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;
13 use Scalar::Util qw/blessed weaken/;
15 use Storable qw/nfreeze thaw/;
17 # not importing first() as it will clash with our own method
24 # De-duplication in _merge_attr() is disabled, but left in for reference
25 *__HM_DEDUP = sub () { 0 };
33 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
37 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
41 my $users_rs = $schema->resultset('User');
42 while( $user = $users_rs->next) {
43 print $user->username;
46 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
47 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
51 A ResultSet is an object which stores a set of conditions representing
52 a query. It is the backbone of DBIx::Class (i.e. the really
53 important/useful bit).
55 No SQL is executed on the database when a ResultSet is created, it
56 just stores all the conditions needed to create the query.
58 A basic ResultSet representing the data of an entire table is returned
59 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
60 L<Source|DBIx::Class::Manual::Glossary/Source> name.
62 my $users_rs = $schema->resultset('User');
64 A new ResultSet is returned from calling L</search> on an existing
65 ResultSet. The new one will contain all the conditions of the
66 original, plus any new conditions added in the C<search> call.
68 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
69 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
72 The query that the ResultSet represents is B<only> executed against
73 the database when these methods are called:
74 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
76 If a resultset is used in a numeric context it returns the L</count>.
77 However, if it is used in a boolean context it is B<always> true. So if
78 you want to check if a resultset has any results, you must use C<if $rs
83 =head2 Chaining resultsets
85 Let's say you've got a query that needs to be run to return some data
86 to the user. But, you have an authorization system in place that
87 prevents certain users from seeing certain information. So, you want
88 to construct the basic query in one method, but add constraints to it in
93 my $request = $self->get_request; # Get a request object somehow.
94 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
96 my $cd_rs = $schema->resultset('CD')->search({
97 title => $request->param('title'),
98 year => $request->param('year'),
101 $self->apply_security_policy( $cd_rs );
103 return $cd_rs->all();
106 sub apply_security_policy {
115 =head3 Resolving conditions and attributes
117 When a resultset is chained from another resultset, conditions and
118 attributes with the same keys need resolving.
120 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
121 into the existing ones from the original resultset.
123 The L</where> and L</having> attributes, and any search conditions, are
124 merged with an SQL C<AND> to the existing condition from the original
127 All other attributes are overridden by any new ones supplied in the
130 =head2 Multiple queries
132 Since a resultset just defines a query, you can do all sorts of
133 things with it with the same object.
135 # Don't hit the DB yet.
136 my $cd_rs = $schema->resultset('CD')->search({
137 title => 'something',
141 # Each of these hits the DB individually.
142 my $count = $cd_rs->count;
143 my $most_recent = $cd_rs->get_column('date_released')->max();
144 my @records = $cd_rs->all;
146 And it's not just limited to SELECT statements.
152 $cd_rs->create({ artist => 'Fred' });
154 Which is the same as:
156 $schema->resultset('CD')->create({
157 title => 'something',
162 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
170 =item Arguments: $source, \%$attrs
172 =item Return Value: $rs
176 The resultset constructor. Takes a source object (usually a
177 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
178 L</ATTRIBUTES> below). Does not perform any queries -- these are
179 executed as needed by the other methods.
181 Generally you won't need to construct a resultset manually. You'll
182 automatically get one from e.g. a L</search> called in scalar context:
184 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
186 IMPORTANT: If called on an object, proxies to new_result instead so
188 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
190 will return a CD object, not a ResultSet.
196 return $class->new_result(@_) if ref $class;
198 my ($source, $attrs) = @_;
199 $source = $source->handle
200 unless $source->isa('DBIx::Class::ResultSourceHandle');
201 $attrs = { %{$attrs||{}} };
203 if ($attrs->{page}) {
204 $attrs->{rows} ||= 10;
207 $attrs->{alias} ||= 'me';
209 # Creation of {} and bless separated to mitigate RH perl bug
210 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
212 _source_handle => $source,
213 cond => $attrs->{where},
221 $attrs->{result_class} || $source->resolve->result_class
231 =item Arguments: $cond, \%attrs?
233 =item Return Value: $resultset (scalar context), @row_objs (list context)
237 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
238 my $new_rs = $cd_rs->search({ year => 2005 });
240 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
241 # year = 2005 OR year = 2004
243 If you need to pass in additional attributes but no additional condition,
244 call it as C<search(undef, \%attrs)>.
246 # "SELECT name, artistid FROM $artist_table"
247 my @all_artists = $schema->resultset('Artist')->search(undef, {
248 columns => [qw/name artistid/],
251 For a list of attributes that can be passed to C<search>, see
252 L</ATTRIBUTES>. For more examples of using this function, see
253 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
254 documentation for the first argument, see L<SQL::Abstract>.
256 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 Note that L</search> does not process/deflate any of the values passed in the
261 L<SQL::Abstract>-compatible search condition structure. This is unlike other
262 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
263 manually that any value passed to this method will stringify to something the
264 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
265 objects, for more info see:
266 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
272 my $rs = $self->search_rs( @_ );
274 my $want = wantarray;
278 elsif (defined $want) {
282 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense');
290 =item Arguments: $cond, \%attrs?
292 =item Return Value: $resultset
296 This method does the same exact thing as search() except it will
297 always return a resultset, even in list context.
304 # Special-case handling for (undef, undef).
305 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
310 $call_attrs = pop(@_) if (
311 @_ > 1 and ( ! defined $_[-1] or ref $_[-1] eq 'HASH' )
314 # see if we can keep the cache (no $rs changes)
316 my %safe = (alias => 1, cache => 1);
317 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
320 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
322 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
324 $cache = $self->get_cache;
327 my $old_attrs = { %{$self->{attrs}} };
328 my $old_having = delete $old_attrs->{having};
329 my $old_where = delete $old_attrs->{where};
331 # reset the selector list
332 if (List::Util::first { exists $call_attrs->{$_} } qw{columns select as}) {
333 delete @{$old_attrs}{qw{select as columns +select +as +columns include_columns}};
336 my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
338 # merge new attrs into inherited
339 foreach my $key (qw/join prefetch/) {
340 next unless exists $call_attrs->{$key};
341 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key});
343 foreach my $key (qw/+select +as +columns include_columns bind/) {
344 next unless exists $call_attrs->{$key};
345 $new_attrs->{$key} = $self->_merge_attr($old_attrs->{$key}, $call_attrs->{$key});
348 # rip apart the rest of @_, parse a condition
351 if (ref $_[0] eq 'HASH') {
352 (keys %{$_[0]}) ? $_[0] : undef
358 $self->throw_exception('Odd number of arguments to search')
366 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
367 if (@_ > 1 and ! $self->result_source->result_class->isa('DBIx::Class::CDBICompat') );
369 for ($old_where, $call_cond) {
371 $new_attrs->{where} = $self->_stack_cond (
372 $_, $new_attrs->{where}
377 if (defined $old_having) {
378 $new_attrs->{having} = $self->_stack_cond (
379 $old_having, $new_attrs->{having}
383 my $rs = (ref $self)->new($self->result_source, $new_attrs);
385 $rs->set_cache($cache) if ($cache);
391 my ($self, $left, $right) = @_;
392 if (defined $left xor defined $right) {
393 return defined $left ? $left : $right;
395 elsif (defined $left) {
396 return { -and => [ map
397 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
405 =head2 search_literal
409 =item Arguments: $sql_fragment, @bind_values
411 =item Return Value: $resultset (scalar context), @row_objs (list context)
415 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
416 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
418 Pass a literal chunk of SQL to be added to the conditional part of the
421 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
422 only be used in that context. C<search_literal> is a convenience method.
423 It is equivalent to calling $schema->search(\[]), but if you want to ensure
424 columns are bound correctly, use C<search>.
426 Example of how to use C<search> instead of C<search_literal>
428 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
429 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
432 See L<DBIx::Class::Manual::Cookbook/Searching> and
433 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
434 require C<search_literal>.
439 my ($self, $sql, @bind) = @_;
441 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
444 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
451 =item Arguments: \%columns_values | @pk_values, \%attrs?
453 =item Return Value: $row_object | undef
457 Finds and returns a single row based on supplied criteria. Takes either a
458 hashref with the same format as L</create> (including inference of foreign
459 keys from related objects), or a list of primary key values in the same
460 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
461 declaration on the L</result_source>.
463 In either case an attempt is made to combine conditions already existing on
464 the resultset with the condition passed to this method.
466 To aid with preparing the correct query for the storage you may supply the
467 C<key> attribute, which is the name of a
468 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
469 unique constraint corresponding to the
470 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
471 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
472 to construct a query that satisfies the named unique constraint fully (
473 non-NULL values for each column member of the constraint) an exception is
476 If no C<key> is specified, the search is carried over all unique constraints
477 which are fully defined by the available condition.
479 If no such constraint is found, C<find> currently defaults to a simple
480 C<< search->(\%column_values) >> which may or may not do what you expect.
481 Note that this fallback behavior may be deprecated in further versions. If
482 you need to search with arbitrary conditions - use L</search>. If the query
483 resulting from this fallback produces more than one row, a warning to the
484 effect is issued, though only the first row is constructed and returned as
487 In addition to C<key>, L</find> recognizes and applies standard
488 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
490 Note that if you have extra concerns about the correctness of the resulting
491 query you need to specify the C<key> attribute and supply the entire condition
492 as an argument to find (since it is not always possible to perform the
493 combination of the resultset condition with the supplied one, especially if
494 the resultset condition contains literal sql).
496 For example, to find a row by its primary key:
498 my $cd = $schema->resultset('CD')->find(5);
500 You can also find a row by a specific unique constraint:
502 my $cd = $schema->resultset('CD')->find(
504 artist => 'Massive Attack',
505 title => 'Mezzanine',
507 { key => 'cd_artist_title' }
510 See also L</find_or_create> and L</update_or_create>.
516 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
518 my $rsrc = $self->result_source;
520 # Parse out the condition from input
522 if (ref $_[0] eq 'HASH') {
523 $call_cond = { %{$_[0]} };
526 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
527 my @c_cols = $rsrc->unique_constraint_columns($constraint);
529 $self->throw_exception(
530 "No constraint columns, maybe a malformed '$constraint' constraint?"
533 $self->throw_exception (
534 'find() expects either a column/value hashref, or a list of values '
535 . "corresponding to the columns of the specified unique constraint '$constraint'"
536 ) unless @c_cols == @_;
539 @{$call_cond}{@c_cols} = @_;
543 for my $key (keys %$call_cond) {
545 my $keyref = ref($call_cond->{$key})
547 my $relinfo = $rsrc->relationship_info($key)
549 my $val = delete $call_cond->{$key};
551 next if $keyref eq 'ARRAY'; # has_many for multi_create
553 my $rel_q = $rsrc->_resolve_condition(
554 $relinfo->{cond}, $val, $key
556 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
557 @related{keys %$rel_q} = values %$rel_q;
561 # relationship conditions take precedence (?)
562 @{$call_cond}{keys %related} = values %related;
564 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
566 if (exists $attrs->{key}) {
567 $final_cond = $self->_qualify_cond_columns (
569 $self->_build_unique_cond (
577 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
578 # This means that we got here after a merger of relationship conditions
579 # in ::Relationship::Base::search_related (the row method), and furthermore
580 # the relationship is of the 'single' type. This means that the condition
581 # provided by the relationship (already attached to $self) is sufficient,
582 # as there can be only one row in the database that would satisfy the
586 # no key was specified - fall down to heuristics mode:
587 # run through all unique queries registered on the resultset, and
588 # 'OR' all qualifying queries together
589 my (@unique_queries, %seen_column_combinations);
590 for my $c_name ($rsrc->unique_constraint_names) {
591 next if $seen_column_combinations{
592 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
595 push @unique_queries, try {
596 $self->_build_unique_cond ($c_name, $call_cond)
600 $final_cond = @unique_queries
601 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
602 : $self->_non_unique_find_fallback ($call_cond, $attrs)
606 # Run the query, passing the result_class since it should propagate for find
607 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
608 if (keys %{$rs->_resolved_attrs->{collapse}}) {
610 carp "Query returned more than one row" if $rs->next;
618 # This is a stop-gap method as agreed during the discussion on find() cleanup:
619 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
621 # It is invoked when find() is called in legacy-mode with insufficiently-unique
622 # condition. It is provided for overrides until a saner way forward is devised
624 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
625 # the road. Please adjust your tests accordingly to catch this situation early
626 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
628 # The method will not be removed without an adequately complete replacement
629 # for strict-mode enforcement
630 sub _non_unique_find_fallback {
631 my ($self, $cond, $attrs) = @_;
633 return $self->_qualify_cond_columns(
635 exists $attrs->{alias}
637 : $self->{attrs}{alias}
642 sub _qualify_cond_columns {
643 my ($self, $cond, $alias) = @_;
645 my %aliased = %$cond;
646 for (keys %aliased) {
647 $aliased{"$alias.$_"} = delete $aliased{$_}
654 sub _build_unique_cond {
655 my ($self, $constraint_name, $extra_cond) = @_;
657 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
659 # combination may fail if $self->{cond} is non-trivial
660 my ($final_cond) = try {
661 $self->_merge_with_rscond ($extra_cond)
666 # trim out everything not in $columns
667 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
669 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
670 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
672 join (', ', map { "'$_'" } @missing),
679 =head2 search_related
683 =item Arguments: $rel, $cond, \%attrs?
685 =item Return Value: $new_resultset
689 $new_rs = $cd_rs->search_related('artist', {
693 Searches the specified relationship, optionally specifying a condition and
694 attributes for matching records. See L</ATTRIBUTES> for more information.
699 return shift->related_resultset(shift)->search(@_);
702 =head2 search_related_rs
704 This method works exactly the same as search_related, except that
705 it guarantees a resultset, even in list context.
709 sub search_related_rs {
710 return shift->related_resultset(shift)->search_rs(@_);
717 =item Arguments: none
719 =item Return Value: $cursor
723 Returns a storage-driven cursor to the given resultset. See
724 L<DBIx::Class::Cursor> for more information.
731 my $attrs = $self->_resolved_attrs_copy;
733 return $self->{cursor}
734 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
735 $attrs->{where},$attrs);
742 =item Arguments: $cond?
744 =item Return Value: $row_object | undef
748 my $cd = $schema->resultset('CD')->single({ year => 2001 });
750 Inflates the first result without creating a cursor if the resultset has
751 any records in it; if not returns C<undef>. Used by L</find> as a lean version
754 While this method can take an optional search condition (just like L</search>)
755 being a fast-code-path it does not recognize search attributes. If you need to
756 add extra joins or similar, call L</search> and then chain-call L</single> on the
757 L<DBIx::Class::ResultSet> returned.
763 As of 0.08100, this method enforces the assumption that the preceding
764 query returns only one row. If more than one row is returned, you will receive
767 Query returned more than one row
769 In this case, you should be using L</next> or L</find> instead, or if you really
770 know what you are doing, use the L</rows> attribute to explicitly limit the size
773 This method will also throw an exception if it is called on a resultset prefetching
774 has_many, as such a prefetch implies fetching multiple rows from the database in
775 order to assemble the resulting object.
782 my ($self, $where) = @_;
784 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
787 my $attrs = $self->_resolved_attrs_copy;
789 if (keys %{$attrs->{collapse}}) {
790 $self->throw_exception(
791 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
796 if (defined $attrs->{where}) {
799 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
800 $where, delete $attrs->{where} ]
803 $attrs->{where} = $where;
807 my @data = $self->result_source->storage->select_single(
808 $attrs->{from}, $attrs->{select},
809 $attrs->{where}, $attrs
812 return (@data ? ($self->_construct_object(@data))[0] : undef);
818 # Recursively collapse the query, accumulating values for each column.
820 sub _collapse_query {
821 my ($self, $query, $collapsed) = @_;
825 if (ref $query eq 'ARRAY') {
826 foreach my $subquery (@$query) {
827 next unless ref $subquery; # -or
828 $collapsed = $self->_collapse_query($subquery, $collapsed);
831 elsif (ref $query eq 'HASH') {
832 if (keys %$query and (keys %$query)[0] eq '-and') {
833 foreach my $subquery (@{$query->{-and}}) {
834 $collapsed = $self->_collapse_query($subquery, $collapsed);
838 foreach my $col (keys %$query) {
839 my $value = $query->{$col};
840 $collapsed->{$col}{$value}++;
852 =item Arguments: $cond?
854 =item Return Value: $resultsetcolumn
858 my $max_length = $rs->get_column('length')->max;
860 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
865 my ($self, $column) = @_;
866 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
874 =item Arguments: $cond, \%attrs?
876 =item Return Value: $resultset (scalar context), @row_objs (list context)
880 # WHERE title LIKE '%blue%'
881 $cd_rs = $rs->search_like({ title => '%blue%'});
883 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
884 that this is simply a convenience method retained for ex Class::DBI users.
885 You most likely want to use L</search> with specific operators.
887 For more information, see L<DBIx::Class::Manual::Cookbook>.
889 This method is deprecated and will be removed in 0.09. Use L</search()>
890 instead. An example conversion is:
892 ->search_like({ foo => 'bar' });
896 ->search({ foo => { like => 'bar' } });
903 'search_like() is deprecated and will be removed in DBIC version 0.09.'
904 .' Instead use ->search({ x => { -like => "y%" } })'
905 .' (note the outer pair of {}s - they are important!)'
907 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
908 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
909 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
910 return $class->search($query, { %$attrs });
917 =item Arguments: $first, $last
919 =item Return Value: $resultset (scalar context), @row_objs (list context)
923 Returns a resultset or object list representing a subset of elements from the
924 resultset slice is called on. Indexes are from 0, i.e., to get the first
927 my ($one, $two, $three) = $rs->slice(0, 2);
932 my ($self, $min, $max) = @_;
933 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
934 $attrs->{offset} = $self->{attrs}{offset} || 0;
935 $attrs->{offset} += $min;
936 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
937 return $self->search(undef, $attrs);
938 #my $slice = (ref $self)->new($self->result_source, $attrs);
939 #return (wantarray ? $slice->all : $slice);
946 =item Arguments: none
948 =item Return Value: $result | undef
952 Returns the next element in the resultset (C<undef> is there is none).
954 Can be used to efficiently iterate over records in the resultset:
956 my $rs = $schema->resultset('CD')->search;
957 while (my $cd = $rs->next) {
961 Note that you need to store the resultset object, and call C<next> on it.
962 Calling C<< resultset('Table')->next >> repeatedly will always return the
963 first record from the resultset.
969 if (my $cache = $self->get_cache) {
970 $self->{all_cache_position} ||= 0;
971 return $cache->[$self->{all_cache_position}++];
973 if ($self->{attrs}{cache}) {
974 delete $self->{pager};
975 $self->{all_cache_position} = 1;
976 return ($self->all)[0];
978 if ($self->{stashed_objects}) {
979 my $obj = shift(@{$self->{stashed_objects}});
980 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
984 exists $self->{stashed_row}
985 ? @{delete $self->{stashed_row}}
986 : $self->cursor->next
988 return undef unless (@row);
989 my ($row, @more) = $self->_construct_object(@row);
990 $self->{stashed_objects} = \@more if @more;
994 sub _construct_object {
995 my ($self, @row) = @_;
997 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
999 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1000 @new = $self->{_attrs}{record_filter}->(@new)
1001 if exists $self->{_attrs}{record_filter};
1005 sub _collapse_result {
1006 my ($self, $as_proto, $row) = @_;
1010 # 'foo' => [ undef, 'foo' ]
1011 # 'foo.bar' => [ 'foo', 'bar' ]
1012 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1014 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1016 my %collapse = %{$self->{_attrs}{collapse}||{}};
1020 # if we're doing collapsing (has_many prefetch) we need to grab records
1021 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1022 # we know we don't have to bother.
1024 # the reason for not using the collapse stuff directly is because if you
1025 # had for e.g. two artists in a row with no cds, the collapse info for
1026 # both would be NULL (undef) so you'd lose the second artist
1028 # store just the index so we can check the array positions from the row
1029 # without having to contruct the full hash
1031 if (keys %collapse) {
1032 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1033 foreach my $i (0 .. $#construct_as) {
1034 next if defined($construct_as[$i][0]); # only self table
1035 if (delete $pri{$construct_as[$i][1]}) {
1036 push(@pri_index, $i);
1038 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1042 # no need to do an if, it'll be empty if @pri_index is empty anyway
1044 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1048 do { # no need to check anything at the front, we always want the first row
1052 foreach my $this_as (@construct_as) {
1053 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1056 push(@const_rows, \%const);
1058 } until ( # no pri_index => no collapse => drop straight out
1061 do { # get another row, stash it, drop out if different PK
1063 @copy = $self->cursor->next;
1064 $self->{stashed_row} = \@copy;
1066 # last thing in do block, counts as true if anything doesn't match
1068 # check xor defined first for NULL vs. NOT NULL then if one is
1069 # defined the other must be so check string equality
1072 (defined $pri_vals{$_} ^ defined $copy[$_])
1073 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1078 my $alias = $self->{attrs}{alias};
1085 foreach my $const (@const_rows) {
1086 scalar @const_keys or do {
1087 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1089 foreach my $key (@const_keys) {
1092 my @parts = split(/\./, $key);
1094 my $data = $const->{$key};
1095 foreach my $p (@parts) {
1096 $target = $target->[1]->{$p} ||= [];
1098 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1099 # collapsing at this point and on final part
1100 my $pos = $collapse_pos{$cur};
1101 CK: foreach my $ck (@ckey) {
1102 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1103 $collapse_pos{$cur} = $data;
1104 delete @collapse_pos{ # clear all positioning for sub-entries
1105 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1112 if (exists $collapse{$cur}) {
1113 $target = $target->[-1];
1116 $target->[0] = $data;
1118 $info->[0] = $const->{$key};
1126 =head2 result_source
1130 =item Arguments: $result_source?
1132 =item Return Value: $result_source
1136 An accessor for the primary ResultSource object from which this ResultSet
1143 =item Arguments: $result_class?
1145 =item Return Value: $result_class
1149 An accessor for the class to use when creating row objects. Defaults to
1150 C<< result_source->result_class >> - which in most cases is the name of the
1151 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1153 Note that changing the result_class will also remove any components
1154 that were originally loaded in the source class via
1155 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1156 in the original source class will not run.
