1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use DBIx::Class::Exception;
9 use DBIx::Class::ResultSetColumn;
10 use DBIx::Class::ResultSourceHandle;
12 use Scalar::Util qw/blessed weaken/;
14 use Storable qw/nfreeze thaw/;
16 # not importing first() as it will clash with our own method
23 # De-duplication in _merge_attr() is disabled, but left in for reference
24 # (the merger is used for other things that ought not to be de-duped)
25 *__HM_DEDUP = sub () { 0 };
33 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
37 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
41 my $users_rs = $schema->resultset('User');
42 while( $user = $users_rs->next) {
43 print $user->username;
46 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
47 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
51 A ResultSet is an object which stores a set of conditions representing
52 a query. It is the backbone of DBIx::Class (i.e. the really
53 important/useful bit).
55 No SQL is executed on the database when a ResultSet is created, it
56 just stores all the conditions needed to create the query.
58 A basic ResultSet representing the data of an entire table is returned
59 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
60 L<Source|DBIx::Class::Manual::Glossary/Source> name.
62 my $users_rs = $schema->resultset('User');
64 A new ResultSet is returned from calling L</search> on an existing
65 ResultSet. The new one will contain all the conditions of the
66 original, plus any new conditions added in the C<search> call.
68 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
69 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
72 The query that the ResultSet represents is B<only> executed against
73 the database when these methods are called:
74 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
76 If a resultset is used in a numeric context it returns the L</count>.
77 However, if it is used in a boolean context it is B<always> true. So if
78 you want to check if a resultset has any results, you must use C<if $rs
83 =head2 Chaining resultsets
85 Let's say you've got a query that needs to be run to return some data
86 to the user. But, you have an authorization system in place that
87 prevents certain users from seeing certain information. So, you want
88 to construct the basic query in one method, but add constraints to it in
93 my $request = $self->get_request; # Get a request object somehow.
94 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
96 my $cd_rs = $schema->resultset('CD')->search({
97 title => $request->param('title'),
98 year => $request->param('year'),
101 $self->apply_security_policy( $cd_rs );
103 return $cd_rs->all();
106 sub apply_security_policy {
115 =head3 Resolving conditions and attributes
117 When a resultset is chained from another resultset, conditions and
118 attributes with the same keys need resolving.
120 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
121 into the existing ones from the original resultset.
123 The L</where> and L</having> attributes, and any search conditions, are
124 merged with an SQL C<AND> to the existing condition from the original
127 All other attributes are overridden by any new ones supplied in the
130 =head2 Multiple queries
132 Since a resultset just defines a query, you can do all sorts of
133 things with it with the same object.
135 # Don't hit the DB yet.
136 my $cd_rs = $schema->resultset('CD')->search({
137 title => 'something',
141 # Each of these hits the DB individually.
142 my $count = $cd_rs->count;
143 my $most_recent = $cd_rs->get_column('date_released')->max();
144 my @records = $cd_rs->all;
146 And it's not just limited to SELECT statements.
152 $cd_rs->create({ artist => 'Fred' });
154 Which is the same as:
156 $schema->resultset('CD')->create({
157 title => 'something',
162 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
170 =item Arguments: $source, \%$attrs
172 =item Return Value: $rs
176 The resultset constructor. Takes a source object (usually a
177 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
178 L</ATTRIBUTES> below). Does not perform any queries -- these are
179 executed as needed by the other methods.
181 Generally you won't need to construct a resultset manually. You'll
182 automatically get one from e.g. a L</search> called in scalar context:
184 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
186 IMPORTANT: If called on an object, proxies to new_result instead so
188 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
190 will return a CD object, not a ResultSet.
196 return $class->new_result(@_) if ref $class;
198 my ($source, $attrs) = @_;
199 $source = $source->resolve
200 if $source->isa('DBIx::Class::ResultSourceHandle');
201 $attrs = { %{$attrs||{}} };
203 if ($attrs->{page}) {
204 $attrs->{rows} ||= 10;
207 $attrs->{alias} ||= 'me';
210 result_source => $source,
211 cond => $attrs->{where},
217 $attrs->{result_class} || $source->result_class
227 =item Arguments: $cond, \%attrs?
229 =item Return Value: $resultset (scalar context), @row_objs (list context)
233 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
234 my $new_rs = $cd_rs->search({ year => 2005 });
236 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
237 # year = 2005 OR year = 2004
239 If you need to pass in additional attributes but no additional condition,
240 call it as C<search(undef, \%attrs)>.
242 # "SELECT name, artistid FROM $artist_table"
243 my @all_artists = $schema->resultset('Artist')->search(undef, {
244 columns => [qw/name artistid/],
247 For a list of attributes that can be passed to C<search>, see
248 L</ATTRIBUTES>. For more examples of using this function, see
249 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
250 documentation for the first argument, see L<SQL::Abstract>.
252 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
256 Note that L</search> does not process/deflate any of the values passed in the
257 L<SQL::Abstract>-compatible search condition structure. This is unlike other
258 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
259 manually that any value passed to this method will stringify to something the
260 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
261 objects, for more info see:
262 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
268 my $rs = $self->search_rs( @_ );
273 elsif (defined wantarray) {
277 # we can be called by a relationship helper, which in
278 # turn may be called in void context due to some braindead
279 # overload or whatever else the user decided to be clever
280 # at this particular day. Thus limit the exception to
281 # external code calls only
282 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
283 if (caller)[0] !~ /^\QDBIx::Class::/;
293 =item Arguments: $cond, \%attrs?
295 =item Return Value: $resultset
299 This method does the same exact thing as search() except it will
300 always return a resultset, even in list context.
304 my $callsites_warned;
308 # Special-case handling for (undef, undef).
309 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
315 if (ref $_[-1] eq 'HASH') {
316 # copy for _normalize_selection
317 $call_attrs = { %{ pop @_ } };
319 elsif (! defined $_[-1] ) {
320 pop @_; # search({}, undef)
324 # see if we can keep the cache (no $rs changes)
326 my %safe = (alias => 1, cache => 1);
327 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
330 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
332 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
334 $cache = $self->get_cache;
337 my $rsrc = $self->result_source;
339 my $old_attrs = { %{$self->{attrs}} };
340 my $old_having = delete $old_attrs->{having};
341 my $old_where = delete $old_attrs->{where};
343 my $new_attrs = { %$old_attrs };
345 # take care of call attrs (only if anything is changing)
346 if (keys %$call_attrs) {
348 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
349 if ( exists $call_attrs->{_trailing_select} or exists $call_attrs->{'+_trailing_select'} );
351 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns _trailing_select +_trailing_select/;
353 # Normalize the selector list (operates on the passed-in attr structure)
354 # Need to do it on every chain instead of only once on _resolved_attrs, in
355 # order to separate 'as'-ed from blind 'select's
356 $self->_normalize_selection ($call_attrs);
358 # start with blind overwriting merge, exclude selector attrs
359 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
360 delete @{$new_attrs}{@selector_attrs};
362 # reset the current selector list if new selectors are supplied
363 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
364 delete @{$old_attrs}{@selector_attrs};
367 for (@selector_attrs) {
368 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
369 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
372 # older deprecated name, use only if {columns} is not there
373 if (my $c = delete $new_attrs->{cols}) {
374 if ($new_attrs->{columns}) {
375 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
378 $new_attrs->{columns} = $c;
383 # join/prefetch use their own crazy merging heuristics
384 foreach my $key (qw/join prefetch/) {
385 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
386 if exists $call_attrs->{$key};
389 # stack binds together
390 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
394 # rip apart the rest of @_, parse a condition
397 if (ref $_[0] eq 'HASH') {
398 (keys %{$_[0]}) ? $_[0] : undef
404 $self->throw_exception('Odd number of arguments to search')
412 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
413 # determine callsite obeying Carp::Clan rules (fucking ugly but don't have better ideas)
416 local $SIG{__WARN__} = sub { $w = shift };
420 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
421 unless $callsites_warned->{$callsite}++;
424 for ($old_where, $call_cond) {
426 $new_attrs->{where} = $self->_stack_cond (
427 $_, $new_attrs->{where}
432 if (defined $old_having) {
433 $new_attrs->{having} = $self->_stack_cond (
434 $old_having, $new_attrs->{having}
438 my $rs = (ref $self)->new($rsrc, $new_attrs);
440 $rs->set_cache($cache) if ($cache);
445 sub _normalize_selection {
446 my ($self, $attrs) = @_;
449 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
450 if exists $attrs->{include_columns};
452 # Keep the X vs +X separation until _resolved_attrs time - this allows to
453 # delay the decision on whether to use a default select list ($rsrc->columns)
454 # allowing stuff like the remove_columns helper to work
456 # select/as +select/+as pairs need special handling - the amount of select/as
457 # elements in each pair does *not* have to be equal (think multicolumn
458 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
459 # supplied at all) - try to infer the alias, either from the -as parameter
460 # of the selector spec, or use the parameter whole if it looks like a column
461 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
462 # is ok as well), but transport it over a separate attribute to make sure it is
463 # the last thing in the select list, thus unable to throw off the corresponding
465 for my $pref ('', '+') {
467 my ($sel, $as) = map {
468 my $key = "${pref}${_}";
470 my $val = [ ref $attrs->{$key} eq 'ARRAY'
472 : $attrs->{$key} || ()
474 delete $attrs->{$key};
478 if (! @$as and ! @$sel ) {
481 elsif (@$as and ! @$sel) {
482 $self->throw_exception(
483 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
487 # no as part supplied at all - try to deduce
488 # if any @$as has been supplied we assume the user knows what (s)he is doing
489 # and blindly keep stacking up pieces
490 my (@new_sel, @new_trailing);
492 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
493 push @$as, $_->{-as};
496 # assume any plain no-space, no-parenthesis string to be a column spec
497 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
498 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
502 # if all else fails - shove the selection to the trailing stack and move on
504 push @new_trailing, $_;
509 $attrs->{"${pref}_trailing_select"} = $self->_merge_attr($attrs->{"${pref}_trailing_select"}, \@new_trailing)
512 elsif (@$as < @$sel) {
513 $self->throw_exception(
514 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
518 # now see what the result for this pair looks like:
521 # if balanced - treat as a columns entry
522 $attrs->{"${pref}columns"} = $self->_merge_attr(
523 $attrs->{"${pref}columns"},
524 [ map { +{ $as->[$_] => $sel->[$_] } } ( 0 .. $#$as ) ]
528 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
529 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
530 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
537 my ($self, $left, $right) = @_;
538 if (defined $left xor defined $right) {
539 return defined $left ? $left : $right;
541 elsif (defined $left) {
542 return { -and => [ map
543 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
551 =head2 search_literal
555 =item Arguments: $sql_fragment, @bind_values
557 =item Return Value: $resultset (scalar context), @row_objs (list context)
561 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
562 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
564 Pass a literal chunk of SQL to be added to the conditional part of the
567 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
568 only be used in that context. C<search_literal> is a convenience method.
569 It is equivalent to calling $schema->search(\[]), but if you want to ensure
570 columns are bound correctly, use C<search>.
572 Example of how to use C<search> instead of C<search_literal>
574 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
575 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
578 See L<DBIx::Class::Manual::Cookbook/Searching> and
579 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
580 require C<search_literal>.
585 my ($self, $sql, @bind) = @_;
587 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
590 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
597 =item Arguments: \%columns_values | @pk_values, \%attrs?
599 =item Return Value: $row_object | undef
603 Finds and returns a single row based on supplied criteria. Takes either a
604 hashref with the same format as L</create> (including inference of foreign
605 keys from related objects), or a list of primary key values in the same
606 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
607 declaration on the L</result_source>.
609 In either case an attempt is made to combine conditions already existing on
610 the resultset with the condition passed to this method.
612 To aid with preparing the correct query for the storage you may supply the
613 C<key> attribute, which is the name of a
614 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
615 unique constraint corresponding to the
616 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
617 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
618 to construct a query that satisfies the named unique constraint fully (
619 non-NULL values for each column member of the constraint) an exception is
622 If no C<key> is specified, the search is carried over all unique constraints
623 which are fully defined by the available condition.
625 If no such constraint is found, C<find> currently defaults to a simple
626 C<< search->(\%column_values) >> which may or may not do what you expect.
627 Note that this fallback behavior may be deprecated in further versions. If
628 you need to search with arbitrary conditions - use L</search>. If the query
629 resulting from this fallback produces more than one row, a warning to the
630 effect is issued, though only the first row is constructed and returned as
633 In addition to C<key>, L</find> recognizes and applies standard
634 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
636 Note that if you have extra concerns about the correctness of the resulting
637 query you need to specify the C<key> attribute and supply the entire condition
638 as an argument to find (since it is not always possible to perform the
639 combination of the resultset condition with the supplied one, especially if
640 the resultset condition contains literal sql).
642 For example, to find a row by its primary key:
644 my $cd = $schema->resultset('CD')->find(5);
646 You can also find a row by a specific unique constraint:
648 my $cd = $schema->resultset('CD')->find(
650 artist => 'Massive Attack',
651 title => 'Mezzanine',
653 { key => 'cd_artist_title' }
656 See also L</find_or_create> and L</update_or_create>.
662 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
664 my $rsrc = $self->result_source;
666 # Parse out the condition from input
668 if (ref $_[0] eq 'HASH') {
669 $call_cond = { %{$_[0]} };
672 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
673 my @c_cols = $rsrc->unique_constraint_columns($constraint);
675 $self->throw_exception(
676 "No constraint columns, maybe a malformed '$constraint' constraint?"
679 $self->throw_exception (
680 'find() expects either a column/value hashref, or a list of values '
681 . "corresponding to the columns of the specified unique constraint '$constraint'"
682 ) unless @c_cols == @_;
685 @{$call_cond}{@c_cols} = @_;
689 for my $key (keys %$call_cond) {
691 my $keyref = ref($call_cond->{$key})
693 my $relinfo = $rsrc->relationship_info($key)
695 my $val = delete $call_cond->{$key};
697 next if $keyref eq 'ARRAY'; # has_many for multi_create
699 my $rel_q = $rsrc->_resolve_condition(
700 $relinfo->{cond}, $val, $key
702 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
703 @related{keys %$rel_q} = values %$rel_q;
707 # relationship conditions take precedence (?)
708 @{$call_cond}{keys %related} = values %related;
710 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
712 if (exists $attrs->{key}) {
713 $final_cond = $self->_qualify_cond_columns (
715 $self->_build_unique_cond (
723 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
724 # This means that we got here after a merger of relationship conditions
725 # in ::Relationship::Base::search_related (the row method), and furthermore
726 # the relationship is of the 'single' type. This means that the condition
727 # provided by the relationship (already attached to $self) is sufficient,
728 # as there can be only one row in the database that would satisfy the
732 # no key was specified - fall down to heuristics mode:
733 # run through all unique queries registered on the resultset, and
734 # 'OR' all qualifying queries together
735 my (@unique_queries, %seen_column_combinations);
736 for my $c_name ($rsrc->unique_constraint_names) {
737 next if $seen_column_combinations{
738 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
741 push @unique_queries, try {
742 $self->_build_unique_cond ($c_name, $call_cond)
746 $final_cond = @unique_queries
747 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
748 : $self->_non_unique_find_fallback ($call_cond, $attrs)
752 # Run the query, passing the result_class since it should propagate for find
753 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
754 if (keys %{$rs->_resolved_attrs->{collapse}}) {
756 carp "Query returned more than one row" if $rs->next;
764 # This is a stop-gap method as agreed during the discussion on find() cleanup:
765 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
767 # It is invoked when find() is called in legacy-mode with insufficiently-unique
768 # condition. It is provided for overrides until a saner way forward is devised
770 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
771 # the road. Please adjust your tests accordingly to catch this situation early
772 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
774 # The method will not be removed without an adequately complete replacement
775 # for strict-mode enforcement
776 sub _non_unique_find_fallback {
777 my ($self, $cond, $attrs) = @_;
779 return $self->_qualify_cond_columns(
781 exists $attrs->{alias}
783 : $self->{attrs}{alias}
788 sub _qualify_cond_columns {
789 my ($self, $cond, $alias) = @_;
791 my %aliased = %$cond;
792 for (keys %aliased) {
793 $aliased{"$alias.$_"} = delete $aliased{$_}
800 sub _build_unique_cond {
801 my ($self, $constraint_name, $extra_cond) = @_;
803 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
805 # combination may fail if $self->{cond} is non-trivial
806 my ($final_cond) = try {
807 $self->_merge_with_rscond ($extra_cond)
812 # trim out everything not in $columns
813 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
815 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
816 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
818 join (', ', map { "'$_'" } @missing),
825 =head2 search_related
829 =item Arguments: $rel, $cond, \%attrs?
831 =item Return Value: $new_resultset
835 $new_rs = $cd_rs->search_related('artist', {
839 Searches the specified relationship, optionally specifying a condition and
840 attributes for matching records. See L</ATTRIBUTES> for more information.
845 return shift->related_resultset(shift)->search(@_);
848 =head2 search_related_rs
850 This method works exactly the same as search_related, except that
851 it guarantees a resultset, even in list context.
855 sub search_related_rs {
856 return shift->related_resultset(shift)->search_rs(@_);
863 =item Arguments: none
865 =item Return Value: $cursor
869 Returns a storage-driven cursor to the given resultset. See
870 L<DBIx::Class::Cursor> for more information.
877 my $attrs = $self->_resolved_attrs_copy;
879 return $self->{cursor}
880 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
881 $attrs->{where},$attrs);
888 =item Arguments: $cond?
890 =item Return Value: $row_object | undef
894 my $cd = $schema->resultset('CD')->single({ year => 2001 });
896 Inflates the first result without creating a cursor if the resultset has
897 any records in it; if not returns C<undef>. Used by L</find> as a lean version
900 While this method can take an optional search condition (just like L</search>)
901 being a fast-code-path it does not recognize search attributes. If you need to
902 add extra joins or similar, call L</search> and then chain-call L</single> on the
903 L<DBIx::Class::ResultSet> returned.
909 As of 0.08100, this method enforces the assumption that the preceding
910 query returns only one row. If more than one row is returned, you will receive
913 Query returned more than one row
915 In this case, you should be using L</next> or L</find> instead, or if you really
916 know what you are doing, use the L</rows> attribute to explicitly limit the size
919 This method will also throw an exception if it is called on a resultset prefetching
920 has_many, as such a prefetch implies fetching multiple rows from the database in
921 order to assemble the resulting object.
928 my ($self, $where) = @_;
930 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
933 my $attrs = $self->_resolved_attrs_copy;
935 if (keys %{$attrs->{collapse}}) {
936 $self->throw_exception(
937 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
942 if (defined $attrs->{where}) {
945 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
946 $where, delete $attrs->{where} ]
949 $attrs->{where} = $where;
953 my @data = $self->result_source->storage->select_single(
954 $attrs->{from}, $attrs->{select},
955 $attrs->{where}, $attrs
958 return (@data ? ($self->_construct_object(@data))[0] : undef);
964 # Recursively collapse the query, accumulating values for each column.
966 sub _collapse_query {
967 my ($self, $query, $collapsed) = @_;
971 if (ref $query eq 'ARRAY') {
972 foreach my $subquery (@$query) {
973 next unless ref $subquery; # -or
974 $collapsed = $self->_collapse_query($subquery, $collapsed);
977 elsif (ref $query eq 'HASH') {
978 if (keys %$query and (keys %$query)[0] eq '-and') {
979 foreach my $subquery (@{$query->{-and}}) {
980 $collapsed = $self->_collapse_query($subquery, $collapsed);
984 foreach my $col (keys %$query) {
985 my $value = $query->{$col};
986 $collapsed->{$col}{$value}++;
998 =item Arguments: $cond?
1000 =item Return Value: $resultsetcolumn
1004 my $max_length = $rs->get_column('length')->max;
1006 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1011 my ($self, $column) = @_;
1012 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1020 =item Arguments: $cond, \%attrs?
1022 =item Return Value: $resultset (scalar context), @row_objs (list context)
1026 # WHERE title LIKE '%blue%'
1027 $cd_rs = $rs->search_like({ title => '%blue%'});
1029 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1030 that this is simply a convenience method retained for ex Class::DBI users.
1031 You most likely want to use L</search> with specific operators.
1033 For more information, see L<DBIx::Class::Manual::Cookbook>.
1035 This method is deprecated and will be removed in 0.09. Use L</search()>
1036 instead. An example conversion is:
1038 ->search_like({ foo => 'bar' });
1042 ->search({ foo => { like => 'bar' } });
1049 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1050 .' Instead use ->search({ x => { -like => "y%" } })'
1051 .' (note the outer pair of {}s - they are important!)'
1053 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1054 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1055 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1056 return $class->search($query, { %$attrs });
1063 =item Arguments: $first, $last
1065 =item Return Value: $resultset (scalar context), @row_objs (list context)
1069 Returns a resultset or object list representing a subset of elements from the
1070 resultset slice is called on. Indexes are from 0, i.e., to get the first
1071 three records, call:
1073 my ($one, $two, $three) = $rs->slice(0, 2);
1078 my ($self, $min, $max) = @_;
1079 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1080 $attrs->{offset} = $self->{attrs}{offset} || 0;
1081 $attrs->{offset} += $min;
1082 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1083 return $self->search(undef, $attrs);
1084 #my $slice = (ref $self)->new($self->result_source, $attrs);
1085 #return (wantarray ? $slice->all : $slice);
1092 =item Arguments: none
1094 =item Return Value: $result | undef
1098 Returns the next element in the resultset (C<undef> is there is none).
1100 Can be used to efficiently iterate over records in the resultset:
1102 my $rs = $schema->resultset('CD')->search;
1103 while (my $cd = $rs->next) {
1107 Note that you need to store the resultset object, and call C<next> on it.
1108 Calling C<< resultset('Table')->next >> repeatedly will always return the
1109 first record from the resultset.
1115 if (my $cache = $self->get_cache) {
1116 $self->{all_cache_position} ||= 0;
1117 return $cache->[$self->{all_cache_position}++];
1119 if ($self->{attrs}{cache}) {
1120 delete $self->{pager};
1121 $self->{all_cache_position} = 1;
1122 return ($self->all)[0];
1124 if ($self->{stashed_objects}) {
1125 my $obj = shift(@{$self->{stashed_objects}});
1126 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1130 exists $self->{stashed_row}
1131 ? @{delete $self->{stashed_row}}
1132 : $self->cursor->next
1134 return undef unless (@row);
1135 my ($row, @more) = $self->_construct_object(@row);
1136 $self->{stashed_objects} = \@more if @more;
1140 sub _construct_object {
1141 my ($self, @row) = @_;
1143 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1145 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1146 @new = $self->{_attrs}{record_filter}->(@new)
1147 if exists $self->{_attrs}{record_filter};
1151 sub _collapse_result {
1152 my ($self, $as_proto, $row) = @_;
1156 # 'foo' => [ undef, 'foo' ]
1157 # 'foo.bar' => [ 'foo', 'bar' ]
1158 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1160 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1162 my %collapse = %{$self->{_attrs}{collapse}||{}};
1166 # if we're doing collapsing (has_many prefetch) we need to grab records
1167 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1168 # we know we don't have to bother.
1170 # the reason for not using the collapse stuff directly is because if you
1171 # had for e.g. two artists in a row with no cds, the collapse info for
1172 # both would be NULL (undef) so you'd lose the second artist
1174 # store just the index so we can check the array positions from the row
1175 # without having to contruct the full hash
1177 if (keys %collapse) {
1178 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1179 foreach my $i (0 .. $#construct_as) {
1180 next if defined($construct_as[$i][0]); # only self table
1181 if (delete $pri{$construct_as[$i][1]}) {
1182 push(@pri_index, $i);
1184 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1188 # no need to do an if, it'll be empty if @pri_index is empty anyway
1190 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1194 do { # no need to check anything at the front, we always want the first row
1198 foreach my $this_as (@construct_as) {
1199 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1202 push(@const_rows, \%const);
1204 } until ( # no pri_index => no collapse => drop straight out
1207 do { # get another row, stash it, drop out if different PK
1209 @copy = $self->cursor->next;
1210 $self->{stashed_row} = \@copy;
1212 # last thing in do block, counts as true if anything doesn't match
1214 # check xor defined first for NULL vs. NOT NULL then if one is
1215 # defined the other must be so check string equality
1218 (defined $pri_vals{$_} ^ defined $copy[$_])
1219 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1224 my $alias = $self->{attrs}{alias};
1231 foreach my $const (@const_rows) {
1232 scalar @const_keys or do {
1233 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1235 foreach my $key (@const_keys) {
1238 my @parts = split(/\./, $key);
1240 my $data = $const->{$key};
1241 foreach my $p (@parts) {
1242 $target = $target->[1]->{$p} ||= [];
1244 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1245 # collapsing at this point and on final part
1246 my $pos = $collapse_pos{$cur};
1247 CK: foreach my $ck (@ckey) {
1248 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1249 $collapse_pos{$cur} = $data;
1250 delete @collapse_pos{ # clear all positioning for sub-entries
1251 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1258 if (exists $collapse{$cur}) {
1259 $target = $target->[-1];
1262 $target->[0] = $data;
1264 $info->[0] = $const->{$key};
1272 =head2 result_source
1276 =item Arguments: $result_source?
1278 =item Return Value: $result_source
1282 An accessor for the primary ResultSource object from which this ResultSet
1289 =item Arguments: $result_class?
1291 =item Return Value: $result_class
1295 An accessor for the class to use when creating row objects. Defaults to
1296 C<< result_source->result_class >> - which in most cases is the name of the
1297 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1299 Note that changing the result_class will also remove any components
1300 that were originally loaded in the source class via
1301 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1302 in the original source class will not run.
1307 my ($self, $result_class) = @_;
1308 if ($result_class) {
1309 unless (ref $result_class) { # don't fire this for an object
1310 $self->ensure_class_loaded($result_class);
1312 $self->_result_class($result_class);
1313 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1314 # permit the user to set result class on one result set only; it only
1315 # chains if provided to search()
1316 #$self->{attrs}{result_class} = $result_class if ref $self;
1318 $self->_result_class;
1325 =item Arguments: $cond, \%attrs??
1327 =item Return Value: $count
1331 Performs an SQL C<COUNT> with the same query as the resultset was built
1332 with to find the number of elements. Passing arguments is equivalent to
1333 C<< $rs->search ($cond, \%attrs)->count >>
1339 return $self->search(@_)->count if @_ and defined $_[0];
1340 return scalar @{ $self->get_cache } if $self->get_cache;
1342 my $attrs = $self->_resolved_attrs_copy;
1344 # this is a little optimization - it is faster to do the limit
1345 # adjustments in software, instead of a subquery
1346 my $rows = delete $attrs->{rows};
1347 my $offset = delete $attrs->{offset};
1350 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1351 $crs = $self->_count_subq_rs ($attrs);
1354 $crs = $self->_count_rs ($attrs);
1356 my $count = $crs->next;
1358 $count -= $offset if $offset;
1359 $count = $rows if $rows and $rows < $count;
1360 $count = 0 if ($count < 0);
1369 =item Arguments: $cond, \%attrs??
1371 =item Return Value: $count_rs
1375 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1376 This can be very handy for subqueries:
1378 ->search( { amount => $some_rs->count_rs->as_query } )
1380 As with regular resultsets the SQL query will be executed only after
1381 the resultset is accessed via L</next> or L</all>. That would return
1382 the same single value obtainable via L</count>.
1388 return $self->search(@_)->count_rs if @_;
1390 # this may look like a lack of abstraction (count() does about the same)
1391 # but in fact an _rs *must* use a subquery for the limits, as the
1392 # software based limiting can not be ported if this $rs is to be used
1393 # in a subquery itself (i.e. ->as_query)
1394 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1395 return $self->_count_subq_rs;
1398 return $self->_count_rs;
1403 # returns a ResultSetColumn object tied to the count query
1406 my ($self, $attrs) = @_;
1408 my $rsrc = $self->result_source;
1409 $attrs ||= $self->_resolved_attrs;
1411 my $tmp_attrs = { %$attrs };
1412 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1413 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1415 # overwrite the selector (supplied by the storage)
1416 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1417 $tmp_attrs->{as} = 'count';
1418 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1420 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1426 # same as above but uses a subquery
1428 sub _count_subq_rs {
1429 my ($self, $attrs) = @_;
1431 my $rsrc = $self->result_source;
1432 $attrs ||= $self->_resolved_attrs;
1434 my $sub_attrs = { %$attrs };
1435 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1436 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1438 # if we multi-prefetch we group_by primary keys only as this is what we would
1439 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1440 if ( keys %{$attrs->{collapse}} ) {
1441 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1444 # Calculate subquery selector
1445 if (my $g = $sub_attrs->{group_by}) {
1447 my $sql_maker = $rsrc->storage->sql_maker;
1449 # necessary as the group_by may refer to aliased functions
1451 for my $sel (@{$attrs->{select}}) {
1452 $sel_index->{$sel->{-as}} = $sel
1453 if (ref $sel eq 'HASH' and $sel->{-as});
1456 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1457 # also look for named aggregates referred in the having clause
1458 # having often contains scalarrefs - thus parse it out entirely
1460 if ($attrs->{having}) {
1461 local $sql_maker->{having_bind};
1462 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1463 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1464 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1465 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1466 # if we don't unset it we screw up retarded but unfortunately working
1467 # 'MAX(foo.bar)' => { '>', 3 }
1468 $sql_maker->{name_sep} = '';
1471 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1473 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1475 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1476 # and if all fails for an utterly naive quoted scalar-with-function
1478 $rquote $sep $lquote (.+?) $rquote
1480 [\s,] \w+ \. (\w+) [\s,]
1482 [\s,] $lquote (.+?) $rquote [\s,]
1484 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1489 my $colpiece = $sel_index->{$_} || $_;
1491 # unqualify join-based group_by's. Arcane but possible query
1492 # also horrible horrible hack to alias a column (not a func.)
1493 # (probably need to introduce SQLA syntax)
1494 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1497 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1499 push @{$sub_attrs->{select}}, $colpiece;
1503 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1504 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1507 return $rsrc->resultset_class
1508 ->new ($rsrc, $sub_attrs)
1510 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1511 ->get_column ('count');
1518 =head2 count_literal
1522 =item Arguments: $sql_fragment, @bind_values
1524 =item Return Value: $count
1528 Counts the results in a literal query. Equivalent to calling L</search_literal>
1529 with the passed arguments, then L</count>.
1533 sub count_literal { shift->search_literal(@_)->count; }
1539 =item Arguments: none
1541 =item Return Value: @objects
1545 Returns all elements in the resultset. Called implicitly if the resultset
1546 is returned in list context.
1553 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1556 return @{ $self->get_cache } if $self->get_cache;
1560 if (keys %{$self->_resolved_attrs->{collapse}}) {
1561 # Using $self->cursor->all is really just an optimisation.
1562 # If we're collapsing has_many prefetches it probably makes
1563 # very little difference, and this is cleaner than hacking
1564 # _construct_object to survive the approach
1565 $self->cursor->reset;
1566 my @row = $self->cursor->next;
1568 push(@obj, $self->_construct_object(@row));
1569 @row = (exists $self->{stashed_row}
1570 ? @{delete $self->{stashed_row}}
1571 : $self->cursor->next);
1574 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1577 $self->set_cache(\@obj) if $self->{attrs}{cache};
1586 =item Arguments: none
1588 =item Return Value: $self
1592 Resets the resultset's cursor, so you can iterate through the elements again.
1593 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1600 delete $self->{_attrs} if exists $self->{_attrs};
1601 $self->{all_cache_position} = 0;
1602 $self->cursor->reset;
1610 =item Arguments: none
1612 =item Return Value: $object | undef
1616 Resets the resultset and returns an object for the first result (or C<undef>
1617 if the resultset is empty).
1622 return $_[0]->reset->next;
1628 # Determines whether and what type of subquery is required for the $rs operation.
1629 # If grouping is necessary either supplies its own, or verifies the current one
1630 # After all is done delegates to the proper storage method.
1632 sub _rs_update_delete {
1633 my ($self, $op, $values) = @_;
1635 my $rsrc = $self->result_source;
1637 # if a condition exists we need to strip all table qualifiers
1638 # if this is not possible we'll force a subquery below
1639 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1641 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1642 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1644 if ($needs_group_by_subq or $needs_subq) {
1646 # make a new $rs selecting only the PKs (that's all we really need)
1647 my $attrs = $self->_resolved_attrs_copy;
1650 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1651 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1653 if ($needs_group_by_subq) {
1654 # make sure no group_by was supplied, or if there is one - make sure it matches
1655 # the columns compiled above perfectly. Anything else can not be sanely executed
1656 # on most databases so croak right then and there
1658 if (my $g = $attrs->{group_by}) {
1659 my @current_group_by = map
1660 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1665 join ("\x00", sort @current_group_by)
1667 join ("\x00", sort @{$attrs->{columns}} )
1669 $self->throw_exception (
1670 "You have just attempted a $op operation on a resultset which does group_by"
1671 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1672 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1673 . ' kind of queries. Please retry the operation with a modified group_by or'
1674 . ' without using one at all.'
1679 $attrs->{group_by} = $attrs->{columns};
1683 my $subrs = (ref $self)->new($rsrc, $attrs);
1684 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1687 return $rsrc->storage->$op(
1689 $op eq 'update' ? $values : (),
1699 =item Arguments: \%values
1701 =item Return Value: $storage_rv
1705 Sets the specified columns in the resultset to the supplied values in a
1706 single query. Note that this will not run any accessor/set_column/update
1707 triggers, nor will it update any row object instances derived from this
1708 resultset (this includes the contents of the L<resultset cache|/set_cache>
1709 if any). See L</update_all> if you need to execute any on-update
1710 triggers or cascades defined either by you or a
1711 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1713 The return value is a pass through of what the underlying
1714 storage backend returned, and may vary. See L<DBI/execute> for the most
1719 Note that L</update> does not process/deflate any of the values passed in.
1720 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1721 ensure manually that any value passed to this method will stringify to
1722 something the RDBMS knows how to deal with. A notable example is the
1723 handling of L<DateTime> objects, for more info see:
1724 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1729 my ($self, $values) = @_;
1730 $self->throw_exception('Values for update must be a hash')
1731 unless ref $values eq 'HASH';
1733 return $self->_rs_update_delete ('update', $values);
1740 =item Arguments: \%values
1742 =item Return Value: 1
1746 Fetches all objects and updates them one at a time via
1747 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1748 triggers, while L</update> will not.
1753 my ($self, $values) = @_;
1754 $self->throw_exception('Values for update_all must be a hash')
1755 unless ref $values eq 'HASH';
1757 my $guard = $self->result_source->schema->txn_scope_guard;
1758 $_->update($values) for $self->all;
1767 =item Arguments: none
1769 =item Return Value: $storage_rv
1773 Deletes the rows matching this resultset in a single query. Note that this
1774 will not run any delete triggers, nor will it alter the
1775 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1776 derived from this resultset (this includes the contents of the
1777 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1778 execute any on-delete triggers or cascades defined either by you or a
1779 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1781 The return value is a pass through of what the underlying storage backend
1782 returned, and may vary. See L<DBI/execute> for the most common case.
1788 $self->throw_exception('delete does not accept any arguments')
1791 return $self->_rs_update_delete ('delete');
1798 =item Arguments: none
1800 =item Return Value: 1
1804 Fetches all objects and deletes them one at a time via
1805 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1806 triggers, while L</delete> will not.
1812 $self->throw_exception('delete_all does not accept any arguments')
1815 my $guard = $self->result_source->schema->txn_scope_guard;
1816 $_->delete for $self->all;
1825 =item Arguments: \@data;
1829 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1830 For the arrayref of hashrefs style each hashref should be a structure suitable
1831 forsubmitting to a $resultset->create(...) method.
1833 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1834 to insert the data, as this is a faster method.
1836 Otherwise, each set of data is inserted into the database using
1837 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1838 accumulated into an array. The array itself, or an array reference
1839 is returned depending on scalar or list context.
1841 Example: Assuming an Artist Class that has many CDs Classes relating:
1843 my $Artist_rs = $schema->resultset("Artist");
1845 ## Void Context Example
1846 $Artist_rs->populate([
1847 { artistid => 4, name => 'Manufactured Crap', cds => [
1848 { title => 'My First CD', year => 2006 },
1849 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1852 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1853 { title => 'My parents sold me to a record company', year => 2005 },
1854 { title => 'Why Am I So Ugly?', year => 2006 },
1855 { title => 'I Got Surgery and am now Popular', year => 2007 }
1860 ## Array Context Example
1861 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1862 { name => "Artist One"},
1863 { name => "Artist Two"},
1864 { name => "Artist Three", cds=> [
1865 { title => "First CD", year => 2007},
1866 { title => "Second CD", year => 2008},
1870 print $ArtistOne->name; ## response is 'Artist One'
1871 print $ArtistThree->cds->count ## reponse is '2'
1873 For the arrayref of arrayrefs style, the first element should be a list of the
1874 fieldsnames to which the remaining elements are rows being inserted. For
1877 $Arstist_rs->populate([
1878 [qw/artistid name/],
1879 [100, 'A Formally Unknown Singer'],
1880 [101, 'A singer that jumped the shark two albums ago'],
1881 [102, 'An actually cool singer'],
1884 Please note an important effect on your data when choosing between void and
1885 wantarray context. Since void context goes straight to C<insert_bulk> in
1886 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1887 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1888 create primary keys for you, you will find that your PKs are empty. In this
1889 case you will have to use the wantarray context in order to create those
1897 # cruft placed in standalone method
1898 my $data = $self->_normalize_populate_args(@_);
1900 if(defined wantarray) {
1902 foreach my $item (@$data) {
1903 push(@created, $self->create($item));
1905 return wantarray ? @created : \@created;
1908 my $first = $data->[0];
1910 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1911 # it relationship data
1912 my (@rels, @columns);
1913 my $rsrc = $self->result_source;
1914 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1915 for (keys %$first) {
1916 my $ref = ref $first->{$_};
1917 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1923 my @pks = $rsrc->primary_columns;
1925 ## do the belongs_to relationships
1926 foreach my $index (0..$#$data) {
1928 # delegate to create() for any dataset without primary keys with specified relationships
1929 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1931 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1932 my @ret = $self->populate($data);
1938 foreach my $rel (@rels) {
1939 next unless ref $data->[$index]->{$rel} eq "HASH";
1940 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1941 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1942 my $related = $result->result_source->_resolve_condition(
1943 $reverse_relinfo->{cond},
1948 delete $data->[$index]->{$rel};
1949 $data->[$index] = {%{$data->[$index]}, %$related};
1951 push @columns, keys %$related if $index == 0;
1955 ## inherit the data locked in the conditions of the resultset
1956 my ($rs_data) = $self->_merge_with_rscond({});
1957 delete @{$rs_data}{@columns};
1958 my @inherit_cols = keys %$rs_data;
1959 my @inherit_data = values %$rs_data;
1961 ## do bulk insert on current row
1962 $rsrc->storage->insert_bulk(
1964 [@columns, @inherit_cols],
1965 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1968 ## do the has_many relationships
1969 foreach my $item (@$data) {
1973 foreach my $rel (@rels) {
1974 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
1976 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
1978 my $child = $main_row->$rel;
1980 my $related = $child->result_source->_resolve_condition(
1981 $rels->{$rel}{cond},
1986 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1987 my @populate = map { {%$_, %$related} } @rows_to_add;
1989 $child->populate( \@populate );
1996 # populate() argumnets went over several incarnations
1997 # What we ultimately support is AoH
1998 sub _normalize_populate_args {
1999 my ($self, $arg) = @_;
2001 if (ref $arg eq 'ARRAY') {
2002 if (ref $arg->[0] eq 'HASH') {
2005 elsif (ref $arg->[0] eq 'ARRAY') {
2007 my @colnames = @{$arg->[0]};
2008 foreach my $values (@{$arg}[1 .. $#$arg]) {
2009 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2015 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2022 =item Arguments: none
2024 =item Return Value: $pager
2028 Return Value a L<Data::Page> object for the current resultset. Only makes
2029 sense for queries with a C<page> attribute.
2031 To get the full count of entries for a paged resultset, call
2032 C<total_entries> on the L<Data::Page> object.
2036 # make a wizard good for both a scalar and a hashref
2037 my $mk_lazy_count_wizard = sub {
2038 require Variable::Magic;
2040 my $stash = { total_rs => shift };
2041 my $slot = shift; # only used by the hashref magic
2043 my $magic = Variable::Magic::wizard (
2044 data => sub { $stash },
2050 # set value lazily, and dispell for good
2051 ${$_[0]} = $_[1]{total_rs}->count;
2052 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2056 # an explicit set implies dispell as well
2057 # the unless() is to work around "fun and giggles" below
2058 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2059 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2066 if ($_[2] eq $slot and !$_[1]{inactive}) {
2067 my $cnt = $_[1]{total_rs}->count;
2068 $_[0]->{$slot} = $cnt;
2070 # attempting to dispell in a fetch handle (works in store), seems
2071 # to invariable segfault on 5.10, 5.12, 5.13 :(
2072 # so use an inactivator instead
2073 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2079 if (! $_[1]{inactive} and $_[2] eq $slot) {
2080 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2082 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2089 $stash->{magic_selfref} = $magic;
2090 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2095 # the tie class for 5.8.1
2097 package # hide from pause
2098 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2099 use base qw/Tie::Hash/;
2101 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2102 sub NEXTKEY { each %{$_[0]{data}} }
2103 sub EXISTS { exists $_[0]{data}{$_[1]} }
2104 sub DELETE { delete $_[0]{data}{$_[1]} }
2105 sub CLEAR { %{$_[0]{data}} = () }
2106 sub SCALAR { scalar %{$_[0]{data}} }
2109 $_[1]{data} = {%{$_[1]{selfref}}};
2110 %{$_[1]{selfref}} = ();
2111 Scalar::Util::weaken ($_[1]{selfref});
2112 return bless ($_[1], $_[0]);
2116 if ($_[1] eq $_[0]{slot}) {
2117 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2118 untie %{$_[0]{selfref}};
2119 %{$_[0]{selfref}} = %{$_[0]{data}};
2128 $_[0]{data}{$_[1]} = $_[2];
2129 if ($_[1] eq $_[0]{slot}) {
2130 untie %{$_[0]{selfref}};
2131 %{$_[0]{selfref}} = %{$_[0]{data}};
2140 return $self->{pager} if $self->{pager};
2142 if ($self->get_cache) {
2143 $self->throw_exception ('Pagers on cached resultsets are not supported');
2146 my $attrs = $self->{attrs};
2147 if (!defined $attrs->{page}) {
2148 $self->throw_exception("Can't create pager for non-paged rs");
2150 elsif ($attrs->{page} <= 0) {
2151 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2153 $attrs->{rows} ||= 10;
2155 # throw away the paging flags and re-run the count (possibly
2156 # with a subselect) to get the real total count
2157 my $count_attrs = { %$attrs };
2158 delete $count_attrs->{$_} for qw/rows offset page pager/;
2159 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2162 ### the following may seem awkward and dirty, but it's a thought-experiment
2163 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2164 ### before talking to ribasushi/mst
2166 my $pager = Data::Page->new(
2167 0, #start with an empty set
2169 $self->{attrs}{page},
2172 my $data_slot = 'total_entries';
2174 # Since we are interested in a cached value (once it's set - it's set), every
2175 # technique will detach from the magic-host once the time comes to fire the
2176 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2178 if ($] < 5.008003) {
2179 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2180 # to weakref the magic container :(
2182 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2183 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2186 elsif ($] < 5.010) {
2187 # We can use magic on the hash value slot. It's interesting that the magic is
2188 # attached to the hash-slot, and does *not* stop working once I do the dummy
2189 # assignments after the cast()
2190 # tested on 5.8.3 and 5.8.9
2191 my $magic = $mk_lazy_count_wizard->($total_rs);
2192 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2194 # this is for fun and giggles
2195 $pager->{$data_slot} = -1;
2196 $pager->{$data_slot} = 0;
2198 # this does not work for scalars, but works with
2200 #my %vals = %$pager;
2205 # And the uvar magic
2206 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2207 # however see the wizard maker for more notes
2208 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2209 Variable::Magic::cast ( %$pager, $magic );
2212 $pager->{$data_slot} = -1;
2213 $pager->{$data_slot} = 0;
2221 return $self->{pager} = $pager;
2228 =item Arguments: $page_number
2230 =item Return Value: $rs
2234 Returns a resultset for the $page_number page of the resultset on which page
2235 is called, where each page contains a number of rows equal to the 'rows'
2236 attribute set on the resultset (10 by default).
2241 my ($self, $page) = @_;
2242 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2249 =item Arguments: \%vals
2251 =item Return Value: $rowobject
2255 Creates a new row object in the resultset's result class and returns
2256 it. The row is not inserted into the database at this point, call
2257 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2258 will tell you whether the row object has been inserted or not.
2260 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2265 my ($self, $values) = @_;
2266 $self->throw_exception( "new_result needs a hash" )
2267 unless (ref $values eq 'HASH');
2269 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2273 @$cols_from_relations
2274 ? (-cols_from_relations => $cols_from_relations)
2276 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2279 return $self->result_class->new(\%new);
2282 # _merge_with_rscond
2284 # Takes a simple hash of K/V data and returns its copy merged with the
2285 # condition already present on the resultset. Additionally returns an
2286 # arrayref of value/condition names, which were inferred from related
2287 # objects (this is needed for in-memory related objects)
2288 sub _merge_with_rscond {
2289 my ($self, $data) = @_;
2291 my (%new_data, @cols_from_relations);
2293 my $alias = $self->{attrs}{alias};
2295 if (! defined $self->{cond}) {
2296 # just massage $data below
2298 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2299 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2300 @cols_from_relations = keys %new_data;
2302 elsif (ref $self->{cond} ne 'HASH') {
2303 $self->throw_exception(
2304 "Can't abstract implicit construct, resultset condition not a hash"
2308 # precendence must be given to passed values over values inherited from
2309 # the cond, so the order here is important.
2310 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2311 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2313 while ( my($col, $value) = each %implied ) {
2314 my $vref = ref $value;
2315 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2316 $new_data{$col} = $value->{'='};
2318 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2319 $new_data{$col} = $value;
2326 %{ $self->_remove_alias($data, $alias) },
2329 return (\%new_data, \@cols_from_relations);
2332 # _has_resolved_attr
2334 # determines if the resultset defines at least one
2335 # of the attributes supplied
2337 # used to determine if a subquery is neccessary
2339 # supports some virtual attributes:
2341 # This will scan for any joins being present on the resultset.
2342 # It is not a mere key-search but a deep inspection of {from}
2345 sub _has_resolved_attr {
2346 my ($self, @attr_names) = @_;
2348 my $attrs = $self->_resolved_attrs;
2352 for my $n (@attr_names) {
2353 if (grep { $n eq $_ } (qw/-join/) ) {
2354 $extra_checks{$n}++;
2358 my $attr = $attrs->{$n};
2360 next if not defined $attr;
2362 if (ref $attr eq 'HASH') {
2363 return 1 if keys %$attr;
2365 elsif (ref $attr eq 'ARRAY') {
2373 # a resolved join is expressed as a multi-level from
2375 $extra_checks{-join}
2377 ref $attrs->{from} eq 'ARRAY'
2379 @{$attrs->{from}} > 1
2387 # Recursively collapse the condition.
2389 sub _collapse_cond {
2390 my ($self, $cond, $collapsed) = @_;
2394 if (ref $cond eq 'ARRAY') {
2395 foreach my $subcond (@$cond) {
2396 next unless ref $subcond; # -or
2397 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2400 elsif (ref $cond eq 'HASH') {
2401 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2402 foreach my $subcond (@{$cond->{-and}}) {
2403 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2407 foreach my $col (keys %$cond) {
2408 my $value = $cond->{$col};
2409 $collapsed->{$col} = $value;
2419 # Remove the specified alias from the specified query hash. A copy is made so
2420 # the original query is not modified.
2423 my ($self, $query, $alias) = @_;
2425 my %orig = %{ $query || {} };
2428 foreach my $key (keys %orig) {
2430 $unaliased{$key} = $orig{$key};
2433 $unaliased{$1} = $orig{$key}
2434 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2444 =item Arguments: none
2446 =item Return Value: \[ $sql, @bind ]
2450 Returns the SQL query and bind vars associated with the invocant.
2452 This is generally used as the RHS for a subquery.
2459 my $attrs = $self->_resolved_attrs_copy;
2464 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2465 # $sql also has no wrapping parenthesis in list ctx
2467 my $sqlbind = $self->result_source->storage
2468 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2477 =item Arguments: \%vals, \%attrs?
2479 =item Return Value: $rowobject
2483 my $artist = $schema->resultset('Artist')->find_or_new(
2484 { artist => 'fred' }, { key => 'artists' });
2486 $cd->cd_to_producer->find_or_new({ producer => $producer },
2487 { key => 'primary });
2489 Find an existing record from this resultset using L</find>. if none exists,
2490 instantiate a new result object and return it. The object will not be saved
2491 into your storage until you call L<DBIx::Class::Row/insert> on it.
2493 You most likely want this method when looking for existing rows using a unique
2494 constraint that is not the primary key, or looking for related rows.
2496 If you want objects to be saved immediately, use L</find_or_create> instead.
2498 B<Note>: Make sure to read the documentation of L</find> and understand the
2499 significance of the C<key> attribute, as its lack may skew your search, and
2500 subsequently result in spurious new objects.
2502 B<Note>: Take care when using C<find_or_new> with a table having
2503 columns with default values that you intend to be automatically
2504 supplied by the database (e.g. an auto_increment primary key column).
2505 In normal usage, the value of such columns should NOT be included at
2506 all in the call to C<find_or_new>, even when set to C<undef>.
2512 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2513 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2514 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2517 return $self->new_result($hash);
2524 =item Arguments: \%vals
2526 =item Return Value: a L<DBIx::Class::Row> $object
2530 Attempt to create a single new row or a row with multiple related rows
2531 in the table represented by the resultset (and related tables). This
2532 will not check for duplicate rows before inserting, use
2533 L</find_or_create> to do that.
2535 To create one row for this resultset, pass a hashref of key/value
2536 pairs representing the columns of the table and the values you wish to
2537 store. If the appropriate relationships are set up, foreign key fields
2538 can also be passed an object representing the foreign row, and the
2539 value will be set to its primary key.
2541 To create related objects, pass a hashref of related-object column values
2542 B<keyed on the relationship name>. If the relationship is of type C<multi>
2543 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2544 The process will correctly identify columns holding foreign keys, and will
2545 transparently populate them from the keys of the corresponding relation.
2546 This can be applied recursively, and will work correctly for a structure
2547 with an arbitrary depth and width, as long as the relationships actually
2548 exists and the correct column data has been supplied.
2551 Instead of hashrefs of plain related data (key/value pairs), you may
2552 also pass new or inserted objects. New objects (not inserted yet, see
2553 L</new>), will be inserted into their appropriate tables.
2555 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2557 Example of creating a new row.
2559 $person_rs->create({
2560 name=>"Some Person",
2561 email=>"somebody@someplace.com"
2564 Example of creating a new row and also creating rows in a related C<has_many>
2565 or C<has_one> resultset. Note Arrayref.
2568 { artistid => 4, name => 'Manufactured Crap', cds => [
2569 { title => 'My First CD', year => 2006 },
2570 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2575 Example of creating a new row and also creating a row in a related
2576 C<belongs_to> resultset. Note Hashref.
2579 title=>"Music for Silly Walks",
2582 name=>"Silly Musician",
2590 When subclassing ResultSet never attempt to override this method. Since
2591 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2592 lot of the internals simply never call it, so your override will be
2593 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2594 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2595 L</create> process you need to intervene.
2602 my ($self, $attrs) = @_;
2603 $self->throw_exception( "create needs a hashref" )
2604 unless ref $attrs eq 'HASH';
2605 return $self->new_result($attrs)->insert;
2608 =head2 find_or_create
2612 =item Arguments: \%vals, \%attrs?
2614 =item Return Value: $rowobject
2618 $cd->cd_to_producer->find_or_create({ producer => $producer },
2619 { key => 'primary' });
2621 Tries to find a record based on its primary key or unique constraints; if none
2622 is found, creates one and returns that instead.
2624 my $cd = $schema->resultset('CD')->find_or_create({
2626 artist => 'Massive Attack',
2627 title => 'Mezzanine',
2631 Also takes an optional C<key> attribute, to search by a specific key or unique
2632 constraint. For example:
2634 my $cd = $schema->resultset('CD')->find_or_create(
2636 artist => 'Massive Attack',
2637 title => 'Mezzanine',
2639 { key => 'cd_artist_title' }
2642 B<Note>: Make sure to read the documentation of L</find> and understand the
2643 significance of the C<key> attribute, as its lack may skew your search, and
2644 subsequently result in spurious row creation.
2646 B<Note>: Because find_or_create() reads from the database and then
2647 possibly inserts based on the result, this method is subject to a race
2648 condition. Another process could create a record in the table after
2649 the find has completed and before the create has started. To avoid
2650 this problem, use find_or_create() inside a transaction.
2652 B<Note>: Take care when using C<find_or_create> with a table having
2653 columns with default values that you intend to be automatically
2654 supplied by the database (e.g. an auto_increment primary key column).
2655 In normal usage, the value of such columns should NOT be included at
2656 all in the call to C<find_or_create>, even when set to C<undef>.
2658 See also L</find> and L</update_or_create>. For information on how to declare
2659 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2663 sub find_or_create {
2665 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2666 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2667 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2670 return $self->create($hash);
2673 =head2 update_or_create
2677 =item Arguments: \%col_values, { key => $unique_constraint }?
2679 =item Return Value: $row_object
2683 $resultset->update_or_create({ col => $val, ... });
2685 Like L</find_or_create>, but if a row is found it is immediately updated via
2686 C<< $found_row->update (\%col_values) >>.
2689 Takes an optional C<key> attribute to search on a specific unique constraint.
2692 # In your application
2693 my $cd = $schema->resultset('CD')->update_or_create(
2695 artist => 'Massive Attack',
2696 title => 'Mezzanine',
2699 { key => 'cd_artist_title' }
2702 $cd->cd_to_producer->update_or_create({
2703 producer => $producer,
2709 B<Note>: Make sure to read the documentation of L</find> and understand the
2710 significance of the C<key> attribute, as its lack may skew your search, and
2711 subsequently result in spurious row creation.
2713 B<Note>: Take care when using C<update_or_create> with a table having
2714 columns with default values that you intend to be automatically
2715 supplied by the database (e.g. an auto_increment primary key column).
2716 In normal usage, the value of such columns should NOT be included at
2717 all in the call to C<update_or_create>, even when set to C<undef>.
2719 See also L</find> and L</find_or_create>. For information on how to declare
2720 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2724 sub update_or_create {
2726 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2727 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2729 my $row = $self->find($cond, $attrs);
2731 $row->update($cond);
2735 return $self->create($cond);
2738 =head2 update_or_new
2742 =item Arguments: \%col_values, { key => $unique_constraint }?
2744 =item Return Value: $rowobject
2748 $resultset->update_or_new({ col => $val, ... });
2750 Like L</find_or_new> but if a row is found it is immediately updated via
2751 C<< $found_row->update (\%col_values) >>.
2755 # In your application
2756 my $cd = $schema->resultset('CD')->update_or_new(
2758 artist => 'Massive Attack',
2759 title => 'Mezzanine',
2762 { key => 'cd_artist_title' }
2765 if ($cd->in_storage) {
2766 # the cd was updated
2769 # the cd is not yet in the database, let's insert it
2773 B<Note>: Make sure to read the documentation of L</find> and understand the
2774 significance of the C<key> attribute, as its lack may skew your search, and
2775 subsequently result in spurious new objects.
2777 B<Note>: Take care when using C<update_or_new> with a table having
2778 columns with default values that you intend to be automatically
2779 supplied by the database (e.g. an auto_increment primary key column).
2780 In normal usage, the value of such columns should NOT be included at
2781 all in the call to C<update_or_new>, even when set to C<undef>.
2783 See also L</find>, L</find_or_create> and L</find_or_new>.
2789 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2790 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2792 my $row = $self->find( $cond, $attrs );
2793 if ( defined $row ) {
2794 $row->update($cond);
2798 return $self->new_result($cond);
2805 =item Arguments: none
2807 =item Return Value: \@cache_objects | undef
2811 Gets the contents of the cache for the resultset, if the cache is set.
2813 The cache is populated either by using the L</prefetch> attribute to
2814 L</search> or by calling L</set_cache>.
2826 =item Arguments: \@cache_objects
2828 =item Return Value: \@cache_objects
2832 Sets the contents of the cache for the resultset. Expects an arrayref
2833 of objects of the same class as those produced by the resultset. Note that
2834 if the cache is set the resultset will return the cached objects rather
2835 than re-querying the database even if the cache attr is not set.
2837 The contents of the cache can also be populated by using the
2838 L</prefetch> attribute to L</search>.
2843 my ( $self, $data ) = @_;
2844 $self->throw_exception("set_cache requires an arrayref")
2845 if defined($data) && (ref $data ne 'ARRAY');
2846 $self->{all_cache} = $data;
2853 =item Arguments: none
2855 =item Return Value: undef
2859 Clears the cache for the resultset.
2864 shift->set_cache(undef);
2871 =item Arguments: none
2873 =item Return Value: true, if the resultset has been paginated
2881 return !!$self->{attrs}{page};
2888 =item Arguments: none
2890 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2898 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2901 =head2 related_resultset
2905 =item Arguments: $relationship_name
2907 =item Return Value: $resultset
2911 Returns a related resultset for the supplied relationship name.
2913 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2917 sub related_resultset {
2918 my ($self, $rel) = @_;
2920 $self->{related_resultsets} ||= {};
2921 return $self->{related_resultsets}{$rel} ||= do {
2922 my $rsrc = $self->result_source;
2923 my $rel_info = $rsrc->relationship_info($rel);
2925 $self->throw_exception(
2926 "search_related: result source '" . $rsrc->source_name .
2927 "' has no such relationship $rel")
2930 my $attrs = $self->_chain_relationship($rel);
2932 my $join_count = $attrs->{seen_join}{$rel};
2934 my $alias = $self->result_source->storage
2935 ->relname_to_table_alias($rel, $join_count);
2937 # since this is search_related, and we already slid the select window inwards
2938 # (the select/as attrs were deleted in the beginning), we need to flip all
2939 # left joins to inner, so we get the expected results
2940 # read the comment on top of the actual function to see what this does
2941 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2944 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2945 delete @{$attrs}{qw(result_class alias)};
2949 if (my $cache = $self->get_cache) {
2950 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2951 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2956 my $rel_source = $rsrc->related_source($rel);
2960 # The reason we do this now instead of passing the alias to the
2961 # search_rs below is that if you wrap/overload resultset on the
2962 # source you need to know what alias it's -going- to have for things
2963 # to work sanely (e.g. RestrictWithObject wants to be able to add
2964 # extra query restrictions, and these may need to be $alias.)
2966 my $rel_attrs = $rel_source->resultset_attributes;
2967 local $rel_attrs->{alias} = $alias;
2969 $rel_source->resultset
2973 where => $attrs->{where},
2976 $new->set_cache($new_cache) if $new_cache;
2981 =head2 current_source_alias
2985 =item Arguments: none
2987 =item Return Value: $source_alias
2991 Returns the current table alias for the result source this resultset is built
2992 on, that will be used in the SQL query. Usually it is C<me>.
2994 Currently the source alias that refers to the result set returned by a
2995 L</search>/L</find> family method depends on how you got to the resultset: it's
2996 C<me> by default, but eg. L</search_related> aliases it to the related result
2997 source name (and keeps C<me> referring to the original result set). The long
2998 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2999 (and make this method unnecessary).
3001 Thus it's currently necessary to use this method in predefined queries (see
3002 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3003 source alias of the current result set:
3005 # in a result set class
3007 my ($self, $user) = @_;
3009 my $me = $self->current_source_alias;
3011 return $self->search(
3012 "$me.modified" => $user->id,
3018 sub current_source_alias {
3021 return ($self->{attrs} || {})->{alias} || 'me';
3024 =head2 as_subselect_rs
3028 =item Arguments: none
3030 =item Return Value: $resultset
3034 Act as a barrier to SQL symbols. The resultset provided will be made into a
3035 "virtual view" by including it as a subquery within the from clause. From this
3036 point on, any joined tables are inaccessible to ->search on the resultset (as if
3037 it were simply where-filtered without joins). For example:
3039 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3041 # 'x' now pollutes the query namespace
3043 # So the following works as expected
3044 my $ok_rs = $rs->search({'x.other' => 1});
3046 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3047 # def) we look for one row with contradictory terms and join in another table
3048 # (aliased 'x_2') which we never use
3049 my $broken_rs = $rs->search({'x.name' => 'def'});
3051 my $rs2 = $rs->as_subselect_rs;
3053 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3054 my $not_joined_rs = $rs2->search({'x.other' => 1});
3056 # works as expected: finds a 'table' row related to two x rows (abc and def)
3057 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3059 Another example of when one might use this would be to select a subset of
3060 columns in a group by clause:
3062 my $rs = $schema->resultset('Bar')->search(undef, {
3063 group_by => [qw{ id foo_id baz_id }],
3064 })->as_subselect_rs->search(undef, {
3065 columns => [qw{ id foo_id }]
3068 In the above example normally columns would have to be equal to the group by,
3069 but because we isolated the group by into a subselect the above works.
3073 sub as_subselect_rs {
3076 my $attrs = $self->_resolved_attrs;
3078 my $fresh_rs = (ref $self)->new (
3079 $self->result_source
3082 # these pieces will be locked in the subquery
3083 delete $fresh_rs->{cond};
3084 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3086 return $fresh_rs->search( {}, {
3088 $attrs->{alias} => $self->as_query,
3089 -alias => $attrs->{alias},
3090 -rsrc => $self->result_source,
3092 alias => $attrs->{alias},
3096 # This code is called by search_related, and makes sure there
3097 # is clear separation between the joins before, during, and
3098 # after the relationship. This information is needed later
3099 # in order to properly resolve prefetch aliases (any alias
3100 # with a relation_chain_depth less than the depth of the
3101 # current prefetch is not considered)
3103 # The increments happen twice per join. An even number means a
3104 # relationship specified via a search_related, whereas an odd
3105 # number indicates a join/prefetch added via attributes
3107 # Also this code will wrap the current resultset (the one we
3108 # chain to) in a subselect IFF it contains limiting attributes
3109 sub _chain_relationship {
3110 my ($self, $rel) = @_;
3111 my $source = $self->result_source;
3112 my $attrs = { %{$self->{attrs}||{}} };
3114 # we need to take the prefetch the attrs into account before we
3115 # ->_resolve_join as otherwise they get lost - captainL
3116 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3118 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3120 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3123 my @force_subq_attrs = qw/offset rows group_by having/;
3126 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3128 $self->_has_resolved_attr (@force_subq_attrs)
3130 # Nuke the prefetch (if any) before the new $rs attrs
3131 # are resolved (prefetch is useless - we are wrapping
3132 # a subquery anyway).
3133 my $rs_copy = $self->search;
3134 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3135 $rs_copy->{attrs}{join},
3136 delete $rs_copy->{attrs}{prefetch},
3141 -alias => $attrs->{alias},
3142 $attrs->{alias} => $rs_copy->as_query,
3144 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3145 $seen->{-relation_chain_depth} = 0;
3147 elsif ($attrs->{from}) { #shallow copy suffices
3148 $from = [ @{$attrs->{from}} ];
3153 -alias => $attrs->{alias},
3154 $attrs->{alias} => $source->from,
3158 my $jpath = ($seen->{-relation_chain_depth})
3159 ? $from->[-1][0]{-join_path}
3162 my @requested_joins = $source->_resolve_join(
3169 push @$from, @requested_joins;
3171 $seen->{-relation_chain_depth}++;
3173 # if $self already had a join/prefetch specified on it, the requested
3174 # $rel might very well be already included. What we do in this case
3175 # is effectively a no-op (except that we bump up the chain_depth on
3176 # the join in question so we could tell it *is* the search_related)
3179 # we consider the last one thus reverse
3180 for my $j (reverse @requested_joins) {
3181 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3182 if ($rel eq $last_j) {
3183 $j->[0]{-relation_chain_depth}++;
3189 unless ($already_joined) {
3190 push @$from, $source->_resolve_join(
3198 $seen->{-relation_chain_depth}++;
3200 return {%$attrs, from => $from, seen_join => $seen};
3203 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3204 sub _resolved_attrs_copy {
3206 return { %{$self->_resolved_attrs (@_)} };
3209 sub _resolved_attrs {
3211 return $self->{_attrs} if $self->{_attrs};
3213 my $attrs = { %{ $self->{attrs} || {} } };
3214 my $source = $self->result_source;
3215 my $alias = $attrs->{alias};
3217 # one last pass of normalization
3218 $self->_normalize_selection($attrs);
3220 # default selection list
3221 $attrs->{columns} = [ $source->columns ]
3222 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3224 # merge selectors together
3225 for (qw/columns select as _trailing_select/) {
3226 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3227 if $attrs->{$_} or $attrs->{"+$_"};
3230 # disassemble columns
3232 if (my $cols = delete $attrs->{columns}) {
3233 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3234 if (ref $c eq 'HASH') {
3235 for my $as (keys %$c) {
3236 push @sel, $c->{$as};
3247 # when trying to weed off duplicates later do not go past this point -
3248 # everything added from here on is unbalanced "anyone's guess" stuff
3249 my $dedup_stop_idx = $#as;
3251 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3253 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3254 if $attrs->{select};
3256 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3258 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3261 # disqualify all $alias.col as-bits (collapser mandated)
3263 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3266 # de-duplicate the result (remove *identical* select/as pairs)
3267 # and also die on duplicate {as} pointing to different {select}s
3268 # not using a c-style for as the condition is prone to shrinkage
3271 while ($i <= $dedup_stop_idx) {
3272 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3277 elsif ($seen->{$as[$i]}++) {
3278 $self->throw_exception(
3279 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3287 $attrs->{select} = \@sel;
3288 $attrs->{as} = \@as;
3290 $attrs->{from} ||= [{
3292 -alias => $self->{attrs}{alias},
3293 $self->{attrs}{alias} => $source->from,
3296 if ( $attrs->{join} || $attrs->{prefetch} ) {
3298 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3299 if ref $attrs->{from} ne 'ARRAY';
3301 my $join = (delete $attrs->{join}) || {};
3303 if ( defined $attrs->{prefetch} ) {
3304 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3307 $attrs->{from} = # have to copy here to avoid corrupting the original
3309 @{ $attrs->{from} },
3310 $source->_resolve_join(
3313 { %{ $attrs->{seen_join} || {} } },
3314 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3315 ? $attrs->{from}[-1][0]{-join_path}
3322 if ( defined $attrs->{order_by} ) {
3323 $attrs->{order_by} = (
3324 ref( $attrs->{order_by} ) eq 'ARRAY'
3325 ? [ @{ $attrs->{order_by} } ]
3326 : [ $attrs->{order_by} || () ]
3330 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3331 $attrs->{group_by} = [ $attrs->{group_by} ];
3334 # generate the distinct induced group_by early, as prefetch will be carried via a
3335 # subquery (since a group_by is present)
3336 if (delete $attrs->{distinct}) {
3337 if ($attrs->{group_by}) {
3338 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3341 # distinct affects only the main selection part, not what prefetch may
3342 # add below. However trailing is not yet a part of the selection as
3343 # prefetch must insert before it
3344 $attrs->{group_by} = $source->storage->_group_over_selection (
3346 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3352 $attrs->{collapse} ||= {};
3353 if ($attrs->{prefetch}) {
3354 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3356 my $prefetch_ordering = [];
3358 # this is a separate structure (we don't look in {from} directly)
3359 # as the resolver needs to shift things off the lists to work
3360 # properly (identical-prefetches on different branches)
3362 if (ref $attrs->{from} eq 'ARRAY') {
3364 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3366 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3367 next unless $j->[0]{-alias};
3368 next unless $j->[0]{-join_path};
3369 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3371 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3374 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3375 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3380 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3382 # we need to somehow mark which columns came from prefetch
3384 my $sel_end = $#{$attrs->{select}};
3385 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3388 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3389 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3391 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3392 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3396 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3397 if $attrs->{_trailing_select};
3399 # if both page and offset are specified, produce a combined offset
3400 # even though it doesn't make much sense, this is what pre 081xx has
3402 if (my $page = delete $attrs->{page}) {
3404 ($attrs->{rows} * ($page - 1))
3406 ($attrs->{offset} || 0)
3410 return $self->{_attrs} = $attrs;
3414 my ($self, $attr) = @_;
3416 if (ref $attr eq 'HASH') {
3417 return $self->_rollout_hash($attr);
3418 } elsif (ref $attr eq 'ARRAY') {
3419 return $self->_rollout_array($attr);
3425 sub _rollout_array {
3426 my ($self, $attr) = @_;
3429 foreach my $element (@{$attr}) {
3430 if (ref $element eq 'HASH') {
3431 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3432 } elsif (ref $element eq 'ARRAY') {
3433 # XXX - should probably recurse here
3434 push( @rolled_array, @{$self->_rollout_array($element)} );
3436 push( @rolled_array, $element );
3439 return \@rolled_array;
3443 my ($self, $attr) = @_;
3446 foreach my $key (keys %{$attr}) {
3447 push( @rolled_array, { $key => $attr->{$key} } );
3449 return \@rolled_array;
3452 sub _calculate_score {
3453 my ($self, $a, $b) = @_;
3455 if (defined $a xor defined $b) {
3458 elsif (not defined $a) {
3462 if (ref $b eq 'HASH') {
3463 my ($b_key) = keys %{$b};
3464 if (ref $a eq 'HASH') {
3465 my ($a_key) = keys %{$a};
3466 if ($a_key eq $b_key) {
3467 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3472 return ($a eq $b_key) ? 1 : 0;
3475 if (ref $a eq 'HASH') {
3476 my ($a_key) = keys %{$a};
3477 return ($b eq $a_key) ? 1 : 0;
3479 return ($b eq $a) ? 1 : 0;
3484 sub _merge_joinpref_attr {
3485 my ($self, $orig, $import) = @_;
3487 return $import unless defined($orig);
3488 return $orig unless defined($import);
3490 $orig = $self->_rollout_attr($orig);
3491 $import = $self->_rollout_attr($import);
3494 foreach my $import_element ( @{$import} ) {
3495 # find best candidate from $orig to merge $b_element into
3496 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3497 foreach my $orig_element ( @{$orig} ) {
3498 my $score = $self->_calculate_score( $orig_element, $import_element );
3499 if ($score > $best_candidate->{score}) {
3500 $best_candidate->{position} = $position;
3501 $best_candidate->{score} = $score;
3505 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3507 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3508 push( @{$orig}, $import_element );
3510 my $orig_best = $orig->[$best_candidate->{position}];
3511 # merge orig_best and b_element together and replace original with merged
3512 if (ref $orig_best ne 'HASH') {
3513 $orig->[$best_candidate->{position}] = $import_element;
3514 } elsif (ref $import_element eq 'HASH') {
3515 my ($key) = keys %{$orig_best};
3516 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3519 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3530 my $hm = Hash::Merge->new;
3532 $hm->specify_behavior({
3535 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3537 if ($defl xor $defr) {
3538 return [ $defl ? $_[0] : $_[1] ];
3543 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3547 return [$_[0], $_[1]];
3551 return $_[1] if !defined $_[0];
3552 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3553 return [$_[0], @{$_[1]}]
3556 return [] if !defined $_[0] and !keys %{$_[1]};
3557 return [ $_[1] ] if !defined $_[0];
3558 return [ $_[0] ] if !keys %{$_[1]};
3559 return [$_[0], $_[1]]
3564 return $_[0] if !defined $_[1];
3565 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3566 return [@{$_[0]}, $_[1]]
3569 my @ret = @{$_[0]} or return $_[1];
3570 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3571 my %idx = map { $_ => 1 } @ret;
3572 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3576 return [ $_[1] ] if ! @{$_[0]};
3577 return $_[0] if !keys %{$_[1]};
3578 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3579 return [ @{$_[0]}, $_[1] ];
3584 return [] if !keys %{$_[0]} and !defined $_[1];
3585 return [ $_[0] ] if !defined $_[1];
3586 return [ $_[1] ] if !keys %{$_[0]};
3587 return [$_[0], $_[1]]
3590 return [] if !keys %{$_[0]} and !@{$_[1]};
3591 return [ $_[0] ] if !@{$_[1]};
3592 return $_[1] if !keys %{$_[0]};
3593 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3594 return [ $_[0], @{$_[1]} ];
3597 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3598 return [ $_[0] ] if !keys %{$_[1]};
3599 return [ $_[1] ] if !keys %{$_[0]};
3600 return [ $_[0] ] if $_[0] eq $_[1];
3601 return [ $_[0], $_[1] ];
3604 } => 'DBIC_RS_ATTR_MERGER');
3608 return $hm->merge ($_[1], $_[2]);
3612 sub STORABLE_freeze {
3613 my ($self, $cloning) = @_;
3614 my $to_serialize = { %$self };
3616 # A cursor in progress can't be serialized (and would make little sense anyway)
3617 delete $to_serialize->{cursor};
3619 nfreeze($to_serialize);
3622 # need this hook for symmetry
3624 my ($self, $cloning, $serialized) = @_;
3626 %$self = %{ thaw($serialized) };
3632 =head2 throw_exception
3634 See L<DBIx::Class::Schema/throw_exception> for details.
3638 sub throw_exception {
3641 if (ref $self and my $rsrc = $self->result_source) {
3642 $rsrc->throw_exception(@_)
3645 DBIx::Class::Exception->throw(@_);
3649 # XXX: FIXME: Attributes docs need clearing up
3653 Attributes are used to refine a ResultSet in various ways when
3654 searching for data. They can be passed to any method which takes an
3655 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3658 These are in no particular order:
3664 =item Value: ( $order_by | \@order_by | \%order_by )
3668 Which column(s) to order the results by.
3670 [The full list of suitable values is documented in
3671 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3674 If a single column name, or an arrayref of names is supplied, the
3675 argument is passed through directly to SQL. The hashref syntax allows
3676 for connection-agnostic specification of ordering direction:
3678 For descending order:
3680 order_by => { -desc => [qw/col1 col2 col3/] }
3682 For explicit ascending order:
3684 order_by => { -asc => 'col' }
3686 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3687 supported, although you are strongly encouraged to use the hashref
3688 syntax as outlined above.
3694 =item Value: \@columns
3698 Shortcut to request a particular set of columns to be retrieved. Each
3699 column spec may be a string (a table column name), or a hash (in which
3700 case the key is the C<as> value, and the value is used as the C<select>
3701 expression). Adds C<me.> onto the start of any column without a C<.> in
3702 it and sets C<select> from that, then auto-populates C<as> from
3703 C<select> as normal. (You may also use the C<cols> attribute, as in
3704 earlier versions of DBIC.)
3706 Essentially C<columns> does the same as L</select> and L</as>.
3708 columns => [ 'foo', { bar => 'baz' } ]
3712 select => [qw/foo baz/],
3719 =item Value: \@columns
3723 Indicates additional columns to be selected from storage. Works the same
3724 as L</columns> but adds columns to the selection. (You may also use the
3725 C<include_columns> attribute, as in earlier versions of DBIC). For
3728 $schema->resultset('CD')->search(undef, {
3729 '+columns' => ['artist.name'],
3733 would return all CDs and include a 'name' column to the information
3734 passed to object inflation. Note that the 'artist' is the name of the
3735 column (or relationship) accessor, and 'name' is the name of the column
3736 accessor in the related table.
3738 =head2 include_columns
3742 =item Value: \@columns
3746 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3752 =item Value: \@select_columns
3756 Indicates which columns should be selected from the storage. You can use
3757 column names, or in the case of RDBMS back ends, function or stored procedure
3760 $rs = $schema->resultset('Employee')->search(undef, {
3763 { count => 'employeeid' },
3764 { max => { length => 'name' }, -as => 'longest_name' }
3769 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3771 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3772 use L</select>, to instruct DBIx::Class how to store the result of the column.
3773 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3774 identifier aliasing. You can however alias a function, so you can use it in
3775 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3776 attribute> supplied as shown in the example above.
3782 Indicates additional columns to be selected from storage. Works the same as
3783 L</select> but adds columns to the default selection, instead of specifying
3792 Indicates additional column names for those added via L</+select>. See L</as>.
3800 =item Value: \@inflation_names
3804 Indicates column names for object inflation. That is L</as> indicates the
3805 slot name in which the column value will be stored within the
3806 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3807 identifier by the C<get_column> method (or via the object accessor B<if one
3808 with the same name already exists>) as shown below. The L</as> attribute has
3809 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3811 $rs = $schema->resultset('Employee')->search(undef, {
3814 { count => 'employeeid' },
3815 { max => { length => 'name' }, -as => 'longest_name' }
3824 If the object against which the search is performed already has an accessor
3825 matching a column name specified in C<as>, the value can be retrieved using
3826 the accessor as normal:
3828 my $name = $employee->name();
3830 If on the other hand an accessor does not exist in the object, you need to
3831 use C<get_column> instead:
3833 my $employee_count = $employee->get_column('employee_count');
3835 You can create your own accessors if required - see
3836 L<DBIx::Class::Manual::Cookbook> for details.
3842 =item Value: ($rel_name | \@rel_names | \%rel_names)
3846 Contains a list of relationships that should be joined for this query. For
3849 # Get CDs by Nine Inch Nails
3850 my $rs = $schema->resultset('CD')->search(
3851 { 'artist.name' => 'Nine Inch Nails' },
3852 { join => 'artist' }
3855 Can also contain a hash reference to refer to the other relation's relations.
3858 package MyApp::Schema::Track;
3859 use base qw/DBIx::Class/;
3860 __PACKAGE__->table('track');
3861 __PACKAGE__->add_columns(qw/trackid cd position title/);
3862 __PACKAGE__->set_primary_key('trackid');
3863 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3866 # In your application
3867 my $rs = $schema->resultset('Artist')->search(
3868 { 'track.title' => 'Teardrop' },
3870 join => { cd => 'track' },
3871 order_by => 'artist.name',
3875 You need to use the relationship (not the table) name in conditions,
3876 because they are aliased as such. The current table is aliased as "me", so
3877 you need to use me.column_name in order to avoid ambiguity. For example:
3879 # Get CDs from 1984 with a 'Foo' track
3880 my $rs = $schema->resultset('CD')->search(
3883 'tracks.name' => 'Foo'
3885 { join => 'tracks' }
3888 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3889 similarly for a third time). For e.g.
3891 my $rs = $schema->resultset('Artist')->search({
3892 'cds.title' => 'Down to Earth',
3893 'cds_2.title' => 'Popular',
3895 join => [ qw/cds cds/ ],
3898 will return a set of all artists that have both a cd with title 'Down
3899 to Earth' and a cd with title 'Popular'.
3901 If you want to fetch related objects from other tables as well, see C<prefetch>
3904 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3910 =item Value: ($rel_name | \@rel_names | \%rel_names)
3914 Contains one or more relationships that should be fetched along with
3915 the main query (when they are accessed afterwards the data will
3916 already be available, without extra queries to the database). This is
3917 useful for when you know you will need the related objects, because it
3918 saves at least one query:
3920 my $rs = $schema->resultset('Tag')->search(
3929 The initial search results in SQL like the following:
3931 SELECT tag.*, cd.*, artist.* FROM tag
3932 JOIN cd ON tag.cd = cd.cdid
3933 JOIN artist ON cd.artist = artist.artistid
3935 L<DBIx::Class> has no need to go back to the database when we access the
3936 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3939 Simple prefetches will be joined automatically, so there is no need
3940 for a C<join> attribute in the above search.
3942 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3943 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3944 with an accessor type of 'single' or 'filter'). A more complex example that
3945 prefetches an artists cds, the tracks on those cds, and the tags associated
3946 with that artist is given below (assuming many-to-many from artists to tags):
3948 my $rs = $schema->resultset('Artist')->search(
3952 { cds => 'tracks' },
3953 { artist_tags => 'tags' }
3959 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3960 attributes will be ignored.
3962 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3963 exactly as you might expect.
3969 Prefetch uses the L</cache> to populate the prefetched relationships. This
3970 may or may not be what you want.
3974 If you specify a condition on a prefetched relationship, ONLY those
3975 rows that match the prefetched condition will be fetched into that relationship.
3976 This means that adding prefetch to a search() B<may alter> what is returned by
3977 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3979 my $artist_rs = $schema->resultset('Artist')->search({
3985 my $count = $artist_rs->first->cds->count;
3987 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3989 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3991 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3993 that cmp_ok() may or may not pass depending on the datasets involved. This
3994 behavior may or may not survive the 0.09 transition.
4006 Makes the resultset paged and specifies the page to retrieve. Effectively
4007 identical to creating a non-pages resultset and then calling ->page($page)
4010 If L<rows> attribute is not specified it defaults to 10 rows per page.
4012 When you have a paged resultset, L</count> will only return the number
4013 of rows in the page. To get the total, use the L</pager> and call
4014 C<total_entries> on it.
4024 Specifies the maximum number of rows for direct retrieval or the number of
4025 rows per page if the page attribute or method is used.
4031 =item Value: $offset
4035 Specifies the (zero-based) row number for the first row to be returned, or the
4036 of the first row of the first page if paging is used.
4042 =item Value: \@columns
4046 A arrayref of columns to group by. Can include columns of joined tables.
4048 group_by => [qw/ column1 column2 ... /]
4054 =item Value: $condition
4058 HAVING is a select statement attribute that is applied between GROUP BY and
4059 ORDER BY. It is applied to the after the grouping calculations have been
4062 having => { 'count_employee' => { '>=', 100 } }
4064 or with an in-place function in which case literal SQL is required:
4066 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4072 =item Value: (0 | 1)
4076 Set to 1 to group by all columns. If the resultset already has a group_by
4077 attribute, this setting is ignored and an appropriate warning is issued.
4083 Adds to the WHERE clause.
4085 # only return rows WHERE deleted IS NULL for all searches
4086 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4088 Can be overridden by passing C<< { where => undef } >> as an attribute
4095 Set to 1 to cache search results. This prevents extra SQL queries if you
4096 revisit rows in your ResultSet:
4098 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4100 while( my $artist = $resultset->next ) {
4104 $rs->first; # without cache, this would issue a query
4106 By default, searches are not cached.
4108 For more examples of using these attributes, see
4109 L<DBIx::Class::Manual::Cookbook>.
4115 =item Value: ( 'update' | 'shared' )
4119 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT