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>
255 and its extension L<DBIx::Class::SQLMaker>.
257 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
261 Note that L</search> does not process/deflate any of the values passed in the
262 L<SQL::Abstract>-compatible search condition structure. This is unlike other
263 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
264 manually that any value passed to this method will stringify to something the
265 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
266 objects, for more info see:
267 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
273 my $rs = $self->search_rs( @_ );
278 elsif (defined wantarray) {
282 # we can be called by a relationship helper, which in
283 # turn may be called in void context due to some braindead
284 # overload or whatever else the user decided to be clever
285 # at this particular day. Thus limit the exception to
286 # external code calls only
287 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
288 if (caller)[0] !~ /^\QDBIx::Class::/;
298 =item Arguments: $cond, \%attrs?
300 =item Return Value: $resultset
304 This method does the same exact thing as search() except it will
305 always return a resultset, even in list context.
312 # Special-case handling for (undef, undef).
313 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
319 if (ref $_[-1] eq 'HASH') {
320 # copy for _normalize_selection
321 $call_attrs = { %{ pop @_ } };
323 elsif (! defined $_[-1] ) {
324 pop @_; # search({}, undef)
328 # see if we can keep the cache (no $rs changes)
330 my %safe = (alias => 1, cache => 1);
331 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
334 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
336 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
338 $cache = $self->get_cache;
341 my $rsrc = $self->result_source;
343 my $old_attrs = { %{$self->{attrs}} };
344 my $old_having = delete $old_attrs->{having};
345 my $old_where = delete $old_attrs->{where};
347 my $new_attrs = { %$old_attrs };
349 # take care of call attrs (only if anything is changing)
350 if (keys %$call_attrs) {
352 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
354 # reset the current selector list if new selectors are supplied
355 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
356 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
359 # Normalize the new selector list (operates on the passed-in attr structure)
360 # Need to do it on every chain instead of only once on _resolved_attrs, in
361 # order to allow detection of empty vs partial 'as'
362 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
363 if $old_attrs->{_dark_selector};
364 $self->_normalize_selection ($call_attrs);
366 # start with blind overwriting merge, exclude selector attrs
367 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
368 delete @{$new_attrs}{@selector_attrs};
370 for (@selector_attrs) {
371 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
372 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
375 # older deprecated name, use only if {columns} is not there
376 if (my $c = delete $new_attrs->{cols}) {
377 if ($new_attrs->{columns}) {
378 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
381 $new_attrs->{columns} = $c;
386 # join/prefetch use their own crazy merging heuristics
387 foreach my $key (qw/join prefetch/) {
388 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
389 if exists $call_attrs->{$key};
392 # stack binds together
393 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
397 # rip apart the rest of @_, parse a condition
400 if (ref $_[0] eq 'HASH') {
401 (keys %{$_[0]}) ? $_[0] : undef
407 $self->throw_exception('Odd number of arguments to search')
415 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
416 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
419 for ($old_where, $call_cond) {
421 $new_attrs->{where} = $self->_stack_cond (
422 $_, $new_attrs->{where}
427 if (defined $old_having) {
428 $new_attrs->{having} = $self->_stack_cond (
429 $old_having, $new_attrs->{having}
433 my $rs = (ref $self)->new($rsrc, $new_attrs);
435 $rs->set_cache($cache) if ($cache);
441 sub _normalize_selection {
442 my ($self, $attrs) = @_;
445 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
446 if exists $attrs->{include_columns};
448 # columns are always placed first, however
450 # Keep the X vs +X separation until _resolved_attrs time - this allows to
451 # delay the decision on whether to use a default select list ($rsrc->columns)
452 # allowing stuff like the remove_columns helper to work
454 # select/as +select/+as pairs need special handling - the amount of select/as
455 # elements in each pair does *not* have to be equal (think multicolumn
456 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
457 # supplied at all) - try to infer the alias, either from the -as parameter
458 # of the selector spec, or use the parameter whole if it looks like a column
459 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
460 # is ok as well), but make sure no more additions to the 'as' chain take place
461 for my $pref ('', '+') {
463 my ($sel, $as) = map {
464 my $key = "${pref}${_}";
466 my $val = [ ref $attrs->{$key} eq 'ARRAY'
468 : $attrs->{$key} || ()
470 delete $attrs->{$key};
474 if (! @$as and ! @$sel ) {
477 elsif (@$as and ! @$sel) {
478 $self->throw_exception(
479 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
483 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
484 # if any @$as has been supplied we assume the user knows what (s)he is doing
485 # and blindly keep stacking up pieces
486 unless ($attrs->{_dark_selector}) {
489 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
490 push @$as, $_->{-as};
492 # assume any plain no-space, no-parenthesis string to be a column spec
493 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
494 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
497 # if all else fails - raise a flag that no more aliasing will be allowed
499 $attrs->{_dark_selector} = {
501 string => ($dark_sel_dumper ||= do {
502 require Data::Dumper::Concise;
503 Data::Dumper::Concise::DumperObject()->Indent(0);
504 })->Values([$_])->Dump
512 elsif (@$as < @$sel) {
513 $self->throw_exception(
514 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
517 elsif ($pref and $attrs->{_dark_selector}) {
518 $self->throw_exception(
519 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
525 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
526 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
531 my ($self, $left, $right) = @_;
532 if (defined $left xor defined $right) {
533 return defined $left ? $left : $right;
535 elsif (defined $left) {
536 return { -and => [ map
537 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
545 =head2 search_literal
549 =item Arguments: $sql_fragment, @bind_values
551 =item Return Value: $resultset (scalar context) || @row_objs (list context)
555 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
556 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
558 Pass a literal chunk of SQL to be added to the conditional part of the
561 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
562 only be used in that context. C<search_literal> is a convenience method.
563 It is equivalent to calling $schema->search(\[]), but if you want to ensure
564 columns are bound correctly, use C<search>.
566 Example of how to use C<search> instead of C<search_literal>
568 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
569 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
572 See L<DBIx::Class::Manual::Cookbook/Searching> and
573 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
574 require C<search_literal>.
579 my ($self, $sql, @bind) = @_;
581 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
584 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
591 =item Arguments: \%columns_values | @pk_values, \%attrs?
593 =item Return Value: $row_object | undef
597 Finds and returns a single row based on supplied criteria. Takes either a
598 hashref with the same format as L</create> (including inference of foreign
599 keys from related objects), or a list of primary key values in the same
600 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
601 declaration on the L</result_source>.
603 In either case an attempt is made to combine conditions already existing on
604 the resultset with the condition passed to this method.
606 To aid with preparing the correct query for the storage you may supply the
607 C<key> attribute, which is the name of a
608 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
609 unique constraint corresponding to the
610 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
611 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
612 to construct a query that satisfies the named unique constraint fully (
613 non-NULL values for each column member of the constraint) an exception is
616 If no C<key> is specified, the search is carried over all unique constraints
617 which are fully defined by the available condition.
619 If no such constraint is found, C<find> currently defaults to a simple
620 C<< search->(\%column_values) >> which may or may not do what you expect.
621 Note that this fallback behavior may be deprecated in further versions. If
622 you need to search with arbitrary conditions - use L</search>. If the query
623 resulting from this fallback produces more than one row, a warning to the
624 effect is issued, though only the first row is constructed and returned as
627 In addition to C<key>, L</find> recognizes and applies standard
628 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
630 Note that if you have extra concerns about the correctness of the resulting
631 query you need to specify the C<key> attribute and supply the entire condition
632 as an argument to find (since it is not always possible to perform the
633 combination of the resultset condition with the supplied one, especially if
634 the resultset condition contains literal sql).
636 For example, to find a row by its primary key:
638 my $cd = $schema->resultset('CD')->find(5);
640 You can also find a row by a specific unique constraint:
642 my $cd = $schema->resultset('CD')->find(
644 artist => 'Massive Attack',
645 title => 'Mezzanine',
647 { key => 'cd_artist_title' }
650 See also L</find_or_create> and L</update_or_create>.
656 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
658 my $rsrc = $self->result_source;
660 # Parse out the condition from input
662 if (ref $_[0] eq 'HASH') {
663 $call_cond = { %{$_[0]} };
666 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
667 my @c_cols = $rsrc->unique_constraint_columns($constraint);
669 $self->throw_exception(
670 "No constraint columns, maybe a malformed '$constraint' constraint?"
673 $self->throw_exception (
674 'find() expects either a column/value hashref, or a list of values '
675 . "corresponding to the columns of the specified unique constraint '$constraint'"
676 ) unless @c_cols == @_;
679 @{$call_cond}{@c_cols} = @_;
683 for my $key (keys %$call_cond) {
685 my $keyref = ref($call_cond->{$key})
687 my $relinfo = $rsrc->relationship_info($key)
689 my $val = delete $call_cond->{$key};
691 next if $keyref eq 'ARRAY'; # has_many for multi_create
693 my $rel_q = $rsrc->_resolve_condition(
694 $relinfo->{cond}, $val, $key, $key
696 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
697 @related{keys %$rel_q} = values %$rel_q;
701 # relationship conditions take precedence (?)
702 @{$call_cond}{keys %related} = values %related;
704 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
706 if (exists $attrs->{key}) {
707 $final_cond = $self->_qualify_cond_columns (
709 $self->_build_unique_cond (
717 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
718 # This means that we got here after a merger of relationship conditions
719 # in ::Relationship::Base::search_related (the row method), and furthermore
720 # the relationship is of the 'single' type. This means that the condition
721 # provided by the relationship (already attached to $self) is sufficient,
722 # as there can be only one row in the database that would satisfy the
726 # no key was specified - fall down to heuristics mode:
727 # run through all unique queries registered on the resultset, and
728 # 'OR' all qualifying queries together
729 my (@unique_queries, %seen_column_combinations);
730 for my $c_name ($rsrc->unique_constraint_names) {
731 next if $seen_column_combinations{
732 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
735 push @unique_queries, try {
736 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
740 $final_cond = @unique_queries
741 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
742 : $self->_non_unique_find_fallback ($call_cond, $attrs)
746 # Run the query, passing the result_class since it should propagate for find
747 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
748 if (keys %{$rs->_resolved_attrs->{collapse}}) {
750 carp "Query returned more than one row" if $rs->next;
758 # This is a stop-gap method as agreed during the discussion on find() cleanup:
759 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
761 # It is invoked when find() is called in legacy-mode with insufficiently-unique
762 # condition. It is provided for overrides until a saner way forward is devised
764 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
765 # the road. Please adjust your tests accordingly to catch this situation early
766 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
768 # The method will not be removed without an adequately complete replacement
769 # for strict-mode enforcement
770 sub _non_unique_find_fallback {
771 my ($self, $cond, $attrs) = @_;
773 return $self->_qualify_cond_columns(
775 exists $attrs->{alias}
777 : $self->{attrs}{alias}
782 sub _qualify_cond_columns {
783 my ($self, $cond, $alias) = @_;
785 my %aliased = %$cond;
786 for (keys %aliased) {
787 $aliased{"$alias.$_"} = delete $aliased{$_}
794 sub _build_unique_cond {
795 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
797 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
799 # combination may fail if $self->{cond} is non-trivial
800 my ($final_cond) = try {
801 $self->_merge_with_rscond ($extra_cond)
806 # trim out everything not in $columns
807 $final_cond = { map {
808 exists $final_cond->{$_}
809 ? ( $_ => $final_cond->{$_} )
813 if (my @missing = grep
814 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
817 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
819 join (', ', map { "'$_'" } @missing),
826 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
828 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
830 carp_unique ( sprintf (
831 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
832 . 'values in column(s): %s). This is almost certainly not what you wanted, '
833 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
835 join (', ', map { "'$_'" } @undefs),
842 =head2 search_related
846 =item Arguments: $rel, $cond, \%attrs?
848 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
852 $new_rs = $cd_rs->search_related('artist', {
856 Searches the specified relationship, optionally specifying a condition and
857 attributes for matching records. See L</ATTRIBUTES> for more information.
859 In list context, C<< ->all() >> is called implicitly on the resultset, thus
860 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
862 See also L</search_related_rs>.
867 return shift->related_resultset(shift)->search(@_);
870 =head2 search_related_rs
872 This method works exactly the same as search_related, except that
873 it guarantees a resultset, even in list context.
877 sub search_related_rs {
878 return shift->related_resultset(shift)->search_rs(@_);
885 =item Arguments: none
887 =item Return Value: $cursor
891 Returns a storage-driven cursor to the given resultset. See
892 L<DBIx::Class::Cursor> for more information.
899 my $attrs = $self->_resolved_attrs_copy;
901 return $self->{cursor}
902 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
903 $attrs->{where},$attrs);
910 =item Arguments: $cond?
912 =item Return Value: $row_object | undef
916 my $cd = $schema->resultset('CD')->single({ year => 2001 });
918 Inflates the first result without creating a cursor if the resultset has
919 any records in it; if not returns C<undef>. Used by L</find> as a lean version
922 While this method can take an optional search condition (just like L</search>)
923 being a fast-code-path it does not recognize search attributes. If you need to
924 add extra joins or similar, call L</search> and then chain-call L</single> on the
925 L<DBIx::Class::ResultSet> returned.
931 As of 0.08100, this method enforces the assumption that the preceding
932 query returns only one row. If more than one row is returned, you will receive
935 Query returned more than one row
937 In this case, you should be using L</next> or L</find> instead, or if you really
938 know what you are doing, use the L</rows> attribute to explicitly limit the size
941 This method will also throw an exception if it is called on a resultset prefetching
942 has_many, as such a prefetch implies fetching multiple rows from the database in
943 order to assemble the resulting object.
950 my ($self, $where) = @_;
952 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
955 my $attrs = $self->_resolved_attrs_copy;
957 if (keys %{$attrs->{collapse}}) {
958 $self->throw_exception(
959 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
964 if (defined $attrs->{where}) {
967 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
968 $where, delete $attrs->{where} ]
971 $attrs->{where} = $where;
975 my @data = $self->result_source->storage->select_single(
976 $attrs->{from}, $attrs->{select},
977 $attrs->{where}, $attrs
980 return (@data ? ($self->_construct_object(@data))[0] : undef);
986 # Recursively collapse the query, accumulating values for each column.
988 sub _collapse_query {
989 my ($self, $query, $collapsed) = @_;
993 if (ref $query eq 'ARRAY') {
994 foreach my $subquery (@$query) {
995 next unless ref $subquery; # -or
996 $collapsed = $self->_collapse_query($subquery, $collapsed);
999 elsif (ref $query eq 'HASH') {
1000 if (keys %$query and (keys %$query)[0] eq '-and') {
1001 foreach my $subquery (@{$query->{-and}}) {
1002 $collapsed = $self->_collapse_query($subquery, $collapsed);
1006 foreach my $col (keys %$query) {
1007 my $value = $query->{$col};
1008 $collapsed->{$col}{$value}++;
1020 =item Arguments: $cond?
1022 =item Return Value: $resultsetcolumn
1026 my $max_length = $rs->get_column('length')->max;
1028 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1033 my ($self, $column) = @_;
1034 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1042 =item Arguments: $cond, \%attrs?
1044 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1048 # WHERE title LIKE '%blue%'
1049 $cd_rs = $rs->search_like({ title => '%blue%'});
1051 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1052 that this is simply a convenience method retained for ex Class::DBI users.
1053 You most likely want to use L</search> with specific operators.
1055 For more information, see L<DBIx::Class::Manual::Cookbook>.
1057 This method is deprecated and will be removed in 0.09. Use L</search()>
1058 instead. An example conversion is:
1060 ->search_like({ foo => 'bar' });
1064 ->search({ foo => { like => 'bar' } });
1071 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1072 .' Instead use ->search({ x => { -like => "y%" } })'
1073 .' (note the outer pair of {}s - they are important!)'
1075 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1076 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1077 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1078 return $class->search($query, { %$attrs });
1085 =item Arguments: $first, $last
1087 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1091 Returns a resultset or object list representing a subset of elements from the
1092 resultset slice is called on. Indexes are from 0, i.e., to get the first
1093 three records, call:
1095 my ($one, $two, $three) = $rs->slice(0, 2);
1100 my ($self, $min, $max) = @_;
1101 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1102 $attrs->{offset} = $self->{attrs}{offset} || 0;
1103 $attrs->{offset} += $min;
1104 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1105 return $self->search(undef, $attrs);
1106 #my $slice = (ref $self)->new($self->result_source, $attrs);
1107 #return (wantarray ? $slice->all : $slice);
1114 =item Arguments: none
1116 =item Return Value: $result | undef
1120 Returns the next element in the resultset (C<undef> is there is none).
1122 Can be used to efficiently iterate over records in the resultset:
1124 my $rs = $schema->resultset('CD')->search;
1125 while (my $cd = $rs->next) {
1129 Note that you need to store the resultset object, and call C<next> on it.
1130 Calling C<< resultset('Table')->next >> repeatedly will always return the
1131 first record from the resultset.
1137 if (my $cache = $self->get_cache) {
1138 $self->{all_cache_position} ||= 0;
1139 return $cache->[$self->{all_cache_position}++];
1141 if ($self->{attrs}{cache}) {
1142 delete $self->{pager};
1143 $self->{all_cache_position} = 1;
1144 return ($self->all)[0];
1146 if ($self->{stashed_objects}) {
1147 my $obj = shift(@{$self->{stashed_objects}});
1148 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1152 exists $self->{stashed_row}
1153 ? @{delete $self->{stashed_row}}
1154 : $self->cursor->next
1156 return undef unless (@row);
1157 my ($row, @more) = $self->_construct_object(@row);
1158 $self->{stashed_objects} = \@more if @more;
1162 sub _construct_object {
1163 my ($self, @row) = @_;
1165 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1167 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1168 @new = $self->{_attrs}{record_filter}->(@new)
1169 if exists $self->{_attrs}{record_filter};
1173 sub _collapse_result {
1174 my ($self, $as_proto, $row) = @_;
1178 # 'foo' => [ undef, 'foo' ]
1179 # 'foo.bar' => [ 'foo', 'bar' ]
1180 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1182 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1184 my %collapse = %{$self->{_attrs}{collapse}||{}};
1188 # if we're doing collapsing (has_many prefetch) we need to grab records
1189 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1190 # we know we don't have to bother.
1192 # the reason for not using the collapse stuff directly is because if you
1193 # had for e.g. two artists in a row with no cds, the collapse info for
1194 # both would be NULL (undef) so you'd lose the second artist
1196 # store just the index so we can check the array positions from the row
1197 # without having to contruct the full hash
1199 if (keys %collapse) {
1200 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1201 foreach my $i (0 .. $#construct_as) {
1202 next if defined($construct_as[$i][0]); # only self table
1203 if (delete $pri{$construct_as[$i][1]}) {
1204 push(@pri_index, $i);
1206 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1210 # no need to do an if, it'll be empty if @pri_index is empty anyway
1212 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1216 do { # no need to check anything at the front, we always want the first row
1220 foreach my $this_as (@construct_as) {
1221 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1224 push(@const_rows, \%const);
1226 } until ( # no pri_index => no collapse => drop straight out
1229 do { # get another row, stash it, drop out if different PK
1231 @copy = $self->cursor->next;
1232 $self->{stashed_row} = \@copy;
1234 # last thing in do block, counts as true if anything doesn't match
1236 # check xor defined first for NULL vs. NOT NULL then if one is
1237 # defined the other must be so check string equality
1240 (defined $pri_vals{$_} ^ defined $copy[$_])
1241 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1246 my $alias = $self->{attrs}{alias};
1253 foreach my $const (@const_rows) {
1254 scalar @const_keys or do {
1255 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1257 foreach my $key (@const_keys) {
1260 my @parts = split(/\./, $key);
1262 my $data = $const->{$key};
1263 foreach my $p (@parts) {
1264 $target = $target->[1]->{$p} ||= [];
1266 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1267 # collapsing at this point and on final part
1268 my $pos = $collapse_pos{$cur};
1269 CK: foreach my $ck (@ckey) {
1270 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1271 $collapse_pos{$cur} = $data;
1272 delete @collapse_pos{ # clear all positioning for sub-entries
1273 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1280 if (exists $collapse{$cur}) {
1281 $target = $target->[-1];
1284 $target->[0] = $data;
1286 $info->[0] = $const->{$key};
1294 =head2 result_source
1298 =item Arguments: $result_source?
1300 =item Return Value: $result_source
1304 An accessor for the primary ResultSource object from which this ResultSet
1311 =item Arguments: $result_class?
1313 =item Return Value: $result_class
1317 An accessor for the class to use when creating row objects. Defaults to
1318 C<< result_source->result_class >> - which in most cases is the name of the
1319 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1321 Note that changing the result_class will also remove any components
1322 that were originally loaded in the source class via
1323 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1324 in the original source class will not run.
1329 my ($self, $result_class) = @_;
1330 if ($result_class) {
1331 unless (ref $result_class) { # don't fire this for an object
1332 $self->ensure_class_loaded($result_class);
1334 $self->_result_class($result_class);
1335 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1336 # permit the user to set result class on one result set only; it only
1337 # chains if provided to search()
1338 #$self->{attrs}{result_class} = $result_class if ref $self;
1340 $self->_result_class;
1347 =item Arguments: $cond, \%attrs??
1349 =item Return Value: $count
1353 Performs an SQL C<COUNT> with the same query as the resultset was built
1354 with to find the number of elements. Passing arguments is equivalent to
1355 C<< $rs->search ($cond, \%attrs)->count >>
1361 return $self->search(@_)->count if @_ and defined $_[0];
1362 return scalar @{ $self->get_cache } if $self->get_cache;
1364 my $attrs = $self->_resolved_attrs_copy;
1366 # this is a little optimization - it is faster to do the limit
1367 # adjustments in software, instead of a subquery
1368 my $rows = delete $attrs->{rows};
1369 my $offset = delete $attrs->{offset};
1372 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1373 $crs = $self->_count_subq_rs ($attrs);
1376 $crs = $self->_count_rs ($attrs);
1378 my $count = $crs->next;
1380 $count -= $offset if $offset;
1381 $count = $rows if $rows and $rows < $count;
1382 $count = 0 if ($count < 0);
1391 =item Arguments: $cond, \%attrs??
1393 =item Return Value: $count_rs
1397 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1398 This can be very handy for subqueries:
1400 ->search( { amount => $some_rs->count_rs->as_query } )
1402 As with regular resultsets the SQL query will be executed only after
1403 the resultset is accessed via L</next> or L</all>. That would return
1404 the same single value obtainable via L</count>.
1410 return $self->search(@_)->count_rs if @_;
1412 # this may look like a lack of abstraction (count() does about the same)
1413 # but in fact an _rs *must* use a subquery for the limits, as the
1414 # software based limiting can not be ported if this $rs is to be used
1415 # in a subquery itself (i.e. ->as_query)
1416 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1417 return $self->_count_subq_rs;
1420 return $self->_count_rs;
1425 # returns a ResultSetColumn object tied to the count query
1428 my ($self, $attrs) = @_;
1430 my $rsrc = $self->result_source;
1431 $attrs ||= $self->_resolved_attrs;
1433 my $tmp_attrs = { %$attrs };
1434 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1435 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1437 # overwrite the selector (supplied by the storage)
1438 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1439 $tmp_attrs->{as} = 'count';
1440 delete @{$tmp_attrs}{qw/columns/};
1442 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1448 # same as above but uses a subquery
1450 sub _count_subq_rs {
1451 my ($self, $attrs) = @_;
1453 my $rsrc = $self->result_source;
1454 $attrs ||= $self->_resolved_attrs;
1456 my $sub_attrs = { %$attrs };
1457 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1458 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1460 # if we multi-prefetch we group_by primary keys only as this is what we would
1461 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1462 if ( keys %{$attrs->{collapse}} ) {
1463 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1466 # Calculate subquery selector
1467 if (my $g = $sub_attrs->{group_by}) {
1469 my $sql_maker = $rsrc->storage->sql_maker;
1471 # necessary as the group_by may refer to aliased functions
1473 for my $sel (@{$attrs->{select}}) {
1474 $sel_index->{$sel->{-as}} = $sel
1475 if (ref $sel eq 'HASH' and $sel->{-as});
1478 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1479 # also look for named aggregates referred in the having clause
1480 # having often contains scalarrefs - thus parse it out entirely
1482 if ($attrs->{having}) {
1483 local $sql_maker->{having_bind};
1484 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1485 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1486 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1487 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1488 # if we don't unset it we screw up retarded but unfortunately working
1489 # 'MAX(foo.bar)' => { '>', 3 }
1490 $sql_maker->{name_sep} = '';
1493 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1495 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1497 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1498 # and if all fails for an utterly naive quoted scalar-with-function
1500 $rquote $sep $lquote (.+?) $rquote
1502 [\s,] \w+ \. (\w+) [\s,]
1504 [\s,] $lquote (.+?) $rquote [\s,]
1506 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1511 my $colpiece = $sel_index->{$_} || $_;
1513 # unqualify join-based group_by's. Arcane but possible query
1514 # also horrible horrible hack to alias a column (not a func.)
1515 # (probably need to introduce SQLA syntax)
1516 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1519 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1521 push @{$sub_attrs->{select}}, $colpiece;
1525 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1526 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1529 return $rsrc->resultset_class
1530 ->new ($rsrc, $sub_attrs)
1532 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1533 ->get_column ('count');
1540 =head2 count_literal
1544 =item Arguments: $sql_fragment, @bind_values
1546 =item Return Value: $count
1550 Counts the results in a literal query. Equivalent to calling L</search_literal>
1551 with the passed arguments, then L</count>.
1555 sub count_literal { shift->search_literal(@_)->count; }
1561 =item Arguments: none
1563 =item Return Value: @objects
1567 Returns all elements in the resultset.
1574 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1577 return @{ $self->get_cache } if $self->get_cache;
1581 if (keys %{$self->_resolved_attrs->{collapse}}) {
1582 # Using $self->cursor->all is really just an optimisation.
1583 # If we're collapsing has_many prefetches it probably makes
1584 # very little difference, and this is cleaner than hacking
1585 # _construct_object to survive the approach
1586 $self->cursor->reset;
1587 my @row = $self->cursor->next;
1589 push(@obj, $self->_construct_object(@row));
1590 @row = (exists $self->{stashed_row}
1591 ? @{delete $self->{stashed_row}}
1592 : $self->cursor->next);
1595 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1598 $self->set_cache(\@obj) if $self->{attrs}{cache};
1607 =item Arguments: none
1609 =item Return Value: $self
1613 Resets the resultset's cursor, so you can iterate through the elements again.
1614 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1621 delete $self->{_attrs} if exists $self->{_attrs};
1622 $self->{all_cache_position} = 0;
1623 $self->cursor->reset;
1631 =item Arguments: none
1633 =item Return Value: $object | undef
1637 Resets the resultset and returns an object for the first result (or C<undef>
1638 if the resultset is empty).
1643 return $_[0]->reset->next;
1649 # Determines whether and what type of subquery is required for the $rs operation.
1650 # If grouping is necessary either supplies its own, or verifies the current one
1651 # After all is done delegates to the proper storage method.
1653 sub _rs_update_delete {
1654 my ($self, $op, $values) = @_;
1656 my $rsrc = $self->result_source;
1658 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1659 my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
1661 if ($needs_group_by_subq or $needs_subq) {
1663 # make a new $rs selecting only the PKs (that's all we really need)
1664 my $attrs = $self->_resolved_attrs_copy;
1667 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1668 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1670 if ($needs_group_by_subq) {
1671 # make sure no group_by was supplied, or if there is one - make sure it matches
1672 # the columns compiled above perfectly. Anything else can not be sanely executed
1673 # on most databases so croak right then and there
1675 if (my $g = $attrs->{group_by}) {
1676 my @current_group_by = map
1677 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1682 join ("\x00", sort @current_group_by)
1684 join ("\x00", sort @{$attrs->{columns}} )
1686 $self->throw_exception (
1687 "You have just attempted a $op operation on a resultset which does group_by"
1688 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1689 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1690 . ' kind of queries. Please retry the operation with a modified group_by or'
1691 . ' without using one at all.'
1696 $attrs->{group_by} = $attrs->{columns};
1700 my $subrs = (ref $self)->new($rsrc, $attrs);
1701 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1704 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1705 # a condition containing 'me' or other table prefixes will not work
1706 # at all. What this code tries to do (badly) is to generate a condition
1707 # with the qualifiers removed, by exploiting the quote mechanism of sqla
1709 # this is atrocious and should be replaced by normal sqla introspection
1711 my ($sql, @bind) = do {
1712 my $sqla = $rsrc->storage->sql_maker;
1713 local $sqla->{_dequalify_idents} = 1;
1714 $sqla->_recurse_where($self->{cond});
1717 return $rsrc->storage->$op(
1719 $op eq 'update' ? $values : (),
1720 $self->{cond} ? \[$sql, @bind] : (),
1729 =item Arguments: \%values
1731 =item Return Value: $storage_rv
1735 Sets the specified columns in the resultset to the supplied values in a
1736 single query. Note that this will not run any accessor/set_column/update
1737 triggers, nor will it update any row object instances derived from this
1738 resultset (this includes the contents of the L<resultset cache|/set_cache>
1739 if any). See L</update_all> if you need to execute any on-update
1740 triggers or cascades defined either by you or a
1741 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1743 The return value is a pass through of what the underlying
1744 storage backend returned, and may vary. See L<DBI/execute> for the most
1749 Note that L</update> does not process/deflate any of the values passed in.
1750 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1751 ensure manually that any value passed to this method will stringify to
1752 something the RDBMS knows how to deal with. A notable example is the
1753 handling of L<DateTime> objects, for more info see:
1754 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1759 my ($self, $values) = @_;
1760 $self->throw_exception('Values for update must be a hash')
1761 unless ref $values eq 'HASH';
1763 return $self->_rs_update_delete ('update', $values);
1770 =item Arguments: \%values
1772 =item Return Value: 1
1776 Fetches all objects and updates them one at a time via
1777 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1778 triggers, while L</update> will not.
1783 my ($self, $values) = @_;
1784 $self->throw_exception('Values for update_all must be a hash')
1785 unless ref $values eq 'HASH';
1787 my $guard = $self->result_source->schema->txn_scope_guard;
1788 $_->update($values) for $self->all;
1797 =item Arguments: none
1799 =item Return Value: $storage_rv
1803 Deletes the rows matching this resultset in a single query. Note that this
1804 will not run any delete triggers, nor will it alter the
1805 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1806 derived from this resultset (this includes the contents of the
1807 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1808 execute any on-delete triggers or cascades defined either by you or a
1809 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1811 The return value is a pass through of what the underlying storage backend
1812 returned, and may vary. See L<DBI/execute> for the most common case.
1818 $self->throw_exception('delete does not accept any arguments')
1821 return $self->_rs_update_delete ('delete');
1828 =item Arguments: none
1830 =item Return Value: 1
1834 Fetches all objects and deletes them one at a time via
1835 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1836 triggers, while L</delete> will not.
1842 $self->throw_exception('delete_all does not accept any arguments')
1845 my $guard = $self->result_source->schema->txn_scope_guard;
1846 $_->delete for $self->all;
1855 =item Arguments: \@data;
1859 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1860 For the arrayref of hashrefs style each hashref should be a structure suitable
1861 for submitting to a $resultset->create(...) method.
1863 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1864 to insert the data, as this is a faster method.
1866 Otherwise, each set of data is inserted into the database using
1867 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1868 accumulated into an array. The array itself, or an array reference
1869 is returned depending on scalar or list context.
1871 Example: Assuming an Artist Class that has many CDs Classes relating:
1873 my $Artist_rs = $schema->resultset("Artist");
1875 ## Void Context Example
1876 $Artist_rs->populate([
1877 { artistid => 4, name => 'Manufactured Crap', cds => [
1878 { title => 'My First CD', year => 2006 },
1879 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1882 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1883 { title => 'My parents sold me to a record company', year => 2005 },
1884 { title => 'Why Am I So Ugly?', year => 2006 },
1885 { title => 'I Got Surgery and am now Popular', year => 2007 }
1890 ## Array Context Example
1891 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1892 { name => "Artist One"},
1893 { name => "Artist Two"},
1894 { name => "Artist Three", cds=> [
1895 { title => "First CD", year => 2007},
1896 { title => "Second CD", year => 2008},
1900 print $ArtistOne->name; ## response is 'Artist One'
1901 print $ArtistThree->cds->count ## reponse is '2'
1903 For the arrayref of arrayrefs style, the first element should be a list of the
1904 fieldsnames to which the remaining elements are rows being inserted. For
1907 $Arstist_rs->populate([
1908 [qw/artistid name/],
1909 [100, 'A Formally Unknown Singer'],
1910 [101, 'A singer that jumped the shark two albums ago'],
1911 [102, 'An actually cool singer'],
1914 Please note an important effect on your data when choosing between void and
1915 wantarray context. Since void context goes straight to C<insert_bulk> in
1916 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1917 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1918 create primary keys for you, you will find that your PKs are empty. In this
1919 case you will have to use the wantarray context in order to create those
1927 # cruft placed in standalone method
1928 my $data = $self->_normalize_populate_args(@_);
1930 if(defined wantarray) {
1932 foreach my $item (@$data) {
1933 push(@created, $self->create($item));
1935 return wantarray ? @created : \@created;
1938 my $first = $data->[0];
1940 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1941 # it relationship data
1942 my (@rels, @columns);
1943 my $rsrc = $self->result_source;
1944 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1945 for (keys %$first) {
1946 my $ref = ref $first->{$_};
1947 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1953 my @pks = $rsrc->primary_columns;
1955 ## do the belongs_to relationships
1956 foreach my $index (0..$#$data) {
1958 # delegate to create() for any dataset without primary keys with specified relationships
1959 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1961 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1962 my @ret = $self->populate($data);
1968 foreach my $rel (@rels) {
1969 next unless ref $data->[$index]->{$rel} eq "HASH";
1970 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1971 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1972 my $related = $result->result_source->_resolve_condition(
1973 $reverse_relinfo->{cond},
1979 delete $data->[$index]->{$rel};
1980 $data->[$index] = {%{$data->[$index]}, %$related};
1982 push @columns, keys %$related if $index == 0;
1986 ## inherit the data locked in the conditions of the resultset
1987 my ($rs_data) = $self->_merge_with_rscond({});
1988 delete @{$rs_data}{@columns};
1989 my @inherit_cols = keys %$rs_data;
1990 my @inherit_data = values %$rs_data;
1992 ## do bulk insert on current row
1993 $rsrc->storage->insert_bulk(
1995 [@columns, @inherit_cols],
1996 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1999 ## do the has_many relationships
2000 foreach my $item (@$data) {
2004 foreach my $rel (@rels) {
2005 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2007 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2009 my $child = $main_row->$rel;
2011 my $related = $child->result_source->_resolve_condition(
2012 $rels->{$rel}{cond},
2018 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2019 my @populate = map { {%$_, %$related} } @rows_to_add;
2021 $child->populate( \@populate );
2028 # populate() argumnets went over several incarnations
2029 # What we ultimately support is AoH
2030 sub _normalize_populate_args {
2031 my ($self, $arg) = @_;
2033 if (ref $arg eq 'ARRAY') {
2034 if (ref $arg->[0] eq 'HASH') {
2037 elsif (ref $arg->[0] eq 'ARRAY') {
2039 my @colnames = @{$arg->[0]};
2040 foreach my $values (@{$arg}[1 .. $#$arg]) {
2041 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2047 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2054 =item Arguments: none
2056 =item Return Value: $pager
2060 Return Value a L<Data::Page> object for the current resultset. Only makes
2061 sense for queries with a C<page> attribute.
2063 To get the full count of entries for a paged resultset, call
2064 C<total_entries> on the L<Data::Page> object.
2068 # make a wizard good for both a scalar and a hashref
2069 my $mk_lazy_count_wizard = sub {
2070 require Variable::Magic;
2072 my $stash = { total_rs => shift };
2073 my $slot = shift; # only used by the hashref magic
2075 my $magic = Variable::Magic::wizard (
2076 data => sub { $stash },
2082 # set value lazily, and dispell for good
2083 ${$_[0]} = $_[1]{total_rs}->count;
2084 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2088 # an explicit set implies dispell as well
2089 # the unless() is to work around "fun and giggles" below
2090 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2091 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2098 if ($_[2] eq $slot and !$_[1]{inactive}) {
2099 my $cnt = $_[1]{total_rs}->count;
2100 $_[0]->{$slot} = $cnt;
2102 # attempting to dispell in a fetch handle (works in store), seems
2103 # to invariable segfault on 5.10, 5.12, 5.13 :(
2104 # so use an inactivator instead
2105 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2111 if (! $_[1]{inactive} and $_[2] eq $slot) {
2112 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2114 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2121 $stash->{magic_selfref} = $magic;
2122 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2127 # the tie class for 5.8.1
2129 package # hide from pause
2130 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2131 use base qw/Tie::Hash/;
2133 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2134 sub NEXTKEY { each %{$_[0]{data}} }
2135 sub EXISTS { exists $_[0]{data}{$_[1]} }
2136 sub DELETE { delete $_[0]{data}{$_[1]} }
2137 sub CLEAR { %{$_[0]{data}} = () }
2138 sub SCALAR { scalar %{$_[0]{data}} }
2141 $_[1]{data} = {%{$_[1]{selfref}}};
2142 %{$_[1]{selfref}} = ();
2143 Scalar::Util::weaken ($_[1]{selfref});
2144 return bless ($_[1], $_[0]);
2148 if ($_[1] eq $_[0]{slot}) {
2149 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2150 untie %{$_[0]{selfref}};
2151 %{$_[0]{selfref}} = %{$_[0]{data}};
2160 $_[0]{data}{$_[1]} = $_[2];
2161 if ($_[1] eq $_[0]{slot}) {
2162 untie %{$_[0]{selfref}};
2163 %{$_[0]{selfref}} = %{$_[0]{data}};
2172 return $self->{pager} if $self->{pager};
2174 my $attrs = $self->{attrs};
2175 if (!defined $attrs->{page}) {
2176 $self->throw_exception("Can't create pager for non-paged rs");
2178 elsif ($attrs->{page} <= 0) {
2179 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2181 $attrs->{rows} ||= 10;
2183 # throw away the paging flags and re-run the count (possibly
2184 # with a subselect) to get the real total count
2185 my $count_attrs = { %$attrs };
2186 delete $count_attrs->{$_} for qw/rows offset page pager/;
2187 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2190 ### the following may seem awkward and dirty, but it's a thought-experiment
2191 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2192 ### before talking to ribasushi/mst
2195 my $pager = Data::Page->new(
2196 0, #start with an empty set
2198 $self->{attrs}{page},
2201 my $data_slot = 'total_entries';
2203 # Since we are interested in a cached value (once it's set - it's set), every
2204 # technique will detach from the magic-host once the time comes to fire the
2205 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2207 if ($] < 5.008003) {
2208 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2209 # to weakref the magic container :(
2211 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2212 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2215 elsif ($] < 5.010) {
2216 # We can use magic on the hash value slot. It's interesting that the magic is
2217 # attached to the hash-slot, and does *not* stop working once I do the dummy
2218 # assignments after the cast()
2219 # tested on 5.8.3 and 5.8.9
2220 my $magic = $mk_lazy_count_wizard->($total_rs);
2221 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2223 # this is for fun and giggles
2224 $pager->{$data_slot} = -1;
2225 $pager->{$data_slot} = 0;
2227 # this does not work for scalars, but works with
2229 #my %vals = %$pager;
2234 # And the uvar magic
2235 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2236 # however see the wizard maker for more notes
2237 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2238 Variable::Magic::cast ( %$pager, $magic );
2241 $pager->{$data_slot} = -1;
2242 $pager->{$data_slot} = 0;
2250 return $self->{pager} = $pager;
2257 =item Arguments: $page_number
2259 =item Return Value: $rs
2263 Returns a resultset for the $page_number page of the resultset on which page
2264 is called, where each page contains a number of rows equal to the 'rows'
2265 attribute set on the resultset (10 by default).
2270 my ($self, $page) = @_;
2271 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2278 =item Arguments: \%vals
2280 =item Return Value: $rowobject
2284 Creates a new row object in the resultset's result class and returns
2285 it. The row is not inserted into the database at this point, call
2286 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2287 will tell you whether the row object has been inserted or not.
2289 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2294 my ($self, $values) = @_;
2295 $self->throw_exception( "new_result needs a hash" )
2296 unless (ref $values eq 'HASH');
2298 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2302 @$cols_from_relations
2303 ? (-cols_from_relations => $cols_from_relations)
2305 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2308 return $self->result_class->new(\%new);
2311 # _merge_with_rscond
2313 # Takes a simple hash of K/V data and returns its copy merged with the
2314 # condition already present on the resultset. Additionally returns an
2315 # arrayref of value/condition names, which were inferred from related
2316 # objects (this is needed for in-memory related objects)
2317 sub _merge_with_rscond {
2318 my ($self, $data) = @_;
2320 my (%new_data, @cols_from_relations);
2322 my $alias = $self->{attrs}{alias};
2324 if (! defined $self->{cond}) {
2325 # just massage $data below
2327 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2328 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2329 @cols_from_relations = keys %new_data;
2331 elsif (ref $self->{cond} ne 'HASH') {
2332 $self->throw_exception(
2333 "Can't abstract implicit construct, resultset condition not a hash"
2337 # precendence must be given to passed values over values inherited from
2338 # the cond, so the order here is important.
2339 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2340 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2342 while ( my($col, $value) = each %implied ) {
2343 my $vref = ref $value;
2349 (keys %$value)[0] eq '='
2351 $new_data{$col} = $value->{'='};
2353 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2354 $new_data{$col} = $value;
2361 %{ $self->_remove_alias($data, $alias) },
2364 return (\%new_data, \@cols_from_relations);
2367 # _has_resolved_attr
2369 # determines if the resultset defines at least one
2370 # of the attributes supplied
2372 # used to determine if a subquery is neccessary
2374 # supports some virtual attributes:
2376 # This will scan for any joins being present on the resultset.
2377 # It is not a mere key-search but a deep inspection of {from}
2380 sub _has_resolved_attr {
2381 my ($self, @attr_names) = @_;
2383 my $attrs = $self->_resolved_attrs;
2387 for my $n (@attr_names) {
2388 if (grep { $n eq $_ } (qw/-join/) ) {
2389 $extra_checks{$n}++;
2393 my $attr = $attrs->{$n};
2395 next if not defined $attr;
2397 if (ref $attr eq 'HASH') {
2398 return 1 if keys %$attr;
2400 elsif (ref $attr eq 'ARRAY') {
2408 # a resolved join is expressed as a multi-level from
2410 $extra_checks{-join}
2412 ref $attrs->{from} eq 'ARRAY'
2414 @{$attrs->{from}} > 1
2422 # Recursively collapse the condition.
2424 sub _collapse_cond {
2425 my ($self, $cond, $collapsed) = @_;
2429 if (ref $cond eq 'ARRAY') {
2430 foreach my $subcond (@$cond) {
2431 next unless ref $subcond; # -or
2432 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2435 elsif (ref $cond eq 'HASH') {
2436 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2437 foreach my $subcond (@{$cond->{-and}}) {
2438 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2442 foreach my $col (keys %$cond) {
2443 my $value = $cond->{$col};
2444 $collapsed->{$col} = $value;
2454 # Remove the specified alias from the specified query hash. A copy is made so
2455 # the original query is not modified.
2458 my ($self, $query, $alias) = @_;
2460 my %orig = %{ $query || {} };
2463 foreach my $key (keys %orig) {
2465 $unaliased{$key} = $orig{$key};
2468 $unaliased{$1} = $orig{$key}
2469 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2479 =item Arguments: none
2481 =item Return Value: \[ $sql, @bind ]
2485 Returns the SQL query and bind vars associated with the invocant.
2487 This is generally used as the RHS for a subquery.
2494 my $attrs = $self->_resolved_attrs_copy;
2499 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2500 # $sql also has no wrapping parenthesis in list ctx
2502 my $sqlbind = $self->result_source->storage
2503 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2512 =item Arguments: \%vals, \%attrs?
2514 =item Return Value: $rowobject
2518 my $artist = $schema->resultset('Artist')->find_or_new(
2519 { artist => 'fred' }, { key => 'artists' });
2521 $cd->cd_to_producer->find_or_new({ producer => $producer },
2522 { key => 'primary });
2524 Find an existing record from this resultset using L</find>. if none exists,
2525 instantiate a new result object and return it. The object will not be saved
2526 into your storage until you call L<DBIx::Class::Row/insert> on it.
2528 You most likely want this method when looking for existing rows using a unique
2529 constraint that is not the primary key, or looking for related rows.
2531 If you want objects to be saved immediately, use L</find_or_create> instead.
2533 B<Note>: Make sure to read the documentation of L</find> and understand the
2534 significance of the C<key> attribute, as its lack may skew your search, and
2535 subsequently result in spurious new objects.
2537 B<Note>: Take care when using C<find_or_new> with a table having
2538 columns with default values that you intend to be automatically
2539 supplied by the database (e.g. an auto_increment primary key column).
2540 In normal usage, the value of such columns should NOT be included at
2541 all in the call to C<find_or_new>, even when set to C<undef>.
2547 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2548 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2549 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2552 return $self->new_result($hash);
2559 =item Arguments: \%vals
2561 =item Return Value: a L<DBIx::Class::Row> $object
2565 Attempt to create a single new row or a row with multiple related rows
2566 in the table represented by the resultset (and related tables). This
2567 will not check for duplicate rows before inserting, use
2568 L</find_or_create> to do that.
2570 To create one row for this resultset, pass a hashref of key/value
2571 pairs representing the columns of the table and the values you wish to
2572 store. If the appropriate relationships are set up, foreign key fields
2573 can also be passed an object representing the foreign row, and the
2574 value will be set to its primary key.
2576 To create related objects, pass a hashref of related-object column values
2577 B<keyed on the relationship name>. If the relationship is of type C<multi>
2578 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2579 The process will correctly identify columns holding foreign keys, and will
2580 transparently populate them from the keys of the corresponding relation.
2581 This can be applied recursively, and will work correctly for a structure
2582 with an arbitrary depth and width, as long as the relationships actually
2583 exists and the correct column data has been supplied.
2586 Instead of hashrefs of plain related data (key/value pairs), you may
2587 also pass new or inserted objects. New objects (not inserted yet, see
2588 L</new>), will be inserted into their appropriate tables.
2590 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2592 Example of creating a new row.
2594 $person_rs->create({
2595 name=>"Some Person",
2596 email=>"somebody@someplace.com"
2599 Example of creating a new row and also creating rows in a related C<has_many>
2600 or C<has_one> resultset. Note Arrayref.
2603 { artistid => 4, name => 'Manufactured Crap', cds => [
2604 { title => 'My First CD', year => 2006 },
2605 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2610 Example of creating a new row and also creating a row in a related
2611 C<belongs_to> resultset. Note Hashref.
2614 title=>"Music for Silly Walks",
2617 name=>"Silly Musician",
2625 When subclassing ResultSet never attempt to override this method. Since
2626 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2627 lot of the internals simply never call it, so your override will be
2628 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2629 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2630 L</create> process you need to intervene.
2637 my ($self, $attrs) = @_;
2638 $self->throw_exception( "create needs a hashref" )
2639 unless ref $attrs eq 'HASH';
2640 return $self->new_result($attrs)->insert;
2643 =head2 find_or_create
2647 =item Arguments: \%vals, \%attrs?
2649 =item Return Value: $rowobject
2653 $cd->cd_to_producer->find_or_create({ producer => $producer },
2654 { key => 'primary' });
2656 Tries to find a record based on its primary key or unique constraints; if none
2657 is found, creates one and returns that instead.
2659 my $cd = $schema->resultset('CD')->find_or_create({
2661 artist => 'Massive Attack',
2662 title => 'Mezzanine',
2666 Also takes an optional C<key> attribute, to search by a specific key or unique
2667 constraint. For example:
2669 my $cd = $schema->resultset('CD')->find_or_create(
2671 artist => 'Massive Attack',
2672 title => 'Mezzanine',
2674 { key => 'cd_artist_title' }
2677 B<Note>: Make sure to read the documentation of L</find> and understand the
2678 significance of the C<key> attribute, as its lack may skew your search, and
2679 subsequently result in spurious row creation.
2681 B<Note>: Because find_or_create() reads from the database and then
2682 possibly inserts based on the result, this method is subject to a race
2683 condition. Another process could create a record in the table after
2684 the find has completed and before the create has started. To avoid
2685 this problem, use find_or_create() inside a transaction.
2687 B<Note>: Take care when using C<find_or_create> with a table having
2688 columns with default values that you intend to be automatically
2689 supplied by the database (e.g. an auto_increment primary key column).
2690 In normal usage, the value of such columns should NOT be included at
2691 all in the call to C<find_or_create>, even when set to C<undef>.
2693 See also L</find> and L</update_or_create>. For information on how to declare
2694 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2698 sub find_or_create {
2700 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2701 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2702 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2705 return $self->create($hash);
2708 =head2 update_or_create
2712 =item Arguments: \%col_values, { key => $unique_constraint }?
2714 =item Return Value: $row_object
2718 $resultset->update_or_create({ col => $val, ... });
2720 Like L</find_or_create>, but if a row is found it is immediately updated via
2721 C<< $found_row->update (\%col_values) >>.
2724 Takes an optional C<key> attribute to search on a specific unique constraint.
2727 # In your application
2728 my $cd = $schema->resultset('CD')->update_or_create(
2730 artist => 'Massive Attack',
2731 title => 'Mezzanine',
2734 { key => 'cd_artist_title' }
2737 $cd->cd_to_producer->update_or_create({
2738 producer => $producer,
2744 B<Note>: Make sure to read the documentation of L</find> and understand the
2745 significance of the C<key> attribute, as its lack may skew your search, and
2746 subsequently result in spurious row creation.
2748 B<Note>: Take care when using C<update_or_create> with a table having
2749 columns with default values that you intend to be automatically
2750 supplied by the database (e.g. an auto_increment primary key column).
2751 In normal usage, the value of such columns should NOT be included at
2752 all in the call to C<update_or_create>, even when set to C<undef>.
2754 See also L</find> and L</find_or_create>. For information on how to declare
2755 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2759 sub update_or_create {
2761 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2762 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2764 my $row = $self->find($cond, $attrs);
2766 $row->update($cond);
2770 return $self->create($cond);
2773 =head2 update_or_new
2777 =item Arguments: \%col_values, { key => $unique_constraint }?
2779 =item Return Value: $rowobject
2783 $resultset->update_or_new({ col => $val, ... });
2785 Like L</find_or_new> but if a row is found it is immediately updated via
2786 C<< $found_row->update (\%col_values) >>.
2790 # In your application
2791 my $cd = $schema->resultset('CD')->update_or_new(
2793 artist => 'Massive Attack',
2794 title => 'Mezzanine',
2797 { key => 'cd_artist_title' }
2800 if ($cd->in_storage) {
2801 # the cd was updated
2804 # the cd is not yet in the database, let's insert it
2808 B<Note>: Make sure to read the documentation of L</find> and understand the
2809 significance of the C<key> attribute, as its lack may skew your search, and
2810 subsequently result in spurious new objects.
2812 B<Note>: Take care when using C<update_or_new> with a table having
2813 columns with default values that you intend to be automatically
2814 supplied by the database (e.g. an auto_increment primary key column).
2815 In normal usage, the value of such columns should NOT be included at
2816 all in the call to C<update_or_new>, even when set to C<undef>.
2818 See also L</find>, L</find_or_create> and L</find_or_new>.
2824 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2825 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2827 my $row = $self->find( $cond, $attrs );
2828 if ( defined $row ) {
2829 $row->update($cond);
2833 return $self->new_result($cond);
2840 =item Arguments: none
2842 =item Return Value: \@cache_objects | undef
2846 Gets the contents of the cache for the resultset, if the cache is set.
2848 The cache is populated either by using the L</prefetch> attribute to
2849 L</search> or by calling L</set_cache>.
2861 =item Arguments: \@cache_objects
2863 =item Return Value: \@cache_objects
2867 Sets the contents of the cache for the resultset. Expects an arrayref
2868 of objects of the same class as those produced by the resultset. Note that
2869 if the cache is set the resultset will return the cached objects rather
2870 than re-querying the database even if the cache attr is not set.
2872 The contents of the cache can also be populated by using the
2873 L</prefetch> attribute to L</search>.
2878 my ( $self, $data ) = @_;
2879 $self->throw_exception("set_cache requires an arrayref")
2880 if defined($data) && (ref $data ne 'ARRAY');
2881 $self->{all_cache} = $data;
2888 =item Arguments: none
2890 =item Return Value: undef
2894 Clears the cache for the resultset.
2899 shift->set_cache(undef);
2906 =item Arguments: none
2908 =item Return Value: true, if the resultset has been paginated
2916 return !!$self->{attrs}{page};
2923 =item Arguments: none
2925 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2933 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2936 =head2 related_resultset
2940 =item Arguments: $relationship_name
2942 =item Return Value: $resultset
2946 Returns a related resultset for the supplied relationship name.
2948 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2952 sub related_resultset {
2953 my ($self, $rel) = @_;
2955 $self->{related_resultsets} ||= {};
2956 return $self->{related_resultsets}{$rel} ||= do {
2957 my $rsrc = $self->result_source;
2958 my $rel_info = $rsrc->relationship_info($rel);
2960 $self->throw_exception(
2961 "search_related: result source '" . $rsrc->source_name .
2962 "' has no such relationship $rel")
2965 my $attrs = $self->_chain_relationship($rel);
2967 my $join_count = $attrs->{seen_join}{$rel};
2969 my $alias = $self->result_source->storage
2970 ->relname_to_table_alias($rel, $join_count);
2972 # since this is search_related, and we already slid the select window inwards
2973 # (the select/as attrs were deleted in the beginning), we need to flip all
2974 # left joins to inner, so we get the expected results
2975 # read the comment on top of the actual function to see what this does
2976 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2979 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2980 delete @{$attrs}{qw(result_class alias)};
2984 if (my $cache = $self->get_cache) {
2985 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2986 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2991 my $rel_source = $rsrc->related_source($rel);
2995 # The reason we do this now instead of passing the alias to the
2996 # search_rs below is that if you wrap/overload resultset on the
2997 # source you need to know what alias it's -going- to have for things
2998 # to work sanely (e.g. RestrictWithObject wants to be able to add
2999 # extra query restrictions, and these may need to be $alias.)
3001 my $rel_attrs = $rel_source->resultset_attributes;
3002 local $rel_attrs->{alias} = $alias;
3004 $rel_source->resultset
3008 where => $attrs->{where},
3011 $new->set_cache($new_cache) if $new_cache;
3016 =head2 current_source_alias
3020 =item Arguments: none
3022 =item Return Value: $source_alias
3026 Returns the current table alias for the result source this resultset is built
3027 on, that will be used in the SQL query. Usually it is C<me>.
3029 Currently the source alias that refers to the result set returned by a
3030 L</search>/L</find> family method depends on how you got to the resultset: it's
3031 C<me> by default, but eg. L</search_related> aliases it to the related result
3032 source name (and keeps C<me> referring to the original result set). The long
3033 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3034 (and make this method unnecessary).
3036 Thus it's currently necessary to use this method in predefined queries (see
3037 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3038 source alias of the current result set:
3040 # in a result set class
3042 my ($self, $user) = @_;
3044 my $me = $self->current_source_alias;
3046 return $self->search(
3047 "$me.modified" => $user->id,
3053 sub current_source_alias {
3056 return ($self->{attrs} || {})->{alias} || 'me';
3059 =head2 as_subselect_rs
3063 =item Arguments: none
3065 =item Return Value: $resultset
3069 Act as a barrier to SQL symbols. The resultset provided will be made into a
3070 "virtual view" by including it as a subquery within the from clause. From this
3071 point on, any joined tables are inaccessible to ->search on the resultset (as if
3072 it were simply where-filtered without joins). For example:
3074 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3076 # 'x' now pollutes the query namespace
3078 # So the following works as expected
3079 my $ok_rs = $rs->search({'x.other' => 1});
3081 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3082 # def) we look for one row with contradictory terms and join in another table
3083 # (aliased 'x_2') which we never use
3084 my $broken_rs = $rs->search({'x.name' => 'def'});
3086 my $rs2 = $rs->as_subselect_rs;
3088 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3089 my $not_joined_rs = $rs2->search({'x.other' => 1});
3091 # works as expected: finds a 'table' row related to two x rows (abc and def)
3092 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3094 Another example of when one might use this would be to select a subset of
3095 columns in a group by clause:
3097 my $rs = $schema->resultset('Bar')->search(undef, {
3098 group_by => [qw{ id foo_id baz_id }],
3099 })->as_subselect_rs->search(undef, {
3100 columns => [qw{ id foo_id }]
3103 In the above example normally columns would have to be equal to the group by,
3104 but because we isolated the group by into a subselect the above works.
3108 sub as_subselect_rs {
3111 my $attrs = $self->_resolved_attrs;
3113 my $fresh_rs = (ref $self)->new (
3114 $self->result_source
3117 # these pieces will be locked in the subquery
3118 delete $fresh_rs->{cond};
3119 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3121 return $fresh_rs->search( {}, {
3123 $attrs->{alias} => $self->as_query,
3124 -alias => $attrs->{alias},
3125 -rsrc => $self->result_source,
3127 alias => $attrs->{alias},
3131 # This code is called by search_related, and makes sure there
3132 # is clear separation between the joins before, during, and
3133 # after the relationship. This information is needed later
3134 # in order to properly resolve prefetch aliases (any alias
3135 # with a relation_chain_depth less than the depth of the
3136 # current prefetch is not considered)
3138 # The increments happen twice per join. An even number means a
3139 # relationship specified via a search_related, whereas an odd
3140 # number indicates a join/prefetch added via attributes
3142 # Also this code will wrap the current resultset (the one we
3143 # chain to) in a subselect IFF it contains limiting attributes
3144 sub _chain_relationship {
3145 my ($self, $rel) = @_;
3146 my $source = $self->result_source;
3147 my $attrs = { %{$self->{attrs}||{}} };
3149 # we need to take the prefetch the attrs into account before we
3150 # ->_resolve_join as otherwise they get lost - captainL
3151 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3153 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3155 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3158 my @force_subq_attrs = qw/offset rows group_by having/;
3161 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3163 $self->_has_resolved_attr (@force_subq_attrs)
3165 # Nuke the prefetch (if any) before the new $rs attrs
3166 # are resolved (prefetch is useless - we are wrapping
3167 # a subquery anyway).
3168 my $rs_copy = $self->search;
3169 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3170 $rs_copy->{attrs}{join},
3171 delete $rs_copy->{attrs}{prefetch},
3176 -alias => $attrs->{alias},
3177 $attrs->{alias} => $rs_copy->as_query,
3179 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3180 $seen->{-relation_chain_depth} = 0;
3182 elsif ($attrs->{from}) { #shallow copy suffices
3183 $from = [ @{$attrs->{from}} ];
3188 -alias => $attrs->{alias},
3189 $attrs->{alias} => $source->from,
3193 my $jpath = ($seen->{-relation_chain_depth})
3194 ? $from->[-1][0]{-join_path}
3197 my @requested_joins = $source->_resolve_join(
3204 push @$from, @requested_joins;
3206 $seen->{-relation_chain_depth}++;
3208 # if $self already had a join/prefetch specified on it, the requested
3209 # $rel might very well be already included. What we do in this case
3210 # is effectively a no-op (except that we bump up the chain_depth on
3211 # the join in question so we could tell it *is* the search_related)
3214 # we consider the last one thus reverse
3215 for my $j (reverse @requested_joins) {
3216 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3217 if ($rel eq $last_j) {
3218 $j->[0]{-relation_chain_depth}++;
3224 unless ($already_joined) {
3225 push @$from, $source->_resolve_join(
3233 $seen->{-relation_chain_depth}++;
3235 return {%$attrs, from => $from, seen_join => $seen};
3238 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3239 sub _resolved_attrs_copy {
3241 return { %{$self->_resolved_attrs (@_)} };
3244 sub _resolved_attrs {
3246 return $self->{_attrs} if $self->{_attrs};
3248 my $attrs = { %{ $self->{attrs} || {} } };
3249 my $source = $self->result_source;
3250 my $alias = $attrs->{alias};
3252 # default selection list
3253 $attrs->{columns} = [ $source->columns ]
3254 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3256 # merge selectors together
3257 for (qw/columns select as/) {
3258 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3259 if $attrs->{$_} or $attrs->{"+$_"};
3262 # disassemble columns
3264 if (my $cols = delete $attrs->{columns}) {
3265 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3266 if (ref $c eq 'HASH') {
3267 for my $as (keys %$c) {
3268 push @sel, $c->{$as};
3279 # when trying to weed off duplicates later do not go past this point -
3280 # everything added from here on is unbalanced "anyone's guess" stuff
3281 my $dedup_stop_idx = $#as;
3283 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3285 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3286 if $attrs->{select};
3288 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3290 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3293 # disqualify all $alias.col as-bits (collapser mandated)
3295 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3298 # de-duplicate the result (remove *identical* select/as pairs)
3299 # and also die on duplicate {as} pointing to different {select}s
3300 # not using a c-style for as the condition is prone to shrinkage
3303 while ($i <= $dedup_stop_idx) {
3304 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3309 elsif ($seen->{$as[$i]}++) {
3310 $self->throw_exception(
3311 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3319 $attrs->{select} = \@sel;
3320 $attrs->{as} = \@as;
3322 $attrs->{from} ||= [{
3324 -alias => $self->{attrs}{alias},
3325 $self->{attrs}{alias} => $source->from,
3328 if ( $attrs->{join} || $attrs->{prefetch} ) {
3330 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3331 if ref $attrs->{from} ne 'ARRAY';
3333 my $join = (delete $attrs->{join}) || {};
3335 if ( defined $attrs->{prefetch} ) {
3336 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3339 $attrs->{from} = # have to copy here to avoid corrupting the original
3341 @{ $attrs->{from} },
3342 $source->_resolve_join(
3345 { %{ $attrs->{seen_join} || {} } },
3346 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3347 ? $attrs->{from}[-1][0]{-join_path}
3354 if ( defined $attrs->{order_by} ) {
3355 $attrs->{order_by} = (
3356 ref( $attrs->{order_by} ) eq 'ARRAY'
3357 ? [ @{ $attrs->{order_by} } ]
3358 : [ $attrs->{order_by} || () ]
3362 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3363 $attrs->{group_by} = [ $attrs->{group_by} ];
3366 # generate the distinct induced group_by early, as prefetch will be carried via a
3367 # subquery (since a group_by is present)
3368 if (delete $attrs->{distinct}) {
3369 if ($attrs->{group_by}) {
3370 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3373 # distinct affects only the main selection part, not what prefetch may
3375 $attrs->{group_by} = $source->storage->_group_over_selection (
3383 $attrs->{collapse} ||= {};
3384 if ($attrs->{prefetch}) {
3386 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3387 if $attrs->{_dark_selector};
3389 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3391 my $prefetch_ordering = [];
3393 # this is a separate structure (we don't look in {from} directly)
3394 # as the resolver needs to shift things off the lists to work
3395 # properly (identical-prefetches on different branches)
3397 if (ref $attrs->{from} eq 'ARRAY') {
3399 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3401 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3402 next unless $j->[0]{-alias};
3403 next unless $j->[0]{-join_path};
3404 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3406 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3409 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3410 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3415 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3417 # we need to somehow mark which columns came from prefetch
3419 my $sel_end = $#{$attrs->{select}};
3420 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3423 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3424 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3426 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3427 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3431 # if both page and offset are specified, produce a combined offset
3432 # even though it doesn't make much sense, this is what pre 081xx has
3434 if (my $page = delete $attrs->{page}) {
3436 ($attrs->{rows} * ($page - 1))
3438 ($attrs->{offset} || 0)
3442 return $self->{_attrs} = $attrs;
3446 my ($self, $attr) = @_;
3448 if (ref $attr eq 'HASH') {
3449 return $self->_rollout_hash($attr);
3450 } elsif (ref $attr eq 'ARRAY') {
3451 return $self->_rollout_array($attr);
3457 sub _rollout_array {
3458 my ($self, $attr) = @_;
3461 foreach my $element (@{$attr}) {
3462 if (ref $element eq 'HASH') {
3463 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3464 } elsif (ref $element eq 'ARRAY') {
3465 # XXX - should probably recurse here
3466 push( @rolled_array, @{$self->_rollout_array($element)} );
3468 push( @rolled_array, $element );
3471 return \@rolled_array;
3475 my ($self, $attr) = @_;
3478 foreach my $key (keys %{$attr}) {
3479 push( @rolled_array, { $key => $attr->{$key} } );
3481 return \@rolled_array;
3484 sub _calculate_score {
3485 my ($self, $a, $b) = @_;
3487 if (defined $a xor defined $b) {
3490 elsif (not defined $a) {
3494 if (ref $b eq 'HASH') {
3495 my ($b_key) = keys %{$b};
3496 if (ref $a eq 'HASH') {
3497 my ($a_key) = keys %{$a};
3498 if ($a_key eq $b_key) {
3499 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3504 return ($a eq $b_key) ? 1 : 0;
3507 if (ref $a eq 'HASH') {
3508 my ($a_key) = keys %{$a};
3509 return ($b eq $a_key) ? 1 : 0;
3511 return ($b eq $a) ? 1 : 0;
3516 sub _merge_joinpref_attr {
3517 my ($self, $orig, $import) = @_;
3519 return $import unless defined($orig);
3520 return $orig unless defined($import);
3522 $orig = $self->_rollout_attr($orig);
3523 $import = $self->_rollout_attr($import);
3526 foreach my $import_element ( @{$import} ) {
3527 # find best candidate from $orig to merge $b_element into
3528 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3529 foreach my $orig_element ( @{$orig} ) {
3530 my $score = $self->_calculate_score( $orig_element, $import_element );
3531 if ($score > $best_candidate->{score}) {
3532 $best_candidate->{position} = $position;
3533 $best_candidate->{score} = $score;
3537 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3539 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3540 push( @{$orig}, $import_element );
3542 my $orig_best = $orig->[$best_candidate->{position}];
3543 # merge orig_best and b_element together and replace original with merged
3544 if (ref $orig_best ne 'HASH') {
3545 $orig->[$best_candidate->{position}] = $import_element;
3546 } elsif (ref $import_element eq 'HASH') {
3547 my ($key) = keys %{$orig_best};
3548 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3551 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3562 require Hash::Merge;
3563 my $hm = Hash::Merge->new;
3565 $hm->specify_behavior({
3568 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3570 if ($defl xor $defr) {
3571 return [ $defl ? $_[0] : $_[1] ];
3576 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3580 return [$_[0], $_[1]];
3584 return $_[1] if !defined $_[0];
3585 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3586 return [$_[0], @{$_[1]}]
3589 return [] if !defined $_[0] and !keys %{$_[1]};
3590 return [ $_[1] ] if !defined $_[0];
3591 return [ $_[0] ] if !keys %{$_[1]};
3592 return [$_[0], $_[1]]
3597 return $_[0] if !defined $_[1];
3598 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3599 return [@{$_[0]}, $_[1]]
3602 my @ret = @{$_[0]} or return $_[1];
3603 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3604 my %idx = map { $_ => 1 } @ret;
3605 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3609 return [ $_[1] ] if ! @{$_[0]};
3610 return $_[0] if !keys %{$_[1]};
3611 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3612 return [ @{$_[0]}, $_[1] ];
3617 return [] if !keys %{$_[0]} and !defined $_[1];
3618 return [ $_[0] ] if !defined $_[1];
3619 return [ $_[1] ] if !keys %{$_[0]};
3620 return [$_[0], $_[1]]
3623 return [] if !keys %{$_[0]} and !@{$_[1]};
3624 return [ $_[0] ] if !@{$_[1]};
3625 return $_[1] if !keys %{$_[0]};
3626 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3627 return [ $_[0], @{$_[1]} ];
3630 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3631 return [ $_[0] ] if !keys %{$_[1]};
3632 return [ $_[1] ] if !keys %{$_[0]};
3633 return [ $_[0] ] if $_[0] eq $_[1];
3634 return [ $_[0], $_[1] ];
3637 } => 'DBIC_RS_ATTR_MERGER');
3641 return $hm->merge ($_[1], $_[2]);
3645 sub STORABLE_freeze {
3646 my ($self, $cloning) = @_;
3647 my $to_serialize = { %$self };
3649 # A cursor in progress can't be serialized (and would make little sense anyway)
3650 delete $to_serialize->{cursor};
3652 Storable::nfreeze($to_serialize);
3655 # need this hook for symmetry
3657 my ($self, $cloning, $serialized) = @_;
3659 %$self = %{ Storable::thaw($serialized) };
3665 =head2 throw_exception
3667 See L<DBIx::Class::Schema/throw_exception> for details.
3671 sub throw_exception {
3674 if (ref $self and my $rsrc = $self->result_source) {
3675 $rsrc->throw_exception(@_)
3678 DBIx::Class::Exception->throw(@_);
3682 # XXX: FIXME: Attributes docs need clearing up
3686 Attributes are used to refine a ResultSet in various ways when
3687 searching for data. They can be passed to any method which takes an
3688 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3691 These are in no particular order:
3697 =item Value: ( $order_by | \@order_by | \%order_by )
3701 Which column(s) to order the results by.
3703 [The full list of suitable values is documented in
3704 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3707 If a single column name, or an arrayref of names is supplied, the
3708 argument is passed through directly to SQL. The hashref syntax allows
3709 for connection-agnostic specification of ordering direction:
3711 For descending order:
3713 order_by => { -desc => [qw/col1 col2 col3/] }
3715 For explicit ascending order:
3717 order_by => { -asc => 'col' }
3719 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3720 supported, although you are strongly encouraged to use the hashref
3721 syntax as outlined above.
3727 =item Value: \@columns
3731 Shortcut to request a particular set of columns to be retrieved. Each
3732 column spec may be a string (a table column name), or a hash (in which
3733 case the key is the C<as> value, and the value is used as the C<select>
3734 expression). Adds C<me.> onto the start of any column without a C<.> in
3735 it and sets C<select> from that, then auto-populates C<as> from
3736 C<select> as normal. (You may also use the C<cols> attribute, as in
3737 earlier versions of DBIC.)
3739 Essentially C<columns> does the same as L</select> and L</as>.
3741 columns => [ 'foo', { bar => 'baz' } ]
3745 select => [qw/foo baz/],
3752 =item Value: \@columns
3756 Indicates additional columns to be selected from storage. Works the same
3757 as L</columns> but adds columns to the selection. (You may also use the
3758 C<include_columns> attribute, as in earlier versions of DBIC). For
3761 $schema->resultset('CD')->search(undef, {
3762 '+columns' => ['artist.name'],
3766 would return all CDs and include a 'name' column to the information
3767 passed to object inflation. Note that the 'artist' is the name of the
3768 column (or relationship) accessor, and 'name' is the name of the column
3769 accessor in the related table.
3771 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3772 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3773 unary plus operator before it.
3775 =head2 include_columns
3779 =item Value: \@columns
3783 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3789 =item Value: \@select_columns
3793 Indicates which columns should be selected from the storage. You can use
3794 column names, or in the case of RDBMS back ends, function or stored procedure
3797 $rs = $schema->resultset('Employee')->search(undef, {
3800 { count => 'employeeid' },
3801 { max => { length => 'name' }, -as => 'longest_name' }
3806 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3808 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3809 use L</select>, to instruct DBIx::Class how to store the result of the column.
3810 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3811 identifier aliasing. You can however alias a function, so you can use it in
3812 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3813 attribute> supplied as shown in the example above.
3815 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3816 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3817 unary plus operator before it.
3823 Indicates additional columns to be selected from storage. Works the same as
3824 L</select> but adds columns to the default selection, instead of specifying
3833 Indicates additional column names for those added via L</+select>. See L</as>.
3841 =item Value: \@inflation_names
3845 Indicates column names for object inflation. That is L</as> indicates the
3846 slot name in which the column value will be stored within the
3847 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3848 identifier by the C<get_column> method (or via the object accessor B<if one
3849 with the same name already exists>) as shown below. The L</as> attribute has
3850 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3852 $rs = $schema->resultset('Employee')->search(undef, {
3855 { count => 'employeeid' },
3856 { max => { length => 'name' }, -as => 'longest_name' }
3865 If the object against which the search is performed already has an accessor
3866 matching a column name specified in C<as>, the value can be retrieved using
3867 the accessor as normal:
3869 my $name = $employee->name();
3871 If on the other hand an accessor does not exist in the object, you need to
3872 use C<get_column> instead:
3874 my $employee_count = $employee->get_column('employee_count');
3876 You can create your own accessors if required - see
3877 L<DBIx::Class::Manual::Cookbook> for details.
3883 =item Value: ($rel_name | \@rel_names | \%rel_names)
3887 Contains a list of relationships that should be joined for this query. For
3890 # Get CDs by Nine Inch Nails
3891 my $rs = $schema->resultset('CD')->search(
3892 { 'artist.name' => 'Nine Inch Nails' },
3893 { join => 'artist' }
3896 Can also contain a hash reference to refer to the other relation's relations.
3899 package MyApp::Schema::Track;
3900 use base qw/DBIx::Class/;
3901 __PACKAGE__->table('track');
3902 __PACKAGE__->add_columns(qw/trackid cd position title/);
3903 __PACKAGE__->set_primary_key('trackid');
3904 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3907 # In your application
3908 my $rs = $schema->resultset('Artist')->search(
3909 { 'track.title' => 'Teardrop' },
3911 join => { cd => 'track' },
3912 order_by => 'artist.name',
3916 You need to use the relationship (not the table) name in conditions,
3917 because they are aliased as such. The current table is aliased as "me", so
3918 you need to use me.column_name in order to avoid ambiguity. For example:
3920 # Get CDs from 1984 with a 'Foo' track
3921 my $rs = $schema->resultset('CD')->search(
3924 'tracks.name' => 'Foo'
3926 { join => 'tracks' }
3929 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3930 similarly for a third time). For e.g.
3932 my $rs = $schema->resultset('Artist')->search({
3933 'cds.title' => 'Down to Earth',
3934 'cds_2.title' => 'Popular',
3936 join => [ qw/cds cds/ ],
3939 will return a set of all artists that have both a cd with title 'Down
3940 to Earth' and a cd with title 'Popular'.
3942 If you want to fetch related objects from other tables as well, see C<prefetch>
3945 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3951 =item Value: ($rel_name | \@rel_names | \%rel_names)
3955 Contains one or more relationships that should be fetched along with
3956 the main query (when they are accessed afterwards the data will
3957 already be available, without extra queries to the database). This is
3958 useful for when you know you will need the related objects, because it
3959 saves at least one query:
3961 my $rs = $schema->resultset('Tag')->search(
3970 The initial search results in SQL like the following:
3972 SELECT tag.*, cd.*, artist.* FROM tag
3973 JOIN cd ON tag.cd = cd.cdid
3974 JOIN artist ON cd.artist = artist.artistid
3976 L<DBIx::Class> has no need to go back to the database when we access the
3977 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3980 Simple prefetches will be joined automatically, so there is no need
3981 for a C<join> attribute in the above search.
3983 L</prefetch> can be used with the any of the relationship types and
3984 multiple prefetches can be specified together. Below is a more complex
3985 example that prefetches a CD's artist, its liner notes (if present),
3986 the cover image, the tracks on that cd, and the guests on those
3990 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3991 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3992 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3993 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3995 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3997 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4000 my $rs = $schema->resultset('CD')->search(
4004 { artist => 'record_label'}, # belongs_to => belongs_to
4005 'liner_note', # might_have
4006 'cover_image', # has_one
4007 { tracks => 'guests' }, # has_many => has_many
4012 This will produce SQL like the following:
4014 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4018 ON artist.artistid = me.artistid
4019 JOIN record_label record_label
4020 ON record_label.labelid = artist.labelid
4021 LEFT JOIN track tracks
4022 ON tracks.cdid = me.cdid
4023 LEFT JOIN guest guests
4024 ON guests.trackid = track.trackid
4025 LEFT JOIN liner_notes liner_note
4026 ON liner_note.cdid = me.cdid
4027 JOIN cd_artwork cover_image
4028 ON cover_image.cdid = me.cdid
4031 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4032 C<tracks>, and C<guests> of the CD will all be available through the
4033 relationship accessors without the need for additional queries to the
4036 However, there is one caveat to be observed: it can be dangerous to
4037 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4038 relationship on a given level. e.g.:
4040 my $rs = $schema->resultset('CD')->search(
4044 'tracks', # has_many
4045 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4050 In fact, C<DBIx::Class> will emit the following warning:
4052 Prefetching multiple has_many rels tracks and cd_to_producer at top
4053 level will explode the number of row objects retrievable via ->next
4054 or ->all. Use at your own risk.
4056 The collapser currently can't identify duplicate tuples for multiple
4057 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4058 result the second L<has_many|DBIx::Class::Relationship/has_many>
4059 relation could contain redundant objects.
4061 =head3 Using L</prefetch> with L</join>
4063 L</prefetch> implies a L</join> with the equivalent argument, and is
4064 properly merged with any existing L</join> specification. So the
4067 my $rs = $schema->resultset('CD')->search(
4068 {'record_label.name' => 'Music Product Ltd.'},
4070 join => {artist => 'record_label'},
4071 prefetch => 'artist',
4075 ... will work, searching on the record label's name, but only
4076 prefetching the C<artist>.
4078 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4080 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4081 prefetched relations. So given:
4083 my $rs = $schema->resultset('CD')->search(
4086 select => ['cd.title'],
4088 prefetch => 'artist',
4092 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4093 becomes: C<'cd_title', 'artist.*'>.
4097 Prefetch does a lot of deep magic. As such, it may not behave exactly
4098 as you might expect.
4104 Prefetch uses the L</cache> to populate the prefetched relationships. This
4105 may or may not be what you want.
4109 If you specify a condition on a prefetched relationship, ONLY those
4110 rows that match the prefetched condition will be fetched into that relationship.
4111 This means that adding prefetch to a search() B<may alter> what is returned by
4112 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4114 my $artist_rs = $schema->resultset('Artist')->search({
4120 my $count = $artist_rs->first->cds->count;
4122 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4124 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4126 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4128 that cmp_ok() may or may not pass depending on the datasets involved. This
4129 behavior may or may not survive the 0.09 transition.
4141 Makes the resultset paged and specifies the page to retrieve. Effectively
4142 identical to creating a non-pages resultset and then calling ->page($page)
4145 If L</rows> attribute is not specified it defaults to 10 rows per page.
4147 When you have a paged resultset, L</count> will only return the number
4148 of rows in the page. To get the total, use the L</pager> and call
4149 C<total_entries> on it.
4159 Specifies the maximum number of rows for direct retrieval or the number of
4160 rows per page if the page attribute or method is used.
4166 =item Value: $offset
4170 Specifies the (zero-based) row number for the first row to be returned, or the
4171 of the first row of the first page if paging is used.
4177 =item Value: \@columns
4181 A arrayref of columns to group by. Can include columns of joined tables.
4183 group_by => [qw/ column1 column2 ... /]
4189 =item Value: $condition
4193 HAVING is a select statement attribute that is applied between GROUP BY and
4194 ORDER BY. It is applied to the after the grouping calculations have been
4197 having => { 'count_employee' => { '>=', 100 } }
4199 or with an in-place function in which case literal SQL is required:
4201 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4207 =item Value: (0 | 1)
4211 Set to 1 to group by all columns. If the resultset already has a group_by
4212 attribute, this setting is ignored and an appropriate warning is issued.
4218 Adds to the WHERE clause.
4220 # only return rows WHERE deleted IS NULL for all searches
4221 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4223 Can be overridden by passing C<< { where => undef } >> as an attribute
4230 Set to 1 to cache search results. This prevents extra SQL queries if you
4231 revisit rows in your ResultSet:
4233 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4235 while( my $artist = $resultset->next ) {
4239 $rs->first; # without cache, this would issue a query
4241 By default, searches are not cached.
4243 For more examples of using these attributes, see
4244 L<DBIx::Class::Manual::Cookbook>.
4250 =item Value: ( 'update' | 'shared' )
4254 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT