1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use DBIx::Class::Exception;
10 use DBIx::Class::ResultSetColumn;
11 use DBIx::Class::ResultSourceHandle;
14 use Scalar::Util qw/blessed weaken/;
16 use Storable qw/nfreeze thaw/;
20 # De-duplication in _merge_attr() is disabled, but left in for reference
21 *__HM_DEDUP = sub () { 0 };
29 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
33 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
37 my $users_rs = $schema->resultset('User');
38 while( $user = $users_rs->next) {
39 print $user->username;
42 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
43 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
47 A ResultSet is an object which stores a set of conditions representing
48 a query. It is the backbone of DBIx::Class (i.e. the really
49 important/useful bit).
51 No SQL is executed on the database when a ResultSet is created, it
52 just stores all the conditions needed to create the query.
54 A basic ResultSet representing the data of an entire table is returned
55 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
56 L<Source|DBIx::Class::Manual::Glossary/Source> name.
58 my $users_rs = $schema->resultset('User');
60 A new ResultSet is returned from calling L</search> on an existing
61 ResultSet. The new one will contain all the conditions of the
62 original, plus any new conditions added in the C<search> call.
64 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
65 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
68 The query that the ResultSet represents is B<only> executed against
69 the database when these methods are called:
70 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
72 If a resultset is used in a numeric context it returns the L</count>.
73 However, if it is used in a boolean context it is B<always> true. So if
74 you want to check if a resultset has any results, you must use C<if $rs
79 =head2 Chaining resultsets
81 Let's say you've got a query that needs to be run to return some data
82 to the user. But, you have an authorization system in place that
83 prevents certain users from seeing certain information. So, you want
84 to construct the basic query in one method, but add constraints to it in
89 my $request = $self->get_request; # Get a request object somehow.
90 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
92 my $cd_rs = $schema->resultset('CD')->search({
93 title => $request->param('title'),
94 year => $request->param('year'),
97 $self->apply_security_policy( $cd_rs );
102 sub apply_security_policy {
111 =head3 Resolving conditions and attributes
113 When a resultset is chained from another resultset, conditions and
114 attributes with the same keys need resolving.
116 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
117 into the existing ones from the original resultset.
119 The L</where> and L</having> attributes, and any search conditions, are
120 merged with an SQL C<AND> to the existing condition from the original
123 All other attributes are overridden by any new ones supplied in the
126 =head2 Multiple queries
128 Since a resultset just defines a query, you can do all sorts of
129 things with it with the same object.
131 # Don't hit the DB yet.
132 my $cd_rs = $schema->resultset('CD')->search({
133 title => 'something',
137 # Each of these hits the DB individually.
138 my $count = $cd_rs->count;
139 my $most_recent = $cd_rs->get_column('date_released')->max();
140 my @records = $cd_rs->all;
142 And it's not just limited to SELECT statements.
148 $cd_rs->create({ artist => 'Fred' });
150 Which is the same as:
152 $schema->resultset('CD')->create({
153 title => 'something',
158 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
166 =item Arguments: $source, \%$attrs
168 =item Return Value: $rs
172 The resultset constructor. Takes a source object (usually a
173 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
174 L</ATTRIBUTES> below). Does not perform any queries -- these are
175 executed as needed by the other methods.
177 Generally you won't need to construct a resultset manually. You'll
178 automatically get one from e.g. a L</search> called in scalar context:
180 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
182 IMPORTANT: If called on an object, proxies to new_result instead so
184 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
186 will return a CD object, not a ResultSet.
192 return $class->new_result(@_) if ref $class;
194 my ($source, $attrs) = @_;
195 $source = $source->handle
196 unless $source->isa('DBIx::Class::ResultSourceHandle');
197 $attrs = { %{$attrs||{}} };
199 if ($attrs->{page}) {
200 $attrs->{rows} ||= 10;
203 $attrs->{alias} ||= 'me';
205 # Creation of {} and bless separated to mitigate RH perl bug
206 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
208 _source_handle => $source,
209 cond => $attrs->{where},
217 $attrs->{result_class} || $source->resolve->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( @_ );
270 my $want = wantarray;
274 elsif (defined $want) {
278 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense');
286 =item Arguments: $cond, \%attrs?
288 =item Return Value: $resultset
292 This method does the same exact thing as search() except it will
293 always return a resultset, even in list context.
300 # Special-case handling for (undef, undef).
301 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
306 $call_attrs = pop(@_) if (
307 @_ > 1 and ( ! defined $_[-1] or ref $_[-1] eq 'HASH' )
310 # see if we can keep the cache (no $rs changes)
312 my %safe = (alias => 1, cache => 1);
313 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
316 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
318 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
320 $cache = $self->get_cache;
323 my $old_attrs = { %{$self->{attrs}} };
324 my $old_having = delete $old_attrs->{having};
325 my $old_where = delete $old_attrs->{where};
327 # reset the selector list
328 if (List::Util::first { exists $call_attrs->{$_} } qw{columns select as}) {
329 delete @{$old_attrs}{qw{select as columns +select +as +columns include_columns}};
332 my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
334 # merge new attrs into inherited
335 foreach my $key (qw/join prefetch/) {
336 next unless exists $call_attrs->{$key};
337 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key});
339 foreach my $key (qw/+select +as +columns include_columns bind/) {
340 next unless exists $call_attrs->{$key};
341 $new_attrs->{$key} = $self->_merge_attr($old_attrs->{$key}, $call_attrs->{$key});
344 # rip apart the rest of @_, parse a condition
347 if (ref $_[0] eq 'HASH') {
348 (keys %{$_[0]}) ? $_[0] : undef
354 $self->throw_exception('Odd number of arguments to search')
362 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
363 if (@_ > 1 and ! $self->result_source->result_class->isa('DBIx::Class::CDBICompat') );
365 for ($old_where, $call_cond) {
367 $new_attrs->{where} = $self->_stack_cond (
368 $_, $new_attrs->{where}
373 if (defined $old_having) {
374 $new_attrs->{having} = $self->_stack_cond (
375 $old_having, $new_attrs->{having}
379 my $rs = (ref $self)->new($self->result_source, $new_attrs);
381 $rs->set_cache($cache) if ($cache);
387 my ($self, $left, $right) = @_;
388 if (defined $left xor defined $right) {
389 return defined $left ? $left : $right;
391 elsif (defined $left) {
392 return { -and => [ map
393 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
401 =head2 search_literal
405 =item Arguments: $sql_fragment, @bind_values
407 =item Return Value: $resultset (scalar context), @row_objs (list context)
411 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
412 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
414 Pass a literal chunk of SQL to be added to the conditional part of the
417 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
418 only be used in that context. C<search_literal> is a convenience method.
419 It is equivalent to calling $schema->search(\[]), but if you want to ensure
420 columns are bound correctly, use C<search>.
422 Example of how to use C<search> instead of C<search_literal>
424 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
425 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
428 See L<DBIx::Class::Manual::Cookbook/Searching> and
429 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
430 require C<search_literal>.
435 my ($self, $sql, @bind) = @_;
437 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
440 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
447 =item Arguments: \%columns_values | @pk_values, \%attrs?
449 =item Return Value: $row_object | undef
453 Finds and returns a single row based on supplied criteria. Takes either a
454 hashref with the same format as L</create> (including inference of foreign
455 keys from related objects), or a list of primary key values in the same
456 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
457 declaration on the L</result_source>.
459 In either case an attempt is made to combine conditions already existing on
460 the resultset with the condition passed to this method.
462 To aid with preparing the correct query for the storage you may supply the
463 C<key> attribute, which is the name of a
464 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
465 unique constraint corresponding to the
466 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
467 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
468 to construct a query that satisfies the named unique constraint fully (
469 non-NULL values for each column member of the constraint) an exception is
472 If no C<key> is specified, the search is carried over all unique constraints
473 which are fully defined by the available condition.
475 If no such constraint is found, C<find> currently defaults to a simple
476 C<< search->(\%column_values) >> which may or may not do what you expect.
477 Note that this fallback behavior may be deprecated in further versions. If
478 you need to search with arbitrary conditions - use L</search>. If the query
479 resulting from this fallback produces more than one row, a warning to the
480 effect is issued, though only the first row is constructed and returned as
483 In addition to C<key>, L</find> recognizes and applies standard
484 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
486 Note that if you have extra concerns about the correctness of the resulting
487 query you need to specify the C<key> attribute and supply the entire condition
488 as an argument to find (since it is not always possible to perform the
489 combination of the resultset condition with the supplied one, especially if
490 the resultset condition contains literal sql).
492 For example, to find a row by its primary key:
494 my $cd = $schema->resultset('CD')->find(5);
496 You can also find a row by a specific unique constraint:
498 my $cd = $schema->resultset('CD')->find(
500 artist => 'Massive Attack',
501 title => 'Mezzanine',
503 { key => 'cd_artist_title' }
506 See also L</find_or_create> and L</update_or_create>.
512 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
514 my $rsrc = $self->result_source;
516 # Parse out the condition from input
518 if (ref $_[0] eq 'HASH') {
519 $call_cond = { %{$_[0]} };
522 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
523 my @c_cols = $rsrc->unique_constraint_columns($constraint);
525 $self->throw_exception(
526 "No constraint columns, maybe a malformed '$constraint' constraint?"
529 $self->throw_exception (
530 'find() expects either a column/value hashref, or a list of values '
531 . "corresponding to the columns of the specified unique constraint '$constraint'"
532 ) unless @c_cols == @_;
535 @{$call_cond}{@c_cols} = @_;
539 for my $key (keys %$call_cond) {
541 my $keyref = ref($call_cond->{$key})
543 my $relinfo = $rsrc->relationship_info($key)
545 my $val = delete $call_cond->{$key};
547 next if $keyref eq 'ARRAY'; # has_many for multi_create
549 my $rel_q = $rsrc->_resolve_condition(
550 $relinfo->{cond}, $val, $key
552 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
553 @related{keys %$rel_q} = values %$rel_q;
557 # relationship conditions take precedence (?)
558 @{$call_cond}{keys %related} = values %related;
560 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
562 if (exists $attrs->{key}) {
563 $final_cond = $self->_qualify_cond_columns (
565 $self->_build_unique_cond (
573 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
574 # This means that we got here after a merger of relationship conditions
575 # in ::Relationship::Base::search_related (the row method), and furthermore
576 # the relationship is of the 'single' type. This means that the condition
577 # provided by the relationship (already attached to $self) is sufficient,
578 # as there can be only one row in the database that would satisfy the
582 # no key was specified - fall down to heuristics mode:
583 # run through all unique queries registered on the resultset, and
584 # 'OR' all qualifying queries together
585 my (@unique_queries, %seen_column_combinations);
586 for my $c_name ($rsrc->unique_constraint_names) {
587 next if $seen_column_combinations{
588 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
591 push @unique_queries, try {
592 $self->_build_unique_cond ($c_name, $call_cond)
596 $final_cond = @unique_queries
597 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
598 : $self->_non_unique_find_fallback ($call_cond, $attrs)
602 # Run the query, passing the result_class since it should propagate for find
603 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
604 if (keys %{$rs->_resolved_attrs->{collapse}}) {
606 carp "Query returned more than one row" if $rs->next;
614 # This is a stop-gap method as agreed during the discussion on find() cleanup:
615 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
617 # It is invoked when find() is called in legacy-mode with insufficiently-unique
618 # condition. It is provided for overrides until a saner way forward is devised
620 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
621 # the road. Please adjust your tests accordingly to catch this situation early
622 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
624 # The method will not be removed without an adequately complete replacement
625 # for strict-mode enforcement
626 sub _non_unique_find_fallback {
627 my ($self, $cond, $attrs) = @_;
629 return $self->_qualify_cond_columns(
631 exists $attrs->{alias}
633 : $self->{attrs}{alias}
638 sub _qualify_cond_columns {
639 my ($self, $cond, $alias) = @_;
641 my %aliased = %$cond;
642 for (keys %aliased) {
643 $aliased{"$alias.$_"} = delete $aliased{$_}
650 sub _build_unique_cond {
651 my ($self, $constraint_name, $extra_cond) = @_;
653 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
655 # combination may fail if $self->{cond} is non-trivial
656 my ($final_cond) = try {
657 $self->_merge_with_rscond ($extra_cond)
662 # trim out everything not in $columns
663 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
665 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
666 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
668 join (', ', map { "'$_'" } @missing),
675 =head2 search_related
679 =item Arguments: $rel, $cond, \%attrs?
681 =item Return Value: $new_resultset
685 $new_rs = $cd_rs->search_related('artist', {
689 Searches the specified relationship, optionally specifying a condition and
690 attributes for matching records. See L</ATTRIBUTES> for more information.
695 return shift->related_resultset(shift)->search(@_);
698 =head2 search_related_rs
700 This method works exactly the same as search_related, except that
701 it guarantees a resultset, even in list context.
705 sub search_related_rs {
706 return shift->related_resultset(shift)->search_rs(@_);
713 =item Arguments: none
715 =item Return Value: $cursor
719 Returns a storage-driven cursor to the given resultset. See
720 L<DBIx::Class::Cursor> for more information.
727 my $attrs = $self->_resolved_attrs_copy;
729 return $self->{cursor}
730 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
731 $attrs->{where},$attrs);
738 =item Arguments: $cond?
740 =item Return Value: $row_object | undef
744 my $cd = $schema->resultset('CD')->single({ year => 2001 });
746 Inflates the first result without creating a cursor if the resultset has
747 any records in it; if not returns C<undef>. Used by L</find> as a lean version
750 While this method can take an optional search condition (just like L</search>)
751 being a fast-code-path it does not recognize search attributes. If you need to
752 add extra joins or similar, call L</search> and then chain-call L</single> on the
753 L<DBIx::Class::ResultSet> returned.
759 As of 0.08100, this method enforces the assumption that the preceding
760 query returns only one row. If more than one row is returned, you will receive
763 Query returned more than one row
765 In this case, you should be using L</next> or L</find> instead, or if you really
766 know what you are doing, use the L</rows> attribute to explicitly limit the size
769 This method will also throw an exception if it is called on a resultset prefetching
770 has_many, as such a prefetch implies fetching multiple rows from the database in
771 order to assemble the resulting object.
778 my ($self, $where) = @_;
780 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
783 my $attrs = $self->_resolved_attrs_copy;
785 if (keys %{$attrs->{collapse}}) {
786 $self->throw_exception(
787 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
792 if (defined $attrs->{where}) {
795 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
796 $where, delete $attrs->{where} ]
799 $attrs->{where} = $where;
803 my @data = $self->result_source->storage->select_single(
804 $attrs->{from}, $attrs->{select},
805 $attrs->{where}, $attrs
808 return (@data ? ($self->_construct_object(@data))[0] : undef);
814 # Recursively collapse the query, accumulating values for each column.
816 sub _collapse_query {
817 my ($self, $query, $collapsed) = @_;
821 if (ref $query eq 'ARRAY') {
822 foreach my $subquery (@$query) {
823 next unless ref $subquery; # -or
824 $collapsed = $self->_collapse_query($subquery, $collapsed);
827 elsif (ref $query eq 'HASH') {
828 if (keys %$query and (keys %$query)[0] eq '-and') {
829 foreach my $subquery (@{$query->{-and}}) {
830 $collapsed = $self->_collapse_query($subquery, $collapsed);
834 foreach my $col (keys %$query) {
835 my $value = $query->{$col};
836 $collapsed->{$col}{$value}++;
848 =item Arguments: $cond?
850 =item Return Value: $resultsetcolumn
854 my $max_length = $rs->get_column('length')->max;
856 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
861 my ($self, $column) = @_;
862 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
870 =item Arguments: $cond, \%attrs?
872 =item Return Value: $resultset (scalar context), @row_objs (list context)
876 # WHERE title LIKE '%blue%'
877 $cd_rs = $rs->search_like({ title => '%blue%'});
879 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
880 that this is simply a convenience method retained for ex Class::DBI users.
881 You most likely want to use L</search> with specific operators.
883 For more information, see L<DBIx::Class::Manual::Cookbook>.
885 This method is deprecated and will be removed in 0.09. Use L</search()>
886 instead. An example conversion is:
888 ->search_like({ foo => 'bar' });
892 ->search({ foo => { like => 'bar' } });
899 'search_like() is deprecated and will be removed in DBIC version 0.09.'
900 .' Instead use ->search({ x => { -like => "y%" } })'
901 .' (note the outer pair of {}s - they are important!)'
903 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
904 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
905 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
906 return $class->search($query, { %$attrs });
913 =item Arguments: $first, $last
915 =item Return Value: $resultset (scalar context), @row_objs (list context)
919 Returns a resultset or object list representing a subset of elements from the
920 resultset slice is called on. Indexes are from 0, i.e., to get the first
923 my ($one, $two, $three) = $rs->slice(0, 2);
928 my ($self, $min, $max) = @_;
929 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
930 $attrs->{offset} = $self->{attrs}{offset} || 0;
931 $attrs->{offset} += $min;
932 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
933 return $self->search(undef, $attrs);
934 #my $slice = (ref $self)->new($self->result_source, $attrs);
935 #return (wantarray ? $slice->all : $slice);
942 =item Arguments: none
944 =item Return Value: $result | undef
948 Returns the next element in the resultset (C<undef> is there is none).
950 Can be used to efficiently iterate over records in the resultset:
952 my $rs = $schema->resultset('CD')->search;
953 while (my $cd = $rs->next) {
957 Note that you need to store the resultset object, and call C<next> on it.
958 Calling C<< resultset('Table')->next >> repeatedly will always return the
959 first record from the resultset.
965 if (my $cache = $self->get_cache) {
966 $self->{all_cache_position} ||= 0;
967 return $cache->[$self->{all_cache_position}++];
969 if ($self->{attrs}{cache}) {
970 delete $self->{pager};
971 $self->{all_cache_position} = 1;
972 return ($self->all)[0];
974 if ($self->{stashed_objects}) {
975 my $obj = shift(@{$self->{stashed_objects}});
976 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
980 exists $self->{stashed_row}
981 ? @{delete $self->{stashed_row}}
982 : $self->cursor->next
984 return undef unless (@row);
985 my ($row, @more) = $self->_construct_object(@row);
986 $self->{stashed_objects} = \@more if @more;
990 sub _construct_object {
991 my ($self, @row) = @_;
993 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
995 my @new = $self->result_class->inflate_result($self->result_source, @$info);
996 @new = $self->{_attrs}{record_filter}->(@new)
997 if exists $self->{_attrs}{record_filter};
1001 sub _collapse_result {
1002 my ($self, $as_proto, $row) = @_;
1006 # 'foo' => [ undef, 'foo' ]
1007 # 'foo.bar' => [ 'foo', 'bar' ]
1008 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1010 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1012 my %collapse = %{$self->{_attrs}{collapse}||{}};
1016 # if we're doing collapsing (has_many prefetch) we need to grab records
1017 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1018 # we know we don't have to bother.
1020 # the reason for not using the collapse stuff directly is because if you
1021 # had for e.g. two artists in a row with no cds, the collapse info for
1022 # both would be NULL (undef) so you'd lose the second artist
1024 # store just the index so we can check the array positions from the row
1025 # without having to contruct the full hash
1027 if (keys %collapse) {
1028 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1029 foreach my $i (0 .. $#construct_as) {
1030 next if defined($construct_as[$i][0]); # only self table
1031 if (delete $pri{$construct_as[$i][1]}) {
1032 push(@pri_index, $i);
1034 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1038 # no need to do an if, it'll be empty if @pri_index is empty anyway
1040 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1044 do { # no need to check anything at the front, we always want the first row
1048 foreach my $this_as (@construct_as) {
1049 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1052 push(@const_rows, \%const);
1054 } until ( # no pri_index => no collapse => drop straight out
1057 do { # get another row, stash it, drop out if different PK
1059 @copy = $self->cursor->next;
1060 $self->{stashed_row} = \@copy;
1062 # last thing in do block, counts as true if anything doesn't match
1064 # check xor defined first for NULL vs. NOT NULL then if one is
1065 # defined the other must be so check string equality
1068 (defined $pri_vals{$_} ^ defined $copy[$_])
1069 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1074 my $alias = $self->{attrs}{alias};
1081 foreach my $const (@const_rows) {
1082 scalar @const_keys or do {
1083 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1085 foreach my $key (@const_keys) {
1088 my @parts = split(/\./, $key);
1090 my $data = $const->{$key};
1091 foreach my $p (@parts) {
1092 $target = $target->[1]->{$p} ||= [];
1094 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1095 # collapsing at this point and on final part
1096 my $pos = $collapse_pos{$cur};
1097 CK: foreach my $ck (@ckey) {
1098 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1099 $collapse_pos{$cur} = $data;
1100 delete @collapse_pos{ # clear all positioning for sub-entries
1101 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1108 if (exists $collapse{$cur}) {
1109 $target = $target->[-1];
1112 $target->[0] = $data;
1114 $info->[0] = $const->{$key};
1122 =head2 result_source
1126 =item Arguments: $result_source?
1128 =item Return Value: $result_source
1132 An accessor for the primary ResultSource object from which this ResultSet
1139 =item Arguments: $result_class?
1141 =item Return Value: $result_class
1145 An accessor for the class to use when creating row objects. Defaults to
1146 C<< result_source->result_class >> - which in most cases is the name of the
1147 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1149 Note that changing the result_class will also remove any components
1150 that were originally loaded in the source class via
1151 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1152 in the original source class will not run.
1157 my ($self, $result_class) = @_;
1158 if ($result_class) {
1159 unless (ref $result_class) { # don't fire this for an object
1160 $self->ensure_class_loaded($result_class);
1162 $self->_result_class($result_class);
1163 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1164 # permit the user to set result class on one result set only; it only
1165 # chains if provided to search()
1166 #$self->{attrs}{result_class} = $result_class if ref $self;
1168 $self->_result_class;
1175 =item Arguments: $cond, \%attrs??
1177 =item Return Value: $count
1181 Performs an SQL C<COUNT> with the same query as the resultset was built
1182 with to find the number of elements. Passing arguments is equivalent to
1183 C<< $rs->search ($cond, \%attrs)->count >>
1189 return $self->search(@_)->count if @_ and defined $_[0];
1190 return scalar @{ $self->get_cache } if $self->get_cache;
1192 my $attrs = $self->_resolved_attrs_copy;
1194 # this is a little optimization - it is faster to do the limit
1195 # adjustments in software, instead of a subquery
1196 my $rows = delete $attrs->{rows};
1197 my $offset = delete $attrs->{offset};
1200 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1201 $crs = $self->_count_subq_rs ($attrs);
1204 $crs = $self->_count_rs ($attrs);
1206 my $count = $crs->next;
1208 $count -= $offset if $offset;
1209 $count = $rows if $rows and $rows < $count;
1210 $count = 0 if ($count < 0);
1219 =item Arguments: $cond, \%attrs??
1221 =item Return Value: $count_rs
1225 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1226 This can be very handy for subqueries:
1228 ->search( { amount => $some_rs->count_rs->as_query } )
1230 As with regular resultsets the SQL query will be executed only after
1231 the resultset is accessed via L</next> or L</all>. That would return
1232 the same single value obtainable via L</count>.
1238 return $self->search(@_)->count_rs if @_;
1240 # this may look like a lack of abstraction (count() does about the same)
1241 # but in fact an _rs *must* use a subquery for the limits, as the
1242 # software based limiting can not be ported if this $rs is to be used
1243 # in a subquery itself (i.e. ->as_query)
1244 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1245 return $self->_count_subq_rs;
1248 return $self->_count_rs;
1253 # returns a ResultSetColumn object tied to the count query
1256 my ($self, $attrs) = @_;
1258 my $rsrc = $self->result_source;
1259 $attrs ||= $self->_resolved_attrs;
1261 my $tmp_attrs = { %$attrs };
1262 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1263 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1265 # overwrite the selector (supplied by the storage)
1266 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1267 $tmp_attrs->{as} = 'count';
1269 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1275 # same as above but uses a subquery
1277 sub _count_subq_rs {
1278 my ($self, $attrs) = @_;
1280 my $rsrc = $self->result_source;
1281 $attrs ||= $self->_resolved_attrs;
1283 my $sub_attrs = { %$attrs };
1284 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1285 delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
1287 # if we multi-prefetch we group_by primary keys only as this is what we would
1288 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1289 if ( keys %{$attrs->{collapse}} ) {
1290 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1293 # Calculate subquery selector
1294 if (my $g = $sub_attrs->{group_by}) {
1296 my $sql_maker = $rsrc->storage->sql_maker;
1298 # necessary as the group_by may refer to aliased functions
1300 for my $sel (@{$attrs->{select}}) {
1301 $sel_index->{$sel->{-as}} = $sel
1302 if (ref $sel eq 'HASH' and $sel->{-as});
1305 for my $g_part (@$g) {
1306 my $colpiece = $sel_index->{$g_part} || $g_part;
1308 # disqualify join-based group_by's. Arcane but possible query
1309 # also horrible horrible hack to alias a column (not a func.)
1310 # (probably need to introduce SQLA syntax)
1311 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1314 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1316 push @{$sub_attrs->{select}}, $colpiece;
1320 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1321 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1324 return $rsrc->resultset_class
1325 ->new ($rsrc, $sub_attrs)
1327 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1328 ->get_column ('count');
1335 =head2 count_literal
1339 =item Arguments: $sql_fragment, @bind_values
1341 =item Return Value: $count
1345 Counts the results in a literal query. Equivalent to calling L</search_literal>
1346 with the passed arguments, then L</count>.
1350 sub count_literal { shift->search_literal(@_)->count; }
1356 =item Arguments: none
1358 =item Return Value: @objects
1362 Returns all elements in the resultset. Called implicitly if the resultset
1363 is returned in list context.
1370 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1373 return @{ $self->get_cache } if $self->get_cache;
1377 if (keys %{$self->_resolved_attrs->{collapse}}) {
1378 # Using $self->cursor->all is really just an optimisation.
1379 # If we're collapsing has_many prefetches it probably makes
1380 # very little difference, and this is cleaner than hacking
1381 # _construct_object to survive the approach
1382 $self->cursor->reset;
1383 my @row = $self->cursor->next;
1385 push(@obj, $self->_construct_object(@row));
1386 @row = (exists $self->{stashed_row}
1387 ? @{delete $self->{stashed_row}}
1388 : $self->cursor->next);
1391 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1394 $self->set_cache(\@obj) if $self->{attrs}{cache};
1403 =item Arguments: none
1405 =item Return Value: $self
1409 Resets the resultset's cursor, so you can iterate through the elements again.
1410 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1417 delete $self->{_attrs} if exists $self->{_attrs};
1418 $self->{all_cache_position} = 0;
1419 $self->cursor->reset;
1427 =item Arguments: none
1429 =item Return Value: $object | undef
1433 Resets the resultset and returns an object for the first result (or C<undef>
1434 if the resultset is empty).
1439 return $_[0]->reset->next;
1445 # Determines whether and what type of subquery is required for the $rs operation.
1446 # If grouping is necessary either supplies its own, or verifies the current one
1447 # After all is done delegates to the proper storage method.
1449 sub _rs_update_delete {
1450 my ($self, $op, $values) = @_;
1452 my $rsrc = $self->result_source;
1454 # if a condition exists we need to strip all table qualifiers
1455 # if this is not possible we'll force a subquery below
1456 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1458 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1459 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1461 if ($needs_group_by_subq or $needs_subq) {
1463 # make a new $rs selecting only the PKs (that's all we really need)
1464 my $attrs = $self->_resolved_attrs_copy;
1467 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1468 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1470 if ($needs_group_by_subq) {
1471 # make sure no group_by was supplied, or if there is one - make sure it matches
1472 # the columns compiled above perfectly. Anything else can not be sanely executed
1473 # on most databases so croak right then and there
1475 if (my $g = $attrs->{group_by}) {
1476 my @current_group_by = map
1477 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1482 join ("\x00", sort @current_group_by)
1484 join ("\x00", sort @{$attrs->{columns}} )
1486 $self->throw_exception (
1487 "You have just attempted a $op operation on a resultset which does group_by"
1488 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1489 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1490 . ' kind of queries. Please retry the operation with a modified group_by or'
1491 . ' without using one at all.'
1496 $attrs->{group_by} = $attrs->{columns};
1500 my $subrs = (ref $self)->new($rsrc, $attrs);
1501 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1504 return $rsrc->storage->$op(
1506 $op eq 'update' ? $values : (),
1516 =item Arguments: \%values
1518 =item Return Value: $storage_rv
1522 Sets the specified columns in the resultset to the supplied values in a
1523 single query. Note that this will not run any accessor/set_column/update
1524 triggers, nor will it update any row object instances derived from this
1525 resultset (this includes the contents of the L<resultset cache|/set_cache>
1526 if any). See L</update_all> if you need to execute any on-update
1527 triggers or cascades defined either by you or a
1528 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1530 The return value is a pass through of what the underlying
1531 storage backend returned, and may vary. See L<DBI/execute> for the most
1536 Note that L</update> does not process/deflate any of the values passed in.
1537 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1538 ensure manually that any value passed to this method will stringify to
1539 something the RDBMS knows how to deal with. A notable example is the
1540 handling of L<DateTime> objects, for more info see:
1541 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1546 my ($self, $values) = @_;
1547 $self->throw_exception('Values for update must be a hash')
1548 unless ref $values eq 'HASH';
1550 return $self->_rs_update_delete ('update', $values);
1557 =item Arguments: \%values
1559 =item Return Value: 1
1563 Fetches all objects and updates them one at a time via
1564 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1565 triggers, while L</update> will not.
1570 my ($self, $values) = @_;
1571 $self->throw_exception('Values for update_all must be a hash')
1572 unless ref $values eq 'HASH';
1574 my $guard = $self->result_source->schema->txn_scope_guard;
1575 $_->update($values) for $self->all;
1584 =item Arguments: none
1586 =item Return Value: $storage_rv
1590 Deletes the rows matching this resultset in a single query. Note that this
1591 will not run any delete triggers, nor will it alter the
1592 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1593 derived from this resultset (this includes the contents of the
1594 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1595 execute any on-delete triggers or cascades defined either by you or a
1596 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1598 The return value is a pass through of what the underlying storage backend
1599 returned, and may vary. See L<DBI/execute> for the most common case.
1605 $self->throw_exception('delete does not accept any arguments')
1608 return $self->_rs_update_delete ('delete');
1615 =item Arguments: none
1617 =item Return Value: 1
1621 Fetches all objects and deletes them one at a time via
1622 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1623 triggers, while L</delete> will not.
1629 $self->throw_exception('delete_all does not accept any arguments')
1632 my $guard = $self->result_source->schema->txn_scope_guard;
1633 $_->delete for $self->all;
1642 =item Arguments: \@data;
1646 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1647 For the arrayref of hashrefs style each hashref should be a structure suitable
1648 forsubmitting to a $resultset->create(...) method.
1650 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1651 to insert the data, as this is a faster method.
1653 Otherwise, each set of data is inserted into the database using
1654 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1655 accumulated into an array. The array itself, or an array reference
1656 is returned depending on scalar or list context.
1658 Example: Assuming an Artist Class that has many CDs Classes relating:
1660 my $Artist_rs = $schema->resultset("Artist");
1662 ## Void Context Example
1663 $Artist_rs->populate([
1664 { artistid => 4, name => 'Manufactured Crap', cds => [
1665 { title => 'My First CD', year => 2006 },
1666 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1669 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1670 { title => 'My parents sold me to a record company', year => 2005 },
1671 { title => 'Why Am I So Ugly?', year => 2006 },
1672 { title => 'I Got Surgery and am now Popular', year => 2007 }
1677 ## Array Context Example
1678 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1679 { name => "Artist One"},
1680 { name => "Artist Two"},
1681 { name => "Artist Three", cds=> [
1682 { title => "First CD", year => 2007},
1683 { title => "Second CD", year => 2008},
1687 print $ArtistOne->name; ## response is 'Artist One'
1688 print $ArtistThree->cds->count ## reponse is '2'
1690 For the arrayref of arrayrefs style, the first element should be a list of the
1691 fieldsnames to which the remaining elements are rows being inserted. For
1694 $Arstist_rs->populate([
1695 [qw/artistid name/],
1696 [100, 'A Formally Unknown Singer'],
1697 [101, 'A singer that jumped the shark two albums ago'],
1698 [102, 'An actually cool singer'],
1701 Please note an important effect on your data when choosing between void and
1702 wantarray context. Since void context goes straight to C<insert_bulk> in
1703 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1704 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1705 create primary keys for you, you will find that your PKs are empty. In this
1706 case you will have to use the wantarray context in order to create those
1714 # cruft placed in standalone method
1715 my $data = $self->_normalize_populate_args(@_);
1717 if(defined wantarray) {
1719 foreach my $item (@$data) {
1720 push(@created, $self->create($item));
1722 return wantarray ? @created : \@created;
1724 my $first = $data->[0];
1726 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1727 # it relationship data
1728 my (@rels, @columns);
1729 for (keys %$first) {
1730 my $ref = ref $first->{$_};
1731 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1737 my @pks = $self->result_source->primary_columns;
1739 ## do the belongs_to relationships
1740 foreach my $index (0..$#$data) {
1742 # delegate to create() for any dataset without primary keys with specified relationships
1743 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1745 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1746 my @ret = $self->populate($data);
1752 foreach my $rel (@rels) {
1753 next unless ref $data->[$index]->{$rel} eq "HASH";
1754 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1755 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1756 my $related = $result->result_source->_resolve_condition(
1757 $result->result_source->relationship_info($reverse)->{cond},
1762 delete $data->[$index]->{$rel};
1763 $data->[$index] = {%{$data->[$index]}, %$related};
1765 push @columns, keys %$related if $index == 0;
1769 ## inherit the data locked in the conditions of the resultset
1770 my ($rs_data) = $self->_merge_with_rscond({});
1771 delete @{$rs_data}{@columns};
1772 my @inherit_cols = keys %$rs_data;
1773 my @inherit_data = values %$rs_data;
1775 ## do bulk insert on current row
1776 $self->result_source->storage->insert_bulk(
1777 $self->result_source,
1778 [@columns, @inherit_cols],
1779 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1782 ## do the has_many relationships
1783 foreach my $item (@$data) {
1785 foreach my $rel (@rels) {
1786 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1788 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1789 || $self->throw_exception('Cannot find the relating object.');
1791 my $child = $parent->$rel;
1793 my $related = $child->result_source->_resolve_condition(
1794 $parent->result_source->relationship_info($rel)->{cond},
1799 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1800 my @populate = map { {%$_, %$related} } @rows_to_add;
1802 $child->populate( \@populate );
1809 # populate() argumnets went over several incarnations
1810 # What we ultimately support is AoH
1811 sub _normalize_populate_args {
1812 my ($self, $arg) = @_;
1814 if (ref $arg eq 'ARRAY') {
1815 if (ref $arg->[0] eq 'HASH') {
1818 elsif (ref $arg->[0] eq 'ARRAY') {
1820 my @colnames = @{$arg->[0]};
1821 foreach my $values (@{$arg}[1 .. $#$arg]) {
1822 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1828 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1835 =item Arguments: none
1837 =item Return Value: $pager
1841 Return Value a L<Data::Page> object for the current resultset. Only makes
1842 sense for queries with a C<page> attribute.
1844 To get the full count of entries for a paged resultset, call
1845 C<total_entries> on the L<Data::Page> object.
1849 # make a wizard good for both a scalar and a hashref
1850 my $mk_lazy_count_wizard = sub {
1851 require Variable::Magic;
1853 my $stash = { total_rs => shift };
1854 my $slot = shift; # only used by the hashref magic
1856 my $magic = Variable::Magic::wizard (
1857 data => sub { $stash },
1863 # set value lazily, and dispell for good
1864 ${$_[0]} = $_[1]{total_rs}->count;
1865 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
1869 # an explicit set implies dispell as well
1870 # the unless() is to work around "fun and giggles" below
1871 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
1872 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1879 if ($_[2] eq $slot and !$_[1]{inactive}) {
1880 my $cnt = $_[1]{total_rs}->count;
1881 $_[0]->{$slot} = $cnt;
1883 # attempting to dispell in a fetch handle (works in store), seems
1884 # to invariable segfault on 5.10, 5.12, 5.13 :(
1885 # so use an inactivator instead
1886 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1892 if (! $_[1]{inactive} and $_[2] eq $slot) {
1893 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1895 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1902 $stash->{magic_selfref} = $magic;
1903 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
1908 # the tie class for 5.8.1
1910 package # hide from pause
1911 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
1912 use base qw/Tie::Hash/;
1914 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
1915 sub NEXTKEY { each %{$_[0]{data}} }
1916 sub EXISTS { exists $_[0]{data}{$_[1]} }
1917 sub DELETE { delete $_[0]{data}{$_[1]} }
1918 sub CLEAR { %{$_[0]{data}} = () }
1919 sub SCALAR { scalar %{$_[0]{data}} }
1922 $_[1]{data} = {%{$_[1]{selfref}}};
1923 %{$_[1]{selfref}} = ();
1924 Scalar::Util::weaken ($_[1]{selfref});
1925 return bless ($_[1], $_[0]);
1929 if ($_[1] eq $_[0]{slot}) {
1930 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
1931 untie %{$_[0]{selfref}};
1932 %{$_[0]{selfref}} = %{$_[0]{data}};
1941 $_[0]{data}{$_[1]} = $_[2];
1942 if ($_[1] eq $_[0]{slot}) {
1943 untie %{$_[0]{selfref}};
1944 %{$_[0]{selfref}} = %{$_[0]{data}};
1953 return $self->{pager} if $self->{pager};
1955 if ($self->get_cache) {
1956 $self->throw_exception ('Pagers on cached resultsets are not supported');
1959 my $attrs = $self->{attrs};
1960 $self->throw_exception("Can't create pager for non-paged rs")
1961 unless $self->{attrs}{page};
1962 $attrs->{rows} ||= 10;
1964 # throw away the paging flags and re-run the count (possibly
1965 # with a subselect) to get the real total count
1966 my $count_attrs = { %$attrs };
1967 delete $count_attrs->{$_} for qw/rows offset page pager/;
1968 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
1971 ### the following may seem awkward and dirty, but it's a thought-experiment
1972 ### necessary for future development of DBIx::DS. Do *NOT* change this code
1973 ### before talking to ribasushi/mst
1975 my $pager = Data::Page->new(
1976 0, #start with an empty set
1978 $self->{attrs}{page},
1981 my $data_slot = 'total_entries';
1983 # Since we are interested in a cached value (once it's set - it's set), every
1984 # technique will detach from the magic-host once the time comes to fire the
1985 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
1987 if ($] < 5.008003) {
1988 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
1989 # to weakref the magic container :(
1991 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
1992 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
1995 elsif ($] < 5.010) {
1996 # We can use magic on the hash value slot. It's interesting that the magic is
1997 # attached to the hash-slot, and does *not* stop working once I do the dummy
1998 # assignments after the cast()
1999 # tested on 5.8.3 and 5.8.9
2000 my $magic = $mk_lazy_count_wizard->($total_rs);
2001 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2003 # this is for fun and giggles
2004 $pager->{$data_slot} = -1;
2005 $pager->{$data_slot} = 0;
2007 # this does not work for scalars, but works with
2009 #my %vals = %$pager;
2014 # And the uvar magic
2015 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2016 # however see the wizard maker for more notes
2017 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2018 Variable::Magic::cast ( %$pager, $magic );
2021 $pager->{$data_slot} = -1;
2022 $pager->{$data_slot} = 0;
2030 return $self->{pager} = $pager;
2037 =item Arguments: $page_number
2039 =item Return Value: $rs
2043 Returns a resultset for the $page_number page of the resultset on which page
2044 is called, where each page contains a number of rows equal to the 'rows'
2045 attribute set on the resultset (10 by default).
2050 my ($self, $page) = @_;
2051 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2058 =item Arguments: \%vals
2060 =item Return Value: $rowobject
2064 Creates a new row object in the resultset's result class and returns
2065 it. The row is not inserted into the database at this point, call
2066 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2067 will tell you whether the row object has been inserted or not.
2069 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2074 my ($self, $values) = @_;
2075 $self->throw_exception( "new_result needs a hash" )
2076 unless (ref $values eq 'HASH');
2078 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2082 @$cols_from_relations
2083 ? (-cols_from_relations => $cols_from_relations)
2085 -source_handle => $self->_source_handle,
2086 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2089 return $self->result_class->new(\%new);
2092 # _merge_with_rscond
2094 # Takes a simple hash of K/V data and returns its copy merged with the
2095 # condition already present on the resultset. Additionally returns an
2096 # arrayref of value/condition names, which were inferred from related
2097 # objects (this is needed for in-memory related objects)
2098 sub _merge_with_rscond {
2099 my ($self, $data) = @_;
2101 my (%new_data, @cols_from_relations);
2103 my $alias = $self->{attrs}{alias};
2105 if (! defined $self->{cond}) {
2106 # just massage $data below
2108 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2109 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2110 @cols_from_relations = keys %new_data;
2112 elsif (ref $self->{cond} ne 'HASH') {
2113 $self->throw_exception(
2114 "Can't abstract implicit construct, resultset condition not a hash"
2118 # precendence must be given to passed values over values inherited from
2119 # the cond, so the order here is important.
2120 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2121 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2123 while ( my($col, $value) = each %implied ) {
2124 my $vref = ref $value;
2125 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2126 $new_data{$col} = $value->{'='};
2128 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2129 $new_data{$col} = $value;
2136 %{ $self->_remove_alias($data, $alias) },
2139 return (\%new_data, \@cols_from_relations);
2142 # _has_resolved_attr
2144 # determines if the resultset defines at least one
2145 # of the attributes supplied
2147 # used to determine if a subquery is neccessary
2149 # supports some virtual attributes:
2151 # This will scan for any joins being present on the resultset.
2152 # It is not a mere key-search but a deep inspection of {from}
2155 sub _has_resolved_attr {
2156 my ($self, @attr_names) = @_;
2158 my $attrs = $self->_resolved_attrs;
2162 for my $n (@attr_names) {
2163 if (grep { $n eq $_ } (qw/-join/) ) {
2164 $extra_checks{$n}++;
2168 my $attr = $attrs->{$n};
2170 next if not defined $attr;
2172 if (ref $attr eq 'HASH') {
2173 return 1 if keys %$attr;
2175 elsif (ref $attr eq 'ARRAY') {
2183 # a resolved join is expressed as a multi-level from
2185 $extra_checks{-join}
2187 ref $attrs->{from} eq 'ARRAY'
2189 @{$attrs->{from}} > 1
2197 # Recursively collapse the condition.
2199 sub _collapse_cond {
2200 my ($self, $cond, $collapsed) = @_;
2204 if (ref $cond eq 'ARRAY') {
2205 foreach my $subcond (@$cond) {
2206 next unless ref $subcond; # -or
2207 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2210 elsif (ref $cond eq 'HASH') {
2211 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2212 foreach my $subcond (@{$cond->{-and}}) {
2213 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2217 foreach my $col (keys %$cond) {
2218 my $value = $cond->{$col};
2219 $collapsed->{$col} = $value;
2229 # Remove the specified alias from the specified query hash. A copy is made so
2230 # the original query is not modified.
2233 my ($self, $query, $alias) = @_;
2235 my %orig = %{ $query || {} };
2238 foreach my $key (keys %orig) {
2240 $unaliased{$key} = $orig{$key};
2243 $unaliased{$1} = $orig{$key}
2244 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2254 =item Arguments: none
2256 =item Return Value: \[ $sql, @bind ]
2260 Returns the SQL query and bind vars associated with the invocant.
2262 This is generally used as the RHS for a subquery.
2269 my $attrs = $self->_resolved_attrs_copy;
2274 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2275 # $sql also has no wrapping parenthesis in list ctx
2277 my $sqlbind = $self->result_source->storage
2278 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2287 =item Arguments: \%vals, \%attrs?
2289 =item Return Value: $rowobject
2293 my $artist = $schema->resultset('Artist')->find_or_new(
2294 { artist => 'fred' }, { key => 'artists' });
2296 $cd->cd_to_producer->find_or_new({ producer => $producer },
2297 { key => 'primary });
2299 Find an existing record from this resultset using L</find>. if none exists,
2300 instantiate a new result object and return it. The object will not be saved
2301 into your storage until you call L<DBIx::Class::Row/insert> on it.
2303 You most likely want this method when looking for existing rows using a unique
2304 constraint that is not the primary key, or looking for related rows.
2306 If you want objects to be saved immediately, use L</find_or_create> instead.
2308 B<Note>: Make sure to read the documentation of L</find> and understand the
2309 significance of the C<key> attribute, as its lack may skew your search, and
2310 subsequently result in spurious new objects.
2312 B<Note>: Take care when using C<find_or_new> with a table having
2313 columns with default values that you intend to be automatically
2314 supplied by the database (e.g. an auto_increment primary key column).
2315 In normal usage, the value of such columns should NOT be included at
2316 all in the call to C<find_or_new>, even when set to C<undef>.
2322 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2323 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2324 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2327 return $self->new_result($hash);
2334 =item Arguments: \%vals
2336 =item Return Value: a L<DBIx::Class::Row> $object
2340 Attempt to create a single new row or a row with multiple related rows
2341 in the table represented by the resultset (and related tables). This
2342 will not check for duplicate rows before inserting, use
2343 L</find_or_create> to do that.
2345 To create one row for this resultset, pass a hashref of key/value
2346 pairs representing the columns of the table and the values you wish to
2347 store. If the appropriate relationships are set up, foreign key fields
2348 can also be passed an object representing the foreign row, and the
2349 value will be set to its primary key.
2351 To create related objects, pass a hashref of related-object column values
2352 B<keyed on the relationship name>. If the relationship is of type C<multi>
2353 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2354 The process will correctly identify columns holding foreign keys, and will
2355 transparently populate them from the keys of the corresponding relation.
2356 This can be applied recursively, and will work correctly for a structure
2357 with an arbitrary depth and width, as long as the relationships actually
2358 exists and the correct column data has been supplied.
2361 Instead of hashrefs of plain related data (key/value pairs), you may
2362 also pass new or inserted objects. New objects (not inserted yet, see
2363 L</new>), will be inserted into their appropriate tables.
2365 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2367 Example of creating a new row.
2369 $person_rs->create({
2370 name=>"Some Person",
2371 email=>"somebody@someplace.com"
2374 Example of creating a new row and also creating rows in a related C<has_many>
2375 or C<has_one> resultset. Note Arrayref.
2378 { artistid => 4, name => 'Manufactured Crap', cds => [
2379 { title => 'My First CD', year => 2006 },
2380 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2385 Example of creating a new row and also creating a row in a related
2386 C<belongs_to> resultset. Note Hashref.
2389 title=>"Music for Silly Walks",
2392 name=>"Silly Musician",
2400 When subclassing ResultSet never attempt to override this method. Since
2401 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2402 lot of the internals simply never call it, so your override will be
2403 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2404 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2405 L</create> process you need to intervene.
2412 my ($self, $attrs) = @_;
2413 $self->throw_exception( "create needs a hashref" )
2414 unless ref $attrs eq 'HASH';
2415 return $self->new_result($attrs)->insert;
2418 =head2 find_or_create
2422 =item Arguments: \%vals, \%attrs?
2424 =item Return Value: $rowobject
2428 $cd->cd_to_producer->find_or_create({ producer => $producer },
2429 { key => 'primary' });
2431 Tries to find a record based on its primary key or unique constraints; if none
2432 is found, creates one and returns that instead.
2434 my $cd = $schema->resultset('CD')->find_or_create({
2436 artist => 'Massive Attack',
2437 title => 'Mezzanine',
2441 Also takes an optional C<key> attribute, to search by a specific key or unique
2442 constraint. For example:
2444 my $cd = $schema->resultset('CD')->find_or_create(
2446 artist => 'Massive Attack',
2447 title => 'Mezzanine',
2449 { key => 'cd_artist_title' }
2452 B<Note>: Make sure to read the documentation of L</find> and understand the
2453 significance of the C<key> attribute, as its lack may skew your search, and
2454 subsequently result in spurious row creation.
2456 B<Note>: Because find_or_create() reads from the database and then
2457 possibly inserts based on the result, this method is subject to a race
2458 condition. Another process could create a record in the table after
2459 the find has completed and before the create has started. To avoid
2460 this problem, use find_or_create() inside a transaction.
2462 B<Note>: Take care when using C<find_or_create> with a table having
2463 columns with default values that you intend to be automatically
2464 supplied by the database (e.g. an auto_increment primary key column).
2465 In normal usage, the value of such columns should NOT be included at
2466 all in the call to C<find_or_create>, even when set to C<undef>.
2468 See also L</find> and L</update_or_create>. For information on how to declare
2469 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2473 sub find_or_create {
2475 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2476 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2477 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2480 return $self->create($hash);
2483 =head2 update_or_create
2487 =item Arguments: \%col_values, { key => $unique_constraint }?
2489 =item Return Value: $row_object
2493 $resultset->update_or_create({ col => $val, ... });
2495 Like L</find_or_create>, but if a row is found it is immediately updated via
2496 C<< $found_row->update (\%col_values) >>.
2499 Takes an optional C<key> attribute to search on a specific unique constraint.
2502 # In your application
2503 my $cd = $schema->resultset('CD')->update_or_create(
2505 artist => 'Massive Attack',
2506 title => 'Mezzanine',
2509 { key => 'cd_artist_title' }
2512 $cd->cd_to_producer->update_or_create({
2513 producer => $producer,
2519 B<Note>: Make sure to read the documentation of L</find> and understand the
2520 significance of the C<key> attribute, as its lack may skew your search, and
2521 subsequently result in spurious row creation.
2523 B<Note>: Take care when using C<update_or_create> with a table having
2524 columns with default values that you intend to be automatically
2525 supplied by the database (e.g. an auto_increment primary key column).
2526 In normal usage, the value of such columns should NOT be included at
2527 all in the call to C<update_or_create>, even when set to C<undef>.
2529 See also L</find> and L</find_or_create>. For information on how to declare
2530 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2534 sub update_or_create {
2536 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2537 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2539 my $row = $self->find($cond, $attrs);
2541 $row->update($cond);
2545 return $self->create($cond);
2548 =head2 update_or_new
2552 =item Arguments: \%col_values, { key => $unique_constraint }?
2554 =item Return Value: $rowobject
2558 $resultset->update_or_new({ col => $val, ... });
2560 Like L</find_or_new> but if a row is found it is immediately updated via
2561 C<< $found_row->update (\%col_values) >>.
2565 # In your application
2566 my $cd = $schema->resultset('CD')->update_or_new(
2568 artist => 'Massive Attack',
2569 title => 'Mezzanine',
2572 { key => 'cd_artist_title' }
2575 if ($cd->in_storage) {
2576 # the cd was updated
2579 # the cd is not yet in the database, let's insert it
2583 B<Note>: Make sure to read the documentation of L</find> and understand the
2584 significance of the C<key> attribute, as its lack may skew your search, and
2585 subsequently result in spurious new objects.
2587 B<Note>: Take care when using C<update_or_new> with a table having
2588 columns with default values that you intend to be automatically
2589 supplied by the database (e.g. an auto_increment primary key column).
2590 In normal usage, the value of such columns should NOT be included at
2591 all in the call to C<update_or_new>, even when set to C<undef>.
2593 See also L</find>, L</find_or_create> and L</find_or_new>.
2599 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2600 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2602 my $row = $self->find( $cond, $attrs );
2603 if ( defined $row ) {
2604 $row->update($cond);
2608 return $self->new_result($cond);
2615 =item Arguments: none
2617 =item Return Value: \@cache_objects | undef
2621 Gets the contents of the cache for the resultset, if the cache is set.
2623 The cache is populated either by using the L</prefetch> attribute to
2624 L</search> or by calling L</set_cache>.
2636 =item Arguments: \@cache_objects
2638 =item Return Value: \@cache_objects
2642 Sets the contents of the cache for the resultset. Expects an arrayref
2643 of objects of the same class as those produced by the resultset. Note that
2644 if the cache is set the resultset will return the cached objects rather
2645 than re-querying the database even if the cache attr is not set.
2647 The contents of the cache can also be populated by using the
2648 L</prefetch> attribute to L</search>.
2653 my ( $self, $data ) = @_;
2654 $self->throw_exception("set_cache requires an arrayref")
2655 if defined($data) && (ref $data ne 'ARRAY');
2656 $self->{all_cache} = $data;
2663 =item Arguments: none
2665 =item Return Value: undef
2669 Clears the cache for the resultset.
2674 shift->set_cache(undef);
2681 =item Arguments: none
2683 =item Return Value: true, if the resultset has been paginated
2691 return !!$self->{attrs}{page};
2698 =item Arguments: none
2700 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2708 return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
2711 =head2 related_resultset
2715 =item Arguments: $relationship_name
2717 =item Return Value: $resultset
2721 Returns a related resultset for the supplied relationship name.
2723 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2727 sub related_resultset {
2728 my ($self, $rel) = @_;
2730 $self->{related_resultsets} ||= {};
2731 return $self->{related_resultsets}{$rel} ||= do {
2732 my $rsrc = $self->result_source;
2733 my $rel_info = $rsrc->relationship_info($rel);
2735 $self->throw_exception(
2736 "search_related: result source '" . $rsrc->source_name .
2737 "' has no such relationship $rel")
2740 my $attrs = $self->_chain_relationship($rel);
2742 my $join_count = $attrs->{seen_join}{$rel};
2744 my $alias = $self->result_source->storage
2745 ->relname_to_table_alias($rel, $join_count);
2747 # since this is search_related, and we already slid the select window inwards
2748 # (the select/as attrs were deleted in the beginning), we need to flip all
2749 # left joins to inner, so we get the expected results
2750 # read the comment on top of the actual function to see what this does
2751 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2754 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2755 delete @{$attrs}{qw(result_class alias)};
2759 if (my $cache = $self->get_cache) {
2760 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2761 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2766 my $rel_source = $rsrc->related_source($rel);
2770 # The reason we do this now instead of passing the alias to the
2771 # search_rs below is that if you wrap/overload resultset on the
2772 # source you need to know what alias it's -going- to have for things
2773 # to work sanely (e.g. RestrictWithObject wants to be able to add
2774 # extra query restrictions, and these may need to be $alias.)
2776 my $rel_attrs = $rel_source->resultset_attributes;
2777 local $rel_attrs->{alias} = $alias;
2779 $rel_source->resultset
2783 where => $attrs->{where},
2786 $new->set_cache($new_cache) if $new_cache;
2791 =head2 current_source_alias
2795 =item Arguments: none
2797 =item Return Value: $source_alias
2801 Returns the current table alias for the result source this resultset is built
2802 on, that will be used in the SQL query. Usually it is C<me>.
2804 Currently the source alias that refers to the result set returned by a
2805 L</search>/L</find> family method depends on how you got to the resultset: it's
2806 C<me> by default, but eg. L</search_related> aliases it to the related result
2807 source name (and keeps C<me> referring to the original result set). The long
2808 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2809 (and make this method unnecessary).
2811 Thus it's currently necessary to use this method in predefined queries (see
2812 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2813 source alias of the current result set:
2815 # in a result set class
2817 my ($self, $user) = @_;
2819 my $me = $self->current_source_alias;
2821 return $self->search(
2822 "$me.modified" => $user->id,
2828 sub current_source_alias {
2831 return ($self->{attrs} || {})->{alias} || 'me';
2834 =head2 as_subselect_rs
2838 =item Arguments: none
2840 =item Return Value: $resultset
2844 Act as a barrier to SQL symbols. The resultset provided will be made into a
2845 "virtual view" by including it as a subquery within the from clause. From this
2846 point on, any joined tables are inaccessible to ->search on the resultset (as if
2847 it were simply where-filtered without joins). For example:
2849 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2851 # 'x' now pollutes the query namespace
2853 # So the following works as expected
2854 my $ok_rs = $rs->search({'x.other' => 1});
2856 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2857 # def) we look for one row with contradictory terms and join in another table
2858 # (aliased 'x_2') which we never use
2859 my $broken_rs = $rs->search({'x.name' => 'def'});
2861 my $rs2 = $rs->as_subselect_rs;
2863 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2864 my $not_joined_rs = $rs2->search({'x.other' => 1});
2866 # works as expected: finds a 'table' row related to two x rows (abc and def)
2867 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2869 Another example of when one might use this would be to select a subset of
2870 columns in a group by clause:
2872 my $rs = $schema->resultset('Bar')->search(undef, {
2873 group_by => [qw{ id foo_id baz_id }],
2874 })->as_subselect_rs->search(undef, {
2875 columns => [qw{ id foo_id }]
2878 In the above example normally columns would have to be equal to the group by,
2879 but because we isolated the group by into a subselect the above works.
2883 sub as_subselect_rs {
2886 my $attrs = $self->_resolved_attrs;
2888 my $fresh_rs = (ref $self)->new (
2889 $self->result_source
2892 # these pieces will be locked in the subquery
2893 delete $fresh_rs->{cond};
2894 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2896 return $fresh_rs->search( {}, {
2898 $attrs->{alias} => $self->as_query,
2899 -alias => $attrs->{alias},
2900 -source_handle => $self->result_source->handle,
2902 alias => $attrs->{alias},
2906 # This code is called by search_related, and makes sure there
2907 # is clear separation between the joins before, during, and
2908 # after the relationship. This information is needed later
2909 # in order to properly resolve prefetch aliases (any alias
2910 # with a relation_chain_depth less than the depth of the
2911 # current prefetch is not considered)
2913 # The increments happen twice per join. An even number means a
2914 # relationship specified via a search_related, whereas an odd
2915 # number indicates a join/prefetch added via attributes
2917 # Also this code will wrap the current resultset (the one we
2918 # chain to) in a subselect IFF it contains limiting attributes
2919 sub _chain_relationship {
2920 my ($self, $rel) = @_;
2921 my $source = $self->result_source;
2922 my $attrs = { %{$self->{attrs}||{}} };
2924 # we need to take the prefetch the attrs into account before we
2925 # ->_resolve_join as otherwise they get lost - captainL
2926 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
2928 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2930 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2933 my @force_subq_attrs = qw/offset rows group_by having/;
2936 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2938 $self->_has_resolved_attr (@force_subq_attrs)
2940 # Nuke the prefetch (if any) before the new $rs attrs
2941 # are resolved (prefetch is useless - we are wrapping
2942 # a subquery anyway).
2943 my $rs_copy = $self->search;
2944 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
2945 $rs_copy->{attrs}{join},
2946 delete $rs_copy->{attrs}{prefetch},
2950 -source_handle => $source->handle,
2951 -alias => $attrs->{alias},
2952 $attrs->{alias} => $rs_copy->as_query,
2954 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2955 $seen->{-relation_chain_depth} = 0;
2957 elsif ($attrs->{from}) { #shallow copy suffices
2958 $from = [ @{$attrs->{from}} ];
2962 -source_handle => $source->handle,
2963 -alias => $attrs->{alias},
2964 $attrs->{alias} => $source->from,
2968 my $jpath = ($seen->{-relation_chain_depth})
2969 ? $from->[-1][0]{-join_path}
2972 my @requested_joins = $source->_resolve_join(
2979 push @$from, @requested_joins;
2981 $seen->{-relation_chain_depth}++;
2983 # if $self already had a join/prefetch specified on it, the requested
2984 # $rel might very well be already included. What we do in this case
2985 # is effectively a no-op (except that we bump up the chain_depth on
2986 # the join in question so we could tell it *is* the search_related)
2989 # we consider the last one thus reverse
2990 for my $j (reverse @requested_joins) {
2991 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2992 if ($rel eq $last_j) {
2993 $j->[0]{-relation_chain_depth}++;
2999 unless ($already_joined) {
3000 push @$from, $source->_resolve_join(
3008 $seen->{-relation_chain_depth}++;
3010 return {%$attrs, from => $from, seen_join => $seen};
3013 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3014 sub _resolved_attrs_copy {
3016 return { %{$self->_resolved_attrs (@_)} };
3019 sub _resolved_attrs {
3021 return $self->{_attrs} if $self->{_attrs};
3023 my $attrs = { %{ $self->{attrs} || {} } };
3024 my $source = $self->result_source;
3025 my $alias = $attrs->{alias};
3028 # resolve selectors, this one is quite hairy
3030 my $selection_pieces;
3032 $attrs->{columns} ||= delete $attrs->{cols}
3033 if exists $attrs->{cols};
3035 # disassemble columns / +columns
3037 $selection_pieces->{columns}{select},
3038 $selection_pieces->{columns}{as},
3039 $selection_pieces->{'+columns'}{select},
3040 $selection_pieces->{'+columns'}{as},
3045 for my $colbit (@$_) {
3047 if (ref $colbit eq 'HASH') {
3048 for my $as (keys %$colbit) {
3049 push @sel, $colbit->{$as};
3062 (ref $attrs->{columns} eq 'ARRAY' ? delete $attrs->{columns} : [ delete $attrs->{columns} ]),
3063 # include_columns is a legacy add-on to +columns
3064 [ map { ref $_ eq 'ARRAY' ? @$_ : ($_ || () ) } delete @{$attrs}{qw/+columns include_columns/} ] )
3067 # make copies of select/as and +select/+as
3069 $selection_pieces->{'select/as'}{select},
3070 $selection_pieces->{'select/as'}{as},
3071 $selection_pieces->{'+select/+as'}{select},
3072 $selection_pieces->{'+select/+as'}{as},
3074 { $_ ? [ ref $_ eq 'ARRAY' ? @$_ : $_ ] : [] }
3075 ( delete @{$attrs}{qw/select as +select +as/} )
3078 # default to * only when neither no non-plus selectors are available
3080 ! @{$selection_pieces->{'select/as'}{select}}
3082 ! @{$selection_pieces->{'columns'}{select}}
3084 for ($source->columns) {
3085 push @{$selection_pieces->{'select/as'}{select}}, $_;
3086 push @{$selection_pieces->{'select/as'}{as}}, $_;
3090 # final composition order (important)
3091 my @sel_pairs = grep {
3092 $selection_pieces->{$_}
3095 ( $selection_pieces->{$_}{select} && @{$selection_pieces->{$_}{select}} )
3097 ( $selection_pieces->{$_}{as} && @{$selection_pieces->{$_}{as}} )
3099 } qw|columns select/as +columns +select/+as|;
3101 # fill in missing as bits for each pair
3102 # if it's the last pair we can let things slide ( bare +select is sadly popular)
3105 for my $i (0 .. $#sel_pairs) {
3107 my $pairname = $sel_pairs[$i];
3109 my ($sel, $as) = @{$selection_pieces->{$pairname}}{qw/select as/};
3111 $self->throw_exception(
3112 "Unable to assemble final selection list: $pairname specified in addition to unbalanced $sel_pairs[$i-1]"
3113 ) if ($out_of_sync);
3115 if (@$sel == @$as) {
3118 elsif (@$sel < @$as) {
3119 $self->throw_exception(
3120 "More 'as' elements than 'select' elements for $pairname, unable to continue"
3124 # try to deduce the 'as' part, will work only if all the selectors are "plain", or contain an explicit -as
3125 # if we can not deduce something - stop right there and leave the rest of the selector un-as'ed
3126 # if there is an extra selection pair coming after that - it will die due to out_of_sync being set
3127 for my $j ($#$as+1 .. $#$sel) {
3128 if (my $ref = ref $sel->[$j]) {
3129 if ($ref eq 'HASH' and exists $sel->[$j]{-as}) {
3130 push @$as, $sel->[$j]{-as};
3138 push @$as, $sel->[$j];
3144 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3145 # disqualify all $alias.col as-bits (collapser mandated)
3146 for (values %$selection_pieces) {
3147 $_->{select} = [ map { (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" } @{$_->{select}} ];
3148 $_->{as} = [ map { $_ =~ /^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$_->{as}} ];
3152 # Blatant bugwardness encoded into multiple tests.
3153 # While columns behaves sensibly, +columns is expected
3154 # to dump *any* foreign columns into the main object
3156 $selection_pieces->{'+columns'}{as} = [ map
3157 { (split /\./, $_)[-1] }
3158 @{$selection_pieces->{'+columns'}{as}}
3163 $attrs->{select} = $self->_merge_attr ($attrs->{select}, $selection_pieces->{$_}{select});
3164 $attrs->{as} = $self->_merge_attr ($attrs->{as}, $selection_pieces->{$_}{as});
3167 # de-duplicate the result (remove *identical* select/as pairs)
3168 # and also die on duplicate {as} pointing to different {select}s
3169 # not using a c-style for as the condition is prone to shrinkage
3172 while ($i <= $#{$attrs->{as}} ) {
3173 my ($sel, $as) = map { $attrs->{$_}[$i] } (qw/select as/);
3175 if ($seen->{"$sel \x00\x00 $as"}++) {
3177 for @{$attrs}{qw/select as/};
3179 elsif ($seen->{$as}++) {
3180 $self->throw_exception(
3181 "inflate_result() alias '$as' specified twice with different SQL-side {select}-ors"
3189 ## selector resolution done
3193 $attrs->{from} ||= [{
3194 -source_handle => $source->handle,
3195 -alias => $self->{attrs}{alias},
3196 $self->{attrs}{alias} => $source->from,
3199 if ( $attrs->{join} || $attrs->{prefetch} ) {
3201 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3202 if ref $attrs->{from} ne 'ARRAY';
3204 my $join = delete $attrs->{join} || {};
3206 if ( defined $attrs->{prefetch} ) {
3207 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3210 $attrs->{from} = # have to copy here to avoid corrupting the original
3212 @{ $attrs->{from} },
3213 $source->_resolve_join(
3216 { %{ $attrs->{seen_join} || {} } },
3217 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3218 ? $attrs->{from}[-1][0]{-join_path}
3225 if ( defined $attrs->{order_by} ) {
3226 $attrs->{order_by} = (
3227 ref( $attrs->{order_by} ) eq 'ARRAY'
3228 ? [ @{ $attrs->{order_by} } ]
3229 : [ $attrs->{order_by} || () ]
3233 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3234 $attrs->{group_by} = [ $attrs->{group_by} ];
3237 # generate the distinct induced group_by early, as prefetch will be carried via a
3238 # subquery (since a group_by is present)
3239 if (delete $attrs->{distinct}) {
3240 if ($attrs->{group_by}) {
3241 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3244 $attrs->{group_by} = $source->storage->_group_over_selection (
3245 @{$attrs}{qw/from select order_by/}
3250 $attrs->{collapse} ||= {};
3251 if ( my $prefetch = delete $attrs->{prefetch} ) {
3252 $prefetch = $self->_merge_joinpref_attr( {}, $prefetch );
3254 my $prefetch_ordering = [];
3256 # this is a separate structure (we don't look in {from} directly)
3257 # as the resolver needs to shift things off the lists to work
3258 # properly (identical-prefetches on different branches)
3260 if (ref $attrs->{from} eq 'ARRAY') {
3262 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3264 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3265 next unless $j->[0]{-alias};
3266 next unless $j->[0]{-join_path};
3267 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3269 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3272 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3273 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3278 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3280 # we need to somehow mark which columns came from prefetch
3281 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3283 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3284 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3286 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3287 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3290 # if both page and offset are specified, produce a combined offset
3291 # even though it doesn't make much sense, this is what pre 081xx has
3293 if (my $page = delete $attrs->{page}) {
3295 ($attrs->{rows} * ($page - 1))
3297 ($attrs->{offset} || 0)
3301 return $self->{_attrs} = $attrs;
3305 my ($self, $attr) = @_;
3307 if (ref $attr eq 'HASH') {
3308 return $self->_rollout_hash($attr);
3309 } elsif (ref $attr eq 'ARRAY') {
3310 return $self->_rollout_array($attr);
3316 sub _rollout_array {
3317 my ($self, $attr) = @_;
3320 foreach my $element (@{$attr}) {
3321 if (ref $element eq 'HASH') {
3322 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3323 } elsif (ref $element eq 'ARRAY') {
3324 # XXX - should probably recurse here
3325 push( @rolled_array, @{$self->_rollout_array($element)} );
3327 push( @rolled_array, $element );
3330 return \@rolled_array;
3334 my ($self, $attr) = @_;
3337 foreach my $key (keys %{$attr}) {
3338 push( @rolled_array, { $key => $attr->{$key} } );
3340 return \@rolled_array;
3343 sub _calculate_score {
3344 my ($self, $a, $b) = @_;
3346 if (defined $a xor defined $b) {
3349 elsif (not defined $a) {
3353 if (ref $b eq 'HASH') {
3354 my ($b_key) = keys %{$b};
3355 if (ref $a eq 'HASH') {
3356 my ($a_key) = keys %{$a};
3357 if ($a_key eq $b_key) {
3358 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3363 return ($a eq $b_key) ? 1 : 0;
3366 if (ref $a eq 'HASH') {
3367 my ($a_key) = keys %{$a};
3368 return ($b eq $a_key) ? 1 : 0;
3370 return ($b eq $a) ? 1 : 0;
3375 sub _merge_joinpref_attr {
3376 my ($self, $orig, $import) = @_;
3378 return $import unless defined($orig);
3379 return $orig unless defined($import);
3381 $orig = $self->_rollout_attr($orig);
3382 $import = $self->_rollout_attr($import);
3385 foreach my $import_element ( @{$import} ) {
3386 # find best candidate from $orig to merge $b_element into
3387 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3388 foreach my $orig_element ( @{$orig} ) {
3389 my $score = $self->_calculate_score( $orig_element, $import_element );
3390 if ($score > $best_candidate->{score}) {
3391 $best_candidate->{position} = $position;
3392 $best_candidate->{score} = $score;
3396 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3398 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3399 push( @{$orig}, $import_element );
3401 my $orig_best = $orig->[$best_candidate->{position}];
3402 # merge orig_best and b_element together and replace original with merged
3403 if (ref $orig_best ne 'HASH') {
3404 $orig->[$best_candidate->{position}] = $import_element;
3405 } elsif (ref $import_element eq 'HASH') {
3406 my ($key) = keys %{$orig_best};
3407 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3410 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3421 my $hm = Hash::Merge->new;
3423 $hm->specify_behavior({
3426 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3428 if ($defl xor $defr) {
3429 return $defl ? $_[0] : $_[1];
3434 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3438 return [$_[0], $_[1]];
3442 return $_[1] if !defined $_[0];
3443 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3444 return [$_[0], @{$_[1]}]
3447 return $_[1] if !defined $_[0];
3448 return $_[0] if !keys %{$_[1]};
3449 return [$_[0], $_[1]]
3454 return $_[0] if !defined $_[1];
3455 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3456 return [@{$_[0]}, $_[1]]
3459 my @ret = @{$_[0]} or return $_[1];
3460 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3461 my %idx = map { $_ => 1 } @ret;
3462 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3466 return [ $_[1] ] if ! @{$_[0]};
3467 return $_[0] if !keys %{$_[1]};
3468 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3469 return [ @{$_[0]}, $_[1] ];
3474 return $_[0] if !defined $_[1];
3475 return $_[1] if !keys %{$_[0]};
3476 return [$_[0], $_[1]]
3479 return $_[0] if !@{$_[1]};
3480 return $_[1] if !keys %{$_[0]};
3481 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3482 return [ $_[0], @{$_[1]} ];
3485 return $_[0] if !keys %{$_[1]};
3486 return $_[1] if !keys %{$_[0]};
3487 return $_[0] if $_[0] eq $_[1];
3488 return [ $_[0], $_[1] ];
3491 } => 'DBIC_RS_ATTR_MERGER');
3495 return $hm->merge ($_[1], $_[2]);
3503 $self->_source_handle($_[0]->handle);
3505 $self->_source_handle->resolve;
3510 sub STORABLE_freeze {
3511 my ($self, $cloning) = @_;
3512 my $to_serialize = { %$self };
3514 # A cursor in progress can't be serialized (and would make little sense anyway)
3515 delete $to_serialize->{cursor};
3517 return nfreeze($to_serialize);
3520 # need this hook for symmetry
3522 my ($self, $cloning, $serialized) = @_;
3524 %$self = %{ thaw($serialized) };
3530 =head2 throw_exception
3532 See L<DBIx::Class::Schema/throw_exception> for details.
3536 sub throw_exception {
3539 if (ref $self && $self->_source_handle->schema) {
3540 $self->_source_handle->schema->throw_exception(@_)
3543 DBIx::Class::Exception->throw(@_);
3547 # XXX: FIXME: Attributes docs need clearing up
3551 Attributes are used to refine a ResultSet in various ways when
3552 searching for data. They can be passed to any method which takes an
3553 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3556 These are in no particular order:
3562 =item Value: ( $order_by | \@order_by | \%order_by )
3566 Which column(s) to order the results by.
3568 [The full list of suitable values is documented in
3569 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3572 If a single column name, or an arrayref of names is supplied, the
3573 argument is passed through directly to SQL. The hashref syntax allows
3574 for connection-agnostic specification of ordering direction:
3576 For descending order:
3578 order_by => { -desc => [qw/col1 col2 col3/] }
3580 For explicit ascending order:
3582 order_by => { -asc => 'col' }
3584 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3585 supported, although you are strongly encouraged to use the hashref
3586 syntax as outlined above.
3592 =item Value: \@columns
3596 Shortcut to request a particular set of columns to be retrieved. Each
3597 column spec may be a string (a table column name), or a hash (in which
3598 case the key is the C<as> value, and the value is used as the C<select>
3599 expression). Adds C<me.> onto the start of any column without a C<.> in
3600 it and sets C<select> from that, then auto-populates C<as> from
3601 C<select> as normal. (You may also use the C<cols> attribute, as in
3602 earlier versions of DBIC.)
3604 Essentially C<columns> does the same as L</select> and L</as>.
3606 columns => [ 'foo', { bar => 'baz' } ]
3610 select => [qw/foo baz/],
3617 =item Value: \@columns
3621 Indicates additional columns to be selected from storage. Works the same
3622 as L</columns> but adds columns to the selection. (You may also use the
3623 C<include_columns> attribute, as in earlier versions of DBIC). For
3626 $schema->resultset('CD')->search(undef, {
3627 '+columns' => ['artist.name'],
3631 would return all CDs and include a 'name' column to the information
3632 passed to object inflation. Note that the 'artist' is the name of the
3633 column (or relationship) accessor, and 'name' is the name of the column
3634 accessor in the related table.
3636 =head2 include_columns
3640 =item Value: \@columns
3644 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3650 =item Value: \@select_columns
3654 Indicates which columns should be selected from the storage. You can use
3655 column names, or in the case of RDBMS back ends, function or stored procedure
3658 $rs = $schema->resultset('Employee')->search(undef, {
3661 { count => 'employeeid' },
3662 { max => { length => 'name' }, -as => 'longest_name' }
3667 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3669 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3670 use L</select>, to instruct DBIx::Class how to store the result of the column.
3671 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3672 identifier aliasing. You can however alias a function, so you can use it in
3673 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3674 attribute> supplied as shown in the example above.
3680 Indicates additional columns to be selected from storage. Works the same as
3681 L</select> but adds columns to the default selection, instead of specifying
3690 Indicates additional column names for those added via L</+select>. See L</as>.
3698 =item Value: \@inflation_names
3702 Indicates column names for object inflation. That is L</as> indicates the
3703 slot name in which the column value will be stored within the
3704 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3705 identifier by the C<get_column> method (or via the object accessor B<if one
3706 with the same name already exists>) as shown below. The L</as> attribute has
3707 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3709 $rs = $schema->resultset('Employee')->search(undef, {
3712 { count => 'employeeid' },
3713 { max => { length => 'name' }, -as => 'longest_name' }
3722 If the object against which the search is performed already has an accessor
3723 matching a column name specified in C<as>, the value can be retrieved using
3724 the accessor as normal:
3726 my $name = $employee->name();
3728 If on the other hand an accessor does not exist in the object, you need to
3729 use C<get_column> instead:
3731 my $employee_count = $employee->get_column('employee_count');
3733 You can create your own accessors if required - see
3734 L<DBIx::Class::Manual::Cookbook> for details.
3740 =item Value: ($rel_name | \@rel_names | \%rel_names)
3744 Contains a list of relationships that should be joined for this query. For
3747 # Get CDs by Nine Inch Nails
3748 my $rs = $schema->resultset('CD')->search(
3749 { 'artist.name' => 'Nine Inch Nails' },
3750 { join => 'artist' }
3753 Can also contain a hash reference to refer to the other relation's relations.
3756 package MyApp::Schema::Track;
3757 use base qw/DBIx::Class/;
3758 __PACKAGE__->table('track');
3759 __PACKAGE__->add_columns(qw/trackid cd position title/);
3760 __PACKAGE__->set_primary_key('trackid');
3761 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3764 # In your application
3765 my $rs = $schema->resultset('Artist')->search(
3766 { 'track.title' => 'Teardrop' },
3768 join => { cd => 'track' },
3769 order_by => 'artist.name',
3773 You need to use the relationship (not the table) name in conditions,
3774 because they are aliased as such. The current table is aliased as "me", so
3775 you need to use me.column_name in order to avoid ambiguity. For example:
3777 # Get CDs from 1984 with a 'Foo' track
3778 my $rs = $schema->resultset('CD')->search(
3781 'tracks.name' => 'Foo'
3783 { join => 'tracks' }
3786 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3787 similarly for a third time). For e.g.
3789 my $rs = $schema->resultset('Artist')->search({
3790 'cds.title' => 'Down to Earth',
3791 'cds_2.title' => 'Popular',
3793 join => [ qw/cds cds/ ],
3796 will return a set of all artists that have both a cd with title 'Down
3797 to Earth' and a cd with title 'Popular'.
3799 If you want to fetch related objects from other tables as well, see C<prefetch>
3802 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3808 =item Value: ($rel_name | \@rel_names | \%rel_names)
3812 Contains one or more relationships that should be fetched along with
3813 the main query (when they are accessed afterwards the data will
3814 already be available, without extra queries to the database). This is
3815 useful for when you know you will need the related objects, because it
3816 saves at least one query:
3818 my $rs = $schema->resultset('Tag')->search(
3827 The initial search results in SQL like the following:
3829 SELECT tag.*, cd.*, artist.* FROM tag
3830 JOIN cd ON tag.cd = cd.cdid
3831 JOIN artist ON cd.artist = artist.artistid
3833 L<DBIx::Class> has no need to go back to the database when we access the
3834 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3837 Simple prefetches will be joined automatically, so there is no need
3838 for a C<join> attribute in the above search.
3840 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3841 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3842 with an accessor type of 'single' or 'filter'). A more complex example that
3843 prefetches an artists cds, the tracks on those cds, and the tags associated
3844 with that artist is given below (assuming many-to-many from artists to tags):
3846 my $rs = $schema->resultset('Artist')->search(
3850 { cds => 'tracks' },
3851 { artist_tags => 'tags' }
3857 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3858 attributes will be ignored.
3860 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3861 exactly as you might expect.
3867 Prefetch uses the L</cache> to populate the prefetched relationships. This
3868 may or may not be what you want.
3872 If you specify a condition on a prefetched relationship, ONLY those
3873 rows that match the prefetched condition will be fetched into that relationship.
3874 This means that adding prefetch to a search() B<may alter> what is returned by
3875 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3877 my $artist_rs = $schema->resultset('Artist')->search({
3883 my $count = $artist_rs->first->cds->count;
3885 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3887 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3889 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3891 that cmp_ok() may or may not pass depending on the datasets involved. This
3892 behavior may or may not survive the 0.09 transition.
3904 Makes the resultset paged and specifies the page to retrieve. Effectively
3905 identical to creating a non-pages resultset and then calling ->page($page)
3908 If L<rows> attribute is not specified it defaults to 10 rows per page.
3910 When you have a paged resultset, L</count> will only return the number
3911 of rows in the page. To get the total, use the L</pager> and call
3912 C<total_entries> on it.
3922 Specifies the maximum number of rows for direct retrieval or the number of
3923 rows per page if the page attribute or method is used.
3929 =item Value: $offset
3933 Specifies the (zero-based) row number for the first row to be returned, or the
3934 of the first row of the first page if paging is used.
3940 =item Value: \@columns
3944 A arrayref of columns to group by. Can include columns of joined tables.
3946 group_by => [qw/ column1 column2 ... /]
3952 =item Value: $condition
3956 HAVING is a select statement attribute that is applied between GROUP BY and
3957 ORDER BY. It is applied to the after the grouping calculations have been
3960 having => { 'count(employee)' => { '>=', 100 } }
3966 =item Value: (0 | 1)
3970 Set to 1 to group by all columns. If the resultset already has a group_by
3971 attribute, this setting is ignored and an appropriate warning is issued.
3977 Adds to the WHERE clause.
3979 # only return rows WHERE deleted IS NULL for all searches
3980 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3982 Can be overridden by passing C<< { where => undef } >> as an attribute
3989 Set to 1 to cache search results. This prevents extra SQL queries if you
3990 revisit rows in your ResultSet:
3992 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3994 while( my $artist = $resultset->next ) {
3998 $rs->first; # without cache, this would issue a query
4000 By default, searches are not cached.
4002 For more examples of using these attributes, see
4003 L<DBIx::Class::Manual::Cookbook>.
4009 =item Value: ( 'update' | 'shared' )
4013 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT