1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::Exception;
8 use DBIx::Class::ResultSetColumn;
9 use Scalar::Util qw/blessed weaken/;
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
78 =head2 Chaining resultsets
80 Let's say you've got a query that needs to be run to return some data
81 to the user. But, you have an authorization system in place that
82 prevents certain users from seeing certain information. So, you want
83 to construct the basic query in one method, but add constraints to it in
88 my $request = $self->get_request; # Get a request object somehow.
89 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
91 my $cd_rs = $schema->resultset('CD')->search({
92 title => $request->param('title'),
93 year => $request->param('year'),
96 $cd_rs = $self->apply_security_policy( $cd_rs );
101 sub apply_security_policy {
110 =head3 Resolving conditions and attributes
112 When a resultset is chained from another resultset, conditions and
113 attributes with the same keys need resolving.
115 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
116 into the existing ones from the original resultset.
118 The L</where> and L</having> attributes, and any search conditions, are
119 merged with an SQL C<AND> to the existing condition from the original
122 All other attributes are overridden by any new ones supplied in the
125 =head2 Multiple queries
127 Since a resultset just defines a query, you can do all sorts of
128 things with it with the same object.
130 # Don't hit the DB yet.
131 my $cd_rs = $schema->resultset('CD')->search({
132 title => 'something',
136 # Each of these hits the DB individually.
137 my $count = $cd_rs->count;
138 my $most_recent = $cd_rs->get_column('date_released')->max();
139 my @records = $cd_rs->all;
141 And it's not just limited to SELECT statements.
147 $cd_rs->create({ artist => 'Fred' });
149 Which is the same as:
151 $schema->resultset('CD')->create({
152 title => 'something',
157 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
165 =item Arguments: $source, \%$attrs
167 =item Return Value: $rs
171 The resultset constructor. Takes a source object (usually a
172 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
173 L</ATTRIBUTES> below). Does not perform any queries -- these are
174 executed as needed by the other methods.
176 Generally you won't need to construct a resultset manually. You'll
177 automatically get one from e.g. a L</search> called in scalar context:
179 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
181 IMPORTANT: If called on an object, proxies to new_result instead so
183 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
185 will return a CD object, not a ResultSet.
191 return $class->new_result(@_) if ref $class;
193 my ($source, $attrs) = @_;
194 $source = $source->resolve
195 if $source->isa('DBIx::Class::ResultSourceHandle');
196 $attrs = { %{$attrs||{}} };
198 if ($attrs->{page}) {
199 $attrs->{rows} ||= 10;
202 $attrs->{alias} ||= 'me';
205 result_source => $source,
206 cond => $attrs->{where},
211 # if there is a dark selector, this means we are already in a
212 # chain and the cleanup/sanification was taken care of by
214 $self->_normalize_selection($attrs)
215 unless $attrs->{_dark_selector};
218 $attrs->{result_class} || $source->result_class
228 =item Arguments: $cond, \%attrs?
230 =item Return Value: $resultset (scalar context) || @row_objs (list context)
234 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
235 my $new_rs = $cd_rs->search({ year => 2005 });
237 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
238 # year = 2005 OR year = 2004
240 In list context, C<< ->all() >> is called implicitly on the resultset, thus
241 returning a list of row objects instead. To avoid that, use L</search_rs>.
243 If you need to pass in additional attributes but no additional condition,
244 call it as C<search(undef, \%attrs)>.
246 # "SELECT name, artistid FROM $artist_table"
247 my @all_artists = $schema->resultset('Artist')->search(undef, {
248 columns => [qw/name artistid/],
251 For a list of attributes that can be passed to C<search>, see
252 L</ATTRIBUTES>. For more examples of using this function, see
253 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
254 documentation for the first argument, see L<SQL::Abstract>.
256 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 Note that L</search> does not process/deflate any of the values passed in the
261 L<SQL::Abstract>-compatible search condition structure. This is unlike other
262 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
263 manually that any value passed to this method will stringify to something the
264 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
265 objects, for more info see:
266 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
272 my $rs = $self->search_rs( @_ );
277 elsif (defined wantarray) {
281 # we can be called by a relationship helper, which in
282 # turn may be called in void context due to some braindead
283 # overload or whatever else the user decided to be clever
284 # at this particular day. Thus limit the exception to
285 # external code calls only
286 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
287 if (caller)[0] !~ /^\QDBIx::Class::/;
297 =item Arguments: $cond, \%attrs?
299 =item Return Value: $resultset
303 This method does the same exact thing as search() except it will
304 always return a resultset, even in list context.
311 # Special-case handling for (undef, undef).
312 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
318 if (ref $_[-1] eq 'HASH') {
319 # copy for _normalize_selection
320 $call_attrs = { %{ pop @_ } };
322 elsif (! defined $_[-1] ) {
323 pop @_; # search({}, undef)
327 # see if we can keep the cache (no $rs changes)
329 my %safe = (alias => 1, cache => 1);
330 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
333 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
335 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
337 $cache = $self->get_cache;
340 my $rsrc = $self->result_source;
342 my $old_attrs = { %{$self->{attrs}} };
343 my $old_having = delete $old_attrs->{having};
344 my $old_where = delete $old_attrs->{where};
346 my $new_attrs = { %$old_attrs };
348 # take care of call attrs (only if anything is changing)
349 if (keys %$call_attrs) {
351 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
353 # reset the current selector list if new selectors are supplied
354 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
355 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
358 # Normalize the new selector list (operates on the passed-in attr structure)
359 # Need to do it on every chain instead of only once on _resolved_attrs, in
360 # order to allow detection of empty vs partial 'as'
361 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
362 if $old_attrs->{_dark_selector};
363 $self->_normalize_selection ($call_attrs);
365 # start with blind overwriting merge, exclude selector attrs
366 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
367 delete @{$new_attrs}{@selector_attrs};
369 for (@selector_attrs) {
370 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
371 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
374 # older deprecated name, use only if {columns} is not there
375 if (my $c = delete $new_attrs->{cols}) {
376 if ($new_attrs->{columns}) {
377 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
380 $new_attrs->{columns} = $c;
385 # join/prefetch use their own crazy merging heuristics
386 foreach my $key (qw/join prefetch/) {
387 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
388 if exists $call_attrs->{$key};
391 # stack binds together
392 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
396 # rip apart the rest of @_, parse a condition
399 if (ref $_[0] eq 'HASH') {
400 (keys %{$_[0]}) ? $_[0] : undef
406 $self->throw_exception('Odd number of arguments to search')
414 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
415 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
418 for ($old_where, $call_cond) {
420 $new_attrs->{where} = $self->_stack_cond (
421 $_, $new_attrs->{where}
426 if (defined $old_having) {
427 $new_attrs->{having} = $self->_stack_cond (
428 $old_having, $new_attrs->{having}
432 my $rs = (ref $self)->new($rsrc, $new_attrs);
434 $rs->set_cache($cache) if ($cache);
440 sub _normalize_selection {
441 my ($self, $attrs) = @_;
444 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
445 if exists $attrs->{include_columns};
447 # columns are always placed first, however
449 # Keep the X vs +X separation until _resolved_attrs time - this allows to
450 # delay the decision on whether to use a default select list ($rsrc->columns)
451 # allowing stuff like the remove_columns helper to work
453 # select/as +select/+as pairs need special handling - the amount of select/as
454 # elements in each pair does *not* have to be equal (think multicolumn
455 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
456 # supplied at all) - try to infer the alias, either from the -as parameter
457 # of the selector spec, or use the parameter whole if it looks like a column
458 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
459 # is ok as well), but make sure no more additions to the 'as' chain take place
460 for my $pref ('', '+') {
462 my ($sel, $as) = map {
463 my $key = "${pref}${_}";
465 my $val = [ ref $attrs->{$key} eq 'ARRAY'
467 : $attrs->{$key} || ()
469 delete $attrs->{$key};
473 if (! @$as and ! @$sel ) {
476 elsif (@$as and ! @$sel) {
477 $self->throw_exception(
478 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
482 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
483 # if any @$as has been supplied we assume the user knows what (s)he is doing
484 # and blindly keep stacking up pieces
485 unless ($attrs->{_dark_selector}) {
488 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
489 push @$as, $_->{-as};
491 # assume any plain no-space, no-parenthesis string to be a column spec
492 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
493 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
496 # if all else fails - raise a flag that no more aliasing will be allowed
498 $attrs->{_dark_selector} = {
500 string => ($dark_sel_dumper ||= do {
501 require Data::Dumper::Concise;
502 Data::Dumper::Concise::DumperObject()->Indent(0);
503 })->Values([$_])->Dump
511 elsif (@$as < @$sel) {
512 $self->throw_exception(
513 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
516 elsif ($pref and $attrs->{_dark_selector}) {
517 $self->throw_exception(
518 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
524 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
525 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
530 my ($self, $left, $right) = @_;
531 if (defined $left xor defined $right) {
532 return defined $left ? $left : $right;
534 elsif (defined $left) {
535 return { -and => [ map
536 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
544 =head2 search_literal
548 =item Arguments: $sql_fragment, @bind_values
550 =item Return Value: $resultset (scalar context) || @row_objs (list context)
554 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
555 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
557 Pass a literal chunk of SQL to be added to the conditional part of the
560 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
561 only be used in that context. C<search_literal> is a convenience method.
562 It is equivalent to calling $schema->search(\[]), but if you want to ensure
563 columns are bound correctly, use C<search>.
565 Example of how to use C<search> instead of C<search_literal>
567 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
568 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
571 See L<DBIx::Class::Manual::Cookbook/Searching> and
572 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
573 require C<search_literal>.
578 my ($self, $sql, @bind) = @_;
580 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
583 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
590 =item Arguments: \%columns_values | @pk_values, \%attrs?
592 =item Return Value: $row_object | undef
596 Finds and returns a single row based on supplied criteria. Takes either a
597 hashref with the same format as L</create> (including inference of foreign
598 keys from related objects), or a list of primary key values in the same
599 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
600 declaration on the L</result_source>.
602 In either case an attempt is made to combine conditions already existing on
603 the resultset with the condition passed to this method.
605 To aid with preparing the correct query for the storage you may supply the
606 C<key> attribute, which is the name of a
607 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
608 unique constraint corresponding to the
609 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
610 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
611 to construct a query that satisfies the named unique constraint fully (
612 non-NULL values for each column member of the constraint) an exception is
615 If no C<key> is specified, the search is carried over all unique constraints
616 which are fully defined by the available condition.
618 If no such constraint is found, C<find> currently defaults to a simple
619 C<< search->(\%column_values) >> which may or may not do what you expect.
620 Note that this fallback behavior may be deprecated in further versions. If
621 you need to search with arbitrary conditions - use L</search>. If the query
622 resulting from this fallback produces more than one row, a warning to the
623 effect is issued, though only the first row is constructed and returned as
626 In addition to C<key>, L</find> recognizes and applies standard
627 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
629 Note that if you have extra concerns about the correctness of the resulting
630 query you need to specify the C<key> attribute and supply the entire condition
631 as an argument to find (since it is not always possible to perform the
632 combination of the resultset condition with the supplied one, especially if
633 the resultset condition contains literal sql).
635 For example, to find a row by its primary key:
637 my $cd = $schema->resultset('CD')->find(5);
639 You can also find a row by a specific unique constraint:
641 my $cd = $schema->resultset('CD')->find(
643 artist => 'Massive Attack',
644 title => 'Mezzanine',
646 { key => 'cd_artist_title' }
649 See also L</find_or_create> and L</update_or_create>.
655 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
657 my $rsrc = $self->result_source;
659 # Parse out the condition from input
661 if (ref $_[0] eq 'HASH') {
662 $call_cond = { %{$_[0]} };
665 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
666 my @c_cols = $rsrc->unique_constraint_columns($constraint);
668 $self->throw_exception(
669 "No constraint columns, maybe a malformed '$constraint' constraint?"
672 $self->throw_exception (
673 'find() expects either a column/value hashref, or a list of values '
674 . "corresponding to the columns of the specified unique constraint '$constraint'"
675 ) unless @c_cols == @_;
678 @{$call_cond}{@c_cols} = @_;
682 for my $key (keys %$call_cond) {
684 my $keyref = ref($call_cond->{$key})
686 my $relinfo = $rsrc->relationship_info($key)
688 my $val = delete $call_cond->{$key};
690 next if $keyref eq 'ARRAY'; # has_many for multi_create
692 my $rel_q = $rsrc->_resolve_condition(
693 $relinfo->{cond}, $val, $key, $key
695 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
696 @related{keys %$rel_q} = values %$rel_q;
700 # relationship conditions take precedence (?)
701 @{$call_cond}{keys %related} = values %related;
703 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
705 if (exists $attrs->{key}) {
706 $final_cond = $self->_qualify_cond_columns (
708 $self->_build_unique_cond (
716 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
717 # This means that we got here after a merger of relationship conditions
718 # in ::Relationship::Base::search_related (the row method), and furthermore
719 # the relationship is of the 'single' type. This means that the condition
720 # provided by the relationship (already attached to $self) is sufficient,
721 # as there can be only one row in the database that would satisfy the
725 # no key was specified - fall down to heuristics mode:
726 # run through all unique queries registered on the resultset, and
727 # 'OR' all qualifying queries together
728 my (@unique_queries, %seen_column_combinations);
729 for my $c_name ($rsrc->unique_constraint_names) {
730 next if $seen_column_combinations{
731 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
734 push @unique_queries, try {
735 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
739 $final_cond = @unique_queries
740 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
741 : $self->_non_unique_find_fallback ($call_cond, $attrs)
745 # Run the query, passing the result_class since it should propagate for find
746 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
747 if (keys %{$rs->_resolved_attrs->{collapse}}) {
749 carp "Query returned more than one row" if $rs->next;
757 # This is a stop-gap method as agreed during the discussion on find() cleanup:
758 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
760 # It is invoked when find() is called in legacy-mode with insufficiently-unique
761 # condition. It is provided for overrides until a saner way forward is devised
763 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
764 # the road. Please adjust your tests accordingly to catch this situation early
765 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
767 # The method will not be removed without an adequately complete replacement
768 # for strict-mode enforcement
769 sub _non_unique_find_fallback {
770 my ($self, $cond, $attrs) = @_;
772 return $self->_qualify_cond_columns(
774 exists $attrs->{alias}
776 : $self->{attrs}{alias}
781 sub _qualify_cond_columns {
782 my ($self, $cond, $alias) = @_;
784 my %aliased = %$cond;
785 for (keys %aliased) {
786 $aliased{"$alias.$_"} = delete $aliased{$_}
793 sub _build_unique_cond {
794 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
796 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
798 # combination may fail if $self->{cond} is non-trivial
799 my ($final_cond) = try {
800 $self->_merge_with_rscond ($extra_cond)
805 # trim out everything not in $columns
806 $final_cond = { map {
807 exists $final_cond->{$_}
808 ? ( $_ => $final_cond->{$_} )
812 if (my @missing = grep
813 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
816 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
818 join (', ', map { "'$_'" } @missing),
825 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
827 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
829 carp_unique ( sprintf (
830 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
831 . 'values in column(s): %s). This is almost certainly not what you wanted, '
832 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
834 join (', ', map { "'$_'" } @undefs),
841 =head2 search_related
845 =item Arguments: $rel, $cond, \%attrs?
847 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
851 $new_rs = $cd_rs->search_related('artist', {
855 Searches the specified relationship, optionally specifying a condition and
856 attributes for matching records. See L</ATTRIBUTES> for more information.
858 In list context, C<< ->all() >> is called implicitly on the resultset, thus
859 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
861 See also L</search_related_rs>.
866 return shift->related_resultset(shift)->search(@_);
869 =head2 search_related_rs
871 This method works exactly the same as search_related, except that
872 it guarantees a resultset, even in list context.
876 sub search_related_rs {
877 return shift->related_resultset(shift)->search_rs(@_);
884 =item Arguments: none
886 =item Return Value: $cursor
890 Returns a storage-driven cursor to the given resultset. See
891 L<DBIx::Class::Cursor> for more information.
898 my $attrs = $self->_resolved_attrs_copy;
900 return $self->{cursor}
901 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
902 $attrs->{where},$attrs);
909 =item Arguments: $cond?
911 =item Return Value: $row_object | undef
915 my $cd = $schema->resultset('CD')->single({ year => 2001 });
917 Inflates the first result without creating a cursor if the resultset has
918 any records in it; if not returns C<undef>. Used by L</find> as a lean version
921 While this method can take an optional search condition (just like L</search>)
922 being a fast-code-path it does not recognize search attributes. If you need to
923 add extra joins or similar, call L</search> and then chain-call L</single> on the
924 L<DBIx::Class::ResultSet> returned.
930 As of 0.08100, this method enforces the assumption that the preceding
931 query returns only one row. If more than one row is returned, you will receive
934 Query returned more than one row
936 In this case, you should be using L</next> or L</find> instead, or if you really
937 know what you are doing, use the L</rows> attribute to explicitly limit the size
940 This method will also throw an exception if it is called on a resultset prefetching
941 has_many, as such a prefetch implies fetching multiple rows from the database in
942 order to assemble the resulting object.
949 my ($self, $where) = @_;
951 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
954 my $attrs = $self->_resolved_attrs_copy;
956 if (keys %{$attrs->{collapse}}) {
957 $self->throw_exception(
958 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
963 if (defined $attrs->{where}) {
966 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
967 $where, delete $attrs->{where} ]
970 $attrs->{where} = $where;
974 my @data = $self->result_source->storage->select_single(
975 $attrs->{from}, $attrs->{select},
976 $attrs->{where}, $attrs
979 return (@data ? ($self->_construct_object(@data))[0] : undef);
985 # Recursively collapse the query, accumulating values for each column.
987 sub _collapse_query {
988 my ($self, $query, $collapsed) = @_;
992 if (ref $query eq 'ARRAY') {
993 foreach my $subquery (@$query) {
994 next unless ref $subquery; # -or
995 $collapsed = $self->_collapse_query($subquery, $collapsed);
998 elsif (ref $query eq 'HASH') {
999 if (keys %$query and (keys %$query)[0] eq '-and') {
1000 foreach my $subquery (@{$query->{-and}}) {
1001 $collapsed = $self->_collapse_query($subquery, $collapsed);
1005 foreach my $col (keys %$query) {
1006 my $value = $query->{$col};
1007 $collapsed->{$col}{$value}++;
1019 =item Arguments: $cond?
1021 =item Return Value: $resultsetcolumn
1025 my $max_length = $rs->get_column('length')->max;
1027 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1032 my ($self, $column) = @_;
1033 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1041 =item Arguments: $cond, \%attrs?
1043 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1047 # WHERE title LIKE '%blue%'
1048 $cd_rs = $rs->search_like({ title => '%blue%'});
1050 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1051 that this is simply a convenience method retained for ex Class::DBI users.
1052 You most likely want to use L</search> with specific operators.
1054 For more information, see L<DBIx::Class::Manual::Cookbook>.
1056 This method is deprecated and will be removed in 0.09. Use L</search()>
1057 instead. An example conversion is:
1059 ->search_like({ foo => 'bar' });
1063 ->search({ foo => { like => 'bar' } });
1070 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1071 .' Instead use ->search({ x => { -like => "y%" } })'
1072 .' (note the outer pair of {}s - they are important!)'
1074 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1075 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1076 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1077 return $class->search($query, { %$attrs });
1084 =item Arguments: $first, $last
1086 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1090 Returns a resultset or object list representing a subset of elements from the
1091 resultset slice is called on. Indexes are from 0, i.e., to get the first
1092 three records, call:
1094 my ($one, $two, $three) = $rs->slice(0, 2);
1099 my ($self, $min, $max) = @_;
1100 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1101 $attrs->{offset} = $self->{attrs}{offset} || 0;
1102 $attrs->{offset} += $min;
1103 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1104 return $self->search(undef, $attrs);
1105 #my $slice = (ref $self)->new($self->result_source, $attrs);
1106 #return (wantarray ? $slice->all : $slice);
1113 =item Arguments: none
1115 =item Return Value: $result | undef
1119 Returns the next element in the resultset (C<undef> is there is none).
1121 Can be used to efficiently iterate over records in the resultset:
1123 my $rs = $schema->resultset('CD')->search;
1124 while (my $cd = $rs->next) {
1128 Note that you need to store the resultset object, and call C<next> on it.
1129 Calling C<< resultset('Table')->next >> repeatedly will always return the
1130 first record from the resultset.
1136 if (my $cache = $self->get_cache) {
1137 $self->{all_cache_position} ||= 0;
1138 return $cache->[$self->{all_cache_position}++];
1140 if ($self->{attrs}{cache}) {
1141 delete $self->{pager};
1142 $self->{all_cache_position} = 1;
1143 return ($self->all)[0];
1145 if ($self->{stashed_objects}) {
1146 my $obj = shift(@{$self->{stashed_objects}});
1147 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1151 exists $self->{stashed_row}
1152 ? @{delete $self->{stashed_row}}
1153 : $self->cursor->next
1155 return undef unless (@row);
1156 my ($row, @more) = $self->_construct_object(@row);
1157 $self->{stashed_objects} = \@more if @more;
1161 sub _construct_object {
1162 my ($self, @row) = @_;
1164 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1166 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1167 @new = $self->{_attrs}{record_filter}->(@new)
1168 if exists $self->{_attrs}{record_filter};
1172 sub _collapse_result {
1173 my ($self, $as_proto, $row) = @_;
1177 # 'foo' => [ undef, 'foo' ]
1178 # 'foo.bar' => [ 'foo', 'bar' ]
1179 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1181 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1183 my %collapse = %{$self->{_attrs}{collapse}||{}};
1187 # if we're doing collapsing (has_many prefetch) we need to grab records
1188 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1189 # we know we don't have to bother.
1191 # the reason for not using the collapse stuff directly is because if you
1192 # had for e.g. two artists in a row with no cds, the collapse info for
1193 # both would be NULL (undef) so you'd lose the second artist
1195 # store just the index so we can check the array positions from the row
1196 # without having to contruct the full hash
1198 if (keys %collapse) {
1199 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1200 foreach my $i (0 .. $#construct_as) {
1201 next if defined($construct_as[$i][0]); # only self table
1202 if (delete $pri{$construct_as[$i][1]}) {
1203 push(@pri_index, $i);
1205 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1209 # no need to do an if, it'll be empty if @pri_index is empty anyway
1211 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1215 do { # no need to check anything at the front, we always want the first row
1219 foreach my $this_as (@construct_as) {
1220 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1223 push(@const_rows, \%const);
1225 } until ( # no pri_index => no collapse => drop straight out
1228 do { # get another row, stash it, drop out if different PK
1230 @copy = $self->cursor->next;
1231 $self->{stashed_row} = \@copy;
1233 # last thing in do block, counts as true if anything doesn't match
1235 # check xor defined first for NULL vs. NOT NULL then if one is
1236 # defined the other must be so check string equality
1239 (defined $pri_vals{$_} ^ defined $copy[$_])
1240 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1245 my $alias = $self->{attrs}{alias};
1252 foreach my $const (@const_rows) {
1253 scalar @const_keys or do {
1254 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1256 foreach my $key (@const_keys) {
1259 my @parts = split(/\./, $key);
1261 my $data = $const->{$key};
1262 foreach my $p (@parts) {
1263 $target = $target->[1]->{$p} ||= [];
1265 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1266 # collapsing at this point and on final part
1267 my $pos = $collapse_pos{$cur};
1268 CK: foreach my $ck (@ckey) {
1269 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1270 $collapse_pos{$cur} = $data;
1271 delete @collapse_pos{ # clear all positioning for sub-entries
1272 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1279 if (exists $collapse{$cur}) {
1280 $target = $target->[-1];
1283 $target->[0] = $data;
1285 $info->[0] = $const->{$key};
1293 =head2 result_source
1297 =item Arguments: $result_source?
1299 =item Return Value: $result_source
1303 An accessor for the primary ResultSource object from which this ResultSet
1310 =item Arguments: $result_class?
1312 =item Return Value: $result_class
1316 An accessor for the class to use when creating row objects. Defaults to
1317 C<< result_source->result_class >> - which in most cases is the name of the
1318 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1320 Note that changing the result_class will also remove any components
1321 that were originally loaded in the source class via
1322 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1323 in the original source class will not run.
1328 my ($self, $result_class) = @_;
1329 if ($result_class) {
1330 unless (ref $result_class) { # don't fire this for an object
1331 $self->ensure_class_loaded($result_class);
1333 $self->_result_class($result_class);
1334 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1335 # permit the user to set result class on one result set only; it only
1336 # chains if provided to search()
1337 #$self->{attrs}{result_class} = $result_class if ref $self;
1339 $self->_result_class;
1346 =item Arguments: $cond, \%attrs??
1348 =item Return Value: $count
1352 Performs an SQL C<COUNT> with the same query as the resultset was built
1353 with to find the number of elements. Passing arguments is equivalent to
1354 C<< $rs->search ($cond, \%attrs)->count >>
1360 return $self->search(@_)->count if @_ and defined $_[0];
1361 return scalar @{ $self->get_cache } if $self->get_cache;
1363 my $attrs = $self->_resolved_attrs_copy;
1365 # this is a little optimization - it is faster to do the limit
1366 # adjustments in software, instead of a subquery
1367 my $rows = delete $attrs->{rows};
1368 my $offset = delete $attrs->{offset};
1371 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1372 $crs = $self->_count_subq_rs ($attrs);
1375 $crs = $self->_count_rs ($attrs);
1377 my $count = $crs->next;
1379 $count -= $offset if $offset;
1380 $count = $rows if $rows and $rows < $count;
1381 $count = 0 if ($count < 0);
1390 =item Arguments: $cond, \%attrs??
1392 =item Return Value: $count_rs
1396 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1397 This can be very handy for subqueries:
1399 ->search( { amount => $some_rs->count_rs->as_query } )
1401 As with regular resultsets the SQL query will be executed only after
1402 the resultset is accessed via L</next> or L</all>. That would return
1403 the same single value obtainable via L</count>.
1409 return $self->search(@_)->count_rs if @_;
1411 # this may look like a lack of abstraction (count() does about the same)
1412 # but in fact an _rs *must* use a subquery for the limits, as the
1413 # software based limiting can not be ported if this $rs is to be used
1414 # in a subquery itself (i.e. ->as_query)
1415 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1416 return $self->_count_subq_rs;
1419 return $self->_count_rs;
1424 # returns a ResultSetColumn object tied to the count query
1427 my ($self, $attrs) = @_;
1429 my $rsrc = $self->result_source;
1430 $attrs ||= $self->_resolved_attrs;
1432 my $tmp_attrs = { %$attrs };
1433 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1434 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1436 # overwrite the selector (supplied by the storage)
1437 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1438 $tmp_attrs->{as} = 'count';
1439 delete @{$tmp_attrs}{qw/columns/};
1441 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1447 # same as above but uses a subquery
1449 sub _count_subq_rs {
1450 my ($self, $attrs) = @_;
1452 my $rsrc = $self->result_source;
1453 $attrs ||= $self->_resolved_attrs;
1455 my $sub_attrs = { %$attrs };
1456 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1457 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1459 # if we multi-prefetch we group_by primary keys only as this is what we would
1460 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1461 if ( keys %{$attrs->{collapse}} ) {
1462 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1465 # Calculate subquery selector
1466 if (my $g = $sub_attrs->{group_by}) {
1468 my $sql_maker = $rsrc->storage->sql_maker;
1470 # necessary as the group_by may refer to aliased functions
1472 for my $sel (@{$attrs->{select}}) {
1473 $sel_index->{$sel->{-as}} = $sel
1474 if (ref $sel eq 'HASH' and $sel->{-as});
1477 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1478 # also look for named aggregates referred in the having clause
1479 # having often contains scalarrefs - thus parse it out entirely
1481 if ($attrs->{having}) {
1482 local $sql_maker->{having_bind};
1483 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1484 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1485 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1486 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1487 # if we don't unset it we screw up retarded but unfortunately working
1488 # 'MAX(foo.bar)' => { '>', 3 }
1489 $sql_maker->{name_sep} = '';
1492 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1494 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1496 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1497 # and if all fails for an utterly naive quoted scalar-with-function
1499 $rquote $sep $lquote (.+?) $rquote
1501 [\s,] \w+ \. (\w+) [\s,]
1503 [\s,] $lquote (.+?) $rquote [\s,]
1505 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1510 my $colpiece = $sel_index->{$_} || $_;
1512 # unqualify join-based group_by's. Arcane but possible query
1513 # also horrible horrible hack to alias a column (not a func.)
1514 # (probably need to introduce SQLA syntax)
1515 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1518 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1520 push @{$sub_attrs->{select}}, $colpiece;
1524 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1525 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1528 return $rsrc->resultset_class
1529 ->new ($rsrc, $sub_attrs)
1531 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1532 ->get_column ('count');
1539 =head2 count_literal
1543 =item Arguments: $sql_fragment, @bind_values
1545 =item Return Value: $count
1549 Counts the results in a literal query. Equivalent to calling L</search_literal>
1550 with the passed arguments, then L</count>.
1554 sub count_literal { shift->search_literal(@_)->count; }
1560 =item Arguments: none
1562 =item Return Value: @objects
1566 Returns all elements in the resultset.
1573 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1576 return @{ $self->get_cache } if $self->get_cache;
1580 if (keys %{$self->_resolved_attrs->{collapse}}) {
1581 # Using $self->cursor->all is really just an optimisation.
1582 # If we're collapsing has_many prefetches it probably makes
1583 # very little difference, and this is cleaner than hacking
1584 # _construct_object to survive the approach
1585 $self->cursor->reset;
1586 my @row = $self->cursor->next;
1588 push(@obj, $self->_construct_object(@row));
1589 @row = (exists $self->{stashed_row}
1590 ? @{delete $self->{stashed_row}}
1591 : $self->cursor->next);
1594 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1597 $self->set_cache(\@obj) if $self->{attrs}{cache};
1606 =item Arguments: none
1608 =item Return Value: $self
1612 Resets the resultset's cursor, so you can iterate through the elements again.
1613 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1620 delete $self->{_attrs} if exists $self->{_attrs};
1621 $self->{all_cache_position} = 0;
1622 $self->cursor->reset;
1630 =item Arguments: none
1632 =item Return Value: $object | undef
1636 Resets the resultset and returns an object for the first result (or C<undef>
1637 if the resultset is empty).
1642 return $_[0]->reset->next;
1648 # Determines whether and what type of subquery is required for the $rs operation.
1649 # If grouping is necessary either supplies its own, or verifies the current one
1650 # After all is done delegates to the proper storage method.
1652 sub _rs_update_delete {
1653 my ($self, $op, $values) = @_;
1655 my $rsrc = $self->result_source;
1657 # if a condition exists we need to strip all table qualifiers
1658 # if this is not possible we'll force a subquery below
1659 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1661 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1662 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1664 if ($needs_group_by_subq or $needs_subq) {
1666 # make a new $rs selecting only the PKs (that's all we really need)
1667 my $attrs = $self->_resolved_attrs_copy;
1670 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1671 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1673 if ($needs_group_by_subq) {
1674 # make sure no group_by was supplied, or if there is one - make sure it matches
1675 # the columns compiled above perfectly. Anything else can not be sanely executed
1676 # on most databases so croak right then and there
1678 if (my $g = $attrs->{group_by}) {
1679 my @current_group_by = map
1680 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1685 join ("\x00", sort @current_group_by)
1687 join ("\x00", sort @{$attrs->{columns}} )
1689 $self->throw_exception (
1690 "You have just attempted a $op operation on a resultset which does group_by"
1691 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1692 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1693 . ' kind of queries. Please retry the operation with a modified group_by or'
1694 . ' without using one at all.'
1699 $attrs->{group_by} = $attrs->{columns};
1703 my $subrs = (ref $self)->new($rsrc, $attrs);
1704 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1707 return $rsrc->storage->$op(
1709 $op eq 'update' ? $values : (),
1719 =item Arguments: \%values
1721 =item Return Value: $storage_rv
1725 Sets the specified columns in the resultset to the supplied values in a
1726 single query. Note that this will not run any accessor/set_column/update
1727 triggers, nor will it update any row object instances derived from this
1728 resultset (this includes the contents of the L<resultset cache|/set_cache>
1729 if any). See L</update_all> if you need to execute any on-update
1730 triggers or cascades defined either by you or a
1731 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1733 The return value is a pass through of what the underlying
1734 storage backend returned, and may vary. See L<DBI/execute> for the most
1739 Note that L</update> does not process/deflate any of the values passed in.
1740 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1741 ensure manually that any value passed to this method will stringify to
1742 something the RDBMS knows how to deal with. A notable example is the
1743 handling of L<DateTime> objects, for more info see:
1744 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1749 my ($self, $values) = @_;
1750 $self->throw_exception('Values for update must be a hash')
1751 unless ref $values eq 'HASH';
1753 return $self->_rs_update_delete ('update', $values);
1760 =item Arguments: \%values
1762 =item Return Value: 1
1766 Fetches all objects and updates them one at a time via
1767 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1768 triggers, while L</update> will not.
1773 my ($self, $values) = @_;
1774 $self->throw_exception('Values for update_all must be a hash')
1775 unless ref $values eq 'HASH';
1777 my $guard = $self->result_source->schema->txn_scope_guard;
1778 $_->update($values) for $self->all;
1787 =item Arguments: none
1789 =item Return Value: $storage_rv
1793 Deletes the rows matching this resultset in a single query. Note that this
1794 will not run any delete triggers, nor will it alter the
1795 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1796 derived from this resultset (this includes the contents of the
1797 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1798 execute any on-delete triggers or cascades defined either by you or a
1799 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1801 The return value is a pass through of what the underlying storage backend
1802 returned, and may vary. See L<DBI/execute> for the most common case.
1808 $self->throw_exception('delete does not accept any arguments')
1811 return $self->_rs_update_delete ('delete');
1818 =item Arguments: none
1820 =item Return Value: 1
1824 Fetches all objects and deletes them one at a time via
1825 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1826 triggers, while L</delete> will not.
1832 $self->throw_exception('delete_all does not accept any arguments')
1835 my $guard = $self->result_source->schema->txn_scope_guard;
1836 $_->delete for $self->all;
1845 =item Arguments: \@data;
1849 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1850 For the arrayref of hashrefs style each hashref should be a structure suitable
1851 for submitting to a $resultset->create(...) method.
1853 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1854 to insert the data, as this is a faster method.
1856 Otherwise, each set of data is inserted into the database using
1857 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1858 accumulated into an array. The array itself, or an array reference
1859 is returned depending on scalar or list context.
1861 Example: Assuming an Artist Class that has many CDs Classes relating:
1863 my $Artist_rs = $schema->resultset("Artist");
1865 ## Void Context Example
1866 $Artist_rs->populate([
1867 { artistid => 4, name => 'Manufactured Crap', cds => [
1868 { title => 'My First CD', year => 2006 },
1869 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1872 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1873 { title => 'My parents sold me to a record company', year => 2005 },
1874 { title => 'Why Am I So Ugly?', year => 2006 },
1875 { title => 'I Got Surgery and am now Popular', year => 2007 }
1880 ## Array Context Example
1881 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1882 { name => "Artist One"},
1883 { name => "Artist Two"},
1884 { name => "Artist Three", cds=> [
1885 { title => "First CD", year => 2007},
1886 { title => "Second CD", year => 2008},
1890 print $ArtistOne->name; ## response is 'Artist One'
1891 print $ArtistThree->cds->count ## reponse is '2'
1893 For the arrayref of arrayrefs style, the first element should be a list of the
1894 fieldsnames to which the remaining elements are rows being inserted. For
1897 $Arstist_rs->populate([
1898 [qw/artistid name/],
1899 [100, 'A Formally Unknown Singer'],
1900 [101, 'A singer that jumped the shark two albums ago'],
1901 [102, 'An actually cool singer'],
1904 Please note an important effect on your data when choosing between void and
1905 wantarray context. Since void context goes straight to C<insert_bulk> in
1906 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1907 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1908 create primary keys for you, you will find that your PKs are empty. In this
1909 case you will have to use the wantarray context in order to create those
1917 # cruft placed in standalone method
1918 my $data = $self->_normalize_populate_args(@_);
1920 if(defined wantarray) {
1922 foreach my $item (@$data) {
1923 push(@created, $self->create($item));
1925 return wantarray ? @created : \@created;
1928 my $first = $data->[0];
1930 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1931 # it relationship data
1932 my (@rels, @columns);
1933 my $rsrc = $self->result_source;
1934 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1935 for (keys %$first) {
1936 my $ref = ref $first->{$_};
1937 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1943 my @pks = $rsrc->primary_columns;
1945 ## do the belongs_to relationships
1946 foreach my $index (0..$#$data) {
1948 # delegate to create() for any dataset without primary keys with specified relationships
1949 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1951 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1952 my @ret = $self->populate($data);
1958 foreach my $rel (@rels) {
1959 next unless ref $data->[$index]->{$rel} eq "HASH";
1960 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1961 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1962 my $related = $result->result_source->_resolve_condition(
1963 $reverse_relinfo->{cond},
1969 delete $data->[$index]->{$rel};
1970 $data->[$index] = {%{$data->[$index]}, %$related};
1972 push @columns, keys %$related if $index == 0;
1976 ## inherit the data locked in the conditions of the resultset
1977 my ($rs_data) = $self->_merge_with_rscond({});
1978 delete @{$rs_data}{@columns};
1979 my @inherit_cols = keys %$rs_data;
1980 my @inherit_data = values %$rs_data;
1982 ## do bulk insert on current row
1983 $rsrc->storage->insert_bulk(
1985 [@columns, @inherit_cols],
1986 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1989 ## do the has_many relationships
1990 foreach my $item (@$data) {
1994 foreach my $rel (@rels) {
1995 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
1997 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
1999 my $child = $main_row->$rel;
2001 my $related = $child->result_source->_resolve_condition(
2002 $rels->{$rel}{cond},
2008 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2009 my @populate = map { {%$_, %$related} } @rows_to_add;
2011 $child->populate( \@populate );
2018 # populate() argumnets went over several incarnations
2019 # What we ultimately support is AoH
2020 sub _normalize_populate_args {
2021 my ($self, $arg) = @_;
2023 if (ref $arg eq 'ARRAY') {
2024 if (ref $arg->[0] eq 'HASH') {
2027 elsif (ref $arg->[0] eq 'ARRAY') {
2029 my @colnames = @{$arg->[0]};
2030 foreach my $values (@{$arg}[1 .. $#$arg]) {
2031 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2037 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2044 =item Arguments: none
2046 =item Return Value: $pager
2050 Return Value a L<Data::Page> object for the current resultset. Only makes
2051 sense for queries with a C<page> attribute.
2053 To get the full count of entries for a paged resultset, call
2054 C<total_entries> on the L<Data::Page> object.
2058 # make a wizard good for both a scalar and a hashref
2059 my $mk_lazy_count_wizard = sub {
2060 require Variable::Magic;
2062 my $stash = { total_rs => shift };
2063 my $slot = shift; # only used by the hashref magic
2065 my $magic = Variable::Magic::wizard (
2066 data => sub { $stash },
2072 # set value lazily, and dispell for good
2073 ${$_[0]} = $_[1]{total_rs}->count;
2074 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2078 # an explicit set implies dispell as well
2079 # the unless() is to work around "fun and giggles" below
2080 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2081 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2088 if ($_[2] eq $slot and !$_[1]{inactive}) {
2089 my $cnt = $_[1]{total_rs}->count;
2090 $_[0]->{$slot} = $cnt;
2092 # attempting to dispell in a fetch handle (works in store), seems
2093 # to invariable segfault on 5.10, 5.12, 5.13 :(
2094 # so use an inactivator instead
2095 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2101 if (! $_[1]{inactive} and $_[2] eq $slot) {
2102 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2104 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2111 $stash->{magic_selfref} = $magic;
2112 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2117 # the tie class for 5.8.1
2119 package # hide from pause
2120 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2121 use base qw/Tie::Hash/;
2123 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2124 sub NEXTKEY { each %{$_[0]{data}} }
2125 sub EXISTS { exists $_[0]{data}{$_[1]} }
2126 sub DELETE { delete $_[0]{data}{$_[1]} }
2127 sub CLEAR { %{$_[0]{data}} = () }
2128 sub SCALAR { scalar %{$_[0]{data}} }
2131 $_[1]{data} = {%{$_[1]{selfref}}};
2132 %{$_[1]{selfref}} = ();
2133 Scalar::Util::weaken ($_[1]{selfref});
2134 return bless ($_[1], $_[0]);
2138 if ($_[1] eq $_[0]{slot}) {
2139 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2140 untie %{$_[0]{selfref}};
2141 %{$_[0]{selfref}} = %{$_[0]{data}};
2150 $_[0]{data}{$_[1]} = $_[2];
2151 if ($_[1] eq $_[0]{slot}) {
2152 untie %{$_[0]{selfref}};
2153 %{$_[0]{selfref}} = %{$_[0]{data}};
2162 return $self->{pager} if $self->{pager};
2164 my $attrs = $self->{attrs};
2165 if (!defined $attrs->{page}) {
2166 $self->throw_exception("Can't create pager for non-paged rs");
2168 elsif ($attrs->{page} <= 0) {
2169 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2171 $attrs->{rows} ||= 10;
2173 # throw away the paging flags and re-run the count (possibly
2174 # with a subselect) to get the real total count
2175 my $count_attrs = { %$attrs };
2176 delete $count_attrs->{$_} for qw/rows offset page pager/;
2177 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2180 ### the following may seem awkward and dirty, but it's a thought-experiment
2181 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2182 ### before talking to ribasushi/mst
2185 my $pager = Data::Page->new(
2186 0, #start with an empty set
2188 $self->{attrs}{page},
2191 my $data_slot = 'total_entries';
2193 # Since we are interested in a cached value (once it's set - it's set), every
2194 # technique will detach from the magic-host once the time comes to fire the
2195 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2197 if ($] < 5.008003) {
2198 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2199 # to weakref the magic container :(
2201 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2202 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2205 elsif ($] < 5.010) {
2206 # We can use magic on the hash value slot. It's interesting that the magic is
2207 # attached to the hash-slot, and does *not* stop working once I do the dummy
2208 # assignments after the cast()
2209 # tested on 5.8.3 and 5.8.9
2210 my $magic = $mk_lazy_count_wizard->($total_rs);
2211 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2213 # this is for fun and giggles
2214 $pager->{$data_slot} = -1;
2215 $pager->{$data_slot} = 0;
2217 # this does not work for scalars, but works with
2219 #my %vals = %$pager;
2224 # And the uvar magic
2225 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2226 # however see the wizard maker for more notes
2227 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2228 Variable::Magic::cast ( %$pager, $magic );
2231 $pager->{$data_slot} = -1;
2232 $pager->{$data_slot} = 0;
2240 return $self->{pager} = $pager;
2247 =item Arguments: $page_number
2249 =item Return Value: $rs
2253 Returns a resultset for the $page_number page of the resultset on which page
2254 is called, where each page contains a number of rows equal to the 'rows'
2255 attribute set on the resultset (10 by default).
2260 my ($self, $page) = @_;
2261 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2268 =item Arguments: \%vals
2270 =item Return Value: $rowobject
2274 Creates a new row object in the resultset's result class and returns
2275 it. The row is not inserted into the database at this point, call
2276 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2277 will tell you whether the row object has been inserted or not.
2279 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2284 my ($self, $values) = @_;
2285 $self->throw_exception( "new_result needs a hash" )
2286 unless (ref $values eq 'HASH');
2288 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2292 @$cols_from_relations
2293 ? (-cols_from_relations => $cols_from_relations)
2295 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2298 return $self->result_class->new(\%new);
2301 # _merge_with_rscond
2303 # Takes a simple hash of K/V data and returns its copy merged with the
2304 # condition already present on the resultset. Additionally returns an
2305 # arrayref of value/condition names, which were inferred from related
2306 # objects (this is needed for in-memory related objects)
2307 sub _merge_with_rscond {
2308 my ($self, $data) = @_;
2310 my (%new_data, @cols_from_relations);
2312 my $alias = $self->{attrs}{alias};
2314 if (! defined $self->{cond}) {
2315 # just massage $data below
2317 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2318 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2319 @cols_from_relations = keys %new_data;
2321 elsif (ref $self->{cond} ne 'HASH') {
2322 $self->throw_exception(
2323 "Can't abstract implicit construct, resultset condition not a hash"
2327 # precendence must be given to passed values over values inherited from
2328 # the cond, so the order here is important.
2329 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2330 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2332 while ( my($col, $value) = each %implied ) {
2333 my $vref = ref $value;
2339 (keys %$value)[0] eq '='
2341 $new_data{$col} = $value->{'='};
2343 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2344 $new_data{$col} = $value;
2351 %{ $self->_remove_alias($data, $alias) },
2354 return (\%new_data, \@cols_from_relations);
2357 # _has_resolved_attr
2359 # determines if the resultset defines at least one
2360 # of the attributes supplied
2362 # used to determine if a subquery is neccessary
2364 # supports some virtual attributes:
2366 # This will scan for any joins being present on the resultset.
2367 # It is not a mere key-search but a deep inspection of {from}
2370 sub _has_resolved_attr {
2371 my ($self, @attr_names) = @_;
2373 my $attrs = $self->_resolved_attrs;
2377 for my $n (@attr_names) {
2378 if (grep { $n eq $_ } (qw/-join/) ) {
2379 $extra_checks{$n}++;
2383 my $attr = $attrs->{$n};
2385 next if not defined $attr;
2387 if (ref $attr eq 'HASH') {
2388 return 1 if keys %$attr;
2390 elsif (ref $attr eq 'ARRAY') {
2398 # a resolved join is expressed as a multi-level from
2400 $extra_checks{-join}
2402 ref $attrs->{from} eq 'ARRAY'
2404 @{$attrs->{from}} > 1
2412 # Recursively collapse the condition.
2414 sub _collapse_cond {
2415 my ($self, $cond, $collapsed) = @_;
2419 if (ref $cond eq 'ARRAY') {
2420 foreach my $subcond (@$cond) {
2421 next unless ref $subcond; # -or
2422 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2425 elsif (ref $cond eq 'HASH') {
2426 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2427 foreach my $subcond (@{$cond->{-and}}) {
2428 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2432 foreach my $col (keys %$cond) {
2433 my $value = $cond->{$col};
2434 $collapsed->{$col} = $value;
2444 # Remove the specified alias from the specified query hash. A copy is made so
2445 # the original query is not modified.
2448 my ($self, $query, $alias) = @_;
2450 my %orig = %{ $query || {} };
2453 foreach my $key (keys %orig) {
2455 $unaliased{$key} = $orig{$key};
2458 $unaliased{$1} = $orig{$key}
2459 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2469 =item Arguments: none
2471 =item Return Value: \[ $sql, @bind ]
2475 Returns the SQL query and bind vars associated with the invocant.
2477 This is generally used as the RHS for a subquery.
2484 my $attrs = $self->_resolved_attrs_copy;
2489 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2490 # $sql also has no wrapping parenthesis in list ctx
2492 my $sqlbind = $self->result_source->storage
2493 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2502 =item Arguments: \%vals, \%attrs?
2504 =item Return Value: $rowobject
2508 my $artist = $schema->resultset('Artist')->find_or_new(
2509 { artist => 'fred' }, { key => 'artists' });
2511 $cd->cd_to_producer->find_or_new({ producer => $producer },
2512 { key => 'primary });
2514 Find an existing record from this resultset using L</find>. if none exists,
2515 instantiate a new result object and return it. The object will not be saved
2516 into your storage until you call L<DBIx::Class::Row/insert> on it.
2518 You most likely want this method when looking for existing rows using a unique
2519 constraint that is not the primary key, or looking for related rows.
2521 If you want objects to be saved immediately, use L</find_or_create> instead.
2523 B<Note>: Make sure to read the documentation of L</find> and understand the
2524 significance of the C<key> attribute, as its lack may skew your search, and
2525 subsequently result in spurious new objects.
2527 B<Note>: Take care when using C<find_or_new> with a table having
2528 columns with default values that you intend to be automatically
2529 supplied by the database (e.g. an auto_increment primary key column).
2530 In normal usage, the value of such columns should NOT be included at
2531 all in the call to C<find_or_new>, even when set to C<undef>.
2537 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2538 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2539 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2542 return $self->new_result($hash);
2549 =item Arguments: \%vals
2551 =item Return Value: a L<DBIx::Class::Row> $object
2555 Attempt to create a single new row or a row with multiple related rows
2556 in the table represented by the resultset (and related tables). This
2557 will not check for duplicate rows before inserting, use
2558 L</find_or_create> to do that.
2560 To create one row for this resultset, pass a hashref of key/value
2561 pairs representing the columns of the table and the values you wish to
2562 store. If the appropriate relationships are set up, foreign key fields
2563 can also be passed an object representing the foreign row, and the
2564 value will be set to its primary key.
2566 To create related objects, pass a hashref of related-object column values
2567 B<keyed on the relationship name>. If the relationship is of type C<multi>
2568 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2569 The process will correctly identify columns holding foreign keys, and will
2570 transparently populate them from the keys of the corresponding relation.
2571 This can be applied recursively, and will work correctly for a structure
2572 with an arbitrary depth and width, as long as the relationships actually
2573 exists and the correct column data has been supplied.
2576 Instead of hashrefs of plain related data (key/value pairs), you may
2577 also pass new or inserted objects. New objects (not inserted yet, see
2578 L</new>), will be inserted into their appropriate tables.
2580 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2582 Example of creating a new row.
2584 $person_rs->create({
2585 name=>"Some Person",
2586 email=>"somebody@someplace.com"
2589 Example of creating a new row and also creating rows in a related C<has_many>
2590 or C<has_one> resultset. Note Arrayref.
2593 { artistid => 4, name => 'Manufactured Crap', cds => [
2594 { title => 'My First CD', year => 2006 },
2595 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2600 Example of creating a new row and also creating a row in a related
2601 C<belongs_to> resultset. Note Hashref.
2604 title=>"Music for Silly Walks",
2607 name=>"Silly Musician",
2615 When subclassing ResultSet never attempt to override this method. Since
2616 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2617 lot of the internals simply never call it, so your override will be
2618 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2619 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2620 L</create> process you need to intervene.
2627 my ($self, $attrs) = @_;
2628 $self->throw_exception( "create needs a hashref" )
2629 unless ref $attrs eq 'HASH';
2630 return $self->new_result($attrs)->insert;
2633 =head2 find_or_create
2637 =item Arguments: \%vals, \%attrs?
2639 =item Return Value: $rowobject
2643 $cd->cd_to_producer->find_or_create({ producer => $producer },
2644 { key => 'primary' });
2646 Tries to find a record based on its primary key or unique constraints; if none
2647 is found, creates one and returns that instead.
2649 my $cd = $schema->resultset('CD')->find_or_create({
2651 artist => 'Massive Attack',
2652 title => 'Mezzanine',
2656 Also takes an optional C<key> attribute, to search by a specific key or unique
2657 constraint. For example:
2659 my $cd = $schema->resultset('CD')->find_or_create(
2661 artist => 'Massive Attack',
2662 title => 'Mezzanine',
2664 { key => 'cd_artist_title' }
2667 B<Note>: Make sure to read the documentation of L</find> and understand the
2668 significance of the C<key> attribute, as its lack may skew your search, and
2669 subsequently result in spurious row creation.
2671 B<Note>: Because find_or_create() reads from the database and then
2672 possibly inserts based on the result, this method is subject to a race
2673 condition. Another process could create a record in the table after
2674 the find has completed and before the create has started. To avoid
2675 this problem, use find_or_create() inside a transaction.
2677 B<Note>: Take care when using C<find_or_create> with a table having
2678 columns with default values that you intend to be automatically
2679 supplied by the database (e.g. an auto_increment primary key column).
2680 In normal usage, the value of such columns should NOT be included at
2681 all in the call to C<find_or_create>, even when set to C<undef>.
2683 See also L</find> and L</update_or_create>. For information on how to declare
2684 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2688 sub find_or_create {
2690 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2691 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2692 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2695 return $self->create($hash);
2698 =head2 update_or_create
2702 =item Arguments: \%col_values, { key => $unique_constraint }?
2704 =item Return Value: $row_object
2708 $resultset->update_or_create({ col => $val, ... });
2710 Like L</find_or_create>, but if a row is found it is immediately updated via
2711 C<< $found_row->update (\%col_values) >>.
2714 Takes an optional C<key> attribute to search on a specific unique constraint.
2717 # In your application
2718 my $cd = $schema->resultset('CD')->update_or_create(
2720 artist => 'Massive Attack',
2721 title => 'Mezzanine',
2724 { key => 'cd_artist_title' }
2727 $cd->cd_to_producer->update_or_create({
2728 producer => $producer,
2734 B<Note>: Make sure to read the documentation of L</find> and understand the
2735 significance of the C<key> attribute, as its lack may skew your search, and
2736 subsequently result in spurious row creation.
2738 B<Note>: Take care when using C<update_or_create> with a table having
2739 columns with default values that you intend to be automatically
2740 supplied by the database (e.g. an auto_increment primary key column).
2741 In normal usage, the value of such columns should NOT be included at
2742 all in the call to C<update_or_create>, even when set to C<undef>.
2744 See also L</find> and L</find_or_create>. For information on how to declare
2745 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2749 sub update_or_create {
2751 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2752 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2754 my $row = $self->find($cond, $attrs);
2756 $row->update($cond);
2760 return $self->create($cond);
2763 =head2 update_or_new
2767 =item Arguments: \%col_values, { key => $unique_constraint }?
2769 =item Return Value: $rowobject
2773 $resultset->update_or_new({ col => $val, ... });
2775 Like L</find_or_new> but if a row is found it is immediately updated via
2776 C<< $found_row->update (\%col_values) >>.
2780 # In your application
2781 my $cd = $schema->resultset('CD')->update_or_new(
2783 artist => 'Massive Attack',
2784 title => 'Mezzanine',
2787 { key => 'cd_artist_title' }
2790 if ($cd->in_storage) {
2791 # the cd was updated
2794 # the cd is not yet in the database, let's insert it
2798 B<Note>: Make sure to read the documentation of L</find> and understand the
2799 significance of the C<key> attribute, as its lack may skew your search, and
2800 subsequently result in spurious new objects.
2802 B<Note>: Take care when using C<update_or_new> with a table having
2803 columns with default values that you intend to be automatically
2804 supplied by the database (e.g. an auto_increment primary key column).
2805 In normal usage, the value of such columns should NOT be included at
2806 all in the call to C<update_or_new>, even when set to C<undef>.
2808 See also L</find>, L</find_or_create> and L</find_or_new>.
2814 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2815 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2817 my $row = $self->find( $cond, $attrs );
2818 if ( defined $row ) {
2819 $row->update($cond);
2823 return $self->new_result($cond);
2830 =item Arguments: none
2832 =item Return Value: \@cache_objects | undef
2836 Gets the contents of the cache for the resultset, if the cache is set.
2838 The cache is populated either by using the L</prefetch> attribute to
2839 L</search> or by calling L</set_cache>.
2851 =item Arguments: \@cache_objects
2853 =item Return Value: \@cache_objects
2857 Sets the contents of the cache for the resultset. Expects an arrayref
2858 of objects of the same class as those produced by the resultset. Note that
2859 if the cache is set the resultset will return the cached objects rather
2860 than re-querying the database even if the cache attr is not set.
2862 The contents of the cache can also be populated by using the
2863 L</prefetch> attribute to L</search>.
2868 my ( $self, $data ) = @_;
2869 $self->throw_exception("set_cache requires an arrayref")
2870 if defined($data) && (ref $data ne 'ARRAY');
2871 $self->{all_cache} = $data;
2878 =item Arguments: none
2880 =item Return Value: undef
2884 Clears the cache for the resultset.
2889 shift->set_cache(undef);
2896 =item Arguments: none
2898 =item Return Value: true, if the resultset has been paginated
2906 return !!$self->{attrs}{page};
2913 =item Arguments: none
2915 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2923 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2926 =head2 related_resultset
2930 =item Arguments: $relationship_name
2932 =item Return Value: $resultset
2936 Returns a related resultset for the supplied relationship name.
2938 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2942 sub related_resultset {
2943 my ($self, $rel) = @_;
2945 $self->{related_resultsets} ||= {};
2946 return $self->{related_resultsets}{$rel} ||= do {
2947 my $rsrc = $self->result_source;
2948 my $rel_info = $rsrc->relationship_info($rel);
2950 $self->throw_exception(
2951 "search_related: result source '" . $rsrc->source_name .
2952 "' has no such relationship $rel")
2955 my $attrs = $self->_chain_relationship($rel);
2957 my $join_count = $attrs->{seen_join}{$rel};
2959 my $alias = $self->result_source->storage
2960 ->relname_to_table_alias($rel, $join_count);
2962 # since this is search_related, and we already slid the select window inwards
2963 # (the select/as attrs were deleted in the beginning), we need to flip all
2964 # left joins to inner, so we get the expected results
2965 # read the comment on top of the actual function to see what this does
2966 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2969 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2970 delete @{$attrs}{qw(result_class alias)};
2974 if (my $cache = $self->get_cache) {
2975 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2976 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2981 my $rel_source = $rsrc->related_source($rel);
2985 # The reason we do this now instead of passing the alias to the
2986 # search_rs below is that if you wrap/overload resultset on the
2987 # source you need to know what alias it's -going- to have for things
2988 # to work sanely (e.g. RestrictWithObject wants to be able to add
2989 # extra query restrictions, and these may need to be $alias.)
2991 my $rel_attrs = $rel_source->resultset_attributes;
2992 local $rel_attrs->{alias} = $alias;
2994 $rel_source->resultset
2998 where => $attrs->{where},
3001 $new->set_cache($new_cache) if $new_cache;
3006 =head2 current_source_alias
3010 =item Arguments: none
3012 =item Return Value: $source_alias
3016 Returns the current table alias for the result source this resultset is built
3017 on, that will be used in the SQL query. Usually it is C<me>.
3019 Currently the source alias that refers to the result set returned by a
3020 L</search>/L</find> family method depends on how you got to the resultset: it's
3021 C<me> by default, but eg. L</search_related> aliases it to the related result
3022 source name (and keeps C<me> referring to the original result set). The long
3023 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3024 (and make this method unnecessary).
3026 Thus it's currently necessary to use this method in predefined queries (see
3027 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3028 source alias of the current result set:
3030 # in a result set class
3032 my ($self, $user) = @_;
3034 my $me = $self->current_source_alias;
3036 return $self->search(
3037 "$me.modified" => $user->id,
3043 sub current_source_alias {
3046 return ($self->{attrs} || {})->{alias} || 'me';
3049 =head2 as_subselect_rs
3053 =item Arguments: none
3055 =item Return Value: $resultset
3059 Act as a barrier to SQL symbols. The resultset provided will be made into a
3060 "virtual view" by including it as a subquery within the from clause. From this
3061 point on, any joined tables are inaccessible to ->search on the resultset (as if
3062 it were simply where-filtered without joins). For example:
3064 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3066 # 'x' now pollutes the query namespace
3068 # So the following works as expected
3069 my $ok_rs = $rs->search({'x.other' => 1});
3071 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3072 # def) we look for one row with contradictory terms and join in another table
3073 # (aliased 'x_2') which we never use
3074 my $broken_rs = $rs->search({'x.name' => 'def'});
3076 my $rs2 = $rs->as_subselect_rs;
3078 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3079 my $not_joined_rs = $rs2->search({'x.other' => 1});
3081 # works as expected: finds a 'table' row related to two x rows (abc and def)
3082 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3084 Another example of when one might use this would be to select a subset of
3085 columns in a group by clause:
3087 my $rs = $schema->resultset('Bar')->search(undef, {
3088 group_by => [qw{ id foo_id baz_id }],
3089 })->as_subselect_rs->search(undef, {
3090 columns => [qw{ id foo_id }]
3093 In the above example normally columns would have to be equal to the group by,
3094 but because we isolated the group by into a subselect the above works.
3098 sub as_subselect_rs {
3101 my $attrs = $self->_resolved_attrs;
3103 my $fresh_rs = (ref $self)->new (
3104 $self->result_source
3107 # these pieces will be locked in the subquery
3108 delete $fresh_rs->{cond};
3109 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3111 return $fresh_rs->search( {}, {
3113 $attrs->{alias} => $self->as_query,
3114 -alias => $attrs->{alias},
3115 -rsrc => $self->result_source,
3117 alias => $attrs->{alias},
3121 # This code is called by search_related, and makes sure there
3122 # is clear separation between the joins before, during, and
3123 # after the relationship. This information is needed later
3124 # in order to properly resolve prefetch aliases (any alias
3125 # with a relation_chain_depth less than the depth of the
3126 # current prefetch is not considered)
3128 # The increments happen twice per join. An even number means a
3129 # relationship specified via a search_related, whereas an odd
3130 # number indicates a join/prefetch added via attributes
3132 # Also this code will wrap the current resultset (the one we
3133 # chain to) in a subselect IFF it contains limiting attributes
3134 sub _chain_relationship {
3135 my ($self, $rel) = @_;
3136 my $source = $self->result_source;
3137 my $attrs = { %{$self->{attrs}||{}} };
3139 # we need to take the prefetch the attrs into account before we
3140 # ->_resolve_join as otherwise they get lost - captainL
3141 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3143 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3145 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3148 my @force_subq_attrs = qw/offset rows group_by having/;
3151 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3153 $self->_has_resolved_attr (@force_subq_attrs)
3155 # Nuke the prefetch (if any) before the new $rs attrs
3156 # are resolved (prefetch is useless - we are wrapping
3157 # a subquery anyway).
3158 my $rs_copy = $self->search;
3159 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3160 $rs_copy->{attrs}{join},
3161 delete $rs_copy->{attrs}{prefetch},
3166 -alias => $attrs->{alias},
3167 $attrs->{alias} => $rs_copy->as_query,
3169 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3170 $seen->{-relation_chain_depth} = 0;
3172 elsif ($attrs->{from}) { #shallow copy suffices
3173 $from = [ @{$attrs->{from}} ];
3178 -alias => $attrs->{alias},
3179 $attrs->{alias} => $source->from,
3183 my $jpath = ($seen->{-relation_chain_depth})
3184 ? $from->[-1][0]{-join_path}
3187 my @requested_joins = $source->_resolve_join(
3194 push @$from, @requested_joins;
3196 $seen->{-relation_chain_depth}++;
3198 # if $self already had a join/prefetch specified on it, the requested
3199 # $rel might very well be already included. What we do in this case
3200 # is effectively a no-op (except that we bump up the chain_depth on
3201 # the join in question so we could tell it *is* the search_related)
3204 # we consider the last one thus reverse
3205 for my $j (reverse @requested_joins) {
3206 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3207 if ($rel eq $last_j) {
3208 $j->[0]{-relation_chain_depth}++;
3214 unless ($already_joined) {
3215 push @$from, $source->_resolve_join(
3223 $seen->{-relation_chain_depth}++;
3225 return {%$attrs, from => $from, seen_join => $seen};
3228 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3229 sub _resolved_attrs_copy {
3231 return { %{$self->_resolved_attrs (@_)} };
3234 sub _resolved_attrs {
3236 return $self->{_attrs} if $self->{_attrs};
3238 my $attrs = { %{ $self->{attrs} || {} } };
3239 my $source = $self->result_source;
3240 my $alias = $attrs->{alias};
3242 # default selection list
3243 $attrs->{columns} = [ $source->columns ]
3244 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3246 # merge selectors together
3247 for (qw/columns select as/) {
3248 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3249 if $attrs->{$_} or $attrs->{"+$_"};
3252 # disassemble columns
3254 if (my $cols = delete $attrs->{columns}) {
3255 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3256 if (ref $c eq 'HASH') {
3257 for my $as (keys %$c) {
3258 push @sel, $c->{$as};
3269 # when trying to weed off duplicates later do not go past this point -
3270 # everything added from here on is unbalanced "anyone's guess" stuff
3271 my $dedup_stop_idx = $#as;
3273 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3275 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3276 if $attrs->{select};
3278 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3280 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3283 # disqualify all $alias.col as-bits (collapser mandated)
3285 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3288 # de-duplicate the result (remove *identical* select/as pairs)
3289 # and also die on duplicate {as} pointing to different {select}s
3290 # not using a c-style for as the condition is prone to shrinkage
3293 while ($i <= $dedup_stop_idx) {
3294 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3299 elsif ($seen->{$as[$i]}++) {
3300 $self->throw_exception(
3301 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3309 $attrs->{select} = \@sel;
3310 $attrs->{as} = \@as;
3312 $attrs->{from} ||= [{
3314 -alias => $self->{attrs}{alias},
3315 $self->{attrs}{alias} => $source->from,
3318 if ( $attrs->{join} || $attrs->{prefetch} ) {
3320 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3321 if ref $attrs->{from} ne 'ARRAY';
3323 my $join = (delete $attrs->{join}) || {};
3325 if ( defined $attrs->{prefetch} ) {
3326 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3329 $attrs->{from} = # have to copy here to avoid corrupting the original
3331 @{ $attrs->{from} },
3332 $source->_resolve_join(
3335 { %{ $attrs->{seen_join} || {} } },
3336 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3337 ? $attrs->{from}[-1][0]{-join_path}
3344 if ( defined $attrs->{order_by} ) {
3345 $attrs->{order_by} = (
3346 ref( $attrs->{order_by} ) eq 'ARRAY'
3347 ? [ @{ $attrs->{order_by} } ]
3348 : [ $attrs->{order_by} || () ]
3352 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3353 $attrs->{group_by} = [ $attrs->{group_by} ];
3356 # generate the distinct induced group_by early, as prefetch will be carried via a
3357 # subquery (since a group_by is present)
3358 if (delete $attrs->{distinct}) {
3359 if ($attrs->{group_by}) {
3360 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3363 # distinct affects only the main selection part, not what prefetch may
3365 $attrs->{group_by} = $source->storage->_group_over_selection (
3373 $attrs->{collapse} ||= {};
3374 if ($attrs->{prefetch}) {
3376 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3377 if $attrs->{_dark_selector};
3379 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3381 my $prefetch_ordering = [];
3383 # this is a separate structure (we don't look in {from} directly)
3384 # as the resolver needs to shift things off the lists to work
3385 # properly (identical-prefetches on different branches)
3387 if (ref $attrs->{from} eq 'ARRAY') {
3389 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3391 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3392 next unless $j->[0]{-alias};
3393 next unless $j->[0]{-join_path};
3394 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3396 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3399 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3400 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3405 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3407 # we need to somehow mark which columns came from prefetch
3409 my $sel_end = $#{$attrs->{select}};
3410 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3413 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3414 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3416 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3417 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3421 # if both page and offset are specified, produce a combined offset
3422 # even though it doesn't make much sense, this is what pre 081xx has
3424 if (my $page = delete $attrs->{page}) {
3426 ($attrs->{rows} * ($page - 1))
3428 ($attrs->{offset} || 0)
3432 return $self->{_attrs} = $attrs;
3436 my ($self, $attr) = @_;
3438 if (ref $attr eq 'HASH') {
3439 return $self->_rollout_hash($attr);
3440 } elsif (ref $attr eq 'ARRAY') {
3441 return $self->_rollout_array($attr);
3447 sub _rollout_array {
3448 my ($self, $attr) = @_;
3451 foreach my $element (@{$attr}) {
3452 if (ref $element eq 'HASH') {
3453 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3454 } elsif (ref $element eq 'ARRAY') {
3455 # XXX - should probably recurse here
3456 push( @rolled_array, @{$self->_rollout_array($element)} );
3458 push( @rolled_array, $element );
3461 return \@rolled_array;
3465 my ($self, $attr) = @_;
3468 foreach my $key (keys %{$attr}) {
3469 push( @rolled_array, { $key => $attr->{$key} } );
3471 return \@rolled_array;
3474 sub _calculate_score {
3475 my ($self, $a, $b) = @_;
3477 if (defined $a xor defined $b) {
3480 elsif (not defined $a) {
3484 if (ref $b eq 'HASH') {
3485 my ($b_key) = keys %{$b};
3486 if (ref $a eq 'HASH') {
3487 my ($a_key) = keys %{$a};
3488 if ($a_key eq $b_key) {
3489 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3494 return ($a eq $b_key) ? 1 : 0;
3497 if (ref $a eq 'HASH') {
3498 my ($a_key) = keys %{$a};
3499 return ($b eq $a_key) ? 1 : 0;
3501 return ($b eq $a) ? 1 : 0;
3506 sub _merge_joinpref_attr {
3507 my ($self, $orig, $import) = @_;
3509 return $import unless defined($orig);
3510 return $orig unless defined($import);
3512 $orig = $self->_rollout_attr($orig);
3513 $import = $self->_rollout_attr($import);
3516 foreach my $import_element ( @{$import} ) {
3517 # find best candidate from $orig to merge $b_element into
3518 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3519 foreach my $orig_element ( @{$orig} ) {
3520 my $score = $self->_calculate_score( $orig_element, $import_element );
3521 if ($score > $best_candidate->{score}) {
3522 $best_candidate->{position} = $position;
3523 $best_candidate->{score} = $score;
3527 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3529 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3530 push( @{$orig}, $import_element );
3532 my $orig_best = $orig->[$best_candidate->{position}];
3533 # merge orig_best and b_element together and replace original with merged
3534 if (ref $orig_best ne 'HASH') {
3535 $orig->[$best_candidate->{position}] = $import_element;
3536 } elsif (ref $import_element eq 'HASH') {
3537 my ($key) = keys %{$orig_best};
3538 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3541 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3552 require Hash::Merge;
3553 my $hm = Hash::Merge->new;
3555 $hm->specify_behavior({
3558 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3560 if ($defl xor $defr) {
3561 return [ $defl ? $_[0] : $_[1] ];
3566 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3570 return [$_[0], $_[1]];
3574 return $_[1] if !defined $_[0];
3575 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3576 return [$_[0], @{$_[1]}]
3579 return [] if !defined $_[0] and !keys %{$_[1]};
3580 return [ $_[1] ] if !defined $_[0];
3581 return [ $_[0] ] if !keys %{$_[1]};
3582 return [$_[0], $_[1]]
3587 return $_[0] if !defined $_[1];
3588 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3589 return [@{$_[0]}, $_[1]]
3592 my @ret = @{$_[0]} or return $_[1];
3593 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3594 my %idx = map { $_ => 1 } @ret;
3595 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3599 return [ $_[1] ] if ! @{$_[0]};
3600 return $_[0] if !keys %{$_[1]};
3601 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3602 return [ @{$_[0]}, $_[1] ];
3607 return [] if !keys %{$_[0]} and !defined $_[1];
3608 return [ $_[0] ] if !defined $_[1];
3609 return [ $_[1] ] if !keys %{$_[0]};
3610 return [$_[0], $_[1]]
3613 return [] if !keys %{$_[0]} and !@{$_[1]};
3614 return [ $_[0] ] if !@{$_[1]};
3615 return $_[1] if !keys %{$_[0]};
3616 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3617 return [ $_[0], @{$_[1]} ];
3620 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3621 return [ $_[0] ] if !keys %{$_[1]};
3622 return [ $_[1] ] if !keys %{$_[0]};
3623 return [ $_[0] ] if $_[0] eq $_[1];
3624 return [ $_[0], $_[1] ];
3627 } => 'DBIC_RS_ATTR_MERGER');
3631 return $hm->merge ($_[1], $_[2]);
3635 sub STORABLE_freeze {
3636 my ($self, $cloning) = @_;
3637 my $to_serialize = { %$self };
3639 # A cursor in progress can't be serialized (and would make little sense anyway)
3640 delete $to_serialize->{cursor};
3642 Storable::nfreeze($to_serialize);
3645 # need this hook for symmetry
3647 my ($self, $cloning, $serialized) = @_;
3649 %$self = %{ Storable::thaw($serialized) };
3655 =head2 throw_exception
3657 See L<DBIx::Class::Schema/throw_exception> for details.
3661 sub throw_exception {
3664 if (ref $self and my $rsrc = $self->result_source) {
3665 $rsrc->throw_exception(@_)
3668 DBIx::Class::Exception->throw(@_);
3672 # XXX: FIXME: Attributes docs need clearing up
3676 Attributes are used to refine a ResultSet in various ways when
3677 searching for data. They can be passed to any method which takes an
3678 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3681 These are in no particular order:
3687 =item Value: ( $order_by | \@order_by | \%order_by )
3691 Which column(s) to order the results by.
3693 [The full list of suitable values is documented in
3694 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3697 If a single column name, or an arrayref of names is supplied, the
3698 argument is passed through directly to SQL. The hashref syntax allows
3699 for connection-agnostic specification of ordering direction:
3701 For descending order:
3703 order_by => { -desc => [qw/col1 col2 col3/] }
3705 For explicit ascending order:
3707 order_by => { -asc => 'col' }
3709 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3710 supported, although you are strongly encouraged to use the hashref
3711 syntax as outlined above.
3717 =item Value: \@columns
3721 Shortcut to request a particular set of columns to be retrieved. Each
3722 column spec may be a string (a table column name), or a hash (in which
3723 case the key is the C<as> value, and the value is used as the C<select>
3724 expression). Adds C<me.> onto the start of any column without a C<.> in
3725 it and sets C<select> from that, then auto-populates C<as> from
3726 C<select> as normal. (You may also use the C<cols> attribute, as in
3727 earlier versions of DBIC.)
3729 Essentially C<columns> does the same as L</select> and L</as>.
3731 columns => [ 'foo', { bar => 'baz' } ]
3735 select => [qw/foo baz/],
3742 =item Value: \@columns
3746 Indicates additional columns to be selected from storage. Works the same
3747 as L</columns> but adds columns to the selection. (You may also use the
3748 C<include_columns> attribute, as in earlier versions of DBIC). For
3751 $schema->resultset('CD')->search(undef, {
3752 '+columns' => ['artist.name'],
3756 would return all CDs and include a 'name' column to the information
3757 passed to object inflation. Note that the 'artist' is the name of the
3758 column (or relationship) accessor, and 'name' is the name of the column
3759 accessor in the related table.
3761 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3762 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3763 unary plus operator before it.
3765 =head2 include_columns
3769 =item Value: \@columns
3773 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3779 =item Value: \@select_columns
3783 Indicates which columns should be selected from the storage. You can use
3784 column names, or in the case of RDBMS back ends, function or stored procedure
3787 $rs = $schema->resultset('Employee')->search(undef, {
3790 { count => 'employeeid' },
3791 { max => { length => 'name' }, -as => 'longest_name' }
3796 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3798 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3799 use L</select>, to instruct DBIx::Class how to store the result of the column.
3800 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3801 identifier aliasing. You can however alias a function, so you can use it in
3802 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3803 attribute> supplied as shown in the example above.
3805 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3806 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3807 unary plus operator before it.
3813 Indicates additional columns to be selected from storage. Works the same as
3814 L</select> but adds columns to the default selection, instead of specifying
3823 Indicates additional column names for those added via L</+select>. See L</as>.
3831 =item Value: \@inflation_names
3835 Indicates column names for object inflation. That is L</as> indicates the
3836 slot name in which the column value will be stored within the
3837 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3838 identifier by the C<get_column> method (or via the object accessor B<if one
3839 with the same name already exists>) as shown below. The L</as> attribute has
3840 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3842 $rs = $schema->resultset('Employee')->search(undef, {
3845 { count => 'employeeid' },
3846 { max => { length => 'name' }, -as => 'longest_name' }
3855 If the object against which the search is performed already has an accessor
3856 matching a column name specified in C<as>, the value can be retrieved using
3857 the accessor as normal:
3859 my $name = $employee->name();
3861 If on the other hand an accessor does not exist in the object, you need to
3862 use C<get_column> instead:
3864 my $employee_count = $employee->get_column('employee_count');
3866 You can create your own accessors if required - see
3867 L<DBIx::Class::Manual::Cookbook> for details.
3873 =item Value: ($rel_name | \@rel_names | \%rel_names)
3877 Contains a list of relationships that should be joined for this query. For
3880 # Get CDs by Nine Inch Nails
3881 my $rs = $schema->resultset('CD')->search(
3882 { 'artist.name' => 'Nine Inch Nails' },
3883 { join => 'artist' }
3886 Can also contain a hash reference to refer to the other relation's relations.
3889 package MyApp::Schema::Track;
3890 use base qw/DBIx::Class/;
3891 __PACKAGE__->table('track');
3892 __PACKAGE__->add_columns(qw/trackid cd position title/);
3893 __PACKAGE__->set_primary_key('trackid');
3894 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3897 # In your application
3898 my $rs = $schema->resultset('Artist')->search(
3899 { 'track.title' => 'Teardrop' },
3901 join => { cd => 'track' },
3902 order_by => 'artist.name',
3906 You need to use the relationship (not the table) name in conditions,
3907 because they are aliased as such. The current table is aliased as "me", so
3908 you need to use me.column_name in order to avoid ambiguity. For example:
3910 # Get CDs from 1984 with a 'Foo' track
3911 my $rs = $schema->resultset('CD')->search(
3914 'tracks.name' => 'Foo'
3916 { join => 'tracks' }
3919 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3920 similarly for a third time). For e.g.
3922 my $rs = $schema->resultset('Artist')->search({
3923 'cds.title' => 'Down to Earth',
3924 'cds_2.title' => 'Popular',
3926 join => [ qw/cds cds/ ],
3929 will return a set of all artists that have both a cd with title 'Down
3930 to Earth' and a cd with title 'Popular'.
3932 If you want to fetch related objects from other tables as well, see C<prefetch>
3935 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3941 =item Value: ($rel_name | \@rel_names | \%rel_names)
3945 Contains one or more relationships that should be fetched along with
3946 the main query (when they are accessed afterwards the data will
3947 already be available, without extra queries to the database). This is
3948 useful for when you know you will need the related objects, because it
3949 saves at least one query:
3951 my $rs = $schema->resultset('Tag')->search(
3960 The initial search results in SQL like the following:
3962 SELECT tag.*, cd.*, artist.* FROM tag
3963 JOIN cd ON tag.cd = cd.cdid
3964 JOIN artist ON cd.artist = artist.artistid
3966 L<DBIx::Class> has no need to go back to the database when we access the
3967 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3970 Simple prefetches will be joined automatically, so there is no need
3971 for a C<join> attribute in the above search.
3973 L</prefetch> can be used with the any of the relationship types and
3974 multiple prefetches can be specified together. Below is a more complex
3975 example that prefetches a CD's artist, its liner notes (if present),
3976 the cover image, the tracks on that cd, and the guests on those
3980 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3981 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3982 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3983 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3985 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3987 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
3990 my $rs = $schema->resultset('CD')->search(
3994 { artist => 'record_label'}, # belongs_to => belongs_to
3995 'liner_note', # might_have
3996 'cover_image', # has_one
3997 { tracks => 'guests' }, # has_many => has_many
4002 This will produce SQL like the following:
4004 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4008 ON artist.artistid = me.artistid
4009 JOIN record_label record_label
4010 ON record_label.labelid = artist.labelid
4011 LEFT JOIN track tracks
4012 ON tracks.cdid = me.cdid
4013 LEFT JOIN guest guests
4014 ON guests.trackid = track.trackid
4015 LEFT JOIN liner_notes liner_note
4016 ON liner_note.cdid = me.cdid
4017 JOIN cd_artwork cover_image
4018 ON cover_image.cdid = me.cdid
4021 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4022 C<tracks>, and C<guests> of the CD will all be available through the
4023 relationship accessors without the need for additional queries to the
4026 However, there is one caveat to be observed: it can be dangerous to
4027 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4028 relationship on a given level. e.g.:
4030 my $rs = $schema->resultset('CD')->search(
4034 'tracks', # has_many
4035 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4040 In fact, C<DBIx::Class> will emit the following warning:
4042 Prefetching multiple has_many rels tracks and cd_to_producer at top
4043 level will explode the number of row objects retrievable via ->next
4044 or ->all. Use at your own risk.
4046 The collapser currently can't identify duplicate tuples for multiple
4047 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4048 result the second L<has_many|DBIx::Class::Relationship/has_many>
4049 relation could contain redundant objects.
4051 =head3 Using L</prefetch> with L</join>
4053 L</prefetch> implies a L</join> with the equivalent argument, and is
4054 properly merged with any existing L</join> specification. So the
4057 my $rs = $schema->resultset('CD')->search(
4058 {'record_label.name' => 'Music Product Ltd.'},
4060 join => {artist => 'record_label'},
4061 prefetch => 'artist',
4065 ... will work, searching on the record label's name, but only
4066 prefetching the C<artist>.
4068 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4070 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4071 prefetched relations. So given:
4073 my $rs = $schema->resultset('CD')->search(
4076 select => ['cd.title'],
4078 prefetch => 'artist',
4082 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4083 becomes: C<'cd_title', 'artist.*'>.
4087 Prefetch does a lot of deep magic. As such, it may not behave exactly
4088 as you might expect.
4094 Prefetch uses the L</cache> to populate the prefetched relationships. This
4095 may or may not be what you want.
4099 If you specify a condition on a prefetched relationship, ONLY those
4100 rows that match the prefetched condition will be fetched into that relationship.
4101 This means that adding prefetch to a search() B<may alter> what is returned by
4102 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4104 my $artist_rs = $schema->resultset('Artist')->search({
4110 my $count = $artist_rs->first->cds->count;
4112 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4114 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4116 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4118 that cmp_ok() may or may not pass depending on the datasets involved. This
4119 behavior may or may not survive the 0.09 transition.
4131 Makes the resultset paged and specifies the page to retrieve. Effectively
4132 identical to creating a non-pages resultset and then calling ->page($page)
4135 If L</rows> attribute is not specified it defaults to 10 rows per page.
4137 When you have a paged resultset, L</count> will only return the number
4138 of rows in the page. To get the total, use the L</pager> and call
4139 C<total_entries> on it.
4149 Specifies the maximum number of rows for direct retrieval or the number of
4150 rows per page if the page attribute or method is used.
4156 =item Value: $offset
4160 Specifies the (zero-based) row number for the first row to be returned, or the
4161 of the first row of the first page if paging is used.
4167 =item Value: \@columns
4171 A arrayref of columns to group by. Can include columns of joined tables.
4173 group_by => [qw/ column1 column2 ... /]
4179 =item Value: $condition
4183 HAVING is a select statement attribute that is applied between GROUP BY and
4184 ORDER BY. It is applied to the after the grouping calculations have been
4187 having => { 'count_employee' => { '>=', 100 } }
4189 or with an in-place function in which case literal SQL is required:
4191 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4197 =item Value: (0 | 1)
4201 Set to 1 to group by all columns. If the resultset already has a group_by
4202 attribute, this setting is ignored and an appropriate warning is issued.
4208 Adds to the WHERE clause.
4210 # only return rows WHERE deleted IS NULL for all searches
4211 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4213 Can be overridden by passing C<< { where => undef } >> as an attribute
4220 Set to 1 to cache search results. This prevents extra SQL queries if you
4221 revisit rows in your ResultSet:
4223 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4225 while( my $artist = $resultset->next ) {
4229 $rs->first; # without cache, this would issue a query
4231 By default, searches are not cached.
4233 For more examples of using these attributes, see
4234 L<DBIx::Class::Manual::Cookbook>.
4240 =item Value: ( 'update' | 'shared' )
4244 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT