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/;
11 use Data::Compare (); # no imports!!! guard against insane architecture
13 # not importing first() as it will clash with our own method
17 # De-duplication in _merge_attr() is disabled, but left in for reference
18 # (the merger is used for other things that ought not to be de-duped)
19 *__HM_DEDUP = sub () { 0 };
29 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
33 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
37 my $users_rs = $schema->resultset('User');
38 while( $user = $users_rs->next) {
39 print $user->username;
42 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
43 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
47 A ResultSet is an object which stores a set of conditions representing
48 a query. It is the backbone of DBIx::Class (i.e. the really
49 important/useful bit).
51 No SQL is executed on the database when a ResultSet is created, it
52 just stores all the conditions needed to create the query.
54 A basic ResultSet representing the data of an entire table is returned
55 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
56 L<Source|DBIx::Class::Manual::Glossary/Source> name.
58 my $users_rs = $schema->resultset('User');
60 A new ResultSet is returned from calling L</search> on an existing
61 ResultSet. The new one will contain all the conditions of the
62 original, plus any new conditions added in the C<search> call.
64 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
65 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
68 The query that the ResultSet represents is B<only> executed against
69 the database when these methods are called:
70 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
72 If a resultset is used in a numeric context it returns the L</count>.
73 However, if it is used in a boolean context it is B<always> true. So if
74 you want to check if a resultset has any results, you must use C<if $rs
79 =head2 Chaining resultsets
81 Let's say you've got a query that needs to be run to return some data
82 to the user. But, you have an authorization system in place that
83 prevents certain users from seeing certain information. So, you want
84 to construct the basic query in one method, but add constraints to it in
89 my $request = $self->get_request; # Get a request object somehow.
90 my $schema = $self->result_source->schema;
92 my $cd_rs = $schema->resultset('CD')->search({
93 title => $request->param('title'),
94 year => $request->param('year'),
97 $cd_rs = $self->apply_security_policy( $cd_rs );
102 sub apply_security_policy {
111 =head3 Resolving conditions and attributes
113 When a resultset is chained from another resultset, conditions and
114 attributes with the same keys need resolving.
116 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
117 into the existing ones from the original resultset.
119 The L</where> and L</having> attributes, and any search conditions, are
120 merged with an SQL C<AND> to the existing condition from the original
123 All other attributes are overridden by any new ones supplied in the
126 =head2 Multiple queries
128 Since a resultset just defines a query, you can do all sorts of
129 things with it with the same object.
131 # Don't hit the DB yet.
132 my $cd_rs = $schema->resultset('CD')->search({
133 title => 'something',
137 # Each of these hits the DB individually.
138 my $count = $cd_rs->count;
139 my $most_recent = $cd_rs->get_column('date_released')->max();
140 my @records = $cd_rs->all;
142 And it's not just limited to SELECT statements.
148 $cd_rs->create({ artist => 'Fred' });
150 Which is the same as:
152 $schema->resultset('CD')->create({
153 title => 'something',
158 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
166 =item Arguments: $source, \%$attrs
168 =item Return Value: $rs
172 The resultset constructor. Takes a source object (usually a
173 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
174 L</ATTRIBUTES> below). Does not perform any queries -- these are
175 executed as needed by the other methods.
177 Generally you won't need to construct a resultset manually. You'll
178 automatically get one from e.g. a L</search> called in scalar context:
180 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
182 IMPORTANT: If called on an object, proxies to new_result instead so
184 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
186 will return a CD object, not a ResultSet.
192 return $class->new_result(@_) if ref $class;
194 my ($source, $attrs) = @_;
195 $source = $source->resolve
196 if $source->isa('DBIx::Class::ResultSourceHandle');
197 $attrs = { %{$attrs||{}} };
199 if ($attrs->{page}) {
200 $attrs->{rows} ||= 10;
203 $attrs->{alias} ||= 'me';
206 result_source => $source,
207 cond => $attrs->{where},
212 # if there is a dark selector, this means we are already in a
213 # chain and the cleanup/sanification was taken care of by
215 $self->_normalize_selection($attrs)
216 unless $attrs->{_dark_selector};
219 $attrs->{result_class} || $source->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context) || @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 In list context, C<< ->all() >> is called implicitly on the resultset, thus
242 returning a list of row objects instead. To avoid that, use L</search_rs>.
244 If you need to pass in additional attributes but no additional condition,
245 call it as C<search(undef, \%attrs)>.
247 # "SELECT name, artistid FROM $artist_table"
248 my @all_artists = $schema->resultset('Artist')->search(undef, {
249 columns => [qw/name artistid/],
252 For a list of attributes that can be passed to C<search>, see
253 L</ATTRIBUTES>. For more examples of using this function, see
254 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
255 documentation for the first argument, see L<SQL::Abstract>
256 and its extension L<DBIx::Class::SQLMaker>.
258 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
262 Note that L</search> does not process/deflate any of the values passed in the
263 L<SQL::Abstract>-compatible search condition structure. This is unlike other
264 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
265 manually that any value passed to this method will stringify to something the
266 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
267 objects, for more info see:
268 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
274 my $rs = $self->search_rs( @_ );
279 elsif (defined wantarray) {
283 # we can be called by a relationship helper, which in
284 # turn may be called in void context due to some braindead
285 # overload or whatever else the user decided to be clever
286 # at this particular day. Thus limit the exception to
287 # external code calls only
288 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
289 if (caller)[0] !~ /^\QDBIx::Class::/;
299 =item Arguments: $cond, \%attrs?
301 =item Return Value: $resultset
305 This method does the same exact thing as search() except it will
306 always return a resultset, even in list context.
313 # Special-case handling for (undef, undef).
314 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
320 if (ref $_[-1] eq 'HASH') {
321 # copy for _normalize_selection
322 $call_attrs = { %{ pop @_ } };
324 elsif (! defined $_[-1] ) {
325 pop @_; # search({}, undef)
329 # see if we can keep the cache (no $rs changes)
331 my %safe = (alias => 1, cache => 1);
332 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
335 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
337 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
339 $cache = $self->get_cache;
342 my $rsrc = $self->result_source;
344 my $old_attrs = { %{$self->{attrs}} };
345 my $old_having = delete $old_attrs->{having};
346 my $old_where = delete $old_attrs->{where};
348 my $new_attrs = { %$old_attrs };
350 # take care of call attrs (only if anything is changing)
351 if (keys %$call_attrs) {
353 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
355 # reset the current selector list if new selectors are supplied
356 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
357 delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
360 # Normalize the new selector list (operates on the passed-in attr structure)
361 # Need to do it on every chain instead of only once on _resolved_attrs, in
362 # order to allow detection of empty vs partial 'as'
363 $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
364 if $old_attrs->{_dark_selector};
365 $self->_normalize_selection ($call_attrs);
367 # start with blind overwriting merge, exclude selector attrs
368 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
369 delete @{$new_attrs}{@selector_attrs};
371 for (@selector_attrs) {
372 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
373 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
376 # older deprecated name, use only if {columns} is not there
377 if (my $c = delete $new_attrs->{cols}) {
378 if ($new_attrs->{columns}) {
379 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
382 $new_attrs->{columns} = $c;
387 # join/prefetch use their own crazy merging heuristics
388 foreach my $key (qw/join prefetch/) {
389 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
390 if exists $call_attrs->{$key};
393 # stack binds together
394 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
398 # rip apart the rest of @_, parse a condition
401 if (ref $_[0] eq 'HASH') {
402 (keys %{$_[0]}) ? $_[0] : undef
408 $self->throw_exception('Odd number of arguments to search')
416 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
417 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
420 for ($old_where, $call_cond) {
422 $new_attrs->{where} = $self->_stack_cond (
423 $_, $new_attrs->{where}
428 if (defined $old_having) {
429 $new_attrs->{having} = $self->_stack_cond (
430 $old_having, $new_attrs->{having}
434 my $rs = (ref $self)->new($rsrc, $new_attrs);
436 $rs->set_cache($cache) if ($cache);
442 sub _normalize_selection {
443 my ($self, $attrs) = @_;
446 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
447 if exists $attrs->{include_columns};
449 # columns are always placed first, however
451 # Keep the X vs +X separation until _resolved_attrs time - this allows to
452 # delay the decision on whether to use a default select list ($rsrc->columns)
453 # allowing stuff like the remove_columns helper to work
455 # select/as +select/+as pairs need special handling - the amount of select/as
456 # elements in each pair does *not* have to be equal (think multicolumn
457 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
458 # supplied at all) - try to infer the alias, either from the -as parameter
459 # of the selector spec, or use the parameter whole if it looks like a column
460 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
461 # is ok as well), but make sure no more additions to the 'as' chain take place
462 for my $pref ('', '+') {
464 my ($sel, $as) = map {
465 my $key = "${pref}${_}";
467 my $val = [ ref $attrs->{$key} eq 'ARRAY'
469 : $attrs->{$key} || ()
471 delete $attrs->{$key};
475 if (! @$as and ! @$sel ) {
478 elsif (@$as and ! @$sel) {
479 $self->throw_exception(
480 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
484 # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
485 # if any @$as has been supplied we assume the user knows what (s)he is doing
486 # and blindly keep stacking up pieces
487 unless ($attrs->{_dark_selector}) {
490 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
491 push @$as, $_->{-as};
493 # assume any plain no-space, no-parenthesis string to be a column spec
494 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
495 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
498 # if all else fails - raise a flag that no more aliasing will be allowed
500 $attrs->{_dark_selector} = {
502 string => ($dark_sel_dumper ||= do {
503 require Data::Dumper::Concise;
504 Data::Dumper::Concise::DumperObject()->Indent(0);
505 })->Values([$_])->Dump
513 elsif (@$as < @$sel) {
514 $self->throw_exception(
515 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
518 elsif ($pref and $attrs->{_dark_selector}) {
519 $self->throw_exception(
520 "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
526 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
527 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
532 my ($self, $left, $right) = @_;
534 # collapse single element top-level conditions
535 # (single pass only, unlikely to need recursion)
536 for ($left, $right) {
537 if (ref $_ eq 'ARRAY') {
545 elsif (ref $_ eq 'HASH') {
546 my ($first, $more) = keys %$_;
549 if (! defined $first) {
553 elsif (! defined $more) {
554 if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
557 elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
564 # merge hashes with weeding out of duplicates (simple cases only)
565 if (ref $left eq 'HASH' and ref $right eq 'HASH') {
567 # shallow copy to destroy
568 $right = { %$right };
569 for (grep { exists $right->{$_} } keys %$left) {
570 # the use of eq_deeply here is justified - the rhs of an
571 # expression can contain a lot of twisted weird stuff
572 delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
575 $right = undef unless keys %$right;
579 if (defined $left xor defined $right) {
580 return defined $left ? $left : $right;
582 elsif (! defined $left) {
586 return { -and => [ $left, $right ] };
590 =head2 search_literal
594 =item Arguments: $sql_fragment, @bind_values
596 =item Return Value: $resultset (scalar context) || @row_objs (list context)
600 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
601 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
603 Pass a literal chunk of SQL to be added to the conditional part of the
606 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
607 only be used in that context. C<search_literal> is a convenience method.
608 It is equivalent to calling $schema->search(\[]), but if you want to ensure
609 columns are bound correctly, use C<search>.
611 Example of how to use C<search> instead of C<search_literal>
613 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
614 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
617 See L<DBIx::Class::Manual::Cookbook/Searching> and
618 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
619 require C<search_literal>.
624 my ($self, $sql, @bind) = @_;
626 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
629 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
636 =item Arguments: \%columns_values | @pk_values, \%attrs?
638 =item Return Value: $row_object | undef
642 Finds and returns a single row based on supplied criteria. Takes either a
643 hashref with the same format as L</create> (including inference of foreign
644 keys from related objects), or a list of primary key values in the same
645 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
646 declaration on the L</result_source>.
648 In either case an attempt is made to combine conditions already existing on
649 the resultset with the condition passed to this method.
651 To aid with preparing the correct query for the storage you may supply the
652 C<key> attribute, which is the name of a
653 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
654 unique constraint corresponding to the
655 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
656 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
657 to construct a query that satisfies the named unique constraint fully (
658 non-NULL values for each column member of the constraint) an exception is
661 If no C<key> is specified, the search is carried over all unique constraints
662 which are fully defined by the available condition.
664 If no such constraint is found, C<find> currently defaults to a simple
665 C<< search->(\%column_values) >> which may or may not do what you expect.
666 Note that this fallback behavior may be deprecated in further versions. If
667 you need to search with arbitrary conditions - use L</search>. If the query
668 resulting from this fallback produces more than one row, a warning to the
669 effect is issued, though only the first row is constructed and returned as
672 In addition to C<key>, L</find> recognizes and applies standard
673 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
675 Note that if you have extra concerns about the correctness of the resulting
676 query you need to specify the C<key> attribute and supply the entire condition
677 as an argument to find (since it is not always possible to perform the
678 combination of the resultset condition with the supplied one, especially if
679 the resultset condition contains literal sql).
681 For example, to find a row by its primary key:
683 my $cd = $schema->resultset('CD')->find(5);
685 You can also find a row by a specific unique constraint:
687 my $cd = $schema->resultset('CD')->find(
689 artist => 'Massive Attack',
690 title => 'Mezzanine',
692 { key => 'cd_artist_title' }
695 See also L</find_or_create> and L</update_or_create>.
701 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
703 my $rsrc = $self->result_source;
706 if (exists $attrs->{key}) {
707 $constraint_name = defined $attrs->{key}
709 : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
713 # Parse out the condition from input
716 if (ref $_[0] eq 'HASH') {
717 $call_cond = { %{$_[0]} };
720 # if only values are supplied we need to default to 'primary'
721 $constraint_name = 'primary' unless defined $constraint_name;
723 my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
725 $self->throw_exception(
726 "No constraint columns, maybe a malformed '$constraint_name' constraint?"
729 $self->throw_exception (
730 'find() expects either a column/value hashref, or a list of values '
731 . "corresponding to the columns of the specified unique constraint '$constraint_name'"
732 ) unless @c_cols == @_;
735 @{$call_cond}{@c_cols} = @_;
739 for my $key (keys %$call_cond) {
741 my $keyref = ref($call_cond->{$key})
743 my $relinfo = $rsrc->relationship_info($key)
745 my $val = delete $call_cond->{$key};
747 next if $keyref eq 'ARRAY'; # has_many for multi_create
749 my $rel_q = $rsrc->_resolve_condition(
750 $relinfo->{cond}, $val, $key, $key
752 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
753 @related{keys %$rel_q} = values %$rel_q;
757 # relationship conditions take precedence (?)
758 @{$call_cond}{keys %related} = values %related;
760 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
762 if (defined $constraint_name) {
763 $final_cond = $self->_qualify_cond_columns (
765 $self->_build_unique_cond (
773 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
774 # This means that we got here after a merger of relationship conditions
775 # in ::Relationship::Base::search_related (the row method), and furthermore
776 # the relationship is of the 'single' type. This means that the condition
777 # provided by the relationship (already attached to $self) is sufficient,
778 # as there can be only one row in the database that would satisfy the
782 # no key was specified - fall down to heuristics mode:
783 # run through all unique queries registered on the resultset, and
784 # 'OR' all qualifying queries together
785 my (@unique_queries, %seen_column_combinations);
786 for my $c_name ($rsrc->unique_constraint_names) {
787 next if $seen_column_combinations{
788 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
791 push @unique_queries, try {
792 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
796 $final_cond = @unique_queries
797 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
798 : $self->_non_unique_find_fallback ($call_cond, $attrs)
802 # Run the query, passing the result_class since it should propagate for find
803 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
804 if (keys %{$rs->_resolved_attrs->{collapse}}) {
806 carp "Query returned more than one row" if $rs->next;
814 # This is a stop-gap method as agreed during the discussion on find() cleanup:
815 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
817 # It is invoked when find() is called in legacy-mode with insufficiently-unique
818 # condition. It is provided for overrides until a saner way forward is devised
820 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
821 # the road. Please adjust your tests accordingly to catch this situation early
822 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
824 # The method will not be removed without an adequately complete replacement
825 # for strict-mode enforcement
826 sub _non_unique_find_fallback {
827 my ($self, $cond, $attrs) = @_;
829 return $self->_qualify_cond_columns(
831 exists $attrs->{alias}
833 : $self->{attrs}{alias}
838 sub _qualify_cond_columns {
839 my ($self, $cond, $alias) = @_;
841 my %aliased = %$cond;
842 for (keys %aliased) {
843 $aliased{"$alias.$_"} = delete $aliased{$_}
850 sub _build_unique_cond {
851 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
853 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
855 # combination may fail if $self->{cond} is non-trivial
856 my ($final_cond) = try {
857 $self->_merge_with_rscond ($extra_cond)
862 # trim out everything not in $columns
863 $final_cond = { map {
864 exists $final_cond->{$_}
865 ? ( $_ => $final_cond->{$_} )
869 if (my @missing = grep
870 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
873 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
875 join (', ', map { "'$_'" } @missing),
882 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
884 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
886 carp_unique ( sprintf (
887 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
888 . 'values in column(s): %s). This is almost certainly not what you wanted, '
889 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
891 join (', ', map { "'$_'" } @undefs),
898 =head2 search_related
902 =item Arguments: $rel, $cond, \%attrs?
904 =item Return Value: $new_resultset (scalar context) || @row_objs (list context)
908 $new_rs = $cd_rs->search_related('artist', {
912 Searches the specified relationship, optionally specifying a condition and
913 attributes for matching records. See L</ATTRIBUTES> for more information.
915 In list context, C<< ->all() >> is called implicitly on the resultset, thus
916 returning a list of row objects instead. To avoid that, use L</search_related_rs>.
918 See also L</search_related_rs>.
923 return shift->related_resultset(shift)->search(@_);
926 =head2 search_related_rs
928 This method works exactly the same as search_related, except that
929 it guarantees a resultset, even in list context.
933 sub search_related_rs {
934 return shift->related_resultset(shift)->search_rs(@_);
941 =item Arguments: none
943 =item Return Value: $cursor
947 Returns a storage-driven cursor to the given resultset. See
948 L<DBIx::Class::Cursor> for more information.
955 my $attrs = $self->_resolved_attrs_copy;
957 return $self->{cursor}
958 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
959 $attrs->{where},$attrs);
966 =item Arguments: $cond?
968 =item Return Value: $row_object | undef
972 my $cd = $schema->resultset('CD')->single({ year => 2001 });
974 Inflates the first result without creating a cursor if the resultset has
975 any records in it; if not returns C<undef>. Used by L</find> as a lean version
978 While this method can take an optional search condition (just like L</search>)
979 being a fast-code-path it does not recognize search attributes. If you need to
980 add extra joins or similar, call L</search> and then chain-call L</single> on the
981 L<DBIx::Class::ResultSet> returned.
987 As of 0.08100, this method enforces the assumption that the preceding
988 query returns only one row. If more than one row is returned, you will receive
991 Query returned more than one row
993 In this case, you should be using L</next> or L</find> instead, or if you really
994 know what you are doing, use the L</rows> attribute to explicitly limit the size
997 This method will also throw an exception if it is called on a resultset prefetching
998 has_many, as such a prefetch implies fetching multiple rows from the database in
999 order to assemble the resulting object.
1006 my ($self, $where) = @_;
1008 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
1011 my $attrs = $self->_resolved_attrs_copy;
1013 if (keys %{$attrs->{collapse}}) {
1014 $self->throw_exception(
1015 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
1020 if (defined $attrs->{where}) {
1023 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
1024 $where, delete $attrs->{where} ]
1027 $attrs->{where} = $where;
1031 my @data = $self->result_source->storage->select_single(
1032 $attrs->{from}, $attrs->{select},
1033 $attrs->{where}, $attrs
1036 return (@data ? ($self->_construct_object(@data))[0] : undef);
1042 # Recursively collapse the query, accumulating values for each column.
1044 sub _collapse_query {
1045 my ($self, $query, $collapsed) = @_;
1049 if (ref $query eq 'ARRAY') {
1050 foreach my $subquery (@$query) {
1051 next unless ref $subquery; # -or
1052 $collapsed = $self->_collapse_query($subquery, $collapsed);
1055 elsif (ref $query eq 'HASH') {
1056 if (keys %$query and (keys %$query)[0] eq '-and') {
1057 foreach my $subquery (@{$query->{-and}}) {
1058 $collapsed = $self->_collapse_query($subquery, $collapsed);
1062 foreach my $col (keys %$query) {
1063 my $value = $query->{$col};
1064 $collapsed->{$col}{$value}++;
1076 =item Arguments: $cond?
1078 =item Return Value: $resultsetcolumn
1082 my $max_length = $rs->get_column('length')->max;
1084 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1089 my ($self, $column) = @_;
1090 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1098 =item Arguments: $cond, \%attrs?
1100 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1104 # WHERE title LIKE '%blue%'
1105 $cd_rs = $rs->search_like({ title => '%blue%'});
1107 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1108 that this is simply a convenience method retained for ex Class::DBI users.
1109 You most likely want to use L</search> with specific operators.
1111 For more information, see L<DBIx::Class::Manual::Cookbook>.
1113 This method is deprecated and will be removed in 0.09. Use L</search()>
1114 instead. An example conversion is:
1116 ->search_like({ foo => 'bar' });
1120 ->search({ foo => { like => 'bar' } });
1127 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1128 .' Instead use ->search({ x => { -like => "y%" } })'
1129 .' (note the outer pair of {}s - they are important!)'
1131 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1132 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1133 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1134 return $class->search($query, { %$attrs });
1141 =item Arguments: $first, $last
1143 =item Return Value: $resultset (scalar context) || @row_objs (list context)
1147 Returns a resultset or object list representing a subset of elements from the
1148 resultset slice is called on. Indexes are from 0, i.e., to get the first
1149 three records, call:
1151 my ($one, $two, $three) = $rs->slice(0, 2);
1156 my ($self, $min, $max) = @_;
1157 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1158 $attrs->{offset} = $self->{attrs}{offset} || 0;
1159 $attrs->{offset} += $min;
1160 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1161 return $self->search(undef, $attrs);
1162 #my $slice = (ref $self)->new($self->result_source, $attrs);
1163 #return (wantarray ? $slice->all : $slice);
1170 =item Arguments: none
1172 =item Return Value: $result | undef
1176 Returns the next element in the resultset (C<undef> is there is none).
1178 Can be used to efficiently iterate over records in the resultset:
1180 my $rs = $schema->resultset('CD')->search;
1181 while (my $cd = $rs->next) {
1185 Note that you need to store the resultset object, and call C<next> on it.
1186 Calling C<< resultset('Table')->next >> repeatedly will always return the
1187 first record from the resultset.
1193 if (my $cache = $self->get_cache) {
1194 $self->{all_cache_position} ||= 0;
1195 return $cache->[$self->{all_cache_position}++];
1197 if ($self->{attrs}{cache}) {
1198 delete $self->{pager};
1199 $self->{all_cache_position} = 1;
1200 return ($self->all)[0];
1202 if ($self->{stashed_objects}) {
1203 my $obj = shift(@{$self->{stashed_objects}});
1204 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1208 exists $self->{stashed_row}
1209 ? @{delete $self->{stashed_row}}
1210 : $self->cursor->next
1212 return undef unless (@row);
1213 my ($row, @more) = $self->_construct_object(@row);
1214 $self->{stashed_objects} = \@more if @more;
1218 sub _construct_object {
1219 my ($self, @row) = @_;
1221 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1223 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1224 @new = $self->{_attrs}{record_filter}->(@new)
1225 if exists $self->{_attrs}{record_filter};
1229 sub _collapse_result {
1230 my ($self, $as_proto, $row) = @_;
1234 # 'foo' => [ undef, 'foo' ]
1235 # 'foo.bar' => [ 'foo', 'bar' ]
1236 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1238 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1240 my %collapse = %{$self->{_attrs}{collapse}||{}};
1244 # if we're doing collapsing (has_many prefetch) we need to grab records
1245 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1246 # we know we don't have to bother.
1248 # the reason for not using the collapse stuff directly is because if you
1249 # had for e.g. two artists in a row with no cds, the collapse info for
1250 # both would be NULL (undef) so you'd lose the second artist
1252 # store just the index so we can check the array positions from the row
1253 # without having to contruct the full hash
1255 if (keys %collapse) {
1256 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1257 foreach my $i (0 .. $#construct_as) {
1258 next if defined($construct_as[$i][0]); # only self table
1259 if (delete $pri{$construct_as[$i][1]}) {
1260 push(@pri_index, $i);
1262 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1266 # no need to do an if, it'll be empty if @pri_index is empty anyway
1268 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1272 do { # no need to check anything at the front, we always want the first row
1276 foreach my $this_as (@construct_as) {
1277 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1280 push(@const_rows, \%const);
1282 } until ( # no pri_index => no collapse => drop straight out
1285 do { # get another row, stash it, drop out if different PK
1287 @copy = $self->cursor->next;
1288 $self->{stashed_row} = \@copy;
1290 # last thing in do block, counts as true if anything doesn't match
1292 # check xor defined first for NULL vs. NOT NULL then if one is
1293 # defined the other must be so check string equality
1296 (defined $pri_vals{$_} ^ defined $copy[$_])
1297 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1302 my $alias = $self->{attrs}{alias};
1309 foreach my $const (@const_rows) {
1310 scalar @const_keys or do {
1311 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1313 foreach my $key (@const_keys) {
1316 my @parts = split(/\./, $key);
1318 my $data = $const->{$key};
1319 foreach my $p (@parts) {
1320 $target = $target->[1]->{$p} ||= [];
1322 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1323 # collapsing at this point and on final part
1324 my $pos = $collapse_pos{$cur};
1325 CK: foreach my $ck (@ckey) {
1326 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1327 $collapse_pos{$cur} = $data;
1328 delete @collapse_pos{ # clear all positioning for sub-entries
1329 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1336 if (exists $collapse{$cur}) {
1337 $target = $target->[-1];
1340 $target->[0] = $data;
1342 $info->[0] = $const->{$key};
1350 =head2 result_source
1354 =item Arguments: $result_source?
1356 =item Return Value: $result_source
1360 An accessor for the primary ResultSource object from which this ResultSet
1367 =item Arguments: $result_class?
1369 =item Return Value: $result_class
1373 An accessor for the class to use when creating row objects. Defaults to
1374 C<< result_source->result_class >> - which in most cases is the name of the
1375 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1377 Note that changing the result_class will also remove any components
1378 that were originally loaded in the source class via
1379 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1380 in the original source class will not run.
1385 my ($self, $result_class) = @_;
1386 if ($result_class) {
1387 unless (ref $result_class) { # don't fire this for an object
1388 $self->ensure_class_loaded($result_class);
1390 $self->_result_class($result_class);
1391 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1392 # permit the user to set result class on one result set only; it only
1393 # chains if provided to search()
1394 #$self->{attrs}{result_class} = $result_class if ref $self;
1396 $self->_result_class;
1403 =item Arguments: $cond, \%attrs??
1405 =item Return Value: $count
1409 Performs an SQL C<COUNT> with the same query as the resultset was built
1410 with to find the number of elements. Passing arguments is equivalent to
1411 C<< $rs->search ($cond, \%attrs)->count >>
1417 return $self->search(@_)->count if @_ and defined $_[0];
1418 return scalar @{ $self->get_cache } if $self->get_cache;
1420 my $attrs = $self->_resolved_attrs_copy;
1422 # this is a little optimization - it is faster to do the limit
1423 # adjustments in software, instead of a subquery
1424 my $rows = delete $attrs->{rows};
1425 my $offset = delete $attrs->{offset};
1428 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1429 $crs = $self->_count_subq_rs ($attrs);
1432 $crs = $self->_count_rs ($attrs);
1434 my $count = $crs->next;
1436 $count -= $offset if $offset;
1437 $count = $rows if $rows and $rows < $count;
1438 $count = 0 if ($count < 0);
1447 =item Arguments: $cond, \%attrs??
1449 =item Return Value: $count_rs
1453 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1454 This can be very handy for subqueries:
1456 ->search( { amount => $some_rs->count_rs->as_query } )
1458 As with regular resultsets the SQL query will be executed only after
1459 the resultset is accessed via L</next> or L</all>. That would return
1460 the same single value obtainable via L</count>.
1466 return $self->search(@_)->count_rs if @_;
1468 # this may look like a lack of abstraction (count() does about the same)
1469 # but in fact an _rs *must* use a subquery for the limits, as the
1470 # software based limiting can not be ported if this $rs is to be used
1471 # in a subquery itself (i.e. ->as_query)
1472 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1473 return $self->_count_subq_rs;
1476 return $self->_count_rs;
1481 # returns a ResultSetColumn object tied to the count query
1484 my ($self, $attrs) = @_;
1486 my $rsrc = $self->result_source;
1487 $attrs ||= $self->_resolved_attrs;
1489 my $tmp_attrs = { %$attrs };
1490 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1491 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1493 # overwrite the selector (supplied by the storage)
1494 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1495 $tmp_attrs->{as} = 'count';
1496 delete @{$tmp_attrs}{qw/columns/};
1498 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1504 # same as above but uses a subquery
1506 sub _count_subq_rs {
1507 my ($self, $attrs) = @_;
1509 my $rsrc = $self->result_source;
1510 $attrs ||= $self->_resolved_attrs;
1512 my $sub_attrs = { %$attrs };
1513 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1514 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
1516 # if we multi-prefetch we group_by primary keys only as this is what we would
1517 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1518 if ( keys %{$attrs->{collapse}} ) {
1519 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1522 # Calculate subquery selector
1523 if (my $g = $sub_attrs->{group_by}) {
1525 my $sql_maker = $rsrc->storage->sql_maker;
1527 # necessary as the group_by may refer to aliased functions
1529 for my $sel (@{$attrs->{select}}) {
1530 $sel_index->{$sel->{-as}} = $sel
1531 if (ref $sel eq 'HASH' and $sel->{-as});
1534 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1535 # also look for named aggregates referred in the having clause
1536 # having often contains scalarrefs - thus parse it out entirely
1538 if ($attrs->{having}) {
1539 local $sql_maker->{having_bind};
1540 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1541 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1542 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1543 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1544 # if we don't unset it we screw up retarded but unfortunately working
1545 # 'MAX(foo.bar)' => { '>', 3 }
1546 $sql_maker->{name_sep} = '';
1549 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1551 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1553 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1554 # and if all fails for an utterly naive quoted scalar-with-function
1556 $rquote $sep $lquote (.+?) $rquote
1558 [\s,] \w+ \. (\w+) [\s,]
1560 [\s,] $lquote (.+?) $rquote [\s,]
1562 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1567 my $colpiece = $sel_index->{$_} || $_;
1569 # unqualify join-based group_by's. Arcane but possible query
1570 # also horrible horrible hack to alias a column (not a func.)
1571 # (probably need to introduce SQLA syntax)
1572 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1575 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1577 push @{$sub_attrs->{select}}, $colpiece;
1581 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1582 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1585 return $rsrc->resultset_class
1586 ->new ($rsrc, $sub_attrs)
1588 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1589 ->get_column ('count');
1596 =head2 count_literal
1600 =item Arguments: $sql_fragment, @bind_values
1602 =item Return Value: $count
1606 Counts the results in a literal query. Equivalent to calling L</search_literal>
1607 with the passed arguments, then L</count>.
1611 sub count_literal { shift->search_literal(@_)->count; }
1617 =item Arguments: none
1619 =item Return Value: @objects
1623 Returns all elements in the resultset.
1630 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1633 return @{ $self->get_cache } if $self->get_cache;
1637 if (keys %{$self->_resolved_attrs->{collapse}}) {
1638 # Using $self->cursor->all is really just an optimisation.
1639 # If we're collapsing has_many prefetches it probably makes
1640 # very little difference, and this is cleaner than hacking
1641 # _construct_object to survive the approach
1642 $self->cursor->reset;
1643 my @row = $self->cursor->next;
1645 push(@obj, $self->_construct_object(@row));
1646 @row = (exists $self->{stashed_row}
1647 ? @{delete $self->{stashed_row}}
1648 : $self->cursor->next);
1651 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1654 $self->set_cache(\@obj) if $self->{attrs}{cache};
1663 =item Arguments: none
1665 =item Return Value: $self
1669 Resets the resultset's cursor, so you can iterate through the elements again.
1670 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1677 delete $self->{_attrs} if exists $self->{_attrs};
1678 $self->{all_cache_position} = 0;
1679 $self->cursor->reset;
1687 =item Arguments: none
1689 =item Return Value: $object | undef
1693 Resets the resultset and returns an object for the first result (or C<undef>
1694 if the resultset is empty).
1699 return $_[0]->reset->next;
1705 # Determines whether and what type of subquery is required for the $rs operation.
1706 # If grouping is necessary either supplies its own, or verifies the current one
1707 # After all is done delegates to the proper storage method.
1709 sub _rs_update_delete {
1710 my ($self, $op, $values) = @_;
1712 my $rsrc = $self->result_source;
1714 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1715 my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
1717 if ($needs_group_by_subq or $needs_subq) {
1719 # make a new $rs selecting only the PKs (that's all we really need)
1720 my $attrs = $self->_resolved_attrs_copy;
1723 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1724 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1726 if ($needs_group_by_subq) {
1727 # make sure no group_by was supplied, or if there is one - make sure it matches
1728 # the columns compiled above perfectly. Anything else can not be sanely executed
1729 # on most databases so croak right then and there
1731 if (my $g = $attrs->{group_by}) {
1732 my @current_group_by = map
1733 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1738 join ("\x00", sort @current_group_by)
1740 join ("\x00", sort @{$attrs->{columns}} )
1742 $self->throw_exception (
1743 "You have just attempted a $op operation on a resultset which does group_by"
1744 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1745 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1746 . ' kind of queries. Please retry the operation with a modified group_by or'
1747 . ' without using one at all.'
1752 $attrs->{group_by} = $attrs->{columns};
1756 my $subrs = (ref $self)->new($rsrc, $attrs);
1757 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1760 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1761 # a condition containing 'me' or other table prefixes will not work
1762 # at all. What this code tries to do (badly) is to generate a condition
1763 # with the qualifiers removed, by exploiting the quote mechanism of sqla
1765 # this is atrocious and should be replaced by normal sqla introspection
1767 my ($sql, @bind) = do {
1768 my $sqla = $rsrc->storage->sql_maker;
1769 local $sqla->{_dequalify_idents} = 1;
1770 $sqla->_recurse_where($self->{cond});
1773 return $rsrc->storage->$op(
1775 $op eq 'update' ? $values : (),
1776 $self->{cond} ? \[$sql, @bind] : (),
1785 =item Arguments: \%values
1787 =item Return Value: $storage_rv
1791 Sets the specified columns in the resultset to the supplied values in a
1792 single query. Note that this will not run any accessor/set_column/update
1793 triggers, nor will it update any row object instances derived from this
1794 resultset (this includes the contents of the L<resultset cache|/set_cache>
1795 if any). See L</update_all> if you need to execute any on-update
1796 triggers or cascades defined either by you or a
1797 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1799 The return value is a pass through of what the underlying
1800 storage backend returned, and may vary. See L<DBI/execute> for the most
1805 Note that L</update> does not process/deflate any of the values passed in.
1806 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1807 ensure manually that any value passed to this method will stringify to
1808 something the RDBMS knows how to deal with. A notable example is the
1809 handling of L<DateTime> objects, for more info see:
1810 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1815 my ($self, $values) = @_;
1816 $self->throw_exception('Values for update must be a hash')
1817 unless ref $values eq 'HASH';
1819 return $self->_rs_update_delete ('update', $values);
1826 =item Arguments: \%values
1828 =item Return Value: 1
1832 Fetches all objects and updates them one at a time via
1833 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1834 triggers, while L</update> will not.
1839 my ($self, $values) = @_;
1840 $self->throw_exception('Values for update_all must be a hash')
1841 unless ref $values eq 'HASH';
1843 my $guard = $self->result_source->schema->txn_scope_guard;
1844 $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
1853 =item Arguments: none
1855 =item Return Value: $storage_rv
1859 Deletes the rows matching this resultset in a single query. Note that this
1860 will not run any delete triggers, nor will it alter the
1861 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1862 derived from this resultset (this includes the contents of the
1863 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1864 execute any on-delete triggers or cascades defined either by you or a
1865 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1867 The return value is a pass through of what the underlying storage backend
1868 returned, and may vary. See L<DBI/execute> for the most common case.
1874 $self->throw_exception('delete does not accept any arguments')
1877 return $self->_rs_update_delete ('delete');
1884 =item Arguments: none
1886 =item Return Value: 1
1890 Fetches all objects and deletes them one at a time via
1891 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1892 triggers, while L</delete> will not.
1898 $self->throw_exception('delete_all does not accept any arguments')
1901 my $guard = $self->result_source->schema->txn_scope_guard;
1902 $_->delete for $self->all;
1911 =item Arguments: \@data;
1915 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1916 For the arrayref of hashrefs style each hashref should be a structure suitable
1917 for submitting to a $resultset->create(...) method.
1919 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1920 to insert the data, as this is a faster method.
1922 Otherwise, each set of data is inserted into the database using
1923 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1924 accumulated into an array. The array itself, or an array reference
1925 is returned depending on scalar or list context.
1927 Example: Assuming an Artist Class that has many CDs Classes relating:
1929 my $Artist_rs = $schema->resultset("Artist");
1931 ## Void Context Example
1932 $Artist_rs->populate([
1933 { artistid => 4, name => 'Manufactured Crap', cds => [
1934 { title => 'My First CD', year => 2006 },
1935 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1938 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1939 { title => 'My parents sold me to a record company', year => 2005 },
1940 { title => 'Why Am I So Ugly?', year => 2006 },
1941 { title => 'I Got Surgery and am now Popular', year => 2007 }
1946 ## Array Context Example
1947 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1948 { name => "Artist One"},
1949 { name => "Artist Two"},
1950 { name => "Artist Three", cds=> [
1951 { title => "First CD", year => 2007},
1952 { title => "Second CD", year => 2008},
1956 print $ArtistOne->name; ## response is 'Artist One'
1957 print $ArtistThree->cds->count ## reponse is '2'
1959 For the arrayref of arrayrefs style, the first element should be a list of the
1960 fieldsnames to which the remaining elements are rows being inserted. For
1963 $Arstist_rs->populate([
1964 [qw/artistid name/],
1965 [100, 'A Formally Unknown Singer'],
1966 [101, 'A singer that jumped the shark two albums ago'],
1967 [102, 'An actually cool singer'],
1970 Please note an important effect on your data when choosing between void and
1971 wantarray context. Since void context goes straight to C<insert_bulk> in
1972 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1973 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1974 create primary keys for you, you will find that your PKs are empty. In this
1975 case you will have to use the wantarray context in order to create those
1983 # cruft placed in standalone method
1984 my $data = $self->_normalize_populate_args(@_);
1986 return unless @$data;
1988 if(defined wantarray) {
1990 foreach my $item (@$data) {
1991 push(@created, $self->create($item));
1993 return wantarray ? @created : \@created;
1996 my $first = $data->[0];
1998 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1999 # it relationship data
2000 my (@rels, @columns);
2001 my $rsrc = $self->result_source;
2002 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
2003 for (keys %$first) {
2004 my $ref = ref $first->{$_};
2005 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
2011 my @pks = $rsrc->primary_columns;
2013 ## do the belongs_to relationships
2014 foreach my $index (0..$#$data) {
2016 # delegate to create() for any dataset without primary keys with specified relationships
2017 if (grep { !defined $data->[$index]->{$_} } @pks ) {
2019 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
2020 my @ret = $self->populate($data);
2026 foreach my $rel (@rels) {
2027 next unless ref $data->[$index]->{$rel} eq "HASH";
2028 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
2029 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
2030 my $related = $result->result_source->_resolve_condition(
2031 $reverse_relinfo->{cond},
2037 delete $data->[$index]->{$rel};
2038 $data->[$index] = {%{$data->[$index]}, %$related};
2040 push @columns, keys %$related if $index == 0;
2044 ## inherit the data locked in the conditions of the resultset
2045 my ($rs_data) = $self->_merge_with_rscond({});
2046 delete @{$rs_data}{@columns};
2047 my @inherit_cols = keys %$rs_data;
2048 my @inherit_data = values %$rs_data;
2050 ## do bulk insert on current row
2051 $rsrc->storage->insert_bulk(
2053 [@columns, @inherit_cols],
2054 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
2057 ## do the has_many relationships
2058 foreach my $item (@$data) {
2062 foreach my $rel (@rels) {
2063 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2065 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2067 my $child = $main_row->$rel;
2069 my $related = $child->result_source->_resolve_condition(
2070 $rels->{$rel}{cond},
2076 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2077 my @populate = map { {%$_, %$related} } @rows_to_add;
2079 $child->populate( \@populate );
2086 # populate() argumnets went over several incarnations
2087 # What we ultimately support is AoH
2088 sub _normalize_populate_args {
2089 my ($self, $arg) = @_;
2091 if (ref $arg eq 'ARRAY') {
2095 elsif (ref $arg->[0] eq 'HASH') {
2098 elsif (ref $arg->[0] eq 'ARRAY') {
2100 my @colnames = @{$arg->[0]};
2101 foreach my $values (@{$arg}[1 .. $#$arg]) {
2102 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2108 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2115 =item Arguments: none
2117 =item Return Value: $pager
2121 Return Value a L<Data::Page> object for the current resultset. Only makes
2122 sense for queries with a C<page> attribute.
2124 To get the full count of entries for a paged resultset, call
2125 C<total_entries> on the L<Data::Page> object.
2129 # make a wizard good for both a scalar and a hashref
2130 my $mk_lazy_count_wizard = sub {
2131 require Variable::Magic;
2133 my $stash = { total_rs => shift };
2134 my $slot = shift; # only used by the hashref magic
2136 my $magic = Variable::Magic::wizard (
2137 data => sub { $stash },
2143 # set value lazily, and dispell for good
2144 ${$_[0]} = $_[1]{total_rs}->count;
2145 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2149 # an explicit set implies dispell as well
2150 # the unless() is to work around "fun and giggles" below
2151 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2152 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2159 if ($_[2] eq $slot and !$_[1]{inactive}) {
2160 my $cnt = $_[1]{total_rs}->count;
2161 $_[0]->{$slot} = $cnt;
2163 # attempting to dispell in a fetch handle (works in store), seems
2164 # to invariable segfault on 5.10, 5.12, 5.13 :(
2165 # so use an inactivator instead
2166 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2172 if (! $_[1]{inactive} and $_[2] eq $slot) {
2173 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2175 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2182 $stash->{magic_selfref} = $magic;
2183 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2188 # the tie class for 5.8.1
2190 package # hide from pause
2191 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2192 use base qw/Tie::Hash/;
2194 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2195 sub NEXTKEY { each %{$_[0]{data}} }
2196 sub EXISTS { exists $_[0]{data}{$_[1]} }
2197 sub DELETE { delete $_[0]{data}{$_[1]} }
2198 sub CLEAR { %{$_[0]{data}} = () }
2199 sub SCALAR { scalar %{$_[0]{data}} }
2202 $_[1]{data} = {%{$_[1]{selfref}}};
2203 %{$_[1]{selfref}} = ();
2204 Scalar::Util::weaken ($_[1]{selfref});
2205 return bless ($_[1], $_[0]);
2209 if ($_[1] eq $_[0]{slot}) {
2210 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2211 untie %{$_[0]{selfref}};
2212 %{$_[0]{selfref}} = %{$_[0]{data}};
2221 $_[0]{data}{$_[1]} = $_[2];
2222 if ($_[1] eq $_[0]{slot}) {
2223 untie %{$_[0]{selfref}};
2224 %{$_[0]{selfref}} = %{$_[0]{data}};
2233 return $self->{pager} if $self->{pager};
2235 my $attrs = $self->{attrs};
2236 if (!defined $attrs->{page}) {
2237 $self->throw_exception("Can't create pager for non-paged rs");
2239 elsif ($attrs->{page} <= 0) {
2240 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2242 $attrs->{rows} ||= 10;
2244 # throw away the paging flags and re-run the count (possibly
2245 # with a subselect) to get the real total count
2246 my $count_attrs = { %$attrs };
2247 delete $count_attrs->{$_} for qw/rows offset page pager/;
2248 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2251 ### the following may seem awkward and dirty, but it's a thought-experiment
2252 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2253 ### before talking to ribasushi/mst
2256 my $pager = Data::Page->new(
2257 0, #start with an empty set
2259 $self->{attrs}{page},
2262 my $data_slot = 'total_entries';
2264 # Since we are interested in a cached value (once it's set - it's set), every
2265 # technique will detach from the magic-host once the time comes to fire the
2266 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2268 if ($] < 5.008003) {
2269 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2270 # to weakref the magic container :(
2272 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2273 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2276 elsif ($] < 5.010) {
2277 # We can use magic on the hash value slot. It's interesting that the magic is
2278 # attached to the hash-slot, and does *not* stop working once I do the dummy
2279 # assignments after the cast()
2280 # tested on 5.8.3 and 5.8.9
2281 my $magic = $mk_lazy_count_wizard->($total_rs);
2282 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2284 # this is for fun and giggles
2285 $pager->{$data_slot} = -1;
2286 $pager->{$data_slot} = 0;
2288 # this does not work for scalars, but works with
2290 #my %vals = %$pager;
2295 # And the uvar magic
2296 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2297 # however see the wizard maker for more notes
2298 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2299 Variable::Magic::cast ( %$pager, $magic );
2302 $pager->{$data_slot} = -1;
2303 $pager->{$data_slot} = 0;
2311 return $self->{pager} = $pager;
2318 =item Arguments: $page_number
2320 =item Return Value: $rs
2324 Returns a resultset for the $page_number page of the resultset on which page
2325 is called, where each page contains a number of rows equal to the 'rows'
2326 attribute set on the resultset (10 by default).
2331 my ($self, $page) = @_;
2332 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2339 =item Arguments: \%vals
2341 =item Return Value: $rowobject
2345 Creates a new row object in the resultset's result class and returns
2346 it. The row is not inserted into the database at this point, call
2347 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2348 will tell you whether the row object has been inserted or not.
2350 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2355 my ($self, $values) = @_;
2356 $self->throw_exception( "new_result needs a hash" )
2357 unless (ref $values eq 'HASH');
2359 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2363 @$cols_from_relations
2364 ? (-cols_from_relations => $cols_from_relations)
2366 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2369 return $self->result_class->new(\%new);
2372 # _merge_with_rscond
2374 # Takes a simple hash of K/V data and returns its copy merged with the
2375 # condition already present on the resultset. Additionally returns an
2376 # arrayref of value/condition names, which were inferred from related
2377 # objects (this is needed for in-memory related objects)
2378 sub _merge_with_rscond {
2379 my ($self, $data) = @_;
2381 my (%new_data, @cols_from_relations);
2383 my $alias = $self->{attrs}{alias};
2385 if (! defined $self->{cond}) {
2386 # just massage $data below
2388 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2389 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2390 @cols_from_relations = keys %new_data;
2392 elsif (ref $self->{cond} ne 'HASH') {
2393 $self->throw_exception(
2394 "Can't abstract implicit construct, resultset condition not a hash"
2398 # precendence must be given to passed values over values inherited from
2399 # the cond, so the order here is important.
2400 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2401 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2403 while ( my($col, $value) = each %implied ) {
2404 my $vref = ref $value;
2410 (keys %$value)[0] eq '='
2412 $new_data{$col} = $value->{'='};
2414 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2415 $new_data{$col} = $value;
2422 %{ $self->_remove_alias($data, $alias) },
2425 return (\%new_data, \@cols_from_relations);
2428 # _has_resolved_attr
2430 # determines if the resultset defines at least one
2431 # of the attributes supplied
2433 # used to determine if a subquery is neccessary
2435 # supports some virtual attributes:
2437 # This will scan for any joins being present on the resultset.
2438 # It is not a mere key-search but a deep inspection of {from}
2441 sub _has_resolved_attr {
2442 my ($self, @attr_names) = @_;
2444 my $attrs = $self->_resolved_attrs;
2448 for my $n (@attr_names) {
2449 if (grep { $n eq $_ } (qw/-join/) ) {
2450 $extra_checks{$n}++;
2454 my $attr = $attrs->{$n};
2456 next if not defined $attr;
2458 if (ref $attr eq 'HASH') {
2459 return 1 if keys %$attr;
2461 elsif (ref $attr eq 'ARRAY') {
2469 # a resolved join is expressed as a multi-level from
2471 $extra_checks{-join}
2473 ref $attrs->{from} eq 'ARRAY'
2475 @{$attrs->{from}} > 1
2483 # Recursively collapse the condition.
2485 sub _collapse_cond {
2486 my ($self, $cond, $collapsed) = @_;
2490 if (ref $cond eq 'ARRAY') {
2491 foreach my $subcond (@$cond) {
2492 next unless ref $subcond; # -or
2493 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2496 elsif (ref $cond eq 'HASH') {
2497 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2498 foreach my $subcond (@{$cond->{-and}}) {
2499 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2503 foreach my $col (keys %$cond) {
2504 my $value = $cond->{$col};
2505 $collapsed->{$col} = $value;
2515 # Remove the specified alias from the specified query hash. A copy is made so
2516 # the original query is not modified.
2519 my ($self, $query, $alias) = @_;
2521 my %orig = %{ $query || {} };
2524 foreach my $key (keys %orig) {
2526 $unaliased{$key} = $orig{$key};
2529 $unaliased{$1} = $orig{$key}
2530 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2540 =item Arguments: none
2542 =item Return Value: \[ $sql, @bind ]
2546 Returns the SQL query and bind vars associated with the invocant.
2548 This is generally used as the RHS for a subquery.
2555 my $attrs = $self->_resolved_attrs_copy;
2560 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2561 # $sql also has no wrapping parenthesis in list ctx
2563 my $sqlbind = $self->result_source->storage
2564 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2573 =item Arguments: \%vals, \%attrs?
2575 =item Return Value: $rowobject
2579 my $artist = $schema->resultset('Artist')->find_or_new(
2580 { artist => 'fred' }, { key => 'artists' });
2582 $cd->cd_to_producer->find_or_new({ producer => $producer },
2583 { key => 'primary });
2585 Find an existing record from this resultset using L</find>. if none exists,
2586 instantiate a new result object and return it. The object will not be saved
2587 into your storage until you call L<DBIx::Class::Row/insert> on it.
2589 You most likely want this method when looking for existing rows using a unique
2590 constraint that is not the primary key, or looking for related rows.
2592 If you want objects to be saved immediately, use L</find_or_create> instead.
2594 B<Note>: Make sure to read the documentation of L</find> and understand the
2595 significance of the C<key> attribute, as its lack may skew your search, and
2596 subsequently result in spurious new objects.
2598 B<Note>: Take care when using C<find_or_new> with a table having
2599 columns with default values that you intend to be automatically
2600 supplied by the database (e.g. an auto_increment primary key column).
2601 In normal usage, the value of such columns should NOT be included at
2602 all in the call to C<find_or_new>, even when set to C<undef>.
2608 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2609 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2610 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2613 return $self->new_result($hash);
2620 =item Arguments: \%vals
2622 =item Return Value: a L<DBIx::Class::Row> $object
2626 Attempt to create a single new row or a row with multiple related rows
2627 in the table represented by the resultset (and related tables). This
2628 will not check for duplicate rows before inserting, use
2629 L</find_or_create> to do that.
2631 To create one row for this resultset, pass a hashref of key/value
2632 pairs representing the columns of the table and the values you wish to
2633 store. If the appropriate relationships are set up, foreign key fields
2634 can also be passed an object representing the foreign row, and the
2635 value will be set to its primary key.
2637 To create related objects, pass a hashref of related-object column values
2638 B<keyed on the relationship name>. If the relationship is of type C<multi>
2639 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2640 The process will correctly identify columns holding foreign keys, and will
2641 transparently populate them from the keys of the corresponding relation.
2642 This can be applied recursively, and will work correctly for a structure
2643 with an arbitrary depth and width, as long as the relationships actually
2644 exists and the correct column data has been supplied.
2647 Instead of hashrefs of plain related data (key/value pairs), you may
2648 also pass new or inserted objects. New objects (not inserted yet, see
2649 L</new>), will be inserted into their appropriate tables.
2651 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2653 Example of creating a new row.
2655 $person_rs->create({
2656 name=>"Some Person",
2657 email=>"somebody@someplace.com"
2660 Example of creating a new row and also creating rows in a related C<has_many>
2661 or C<has_one> resultset. Note Arrayref.
2664 { artistid => 4, name => 'Manufactured Crap', cds => [
2665 { title => 'My First CD', year => 2006 },
2666 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2671 Example of creating a new row and also creating a row in a related
2672 C<belongs_to> resultset. Note Hashref.
2675 title=>"Music for Silly Walks",
2678 name=>"Silly Musician",
2686 When subclassing ResultSet never attempt to override this method. Since
2687 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2688 lot of the internals simply never call it, so your override will be
2689 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2690 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2691 L</create> process you need to intervene.
2698 my ($self, $attrs) = @_;
2699 $self->throw_exception( "create needs a hashref" )
2700 unless ref $attrs eq 'HASH';
2701 return $self->new_result($attrs)->insert;
2704 =head2 find_or_create
2708 =item Arguments: \%vals, \%attrs?
2710 =item Return Value: $rowobject
2714 $cd->cd_to_producer->find_or_create({ producer => $producer },
2715 { key => 'primary' });
2717 Tries to find a record based on its primary key or unique constraints; if none
2718 is found, creates one and returns that instead.
2720 my $cd = $schema->resultset('CD')->find_or_create({
2722 artist => 'Massive Attack',
2723 title => 'Mezzanine',
2727 Also takes an optional C<key> attribute, to search by a specific key or unique
2728 constraint. For example:
2730 my $cd = $schema->resultset('CD')->find_or_create(
2732 artist => 'Massive Attack',
2733 title => 'Mezzanine',
2735 { key => 'cd_artist_title' }
2738 B<Note>: Make sure to read the documentation of L</find> and understand the
2739 significance of the C<key> attribute, as its lack may skew your search, and
2740 subsequently result in spurious row creation.
2742 B<Note>: Because find_or_create() reads from the database and then
2743 possibly inserts based on the result, this method is subject to a race
2744 condition. Another process could create a record in the table after
2745 the find has completed and before the create has started. To avoid
2746 this problem, use find_or_create() inside a transaction.
2748 B<Note>: Take care when using C<find_or_create> with a table having
2749 columns with default values that you intend to be automatically
2750 supplied by the database (e.g. an auto_increment primary key column).
2751 In normal usage, the value of such columns should NOT be included at
2752 all in the call to C<find_or_create>, even when set to C<undef>.
2754 See also L</find> and L</update_or_create>. For information on how to declare
2755 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2759 sub find_or_create {
2761 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2762 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2763 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2766 return $self->create($hash);
2769 =head2 update_or_create
2773 =item Arguments: \%col_values, { key => $unique_constraint }?
2775 =item Return Value: $row_object
2779 $resultset->update_or_create({ col => $val, ... });
2781 Like L</find_or_create>, but if a row is found it is immediately updated via
2782 C<< $found_row->update (\%col_values) >>.
2785 Takes an optional C<key> attribute to search on a specific unique constraint.
2788 # In your application
2789 my $cd = $schema->resultset('CD')->update_or_create(
2791 artist => 'Massive Attack',
2792 title => 'Mezzanine',
2795 { key => 'cd_artist_title' }
2798 $cd->cd_to_producer->update_or_create({
2799 producer => $producer,
2805 B<Note>: Make sure to read the documentation of L</find> and understand the
2806 significance of the C<key> attribute, as its lack may skew your search, and
2807 subsequently result in spurious row creation.
2809 B<Note>: Take care when using C<update_or_create> with a table having
2810 columns with default values that you intend to be automatically
2811 supplied by the database (e.g. an auto_increment primary key column).
2812 In normal usage, the value of such columns should NOT be included at
2813 all in the call to C<update_or_create>, even when set to C<undef>.
2815 See also L</find> and L</find_or_create>. For information on how to declare
2816 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2820 sub update_or_create {
2822 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2823 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2825 my $row = $self->find($cond, $attrs);
2827 $row->update($cond);
2831 return $self->create($cond);
2834 =head2 update_or_new
2838 =item Arguments: \%col_values, { key => $unique_constraint }?
2840 =item Return Value: $rowobject
2844 $resultset->update_or_new({ col => $val, ... });
2846 Like L</find_or_new> but if a row is found it is immediately updated via
2847 C<< $found_row->update (\%col_values) >>.
2851 # In your application
2852 my $cd = $schema->resultset('CD')->update_or_new(
2854 artist => 'Massive Attack',
2855 title => 'Mezzanine',
2858 { key => 'cd_artist_title' }
2861 if ($cd->in_storage) {
2862 # the cd was updated
2865 # the cd is not yet in the database, let's insert it
2869 B<Note>: Make sure to read the documentation of L</find> and understand the
2870 significance of the C<key> attribute, as its lack may skew your search, and
2871 subsequently result in spurious new objects.
2873 B<Note>: Take care when using C<update_or_new> with a table having
2874 columns with default values that you intend to be automatically
2875 supplied by the database (e.g. an auto_increment primary key column).
2876 In normal usage, the value of such columns should NOT be included at
2877 all in the call to C<update_or_new>, even when set to C<undef>.
2879 See also L</find>, L</find_or_create> and L</find_or_new>.
2885 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2886 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2888 my $row = $self->find( $cond, $attrs );
2889 if ( defined $row ) {
2890 $row->update($cond);
2894 return $self->new_result($cond);
2901 =item Arguments: none
2903 =item Return Value: \@cache_objects | undef
2907 Gets the contents of the cache for the resultset, if the cache is set.
2909 The cache is populated either by using the L</prefetch> attribute to
2910 L</search> or by calling L</set_cache>.
2922 =item Arguments: \@cache_objects
2924 =item Return Value: \@cache_objects
2928 Sets the contents of the cache for the resultset. Expects an arrayref
2929 of objects of the same class as those produced by the resultset. Note that
2930 if the cache is set the resultset will return the cached objects rather
2931 than re-querying the database even if the cache attr is not set.
2933 The contents of the cache can also be populated by using the
2934 L</prefetch> attribute to L</search>.
2939 my ( $self, $data ) = @_;
2940 $self->throw_exception("set_cache requires an arrayref")
2941 if defined($data) && (ref $data ne 'ARRAY');
2942 $self->{all_cache} = $data;
2949 =item Arguments: none
2951 =item Return Value: undef
2955 Clears the cache for the resultset.
2960 shift->set_cache(undef);
2967 =item Arguments: none
2969 =item Return Value: true, if the resultset has been paginated
2977 return !!$self->{attrs}{page};
2984 =item Arguments: none
2986 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2994 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2997 =head2 related_resultset
3001 =item Arguments: $relationship_name
3003 =item Return Value: $resultset
3007 Returns a related resultset for the supplied relationship name.
3009 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
3013 sub related_resultset {
3014 my ($self, $rel) = @_;
3016 $self->{related_resultsets} ||= {};
3017 return $self->{related_resultsets}{$rel} ||= do {
3018 my $rsrc = $self->result_source;
3019 my $rel_info = $rsrc->relationship_info($rel);
3021 $self->throw_exception(
3022 "search_related: result source '" . $rsrc->source_name .
3023 "' has no such relationship $rel")
3026 my $attrs = $self->_chain_relationship($rel);
3028 my $join_count = $attrs->{seen_join}{$rel};
3030 my $alias = $self->result_source->storage
3031 ->relname_to_table_alias($rel, $join_count);
3033 # since this is search_related, and we already slid the select window inwards
3034 # (the select/as attrs were deleted in the beginning), we need to flip all
3035 # left joins to inner, so we get the expected results
3036 # read the comment on top of the actual function to see what this does
3037 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
3040 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
3041 delete @{$attrs}{qw(result_class alias)};
3045 if (my $cache = $self->get_cache) {
3046 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
3047 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
3052 my $rel_source = $rsrc->related_source($rel);
3056 # The reason we do this now instead of passing the alias to the
3057 # search_rs below is that if you wrap/overload resultset on the
3058 # source you need to know what alias it's -going- to have for things
3059 # to work sanely (e.g. RestrictWithObject wants to be able to add
3060 # extra query restrictions, and these may need to be $alias.)
3062 my $rel_attrs = $rel_source->resultset_attributes;
3063 local $rel_attrs->{alias} = $alias;
3065 $rel_source->resultset
3069 where => $attrs->{where},
3072 $new->set_cache($new_cache) if $new_cache;
3077 =head2 current_source_alias
3081 =item Arguments: none
3083 =item Return Value: $source_alias
3087 Returns the current table alias for the result source this resultset is built
3088 on, that will be used in the SQL query. Usually it is C<me>.
3090 Currently the source alias that refers to the result set returned by a
3091 L</search>/L</find> family method depends on how you got to the resultset: it's
3092 C<me> by default, but eg. L</search_related> aliases it to the related result
3093 source name (and keeps C<me> referring to the original result set). The long
3094 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3095 (and make this method unnecessary).
3097 Thus it's currently necessary to use this method in predefined queries (see
3098 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3099 source alias of the current result set:
3101 # in a result set class
3103 my ($self, $user) = @_;
3105 my $me = $self->current_source_alias;
3107 return $self->search(
3108 "$me.modified" => $user->id,
3114 sub current_source_alias {
3117 return ($self->{attrs} || {})->{alias} || 'me';
3120 =head2 as_subselect_rs
3124 =item Arguments: none
3126 =item Return Value: $resultset
3130 Act as a barrier to SQL symbols. The resultset provided will be made into a
3131 "virtual view" by including it as a subquery within the from clause. From this
3132 point on, any joined tables are inaccessible to ->search on the resultset (as if
3133 it were simply where-filtered without joins). For example:
3135 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3137 # 'x' now pollutes the query namespace
3139 # So the following works as expected
3140 my $ok_rs = $rs->search({'x.other' => 1});
3142 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3143 # def) we look for one row with contradictory terms and join in another table
3144 # (aliased 'x_2') which we never use
3145 my $broken_rs = $rs->search({'x.name' => 'def'});
3147 my $rs2 = $rs->as_subselect_rs;
3149 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3150 my $not_joined_rs = $rs2->search({'x.other' => 1});
3152 # works as expected: finds a 'table' row related to two x rows (abc and def)
3153 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3155 Another example of when one might use this would be to select a subset of
3156 columns in a group by clause:
3158 my $rs = $schema->resultset('Bar')->search(undef, {
3159 group_by => [qw{ id foo_id baz_id }],
3160 })->as_subselect_rs->search(undef, {
3161 columns => [qw{ id foo_id }]
3164 In the above example normally columns would have to be equal to the group by,
3165 but because we isolated the group by into a subselect the above works.
3169 sub as_subselect_rs {
3172 my $attrs = $self->_resolved_attrs;
3174 my $fresh_rs = (ref $self)->new (
3175 $self->result_source
3178 # these pieces will be locked in the subquery
3179 delete $fresh_rs->{cond};
3180 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3182 return $fresh_rs->search( {}, {
3184 $attrs->{alias} => $self->as_query,
3185 -alias => $attrs->{alias},
3186 -rsrc => $self->result_source,
3188 alias => $attrs->{alias},
3192 # This code is called by search_related, and makes sure there
3193 # is clear separation between the joins before, during, and
3194 # after the relationship. This information is needed later
3195 # in order to properly resolve prefetch aliases (any alias
3196 # with a relation_chain_depth less than the depth of the
3197 # current prefetch is not considered)
3199 # The increments happen twice per join. An even number means a
3200 # relationship specified via a search_related, whereas an odd
3201 # number indicates a join/prefetch added via attributes
3203 # Also this code will wrap the current resultset (the one we
3204 # chain to) in a subselect IFF it contains limiting attributes
3205 sub _chain_relationship {
3206 my ($self, $rel) = @_;
3207 my $source = $self->result_source;
3208 my $attrs = { %{$self->{attrs}||{}} };
3210 # we need to take the prefetch the attrs into account before we
3211 # ->_resolve_join as otherwise they get lost - captainL
3212 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3214 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3216 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3219 my @force_subq_attrs = qw/offset rows group_by having/;
3222 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3224 $self->_has_resolved_attr (@force_subq_attrs)
3226 # Nuke the prefetch (if any) before the new $rs attrs
3227 # are resolved (prefetch is useless - we are wrapping
3228 # a subquery anyway).
3229 my $rs_copy = $self->search;
3230 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3231 $rs_copy->{attrs}{join},
3232 delete $rs_copy->{attrs}{prefetch},
3237 -alias => $attrs->{alias},
3238 $attrs->{alias} => $rs_copy->as_query,
3240 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3241 $seen->{-relation_chain_depth} = 0;
3243 elsif ($attrs->{from}) { #shallow copy suffices
3244 $from = [ @{$attrs->{from}} ];
3249 -alias => $attrs->{alias},
3250 $attrs->{alias} => $source->from,
3254 my $jpath = ($seen->{-relation_chain_depth})
3255 ? $from->[-1][0]{-join_path}
3258 my @requested_joins = $source->_resolve_join(
3265 push @$from, @requested_joins;
3267 $seen->{-relation_chain_depth}++;
3269 # if $self already had a join/prefetch specified on it, the requested
3270 # $rel might very well be already included. What we do in this case
3271 # is effectively a no-op (except that we bump up the chain_depth on
3272 # the join in question so we could tell it *is* the search_related)
3275 # we consider the last one thus reverse
3276 for my $j (reverse @requested_joins) {
3277 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3278 if ($rel eq $last_j) {
3279 $j->[0]{-relation_chain_depth}++;
3285 unless ($already_joined) {
3286 push @$from, $source->_resolve_join(
3294 $seen->{-relation_chain_depth}++;
3296 return {%$attrs, from => $from, seen_join => $seen};
3299 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3300 sub _resolved_attrs_copy {
3302 return { %{$self->_resolved_attrs (@_)} };
3305 sub _resolved_attrs {
3307 return $self->{_attrs} if $self->{_attrs};
3309 my $attrs = { %{ $self->{attrs} || {} } };
3310 my $source = $self->result_source;
3311 my $alias = $attrs->{alias};
3313 # default selection list
3314 $attrs->{columns} = [ $source->columns ]
3315 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
3317 # merge selectors together
3318 for (qw/columns select as/) {
3319 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
3320 if $attrs->{$_} or $attrs->{"+$_"};
3323 # disassemble columns
3325 if (my $cols = delete $attrs->{columns}) {
3326 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3327 if (ref $c eq 'HASH') {
3328 for my $as (keys %$c) {
3329 push @sel, $c->{$as};
3340 # when trying to weed off duplicates later do not go past this point -
3341 # everything added from here on is unbalanced "anyone's guess" stuff
3342 my $dedup_stop_idx = $#as;
3344 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3346 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3347 if $attrs->{select};
3349 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3351 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3354 # disqualify all $alias.col as-bits (collapser mandated)
3356 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3359 # de-duplicate the result (remove *identical* select/as pairs)
3360 # and also die on duplicate {as} pointing to different {select}s
3361 # not using a c-style for as the condition is prone to shrinkage
3364 while ($i <= $dedup_stop_idx) {
3365 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3370 elsif ($seen->{$as[$i]}++) {
3371 $self->throw_exception(
3372 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3380 $attrs->{select} = \@sel;
3381 $attrs->{as} = \@as;
3383 $attrs->{from} ||= [{
3385 -alias => $self->{attrs}{alias},
3386 $self->{attrs}{alias} => $source->from,
3389 if ( $attrs->{join} || $attrs->{prefetch} ) {
3391 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3392 if ref $attrs->{from} ne 'ARRAY';
3394 my $join = (delete $attrs->{join}) || {};
3396 if ( defined $attrs->{prefetch} ) {
3397 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3400 $attrs->{from} = # have to copy here to avoid corrupting the original
3402 @{ $attrs->{from} },
3403 $source->_resolve_join(
3406 { %{ $attrs->{seen_join} || {} } },
3407 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3408 ? $attrs->{from}[-1][0]{-join_path}
3415 if ( defined $attrs->{order_by} ) {
3416 $attrs->{order_by} = (
3417 ref( $attrs->{order_by} ) eq 'ARRAY'
3418 ? [ @{ $attrs->{order_by} } ]
3419 : [ $attrs->{order_by} || () ]
3423 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3424 $attrs->{group_by} = [ $attrs->{group_by} ];
3427 # generate the distinct induced group_by early, as prefetch will be carried via a
3428 # subquery (since a group_by is present)
3429 if (delete $attrs->{distinct}) {
3430 if ($attrs->{group_by}) {
3431 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3434 # distinct affects only the main selection part, not what prefetch may
3436 $attrs->{group_by} = $source->storage->_group_over_selection (
3444 $attrs->{collapse} ||= {};
3445 if ($attrs->{prefetch}) {
3447 $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
3448 if $attrs->{_dark_selector};
3450 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3452 my $prefetch_ordering = [];
3454 # this is a separate structure (we don't look in {from} directly)
3455 # as the resolver needs to shift things off the lists to work
3456 # properly (identical-prefetches on different branches)
3458 if (ref $attrs->{from} eq 'ARRAY') {
3460 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3462 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3463 next unless $j->[0]{-alias};
3464 next unless $j->[0]{-join_path};
3465 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3467 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3470 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3471 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3476 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3478 # we need to somehow mark which columns came from prefetch
3480 my $sel_end = $#{$attrs->{select}};
3481 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3484 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3485 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3487 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3488 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3492 # if both page and offset are specified, produce a combined offset
3493 # even though it doesn't make much sense, this is what pre 081xx has
3495 if (my $page = delete $attrs->{page}) {
3497 ($attrs->{rows} * ($page - 1))
3499 ($attrs->{offset} || 0)
3503 return $self->{_attrs} = $attrs;
3507 my ($self, $attr) = @_;
3509 if (ref $attr eq 'HASH') {
3510 return $self->_rollout_hash($attr);
3511 } elsif (ref $attr eq 'ARRAY') {
3512 return $self->_rollout_array($attr);
3518 sub _rollout_array {
3519 my ($self, $attr) = @_;
3522 foreach my $element (@{$attr}) {
3523 if (ref $element eq 'HASH') {
3524 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3525 } elsif (ref $element eq 'ARRAY') {
3526 # XXX - should probably recurse here
3527 push( @rolled_array, @{$self->_rollout_array($element)} );
3529 push( @rolled_array, $element );
3532 return \@rolled_array;
3536 my ($self, $attr) = @_;
3539 foreach my $key (keys %{$attr}) {
3540 push( @rolled_array, { $key => $attr->{$key} } );
3542 return \@rolled_array;
3545 sub _calculate_score {
3546 my ($self, $a, $b) = @_;
3548 if (defined $a xor defined $b) {
3551 elsif (not defined $a) {
3555 if (ref $b eq 'HASH') {
3556 my ($b_key) = keys %{$b};
3557 if (ref $a eq 'HASH') {
3558 my ($a_key) = keys %{$a};
3559 if ($a_key eq $b_key) {
3560 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3565 return ($a eq $b_key) ? 1 : 0;
3568 if (ref $a eq 'HASH') {
3569 my ($a_key) = keys %{$a};
3570 return ($b eq $a_key) ? 1 : 0;
3572 return ($b eq $a) ? 1 : 0;
3577 sub _merge_joinpref_attr {
3578 my ($self, $orig, $import) = @_;
3580 return $import unless defined($orig);
3581 return $orig unless defined($import);
3583 $orig = $self->_rollout_attr($orig);
3584 $import = $self->_rollout_attr($import);
3587 foreach my $import_element ( @{$import} ) {
3588 # find best candidate from $orig to merge $b_element into
3589 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3590 foreach my $orig_element ( @{$orig} ) {
3591 my $score = $self->_calculate_score( $orig_element, $import_element );
3592 if ($score > $best_candidate->{score}) {
3593 $best_candidate->{position} = $position;
3594 $best_candidate->{score} = $score;
3598 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3600 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3601 push( @{$orig}, $import_element );
3603 my $orig_best = $orig->[$best_candidate->{position}];
3604 # merge orig_best and b_element together and replace original with merged
3605 if (ref $orig_best ne 'HASH') {
3606 $orig->[$best_candidate->{position}] = $import_element;
3607 } elsif (ref $import_element eq 'HASH') {
3608 my ($key) = keys %{$orig_best};
3609 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3612 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3623 require Hash::Merge;
3624 my $hm = Hash::Merge->new;
3626 $hm->specify_behavior({
3629 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3631 if ($defl xor $defr) {
3632 return [ $defl ? $_[0] : $_[1] ];
3637 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3641 return [$_[0], $_[1]];
3645 return $_[1] if !defined $_[0];
3646 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3647 return [$_[0], @{$_[1]}]
3650 return [] if !defined $_[0] and !keys %{$_[1]};
3651 return [ $_[1] ] if !defined $_[0];
3652 return [ $_[0] ] if !keys %{$_[1]};
3653 return [$_[0], $_[1]]
3658 return $_[0] if !defined $_[1];
3659 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3660 return [@{$_[0]}, $_[1]]
3663 my @ret = @{$_[0]} or return $_[1];
3664 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3665 my %idx = map { $_ => 1 } @ret;
3666 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3670 return [ $_[1] ] if ! @{$_[0]};
3671 return $_[0] if !keys %{$_[1]};
3672 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3673 return [ @{$_[0]}, $_[1] ];
3678 return [] if !keys %{$_[0]} and !defined $_[1];
3679 return [ $_[0] ] if !defined $_[1];
3680 return [ $_[1] ] if !keys %{$_[0]};
3681 return [$_[0], $_[1]]
3684 return [] if !keys %{$_[0]} and !@{$_[1]};
3685 return [ $_[0] ] if !@{$_[1]};
3686 return $_[1] if !keys %{$_[0]};
3687 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3688 return [ $_[0], @{$_[1]} ];
3691 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3692 return [ $_[0] ] if !keys %{$_[1]};
3693 return [ $_[1] ] if !keys %{$_[0]};
3694 return [ $_[0] ] if $_[0] eq $_[1];
3695 return [ $_[0], $_[1] ];
3698 } => 'DBIC_RS_ATTR_MERGER');
3702 return $hm->merge ($_[1], $_[2]);
3706 sub STORABLE_freeze {
3707 my ($self, $cloning) = @_;
3708 my $to_serialize = { %$self };
3710 # A cursor in progress can't be serialized (and would make little sense anyway)
3711 delete $to_serialize->{cursor};
3713 Storable::nfreeze($to_serialize);
3716 # need this hook for symmetry
3718 my ($self, $cloning, $serialized) = @_;
3720 %$self = %{ Storable::thaw($serialized) };
3726 =head2 throw_exception
3728 See L<DBIx::Class::Schema/throw_exception> for details.
3732 sub throw_exception {
3735 if (ref $self and my $rsrc = $self->result_source) {
3736 $rsrc->throw_exception(@_)
3739 DBIx::Class::Exception->throw(@_);
3743 # XXX: FIXME: Attributes docs need clearing up
3747 Attributes are used to refine a ResultSet in various ways when
3748 searching for data. They can be passed to any method which takes an
3749 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3752 These are in no particular order:
3758 =item Value: ( $order_by | \@order_by | \%order_by )
3762 Which column(s) to order the results by.
3764 [The full list of suitable values is documented in
3765 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3768 If a single column name, or an arrayref of names is supplied, the
3769 argument is passed through directly to SQL. The hashref syntax allows
3770 for connection-agnostic specification of ordering direction:
3772 For descending order:
3774 order_by => { -desc => [qw/col1 col2 col3/] }
3776 For explicit ascending order:
3778 order_by => { -asc => 'col' }
3780 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3781 supported, although you are strongly encouraged to use the hashref
3782 syntax as outlined above.
3788 =item Value: \@columns
3792 Shortcut to request a particular set of columns to be retrieved. Each
3793 column spec may be a string (a table column name), or a hash (in which
3794 case the key is the C<as> value, and the value is used as the C<select>
3795 expression). Adds C<me.> onto the start of any column without a C<.> in
3796 it and sets C<select> from that, then auto-populates C<as> from
3797 C<select> as normal. (You may also use the C<cols> attribute, as in
3798 earlier versions of DBIC.)
3800 Essentially C<columns> does the same as L</select> and L</as>.
3802 columns => [ 'foo', { bar => 'baz' } ]
3806 select => [qw/foo baz/],
3813 =item Value: \@columns
3817 Indicates additional columns to be selected from storage. Works the same
3818 as L</columns> but adds columns to the selection. (You may also use the
3819 C<include_columns> attribute, as in earlier versions of DBIC). For
3822 $schema->resultset('CD')->search(undef, {
3823 '+columns' => ['artist.name'],
3827 would return all CDs and include a 'name' column to the information
3828 passed to object inflation. Note that the 'artist' is the name of the
3829 column (or relationship) accessor, and 'name' is the name of the column
3830 accessor in the related table.
3832 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3833 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3834 unary plus operator before it.
3836 =head2 include_columns
3840 =item Value: \@columns
3844 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3850 =item Value: \@select_columns
3854 Indicates which columns should be selected from the storage. You can use
3855 column names, or in the case of RDBMS back ends, function or stored procedure
3858 $rs = $schema->resultset('Employee')->search(undef, {
3861 { count => 'employeeid' },
3862 { max => { length => 'name' }, -as => 'longest_name' }
3867 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3869 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3870 use L</select>, to instruct DBIx::Class how to store the result of the column.
3871 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3872 identifier aliasing. You can however alias a function, so you can use it in
3873 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3874 attribute> supplied as shown in the example above.
3876 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3877 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3878 unary plus operator before it.
3884 Indicates additional columns to be selected from storage. Works the same as
3885 L</select> but adds columns to the default selection, instead of specifying
3894 Indicates additional column names for those added via L</+select>. See L</as>.
3902 =item Value: \@inflation_names
3906 Indicates column names for object inflation. That is L</as> indicates the
3907 slot name in which the column value will be stored within the
3908 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3909 identifier by the C<get_column> method (or via the object accessor B<if one
3910 with the same name already exists>) as shown below. The L</as> attribute has
3911 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3913 $rs = $schema->resultset('Employee')->search(undef, {
3916 { count => 'employeeid' },
3917 { max => { length => 'name' }, -as => 'longest_name' }
3926 If the object against which the search is performed already has an accessor
3927 matching a column name specified in C<as>, the value can be retrieved using
3928 the accessor as normal:
3930 my $name = $employee->name();
3932 If on the other hand an accessor does not exist in the object, you need to
3933 use C<get_column> instead:
3935 my $employee_count = $employee->get_column('employee_count');
3937 You can create your own accessors if required - see
3938 L<DBIx::Class::Manual::Cookbook> for details.
3944 =item Value: ($rel_name | \@rel_names | \%rel_names)
3948 Contains a list of relationships that should be joined for this query. For
3951 # Get CDs by Nine Inch Nails
3952 my $rs = $schema->resultset('CD')->search(
3953 { 'artist.name' => 'Nine Inch Nails' },
3954 { join => 'artist' }
3957 Can also contain a hash reference to refer to the other relation's relations.
3960 package MyApp::Schema::Track;
3961 use base qw/DBIx::Class/;
3962 __PACKAGE__->table('track');
3963 __PACKAGE__->add_columns(qw/trackid cd position title/);
3964 __PACKAGE__->set_primary_key('trackid');
3965 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3968 # In your application
3969 my $rs = $schema->resultset('Artist')->search(
3970 { 'track.title' => 'Teardrop' },
3972 join => { cd => 'track' },
3973 order_by => 'artist.name',
3977 You need to use the relationship (not the table) name in conditions,
3978 because they are aliased as such. The current table is aliased as "me", so
3979 you need to use me.column_name in order to avoid ambiguity. For example:
3981 # Get CDs from 1984 with a 'Foo' track
3982 my $rs = $schema->resultset('CD')->search(
3985 'tracks.name' => 'Foo'
3987 { join => 'tracks' }
3990 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3991 similarly for a third time). For e.g.
3993 my $rs = $schema->resultset('Artist')->search({
3994 'cds.title' => 'Down to Earth',
3995 'cds_2.title' => 'Popular',
3997 join => [ qw/cds cds/ ],
4000 will return a set of all artists that have both a cd with title 'Down
4001 to Earth' and a cd with title 'Popular'.
4003 If you want to fetch related objects from other tables as well, see C<prefetch>
4006 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
4012 =item Value: ($rel_name | \@rel_names | \%rel_names)
4016 Contains one or more relationships that should be fetched along with
4017 the main query (when they are accessed afterwards the data will
4018 already be available, without extra queries to the database). This is
4019 useful for when you know you will need the related objects, because it
4020 saves at least one query:
4022 my $rs = $schema->resultset('Tag')->search(
4031 The initial search results in SQL like the following:
4033 SELECT tag.*, cd.*, artist.* FROM tag
4034 JOIN cd ON tag.cd = cd.cdid
4035 JOIN artist ON cd.artist = artist.artistid
4037 L<DBIx::Class> has no need to go back to the database when we access the
4038 C<cd> or C<artist> relationships, which saves us two SQL statements in this
4041 Simple prefetches will be joined automatically, so there is no need
4042 for a C<join> attribute in the above search.
4044 L</prefetch> can be used with the any of the relationship types and
4045 multiple prefetches can be specified together. Below is a more complex
4046 example that prefetches a CD's artist, its liner notes (if present),
4047 the cover image, the tracks on that cd, and the guests on those
4051 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
4052 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
4053 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
4054 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
4056 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
4058 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
4061 my $rs = $schema->resultset('CD')->search(
4065 { artist => 'record_label'}, # belongs_to => belongs_to
4066 'liner_note', # might_have
4067 'cover_image', # has_one
4068 { tracks => 'guests' }, # has_many => has_many
4073 This will produce SQL like the following:
4075 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4079 ON artist.artistid = me.artistid
4080 JOIN record_label record_label
4081 ON record_label.labelid = artist.labelid
4082 LEFT JOIN track tracks
4083 ON tracks.cdid = me.cdid
4084 LEFT JOIN guest guests
4085 ON guests.trackid = track.trackid
4086 LEFT JOIN liner_notes liner_note
4087 ON liner_note.cdid = me.cdid
4088 JOIN cd_artwork cover_image
4089 ON cover_image.cdid = me.cdid
4092 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4093 C<tracks>, and C<guests> of the CD will all be available through the
4094 relationship accessors without the need for additional queries to the
4097 However, there is one caveat to be observed: it can be dangerous to
4098 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4099 relationship on a given level. e.g.:
4101 my $rs = $schema->resultset('CD')->search(
4105 'tracks', # has_many
4106 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4111 In fact, C<DBIx::Class> will emit the following warning:
4113 Prefetching multiple has_many rels tracks and cd_to_producer at top
4114 level will explode the number of row objects retrievable via ->next
4115 or ->all. Use at your own risk.
4117 The collapser currently can't identify duplicate tuples for multiple
4118 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4119 result the second L<has_many|DBIx::Class::Relationship/has_many>
4120 relation could contain redundant objects.
4122 =head3 Using L</prefetch> with L</join>
4124 L</prefetch> implies a L</join> with the equivalent argument, and is
4125 properly merged with any existing L</join> specification. So the
4128 my $rs = $schema->resultset('CD')->search(
4129 {'record_label.name' => 'Music Product Ltd.'},
4131 join => {artist => 'record_label'},
4132 prefetch => 'artist',
4136 ... will work, searching on the record label's name, but only
4137 prefetching the C<artist>.
4139 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4141 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4142 prefetched relations. So given:
4144 my $rs = $schema->resultset('CD')->search(
4147 select => ['cd.title'],
4149 prefetch => 'artist',
4153 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4154 becomes: C<'cd_title', 'artist.*'>.
4158 Prefetch does a lot of deep magic. As such, it may not behave exactly
4159 as you might expect.
4165 Prefetch uses the L</cache> to populate the prefetched relationships. This
4166 may or may not be what you want.
4170 If you specify a condition on a prefetched relationship, ONLY those
4171 rows that match the prefetched condition will be fetched into that relationship.
4172 This means that adding prefetch to a search() B<may alter> what is returned by
4173 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4175 my $artist_rs = $schema->resultset('Artist')->search({
4181 my $count = $artist_rs->first->cds->count;
4183 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4185 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4187 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4189 that cmp_ok() may or may not pass depending on the datasets involved. This
4190 behavior may or may not survive the 0.09 transition.
4202 Makes the resultset paged and specifies the page to retrieve. Effectively
4203 identical to creating a non-pages resultset and then calling ->page($page)
4206 If L</rows> attribute is not specified it defaults to 10 rows per page.
4208 When you have a paged resultset, L</count> will only return the number
4209 of rows in the page. To get the total, use the L</pager> and call
4210 C<total_entries> on it.
4220 Specifies the maximum number of rows for direct retrieval or the number of
4221 rows per page if the page attribute or method is used.
4227 =item Value: $offset
4231 Specifies the (zero-based) row number for the first row to be returned, or the
4232 of the first row of the first page if paging is used.
4238 =item Value: \@columns
4242 A arrayref of columns to group by. Can include columns of joined tables.
4244 group_by => [qw/ column1 column2 ... /]
4250 =item Value: $condition
4254 HAVING is a select statement attribute that is applied between GROUP BY and
4255 ORDER BY. It is applied to the after the grouping calculations have been
4258 having => { 'count_employee' => { '>=', 100 } }
4260 or with an in-place function in which case literal SQL is required:
4262 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4268 =item Value: (0 | 1)
4272 Set to 1 to group by all columns. If the resultset already has a group_by
4273 attribute, this setting is ignored and an appropriate warning is issued.
4279 Adds to the WHERE clause.
4281 # only return rows WHERE deleted IS NULL for all searches
4282 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4284 Can be overridden by passing C<< { where => undef } >> as an attribute
4291 Set to 1 to cache search results. This prevents extra SQL queries if you
4292 revisit rows in your ResultSet:
4294 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4296 while( my $artist = $resultset->next ) {
4300 $rs->first; # without cache, this would issue a query
4302 By default, searches are not cached.
4304 For more examples of using these attributes, see
4305 L<DBIx::Class::Manual::Cookbook>.
4311 =item Value: ( 'update' | 'shared' )
4315 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT