1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::ResultSetColumn;
8 use Scalar::Util qw/blessed weaken/;
10 use Data::Compare (); # no imports!!! guard against insane architecture
12 # not importing first() as it will clash with our own method
16 # De-duplication in _merge_attr() is disabled, but left in for reference
17 # (the merger is used for other things that ought not to be de-duped)
18 *__HM_DEDUP = sub () { 0 };
28 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
32 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
36 my $users_rs = $schema->resultset('User');
37 while( $user = $users_rs->next) {
38 print $user->username;
41 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
42 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
46 A ResultSet is an object which stores a set of conditions representing
47 a query. It is the backbone of DBIx::Class (i.e. the really
48 important/useful bit).
50 No SQL is executed on the database when a ResultSet is created, it
51 just stores all the conditions needed to create the query.
53 A basic ResultSet representing the data of an entire table is returned
54 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
55 L<Source|DBIx::Class::Manual::Glossary/Source> name.
57 my $users_rs = $schema->resultset('User');
59 A new ResultSet is returned from calling L</search> on an existing
60 ResultSet. The new one will contain all the conditions of the
61 original, plus any new conditions added in the C<search> call.
63 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
64 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
67 The query that the ResultSet represents is B<only> executed against
68 the database when these methods are called:
69 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
71 If a resultset is used in a numeric context it returns the L</count>.
72 However, if it is used in a boolean context it is B<always> true. So if
73 you want to check if a resultset has any results, you must use C<if $rs
76 =head1 CUSTOM ResultSet CLASSES THAT USE Moose
78 If you want to make your custom ResultSet classes with L<Moose>, use a template
81 package MyApp::Schema::ResultSet::User;
84 use namespace::autoclean;
86 extends 'DBIx::Class::ResultSet';
88 sub BUILDARGS { $_[2] }
92 __PACKAGE__->meta->make_immutable;
96 The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
97 clash with the regular ResultSet constructor. Alternatively, you can use:
99 __PACKAGE__->meta->make_immutable(inline_constructor => 0);
101 The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
102 signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
106 =head2 Chaining resultsets
108 Let's say you've got a query that needs to be run to return some data
109 to the user. But, you have an authorization system in place that
110 prevents certain users from seeing certain information. So, you want
111 to construct the basic query in one method, but add constraints to it in
116 my $request = $self->get_request; # Get a request object somehow.
117 my $schema = $self->result_source->schema;
119 my $cd_rs = $schema->resultset('CD')->search({
120 title => $request->param('title'),
121 year => $request->param('year'),
124 $cd_rs = $self->apply_security_policy( $cd_rs );
126 return $cd_rs->all();
129 sub apply_security_policy {
138 =head3 Resolving conditions and attributes
140 When a resultset is chained from another resultset, conditions and
141 attributes with the same keys need resolving.
143 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
144 into the existing ones from the original resultset.
146 The L</where> and L</having> attributes, and any search conditions, are
147 merged with an SQL C<AND> to the existing condition from the original
150 All other attributes are overridden by any new ones supplied in the
153 =head2 Multiple queries
155 Since a resultset just defines a query, you can do all sorts of
156 things with it with the same object.
158 # Don't hit the DB yet.
159 my $cd_rs = $schema->resultset('CD')->search({
160 title => 'something',
164 # Each of these hits the DB individually.
165 my $count = $cd_rs->count;
166 my $most_recent = $cd_rs->get_column('date_released')->max();
167 my @records = $cd_rs->all;
169 And it's not just limited to SELECT statements.
175 $cd_rs->create({ artist => 'Fred' });
177 Which is the same as:
179 $schema->resultset('CD')->create({
180 title => 'something',
185 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
193 =item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
195 =item Return Value: L<$resultset|/search>
199 The resultset constructor. Takes a source object (usually a
200 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
201 L</ATTRIBUTES> below). Does not perform any queries -- these are
202 executed as needed by the other methods.
204 Generally you never construct a resultset manually. Instead you get one
206 C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
207 or C<< $another_resultset->L<search|/search>(...) >> (the later called in
210 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
216 If called on an object, proxies to L</new_result> instead, so
218 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
220 will return a CD object, not a ResultSet, and is equivalent to:
222 my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
224 Please also keep in mind that many internals call L</new_result> directly,
225 so overloading this method with the idea of intercepting new result object
226 creation B<will not work>. See also warning pertaining to L</create>.
234 return $class->new_result(@_) if ref $class;
236 my ($source, $attrs) = @_;
237 $source = $source->resolve
238 if $source->isa('DBIx::Class::ResultSourceHandle');
239 $attrs = { %{$attrs||{}} };
241 if ($attrs->{page}) {
242 $attrs->{rows} ||= 10;
245 $attrs->{alias} ||= 'me';
248 result_source => $source,
249 cond => $attrs->{where},
254 # if there is a dark selector, this means we are already in a
255 # chain and the cleanup/sanification was taken care of by
257 $self->_normalize_selection($attrs)
258 unless $attrs->{_dark_selector};
261 $attrs->{result_class} || $source->result_class
271 =item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
273 =item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
277 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
278 my $new_rs = $cd_rs->search({ year => 2005 });
280 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
281 # year = 2005 OR year = 2004
283 In list context, C<< ->all() >> is called implicitly on the resultset, thus
284 returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
285 To avoid that, use L</search_rs>.
287 If you need to pass in additional attributes but no additional condition,
288 call it as C<search(undef, \%attrs)>.
290 # "SELECT name, artistid FROM $artist_table"
291 my @all_artists = $schema->resultset('Artist')->search(undef, {
292 columns => [qw/name artistid/],
295 For a list of attributes that can be passed to C<search>, see
296 L</ATTRIBUTES>. For more examples of using this function, see
297 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
298 documentation for the first argument, see L<SQL::Abstract>
299 and its extension L<DBIx::Class::SQLMaker>.
301 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
305 Note that L</search> does not process/deflate any of the values passed in the
306 L<SQL::Abstract>-compatible search condition structure. This is unlike other
307 condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
308 manually that any value passed to this method will stringify to something the
309 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
310 objects, for more info see:
311 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
317 my $rs = $self->search_rs( @_ );
322 elsif (defined wantarray) {
326 # we can be called by a relationship helper, which in
327 # turn may be called in void context due to some braindead
328 # overload or whatever else the user decided to be clever
329 # at this particular day. Thus limit the exception to
330 # external code calls only
331 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
332 if (caller)[0] !~ /^\QDBIx::Class::/;
342 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
344 =item Return Value: L<$resultset|/search>
348 This method does the same exact thing as search() except it will
349 always return a resultset, even in list context.
356 my $rsrc = $self->result_source;
357 my ($call_cond, $call_attrs);
359 # Special-case handling for (undef, undef) or (undef)
360 # Note that (foo => undef) is valid deprecated syntax
361 @_ = () if not scalar grep { defined $_ } @_;
367 # fish out attrs in the ($condref, $attr) case
368 elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
369 ($call_cond, $call_attrs) = @_;
372 $self->throw_exception('Odd number of arguments to search')
376 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
377 unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
379 for my $i (0 .. $#_) {
381 $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
382 if (! defined $_[$i] or ref $_[$i] ne '');
388 # see if we can keep the cache (no $rs changes)
390 my %safe = (alias => 1, cache => 1);
391 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
394 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
396 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
398 $cache = $self->get_cache;
401 my $old_attrs = { %{$self->{attrs}} };
402 my $old_having = delete $old_attrs->{having};
403 my $old_where = delete $old_attrs->{where};
405 my $new_attrs = { %$old_attrs };
407 # take care of call attrs (only if anything is changing)
408 if ($call_attrs and keys %$call_attrs) {
410 # copy for _normalize_selection
411 $call_attrs = { %$call_attrs };
413 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
415 # reset the current selector list if new selectors are supplied
416 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
417 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
420 # Normalize the new selector list (operates on the passed-in attr structure)
421 # Need to do it on every chain instead of only once on _resolved_attrs, in
422 # order to allow detection of empty vs partial 'as'
423 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
424 if $old_attrs->{_dark_selector};
425 $self->_normalize_selection ($call_attrs);
427 # start with blind overwriting merge, exclude selector attrs
428 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
429 delete @{$new_attrs}{@selector_attrs};
431 for (@selector_attrs) {
432 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
433 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
436 # older deprecated name, use only if {columns} is not there
437 if (my $c = delete $new_attrs->{cols}) {
438 if ($new_attrs->{columns}) {
439 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
442 $new_attrs->{columns} = $c;
447 # join/prefetch use their own crazy merging heuristics
448 foreach my $key (qw/join prefetch/) {
449 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
450 if exists $call_attrs->{$key};
453 # stack binds together
454 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
458 for ($old_where, $call_cond) {
460 $new_attrs->{where} = $self->_stack_cond (
461 $_, $new_attrs->{where}
466 if (defined $old_having) {
467 $new_attrs->{having} = $self->_stack_cond (
468 $old_having, $new_attrs->{having}
472 my $rs = (ref $self)->new($rsrc, $new_attrs);
474 $rs->set_cache($cache) if ($cache);
480 sub _normalize_selection {
481 my ($self, $attrs) = @_;
484 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
485 if exists $attrs->{include_columns};
487 # columns are always placed first, however
489 # Keep the X vs +X separation until _resolved_attrs time - this allows to
490 # delay the decision on whether to use a default select list ($rsrc->columns)
491 # allowing stuff like the remove_columns helper to work
493 # select/as +select/+as pairs need special handling - the amount of select/as
494 # elements in each pair does *not* have to be equal (think multicolumn
495 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
496 # supplied at all) - try to infer the alias, either from the -as parameter
497 # of the selector spec, or use the parameter whole if it looks like a column
498 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
499 # is ok as well), but make sure no more additions to the 'as' chain take place
500 for my $pref ('', '+') {
502 my ($sel, $as) = map {
503 my $key = "${pref}${_}";
505 my $val = [ ref $attrs->{$key} eq 'ARRAY'
507 : $attrs->{$key} || ()
509 delete $attrs->{$key};
513 if (! @$as and ! @$sel ) {
516 elsif (@$as and ! @$sel) {
517 $self->throw_exception(
518 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
522 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
523 # if any @$as has been supplied we assume the user knows what (s)he is doing
524 # and blindly keep stacking up pieces
525 unless ($attrs->{_dark_selector}) {
528 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
529 push @$as, $_->{-as};
531 # assume any plain no-space, no-parenthesis string to be a column spec
532 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
533 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
536 # if all else fails - raise a flag that no more aliasing will be allowed
538 $attrs->{_dark_selector} = {
540 string => ($dark_sel_dumper ||= do {
541 require Data::Dumper::Concise;
542 Data::Dumper::Concise::DumperObject()->Indent(0);
543 })->Values([$_])->Dump
551 elsif (@$as < @$sel) {
552 $self->throw_exception(
553 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
556 elsif ($pref and $attrs->{_dark_selector}) {
557 $self->throw_exception(
558 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
564 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
565 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
570 my ($self, $left, $right) = @_;
572 # collapse single element top-level conditions
573 # (single pass only, unlikely to need recursion)
574 for ($left, $right) {
575 if (ref $_ eq 'ARRAY') {
583 elsif (ref $_ eq 'HASH') {
584 my ($first, $more) = keys %$_;
587 if (! defined $first) {
591 elsif (! defined $more) {
592 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
595 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
602 # merge hashes with weeding out of duplicates (simple cases only)
603 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
605 # shallow copy to destroy
606 $right = { %$right };
607 for (grep { exists $right->{$_} } keys %$left) {
608 # the use of eq_deeply here is justified - the rhs of an
609 # expression can contain a lot of twisted weird stuff
610 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
613 $right = undef unless keys %$right;
617 if (defined $left xor defined $right) {
618 return defined $left ? $left : $right;
620 elsif (! defined $left) {
624 return { -and => [ $left, $right ] };
628 =head2 search_literal
630 B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
631 should only be used in that context. C<search_literal> is a convenience
632 method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
633 want to ensure columns are bound correctly, use L</search>.
635 See L<DBIx::Class::Manual::Cookbook/Searching> and
636 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
637 require C<search_literal>.
641 =item Arguments: $sql_fragment, @standalone_bind_values
643 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
647 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
648 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
650 Pass a literal chunk of SQL to be added to the conditional part of the
653 Example of how to use C<search> instead of C<search_literal>
655 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
656 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
661 my ($self, $sql, @bind) = @_;
663 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
666 return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
673 =item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
675 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
679 Finds and returns a single row based on supplied criteria. Takes either a
680 hashref with the same format as L</create> (including inference of foreign
681 keys from related objects), or a list of primary key values in the same
682 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
683 declaration on the L</result_source>.
685 In either case an attempt is made to combine conditions already existing on
686 the resultset with the condition passed to this method.
688 To aid with preparing the correct query for the storage you may supply the
689 C<key> attribute, which is the name of a
690 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
691 unique constraint corresponding to the
692 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
693 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
694 to construct a query that satisfies the named unique constraint fully (
695 non-NULL values for each column member of the constraint) an exception is
698 If no C<key> is specified, the search is carried over all unique constraints
699 which are fully defined by the available condition.
701 If no such constraint is found, C<find> currently defaults to a simple
702 C<< search->(\%column_values) >> which may or may not do what you expect.
703 Note that this fallback behavior may be deprecated in further versions. If
704 you need to search with arbitrary conditions - use L</search>. If the query
705 resulting from this fallback produces more than one row, a warning to the
706 effect is issued, though only the first row is constructed and returned as
709 In addition to C<key>, L</find> recognizes and applies standard
710 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
712 Note that if you have extra concerns about the correctness of the resulting
713 query you need to specify the C<key> attribute and supply the entire condition
714 as an argument to find (since it is not always possible to perform the
715 combination of the resultset condition with the supplied one, especially if
716 the resultset condition contains literal sql).
718 For example, to find a row by its primary key:
720 my $cd = $schema->resultset('CD')->find(5);
722 You can also find a row by a specific unique constraint:
724 my $cd = $schema->resultset('CD')->find(
726 artist => 'Massive Attack',
727 title => 'Mezzanine',
729 { key => 'cd_artist_title' }
732 See also L</find_or_create> and L</update_or_create>.
738 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
740 my $rsrc = $self->result_source;
743 if (exists $attrs->{key}) {
744 $constraint_name = defined $attrs->{key}
746 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
750 # Parse out the condition from input
753 if (ref $_[0] eq 'HASH') {
754 $call_cond = { %{$_[0]} };
757 # if only values are supplied we need to default to 'primary'
758 $constraint_name = 'primary' unless defined $constraint_name;
760 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
762 $self->throw_exception(
763 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
766 $self->throw_exception (
767 'find() expects either a column/value hashref, or a list of values '
768 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
769 ) unless @c_cols == @_;
772 @{$call_cond}{@c_cols} = @_;
776 for my $key (keys %$call_cond) {
778 my $keyref = ref($call_cond->{$key})
780 my $relinfo = $rsrc->relationship_info($key)
782 my $val = delete $call_cond->{$key};
784 next if $keyref eq 'ARRAY'; # has_many for multi_create
786 my $rel_q = $rsrc->_resolve_condition(
787 $relinfo->{cond}, $val, $key, $key
789 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
790 @related{keys %$rel_q} = values %$rel_q;
794 # relationship conditions take precedence (?)
795 @{$call_cond}{keys %related} = values %related;
797 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
799 if (defined $constraint_name) {
800 $final_cond = $self->_qualify_cond_columns (
802 $self->_build_unique_cond (
810 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
811 # This means that we got here after a merger of relationship conditions
812 # in ::Relationship::Base::search_related (the row method), and furthermore
813 # the relationship is of the 'single' type. This means that the condition
814 # provided by the relationship (already attached to $self) is sufficient,
815 # as there can be only one row in the database that would satisfy the
819 # no key was specified - fall down to heuristics mode:
820 # run through all unique queries registered on the resultset, and
821 # 'OR' all qualifying queries together
822 my (@unique_queries, %seen_column_combinations);
823 for my $c_name ($rsrc->unique_constraint_names) {
824 next if $seen_column_combinations{
825 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
828 push @unique_queries, try {
829 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
833 $final_cond = @unique_queries
834 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
835 : $self->_non_unique_find_fallback ($call_cond, $attrs)
839 # Run the query, passing the result_class since it should propagate for find
840 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
841 if ($rs->_resolved_attrs->{collapse}) {
843 carp "Query returned more than one row" if $rs->next;
851 # This is a stop-gap method as agreed during the discussion on find() cleanup:
852 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
854 # It is invoked when find() is called in legacy-mode with insufficiently-unique
855 # condition. It is provided for overrides until a saner way forward is devised
857 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
858 # the road. Please adjust your tests accordingly to catch this situation early
859 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
861 # The method will not be removed without an adequately complete replacement
862 # for strict-mode enforcement
863 sub _non_unique_find_fallback {
864 my ($self, $cond, $attrs) = @_;
866 return $self->_qualify_cond_columns(
868 exists $attrs->{alias}
870 : $self->{attrs}{alias}
875 sub _qualify_cond_columns {
876 my ($self, $cond, $alias) = @_;
878 my %aliased = %$cond;
879 for (keys %aliased) {
880 $aliased{"$alias.$_"} = delete $aliased{$_}
887 sub _build_unique_cond {
888 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
890 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
892 # combination may fail if $self->{cond} is non-trivial
893 my ($final_cond) = try {
894 $self->_merge_with_rscond ($extra_cond)
899 # trim out everything not in $columns
900 $final_cond = { map {
901 exists $final_cond->{$_}
902 ? ( $_ => $final_cond->{$_} )
906 if (my @missing = grep
907 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
910 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
912 join (', ', map { "'$_'" } @missing),
919 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
921 my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
923 carp_unique ( sprintf (
924 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
925 . 'values in column(s): %s). This is almost certainly not what you wanted, '
926 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
928 join (', ', map { "'$_'" } @undefs),
935 =head2 search_related
939 =item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
941 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
945 $new_rs = $cd_rs->search_related('artist', {
949 Searches the specified relationship, optionally specifying a condition and
950 attributes for matching records. See L</ATTRIBUTES> for more information.
952 In list context, C<< ->all() >> is called implicitly on the resultset, thus
953 returning a list of result objects instead. To avoid that, use L</search_related_rs>.
955 See also L</search_related_rs>.
960 return shift->related_resultset(shift)->search(@_);
963 =head2 search_related_rs
965 This method works exactly the same as search_related, except that
966 it guarantees a resultset, even in list context.
970 sub search_related_rs {
971 return shift->related_resultset(shift)->search_rs(@_);
978 =item Arguments: none
980 =item Return Value: L<$cursor|DBIx::Class::Cursor>
984 Returns a storage-driven cursor to the given resultset. See
985 L<DBIx::Class::Cursor> for more information.
992 return $self->{cursor} ||= do {
993 my $attrs = { %{$self->_resolved_attrs } };
994 $self->result_source->storage->select(
995 $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
1004 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1006 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1010 my $cd = $schema->resultset('CD')->single({ year => 2001 });
1012 Inflates the first result without creating a cursor if the resultset has
1013 any records in it; if not returns C<undef>. Used by L</find> as a lean version
1016 While this method can take an optional search condition (just like L</search>)
1017 being a fast-code-path it does not recognize search attributes. If you need to
1018 add extra joins or similar, call L</search> and then chain-call L</single> on the
1019 L<DBIx::Class::ResultSet> returned.
1025 As of 0.08100, this method enforces the assumption that the preceding
1026 query returns only one row. If more than one row is returned, you will receive
1029 Query returned more than one row
1031 In this case, you should be using L</next> or L</find> instead, or if you really
1032 know what you are doing, use the L</rows> attribute to explicitly limit the size
1035 This method will also throw an exception if it is called on a resultset prefetching
1036 has_many, as such a prefetch implies fetching multiple rows from the database in
1037 order to assemble the resulting object.
1044 my ($self, $where) = @_;
1046 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1049 my $attrs = { %{$self->_resolved_attrs} };
1051 $self->throw_exception(
1052 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
1053 ) if $attrs->{collapse};
1056 if (defined $attrs->{where}) {
1059 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1060 $where, delete $attrs->{where} ]
1063 $attrs->{where} = $where;
1067 my $data = [ $self->result_source->storage->select_single(
1068 $attrs->{from}, $attrs->{select},
1069 $attrs->{where}, $attrs
1071 return undef unless @$data;
1072 $self->{stashed_rows} = [ $data ];
1073 $self->_construct_objects->[0];
1079 # Recursively collapse the query, accumulating values for each column.
1081 sub _collapse_query {
1082 my ($self, $query, $collapsed) = @_;
1086 if (ref $query eq 'ARRAY') {
1087 foreach my $subquery (@$query) {
1088 next unless ref $subquery; # -or
1089 $collapsed = $self->_collapse_query($subquery, $collapsed);
1092 elsif (ref $query eq 'HASH') {
1093 if (keys %$query and (keys %$query)[0] eq '-and') {
1094 foreach my $subquery (@{$query->{-and}}) {
1095 $collapsed = $self->_collapse_query($subquery, $collapsed);
1099 foreach my $col (keys %$query) {
1100 my $value = $query->{$col};
1101 $collapsed->{$col}{$value}++;
1113 =item Arguments: L<$cond?|DBIx::Class::SQLMaker>
1115 =item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
1119 my $max_length = $rs->get_column('length')->max;
1121 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1126 my ($self, $column) = @_;
1127 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1135 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1137 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1141 # WHERE title LIKE '%blue%'
1142 $cd_rs = $rs->search_like({ title => '%blue%'});
1144 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1145 that this is simply a convenience method retained for ex Class::DBI users.
1146 You most likely want to use L</search> with specific operators.
1148 For more information, see L<DBIx::Class::Manual::Cookbook>.
1150 This method is deprecated and will be removed in 0.09. Use L</search()>
1151 instead. An example conversion is:
1153 ->search_like({ foo => 'bar' });
1157 ->search({ foo => { like => 'bar' } });
1164 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1165 .' Instead use ->search({ x => { -like => "y%" } })'
1166 .' (note the outer pair of {}s - they are important!)'
1168 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1169 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1170 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1171 return $class->search($query, { %$attrs });
1178 =item Arguments: $first, $last
1180 =item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
1184 Returns a resultset or object list representing a subset of elements from the
1185 resultset slice is called on. Indexes are from 0, i.e., to get the first
1186 three records, call:
1188 my ($one, $two, $three) = $rs->slice(0, 2);
1193 my ($self, $min, $max) = @_;
1194 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1195 $attrs->{offset} = $self->{attrs}{offset} || 0;
1196 $attrs->{offset} += $min;
1197 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1198 return $self->search(undef, $attrs);
1199 #my $slice = (ref $self)->new($self->result_source, $attrs);
1200 #return (wantarray ? $slice->all : $slice);
1207 =item Arguments: none
1209 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1213 Returns the next element in the resultset (C<undef> is there is none).
1215 Can be used to efficiently iterate over records in the resultset:
1217 my $rs = $schema->resultset('CD')->search;
1218 while (my $cd = $rs->next) {
1222 Note that you need to store the resultset object, and call C<next> on it.
1223 Calling C<< resultset('Table')->next >> repeatedly will always return the
1224 first record from the resultset.
1231 if (my $cache = $self->get_cache) {
1232 $self->{all_cache_position} ||= 0;
1233 return $cache->[$self->{all_cache_position}++];
1236 if ($self->{attrs}{cache}) {
1237 delete $self->{pager};
1238 $self->{all_cache_position} = 1;
1239 return ($self->all)[0];
1242 return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] };
1244 $self->{stashed_objects} = $self->_construct_objects
1247 return shift @{$self->{stashed_objects}};
1250 # Constructs as many objects as it can in one pass while respecting
1251 # cursor laziness. Several modes of operation:
1253 # * Always builds everything present in @{$self->{stashed_rows}}
1254 # * If called with $fetch_all true - pulls everything off the cursor and
1255 # builds all objects in one pass
1256 # * If $self->_resolved_attrs->{collapse} is true, checks the order_by
1257 # and if the resultset is ordered properly by the left side:
1258 # * Fetches stuff off the cursor until the "master object" changes,
1259 # and saves the last extra row (if any) in @{$self->{stashed_rows}}
1261 # * Just fetches, and collapses/constructs everything as if $fetch_all
1262 # was requested (there is no other way to collapse except for an
1264 # * If no collapse is requested - just get the next row, construct and
1266 sub _construct_objects {
1267 my ($self, $fetch_all) = @_;
1269 my $rsrc = $self->result_source;
1270 my $attrs = $self->_resolved_attrs;
1271 my $cursor = $self->cursor;
1273 # this will be used as both initial raw-row collector AND as a RV of
1274 # _construct_objects. Not regrowing the array twice matters a lot...
1275 # a suprising amount actually
1276 my $rows = (delete $self->{stashed_rows}) || [];
1278 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1279 $rows = [ @$rows, $cursor->all ];
1281 elsif (!$attrs->{collapse}) {
1282 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1283 push @$rows, do { my @r = $cursor->next; @r ? \@r : () }
1287 $attrs->{_ordered_for_collapse} ||= (!$attrs->{order_by}) ? undef : do {
1288 my $st = $rsrc->schema->storage;
1291 ( $st->_extract_order_criteria($attrs->{order_by}) )
1294 my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
1296 for (0 .. $#ord_cols) {
1298 ! $colinfos->{$ord_cols[$_]}
1300 $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
1302 splice @ord_cols, $_;
1307 # since all we check here are the start of the order_by belonging to the
1308 # top level $rsrc, a present identifying set will mean that the resultset
1309 # is ordered by its leftmost table in a tsable manner
1310 (@ord_cols and $rsrc->_identifying_column_set({ map
1311 { $colinfos->{$_}{-colname} => $colinfos->{$_} }
1316 if ($attrs->{_ordered_for_collapse}) {
1317 push @$rows, do { my @r = $cursor->next; @r ? \@r : () };
1319 # instead of looping over ->next, use ->all in stealth mode
1320 # *without* calling a ->reset afterwards
1321 # FIXME - encapsulation breach, got to be a better way
1322 elsif (! $cursor->{_done}) {
1323 push @$rows, $cursor->all;
1324 $cursor->{_done} = 1;
1329 return undef unless @$rows;
1331 my $res_class = $self->result_class;
1332 my $inflator = $res_class->can ('inflate_result')
1333 or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
1335 my $infmap = $attrs->{as};
1337 if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) {
1338 # construct a much simpler array->hash folder for the one-table cases right here
1340 # FIXME SUBOPTIMAL this is a very very very hot spot
1341 # while rather optimal we can *still* do much better, by
1342 # building a smarter [Row|HRI]::inflate_result(), and
1343 # switch to feeding it data via a much leaner interface
1345 # crude unscientific benchmarking indicated the shortcut eval is not worth it for
1346 # this particular resultset size
1348 my @as_idx = 0..$#$infmap;
1349 for my $r (@$rows) {
1350 $r = $inflator->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } @as_idx } );
1355 '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows',
1356 join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
1361 ($self->{_row_parser} ||= eval sprintf 'sub { %s }', $rsrc->_mk_row_parser({
1362 inflate_map => $infmap,
1363 selection => $attrs->{select},
1364 collapse => $attrs->{collapse},
1365 }) or die $@)->($rows, $fetch_all ? () : (
1366 # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
1367 sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
1368 ($self->{stashed_rows} = []), # where does it stuff excess
1369 )); # modify $rows in-place, shrinking/extending as necessary
1371 $_ = $inflator->($res_class, $rsrc, @$_) for @$rows;
1376 if ($attrs->{record_filter}) {
1377 $_ = $attrs->{record_filter}->($_) for @$rows;
1383 =head2 result_source
1387 =item Arguments: L<$result_source?|DBIx::Class::ResultSource>
1389 =item Return Value: L<$result_source|DBIx::Class::ResultSource>
1393 An accessor for the primary ResultSource object from which this ResultSet
1400 =item Arguments: $result_class?
1402 =item Return Value: $result_class
1406 An accessor for the class to use when creating result objects. Defaults to
1407 C<< result_source->result_class >> - which in most cases is the name of the
1408 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1410 Note that changing the result_class will also remove any components
1411 that were originally loaded in the source class via
1412 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1413 in the original source class will not run.
1418 my ($self, $result_class) = @_;
1419 if ($result_class) {
1420 unless (ref $result_class) { # don't fire this for an object
1421 $self->ensure_class_loaded($result_class);
1423 $self->_result_class($result_class);
1424 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1425 # permit the user to set result class on one result set only; it only
1426 # chains if provided to search()
1427 #$self->{attrs}{result_class} = $result_class if ref $self;
1429 $self->_result_class;
1436 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1438 =item Return Value: $count
1442 Performs an SQL C<COUNT> with the same query as the resultset was built
1443 with to find the number of elements. Passing arguments is equivalent to
1444 C<< $rs->search ($cond, \%attrs)->count >>
1450 return $self->search(@_)->count if @_ and defined $_[0];
1451 return scalar @{ $self->get_cache } if $self->get_cache;
1453 my $attrs = { %{ $self->_resolved_attrs } };
1455 # this is a little optimization - it is faster to do the limit
1456 # adjustments in software, instead of a subquery
1457 my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
1460 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1461 $crs = $self->_count_subq_rs ($attrs);
1464 $crs = $self->_count_rs ($attrs);
1466 my $count = $crs->next;
1468 $count -= $offset if $offset;
1469 $count = $rows if $rows and $rows < $count;
1470 $count = 0 if ($count < 0);
1479 =item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
1481 =item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
1485 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1486 This can be very handy for subqueries:
1488 ->search( { amount => $some_rs->count_rs->as_query } )
1490 As with regular resultsets the SQL query will be executed only after
1491 the resultset is accessed via L</next> or L</all>. That would return
1492 the same single value obtainable via L</count>.
1498 return $self->search(@_)->count_rs if @_;
1500 # this may look like a lack of abstraction (count() does about the same)
1501 # but in fact an _rs *must* use a subquery for the limits, as the
1502 # software based limiting can not be ported if this $rs is to be used
1503 # in a subquery itself (i.e. ->as_query)
1504 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1505 return $self->_count_subq_rs;
1508 return $self->_count_rs;
1513 # returns a ResultSetColumn object tied to the count query
1516 my ($self, $attrs) = @_;
1518 my $rsrc = $self->result_source;
1519 $attrs ||= $self->_resolved_attrs;
1521 my $tmp_attrs = { %$attrs };
1522 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1523 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1525 # overwrite the selector (supplied by the storage)
1526 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1527 $tmp_attrs->{as} = 'count';
1529 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1535 # same as above but uses a subquery
1537 sub _count_subq_rs {
1538 my ($self, $attrs) = @_;
1540 my $rsrc = $self->result_source;
1541 $attrs ||= $self->_resolved_attrs;
1543 my $sub_attrs = { %$attrs };
1544 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1545 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1547 # if we multi-prefetch we group_by something unique, as this is what we would
1548 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1549 if ( $attrs->{collapse} ) {
1550 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
1551 $rsrc->_identifying_column_set || $self->throw_exception(
1552 'Unable to construct a unique group_by criteria properly collapsing the '
1553 . 'has_many prefetch before count()'
1558 # Calculate subquery selector
1559 if (my $g = $sub_attrs->{group_by}) {
1561 my $sql_maker = $rsrc->storage->sql_maker;
1563 # necessary as the group_by may refer to aliased functions
1565 for my $sel (@{$attrs->{select}}) {
1566 $sel_index->{$sel->{-as}} = $sel
1567 if (ref $sel eq 'HASH' and $sel->{-as});
1570 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1571 # also look for named aggregates referred in the having clause
1572 # having often contains scalarrefs - thus parse it out entirely
1574 if ($attrs->{having}) {
1575 local $sql_maker->{having_bind};
1576 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1577 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1578 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1579 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1580 # if we don't unset it we screw up retarded but unfortunately working
1581 # 'MAX(foo.bar)' => { '>', 3 }
1582 $sql_maker->{name_sep} = '';
1585 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1587 my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1590 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1591 # and if all fails for an utterly naive quoted scalar-with-function
1592 while ($having_sql =~ /
1593 $rquote $sep $lquote (.+?) $rquote
1595 [\s,] \w+ \. (\w+) [\s,]
1597 [\s,] $lquote (.+?) $rquote [\s,]
1599 my $part = $1 || $2 || $3; # one of them matched if we got here
1600 unless ($seen_having{$part}++) {
1607 my $colpiece = $sel_index->{$_} || $_;
1609 # unqualify join-based group_by's. Arcane but possible query
1610 # also horrible horrible hack to alias a column (not a func.)
1611 # (probably need to introduce SQLA syntax)
1612 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1615 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1617 push @{$sub_attrs->{select}}, $colpiece;
1621 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1622 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1625 return $rsrc->resultset_class
1626 ->new ($rsrc, $sub_attrs)
1628 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1629 ->get_column ('count');
1636 =head2 count_literal
1638 B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
1639 should only be used in that context. See L</search_literal> for further info.
1643 =item Arguments: $sql_fragment, @standalone_bind_values
1645 =item Return Value: $count
1649 Counts the results in a literal query. Equivalent to calling L</search_literal>
1650 with the passed arguments, then L</count>.
1654 sub count_literal { shift->search_literal(@_)->count; }
1660 =item Arguments: none
1662 =item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
1666 Returns all elements in the resultset.
1673 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1676 delete @{$self}{qw/stashed_rows stashed_objects/};
1678 if (my $c = $self->get_cache) {
1682 $self->cursor->reset;
1684 my $objs = $self->_construct_objects('fetch_all') || [];
1686 $self->set_cache($objs) if $self->{attrs}{cache};
1695 =item Arguments: none
1697 =item Return Value: $self
1701 Resets the resultset's cursor, so you can iterate through the elements again.
1702 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1710 delete @{$self}{qw/stashed_rows stashed_objects/};
1711 $self->{all_cache_position} = 0;
1712 $self->cursor->reset;
1720 =item Arguments: none
1722 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
1726 L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
1727 an object for the first result (or C<undef> if the resultset is empty).
1732 return $_[0]->reset->next;
1738 # Determines whether and what type of subquery is required for the $rs operation.
1739 # If grouping is necessary either supplies its own, or verifies the current one
1740 # After all is done delegates to the proper storage method.
1742 sub _rs_update_delete {
1743 my ($self, $op, $values) = @_;
1745 my $rsrc = $self->result_source;
1746 my $storage = $rsrc->schema->storage;
1748 my $attrs = { %{$self->_resolved_attrs} };
1750 my $join_classifications;
1751 my $existing_group_by = delete $attrs->{group_by};
1753 # do we need a subquery for any reason?
1755 defined $existing_group_by
1757 # if {from} is unparseable wrap a subq
1758 ref($attrs->{from}) ne 'ARRAY'
1760 # limits call for a subq
1761 $self->_has_resolved_attr(qw/rows offset/)
1764 # simplify the joinmap, so we can further decide if a subq is necessary
1765 if (!$needs_subq and @{$attrs->{from}} > 1) {
1766 $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
1768 # check if there are any joins left after the prune
1769 if ( @{$attrs->{from}} > 1 ) {
1770 $join_classifications = $storage->_resolve_aliastypes_from_select_args (
1771 [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
1777 # any non-pruneable joins imply subq
1778 $needs_subq = scalar keys %{ $join_classifications->{restricting} || {} };
1782 # check if the head is composite (by now all joins are thrown out unless $needs_subq)
1784 (ref $attrs->{from}[0]) ne 'HASH'
1786 ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
1790 # do we need anything like a subquery?
1791 if (! $needs_subq) {
1792 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1793 # a condition containing 'me' or other table prefixes will not work
1794 # at all. Tell SQLMaker to dequalify idents via a gross hack.
1796 my $sqla = $rsrc->storage->sql_maker;
1797 local $sqla->{_dequalify_idents} = 1;
1798 \[ $sqla->_recurse_where($self->{cond}) ];
1802 # we got this far - means it is time to wrap a subquery
1803 my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
1805 "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
1811 # make a new $rs selecting only the PKs (that's all we really need for the subq)
1812 delete $attrs->{$_} for qw/collapse select _prefetch_selector_range as/;
1813 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
1814 $attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
1815 my $subrs = (ref $self)->new($rsrc, $attrs);
1817 if (@$idcols == 1) {
1818 $cond = { $idcols->[0] => { -in => $subrs->as_query } };
1820 elsif ($storage->_use_multicolumn_in) {
1821 # no syntax for calling this properly yet
1822 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
1823 $cond = $storage->sql_maker->_where_op_multicolumn_in (
1824 $idcols, # how do I convey a list of idents...? can binds reside on lhs?
1829 # if all else fails - get all primary keys and operate over a ORed set
1830 # wrap in a transaction for consistency
1831 # this is where the group_by/multiplication starts to matter
1835 keys %{ $join_classifications->{multiplying} || {} }
1837 # make sure if there is a supplied group_by it matches the columns compiled above
1838 # perfectly. Anything else can not be sanely executed on most databases so croak
1839 # right then and there
1840 if ($existing_group_by) {
1841 my @current_group_by = map
1842 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1847 join ("\x00", sort @current_group_by)
1849 join ("\x00", sort @{$attrs->{columns}} )
1851 $self->throw_exception (
1852 "You have just attempted a $op operation on a resultset which does group_by"
1853 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1854 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1855 . ' kind of queries. Please retry the operation with a modified group_by or'
1856 . ' without using one at all.'
1861 $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
1864 $guard = $storage->txn_scope_guard;
1867 for my $row ($subrs->cursor->all) {
1869 { $idcols->[$_] => $row->[$_] }
1876 my $res = $storage->$op (
1878 $op eq 'update' ? $values : (),
1882 $guard->commit if $guard;
1891 =item Arguments: \%values
1893 =item Return Value: $underlying_storage_rv
1897 Sets the specified columns in the resultset to the supplied values in a
1898 single query. Note that this will not run any accessor/set_column/update
1899 triggers, nor will it update any result object instances derived from this
1900 resultset (this includes the contents of the L<resultset cache|/set_cache>
1901 if any). See L</update_all> if you need to execute any on-update
1902 triggers or cascades defined either by you or a
1903 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1905 The return value is a pass through of what the underlying
1906 storage backend returned, and may vary. See L<DBI/execute> for the most
1911 Note that L</update> does not process/deflate any of the values passed in.
1912 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1913 ensure manually that any value passed to this method will stringify to
1914 something the RDBMS knows how to deal with. A notable example is the
1915 handling of L<DateTime> objects, for more info see:
1916 L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
1921 my ($self, $values) = @_;
1922 $self->throw_exception('Values for update must be a hash')
1923 unless ref $values eq 'HASH';
1925 return $self->_rs_update_delete ('update', $values);
1932 =item Arguments: \%values
1934 =item Return Value: 1
1938 Fetches all objects and updates them one at a time via
1939 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1940 triggers, while L</update> will not.
1945 my ($self, $values) = @_;
1946 $self->throw_exception('Values for update_all must be a hash')
1947 unless ref $values eq 'HASH';
1949 my $guard = $self->result_source->schema->txn_scope_guard;
1950 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
1959 =item Arguments: none
1961 =item Return Value: $underlying_storage_rv
1965 Deletes the rows matching this resultset in a single query. Note that this
1966 will not run any delete triggers, nor will it alter the
1967 L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
1968 derived from this resultset (this includes the contents of the
1969 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1970 execute any on-delete triggers or cascades defined either by you or a
1971 L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
1973 The return value is a pass through of what the underlying storage backend
1974 returned, and may vary. See L<DBI/execute> for the most common case.
1980 $self->throw_exception('delete does not accept any arguments')
1983 return $self->_rs_update_delete ('delete');
1990 =item Arguments: none
1992 =item Return Value: 1
1996 Fetches all objects and deletes them one at a time via
1997 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1998 triggers, while L</delete> will not.
2004 $self->throw_exception('delete_all does not accept any arguments')
2007 my $guard = $self->result_source->schema->txn_scope_guard;
2008 $_->delete for $self->all;
2017 =item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
2019 =item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
2023 Accepts either an arrayref of hashrefs or alternatively an arrayref of
2030 The context of this method call has an important effect on what is
2031 submitted to storage. In void context data is fed directly to fastpath
2032 insertion routines provided by the underlying storage (most often
2033 L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
2034 L<insert|DBIx::Class::Row/insert> calls on the
2035 L<Result|DBIx::Class::Manual::ResultClass> class, including any
2036 augmentation of these methods provided by components. For example if you
2037 are using something like L<DBIx::Class::UUIDColumns> to create primary
2038 keys for you, you will find that your PKs are empty. In this case you
2039 will have to explicitly force scalar or list context in order to create
2044 In non-void (scalar or list) context, this method is simply a wrapper
2045 for L</create>. Depending on list or scalar context either a list of
2046 L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
2047 containing these objects is returned.
2049 When supplying data in "arrayref of arrayrefs" invocation style, the
2050 first element should be a list of column names and each subsequent
2051 element should be a data value in the earlier specified column order.
2054 $Arstist_rs->populate([
2055 [ qw( artistid name ) ],
2056 [ 100, 'A Formally Unknown Singer' ],
2057 [ 101, 'A singer that jumped the shark two albums ago' ],
2058 [ 102, 'An actually cool singer' ],
2061 For the arrayref of hashrefs style each hashref should be a structure
2062 suitable for passing to L</create>. Multi-create is also permitted with
2065 $schema->resultset("Artist")->populate([
2066 { artistid => 4, name => 'Manufactured Crap', cds => [
2067 { title => 'My First CD', year => 2006 },
2068 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2071 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
2072 { title => 'My parents sold me to a record company', year => 2005 },
2073 { title => 'Why Am I So Ugly?', year => 2006 },
2074 { title => 'I Got Surgery and am now Popular', year => 2007 }
2079 If you attempt a void-context multi-create as in the example above (each
2080 Artist also has the related list of CDs), and B<do not> supply the
2081 necessary autoinc foreign key information, this method will proxy to the
2082 less efficient L</create>, and then throw the Result objects away. In this
2083 case there are obviously no benefits to using this method over L</create>.
2090 # cruft placed in standalone method
2091 my $data = $self->_normalize_populate_args(@_);
2093 return unless @$data;
2095 if(defined wantarray) {
2096 my @created = map { $self->create($_) } @$data;
2097 return wantarray ? @created : \@created;
2100 my $first = $data->[0];
2102 # if a column is a registered relationship, and is a non-blessed hash/array, consider
2103 # it relationship data
2104 my (@rels, @columns);
2105 my $rsrc = $self->result_source;
2106 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2107 for (keys %$first) {
2108 my $ref = ref $first->{$_};
2109 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2115 my @pks = $rsrc->primary_columns;
2117 ## do the belongs_to relationships
2118 foreach my $index (0..$#$data) {
2120 # delegate to create() for any dataset without primary keys with specified relationships
2121 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2123 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2124 my @ret = $self->populate($data);
2130 foreach my $rel (@rels) {
2131 next unless ref $data->[$index]->{$rel} eq "HASH";
2132 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2133 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2134 my $related = $result->result_source->_resolve_condition(
2135 $reverse_relinfo->{cond},
2141 delete $data->[$index]->{$rel};
2142 $data->[$index] = {%{$data->[$index]}, %$related};
2144 push @columns, keys %$related if $index == 0;
2148 ## inherit the data locked in the conditions of the resultset
2149 my ($rs_data) = $self->_merge_with_rscond({});
2150 delete @{$rs_data}{@columns};
2152 ## do bulk insert on current row
2153 $rsrc->storage->insert_bulk(
2155 [@columns, keys %$rs_data],
2156 [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
2159 ## do the has_many relationships
2160 foreach my $item (@$data) {
2164 foreach my $rel (@rels) {
2165 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2167 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2169 my $child = $main_row->$rel;
2171 my $related = $child->result_source->_resolve_condition(
2172 $rels->{$rel}{cond},
2178 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2179 my @populate = map { {%$_, %$related} } @rows_to_add;
2181 $child->populate( \@populate );
2188 # populate() argumnets went over several incarnations
2189 # What we ultimately support is AoH
2190 sub _normalize_populate_args {
2191 my ($self, $arg) = @_;
2193 if (ref $arg eq 'ARRAY') {
2197 elsif (ref $arg->[0] eq 'HASH') {
2200 elsif (ref $arg->[0] eq 'ARRAY') {
2202 my @colnames = @{$arg->[0]};
2203 foreach my $values (@{$arg}[1 .. $#$arg]) {
2204 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2210 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2217 =item Arguments: none
2219 =item Return Value: L<$pager|Data::Page>
2223 Returns a L<Data::Page> object for the current resultset. Only makes
2224 sense for queries with a C<page> attribute.
2226 To get the full count of entries for a paged resultset, call
2227 C<total_entries> on the L<Data::Page> object.
2234 return $self->{pager} if $self->{pager};
2236 my $attrs = $self->{attrs};
2237 if (!defined $attrs->{page}) {
2238 $self->throw_exception("Can't create pager for non-paged rs");
2240 elsif ($attrs->{page} <= 0) {
2241 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2243 $attrs->{rows} ||= 10;
2245 # throw away the paging flags and re-run the count (possibly
2246 # with a subselect) to get the real total count
2247 my $count_attrs = { %$attrs };
2248 delete @{$count_attrs}{qw/rows offset page pager/};
2250 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2252 require DBIx::Class::ResultSet::Pager;
2253 return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
2254 sub { $total_rs->count }, #lazy-get the total
2256 $self->{attrs}{page},
2264 =item Arguments: $page_number
2266 =item Return Value: L<$resultset|/search>
2270 Returns a resultset for the $page_number page of the resultset on which page
2271 is called, where each page contains a number of rows equal to the 'rows'
2272 attribute set on the resultset (10 by default).
2277 my ($self, $page) = @_;
2278 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2285 =item Arguments: \%col_data
2287 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2291 Creates a new result object in the resultset's result class and returns
2292 it. The row is not inserted into the database at this point, call
2293 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2294 will tell you whether the result object has been inserted or not.
2296 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2301 my ($self, $values) = @_;
2303 $self->throw_exception( "new_result takes only one argument - a hashref of values" )
2306 $self->throw_exception( "new_result expects a hashref" )
2307 unless (ref $values eq 'HASH');
2309 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2313 @$cols_from_relations
2314 ? (-cols_from_relations => $cols_from_relations)
2316 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2319 return $self->result_class->new(\%new);
2322 # _merge_with_rscond
2324 # Takes a simple hash of K/V data and returns its copy merged with the
2325 # condition already present on the resultset. Additionally returns an
2326 # arrayref of value/condition names, which were inferred from related
2327 # objects (this is needed for in-memory related objects)
2328 sub _merge_with_rscond {
2329 my ($self, $data) = @_;
2331 my (%new_data, @cols_from_relations);
2333 my $alias = $self->{attrs}{alias};
2335 if (! defined $self->{cond}) {
2336 # just massage $data below
2338 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2339 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2340 @cols_from_relations = keys %new_data;
2342 elsif (ref $self->{cond} ne 'HASH') {
2343 $self->throw_exception(
2344 "Can't abstract implicit construct, resultset condition not a hash"
2348 # precendence must be given to passed values over values inherited from
2349 # the cond, so the order here is important.
2350 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2351 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2353 while ( my($col, $value) = each %implied ) {
2354 my $vref = ref $value;
2360 (keys %$value)[0] eq '='
2362 $new_data{$col} = $value->{'='};
2364 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2365 $new_data{$col} = $value;
2372 %{ $self->_remove_alias($data, $alias) },
2375 return (\%new_data, \@cols_from_relations);
2378 # _has_resolved_attr
2380 # determines if the resultset defines at least one
2381 # of the attributes supplied
2383 # used to determine if a subquery is neccessary
2385 # supports some virtual attributes:
2387 # This will scan for any joins being present on the resultset.
2388 # It is not a mere key-search but a deep inspection of {from}
2391 sub _has_resolved_attr {
2392 my ($self, @attr_names) = @_;
2394 my $attrs = $self->_resolved_attrs;
2398 for my $n (@attr_names) {
2399 if (grep { $n eq $_ } (qw/-join/) ) {
2400 $extra_checks{$n}++;
2404 my $attr = $attrs->{$n};
2406 next if not defined $attr;
2408 if (ref $attr eq 'HASH') {
2409 return 1 if keys %$attr;
2411 elsif (ref $attr eq 'ARRAY') {
2419 # a resolved join is expressed as a multi-level from
2421 $extra_checks{-join}
2423 ref $attrs->{from} eq 'ARRAY'
2425 @{$attrs->{from}} > 1
2433 # Recursively collapse the condition.
2435 sub _collapse_cond {
2436 my ($self, $cond, $collapsed) = @_;
2440 if (ref $cond eq 'ARRAY') {
2441 foreach my $subcond (@$cond) {
2442 next unless ref $subcond; # -or
2443 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2446 elsif (ref $cond eq 'HASH') {
2447 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2448 foreach my $subcond (@{$cond->{-and}}) {
2449 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2453 foreach my $col (keys %$cond) {
2454 my $value = $cond->{$col};
2455 $collapsed->{$col} = $value;
2465 # Remove the specified alias from the specified query hash. A copy is made so
2466 # the original query is not modified.
2469 my ($self, $query, $alias) = @_;
2471 my %orig = %{ $query || {} };
2474 foreach my $key (keys %orig) {
2476 $unaliased{$key} = $orig{$key};
2479 $unaliased{$1} = $orig{$key}
2480 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2490 =item Arguments: none
2492 =item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
2496 Returns the SQL query and bind vars associated with the invocant.
2498 This is generally used as the RHS for a subquery.
2505 my $attrs = { %{ $self->_resolved_attrs } };
2510 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2511 # $sql also has no wrapping parenthesis in list ctx
2513 my $sqlbind = $self->result_source->storage
2514 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2523 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2525 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2529 my $artist = $schema->resultset('Artist')->find_or_new(
2530 { artist => 'fred' }, { key => 'artists' });
2532 $cd->cd_to_producer->find_or_new({ producer => $producer },
2533 { key => 'primary });
2535 Find an existing record from this resultset using L</find>. if none exists,
2536 instantiate a new result object and return it. The object will not be saved
2537 into your storage until you call L<DBIx::Class::Row/insert> on it.
2539 You most likely want this method when looking for existing rows using a unique
2540 constraint that is not the primary key, or looking for related rows.
2542 If you want objects to be saved immediately, use L</find_or_create> instead.
2544 B<Note>: Make sure to read the documentation of L</find> and understand the
2545 significance of the C<key> attribute, as its lack may skew your search, and
2546 subsequently result in spurious new objects.
2548 B<Note>: Take care when using C<find_or_new> with a table having
2549 columns with default values that you intend to be automatically
2550 supplied by the database (e.g. an auto_increment primary key column).
2551 In normal usage, the value of such columns should NOT be included at
2552 all in the call to C<find_or_new>, even when set to C<undef>.
2558 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2559 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2560 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2563 return $self->new_result($hash);
2570 =item Arguments: \%col_data
2572 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2576 Attempt to create a single new row or a row with multiple related rows
2577 in the table represented by the resultset (and related tables). This
2578 will not check for duplicate rows before inserting, use
2579 L</find_or_create> to do that.
2581 To create one row for this resultset, pass a hashref of key/value
2582 pairs representing the columns of the table and the values you wish to
2583 store. If the appropriate relationships are set up, foreign key fields
2584 can also be passed an object representing the foreign row, and the
2585 value will be set to its primary key.
2587 To create related objects, pass a hashref of related-object column values
2588 B<keyed on the relationship name>. If the relationship is of type C<multi>
2589 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2590 The process will correctly identify columns holding foreign keys, and will
2591 transparently populate them from the keys of the corresponding relation.
2592 This can be applied recursively, and will work correctly for a structure
2593 with an arbitrary depth and width, as long as the relationships actually
2594 exists and the correct column data has been supplied.
2596 Instead of hashrefs of plain related data (key/value pairs), you may
2597 also pass new or inserted objects. New objects (not inserted yet, see
2598 L</new_result>), will be inserted into their appropriate tables.
2600 Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
2602 Example of creating a new row.
2604 $person_rs->create({
2605 name=>"Some Person",
2606 email=>"somebody@someplace.com"
2609 Example of creating a new row and also creating rows in a related C<has_many>
2610 or C<has_one> resultset. Note Arrayref.
2613 { artistid => 4, name => 'Manufactured Crap', cds => [
2614 { title => 'My First CD', year => 2006 },
2615 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2620 Example of creating a new row and also creating a row in a related
2621 C<belongs_to> resultset. Note Hashref.
2624 title=>"Music for Silly Walks",
2627 name=>"Silly Musician",
2635 When subclassing ResultSet never attempt to override this method. Since
2636 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2637 lot of the internals simply never call it, so your override will be
2638 bypassed more often than not. Override either L<DBIx::Class::Row/new>
2639 or L<DBIx::Class::Row/insert> depending on how early in the
2640 L</create> process you need to intervene. See also warning pertaining to
2648 my ($self, $attrs) = @_;
2649 $self->throw_exception( "create needs a hashref" )
2650 unless ref $attrs eq 'HASH';
2651 return $self->new_result($attrs)->insert;
2654 =head2 find_or_create
2658 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2660 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2664 $cd->cd_to_producer->find_or_create({ producer => $producer },
2665 { key => 'primary' });
2667 Tries to find a record based on its primary key or unique constraints; if none
2668 is found, creates one and returns that instead.
2670 my $cd = $schema->resultset('CD')->find_or_create({
2672 artist => 'Massive Attack',
2673 title => 'Mezzanine',
2677 Also takes an optional C<key> attribute, to search by a specific key or unique
2678 constraint. For example:
2680 my $cd = $schema->resultset('CD')->find_or_create(
2682 artist => 'Massive Attack',
2683 title => 'Mezzanine',
2685 { key => 'cd_artist_title' }
2688 B<Note>: Make sure to read the documentation of L</find> and understand the
2689 significance of the C<key> attribute, as its lack may skew your search, and
2690 subsequently result in spurious row creation.
2692 B<Note>: Because find_or_create() reads from the database and then
2693 possibly inserts based on the result, this method is subject to a race
2694 condition. Another process could create a record in the table after
2695 the find has completed and before the create has started. To avoid
2696 this problem, use find_or_create() inside a transaction.
2698 B<Note>: Take care when using C<find_or_create> with a table having
2699 columns with default values that you intend to be automatically
2700 supplied by the database (e.g. an auto_increment primary key column).
2701 In normal usage, the value of such columns should NOT be included at
2702 all in the call to C<find_or_create>, even when set to C<undef>.
2704 See also L</find> and L</update_or_create>. For information on how to declare
2705 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2707 If you need to know if an existing row was found or a new one created use
2708 L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2709 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2712 my $cd = $schema->resultset('CD')->find_or_new({
2714 artist => 'Massive Attack',
2715 title => 'Mezzanine',
2719 if( !$cd->in_storage ) {
2726 sub find_or_create {
2728 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2729 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2730 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2733 return $self->create($hash);
2736 =head2 update_or_create
2740 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2742 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2746 $resultset->update_or_create({ col => $val, ... });
2748 Like L</find_or_create>, but if a row is found it is immediately updated via
2749 C<< $found_row->update (\%col_data) >>.
2752 Takes an optional C<key> attribute to search on a specific unique constraint.
2755 # In your application
2756 my $cd = $schema->resultset('CD')->update_or_create(
2758 artist => 'Massive Attack',
2759 title => 'Mezzanine',
2762 { key => 'cd_artist_title' }
2765 $cd->cd_to_producer->update_or_create({
2766 producer => $producer,
2772 B<Note>: Make sure to read the documentation of L</find> and understand the
2773 significance of the C<key> attribute, as its lack may skew your search, and
2774 subsequently result in spurious row creation.
2776 B<Note>: Take care when using C<update_or_create> with a table having
2777 columns with default values that you intend to be automatically
2778 supplied by the database (e.g. an auto_increment primary key column).
2779 In normal usage, the value of such columns should NOT be included at
2780 all in the call to C<update_or_create>, even when set to C<undef>.
2782 See also L</find> and L</find_or_create>. For information on how to declare
2783 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2785 If you need to know if an existing row was updated or a new one created use
2786 L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
2787 to call L<DBIx::Class::Row/insert> to save the newly created row to the
2792 sub update_or_create {
2794 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2795 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2797 my $row = $self->find($cond, $attrs);
2799 $row->update($cond);
2803 return $self->create($cond);
2806 =head2 update_or_new
2810 =item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
2812 =item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
2816 $resultset->update_or_new({ col => $val, ... });
2818 Like L</find_or_new> but if a row is found it is immediately updated via
2819 C<< $found_row->update (\%col_data) >>.
2823 # In your application
2824 my $cd = $schema->resultset('CD')->update_or_new(
2826 artist => 'Massive Attack',
2827 title => 'Mezzanine',
2830 { key => 'cd_artist_title' }
2833 if ($cd->in_storage) {
2834 # the cd was updated
2837 # the cd is not yet in the database, let's insert it
2841 B<Note>: Make sure to read the documentation of L</find> and understand the
2842 significance of the C<key> attribute, as its lack may skew your search, and
2843 subsequently result in spurious new objects.
2845 B<Note>: Take care when using C<update_or_new> with a table having
2846 columns with default values that you intend to be automatically
2847 supplied by the database (e.g. an auto_increment primary key column).
2848 In normal usage, the value of such columns should NOT be included at
2849 all in the call to C<update_or_new>, even when set to C<undef>.
2851 See also L</find>, L</find_or_create> and L</find_or_new>.
2857 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2858 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2860 my $row = $self->find( $cond, $attrs );
2861 if ( defined $row ) {
2862 $row->update($cond);
2866 return $self->new_result($cond);
2873 =item Arguments: none
2875 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
2879 Gets the contents of the cache for the resultset, if the cache is set.
2881 The cache is populated either by using the L</prefetch> attribute to
2882 L</search> or by calling L</set_cache>.
2894 =item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2896 =item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
2900 Sets the contents of the cache for the resultset. Expects an arrayref
2901 of objects of the same class as those produced by the resultset. Note that
2902 if the cache is set, the resultset will return the cached objects rather
2903 than re-querying the database even if the cache attr is not set.
2905 The contents of the cache can also be populated by using the
2906 L</prefetch> attribute to L</search>.
2911 my ( $self, $data ) = @_;
2912 $self->throw_exception("set_cache requires an arrayref")
2913 if defined($data) && (ref $data ne 'ARRAY');
2914 $self->{all_cache} = $data;
2921 =item Arguments: none
2923 =item Return Value: undef
2927 Clears the cache for the resultset.
2932 shift->set_cache(undef);
2939 =item Arguments: none
2941 =item Return Value: true, if the resultset has been paginated
2949 return !!$self->{attrs}{page};
2956 =item Arguments: none
2958 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2966 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2969 =head2 related_resultset
2973 =item Arguments: $rel_name
2975 =item Return Value: L<$resultset|/search>
2979 Returns a related resultset for the supplied relationship name.
2981 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2985 sub related_resultset {
2986 my ($self, $rel) = @_;
2988 $self->{related_resultsets} ||= {};
2989 return $self->{related_resultsets}{$rel} ||= do {
2990 my $rsrc = $self->result_source;
2991 my $rel_info = $rsrc->relationship_info($rel);
2993 $self->throw_exception(
2994 "search_related: result source '" . $rsrc->source_name .
2995 "' has no such relationship $rel")
2998 my $attrs = $self->_chain_relationship($rel);
3000 my $join_count = $attrs->{seen_join}{$rel};
3002 my $alias = $self->result_source->storage
3003 ->relname_to_table_alias($rel, $join_count);
3005 # since this is search_related, and we already slid the select window inwards
3006 # (the select/as attrs were deleted in the beginning), we need to flip all
3007 # left joins to inner, so we get the expected results
3008 # read the comment on top of the actual function to see what this does
3009 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3012 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3013 delete @{$attrs}{qw(result_class alias)};
3017 if (my $cache = $self->get_cache) {
3018 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
3019 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache||[]} }
3024 my $rel_source = $rsrc->related_source($rel);
3028 # The reason we do this now instead of passing the alias to the
3029 # search_rs below is that if you wrap/overload resultset on the
3030 # source you need to know what alias it's -going- to have for things
3031 # to work sanely (e.g. RestrictWithObject wants to be able to add
3032 # extra query restrictions, and these may need to be $alias.)
3034 my $rel_attrs = $rel_source->resultset_attributes;
3035 local $rel_attrs->{alias} = $alias;
3037 $rel_source->resultset
3041 where => $attrs->{where},
3044 $new->set_cache($new_cache) if $new_cache;
3049 =head2 current_source_alias
3053 =item Arguments: none
3055 =item Return Value: $source_alias
3059 Returns the current table alias for the result source this resultset is built
3060 on, that will be used in the SQL query. Usually it is C<me>.
3062 Currently the source alias that refers to the result set returned by a
3063 L</search>/L</find> family method depends on how you got to the resultset: it's
3064 C<me> by default, but eg. L</search_related> aliases it to the related result
3065 source name (and keeps C<me> referring to the original result set). The long
3066 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3067 (and make this method unnecessary).
3069 Thus it's currently necessary to use this method in predefined queries (see
3070 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3071 source alias of the current result set:
3073 # in a result set class
3075 my ($self, $user) = @_;
3077 my $me = $self->current_source_alias;
3079 return $self->search({
3080 "$me.modified" => $user->id,
3086 sub current_source_alias {
3087 return (shift->{attrs} || {})->{alias} || 'me';
3090 =head2 as_subselect_rs
3094 =item Arguments: none
3096 =item Return Value: L<$resultset|/search>
3100 Act as a barrier to SQL symbols. The resultset provided will be made into a
3101 "virtual view" by including it as a subquery within the from clause. From this
3102 point on, any joined tables are inaccessible to ->search on the resultset (as if
3103 it were simply where-filtered without joins). For example:
3105 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3107 # 'x' now pollutes the query namespace
3109 # So the following works as expected
3110 my $ok_rs = $rs->search({'x.other' => 1});
3112 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3113 # def) we look for one row with contradictory terms and join in another table
3114 # (aliased 'x_2') which we never use
3115 my $broken_rs = $rs->search({'x.name' => 'def'});
3117 my $rs2 = $rs->as_subselect_rs;
3119 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3120 my $not_joined_rs = $rs2->search({'x.other' => 1});
3122 # works as expected: finds a 'table' row related to two x rows (abc and def)
3123 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3125 Another example of when one might use this would be to select a subset of
3126 columns in a group by clause:
3128 my $rs = $schema->resultset('Bar')->search(undef, {
3129 group_by => [qw{ id foo_id baz_id }],
3130 })->as_subselect_rs->search(undef, {
3131 columns => [qw{ id foo_id }]
3134 In the above example normally columns would have to be equal to the group by,
3135 but because we isolated the group by into a subselect the above works.
3139 sub as_subselect_rs {
3142 my $attrs = $self->_resolved_attrs;
3144 my $fresh_rs = (ref $self)->new (
3145 $self->result_source
3148 # these pieces will be locked in the subquery
3149 delete $fresh_rs->{cond};
3150 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3152 return $fresh_rs->search( {}, {
3154 $attrs->{alias} => $self->as_query,
3155 -alias => $attrs->{alias},
3156 -rsrc => $self->result_source,
3158 alias => $attrs->{alias},
3162 # This code is called by search_related, and makes sure there
3163 # is clear separation between the joins before, during, and
3164 # after the relationship. This information is needed later
3165 # in order to properly resolve prefetch aliases (any alias
3166 # with a relation_chain_depth less than the depth of the
3167 # current prefetch is not considered)
3169 # The increments happen twice per join. An even number means a
3170 # relationship specified via a search_related, whereas an odd
3171 # number indicates a join/prefetch added via attributes
3173 # Also this code will wrap the current resultset (the one we
3174 # chain to) in a subselect IFF it contains limiting attributes
3175 sub _chain_relationship {
3176 my ($self, $rel) = @_;
3177 my $source = $self->result_source;
3178 my $attrs = { %{$self->{attrs}||{}} };
3180 # we need to take the prefetch the attrs into account before we
3181 # ->_resolve_join as otherwise they get lost - captainL
3182 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3184 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3186 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3189 my @force_subq_attrs = qw/offset rows group_by having/;
3192 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3194 $self->_has_resolved_attr (@force_subq_attrs)
3196 # Nuke the prefetch (if any) before the new $rs attrs
3197 # are resolved (prefetch is useless - we are wrapping
3198 # a subquery anyway).
3199 my $rs_copy = $self->search;
3200 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3201 $rs_copy->{attrs}{join},
3202 delete $rs_copy->{attrs}{prefetch},
3207 -alias => $attrs->{alias},
3208 $attrs->{alias} => $rs_copy->as_query,
3210 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3211 $seen->{-relation_chain_depth} = 0;
3213 elsif ($attrs->{from}) { #shallow copy suffices
3214 $from = [ @{$attrs->{from}} ];
3219 -alias => $attrs->{alias},
3220 $attrs->{alias} => $source->from,
3224 my $jpath = ($seen->{-relation_chain_depth})
3225 ? $from->[-1][0]{-join_path}
3228 my @requested_joins = $source->_resolve_join(
3235 push @$from, @requested_joins;
3237 $seen->{-relation_chain_depth}++;
3239 # if $self already had a join/prefetch specified on it, the requested
3240 # $rel might very well be already included. What we do in this case
3241 # is effectively a no-op (except that we bump up the chain_depth on
3242 # the join in question so we could tell it *is* the search_related)
3245 # we consider the last one thus reverse
3246 for my $j (reverse @requested_joins) {
3247 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3248 if ($rel eq $last_j) {
3249 $j->[0]{-relation_chain_depth}++;
3255 unless ($already_joined) {
3256 push @$from, $source->_resolve_join(
3264 $seen->{-relation_chain_depth}++;
3266 return {%$attrs, from => $from, seen_join => $seen};
3269 sub _resolved_attrs {
3271 return $self->{_attrs} if $self->{_attrs};
3273 my $attrs = { %{ $self->{attrs} || {} } };
3274 my $source = $self->result_source;
3275 my $alias = $attrs->{alias};
3277 # default selection list
3278 $attrs->{columns} = [ $source->columns ]
3279 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3281 # merge selectors together
3282 for (qw/columns select as/) {
3283 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3284 if $attrs->{$_} or $attrs->{"+$_"};
3287 # disassemble columns
3289 if (my $cols = delete $attrs->{columns}) {
3290 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3291 if (ref $c eq 'HASH') {
3292 for my $as (sort keys %$c) {
3293 push @sel, $c->{$as};
3304 # when trying to weed off duplicates later do not go past this point -
3305 # everything added from here on is unbalanced "anyone's guess" stuff
3306 my $dedup_stop_idx = $#as;
3308 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3310 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3311 if $attrs->{select};
3313 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3314 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
3316 # disqualify all $alias.col as-bits (inflate-map mandated)
3317 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
3319 # de-duplicate the result (remove *identical* select/as pairs)
3320 # and also die on duplicate {as} pointing to different {select}s
3321 # not using a c-style for as the condition is prone to shrinkage
3324 while ($i <= $dedup_stop_idx) {
3325 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3330 elsif ($seen->{$as[$i]}++) {
3331 $self->throw_exception(
3332 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3340 $attrs->{select} = \@sel;
3341 $attrs->{as} = \@as;
3343 $attrs->{from} ||= [{
3345 -alias => $self->{attrs}{alias},
3346 $self->{attrs}{alias} => $source->from,
3349 if ( $attrs->{join} || $attrs->{prefetch} ) {
3351 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3352 if ref $attrs->{from} ne 'ARRAY';
3354 my $join = (delete $attrs->{join}) || {};
3356 if ( defined $attrs->{prefetch} ) {
3357 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3360 $attrs->{from} = # have to copy here to avoid corrupting the original
3362 @{ $attrs->{from} },
3363 $source->_resolve_join(
3366 { %{ $attrs->{seen_join} || {} } },
3367 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3368 ? $attrs->{from}[-1][0]{-join_path}
3375 if ( defined $attrs->{order_by} ) {
3376 $attrs->{order_by} = (
3377 ref( $attrs->{order_by} ) eq 'ARRAY'
3378 ? [ @{ $attrs->{order_by} } ]
3379 : [ $attrs->{order_by} || () ]
3383 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3384 $attrs->{group_by} = [ $attrs->{group_by} ];
3387 # generate the distinct induced group_by early, as prefetch will be carried via a
3388 # subquery (since a group_by is present)
3389 if (delete $attrs->{distinct}) {
3390 if ($attrs->{group_by}) {
3391 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3394 # distinct affects only the main selection part, not what prefetch may
3396 $attrs->{group_by} = $source->storage->_group_over_selection (
3404 # generate selections based on the prefetch helper
3406 $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
3407 if defined $attrs->{prefetch};
3411 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3412 if $attrs->{_dark_selector};
3414 $attrs->{collapse} = 1;
3416 # this is a separate structure (we don't look in {from} directly)
3417 # as the resolver needs to shift things off the lists to work
3418 # properly (identical-prefetches on different branches)
3420 if (ref $attrs->{from} eq 'ARRAY') {
3422 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3424 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3425 next unless $j->[0]{-alias};
3426 next unless $j->[0]{-join_path};
3427 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3429 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3432 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3433 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3437 my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
3439 # we need to somehow mark which columns came from prefetch
3441 my $sel_end = $#{$attrs->{select}};
3442 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3445 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3446 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3449 if ( ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
3450 $attrs->{_single_object_inflation} = 1;
3451 $attrs->{collapse} = 0;
3454 # run through the resulting joinstructure (starting from our current slot)
3455 # and unset collapse if proven unnesessary
3456 if ($attrs->{collapse} && ref $attrs->{from} eq 'ARRAY') {
3458 if (@{$attrs->{from}} > 1) {
3460 # find where our table-spec starts and consider only things after us
3461 my @fromlist = @{$attrs->{from}};
3463 my $t = shift @fromlist;
3464 $t = $t->[0] if ref $t eq 'ARRAY'; #me vs join from-spec mismatch
3465 last if ($t->{-alias} && $t->{-alias} eq $alias);
3469 $attrs->{collapse} = ! $_->[0]{-is_single}
3474 # no joins - no collapse
3475 $attrs->{collapse} = 0;
3479 if (! $attrs->{order_by} and $attrs->{collapse}) {
3480 # default order for collapsing unless the user asked for something
3481 $attrs->{order_by} = [ map { "$alias.$_" } $source->primary_columns ];
3482 $attrs->{_ordered_for_collapse} = 1;
3483 $attrs->{_order_is_artificial} = 1;
3486 # if both page and offset are specified, produce a combined offset
3487 # even though it doesn't make much sense, this is what pre 081xx has
3489 if (my $page = delete $attrs->{page}) {
3491 ($attrs->{rows} * ($page - 1))
3493 ($attrs->{offset} || 0)
3497 return $self->{_attrs} = $attrs;
3501 my ($self, $attr) = @_;
3503 if (ref $attr eq 'HASH') {
3504 return $self->_rollout_hash($attr);
3505 } elsif (ref $attr eq 'ARRAY') {
3506 return $self->_rollout_array($attr);
3512 sub _rollout_array {
3513 my ($self, $attr) = @_;
3516 foreach my $element (@{$attr}) {
3517 if (ref $element eq 'HASH') {
3518 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3519 } elsif (ref $element eq 'ARRAY') {
3520 # XXX - should probably recurse here
3521 push( @rolled_array, @{$self->_rollout_array($element)} );
3523 push( @rolled_array, $element );
3526 return \@rolled_array;
3530 my ($self, $attr) = @_;
3533 foreach my $key (keys %{$attr}) {
3534 push( @rolled_array, { $key => $attr->{$key} } );
3536 return \@rolled_array;
3539 sub _calculate_score {
3540 my ($self, $a, $b) = @_;
3542 if (defined $a xor defined $b) {
3545 elsif (not defined $a) {
3549 if (ref $b eq 'HASH') {
3550 my ($b_key) = keys %{$b};
3551 if (ref $a eq 'HASH') {
3552 my ($a_key) = keys %{$a};
3553 if ($a_key eq $b_key) {
3554 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3559 return ($a eq $b_key) ? 1 : 0;
3562 if (ref $a eq 'HASH') {
3563 my ($a_key) = keys %{$a};
3564 return ($b eq $a_key) ? 1 : 0;
3566 return ($b eq $a) ? 1 : 0;
3571 sub _merge_joinpref_attr {
3572 my ($self, $orig, $import) = @_;
3574 return $import unless defined($orig);
3575 return $orig unless defined($import);
3577 $orig = $self->_rollout_attr($orig);
3578 $import = $self->_rollout_attr($import);
3581 foreach my $import_element ( @{$import} ) {
3582 # find best candidate from $orig to merge $b_element into
3583 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3584 foreach my $orig_element ( @{$orig} ) {
3585 my $score = $self->_calculate_score( $orig_element, $import_element );
3586 if ($score > $best_candidate->{score}) {
3587 $best_candidate->{position} = $position;
3588 $best_candidate->{score} = $score;
3592 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3593 $import_key = '' if not defined $import_key;
3595 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3596 push( @{$orig}, $import_element );
3598 my $orig_best = $orig->[$best_candidate->{position}];
3599 # merge orig_best and b_element together and replace original with merged
3600 if (ref $orig_best ne 'HASH') {
3601 $orig->[$best_candidate->{position}] = $import_element;
3602 } elsif (ref $import_element eq 'HASH') {
3603 my ($key) = keys %{$orig_best};
3604 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3607 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3610 return @$orig ? $orig : ();
3618 require Hash::Merge;
3619 my $hm = Hash::Merge->new;
3621 $hm->specify_behavior({
3624 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3626 if ($defl xor $defr) {
3627 return [ $defl ? $_[0] : $_[1] ];
3632 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3636 return [$_[0], $_[1]];
3640 return $_[1] if !defined $_[0];
3641 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3642 return [$_[0], @{$_[1]}]
3645 return [] if !defined $_[0] and !keys %{$_[1]};
3646 return [ $_[1] ] if !defined $_[0];
3647 return [ $_[0] ] if !keys %{$_[1]};
3648 return [$_[0], $_[1]]
3653 return $_[0] if !defined $_[1];
3654 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3655 return [@{$_[0]}, $_[1]]
3658 my @ret = @{$_[0]} or return $_[1];
3659 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3660 my %idx = map { $_ => 1 } @ret;
3661 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3665 return [ $_[1] ] if ! @{$_[0]};
3666 return $_[0] if !keys %{$_[1]};
3667 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3668 return [ @{$_[0]}, $_[1] ];
3673 return [] if !keys %{$_[0]} and !defined $_[1];
3674 return [ $_[0] ] if !defined $_[1];
3675 return [ $_[1] ] if !keys %{$_[0]};
3676 return [$_[0], $_[1]]
3679 return [] if !keys %{$_[0]} and !@{$_[1]};
3680 return [ $_[0] ] if !@{$_[1]};
3681 return $_[1] if !keys %{$_[0]};
3682 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3683 return [ $_[0], @{$_[1]} ];
3686 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3687 return [ $_[0] ] if !keys %{$_[1]};
3688 return [ $_[1] ] if !keys %{$_[0]};
3689 return [ $_[0] ] if $_[0] eq $_[1];
3690 return [ $_[0], $_[1] ];
3693 } => 'DBIC_RS_ATTR_MERGER');
3697 return $hm->merge ($_[1], $_[2]);
3701 sub STORABLE_freeze {
3702 my ($self, $cloning) = @_;
3703 my $to_serialize = { %$self };
3705 # A cursor in progress can't be serialized (and would make little sense anyway)
3706 # the parser can be regenerated (and can't be serialized)
3707 delete @{$to_serialize}{qw/cursor _row_parser/};
3709 # nor is it sensical to store a not-yet-fired-count pager
3710 if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
3711 delete $to_serialize->{pager};
3714 Storable::nfreeze($to_serialize);
3717 # need this hook for symmetry
3719 my ($self, $cloning, $serialized) = @_;
3721 %$self = %{ Storable::thaw($serialized) };
3727 =head2 throw_exception
3729 See L<DBIx::Class::Schema/throw_exception> for details.
3733 sub throw_exception {
3736 if (ref $self and my $rsrc = $self->result_source) {
3737 $rsrc->throw_exception(@_)
3740 DBIx::Class::Exception->throw(@_);
3744 # XXX: FIXME: Attributes docs need clearing up
3748 Attributes are used to refine a ResultSet in various ways when
3749 searching for data. They can be passed to any method which takes an
3750 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3753 Default attributes can be set on the result class using
3754 L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
3755 the CAVEATS on that feature before using it!)
3757 These are in no particular order:
3763 =item Value: ( $order_by | \@order_by | \%order_by )
3767 Which column(s) to order the results by.
3769 [The full list of suitable values is documented in
3770 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3773 If a single column name, or an arrayref of names is supplied, the
3774 argument is passed through directly to SQL. The hashref syntax allows
3775 for connection-agnostic specification of ordering direction:
3777 For descending order:
3779 order_by => { -desc => [qw/col1 col2 col3/] }
3781 For explicit ascending order:
3783 order_by => { -asc => 'col' }
3785 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3786 supported, although you are strongly encouraged to use the hashref
3787 syntax as outlined above.
3793 =item Value: \@columns
3797 Shortcut to request a particular set of columns to be retrieved. Each
3798 column spec may be a string (a table column name), or a hash (in which
3799 case the key is the C<as> value, and the value is used as the C<select>
3800 expression). Adds C<me.> onto the start of any column without a C<.> in
3801 it and sets C<select> from that, then auto-populates C<as> from
3802 C<select> as normal. (You may also use the C<cols> attribute, as in
3803 earlier versions of DBIC.)
3805 Essentially C<columns> does the same as L</select> and L</as>.
3807 columns => [ 'foo', { bar => 'baz' } ]
3811 select => [qw/foo baz/],
3818 =item Value: \@columns
3822 Indicates additional columns to be selected from storage. Works the same
3823 as L</columns> but adds columns to the selection. (You may also use the
3824 C<include_columns> attribute, as in earlier versions of DBIC). For
3827 $schema->resultset('CD')->search(undef, {
3828 '+columns' => ['artist.name'],
3832 would return all CDs and include a 'name' column to the information
3833 passed to object inflation. Note that the 'artist' is the name of the
3834 column (or relationship) accessor, and 'name' is the name of the column
3835 accessor in the related table.
3837 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3838 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3839 unary plus operator before it.
3841 =head2 include_columns
3845 =item Value: \@columns
3849 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3855 =item Value: \@select_columns
3859 Indicates which columns should be selected from the storage. You can use
3860 column names, or in the case of RDBMS back ends, function or stored procedure
3863 $rs = $schema->resultset('Employee')->search(undef, {
3866 { count => 'employeeid' },
3867 { max => { length => 'name' }, -as => 'longest_name' }
3872 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3874 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3875 use L</select>, to instruct DBIx::Class how to store the result of the column.
3876 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3877 identifier aliasing. You can however alias a function, so you can use it in
3878 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3879 attribute> supplied as shown in the example above.
3881 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3882 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3883 unary plus operator before it.
3889 Indicates additional columns to be selected from storage. Works the same as
3890 L</select> but adds columns to the default selection, instead of specifying
3899 Indicates additional column names for those added via L</+select>. See L</as>.
3907 =item Value: \@inflation_names
3911 Indicates column names for object inflation. That is L</as> indicates the
3912 slot name in which the column value will be stored within the
3913 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3914 identifier by the C<get_column> method (or via the object accessor B<if one
3915 with the same name already exists>) as shown below. The L</as> attribute has
3916 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3918 $rs = $schema->resultset('Employee')->search(undef, {
3921 { count => 'employeeid' },
3922 { max => { length => 'name' }, -as => 'longest_name' }
3931 If the object against which the search is performed already has an accessor
3932 matching a column name specified in C<as>, the value can be retrieved using
3933 the accessor as normal:
3935 my $name = $employee->name();
3937 If on the other hand an accessor does not exist in the object, you need to
3938 use C<get_column> instead:
3940 my $employee_count = $employee->get_column('employee_count');
3942 You can create your own accessors if required - see
3943 L<DBIx::Class::Manual::Cookbook> for details.
3949 =item Value: ($rel_name | \@rel_names | \%rel_names)
3953 Contains a list of relationships that should be joined for this query. For
3956 # Get CDs by Nine Inch Nails
3957 my $rs = $schema->resultset('CD')->search(
3958 { 'artist.name' => 'Nine Inch Nails' },
3959 { join => 'artist' }
3962 Can also contain a hash reference to refer to the other relation's relations.
3965 package MyApp::Schema::Track;
3966 use base qw/DBIx::Class/;
3967 __PACKAGE__->table('track');
3968 __PACKAGE__->add_columns(qw/trackid cd position title/);
3969 __PACKAGE__->set_primary_key('trackid');
3970 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3973 # In your application
3974 my $rs = $schema->resultset('Artist')->search(
3975 { 'track.title' => 'Teardrop' },
3977 join => { cd => 'track' },
3978 order_by => 'artist.name',
3982 You need to use the relationship (not the table) name in conditions,
3983 because they are aliased as such. The current table is aliased as "me", so
3984 you need to use me.column_name in order to avoid ambiguity. For example:
3986 # Get CDs from 1984 with a 'Foo' track
3987 my $rs = $schema->resultset('CD')->search(
3990 'tracks.name' => 'Foo'
3992 { join => 'tracks' }
3995 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3996 similarly for a third time). For e.g.
3998 my $rs = $schema->resultset('Artist')->search({
3999 'cds.title' => 'Down to Earth',
4000 'cds_2.title' => 'Popular',
4002 join => [ qw/cds cds/ ],
4005 will return a set of all artists that have both a cd with title 'Down
4006 to Earth' and a cd with title 'Popular'.
4008 If you want to fetch related objects from other tables as well, see C<prefetch>
4011 NOTE: An internal join-chain pruner will discard certain joins while
4012 constructing the actual SQL query, as long as the joins in question do not
4013 affect the retrieved result. This for example includes 1:1 left joins
4014 that are not part of the restriction specification (WHERE/HAVING) nor are
4015 a part of the query selection.
4017 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4023 =item Value: ($rel_name | \@rel_names | \%rel_names)
4027 Contains one or more relationships that should be fetched along with
4028 the main query (when they are accessed afterwards the data will
4029 already be available, without extra queries to the database). This is
4030 useful for when you know you will need the related objects, because it
4031 saves at least one query:
4033 my $rs = $schema->resultset('Tag')->search(
4042 The initial search results in SQL like the following:
4044 SELECT tag.*, cd.*, artist.* FROM tag
4045 JOIN cd ON tag.cd = cd.cdid
4046 JOIN artist ON cd.artist = artist.artistid
4048 L<DBIx::Class> has no need to go back to the database when we access the
4049 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4052 Simple prefetches will be joined automatically, so there is no need
4053 for a C<join> attribute in the above search.
4055 L</prefetch> can be used with the any of the relationship types and
4056 multiple prefetches can be specified together. Below is a more complex
4057 example that prefetches a CD's artist, its liner notes (if present),
4058 the cover image, the tracks on that cd, and the guests on those
4062 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4063 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4064 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
4065 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4067 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4069 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4072 my $rs = $schema->resultset('CD')->search(
4076 { artist => 'record_label'}, # belongs_to => belongs_to
4077 'liner_note', # might_have
4078 'cover_image', # has_one
4079 { tracks => 'guests' }, # has_many => has_many
4084 This will produce SQL like the following:
4086 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4090 ON artist.artistid = me.artistid
4091 JOIN record_label record_label
4092 ON record_label.labelid = artist.labelid
4093 LEFT JOIN track tracks
4094 ON tracks.cdid = me.cdid
4095 LEFT JOIN guest guests
4096 ON guests.trackid = track.trackid
4097 LEFT JOIN liner_notes liner_note
4098 ON liner_note.cdid = me.cdid
4099 JOIN cd_artwork cover_image
4100 ON cover_image.cdid = me.cdid
4103 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4104 C<tracks>, and C<guests> of the CD will all be available through the
4105 relationship accessors without the need for additional queries to the
4108 However, there is one caveat to be observed: it can be dangerous to
4109 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4110 relationship on a given level. e.g.:
4112 my $rs = $schema->resultset('CD')->search(
4116 'tracks', # has_many
4117 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4122 The collapser currently can't identify duplicate tuples for multiple
4123 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4124 result the second L<has_many|DBIx::Class::Relationship/has_many>
4125 relation could contain redundant objects.
4127 =head3 Using L</prefetch> with L</join>
4129 L</prefetch> implies a L</join> with the equivalent argument, and is
4130 properly merged with any existing L</join> specification. So the
4133 my $rs = $schema->resultset('CD')->search(
4134 {'record_label.name' => 'Music Product Ltd.'},
4136 join => {artist => 'record_label'},
4137 prefetch => 'artist',
4141 ... will work, searching on the record label's name, but only
4142 prefetching the C<artist>.
4144 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4146 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4147 prefetched relations. So given:
4149 my $rs = $schema->resultset('CD')->search(
4152 select => ['cd.title'],
4154 prefetch => 'artist',
4158 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4159 becomes: C<'cd_title', 'artist.*'>.
4163 Prefetch does a lot of deep magic. As such, it may not behave exactly
4164 as you might expect.
4170 Prefetch uses the L</cache> to populate the prefetched relationships. This
4171 may or may not be what you want.
4175 If you specify a condition on a prefetched relationship, ONLY those
4176 rows that match the prefetched condition will be fetched into that relationship.
4177 This means that adding prefetch to a search() B<may alter> what is returned by
4178 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4180 my $artist_rs = $schema->resultset('Artist')->search({
4186 my $count = $artist_rs->first->cds->count;
4188 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4190 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4192 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4194 that cmp_ok() may or may not pass depending on the datasets involved. This
4195 behavior may or may not survive the 0.09 transition.
4203 =item Value: $source_alias
4207 Sets the source alias for the query. Normally, this defaults to C<me>, but
4208 nested search queries (sub-SELECTs) might need specific aliases set to
4209 reference inner queries. For example:
4212 ->related_resultset('CDs')
4213 ->related_resultset('Tracks')
4215 'track.id' => { -ident => 'none_search.id' },
4219 my $ids = $self->search({
4222 alias => 'none_search',
4223 group_by => 'none_search.id',
4224 })->get_column('id')->as_query;
4226 $self->search({ id => { -in => $ids } })
4228 This attribute is directly tied to L</current_source_alias>.
4238 Makes the resultset paged and specifies the page to retrieve. Effectively
4239 identical to creating a non-pages resultset and then calling ->page($page)
4242 If L</rows> attribute is not specified it defaults to 10 rows per page.
4244 When you have a paged resultset, L</count> will only return the number
4245 of rows in the page. To get the total, use the L</pager> and call
4246 C<total_entries> on it.
4256 Specifies the maximum number of rows for direct retrieval or the number of
4257 rows per page if the page attribute or method is used.
4263 =item Value: $offset
4267 Specifies the (zero-based) row number for the first row to be returned, or the
4268 of the first row of the first page if paging is used.
4270 =head2 software_limit
4274 =item Value: (0 | 1)
4278 When combined with L</rows> and/or L</offset> the generated SQL will not
4279 include any limit dialect stanzas. Instead the entire result will be selected
4280 as if no limits were specified, and DBIC will perform the limit locally, by
4281 artificially advancing and finishing the resulting L</cursor>.
4283 This is the recommended way of performing resultset limiting when no sane RDBMS
4284 implementation is available (e.g.
4285 L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
4286 L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
4292 =item Value: \@columns
4296 A arrayref of columns to group by. Can include columns of joined tables.
4298 group_by => [qw/ column1 column2 ... /]
4304 =item Value: $condition
4308 HAVING is a select statement attribute that is applied between GROUP BY and
4309 ORDER BY. It is applied to the after the grouping calculations have been
4312 having => { 'count_employee' => { '>=', 100 } }
4314 or with an in-place function in which case literal SQL is required:
4316 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4322 =item Value: (0 | 1)
4326 Set to 1 to group by all columns. If the resultset already has a group_by
4327 attribute, this setting is ignored and an appropriate warning is issued.
4333 Adds to the WHERE clause.
4335 # only return rows WHERE deleted IS NULL for all searches
4336 __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
4338 Can be overridden by passing C<< { where => undef } >> as an attribute
4341 For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
4347 Set to 1 to cache search results. This prevents extra SQL queries if you
4348 revisit rows in your ResultSet:
4350 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4352 while( my $artist = $resultset->next ) {
4356 $rs->first; # without cache, this would issue a query
4358 By default, searches are not cached.
4360 For more examples of using these attributes, see
4361 L<DBIx::Class::Manual::Cookbook>.
4367 =item Value: ( 'update' | 'shared' | \$scalar )
4371 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
4372 ... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
4375 =head1 DBIC BIND VALUES
4377 Because DBIC may need more information to bind values than just the column name
4378 and value itself, it uses a special format for both passing and receiving bind
4379 values. Each bind value should be composed of an arrayref of
4380 C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
4386 If present (in any form), this is what is being passed directly to bind_param.
4387 Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
4388 a single numerical type, while DBD::Pg takes a hashref if bind options.)
4390 If this is specified, all other bind options described below are ignored.
4394 If present, this is used to infer the actual bind attribute by passing to
4395 C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
4396 "data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
4398 Note that the data type is somewhat freeform (hence the sqlt_ prefix);
4399 currently drivers are expected to "Do the Right Thing" when given a common
4400 datatype name. (Not ideal, but that's what we got at this point.)
4404 Currently used to correctly allocate buffers for bind_param_inout().
4405 Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
4406 or to a sensible value based on the "data_type".
4410 Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
4411 explicitly specified they are never overriden). Also used by some weird DBDs,
4412 where the column name should be available at bind_param time (e.g. Oracle).
4416 For backwards compatibility and convenience, the following shortcuts are
4419 [ $name => $val ] === [ { dbic_colname => $name }, $val ]
4420 [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
4421 [ undef, $val ] === [ {}, $val ]
4423 =head1 AUTHOR AND CONTRIBUTORS
4425 See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
4429 You may distribute this code under the same terms as Perl itself.