1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use DBIx::Class::Exception;
8 use DBIx::Class::ResultSetColumn;
9 use Scalar::Util qw/blessed weaken/;
12 # not importing first() as it will clash with our own method
19 # De-duplication in _merge_attr() is disabled, but left in for reference
20 # (the merger is used for other things that ought not to be de-duped)
21 *__HM_DEDUP = sub () { 0 };
29 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
33 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
37 my $users_rs = $schema->resultset('User');
38 while( $user = $users_rs->next) {
39 print $user->username;
42 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
43 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
47 A ResultSet is an object which stores a set of conditions representing
48 a query. It is the backbone of DBIx::Class (i.e. the really
49 important/useful bit).
51 No SQL is executed on the database when a ResultSet is created, it
52 just stores all the conditions needed to create the query.
54 A basic ResultSet representing the data of an entire table is returned
55 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
56 L<Source|DBIx::Class::Manual::Glossary/Source> name.
58 my $users_rs = $schema->resultset('User');
60 A new ResultSet is returned from calling L</search> on an existing
61 ResultSet. The new one will contain all the conditions of the
62 original, plus any new conditions added in the C<search> call.
64 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
65 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
68 The query that the ResultSet represents is B<only> executed against
69 the database when these methods are called:
70 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
72 If a resultset is used in a numeric context it returns the L</count>.
73 However, if it is used in a boolean context it is B<always> true. So if
74 you want to check if a resultset has any results, you must use C<if $rs
79 =head2 Chaining resultsets
81 Let's say you've got a query that needs to be run to return some data
82 to the user. But, you have an authorization system in place that
83 prevents certain users from seeing certain information. So, you want
84 to construct the basic query in one method, but add constraints to it in
89 my $request = $self->get_request; # Get a request object somehow.
90 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
92 my $cd_rs = $schema->resultset('CD')->search({
93 title => $request->param('title'),
94 year => $request->param('year'),
97 $cd_rs = $self->apply_security_policy( $cd_rs );
102 sub apply_security_policy {
111 =head3 Resolving conditions and attributes
113 When a resultset is chained from another resultset, conditions and
114 attributes with the same keys need resolving.
116 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
117 into the existing ones from the original resultset.
119 The L</where> and L</having> attributes, and any search conditions, are
120 merged with an SQL C<AND> to the existing condition from the original
123 All other attributes are overridden by any new ones supplied in the
126 =head2 Multiple queries
128 Since a resultset just defines a query, you can do all sorts of
129 things with it with the same object.
131 # Don't hit the DB yet.
132 my $cd_rs = $schema->resultset('CD')->search({
133 title => 'something',
137 # Each of these hits the DB individually.
138 my $count = $cd_rs->count;
139 my $most_recent = $cd_rs->get_column('date_released')->max();
140 my @records = $cd_rs->all;
142 And it's not just limited to SELECT statements.
148 $cd_rs->create({ artist => 'Fred' });
150 Which is the same as:
152 $schema->resultset('CD')->create({
153 title => 'something',
158 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
166 =item Arguments: $source, \%$attrs
168 =item Return Value: $rs
172 The resultset constructor. Takes a source object (usually a
173 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
174 L</ATTRIBUTES> below). Does not perform any queries -- these are
175 executed as needed by the other methods.
177 Generally you won't need to construct a resultset manually. You'll
178 automatically get one from e.g. a L</search> called in scalar context:
180 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
182 IMPORTANT: If called on an object, proxies to new_result instead so
184 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
186 will return a CD object, not a ResultSet.
192 return $class->new_result(@_) if ref $class;
194 my ($source, $attrs) = @_;
195 $source = $source->resolve
196 if $source->isa('DBIx::Class::ResultSourceHandle');
197 $attrs = { %{$attrs||{}} };
199 if ($attrs->{page}) {
200 $attrs->{rows} ||= 10;
203 $attrs->{alias} ||= 'me';
206 result_source => $source,
207 cond => $attrs->{where},
213 $attrs->{result_class} || $source->result_class
223 =item Arguments: $cond, \%attrs?
225 =item Return Value: $resultset (scalar context), @row_objs (list context)
229 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
230 my $new_rs = $cd_rs->search({ year => 2005 });
232 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
233 # year = 2005 OR year = 2004
235 If you need to pass in additional attributes but no additional condition,
236 call it as C<search(undef, \%attrs)>.
238 # "SELECT name, artistid FROM $artist_table"
239 my @all_artists = $schema->resultset('Artist')->search(undef, {
240 columns => [qw/name artistid/],
243 For a list of attributes that can be passed to C<search>, see
244 L</ATTRIBUTES>. For more examples of using this function, see
245 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
246 documentation for the first argument, see L<SQL::Abstract>.
248 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
252 Note that L</search> does not process/deflate any of the values passed in the
253 L<SQL::Abstract>-compatible search condition structure. This is unlike other
254 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
255 manually that any value passed to this method will stringify to something the
256 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
257 objects, for more info see:
258 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
264 my $rs = $self->search_rs( @_ );
269 elsif (defined wantarray) {
273 # we can be called by a relationship helper, which in
274 # turn may be called in void context due to some braindead
275 # overload or whatever else the user decided to be clever
276 # at this particular day. Thus limit the exception to
277 # external code calls only
278 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
279 if (caller)[0] !~ /^\QDBIx::Class::/;
289 =item Arguments: $cond, \%attrs?
291 =item Return Value: $resultset
295 This method does the same exact thing as search() except it will
296 always return a resultset, even in list context.
300 my $callsites_warned;
304 # Special-case handling for (undef, undef).
305 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
311 if (ref $_[-1] eq 'HASH') {
312 # copy for _normalize_selection
313 $call_attrs = { %{ pop @_ } };
315 elsif (! defined $_[-1] ) {
316 pop @_; # search({}, undef)
320 # see if we can keep the cache (no $rs changes)
322 my %safe = (alias => 1, cache => 1);
323 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
326 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
328 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
330 $cache = $self->get_cache;
333 my $rsrc = $self->result_source;
335 my $old_attrs = { %{$self->{attrs}} };
336 my $old_having = delete $old_attrs->{having};
337 my $old_where = delete $old_attrs->{where};
339 my $new_attrs = { %$old_attrs };
341 # take care of call attrs (only if anything is changing)
342 if (keys %$call_attrs) {
344 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
345 if ( exists $call_attrs->{_trailing_select} or exists $call_attrs->{'+_trailing_select'} );
347 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns _trailing_select +_trailing_select/;
349 # Normalize the selector list (operates on the passed-in attr structure)
350 # Need to do it on every chain instead of only once on _resolved_attrs, in
351 # order to separate 'as'-ed from blind 'select's
352 $self->_normalize_selection ($call_attrs);
354 # start with blind overwriting merge, exclude selector attrs
355 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
356 delete @{$new_attrs}{@selector_attrs};
358 # reset the current selector list if new selectors are supplied
359 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
360 delete @{$old_attrs}{@selector_attrs};
363 for (@selector_attrs) {
364 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
365 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
368 # older deprecated name, use only if {columns} is not there
369 if (my $c = delete $new_attrs->{cols}) {
370 if ($new_attrs->{columns}) {
371 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
374 $new_attrs->{columns} = $c;
379 # join/prefetch use their own crazy merging heuristics
380 foreach my $key (qw/join prefetch/) {
381 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
382 if exists $call_attrs->{$key};
385 # stack binds together
386 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
390 # rip apart the rest of @_, parse a condition
393 if (ref $_[0] eq 'HASH') {
394 (keys %{$_[0]}) ? $_[0] : undef
400 $self->throw_exception('Odd number of arguments to search')
408 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
409 # determine callsite obeying Carp::Clan rules (fucking ugly but don't have better ideas)
412 local $SIG{__WARN__} = sub { $w = shift };
416 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
417 unless $callsites_warned->{$callsite}++;
420 for ($old_where, $call_cond) {
422 $new_attrs->{where} = $self->_stack_cond (
423 $_, $new_attrs->{where}
428 if (defined $old_having) {
429 $new_attrs->{having} = $self->_stack_cond (
430 $old_having, $new_attrs->{having}
434 my $rs = (ref $self)->new($rsrc, $new_attrs);
436 $rs->set_cache($cache) if ($cache);
441 sub _normalize_selection {
442 my ($self, $attrs) = @_;
445 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
446 if exists $attrs->{include_columns};
448 # Keep the X vs +X separation until _resolved_attrs time - this allows to
449 # delay the decision on whether to use a default select list ($rsrc->columns)
450 # allowing stuff like the remove_columns helper to work
452 # select/as +select/+as pairs need special handling - the amount of select/as
453 # elements in each pair does *not* have to be equal (think multicolumn
454 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
455 # supplied at all) - try to infer the alias, either from the -as parameter
456 # of the selector spec, or use the parameter whole if it looks like a column
457 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
458 # is ok as well), but transport it over a separate attribute to make sure it is
459 # the last thing in the select list, thus unable to throw off the corresponding
461 for my $pref ('', '+') {
463 my ($sel, $as) = map {
464 my $key = "${pref}${_}";
466 my $val = [ ref $attrs->{$key} eq 'ARRAY'
468 : $attrs->{$key} || ()
470 delete $attrs->{$key};
474 if (! @$as and ! @$sel ) {
477 elsif (@$as and ! @$sel) {
478 $self->throw_exception(
479 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
483 # no as part supplied at all - try to deduce
484 # if any @$as has been supplied we assume the user knows what (s)he is doing
485 # and blindly keep stacking up pieces
486 my (@new_sel, @new_trailing);
488 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
489 push @$as, $_->{-as};
492 # assume any plain no-space, no-parenthesis string to be a column spec
493 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
494 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
498 # if all else fails - shove the selection to the trailing stack and move on
500 push @new_trailing, $_;
505 $attrs->{"${pref}_trailing_select"} = $self->_merge_attr($attrs->{"${pref}_trailing_select"}, \@new_trailing)
508 elsif (@$as < @$sel) {
509 $self->throw_exception(
510 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
514 # now see what the result for this pair looks like:
517 # if balanced - treat as a columns entry
518 $attrs->{"${pref}columns"} = $self->_merge_attr(
519 $attrs->{"${pref}columns"},
520 [ map { +{ $as->[$_] => $sel->[$_] } } ( 0 .. $#$as ) ]
524 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
525 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
526 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
533 my ($self, $left, $right) = @_;
534 if (defined $left xor defined $right) {
535 return defined $left ? $left : $right;
537 elsif (defined $left) {
538 return { -and => [ map
539 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
547 =head2 search_literal
551 =item Arguments: $sql_fragment, @bind_values
553 =item Return Value: $resultset (scalar context), @row_objs (list context)
557 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
558 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
560 Pass a literal chunk of SQL to be added to the conditional part of the
563 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
564 only be used in that context. C<search_literal> is a convenience method.
565 It is equivalent to calling $schema->search(\[]), but if you want to ensure
566 columns are bound correctly, use C<search>.
568 Example of how to use C<search> instead of C<search_literal>
570 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
571 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
574 See L<DBIx::Class::Manual::Cookbook/Searching> and
575 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
576 require C<search_literal>.
581 my ($self, $sql, @bind) = @_;
583 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
586 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
593 =item Arguments: \%columns_values | @pk_values, \%attrs?
595 =item Return Value: $row_object | undef
599 Finds and returns a single row based on supplied criteria. Takes either a
600 hashref with the same format as L</create> (including inference of foreign
601 keys from related objects), or a list of primary key values in the same
602 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
603 declaration on the L</result_source>.
605 In either case an attempt is made to combine conditions already existing on
606 the resultset with the condition passed to this method.
608 To aid with preparing the correct query for the storage you may supply the
609 C<key> attribute, which is the name of a
610 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
611 unique constraint corresponding to the
612 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
613 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
614 to construct a query that satisfies the named unique constraint fully (
615 non-NULL values for each column member of the constraint) an exception is
618 If no C<key> is specified, the search is carried over all unique constraints
619 which are fully defined by the available condition.
621 If no such constraint is found, C<find> currently defaults to a simple
622 C<< search->(\%column_values) >> which may or may not do what you expect.
623 Note that this fallback behavior may be deprecated in further versions. If
624 you need to search with arbitrary conditions - use L</search>. If the query
625 resulting from this fallback produces more than one row, a warning to the
626 effect is issued, though only the first row is constructed and returned as
629 In addition to C<key>, L</find> recognizes and applies standard
630 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
632 Note that if you have extra concerns about the correctness of the resulting
633 query you need to specify the C<key> attribute and supply the entire condition
634 as an argument to find (since it is not always possible to perform the
635 combination of the resultset condition with the supplied one, especially if
636 the resultset condition contains literal sql).
638 For example, to find a row by its primary key:
640 my $cd = $schema->resultset('CD')->find(5);
642 You can also find a row by a specific unique constraint:
644 my $cd = $schema->resultset('CD')->find(
646 artist => 'Massive Attack',
647 title => 'Mezzanine',
649 { key => 'cd_artist_title' }
652 See also L</find_or_create> and L</update_or_create>.
658 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
660 my $rsrc = $self->result_source;
662 # Parse out the condition from input
664 if (ref $_[0] eq 'HASH') {
665 $call_cond = { %{$_[0]} };
668 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
669 my @c_cols = $rsrc->unique_constraint_columns($constraint);
671 $self->throw_exception(
672 "No constraint columns, maybe a malformed '$constraint' constraint?"
675 $self->throw_exception (
676 'find() expects either a column/value hashref, or a list of values '
677 . "corresponding to the columns of the specified unique constraint '$constraint'"
678 ) unless @c_cols == @_;
681 @{$call_cond}{@c_cols} = @_;
685 for my $key (keys %$call_cond) {
687 my $keyref = ref($call_cond->{$key})
689 my $relinfo = $rsrc->relationship_info($key)
691 my $val = delete $call_cond->{$key};
693 next if $keyref eq 'ARRAY'; # has_many for multi_create
695 my $rel_q = $rsrc->_resolve_condition(
696 $relinfo->{cond}, $val, $key
698 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
699 @related{keys %$rel_q} = values %$rel_q;
703 # relationship conditions take precedence (?)
704 @{$call_cond}{keys %related} = values %related;
706 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
708 if (exists $attrs->{key}) {
709 $final_cond = $self->_qualify_cond_columns (
711 $self->_build_unique_cond (
719 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
720 # This means that we got here after a merger of relationship conditions
721 # in ::Relationship::Base::search_related (the row method), and furthermore
722 # the relationship is of the 'single' type. This means that the condition
723 # provided by the relationship (already attached to $self) is sufficient,
724 # as there can be only one row in the database that would satisfy the
728 # no key was specified - fall down to heuristics mode:
729 # run through all unique queries registered on the resultset, and
730 # 'OR' all qualifying queries together
731 my (@unique_queries, %seen_column_combinations);
732 for my $c_name ($rsrc->unique_constraint_names) {
733 next if $seen_column_combinations{
734 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
737 push @unique_queries, try {
738 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
742 $final_cond = @unique_queries
743 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
744 : $self->_non_unique_find_fallback ($call_cond, $attrs)
748 # Run the query, passing the result_class since it should propagate for find
749 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
750 if (keys %{$rs->_resolved_attrs->{collapse}}) {
752 carp "Query returned more than one row" if $rs->next;
760 # This is a stop-gap method as agreed during the discussion on find() cleanup:
761 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
763 # It is invoked when find() is called in legacy-mode with insufficiently-unique
764 # condition. It is provided for overrides until a saner way forward is devised
766 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
767 # the road. Please adjust your tests accordingly to catch this situation early
768 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
770 # The method will not be removed without an adequately complete replacement
771 # for strict-mode enforcement
772 sub _non_unique_find_fallback {
773 my ($self, $cond, $attrs) = @_;
775 return $self->_qualify_cond_columns(
777 exists $attrs->{alias}
779 : $self->{attrs}{alias}
784 sub _qualify_cond_columns {
785 my ($self, $cond, $alias) = @_;
787 my %aliased = %$cond;
788 for (keys %aliased) {
789 $aliased{"$alias.$_"} = delete $aliased{$_}
796 my $callsites_warned_ucond;
797 sub _build_unique_cond {
798 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
800 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
802 # combination may fail if $self->{cond} is non-trivial
803 my ($final_cond) = try {
804 $self->_merge_with_rscond ($extra_cond)
809 # trim out everything not in $columns
810 $final_cond = { map {
811 exists $final_cond->{$_}
812 ? ( $_ => $final_cond->{$_} )
816 if (my @missing = grep
817 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
820 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
822 join (', ', map { "'$_'" } @missing),
829 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
831 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
835 local $SIG{__WARN__} = sub { $w = shift };
841 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
842 . 'values in column(s): %s). This is almost certainly not what you wanted, '
843 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
845 join (', ', map { "'$_'" } @undefs),
846 )) unless $callsites_warned_ucond->{$callsite}++;
852 =head2 search_related
856 =item Arguments: $rel, $cond, \%attrs?
858 =item Return Value: $new_resultset
862 $new_rs = $cd_rs->search_related('artist', {
866 Searches the specified relationship, optionally specifying a condition and
867 attributes for matching records. See L</ATTRIBUTES> for more information.
872 return shift->related_resultset(shift)->search(@_);
875 =head2 search_related_rs
877 This method works exactly the same as search_related, except that
878 it guarantees a resultset, even in list context.
882 sub search_related_rs {
883 return shift->related_resultset(shift)->search_rs(@_);
890 =item Arguments: none
892 =item Return Value: $cursor
896 Returns a storage-driven cursor to the given resultset. See
897 L<DBIx::Class::Cursor> for more information.
904 my $attrs = $self->_resolved_attrs_copy;
906 return $self->{cursor}
907 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
908 $attrs->{where},$attrs);
915 =item Arguments: $cond?
917 =item Return Value: $row_object | undef
921 my $cd = $schema->resultset('CD')->single({ year => 2001 });
923 Inflates the first result without creating a cursor if the resultset has
924 any records in it; if not returns C<undef>. Used by L</find> as a lean version
927 While this method can take an optional search condition (just like L</search>)
928 being a fast-code-path it does not recognize search attributes. If you need to
929 add extra joins or similar, call L</search> and then chain-call L</single> on the
930 L<DBIx::Class::ResultSet> returned.
936 As of 0.08100, this method enforces the assumption that the preceding
937 query returns only one row. If more than one row is returned, you will receive
940 Query returned more than one row
942 In this case, you should be using L</next> or L</find> instead, or if you really
943 know what you are doing, use the L</rows> attribute to explicitly limit the size
946 This method will also throw an exception if it is called on a resultset prefetching
947 has_many, as such a prefetch implies fetching multiple rows from the database in
948 order to assemble the resulting object.
955 my ($self, $where) = @_;
957 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
960 my $attrs = $self->_resolved_attrs_copy;
962 if (keys %{$attrs->{collapse}}) {
963 $self->throw_exception(
964 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
969 if (defined $attrs->{where}) {
972 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
973 $where, delete $attrs->{where} ]
976 $attrs->{where} = $where;
980 my @data = $self->result_source->storage->select_single(
981 $attrs->{from}, $attrs->{select},
982 $attrs->{where}, $attrs
985 return (@data ? ($self->_construct_object(@data))[0] : undef);
991 # Recursively collapse the query, accumulating values for each column.
993 sub _collapse_query {
994 my ($self, $query, $collapsed) = @_;
998 if (ref $query eq 'ARRAY') {
999 foreach my $subquery (@$query) {
1000 next unless ref $subquery; # -or
1001 $collapsed = $self->_collapse_query($subquery, $collapsed);
1004 elsif (ref $query eq 'HASH') {
1005 if (keys %$query and (keys %$query)[0] eq '-and') {
1006 foreach my $subquery (@{$query->{-and}}) {
1007 $collapsed = $self->_collapse_query($subquery, $collapsed);
1011 foreach my $col (keys %$query) {
1012 my $value = $query->{$col};
1013 $collapsed->{$col}{$value}++;
1025 =item Arguments: $cond?
1027 =item Return Value: $resultsetcolumn
1031 my $max_length = $rs->get_column('length')->max;
1033 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1038 my ($self, $column) = @_;
1039 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1047 =item Arguments: $cond, \%attrs?
1049 =item Return Value: $resultset (scalar context), @row_objs (list context)
1053 # WHERE title LIKE '%blue%'
1054 $cd_rs = $rs->search_like({ title => '%blue%'});
1056 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1057 that this is simply a convenience method retained for ex Class::DBI users.
1058 You most likely want to use L</search> with specific operators.
1060 For more information, see L<DBIx::Class::Manual::Cookbook>.
1062 This method is deprecated and will be removed in 0.09. Use L</search()>
1063 instead. An example conversion is:
1065 ->search_like({ foo => 'bar' });
1069 ->search({ foo => { like => 'bar' } });
1076 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1077 .' Instead use ->search({ x => { -like => "y%" } })'
1078 .' (note the outer pair of {}s - they are important!)'
1080 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1081 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1082 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1083 return $class->search($query, { %$attrs });
1090 =item Arguments: $first, $last
1092 =item Return Value: $resultset (scalar context), @row_objs (list context)
1096 Returns a resultset or object list representing a subset of elements from the
1097 resultset slice is called on. Indexes are from 0, i.e., to get the first
1098 three records, call:
1100 my ($one, $two, $three) = $rs->slice(0, 2);
1105 my ($self, $min, $max) = @_;
1106 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1107 $attrs->{offset} = $self->{attrs}{offset} || 0;
1108 $attrs->{offset} += $min;
1109 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1110 return $self->search(undef, $attrs);
1111 #my $slice = (ref $self)->new($self->result_source, $attrs);
1112 #return (wantarray ? $slice->all : $slice);
1119 =item Arguments: none
1121 =item Return Value: $result | undef
1125 Returns the next element in the resultset (C<undef> is there is none).
1127 Can be used to efficiently iterate over records in the resultset:
1129 my $rs = $schema->resultset('CD')->search;
1130 while (my $cd = $rs->next) {
1134 Note that you need to store the resultset object, and call C<next> on it.
1135 Calling C<< resultset('Table')->next >> repeatedly will always return the
1136 first record from the resultset.
1142 if (my $cache = $self->get_cache) {
1143 $self->{all_cache_position} ||= 0;
1144 return $cache->[$self->{all_cache_position}++];
1146 if ($self->{attrs}{cache}) {
1147 delete $self->{pager};
1148 $self->{all_cache_position} = 1;
1149 return ($self->all)[0];
1151 if ($self->{stashed_objects}) {
1152 my $obj = shift(@{$self->{stashed_objects}});
1153 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1157 exists $self->{stashed_row}
1158 ? @{delete $self->{stashed_row}}
1159 : $self->cursor->next
1161 return undef unless (@row);
1162 my ($row, @more) = $self->_construct_object(@row);
1163 $self->{stashed_objects} = \@more if @more;
1167 sub _construct_object {
1168 my ($self, @row) = @_;
1170 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1172 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1173 @new = $self->{_attrs}{record_filter}->(@new)
1174 if exists $self->{_attrs}{record_filter};
1178 sub _collapse_result {
1179 my ($self, $as_proto, $row) = @_;
1183 # 'foo' => [ undef, 'foo' ]
1184 # 'foo.bar' => [ 'foo', 'bar' ]
1185 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1187 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1189 my %collapse = %{$self->{_attrs}{collapse}||{}};
1193 # if we're doing collapsing (has_many prefetch) we need to grab records
1194 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1195 # we know we don't have to bother.
1197 # the reason for not using the collapse stuff directly is because if you
1198 # had for e.g. two artists in a row with no cds, the collapse info for
1199 # both would be NULL (undef) so you'd lose the second artist
1201 # store just the index so we can check the array positions from the row
1202 # without having to contruct the full hash
1204 if (keys %collapse) {
1205 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1206 foreach my $i (0 .. $#construct_as) {
1207 next if defined($construct_as[$i][0]); # only self table
1208 if (delete $pri{$construct_as[$i][1]}) {
1209 push(@pri_index, $i);
1211 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1215 # no need to do an if, it'll be empty if @pri_index is empty anyway
1217 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1221 do { # no need to check anything at the front, we always want the first row
1225 foreach my $this_as (@construct_as) {
1226 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1229 push(@const_rows, \%const);
1231 } until ( # no pri_index => no collapse => drop straight out
1234 do { # get another row, stash it, drop out if different PK
1236 @copy = $self->cursor->next;
1237 $self->{stashed_row} = \@copy;
1239 # last thing in do block, counts as true if anything doesn't match
1241 # check xor defined first for NULL vs. NOT NULL then if one is
1242 # defined the other must be so check string equality
1245 (defined $pri_vals{$_} ^ defined $copy[$_])
1246 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1251 my $alias = $self->{attrs}{alias};
1258 foreach my $const (@const_rows) {
1259 scalar @const_keys or do {
1260 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1262 foreach my $key (@const_keys) {
1265 my @parts = split(/\./, $key);
1267 my $data = $const->{$key};
1268 foreach my $p (@parts) {
1269 $target = $target->[1]->{$p} ||= [];
1271 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1272 # collapsing at this point and on final part
1273 my $pos = $collapse_pos{$cur};
1274 CK: foreach my $ck (@ckey) {
1275 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1276 $collapse_pos{$cur} = $data;
1277 delete @collapse_pos{ # clear all positioning for sub-entries
1278 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1285 if (exists $collapse{$cur}) {
1286 $target = $target->[-1];
1289 $target->[0] = $data;
1291 $info->[0] = $const->{$key};
1299 =head2 result_source
1303 =item Arguments: $result_source?
1305 =item Return Value: $result_source
1309 An accessor for the primary ResultSource object from which this ResultSet
1316 =item Arguments: $result_class?
1318 =item Return Value: $result_class
1322 An accessor for the class to use when creating row objects. Defaults to
1323 C<< result_source->result_class >> - which in most cases is the name of the
1324 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1326 Note that changing the result_class will also remove any components
1327 that were originally loaded in the source class via
1328 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1329 in the original source class will not run.
1334 my ($self, $result_class) = @_;
1335 if ($result_class) {
1336 unless (ref $result_class) { # don't fire this for an object
1337 $self->ensure_class_loaded($result_class);
1339 $self->_result_class($result_class);
1340 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1341 # permit the user to set result class on one result set only; it only
1342 # chains if provided to search()
1343 #$self->{attrs}{result_class} = $result_class if ref $self;
1345 $self->_result_class;
1352 =item Arguments: $cond, \%attrs??
1354 =item Return Value: $count
1358 Performs an SQL C<COUNT> with the same query as the resultset was built
1359 with to find the number of elements. Passing arguments is equivalent to
1360 C<< $rs->search ($cond, \%attrs)->count >>
1366 return $self->search(@_)->count if @_ and defined $_[0];
1367 return scalar @{ $self->get_cache } if $self->get_cache;
1369 my $attrs = $self->_resolved_attrs_copy;
1371 # this is a little optimization - it is faster to do the limit
1372 # adjustments in software, instead of a subquery
1373 my $rows = delete $attrs->{rows};
1374 my $offset = delete $attrs->{offset};
1377 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1378 $crs = $self->_count_subq_rs ($attrs);
1381 $crs = $self->_count_rs ($attrs);
1383 my $count = $crs->next;
1385 $count -= $offset if $offset;
1386 $count = $rows if $rows and $rows < $count;
1387 $count = 0 if ($count < 0);
1396 =item Arguments: $cond, \%attrs??
1398 =item Return Value: $count_rs
1402 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1403 This can be very handy for subqueries:
1405 ->search( { amount => $some_rs->count_rs->as_query } )
1407 As with regular resultsets the SQL query will be executed only after
1408 the resultset is accessed via L</next> or L</all>. That would return
1409 the same single value obtainable via L</count>.
1415 return $self->search(@_)->count_rs if @_;
1417 # this may look like a lack of abstraction (count() does about the same)
1418 # but in fact an _rs *must* use a subquery for the limits, as the
1419 # software based limiting can not be ported if this $rs is to be used
1420 # in a subquery itself (i.e. ->as_query)
1421 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1422 return $self->_count_subq_rs;
1425 return $self->_count_rs;
1430 # returns a ResultSetColumn object tied to the count query
1433 my ($self, $attrs) = @_;
1435 my $rsrc = $self->result_source;
1436 $attrs ||= $self->_resolved_attrs;
1438 my $tmp_attrs = { %$attrs };
1439 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1440 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1442 # overwrite the selector (supplied by the storage)
1443 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1444 $tmp_attrs->{as} = 'count';
1445 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1447 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1453 # same as above but uses a subquery
1455 sub _count_subq_rs {
1456 my ($self, $attrs) = @_;
1458 my $rsrc = $self->result_source;
1459 $attrs ||= $self->_resolved_attrs;
1461 my $sub_attrs = { %$attrs };
1462 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1463 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1465 # if we multi-prefetch we group_by primary keys only as this is what we would
1466 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1467 if ( keys %{$attrs->{collapse}} ) {
1468 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1471 # Calculate subquery selector
1472 if (my $g = $sub_attrs->{group_by}) {
1474 my $sql_maker = $rsrc->storage->sql_maker;
1476 # necessary as the group_by may refer to aliased functions
1478 for my $sel (@{$attrs->{select}}) {
1479 $sel_index->{$sel->{-as}} = $sel
1480 if (ref $sel eq 'HASH' and $sel->{-as});
1483 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1484 # also look for named aggregates referred in the having clause
1485 # having often contains scalarrefs - thus parse it out entirely
1487 if ($attrs->{having}) {
1488 local $sql_maker->{having_bind};
1489 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1490 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1491 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1492 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1493 # if we don't unset it we screw up retarded but unfortunately working
1494 # 'MAX(foo.bar)' => { '>', 3 }
1495 $sql_maker->{name_sep} = '';
1498 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1500 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1502 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1503 # and if all fails for an utterly naive quoted scalar-with-function
1505 $rquote $sep $lquote (.+?) $rquote
1507 [\s,] \w+ \. (\w+) [\s,]
1509 [\s,] $lquote (.+?) $rquote [\s,]
1511 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1516 my $colpiece = $sel_index->{$_} || $_;
1518 # unqualify join-based group_by's. Arcane but possible query
1519 # also horrible horrible hack to alias a column (not a func.)
1520 # (probably need to introduce SQLA syntax)
1521 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1524 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1526 push @{$sub_attrs->{select}}, $colpiece;
1530 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1531 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1534 return $rsrc->resultset_class
1535 ->new ($rsrc, $sub_attrs)
1537 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1538 ->get_column ('count');
1545 =head2 count_literal
1549 =item Arguments: $sql_fragment, @bind_values
1551 =item Return Value: $count
1555 Counts the results in a literal query. Equivalent to calling L</search_literal>
1556 with the passed arguments, then L</count>.
1560 sub count_literal { shift->search_literal(@_)->count; }
1566 =item Arguments: none
1568 =item Return Value: @objects
1572 Returns all elements in the resultset. Called implicitly if the resultset
1573 is returned in list context.
1580 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1583 return @{ $self->get_cache } if $self->get_cache;
1587 if (keys %{$self->_resolved_attrs->{collapse}}) {
1588 # Using $self->cursor->all is really just an optimisation.
1589 # If we're collapsing has_many prefetches it probably makes
1590 # very little difference, and this is cleaner than hacking
1591 # _construct_object to survive the approach
1592 $self->cursor->reset;
1593 my @row = $self->cursor->next;
1595 push(@obj, $self->_construct_object(@row));
1596 @row = (exists $self->{stashed_row}
1597 ? @{delete $self->{stashed_row}}
1598 : $self->cursor->next);
1601 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1604 $self->set_cache(\@obj) if $self->{attrs}{cache};
1613 =item Arguments: none
1615 =item Return Value: $self
1619 Resets the resultset's cursor, so you can iterate through the elements again.
1620 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1627 delete $self->{_attrs} if exists $self->{_attrs};
1628 $self->{all_cache_position} = 0;
1629 $self->cursor->reset;
1637 =item Arguments: none
1639 =item Return Value: $object | undef
1643 Resets the resultset and returns an object for the first result (or C<undef>
1644 if the resultset is empty).
1649 return $_[0]->reset->next;
1655 # Determines whether and what type of subquery is required for the $rs operation.
1656 # If grouping is necessary either supplies its own, or verifies the current one
1657 # After all is done delegates to the proper storage method.
1659 sub _rs_update_delete {
1660 my ($self, $op, $values) = @_;
1662 my $rsrc = $self->result_source;
1664 # if a condition exists we need to strip all table qualifiers
1665 # if this is not possible we'll force a subquery below
1666 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1668 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1669 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1671 if ($needs_group_by_subq or $needs_subq) {
1673 # make a new $rs selecting only the PKs (that's all we really need)
1674 my $attrs = $self->_resolved_attrs_copy;
1677 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1678 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1680 if ($needs_group_by_subq) {
1681 # make sure no group_by was supplied, or if there is one - make sure it matches
1682 # the columns compiled above perfectly. Anything else can not be sanely executed
1683 # on most databases so croak right then and there
1685 if (my $g = $attrs->{group_by}) {
1686 my @current_group_by = map
1687 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1692 join ("\x00", sort @current_group_by)
1694 join ("\x00", sort @{$attrs->{columns}} )
1696 $self->throw_exception (
1697 "You have just attempted a $op operation on a resultset which does group_by"
1698 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1699 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1700 . ' kind of queries. Please retry the operation with a modified group_by or'
1701 . ' without using one at all.'
1706 $attrs->{group_by} = $attrs->{columns};
1710 my $subrs = (ref $self)->new($rsrc, $attrs);
1711 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1714 return $rsrc->storage->$op(
1716 $op eq 'update' ? $values : (),
1726 =item Arguments: \%values
1728 =item Return Value: $storage_rv
1732 Sets the specified columns in the resultset to the supplied values in a
1733 single query. Note that this will not run any accessor/set_column/update
1734 triggers, nor will it update any row object instances derived from this
1735 resultset (this includes the contents of the L<resultset cache|/set_cache>
1736 if any). See L</update_all> if you need to execute any on-update
1737 triggers or cascades defined either by you or a
1738 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1740 The return value is a pass through of what the underlying
1741 storage backend returned, and may vary. See L<DBI/execute> for the most
1746 Note that L</update> does not process/deflate any of the values passed in.
1747 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1748 ensure manually that any value passed to this method will stringify to
1749 something the RDBMS knows how to deal with. A notable example is the
1750 handling of L<DateTime> objects, for more info see:
1751 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1756 my ($self, $values) = @_;
1757 $self->throw_exception('Values for update must be a hash')
1758 unless ref $values eq 'HASH';
1760 return $self->_rs_update_delete ('update', $values);
1767 =item Arguments: \%values
1769 =item Return Value: 1
1773 Fetches all objects and updates them one at a time via
1774 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1775 triggers, while L</update> will not.
1780 my ($self, $values) = @_;
1781 $self->throw_exception('Values for update_all must be a hash')
1782 unless ref $values eq 'HASH';
1784 my $guard = $self->result_source->schema->txn_scope_guard;
1785 $_->update($values) for $self->all;
1794 =item Arguments: none
1796 =item Return Value: $storage_rv
1800 Deletes the rows matching this resultset in a single query. Note that this
1801 will not run any delete triggers, nor will it alter the
1802 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1803 derived from this resultset (this includes the contents of the
1804 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1805 execute any on-delete triggers or cascades defined either by you or a
1806 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1808 The return value is a pass through of what the underlying storage backend
1809 returned, and may vary. See L<DBI/execute> for the most common case.
1815 $self->throw_exception('delete does not accept any arguments')
1818 return $self->_rs_update_delete ('delete');
1825 =item Arguments: none
1827 =item Return Value: 1
1831 Fetches all objects and deletes them one at a time via
1832 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1833 triggers, while L</delete> will not.
1839 $self->throw_exception('delete_all does not accept any arguments')
1842 my $guard = $self->result_source->schema->txn_scope_guard;
1843 $_->delete for $self->all;
1852 =item Arguments: \@data;
1856 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1857 For the arrayref of hashrefs style each hashref should be a structure suitable
1858 forsubmitting to a $resultset->create(...) method.
1860 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1861 to insert the data, as this is a faster method.
1863 Otherwise, each set of data is inserted into the database using
1864 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1865 accumulated into an array. The array itself, or an array reference
1866 is returned depending on scalar or list context.
1868 Example: Assuming an Artist Class that has many CDs Classes relating:
1870 my $Artist_rs = $schema->resultset("Artist");
1872 ## Void Context Example
1873 $Artist_rs->populate([
1874 { artistid => 4, name => 'Manufactured Crap', cds => [
1875 { title => 'My First CD', year => 2006 },
1876 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1879 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1880 { title => 'My parents sold me to a record company', year => 2005 },
1881 { title => 'Why Am I So Ugly?', year => 2006 },
1882 { title => 'I Got Surgery and am now Popular', year => 2007 }
1887 ## Array Context Example
1888 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1889 { name => "Artist One"},
1890 { name => "Artist Two"},
1891 { name => "Artist Three", cds=> [
1892 { title => "First CD", year => 2007},
1893 { title => "Second CD", year => 2008},
1897 print $ArtistOne->name; ## response is 'Artist One'
1898 print $ArtistThree->cds->count ## reponse is '2'
1900 For the arrayref of arrayrefs style, the first element should be a list of the
1901 fieldsnames to which the remaining elements are rows being inserted. For
1904 $Arstist_rs->populate([
1905 [qw/artistid name/],
1906 [100, 'A Formally Unknown Singer'],
1907 [101, 'A singer that jumped the shark two albums ago'],
1908 [102, 'An actually cool singer'],
1911 Please note an important effect on your data when choosing between void and
1912 wantarray context. Since void context goes straight to C<insert_bulk> in
1913 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1914 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1915 create primary keys for you, you will find that your PKs are empty. In this
1916 case you will have to use the wantarray context in order to create those
1924 # cruft placed in standalone method
1925 my $data = $self->_normalize_populate_args(@_);
1927 if(defined wantarray) {
1929 foreach my $item (@$data) {
1930 push(@created, $self->create($item));
1932 return wantarray ? @created : \@created;
1935 my $first = $data->[0];
1937 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1938 # it relationship data
1939 my (@rels, @columns);
1940 my $rsrc = $self->result_source;
1941 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1942 for (keys %$first) {
1943 my $ref = ref $first->{$_};
1944 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1950 my @pks = $rsrc->primary_columns;
1952 ## do the belongs_to relationships
1953 foreach my $index (0..$#$data) {
1955 # delegate to create() for any dataset without primary keys with specified relationships
1956 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1958 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1959 my @ret = $self->populate($data);
1965 foreach my $rel (@rels) {
1966 next unless ref $data->[$index]->{$rel} eq "HASH";
1967 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1968 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1969 my $related = $result->result_source->_resolve_condition(
1970 $reverse_relinfo->{cond},
1975 delete $data->[$index]->{$rel};
1976 $data->[$index] = {%{$data->[$index]}, %$related};
1978 push @columns, keys %$related if $index == 0;
1982 ## inherit the data locked in the conditions of the resultset
1983 my ($rs_data) = $self->_merge_with_rscond({});
1984 delete @{$rs_data}{@columns};
1985 my @inherit_cols = keys %$rs_data;
1986 my @inherit_data = values %$rs_data;
1988 ## do bulk insert on current row
1989 $rsrc->storage->insert_bulk(
1991 [@columns, @inherit_cols],
1992 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1995 ## do the has_many relationships
1996 foreach my $item (@$data) {
2000 foreach my $rel (@rels) {
2001 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
2003 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
2005 my $child = $main_row->$rel;
2007 my $related = $child->result_source->_resolve_condition(
2008 $rels->{$rel}{cond},
2013 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
2014 my @populate = map { {%$_, %$related} } @rows_to_add;
2016 $child->populate( \@populate );
2023 # populate() argumnets went over several incarnations
2024 # What we ultimately support is AoH
2025 sub _normalize_populate_args {
2026 my ($self, $arg) = @_;
2028 if (ref $arg eq 'ARRAY') {
2029 if (ref $arg->[0] eq 'HASH') {
2032 elsif (ref $arg->[0] eq 'ARRAY') {
2034 my @colnames = @{$arg->[0]};
2035 foreach my $values (@{$arg}[1 .. $#$arg]) {
2036 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2042 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2049 =item Arguments: none
2051 =item Return Value: $pager
2055 Return Value a L<Data::Page> object for the current resultset. Only makes
2056 sense for queries with a C<page> attribute.
2058 To get the full count of entries for a paged resultset, call
2059 C<total_entries> on the L<Data::Page> object.
2063 # make a wizard good for both a scalar and a hashref
2064 my $mk_lazy_count_wizard = sub {
2065 require Variable::Magic;
2067 my $stash = { total_rs => shift };
2068 my $slot = shift; # only used by the hashref magic
2070 my $magic = Variable::Magic::wizard (
2071 data => sub { $stash },
2077 # set value lazily, and dispell for good
2078 ${$_[0]} = $_[1]{total_rs}->count;
2079 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2083 # an explicit set implies dispell as well
2084 # the unless() is to work around "fun and giggles" below
2085 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2086 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2093 if ($_[2] eq $slot and !$_[1]{inactive}) {
2094 my $cnt = $_[1]{total_rs}->count;
2095 $_[0]->{$slot} = $cnt;
2097 # attempting to dispell in a fetch handle (works in store), seems
2098 # to invariable segfault on 5.10, 5.12, 5.13 :(
2099 # so use an inactivator instead
2100 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2106 if (! $_[1]{inactive} and $_[2] eq $slot) {
2107 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2109 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2116 $stash->{magic_selfref} = $magic;
2117 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2122 # the tie class for 5.8.1
2124 package # hide from pause
2125 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2126 use base qw/Tie::Hash/;
2128 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2129 sub NEXTKEY { each %{$_[0]{data}} }
2130 sub EXISTS { exists $_[0]{data}{$_[1]} }
2131 sub DELETE { delete $_[0]{data}{$_[1]} }
2132 sub CLEAR { %{$_[0]{data}} = () }
2133 sub SCALAR { scalar %{$_[0]{data}} }
2136 $_[1]{data} = {%{$_[1]{selfref}}};
2137 %{$_[1]{selfref}} = ();
2138 Scalar::Util::weaken ($_[1]{selfref});
2139 return bless ($_[1], $_[0]);
2143 if ($_[1] eq $_[0]{slot}) {
2144 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2145 untie %{$_[0]{selfref}};
2146 %{$_[0]{selfref}} = %{$_[0]{data}};
2155 $_[0]{data}{$_[1]} = $_[2];
2156 if ($_[1] eq $_[0]{slot}) {
2157 untie %{$_[0]{selfref}};
2158 %{$_[0]{selfref}} = %{$_[0]{data}};
2167 return $self->{pager} if $self->{pager};
2169 if ($self->get_cache) {
2170 $self->throw_exception ('Pagers on cached resultsets are not supported');
2173 my $attrs = $self->{attrs};
2174 if (!defined $attrs->{page}) {
2175 $self->throw_exception("Can't create pager for non-paged rs");
2177 elsif ($attrs->{page} <= 0) {
2178 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2180 $attrs->{rows} ||= 10;
2182 # throw away the paging flags and re-run the count (possibly
2183 # with a subselect) to get the real total count
2184 my $count_attrs = { %$attrs };
2185 delete $count_attrs->{$_} for qw/rows offset page pager/;
2186 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2189 ### the following may seem awkward and dirty, but it's a thought-experiment
2190 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2191 ### before talking to ribasushi/mst
2194 my $pager = Data::Page->new(
2195 0, #start with an empty set
2197 $self->{attrs}{page},
2200 my $data_slot = 'total_entries';
2202 # Since we are interested in a cached value (once it's set - it's set), every
2203 # technique will detach from the magic-host once the time comes to fire the
2204 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2206 if ($] < 5.008003) {
2207 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2208 # to weakref the magic container :(
2210 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2211 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2214 elsif ($] < 5.010) {
2215 # We can use magic on the hash value slot. It's interesting that the magic is
2216 # attached to the hash-slot, and does *not* stop working once I do the dummy
2217 # assignments after the cast()
2218 # tested on 5.8.3 and 5.8.9
2219 my $magic = $mk_lazy_count_wizard->($total_rs);
2220 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2222 # this is for fun and giggles
2223 $pager->{$data_slot} = -1;
2224 $pager->{$data_slot} = 0;
2226 # this does not work for scalars, but works with
2228 #my %vals = %$pager;
2233 # And the uvar magic
2234 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2235 # however see the wizard maker for more notes
2236 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2237 Variable::Magic::cast ( %$pager, $magic );
2240 $pager->{$data_slot} = -1;
2241 $pager->{$data_slot} = 0;
2249 return $self->{pager} = $pager;
2256 =item Arguments: $page_number
2258 =item Return Value: $rs
2262 Returns a resultset for the $page_number page of the resultset on which page
2263 is called, where each page contains a number of rows equal to the 'rows'
2264 attribute set on the resultset (10 by default).
2269 my ($self, $page) = @_;
2270 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2277 =item Arguments: \%vals
2279 =item Return Value: $rowobject
2283 Creates a new row object in the resultset's result class and returns
2284 it. The row is not inserted into the database at this point, call
2285 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2286 will tell you whether the row object has been inserted or not.
2288 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2293 my ($self, $values) = @_;
2294 $self->throw_exception( "new_result needs a hash" )
2295 unless (ref $values eq 'HASH');
2297 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2301 @$cols_from_relations
2302 ? (-cols_from_relations => $cols_from_relations)
2304 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2307 return $self->result_class->new(\%new);
2310 # _merge_with_rscond
2312 # Takes a simple hash of K/V data and returns its copy merged with the
2313 # condition already present on the resultset. Additionally returns an
2314 # arrayref of value/condition names, which were inferred from related
2315 # objects (this is needed for in-memory related objects)
2316 sub _merge_with_rscond {
2317 my ($self, $data) = @_;
2319 my (%new_data, @cols_from_relations);
2321 my $alias = $self->{attrs}{alias};
2323 if (! defined $self->{cond}) {
2324 # just massage $data below
2326 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2327 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2328 @cols_from_relations = keys %new_data;
2330 elsif (ref $self->{cond} ne 'HASH') {
2331 $self->throw_exception(
2332 "Can't abstract implicit construct, resultset condition not a hash"
2336 # precendence must be given to passed values over values inherited from
2337 # the cond, so the order here is important.
2338 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2339 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2341 while ( my($col, $value) = each %implied ) {
2342 my $vref = ref $value;
2343 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2344 $new_data{$col} = $value->{'='};
2346 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2347 $new_data{$col} = $value;
2354 %{ $self->_remove_alias($data, $alias) },
2357 return (\%new_data, \@cols_from_relations);
2360 # _has_resolved_attr
2362 # determines if the resultset defines at least one
2363 # of the attributes supplied
2365 # used to determine if a subquery is neccessary
2367 # supports some virtual attributes:
2369 # This will scan for any joins being present on the resultset.
2370 # It is not a mere key-search but a deep inspection of {from}
2373 sub _has_resolved_attr {
2374 my ($self, @attr_names) = @_;
2376 my $attrs = $self->_resolved_attrs;
2380 for my $n (@attr_names) {
2381 if (grep { $n eq $_ } (qw/-join/) ) {
2382 $extra_checks{$n}++;
2386 my $attr = $attrs->{$n};
2388 next if not defined $attr;
2390 if (ref $attr eq 'HASH') {
2391 return 1 if keys %$attr;
2393 elsif (ref $attr eq 'ARRAY') {
2401 # a resolved join is expressed as a multi-level from
2403 $extra_checks{-join}
2405 ref $attrs->{from} eq 'ARRAY'
2407 @{$attrs->{from}} > 1
2415 # Recursively collapse the condition.
2417 sub _collapse_cond {
2418 my ($self, $cond, $collapsed) = @_;
2422 if (ref $cond eq 'ARRAY') {
2423 foreach my $subcond (@$cond) {
2424 next unless ref $subcond; # -or
2425 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2428 elsif (ref $cond eq 'HASH') {
2429 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2430 foreach my $subcond (@{$cond->{-and}}) {
2431 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2435 foreach my $col (keys %$cond) {
2436 my $value = $cond->{$col};
2437 $collapsed->{$col} = $value;
2447 # Remove the specified alias from the specified query hash. A copy is made so
2448 # the original query is not modified.
2451 my ($self, $query, $alias) = @_;
2453 my %orig = %{ $query || {} };
2456 foreach my $key (keys %orig) {
2458 $unaliased{$key} = $orig{$key};
2461 $unaliased{$1} = $orig{$key}
2462 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2472 =item Arguments: none
2474 =item Return Value: \[ $sql, @bind ]
2478 Returns the SQL query and bind vars associated with the invocant.
2480 This is generally used as the RHS for a subquery.
2487 my $attrs = $self->_resolved_attrs_copy;
2492 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2493 # $sql also has no wrapping parenthesis in list ctx
2495 my $sqlbind = $self->result_source->storage
2496 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2505 =item Arguments: \%vals, \%attrs?
2507 =item Return Value: $rowobject
2511 my $artist = $schema->resultset('Artist')->find_or_new(
2512 { artist => 'fred' }, { key => 'artists' });
2514 $cd->cd_to_producer->find_or_new({ producer => $producer },
2515 { key => 'primary });
2517 Find an existing record from this resultset using L</find>. if none exists,
2518 instantiate a new result object and return it. The object will not be saved
2519 into your storage until you call L<DBIx::Class::Row/insert> on it.
2521 You most likely want this method when looking for existing rows using a unique
2522 constraint that is not the primary key, or looking for related rows.
2524 If you want objects to be saved immediately, use L</find_or_create> instead.
2526 B<Note>: Make sure to read the documentation of L</find> and understand the
2527 significance of the C<key> attribute, as its lack may skew your search, and
2528 subsequently result in spurious new objects.
2530 B<Note>: Take care when using C<find_or_new> with a table having
2531 columns with default values that you intend to be automatically
2532 supplied by the database (e.g. an auto_increment primary key column).
2533 In normal usage, the value of such columns should NOT be included at
2534 all in the call to C<find_or_new>, even when set to C<undef>.
2540 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2541 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2542 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2545 return $self->new_result($hash);
2552 =item Arguments: \%vals
2554 =item Return Value: a L<DBIx::Class::Row> $object
2558 Attempt to create a single new row or a row with multiple related rows
2559 in the table represented by the resultset (and related tables). This
2560 will not check for duplicate rows before inserting, use
2561 L</find_or_create> to do that.
2563 To create one row for this resultset, pass a hashref of key/value
2564 pairs representing the columns of the table and the values you wish to
2565 store. If the appropriate relationships are set up, foreign key fields
2566 can also be passed an object representing the foreign row, and the
2567 value will be set to its primary key.
2569 To create related objects, pass a hashref of related-object column values
2570 B<keyed on the relationship name>. If the relationship is of type C<multi>
2571 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2572 The process will correctly identify columns holding foreign keys, and will
2573 transparently populate them from the keys of the corresponding relation.
2574 This can be applied recursively, and will work correctly for a structure
2575 with an arbitrary depth and width, as long as the relationships actually
2576 exists and the correct column data has been supplied.
2579 Instead of hashrefs of plain related data (key/value pairs), you may
2580 also pass new or inserted objects. New objects (not inserted yet, see
2581 L</new>), will be inserted into their appropriate tables.
2583 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2585 Example of creating a new row.
2587 $person_rs->create({
2588 name=>"Some Person",
2589 email=>"somebody@someplace.com"
2592 Example of creating a new row and also creating rows in a related C<has_many>
2593 or C<has_one> resultset. Note Arrayref.
2596 { artistid => 4, name => 'Manufactured Crap', cds => [
2597 { title => 'My First CD', year => 2006 },
2598 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2603 Example of creating a new row and also creating a row in a related
2604 C<belongs_to> resultset. Note Hashref.
2607 title=>"Music for Silly Walks",
2610 name=>"Silly Musician",
2618 When subclassing ResultSet never attempt to override this method. Since
2619 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2620 lot of the internals simply never call it, so your override will be
2621 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2622 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2623 L</create> process you need to intervene.
2630 my ($self, $attrs) = @_;
2631 $self->throw_exception( "create needs a hashref" )
2632 unless ref $attrs eq 'HASH';
2633 return $self->new_result($attrs)->insert;
2636 =head2 find_or_create
2640 =item Arguments: \%vals, \%attrs?
2642 =item Return Value: $rowobject
2646 $cd->cd_to_producer->find_or_create({ producer => $producer },
2647 { key => 'primary' });
2649 Tries to find a record based on its primary key or unique constraints; if none
2650 is found, creates one and returns that instead.
2652 my $cd = $schema->resultset('CD')->find_or_create({
2654 artist => 'Massive Attack',
2655 title => 'Mezzanine',
2659 Also takes an optional C<key> attribute, to search by a specific key or unique
2660 constraint. For example:
2662 my $cd = $schema->resultset('CD')->find_or_create(
2664 artist => 'Massive Attack',
2665 title => 'Mezzanine',
2667 { key => 'cd_artist_title' }
2670 B<Note>: Make sure to read the documentation of L</find> and understand the
2671 significance of the C<key> attribute, as its lack may skew your search, and
2672 subsequently result in spurious row creation.
2674 B<Note>: Because find_or_create() reads from the database and then
2675 possibly inserts based on the result, this method is subject to a race
2676 condition. Another process could create a record in the table after
2677 the find has completed and before the create has started. To avoid
2678 this problem, use find_or_create() inside a transaction.
2680 B<Note>: Take care when using C<find_or_create> with a table having
2681 columns with default values that you intend to be automatically
2682 supplied by the database (e.g. an auto_increment primary key column).
2683 In normal usage, the value of such columns should NOT be included at
2684 all in the call to C<find_or_create>, even when set to C<undef>.
2686 See also L</find> and L</update_or_create>. For information on how to declare
2687 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2691 sub find_or_create {
2693 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2694 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2695 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2698 return $self->create($hash);
2701 =head2 update_or_create
2705 =item Arguments: \%col_values, { key => $unique_constraint }?
2707 =item Return Value: $row_object
2711 $resultset->update_or_create({ col => $val, ... });
2713 Like L</find_or_create>, but if a row is found it is immediately updated via
2714 C<< $found_row->update (\%col_values) >>.
2717 Takes an optional C<key> attribute to search on a specific unique constraint.
2720 # In your application
2721 my $cd = $schema->resultset('CD')->update_or_create(
2723 artist => 'Massive Attack',
2724 title => 'Mezzanine',
2727 { key => 'cd_artist_title' }
2730 $cd->cd_to_producer->update_or_create({
2731 producer => $producer,
2737 B<Note>: Make sure to read the documentation of L</find> and understand the
2738 significance of the C<key> attribute, as its lack may skew your search, and
2739 subsequently result in spurious row creation.
2741 B<Note>: Take care when using C<update_or_create> with a table having
2742 columns with default values that you intend to be automatically
2743 supplied by the database (e.g. an auto_increment primary key column).
2744 In normal usage, the value of such columns should NOT be included at
2745 all in the call to C<update_or_create>, even when set to C<undef>.
2747 See also L</find> and L</find_or_create>. For information on how to declare
2748 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2752 sub update_or_create {
2754 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2755 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2757 my $row = $self->find($cond, $attrs);
2759 $row->update($cond);
2763 return $self->create($cond);
2766 =head2 update_or_new
2770 =item Arguments: \%col_values, { key => $unique_constraint }?
2772 =item Return Value: $rowobject
2776 $resultset->update_or_new({ col => $val, ... });
2778 Like L</find_or_new> but if a row is found it is immediately updated via
2779 C<< $found_row->update (\%col_values) >>.
2783 # In your application
2784 my $cd = $schema->resultset('CD')->update_or_new(
2786 artist => 'Massive Attack',
2787 title => 'Mezzanine',
2790 { key => 'cd_artist_title' }
2793 if ($cd->in_storage) {
2794 # the cd was updated
2797 # the cd is not yet in the database, let's insert it
2801 B<Note>: Make sure to read the documentation of L</find> and understand the
2802 significance of the C<key> attribute, as its lack may skew your search, and
2803 subsequently result in spurious new objects.
2805 B<Note>: Take care when using C<update_or_new> with a table having
2806 columns with default values that you intend to be automatically
2807 supplied by the database (e.g. an auto_increment primary key column).
2808 In normal usage, the value of such columns should NOT be included at
2809 all in the call to C<update_or_new>, even when set to C<undef>.
2811 See also L</find>, L</find_or_create> and L</find_or_new>.
2817 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2818 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2820 my $row = $self->find( $cond, $attrs );
2821 if ( defined $row ) {
2822 $row->update($cond);
2826 return $self->new_result($cond);
2833 =item Arguments: none
2835 =item Return Value: \@cache_objects | undef
2839 Gets the contents of the cache for the resultset, if the cache is set.
2841 The cache is populated either by using the L</prefetch> attribute to
2842 L</search> or by calling L</set_cache>.
2854 =item Arguments: \@cache_objects
2856 =item Return Value: \@cache_objects
2860 Sets the contents of the cache for the resultset. Expects an arrayref
2861 of objects of the same class as those produced by the resultset. Note that
2862 if the cache is set the resultset will return the cached objects rather
2863 than re-querying the database even if the cache attr is not set.
2865 The contents of the cache can also be populated by using the
2866 L</prefetch> attribute to L</search>.
2871 my ( $self, $data ) = @_;
2872 $self->throw_exception("set_cache requires an arrayref")
2873 if defined($data) && (ref $data ne 'ARRAY');
2874 $self->{all_cache} = $data;
2881 =item Arguments: none
2883 =item Return Value: undef
2887 Clears the cache for the resultset.
2892 shift->set_cache(undef);
2899 =item Arguments: none
2901 =item Return Value: true, if the resultset has been paginated
2909 return !!$self->{attrs}{page};
2916 =item Arguments: none
2918 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2926 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2929 =head2 related_resultset
2933 =item Arguments: $relationship_name
2935 =item Return Value: $resultset
2939 Returns a related resultset for the supplied relationship name.
2941 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2945 sub related_resultset {
2946 my ($self, $rel) = @_;
2948 $self->{related_resultsets} ||= {};
2949 return $self->{related_resultsets}{$rel} ||= do {
2950 my $rsrc = $self->result_source;
2951 my $rel_info = $rsrc->relationship_info($rel);
2953 $self->throw_exception(
2954 "search_related: result source '" . $rsrc->source_name .
2955 "' has no such relationship $rel")
2958 my $attrs = $self->_chain_relationship($rel);
2960 my $join_count = $attrs->{seen_join}{$rel};
2962 my $alias = $self->result_source->storage
2963 ->relname_to_table_alias($rel, $join_count);
2965 # since this is search_related, and we already slid the select window inwards
2966 # (the select/as attrs were deleted in the beginning), we need to flip all
2967 # left joins to inner, so we get the expected results
2968 # read the comment on top of the actual function to see what this does
2969 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2972 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2973 delete @{$attrs}{qw(result_class alias)};
2977 if (my $cache = $self->get_cache) {
2978 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2979 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2984 my $rel_source = $rsrc->related_source($rel);
2988 # The reason we do this now instead of passing the alias to the
2989 # search_rs below is that if you wrap/overload resultset on the
2990 # source you need to know what alias it's -going- to have for things
2991 # to work sanely (e.g. RestrictWithObject wants to be able to add
2992 # extra query restrictions, and these may need to be $alias.)
2994 my $rel_attrs = $rel_source->resultset_attributes;
2995 local $rel_attrs->{alias} = $alias;
2997 $rel_source->resultset
3001 where => $attrs->{where},
3004 $new->set_cache($new_cache) if $new_cache;
3009 =head2 current_source_alias
3013 =item Arguments: none
3015 =item Return Value: $source_alias
3019 Returns the current table alias for the result source this resultset is built
3020 on, that will be used in the SQL query. Usually it is C<me>.
3022 Currently the source alias that refers to the result set returned by a
3023 L</search>/L</find> family method depends on how you got to the resultset: it's
3024 C<me> by default, but eg. L</search_related> aliases it to the related result
3025 source name (and keeps C<me> referring to the original result set). The long
3026 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3027 (and make this method unnecessary).
3029 Thus it's currently necessary to use this method in predefined queries (see
3030 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3031 source alias of the current result set:
3033 # in a result set class
3035 my ($self, $user) = @_;
3037 my $me = $self->current_source_alias;
3039 return $self->search(
3040 "$me.modified" => $user->id,
3046 sub current_source_alias {
3049 return ($self->{attrs} || {})->{alias} || 'me';
3052 =head2 as_subselect_rs
3056 =item Arguments: none
3058 =item Return Value: $resultset
3062 Act as a barrier to SQL symbols. The resultset provided will be made into a
3063 "virtual view" by including it as a subquery within the from clause. From this
3064 point on, any joined tables are inaccessible to ->search on the resultset (as if
3065 it were simply where-filtered without joins). For example:
3067 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3069 # 'x' now pollutes the query namespace
3071 # So the following works as expected
3072 my $ok_rs = $rs->search({'x.other' => 1});
3074 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3075 # def) we look for one row with contradictory terms and join in another table
3076 # (aliased 'x_2') which we never use
3077 my $broken_rs = $rs->search({'x.name' => 'def'});
3079 my $rs2 = $rs->as_subselect_rs;
3081 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3082 my $not_joined_rs = $rs2->search({'x.other' => 1});
3084 # works as expected: finds a 'table' row related to two x rows (abc and def)
3085 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3087 Another example of when one might use this would be to select a subset of
3088 columns in a group by clause:
3090 my $rs = $schema->resultset('Bar')->search(undef, {
3091 group_by => [qw{ id foo_id baz_id }],
3092 })->as_subselect_rs->search(undef, {
3093 columns => [qw{ id foo_id }]
3096 In the above example normally columns would have to be equal to the group by,
3097 but because we isolated the group by into a subselect the above works.
3101 sub as_subselect_rs {
3104 my $attrs = $self->_resolved_attrs;
3106 my $fresh_rs = (ref $self)->new (
3107 $self->result_source
3110 # these pieces will be locked in the subquery
3111 delete $fresh_rs->{cond};
3112 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3114 return $fresh_rs->search( {}, {
3116 $attrs->{alias} => $self->as_query,
3117 -alias => $attrs->{alias},
3118 -rsrc => $self->result_source,
3120 alias => $attrs->{alias},
3124 # This code is called by search_related, and makes sure there
3125 # is clear separation between the joins before, during, and
3126 # after the relationship. This information is needed later
3127 # in order to properly resolve prefetch aliases (any alias
3128 # with a relation_chain_depth less than the depth of the
3129 # current prefetch is not considered)
3131 # The increments happen twice per join. An even number means a
3132 # relationship specified via a search_related, whereas an odd
3133 # number indicates a join/prefetch added via attributes
3135 # Also this code will wrap the current resultset (the one we
3136 # chain to) in a subselect IFF it contains limiting attributes
3137 sub _chain_relationship {
3138 my ($self, $rel) = @_;
3139 my $source = $self->result_source;
3140 my $attrs = { %{$self->{attrs}||{}} };
3142 # we need to take the prefetch the attrs into account before we
3143 # ->_resolve_join as otherwise they get lost - captainL
3144 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3146 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3148 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3151 my @force_subq_attrs = qw/offset rows group_by having/;
3154 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3156 $self->_has_resolved_attr (@force_subq_attrs)
3158 # Nuke the prefetch (if any) before the new $rs attrs
3159 # are resolved (prefetch is useless - we are wrapping
3160 # a subquery anyway).
3161 my $rs_copy = $self->search;
3162 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3163 $rs_copy->{attrs}{join},
3164 delete $rs_copy->{attrs}{prefetch},
3169 -alias => $attrs->{alias},
3170 $attrs->{alias} => $rs_copy->as_query,
3172 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3173 $seen->{-relation_chain_depth} = 0;
3175 elsif ($attrs->{from}) { #shallow copy suffices
3176 $from = [ @{$attrs->{from}} ];
3181 -alias => $attrs->{alias},
3182 $attrs->{alias} => $source->from,
3186 my $jpath = ($seen->{-relation_chain_depth})
3187 ? $from->[-1][0]{-join_path}
3190 my @requested_joins = $source->_resolve_join(
3197 push @$from, @requested_joins;
3199 $seen->{-relation_chain_depth}++;
3201 # if $self already had a join/prefetch specified on it, the requested
3202 # $rel might very well be already included. What we do in this case
3203 # is effectively a no-op (except that we bump up the chain_depth on
3204 # the join in question so we could tell it *is* the search_related)
3207 # we consider the last one thus reverse
3208 for my $j (reverse @requested_joins) {
3209 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3210 if ($rel eq $last_j) {
3211 $j->[0]{-relation_chain_depth}++;
3217 unless ($already_joined) {
3218 push @$from, $source->_resolve_join(
3226 $seen->{-relation_chain_depth}++;
3228 return {%$attrs, from => $from, seen_join => $seen};
3231 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3232 sub _resolved_attrs_copy {
3234 return { %{$self->_resolved_attrs (@_)} };
3237 sub _resolved_attrs {
3239 return $self->{_attrs} if $self->{_attrs};
3241 my $attrs = { %{ $self->{attrs} || {} } };
3242 my $source = $self->result_source;
3243 my $alias = $attrs->{alias};
3245 # one last pass of normalization
3246 $self->_normalize_selection($attrs);
3248 # default selection list
3249 $attrs->{columns} = [ $source->columns ]
3250 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3252 # merge selectors together
3253 for (qw/columns select as _trailing_select/) {
3254 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3255 if $attrs->{$_} or $attrs->{"+$_"};
3258 # disassemble columns
3260 if (my $cols = delete $attrs->{columns}) {
3261 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3262 if (ref $c eq 'HASH') {
3263 for my $as (keys %$c) {
3264 push @sel, $c->{$as};
3275 # when trying to weed off duplicates later do not go past this point -
3276 # everything added from here on is unbalanced "anyone's guess" stuff
3277 my $dedup_stop_idx = $#as;
3279 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3281 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3282 if $attrs->{select};
3284 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3286 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3289 # disqualify all $alias.col as-bits (collapser mandated)
3291 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3294 # de-duplicate the result (remove *identical* select/as pairs)
3295 # and also die on duplicate {as} pointing to different {select}s
3296 # not using a c-style for as the condition is prone to shrinkage
3299 while ($i <= $dedup_stop_idx) {
3300 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3305 elsif ($seen->{$as[$i]}++) {
3306 $self->throw_exception(
3307 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3315 $attrs->{select} = \@sel;
3316 $attrs->{as} = \@as;
3318 $attrs->{from} ||= [{
3320 -alias => $self->{attrs}{alias},
3321 $self->{attrs}{alias} => $source->from,
3324 if ( $attrs->{join} || $attrs->{prefetch} ) {
3326 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3327 if ref $attrs->{from} ne 'ARRAY';
3329 my $join = (delete $attrs->{join}) || {};
3331 if ( defined $attrs->{prefetch} ) {
3332 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3335 $attrs->{from} = # have to copy here to avoid corrupting the original
3337 @{ $attrs->{from} },
3338 $source->_resolve_join(
3341 { %{ $attrs->{seen_join} || {} } },
3342 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3343 ? $attrs->{from}[-1][0]{-join_path}
3350 if ( defined $attrs->{order_by} ) {
3351 $attrs->{order_by} = (
3352 ref( $attrs->{order_by} ) eq 'ARRAY'
3353 ? [ @{ $attrs->{order_by} } ]
3354 : [ $attrs->{order_by} || () ]
3358 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3359 $attrs->{group_by} = [ $attrs->{group_by} ];
3362 # generate the distinct induced group_by early, as prefetch will be carried via a
3363 # subquery (since a group_by is present)
3364 if (delete $attrs->{distinct}) {
3365 if ($attrs->{group_by}) {
3366 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3369 # distinct affects only the main selection part, not what prefetch may
3370 # add below. However trailing is not yet a part of the selection as
3371 # prefetch must insert before it
3372 $attrs->{group_by} = $source->storage->_group_over_selection (
3374 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3380 $attrs->{collapse} ||= {};
3381 if ($attrs->{prefetch}) {
3382 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3384 my $prefetch_ordering = [];
3386 # this is a separate structure (we don't look in {from} directly)
3387 # as the resolver needs to shift things off the lists to work
3388 # properly (identical-prefetches on different branches)
3390 if (ref $attrs->{from} eq 'ARRAY') {
3392 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3394 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3395 next unless $j->[0]{-alias};
3396 next unless $j->[0]{-join_path};
3397 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3399 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3402 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3403 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3408 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3410 # we need to somehow mark which columns came from prefetch
3412 my $sel_end = $#{$attrs->{select}};
3413 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3416 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3417 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3419 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3420 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3424 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3425 if $attrs->{_trailing_select};
3427 # if both page and offset are specified, produce a combined offset
3428 # even though it doesn't make much sense, this is what pre 081xx has
3430 if (my $page = delete $attrs->{page}) {
3432 ($attrs->{rows} * ($page - 1))
3434 ($attrs->{offset} || 0)
3438 return $self->{_attrs} = $attrs;
3442 my ($self, $attr) = @_;
3444 if (ref $attr eq 'HASH') {
3445 return $self->_rollout_hash($attr);
3446 } elsif (ref $attr eq 'ARRAY') {
3447 return $self->_rollout_array($attr);
3453 sub _rollout_array {
3454 my ($self, $attr) = @_;
3457 foreach my $element (@{$attr}) {
3458 if (ref $element eq 'HASH') {
3459 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3460 } elsif (ref $element eq 'ARRAY') {
3461 # XXX - should probably recurse here
3462 push( @rolled_array, @{$self->_rollout_array($element)} );
3464 push( @rolled_array, $element );
3467 return \@rolled_array;
3471 my ($self, $attr) = @_;
3474 foreach my $key (keys %{$attr}) {
3475 push( @rolled_array, { $key => $attr->{$key} } );
3477 return \@rolled_array;
3480 sub _calculate_score {
3481 my ($self, $a, $b) = @_;
3483 if (defined $a xor defined $b) {
3486 elsif (not defined $a) {
3490 if (ref $b eq 'HASH') {
3491 my ($b_key) = keys %{$b};
3492 if (ref $a eq 'HASH') {
3493 my ($a_key) = keys %{$a};
3494 if ($a_key eq $b_key) {
3495 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3500 return ($a eq $b_key) ? 1 : 0;
3503 if (ref $a eq 'HASH') {
3504 my ($a_key) = keys %{$a};
3505 return ($b eq $a_key) ? 1 : 0;
3507 return ($b eq $a) ? 1 : 0;
3512 sub _merge_joinpref_attr {
3513 my ($self, $orig, $import) = @_;
3515 return $import unless defined($orig);
3516 return $orig unless defined($import);
3518 $orig = $self->_rollout_attr($orig);
3519 $import = $self->_rollout_attr($import);
3522 foreach my $import_element ( @{$import} ) {
3523 # find best candidate from $orig to merge $b_element into
3524 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3525 foreach my $orig_element ( @{$orig} ) {
3526 my $score = $self->_calculate_score( $orig_element, $import_element );
3527 if ($score > $best_candidate->{score}) {
3528 $best_candidate->{position} = $position;
3529 $best_candidate->{score} = $score;
3533 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3535 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3536 push( @{$orig}, $import_element );
3538 my $orig_best = $orig->[$best_candidate->{position}];
3539 # merge orig_best and b_element together and replace original with merged
3540 if (ref $orig_best ne 'HASH') {
3541 $orig->[$best_candidate->{position}] = $import_element;
3542 } elsif (ref $import_element eq 'HASH') {
3543 my ($key) = keys %{$orig_best};
3544 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3547 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3558 require Hash::Merge;
3559 my $hm = Hash::Merge->new;
3561 $hm->specify_behavior({
3564 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3566 if ($defl xor $defr) {
3567 return [ $defl ? $_[0] : $_[1] ];
3572 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3576 return [$_[0], $_[1]];
3580 return $_[1] if !defined $_[0];
3581 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3582 return [$_[0], @{$_[1]}]
3585 return [] if !defined $_[0] and !keys %{$_[1]};
3586 return [ $_[1] ] if !defined $_[0];
3587 return [ $_[0] ] if !keys %{$_[1]};
3588 return [$_[0], $_[1]]
3593 return $_[0] if !defined $_[1];
3594 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3595 return [@{$_[0]}, $_[1]]
3598 my @ret = @{$_[0]} or return $_[1];
3599 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3600 my %idx = map { $_ => 1 } @ret;
3601 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3605 return [ $_[1] ] if ! @{$_[0]};
3606 return $_[0] if !keys %{$_[1]};
3607 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3608 return [ @{$_[0]}, $_[1] ];
3613 return [] if !keys %{$_[0]} and !defined $_[1];
3614 return [ $_[0] ] if !defined $_[1];
3615 return [ $_[1] ] if !keys %{$_[0]};
3616 return [$_[0], $_[1]]
3619 return [] if !keys %{$_[0]} and !@{$_[1]};
3620 return [ $_[0] ] if !@{$_[1]};
3621 return $_[1] if !keys %{$_[0]};
3622 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3623 return [ $_[0], @{$_[1]} ];
3626 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3627 return [ $_[0] ] if !keys %{$_[1]};
3628 return [ $_[1] ] if !keys %{$_[0]};
3629 return [ $_[0] ] if $_[0] eq $_[1];
3630 return [ $_[0], $_[1] ];
3633 } => 'DBIC_RS_ATTR_MERGER');
3637 return $hm->merge ($_[1], $_[2]);
3641 sub STORABLE_freeze {
3642 my ($self, $cloning) = @_;
3643 my $to_serialize = { %$self };
3645 # A cursor in progress can't be serialized (and would make little sense anyway)
3646 delete $to_serialize->{cursor};
3648 Storable::nfreeze($to_serialize);
3651 # need this hook for symmetry
3653 my ($self, $cloning, $serialized) = @_;
3655 %$self = %{ Storable::thaw($serialized) };
3661 =head2 throw_exception
3663 See L<DBIx::Class::Schema/throw_exception> for details.
3667 sub throw_exception {
3670 if (ref $self and my $rsrc = $self->result_source) {
3671 $rsrc->throw_exception(@_)
3674 DBIx::Class::Exception->throw(@_);
3678 # XXX: FIXME: Attributes docs need clearing up
3682 Attributes are used to refine a ResultSet in various ways when
3683 searching for data. They can be passed to any method which takes an
3684 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3687 These are in no particular order:
3693 =item Value: ( $order_by | \@order_by | \%order_by )
3697 Which column(s) to order the results by.
3699 [The full list of suitable values is documented in
3700 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3703 If a single column name, or an arrayref of names is supplied, the
3704 argument is passed through directly to SQL. The hashref syntax allows
3705 for connection-agnostic specification of ordering direction:
3707 For descending order:
3709 order_by => { -desc => [qw/col1 col2 col3/] }
3711 For explicit ascending order:
3713 order_by => { -asc => 'col' }
3715 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3716 supported, although you are strongly encouraged to use the hashref
3717 syntax as outlined above.
3723 =item Value: \@columns
3727 Shortcut to request a particular set of columns to be retrieved. Each
3728 column spec may be a string (a table column name), or a hash (in which
3729 case the key is the C<as> value, and the value is used as the C<select>
3730 expression). Adds C<me.> onto the start of any column without a C<.> in
3731 it and sets C<select> from that, then auto-populates C<as> from
3732 C<select> as normal. (You may also use the C<cols> attribute, as in
3733 earlier versions of DBIC.)
3735 Essentially C<columns> does the same as L</select> and L</as>.
3737 columns => [ 'foo', { bar => 'baz' } ]
3741 select => [qw/foo baz/],
3748 =item Value: \@columns
3752 Indicates additional columns to be selected from storage. Works the same
3753 as L</columns> but adds columns to the selection. (You may also use the
3754 C<include_columns> attribute, as in earlier versions of DBIC). For
3757 $schema->resultset('CD')->search(undef, {
3758 '+columns' => ['artist.name'],
3762 would return all CDs and include a 'name' column to the information
3763 passed to object inflation. Note that the 'artist' is the name of the
3764 column (or relationship) accessor, and 'name' is the name of the column
3765 accessor in the related table.
3767 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3768 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3769 unary plus operator before it.
3771 =head2 include_columns
3775 =item Value: \@columns
3779 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3785 =item Value: \@select_columns
3789 Indicates which columns should be selected from the storage. You can use
3790 column names, or in the case of RDBMS back ends, function or stored procedure
3793 $rs = $schema->resultset('Employee')->search(undef, {
3796 { count => 'employeeid' },
3797 { max => { length => 'name' }, -as => 'longest_name' }
3802 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3804 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3805 use L</select>, to instruct DBIx::Class how to store the result of the column.
3806 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3807 identifier aliasing. You can however alias a function, so you can use it in
3808 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3809 attribute> supplied as shown in the example above.
3811 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3812 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3813 unary plus operator before it.
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