1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use DBIx::Class::Exception;
9 use DBIx::Class::ResultSetColumn;
10 use DBIx::Class::ResultSourceHandle;
12 use Scalar::Util qw/blessed weaken/;
14 use Storable qw/nfreeze thaw/;
16 # not importing first() as it will clash with our own method
23 # De-duplication in _merge_attr() is disabled, but left in for reference
24 # (the merger is used for other things that ought not to be de-duped)
25 *__HM_DEDUP = sub () { 0 };
33 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
37 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
41 my $users_rs = $schema->resultset('User');
42 while( $user = $users_rs->next) {
43 print $user->username;
46 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
47 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
51 A ResultSet is an object which stores a set of conditions representing
52 a query. It is the backbone of DBIx::Class (i.e. the really
53 important/useful bit).
55 No SQL is executed on the database when a ResultSet is created, it
56 just stores all the conditions needed to create the query.
58 A basic ResultSet representing the data of an entire table is returned
59 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
60 L<Source|DBIx::Class::Manual::Glossary/Source> name.
62 my $users_rs = $schema->resultset('User');
64 A new ResultSet is returned from calling L</search> on an existing
65 ResultSet. The new one will contain all the conditions of the
66 original, plus any new conditions added in the C<search> call.
68 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
69 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
72 The query that the ResultSet represents is B<only> executed against
73 the database when these methods are called:
74 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
76 If a resultset is used in a numeric context it returns the L</count>.
77 However, if it is used in a boolean context it is B<always> true. So if
78 you want to check if a resultset has any results, you must use C<if $rs
83 =head2 Chaining resultsets
85 Let's say you've got a query that needs to be run to return some data
86 to the user. But, you have an authorization system in place that
87 prevents certain users from seeing certain information. So, you want
88 to construct the basic query in one method, but add constraints to it in
93 my $request = $self->get_request; # Get a request object somehow.
94 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
96 my $cd_rs = $schema->resultset('CD')->search({
97 title => $request->param('title'),
98 year => $request->param('year'),
101 $self->apply_security_policy( $cd_rs );
103 return $cd_rs->all();
106 sub apply_security_policy {
115 =head3 Resolving conditions and attributes
117 When a resultset is chained from another resultset, conditions and
118 attributes with the same keys need resolving.
120 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
121 into the existing ones from the original resultset.
123 The L</where> and L</having> attributes, and any search conditions, are
124 merged with an SQL C<AND> to the existing condition from the original
127 All other attributes are overridden by any new ones supplied in the
130 =head2 Multiple queries
132 Since a resultset just defines a query, you can do all sorts of
133 things with it with the same object.
135 # Don't hit the DB yet.
136 my $cd_rs = $schema->resultset('CD')->search({
137 title => 'something',
141 # Each of these hits the DB individually.
142 my $count = $cd_rs->count;
143 my $most_recent = $cd_rs->get_column('date_released')->max();
144 my @records = $cd_rs->all;
146 And it's not just limited to SELECT statements.
152 $cd_rs->create({ artist => 'Fred' });
154 Which is the same as:
156 $schema->resultset('CD')->create({
157 title => 'something',
162 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
170 =item Arguments: $source, \%$attrs
172 =item Return Value: $rs
176 The resultset constructor. Takes a source object (usually a
177 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
178 L</ATTRIBUTES> below). Does not perform any queries -- these are
179 executed as needed by the other methods.
181 Generally you won't need to construct a resultset manually. You'll
182 automatically get one from e.g. a L</search> called in scalar context:
184 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
186 IMPORTANT: If called on an object, proxies to new_result instead so
188 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
190 will return a CD object, not a ResultSet.
196 return $class->new_result(@_) if ref $class;
198 my ($source, $attrs) = @_;
199 $source = $source->resolve
200 if $source->isa('DBIx::Class::ResultSourceHandle');
201 $attrs = { %{$attrs||{}} };
203 if ($attrs->{page}) {
204 $attrs->{rows} ||= 10;
207 $attrs->{alias} ||= 'me';
210 result_source => $source,
211 cond => $attrs->{where},
217 $attrs->{result_class} || $source->result_class
227 =item Arguments: $cond, \%attrs?
229 =item Return Value: $resultset (scalar context), @row_objs (list context)
233 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
234 my $new_rs = $cd_rs->search({ year => 2005 });
236 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
237 # year = 2005 OR year = 2004
239 If you need to pass in additional attributes but no additional condition,
240 call it as C<search(undef, \%attrs)>.
242 # "SELECT name, artistid FROM $artist_table"
243 my @all_artists = $schema->resultset('Artist')->search(undef, {
244 columns => [qw/name artistid/],
247 For a list of attributes that can be passed to C<search>, see
248 L</ATTRIBUTES>. For more examples of using this function, see
249 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
250 documentation for the first argument, see L<SQL::Abstract>.
252 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
256 Note that L</search> does not process/deflate any of the values passed in the
257 L<SQL::Abstract>-compatible search condition structure. This is unlike other
258 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
259 manually that any value passed to this method will stringify to something the
260 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
261 objects, for more info see:
262 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
268 my $rs = $self->search_rs( @_ );
273 elsif (defined wantarray) {
277 # we can be called by a relationship helper, which in
278 # turn may be called in void context due to some braindead
279 # overload or whatever else the user decided to be clever
280 # at this particular day. Thus limit the exception to
281 # external code calls only
282 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
283 if (caller)[0] !~ /^\QDBIx::Class::/;
293 =item Arguments: $cond, \%attrs?
295 =item Return Value: $resultset
299 This method does the same exact thing as search() except it will
300 always return a resultset, even in list context.
304 my $callsites_warned;
308 # Special-case handling for (undef, undef).
309 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
315 if (ref $_[-1] eq 'HASH') {
316 # copy for _normalize_selection
317 $call_attrs = { %{ pop @_ } };
319 elsif (! defined $_[-1] ) {
320 pop @_; # search({}, undef)
324 # see if we can keep the cache (no $rs changes)
326 my %safe = (alias => 1, cache => 1);
327 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
330 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
332 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
334 $cache = $self->get_cache;
337 my $rsrc = $self->result_source;
339 my $old_attrs = { %{$self->{attrs}} };
340 my $old_having = delete $old_attrs->{having};
341 my $old_where = delete $old_attrs->{where};
343 my $new_attrs = { %$old_attrs };
345 # take care of call attrs (only if anything is changing)
346 if (keys %$call_attrs) {
348 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
349 if ( exists $call_attrs->{_trailing_select} or exists $call_attrs->{'+_trailing_select'} );
351 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns _trailing_select +_trailing_select/;
353 # Normalize the selector list (operates on the passed-in attr structure)
354 # Need to do it on every chain instead of only once on _resolved_attrs, in
355 # order to separate 'as'-ed from blind 'select's
356 $self->_normalize_selection ($call_attrs);
358 # start with blind overwriting merge, exclude selector attrs
359 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
360 delete @{$new_attrs}{@selector_attrs};
362 # reset the current selector list if new selectors are supplied
363 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
364 delete @{$old_attrs}{@selector_attrs};
367 for (@selector_attrs) {
368 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
369 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
372 # older deprecated name, use only if {columns} is not there
373 if (my $c = delete $new_attrs->{cols}) {
374 if ($new_attrs->{columns}) {
375 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
378 $new_attrs->{columns} = $c;
383 # join/prefetch use their own crazy merging heuristics
384 foreach my $key (qw/join prefetch/) {
385 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
386 if exists $call_attrs->{$key};
389 # stack binds together
390 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
394 # rip apart the rest of @_, parse a condition
397 if (ref $_[0] eq 'HASH') {
398 (keys %{$_[0]}) ? $_[0] : undef
404 $self->throw_exception('Odd number of arguments to search')
412 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
413 # determine callsite obeying Carp::Clan rules (fucking ugly but don't have better ideas)
416 local $SIG{__WARN__} = sub { $w = shift };
420 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
421 unless $callsites_warned->{$callsite}++;
424 for ($old_where, $call_cond) {
426 $new_attrs->{where} = $self->_stack_cond (
427 $_, $new_attrs->{where}
432 if (defined $old_having) {
433 $new_attrs->{having} = $self->_stack_cond (
434 $old_having, $new_attrs->{having}
438 my $rs = (ref $self)->new($rsrc, $new_attrs);
440 $rs->set_cache($cache) if ($cache);
445 sub _normalize_selection {
446 my ($self, $attrs) = @_;
449 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
450 if exists $attrs->{include_columns};
452 # Keep the X vs +X separation until _resolved_attrs time - this allows to
453 # delay the decision on whether to use a default select list ($rsrc->columns)
454 # allowing stuff like the remove_columns helper to work
456 # select/as +select/+as pairs need special handling - the amount of select/as
457 # elements in each pair does *not* have to be equal (think multicolumn
458 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
459 # supplied at all) - try to infer the alias, either from the -as parameter
460 # of the selector spec, or use the parameter whole if it looks like a column
461 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
462 # is ok as well), but transport it over a separate attribute to make sure it is
463 # the last thing in the select list, thus unable to throw off the corresponding
465 for my $pref ('', '+') {
467 my ($sel, $as) = map {
468 my $key = "${pref}${_}";
470 my $val = [ ref $attrs->{$key} eq 'ARRAY'
472 : $attrs->{$key} || ()
474 delete $attrs->{$key};
478 if (! @$as and ! @$sel ) {
481 elsif (@$as and ! @$sel) {
482 $self->throw_exception(
483 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
487 # no as part supplied at all - try to deduce
488 # if any @$as has been supplied we assume the user knows what (s)he is doing
489 # and blindly keep stacking up pieces
490 my (@new_sel, @new_trailing);
492 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
493 push @$as, $_->{-as};
496 # assume any plain no-space, no-parenthesis string to be a column spec
497 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
498 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
502 # if all else fails - shove the selection to the trailing stack and move on
504 push @new_trailing, $_;
509 $attrs->{"${pref}_trailing_select"} = $self->_merge_attr($attrs->{"${pref}_trailing_select"}, \@new_trailing)
512 elsif (@$as < @$sel) {
513 $self->throw_exception(
514 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
518 # now see what the result for this pair looks like:
521 # if balanced - treat as a columns entry
522 $attrs->{"${pref}columns"} = $self->_merge_attr(
523 $attrs->{"${pref}columns"},
524 [ map { +{ $as->[$_] => $sel->[$_] } } ( 0 .. $#$as ) ]
528 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
529 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
530 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
537 my ($self, $left, $right) = @_;
538 if (defined $left xor defined $right) {
539 return defined $left ? $left : $right;
541 elsif (defined $left) {
542 return { -and => [ map
543 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
551 =head2 search_literal
555 =item Arguments: $sql_fragment, @bind_values
557 =item Return Value: $resultset (scalar context), @row_objs (list context)
561 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
562 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
564 Pass a literal chunk of SQL to be added to the conditional part of the
567 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
568 only be used in that context. C<search_literal> is a convenience method.
569 It is equivalent to calling $schema->search(\[]), but if you want to ensure
570 columns are bound correctly, use C<search>.
572 Example of how to use C<search> instead of C<search_literal>
574 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
575 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
578 See L<DBIx::Class::Manual::Cookbook/Searching> and
579 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
580 require C<search_literal>.
585 my ($self, $sql, @bind) = @_;
587 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
590 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
597 =item Arguments: \%columns_values | @pk_values, \%attrs?
599 =item Return Value: $row_object | undef
603 Finds and returns a single row based on supplied criteria. Takes either a
604 hashref with the same format as L</create> (including inference of foreign
605 keys from related objects), or a list of primary key values in the same
606 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
607 declaration on the L</result_source>.
609 In either case an attempt is made to combine conditions already existing on
610 the resultset with the condition passed to this method.
612 To aid with preparing the correct query for the storage you may supply the
613 C<key> attribute, which is the name of a
614 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
615 unique constraint corresponding to the
616 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
617 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
618 to construct a query that satisfies the named unique constraint fully (
619 non-NULL values for each column member of the constraint) an exception is
622 If no C<key> is specified, the search is carried over all unique constraints
623 which are fully defined by the available condition.
625 If no such constraint is found, C<find> currently defaults to a simple
626 C<< search->(\%column_values) >> which may or may not do what you expect.
627 Note that this fallback behavior may be deprecated in further versions. If
628 you need to search with arbitrary conditions - use L</search>. If the query
629 resulting from this fallback produces more than one row, a warning to the
630 effect is issued, though only the first row is constructed and returned as
633 In addition to C<key>, L</find> recognizes and applies standard
634 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
636 Note that if you have extra concerns about the correctness of the resulting
637 query you need to specify the C<key> attribute and supply the entire condition
638 as an argument to find (since it is not always possible to perform the
639 combination of the resultset condition with the supplied one, especially if
640 the resultset condition contains literal sql).
642 For example, to find a row by its primary key:
644 my $cd = $schema->resultset('CD')->find(5);
646 You can also find a row by a specific unique constraint:
648 my $cd = $schema->resultset('CD')->find(
650 artist => 'Massive Attack',
651 title => 'Mezzanine',
653 { key => 'cd_artist_title' }
656 See also L</find_or_create> and L</update_or_create>.
662 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
664 my $rsrc = $self->result_source;
666 # Parse out the condition from input
668 if (ref $_[0] eq 'HASH') {
669 $call_cond = { %{$_[0]} };
672 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
673 my @c_cols = $rsrc->unique_constraint_columns($constraint);
675 $self->throw_exception(
676 "No constraint columns, maybe a malformed '$constraint' constraint?"
679 $self->throw_exception (
680 'find() expects either a column/value hashref, or a list of values '
681 . "corresponding to the columns of the specified unique constraint '$constraint'"
682 ) unless @c_cols == @_;
685 @{$call_cond}{@c_cols} = @_;
689 for my $key (keys %$call_cond) {
691 my $keyref = ref($call_cond->{$key})
693 my $relinfo = $rsrc->relationship_info($key)
695 my $val = delete $call_cond->{$key};
697 next if $keyref eq 'ARRAY'; # has_many for multi_create
699 my $rel_q = $rsrc->_resolve_condition(
700 $relinfo->{cond}, $val, $key
702 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
703 @related{keys %$rel_q} = values %$rel_q;
707 # relationship conditions take precedence (?)
708 @{$call_cond}{keys %related} = values %related;
710 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
712 if (exists $attrs->{key}) {
713 $final_cond = $self->_qualify_cond_columns (
715 $self->_build_unique_cond (
723 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
724 # This means that we got here after a merger of relationship conditions
725 # in ::Relationship::Base::search_related (the row method), and furthermore
726 # the relationship is of the 'single' type. This means that the condition
727 # provided by the relationship (already attached to $self) is sufficient,
728 # as there can be only one row in the database that would satisfy the
732 # no key was specified - fall down to heuristics mode:
733 # run through all unique queries registered on the resultset, and
734 # 'OR' all qualifying queries together
735 my (@unique_queries, %seen_column_combinations);
736 for my $c_name ($rsrc->unique_constraint_names) {
737 next if $seen_column_combinations{
738 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
741 push @unique_queries, try {
742 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
746 $final_cond = @unique_queries
747 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
748 : $self->_non_unique_find_fallback ($call_cond, $attrs)
752 # Run the query, passing the result_class since it should propagate for find
753 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
754 if (keys %{$rs->_resolved_attrs->{collapse}}) {
756 carp "Query returned more than one row" if $rs->next;
764 # This is a stop-gap method as agreed during the discussion on find() cleanup:
765 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
767 # It is invoked when find() is called in legacy-mode with insufficiently-unique
768 # condition. It is provided for overrides until a saner way forward is devised
770 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
771 # the road. Please adjust your tests accordingly to catch this situation early
772 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
774 # The method will not be removed without an adequately complete replacement
775 # for strict-mode enforcement
776 sub _non_unique_find_fallback {
777 my ($self, $cond, $attrs) = @_;
779 return $self->_qualify_cond_columns(
781 exists $attrs->{alias}
783 : $self->{attrs}{alias}
788 sub _qualify_cond_columns {
789 my ($self, $cond, $alias) = @_;
791 my %aliased = %$cond;
792 for (keys %aliased) {
793 $aliased{"$alias.$_"} = delete $aliased{$_}
800 my $callsites_warned_ucond;
801 sub _build_unique_cond {
802 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
804 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
806 # combination may fail if $self->{cond} is non-trivial
807 my ($final_cond) = try {
808 $self->_merge_with_rscond ($extra_cond)
813 # trim out everything not in $columns
814 $final_cond = { map {
815 exists $final_cond->{$_}
816 ? ( $_ => $final_cond->{$_} )
820 if (my @missing = grep
821 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
824 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
826 join (', ', map { "'$_'" } @missing),
833 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
835 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
839 local $SIG{__WARN__} = sub { $w = shift };
845 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
846 . 'values in column(s): %s). This is almost certainly not what you wanted, '
847 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
849 join (', ', map { "'$_'" } @undefs),
850 )) unless $callsites_warned_ucond->{$callsite}++;
856 =head2 search_related
860 =item Arguments: $rel, $cond, \%attrs?
862 =item Return Value: $new_resultset
866 $new_rs = $cd_rs->search_related('artist', {
870 Searches the specified relationship, optionally specifying a condition and
871 attributes for matching records. See L</ATTRIBUTES> for more information.
876 return shift->related_resultset(shift)->search(@_);
879 =head2 search_related_rs
881 This method works exactly the same as search_related, except that
882 it guarantees a resultset, even in list context.
886 sub search_related_rs {
887 return shift->related_resultset(shift)->search_rs(@_);
894 =item Arguments: none
896 =item Return Value: $cursor
900 Returns a storage-driven cursor to the given resultset. See
901 L<DBIx::Class::Cursor> for more information.
908 my $attrs = $self->_resolved_attrs_copy;
910 return $self->{cursor}
911 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
912 $attrs->{where},$attrs);
919 =item Arguments: $cond?
921 =item Return Value: $row_object | undef
925 my $cd = $schema->resultset('CD')->single({ year => 2001 });
927 Inflates the first result without creating a cursor if the resultset has
928 any records in it; if not returns C<undef>. Used by L</find> as a lean version
931 While this method can take an optional search condition (just like L</search>)
932 being a fast-code-path it does not recognize search attributes. If you need to
933 add extra joins or similar, call L</search> and then chain-call L</single> on the
934 L<DBIx::Class::ResultSet> returned.
940 As of 0.08100, this method enforces the assumption that the preceding
941 query returns only one row. If more than one row is returned, you will receive
944 Query returned more than one row
946 In this case, you should be using L</next> or L</find> instead, or if you really
947 know what you are doing, use the L</rows> attribute to explicitly limit the size
950 This method will also throw an exception if it is called on a resultset prefetching
951 has_many, as such a prefetch implies fetching multiple rows from the database in
952 order to assemble the resulting object.
959 my ($self, $where) = @_;
961 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
964 my $attrs = $self->_resolved_attrs_copy;
966 if (keys %{$attrs->{collapse}}) {
967 $self->throw_exception(
968 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
973 if (defined $attrs->{where}) {
976 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
977 $where, delete $attrs->{where} ]
980 $attrs->{where} = $where;
984 my @data = $self->result_source->storage->select_single(
985 $attrs->{from}, $attrs->{select},
986 $attrs->{where}, $attrs
989 return (@data ? ($self->_construct_object(@data))[0] : undef);
995 # Recursively collapse the query, accumulating values for each column.
997 sub _collapse_query {
998 my ($self, $query, $collapsed) = @_;
1002 if (ref $query eq 'ARRAY') {
1003 foreach my $subquery (@$query) {
1004 next unless ref $subquery; # -or
1005 $collapsed = $self->_collapse_query($subquery, $collapsed);
1008 elsif (ref $query eq 'HASH') {
1009 if (keys %$query and (keys %$query)[0] eq '-and') {
1010 foreach my $subquery (@{$query->{-and}}) {
1011 $collapsed = $self->_collapse_query($subquery, $collapsed);
1015 foreach my $col (keys %$query) {
1016 my $value = $query->{$col};
1017 $collapsed->{$col}{$value}++;
1029 =item Arguments: $cond?
1031 =item Return Value: $resultsetcolumn
1035 my $max_length = $rs->get_column('length')->max;
1037 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1042 my ($self, $column) = @_;
1043 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1051 =item Arguments: $cond, \%attrs?
1053 =item Return Value: $resultset (scalar context), @row_objs (list context)
1057 # WHERE title LIKE '%blue%'
1058 $cd_rs = $rs->search_like({ title => '%blue%'});
1060 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1061 that this is simply a convenience method retained for ex Class::DBI users.
1062 You most likely want to use L</search> with specific operators.
1064 For more information, see L<DBIx::Class::Manual::Cookbook>.
1066 This method is deprecated and will be removed in 0.09. Use L</search()>
1067 instead. An example conversion is:
1069 ->search_like({ foo => 'bar' });
1073 ->search({ foo => { like => 'bar' } });
1080 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1081 .' Instead use ->search({ x => { -like => "y%" } })'
1082 .' (note the outer pair of {}s - they are important!)'
1084 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1085 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1086 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1087 return $class->search($query, { %$attrs });
1094 =item Arguments: $first, $last
1096 =item Return Value: $resultset (scalar context), @row_objs (list context)
1100 Returns a resultset or object list representing a subset of elements from the
1101 resultset slice is called on. Indexes are from 0, i.e., to get the first
1102 three records, call:
1104 my ($one, $two, $three) = $rs->slice(0, 2);
1109 my ($self, $min, $max) = @_;
1110 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1111 $attrs->{offset} = $self->{attrs}{offset} || 0;
1112 $attrs->{offset} += $min;
1113 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1114 return $self->search(undef, $attrs);
1115 #my $slice = (ref $self)->new($self->result_source, $attrs);
1116 #return (wantarray ? $slice->all : $slice);
1123 =item Arguments: none
1125 =item Return Value: $result | undef
1129 Returns the next element in the resultset (C<undef> is there is none).
1131 Can be used to efficiently iterate over records in the resultset:
1133 my $rs = $schema->resultset('CD')->search;
1134 while (my $cd = $rs->next) {
1138 Note that you need to store the resultset object, and call C<next> on it.
1139 Calling C<< resultset('Table')->next >> repeatedly will always return the
1140 first record from the resultset.
1146 if (my $cache = $self->get_cache) {
1147 $self->{all_cache_position} ||= 0;
1148 return $cache->[$self->{all_cache_position}++];
1150 if ($self->{attrs}{cache}) {
1151 delete $self->{pager};
1152 $self->{all_cache_position} = 1;
1153 return ($self->all)[0];
1155 if ($self->{stashed_objects}) {
1156 my $obj = shift(@{$self->{stashed_objects}});
1157 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1161 exists $self->{stashed_row}
1162 ? @{delete $self->{stashed_row}}
1163 : $self->cursor->next
1165 return undef unless (@row);
1166 my ($row, @more) = $self->_construct_object(@row);
1167 $self->{stashed_objects} = \@more if @more;
1171 sub _construct_object {
1172 my ($self, @row) = @_;
1174 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1176 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1177 @new = $self->{_attrs}{record_filter}->(@new)
1178 if exists $self->{_attrs}{record_filter};
1182 sub _collapse_result {
1183 my ($self, $as_proto, $row) = @_;
1187 # 'foo' => [ undef, 'foo' ]
1188 # 'foo.bar' => [ 'foo', 'bar' ]
1189 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1191 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1193 my %collapse = %{$self->{_attrs}{collapse}||{}};
1197 # if we're doing collapsing (has_many prefetch) we need to grab records
1198 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1199 # we know we don't have to bother.
1201 # the reason for not using the collapse stuff directly is because if you
1202 # had for e.g. two artists in a row with no cds, the collapse info for
1203 # both would be NULL (undef) so you'd lose the second artist
1205 # store just the index so we can check the array positions from the row
1206 # without having to contruct the full hash
1208 if (keys %collapse) {
1209 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1210 foreach my $i (0 .. $#construct_as) {
1211 next if defined($construct_as[$i][0]); # only self table
1212 if (delete $pri{$construct_as[$i][1]}) {
1213 push(@pri_index, $i);
1215 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1219 # no need to do an if, it'll be empty if @pri_index is empty anyway
1221 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1225 do { # no need to check anything at the front, we always want the first row
1229 foreach my $this_as (@construct_as) {
1230 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1233 push(@const_rows, \%const);
1235 } until ( # no pri_index => no collapse => drop straight out
1238 do { # get another row, stash it, drop out if different PK
1240 @copy = $self->cursor->next;
1241 $self->{stashed_row} = \@copy;
1243 # last thing in do block, counts as true if anything doesn't match
1245 # check xor defined first for NULL vs. NOT NULL then if one is
1246 # defined the other must be so check string equality
1249 (defined $pri_vals{$_} ^ defined $copy[$_])
1250 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1255 my $alias = $self->{attrs}{alias};
1262 foreach my $const (@const_rows) {
1263 scalar @const_keys or do {
1264 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1266 foreach my $key (@const_keys) {
1269 my @parts = split(/\./, $key);
1271 my $data = $const->{$key};
1272 foreach my $p (@parts) {
1273 $target = $target->[1]->{$p} ||= [];
1275 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1276 # collapsing at this point and on final part
1277 my $pos = $collapse_pos{$cur};
1278 CK: foreach my $ck (@ckey) {
1279 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1280 $collapse_pos{$cur} = $data;
1281 delete @collapse_pos{ # clear all positioning for sub-entries
1282 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1289 if (exists $collapse{$cur}) {
1290 $target = $target->[-1];
1293 $target->[0] = $data;
1295 $info->[0] = $const->{$key};
1303 =head2 result_source
1307 =item Arguments: $result_source?
1309 =item Return Value: $result_source
1313 An accessor for the primary ResultSource object from which this ResultSet
1320 =item Arguments: $result_class?
1322 =item Return Value: $result_class
1326 An accessor for the class to use when creating row objects. Defaults to
1327 C<< result_source->result_class >> - which in most cases is the name of the
1328 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1330 Note that changing the result_class will also remove any components
1331 that were originally loaded in the source class via
1332 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1333 in the original source class will not run.
1338 my ($self, $result_class) = @_;
1339 if ($result_class) {
1340 unless (ref $result_class) { # don't fire this for an object
1341 $self->ensure_class_loaded($result_class);
1343 $self->_result_class($result_class);
1344 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1345 # permit the user to set result class on one result set only; it only
1346 # chains if provided to search()
1347 #$self->{attrs}{result_class} = $result_class if ref $self;
1349 $self->_result_class;
1356 =item Arguments: $cond, \%attrs??
1358 =item Return Value: $count
1362 Performs an SQL C<COUNT> with the same query as the resultset was built
1363 with to find the number of elements. Passing arguments is equivalent to
1364 C<< $rs->search ($cond, \%attrs)->count >>
1370 return $self->search(@_)->count if @_ and defined $_[0];
1371 return scalar @{ $self->get_cache } if $self->get_cache;
1373 my $attrs = $self->_resolved_attrs_copy;
1375 # this is a little optimization - it is faster to do the limit
1376 # adjustments in software, instead of a subquery
1377 my $rows = delete $attrs->{rows};
1378 my $offset = delete $attrs->{offset};
1381 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1382 $crs = $self->_count_subq_rs ($attrs);
1385 $crs = $self->_count_rs ($attrs);
1387 my $count = $crs->next;
1389 $count -= $offset if $offset;
1390 $count = $rows if $rows and $rows < $count;
1391 $count = 0 if ($count < 0);
1400 =item Arguments: $cond, \%attrs??
1402 =item Return Value: $count_rs
1406 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1407 This can be very handy for subqueries:
1409 ->search( { amount => $some_rs->count_rs->as_query } )
1411 As with regular resultsets the SQL query will be executed only after
1412 the resultset is accessed via L</next> or L</all>. That would return
1413 the same single value obtainable via L</count>.
1419 return $self->search(@_)->count_rs if @_;
1421 # this may look like a lack of abstraction (count() does about the same)
1422 # but in fact an _rs *must* use a subquery for the limits, as the
1423 # software based limiting can not be ported if this $rs is to be used
1424 # in a subquery itself (i.e. ->as_query)
1425 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1426 return $self->_count_subq_rs;
1429 return $self->_count_rs;
1434 # returns a ResultSetColumn object tied to the count query
1437 my ($self, $attrs) = @_;
1439 my $rsrc = $self->result_source;
1440 $attrs ||= $self->_resolved_attrs;
1442 my $tmp_attrs = { %$attrs };
1443 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1444 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1446 # overwrite the selector (supplied by the storage)
1447 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1448 $tmp_attrs->{as} = 'count';
1449 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1451 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1457 # same as above but uses a subquery
1459 sub _count_subq_rs {
1460 my ($self, $attrs) = @_;
1462 my $rsrc = $self->result_source;
1463 $attrs ||= $self->_resolved_attrs;
1465 my $sub_attrs = { %$attrs };
1466 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1467 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1469 # if we multi-prefetch we group_by primary keys only as this is what we would
1470 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1471 if ( keys %{$attrs->{collapse}} ) {
1472 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1475 # Calculate subquery selector
1476 if (my $g = $sub_attrs->{group_by}) {
1478 my $sql_maker = $rsrc->storage->sql_maker;
1480 # necessary as the group_by may refer to aliased functions
1482 for my $sel (@{$attrs->{select}}) {
1483 $sel_index->{$sel->{-as}} = $sel
1484 if (ref $sel eq 'HASH' and $sel->{-as});
1487 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1488 # also look for named aggregates referred in the having clause
1489 # having often contains scalarrefs - thus parse it out entirely
1491 if ($attrs->{having}) {
1492 local $sql_maker->{having_bind};
1493 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1494 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1495 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1496 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1497 # if we don't unset it we screw up retarded but unfortunately working
1498 # 'MAX(foo.bar)' => { '>', 3 }
1499 $sql_maker->{name_sep} = '';
1502 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1504 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1506 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1507 # and if all fails for an utterly naive quoted scalar-with-function
1509 $rquote $sep $lquote (.+?) $rquote
1511 [\s,] \w+ \. (\w+) [\s,]
1513 [\s,] $lquote (.+?) $rquote [\s,]
1515 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1520 my $colpiece = $sel_index->{$_} || $_;
1522 # unqualify join-based group_by's. Arcane but possible query
1523 # also horrible horrible hack to alias a column (not a func.)
1524 # (probably need to introduce SQLA syntax)
1525 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1528 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1530 push @{$sub_attrs->{select}}, $colpiece;
1534 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1535 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1538 return $rsrc->resultset_class
1539 ->new ($rsrc, $sub_attrs)
1541 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1542 ->get_column ('count');
1549 =head2 count_literal
1553 =item Arguments: $sql_fragment, @bind_values
1555 =item Return Value: $count
1559 Counts the results in a literal query. Equivalent to calling L</search_literal>
1560 with the passed arguments, then L</count>.
1564 sub count_literal { shift->search_literal(@_)->count; }
1570 =item Arguments: none
1572 =item Return Value: @objects
1576 Returns all elements in the resultset. Called implicitly if the resultset
1577 is returned in list context.
1584 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1587 return @{ $self->get_cache } if $self->get_cache;
1591 if (keys %{$self->_resolved_attrs->{collapse}}) {
1592 # Using $self->cursor->all is really just an optimisation.
1593 # If we're collapsing has_many prefetches it probably makes
1594 # very little difference, and this is cleaner than hacking
1595 # _construct_object to survive the approach
1596 $self->cursor->reset;
1597 my @row = $self->cursor->next;
1599 push(@obj, $self->_construct_object(@row));
1600 @row = (exists $self->{stashed_row}
1601 ? @{delete $self->{stashed_row}}
1602 : $self->cursor->next);
1605 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1608 $self->set_cache(\@obj) if $self->{attrs}{cache};
1617 =item Arguments: none
1619 =item Return Value: $self
1623 Resets the resultset's cursor, so you can iterate through the elements again.
1624 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1631 delete $self->{_attrs} if exists $self->{_attrs};
1632 $self->{all_cache_position} = 0;
1633 $self->cursor->reset;
1641 =item Arguments: none
1643 =item Return Value: $object | undef
1647 Resets the resultset and returns an object for the first result (or C<undef>
1648 if the resultset is empty).
1653 return $_[0]->reset->next;
1659 # Determines whether and what type of subquery is required for the $rs operation.
1660 # If grouping is necessary either supplies its own, or verifies the current one
1661 # After all is done delegates to the proper storage method.
1663 sub _rs_update_delete {
1664 my ($self, $op, $values) = @_;
1666 my $rsrc = $self->result_source;
1668 # if a condition exists we need to strip all table qualifiers
1669 # if this is not possible we'll force a subquery below
1670 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1672 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1673 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1675 if ($needs_group_by_subq or $needs_subq) {
1677 # make a new $rs selecting only the PKs (that's all we really need)
1678 my $attrs = $self->_resolved_attrs_copy;
1681 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1682 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1684 if ($needs_group_by_subq) {
1685 # make sure no group_by was supplied, or if there is one - make sure it matches
1686 # the columns compiled above perfectly. Anything else can not be sanely executed
1687 # on most databases so croak right then and there
1689 if (my $g = $attrs->{group_by}) {
1690 my @current_group_by = map
1691 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1696 join ("\x00", sort @current_group_by)
1698 join ("\x00", sort @{$attrs->{columns}} )
1700 $self->throw_exception (
1701 "You have just attempted a $op operation on a resultset which does group_by"
1702 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1703 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1704 . ' kind of queries. Please retry the operation with a modified group_by or'
1705 . ' without using one at all.'
1710 $attrs->{group_by} = $attrs->{columns};
1714 my $subrs = (ref $self)->new($rsrc, $attrs);
1715 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1718 return $rsrc->storage->$op(
1720 $op eq 'update' ? $values : (),
1730 =item Arguments: \%values
1732 =item Return Value: $storage_rv
1736 Sets the specified columns in the resultset to the supplied values in a
1737 single query. Note that this will not run any accessor/set_column/update
1738 triggers, nor will it update any row object instances derived from this
1739 resultset (this includes the contents of the L<resultset cache|/set_cache>
1740 if any). See L</update_all> if you need to execute any on-update
1741 triggers or cascades defined either by you or a
1742 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1744 The return value is a pass through of what the underlying
1745 storage backend returned, and may vary. See L<DBI/execute> for the most
1750 Note that L</update> does not process/deflate any of the values passed in.
1751 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1752 ensure manually that any value passed to this method will stringify to
1753 something the RDBMS knows how to deal with. A notable example is the
1754 handling of L<DateTime> objects, for more info see:
1755 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1760 my ($self, $values) = @_;
1761 $self->throw_exception('Values for update must be a hash')
1762 unless ref $values eq 'HASH';
1764 return $self->_rs_update_delete ('update', $values);
1771 =item Arguments: \%values
1773 =item Return Value: 1
1777 Fetches all objects and updates them one at a time via
1778 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1779 triggers, while L</update> will not.
1784 my ($self, $values) = @_;
1785 $self->throw_exception('Values for update_all must be a hash')
1786 unless ref $values eq 'HASH';
1788 my $guard = $self->result_source->schema->txn_scope_guard;
1789 $_->update($values) for $self->all;
1798 =item Arguments: none
1800 =item Return Value: $storage_rv
1804 Deletes the rows matching this resultset in a single query. Note that this
1805 will not run any delete triggers, nor will it alter the
1806 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1807 derived from this resultset (this includes the contents of the
1808 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1809 execute any on-delete triggers or cascades defined either by you or a
1810 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1812 The return value is a pass through of what the underlying storage backend
1813 returned, and may vary. See L<DBI/execute> for the most common case.
1819 $self->throw_exception('delete does not accept any arguments')
1822 return $self->_rs_update_delete ('delete');
1829 =item Arguments: none
1831 =item Return Value: 1
1835 Fetches all objects and deletes them one at a time via
1836 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1837 triggers, while L</delete> will not.
1843 $self->throw_exception('delete_all does not accept any arguments')
1846 my $guard = $self->result_source->schema->txn_scope_guard;
1847 $_->delete for $self->all;
1856 =item Arguments: \@data;
1860 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1861 For the arrayref of hashrefs style each hashref should be a structure suitable
1862 forsubmitting to a $resultset->create(...) method.
1864 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1865 to insert the data, as this is a faster method.
1867 Otherwise, each set of data is inserted into the database using
1868 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1869 accumulated into an array. The array itself, or an array reference
1870 is returned depending on scalar or list context.
1872 Example: Assuming an Artist Class that has many CDs Classes relating:
1874 my $Artist_rs = $schema->resultset("Artist");
1876 ## Void Context Example
1877 $Artist_rs->populate([
1878 { artistid => 4, name => 'Manufactured Crap', cds => [
1879 { title => 'My First CD', year => 2006 },
1880 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1883 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1884 { title => 'My parents sold me to a record company', year => 2005 },
1885 { title => 'Why Am I So Ugly?', year => 2006 },
1886 { title => 'I Got Surgery and am now Popular', year => 2007 }
1891 ## Array Context Example
1892 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1893 { name => "Artist One"},
1894 { name => "Artist Two"},
1895 { name => "Artist Three", cds=> [
1896 { title => "First CD", year => 2007},
1897 { title => "Second CD", year => 2008},
1901 print $ArtistOne->name; ## response is 'Artist One'
1902 print $ArtistThree->cds->count ## reponse is '2'
1904 For the arrayref of arrayrefs style, the first element should be a list of the
1905 fieldsnames to which the remaining elements are rows being inserted. For
1908 $Arstist_rs->populate([
1909 [qw/artistid name/],
1910 [100, 'A Formally Unknown Singer'],
1911 [101, 'A singer that jumped the shark two albums ago'],
1912 [102, 'An actually cool singer'],
1915 Please note an important effect on your data when choosing between void and
1916 wantarray context. Since void context goes straight to C<insert_bulk> in
1917 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1918 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1919 create primary keys for you, you will find that your PKs are empty. In this
1920 case you will have to use the wantarray context in order to create those
1928 # cruft placed in standalone method
1929 my $data = $self->_normalize_populate_args(@_);
1931 if(defined wantarray) {
1933 foreach my $item (@$data) {
1934 push(@created, $self->create($item));
1936 return wantarray ? @created : \@created;
1939 my $first = $data->[0];
1941 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1942 # it relationship data
1943 my (@rels, @columns);
1944 my $rsrc = $self->result_source;
1945 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1946 for (keys %$first) {
1947 my $ref = ref $first->{$_};
1948 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1954 my @pks = $rsrc->primary_columns;
1956 ## do the belongs_to relationships
1957 foreach my $index (0..$#$data) {
1959 # delegate to create() for any dataset without primary keys with specified relationships
1960 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1962 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1963 my @ret = $self->populate($data);
1969 foreach my $rel (@rels) {
1970 next unless ref $data->[$index]->{$rel} eq "HASH";
1971 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1972 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1973 my $related = $result->result_source->_resolve_condition(
1974 $reverse_relinfo->{cond},
1979 delete $data->[$index]->{$rel};
1980 $data->[$index] = {%{$data->[$index]}, %$related};
1982 push @columns, keys %$related if $index == 0;
1986 ## inherit the data locked in the conditions of the resultset
1987 my ($rs_data) = $self->_merge_with_rscond({});
1988 delete @{$rs_data}{@columns};
1989 my @inherit_cols = keys %$rs_data;
1990 my @inherit_data = values %$rs_data;
1992 ## do bulk insert on current row
1993 $rsrc->storage->insert_bulk(
1995 [@columns, @inherit_cols],
1996 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1999 ## do the has_many relationships
2000 foreach my $item (@$data) {
2004 foreach my $rel (@rels) {
2005 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2007 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2009 my $child = $main_row->$rel;
2011 my $related = $child->result_source->_resolve_condition(
2012 $rels->{$rel}{cond},
2017 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2018 my @populate = map { {%$_, %$related} } @rows_to_add;
2020 $child->populate( \@populate );
2027 # populate() argumnets went over several incarnations
2028 # What we ultimately support is AoH
2029 sub _normalize_populate_args {
2030 my ($self, $arg) = @_;
2032 if (ref $arg eq 'ARRAY') {
2033 if (ref $arg->[0] eq 'HASH') {
2036 elsif (ref $arg->[0] eq 'ARRAY') {
2038 my @colnames = @{$arg->[0]};
2039 foreach my $values (@{$arg}[1 .. $#$arg]) {
2040 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2046 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2053 =item Arguments: none
2055 =item Return Value: $pager
2059 Return Value a L<Data::Page> object for the current resultset. Only makes
2060 sense for queries with a C<page> attribute.
2062 To get the full count of entries for a paged resultset, call
2063 C<total_entries> on the L<Data::Page> object.
2067 # make a wizard good for both a scalar and a hashref
2068 my $mk_lazy_count_wizard = sub {
2069 require Variable::Magic;
2071 my $stash = { total_rs => shift };
2072 my $slot = shift; # only used by the hashref magic
2074 my $magic = Variable::Magic::wizard (
2075 data => sub { $stash },
2081 # set value lazily, and dispell for good
2082 ${$_[0]} = $_[1]{total_rs}->count;
2083 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2087 # an explicit set implies dispell as well
2088 # the unless() is to work around "fun and giggles" below
2089 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2090 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2097 if ($_[2] eq $slot and !$_[1]{inactive}) {
2098 my $cnt = $_[1]{total_rs}->count;
2099 $_[0]->{$slot} = $cnt;
2101 # attempting to dispell in a fetch handle (works in store), seems
2102 # to invariable segfault on 5.10, 5.12, 5.13 :(
2103 # so use an inactivator instead
2104 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2110 if (! $_[1]{inactive} and $_[2] eq $slot) {
2111 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2113 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2120 $stash->{magic_selfref} = $magic;
2121 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2126 # the tie class for 5.8.1
2128 package # hide from pause
2129 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2130 use base qw/Tie::Hash/;
2132 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2133 sub NEXTKEY { each %{$_[0]{data}} }
2134 sub EXISTS { exists $_[0]{data}{$_[1]} }
2135 sub DELETE { delete $_[0]{data}{$_[1]} }
2136 sub CLEAR { %{$_[0]{data}} = () }
2137 sub SCALAR { scalar %{$_[0]{data}} }
2140 $_[1]{data} = {%{$_[1]{selfref}}};
2141 %{$_[1]{selfref}} = ();
2142 Scalar::Util::weaken ($_[1]{selfref});
2143 return bless ($_[1], $_[0]);
2147 if ($_[1] eq $_[0]{slot}) {
2148 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2149 untie %{$_[0]{selfref}};
2150 %{$_[0]{selfref}} = %{$_[0]{data}};
2159 $_[0]{data}{$_[1]} = $_[2];
2160 if ($_[1] eq $_[0]{slot}) {
2161 untie %{$_[0]{selfref}};
2162 %{$_[0]{selfref}} = %{$_[0]{data}};
2171 return $self->{pager} if $self->{pager};
2173 if ($self->get_cache) {
2174 $self->throw_exception ('Pagers on cached resultsets are not supported');
2177 my $attrs = $self->{attrs};
2178 if (!defined $attrs->{page}) {
2179 $self->throw_exception("Can't create pager for non-paged rs");
2181 elsif ($attrs->{page} <= 0) {
2182 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2184 $attrs->{rows} ||= 10;
2186 # throw away the paging flags and re-run the count (possibly
2187 # with a subselect) to get the real total count
2188 my $count_attrs = { %$attrs };
2189 delete $count_attrs->{$_} for qw/rows offset page pager/;
2190 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2193 ### the following may seem awkward and dirty, but it's a thought-experiment
2194 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2195 ### before talking to ribasushi/mst
2197 my $pager = Data::Page->new(
2198 0, #start with an empty set
2200 $self->{attrs}{page},
2203 my $data_slot = 'total_entries';
2205 # Since we are interested in a cached value (once it's set - it's set), every
2206 # technique will detach from the magic-host once the time comes to fire the
2207 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2209 if ($] < 5.008003) {
2210 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2211 # to weakref the magic container :(
2213 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2214 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2217 elsif ($] < 5.010) {
2218 # We can use magic on the hash value slot. It's interesting that the magic is
2219 # attached to the hash-slot, and does *not* stop working once I do the dummy
2220 # assignments after the cast()
2221 # tested on 5.8.3 and 5.8.9
2222 my $magic = $mk_lazy_count_wizard->($total_rs);
2223 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2225 # this is for fun and giggles
2226 $pager->{$data_slot} = -1;
2227 $pager->{$data_slot} = 0;
2229 # this does not work for scalars, but works with
2231 #my %vals = %$pager;
2236 # And the uvar magic
2237 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2238 # however see the wizard maker for more notes
2239 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2240 Variable::Magic::cast ( %$pager, $magic );
2243 $pager->{$data_slot} = -1;
2244 $pager->{$data_slot} = 0;
2252 return $self->{pager} = $pager;
2259 =item Arguments: $page_number
2261 =item Return Value: $rs
2265 Returns a resultset for the $page_number page of the resultset on which page
2266 is called, where each page contains a number of rows equal to the 'rows'
2267 attribute set on the resultset (10 by default).
2272 my ($self, $page) = @_;
2273 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2280 =item Arguments: \%vals
2282 =item Return Value: $rowobject
2286 Creates a new row object in the resultset's result class and returns
2287 it. The row is not inserted into the database at this point, call
2288 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2289 will tell you whether the row object has been inserted or not.
2291 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2296 my ($self, $values) = @_;
2297 $self->throw_exception( "new_result needs a hash" )
2298 unless (ref $values eq 'HASH');
2300 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2304 @$cols_from_relations
2305 ? (-cols_from_relations => $cols_from_relations)
2307 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2310 return $self->result_class->new(\%new);
2313 # _merge_with_rscond
2315 # Takes a simple hash of K/V data and returns its copy merged with the
2316 # condition already present on the resultset. Additionally returns an
2317 # arrayref of value/condition names, which were inferred from related
2318 # objects (this is needed for in-memory related objects)
2319 sub _merge_with_rscond {
2320 my ($self, $data) = @_;
2322 my (%new_data, @cols_from_relations);
2324 my $alias = $self->{attrs}{alias};
2326 if (! defined $self->{cond}) {
2327 # just massage $data below
2329 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2330 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2331 @cols_from_relations = keys %new_data;
2333 elsif (ref $self->{cond} ne 'HASH') {
2334 $self->throw_exception(
2335 "Can't abstract implicit construct, resultset condition not a hash"
2339 # precendence must be given to passed values over values inherited from
2340 # the cond, so the order here is important.
2341 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2342 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2344 while ( my($col, $value) = each %implied ) {
2345 my $vref = ref $value;
2351 (keys %$value)[0] eq '='
2353 $new_data{$col} = $value->{'='};
2355 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2356 $new_data{$col} = $value;
2363 %{ $self->_remove_alias($data, $alias) },
2366 return (\%new_data, \@cols_from_relations);
2369 # _has_resolved_attr
2371 # determines if the resultset defines at least one
2372 # of the attributes supplied
2374 # used to determine if a subquery is neccessary
2376 # supports some virtual attributes:
2378 # This will scan for any joins being present on the resultset.
2379 # It is not a mere key-search but a deep inspection of {from}
2382 sub _has_resolved_attr {
2383 my ($self, @attr_names) = @_;
2385 my $attrs = $self->_resolved_attrs;
2389 for my $n (@attr_names) {
2390 if (grep { $n eq $_ } (qw/-join/) ) {
2391 $extra_checks{$n}++;
2395 my $attr = $attrs->{$n};
2397 next if not defined $attr;
2399 if (ref $attr eq 'HASH') {
2400 return 1 if keys %$attr;
2402 elsif (ref $attr eq 'ARRAY') {
2410 # a resolved join is expressed as a multi-level from
2412 $extra_checks{-join}
2414 ref $attrs->{from} eq 'ARRAY'
2416 @{$attrs->{from}} > 1
2424 # Recursively collapse the condition.
2426 sub _collapse_cond {
2427 my ($self, $cond, $collapsed) = @_;
2431 if (ref $cond eq 'ARRAY') {
2432 foreach my $subcond (@$cond) {
2433 next unless ref $subcond; # -or
2434 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2437 elsif (ref $cond eq 'HASH') {
2438 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2439 foreach my $subcond (@{$cond->{-and}}) {
2440 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2444 foreach my $col (keys %$cond) {
2445 my $value = $cond->{$col};
2446 $collapsed->{$col} = $value;
2456 # Remove the specified alias from the specified query hash. A copy is made so
2457 # the original query is not modified.
2460 my ($self, $query, $alias) = @_;
2462 my %orig = %{ $query || {} };
2465 foreach my $key (keys %orig) {
2467 $unaliased{$key} = $orig{$key};
2470 $unaliased{$1} = $orig{$key}
2471 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2481 =item Arguments: none
2483 =item Return Value: \[ $sql, @bind ]
2487 Returns the SQL query and bind vars associated with the invocant.
2489 This is generally used as the RHS for a subquery.
2496 my $attrs = $self->_resolved_attrs_copy;
2501 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2502 # $sql also has no wrapping parenthesis in list ctx
2504 my $sqlbind = $self->result_source->storage
2505 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2514 =item Arguments: \%vals, \%attrs?
2516 =item Return Value: $rowobject
2520 my $artist = $schema->resultset('Artist')->find_or_new(
2521 { artist => 'fred' }, { key => 'artists' });
2523 $cd->cd_to_producer->find_or_new({ producer => $producer },
2524 { key => 'primary });
2526 Find an existing record from this resultset using L</find>. if none exists,
2527 instantiate a new result object and return it. The object will not be saved
2528 into your storage until you call L<DBIx::Class::Row/insert> on it.
2530 You most likely want this method when looking for existing rows using a unique
2531 constraint that is not the primary key, or looking for related rows.
2533 If you want objects to be saved immediately, use L</find_or_create> instead.
2535 B<Note>: Make sure to read the documentation of L</find> and understand the
2536 significance of the C<key> attribute, as its lack may skew your search, and
2537 subsequently result in spurious new objects.
2539 B<Note>: Take care when using C<find_or_new> with a table having
2540 columns with default values that you intend to be automatically
2541 supplied by the database (e.g. an auto_increment primary key column).
2542 In normal usage, the value of such columns should NOT be included at
2543 all in the call to C<find_or_new>, even when set to C<undef>.
2549 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2550 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2551 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2554 return $self->new_result($hash);
2561 =item Arguments: \%vals
2563 =item Return Value: a L<DBIx::Class::Row> $object
2567 Attempt to create a single new row or a row with multiple related rows
2568 in the table represented by the resultset (and related tables). This
2569 will not check for duplicate rows before inserting, use
2570 L</find_or_create> to do that.
2572 To create one row for this resultset, pass a hashref of key/value
2573 pairs representing the columns of the table and the values you wish to
2574 store. If the appropriate relationships are set up, foreign key fields
2575 can also be passed an object representing the foreign row, and the
2576 value will be set to its primary key.
2578 To create related objects, pass a hashref of related-object column values
2579 B<keyed on the relationship name>. If the relationship is of type C<multi>
2580 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2581 The process will correctly identify columns holding foreign keys, and will
2582 transparently populate them from the keys of the corresponding relation.
2583 This can be applied recursively, and will work correctly for a structure
2584 with an arbitrary depth and width, as long as the relationships actually
2585 exists and the correct column data has been supplied.
2588 Instead of hashrefs of plain related data (key/value pairs), you may
2589 also pass new or inserted objects. New objects (not inserted yet, see
2590 L</new>), will be inserted into their appropriate tables.
2592 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2594 Example of creating a new row.
2596 $person_rs->create({
2597 name=>"Some Person",
2598 email=>"somebody@someplace.com"
2601 Example of creating a new row and also creating rows in a related C<has_many>
2602 or C<has_one> resultset. Note Arrayref.
2605 { artistid => 4, name => 'Manufactured Crap', cds => [
2606 { title => 'My First CD', year => 2006 },
2607 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2612 Example of creating a new row and also creating a row in a related
2613 C<belongs_to> resultset. Note Hashref.
2616 title=>"Music for Silly Walks",
2619 name=>"Silly Musician",
2627 When subclassing ResultSet never attempt to override this method. Since
2628 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2629 lot of the internals simply never call it, so your override will be
2630 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2631 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2632 L</create> process you need to intervene.
2639 my ($self, $attrs) = @_;
2640 $self->throw_exception( "create needs a hashref" )
2641 unless ref $attrs eq 'HASH';
2642 return $self->new_result($attrs)->insert;
2645 =head2 find_or_create
2649 =item Arguments: \%vals, \%attrs?
2651 =item Return Value: $rowobject
2655 $cd->cd_to_producer->find_or_create({ producer => $producer },
2656 { key => 'primary' });
2658 Tries to find a record based on its primary key or unique constraints; if none
2659 is found, creates one and returns that instead.
2661 my $cd = $schema->resultset('CD')->find_or_create({
2663 artist => 'Massive Attack',
2664 title => 'Mezzanine',
2668 Also takes an optional C<key> attribute, to search by a specific key or unique
2669 constraint. For example:
2671 my $cd = $schema->resultset('CD')->find_or_create(
2673 artist => 'Massive Attack',
2674 title => 'Mezzanine',
2676 { key => 'cd_artist_title' }
2679 B<Note>: Make sure to read the documentation of L</find> and understand the
2680 significance of the C<key> attribute, as its lack may skew your search, and
2681 subsequently result in spurious row creation.
2683 B<Note>: Because find_or_create() reads from the database and then
2684 possibly inserts based on the result, this method is subject to a race
2685 condition. Another process could create a record in the table after
2686 the find has completed and before the create has started. To avoid
2687 this problem, use find_or_create() inside a transaction.
2689 B<Note>: Take care when using C<find_or_create> with a table having
2690 columns with default values that you intend to be automatically
2691 supplied by the database (e.g. an auto_increment primary key column).
2692 In normal usage, the value of such columns should NOT be included at
2693 all in the call to C<find_or_create>, even when set to C<undef>.
2695 See also L</find> and L</update_or_create>. For information on how to declare
2696 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2700 sub find_or_create {
2702 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2703 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2704 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2707 return $self->create($hash);
2710 =head2 update_or_create
2714 =item Arguments: \%col_values, { key => $unique_constraint }?
2716 =item Return Value: $row_object
2720 $resultset->update_or_create({ col => $val, ... });
2722 Like L</find_or_create>, but if a row is found it is immediately updated via
2723 C<< $found_row->update (\%col_values) >>.
2726 Takes an optional C<key> attribute to search on a specific unique constraint.
2729 # In your application
2730 my $cd = $schema->resultset('CD')->update_or_create(
2732 artist => 'Massive Attack',
2733 title => 'Mezzanine',
2736 { key => 'cd_artist_title' }
2739 $cd->cd_to_producer->update_or_create({
2740 producer => $producer,
2746 B<Note>: Make sure to read the documentation of L</find> and understand the
2747 significance of the C<key> attribute, as its lack may skew your search, and
2748 subsequently result in spurious row creation.
2750 B<Note>: Take care when using C<update_or_create> with a table having
2751 columns with default values that you intend to be automatically
2752 supplied by the database (e.g. an auto_increment primary key column).
2753 In normal usage, the value of such columns should NOT be included at
2754 all in the call to C<update_or_create>, even when set to C<undef>.
2756 See also L</find> and L</find_or_create>. For information on how to declare
2757 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2761 sub update_or_create {
2763 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2764 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2766 my $row = $self->find($cond, $attrs);
2768 $row->update($cond);
2772 return $self->create($cond);
2775 =head2 update_or_new
2779 =item Arguments: \%col_values, { key => $unique_constraint }?
2781 =item Return Value: $rowobject
2785 $resultset->update_or_new({ col => $val, ... });
2787 Like L</find_or_new> but if a row is found it is immediately updated via
2788 C<< $found_row->update (\%col_values) >>.
2792 # In your application
2793 my $cd = $schema->resultset('CD')->update_or_new(
2795 artist => 'Massive Attack',
2796 title => 'Mezzanine',
2799 { key => 'cd_artist_title' }
2802 if ($cd->in_storage) {
2803 # the cd was updated
2806 # the cd is not yet in the database, let's insert it
2810 B<Note>: Make sure to read the documentation of L</find> and understand the
2811 significance of the C<key> attribute, as its lack may skew your search, and
2812 subsequently result in spurious new objects.
2814 B<Note>: Take care when using C<update_or_new> with a table having
2815 columns with default values that you intend to be automatically
2816 supplied by the database (e.g. an auto_increment primary key column).
2817 In normal usage, the value of such columns should NOT be included at
2818 all in the call to C<update_or_new>, even when set to C<undef>.
2820 See also L</find>, L</find_or_create> and L</find_or_new>.
2826 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2827 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2829 my $row = $self->find( $cond, $attrs );
2830 if ( defined $row ) {
2831 $row->update($cond);
2835 return $self->new_result($cond);
2842 =item Arguments: none
2844 =item Return Value: \@cache_objects | undef
2848 Gets the contents of the cache for the resultset, if the cache is set.
2850 The cache is populated either by using the L</prefetch> attribute to
2851 L</search> or by calling L</set_cache>.
2863 =item Arguments: \@cache_objects
2865 =item Return Value: \@cache_objects
2869 Sets the contents of the cache for the resultset. Expects an arrayref
2870 of objects of the same class as those produced by the resultset. Note that
2871 if the cache is set the resultset will return the cached objects rather
2872 than re-querying the database even if the cache attr is not set.
2874 The contents of the cache can also be populated by using the
2875 L</prefetch> attribute to L</search>.
2880 my ( $self, $data ) = @_;
2881 $self->throw_exception("set_cache requires an arrayref")
2882 if defined($data) && (ref $data ne 'ARRAY');
2883 $self->{all_cache} = $data;
2890 =item Arguments: none
2892 =item Return Value: undef
2896 Clears the cache for the resultset.
2901 shift->set_cache(undef);
2908 =item Arguments: none
2910 =item Return Value: true, if the resultset has been paginated
2918 return !!$self->{attrs}{page};
2925 =item Arguments: none
2927 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2935 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2938 =head2 related_resultset
2942 =item Arguments: $relationship_name
2944 =item Return Value: $resultset
2948 Returns a related resultset for the supplied relationship name.
2950 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2954 sub related_resultset {
2955 my ($self, $rel) = @_;
2957 $self->{related_resultsets} ||= {};
2958 return $self->{related_resultsets}{$rel} ||= do {
2959 my $rsrc = $self->result_source;
2960 my $rel_info = $rsrc->relationship_info($rel);
2962 $self->throw_exception(
2963 "search_related: result source '" . $rsrc->source_name .
2964 "' has no such relationship $rel")
2967 my $attrs = $self->_chain_relationship($rel);
2969 my $join_count = $attrs->{seen_join}{$rel};
2971 my $alias = $self->result_source->storage
2972 ->relname_to_table_alias($rel, $join_count);
2974 # since this is search_related, and we already slid the select window inwards
2975 # (the select/as attrs were deleted in the beginning), we need to flip all
2976 # left joins to inner, so we get the expected results
2977 # read the comment on top of the actual function to see what this does
2978 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2981 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2982 delete @{$attrs}{qw(result_class alias)};
2986 if (my $cache = $self->get_cache) {
2987 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2988 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2993 my $rel_source = $rsrc->related_source($rel);
2997 # The reason we do this now instead of passing the alias to the
2998 # search_rs below is that if you wrap/overload resultset on the
2999 # source you need to know what alias it's -going- to have for things
3000 # to work sanely (e.g. RestrictWithObject wants to be able to add
3001 # extra query restrictions, and these may need to be $alias.)
3003 my $rel_attrs = $rel_source->resultset_attributes;
3004 local $rel_attrs->{alias} = $alias;
3006 $rel_source->resultset
3010 where => $attrs->{where},
3013 $new->set_cache($new_cache) if $new_cache;
3018 =head2 current_source_alias
3022 =item Arguments: none
3024 =item Return Value: $source_alias
3028 Returns the current table alias for the result source this resultset is built
3029 on, that will be used in the SQL query. Usually it is C<me>.
3031 Currently the source alias that refers to the result set returned by a
3032 L</search>/L</find> family method depends on how you got to the resultset: it's
3033 C<me> by default, but eg. L</search_related> aliases it to the related result
3034 source name (and keeps C<me> referring to the original result set). The long
3035 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3036 (and make this method unnecessary).
3038 Thus it's currently necessary to use this method in predefined queries (see
3039 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3040 source alias of the current result set:
3042 # in a result set class
3044 my ($self, $user) = @_;
3046 my $me = $self->current_source_alias;
3048 return $self->search(
3049 "$me.modified" => $user->id,
3055 sub current_source_alias {
3058 return ($self->{attrs} || {})->{alias} || 'me';
3061 =head2 as_subselect_rs
3065 =item Arguments: none
3067 =item Return Value: $resultset
3071 Act as a barrier to SQL symbols. The resultset provided will be made into a
3072 "virtual view" by including it as a subquery within the from clause. From this
3073 point on, any joined tables are inaccessible to ->search on the resultset (as if
3074 it were simply where-filtered without joins). For example:
3076 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3078 # 'x' now pollutes the query namespace
3080 # So the following works as expected
3081 my $ok_rs = $rs->search({'x.other' => 1});
3083 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3084 # def) we look for one row with contradictory terms and join in another table
3085 # (aliased 'x_2') which we never use
3086 my $broken_rs = $rs->search({'x.name' => 'def'});
3088 my $rs2 = $rs->as_subselect_rs;
3090 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3091 my $not_joined_rs = $rs2->search({'x.other' => 1});
3093 # works as expected: finds a 'table' row related to two x rows (abc and def)
3094 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3096 Another example of when one might use this would be to select a subset of
3097 columns in a group by clause:
3099 my $rs = $schema->resultset('Bar')->search(undef, {
3100 group_by => [qw{ id foo_id baz_id }],
3101 })->as_subselect_rs->search(undef, {
3102 columns => [qw{ id foo_id }]
3105 In the above example normally columns would have to be equal to the group by,
3106 but because we isolated the group by into a subselect the above works.
3110 sub as_subselect_rs {
3113 my $attrs = $self->_resolved_attrs;
3115 my $fresh_rs = (ref $self)->new (
3116 $self->result_source
3119 # these pieces will be locked in the subquery
3120 delete $fresh_rs->{cond};
3121 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3123 return $fresh_rs->search( {}, {
3125 $attrs->{alias} => $self->as_query,
3126 -alias => $attrs->{alias},
3127 -rsrc => $self->result_source,
3129 alias => $attrs->{alias},
3133 # This code is called by search_related, and makes sure there
3134 # is clear separation between the joins before, during, and
3135 # after the relationship. This information is needed later
3136 # in order to properly resolve prefetch aliases (any alias
3137 # with a relation_chain_depth less than the depth of the
3138 # current prefetch is not considered)
3140 # The increments happen twice per join. An even number means a
3141 # relationship specified via a search_related, whereas an odd
3142 # number indicates a join/prefetch added via attributes
3144 # Also this code will wrap the current resultset (the one we
3145 # chain to) in a subselect IFF it contains limiting attributes
3146 sub _chain_relationship {
3147 my ($self, $rel) = @_;
3148 my $source = $self->result_source;
3149 my $attrs = { %{$self->{attrs}||{}} };
3151 # we need to take the prefetch the attrs into account before we
3152 # ->_resolve_join as otherwise they get lost - captainL
3153 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3155 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3157 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3160 my @force_subq_attrs = qw/offset rows group_by having/;
3163 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3165 $self->_has_resolved_attr (@force_subq_attrs)
3167 # Nuke the prefetch (if any) before the new $rs attrs
3168 # are resolved (prefetch is useless - we are wrapping
3169 # a subquery anyway).
3170 my $rs_copy = $self->search;
3171 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3172 $rs_copy->{attrs}{join},
3173 delete $rs_copy->{attrs}{prefetch},
3178 -alias => $attrs->{alias},
3179 $attrs->{alias} => $rs_copy->as_query,
3181 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3182 $seen->{-relation_chain_depth} = 0;
3184 elsif ($attrs->{from}) { #shallow copy suffices
3185 $from = [ @{$attrs->{from}} ];
3190 -alias => $attrs->{alias},
3191 $attrs->{alias} => $source->from,
3195 my $jpath = ($seen->{-relation_chain_depth})
3196 ? $from->[-1][0]{-join_path}
3199 my @requested_joins = $source->_resolve_join(
3206 push @$from, @requested_joins;
3208 $seen->{-relation_chain_depth}++;
3210 # if $self already had a join/prefetch specified on it, the requested
3211 # $rel might very well be already included. What we do in this case
3212 # is effectively a no-op (except that we bump up the chain_depth on
3213 # the join in question so we could tell it *is* the search_related)
3216 # we consider the last one thus reverse
3217 for my $j (reverse @requested_joins) {
3218 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3219 if ($rel eq $last_j) {
3220 $j->[0]{-relation_chain_depth}++;
3226 unless ($already_joined) {
3227 push @$from, $source->_resolve_join(
3235 $seen->{-relation_chain_depth}++;
3237 return {%$attrs, from => $from, seen_join => $seen};
3240 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3241 sub _resolved_attrs_copy {
3243 return { %{$self->_resolved_attrs (@_)} };
3246 sub _resolved_attrs {
3248 return $self->{_attrs} if $self->{_attrs};
3250 my $attrs = { %{ $self->{attrs} || {} } };
3251 my $source = $self->result_source;
3252 my $alias = $attrs->{alias};
3254 # one last pass of normalization
3255 $self->_normalize_selection($attrs);
3257 # default selection list
3258 $attrs->{columns} = [ $source->columns ]
3259 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3261 # merge selectors together
3262 for (qw/columns select as _trailing_select/) {
3263 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3264 if $attrs->{$_} or $attrs->{"+$_"};
3267 # disassemble columns
3269 if (my $cols = delete $attrs->{columns}) {
3270 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3271 if (ref $c eq 'HASH') {
3272 for my $as (keys %$c) {
3273 push @sel, $c->{$as};
3284 # when trying to weed off duplicates later do not go past this point -
3285 # everything added from here on is unbalanced "anyone's guess" stuff
3286 my $dedup_stop_idx = $#as;
3288 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3290 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3291 if $attrs->{select};
3293 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3295 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3298 # disqualify all $alias.col as-bits (collapser mandated)
3300 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3303 # de-duplicate the result (remove *identical* select/as pairs)
3304 # and also die on duplicate {as} pointing to different {select}s
3305 # not using a c-style for as the condition is prone to shrinkage
3308 while ($i <= $dedup_stop_idx) {
3309 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3314 elsif ($seen->{$as[$i]}++) {
3315 $self->throw_exception(
3316 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3324 $attrs->{select} = \@sel;
3325 $attrs->{as} = \@as;
3327 $attrs->{from} ||= [{
3329 -alias => $self->{attrs}{alias},
3330 $self->{attrs}{alias} => $source->from,
3333 if ( $attrs->{join} || $attrs->{prefetch} ) {
3335 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3336 if ref $attrs->{from} ne 'ARRAY';
3338 my $join = (delete $attrs->{join}) || {};
3340 if ( defined $attrs->{prefetch} ) {
3341 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3344 $attrs->{from} = # have to copy here to avoid corrupting the original
3346 @{ $attrs->{from} },
3347 $source->_resolve_join(
3350 { %{ $attrs->{seen_join} || {} } },
3351 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3352 ? $attrs->{from}[-1][0]{-join_path}
3359 if ( defined $attrs->{order_by} ) {
3360 $attrs->{order_by} = (
3361 ref( $attrs->{order_by} ) eq 'ARRAY'
3362 ? [ @{ $attrs->{order_by} } ]
3363 : [ $attrs->{order_by} || () ]
3367 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3368 $attrs->{group_by} = [ $attrs->{group_by} ];
3371 # generate the distinct induced group_by early, as prefetch will be carried via a
3372 # subquery (since a group_by is present)
3373 if (delete $attrs->{distinct}) {
3374 if ($attrs->{group_by}) {
3375 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3378 # distinct affects only the main selection part, not what prefetch may
3379 # add below. However trailing is not yet a part of the selection as
3380 # prefetch must insert before it
3381 $attrs->{group_by} = $source->storage->_group_over_selection (
3383 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3389 $attrs->{collapse} ||= {};
3390 if ($attrs->{prefetch}) {
3391 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3393 my $prefetch_ordering = [];
3395 # this is a separate structure (we don't look in {from} directly)
3396 # as the resolver needs to shift things off the lists to work
3397 # properly (identical-prefetches on different branches)
3399 if (ref $attrs->{from} eq 'ARRAY') {
3401 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3403 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3404 next unless $j->[0]{-alias};
3405 next unless $j->[0]{-join_path};
3406 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3408 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3411 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3412 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3417 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3419 # we need to somehow mark which columns came from prefetch
3421 my $sel_end = $#{$attrs->{select}};
3422 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3425 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3426 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3428 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3429 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3433 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3434 if $attrs->{_trailing_select};
3436 # if both page and offset are specified, produce a combined offset
3437 # even though it doesn't make much sense, this is what pre 081xx has
3439 if (my $page = delete $attrs->{page}) {
3441 ($attrs->{rows} * ($page - 1))
3443 ($attrs->{offset} || 0)
3447 return $self->{_attrs} = $attrs;
3451 my ($self, $attr) = @_;
3453 if (ref $attr eq 'HASH') {
3454 return $self->_rollout_hash($attr);
3455 } elsif (ref $attr eq 'ARRAY') {
3456 return $self->_rollout_array($attr);
3462 sub _rollout_array {
3463 my ($self, $attr) = @_;
3466 foreach my $element (@{$attr}) {
3467 if (ref $element eq 'HASH') {
3468 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3469 } elsif (ref $element eq 'ARRAY') {
3470 # XXX - should probably recurse here
3471 push( @rolled_array, @{$self->_rollout_array($element)} );
3473 push( @rolled_array, $element );
3476 return \@rolled_array;
3480 my ($self, $attr) = @_;
3483 foreach my $key (keys %{$attr}) {
3484 push( @rolled_array, { $key => $attr->{$key} } );
3486 return \@rolled_array;
3489 sub _calculate_score {
3490 my ($self, $a, $b) = @_;
3492 if (defined $a xor defined $b) {
3495 elsif (not defined $a) {
3499 if (ref $b eq 'HASH') {
3500 my ($b_key) = keys %{$b};
3501 if (ref $a eq 'HASH') {
3502 my ($a_key) = keys %{$a};
3503 if ($a_key eq $b_key) {
3504 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3509 return ($a eq $b_key) ? 1 : 0;
3512 if (ref $a eq 'HASH') {
3513 my ($a_key) = keys %{$a};
3514 return ($b eq $a_key) ? 1 : 0;
3516 return ($b eq $a) ? 1 : 0;
3521 sub _merge_joinpref_attr {
3522 my ($self, $orig, $import) = @_;
3524 return $import unless defined($orig);
3525 return $orig unless defined($import);
3527 $orig = $self->_rollout_attr($orig);
3528 $import = $self->_rollout_attr($import);
3531 foreach my $import_element ( @{$import} ) {
3532 # find best candidate from $orig to merge $b_element into
3533 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3534 foreach my $orig_element ( @{$orig} ) {
3535 my $score = $self->_calculate_score( $orig_element, $import_element );
3536 if ($score > $best_candidate->{score}) {
3537 $best_candidate->{position} = $position;
3538 $best_candidate->{score} = $score;
3542 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3544 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3545 push( @{$orig}, $import_element );
3547 my $orig_best = $orig->[$best_candidate->{position}];
3548 # merge orig_best and b_element together and replace original with merged
3549 if (ref $orig_best ne 'HASH') {
3550 $orig->[$best_candidate->{position}] = $import_element;
3551 } elsif (ref $import_element eq 'HASH') {
3552 my ($key) = keys %{$orig_best};
3553 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3556 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3567 my $hm = Hash::Merge->new;
3569 $hm->specify_behavior({
3572 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3574 if ($defl xor $defr) {
3575 return [ $defl ? $_[0] : $_[1] ];
3580 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3584 return [$_[0], $_[1]];
3588 return $_[1] if !defined $_[0];
3589 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3590 return [$_[0], @{$_[1]}]
3593 return [] if !defined $_[0] and !keys %{$_[1]};
3594 return [ $_[1] ] if !defined $_[0];
3595 return [ $_[0] ] if !keys %{$_[1]};
3596 return [$_[0], $_[1]]
3601 return $_[0] if !defined $_[1];
3602 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3603 return [@{$_[0]}, $_[1]]
3606 my @ret = @{$_[0]} or return $_[1];
3607 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3608 my %idx = map { $_ => 1 } @ret;
3609 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3613 return [ $_[1] ] if ! @{$_[0]};
3614 return $_[0] if !keys %{$_[1]};
3615 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3616 return [ @{$_[0]}, $_[1] ];
3621 return [] if !keys %{$_[0]} and !defined $_[1];
3622 return [ $_[0] ] if !defined $_[1];
3623 return [ $_[1] ] if !keys %{$_[0]};
3624 return [$_[0], $_[1]]
3627 return [] if !keys %{$_[0]} and !@{$_[1]};
3628 return [ $_[0] ] if !@{$_[1]};
3629 return $_[1] if !keys %{$_[0]};
3630 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3631 return [ $_[0], @{$_[1]} ];
3634 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3635 return [ $_[0] ] if !keys %{$_[1]};
3636 return [ $_[1] ] if !keys %{$_[0]};
3637 return [ $_[0] ] if $_[0] eq $_[1];
3638 return [ $_[0], $_[1] ];
3641 } => 'DBIC_RS_ATTR_MERGER');
3645 return $hm->merge ($_[1], $_[2]);
3649 sub STORABLE_freeze {
3650 my ($self, $cloning) = @_;
3651 my $to_serialize = { %$self };
3653 # A cursor in progress can't be serialized (and would make little sense anyway)
3654 delete $to_serialize->{cursor};
3656 nfreeze($to_serialize);
3659 # need this hook for symmetry
3661 my ($self, $cloning, $serialized) = @_;
3663 %$self = %{ thaw($serialized) };
3669 =head2 throw_exception
3671 See L<DBIx::Class::Schema/throw_exception> for details.
3675 sub throw_exception {
3678 if (ref $self and my $rsrc = $self->result_source) {
3679 $rsrc->throw_exception(@_)
3682 DBIx::Class::Exception->throw(@_);
3686 # XXX: FIXME: Attributes docs need clearing up
3690 Attributes are used to refine a ResultSet in various ways when
3691 searching for data. They can be passed to any method which takes an
3692 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3695 These are in no particular order:
3701 =item Value: ( $order_by | \@order_by | \%order_by )
3705 Which column(s) to order the results by.
3707 [The full list of suitable values is documented in
3708 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3711 If a single column name, or an arrayref of names is supplied, the
3712 argument is passed through directly to SQL. The hashref syntax allows
3713 for connection-agnostic specification of ordering direction:
3715 For descending order:
3717 order_by => { -desc => [qw/col1 col2 col3/] }
3719 For explicit ascending order:
3721 order_by => { -asc => 'col' }
3723 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3724 supported, although you are strongly encouraged to use the hashref
3725 syntax as outlined above.
3731 =item Value: \@columns
3735 Shortcut to request a particular set of columns to be retrieved. Each
3736 column spec may be a string (a table column name), or a hash (in which
3737 case the key is the C<as> value, and the value is used as the C<select>
3738 expression). Adds C<me.> onto the start of any column without a C<.> in
3739 it and sets C<select> from that, then auto-populates C<as> from
3740 C<select> as normal. (You may also use the C<cols> attribute, as in
3741 earlier versions of DBIC.)
3743 Essentially C<columns> does the same as L</select> and L</as>.
3745 columns => [ 'foo', { bar => 'baz' } ]
3749 select => [qw/foo baz/],
3756 =item Value: \@columns
3760 Indicates additional columns to be selected from storage. Works the same
3761 as L</columns> but adds columns to the selection. (You may also use the
3762 C<include_columns> attribute, as in earlier versions of DBIC). For
3765 $schema->resultset('CD')->search(undef, {
3766 '+columns' => ['artist.name'],
3770 would return all CDs and include a 'name' column to the information
3771 passed to object inflation. Note that the 'artist' is the name of the
3772 column (or relationship) accessor, and 'name' is the name of the column
3773 accessor in the related table.
3775 =head2 include_columns
3779 =item Value: \@columns
3783 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3789 =item Value: \@select_columns
3793 Indicates which columns should be selected from the storage. You can use
3794 column names, or in the case of RDBMS back ends, function or stored procedure
3797 $rs = $schema->resultset('Employee')->search(undef, {
3800 { count => 'employeeid' },
3801 { max => { length => 'name' }, -as => 'longest_name' }
3806 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3808 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3809 use L</select>, to instruct DBIx::Class how to store the result of the column.
3810 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3811 identifier aliasing. You can however alias a function, so you can use it in
3812 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3813 attribute> supplied as shown in the example above.
3819 Indicates additional columns to be selected from storage. Works the same as
3820 L</select> but adds columns to the default selection, instead of specifying
3829 Indicates additional column names for those added via L</+select>. See L</as>.
3837 =item Value: \@inflation_names
3841 Indicates column names for object inflation. That is L</as> indicates the
3842 slot name in which the column value will be stored within the
3843 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3844 identifier by the C<get_column> method (or via the object accessor B<if one
3845 with the same name already exists>) as shown below. The L</as> attribute has
3846 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3848 $rs = $schema->resultset('Employee')->search(undef, {
3851 { count => 'employeeid' },
3852 { max => { length => 'name' }, -as => 'longest_name' }
3861 If the object against which the search is performed already has an accessor
3862 matching a column name specified in C<as>, the value can be retrieved using
3863 the accessor as normal:
3865 my $name = $employee->name();
3867 If on the other hand an accessor does not exist in the object, you need to
3868 use C<get_column> instead:
3870 my $employee_count = $employee->get_column('employee_count');
3872 You can create your own accessors if required - see
3873 L<DBIx::Class::Manual::Cookbook> for details.
3879 =item Value: ($rel_name | \@rel_names | \%rel_names)
3883 Contains a list of relationships that should be joined for this query. For
3886 # Get CDs by Nine Inch Nails
3887 my $rs = $schema->resultset('CD')->search(
3888 { 'artist.name' => 'Nine Inch Nails' },
3889 { join => 'artist' }
3892 Can also contain a hash reference to refer to the other relation's relations.
3895 package MyApp::Schema::Track;
3896 use base qw/DBIx::Class/;
3897 __PACKAGE__->table('track');
3898 __PACKAGE__->add_columns(qw/trackid cd position title/);
3899 __PACKAGE__->set_primary_key('trackid');
3900 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3903 # In your application
3904 my $rs = $schema->resultset('Artist')->search(
3905 { 'track.title' => 'Teardrop' },
3907 join => { cd => 'track' },
3908 order_by => 'artist.name',
3912 You need to use the relationship (not the table) name in conditions,
3913 because they are aliased as such. The current table is aliased as "me", so
3914 you need to use me.column_name in order to avoid ambiguity. For example:
3916 # Get CDs from 1984 with a 'Foo' track
3917 my $rs = $schema->resultset('CD')->search(
3920 'tracks.name' => 'Foo'
3922 { join => 'tracks' }
3925 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3926 similarly for a third time). For e.g.
3928 my $rs = $schema->resultset('Artist')->search({
3929 'cds.title' => 'Down to Earth',
3930 'cds_2.title' => 'Popular',
3932 join => [ qw/cds cds/ ],
3935 will return a set of all artists that have both a cd with title 'Down
3936 to Earth' and a cd with title 'Popular'.
3938 If you want to fetch related objects from other tables as well, see C<prefetch>
3941 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3947 =item Value: ($rel_name | \@rel_names | \%rel_names)
3951 Contains one or more relationships that should be fetched along with
3952 the main query (when they are accessed afterwards the data will
3953 already be available, without extra queries to the database). This is
3954 useful for when you know you will need the related objects, because it
3955 saves at least one query:
3957 my $rs = $schema->resultset('Tag')->search(
3966 The initial search results in SQL like the following:
3968 SELECT tag.*, cd.*, artist.* FROM tag
3969 JOIN cd ON tag.cd = cd.cdid
3970 JOIN artist ON cd.artist = artist.artistid
3972 L<DBIx::Class> has no need to go back to the database when we access the
3973 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3976 Simple prefetches will be joined automatically, so there is no need
3977 for a C<join> attribute in the above search.
3979 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3980 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3981 with an accessor type of 'single' or 'filter'). A more complex example that
3982 prefetches an artists cds, the tracks on those cds, and the tags associated
3983 with that artist is given below (assuming many-to-many from artists to tags):
3985 my $rs = $schema->resultset('Artist')->search(
3989 { cds => 'tracks' },
3990 { artist_tags => 'tags' }
3996 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3997 attributes will be ignored.
3999 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
4000 exactly as you might expect.
4006 Prefetch uses the L</cache> to populate the prefetched relationships. This
4007 may or may not be what you want.
4011 If you specify a condition on a prefetched relationship, ONLY those
4012 rows that match the prefetched condition will be fetched into that relationship.
4013 This means that adding prefetch to a search() B<may alter> what is returned by
4014 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4016 my $artist_rs = $schema->resultset('Artist')->search({
4022 my $count = $artist_rs->first->cds->count;
4024 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4026 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4028 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4030 that cmp_ok() may or may not pass depending on the datasets involved. This
4031 behavior may or may not survive the 0.09 transition.
4043 Makes the resultset paged and specifies the page to retrieve. Effectively
4044 identical to creating a non-pages resultset and then calling ->page($page)
4047 If L<rows> attribute is not specified it defaults to 10 rows per page.
4049 When you have a paged resultset, L</count> will only return the number
4050 of rows in the page. To get the total, use the L</pager> and call
4051 C<total_entries> on it.
4061 Specifies the maximum number of rows for direct retrieval or the number of
4062 rows per page if the page attribute or method is used.
4068 =item Value: $offset
4072 Specifies the (zero-based) row number for the first row to be returned, or the
4073 of the first row of the first page if paging is used.
4079 =item Value: \@columns
4083 A arrayref of columns to group by. Can include columns of joined tables.
4085 group_by => [qw/ column1 column2 ... /]
4091 =item Value: $condition
4095 HAVING is a select statement attribute that is applied between GROUP BY and
4096 ORDER BY. It is applied to the after the grouping calculations have been
4099 having => { 'count_employee' => { '>=', 100 } }
4101 or with an in-place function in which case literal SQL is required:
4103 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4109 =item Value: (0 | 1)
4113 Set to 1 to group by all columns. If the resultset already has a group_by
4114 attribute, this setting is ignored and an appropriate warning is issued.
4120 Adds to the WHERE clause.
4122 # only return rows WHERE deleted IS NULL for all searches
4123 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4125 Can be overridden by passing C<< { where => undef } >> as an attribute
4132 Set to 1 to cache search results. This prevents extra SQL queries if you
4133 revisit rows in your ResultSet:
4135 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4137 while( my $artist = $resultset->next ) {
4141 $rs->first; # without cache, this would issue a query
4143 By default, searches are not cached.
4145 For more examples of using these attributes, see
4146 L<DBIx::Class::Manual::Cookbook>.
4152 =item Value: ( 'update' | 'shared' )
4156 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT