed directly to fastpath
2165 insertion routines provided by the underlying storage (most often
2166 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2167 L<insert|DBIx::Class::Row/insert> calls on the
2168 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2169 augmentation of these methods provided by components. For example if you
2170 are using something like L<DBIx::Class::UUIDColumns> to create primary
2171 keys for you, you will find that your PKs are empty. In this case you
2172 will have to explicitly force scalar or list context in order to create
2177 In non-void (scalar or list) context, this method is simply a wrapper
2178 for L</create>. Depending on list or scalar context either a list of
2179 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2180 containing these objects is returned.
2182 When supplying data in "arrayref of arrayrefs" invocation style, the
2183 first element should be a list of column names and each subsequent
2184 element should be a data value in the earlier specified column order.
2187 $schema->resultset("Artist")->populate([
2188 [ qw( artistid name ) ],
2189 [ 100, 'A Formally Unknown Singer' ],
2190 [ 101, 'A singer that jumped the shark two albums ago' ],
2191 [ 102, 'An actually cool singer' ],
2194 For the arrayref of hashrefs style each hashref should be a structure
2195 suitable for passing to L</create>. Multi-create is also permitted with
2198 $schema->resultset("Artist")->populate([
2199 { artistid => 4, name => 'Manufactured Crap', cds => [
2200 { title => 'My First CD', year => 2006 },
2201 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2204 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2205 { title => 'My parents sold me to a record company', year => 2005 },
2206 { title => 'Why Am I So Ugly?', year => 2006 },
2207 { title => 'I Got Surgery and am now Popular', year => 2007 }
2212 If you attempt a void-context multi-create as in the example above (each
2213 Artist also has the related list of CDs), and B<do not> supply the
2214 necessary autoinc foreign key information, this method will proxy to the
2215 less efficient L</create>, and then throw the Result objects away. In this
2216 case there are obviously no benefits to using this method over L</create>.
2225 # this is naive and just a quick check
2226 # the types will need to be checked more thoroughly when the
2227 # multi-source populate gets added
2228 if (ref $_[0] eq 'ARRAY') {
2229 return unless @{$_[0]};
2231 $data = $_[0] if (ref $_[0][0] eq 'HASH' or ref $_[0][0] eq 'ARRAY');
2234 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs')
2237 # FIXME - no cref handling
2238 # At this point assume either hashes or arrays
2240 if(defined wantarray) {
2243 $guard = $self->result_source->schema->storage->txn_scope_guard
2244 if ( @$data > 2 or ( @$data == 2 and ref $data->[0] eq 'ARRAY' ) );
2246 if (ref $data->[0] eq 'ARRAY') {
2248 { my $vals = $_; $self->new_result({ map { $data->[0][$_] => $vals->[$_] } 0..$#{$data->[0]} })->insert }
2249 @{$data}[1 .. $#$data]
2253 @results = map { $self->new_result($_)->insert } @$data;
2256 $guard->commit if $guard;
2257 return wantarray ? @results : \@results;
2260 # we have to deal with *possibly incomplete* related data
2261 # this means we have to walk the data structure twice
2262 # whether we want this or not
2263 # jnap, I hate you ;)
2264 my $rsrc = $self->result_source;
2265 my $rel_info = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2267 my ($colinfo, $colnames, $slices_with_rels);
2271 for my $i (0 .. $#$data) {
2273 my $current_slice_seen_rel_infos;
2275 ### Determine/Supplement collists
2276 ### BEWARE - This is a hot piece of code, a lot of weird idioms were used
2277 if( ref $data->[$i] eq 'ARRAY' ) {
2279 # positional(!) explicit column list
2282 $colinfo->{$data->[0][$_]} = { pos => $_, name => $data->[0][$_] } and push @$colnames, $data->[0][$_]
2283 for 0 .. $#{$data->[0]};
2290 for (values %$colinfo) {
2291 if ($_->{is_rel} ||= (
2292 $rel_info->{$_->{name}}
2295 ref $data->[$i][$_->{pos}] eq 'ARRAY'
2297 ref $data->[$i][$_->{pos}] eq 'HASH'
2299 ( defined blessed $data->[$i][$_->{pos}] and $data->[$i][$_->{pos}]->isa('DBIx::Class::Row') )
2305 # moar sanity check... sigh
2306 for ( ref $data->[$i][$_->{pos}] eq 'ARRAY' ? @{$data->[$i][$_->{pos}]} : $data->[$i][$_->{pos}] ) {
2307 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2308 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2309 return my $throwaway = $self->populate(@_);
2313 push @$current_slice_seen_rel_infos, $rel_info->{$_->{name}};
2318 if ($current_slice_seen_rel_infos) {
2319 push @$slices_with_rels, { map { $colnames->[$_] => $data->[$i][$_] } 0 .. $#$colnames };
2321 # this is needed further down to decide whether or not to fallback to create()
2322 $colinfo->{$colnames->[$_]}{seen_null} ||= ! defined $data->[$i][$_]
2323 for 0 .. $#$colnames;
2326 elsif( ref $data->[$i] eq 'HASH' ) {
2328 for ( sort keys %{$data->[$i]} ) {
2330 $colinfo->{$_} ||= do {
2332 $self->throw_exception("Column '$_' must be present in supplied explicit column list")
2333 if $data_start; # it will be 0 on AoH, 1 on AoA
2335 push @$colnames, $_;
2338 { pos => $#$colnames, name => $_ }
2341 if ($colinfo->{$_}{is_rel} ||= (
2345 ref $data->[$i]{$_} eq 'ARRAY'
2347 ref $data->[$i]{$_} eq 'HASH'
2349 ( defined blessed $data->[$i]{$_} and $data->[$i]{$_}->isa('DBIx::Class::Row') )
2355 # moar sanity check... sigh
2356 for ( ref $data->[$i]{$_} eq 'ARRAY' ? @{$data->[$i]{$_}} : $data->[$i]{$_} ) {
2357 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2358 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2359 return my $throwaway = $self->populate(@_);
2363 push @$current_slice_seen_rel_infos, $rel_info->{$_};
2367 if ($current_slice_seen_rel_infos) {
2368 push @$slices_with_rels, $data->[$i];
2370 # this is needed further down to decide whether or not to fallback to create()
2371 $colinfo->{$_}{seen_null} ||= ! defined $data->[$i]{$_}
2372 for keys %{$data->[$i]};
2376 $self->throw_exception('Unexpected populate() data structure member type: ' . ref $data->[$i] );
2380 { $_->{attrs}{is_depends_on} }
2381 @{ $current_slice_seen_rel_infos || [] }
2383 carp_unique("Fast-path populate() of belongs_to relationship data is not possible - falling back to regular create()");
2384 return my $throwaway = $self->populate(@_);
2388 if( $slices_with_rels ) {
2390 # need to exclude the rel "columns"
2391 $colnames = [ grep { ! $colinfo->{$_}{is_rel} } @$colnames ];
2393 # extra sanity check - ensure the main source is in fact identifiable
2394 # the localizing of nullability is insane, but oh well... the use-case is legit
2395 my $ci = $rsrc->columns_info($colnames);
2397 $ci->{$_} = { %{$ci->{$_}}, is_nullable => 0 }
2398 for grep { ! $colinfo->{$_}{seen_null} } keys %$ci;
2400 unless( $rsrc->_identifying_column_set($ci) ) {
2401 carp_unique("Fast-path populate() of non-uniquely identifiable rows with related data is not possible - falling back to regular create()");
2402 return my $throwaway = $self->populate(@_);
2406 ### inherit the data locked in the conditions of the resultset
2407 my ($rs_data) = $self->_merge_with_rscond({});
2408 delete @{$rs_data}{@$colnames}; # passed-in stuff takes precedence
2410 # if anything left - decompose rs_data
2412 if (keys %$rs_data) {
2413 push @$rs_data_vals, $rs_data->{$_}
2414 for sort keys %$rs_data;
2418 $guard = $rsrc->schema->storage->txn_scope_guard
2419 if $slices_with_rels;
2421 ### main source data
2422 # FIXME - need to switch entirely to a coderef-based thing,
2423 # so that large sets aren't copied several times... I think
2424 $rsrc->storage->insert_bulk(
2426 [ @$colnames, sort keys %$rs_data ],
2428 ref $data->[$_] eq 'ARRAY'
2430 $slices_with_rels ? [ @{$data->[$_]}[0..$#$colnames], @{$rs_data_vals||[]} ] # the collist changed
2431 : $rs_data_vals ? [ @{$data->[$_]}, @$rs_data_vals ]
2434 : [ @{$data->[$_]}{@$colnames}, @{$rs_data_vals||[]} ]
2435 } $data_start .. $#$data ],
2438 ### do the children relationships
2439 if ( $slices_with_rels ) {
2440 my @rels = grep { $colinfo->{$_}{is_rel} } keys %$colinfo
2441 or die 'wtf... please report a bug with DBIC_TRACE=1 output (stacktrace)';
2443 for my $sl (@$slices_with_rels) {
2445 my ($main_proto, $main_proto_rs);
2446 for my $rel (@rels) {
2447 next unless defined $sl->{$rel};
2451 (map { $_ => $sl->{$_} } @$colnames),
2454 unless (defined $colinfo->{$rel}{rs}) {
2456 $colinfo->{$rel}{rs} = $rsrc->related_source($rel)->resultset;
2458 $colinfo->{$rel}{fk_map} = { reverse %{ $rsrc->_resolve_relationship_condition(
2460 self_alias => "\xFE", # irrelevant
2461 foreign_alias => "\xFF", # irrelevant
2462 )->{identity_map} || {} } };
2466 $colinfo->{$rel}{rs}->search({ map # only so that we inherit them values properly, no actual search
2469 ( $main_proto_rs ||= $rsrc->resultset->search($main_proto) )
2470 ->get_column( $colinfo->{$rel}{fk_map}{$_} )
2474 keys %{$colinfo->{$rel}{fk_map}}
2475 })->populate( ref $sl->{$rel} eq 'ARRAY' ? $sl->{$rel} : [ $sl->{$rel} ] );
2482 $guard->commit if $guard;
2489 =item Arguments: none
2491 =item Return Value: L<$pager|Data::Page>
2495 Returns a L<Data::Page> object for the current resultset. Only makes
2496 sense for queries with a C<page> attribute.
2498 To get the full count of entries for a paged resultset, call
2499 C<total_entries> on the L<Data::Page> object.
2506 return $self->{pager} if $self->{pager};
2508 my $attrs = $self->{attrs};
2509 if (!defined $attrs->{page}) {
2510 $self->throw_exception("Can't create pager for non-paged rs");
2512 elsif ($attrs->{page} <= 0) {
2513 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2515 $attrs->{rows} ||= 10;
2517 # throw away the paging flags and re-run the count (possibly
2518 # with a subselect) to get the real total count
2519 my $count_attrs = { %$attrs };
2520 delete @{$count_attrs}{qw/rows offset page pager/};
2522 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2524 require DBIx::Class::ResultSet::Pager;
2525 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2526 sub { $total_rs->count }, #lazy-get the total
2528 $self->{attrs}{page},
2536 =item Arguments: $page_number
2538 =item Return Value: L<$resultset|/search>
2542 Returns a resultset for the $page_number page of the resultset on which page
2543 is called, where each page contains a number of rows equal to the 'rows'
2544 attribute set on the resultset (10 by default).
2549 my ($self, $page) = @_;
2550 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2557 =item Arguments: \%col_data
2559 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2563 Creates a new result object in the resultset's result class and returns
2564 it. The row is not inserted into the database at this point, call
2565 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2566 will tell you whether the result object has been inserted or not.
2568 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2573 my ($self, $values) = @_;
2575 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2578 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2579 unless (ref $values eq 'HASH');
2581 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2583 my $new = $self->result_class->new({
2585 ( @$cols_from_relations
2586 ? (-cols_from_relations => $cols_from_relations)
2589 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2593 reftype($new) eq 'HASH'
2599 carp_unique (sprintf (
2600 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2601 $self->result_class,
2608 # _merge_with_rscond
2610 # Takes a simple hash of K/V data and returns its copy merged with the
2611 # condition already present on the resultset. Additionally returns an
2612 # arrayref of value/condition names, which were inferred from related
2613 # objects (this is needed for in-memory related objects)
2614 sub _merge_with_rscond {
2615 my ($self, $data) = @_;
2617 my ($implied_data, @cols_from_relations);
2619 my $alias = $self->{attrs}{alias};
2621 if (! defined $self->{cond}) {
2622 # just massage $data below
2624 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2625 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2626 @cols_from_relations = keys %{ $implied_data || {} };
2629 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2630 $implied_data = { map {
2631 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2637 { %{ $self->_remove_alias($_, $alias) } }
2638 # precedence must be given to passed values over values inherited from
2639 # the cond, so the order here is important.
2640 ( $implied_data||(), $data)
2642 \@cols_from_relations
2646 # _has_resolved_attr
2648 # determines if the resultset defines at least one
2649 # of the attributes supplied
2651 # used to determine if a subquery is necessary
2653 # supports some virtual attributes:
2655 # This will scan for any joins being present on the resultset.
2656 # It is not a mere key-search but a deep inspection of {from}
2659 sub _has_resolved_attr {
2660 my ($self, @attr_names) = @_;
2662 my $attrs = $self->_resolved_attrs;
2666 for my $n (@attr_names) {
2667 if (grep { $n eq $_ } (qw/-join/) ) {
2668 $extra_checks{$n}++;
2672 my $attr = $attrs->{$n};
2674 next if not defined $attr;
2676 if (ref $attr eq 'HASH') {
2677 return 1 if keys %$attr;
2679 elsif (ref $attr eq 'ARRAY') {
2687 # a resolved join is expressed as a multi-level from
2689 $extra_checks{-join}
2691 ref $attrs->{from} eq 'ARRAY'
2693 @{$attrs->{from}} > 1
2701 # Remove the specified alias from the specified query hash. A copy is made so
2702 # the original query is not modified.
2705 my ($self, $query, $alias) = @_;
2707 my %orig = %{ $query || {} };
2710 foreach my $key (keys %orig) {
2712 $unaliased{$key} = $orig{$key};
2715 $unaliased{$1} = $orig{$key}
2716 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2726 =item Arguments: none
2728 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2732 Returns the SQL query and bind vars associated with the invocant.
2734 This is generally used as the RHS for a subquery.
2741 my $attrs = { %{ $self->_resolved_attrs } };
2743 my $aq = $self->result_source->storage->_select_args_to_query (
2744 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2754 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2756 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2760 my $artist = $schema->resultset('Artist')->find_or_new(
2761 { artist => 'fred' }, { key => 'artists' });
2763 $cd->cd_to_producer->find_or_new({ producer => $producer },
2764 { key => 'primary' });
2766 Find an existing record from this resultset using L</find>. if none exists,
2767 instantiate a new result object and return it. The object will not be saved
2768 into your storage until you call L<DBIx::Class::Row/insert> on it.
2770 You most likely want this method when looking for existing rows using a unique
2771 constraint that is not the primary key, or looking for related rows.
2773 If you want objects to be saved immediately, use L</find_or_create> instead.
2775 B<Note>: Make sure to read the documentation of L</find> and understand the
2776 significance of the C<key> attribute, as its lack may skew your search, and
2777 subsequently result in spurious new objects.
2779 B<Note>: Take care when using C<find_or_new> with a table having
2780 columns with default values that you intend to be automatically
2781 supplied by the database (e.g. an auto_increment primary key column).
2782 In normal usage, the value of such columns should NOT be included at
2783 all in the call to C<find_or_new>, even when set to C<undef>.
2789 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2790 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2791 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2794 return $self->new_result($hash);
2801 =item Arguments: \%col_data
2803 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2807 Attempt to create a single new row or a row with multiple related rows
2808 in the table represented by the resultset (and related tables). This
2809 will not check for duplicate rows before inserting, use
2810 L</find_or_create> to do that.
2812 To create one row for this resultset, pass a hashref of key/value
2813 pairs representing the columns of the table and the values you wish to
2814 store. If the appropriate relationships are set up, foreign key fields
2815 can also be passed an object representing the foreign row, and the
2816 value will be set to its primary key.
2818 To create related objects, pass a hashref of related-object column values
2819 B<keyed on the relationship name>. If the relationship is of type C<multi>
2820 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2821 The process will correctly identify columns holding foreign keys, and will
2822 transparently populate them from the keys of the corresponding relation.
2823 This can be applied recursively, and will work correctly for a structure
2824 with an arbitrary depth and width, as long as the relationships actually
2825 exists and the correct column data has been supplied.
2827 Instead of hashrefs of plain related data (key/value pairs), you may
2828 also pass new or inserted objects. New objects (not inserted yet, see
2829 L</new_result>), will be inserted into their appropriate tables.
2831 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2833 Example of creating a new row.
2835 $person_rs->create({
2836 name=>"Some Person",
2837 email=>"somebody@someplace.com"
2840 Example of creating a new row and also creating rows in a related C<has_many>
2841 or C<has_one> resultset. Note Arrayref.
2844 { artistid => 4, name => 'Manufactured Crap', cds => [
2845 { title => 'My First CD', year => 2006 },
2846 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2851 Example of creating a new row and also creating a row in a related
2852 C<belongs_to> resultset. Note Hashref.
2855 title=>"Music for Silly Walks",
2858 name=>"Silly Musician",
2866 When subclassing ResultSet never attempt to override this method. Since
2867 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2868 lot of the internals simply never call it, so your override will be
2869 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2870 or L<DBIx::Class::Row/insert> depending on how early in the
2871 L</create> process you need to intervene. See also warning pertaining to
2879 #my ($self, $col_data) = @_;
2880 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2881 return shift->new_result(shift)->insert;
2884 =head2 find_or_create
2888 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2890 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2894 $cd->cd_to_producer->find_or_create({ producer => $producer },
2895 { key => 'primary' });
2897 Tries to find a record based on its primary key or unique constraints; if none
2898 is found, creates one and returns that instead.
2900 my $cd = $schema->resultset('CD')->find_or_create({
2902 artist => 'Massive Attack',
2903 title => 'Mezzanine',
2907 Also takes an optional C<key> attribute, to search by a specific key or unique
2908 constraint. For example:
2910 my $cd = $schema->resultset('CD')->find_or_create(
2912 artist => 'Massive Attack',
2913 title => 'Mezzanine',
2915 { key => 'cd_artist_title' }
2918 B<Note>: Make sure to read the documentation of L</find> and understand the
2919 significance of the C<key> attribute, as its lack may skew your search, and
2920 subsequently result in spurious row creation.
2922 B<Note>: Because find_or_create() reads from the database and then
2923 possibly inserts based on the result, this method is subject to a race
2924 condition. Another process could create a record in the table after
2925 the find has completed and before the create has started. To avoid
2926 this problem, use find_or_create() inside a transaction.
2928 B<Note>: Take care when using C<find_or_create> with a table having
2929 columns with default values that you intend to be automatically
2930 supplied by the database (e.g. an auto_increment primary key column).
2931 In normal usage, the value of such columns should NOT be included at
2932 all in the call to C<find_or_create>, even when set to C<undef>.
2934 See also L</find> and L</update_or_create>. For information on how to declare
2935 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2937 If you need to know if an existing row was found or a new one created use
2938 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2939 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2942 my $cd = $schema->resultset('CD')->find_or_new({
2944 artist => 'Massive Attack',
2945 title => 'Mezzanine',
2949 if( !$cd->in_storage ) {
2956 sub find_or_create {
2958 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2959 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2960 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2963 return $self->new_result($hash)->insert;
2966 =head2 update_or_create
2970 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2972 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2976 $resultset->update_or_create({ col => $val, ... });
2978 Like L</find_or_create>, but if a row is found it is immediately updated via
2979 C<< $found_row->update (\%col_data) >>.
2982 Takes an optional C<key> attribute to search on a specific unique constraint.
2985 # In your application
2986 my $cd = $schema->resultset('CD')->update_or_create(
2988 artist => 'Massive Attack',
2989 title => 'Mezzanine',
2992 { key => 'cd_artist_title' }
2995 $cd->cd_to_producer->update_or_create({
2996 producer => $producer,
3002 B<Note>: Make sure to read the documentation of L</find> and understand the
3003 significance of the C<key> attribute, as its lack may skew your search, and
3004 subsequently result in spurious row creation.
3006 B<Note>: Take care when using C<update_or_create> with a table having
3007 columns with default values that you intend to be automatically
3008 supplied by the database (e.g. an auto_increment primary key column).
3009 In normal usage, the value of such columns should NOT be included at
3010 all in the call to C<update_or_create>, even when set to C<undef>.
3012 See also L</find> and L</find_or_create>. For information on how to declare
3013 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3015 If you need to know if an existing row was updated or a new one created use
3016 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3017 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3022 sub update_or_create {
3024 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3025 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3027 my $row = $self->find($cond, $attrs);
3029 $row->update($cond);
3033 return $self->new_result($cond)->insert;
3036 =head2 update_or_new
3040 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3042 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3046 $resultset->update_or_new({ col => $val, ... });
3048 Like L</find_or_new> but if a row is found it is immediately updated via
3049 C<< $found_row->update (\%col_data) >>.
3053 # In your application
3054 my $cd = $schema->resultset('CD')->update_or_new(
3056 artist => 'Massive Attack',
3057 title => 'Mezzanine',
3060 { key => 'cd_artist_title' }
3063 if ($cd->in_storage) {
3064 # the cd was updated
3067 # the cd is not yet in the database, let's insert it
3071 B<Note>: Make sure to read the documentation of L</find> and understand the
3072 significance of the C<key> attribute, as its lack may skew your search, and
3073 subsequently result in spurious new objects.
3075 B<Note>: Take care when using C<update_or_new> with a table having
3076 columns with default values that you intend to be automatically
3077 supplied by the database (e.g. an auto_increment primary key column).
3078 In normal usage, the value of such columns should NOT be included at
3079 all in the call to C<update_or_new>, even when set to C<undef>.
3081 See also L</find>, L</find_or_create> and L</find_or_new>.
3087 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3088 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3090 my $row = $self->find( $cond, $attrs );
3091 if ( defined $row ) {
3092 $row->update($cond);
3096 return $self->new_result($cond);
3103 =item Arguments: none
3105 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3109 Gets the contents of the cache for the resultset, if the cache is set.
3111 The cache is populated either by using the L</prefetch> attribute to
3112 L</search> or by calling L</set_cache>.
3124 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3126 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3130 Sets the contents of the cache for the resultset. Expects an arrayref
3131 of objects of the same class as those produced by the resultset. Note that
3132 if the cache is set, the resultset will return the cached objects rather
3133 than re-querying the database even if the cache attr is not set.
3135 The contents of the cache can also be populated by using the
3136 L</prefetch> attribute to L</search>.
3141 my ( $self, $data ) = @_;
3142 $self->throw_exception("set_cache requires an arrayref")
3143 if defined($data) && (ref $data ne 'ARRAY');
3144 $self->{all_cache} = $data;
3151 =item Arguments: none
3153 =item Return Value: undef
3157 Clears the cache for the resultset.
3162 shift->set_cache(undef);
3169 =item Arguments: none
3171 =item Return Value: true, if the resultset has been paginated
3179 return !!$self->{attrs}{page};
3186 =item Arguments: none
3188 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3196 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3199 =head2 related_resultset
3203 =item Arguments: $rel_name
3205 =item Return Value: L<$resultset|/search>
3209 Returns a related resultset for the supplied relationship name.
3211 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3215 sub related_resultset {
3216 my ($self, $rel) = @_;
3218 return $self->{related_resultsets}{$rel}
3219 if defined $self->{related_resultsets}{$rel};
3221 return $self->{related_resultsets}{$rel} = do {
3222 my $rsrc = $self->result_source;
3223 my $rel_info = $rsrc->relationship_info($rel);
3225 $self->throw_exception(
3226 "search_related: result source '" . $rsrc->source_name .
3227 "' has no such relationship $rel")
3230 my $attrs = $self->_chain_relationship($rel);
3232 my $join_count = $attrs->{seen_join}{$rel};
3234 my $alias = $self->result_source->storage
3235 ->relname_to_table_alias($rel, $join_count);
3237 # since this is search_related, and we already slid the select window inwards
3238 # (the select/as attrs were deleted in the beginning), we need to flip all
3239 # left joins to inner, so we get the expected results
3240 # read the comment on top of the actual function to see what this does
3241 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3244 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3245 delete @{$attrs}{qw(result_class alias)};
3247 my $rel_source = $rsrc->related_source($rel);
3251 # The reason we do this now instead of passing the alias to the
3252 # search_rs below is that if you wrap/overload resultset on the
3253 # source you need to know what alias it's -going- to have for things
3254 # to work sanely (e.g. RestrictWithObject wants to be able to add
3255 # extra query restrictions, and these may need to be $alias.)
3257 my $rel_attrs = $rel_source->resultset_attributes;
3258 local $rel_attrs->{alias} = $alias;
3260 $rel_source->resultset
3264 where => $attrs->{where},
3268 if (my $cache = $self->get_cache) {
3269 my @related_cache = map
3270 { $_->related_resultset($rel)->get_cache || () }
3274 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3281 =head2 current_source_alias
3285 =item Arguments: none
3287 =item Return Value: $source_alias
3291 Returns the current table alias for the result source this resultset is built
3292 on, that will be used in the SQL query. Usually it is C<me>.
3294 Currently the source alias that refers to the result set returned by a
3295 L</search>/L</find> family method depends on how you got to the resultset: it's
3296 C<me> by default, but eg. L</search_related> aliases it to the related result
3297 source name (and keeps C<me> referring to the original result set). The long
3298 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3299 (and make this method unnecessary).
3301 Thus it's currently necessary to use this method in predefined queries (see
3302 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3303 source alias of the current result set:
3305 # in a result set class
3307 my ($self, $user) = @_;
3309 my $me = $self->current_source_alias;
3311 return $self->search({
3312 "$me.modified" => $user->id,
3318 sub current_source_alias {
3319 return (shift->{attrs} || {})->{alias} || 'me';
3322 =head2 as_subselect_rs
3326 =item Arguments: none
3328 =item Return Value: L<$resultset|/search>
3332 Act as a barrier to SQL symbols. The resultset provided will be made into a
3333 "virtual view" by including it as a subquery within the from clause. From this
3334 point on, any joined tables are inaccessible to ->search on the resultset (as if
3335 it were simply where-filtered without joins). For example:
3337 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3339 # 'x' now pollutes the query namespace
3341 # So the following works as expected
3342 my $ok_rs = $rs->search({'x.other' => 1});
3344 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3345 # def) we look for one row with contradictory terms and join in another table
3346 # (aliased 'x_2') which we never use
3347 my $broken_rs = $rs->search({'x.name' => 'def'});
3349 my $rs2 = $rs->as_subselect_rs;
3351 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3352 my $not_joined_rs = $rs2->search({'x.other' => 1});
3354 # works as expected: finds a 'table' row related to two x rows (abc and def)
3355 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3357 Another example of when one might use this would be to select a subset of
3358 columns in a group by clause:
3360 my $rs = $schema->resultset('Bar')->search(undef, {
3361 group_by => [qw{ id foo_id baz_id }],
3362 })->as_subselect_rs->search(undef, {
3363 columns => [qw{ id foo_id }]
3366 In the above example normally columns would have to be equal to the group by,
3367 but because we isolated the group by into a subselect the above works.
3371 sub as_subselect_rs {
3374 my $attrs = $self->_resolved_attrs;
3376 my $fresh_rs = (ref $self)->new (
3377 $self->result_source
3380 # these pieces will be locked in the subquery
3381 delete $fresh_rs->{cond};
3382 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3384 return $fresh_rs->search( {}, {
3386 $attrs->{alias} => $self->as_query,
3387 -alias => $attrs->{alias},
3388 -rsrc => $self->result_source,
3390 alias => $attrs->{alias},
3394 # This code is called by search_related, and makes sure there
3395 # is clear separation between the joins before, during, and
3396 # after the relationship. This information is needed later
3397 # in order to properly resolve prefetch aliases (any alias
3398 # with a relation_chain_depth less than the depth of the
3399 # current prefetch is not considered)
3401 # The increments happen twice per join. An even number means a
3402 # relationship specified via a search_related, whereas an odd
3403 # number indicates a join/prefetch added via attributes
3405 # Also this code will wrap the current resultset (the one we
3406 # chain to) in a subselect IFF it contains limiting attributes
3407 sub _chain_relationship {
3408 my ($self, $rel) = @_;
3409 my $source = $self->result_source;
3410 my $attrs = { %{$self->{attrs}||{}} };
3412 # we need to take the prefetch the attrs into account before we
3413 # ->_resolve_join as otherwise they get lost - captainL
3414 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3416 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3418 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3421 my @force_subq_attrs = qw/offset rows group_by having/;
3424 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3426 $self->_has_resolved_attr (@force_subq_attrs)
3428 # Nuke the prefetch (if any) before the new $rs attrs
3429 # are resolved (prefetch is useless - we are wrapping
3430 # a subquery anyway).
3431 my $rs_copy = $self->search;
3432 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3433 $rs_copy->{attrs}{join},
3434 delete $rs_copy->{attrs}{prefetch},
3439 -alias => $attrs->{alias},
3440 $attrs->{alias} => $rs_copy->as_query,
3442 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3443 $seen->{-relation_chain_depth} = 0;
3445 elsif ($attrs->{from}) { #shallow copy suffices
3446 $from = [ @{$attrs->{from}} ];
3451 -alias => $attrs->{alias},
3452 $attrs->{alias} => $source->from,
3456 my $jpath = ($seen->{-relation_chain_depth})
3457 ? $from->[-1][0]{-join_path}
3460 my @requested_joins = $source->_resolve_join(
3467 push @$from, @requested_joins;
3469 $seen->{-relation_chain_depth}++;
3471 # if $self already had a join/prefetch specified on it, the requested
3472 # $rel might very well be already included. What we do in this case
3473 # is effectively a no-op (except that we bump up the chain_depth on
3474 # the join in question so we could tell it *is* the search_related)
3477 # we consider the last one thus reverse
3478 for my $j (reverse @requested_joins) {
3479 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3480 if ($rel eq $last_j) {
3481 $j->[0]{-relation_chain_depth}++;
3487 unless ($already_joined) {
3488 push @$from, $source->_resolve_join(
3496 $seen->{-relation_chain_depth}++;
3498 return {%$attrs, from => $from, seen_join => $seen};
3501 sub _resolved_attrs {
3503 return $self->{_attrs} if $self->{_attrs};
3505 my $attrs = { %{ $self->{attrs} || {} } };
3506 my $source = $attrs->{result_source} = $self->result_source;
3507 my $alias = $attrs->{alias};
3509 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3510 if $attrs->{collapse} and $attrs->{distinct};
3512 # default selection list
3513 $attrs->{columns} = [ $source->columns ]
3514 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3516 # merge selectors together
3517 for (qw/columns select as/) {
3518 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3519 if $attrs->{$_} or $attrs->{"+$_"};
3522 # disassemble columns
3524 if (my $cols = delete $attrs->{columns}) {
3525 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3526 if (ref $c eq 'HASH') {
3527 for my $as (sort keys %$c) {
3528 push @sel, $c->{$as};
3539 # when trying to weed off duplicates later do not go past this point -
3540 # everything added from here on is unbalanced "anyone's guess" stuff
3541 my $dedup_stop_idx = $#as;
3543 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3545 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3546 if $attrs->{select};
3548 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3549 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3551 # disqualify all $alias.col as-bits (inflate-map mandated)
3552 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3554 # de-duplicate the result (remove *identical* select/as pairs)
3555 # and also die on duplicate {as} pointing to different {select}s
3556 # not using a c-style for as the condition is prone to shrinkage
3559 while ($i <= $dedup_stop_idx) {
3560 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3565 elsif ($seen->{$as[$i]}++) {
3566 $self->throw_exception(
3567 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3575 $attrs->{select} = \@sel;
3576 $attrs->{as} = \@as;
3578 $attrs->{from} ||= [{
3580 -alias => $self->{attrs}{alias},
3581 $self->{attrs}{alias} => $source->from,
3584 if ( $attrs->{join} || $attrs->{prefetch} ) {
3586 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3587 if ref $attrs->{from} ne 'ARRAY';
3589 my $join = (delete $attrs->{join}) || {};
3591 if ( defined $attrs->{prefetch} ) {
3592 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3595 $attrs->{from} = # have to copy here to avoid corrupting the original
3597 @{ $attrs->{from} },
3598 $source->_resolve_join(
3601 { %{ $attrs->{seen_join} || {} } },
3602 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3603 ? $attrs->{from}[-1][0]{-join_path}
3610 if ( defined $attrs->{order_by} ) {
3611 $attrs->{order_by} = (
3612 ref( $attrs->{order_by} ) eq 'ARRAY'
3613 ? [ @{ $attrs->{order_by} } ]
3614 : [ $attrs->{order_by} || () ]
3618 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3619 $attrs->{group_by} = [ $attrs->{group_by} ];
3623 # generate selections based on the prefetch helper
3624 my ($prefetch, @prefetch_select, @prefetch_as);
3625 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3626 if defined $attrs->{prefetch};
3630 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3631 if $attrs->{_dark_selector};
3633 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3634 if defined $attrs->{collapse} and ! $attrs->{collapse};
3636 $attrs->{collapse} = 1;
3638 # this is a separate structure (we don't look in {from} directly)
3639 # as the resolver needs to shift things off the lists to work
3640 # properly (identical-prefetches on different branches)
3642 if (ref $attrs->{from} eq 'ARRAY') {
3644 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3646 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3647 next unless $j->[0]{-alias};
3648 next unless $j->[0]{-join_path};
3649 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3651 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3654 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3655 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3659 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3661 # save these for after distinct resolution
3662 @prefetch_select = map { $_->[0] } @prefetch;
3663 @prefetch_as = map { $_->[1] } @prefetch;
3666 # run through the resulting joinstructure (starting from our current slot)
3667 # and unset collapse if proven unnecessary
3669 # also while we are at it find out if the current root source has
3670 # been premultiplied by previous related_source chaining
3672 # this allows to predict whether a root object with all other relation
3673 # data set to NULL is in fact unique
3674 if ($attrs->{collapse}) {
3676 if (ref $attrs->{from} eq 'ARRAY') {
3678 if (@{$attrs->{from}} == 1) {
3679 # no joins - no collapse
3680 $attrs->{collapse} = 0;
3683 # find where our table-spec starts
3684 my @fromlist = @{$attrs->{from}};
3686 my $t = shift @fromlist;
3689 # me vs join from-spec distinction - a ref means non-root
3690 if (ref $t eq 'ARRAY') {
3692 $is_multi ||= ! $t->{-is_single};
3694 last if ($t->{-alias} && $t->{-alias} eq $alias);
3695 $attrs->{_main_source_premultiplied} ||= $is_multi;
3698 # no non-singles remaining, nor any premultiplication - nothing to collapse
3700 ! $attrs->{_main_source_premultiplied}
3702 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3704 $attrs->{collapse} = 0;
3710 # if we can not analyze the from - err on the side of safety
3711 $attrs->{_main_source_premultiplied} = 1;
3715 # generate the distinct induced group_by before injecting the prefetched select/as parts
3716 if (delete $attrs->{distinct}) {
3717 if ($attrs->{group_by}) {
3718 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3721 $attrs->{_grouped_by_distinct} = 1;
3722 # distinct affects only the main selection part, not what prefetch may add below
3723 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3725 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3726 # The thinking is: if we are collapsing the subquerying prefetch engine will
3727 # rip stuff apart for us anyway, and we do not want to have a potentially
3728 # function-converted external order_by
3729 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3730 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3734 # inject prefetch-bound selection (if any)
3735 push @{$attrs->{select}}, @prefetch_select;
3736 push @{$attrs->{as}}, @prefetch_as;
3738 $attrs->{_simple_passthrough_construction} = !(
3741 grep { $_ =~ /\./ } @{$attrs->{as}}
3744 # if both page and offset are specified, produce a combined offset
3745 # even though it doesn't make much sense, this is what pre 081xx has
3747 if (my $page = delete $attrs->{page}) {
3749 ($attrs->{rows} * ($page - 1))
3751 ($attrs->{offset} || 0)
3755 return $self->{_attrs} = $attrs;
3759 my ($self, $attr) = @_;
3761 if (ref $attr eq 'HASH') {
3762 return $self->_rollout_hash($attr);
3763 } elsif (ref $attr eq 'ARRAY') {
3764 return $self->_rollout_array($attr);
3770 sub _rollout_array {
3771 my ($self, $attr) = @_;
3774 foreach my $element (@{$attr}) {
3775 if (ref $element eq 'HASH') {
3776 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3777 } elsif (ref $element eq 'ARRAY') {
3778 # XXX - should probably recurse here
3779 push( @rolled_array, @{$self->_rollout_array($element)} );
3781 push( @rolled_array, $element );
3784 return \@rolled_array;
3788 my ($self, $attr) = @_;
3791 foreach my $key (keys %{$attr}) {
3792 push( @rolled_array, { $key => $attr->{$key} } );
3794 return \@rolled_array;
3797 sub _calculate_score {
3798 my ($self, $a, $b) = @_;
3800 if (defined $a xor defined $b) {
3803 elsif (not defined $a) {
3807 if (ref $b eq 'HASH') {
3808 my ($b_key) = keys %{$b};
3809 if (ref $a eq 'HASH') {
3810 my ($a_key) = keys %{$a};
3811 if ($a_key eq $b_key) {
3812 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3817 return ($a eq $b_key) ? 1 : 0;
3820 if (ref $a eq 'HASH') {
3821 my ($a_key) = keys %{$a};
3822 return ($b eq $a_key) ? 1 : 0;
3824 return ($b eq $a) ? 1 : 0;
3829 sub _merge_joinpref_attr {
3830 my ($self, $orig, $import) = @_;
3832 return $import unless defined($orig);
3833 return $orig unless defined($import);
3835 $orig = $self->_rollout_attr($orig);
3836 $import = $self->_rollout_attr($import);
3839 foreach my $import_element ( @{$import} ) {
3840 # find best candidate from $orig to merge $b_element into
3841 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3842 foreach my $orig_element ( @{$orig} ) {
3843 my $score = $self->_calculate_score( $orig_element, $import_element );
3844 if ($score > $best_candidate->{score}) {
3845 $best_candidate->{position} = $position;
3846 $best_candidate->{score} = $score;
3850 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3851 $import_key = '' if not defined $import_key;
3853 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3854 push( @{$orig}, $import_element );
3856 my $orig_best = $orig->[$best_candidate->{position}];
3857 # merge orig_best and b_element together and replace original with merged
3858 if (ref $orig_best ne 'HASH') {
3859 $orig->[$best_candidate->{position}] = $import_element;
3860 } elsif (ref $import_element eq 'HASH') {
3861 my ($key) = keys %{$orig_best};
3862 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3865 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3868 return @$orig ? $orig : ();
3876 require Hash::Merge;
3877 my $hm = Hash::Merge->new;
3879 $hm->specify_behavior({
3882 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3884 if ($defl xor $defr) {
3885 return [ $defl ? $_[0] : $_[1] ];
3890 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3894 return [$_[0], $_[1]];
3898 return $_[1] if !defined $_[0];
3899 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3900 return [$_[0], @{$_[1]}]
3903 return [] if !defined $_[0] and !keys %{$_[1]};
3904 return [ $_[1] ] if !defined $_[0];
3905 return [ $_[0] ] if !keys %{$_[1]};
3906 return [$_[0], $_[1]]
3911 return $_[0] if !defined $_[1];
3912 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3913 return [@{$_[0]}, $_[1]]
3916 my @ret = @{$_[0]} or return $_[1];
3917 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3918 my %idx = map { $_ => 1 } @ret;
3919 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3923 return [ $_[1] ] if ! @{$_[0]};
3924 return $_[0] if !keys %{$_[1]};
3925 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3926 return [ @{$_[0]}, $_[1] ];
3931 return [] if !keys %{$_[0]} and !defined $_[1];
3932 return [ $_[0] ] if !defined $_[1];
3933 return [ $_[1] ] if !keys %{$_[0]};
3934 return [$_[0], $_[1]]
3937 return [] if !keys %{$_[0]} and !@{$_[1]};
3938 return [ $_[0] ] if !@{$_[1]};
3939 return $_[1] if !keys %{$_[0]};
3940 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3941 return [ $_[0], @{$_[1]} ];
3944 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3945 return [ $_[0] ] if !keys %{$_[1]};
3946 return [ $_[1] ] if !keys %{$_[0]};
3947 return [ $_[0] ] if $_[0] eq $_[1];
3948 return [ $_[0], $_[1] ];
3951 } => 'DBIC_RS_ATTR_MERGER');
3955 return $hm->merge ($_[1], $_[2]);
3959 sub STORABLE_freeze {
3960 my ($self, $cloning) = @_;
3961 my $to_serialize = { %$self };
3963 # A cursor in progress can't be serialized (and would make little sense anyway)
3964 # the parser can be regenerated (and can't be serialized)
3965 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3967 # nor is it sensical to store a not-yet-fired-count pager
3968 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3969 delete $to_serialize->{pager};
3972 Storable::nfreeze($to_serialize);
3975 # need this hook for symmetry
3977 my ($self, $cloning, $serialized) = @_;
3979 %$self = %{ Storable::thaw($serialized) };
3985 =head2 throw_exception
3987 See L<DBIx::Class::Schema/throw_exception> for details.
3991 sub throw_exception {
3994 if (ref $self and my $rsrc = $self->result_source) {
3995 $rsrc->throw_exception(@_)
3998 DBIx::Class::Exception->throw(@_);
4006 # XXX: FIXME: Attributes docs need clearing up
4010 Attributes are used to refine a ResultSet in various ways when
4011 searching for data. They can be passed to any method which takes an
4012 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4015 Default attributes can be set on the result class using
4016 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4017 the CAVEATS on that feature before using it!)
4019 These are in no particular order:
4025 =item Value: ( $order_by | \@order_by | \%order_by )
4029 Which column(s) to order the results by.
4031 [The full list of suitable values is documented in
4032 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4035 If a single column name, or an arrayref of names is supplied, the
4036 argument is passed through directly to SQL. The hashref syntax allows
4037 for connection-agnostic specification of ordering direction:
4039 For descending order:
4041 order_by => { -desc => [qw/col1 col2 col3/] }
4043 For explicit ascending order:
4045 order_by => { -asc => 'col' }
4047 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4048 supported, although you are strongly encouraged to use the hashref
4049 syntax as outlined above.
4055 =item Value: \@columns | \%columns | $column
4059 Shortcut to request a particular set of columns to be retrieved. Each
4060 column spec may be a string (a table column name), or a hash (in which
4061 case the key is the C<as> value, and the value is used as the C<select>
4062 expression). Adds the L</current_source_alias> onto the start of any column without a C<.> in
4063 it and sets C<select> from that, then auto-populates C<as> from
4064 C<select> as normal. (You may also use the C<cols> attribute, as in
4065 earlier versions of DBIC, but this is deprecated)
4067 Essentially C<columns> does the same as L</select> and L</as>.
4069 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
4073 select => [qw(some_column another_column)],
4074 as => [qw(some_column dbic_slot)]
4076 If you want to individually retrieve related columns (in essence perform
4077 manual prefetch) you have to make sure to specify the correct inflation slot
4078 chain such that it matches existing relationships:
4080 my $rs = $schema->resultset('Artist')->search({}, {
4081 # required to tell DBIC to collapse has_many relationships
4083 join => { cds => 'tracks'},
4085 'cds.cdid' => 'cds.cdid',
4086 'cds.tracks.title' => 'tracks.title',
4092 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
4093 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
4094 with a unary plus operator before it, which is the same as simply C<columns>.
4098 =item Value: \@extra_columns
4102 Indicates additional columns to be selected from storage. Works the same as
4103 L</columns> but adds columns to the current selection. (You may also use the
4104 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4107 $schema->resultset('CD')->search(undef, {
4108 '+columns' => ['artist.name'],
4112 would return all CDs and include a 'name' column to the information
4113 passed to object inflation. Note that the 'artist' is the name of the
4114 column (or relationship) accessor, and 'name' is the name of the column
4115 accessor in the related table.
4121 =item Value: \@select_columns
4125 Indicates which columns should be selected from the storage. You can use
4126 column names, or in the case of RDBMS back ends, function or stored procedure
4129 $rs = $schema->resultset('Employee')->search(undef, {
4132 { count => 'employeeid' },
4133 { max => { length => 'name' }, -as => 'longest_name' }
4138 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4140 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4141 use L</select>, to instruct DBIx::Class how to store the result of the column.
4142 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4143 identifier aliasing. You can however alias a function, so you can use it in
4144 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4145 attribute> supplied as shown in the example above.
4149 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4150 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4151 with a unary plus operator before it, which is the same as simply C<select>.
4155 =item Value: \@extra_select_columns
4159 Indicates additional columns to be selected from storage. Works the same as
4160 L</select> but adds columns to the current selection, instead of specifying
4161 a new explicit list.
4167 =item Value: \@inflation_names
4171 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4172 slot name in which the column value will be stored within the
4173 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4174 identifier by the C<get_column> method (or via the object accessor B<if one
4175 with the same name already exists>) as shown below. The L</as> attribute has
4176 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4178 $rs = $schema->resultset('Employee')->search(undef, {
4181 { count => 'employeeid' },
4182 { max => { length => 'name' }, -as => 'longest_name' }
4191 If the object against which the search is performed already has an accessor
4192 matching a column name specified in C<as>, the value can be retrieved using
4193 the accessor as normal:
4195 my $name = $employee->name();
4197 If on the other hand an accessor does not exist in the object, you need to
4198 use C<get_column> instead:
4200 my $employee_count = $employee->get_column('employee_count');
4202 You can create your own accessors if required - see
4203 L<DBIx::Class::Manual::Cookbook> for details.
4207 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4208 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4209 with a unary plus operator before it, which is the same as simply C<as>.
4213 =item Value: \@extra_inflation_names
4217 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4223 =item Value: ($rel_name | \@rel_names | \%rel_names)
4227 Contains a list of relationships that should be joined for this query. For
4230 # Get CDs by Nine Inch Nails
4231 my $rs = $schema->resultset('CD')->search(
4232 { 'artist.name' => 'Nine Inch Nails' },
4233 { join => 'artist' }
4236 Can also contain a hash reference to refer to the other relation's relations.
4239 package MyApp::Schema::Track;
4240 use base qw/DBIx::Class/;
4241 __PACKAGE__->table('track');
4242 __PACKAGE__->add_columns(qw/trackid cd position title/);
4243 __PACKAGE__->set_primary_key('trackid');
4244 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4247 # In your application
4248 my $rs = $schema->resultset('Artist')->search(
4249 { 'track.title' => 'Teardrop' },
4251 join => { cd => 'track' },
4252 order_by => 'artist.name',
4256 You need to use the relationship (not the table) name in conditions,
4257 because they are aliased as such. The current table is aliased as "me", so
4258 you need to use me.column_name in order to avoid ambiguity. For example:
4260 # Get CDs from 1984 with a 'Foo' track
4261 my $rs = $schema->resultset('CD')->search(
4264 'tracks.name' => 'Foo'
4266 { join => 'tracks' }
4269 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4270 similarly for a third time). For e.g.
4272 my $rs = $schema->resultset('Artist')->search({
4273 'cds.title' => 'Down to Earth',
4274 'cds_2.title' => 'Popular',
4276 join => [ qw/cds cds/ ],
4279 will return a set of all artists that have both a cd with title 'Down
4280 to Earth' and a cd with title 'Popular'.
4282 If you want to fetch related objects from other tables as well, see L</prefetch>
4285 NOTE: An internal join-chain pruner will discard certain joins while
4286 constructing the actual SQL query, as long as the joins in question do not
4287 affect the retrieved result. This for example includes 1:1 left joins
4288 that are not part of the restriction specification (WHERE/HAVING) nor are
4289 a part of the query selection.
4291 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4297 =item Value: (0 | 1)
4301 When set to a true value, indicates that any rows fetched from joined has_many
4302 relationships are to be aggregated into the corresponding "parent" object. For
4303 example, the resultset:
4305 my $rs = $schema->resultset('CD')->search({}, {
4306 '+columns' => [ qw/ tracks.title tracks.position / ],
4311 While executing the following query:
4313 SELECT me.*, tracks.title, tracks.position
4315 LEFT JOIN track tracks
4316 ON tracks.cdid = me.cdid
4318 Will return only as many objects as there are rows in the CD source, even
4319 though the result of the query may span many rows. Each of these CD objects
4320 will in turn have multiple "Track" objects hidden behind the has_many
4321 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4322 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4323 product"), with each CD object containing exactly one of all fetched Track data.
4325 When a collapse is requested on a non-ordered resultset, an order by some
4326 unique part of the main source (the left-most table) is inserted automatically.
4327 This is done so that the resultset is allowed to be "lazy" - calling
4328 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4329 object with all of its related data.
4331 If an L</order_by> is already declared, and orders the resultset in a way that
4332 makes collapsing as described above impossible (e.g. C<< ORDER BY
4333 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4334 switch to "eager" mode and slurp the entire resultset before constructing the
4335 first object returned by L</next>.
4337 Setting this attribute on a resultset that does not join any has_many
4338 relations is a no-op.
4340 For a more in-depth discussion, see L</PREFETCHING>.
4346 =item Value: ($rel_name | \@rel_names | \%rel_names)
4350 This attribute is a shorthand for specifying a L</join> spec, adding all
4351 columns from the joined related sources as L</+columns> and setting
4352 L</collapse> to a true value. For example, the following two queries are
4355 my $rs = $schema->resultset('Artist')->search({}, {
4356 prefetch => { cds => ['genre', 'tracks' ] },
4361 my $rs = $schema->resultset('Artist')->search({}, {
4362 join => { cds => ['genre', 'tracks' ] },
4366 { +{ "cds.$_" => "cds.$_" } }
4367 $schema->source('Artist')->related_source('cds')->columns
4370 { +{ "cds.genre.$_" => "genre.$_" } }
4371 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4374 { +{ "cds.tracks.$_" => "tracks.$_" } }
4375 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4380 Both producing the following SQL:
4382 SELECT me.artistid, me.name, me.rank, me.charfield,
4383 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4384 genre.genreid, genre.name,
4385 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4388 ON cds.artist = me.artistid
4389 LEFT JOIN genre genre
4390 ON genre.genreid = cds.genreid
4391 LEFT JOIN track tracks
4392 ON tracks.cd = cds.cdid
4393 ORDER BY me.artistid
4395 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4396 the arguments are properly merged and generally do the right thing. For
4397 example, you may want to do the following:
4399 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4400 { 'genre.genreid' => undef },
4402 join => { cds => 'genre' },
4407 Which generates the following SQL:
4409 SELECT me.artistid, me.name, me.rank, me.charfield,
4410 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4413 ON cds.artist = me.artistid
4414 LEFT JOIN genre genre
4415 ON genre.genreid = cds.genreid
4416 WHERE genre.genreid IS NULL
4417 ORDER BY me.artistid
4419 For a more in-depth discussion, see L</PREFETCHING>.
4425 =item Value: $source_alias
4429 Sets the source alias for the query. Normally, this defaults to C<me>, but
4430 nested search queries (sub-SELECTs) might need specific aliases set to
4431 reference inner queries. For example:
4434 ->related_resultset('CDs')
4435 ->related_resultset('Tracks')
4437 'track.id' => { -ident => 'none_search.id' },
4441 my $ids = $self->search({
4444 alias => 'none_search',
4445 group_by => 'none_search.id',
4446 })->get_column('id')->as_query;
4448 $self->search({ id => { -in => $ids } })
4450 This attribute is directly tied to L</current_source_alias>.
4460 Makes the resultset paged and specifies the page to retrieve. Effectively
4461 identical to creating a non-pages resultset and then calling ->page($page)
4464 If L</rows> attribute is not specified it defaults to 10 rows per page.
4466 When you have a paged resultset, L</count> will only return the number
4467 of rows in the page. To get the total, use the L</pager> and call
4468 C<total_entries> on it.
4478 Specifies the maximum number of rows for direct retrieval or the number of
4479 rows per page if the page attribute or method is used.
4485 =item Value: $offset
4489 Specifies the (zero-based) row number for the first row to be returned, or the
4490 of the first row of the first page if paging is used.
4492 =head2 software_limit
4496 =item Value: (0 | 1)
4500 When combined with L</rows> and/or L</offset> the generated SQL will not
4501 include any limit dialect stanzas. Instead the entire result will be selected
4502 as if no limits were specified, and DBIC will perform the limit locally, by
4503 artificially advancing and finishing the resulting L</cursor>.
4505 This is the recommended way of performing resultset limiting when no sane RDBMS
4506 implementation is available (e.g.
4507 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4508 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4514 =item Value: \@columns
4518 A arrayref of columns to group by. Can include columns of joined tables.
4520 group_by => [qw/ column1 column2 ... /]
4526 =item Value: $condition
4530 HAVING is a select statement attribute that is applied between GROUP BY and
4531 ORDER BY. It is applied to the after the grouping calculations have been
4534 having => { 'count_employee' => { '>=', 100 } }
4536 or with an in-place function in which case literal SQL is required:
4538 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4544 =item Value: (0 | 1)
4548 Set to 1 to automatically generate a L</group_by> clause based on the selection
4549 (including intelligent handling of L</order_by> contents). Note that the group
4550 criteria calculation takes place over the B<final> selection. This includes
4551 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4552 L</search> calls, and standalone columns selected via
4553 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4554 extra selections specified via L</prefetch> - such selections are explicitly
4555 excluded from group criteria calculations.
4557 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4558 setting is ignored and an appropriate warning is issued.
4564 Adds to the WHERE clause.
4566 # only return rows WHERE deleted IS NULL for all searches
4567 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4569 Can be overridden by passing C<< { where => undef } >> as an attribute
4572 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4578 Set to 1 to cache search results. This prevents extra SQL queries if you
4579 revisit rows in your ResultSet:
4581 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4583 while( my $artist = $resultset->next ) {
4587 $rs->first; # without cache, this would issue a query
4589 By default, searches are not cached.
4591 For more examples of using these attributes, see
4592 L<DBIx::Class::Manual::Cookbook>.
4598 =item Value: ( 'update' | 'shared' | \$scalar )
4602 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4603 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4608 DBIx::Class supports arbitrary related data prefetching from multiple related
4609 sources. Any combination of relationship types and column sets are supported.
4610 If L<collapsing|/collapse> is requested, there is an additional requirement of
4611 selecting enough data to make every individual object uniquely identifiable.
4613 Here are some more involved examples, based on the following relationship map:
4616 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4617 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4618 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4620 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4622 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4626 my $rs = $schema->resultset('Tag')->search(
4635 The initial search results in SQL like the following:
4637 SELECT tag.*, cd.*, artist.* FROM tag
4638 JOIN cd ON tag.cd = cd.cdid
4639 JOIN artist ON cd.artist = artist.artistid
4641 L<DBIx::Class> has no need to go back to the database when we access the
4642 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4645 Simple prefetches will be joined automatically, so there is no need
4646 for a C<join> attribute in the above search.
4648 The L</prefetch> attribute can be used with any of the relationship types
4649 and multiple prefetches can be specified together. Below is a more complex
4650 example that prefetches a CD's artist, its liner notes (if present),
4651 the cover image, the tracks on that CD, and the guests on those
4654 my $rs = $schema->resultset('CD')->search(
4658 { artist => 'record_label'}, # belongs_to => belongs_to
4659 'liner_note', # might_have
4660 'cover_image', # has_one
4661 { tracks => 'guests' }, # has_many => has_many
4666 This will produce SQL like the following:
4668 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4672 ON artist.artistid = me.artistid
4673 JOIN record_label record_label
4674 ON record_label.labelid = artist.labelid
4675 LEFT JOIN track tracks
4676 ON tracks.cdid = me.cdid
4677 LEFT JOIN guest guests
4678 ON guests.trackid = track.trackid
4679 LEFT JOIN liner_notes liner_note
4680 ON liner_note.cdid = me.cdid
4681 JOIN cd_artwork cover_image
4682 ON cover_image.cdid = me.cdid
4685 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4686 C<tracks>, and C<guests> of the CD will all be available through the
4687 relationship accessors without the need for additional queries to the
4692 Prefetch does a lot of deep magic. As such, it may not behave exactly
4693 as you might expect.
4699 Prefetch uses the L</cache> to populate the prefetched relationships. This
4700 may or may not be what you want.
4704 If you specify a condition on a prefetched relationship, ONLY those
4705 rows that match the prefetched condition will be fetched into that relationship.
4706 This means that adding prefetch to a search() B<may alter> what is returned by
4707 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4709 my $artist_rs = $schema->resultset('Artist')->search({
4715 my $count = $artist_rs->first->cds->count;
4717 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4719 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4721 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4723 That cmp_ok() may or may not pass depending on the datasets involved. In other
4724 words the C<WHERE> condition would apply to the entire dataset, just like
4725 it would in regular SQL. If you want to add a condition only to the "right side"
4726 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4727 condition|DBIx::Class::Relationship::Base/condition>
4731 =head1 DBIC BIND VALUES
4733 Because DBIC may need more information to bind values than just the column name
4734 and value itself, it uses a special format for both passing and receiving bind
4735 values. Each bind value should be composed of an arrayref of
4736 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4742 If present (in any form), this is what is being passed directly to bind_param.
4743 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4744 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4746 If this is specified, all other bind options described below are ignored.
4750 If present, this is used to infer the actual bind attribute by passing to
4751 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4752 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4754 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4755 currently drivers are expected to "Do the Right Thing" when given a common
4756 datatype name. (Not ideal, but that's what we got at this point.)
4760 Currently used to correctly allocate buffers for bind_param_inout().
4761 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4762 or to a sensible value based on the "data_type".
4766 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4767 explicitly specified they are never overridden). Also used by some weird DBDs,
4768 where the column name should be available at bind_param time (e.g. Oracle).
4772 For backwards compatibility and convenience, the following shortcuts are
4775 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4776 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4777 [ undef, $val ] === [ {}, $val ]
4778 $val === [ {}, $val ]
4780 =head1 AUTHOR AND CONTRIBUTORS
4782 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4786 You may distribute this code under the same terms as Perl itself.