1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::Exception;
8 use DBIx::Class::ResultSetColumn;
9 use Scalar::Util qw/blessed weaken/;
12 # not importing first() as it will clash with our own method
16 # De-duplication in _merge_attr() is disabled, but left in for reference
17 # (the merger is used for other things that ought not to be de-duped)
18 *__HM_DEDUP = sub () { 0 };
28 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
32 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
36 my $users_rs = $schema->resultset('User');
37 while( $user = $users_rs->next) {
38 print $user->username;
41 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
42 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
46 A ResultSet is an object which stores a set of conditions representing
47 a query. It is the backbone of DBIx::Class (i.e. the really
48 important/useful bit).
50 No SQL is executed on the database when a ResultSet is created, it
51 just stores all the conditions needed to create the query.
53 A basic ResultSet representing the data of an entire table is returned
54 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
55 L<Source|DBIx::Class::Manual::Glossary/Source> name.
57 my $users_rs = $schema->resultset('User');
59 A new ResultSet is returned from calling L</search> on an existing
60 ResultSet. The new one will contain all the conditions of the
61 original, plus any new conditions added in the C<search> call.
63 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
64 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
67 The query that the ResultSet represents is B<only> executed against
68 the database when these methods are called:
69 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
71 If a resultset is used in a numeric context it returns the L</count>.
72 However, if it is used in a boolean context it is B<always> true. So if
73 you want to check if a resultset has any results, you must use C<if $rs
78 =head2 Chaining resultsets
80 Let's say you've got a query that needs to be run to return some data
81 to the user. But, you have an authorization system in place that
82 prevents certain users from seeing certain information. So, you want
83 to construct the basic query in one method, but add constraints to it in
88 my $request = $self->get_request; # Get a request object somehow.
89 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
91 my $cd_rs = $schema->resultset('CD')->search({
92 title => $request->param('title'),
93 year => $request->param('year'),
96 $cd_rs = $self->apply_security_policy( $cd_rs );
101 sub apply_security_policy {
110 =head3 Resolving conditions and attributes
112 When a resultset is chained from another resultset, conditions and
113 attributes with the same keys need resolving.
115 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
116 into the existing ones from the original resultset.
118 The L</where> and L</having> attributes, and any search conditions, are
119 merged with an SQL C<AND> to the existing condition from the original
122 All other attributes are overridden by any new ones supplied in the
125 =head2 Multiple queries
127 Since a resultset just defines a query, you can do all sorts of
128 things with it with the same object.
130 # Don't hit the DB yet.
131 my $cd_rs = $schema->resultset('CD')->search({
132 title => 'something',
136 # Each of these hits the DB individually.
137 my $count = $cd_rs->count;
138 my $most_recent = $cd_rs->get_column('date_released')->max();
139 my @records = $cd_rs->all;
141 And it's not just limited to SELECT statements.
147 $cd_rs->create({ artist => 'Fred' });
149 Which is the same as:
151 $schema->resultset('CD')->create({
152 title => 'something',
157 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
165 =item Arguments: $source, \%$attrs
167 =item Return Value: $rs
171 The resultset constructor. Takes a source object (usually a
172 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
173 L</ATTRIBUTES> below). Does not perform any queries -- these are
174 executed as needed by the other methods.
176 Generally you won't need to construct a resultset manually. You'll
177 automatically get one from e.g. a L</search> called in scalar context:
179 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
181 IMPORTANT: If called on an object, proxies to new_result instead so
183 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
185 will return a CD object, not a ResultSet.
191 return $class->new_result(@_) if ref $class;
193 my ($source, $attrs) = @_;
194 $source = $source->resolve
195 if $source->isa('DBIx::Class::ResultSourceHandle');
196 $attrs = { %{$attrs||{}} };
198 if ($attrs->{page}) {
199 $attrs->{rows} ||= 10;
202 $attrs->{alias} ||= 'me';
205 result_source => $source,
206 cond => $attrs->{where},
211 # if there is a dark selector, this means we are already in a
212 # chain and the cleanup/sanification was taken care of by
214 $self->_normalize_selection($attrs)
215 unless $attrs->{_dark_selector};
218 $attrs->{result_class} || $source->result_class
228 =item Arguments: $cond, \%attrs?
230 =item Return Value: $resultset (scalar context) || @row_objs (list context)
234 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
235 my $new_rs = $cd_rs->search({ year => 2005 });
237 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
238 # year = 2005 OR year = 2004
240 In list context, C<< ->all() >> is called implicitly on the resultset, thus
241 returning a list of row objects instead. To avoid that, use L</search_rs>.
243 If you need to pass in additional attributes but no additional condition,
244 call it as C<search(undef, \%attrs)>.
246 # "SELECT name, artistid FROM $artist_table"
247 my @all_artists = $schema->resultset('Artist')->search(undef, {
248 columns => [qw/name artistid/],
251 For a list of attributes that can be passed to C<search>, see
252 L</ATTRIBUTES>. For more examples of using this function, see
253 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
254 documentation for the first argument, see L<SQL::Abstract>.
256 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 Note that L</search> does not process/deflate any of the values passed in the
261 L<SQL::Abstract>-compatible search condition structure. This is unlike other
262 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
263 manually that any value passed to this method will stringify to something the
264 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
265 objects, for more info see:
266 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
272 my $rs = $self->search_rs( @_ );
277 elsif (defined wantarray) {
281 # we can be called by a relationship helper, which in
282 # turn may be called in void context due to some braindead
283 # overload or whatever else the user decided to be clever
284 # at this particular day. Thus limit the exception to
285 # external code calls only
286 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
287 if (caller)[0] !~ /^\QDBIx::Class::/;
297 =item Arguments: $cond, \%attrs?
299 =item Return Value: $resultset
303 This method does the same exact thing as search() except it will
304 always return a resultset, even in list context.
311 # Special-case handling for (undef, undef).
312 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
318 if (ref $_[-1] eq 'HASH') {
319 # copy for _normalize_selection
320 $call_attrs = { %{ pop @_ } };
322 elsif (! defined $_[-1] ) {
323 pop @_; # search({}, undef)
327 # see if we can keep the cache (no $rs changes)
329 my %safe = (alias => 1, cache => 1);
330 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
333 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
335 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
337 $cache = $self->get_cache;
340 my $rsrc = $self->result_source;
342 my $old_attrs = { %{$self->{attrs}} };
343 my $old_having = delete $old_attrs->{having};
344 my $old_where = delete $old_attrs->{where};
346 my $new_attrs = { %$old_attrs };
348 # take care of call attrs (only if anything is changing)
349 if (keys %$call_attrs) {
351 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
353 # reset the current selector list if new selectors are supplied
354 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
355 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
358 # Normalize the new selector list (operates on the passed-in attr structure)
359 # Need to do it on every chain instead of only once on _resolved_attrs, in
360 # order to allow detection of empty vs partial 'as'
361 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
362 if $old_attrs->{_dark_selector};
363 $self->_normalize_selection ($call_attrs);
365 # start with blind overwriting merge, exclude selector attrs
366 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
367 delete @{$new_attrs}{@selector_attrs};
369 for (@selector_attrs) {
370 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
371 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
374 # older deprecated name, use only if {columns} is not there
375 if (my $c = delete $new_attrs->{cols}) {
376 if ($new_attrs->{columns}) {
377 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
380 $new_attrs->{columns} = $c;
385 # join/prefetch use their own crazy merging heuristics
386 foreach my $key (qw/join prefetch/) {
387 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
388 if exists $call_attrs->{$key};
391 # stack binds together
392 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
396 # rip apart the rest of @_, parse a condition
399 if (ref $_[0] eq 'HASH') {
400 (keys %{$_[0]}) ? $_[0] : undef
406 $self->throw_exception('Odd number of arguments to search')
414 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
415 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
418 for ($old_where, $call_cond) {
420 $new_attrs->{where} = $self->_stack_cond (
421 $_, $new_attrs->{where}
426 if (defined $old_having) {
427 $new_attrs->{having} = $self->_stack_cond (
428 $old_having, $new_attrs->{having}
432 my $rs = (ref $self)->new($rsrc, $new_attrs);
434 $rs->set_cache($cache) if ($cache);
440 sub _normalize_selection {
441 my ($self, $attrs) = @_;
444 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
445 if exists $attrs->{include_columns};
447 # columns are always placed first, however
449 # Keep the X vs +X separation until _resolved_attrs time - this allows to
450 # delay the decision on whether to use a default select list ($rsrc->columns)
451 # allowing stuff like the remove_columns helper to work
453 # select/as +select/+as pairs need special handling - the amount of select/as
454 # elements in each pair does *not* have to be equal (think multicolumn
455 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
456 # supplied at all) - try to infer the alias, either from the -as parameter
457 # of the selector spec, or use the parameter whole if it looks like a column
458 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
459 # is ok as well), but make sure no more additions to the 'as' chain take place
460 for my $pref ('', '+') {
462 my ($sel, $as) = map {
463 my $key = "${pref}${_}";
465 my $val = [ ref $attrs->{$key} eq 'ARRAY'
467 : $attrs->{$key} || ()
469 delete $attrs->{$key};
473 if (! @$as and ! @$sel ) {
476 elsif (@$as and ! @$sel) {
477 $self->throw_exception(
478 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
482 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
483 # if any @$as has been supplied we assume the user knows what (s)he is doing
484 # and blindly keep stacking up pieces
485 unless ($attrs->{_dark_selector}) {
488 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
489 push @$as, $_->{-as};
491 # assume any plain no-space, no-parenthesis string to be a column spec
492 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
493 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
496 # if all else fails - raise a flag that no more aliasing will be allowed
498 $attrs->{_dark_selector} = {
500 string => ($dark_sel_dumper ||= do {
501 require Data::Dumper::Concise;
502 Data::Dumper::Concise::DumperObject()->Indent(0);
503 })->Values([$_])->Dump
511 elsif (@$as < @$sel) {
512 $self->throw_exception(
513 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
516 elsif ($pref and $attrs->{_dark_selector}) {
517 $self->throw_exception(
518 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
524 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
525 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
530 my ($self, $left, $right) = @_;
531 if (defined $left xor defined $right) {
532 return defined $left ? $left : $right;
534 elsif (defined $left) {
535 return { -and => [ map
536 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
544 =head2 search_literal
548 =item Arguments: $sql_fragment, @bind_values
550 =item Return Value: $resultset (scalar context) || @row_objs (list context)
554 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
555 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
557 Pass a literal chunk of SQL to be added to the conditional part of the
560 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
561 only be used in that context. C<search_literal> is a convenience method.
562 It is equivalent to calling $schema->search(\[]), but if you want to ensure
563 columns are bound correctly, use C<search>.
565 Example of how to use C<search> instead of C<search_literal>
567 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
568 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
571 See L<DBIx::Class::Manual::Cookbook/Searching> and
572 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
573 require C<search_literal>.
578 my ($self, $sql, @bind) = @_;
580 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
583 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
590 =item Arguments: \%columns_values | @pk_values, \%attrs?
592 =item Return Value: $row_object | undef
596 Finds and returns a single row based on supplied criteria. Takes either a
597 hashref with the same format as L</create> (including inference of foreign
598 keys from related objects), or a list of primary key values in the same
599 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
600 declaration on the L</result_source>.
602 In either case an attempt is made to combine conditions already existing on
603 the resultset with the condition passed to this method.
605 To aid with preparing the correct query for the storage you may supply the
606 C<key> attribute, which is the name of a
607 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
608 unique constraint corresponding to the
609 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
610 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
611 to construct a query that satisfies the named unique constraint fully (
612 non-NULL values for each column member of the constraint) an exception is
615 If no C<key> is specified, the search is carried over all unique constraints
616 which are fully defined by the available condition.
618 If no such constraint is found, C<find> currently defaults to a simple
619 C<< search->(\%column_values) >> which may or may not do what you expect.
620 Note that this fallback behavior may be deprecated in further versions. If
621 you need to search with arbitrary conditions - use L</search>. If the query
622 resulting from this fallback produces more than one row, a warning to the
623 effect is issued, though only the first row is constructed and returned as
626 In addition to C<key>, L</find> recognizes and applies standard
627 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
629 Note that if you have extra concerns about the correctness of the resulting
630 query you need to specify the C<key> attribute and supply the entire condition
631 as an argument to find (since it is not always possible to perform the
632 combination of the resultset condition with the supplied one, especially if
633 the resultset condition contains literal sql).
635 For example, to find a row by its primary key:
637 my $cd = $schema->resultset('CD')->find(5);
639 You can also find a row by a specific unique constraint:
641 my $cd = $schema->resultset('CD')->find(
643 artist => 'Massive Attack',
644 title => 'Mezzanine',
646 { key => 'cd_artist_title' }
649 See also L</find_or_create> and L</update_or_create>.
655 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
657 my $rsrc = $self->result_source;
659 # Parse out the condition from input
661 if (ref $_[0] eq 'HASH') {
662 $call_cond = { %{$_[0]} };
665 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
666 my @c_cols = $rsrc->unique_constraint_columns($constraint);
668 $self->throw_exception(
669 "No constraint columns, maybe a malformed '$constraint' constraint?"
672 $self->throw_exception (
673 'find() expects either a column/value hashref, or a list of values '
674 . "corresponding to the columns of the specified unique constraint '$constraint'"
675 ) unless @c_cols == @_;
678 @{$call_cond}{@c_cols} = @_;
682 for my $key (keys %$call_cond) {
684 my $keyref = ref($call_cond->{$key})
686 my $relinfo = $rsrc->relationship_info($key)
688 my $val = delete $call_cond->{$key};
690 next if $keyref eq 'ARRAY'; # has_many for multi_create
692 my $rel_q = $rsrc->_resolve_condition(
693 $relinfo->{cond}, $val, $key, $key
695 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
696 @related{keys %$rel_q} = values %$rel_q;
700 # relationship conditions take precedence (?)
701 @{$call_cond}{keys %related} = values %related;
703 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
705 if (exists $attrs->{key}) {
706 $final_cond = $self->_qualify_cond_columns (
708 $self->_build_unique_cond (
716 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
717 # This means that we got here after a merger of relationship conditions
718 # in ::Relationship::Base::search_related (the row method), and furthermore
719 # the relationship is of the 'single' type. This means that the condition
720 # provided by the relationship (already attached to $self) is sufficient,
721 # as there can be only one row in the database that would satisfy the
725 # no key was specified - fall down to heuristics mode:
726 # run through all unique queries registered on the resultset, and
727 # 'OR' all qualifying queries together
728 my (@unique_queries, %seen_column_combinations);
729 for my $c_name ($rsrc->unique_constraint_names) {
730 next if $seen_column_combinations{
731 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
734 push @unique_queries, try {
735 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
739 $final_cond = @unique_queries
740 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
741 : $self->_non_unique_find_fallback ($call_cond, $attrs)
745 # Run the query, passing the result_class since it should propagate for find
746 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
747 if (keys %{$rs->_resolved_attrs->{collapse}}) {
749 carp "Query returned more than one row" if $rs->next;
757 # This is a stop-gap method as agreed during the discussion on find() cleanup:
758 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
760 # It is invoked when find() is called in legacy-mode with insufficiently-unique
761 # condition. It is provided for overrides until a saner way forward is devised
763 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
764 # the road. Please adjust your tests accordingly to catch this situation early
765 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
767 # The method will not be removed without an adequately complete replacement
768 # for strict-mode enforcement
769 sub _non_unique_find_fallback {
770 my ($self, $cond, $attrs) = @_;
772 return $self->_qualify_cond_columns(
774 exists $attrs->{alias}
776 : $self->{attrs}{alias}
781 sub _qualify_cond_columns {
782 my ($self, $cond, $alias) = @_;
784 my %aliased = %$cond;
785 for (keys %aliased) {
786 $aliased{"$alias.$_"} = delete $aliased{$_}
793 sub _build_unique_cond {
794 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
796 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
798 # combination may fail if $self->{cond} is non-trivial
799 my ($final_cond) = try {
800 $self->_merge_with_rscond ($extra_cond)
805 # trim out everything not in $columns
806 $final_cond = { map {
807 exists $final_cond->{$_}
808 ? ( $_ => $final_cond->{$_} )
812 if (my @missing = grep
813 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
816 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
818 join (', ', map { "'$_'" } @missing),
825 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
827 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
829 carp_unique ( sprintf (
830 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
831 . 'values in column(s): %s). This is almost certainly not what you wanted, '
832 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
834 join (', ', map { "'$_'" } @undefs),
841 =head2 search_related
845 =item Arguments: $rel, $cond, \%attrs?
847 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
851 $new_rs = $cd_rs->search_related('artist', {
855 Searches the specified relationship, optionally specifying a condition and
856 attributes for matching records. See L</ATTRIBUTES> for more information.
858 In list context, C<< ->all() >> is called implicitly on the resultset, thus
859 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
861 See also L</search_related_rs>.
866 return shift->related_resultset(shift)->search(@_);
869 =head2 search_related_rs
871 This method works exactly the same as search_related, except that
872 it guarantees a resultset, even in list context.
876 sub search_related_rs {
877 return shift->related_resultset(shift)->search_rs(@_);
884 =item Arguments: none
886 =item Return Value: $cursor
890 Returns a storage-driven cursor to the given resultset. See
891 L<DBIx::Class::Cursor> for more information.
898 my $attrs = $self->_resolved_attrs_copy;
900 return $self->{cursor}
901 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
902 $attrs->{where},$attrs);
909 =item Arguments: $cond?
911 =item Return Value: $row_object | undef
915 my $cd = $schema->resultset('CD')->single({ year => 2001 });
917 Inflates the first result without creating a cursor if the resultset has
918 any records in it; if not returns C<undef>. Used by L</find> as a lean version
921 While this method can take an optional search condition (just like L</search>)
922 being a fast-code-path it does not recognize search attributes. If you need to
923 add extra joins or similar, call L</search> and then chain-call L</single> on the
924 L<DBIx::Class::ResultSet> returned.
930 As of 0.08100, this method enforces the assumption that the preceding
931 query returns only one row. If more than one row is returned, you will receive
934 Query returned more than one row
936 In this case, you should be using L</next> or L</find> instead, or if you really
937 know what you are doing, use the L</rows> attribute to explicitly limit the size
940 This method will also throw an exception if it is called on a resultset prefetching
941 has_many, as such a prefetch implies fetching multiple rows from the database in
942 order to assemble the resulting object.
949 my ($self, $where) = @_;
951 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
954 my $attrs = $self->_resolved_attrs_copy;
956 if (keys %{$attrs->{collapse}}) {
957 $self->throw_exception(
958 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
963 if (defined $attrs->{where}) {
966 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
967 $where, delete $attrs->{where} ]
970 $attrs->{where} = $where;
974 my @data = $self->result_source->storage->select_single(
975 $attrs->{from}, $attrs->{select},
976 $attrs->{where}, $attrs
979 return (@data ? ($self->_construct_object(@data))[0] : undef);
985 # Recursively collapse the query, accumulating values for each column.
987 sub _collapse_query {
988 my ($self, $query, $collapsed) = @_;
992 if (ref $query eq 'ARRAY') {
993 foreach my $subquery (@$query) {
994 next unless ref $subquery; # -or
995 $collapsed = $self->_collapse_query($subquery, $collapsed);
998 elsif (ref $query eq 'HASH') {
999 if (keys %$query and (keys %$query)[0] eq '-and') {
1000 foreach my $subquery (@{$query->{-and}}) {
1001 $collapsed = $self->_collapse_query($subquery, $collapsed);
1005 foreach my $col (keys %$query) {
1006 my $value = $query->{$col};
1007 $collapsed->{$col}{$value}++;
1019 =item Arguments: $cond?
1021 =item Return Value: $resultsetcolumn
1025 my $max_length = $rs->get_column('length')->max;
1027 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1032 my ($self, $column) = @_;
1033 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1041 =item Arguments: $cond, \%attrs?
1043 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1047 # WHERE title LIKE '%blue%'
1048 $cd_rs = $rs->search_like({ title => '%blue%'});
1050 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1051 that this is simply a convenience method retained for ex Class::DBI users.
1052 You most likely want to use L</search> with specific operators.
1054 For more information, see L<DBIx::Class::Manual::Cookbook>.
1056 This method is deprecated and will be removed in 0.09. Use L</search()>
1057 instead. An example conversion is:
1059 ->search_like({ foo => 'bar' });
1063 ->search({ foo => { like => 'bar' } });
1070 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1071 .' Instead use ->search({ x => { -like => "y%" } })'
1072 .' (note the outer pair of {}s - they are important!)'
1074 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1075 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1076 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1077 return $class->search($query, { %$attrs });
1084 =item Arguments: $first, $last
1086 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1090 Returns a resultset or object list representing a subset of elements from the
1091 resultset slice is called on. Indexes are from 0, i.e., to get the first
1092 three records, call:
1094 my ($one, $two, $three) = $rs->slice(0, 2);
1099 my ($self, $min, $max) = @_;
1100 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1101 $attrs->{offset} = $self->{attrs}{offset} || 0;
1102 $attrs->{offset} += $min;
1103 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1104 return $self->search(undef, $attrs);
1105 #my $slice = (ref $self)->new($self->result_source, $attrs);
1106 #return (wantarray ? $slice->all : $slice);
1113 =item Arguments: none
1115 =item Return Value: $result | undef
1119 Returns the next element in the resultset (C<undef> is there is none).
1121 Can be used to efficiently iterate over records in the resultset:
1123 my $rs = $schema->resultset('CD')->search;
1124 while (my $cd = $rs->next) {
1128 Note that you need to store the resultset object, and call C<next> on it.
1129 Calling C<< resultset('Table')->next >> repeatedly will always return the
1130 first record from the resultset.
1136 if (my $cache = $self->get_cache) {
1137 $self->{all_cache_position} ||= 0;
1138 return $cache->[$self->{all_cache_position}++];
1140 if ($self->{attrs}{cache}) {
1141 delete $self->{pager};
1142 $self->{all_cache_position} = 1;
1143 return ($self->all)[0];
1145 if ($self->{stashed_objects}) {
1146 my $obj = shift(@{$self->{stashed_objects}});
1147 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1151 exists $self->{stashed_row}
1152 ? @{delete $self->{stashed_row}}
1153 : $self->cursor->next
1155 return undef unless (@row);
1156 my ($row, @more) = $self->_construct_object(@row);
1157 $self->{stashed_objects} = \@more if @more;
1161 sub _construct_object {
1162 my ($self, @row) = @_;
1164 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1166 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1167 @new = $self->{_attrs}{record_filter}->(@new)
1168 if exists $self->{_attrs}{record_filter};
1172 sub _collapse_result {
1173 my ($self, $as_proto, $row) = @_;
1177 # 'foo' => [ undef, 'foo' ]
1178 # 'foo.bar' => [ 'foo', 'bar' ]
1179 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1181 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1183 my %collapse = %{$self->{_attrs}{collapse}||{}};
1187 # if we're doing collapsing (has_many prefetch) we need to grab records
1188 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1189 # we know we don't have to bother.
1191 # the reason for not using the collapse stuff directly is because if you
1192 # had for e.g. two artists in a row with no cds, the collapse info for
1193 # both would be NULL (undef) so you'd lose the second artist
1195 # store just the index so we can check the array positions from the row
1196 # without having to contruct the full hash
1198 if (keys %collapse) {
1199 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1200 foreach my $i (0 .. $#construct_as) {
1201 next if defined($construct_as[$i][0]); # only self table
1202 if (delete $pri{$construct_as[$i][1]}) {
1203 push(@pri_index, $i);
1205 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1209 # no need to do an if, it'll be empty if @pri_index is empty anyway
1211 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1215 do { # no need to check anything at the front, we always want the first row
1219 foreach my $this_as (@construct_as) {
1220 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1223 push(@const_rows, \%const);
1225 } until ( # no pri_index => no collapse => drop straight out
1228 do { # get another row, stash it, drop out if different PK
1230 @copy = $self->cursor->next;
1231 $self->{stashed_row} = \@copy;
1233 # last thing in do block, counts as true if anything doesn't match
1235 # check xor defined first for NULL vs. NOT NULL then if one is
1236 # defined the other must be so check string equality
1239 (defined $pri_vals{$_} ^ defined $copy[$_])
1240 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1245 my $alias = $self->{attrs}{alias};
1252 foreach my $const (@const_rows) {
1253 scalar @const_keys or do {
1254 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1256 foreach my $key (@const_keys) {
1259 my @parts = split(/\./, $key);
1261 my $data = $const->{$key};
1262 foreach my $p (@parts) {
1263 $target = $target->[1]->{$p} ||= [];
1265 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1266 # collapsing at this point and on final part
1267 my $pos = $collapse_pos{$cur};
1268 CK: foreach my $ck (@ckey) {
1269 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1270 $collapse_pos{$cur} = $data;
1271 delete @collapse_pos{ # clear all positioning for sub-entries
1272 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1279 if (exists $collapse{$cur}) {
1280 $target = $target->[-1];
1283 $target->[0] = $data;
1285 $info->[0] = $const->{$key};
1293 =head2 result_source
1297 =item Arguments: $result_source?
1299 =item Return Value: $result_source
1303 An accessor for the primary ResultSource object from which this ResultSet
1310 =item Arguments: $result_class?
1312 =item Return Value: $result_class
1316 An accessor for the class to use when creating row objects. Defaults to
1317 C<< result_source->result_class >> - which in most cases is the name of the
1318 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1320 Note that changing the result_class will also remove any components
1321 that were originally loaded in the source class via
1322 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1323 in the original source class will not run.
1328 my ($self, $result_class) = @_;
1329 if ($result_class) {
1330 unless (ref $result_class) { # don't fire this for an object
1331 $self->ensure_class_loaded($result_class);
1333 $self->_result_class($result_class);
1334 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1335 # permit the user to set result class on one result set only; it only
1336 # chains if provided to search()
1337 #$self->{attrs}{result_class} = $result_class if ref $self;
1339 $self->_result_class;
1346 =item Arguments: $cond, \%attrs??
1348 =item Return Value: $count
1352 Performs an SQL C<COUNT> with the same query as the resultset was built
1353 with to find the number of elements. Passing arguments is equivalent to
1354 C<< $rs->search ($cond, \%attrs)->count >>
1360 return $self->search(@_)->count if @_ and defined $_[0];
1361 return scalar @{ $self->get_cache } if $self->get_cache;
1363 my $attrs = $self->_resolved_attrs_copy;
1365 # this is a little optimization - it is faster to do the limit
1366 # adjustments in software, instead of a subquery
1367 my $rows = delete $attrs->{rows};
1368 my $offset = delete $attrs->{offset};
1371 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1372 $crs = $self->_count_subq_rs ($attrs);
1375 $crs = $self->_count_rs ($attrs);
1377 my $count = $crs->next;
1379 $count -= $offset if $offset;
1380 $count = $rows if $rows and $rows < $count;
1381 $count = 0 if ($count < 0);
1390 =item Arguments: $cond, \%attrs??
1392 =item Return Value: $count_rs
1396 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1397 This can be very handy for subqueries:
1399 ->search( { amount => $some_rs->count_rs->as_query } )
1401 As with regular resultsets the SQL query will be executed only after
1402 the resultset is accessed via L</next> or L</all>. That would return
1403 the same single value obtainable via L</count>.
1409 return $self->search(@_)->count_rs if @_;
1411 # this may look like a lack of abstraction (count() does about the same)
1412 # but in fact an _rs *must* use a subquery for the limits, as the
1413 # software based limiting can not be ported if this $rs is to be used
1414 # in a subquery itself (i.e. ->as_query)
1415 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1416 return $self->_count_subq_rs;
1419 return $self->_count_rs;
1424 # returns a ResultSetColumn object tied to the count query
1427 my ($self, $attrs) = @_;
1429 my $rsrc = $self->result_source;
1430 $attrs ||= $self->_resolved_attrs;
1432 my $tmp_attrs = { %$attrs };
1433 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1434 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1436 # overwrite the selector (supplied by the storage)
1437 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1438 $tmp_attrs->{as} = 'count';
1439 delete @{$tmp_attrs}{qw/columns/};
1441 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1447 # same as above but uses a subquery
1449 sub _count_subq_rs {
1450 my ($self, $attrs) = @_;
1452 my $rsrc = $self->result_source;
1453 $attrs ||= $self->_resolved_attrs;
1455 my $sub_attrs = { %$attrs };
1456 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1457 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1459 # if we multi-prefetch we group_by primary keys only as this is what we would
1460 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1461 if ( keys %{$attrs->{collapse}} ) {
1462 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1465 # Calculate subquery selector
1466 if (my $g = $sub_attrs->{group_by}) {
1468 my $sql_maker = $rsrc->storage->sql_maker;
1470 # necessary as the group_by may refer to aliased functions
1472 for my $sel (@{$attrs->{select}}) {
1473 $sel_index->{$sel->{-as}} = $sel
1474 if (ref $sel eq 'HASH' and $sel->{-as});
1477 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1478 # also look for named aggregates referred in the having clause
1479 # having often contains scalarrefs - thus parse it out entirely
1481 if ($attrs->{having}) {
1482 local $sql_maker->{having_bind};
1483 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1484 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1485 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1486 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1487 # if we don't unset it we screw up retarded but unfortunately working
1488 # 'MAX(foo.bar)' => { '>', 3 }
1489 $sql_maker->{name_sep} = '';
1492 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1494 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1496 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1497 # and if all fails for an utterly naive quoted scalar-with-function
1499 $rquote $sep $lquote (.+?) $rquote
1501 [\s,] \w+ \. (\w+) [\s,]
1503 [\s,] $lquote (.+?) $rquote [\s,]
1505 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1510 my $colpiece = $sel_index->{$_} || $_;
1512 # unqualify join-based group_by's. Arcane but possible query
1513 # also horrible horrible hack to alias a column (not a func.)
1514 # (probably need to introduce SQLA syntax)
1515 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1518 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1520 push @{$sub_attrs->{select}}, $colpiece;
1524 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1525 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1528 return $rsrc->resultset_class
1529 ->new ($rsrc, $sub_attrs)
1531 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1532 ->get_column ('count');
1539 =head2 count_literal
1543 =item Arguments: $sql_fragment, @bind_values
1545 =item Return Value: $count
1549 Counts the results in a literal query. Equivalent to calling L</search_literal>
1550 with the passed arguments, then L</count>.
1554 sub count_literal { shift->search_literal(@_)->count; }
1560 =item Arguments: none
1562 =item Return Value: @objects
1566 Returns all elements in the resultset.
1573 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1576 return @{ $self->get_cache } if $self->get_cache;
1580 if (keys %{$self->_resolved_attrs->{collapse}}) {
1581 # Using $self->cursor->all is really just an optimisation.
1582 # If we're collapsing has_many prefetches it probably makes
1583 # very little difference, and this is cleaner than hacking
1584 # _construct_object to survive the approach
1585 $self->cursor->reset;
1586 my @row = $self->cursor->next;
1588 push(@obj, $self->_construct_object(@row));
1589 @row = (exists $self->{stashed_row}
1590 ? @{delete $self->{stashed_row}}
1591 : $self->cursor->next);
1594 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1597 $self->set_cache(\@obj) if $self->{attrs}{cache};
1606 =item Arguments: none
1608 =item Return Value: $self
1612 Resets the resultset's cursor, so you can iterate through the elements again.
1613 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1620 delete $self->{_attrs} if exists $self->{_attrs};
1621 $self->{all_cache_position} = 0;
1622 $self->cursor->reset;
1630 =item Arguments: none
1632 =item Return Value: $object | undef
1636 Resets the resultset and returns an object for the first result (or C<undef>
1637 if the resultset is empty).
1642 return $_[0]->reset->next;
1648 # Determines whether and what type of subquery is required for the $rs operation.
1649 # If grouping is necessary either supplies its own, or verifies the current one
1650 # After all is done delegates to the proper storage method.
1652 sub _rs_update_delete {
1653 my ($self, $op, $values) = @_;
1655 my $rsrc = $self->result_source;
1657 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1658 my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
1660 if ($needs_group_by_subq or $needs_subq) {
1662 # make a new $rs selecting only the PKs (that's all we really need)
1663 my $attrs = $self->_resolved_attrs_copy;
1666 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1667 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1669 if ($needs_group_by_subq) {
1670 # make sure no group_by was supplied, or if there is one - make sure it matches
1671 # the columns compiled above perfectly. Anything else can not be sanely executed
1672 # on most databases so croak right then and there
1674 if (my $g = $attrs->{group_by}) {
1675 my @current_group_by = map
1676 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1681 join ("\x00", sort @current_group_by)
1683 join ("\x00", sort @{$attrs->{columns}} )
1685 $self->throw_exception (
1686 "You have just attempted a $op operation on a resultset which does group_by"
1687 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1688 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1689 . ' kind of queries. Please retry the operation with a modified group_by or'
1690 . ' without using one at all.'
1695 $attrs->{group_by} = $attrs->{columns};
1699 my $subrs = (ref $self)->new($rsrc, $attrs);
1700 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1703 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1704 # a condition containing 'me' or other table prefixes will not work
1705 # at all. What this code tries to do (badly) is to generate a condition
1706 # with the qualifiers removed, by exploiting the quote mechanism of sqla
1708 # this is atrocious and should be replaced by normal sqla introspection
1710 my ($sql, @bind) = do {
1711 my $sqla = $rsrc->storage->sql_maker;
1712 local $sqla->{_dequalify_idents} = 1;
1713 $sqla->_recurse_where($self->{cond});
1716 return $rsrc->storage->$op(
1718 $op eq 'update' ? $values : (),
1719 $self->{cond} ? \[$sql, @bind] : (),
1728 =item Arguments: \%values
1730 =item Return Value: $storage_rv
1734 Sets the specified columns in the resultset to the supplied values in a
1735 single query. Note that this will not run any accessor/set_column/update
1736 triggers, nor will it update any row object instances derived from this
1737 resultset (this includes the contents of the L<resultset cache|/set_cache>
1738 if any). See L</update_all> if you need to execute any on-update
1739 triggers or cascades defined either by you or a
1740 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1742 The return value is a pass through of what the underlying
1743 storage backend returned, and may vary. See L<DBI/execute> for the most
1748 Note that L</update> does not process/deflate any of the values passed in.
1749 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1750 ensure manually that any value passed to this method will stringify to
1751 something the RDBMS knows how to deal with. A notable example is the
1752 handling of L<DateTime> objects, for more info see:
1753 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1758 my ($self, $values) = @_;
1759 $self->throw_exception('Values for update must be a hash')
1760 unless ref $values eq 'HASH';
1762 return $self->_rs_update_delete ('update', $values);
1769 =item Arguments: \%values
1771 =item Return Value: 1
1775 Fetches all objects and updates them one at a time via
1776 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1777 triggers, while L</update> will not.
1782 my ($self, $values) = @_;
1783 $self->throw_exception('Values for update_all must be a hash')
1784 unless ref $values eq 'HASH';
1786 my $guard = $self->result_source->schema->txn_scope_guard;
1787 $_->update($values) for $self->all;
1796 =item Arguments: none
1798 =item Return Value: $storage_rv
1802 Deletes the rows matching this resultset in a single query. Note that this
1803 will not run any delete triggers, nor will it alter the
1804 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1805 derived from this resultset (this includes the contents of the
1806 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1807 execute any on-delete triggers or cascades defined either by you or a
1808 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1810 The return value is a pass through of what the underlying storage backend
1811 returned, and may vary. See L<DBI/execute> for the most common case.
1817 $self->throw_exception('delete does not accept any arguments')
1820 return $self->_rs_update_delete ('delete');
1827 =item Arguments: none
1829 =item Return Value: 1
1833 Fetches all objects and deletes them one at a time via
1834 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1835 triggers, while L</delete> will not.
1841 $self->throw_exception('delete_all does not accept any arguments')
1844 my $guard = $self->result_source->schema->txn_scope_guard;
1845 $_->delete for $self->all;
1854 =item Arguments: \@data;
1858 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1859 For the arrayref of hashrefs style each hashref should be a structure suitable
1860 for submitting to a $resultset->create(...) method.
1862 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1863 to insert the data, as this is a faster method.
1865 Otherwise, each set of data is inserted into the database using
1866 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1867 accumulated into an array. The array itself, or an array reference
1868 is returned depending on scalar or list context.
1870 Example: Assuming an Artist Class that has many CDs Classes relating:
1872 my $Artist_rs = $schema->resultset("Artist");
1874 ## Void Context Example
1875 $Artist_rs->populate([
1876 { artistid => 4, name => 'Manufactured Crap', cds => [
1877 { title => 'My First CD', year => 2006 },
1878 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1881 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1882 { title => 'My parents sold me to a record company', year => 2005 },
1883 { title => 'Why Am I So Ugly?', year => 2006 },
1884 { title => 'I Got Surgery and am now Popular', year => 2007 }
1889 ## Array Context Example
1890 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1891 { name => "Artist One"},
1892 { name => "Artist Two"},
1893 { name => "Artist Three", cds=> [
1894 { title => "First CD", year => 2007},
1895 { title => "Second CD", year => 2008},
1899 print $ArtistOne->name; ## response is 'Artist One'
1900 print $ArtistThree->cds->count ## reponse is '2'
1902 For the arrayref of arrayrefs style, the first element should be a list of the
1903 fieldsnames to which the remaining elements are rows being inserted. For
1906 $Arstist_rs->populate([
1907 [qw/artistid name/],
1908 [100, 'A Formally Unknown Singer'],
1909 [101, 'A singer that jumped the shark two albums ago'],
1910 [102, 'An actually cool singer'],
1913 Please note an important effect on your data when choosing between void and
1914 wantarray context. Since void context goes straight to C<insert_bulk> in
1915 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1916 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1917 create primary keys for you, you will find that your PKs are empty. In this
1918 case you will have to use the wantarray context in order to create those
1926 # cruft placed in standalone method
1927 my $data = $self->_normalize_populate_args(@_);
1929 if(defined wantarray) {
1931 foreach my $item (@$data) {
1932 push(@created, $self->create($item));
1934 return wantarray ? @created : \@created;
1937 my $first = $data->[0];
1939 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1940 # it relationship data
1941 my (@rels, @columns);
1942 my $rsrc = $self->result_source;
1943 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1944 for (keys %$first) {
1945 my $ref = ref $first->{$_};
1946 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1952 my @pks = $rsrc->primary_columns;
1954 ## do the belongs_to relationships
1955 foreach my $index (0..$#$data) {
1957 # delegate to create() for any dataset without primary keys with specified relationships
1958 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1960 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1961 my @ret = $self->populate($data);
1967 foreach my $rel (@rels) {
1968 next unless ref $data->[$index]->{$rel} eq "HASH";
1969 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1970 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1971 my $related = $result->result_source->_resolve_condition(
1972 $reverse_relinfo->{cond},
1978 delete $data->[$index]->{$rel};
1979 $data->[$index] = {%{$data->[$index]}, %$related};
1981 push @columns, keys %$related if $index == 0;
1985 ## inherit the data locked in the conditions of the resultset
1986 my ($rs_data) = $self->_merge_with_rscond({});
1987 delete @{$rs_data}{@columns};
1988 my @inherit_cols = keys %$rs_data;
1989 my @inherit_data = values %$rs_data;
1991 ## do bulk insert on current row
1992 $rsrc->storage->insert_bulk(
1994 [@columns, @inherit_cols],
1995 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1998 ## do the has_many relationships
1999 foreach my $item (@$data) {
2003 foreach my $rel (@rels) {
2004 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2006 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2008 my $child = $main_row->$rel;
2010 my $related = $child->result_source->_resolve_condition(
2011 $rels->{$rel}{cond},
2017 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2018 my @populate = map { {%$_, %$related} } @rows_to_add;
2020 $child->populate( \@populate );
2027 # populate() argumnets went over several incarnations
2028 # What we ultimately support is AoH
2029 sub _normalize_populate_args {
2030 my ($self, $arg) = @_;
2032 if (ref $arg eq 'ARRAY') {
2033 if (ref $arg->[0] eq 'HASH') {
2036 elsif (ref $arg->[0] eq 'ARRAY') {
2038 my @colnames = @{$arg->[0]};
2039 foreach my $values (@{$arg}[1 .. $#$arg]) {
2040 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2046 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2053 =item Arguments: none
2055 =item Return Value: $pager
2059 Return Value a L<Data::Page> object for the current resultset. Only makes
2060 sense for queries with a C<page> attribute.
2062 To get the full count of entries for a paged resultset, call
2063 C<total_entries> on the L<Data::Page> object.
2067 # make a wizard good for both a scalar and a hashref
2068 my $mk_lazy_count_wizard = sub {
2069 require Variable::Magic;
2071 my $stash = { total_rs => shift };
2072 my $slot = shift; # only used by the hashref magic
2074 my $magic = Variable::Magic::wizard (
2075 data => sub { $stash },
2081 # set value lazily, and dispell for good
2082 ${$_[0]} = $_[1]{total_rs}->count;
2083 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2087 # an explicit set implies dispell as well
2088 # the unless() is to work around "fun and giggles" below
2089 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2090 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2097 if ($_[2] eq $slot and !$_[1]{inactive}) {
2098 my $cnt = $_[1]{total_rs}->count;
2099 $_[0]->{$slot} = $cnt;
2101 # attempting to dispell in a fetch handle (works in store), seems
2102 # to invariable segfault on 5.10, 5.12, 5.13 :(
2103 # so use an inactivator instead
2104 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2110 if (! $_[1]{inactive} and $_[2] eq $slot) {
2111 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2113 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2120 $stash->{magic_selfref} = $magic;
2121 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2126 # the tie class for 5.8.1
2128 package # hide from pause
2129 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2130 use base qw/Tie::Hash/;
2132 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2133 sub NEXTKEY { each %{$_[0]{data}} }
2134 sub EXISTS { exists $_[0]{data}{$_[1]} }
2135 sub DELETE { delete $_[0]{data}{$_[1]} }
2136 sub CLEAR { %{$_[0]{data}} = () }
2137 sub SCALAR { scalar %{$_[0]{data}} }
2140 $_[1]{data} = {%{$_[1]{selfref}}};
2141 %{$_[1]{selfref}} = ();
2142 Scalar::Util::weaken ($_[1]{selfref});
2143 return bless ($_[1], $_[0]);
2147 if ($_[1] eq $_[0]{slot}) {
2148 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2149 untie %{$_[0]{selfref}};
2150 %{$_[0]{selfref}} = %{$_[0]{data}};
2159 $_[0]{data}{$_[1]} = $_[2];
2160 if ($_[1] eq $_[0]{slot}) {
2161 untie %{$_[0]{selfref}};
2162 %{$_[0]{selfref}} = %{$_[0]{data}};
2171 return $self->{pager} if $self->{pager};
2173 my $attrs = $self->{attrs};
2174 if (!defined $attrs->{page}) {
2175 $self->throw_exception("Can't create pager for non-paged rs");
2177 elsif ($attrs->{page} <= 0) {
2178 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2180 $attrs->{rows} ||= 10;
2182 # throw away the paging flags and re-run the count (possibly
2183 # with a subselect) to get the real total count
2184 my $count_attrs = { %$attrs };
2185 delete $count_attrs->{$_} for qw/rows offset page pager/;
2186 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2189 ### the following may seem awkward and dirty, but it's a thought-experiment
2190 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2191 ### before talking to ribasushi/mst
2194 my $pager = Data::Page->new(
2195 0, #start with an empty set
2197 $self->{attrs}{page},
2200 my $data_slot = 'total_entries';
2202 # Since we are interested in a cached value (once it's set - it's set), every
2203 # technique will detach from the magic-host once the time comes to fire the
2204 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2206 if ($] < 5.008003) {
2207 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2208 # to weakref the magic container :(
2210 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2211 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2214 elsif ($] < 5.010) {
2215 # We can use magic on the hash value slot. It's interesting that the magic is
2216 # attached to the hash-slot, and does *not* stop working once I do the dummy
2217 # assignments after the cast()
2218 # tested on 5.8.3 and 5.8.9
2219 my $magic = $mk_lazy_count_wizard->($total_rs);
2220 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2222 # this is for fun and giggles
2223 $pager->{$data_slot} = -1;
2224 $pager->{$data_slot} = 0;
2226 # this does not work for scalars, but works with
2228 #my %vals = %$pager;
2233 # And the uvar magic
2234 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2235 # however see the wizard maker for more notes
2236 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2237 Variable::Magic::cast ( %$pager, $magic );
2240 $pager->{$data_slot} = -1;
2241 $pager->{$data_slot} = 0;
2249 return $self->{pager} = $pager;
2256 =item Arguments: $page_number
2258 =item Return Value: $rs
2262 Returns a resultset for the $page_number page of the resultset on which page
2263 is called, where each page contains a number of rows equal to the 'rows'
2264 attribute set on the resultset (10 by default).
2269 my ($self, $page) = @_;
2270 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2277 =item Arguments: \%vals
2279 =item Return Value: $rowobject
2283 Creates a new row object in the resultset's result class and returns
2284 it. The row is not inserted into the database at this point, call
2285 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2286 will tell you whether the row object has been inserted or not.
2288 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2293 my ($self, $values) = @_;
2294 $self->throw_exception( "new_result needs a hash" )
2295 unless (ref $values eq 'HASH');
2297 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2301 @$cols_from_relations
2302 ? (-cols_from_relations => $cols_from_relations)
2304 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2307 return $self->result_class->new(\%new);
2310 # _merge_with_rscond
2312 # Takes a simple hash of K/V data and returns its copy merged with the
2313 # condition already present on the resultset. Additionally returns an
2314 # arrayref of value/condition names, which were inferred from related
2315 # objects (this is needed for in-memory related objects)
2316 sub _merge_with_rscond {
2317 my ($self, $data) = @_;
2319 my (%new_data, @cols_from_relations);
2321 my $alias = $self->{attrs}{alias};
2323 if (! defined $self->{cond}) {
2324 # just massage $data below
2326 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2327 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2328 @cols_from_relations = keys %new_data;
2330 elsif (ref $self->{cond} ne 'HASH') {
2331 $self->throw_exception(
2332 "Can't abstract implicit construct, resultset condition not a hash"
2336 # precendence must be given to passed values over values inherited from
2337 # the cond, so the order here is important.
2338 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2339 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2341 while ( my($col, $value) = each %implied ) {
2342 my $vref = ref $value;
2348 (keys %$value)[0] eq '='
2350 $new_data{$col} = $value->{'='};
2352 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2353 $new_data{$col} = $value;
2360 %{ $self->_remove_alias($data, $alias) },
2363 return (\%new_data, \@cols_from_relations);
2366 # _has_resolved_attr
2368 # determines if the resultset defines at least one
2369 # of the attributes supplied
2371 # used to determine if a subquery is neccessary
2373 # supports some virtual attributes:
2375 # This will scan for any joins being present on the resultset.
2376 # It is not a mere key-search but a deep inspection of {from}
2379 sub _has_resolved_attr {
2380 my ($self, @attr_names) = @_;
2382 my $attrs = $self->_resolved_attrs;
2386 for my $n (@attr_names) {
2387 if (grep { $n eq $_ } (qw/-join/) ) {
2388 $extra_checks{$n}++;
2392 my $attr = $attrs->{$n};
2394 next if not defined $attr;
2396 if (ref $attr eq 'HASH') {
2397 return 1 if keys %$attr;
2399 elsif (ref $attr eq 'ARRAY') {
2407 # a resolved join is expressed as a multi-level from
2409 $extra_checks{-join}
2411 ref $attrs->{from} eq 'ARRAY'
2413 @{$attrs->{from}} > 1
2421 # Recursively collapse the condition.
2423 sub _collapse_cond {
2424 my ($self, $cond, $collapsed) = @_;
2428 if (ref $cond eq 'ARRAY') {
2429 foreach my $subcond (@$cond) {
2430 next unless ref $subcond; # -or
2431 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2434 elsif (ref $cond eq 'HASH') {
2435 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2436 foreach my $subcond (@{$cond->{-and}}) {
2437 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2441 foreach my $col (keys %$cond) {
2442 my $value = $cond->{$col};
2443 $collapsed->{$col} = $value;
2453 # Remove the specified alias from the specified query hash. A copy is made so
2454 # the original query is not modified.
2457 my ($self, $query, $alias) = @_;
2459 my %orig = %{ $query || {} };
2462 foreach my $key (keys %orig) {
2464 $unaliased{$key} = $orig{$key};
2467 $unaliased{$1} = $orig{$key}
2468 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2478 =item Arguments: none
2480 =item Return Value: \[ $sql, @bind ]
2484 Returns the SQL query and bind vars associated with the invocant.
2486 This is generally used as the RHS for a subquery.
2493 my $attrs = $self->_resolved_attrs_copy;
2498 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2499 # $sql also has no wrapping parenthesis in list ctx
2501 my $sqlbind = $self->result_source->storage
2502 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2511 =item Arguments: \%vals, \%attrs?
2513 =item Return Value: $rowobject
2517 my $artist = $schema->resultset('Artist')->find_or_new(
2518 { artist => 'fred' }, { key => 'artists' });
2520 $cd->cd_to_producer->find_or_new({ producer => $producer },
2521 { key => 'primary });
2523 Find an existing record from this resultset using L</find>. if none exists,
2524 instantiate a new result object and return it. The object will not be saved
2525 into your storage until you call L<DBIx::Class::Row/insert> on it.
2527 You most likely want this method when looking for existing rows using a unique
2528 constraint that is not the primary key, or looking for related rows.
2530 If you want objects to be saved immediately, use L</find_or_create> instead.
2532 B<Note>: Make sure to read the documentation of L</find> and understand the
2533 significance of the C<key> attribute, as its lack may skew your search, and
2534 subsequently result in spurious new objects.
2536 B<Note>: Take care when using C<find_or_new> with a table having
2537 columns with default values that you intend to be automatically
2538 supplied by the database (e.g. an auto_increment primary key column).
2539 In normal usage, the value of such columns should NOT be included at
2540 all in the call to C<find_or_new>, even when set to C<undef>.
2546 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2547 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2548 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2551 return $self->new_result($hash);
2558 =item Arguments: \%vals
2560 =item Return Value: a L<DBIx::Class::Row> $object
2564 Attempt to create a single new row or a row with multiple related rows
2565 in the table represented by the resultset (and related tables). This
2566 will not check for duplicate rows before inserting, use
2567 L</find_or_create> to do that.
2569 To create one row for this resultset, pass a hashref of key/value
2570 pairs representing the columns of the table and the values you wish to
2571 store. If the appropriate relationships are set up, foreign key fields
2572 can also be passed an object representing the foreign row, and the
2573 value will be set to its primary key.
2575 To create related objects, pass a hashref of related-object column values
2576 B<keyed on the relationship name>. If the relationship is of type C<multi>
2577 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2578 The process will correctly identify columns holding foreign keys, and will
2579 transparently populate them from the keys of the corresponding relation.
2580 This can be applied recursively, and will work correctly for a structure
2581 with an arbitrary depth and width, as long as the relationships actually
2582 exists and the correct column data has been supplied.
2585 Instead of hashrefs of plain related data (key/value pairs), you may
2586 also pass new or inserted objects. New objects (not inserted yet, see
2587 L</new>), will be inserted into their appropriate tables.
2589 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2591 Example of creating a new row.
2593 $person_rs->create({
2594 name=>"Some Person",
2595 email=>"somebody@someplace.com"
2598 Example of creating a new row and also creating rows in a related C<has_many>
2599 or C<has_one> resultset. Note Arrayref.
2602 { artistid => 4, name => 'Manufactured Crap', cds => [
2603 { title => 'My First CD', year => 2006 },
2604 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2609 Example of creating a new row and also creating a row in a related
2610 C<belongs_to> resultset. Note Hashref.
2613 title=>"Music for Silly Walks",
2616 name=>"Silly Musician",
2624 When subclassing ResultSet never attempt to override this method. Since
2625 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2626 lot of the internals simply never call it, so your override will be
2627 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2628 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2629 L</create> process you need to intervene.
2636 my ($self, $attrs) = @_;
2637 $self->throw_exception( "create needs a hashref" )
2638 unless ref $attrs eq 'HASH';
2639 return $self->new_result($attrs)->insert;
2642 =head2 find_or_create
2646 =item Arguments: \%vals, \%attrs?
2648 =item Return Value: $rowobject
2652 $cd->cd_to_producer->find_or_create({ producer => $producer },
2653 { key => 'primary' });
2655 Tries to find a record based on its primary key or unique constraints; if none
2656 is found, creates one and returns that instead.
2658 my $cd = $schema->resultset('CD')->find_or_create({
2660 artist => 'Massive Attack',
2661 title => 'Mezzanine',
2665 Also takes an optional C<key> attribute, to search by a specific key or unique
2666 constraint. For example:
2668 my $cd = $schema->resultset('CD')->find_or_create(
2670 artist => 'Massive Attack',
2671 title => 'Mezzanine',
2673 { key => 'cd_artist_title' }
2676 B<Note>: Make sure to read the documentation of L</find> and understand the
2677 significance of the C<key> attribute, as its lack may skew your search, and
2678 subsequently result in spurious row creation.
2680 B<Note>: Because find_or_create() reads from the database and then
2681 possibly inserts based on the result, this method is subject to a race
2682 condition. Another process could create a record in the table after
2683 the find has completed and before the create has started. To avoid
2684 this problem, use find_or_create() inside a transaction.
2686 B<Note>: Take care when using C<find_or_create> with a table having
2687 columns with default values that you intend to be automatically
2688 supplied by the database (e.g. an auto_increment primary key column).
2689 In normal usage, the value of such columns should NOT be included at
2690 all in the call to C<find_or_create>, even when set to C<undef>.
2692 See also L</find> and L</update_or_create>. For information on how to declare
2693 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2697 sub find_or_create {
2699 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2700 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2701 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2704 return $self->create($hash);
2707 =head2 update_or_create
2711 =item Arguments: \%col_values, { key => $unique_constraint }?
2713 =item Return Value: $row_object
2717 $resultset->update_or_create({ col => $val, ... });
2719 Like L</find_or_create>, but if a row is found it is immediately updated via
2720 C<< $found_row->update (\%col_values) >>.
2723 Takes an optional C<key> attribute to search on a specific unique constraint.
2726 # In your application
2727 my $cd = $schema->resultset('CD')->update_or_create(
2729 artist => 'Massive Attack',
2730 title => 'Mezzanine',
2733 { key => 'cd_artist_title' }
2736 $cd->cd_to_producer->update_or_create({
2737 producer => $producer,
2743 B<Note>: Make sure to read the documentation of L</find> and understand the
2744 significance of the C<key> attribute, as its lack may skew your search, and
2745 subsequently result in spurious row creation.
2747 B<Note>: Take care when using C<update_or_create> with a table having
2748 columns with default values that you intend to be automatically
2749 supplied by the database (e.g. an auto_increment primary key column).
2750 In normal usage, the value of such columns should NOT be included at
2751 all in the call to C<update_or_create>, even when set to C<undef>.
2753 See also L</find> and L</find_or_create>. For information on how to declare
2754 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2758 sub update_or_create {
2760 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2761 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2763 my $row = $self->find($cond, $attrs);
2765 $row->update($cond);
2769 return $self->create($cond);
2772 =head2 update_or_new
2776 =item Arguments: \%col_values, { key => $unique_constraint }?
2778 =item Return Value: $rowobject
2782 $resultset->update_or_new({ col => $val, ... });
2784 Like L</find_or_new> but if a row is found it is immediately updated via
2785 C<< $found_row->update (\%col_values) >>.
2789 # In your application
2790 my $cd = $schema->resultset('CD')->update_or_new(
2792 artist => 'Massive Attack',
2793 title => 'Mezzanine',
2796 { key => 'cd_artist_title' }
2799 if ($cd->in_storage) {
2800 # the cd was updated
2803 # the cd is not yet in the database, let's insert it
2807 B<Note>: Make sure to read the documentation of L</find> and understand the
2808 significance of the C<key> attribute, as its lack may skew your search, and
2809 subsequently result in spurious new objects.
2811 B<Note>: Take care when using C<update_or_new> with a table having
2812 columns with default values that you intend to be automatically
2813 supplied by the database (e.g. an auto_increment primary key column).
2814 In normal usage, the value of such columns should NOT be included at
2815 all in the call to C<update_or_new>, even when set to C<undef>.
2817 See also L</find>, L</find_or_create> and L</find_or_new>.
2823 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2824 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2826 my $row = $self->find( $cond, $attrs );
2827 if ( defined $row ) {
2828 $row->update($cond);
2832 return $self->new_result($cond);
2839 =item Arguments: none
2841 =item Return Value: \@cache_objects | undef
2845 Gets the contents of the cache for the resultset, if the cache is set.
2847 The cache is populated either by using the L</prefetch> attribute to
2848 L</search> or by calling L</set_cache>.
2860 =item Arguments: \@cache_objects
2862 =item Return Value: \@cache_objects
2866 Sets the contents of the cache for the resultset. Expects an arrayref
2867 of objects of the same class as those produced by the resultset. Note that
2868 if the cache is set the resultset will return the cached objects rather
2869 than re-querying the database even if the cache attr is not set.
2871 The contents of the cache can also be populated by using the
2872 L</prefetch> attribute to L</search>.
2877 my ( $self, $data ) = @_;
2878 $self->throw_exception("set_cache requires an arrayref")
2879 if defined($data) && (ref $data ne 'ARRAY');
2880 $self->{all_cache} = $data;
2887 =item Arguments: none
2889 =item Return Value: undef
2893 Clears the cache for the resultset.
2898 shift->set_cache(undef);
2905 =item Arguments: none
2907 =item Return Value: true, if the resultset has been paginated
2915 return !!$self->{attrs}{page};
2922 =item Arguments: none
2924 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2932 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2935 =head2 related_resultset
2939 =item Arguments: $relationship_name
2941 =item Return Value: $resultset
2945 Returns a related resultset for the supplied relationship name.
2947 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2951 sub related_resultset {
2952 my ($self, $rel) = @_;
2954 $self->{related_resultsets} ||= {};
2955 return $self->{related_resultsets}{$rel} ||= do {
2956 my $rsrc = $self->result_source;
2957 my $rel_info = $rsrc->relationship_info($rel);
2959 $self->throw_exception(
2960 "search_related: result source '" . $rsrc->source_name .
2961 "' has no such relationship $rel")
2964 my $attrs = $self->_chain_relationship($rel);
2966 my $join_count = $attrs->{seen_join}{$rel};
2968 my $alias = $self->result_source->storage
2969 ->relname_to_table_alias($rel, $join_count);
2971 # since this is search_related, and we already slid the select window inwards
2972 # (the select/as attrs were deleted in the beginning), we need to flip all
2973 # left joins to inner, so we get the expected results
2974 # read the comment on top of the actual function to see what this does
2975 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2978 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2979 delete @{$attrs}{qw(result_class alias)};
2983 if (my $cache = $self->get_cache) {
2984 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2985 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2990 my $rel_source = $rsrc->related_source($rel);
2994 # The reason we do this now instead of passing the alias to the
2995 # search_rs below is that if you wrap/overload resultset on the
2996 # source you need to know what alias it's -going- to have for things
2997 # to work sanely (e.g. RestrictWithObject wants to be able to add
2998 # extra query restrictions, and these may need to be $alias.)
3000 my $rel_attrs = $rel_source->resultset_attributes;
3001 local $rel_attrs->{alias} = $alias;
3003 $rel_source->resultset
3007 where => $attrs->{where},
3010 $new->set_cache($new_cache) if $new_cache;
3015 =head2 current_source_alias
3019 =item Arguments: none
3021 =item Return Value: $source_alias
3025 Returns the current table alias for the result source this resultset is built
3026 on, that will be used in the SQL query. Usually it is C<me>.
3028 Currently the source alias that refers to the result set returned by a
3029 L</search>/L</find> family method depends on how you got to the resultset: it's
3030 C<me> by default, but eg. L</search_related> aliases it to the related result
3031 source name (and keeps C<me> referring to the original result set). The long
3032 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3033 (and make this method unnecessary).
3035 Thus it's currently necessary to use this method in predefined queries (see
3036 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3037 source alias of the current result set:
3039 # in a result set class
3041 my ($self, $user) = @_;
3043 my $me = $self->current_source_alias;
3045 return $self->search(
3046 "$me.modified" => $user->id,
3052 sub current_source_alias {
3055 return ($self->{attrs} || {})->{alias} || 'me';
3058 =head2 as_subselect_rs
3062 =item Arguments: none
3064 =item Return Value: $resultset
3068 Act as a barrier to SQL symbols. The resultset provided will be made into a
3069 "virtual view" by including it as a subquery within the from clause. From this
3070 point on, any joined tables are inaccessible to ->search on the resultset (as if
3071 it were simply where-filtered without joins). For example:
3073 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3075 # 'x' now pollutes the query namespace
3077 # So the following works as expected
3078 my $ok_rs = $rs->search({'x.other' => 1});
3080 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3081 # def) we look for one row with contradictory terms and join in another table
3082 # (aliased 'x_2') which we never use
3083 my $broken_rs = $rs->search({'x.name' => 'def'});
3085 my $rs2 = $rs->as_subselect_rs;
3087 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3088 my $not_joined_rs = $rs2->search({'x.other' => 1});
3090 # works as expected: finds a 'table' row related to two x rows (abc and def)
3091 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3093 Another example of when one might use this would be to select a subset of
3094 columns in a group by clause:
3096 my $rs = $schema->resultset('Bar')->search(undef, {
3097 group_by => [qw{ id foo_id baz_id }],
3098 })->as_subselect_rs->search(undef, {
3099 columns => [qw{ id foo_id }]
3102 In the above example normally columns would have to be equal to the group by,
3103 but because we isolated the group by into a subselect the above works.
3107 sub as_subselect_rs {
3110 my $attrs = $self->_resolved_attrs;
3112 my $fresh_rs = (ref $self)->new (
3113 $self->result_source
3116 # these pieces will be locked in the subquery
3117 delete $fresh_rs->{cond};
3118 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3120 return $fresh_rs->search( {}, {
3122 $attrs->{alias} => $self->as_query,
3123 -alias => $attrs->{alias},
3124 -rsrc => $self->result_source,
3126 alias => $attrs->{alias},
3130 # This code is called by search_related, and makes sure there
3131 # is clear separation between the joins before, during, and
3132 # after the relationship. This information is needed later
3133 # in order to properly resolve prefetch aliases (any alias
3134 # with a relation_chain_depth less than the depth of the
3135 # current prefetch is not considered)
3137 # The increments happen twice per join. An even number means a
3138 # relationship specified via a search_related, whereas an odd
3139 # number indicates a join/prefetch added via attributes
3141 # Also this code will wrap the current resultset (the one we
3142 # chain to) in a subselect IFF it contains limiting attributes
3143 sub _chain_relationship {
3144 my ($self, $rel) = @_;
3145 my $source = $self->result_source;
3146 my $attrs = { %{$self->{attrs}||{}} };
3148 # we need to take the prefetch the attrs into account before we
3149 # ->_resolve_join as otherwise they get lost - captainL
3150 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3152 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3154 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3157 my @force_subq_attrs = qw/offset rows group_by having/;
3160 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3162 $self->_has_resolved_attr (@force_subq_attrs)
3164 # Nuke the prefetch (if any) before the new $rs attrs
3165 # are resolved (prefetch is useless - we are wrapping
3166 # a subquery anyway).
3167 my $rs_copy = $self->search;
3168 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3169 $rs_copy->{attrs}{join},
3170 delete $rs_copy->{attrs}{prefetch},
3175 -alias => $attrs->{alias},
3176 $attrs->{alias} => $rs_copy->as_query,
3178 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3179 $seen->{-relation_chain_depth} = 0;
3181 elsif ($attrs->{from}) { #shallow copy suffices
3182 $from = [ @{$attrs->{from}} ];
3187 -alias => $attrs->{alias},
3188 $attrs->{alias} => $source->from,
3192 my $jpath = ($seen->{-relation_chain_depth})
3193 ? $from->[-1][0]{-join_path}
3196 my @requested_joins = $source->_resolve_join(
3203 push @$from, @requested_joins;
3205 $seen->{-relation_chain_depth}++;
3207 # if $self already had a join/prefetch specified on it, the requested
3208 # $rel might very well be already included. What we do in this case
3209 # is effectively a no-op (except that we bump up the chain_depth on
3210 # the join in question so we could tell it *is* the search_related)
3213 # we consider the last one thus reverse
3214 for my $j (reverse @requested_joins) {
3215 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3216 if ($rel eq $last_j) {
3217 $j->[0]{-relation_chain_depth}++;
3223 unless ($already_joined) {
3224 push @$from, $source->_resolve_join(
3232 $seen->{-relation_chain_depth}++;
3234 return {%$attrs, from => $from, seen_join => $seen};
3237 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3238 sub _resolved_attrs_copy {
3240 return { %{$self->_resolved_attrs (@_)} };
3243 sub _resolved_attrs {
3245 return $self->{_attrs} if $self->{_attrs};
3247 my $attrs = { %{ $self->{attrs} || {} } };
3248 my $source = $self->result_source;
3249 my $alias = $attrs->{alias};
3251 # default selection list
3252 $attrs->{columns} = [ $source->columns ]
3253 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3255 # merge selectors together
3256 for (qw/columns select as/) {
3257 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3258 if $attrs->{$_} or $attrs->{"+$_"};
3261 # disassemble columns
3263 if (my $cols = delete $attrs->{columns}) {
3264 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3265 if (ref $c eq 'HASH') {
3266 for my $as (keys %$c) {
3267 push @sel, $c->{$as};
3278 # when trying to weed off duplicates later do not go past this point -
3279 # everything added from here on is unbalanced "anyone's guess" stuff
3280 my $dedup_stop_idx = $#as;
3282 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3284 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3285 if $attrs->{select};
3287 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3289 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3292 # disqualify all $alias.col as-bits (collapser mandated)
3294 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3297 # de-duplicate the result (remove *identical* select/as pairs)
3298 # and also die on duplicate {as} pointing to different {select}s
3299 # not using a c-style for as the condition is prone to shrinkage
3302 while ($i <= $dedup_stop_idx) {
3303 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3308 elsif ($seen->{$as[$i]}++) {
3309 $self->throw_exception(
3310 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3318 $attrs->{select} = \@sel;
3319 $attrs->{as} = \@as;
3321 $attrs->{from} ||= [{
3323 -alias => $self->{attrs}{alias},
3324 $self->{attrs}{alias} => $source->from,
3327 if ( $attrs->{join} || $attrs->{prefetch} ) {
3329 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3330 if ref $attrs->{from} ne 'ARRAY';
3332 my $join = (delete $attrs->{join}) || {};
3334 if ( defined $attrs->{prefetch} ) {
3335 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3338 $attrs->{from} = # have to copy here to avoid corrupting the original
3340 @{ $attrs->{from} },
3341 $source->_resolve_join(
3344 { %{ $attrs->{seen_join} || {} } },
3345 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3346 ? $attrs->{from}[-1][0]{-join_path}
3353 if ( defined $attrs->{order_by} ) {
3354 $attrs->{order_by} = (
3355 ref( $attrs->{order_by} ) eq 'ARRAY'
3356 ? [ @{ $attrs->{order_by} } ]
3357 : [ $attrs->{order_by} || () ]
3361 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3362 $attrs->{group_by} = [ $attrs->{group_by} ];
3365 # generate the distinct induced group_by early, as prefetch will be carried via a
3366 # subquery (since a group_by is present)
3367 if (delete $attrs->{distinct}) {
3368 if ($attrs->{group_by}) {
3369 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3372 # distinct affects only the main selection part, not what prefetch may
3374 $attrs->{group_by} = $source->storage->_group_over_selection (
3382 $attrs->{collapse} ||= {};
3383 if ($attrs->{prefetch}) {
3385 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3386 if $attrs->{_dark_selector};
3388 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3390 my $prefetch_ordering = [];
3392 # this is a separate structure (we don't look in {from} directly)
3393 # as the resolver needs to shift things off the lists to work
3394 # properly (identical-prefetches on different branches)
3396 if (ref $attrs->{from} eq 'ARRAY') {
3398 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3400 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3401 next unless $j->[0]{-alias};
3402 next unless $j->[0]{-join_path};
3403 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3405 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3408 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3409 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3414 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3416 # we need to somehow mark which columns came from prefetch
3418 my $sel_end = $#{$attrs->{select}};
3419 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3422 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3423 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3425 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3426 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3430 # if both page and offset are specified, produce a combined offset
3431 # even though it doesn't make much sense, this is what pre 081xx has
3433 if (my $page = delete $attrs->{page}) {
3435 ($attrs->{rows} * ($page - 1))
3437 ($attrs->{offset} || 0)
3441 return $self->{_attrs} = $attrs;
3445 my ($self, $attr) = @_;
3447 if (ref $attr eq 'HASH') {
3448 return $self->_rollout_hash($attr);
3449 } elsif (ref $attr eq 'ARRAY') {
3450 return $self->_rollout_array($attr);
3456 sub _rollout_array {
3457 my ($self, $attr) = @_;
3460 foreach my $element (@{$attr}) {
3461 if (ref $element eq 'HASH') {
3462 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3463 } elsif (ref $element eq 'ARRAY') {
3464 # XXX - should probably recurse here
3465 push( @rolled_array, @{$self->_rollout_array($element)} );
3467 push( @rolled_array, $element );
3470 return \@rolled_array;
3474 my ($self, $attr) = @_;
3477 foreach my $key (keys %{$attr}) {
3478 push( @rolled_array, { $key => $attr->{$key} } );
3480 return \@rolled_array;
3483 sub _calculate_score {
3484 my ($self, $a, $b) = @_;
3486 if (defined $a xor defined $b) {
3489 elsif (not defined $a) {
3493 if (ref $b eq 'HASH') {
3494 my ($b_key) = keys %{$b};
3495 if (ref $a eq 'HASH') {
3496 my ($a_key) = keys %{$a};
3497 if ($a_key eq $b_key) {
3498 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3503 return ($a eq $b_key) ? 1 : 0;
3506 if (ref $a eq 'HASH') {
3507 my ($a_key) = keys %{$a};
3508 return ($b eq $a_key) ? 1 : 0;
3510 return ($b eq $a) ? 1 : 0;
3515 sub _merge_joinpref_attr {
3516 my ($self, $orig, $import) = @_;
3518 return $import unless defined($orig);
3519 return $orig unless defined($import);
3521 $orig = $self->_rollout_attr($orig);
3522 $import = $self->_rollout_attr($import);
3525 foreach my $import_element ( @{$import} ) {
3526 # find best candidate from $orig to merge $b_element into
3527 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3528 foreach my $orig_element ( @{$orig} ) {
3529 my $score = $self->_calculate_score( $orig_element, $import_element );
3530 if ($score > $best_candidate->{score}) {
3531 $best_candidate->{position} = $position;
3532 $best_candidate->{score} = $score;
3536 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3538 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3539 push( @{$orig}, $import_element );
3541 my $orig_best = $orig->[$best_candidate->{position}];
3542 # merge orig_best and b_element together and replace original with merged
3543 if (ref $orig_best ne 'HASH') {
3544 $orig->[$best_candidate->{position}] = $import_element;
3545 } elsif (ref $import_element eq 'HASH') {
3546 my ($key) = keys %{$orig_best};
3547 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3550 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3561 require Hash::Merge;
3562 my $hm = Hash::Merge->new;
3564 $hm->specify_behavior({
3567 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3569 if ($defl xor $defr) {
3570 return [ $defl ? $_[0] : $_[1] ];
3575 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3579 return [$_[0], $_[1]];
3583 return $_[1] if !defined $_[0];
3584 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3585 return [$_[0], @{$_[1]}]
3588 return [] if !defined $_[0] and !keys %{$_[1]};
3589 return [ $_[1] ] if !defined $_[0];
3590 return [ $_[0] ] if !keys %{$_[1]};
3591 return [$_[0], $_[1]]
3596 return $_[0] if !defined $_[1];
3597 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3598 return [@{$_[0]}, $_[1]]
3601 my @ret = @{$_[0]} or return $_[1];
3602 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3603 my %idx = map { $_ => 1 } @ret;
3604 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3608 return [ $_[1] ] if ! @{$_[0]};
3609 return $_[0] if !keys %{$_[1]};
3610 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3611 return [ @{$_[0]}, $_[1] ];
3616 return [] if !keys %{$_[0]} and !defined $_[1];
3617 return [ $_[0] ] if !defined $_[1];
3618 return [ $_[1] ] if !keys %{$_[0]};
3619 return [$_[0], $_[1]]
3622 return [] if !keys %{$_[0]} and !@{$_[1]};
3623 return [ $_[0] ] if !@{$_[1]};
3624 return $_[1] if !keys %{$_[0]};
3625 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3626 return [ $_[0], @{$_[1]} ];
3629 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3630 return [ $_[0] ] if !keys %{$_[1]};
3631 return [ $_[1] ] if !keys %{$_[0]};
3632 return [ $_[0] ] if $_[0] eq $_[1];
3633 return [ $_[0], $_[1] ];
3636 } => 'DBIC_RS_ATTR_MERGER');
3640 return $hm->merge ($_[1], $_[2]);
3644 sub STORABLE_freeze {
3645 my ($self, $cloning) = @_;
3646 my $to_serialize = { %$self };
3648 # A cursor in progress can't be serialized (and would make little sense anyway)
3649 delete $to_serialize->{cursor};
3651 Storable::nfreeze($to_serialize);
3654 # need this hook for symmetry
3656 my ($self, $cloning, $serialized) = @_;
3658 %$self = %{ Storable::thaw($serialized) };
3664 =head2 throw_exception
3666 See L<DBIx::Class::Schema/throw_exception> for details.
3670 sub throw_exception {
3673 if (ref $self and my $rsrc = $self->result_source) {
3674 $rsrc->throw_exception(@_)
3677 DBIx::Class::Exception->throw(@_);
3681 # XXX: FIXME: Attributes docs need clearing up
3685 Attributes are used to refine a ResultSet in various ways when
3686 searching for data. They can be passed to any method which takes an
3687 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3690 These are in no particular order:
3696 =item Value: ( $order_by | \@order_by | \%order_by )
3700 Which column(s) to order the results by.
3702 [The full list of suitable values is documented in
3703 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3706 If a single column name, or an arrayref of names is supplied, the
3707 argument is passed through directly to SQL. The hashref syntax allows
3708 for connection-agnostic specification of ordering direction:
3710 For descending order:
3712 order_by => { -desc => [qw/col1 col2 col3/] }
3714 For explicit ascending order:
3716 order_by => { -asc => 'col' }
3718 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3719 supported, although you are strongly encouraged to use the hashref
3720 syntax as outlined above.
3726 =item Value: \@columns
3730 Shortcut to request a particular set of columns to be retrieved. Each
3731 column spec may be a string (a table column name), or a hash (in which
3732 case the key is the C<as> value, and the value is used as the C<select>
3733 expression). Adds C<me.> onto the start of any column without a C<.> in
3734 it and sets C<select> from that, then auto-populates C<as> from
3735 C<select> as normal. (You may also use the C<cols> attribute, as in
3736 earlier versions of DBIC.)
3738 Essentially C<columns> does the same as L</select> and L</as>.
3740 columns => [ 'foo', { bar => 'baz' } ]
3744 select => [qw/foo baz/],
3751 =item Value: \@columns
3755 Indicates additional columns to be selected from storage. Works the same
3756 as L</columns> but adds columns to the selection. (You may also use the
3757 C<include_columns> attribute, as in earlier versions of DBIC). For
3760 $schema->resultset('CD')->search(undef, {
3761 '+columns' => ['artist.name'],
3765 would return all CDs and include a 'name' column to the information
3766 passed to object inflation. Note that the 'artist' is the name of the
3767 column (or relationship) accessor, and 'name' is the name of the column
3768 accessor in the related table.
3770 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3771 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3772 unary plus operator before it.
3774 =head2 include_columns
3778 =item Value: \@columns
3782 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3788 =item Value: \@select_columns
3792 Indicates which columns should be selected from the storage. You can use
3793 column names, or in the case of RDBMS back ends, function or stored procedure
3796 $rs = $schema->resultset('Employee')->search(undef, {
3799 { count => 'employeeid' },
3800 { max => { length => 'name' }, -as => 'longest_name' }
3805 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3807 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3808 use L</select>, to instruct DBIx::Class how to store the result of the column.
3809 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3810 identifier aliasing. You can however alias a function, so you can use it in
3811 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3812 attribute> supplied as shown in the example above.
3814 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3815 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3816 unary plus operator before it.
3822 Indicates additional columns to be selected from storage. Works the same as
3823 L</select> but adds columns to the default selection, instead of specifying
3832 Indicates additional column names for those added via L</+select>. See L</as>.
3840 =item Value: \@inflation_names
3844 Indicates column names for object inflation. That is L</as> indicates the
3845 slot name in which the column value will be stored within the
3846 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3847 identifier by the C<get_column> method (or via the object accessor B<if one
3848 with the same name already exists>) as shown below. The L</as> attribute has
3849 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3851 $rs = $schema->resultset('Employee')->search(undef, {
3854 { count => 'employeeid' },
3855 { max => { length => 'name' }, -as => 'longest_name' }
3864 If the object against which the search is performed already has an accessor
3865 matching a column name specified in C<as>, the value can be retrieved using
3866 the accessor as normal:
3868 my $name = $employee->name();
3870 If on the other hand an accessor does not exist in the object, you need to
3871 use C<get_column> instead:
3873 my $employee_count = $employee->get_column('employee_count');
3875 You can create your own accessors if required - see
3876 L<DBIx::Class::Manual::Cookbook> for details.
3882 =item Value: ($rel_name | \@rel_names | \%rel_names)
3886 Contains a list of relationships that should be joined for this query. For
3889 # Get CDs by Nine Inch Nails
3890 my $rs = $schema->resultset('CD')->search(
3891 { 'artist.name' => 'Nine Inch Nails' },
3892 { join => 'artist' }
3895 Can also contain a hash reference to refer to the other relation's relations.
3898 package MyApp::Schema::Track;
3899 use base qw/DBIx::Class/;
3900 __PACKAGE__->table('track');
3901 __PACKAGE__->add_columns(qw/trackid cd position title/);
3902 __PACKAGE__->set_primary_key('trackid');
3903 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3906 # In your application
3907 my $rs = $schema->resultset('Artist')->search(
3908 { 'track.title' => 'Teardrop' },
3910 join => { cd => 'track' },
3911 order_by => 'artist.name',
3915 You need to use the relationship (not the table) name in conditions,
3916 because they are aliased as such. The current table is aliased as "me", so
3917 you need to use me.column_name in order to avoid ambiguity. For example:
3919 # Get CDs from 1984 with a 'Foo' track
3920 my $rs = $schema->resultset('CD')->search(
3923 'tracks.name' => 'Foo'
3925 { join => 'tracks' }
3928 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3929 similarly for a third time). For e.g.
3931 my $rs = $schema->resultset('Artist')->search({
3932 'cds.title' => 'Down to Earth',
3933 'cds_2.title' => 'Popular',
3935 join => [ qw/cds cds/ ],
3938 will return a set of all artists that have both a cd with title 'Down
3939 to Earth' and a cd with title 'Popular'.
3941 If you want to fetch related objects from other tables as well, see C<prefetch>
3944 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3950 =item Value: ($rel_name | \@rel_names | \%rel_names)
3954 Contains one or more relationships that should be fetched along with
3955 the main query (when they are accessed afterwards the data will
3956 already be available, without extra queries to the database). This is
3957 useful for when you know you will need the related objects, because it
3958 saves at least one query:
3960 my $rs = $schema->resultset('Tag')->search(
3969 The initial search results in SQL like the following:
3971 SELECT tag.*, cd.*, artist.* FROM tag
3972 JOIN cd ON tag.cd = cd.cdid
3973 JOIN artist ON cd.artist = artist.artistid
3975 L<DBIx::Class> has no need to go back to the database when we access the
3976 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3979 Simple prefetches will be joined automatically, so there is no need
3980 for a C<join> attribute in the above search.
3982 L</prefetch> can be used with the any of the relationship types and
3983 multiple prefetches can be specified together. Below is a more complex
3984 example that prefetches a CD's artist, its liner notes (if present),
3985 the cover image, the tracks on that cd, and the guests on those
3989 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3990 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3991 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3992 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3994 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3996 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
3999 my $rs = $schema->resultset('CD')->search(
4003 { artist => 'record_label'}, # belongs_to => belongs_to
4004 'liner_note', # might_have
4005 'cover_image', # has_one
4006 { tracks => 'guests' }, # has_many => has_many
4011 This will produce SQL like the following:
4013 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4017 ON artist.artistid = me.artistid
4018 JOIN record_label record_label
4019 ON record_label.labelid = artist.labelid
4020 LEFT JOIN track tracks
4021 ON tracks.cdid = me.cdid
4022 LEFT JOIN guest guests
4023 ON guests.trackid = track.trackid
4024 LEFT JOIN liner_notes liner_note
4025 ON liner_note.cdid = me.cdid
4026 JOIN cd_artwork cover_image
4027 ON cover_image.cdid = me.cdid
4030 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4031 C<tracks>, and C<guests> of the CD will all be available through the
4032 relationship accessors without the need for additional queries to the
4035 However, there is one caveat to be observed: it can be dangerous to
4036 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4037 relationship on a given level. e.g.:
4039 my $rs = $schema->resultset('CD')->search(
4043 'tracks', # has_many
4044 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4049 In fact, C<DBIx::Class> will emit the following warning:
4051 Prefetching multiple has_many rels tracks and cd_to_producer at top
4052 level will explode the number of row objects retrievable via ->next
4053 or ->all. Use at your own risk.
4055 The collapser currently can't identify duplicate tuples for multiple
4056 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4057 result the second L<has_many|DBIx::Class::Relationship/has_many>
4058 relation could contain redundant objects.
4060 =head3 Using L</prefetch> with L</join>
4062 L</prefetch> implies a L</join> with the equivalent argument, and is
4063 properly merged with any existing L</join> specification. So the
4066 my $rs = $schema->resultset('CD')->search(
4067 {'record_label.name' => 'Music Product Ltd.'},
4069 join => {artist => 'record_label'},
4070 prefetch => 'artist',
4074 ... will work, searching on the record label's name, but only
4075 prefetching the C<artist>.
4077 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4079 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4080 prefetched relations. So given:
4082 my $rs = $schema->resultset('CD')->search(
4085 select => ['cd.title'],
4087 prefetch => 'artist',
4091 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4092 becomes: C<'cd_title', 'artist.*'>.
4096 Prefetch does a lot of deep magic. As such, it may not behave exactly
4097 as you might expect.
4103 Prefetch uses the L</cache> to populate the prefetched relationships. This
4104 may or may not be what you want.
4108 If you specify a condition on a prefetched relationship, ONLY those
4109 rows that match the prefetched condition will be fetched into that relationship.
4110 This means that adding prefetch to a search() B<may alter> what is returned by
4111 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4113 my $artist_rs = $schema->resultset('Artist')->search({
4119 my $count = $artist_rs->first->cds->count;
4121 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4123 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4125 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4127 that cmp_ok() may or may not pass depending on the datasets involved. This
4128 behavior may or may not survive the 0.09 transition.
4140 Makes the resultset paged and specifies the page to retrieve. Effectively
4141 identical to creating a non-pages resultset and then calling ->page($page)
4144 If L</rows> attribute is not specified it defaults to 10 rows per page.
4146 When you have a paged resultset, L</count> will only return the number
4147 of rows in the page. To get the total, use the L</pager> and call
4148 C<total_entries> on it.
4158 Specifies the maximum number of rows for direct retrieval or the number of
4159 rows per page if the page attribute or method is used.
4165 =item Value: $offset
4169 Specifies the (zero-based) row number for the first row to be returned, or the
4170 of the first row of the first page if paging is used.
4176 =item Value: \@columns
4180 A arrayref of columns to group by. Can include columns of joined tables.
4182 group_by => [qw/ column1 column2 ... /]
4188 =item Value: $condition
4192 HAVING is a select statement attribute that is applied between GROUP BY and
4193 ORDER BY. It is applied to the after the grouping calculations have been
4196 having => { 'count_employee' => { '>=', 100 } }
4198 or with an in-place function in which case literal SQL is required:
4200 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4206 =item Value: (0 | 1)
4210 Set to 1 to group by all columns. If the resultset already has a group_by
4211 attribute, this setting is ignored and an appropriate warning is issued.
4217 Adds to the WHERE clause.
4219 # only return rows WHERE deleted IS NULL for all searches
4220 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4222 Can be overridden by passing C<< { where => undef } >> as an attribute
4229 Set to 1 to cache search results. This prevents extra SQL queries if you
4230 revisit rows in your ResultSet:
4232 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4234 while( my $artist = $resultset->next ) {
4238 $rs->first; # without cache, this would issue a query
4240 By default, searches are not cached.
4242 For more examples of using these attributes, see
4243 L<DBIx::Class::Manual::Cookbook>.
4249 =item Value: ( 'update' | 'shared' )
4253 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT