1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken reftype/;
9 use DBIx::Class::_Util qw(
10 fail_on_internal_wantarray fail_on_internal_call UNRESOLVABLE_CONDITION
13 use Data::Compare (); # no imports!!! guard against insane architecture
15 # not importing first() as it will clash with our own method
19 # De-duplication in _merge_attr() is disabled, but left in for reference
20 # (the merger is used for other things that ought not to be de-duped)
21 *__HM_DEDUP = sub () { 0 };
31 # this is real - CDBICompat overrides it with insanity
32 # yes, prototype won't matter, but that's for now ;)
35 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
39 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
43 my $users_rs = $schema->resultset('User');
44 while( $user = $users_rs->next) {
45 print $user->username;
48 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
49 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
53 A ResultSet is an object which stores a set of conditions representing
54 a query. It is the backbone of DBIx::Class (i.e. the really
55 important/useful bit).
57 No SQL is executed on the database when a ResultSet is created, it
58 just stores all the conditions needed to create the query.
60 A basic ResultSet representing the data of an entire table is returned
61 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
62 L<Source|DBIx::Class::Manual::Glossary/Source> name.
64 my $users_rs = $schema->resultset('User');
66 A new ResultSet is returned from calling L</search> on an existing
67 ResultSet. The new one will contain all the conditions of the
68 original, plus any new conditions added in the C<search> call.
70 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
71 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
74 The query that the ResultSet represents is B<only> executed against
75 the database when these methods are called:
76 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
78 If a resultset is used in a numeric context it returns the L</count>.
79 However, if it is used in a boolean context it is B<always> true. So if
80 you want to check if a resultset has any results, you must use C<if $rs
85 =head2 Chaining resultsets
87 Let's say you've got a query that needs to be run to return some data
88 to the user. But, you have an authorization system in place that
89 prevents certain users from seeing certain information. So, you want
90 to construct the basic query in one method, but add constraints to it in
95 my $request = $self->get_request; # Get a request object somehow.
96 my $schema = $self->result_source->schema;
98 my $cd_rs = $schema->resultset('CD')->search({
99 title => $request->param('title'),
100 year => $request->param('year'),
103 $cd_rs = $self->apply_security_policy( $cd_rs );
105 return $cd_rs->all();
108 sub apply_security_policy {
117 =head3 Resolving conditions and attributes
119 When a resultset is chained from another resultset (e.g.:
120 C<< my $new_rs = $old_rs->search(\%extra_cond, \%attrs) >>), conditions
121 and attributes with the same keys need resolving.
123 If any of L</columns>, L</select>, L</as> are present, they reset the
124 original selection, and start the selection "clean".
126 The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
127 are merged into the existing ones from the original resultset.
129 The L</where> and L</having> attributes, and any search conditions, are
130 merged with an SQL C<AND> to the existing condition from the original
133 All other attributes are overridden by any new ones supplied in the
136 =head2 Multiple queries
138 Since a resultset just defines a query, you can do all sorts of
139 things with it with the same object.
141 # Don't hit the DB yet.
142 my $cd_rs = $schema->resultset('CD')->search({
143 title => 'something',
147 # Each of these hits the DB individually.
148 my $count = $cd_rs->count;
149 my $most_recent = $cd_rs->get_column('date_released')->max();
150 my @records = $cd_rs->all;
152 And it's not just limited to SELECT statements.
158 $cd_rs->create({ artist => 'Fred' });
160 Which is the same as:
162 $schema->resultset('CD')->create({
163 title => 'something',
168 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
170 =head2 Custom ResultSet classes
172 To add methods to your resultsets, you can subclass L<DBIx::Class::ResultSet>, similar to:
174 package MyApp::Schema::ResultSet::User;
179 use base 'DBIx::Class::ResultSet';
183 $self->search({ $self->current_source_alias . '.active' => 1 });
188 $self->search({ $self->current_source_alias . '.verified' => 0 });
191 sub created_n_days_ago {
192 my ($self, $days_ago) = @_;
194 $self->current_source_alias . '.create_date' => {
196 $self->result_source->schema->storage->datetime_parser->format_datetime(
197 DateTime->now( time_zone => 'UTC' )->subtract( days => $days_ago )
202 sub users_to_warn { shift->active->unverified->created_n_days_ago(7) }
206 See L<DBIx::Class::Schema/load_namespaces> on how DBIC can discover and
207 automatically attach L<Result|DBIx::Class::Manual::ResultClass>-specific
208 L<ResulSet|DBIx::Class::ResultSet> classes.
210 =head3 ResultSet subclassing with Moose and similar constructor-providers
212 Using L<Moose> or L<Moo> in your ResultSet classes is usually overkill, but
213 you may find it useful if your ResultSets contain a lot of business logic
214 (e.g. C<has xml_parser>, C<has json>, etc) or if you just prefer to organize
217 In order to write custom ResultSet classes with L<Moo> you need to use the
218 following template. The L<BUILDARGS|Moo/BUILDARGS> is necessary due to the
219 unusual signature of the L<constructor provided by DBIC
220 |DBIx::Class::ResultSet/new> C<< ->new($source, \%args) >>.
223 extends 'DBIx::Class::ResultSet';
224 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
230 If you want to build your custom ResultSet classes with L<Moose>, you need
231 a similar, though a little more elaborate template in order to interface the
232 inlining of the L<Moose>-provided
233 L<object constructor|Moose::Manual::Construction/WHERE'S THE CONSTRUCTOR?>,
236 package MyApp::Schema::ResultSet::User;
239 use MooseX::NonMoose;
240 extends 'DBIx::Class::ResultSet';
242 sub BUILDARGS { $_[2] } # ::RS::new() expects my ($class, $rsrc, $args) = @_
246 __PACKAGE__->meta->make_immutable;
250 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
251 entirely overwrite the DBIC one (in contrast L<Moo> does this automatically).
252 Alternatively, you can skip L<MooseX::NonMoose> and get by with just L<Moose>
255 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
263 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
265 =item Return Value: L<$resultset|/search>
269 The resultset constructor. Takes a source object (usually a
270 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
271 L</ATTRIBUTES> below). Does not perform any queries -- these are
272 executed as needed by the other methods.
274 Generally you never construct a resultset manually. Instead you get one
276 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
277 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
280 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
286 If called on an object, proxies to L</new_result> instead, so
288 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
290 will return a CD object, not a ResultSet, and is equivalent to:
292 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
294 Please also keep in mind that many internals call L</new_result> directly,
295 so overloading this method with the idea of intercepting new result object
296 creation B<will not work>. See also warning pertaining to L</create>.
306 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
307 return $class->new_result(@_);
310 my ($source, $attrs) = @_;
311 $source = $source->resolve
312 if $source->isa('DBIx::Class::ResultSourceHandle');
314 $attrs = { %{$attrs||{}} };
315 delete @{$attrs}{qw(_last_sqlmaker_alias_map _simple_passthrough_construction)};
317 if ($attrs->{page}) {
318 $attrs->{rows} ||= 10;
321 $attrs->{alias} ||= 'me';
324 result_source => $source,
325 cond => $attrs->{where},
330 # if there is a dark selector, this means we are already in a
331 # chain and the cleanup/sanification was taken care of by
333 $self->_normalize_selection($attrs)
334 unless $attrs->{_dark_selector};
337 $attrs->{result_class} || $source->result_class
347 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
349 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
353 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
354 my $new_rs = $cd_rs->search({ year => 2005 });
356 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
357 # year = 2005 OR year = 2004
359 In list context, C<< ->all() >> is called implicitly on the resultset, thus
360 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
361 To avoid that, use L</search_rs>.
363 If you need to pass in additional attributes but no additional condition,
364 call it as C<search(undef, \%attrs)>.
366 # "SELECT name, artistid FROM $artist_table"
367 my @all_artists = $schema->resultset('Artist')->search(undef, {
368 columns => [qw/name artistid/],
371 For a list of attributes that can be passed to C<search>, see
372 L</ATTRIBUTES>. For more examples of using this function, see
373 L<Searching|DBIx::Class::Manual::Cookbook/SEARCHING>. For a complete
374 documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
375 and its extension L<DBIx::Class::SQLMaker>.
377 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
381 Note that L</search> does not process/deflate any of the values passed in the
382 L<SQL::Abstract>-compatible search condition structure. This is unlike other
383 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
384 manually that any value passed to this method will stringify to something the
385 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
386 objects, for more info see:
387 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
393 my $rs = $self->search_rs( @_ );
396 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_WANTARRAY and my $sog = fail_on_internal_wantarray;
399 elsif (defined wantarray) {
403 # we can be called by a relationship helper, which in
404 # turn may be called in void context due to some braindead
405 # overload or whatever else the user decided to be clever
406 # at this particular day. Thus limit the exception to
407 # external code calls only
408 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
409 if (caller)[0] !~ /^\QDBIx::Class::/;
419 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
421 =item Return Value: L<$resultset|/search>
425 This method does the same exact thing as search() except it will
426 always return a resultset, even in list context.
433 my $rsrc = $self->result_source;
434 my ($call_cond, $call_attrs);
436 # Special-case handling for (undef, undef) or (undef)
437 # Note that (foo => undef) is valid deprecated syntax
438 @_ = () if not scalar grep { defined $_ } @_;
444 # fish out attrs in the ($condref, $attr) case
445 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
446 ($call_cond, $call_attrs) = @_;
449 $self->throw_exception('Odd number of arguments to search')
453 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
454 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
456 for my $i (0 .. $#_) {
458 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
459 if (! defined $_[$i] or ref $_[$i] ne '');
465 # see if we can keep the cache (no $rs changes)
467 my %safe = (alias => 1, cache => 1);
468 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
471 ref $call_cond eq 'HASH' && ! keys %$call_cond
473 ref $call_cond eq 'ARRAY' && ! @$call_cond
475 $cache = $self->get_cache;
478 my $old_attrs = { %{$self->{attrs}} };
479 my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
481 my $new_attrs = { %$old_attrs };
483 # take care of call attrs (only if anything is changing)
484 if ($call_attrs and keys %$call_attrs) {
486 # copy for _normalize_selection
487 $call_attrs = { %$call_attrs };
489 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
491 # reset the current selector list if new selectors are supplied
492 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
493 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
496 # Normalize the new selector list (operates on the passed-in attr structure)
497 # Need to do it on every chain instead of only once on _resolved_attrs, in
498 # order to allow detection of empty vs partial 'as'
499 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
500 if $old_attrs->{_dark_selector};
501 $self->_normalize_selection ($call_attrs);
503 # start with blind overwriting merge, exclude selector attrs
504 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
505 delete @{$new_attrs}{@selector_attrs};
507 for (@selector_attrs) {
508 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
509 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
512 # older deprecated name, use only if {columns} is not there
513 if (my $c = delete $new_attrs->{cols}) {
514 carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
515 if ($new_attrs->{columns}) {
516 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
519 $new_attrs->{columns} = $c;
524 # join/prefetch use their own crazy merging heuristics
525 foreach my $key (qw/join prefetch/) {
526 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
527 if exists $call_attrs->{$key};
530 # stack binds together
531 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
535 for ($old_where, $call_cond) {
537 $new_attrs->{where} = $self->_stack_cond (
538 $_, $new_attrs->{where}
543 if (defined $old_having) {
544 $new_attrs->{having} = $self->_stack_cond (
545 $old_having, $new_attrs->{having}
549 my $rs = (ref $self)->new($rsrc, $new_attrs);
551 $rs->set_cache($cache) if ($cache);
557 sub _normalize_selection {
558 my ($self, $attrs) = @_;
561 if ( exists $attrs->{include_columns} ) {
562 carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
563 $attrs->{'+columns'} = $self->_merge_attr(
564 $attrs->{'+columns'}, delete $attrs->{include_columns}
568 # columns are always placed first, however
570 # Keep the X vs +X separation until _resolved_attrs time - this allows to
571 # delay the decision on whether to use a default select list ($rsrc->columns)
572 # allowing stuff like the remove_columns helper to work
574 # select/as +select/+as pairs need special handling - the amount of select/as
575 # elements in each pair does *not* have to be equal (think multicolumn
576 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
577 # supplied at all) - try to infer the alias, either from the -as parameter
578 # of the selector spec, or use the parameter whole if it looks like a column
579 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
580 # is ok as well), but make sure no more additions to the 'as' chain take place
581 for my $pref ('', '+') {
583 my ($sel, $as) = map {
584 my $key = "${pref}${_}";
586 my $val = [ ref $attrs->{$key} eq 'ARRAY'
588 : $attrs->{$key} || ()
590 delete $attrs->{$key};
594 if (! @$as and ! @$sel ) {
597 elsif (@$as and ! @$sel) {
598 $self->throw_exception(
599 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
603 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
604 # if any @$as has been supplied we assume the user knows what (s)he is doing
605 # and blindly keep stacking up pieces
606 unless ($attrs->{_dark_selector}) {
609 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
610 push @$as, $_->{-as};
612 # assume any plain no-space, no-parenthesis string to be a column spec
613 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
614 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
617 # if all else fails - raise a flag that no more aliasing will be allowed
619 $attrs->{_dark_selector} = {
621 string => ($dark_sel_dumper ||= do {
622 require Data::Dumper::Concise;
623 Data::Dumper::Concise::DumperObject()->Indent(0);
624 })->Values([$_])->Dump
632 elsif (@$as < @$sel) {
633 $self->throw_exception(
634 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
637 elsif ($pref and $attrs->{_dark_selector}) {
638 $self->throw_exception(
639 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
645 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
646 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
651 my ($self, $left, $right) = @_;
654 (ref $_ eq 'ARRAY' and !@$_)
656 (ref $_ eq 'HASH' and ! keys %$_)
657 ) and $_ = undef for ($left, $right);
659 # either on of the two undef or both undef
660 if ( ( (defined $left) xor (defined $right) ) or ! defined $left ) {
661 return defined $left ? $left : $right;
664 my $cond = $self->result_source->schema->storage->_collapse_cond({ -and => [$left, $right] });
666 for my $c (grep { ref $cond->{$_} eq 'ARRAY' and ($cond->{$_}[0]||'') eq '-and' } keys %$cond) {
668 my @vals = sort @{$cond->{$c}}[ 1..$#{$cond->{$c}} ];
669 my @fin = shift @vals;
672 push @fin, $v unless Data::Compare::Compare( $fin[-1], $v );
675 $cond->{$c} = (@fin == 1) ? $fin[0] : [-and => @fin ];
681 =head2 search_literal
683 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
684 should only be used in that context. C<search_literal> is a convenience
685 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
686 want to ensure columns are bound correctly, use L</search>.
688 See L<DBIx::Class::Manual::Cookbook/SEARCHING> and
689 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
690 require C<search_literal>.
694 =item Arguments: $sql_fragment, @standalone_bind_values
696 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
700 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
701 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
703 Pass a literal chunk of SQL to be added to the conditional part of the
706 Example of how to use C<search> instead of C<search_literal>
708 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
709 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
714 my ($self, $sql, @bind) = @_;
716 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
719 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
726 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
728 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
732 Finds and returns a single row based on supplied criteria. Takes either a
733 hashref with the same format as L</create> (including inference of foreign
734 keys from related objects), or a list of primary key values in the same
735 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
736 declaration on the L</result_source>.
738 In either case an attempt is made to combine conditions already existing on
739 the resultset with the condition passed to this method.
741 To aid with preparing the correct query for the storage you may supply the
742 C<key> attribute, which is the name of a
743 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
744 unique constraint corresponding to the
745 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
746 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
747 to construct a query that satisfies the named unique constraint fully (
748 non-NULL values for each column member of the constraint) an exception is
751 If no C<key> is specified, the search is carried over all unique constraints
752 which are fully defined by the available condition.
754 If no such constraint is found, C<find> currently defaults to a simple
755 C<< search->(\%column_values) >> which may or may not do what you expect.
756 Note that this fallback behavior may be deprecated in further versions. If
757 you need to search with arbitrary conditions - use L</search>. If the query
758 resulting from this fallback produces more than one row, a warning to the
759 effect is issued, though only the first row is constructed and returned as
762 In addition to C<key>, L</find> recognizes and applies standard
763 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
765 Note that if you have extra concerns about the correctness of the resulting
766 query you need to specify the C<key> attribute and supply the entire condition
767 as an argument to find (since it is not always possible to perform the
768 combination of the resultset condition with the supplied one, especially if
769 the resultset condition contains literal sql).
771 For example, to find a row by its primary key:
773 my $cd = $schema->resultset('CD')->find(5);
775 You can also find a row by a specific unique constraint:
777 my $cd = $schema->resultset('CD')->find(
779 artist => 'Massive Attack',
780 title => 'Mezzanine',
782 { key => 'cd_artist_title' }
785 See also L</find_or_create> and L</update_or_create>.
791 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
793 my $rsrc = $self->result_source;
796 if (exists $attrs->{key}) {
797 $constraint_name = defined $attrs->{key}
799 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
803 # Parse out the condition from input
806 if (ref $_[0] eq 'HASH') {
807 $call_cond = { %{$_[0]} };
810 # if only values are supplied we need to default to 'primary'
811 $constraint_name = 'primary' unless defined $constraint_name;
813 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
815 $self->throw_exception(
816 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
819 $self->throw_exception (
820 'find() expects either a column/value hashref, or a list of values '
821 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
822 ) unless @c_cols == @_;
825 @{$call_cond}{@c_cols} = @_;
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;
851 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
853 if (defined $constraint_name) {
854 $final_cond = $self->_qualify_cond_columns (
856 $self->_build_unique_cond (
864 elsif ($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 # no key was specified - fall down to heuristics mode:
874 # run through all unique queries registered on the resultset, and
875 # 'OR' all qualifying queries together
876 my (@unique_queries, %seen_column_combinations);
877 for my $c_name ($rsrc->unique_constraint_names) {
878 next if $seen_column_combinations{
879 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
882 push @unique_queries, try {
883 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
887 $final_cond = @unique_queries
888 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
889 : $self->_non_unique_find_fallback ($call_cond, $attrs)
893 # Run the query, passing the result_class since it should propagate for find
894 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
895 if ($rs->_resolved_attrs->{collapse}) {
897 carp "Query returned more than one row" if $rs->next;
905 # This is a stop-gap method as agreed during the discussion on find() cleanup:
906 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
908 # It is invoked when find() is called in legacy-mode with insufficiently-unique
909 # condition. It is provided for overrides until a saner way forward is devised
911 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
912 # the road. Please adjust your tests accordingly to catch this situation early
913 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
915 # The method will not be removed without an adequately complete replacement
916 # for strict-mode enforcement
917 sub _non_unique_find_fallback {
918 my ($self, $cond, $attrs) = @_;
920 return $self->_qualify_cond_columns(
922 exists $attrs->{alias}
924 : $self->{attrs}{alias}
929 sub _qualify_cond_columns {
930 my ($self, $cond, $alias) = @_;
932 my %aliased = %$cond;
933 for (keys %aliased) {
934 $aliased{"$alias.$_"} = delete $aliased{$_}
941 sub _build_unique_cond {
942 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
944 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
946 # combination may fail if $self->{cond} is non-trivial
947 my ($final_cond) = try {
948 $self->_merge_with_rscond ($extra_cond)
953 # trim out everything not in $columns
954 $final_cond = { map {
955 exists $final_cond->{$_}
956 ? ( $_ => $final_cond->{$_} )
960 if (my @missing = grep
961 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
964 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
966 join (', ', map { "'$_'" } @missing),
973 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
975 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
977 carp_unique ( sprintf (
978 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
979 . 'values in column(s): %s). This is almost certainly not what you wanted, '
980 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
982 join (', ', map { "'$_'" } @undefs),
989 =head2 search_related
993 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
995 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
999 $new_rs = $cd_rs->search_related('artist', {
1003 Searches the specified relationship, optionally specifying a condition and
1004 attributes for matching records. See L</ATTRIBUTES> for more information.
1006 In list context, C<< ->all() >> is called implicitly on the resultset, thus
1007 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
1009 See also L</search_related_rs>.
1013 sub search_related {
1014 return shift->related_resultset(shift)->search(@_);
1017 =head2 search_related_rs
1019 This method works exactly the same as search_related, except that
1020 it guarantees a resultset, even in list context.
1024 sub search_related_rs {
1025 return shift->related_resultset(shift)->search_rs(@_);
1032 =item Arguments: none
1034 =item Return Value: L<$cursor|DBIx::Class::Cursor>
1038 Returns a storage-driven cursor to the given resultset. See
1039 L<DBIx::Class::Cursor> for more information.
1046 return $self->{cursor} ||= do {
1047 my $attrs = $self->_resolved_attrs;
1048 $self->result_source->storage->select(
1049 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1058 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1060 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1064 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1066 Inflates the first result without creating a cursor if the resultset has
1067 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1070 While this method can take an optional search condition (just like L</search>)
1071 being a fast-code-path it does not recognize search attributes. If you need to
1072 add extra joins or similar, call L</search> and then chain-call L</single> on the
1073 L<DBIx::Class::ResultSet> returned.
1079 As of 0.08100, this method enforces the assumption that the preceding
1080 query returns only one row. If more than one row is returned, you will receive
1083 Query returned more than one row
1085 In this case, you should be using L</next> or L</find> instead, or if you really
1086 know what you are doing, use the L</rows> attribute to explicitly limit the size
1089 This method will also throw an exception if it is called on a resultset prefetching
1090 has_many, as such a prefetch implies fetching multiple rows from the database in
1091 order to assemble the resulting object.
1098 my ($self, $where) = @_;
1100 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1103 my $attrs = { %{$self->_resolved_attrs} };
1105 $self->throw_exception(
1106 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
1107 ) if $attrs->{collapse};
1110 if (defined $attrs->{where}) {
1113 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1114 $where, delete $attrs->{where} ]
1117 $attrs->{where} = $where;
1121 my $data = [ $self->result_source->storage->select_single(
1122 $attrs->{from}, $attrs->{select},
1123 $attrs->{where}, $attrs
1126 return undef unless @$data;
1127 $self->{_stashed_rows} = [ $data ];
1128 $self->_construct_results->[0];
1135 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1137 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1141 my $max_length = $rs->get_column('length')->max;
1143 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1148 my ($self, $column) = @_;
1149 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1157 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1159 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1163 # WHERE title LIKE '%blue%'
1164 $cd_rs = $rs->search_like({ title => '%blue%'});
1166 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1167 that this is simply a convenience method retained for ex Class::DBI users.
1168 You most likely want to use L</search> with specific operators.
1170 For more information, see L<DBIx::Class::Manual::Cookbook>.
1172 This method is deprecated and will be removed in 0.09. Use L</search()>
1173 instead. An example conversion is:
1175 ->search_like({ foo => 'bar' });
1179 ->search({ foo => { like => 'bar' } });
1186 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1187 .' Instead use ->search({ x => { -like => "y%" } })'
1188 .' (note the outer pair of {}s - they are important!)'
1190 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1191 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1192 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1193 return $class->search($query, { %$attrs });
1200 =item Arguments: $first, $last
1202 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1206 Returns a resultset or object list representing a subset of elements from the
1207 resultset slice is called on. Indexes are from 0, i.e., to get the first
1208 three records, call:
1210 my ($one, $two, $three) = $rs->slice(0, 2);
1215 my ($self, $min, $max) = @_;
1216 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1217 $attrs->{offset} = $self->{attrs}{offset} || 0;
1218 $attrs->{offset} += $min;
1219 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1220 return $self->search(undef, $attrs);
1227 =item Arguments: none
1229 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1233 Returns the next element in the resultset (C<undef> is there is none).
1235 Can be used to efficiently iterate over records in the resultset:
1237 my $rs = $schema->resultset('CD')->search;
1238 while (my $cd = $rs->next) {
1242 Note that you need to store the resultset object, and call C<next> on it.
1243 Calling C<< resultset('Table')->next >> repeatedly will always return the
1244 first record from the resultset.
1251 if (my $cache = $self->get_cache) {
1252 $self->{all_cache_position} ||= 0;
1253 return $cache->[$self->{all_cache_position}++];
1256 if ($self->{attrs}{cache}) {
1257 delete $self->{pager};
1258 $self->{all_cache_position} = 1;
1259 return ($self->all)[0];
1262 return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
1264 $self->{_stashed_results} = $self->_construct_results
1267 return shift @{$self->{_stashed_results}};
1270 # Constructs as many results as it can in one pass while respecting
1271 # cursor laziness. Several modes of operation:
1273 # * Always builds everything present in @{$self->{_stashed_rows}}
1274 # * If called with $fetch_all true - pulls everything off the cursor and
1275 # builds all result structures (or objects) in one pass
1276 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1277 # and if the resultset is ordered properly by the left side:
1278 # * Fetches stuff off the cursor until the "master object" changes,
1279 # and saves the last extra row (if any) in @{$self->{_stashed_rows}}
1281 # * Just fetches, and collapses/constructs everything as if $fetch_all
1282 # was requested (there is no other way to collapse except for an
1284 # * If no collapse is requested - just get the next row, construct and
1286 sub _construct_results {
1287 my ($self, $fetch_all) = @_;
1289 my $rsrc = $self->result_source;
1290 my $attrs = $self->_resolved_attrs;
1295 ! $attrs->{order_by}
1299 my @pcols = $rsrc->primary_columns
1301 # default order for collapsing unless the user asked for something
1302 $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
1303 $attrs->{_ordered_for_collapse} = 1;
1304 $attrs->{_order_is_artificial} = 1;
1307 # this will be used as both initial raw-row collector AND as a RV of
1308 # _construct_results. Not regrowing the array twice matters a lot...
1309 # a surprising amount actually
1310 my $rows = delete $self->{_stashed_rows};
1312 my $cursor; # we may not need one at all
1314 my $did_fetch_all = $fetch_all;
1317 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1318 $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
1320 elsif( $attrs->{collapse} ) {
1322 # a cursor will need to be closed over in case of collapse
1323 $cursor = $self->cursor;
1325 $attrs->{_ordered_for_collapse} = (
1331 ->_extract_colinfo_of_stable_main_source_order_by_portion($attrs)
1333 ) unless defined $attrs->{_ordered_for_collapse};
1335 if (! $attrs->{_ordered_for_collapse}) {
1338 # instead of looping over ->next, use ->all in stealth mode
1339 # *without* calling a ->reset afterwards
1340 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1341 if (! $cursor->{_done}) {
1342 $rows = [ ($rows ? @$rows : ()), $cursor->all ];
1343 $cursor->{_done} = 1;
1348 if (! $did_fetch_all and ! @{$rows||[]} ) {
1349 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1350 $cursor ||= $self->cursor;
1351 if (scalar (my @r = $cursor->next) ) {
1356 return undef unless @{$rows||[]};
1358 # sanity check - people are too clever for their own good
1359 if ($attrs->{collapse} and my $aliastypes = $attrs->{_last_sqlmaker_alias_map} ) {
1361 my $multiplied_selectors;
1362 for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
1364 $aliastypes->{multiplying}{$sel_alias}
1366 $aliastypes->{premultiplied}{$sel_alias}
1368 $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
1372 for my $i (0 .. $#{$attrs->{as}} ) {
1373 my $sel = $attrs->{select}[$i];
1375 if (ref $sel eq 'SCALAR') {
1378 elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
1382 $self->throw_exception(
1383 'Result collapse not possible - selection from a has_many source redirected to the main object'
1384 ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
1388 # hotspot - skip the setter
1389 my $res_class = $self->_result_class;
1391 my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
1392 $res_class->can ('inflate_result')
1393 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1396 my $infmap = $attrs->{as};
1398 $self->{_result_inflator}{is_core_row} = ( (
1401 ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
1402 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
1404 $self->{_result_inflator}{is_hri} = ( (
1405 ! $self->{_result_inflator}{is_core_row}
1408 require DBIx::Class::ResultClass::HashRefInflator
1410 DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
1412 ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
1415 if ($attrs->{_simple_passthrough_construction}) {
1416 # construct a much simpler array->hash folder for the one-table HRI cases right here
1417 if ($self->{_result_inflator}{is_hri}) {
1418 for my $r (@$rows) {
1419 $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
1422 # FIXME SUBOPTIMAL this is a very very very hot spot
1423 # while rather optimal we can *still* do much better, by
1424 # building a smarter Row::inflate_result(), and
1425 # switch to feeding it data via a much leaner interface
1427 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1428 # this particular resultset size
1429 elsif ( $self->{_result_inflator}{is_core_row} and @$rows < 60 ) {
1430 for my $r (@$rows) {
1431 $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
1436 ( $self->{_result_inflator}{is_core_row}
1437 ? '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows'
1438 # a custom inflator may be a multiplier/reductor - put it in direct list ctx
1439 : '@$rows = map { $inflator_cref->($res_class, $rsrc, { %s } ) } @$rows'
1441 ( join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) )
1447 $self->{_result_inflator}{is_hri} ? 'hri'
1448 : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
1449 : 'classic_nonpruning'
1452 # $args and $attrs to _mk_row_parser are separated to delineate what is
1453 # core collapser stuff and what is dbic $rs specific
1454 @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
1456 inflate_map => $infmap,
1457 collapse => $attrs->{collapse},
1458 premultiplied => $attrs->{_main_source_premultiplied},
1459 hri_style => $self->{_result_inflator}{is_hri},
1460 prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
1461 }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
1463 # column_info metadata historically hasn't been too reliable.
1464 # We need to start fixing this somehow (the collapse resolver
1465 # can't work without it). Add an explicit check for the *main*
1466 # result, hopefully this will gradually weed out such errors
1468 # FIXME - this is a temporary kludge that reduces performance
1469 # It is however necessary for the time being
1470 my ($unrolled_non_null_cols_to_check, $err);
1472 if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
1475 'Collapse aborted due to invalid ResultSource metadata - the following '
1476 . 'selections are declared non-nullable but NULLs were retrieved: '
1480 COL: for my $i (@$check_non_null_cols) {
1481 ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
1484 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1487 $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
1491 ($did_fetch_all or ! $attrs->{collapse}) ? undef
1492 : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
1494 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1495 my @r = $cursor->next or return;
1496 if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
1497 $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
1503 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1504 my @r = $cursor->next or return;
1509 $self->{_row_parser}{$parser_type}{cref}->(
1511 $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
1514 # simple in-place substitution, does not regrow $rows
1515 if ($self->{_result_inflator}{is_core_row}) {
1516 $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
1518 # Special-case multi-object HRI - there is no $inflator_cref pass at all
1519 elsif ( ! $self->{_result_inflator}{is_hri} ) {
1520 # the inflator may be a multiplier/reductor - put it in list ctx
1521 @$rows = map { $inflator_cref->($res_class, $rsrc, @$_) } @$rows;
1525 # The @$rows check seems odd at first - why wouldn't we want to warn
1526 # regardless? The issue is things like find() etc, where the user
1527 # *knows* only one result will come back. In these cases the ->all
1528 # is not a pessimization, but rather something we actually want
1530 'Unable to properly collapse has_many results in iterator mode due '
1531 . 'to order criteria - performed an eager cursor slurp underneath. '
1532 . 'Consider using ->all() instead'
1533 ) if ( ! $fetch_all and @$rows > 1 );
1538 =head2 result_source
1542 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1544 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1548 An accessor for the primary ResultSource object from which this ResultSet
1555 =item Arguments: $result_class?
1557 =item Return Value: $result_class
1561 An accessor for the class to use when creating result objects. Defaults to
1562 C<< result_source->result_class >> - which in most cases is the name of the
1563 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1565 Note that changing the result_class will also remove any components
1566 that were originally loaded in the source class via
1567 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1568 in the original source class will not run.
1573 my ($self, $result_class) = @_;
1574 if ($result_class) {
1576 # don't fire this for an object
1577 $self->ensure_class_loaded($result_class)
1578 unless ref($result_class);
1580 if ($self->get_cache) {
1581 carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
1583 # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
1584 elsif ($self->{cursor} && $self->{cursor}{_pos}) {
1585 $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
1588 $self->_result_class($result_class);
1590 delete $self->{_result_inflator};
1592 $self->_result_class;
1599 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1601 =item Return Value: $count
1605 Performs an SQL C<COUNT> with the same query as the resultset was built
1606 with to find the number of elements. Passing arguments is equivalent to
1607 C<< $rs->search ($cond, \%attrs)->count >>
1613 return $self->search(@_)->count if @_ and defined $_[0];
1614 return scalar @{ $self->get_cache } if $self->get_cache;
1616 my $attrs = { %{ $self->_resolved_attrs } };
1618 # this is a little optimization - it is faster to do the limit
1619 # adjustments in software, instead of a subquery
1620 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1623 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1624 $crs = $self->_count_subq_rs ($attrs);
1627 $crs = $self->_count_rs ($attrs);
1629 my $count = $crs->next;
1631 $count -= $offset if $offset;
1632 $count = $rows if $rows and $rows < $count;
1633 $count = 0 if ($count < 0);
1642 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1644 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1648 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1649 This can be very handy for subqueries:
1651 ->search( { amount => $some_rs->count_rs->as_query } )
1653 As with regular resultsets the SQL query will be executed only after
1654 the resultset is accessed via L</next> or L</all>. That would return
1655 the same single value obtainable via L</count>.
1661 return $self->search(@_)->count_rs if @_;
1663 # this may look like a lack of abstraction (count() does about the same)
1664 # but in fact an _rs *must* use a subquery for the limits, as the
1665 # software based limiting can not be ported if this $rs is to be used
1666 # in a subquery itself (i.e. ->as_query)
1667 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1668 return $self->_count_subq_rs($self->{_attrs});
1671 return $self->_count_rs($self->{_attrs});
1676 # returns a ResultSetColumn object tied to the count query
1679 my ($self, $attrs) = @_;
1681 my $rsrc = $self->result_source;
1683 my $tmp_attrs = { %$attrs };
1684 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1685 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1687 # overwrite the selector (supplied by the storage)
1688 $rsrc->resultset_class->new($rsrc, {
1690 select => $rsrc->storage->_count_select ($rsrc, $attrs),
1692 })->get_column ('count');
1696 # same as above but uses a subquery
1698 sub _count_subq_rs {
1699 my ($self, $attrs) = @_;
1701 my $rsrc = $self->result_source;
1703 my $sub_attrs = { %$attrs };
1704 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1705 delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
1707 # if we multi-prefetch we group_by something unique, as this is what we would
1708 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1709 if ( $attrs->{collapse} ) {
1710 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1711 $rsrc->_identifying_column_set || $self->throw_exception(
1712 'Unable to construct a unique group_by criteria properly collapsing the '
1713 . 'has_many prefetch before count()'
1718 # Calculate subquery selector
1719 if (my $g = $sub_attrs->{group_by}) {
1721 my $sql_maker = $rsrc->storage->sql_maker;
1723 # necessary as the group_by may refer to aliased functions
1725 for my $sel (@{$attrs->{select}}) {
1726 $sel_index->{$sel->{-as}} = $sel
1727 if (ref $sel eq 'HASH' and $sel->{-as});
1730 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1731 # also look for named aggregates referred in the having clause
1732 # having often contains scalarrefs - thus parse it out entirely
1734 if ($attrs->{having}) {
1735 local $sql_maker->{having_bind};
1736 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1737 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1738 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1739 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1740 # if we don't unset it we screw up retarded but unfortunately working
1741 # 'MAX(foo.bar)' => { '>', 3 }
1742 $sql_maker->{name_sep} = '';
1745 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1747 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1750 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1751 # and if all fails for an utterly naive quoted scalar-with-function
1752 while ($having_sql =~ /
1753 $rquote $sep $lquote (.+?) $rquote
1755 [\s,] \w+ \. (\w+) [\s,]
1757 [\s,] $lquote (.+?) $rquote [\s,]
1759 my $part = $1 || $2 || $3; # one of them matched if we got here
1760 unless ($seen_having{$part}++) {
1767 my $colpiece = $sel_index->{$_} || $_;
1769 # unqualify join-based group_by's. Arcane but possible query
1770 # also horrible horrible hack to alias a column (not a func.)
1771 # (probably need to introduce SQLA syntax)
1772 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1775 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1777 push @{$sub_attrs->{select}}, $colpiece;
1781 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1782 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1785 return $rsrc->resultset_class
1786 ->new ($rsrc, $sub_attrs)
1788 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1789 ->get_column ('count');
1793 =head2 count_literal
1795 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1796 should only be used in that context. See L</search_literal> for further info.
1800 =item Arguments: $sql_fragment, @standalone_bind_values
1802 =item Return Value: $count
1806 Counts the results in a literal query. Equivalent to calling L</search_literal>
1807 with the passed arguments, then L</count>.
1811 sub count_literal { shift->search_literal(@_)->count; }
1817 =item Arguments: none
1819 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1823 Returns all elements in the resultset.
1830 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1833 delete @{$self}{qw/_stashed_rows _stashed_results/};
1835 if (my $c = $self->get_cache) {
1839 $self->cursor->reset;
1841 my $objs = $self->_construct_results('fetch_all') || [];
1843 $self->set_cache($objs) if $self->{attrs}{cache};
1852 =item Arguments: none
1854 =item Return Value: $self
1858 Resets the resultset's cursor, so you can iterate through the elements again.
1859 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1867 delete @{$self}{qw/_stashed_rows _stashed_results/};
1868 $self->{all_cache_position} = 0;
1869 $self->cursor->reset;
1877 =item Arguments: none
1879 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1883 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1884 an object for the first result (or C<undef> if the resultset is empty).
1889 return $_[0]->reset->next;
1895 # Determines whether and what type of subquery is required for the $rs operation.
1896 # If grouping is necessary either supplies its own, or verifies the current one
1897 # After all is done delegates to the proper storage method.
1899 sub _rs_update_delete {
1900 my ($self, $op, $values) = @_;
1902 my $rsrc = $self->result_source;
1903 my $storage = $rsrc->schema->storage;
1905 my $attrs = { %{$self->_resolved_attrs} };
1907 my $join_classifications;
1908 my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
1910 # do we need a subquery for any reason?
1912 defined $existing_group_by
1914 # if {from} is unparseable wrap a subq
1915 ref($attrs->{from}) ne 'ARRAY'
1917 # limits call for a subq
1918 $self->_has_resolved_attr(qw/rows offset/)
1921 # simplify the joinmap, so we can further decide if a subq is necessary
1922 if (!$needs_subq and @{$attrs->{from}} > 1) {
1924 ($attrs->{from}, $join_classifications) =
1925 $storage->_prune_unused_joins ($attrs);
1927 # any non-pruneable non-local restricting joins imply subq
1928 $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
1931 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1933 (ref $attrs->{from}[0]) ne 'HASH'
1935 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1939 # do we need anything like a subquery?
1940 if (! $needs_subq) {
1941 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1942 # a condition containing 'me' or other table prefixes will not work
1943 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1945 my $sqla = $rsrc->storage->sql_maker;
1946 local $sqla->{_dequalify_idents} = 1;
1947 \[ $sqla->_recurse_where($self->{cond}) ];
1951 # we got this far - means it is time to wrap a subquery
1952 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1954 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1960 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1961 delete $attrs->{$_} for qw/select as collapse/;
1962 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1964 # this will be consumed by the pruner waaaaay down the stack
1965 $attrs->{_force_prune_multiplying_joins} = 1;
1967 my $subrs = (ref $self)->new($rsrc, $attrs);
1969 if (@$idcols == 1) {
1970 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1972 elsif ($storage->_use_multicolumn_in) {
1973 # no syntax for calling this properly yet
1974 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1975 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1976 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1981 # if all else fails - get all primary keys and operate over a ORed set
1982 # wrap in a transaction for consistency
1983 # this is where the group_by/multiplication starts to matter
1987 # we do not need to check pre-multipliers, since if the premulti is there, its
1988 # parent (who is multi) will be there too
1989 keys %{ $join_classifications->{multiplying} || {} }
1991 # make sure if there is a supplied group_by it matches the columns compiled above
1992 # perfectly. Anything else can not be sanely executed on most databases so croak
1993 # right then and there
1994 if ($existing_group_by) {
1995 my @current_group_by = map
1996 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
2001 join ("\x00", sort @current_group_by)
2003 join ("\x00", sort @{$attrs->{columns}} )
2005 $self->throw_exception (
2006 "You have just attempted a $op operation on a resultset which does group_by"
2007 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
2008 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
2009 . ' kind of queries. Please retry the operation with a modified group_by or'
2010 . ' without using one at all.'
2015 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
2018 $guard = $storage->txn_scope_guard;
2020 for my $row ($subrs->cursor->all) {
2022 { $idcols->[$_] => $row->[$_] }
2029 my $res = $cond ? $storage->$op (
2031 $op eq 'update' ? $values : (),
2035 $guard->commit if $guard;
2044 =item Arguments: \%values
2046 =item Return Value: $underlying_storage_rv
2050 Sets the specified columns in the resultset to the supplied values in a
2051 single query. Note that this will not run any accessor/set_column/update
2052 triggers, nor will it update any result object instances derived from this
2053 resultset (this includes the contents of the L<resultset cache|/set_cache>
2054 if any). See L</update_all> if you need to execute any on-update
2055 triggers or cascades defined either by you or a
2056 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2058 The return value is a pass through of what the underlying
2059 storage backend returned, and may vary. See L<DBI/execute> for the most
2064 Note that L</update> does not process/deflate any of the values passed in.
2065 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
2066 ensure manually that any value passed to this method will stringify to
2067 something the RDBMS knows how to deal with. A notable example is the
2068 handling of L<DateTime> objects, for more info see:
2069 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
2074 my ($self, $values) = @_;
2075 $self->throw_exception('Values for update must be a hash')
2076 unless ref $values eq 'HASH';
2078 return $self->_rs_update_delete ('update', $values);
2085 =item Arguments: \%values
2087 =item Return Value: 1
2091 Fetches all objects and updates them one at a time via
2092 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
2093 triggers, while L</update> will not.
2098 my ($self, $values) = @_;
2099 $self->throw_exception('Values for update_all must be a hash')
2100 unless ref $values eq 'HASH';
2102 my $guard = $self->result_source->schema->txn_scope_guard;
2103 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
2112 =item Arguments: none
2114 =item Return Value: $underlying_storage_rv
2118 Deletes the rows matching this resultset in a single query. Note that this
2119 will not run any delete triggers, nor will it alter the
2120 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
2121 derived from this resultset (this includes the contents of the
2122 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
2123 execute any on-delete triggers or cascades defined either by you or a
2124 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
2126 The return value is a pass through of what the underlying storage backend
2127 returned, and may vary. See L<DBI/execute> for the most common case.
2133 $self->throw_exception('delete does not accept any arguments')
2136 return $self->_rs_update_delete ('delete');
2143 =item Arguments: none
2145 =item Return Value: 1
2149 Fetches all objects and deletes them one at a time via
2150 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
2151 triggers, while L</delete> will not.
2157 $self->throw_exception('delete_all does not accept any arguments')
2160 my $guard = $self->result_source->schema->txn_scope_guard;
2161 $_->delete for $self->all;
2170 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2172 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2176 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2183 The context of this method call has an important effect on what is
2184 submitted to storage. In void context data is fed directly to fastpath
2185 insertion routines provided by the underlying storage (most often
2186 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2187 L<insert|DBIx::Class::Row/insert> calls on the
2188 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2189 augmentation of these methods provided by components. For example if you
2190 are using something like L<DBIx::Class::UUIDColumns> to create primary
2191 keys for you, you will find that your PKs are empty. In this case you
2192 will have to explicitly force scalar or list context in order to create
2197 In non-void (scalar or list) context, this method is simply a wrapper
2198 for L</create>. Depending on list or scalar context either a list of
2199 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2200 containing these objects is returned.
2202 When supplying data in "arrayref of arrayrefs" invocation style, the
2203 first element should be a list of column names and each subsequent
2204 element should be a data value in the earlier specified column order.
2207 $schema->resultset("Artist")->populate([
2208 [ qw( artistid name ) ],
2209 [ 100, 'A Formally Unknown Singer' ],
2210 [ 101, 'A singer that jumped the shark two albums ago' ],
2211 [ 102, 'An actually cool singer' ],
2214 For the arrayref of hashrefs style each hashref should be a structure
2215 suitable for passing to L</create>. Multi-create is also permitted with
2218 $schema->resultset("Artist")->populate([
2219 { artistid => 4, name => 'Manufactured Crap', cds => [
2220 { title => 'My First CD', year => 2006 },
2221 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2224 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2225 { title => 'My parents sold me to a record company', year => 2005 },
2226 { title => 'Why Am I So Ugly?', year => 2006 },
2227 { title => 'I Got Surgery and am now Popular', year => 2007 }
2232 If you attempt a void-context multi-create as in the example above (each
2233 Artist also has the related list of CDs), and B<do not> supply the
2234 necessary autoinc foreign key information, this method will proxy to the
2235 less efficient L</create>, and then throw the Result objects away. In this
2236 case there are obviously no benefits to using this method over L</create>.
2245 # this is naive and just a quick check
2246 # the types will need to be checked more thoroughly when the
2247 # multi-source populate gets added
2248 if (ref $_[0] eq 'ARRAY') {
2249 return unless @{$_[0]};
2251 $data = $_[0] if (ref $_[0][0] eq 'HASH' or ref $_[0][0] eq 'ARRAY');
2254 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs')
2257 # FIXME - no cref handling
2258 # At this point assume either hashes or arrays
2260 if(defined wantarray) {
2263 $guard = $self->result_source->schema->storage->txn_scope_guard
2264 if ( @$data > 2 or ( @$data == 2 and ref $data->[0] eq 'ARRAY' ) );
2266 if (ref $data->[0] eq 'ARRAY') {
2268 { my $vals = $_; $self->new_result({ map { $data->[0][$_] => $vals->[$_] } 0..$#{$data->[0]} })->insert }
2269 @{$data}[1 .. $#$data]
2273 @results = map { $self->new_result($_)->insert } @$data;
2276 $guard->commit if $guard;
2277 return wantarray ? @results : \@results;
2280 # we have to deal with *possibly incomplete* related data
2281 # this means we have to walk the data structure twice
2282 # whether we want this or not
2283 # jnap, I hate you ;)
2284 my $rsrc = $self->result_source;
2285 my $rel_info = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2287 my ($colinfo, $colnames, $slices_with_rels);
2291 for my $i (0 .. $#$data) {
2293 my $current_slice_seen_rel_infos;
2295 ### Determine/Supplement collists
2296 ### BEWARE - This is a hot piece of code, a lot of weird idioms were used
2297 if( ref $data->[$i] eq 'ARRAY' ) {
2299 # positional(!) explicit column list
2302 $colinfo->{$data->[0][$_]} = { pos => $_, name => $data->[0][$_] } and push @$colnames, $data->[0][$_]
2303 for 0 .. $#{$data->[0]};
2310 for (values %$colinfo) {
2311 if ($_->{is_rel} ||= (
2312 $rel_info->{$_->{name}}
2315 ref $data->[$i][$_->{pos}] eq 'ARRAY'
2317 ref $data->[$i][$_->{pos}] eq 'HASH'
2319 ( defined blessed $data->[$i][$_->{pos}] and $data->[$i][$_->{pos}]->isa('DBIx::Class::Row') )
2325 # moar sanity check... sigh
2326 for ( ref $data->[$i][$_->{pos}] eq 'ARRAY' ? @{$data->[$i][$_->{pos}]} : $data->[$i][$_->{pos}] ) {
2327 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2328 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2329 return my $throwaway = $self->populate(@_);
2333 push @$current_slice_seen_rel_infos, $rel_info->{$_->{name}};
2338 if ($current_slice_seen_rel_infos) {
2339 push @$slices_with_rels, { map { $colnames->[$_] => $data->[$i][$_] } 0 .. $#$colnames };
2341 # this is needed further down to decide whether or not to fallback to create()
2342 $colinfo->{$colnames->[$_]}{seen_null} ||= ! defined $data->[$i][$_]
2343 for 0 .. $#$colnames;
2346 elsif( ref $data->[$i] eq 'HASH' ) {
2348 for ( sort keys %{$data->[$i]} ) {
2350 $colinfo->{$_} ||= do {
2352 $self->throw_exception("Column '$_' must be present in supplied explicit column list")
2353 if $data_start; # it will be 0 on AoH, 1 on AoA
2355 push @$colnames, $_;
2358 { pos => $#$colnames, name => $_ }
2361 if ($colinfo->{$_}{is_rel} ||= (
2365 ref $data->[$i]{$_} eq 'ARRAY'
2367 ref $data->[$i]{$_} eq 'HASH'
2369 ( defined blessed $data->[$i]{$_} and $data->[$i]{$_}->isa('DBIx::Class::Row') )
2375 # moar sanity check... sigh
2376 for ( ref $data->[$i]{$_} eq 'ARRAY' ? @{$data->[$i]{$_}} : $data->[$i]{$_} ) {
2377 if ( defined blessed $_ and $_->isa('DBIx::Class::Row' ) ) {
2378 carp_unique("Fast-path populate() with supplied related objects is not possible - falling back to regular create()");
2379 return my $throwaway = $self->populate(@_);
2383 push @$current_slice_seen_rel_infos, $rel_info->{$_};
2387 if ($current_slice_seen_rel_infos) {
2388 push @$slices_with_rels, $data->[$i];
2390 # this is needed further down to decide whether or not to fallback to create()
2391 $colinfo->{$_}{seen_null} ||= ! defined $data->[$i]{$_}
2392 for keys %{$data->[$i]};
2396 $self->throw_exception('Unexpected populate() data structure member type: ' . ref $data->[$i] );
2400 { $_->{attrs}{is_depends_on} }
2401 @{ $current_slice_seen_rel_infos || [] }
2403 carp_unique("Fast-path populate() of belongs_to relationship data is not possible - falling back to regular create()");
2404 return my $throwaway = $self->populate(@_);
2408 if( $slices_with_rels ) {
2410 # need to exclude the rel "columns"
2411 $colnames = [ grep { ! $colinfo->{$_}{is_rel} } @$colnames ];
2413 # extra sanity check - ensure the main source is in fact identifiable
2414 # the localizing of nullability is insane, but oh well... the use-case is legit
2415 my $ci = $rsrc->columns_info($colnames);
2417 $ci->{$_} = { %{$ci->{$_}}, is_nullable => 0 }
2418 for grep { ! $colinfo->{$_}{seen_null} } keys %$ci;
2420 unless( $rsrc->_identifying_column_set($ci) ) {
2421 carp_unique("Fast-path populate() of non-uniquely identifiable rows with related data is not possible - falling back to regular create()");
2422 return my $throwaway = $self->populate(@_);
2426 ### inherit the data locked in the conditions of the resultset
2427 my ($rs_data) = $self->_merge_with_rscond({});
2428 delete @{$rs_data}{@$colnames}; # passed-in stuff takes precedence
2430 # if anything left - decompose rs_data
2432 if (keys %$rs_data) {
2433 push @$rs_data_vals, $rs_data->{$_}
2434 for sort keys %$rs_data;
2438 $guard = $rsrc->schema->storage->txn_scope_guard
2439 if $slices_with_rels;
2441 ### main source data
2442 # FIXME - need to switch entirely to a coderef-based thing,
2443 # so that large sets aren't copied several times... I think
2444 $rsrc->storage->insert_bulk(
2446 [ @$colnames, sort keys %$rs_data ],
2448 ref $data->[$_] eq 'ARRAY'
2450 $slices_with_rels ? [ @{$data->[$_]}[0..$#$colnames], @{$rs_data_vals||[]} ] # the collist changed
2451 : $rs_data_vals ? [ @{$data->[$_]}, @$rs_data_vals ]
2454 : [ @{$data->[$_]}{@$colnames}, @{$rs_data_vals||[]} ]
2455 } $data_start .. $#$data ],
2458 ### do the children relationships
2459 if ( $slices_with_rels ) {
2460 my @rels = grep { $colinfo->{$_}{is_rel} } keys %$colinfo
2461 or die 'wtf... please report a bug with DBIC_TRACE=1 output (stacktrace)';
2463 for my $sl (@$slices_with_rels) {
2465 my ($main_proto, $main_proto_rs);
2466 for my $rel (@rels) {
2467 next unless defined $sl->{$rel};
2471 (map { $_ => $sl->{$_} } @$colnames),
2474 unless (defined $colinfo->{$rel}{rs}) {
2476 $colinfo->{$rel}{rs} = $rsrc->related_source($rel)->resultset;
2478 $colinfo->{$rel}{fk_map} = { reverse %{ $rsrc->_resolve_relationship_condition(
2480 self_alias => "\xFE", # irrelevant
2481 foreign_alias => "\xFF", # irrelevant
2482 )->{identity_map} || {} } };
2486 $colinfo->{$rel}{rs}->search({ map # only so that we inherit them values properly, no actual search
2489 ( $main_proto_rs ||= $rsrc->resultset->search($main_proto) )
2490 ->get_column( $colinfo->{$rel}{fk_map}{$_} )
2494 keys %{$colinfo->{$rel}{fk_map}}
2495 })->populate( ref $sl->{$rel} eq 'ARRAY' ? $sl->{$rel} : [ $sl->{$rel} ] );
2502 $guard->commit if $guard;
2509 =item Arguments: none
2511 =item Return Value: L<$pager|Data::Page>
2515 Returns a L<Data::Page> object for the current resultset. Only makes
2516 sense for queries with a C<page> attribute.
2518 To get the full count of entries for a paged resultset, call
2519 C<total_entries> on the L<Data::Page> object.
2526 return $self->{pager} if $self->{pager};
2528 my $attrs = $self->{attrs};
2529 if (!defined $attrs->{page}) {
2530 $self->throw_exception("Can't create pager for non-paged rs");
2532 elsif ($attrs->{page} <= 0) {
2533 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2535 $attrs->{rows} ||= 10;
2537 # throw away the paging flags and re-run the count (possibly
2538 # with a subselect) to get the real total count
2539 my $count_attrs = { %$attrs };
2540 delete @{$count_attrs}{qw/rows offset page pager/};
2542 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2544 require DBIx::Class::ResultSet::Pager;
2545 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2546 sub { $total_rs->count }, #lazy-get the total
2548 $self->{attrs}{page},
2556 =item Arguments: $page_number
2558 =item Return Value: L<$resultset|/search>
2562 Returns a resultset for the $page_number page of the resultset on which page
2563 is called, where each page contains a number of rows equal to the 'rows'
2564 attribute set on the resultset (10 by default).
2569 my ($self, $page) = @_;
2570 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2577 =item Arguments: \%col_data
2579 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2583 Creates a new result object in the resultset's result class and returns
2584 it. The row is not inserted into the database at this point, call
2585 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2586 will tell you whether the result object has been inserted or not.
2588 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2593 my ($self, $values) = @_;
2595 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2598 $self->throw_exception( "Result object instantiation requires a hashref as argument" )
2599 unless (ref $values eq 'HASH');
2601 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2603 my $new = $self->result_class->new({
2605 ( @$cols_from_relations
2606 ? (-cols_from_relations => $cols_from_relations)
2609 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2613 reftype($new) eq 'HASH'
2619 carp_unique (sprintf (
2620 "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
2621 $self->result_class,
2628 # _merge_with_rscond
2630 # Takes a simple hash of K/V data and returns its copy merged with the
2631 # condition already present on the resultset. Additionally returns an
2632 # arrayref of value/condition names, which were inferred from related
2633 # objects (this is needed for in-memory related objects)
2634 sub _merge_with_rscond {
2635 my ($self, $data) = @_;
2637 my ($implied_data, @cols_from_relations);
2639 my $alias = $self->{attrs}{alias};
2641 if (! defined $self->{cond}) {
2642 # just massage $data below
2644 elsif ($self->{cond} eq UNRESOLVABLE_CONDITION) {
2645 $implied_data = $self->{attrs}{related_objects}; # nothing might have been inserted yet
2646 @cols_from_relations = keys %{ $implied_data || {} };
2649 my $eqs = $self->result_source->schema->storage->_extract_fixed_condition_columns($self->{cond}, 'consider_nulls');
2650 $implied_data = { map {
2651 ( ($eqs->{$_}||'') eq UNRESOLVABLE_CONDITION ) ? () : ( $_ => $eqs->{$_} )
2657 { %{ $self->_remove_alias($_, $alias) } }
2658 # precedence must be given to passed values over values inherited from
2659 # the cond, so the order here is important.
2660 ( $implied_data||(), $data)
2662 \@cols_from_relations
2666 # _has_resolved_attr
2668 # determines if the resultset defines at least one
2669 # of the attributes supplied
2671 # used to determine if a subquery is necessary
2673 # supports some virtual attributes:
2675 # This will scan for any joins being present on the resultset.
2676 # It is not a mere key-search but a deep inspection of {from}
2679 sub _has_resolved_attr {
2680 my ($self, @attr_names) = @_;
2682 my $attrs = $self->_resolved_attrs;
2686 for my $n (@attr_names) {
2687 if (grep { $n eq $_ } (qw/-join/) ) {
2688 $extra_checks{$n}++;
2692 my $attr = $attrs->{$n};
2694 next if not defined $attr;
2696 if (ref $attr eq 'HASH') {
2697 return 1 if keys %$attr;
2699 elsif (ref $attr eq 'ARRAY') {
2707 # a resolved join is expressed as a multi-level from
2709 $extra_checks{-join}
2711 ref $attrs->{from} eq 'ARRAY'
2713 @{$attrs->{from}} > 1
2721 # Remove the specified alias from the specified query hash. A copy is made so
2722 # the original query is not modified.
2725 my ($self, $query, $alias) = @_;
2727 my %orig = %{ $query || {} };
2730 foreach my $key (keys %orig) {
2732 $unaliased{$key} = $orig{$key};
2735 $unaliased{$1} = $orig{$key}
2736 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2746 =item Arguments: none
2748 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2752 Returns the SQL query and bind vars associated with the invocant.
2754 This is generally used as the RHS for a subquery.
2761 my $attrs = { %{ $self->_resolved_attrs } };
2763 my $aq = $self->result_source->storage->_select_args_to_query (
2764 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
2774 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2776 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2780 my $artist = $schema->resultset('Artist')->find_or_new(
2781 { artist => 'fred' }, { key => 'artists' });
2783 $cd->cd_to_producer->find_or_new({ producer => $producer },
2784 { key => 'primary' });
2786 Find an existing record from this resultset using L</find>. if none exists,
2787 instantiate a new result object and return it. The object will not be saved
2788 into your storage until you call L<DBIx::Class::Row/insert> on it.
2790 You most likely want this method when looking for existing rows using a unique
2791 constraint that is not the primary key, or looking for related rows.
2793 If you want objects to be saved immediately, use L</find_or_create> instead.
2795 B<Note>: Make sure to read the documentation of L</find> and understand the
2796 significance of the C<key> attribute, as its lack may skew your search, and
2797 subsequently result in spurious new objects.
2799 B<Note>: Take care when using C<find_or_new> with a table having
2800 columns with default values that you intend to be automatically
2801 supplied by the database (e.g. an auto_increment primary key column).
2802 In normal usage, the value of such columns should NOT be included at
2803 all in the call to C<find_or_new>, even when set to C<undef>.
2809 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2810 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2811 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2814 return $self->new_result($hash);
2821 =item Arguments: \%col_data
2823 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2827 Attempt to create a single new row or a row with multiple related rows
2828 in the table represented by the resultset (and related tables). This
2829 will not check for duplicate rows before inserting, use
2830 L</find_or_create> to do that.
2832 To create one row for this resultset, pass a hashref of key/value
2833 pairs representing the columns of the table and the values you wish to
2834 store. If the appropriate relationships are set up, foreign key fields
2835 can also be passed an object representing the foreign row, and the
2836 value will be set to its primary key.
2838 To create related objects, pass a hashref of related-object column values
2839 B<keyed on the relationship name>. If the relationship is of type C<multi>
2840 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2841 The process will correctly identify columns holding foreign keys, and will
2842 transparently populate them from the keys of the corresponding relation.
2843 This can be applied recursively, and will work correctly for a structure
2844 with an arbitrary depth and width, as long as the relationships actually
2845 exists and the correct column data has been supplied.
2847 Instead of hashrefs of plain related data (key/value pairs), you may
2848 also pass new or inserted objects. New objects (not inserted yet, see
2849 L</new_result>), will be inserted into their appropriate tables.
2851 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2853 Example of creating a new row.
2855 $person_rs->create({
2856 name=>"Some Person",
2857 email=>"somebody@someplace.com"
2860 Example of creating a new row and also creating rows in a related C<has_many>
2861 or C<has_one> resultset. Note Arrayref.
2864 { artistid => 4, name => 'Manufactured Crap', cds => [
2865 { title => 'My First CD', year => 2006 },
2866 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2871 Example of creating a new row and also creating a row in a related
2872 C<belongs_to> resultset. Note Hashref.
2875 title=>"Music for Silly Walks",
2878 name=>"Silly Musician",
2886 When subclassing ResultSet never attempt to override this method. Since
2887 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2888 lot of the internals simply never call it, so your override will be
2889 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2890 or L<DBIx::Class::Row/insert> depending on how early in the
2891 L</create> process you need to intervene. See also warning pertaining to
2899 #my ($self, $col_data) = @_;
2900 DBIx::Class::_ENV_::ASSERT_NO_INTERNAL_INDIRECT_CALLS and fail_on_internal_call;
2901 return shift->new_result(shift)->insert;
2904 =head2 find_or_create
2908 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2910 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2914 $cd->cd_to_producer->find_or_create({ producer => $producer },
2915 { key => 'primary' });
2917 Tries to find a record based on its primary key or unique constraints; if none
2918 is found, creates one and returns that instead.
2920 my $cd = $schema->resultset('CD')->find_or_create({
2922 artist => 'Massive Attack',
2923 title => 'Mezzanine',
2927 Also takes an optional C<key> attribute, to search by a specific key or unique
2928 constraint. For example:
2930 my $cd = $schema->resultset('CD')->find_or_create(
2932 artist => 'Massive Attack',
2933 title => 'Mezzanine',
2935 { key => 'cd_artist_title' }
2938 B<Note>: Make sure to read the documentation of L</find> and understand the
2939 significance of the C<key> attribute, as its lack may skew your search, and
2940 subsequently result in spurious row creation.
2942 B<Note>: Because find_or_create() reads from the database and then
2943 possibly inserts based on the result, this method is subject to a race
2944 condition. Another process could create a record in the table after
2945 the find has completed and before the create has started. To avoid
2946 this problem, use find_or_create() inside a transaction.
2948 B<Note>: Take care when using C<find_or_create> with a table having
2949 columns with default values that you intend to be automatically
2950 supplied by the database (e.g. an auto_increment primary key column).
2951 In normal usage, the value of such columns should NOT be included at
2952 all in the call to C<find_or_create>, even when set to C<undef>.
2954 See also L</find> and L</update_or_create>. For information on how to declare
2955 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2957 If you need to know if an existing row was found or a new one created use
2958 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2959 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2962 my $cd = $schema->resultset('CD')->find_or_new({
2964 artist => 'Massive Attack',
2965 title => 'Mezzanine',
2969 if( !$cd->in_storage ) {
2976 sub find_or_create {
2978 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2979 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2980 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2983 return $self->new_result($hash)->insert;
2986 =head2 update_or_create
2990 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2992 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2996 $resultset->update_or_create({ col => $val, ... });
2998 Like L</find_or_create>, but if a row is found it is immediately updated via
2999 C<< $found_row->update (\%col_data) >>.
3002 Takes an optional C<key> attribute to search on a specific unique constraint.
3005 # In your application
3006 my $cd = $schema->resultset('CD')->update_or_create(
3008 artist => 'Massive Attack',
3009 title => 'Mezzanine',
3012 { key => 'cd_artist_title' }
3015 $cd->cd_to_producer->update_or_create({
3016 producer => $producer,
3022 B<Note>: Make sure to read the documentation of L</find> and understand the
3023 significance of the C<key> attribute, as its lack may skew your search, and
3024 subsequently result in spurious row creation.
3026 B<Note>: Take care when using C<update_or_create> with a table having
3027 columns with default values that you intend to be automatically
3028 supplied by the database (e.g. an auto_increment primary key column).
3029 In normal usage, the value of such columns should NOT be included at
3030 all in the call to C<update_or_create>, even when set to C<undef>.
3032 See also L</find> and L</find_or_create>. For information on how to declare
3033 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
3035 If you need to know if an existing row was updated or a new one created use
3036 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
3037 to call L<DBIx::Class::Row/insert> to save the newly created row to the
3042 sub update_or_create {
3044 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
3045 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3047 my $row = $self->find($cond, $attrs);
3049 $row->update($cond);
3053 return $self->new_result($cond)->insert;
3056 =head2 update_or_new
3060 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
3062 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
3066 $resultset->update_or_new({ col => $val, ... });
3068 Like L</find_or_new> but if a row is found it is immediately updated via
3069 C<< $found_row->update (\%col_data) >>.
3073 # In your application
3074 my $cd = $schema->resultset('CD')->update_or_new(
3076 artist => 'Massive Attack',
3077 title => 'Mezzanine',
3080 { key => 'cd_artist_title' }
3083 if ($cd->in_storage) {
3084 # the cd was updated
3087 # the cd is not yet in the database, let's insert it
3091 B<Note>: Make sure to read the documentation of L</find> and understand the
3092 significance of the C<key> attribute, as its lack may skew your search, and
3093 subsequently result in spurious new objects.
3095 B<Note>: Take care when using C<update_or_new> with a table having
3096 columns with default values that you intend to be automatically
3097 supplied by the database (e.g. an auto_increment primary key column).
3098 In normal usage, the value of such columns should NOT be included at
3099 all in the call to C<update_or_new>, even when set to C<undef>.
3101 See also L</find>, L</find_or_create> and L</find_or_new>.
3107 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
3108 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
3110 my $row = $self->find( $cond, $attrs );
3111 if ( defined $row ) {
3112 $row->update($cond);
3116 return $self->new_result($cond);
3123 =item Arguments: none
3125 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
3129 Gets the contents of the cache for the resultset, if the cache is set.
3131 The cache is populated either by using the L</prefetch> attribute to
3132 L</search> or by calling L</set_cache>.
3144 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3146 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
3150 Sets the contents of the cache for the resultset. Expects an arrayref
3151 of objects of the same class as those produced by the resultset. Note that
3152 if the cache is set, the resultset will return the cached objects rather
3153 than re-querying the database even if the cache attr is not set.
3155 The contents of the cache can also be populated by using the
3156 L</prefetch> attribute to L</search>.
3161 my ( $self, $data ) = @_;
3162 $self->throw_exception("set_cache requires an arrayref")
3163 if defined($data) && (ref $data ne 'ARRAY');
3164 $self->{all_cache} = $data;
3171 =item Arguments: none
3173 =item Return Value: undef
3177 Clears the cache for the resultset.
3182 shift->set_cache(undef);
3189 =item Arguments: none
3191 =item Return Value: true, if the resultset has been paginated
3199 return !!$self->{attrs}{page};
3206 =item Arguments: none
3208 =item Return Value: true, if the resultset has been ordered with C<order_by>.
3216 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
3219 =head2 related_resultset
3223 =item Arguments: $rel_name
3225 =item Return Value: L<$resultset|/search>
3229 Returns a related resultset for the supplied relationship name.
3231 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3235 sub related_resultset {
3236 my ($self, $rel) = @_;
3238 return $self->{related_resultsets}{$rel}
3239 if defined $self->{related_resultsets}{$rel};
3241 return $self->{related_resultsets}{$rel} = do {
3242 my $rsrc = $self->result_source;
3243 my $rel_info = $rsrc->relationship_info($rel);
3245 $self->throw_exception(
3246 "search_related: result source '" . $rsrc->source_name .
3247 "' has no such relationship $rel")
3250 my $attrs = $self->_chain_relationship($rel);
3252 my $join_count = $attrs->{seen_join}{$rel};
3254 my $alias = $self->result_source->storage
3255 ->relname_to_table_alias($rel, $join_count);
3257 # since this is search_related, and we already slid the select window inwards
3258 # (the select/as attrs were deleted in the beginning), we need to flip all
3259 # left joins to inner, so we get the expected results
3260 # read the comment on top of the actual function to see what this does
3261 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3264 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3265 delete @{$attrs}{qw(result_class alias)};
3267 my $rel_source = $rsrc->related_source($rel);
3271 # The reason we do this now instead of passing the alias to the
3272 # search_rs below is that if you wrap/overload resultset on the
3273 # source you need to know what alias it's -going- to have for things
3274 # to work sanely (e.g. RestrictWithObject wants to be able to add
3275 # extra query restrictions, and these may need to be $alias.)
3277 my $rel_attrs = $rel_source->resultset_attributes;
3278 local $rel_attrs->{alias} = $alias;
3280 $rel_source->resultset
3284 where => $attrs->{where},
3288 if (my $cache = $self->get_cache) {
3289 my @related_cache = map
3290 { $_->related_resultset($rel)->get_cache || () }
3294 $new->set_cache([ map @$_, @related_cache ]) if @related_cache == @$cache;
3301 =head2 current_source_alias
3305 =item Arguments: none
3307 =item Return Value: $source_alias
3311 Returns the current table alias for the result source this resultset is built
3312 on, that will be used in the SQL query. Usually it is C<me>.
3314 Currently the source alias that refers to the result set returned by a
3315 L</search>/L</find> family method depends on how you got to the resultset: it's
3316 C<me> by default, but eg. L</search_related> aliases it to the related result
3317 source name (and keeps C<me> referring to the original result set). The long
3318 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3319 (and make this method unnecessary).
3321 Thus it's currently necessary to use this method in predefined queries (see
3322 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3323 source alias of the current result set:
3325 # in a result set class
3327 my ($self, $user) = @_;
3329 my $me = $self->current_source_alias;
3331 return $self->search({
3332 "$me.modified" => $user->id,
3338 sub current_source_alias {
3339 return (shift->{attrs} || {})->{alias} || 'me';
3342 =head2 as_subselect_rs
3346 =item Arguments: none
3348 =item Return Value: L<$resultset|/search>
3352 Act as a barrier to SQL symbols. The resultset provided will be made into a
3353 "virtual view" by including it as a subquery within the from clause. From this
3354 point on, any joined tables are inaccessible to ->search on the resultset (as if
3355 it were simply where-filtered without joins). For example:
3357 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3359 # 'x' now pollutes the query namespace
3361 # So the following works as expected
3362 my $ok_rs = $rs->search({'x.other' => 1});
3364 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3365 # def) we look for one row with contradictory terms and join in another table
3366 # (aliased 'x_2') which we never use
3367 my $broken_rs = $rs->search({'x.name' => 'def'});
3369 my $rs2 = $rs->as_subselect_rs;
3371 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3372 my $not_joined_rs = $rs2->search({'x.other' => 1});
3374 # works as expected: finds a 'table' row related to two x rows (abc and def)
3375 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3377 Another example of when one might use this would be to select a subset of
3378 columns in a group by clause:
3380 my $rs = $schema->resultset('Bar')->search(undef, {
3381 group_by => [qw{ id foo_id baz_id }],
3382 })->as_subselect_rs->search(undef, {
3383 columns => [qw{ id foo_id }]
3386 In the above example normally columns would have to be equal to the group by,
3387 but because we isolated the group by into a subselect the above works.
3391 sub as_subselect_rs {
3394 my $attrs = $self->_resolved_attrs;
3396 my $fresh_rs = (ref $self)->new (
3397 $self->result_source
3400 # these pieces will be locked in the subquery
3401 delete $fresh_rs->{cond};
3402 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3404 return $fresh_rs->search( {}, {
3406 $attrs->{alias} => $self->as_query,
3407 -alias => $attrs->{alias},
3408 -rsrc => $self->result_source,
3410 alias => $attrs->{alias},
3414 # This code is called by search_related, and makes sure there
3415 # is clear separation between the joins before, during, and
3416 # after the relationship. This information is needed later
3417 # in order to properly resolve prefetch aliases (any alias
3418 # with a relation_chain_depth less than the depth of the
3419 # current prefetch is not considered)
3421 # The increments happen twice per join. An even number means a
3422 # relationship specified via a search_related, whereas an odd
3423 # number indicates a join/prefetch added via attributes
3425 # Also this code will wrap the current resultset (the one we
3426 # chain to) in a subselect IFF it contains limiting attributes
3427 sub _chain_relationship {
3428 my ($self, $rel) = @_;
3429 my $source = $self->result_source;
3430 my $attrs = { %{$self->{attrs}||{}} };
3432 # we need to take the prefetch the attrs into account before we
3433 # ->_resolve_join as otherwise they get lost - captainL
3434 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3436 delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
3438 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3441 my @force_subq_attrs = qw/offset rows group_by having/;
3444 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3446 $self->_has_resolved_attr (@force_subq_attrs)
3448 # Nuke the prefetch (if any) before the new $rs attrs
3449 # are resolved (prefetch is useless - we are wrapping
3450 # a subquery anyway).
3451 my $rs_copy = $self->search;
3452 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3453 $rs_copy->{attrs}{join},
3454 delete $rs_copy->{attrs}{prefetch},
3459 -alias => $attrs->{alias},
3460 $attrs->{alias} => $rs_copy->as_query,
3462 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3463 $seen->{-relation_chain_depth} = 0;
3465 elsif ($attrs->{from}) { #shallow copy suffices
3466 $from = [ @{$attrs->{from}} ];
3471 -alias => $attrs->{alias},
3472 $attrs->{alias} => $source->from,
3476 my $jpath = ($seen->{-relation_chain_depth})
3477 ? $from->[-1][0]{-join_path}
3480 my @requested_joins = $source->_resolve_join(
3487 push @$from, @requested_joins;
3489 $seen->{-relation_chain_depth}++;
3491 # if $self already had a join/prefetch specified on it, the requested
3492 # $rel might very well be already included. What we do in this case
3493 # is effectively a no-op (except that we bump up the chain_depth on
3494 # the join in question so we could tell it *is* the search_related)
3497 # we consider the last one thus reverse
3498 for my $j (reverse @requested_joins) {
3499 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3500 if ($rel eq $last_j) {
3501 $j->[0]{-relation_chain_depth}++;
3507 unless ($already_joined) {
3508 push @$from, $source->_resolve_join(
3516 $seen->{-relation_chain_depth}++;
3518 return {%$attrs, from => $from, seen_join => $seen};
3521 sub _resolved_attrs {
3523 return $self->{_attrs} if $self->{_attrs};
3525 my $attrs = { %{ $self->{attrs} || {} } };
3526 my $source = $attrs->{result_source} = $self->result_source;
3527 my $alias = $attrs->{alias};
3529 $self->throw_exception("Specifying distinct => 1 in conjunction with collapse => 1 is unsupported")
3530 if $attrs->{collapse} and $attrs->{distinct};
3532 # default selection list
3533 $attrs->{columns} = [ $source->columns ]
3534 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3536 # merge selectors together
3537 for (qw/columns select as/) {
3538 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3539 if $attrs->{$_} or $attrs->{"+$_"};
3542 # disassemble columns
3544 if (my $cols = delete $attrs->{columns}) {
3545 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3546 if (ref $c eq 'HASH') {
3547 for my $as (sort keys %$c) {
3548 push @sel, $c->{$as};
3559 # when trying to weed off duplicates later do not go past this point -
3560 # everything added from here on is unbalanced "anyone's guess" stuff
3561 my $dedup_stop_idx = $#as;
3563 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3565 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3566 if $attrs->{select};
3568 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3569 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3571 # disqualify all $alias.col as-bits (inflate-map mandated)
3572 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3574 # de-duplicate the result (remove *identical* select/as pairs)
3575 # and also die on duplicate {as} pointing to different {select}s
3576 # not using a c-style for as the condition is prone to shrinkage
3579 while ($i <= $dedup_stop_idx) {
3580 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3585 elsif ($seen->{$as[$i]}++) {
3586 $self->throw_exception(
3587 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3595 $attrs->{select} = \@sel;
3596 $attrs->{as} = \@as;
3598 $attrs->{from} ||= [{
3600 -alias => $self->{attrs}{alias},
3601 $self->{attrs}{alias} => $source->from,
3604 if ( $attrs->{join} || $attrs->{prefetch} ) {
3606 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3607 if ref $attrs->{from} ne 'ARRAY';
3609 my $join = (delete $attrs->{join}) || {};
3611 if ( defined $attrs->{prefetch} ) {
3612 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3615 $attrs->{from} = # have to copy here to avoid corrupting the original
3617 @{ $attrs->{from} },
3618 $source->_resolve_join(
3621 { %{ $attrs->{seen_join} || {} } },
3622 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3623 ? $attrs->{from}[-1][0]{-join_path}
3630 if ( defined $attrs->{order_by} ) {
3631 $attrs->{order_by} = (
3632 ref( $attrs->{order_by} ) eq 'ARRAY'
3633 ? [ @{ $attrs->{order_by} } ]
3634 : [ $attrs->{order_by} || () ]
3638 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3639 $attrs->{group_by} = [ $attrs->{group_by} ];
3643 # generate selections based on the prefetch helper
3644 my ($prefetch, @prefetch_select, @prefetch_as);
3645 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3646 if defined $attrs->{prefetch};
3650 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3651 if $attrs->{_dark_selector};
3653 $self->throw_exception("Specifying prefetch in conjunction with an explicit collapse => 0 is unsupported")
3654 if defined $attrs->{collapse} and ! $attrs->{collapse};
3656 $attrs->{collapse} = 1;
3658 # this is a separate structure (we don't look in {from} directly)
3659 # as the resolver needs to shift things off the lists to work
3660 # properly (identical-prefetches on different branches)
3662 if (ref $attrs->{from} eq 'ARRAY') {
3664 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3666 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3667 next unless $j->[0]{-alias};
3668 next unless $j->[0]{-join_path};
3669 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3671 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3674 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3675 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3679 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3681 # save these for after distinct resolution
3682 @prefetch_select = map { $_->[0] } @prefetch;
3683 @prefetch_as = map { $_->[1] } @prefetch;
3686 # run through the resulting joinstructure (starting from our current slot)
3687 # and unset collapse if proven unnecessary
3689 # also while we are at it find out if the current root source has
3690 # been premultiplied by previous related_source chaining
3692 # this allows to predict whether a root object with all other relation
3693 # data set to NULL is in fact unique
3694 if ($attrs->{collapse}) {
3696 if (ref $attrs->{from} eq 'ARRAY') {
3698 if (@{$attrs->{from}} == 1) {
3699 # no joins - no collapse
3700 $attrs->{collapse} = 0;
3703 # find where our table-spec starts
3704 my @fromlist = @{$attrs->{from}};
3706 my $t = shift @fromlist;
3709 # me vs join from-spec distinction - a ref means non-root
3710 if (ref $t eq 'ARRAY') {
3712 $is_multi ||= ! $t->{-is_single};
3714 last if ($t->{-alias} && $t->{-alias} eq $alias);
3715 $attrs->{_main_source_premultiplied} ||= $is_multi;
3718 # no non-singles remaining, nor any premultiplication - nothing to collapse
3720 ! $attrs->{_main_source_premultiplied}
3722 ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
3724 $attrs->{collapse} = 0;
3730 # if we can not analyze the from - err on the side of safety
3731 $attrs->{_main_source_premultiplied} = 1;
3735 # generate the distinct induced group_by before injecting the prefetched select/as parts
3736 if (delete $attrs->{distinct}) {
3737 if ($attrs->{group_by}) {
3738 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3741 $attrs->{_grouped_by_distinct} = 1;
3742 # distinct affects only the main selection part, not what prefetch may add below
3743 ($attrs->{group_by}, my $new_order) = $source->storage->_group_over_selection($attrs);
3745 # FIXME possibly ignore a rewritten order_by (may turn out to be an issue)
3746 # The thinking is: if we are collapsing the subquerying prefetch engine will
3747 # rip stuff apart for us anyway, and we do not want to have a potentially
3748 # function-converted external order_by
3749 # ( there is an explicit if ( collapse && _grouped_by_distinct ) check in DBIHacks )
3750 $attrs->{order_by} = $new_order unless $attrs->{collapse};
3754 # inject prefetch-bound selection (if any)
3755 push @{$attrs->{select}}, @prefetch_select;
3756 push @{$attrs->{as}}, @prefetch_as;
3758 $attrs->{_simple_passthrough_construction} = !(
3761 grep { $_ =~ /\./ } @{$attrs->{as}}
3764 # if both page and offset are specified, produce a combined offset
3765 # even though it doesn't make much sense, this is what pre 081xx has
3767 if (my $page = delete $attrs->{page}) {
3769 ($attrs->{rows} * ($page - 1))
3771 ($attrs->{offset} || 0)
3775 return $self->{_attrs} = $attrs;
3779 my ($self, $attr) = @_;
3781 if (ref $attr eq 'HASH') {
3782 return $self->_rollout_hash($attr);
3783 } elsif (ref $attr eq 'ARRAY') {
3784 return $self->_rollout_array($attr);
3790 sub _rollout_array {
3791 my ($self, $attr) = @_;
3794 foreach my $element (@{$attr}) {
3795 if (ref $element eq 'HASH') {
3796 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3797 } elsif (ref $element eq 'ARRAY') {
3798 # XXX - should probably recurse here
3799 push( @rolled_array, @{$self->_rollout_array($element)} );
3801 push( @rolled_array, $element );
3804 return \@rolled_array;
3808 my ($self, $attr) = @_;
3811 foreach my $key (keys %{$attr}) {
3812 push( @rolled_array, { $key => $attr->{$key} } );
3814 return \@rolled_array;
3817 sub _calculate_score {
3818 my ($self, $a, $b) = @_;
3820 if (defined $a xor defined $b) {
3823 elsif (not defined $a) {
3827 if (ref $b eq 'HASH') {
3828 my ($b_key) = keys %{$b};
3829 if (ref $a eq 'HASH') {
3830 my ($a_key) = keys %{$a};
3831 if ($a_key eq $b_key) {
3832 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3837 return ($a eq $b_key) ? 1 : 0;
3840 if (ref $a eq 'HASH') {
3841 my ($a_key) = keys %{$a};
3842 return ($b eq $a_key) ? 1 : 0;
3844 return ($b eq $a) ? 1 : 0;
3849 sub _merge_joinpref_attr {
3850 my ($self, $orig, $import) = @_;
3852 return $import unless defined($orig);
3853 return $orig unless defined($import);
3855 $orig = $self->_rollout_attr($orig);
3856 $import = $self->_rollout_attr($import);
3859 foreach my $import_element ( @{$import} ) {
3860 # find best candidate from $orig to merge $b_element into
3861 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3862 foreach my $orig_element ( @{$orig} ) {
3863 my $score = $self->_calculate_score( $orig_element, $import_element );
3864 if ($score > $best_candidate->{score}) {
3865 $best_candidate->{position} = $position;
3866 $best_candidate->{score} = $score;
3870 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3871 $import_key = '' if not defined $import_key;
3873 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3874 push( @{$orig}, $import_element );
3876 my $orig_best = $orig->[$best_candidate->{position}];
3877 # merge orig_best and b_element together and replace original with merged
3878 if (ref $orig_best ne 'HASH') {
3879 $orig->[$best_candidate->{position}] = $import_element;
3880 } elsif (ref $import_element eq 'HASH') {
3881 my ($key) = keys %{$orig_best};
3882 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3885 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3888 return @$orig ? $orig : ();
3896 require Hash::Merge;
3897 my $hm = Hash::Merge->new;
3899 $hm->specify_behavior({
3902 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3904 if ($defl xor $defr) {
3905 return [ $defl ? $_[0] : $_[1] ];
3910 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3914 return [$_[0], $_[1]];
3918 return $_[1] if !defined $_[0];
3919 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3920 return [$_[0], @{$_[1]}]
3923 return [] if !defined $_[0] and !keys %{$_[1]};
3924 return [ $_[1] ] if !defined $_[0];
3925 return [ $_[0] ] if !keys %{$_[1]};
3926 return [$_[0], $_[1]]
3931 return $_[0] if !defined $_[1];
3932 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3933 return [@{$_[0]}, $_[1]]
3936 my @ret = @{$_[0]} or return $_[1];
3937 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3938 my %idx = map { $_ => 1 } @ret;
3939 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3943 return [ $_[1] ] if ! @{$_[0]};
3944 return $_[0] if !keys %{$_[1]};
3945 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3946 return [ @{$_[0]}, $_[1] ];
3951 return [] if !keys %{$_[0]} and !defined $_[1];
3952 return [ $_[0] ] if !defined $_[1];
3953 return [ $_[1] ] if !keys %{$_[0]};
3954 return [$_[0], $_[1]]
3957 return [] if !keys %{$_[0]} and !@{$_[1]};
3958 return [ $_[0] ] if !@{$_[1]};
3959 return $_[1] if !keys %{$_[0]};
3960 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3961 return [ $_[0], @{$_[1]} ];
3964 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3965 return [ $_[0] ] if !keys %{$_[1]};
3966 return [ $_[1] ] if !keys %{$_[0]};
3967 return [ $_[0] ] if $_[0] eq $_[1];
3968 return [ $_[0], $_[1] ];
3971 } => 'DBIC_RS_ATTR_MERGER');
3975 return $hm->merge ($_[1], $_[2]);
3979 sub STORABLE_freeze {
3980 my ($self, $cloning) = @_;
3981 my $to_serialize = { %$self };
3983 # A cursor in progress can't be serialized (and would make little sense anyway)
3984 # the parser can be regenerated (and can't be serialized)
3985 delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
3987 # nor is it sensical to store a not-yet-fired-count pager
3988 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3989 delete $to_serialize->{pager};
3992 Storable::nfreeze($to_serialize);
3995 # need this hook for symmetry
3997 my ($self, $cloning, $serialized) = @_;
3999 %$self = %{ Storable::thaw($serialized) };
4005 =head2 throw_exception
4007 See L<DBIx::Class::Schema/throw_exception> for details.
4011 sub throw_exception {
4014 if (ref $self and my $rsrc = $self->result_source) {
4015 $rsrc->throw_exception(@_)
4018 DBIx::Class::Exception->throw(@_);
4026 # XXX: FIXME: Attributes docs need clearing up
4030 Attributes are used to refine a ResultSet in various ways when
4031 searching for data. They can be passed to any method which takes an
4032 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
4035 Default attributes can be set on the result class using
4036 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
4037 the CAVEATS on that feature before using it!)
4039 These are in no particular order:
4045 =item Value: ( $order_by | \@order_by | \%order_by )
4049 Which column(s) to order the results by.
4051 [The full list of suitable values is documented in
4052 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
4055 If a single column name, or an arrayref of names is supplied, the
4056 argument is passed through directly to SQL. The hashref syntax allows
4057 for connection-agnostic specification of ordering direction:
4059 For descending order:
4061 order_by => { -desc => [qw/col1 col2 col3/] }
4063 For explicit ascending order:
4065 order_by => { -asc => 'col' }
4067 The old scalarref syntax (i.e. order_by => \'year DESC') is still
4068 supported, although you are strongly encouraged to use the hashref
4069 syntax as outlined above.
4075 =item Value: \@columns | \%columns | $column
4079 Shortcut to request a particular set of columns to be retrieved. Each
4080 column spec may be a string (a table column name), or a hash (in which
4081 case the key is the C<as> value, and the value is used as the C<select>
4082 expression). Adds the L</current_source_alias> onto the start of any column without a C<.> in
4083 it and sets C<select> from that, then auto-populates C<as> from
4084 C<select> as normal. (You may also use the C<cols> attribute, as in
4085 earlier versions of DBIC, but this is deprecated)
4087 Essentially C<columns> does the same as L</select> and L</as>.
4089 columns => [ 'some_column', { dbic_slot => 'another_column' } ]
4093 select => [qw(some_column another_column)],
4094 as => [qw(some_column dbic_slot)]
4096 If you want to individually retrieve related columns (in essence perform
4097 manual prefetch) you have to make sure to specify the correct inflation slot
4098 chain such that it matches existing relationships:
4100 my $rs = $schema->resultset('Artist')->search({}, {
4101 # required to tell DBIC to collapse has_many relationships
4103 join => { cds => 'tracks'},
4105 'cds.cdid' => 'cds.cdid',
4106 'cds.tracks.title' => 'tracks.title',
4112 B<NOTE:> You B<MUST> explicitly quote C<'+columns'> when using this attribute.
4113 Not doing so causes Perl to incorrectly interpret C<+columns> as a bareword
4114 with a unary plus operator before it, which is the same as simply C<columns>.
4118 =item Value: \@extra_columns
4122 Indicates additional columns to be selected from storage. Works the same as
4123 L</columns> but adds columns to the current selection. (You may also use the
4124 C<include_columns> attribute, as in earlier versions of DBIC, but this is
4127 $schema->resultset('CD')->search(undef, {
4128 '+columns' => ['artist.name'],
4132 would return all CDs and include a 'name' column to the information
4133 passed to object inflation. Note that the 'artist' is the name of the
4134 column (or relationship) accessor, and 'name' is the name of the column
4135 accessor in the related table.
4141 =item Value: \@select_columns
4145 Indicates which columns should be selected from the storage. You can use
4146 column names, or in the case of RDBMS back ends, function or stored procedure
4149 $rs = $schema->resultset('Employee')->search(undef, {
4152 { count => 'employeeid' },
4153 { max => { length => 'name' }, -as => 'longest_name' }
4158 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
4160 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
4161 use L</select>, to instruct DBIx::Class how to store the result of the column.
4162 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
4163 identifier aliasing. You can however alias a function, so you can use it in
4164 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
4165 attribute> supplied as shown in the example above.
4169 B<NOTE:> You B<MUST> explicitly quote C<'+select'> when using this attribute.
4170 Not doing so causes Perl to incorrectly interpret C<+select> as a bareword
4171 with a unary plus operator before it, which is the same as simply C<select>.
4175 =item Value: \@extra_select_columns
4179 Indicates additional columns to be selected from storage. Works the same as
4180 L</select> but adds columns to the current selection, instead of specifying
4181 a new explicit list.
4187 =item Value: \@inflation_names
4191 Indicates DBIC-side names for object inflation. That is L</as> indicates the
4192 slot name in which the column value will be stored within the
4193 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
4194 identifier by the C<get_column> method (or via the object accessor B<if one
4195 with the same name already exists>) as shown below. The L</as> attribute has
4196 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
4198 $rs = $schema->resultset('Employee')->search(undef, {
4201 { count => 'employeeid' },
4202 { max => { length => 'name' }, -as => 'longest_name' }
4211 If the object against which the search is performed already has an accessor
4212 matching a column name specified in C<as>, the value can be retrieved using
4213 the accessor as normal:
4215 my $name = $employee->name();
4217 If on the other hand an accessor does not exist in the object, you need to
4218 use C<get_column> instead:
4220 my $employee_count = $employee->get_column('employee_count');
4222 You can create your own accessors if required - see
4223 L<DBIx::Class::Manual::Cookbook> for details.
4227 B<NOTE:> You B<MUST> explicitly quote C<'+as'> when using this attribute.
4228 Not doing so causes Perl to incorrectly interpret C<+as> as a bareword
4229 with a unary plus operator before it, which is the same as simply C<as>.
4233 =item Value: \@extra_inflation_names
4237 Indicates additional inflation names for selectors added via L</+select>. See L</as>.
4243 =item Value: ($rel_name | \@rel_names | \%rel_names)
4247 Contains a list of relationships that should be joined for this query. For
4250 # Get CDs by Nine Inch Nails
4251 my $rs = $schema->resultset('CD')->search(
4252 { 'artist.name' => 'Nine Inch Nails' },
4253 { join => 'artist' }
4256 Can also contain a hash reference to refer to the other relation's relations.
4259 package MyApp::Schema::Track;
4260 use base qw/DBIx::Class/;
4261 __PACKAGE__->table('track');
4262 __PACKAGE__->add_columns(qw/trackid cd position title/);
4263 __PACKAGE__->set_primary_key('trackid');
4264 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
4267 # In your application
4268 my $rs = $schema->resultset('Artist')->search(
4269 { 'track.title' => 'Teardrop' },
4271 join => { cd => 'track' },
4272 order_by => 'artist.name',
4276 You need to use the relationship (not the table) name in conditions,
4277 because they are aliased as such. The current table is aliased as "me", so
4278 you need to use me.column_name in order to avoid ambiguity. For example:
4280 # Get CDs from 1984 with a 'Foo' track
4281 my $rs = $schema->resultset('CD')->search(
4284 'tracks.name' => 'Foo'
4286 { join => 'tracks' }
4289 If the same join is supplied twice, it will be aliased to <rel>_2 (and
4290 similarly for a third time). For e.g.
4292 my $rs = $schema->resultset('Artist')->search({
4293 'cds.title' => 'Down to Earth',
4294 'cds_2.title' => 'Popular',
4296 join => [ qw/cds cds/ ],
4299 will return a set of all artists that have both a cd with title 'Down
4300 to Earth' and a cd with title 'Popular'.
4302 If you want to fetch related objects from other tables as well, see L</prefetch>
4305 NOTE: An internal join-chain pruner will discard certain joins while
4306 constructing the actual SQL query, as long as the joins in question do not
4307 affect the retrieved result. This for example includes 1:1 left joins
4308 that are not part of the restriction specification (WHERE/HAVING) nor are
4309 a part of the query selection.
4311 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4317 =item Value: (0 | 1)
4321 When set to a true value, indicates that any rows fetched from joined has_many
4322 relationships are to be aggregated into the corresponding "parent" object. For
4323 example, the resultset:
4325 my $rs = $schema->resultset('CD')->search({}, {
4326 '+columns' => [ qw/ tracks.title tracks.position / ],
4331 While executing the following query:
4333 SELECT me.*, tracks.title, tracks.position
4335 LEFT JOIN track tracks
4336 ON tracks.cdid = me.cdid
4338 Will return only as many objects as there are rows in the CD source, even
4339 though the result of the query may span many rows. Each of these CD objects
4340 will in turn have multiple "Track" objects hidden behind the has_many
4341 generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
4342 of this resultset would be as many CD objects as there are tracks (a "Cartesian
4343 product"), with each CD object containing exactly one of all fetched Track data.
4345 When a collapse is requested on a non-ordered resultset, an order by some
4346 unique part of the main source (the left-most table) is inserted automatically.
4347 This is done so that the resultset is allowed to be "lazy" - calling
4348 L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
4349 object with all of its related data.
4351 If an L</order_by> is already declared, and orders the resultset in a way that
4352 makes collapsing as described above impossible (e.g. C<< ORDER BY
4353 has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
4354 switch to "eager" mode and slurp the entire resultset before constructing the
4355 first object returned by L</next>.
4357 Setting this attribute on a resultset that does not join any has_many
4358 relations is a no-op.
4360 For a more in-depth discussion, see L</PREFETCHING>.
4366 =item Value: ($rel_name | \@rel_names | \%rel_names)
4370 This attribute is a shorthand for specifying a L</join> spec, adding all
4371 columns from the joined related sources as L</+columns> and setting
4372 L</collapse> to a true value. For example, the following two queries are
4375 my $rs = $schema->resultset('Artist')->search({}, {
4376 prefetch => { cds => ['genre', 'tracks' ] },
4381 my $rs = $schema->resultset('Artist')->search({}, {
4382 join => { cds => ['genre', 'tracks' ] },
4386 { +{ "cds.$_" => "cds.$_" } }
4387 $schema->source('Artist')->related_source('cds')->columns
4390 { +{ "cds.genre.$_" => "genre.$_" } }
4391 $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
4394 { +{ "cds.tracks.$_" => "tracks.$_" } }
4395 $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
4400 Both producing the following SQL:
4402 SELECT me.artistid, me.name, me.rank, me.charfield,
4403 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
4404 genre.genreid, genre.name,
4405 tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
4408 ON cds.artist = me.artistid
4409 LEFT JOIN genre genre
4410 ON genre.genreid = cds.genreid
4411 LEFT JOIN track tracks
4412 ON tracks.cd = cds.cdid
4413 ORDER BY me.artistid
4415 While L</prefetch> implies a L</join>, it is ok to mix the two together, as
4416 the arguments are properly merged and generally do the right thing. For
4417 example, you may want to do the following:
4419 my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
4420 { 'genre.genreid' => undef },
4422 join => { cds => 'genre' },
4427 Which generates the following SQL:
4429 SELECT me.artistid, me.name, me.rank, me.charfield,
4430 cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
4433 ON cds.artist = me.artistid
4434 LEFT JOIN genre genre
4435 ON genre.genreid = cds.genreid
4436 WHERE genre.genreid IS NULL
4437 ORDER BY me.artistid
4439 For a more in-depth discussion, see L</PREFETCHING>.
4445 =item Value: $source_alias
4449 Sets the source alias for the query. Normally, this defaults to C<me>, but
4450 nested search queries (sub-SELECTs) might need specific aliases set to
4451 reference inner queries. For example:
4454 ->related_resultset('CDs')
4455 ->related_resultset('Tracks')
4457 'track.id' => { -ident => 'none_search.id' },
4461 my $ids = $self->search({
4464 alias => 'none_search',
4465 group_by => 'none_search.id',
4466 })->get_column('id')->as_query;
4468 $self->search({ id => { -in => $ids } })
4470 This attribute is directly tied to L</current_source_alias>.
4480 Makes the resultset paged and specifies the page to retrieve. Effectively
4481 identical to creating a non-pages resultset and then calling ->page($page)
4484 If L</rows> attribute is not specified it defaults to 10 rows per page.
4486 When you have a paged resultset, L</count> will only return the number
4487 of rows in the page. To get the total, use the L</pager> and call
4488 C<total_entries> on it.
4498 Specifies the maximum number of rows for direct retrieval or the number of
4499 rows per page if the page attribute or method is used.
4505 =item Value: $offset
4509 Specifies the (zero-based) row number for the first row to be returned, or the
4510 of the first row of the first page if paging is used.
4512 =head2 software_limit
4516 =item Value: (0 | 1)
4520 When combined with L</rows> and/or L</offset> the generated SQL will not
4521 include any limit dialect stanzas. Instead the entire result will be selected
4522 as if no limits were specified, and DBIC will perform the limit locally, by
4523 artificially advancing and finishing the resulting L</cursor>.
4525 This is the recommended way of performing resultset limiting when no sane RDBMS
4526 implementation is available (e.g.
4527 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4528 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4534 =item Value: \@columns
4538 A arrayref of columns to group by. Can include columns of joined tables.
4540 group_by => [qw/ column1 column2 ... /]
4546 =item Value: $condition
4550 HAVING is a select statement attribute that is applied between GROUP BY and
4551 ORDER BY. It is applied to the after the grouping calculations have been
4554 having => { 'count_employee' => { '>=', 100 } }
4556 or with an in-place function in which case literal SQL is required:
4558 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4564 =item Value: (0 | 1)
4568 Set to 1 to automatically generate a L</group_by> clause based on the selection
4569 (including intelligent handling of L</order_by> contents). Note that the group
4570 criteria calculation takes place over the B<final> selection. This includes
4571 any L</+columns>, L</+select> or L</order_by> additions in subsequent
4572 L</search> calls, and standalone columns selected via
4573 L<DBIx::Class::ResultSetColumn> (L</get_column>). A notable exception are the
4574 extra selections specified via L</prefetch> - such selections are explicitly
4575 excluded from group criteria calculations.
4577 If the final ResultSet also explicitly defines a L</group_by> attribute, this
4578 setting is ignored and an appropriate warning is issued.
4584 Adds to the WHERE clause.
4586 # only return rows WHERE deleted IS NULL for all searches
4587 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4589 Can be overridden by passing C<< { where => undef } >> as an attribute
4592 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4598 Set to 1 to cache search results. This prevents extra SQL queries if you
4599 revisit rows in your ResultSet:
4601 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4603 while( my $artist = $resultset->next ) {
4607 $rs->first; # without cache, this would issue a query
4609 By default, searches are not cached.
4611 For more examples of using these attributes, see
4612 L<DBIx::Class::Manual::Cookbook>.
4618 =item Value: ( 'update' | 'shared' | \$scalar )
4622 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4623 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4628 DBIx::Class supports arbitrary related data prefetching from multiple related
4629 sources. Any combination of relationship types and column sets are supported.
4630 If L<collapsing|/collapse> is requested, there is an additional requirement of
4631 selecting enough data to make every individual object uniquely identifiable.
4633 Here are some more involved examples, based on the following relationship map:
4636 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4637 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4638 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4640 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4642 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4646 my $rs = $schema->resultset('Tag')->search(
4655 The initial search results in SQL like the following:
4657 SELECT tag.*, cd.*, artist.* FROM tag
4658 JOIN cd ON tag.cd = cd.cdid
4659 JOIN artist ON cd.artist = artist.artistid
4661 L<DBIx::Class> has no need to go back to the database when we access the
4662 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4665 Simple prefetches will be joined automatically, so there is no need
4666 for a C<join> attribute in the above search.
4668 The L</prefetch> attribute can be used with any of the relationship types
4669 and multiple prefetches can be specified together. Below is a more complex
4670 example that prefetches a CD's artist, its liner notes (if present),
4671 the cover image, the tracks on that CD, and the guests on those
4674 my $rs = $schema->resultset('CD')->search(
4678 { artist => 'record_label'}, # belongs_to => belongs_to
4679 'liner_note', # might_have
4680 'cover_image', # has_one
4681 { tracks => 'guests' }, # has_many => has_many
4686 This will produce SQL like the following:
4688 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4692 ON artist.artistid = me.artistid
4693 JOIN record_label record_label
4694 ON record_label.labelid = artist.labelid
4695 LEFT JOIN track tracks
4696 ON tracks.cdid = me.cdid
4697 LEFT JOIN guest guests
4698 ON guests.trackid = track.trackid
4699 LEFT JOIN liner_notes liner_note
4700 ON liner_note.cdid = me.cdid
4701 JOIN cd_artwork cover_image
4702 ON cover_image.cdid = me.cdid
4705 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4706 C<tracks>, and C<guests> of the CD will all be available through the
4707 relationship accessors without the need for additional queries to the
4712 Prefetch does a lot of deep magic. As such, it may not behave exactly
4713 as you might expect.
4719 Prefetch uses the L</cache> to populate the prefetched relationships. This
4720 may or may not be what you want.
4724 If you specify a condition on a prefetched relationship, ONLY those
4725 rows that match the prefetched condition will be fetched into that relationship.
4726 This means that adding prefetch to a search() B<may alter> what is returned by
4727 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4729 my $artist_rs = $schema->resultset('Artist')->search({
4735 my $count = $artist_rs->first->cds->count;
4737 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4739 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4741 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4743 That cmp_ok() may or may not pass depending on the datasets involved. In other
4744 words the C<WHERE> condition would apply to the entire dataset, just like
4745 it would in regular SQL. If you want to add a condition only to the "right side"
4746 of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
4747 condition|DBIx::Class::Relationship::Base/condition>
4751 =head1 DBIC BIND VALUES
4753 Because DBIC may need more information to bind values than just the column name
4754 and value itself, it uses a special format for both passing and receiving bind
4755 values. Each bind value should be composed of an arrayref of
4756 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4762 If present (in any form), this is what is being passed directly to bind_param.
4763 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4764 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4766 If this is specified, all other bind options described below are ignored.
4770 If present, this is used to infer the actual bind attribute by passing to
4771 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4772 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4774 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4775 currently drivers are expected to "Do the Right Thing" when given a common
4776 datatype name. (Not ideal, but that's what we got at this point.)
4780 Currently used to correctly allocate buffers for bind_param_inout().
4781 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4782 or to a sensible value based on the "data_type".
4786 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4787 explicitly specified they are never overridden). Also used by some weird DBDs,
4788 where the column name should be available at bind_param time (e.g. Oracle).
4792 For backwards compatibility and convenience, the following shortcuts are
4795 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4796 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4797 [ undef, $val ] === [ {}, $val ]
4798 $val === [ {}, $val ]
4800 =head1 AUTHOR AND CONTRIBUTORS
4802 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4806 You may distribute this code under the same terms as Perl itself.