1161 my ($self, $result_class) = @_;
1162 if ($result_class) {
1163 unless (ref $result_class) { # don't fire this for an object
1164 $self->ensure_class_loaded($result_class);
1166 $self->_result_class($result_class);
1167 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1168 # permit the user to set result class on one result set only; it only
1169 # chains if provided to search()
1170 #$self->{attrs}{result_class} = $result_class if ref $self;
1172 $self->_result_class;
1179 =item Arguments: $cond, \%attrs??
1181 =item Return Value: $count
1185 Performs an SQL C<COUNT> with the same query as the resultset was built
1186 with to find the number of elements. Passing arguments is equivalent to
1187 C<< $rs->search ($cond, \%attrs)->count >>
1193 return $self->search(@_)->count if @_ and defined $_[0];
1194 return scalar @{ $self->get_cache } if $self->get_cache;
1196 my $attrs = $self->_resolved_attrs_copy;
1198 # this is a little optimization - it is faster to do the limit
1199 # adjustments in software, instead of a subquery
1200 my $rows = delete $attrs->{rows};
1201 my $offset = delete $attrs->{offset};
1204 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1205 $crs = $self->_count_subq_rs ($attrs);
1208 $crs = $self->_count_rs ($attrs);
1210 my $count = $crs->next;
1212 $count -= $offset if $offset;
1213 $count = $rows if $rows and $rows < $count;
1214 $count = 0 if ($count < 0);
1223 =item Arguments: $cond, \%attrs??
1225 =item Return Value: $count_rs
1229 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1230 This can be very handy for subqueries:
1232 ->search( { amount => $some_rs->count_rs->as_query } )
1234 As with regular resultsets the SQL query will be executed only after
1235 the resultset is accessed via L</next> or L</all>. That would return
1236 the same single value obtainable via L</count>.
1242 return $self->search(@_)->count_rs if @_;
1244 # this may look like a lack of abstraction (count() does about the same)
1245 # but in fact an _rs *must* use a subquery for the limits, as the
1246 # software based limiting can not be ported if this $rs is to be used
1247 # in a subquery itself (i.e. ->as_query)
1248 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1249 return $self->_count_subq_rs;
1252 return $self->_count_rs;
1257 # returns a ResultSetColumn object tied to the count query
1260 my ($self, $attrs) = @_;
1262 my $rsrc = $self->result_source;
1263 $attrs ||= $self->_resolved_attrs;
1265 my $tmp_attrs = { %$attrs };
1266 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1267 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1269 # overwrite the selector (supplied by the storage)
1270 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1271 $tmp_attrs->{as} = 'count';
1273 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1279 # same as above but uses a subquery
1281 sub _count_subq_rs {
1282 my ($self, $attrs) = @_;
1284 my $rsrc = $self->result_source;
1285 $attrs ||= $self->_resolved_attrs;
1287 my $sub_attrs = { %$attrs };
1288 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1289 delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
1291 # if we multi-prefetch we group_by primary keys only as this is what we would
1292 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1293 if ( keys %{$attrs->{collapse}} ) {
1294 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1297 # Calculate subquery selector
1298 if (my $g = $sub_attrs->{group_by}) {
1300 my $sql_maker = $rsrc->storage->sql_maker;
1302 # necessary as the group_by may refer to aliased functions
1304 for my $sel (@{$attrs->{select}}) {
1305 $sel_index->{$sel->{-as}} = $sel
1306 if (ref $sel eq 'HASH' and $sel->{-as});
1309 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1310 # also look for named aggregates referred in the having clause
1311 # having often contains scalarrefs - thus parse it out entirely
1313 if ($attrs->{having}) {
1314 local $sql_maker->{having_bind};
1315 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1316 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1317 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1318 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1319 # if we don't unset it we screw up retarded but unfortunately working
1320 # 'MAX(foo.bar)' => { '>', 3 }
1321 $sql_maker->{name_sep} = '';
1324 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1326 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1328 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1329 # and if all fails for an utterly naive quoted scalar-with-function
1331 $rquote $sep $lquote (.+?) $rquote
1333 [\s,] \w+ \. (\w+) [\s,]
1335 [\s,] $lquote (.+?) $rquote [\s,]
1337 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1342 my $colpiece = $sel_index->{$_} || $_;
1344 # unqualify join-based group_by's. Arcane but possible query
1345 # also horrible horrible hack to alias a column (not a func.)
1346 # (probably need to introduce SQLA syntax)
1347 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1350 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1352 push @{$sub_attrs->{select}}, $colpiece;
1356 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1357 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1360 return $rsrc->resultset_class
1361 ->new ($rsrc, $sub_attrs)
1363 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1364 ->get_column ('count');
1371 =head2 count_literal
1375 =item Arguments: $sql_fragment, @bind_values
1377 =item Return Value: $count
1381 Counts the results in a literal query. Equivalent to calling L</search_literal>
1382 with the passed arguments, then L</count>.
1386 sub count_literal { shift->search_literal(@_)->count; }
1392 =item Arguments: none
1394 =item Return Value: @objects
1398 Returns all elements in the resultset. Called implicitly if the resultset
1399 is returned in list context.
1406 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1409 return @{ $self->get_cache } if $self->get_cache;
1413 if (keys %{$self->_resolved_attrs->{collapse}}) {
1414 # Using $self->cursor->all is really just an optimisation.
1415 # If we're collapsing has_many prefetches it probably makes
1416 # very little difference, and this is cleaner than hacking
1417 # _construct_object to survive the approach
1418 $self->cursor->reset;
1419 my @row = $self->cursor->next;
1421 push(@obj, $self->_construct_object(@row));
1422 @row = (exists $self->{stashed_row}
1423 ? @{delete $self->{stashed_row}}
1424 : $self->cursor->next);
1427 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1430 $self->set_cache(\@obj) if $self->{attrs}{cache};
1439 =item Arguments: none
1441 =item Return Value: $self
1445 Resets the resultset's cursor, so you can iterate through the elements again.
1446 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1453 delete $self->{_attrs} if exists $self->{_attrs};
1454 $self->{all_cache_position} = 0;
1455 $self->cursor->reset;
1463 =item Arguments: none
1465 =item Return Value: $object | undef
1469 Resets the resultset and returns an object for the first result (or C<undef>
1470 if the resultset is empty).
1475 return $_[0]->reset->next;
1481 # Determines whether and what type of subquery is required for the $rs operation.
1482 # If grouping is necessary either supplies its own, or verifies the current one
1483 # After all is done delegates to the proper storage method.
1485 sub _rs_update_delete {
1486 my ($self, $op, $values) = @_;
1488 my $rsrc = $self->result_source;
1490 # if a condition exists we need to strip all table qualifiers
1491 # if this is not possible we'll force a subquery below
1492 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1494 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1495 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1497 if ($needs_group_by_subq or $needs_subq) {
1499 # make a new $rs selecting only the PKs (that's all we really need)
1500 my $attrs = $self->_resolved_attrs_copy;
1503 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1504 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1506 if ($needs_group_by_subq) {
1507 # make sure no group_by was supplied, or if there is one - make sure it matches
1508 # the columns compiled above perfectly. Anything else can not be sanely executed
1509 # on most databases so croak right then and there
1511 if (my $g = $attrs->{group_by}) {
1512 my @current_group_by = map
1513 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1518 join ("\x00", sort @current_group_by)
1520 join ("\x00", sort @{$attrs->{columns}} )
1522 $self->throw_exception (
1523 "You have just attempted a $op operation on a resultset which does group_by"
1524 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1525 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1526 . ' kind of queries. Please retry the operation with a modified group_by or'
1527 . ' without using one at all.'
1532 $attrs->{group_by} = $attrs->{columns};
1536 my $subrs = (ref $self)->new($rsrc, $attrs);
1537 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1540 return $rsrc->storage->$op(
1542 $op eq 'update' ? $values : (),
1552 =item Arguments: \%values
1554 =item Return Value: $storage_rv
1558 Sets the specified columns in the resultset to the supplied values in a
1559 single query. Note that this will not run any accessor/set_column/update
1560 triggers, nor will it update any row object instances derived from this
1561 resultset (this includes the contents of the L<resultset cache|/set_cache>
1562 if any). See L</update_all> if you need to execute any on-update
1563 triggers or cascades defined either by you or a
1564 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1566 The return value is a pass through of what the underlying
1567 storage backend returned, and may vary. See L<DBI/execute> for the most
1572 Note that L</update> does not process/deflate any of the values passed in.
1573 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1574 ensure manually that any value passed to this method will stringify to
1575 something the RDBMS knows how to deal with. A notable example is the
1576 handling of L<DateTime> objects, for more info see:
1577 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1582 my ($self, $values) = @_;
1583 $self->throw_exception('Values for update must be a hash')
1584 unless ref $values eq 'HASH';
1586 return $self->_rs_update_delete ('update', $values);
1593 =item Arguments: \%values
1595 =item Return Value: 1
1599 Fetches all objects and updates them one at a time via
1600 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1601 triggers, while L</update> will not.
1606 my ($self, $values) = @_;
1607 $self->throw_exception('Values for update_all must be a hash')
1608 unless ref $values eq 'HASH';
1610 my $guard = $self->result_source->schema->txn_scope_guard;
1611 $_->update($values) for $self->all;
1620 =item Arguments: none
1622 =item Return Value: $storage_rv
1626 Deletes the rows matching this resultset in a single query. Note that this
1627 will not run any delete triggers, nor will it alter the
1628 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1629 derived from this resultset (this includes the contents of the
1630 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1631 execute any on-delete triggers or cascades defined either by you or a
1632 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1634 The return value is a pass through of what the underlying storage backend
1635 returned, and may vary. See L<DBI/execute> for the most common case.
1641 $self->throw_exception('delete does not accept any arguments')
1644 return $self->_rs_update_delete ('delete');
1651 =item Arguments: none
1653 =item Return Value: 1
1657 Fetches all objects and deletes them one at a time via
1658 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1659 triggers, while L</delete> will not.
1665 $self->throw_exception('delete_all does not accept any arguments')
1668 my $guard = $self->result_source->schema->txn_scope_guard;
1669 $_->delete for $self->all;
1678 =item Arguments: \@data;
1682 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1683 For the arrayref of hashrefs style each hashref should be a structure suitable
1684 forsubmitting to a $resultset->create(...) method.
1686 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1687 to insert the data, as this is a faster method.
1689 Otherwise, each set of data is inserted into the database using
1690 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1691 accumulated into an array. The array itself, or an array reference
1692 is returned depending on scalar or list context.
1694 Example: Assuming an Artist Class that has many CDs Classes relating:
1696 my $Artist_rs = $schema->resultset("Artist");
1698 ## Void Context Example
1699 $Artist_rs->populate([
1700 { artistid => 4, name => 'Manufactured Crap', cds => [
1701 { title => 'My First CD', year => 2006 },
1702 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1705 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1706 { title => 'My parents sold me to a record company', year => 2005 },
1707 { title => 'Why Am I So Ugly?', year => 2006 },
1708 { title => 'I Got Surgery and am now Popular', year => 2007 }
1713 ## Array Context Example
1714 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1715 { name => "Artist One"},
1716 { name => "Artist Two"},
1717 { name => "Artist Three", cds=> [
1718 { title => "First CD", year => 2007},
1719 { title => "Second CD", year => 2008},
1723 print $ArtistOne->name; ## response is 'Artist One'
1724 print $ArtistThree->cds->count ## reponse is '2'
1726 For the arrayref of arrayrefs style, the first element should be a list of the
1727 fieldsnames to which the remaining elements are rows being inserted. For
1730 $Arstist_rs->populate([
1731 [qw/artistid name/],
1732 [100, 'A Formally Unknown Singer'],
1733 [101, 'A singer that jumped the shark two albums ago'],
1734 [102, 'An actually cool singer'],
1737 Please note an important effect on your data when choosing between void and
1738 wantarray context. Since void context goes straight to C<insert_bulk> in
1739 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1740 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1741 create primary keys for you, you will find that your PKs are empty. In this
1742 case you will have to use the wantarray context in order to create those
1750 # cruft placed in standalone method
1751 my $data = $self->_normalize_populate_args(@_);
1753 if(defined wantarray) {
1755 foreach my $item (@$data) {
1756 push(@created, $self->create($item));
1758 return wantarray ? @created : \@created;
1760 my $first = $data->[0];
1762 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1763 # it relationship data
1764 my (@rels, @columns);
1765 for (keys %$first) {
1766 my $ref = ref $first->{$_};
1767 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1773 my @pks = $self->result_source->primary_columns;
1775 ## do the belongs_to relationships
1776 foreach my $index (0..$#$data) {
1778 # delegate to create() for any dataset without primary keys with specified relationships
1779 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1781 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1782 my @ret = $self->populate($data);
1788 foreach my $rel (@rels) {
1789 next unless ref $data->[$index]->{$rel} eq "HASH";
1790 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1791 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1792 my $related = $result->result_source->_resolve_condition(
1793 $result->result_source->relationship_info($reverse)->{cond},
1798 delete $data->[$index]->{$rel};
1799 $data->[$index] = {%{$data->[$index]}, %$related};
1801 push @columns, keys %$related if $index == 0;
1805 ## inherit the data locked in the conditions of the resultset
1806 my ($rs_data) = $self->_merge_with_rscond({});
1807 delete @{$rs_data}{@columns};
1808 my @inherit_cols = keys %$rs_data;
1809 my @inherit_data = values %$rs_data;
1811 ## do bulk insert on current row
1812 $self->result_source->storage->insert_bulk(
1813 $self->result_source,
1814 [@columns, @inherit_cols],
1815 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1818 ## do the has_many relationships
1819 foreach my $item (@$data) {
1821 foreach my $rel (@rels) {
1822 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1824 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1825 || $self->throw_exception('Cannot find the relating object.');
1827 my $child = $parent->$rel;
1829 my $related = $child->result_source->_resolve_condition(
1830 $parent->result_source->relationship_info($rel)->{cond},
1835 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1836 my @populate = map { {%$_, %$related} } @rows_to_add;
1838 $child->populate( \@populate );
1845 # populate() argumnets went over several incarnations
1846 # What we ultimately support is AoH
1847 sub _normalize_populate_args {
1848 my ($self, $arg) = @_;
1850 if (ref $arg eq 'ARRAY') {
1851 if (ref $arg->[0] eq 'HASH') {
1854 elsif (ref $arg->[0] eq 'ARRAY') {
1856 my @colnames = @{$arg->[0]};
1857 foreach my $values (@{$arg}[1 .. $#$arg]) {
1858 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1864 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1871 =item Arguments: none
1873 =item Return Value: $pager
1877 Return Value a L<Data::Page> object for the current resultset. Only makes
1878 sense for queries with a C<page> attribute.
1880 To get the full count of entries for a paged resultset, call
1881 C<total_entries> on the L<Data::Page> object.
1885 # make a wizard good for both a scalar and a hashref
1886 my $mk_lazy_count_wizard = sub {
1887 require Variable::Magic;
1889 my $stash = { total_rs => shift };
1890 my $slot = shift; # only used by the hashref magic
1892 my $magic = Variable::Magic::wizard (
1893 data => sub { $stash },
1899 # set value lazily, and dispell for good
1900 ${$_[0]} = $_[1]{total_rs}->count;
1901 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
1905 # an explicit set implies dispell as well
1906 # the unless() is to work around "fun and giggles" below
1907 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
1908 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1915 if ($_[2] eq $slot and !$_[1]{inactive}) {
1916 my $cnt = $_[1]{total_rs}->count;
1917 $_[0]->{$slot} = $cnt;
1919 # attempting to dispell in a fetch handle (works in store), seems
1920 # to invariable segfault on 5.10, 5.12, 5.13 :(
1921 # so use an inactivator instead
1922 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1928 if (! $_[1]{inactive} and $_[2] eq $slot) {
1929 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1931 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1938 $stash->{magic_selfref} = $magic;
1939 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
1944 # the tie class for 5.8.1
1946 package # hide from pause
1947 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
1948 use base qw/Tie::Hash/;
1950 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
1951 sub NEXTKEY { each %{$_[0]{data}} }
1952 sub EXISTS { exists $_[0]{data}{$_[1]} }
1953 sub DELETE { delete $_[0]{data}{$_[1]} }
1954 sub CLEAR { %{$_[0]{data}} = () }
1955 sub SCALAR { scalar %{$_[0]{data}} }
1958 $_[1]{data} = {%{$_[1]{selfref}}};
1959 %{$_[1]{selfref}} = ();
1960 Scalar::Util::weaken ($_[1]{selfref});
1961 return bless ($_[1], $_[0]);
1965 if ($_[1] eq $_[0]{slot}) {
1966 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
1967 untie %{$_[0]{selfref}};
1968 %{$_[0]{selfref}} = %{$_[0]{data}};
1977 $_[0]{data}{$_[1]} = $_[2];
1978 if ($_[1] eq $_[0]{slot}) {
1979 untie %{$_[0]{selfref}};
1980 %{$_[0]{selfref}} = %{$_[0]{data}};
1989 return $self->{pager} if $self->{pager};
1991 if ($self->get_cache) {
1992 $self->throw_exception ('Pagers on cached resultsets are not supported');
1995 my $attrs = $self->{attrs};
1996 if (!defined $attrs->{page}) {
1997 $self->throw_exception("Can't create pager for non-paged rs");
1999 elsif ($attrs->{page} <= 0) {
2000 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2002 $attrs->{rows} ||= 10;
2004 # throw away the paging flags and re-run the count (possibly
2005 # with a subselect) to get the real total count
2006 my $count_attrs = { %$attrs };
2007 delete $count_attrs->{$_} for qw/rows offset page pager/;
2008 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2011 ### the following may seem awkward and dirty, but it's a thought-experiment
2012 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2013 ### before talking to ribasushi/mst
2015 my $pager = Data::Page->new(
2016 0, #start with an empty set
2018 $self->{attrs}{page},
2021 my $data_slot = 'total_entries';
2023 # Since we are interested in a cached value (once it's set - it's set), every
2024 # technique will detach from the magic-host once the time comes to fire the
2025 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2027 if ($] < 5.008003) {
2028 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2029 # to weakref the magic container :(
2031 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2032 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2035 elsif ($] < 5.010) {
2036 # We can use magic on the hash value slot. It's interesting that the magic is
2037 # attached to the hash-slot, and does *not* stop working once I do the dummy
2038 # assignments after the cast()
2039 # tested on 5.8.3 and 5.8.9
2040 my $magic = $mk_lazy_count_wizard->($total_rs);
2041 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2043 # this is for fun and giggles
2044 $pager->{$data_slot} = -1;
2045 $pager->{$data_slot} = 0;
2047 # this does not work for scalars, but works with
2049 #my %vals = %$pager;
2054 # And the uvar magic
2055 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2056 # however see the wizard maker for more notes
2057 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2058 Variable::Magic::cast ( %$pager, $magic );
2061 $pager->{$data_slot} = -1;
2062 $pager->{$data_slot} = 0;
2070 return $self->{pager} = $pager;
2077 =item Arguments: $page_number
2079 =item Return Value: $rs
2083 Returns a resultset for the $page_number page of the resultset on which page
2084 is called, where each page contains a number of rows equal to the 'rows'
2085 attribute set on the resultset (10 by default).
2090 my ($self, $page) = @_;
2091 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2098 =item Arguments: \%vals
2100 =item Return Value: $rowobject
2104 Creates a new row object in the resultset's result class and returns
2105 it. The row is not inserted into the database at this point, call
2106 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2107 will tell you whether the row object has been inserted or not.
2109 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2114 my ($self, $values) = @_;
2115 $self->throw_exception( "new_result needs a hash" )
2116 unless (ref $values eq 'HASH');
2118 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2122 @$cols_from_relations
2123 ? (-cols_from_relations => $cols_from_relations)
2125 -source_handle => $self->_source_handle,
2126 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2129 return $self->result_class->new(\%new);
2132 # _merge_with_rscond
2134 # Takes a simple hash of K/V data and returns its copy merged with the
2135 # condition already present on the resultset. Additionally returns an
2136 # arrayref of value/condition names, which were inferred from related
2137 # objects (this is needed for in-memory related objects)
2138 sub _merge_with_rscond {
2139 my ($self, $data) = @_;
2141 my (%new_data, @cols_from_relations);
2143 my $alias = $self->{attrs}{alias};
2145 if (! defined $self->{cond}) {
2146 # just massage $data below
2148 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2149 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2150 @cols_from_relations = keys %new_data;
2152 elsif (ref $self->{cond} ne 'HASH') {
2153 $self->throw_exception(
2154 "Can't abstract implicit construct, resultset condition not a hash"
2158 # precendence must be given to passed values over values inherited from
2159 # the cond, so the order here is important.
2160 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2161 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2163 while ( my($col, $value) = each %implied ) {
2164 my $vref = ref $value;
2165 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2166 $new_data{$col} = $value->{'='};
2168 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2169 $new_data{$col} = $value;
2176 %{ $self->_remove_alias($data, $alias) },
2179 return (\%new_data, \@cols_from_relations);
2182 # _has_resolved_attr
2184 # determines if the resultset defines at least one
2185 # of the attributes supplied
2187 # used to determine if a subquery is neccessary
2189 # supports some virtual attributes:
2191 # This will scan for any joins being present on the resultset.
2192 # It is not a mere key-search but a deep inspection of {from}
2195 sub _has_resolved_attr {
2196 my ($self, @attr_names) = @_;
2198 my $attrs = $self->_resolved_attrs;
2202 for my $n (@attr_names) {
2203 if (grep { $n eq $_ } (qw/-join/) ) {
2204 $extra_checks{$n}++;
2208 my $attr = $attrs->{$n};
2210 next if not defined $attr;
2212 if (ref $attr eq 'HASH') {
2213 return 1 if keys %$attr;
2215 elsif (ref $attr eq 'ARRAY') {
2223 # a resolved join is expressed as a multi-level from
2225 $extra_checks{-join}
2227 ref $attrs->{from} eq 'ARRAY'
2229 @{$attrs->{from}} > 1
2237 # Recursively collapse the condition.
2239 sub _collapse_cond {
2240 my ($self, $cond, $collapsed) = @_;
2244 if (ref $cond eq 'ARRAY') {
2245 foreach my $subcond (@$cond) {
2246 next unless ref $subcond; # -or
2247 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2250 elsif (ref $cond eq 'HASH') {
2251 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2252 foreach my $subcond (@{$cond->{-and}}) {
2253 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2257 foreach my $col (keys %$cond) {
2258 my $value = $cond->{$col};
2259 $collapsed->{$col} = $value;
2269 # Remove the specified alias from the specified query hash. A copy is made so
2270 # the original query is not modified.
2273 my ($self, $query, $alias) = @_;
2275 my %orig = %{ $query || {} };
2278 foreach my $key (keys %orig) {
2280 $unaliased{$key} = $orig{$key};
2283 $unaliased{$1} = $orig{$key}
2284 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2294 =item Arguments: none
2296 =item Return Value: \[ $sql, @bind ]
2300 Returns the SQL query and bind vars associated with the invocant.
2302 This is generally used as the RHS for a subquery.
2309 my $attrs = $self->_resolved_attrs_copy;
2314 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2315 # $sql also has no wrapping parenthesis in list ctx
2317 my $sqlbind = $self->result_source->storage
2318 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2327 =item Arguments: \%vals, \%attrs?
2329 =item Return Value: $rowobject
2333 my $artist = $schema->resultset('Artist')->find_or_new(
2334 { artist => 'fred' }, { key => 'artists' });
2336 $cd->cd_to_producer->find_or_new({ producer => $producer },
2337 { key => 'primary });
2339 Find an existing record from this resultset using L</find>. if none exists,
2340 instantiate a new result object and return it. The object will not be saved
2341 into your storage until you call L<DBIx::Class::Row/insert> on it.
2343 You most likely want this method when looking for existing rows using a unique
2344 constraint that is not the primary key, or looking for related rows.
2346 If you want objects to be saved immediately, use L</find_or_create> instead.
2348 B<Note>: Make sure to read the documentation of L</find> and understand the
2349 significance of the C<key> attribute, as its lack may skew your search, and
2350 subsequently result in spurious new objects.
2352 B<Note>: Take care when using C<find_or_new> with a table having
2353 columns with default values that you intend to be automatically
2354 supplied by the database (e.g. an auto_increment primary key column).
2355 In normal usage, the value of such columns should NOT be included at
2356 all in the call to C<find_or_new>, even when set to C<undef>.
2362 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2363 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2364 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2367 return $self->new_result($hash);
2374 =item Arguments: \%vals
2376 =item Return Value: a L<DBIx::Class::Row> $object
2380 Attempt to create a single new row or a row with multiple related rows
2381 in the table represented by the resultset (and related tables). This
2382 will not check for duplicate rows before inserting, use
2383 L</find_or_create> to do that.
2385 To create one row for this resultset, pass a hashref of key/value
2386 pairs representing the columns of the table and the values you wish to
2387 store. If the appropriate relationships are set up, foreign key fields
2388 can also be passed an object representing the foreign row, and the
2389 value will be set to its primary key.
2391 To create related objects, pass a hashref of related-object column values
2392 B<keyed on the relationship name>. If the relationship is of type C<multi>
2393 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2394 The process will correctly identify columns holding foreign keys, and will
2395 transparently populate them from the keys of the corresponding relation.
2396 This can be applied recursively, and will work correctly for a structure
2397 with an arbitrary depth and width, as long as the relationships actually
2398 exists and the correct column data has been supplied.
2401 Instead of hashrefs of plain related data (key/value pairs), you may
2402 also pass new or inserted objects. New objects (not inserted yet, see
2403 L</new>), will be inserted into their appropriate tables.
2405 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2407 Example of creating a new row.
2409 $person_rs->create({
2410 name=>"Some Person",
2411 email=>"somebody@someplace.com"
2414 Example of creating a new row and also creating rows in a related C<has_many>
2415 or C<has_one> resultset. Note Arrayref.
2418 { artistid => 4, name => 'Manufactured Crap', cds => [
2419 { title => 'My First CD', year => 2006 },
2420 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2425 Example of creating a new row and also creating a row in a related
2426 C<belongs_to> resultset. Note Hashref.
2429 title=>"Music for Silly Walks",
2432 name=>"Silly Musician",
2440 When subclassing ResultSet never attempt to override this method. Since
2441 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2442 lot of the internals simply never call it, so your override will be
2443 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2444 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2445 L</create> process you need to intervene.
2452 my ($self, $attrs) = @_;
2453 $self->throw_exception( "create needs a hashref" )
2454 unless ref $attrs eq 'HASH';
2455 return $self->new_result($attrs)->insert;
2458 =head2 find_or_create
2462 =item Arguments: \%vals, \%attrs?
2464 =item Return Value: $rowobject
2468 $cd->cd_to_producer->find_or_create({ producer => $producer },
2469 { key => 'primary' });
2471 Tries to find a record based on its primary key or unique constraints; if none
2472 is found, creates one and returns that instead.
2474 my $cd = $schema->resultset('CD')->find_or_create({
2476 artist => 'Massive Attack',
2477 title => 'Mezzanine',
2481 Also takes an optional C<key> attribute, to search by a specific key or unique
2482 constraint. For example:
2484 my $cd = $schema->resultset('CD')->find_or_create(
2486 artist => 'Massive Attack',
2487 title => 'Mezzanine',
2489 { key => 'cd_artist_title' }
2492 B<Note>: Make sure to read the documentation of L</find> and understand the
2493 significance of the C<key> attribute, as its lack may skew your search, and
2494 subsequently result in spurious row creation.
2496 B<Note>: Because find_or_create() reads from the database and then
2497 possibly inserts based on the result, this method is subject to a race
2498 condition. Another process could create a record in the table after
2499 the find has completed and before the create has started. To avoid
2500 this problem, use find_or_create() inside a transaction.
2502 B<Note>: Take care when using C<find_or_create> with a table having
2503 columns with default values that you intend to be automatically
2504 supplied by the database (e.g. an auto_increment primary key column).
2505 In normal usage, the value of such columns should NOT be included at
2506 all in the call to C<find_or_create>, even when set to C<undef>.
2508 See also L</find> and L</update_or_create>. For information on how to declare
2509 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2513 sub find_or_create {
2515 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2516 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2517 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2520 return $self->create($hash);
2523 =head2 update_or_create
2527 =item Arguments: \%col_values, { key => $unique_constraint }?
2529 =item Return Value: $row_object
2533 $resultset->update_or_create({ col => $val, ... });
2535 Like L</find_or_create>, but if a row is found it is immediately updated via
2536 C<< $found_row->update (\%col_values) >>.
2539 Takes an optional C<key> attribute to search on a specific unique constraint.
2542 # In your application
2543 my $cd = $schema->resultset('CD')->update_or_create(
2545 artist => 'Massive Attack',
2546 title => 'Mezzanine',
2549 { key => 'cd_artist_title' }
2552 $cd->cd_to_producer->update_or_create({
2553 producer => $producer,
2559 B<Note>: Make sure to read the documentation of L</find> and understand the
2560 significance of the C<key> attribute, as its lack may skew your search, and
2561 subsequently result in spurious row creation.
2563 B<Note>: Take care when using C<update_or_create> with a table having
2564 columns with default values that you intend to be automatically
2565 supplied by the database (e.g. an auto_increment primary key column).
2566 In normal usage, the value of such columns should NOT be included at
2567 all in the call to C<update_or_create>, even when set to C<undef>.
2569 See also L</find> and L</find_or_create>. For information on how to declare
2570 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2574 sub update_or_create {
2576 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2577 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2579 my $row = $self->find($cond, $attrs);
2581 $row->update($cond);
2585 return $self->create($cond);
2588 =head2 update_or_new
2592 =item Arguments: \%col_values, { key => $unique_constraint }?
2594 =item Return Value: $rowobject
2598 $resultset->update_or_new({ col => $val, ... });
2600 Like L</find_or_new> but if a row is found it is immediately updated via
2601 C<< $found_row->update (\%col_values) >>.
2605 # In your application
2606 my $cd = $schema->resultset('CD')->update_or_new(
2608 artist => 'Massive Attack',
2609 title => 'Mezzanine',
2612 { key => 'cd_artist_title' }
2615 if ($cd->in_storage) {
2616 # the cd was updated
2619 # the cd is not yet in the database, let's insert it
2623 B<Note>: Make sure to read the documentation of L</find> and understand the
2624 significance of the C<key> attribute, as its lack may skew your search, and
2625 subsequently result in spurious new objects.
2627 B<Note>: Take care when using C<update_or_new> with a table having
2628 columns with default values that you intend to be automatically
2629 supplied by the database (e.g. an auto_increment primary key column).
2630 In normal usage, the value of such columns should NOT be included at
2631 all in the call to C<update_or_new>, even when set to C<undef>.
2633 See also L</find>, L</find_or_create> and L</find_or_new>.
2639 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2640 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2642 my $row = $self->find( $cond, $attrs );
2643 if ( defined $row ) {
2644 $row->update($cond);
2648 return $self->new_result($cond);
2655 =item Arguments: none
2657 =item Return Value: \@cache_objects | undef
2661 Gets the contents of the cache for the resultset, if the cache is set.
2663 The cache is populated either by using the L</prefetch> attribute to
2664 L</search> or by calling L</set_cache>.
2676 =item Arguments: \@cache_objects
2678 =item Return Value: \@cache_objects
2682 Sets the contents of the cache for the resultset. Expects an arrayref
2683 of objects of the same class as those produced by the resultset. Note that
2684 if the cache is set the resultset will return the cached objects rather
2685 than re-querying the database even if the cache attr is not set.
2687 The contents of the cache can also be populated by using the
2688 L</prefetch> attribute to L</search>.
2693 my ( $self, $data ) = @_;
2694 $self->throw_exception("set_cache requires an arrayref")
2695 if defined($data) && (ref $data ne 'ARRAY');
2696 $self->{all_cache} = $data;
2703 =item Arguments: none
2705 =item Return Value: undef
2709 Clears the cache for the resultset.
2714 shift->set_cache(undef);
2721 =item Arguments: none
2723 =item Return Value: true, if the resultset has been paginated
2731 return !!$self->{attrs}{page};
2738 =item Arguments: none
2740 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2748 return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
2751 =head2 related_resultset
2755 =item Arguments: $relationship_name
2757 =item Return Value: $resultset
2761 Returns a related resultset for the supplied relationship name.
2763 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2767 sub related_resultset {
2768 my ($self, $rel) = @_;
2770 $self->{related_resultsets} ||= {};
2771 return $self->{related_resultsets}{$rel} ||= do {
2772 my $rsrc = $self->result_source;
2773 my $rel_info = $rsrc->relationship_info($rel);
2775 $self->throw_exception(
2776 "search_related: result source '" . $rsrc->source_name .
2777 "' has no such relationship $rel")
2780 my $attrs = $self->_chain_relationship($rel);
2782 my $join_count = $attrs->{seen_join}{$rel};
2784 my $alias = $self->result_source->storage
2785 ->relname_to_table_alias($rel, $join_count);
2787 # since this is search_related, and we already slid the select window inwards
2788 # (the select/as attrs were deleted in the beginning), we need to flip all
2789 # left joins to inner, so we get the expected results
2790 # read the comment on top of the actual function to see what this does
2791 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2794 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2795 delete @{$attrs}{qw(result_class alias)};
2799 if (my $cache = $self->get_cache) {
2800 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2801 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2806 my $rel_source = $rsrc->related_source($rel);
2810 # The reason we do this now instead of passing the alias to the
2811 # search_rs below is that if you wrap/overload resultset on the
2812 # source you need to know what alias it's -going- to have for things
2813 # to work sanely (e.g. RestrictWithObject wants to be able to add
2814 # extra query restrictions, and these may need to be $alias.)
2816 my $rel_attrs = $rel_source->resultset_attributes;
2817 local $rel_attrs->{alias} = $alias;
2819 $rel_source->resultset
2823 where => $attrs->{where},
2826 $new->set_cache($new_cache) if $new_cache;
2831 =head2 current_source_alias
2835 =item Arguments: none
2837 =item Return Value: $source_alias
2841 Returns the current table alias for the result source this resultset is built
2842 on, that will be used in the SQL query. Usually it is C<me>.
2844 Currently the source alias that refers to the result set returned by a
2845 L</search>/L</find> family method depends on how you got to the resultset: it's
2846 C<me> by default, but eg. L</search_related> aliases it to the related result
2847 source name (and keeps C<me> referring to the original result set). The long
2848 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2849 (and make this method unnecessary).
2851 Thus it's currently necessary to use this method in predefined queries (see
2852 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2853 source alias of the current result set:
2855 # in a result set class
2857 my ($self, $user) = @_;
2859 my $me = $self->current_source_alias;
2861 return $self->search(
2862 "$me.modified" => $user->id,
2868 sub current_source_alias {
2871 return ($self->{attrs} || {})->{alias} || 'me';
2874 =head2 as_subselect_rs
2878 =item Arguments: none
2880 =item Return Value: $resultset
2884 Act as a barrier to SQL symbols. The resultset provided will be made into a
2885 "virtual view" by including it as a subquery within the from clause. From this
2886 point on, any joined tables are inaccessible to ->search on the resultset (as if
2887 it were simply where-filtered without joins). For example:
2889 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2891 # 'x' now pollutes the query namespace
2893 # So the following works as expected
2894 my $ok_rs = $rs->search({'x.other' => 1});
2896 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2897 # def) we look for one row with contradictory terms and join in another table
2898 # (aliased 'x_2') which we never use
2899 my $broken_rs = $rs->search({'x.name' => 'def'});
2901 my $rs2 = $rs->as_subselect_rs;
2903 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2904 my $not_joined_rs = $rs2->search({'x.other' => 1});
2906 # works as expected: finds a 'table' row related to two x rows (abc and def)
2907 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2909 Another example of when one might use this would be to select a subset of
2910 columns in a group by clause:
2912 my $rs = $schema->resultset('Bar')->search(undef, {
2913 group_by => [qw{ id foo_id baz_id }],
2914 })->as_subselect_rs->search(undef, {
2915 columns => [qw{ id foo_id }]
2918 In the above example normally columns would have to be equal to the group by,
2919 but because we isolated the group by into a subselect the above works.
2923 sub as_subselect_rs {
2926 my $attrs = $self->_resolved_attrs;
2928 my $fresh_rs = (ref $self)->new (
2929 $self->result_source
2932 # these pieces will be locked in the subquery
2933 delete $fresh_rs->{cond};
2934 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2936 return $fresh_rs->search( {}, {
2938 $attrs->{alias} => $self->as_query,
2939 -alias => $attrs->{alias},
2940 -source_handle => $self->result_source->handle,
2942 alias => $attrs->{alias},
2946 # This code is called by search_related, and makes sure there
2947 # is clear separation between the joins before, during, and
2948 # after the relationship. This information is needed later
2949 # in order to properly resolve prefetch aliases (any alias
2950 # with a relation_chain_depth less than the depth of the
2951 # current prefetch is not considered)
2953 # The increments happen twice per join. An even number means a
2954 # relationship specified via a search_related, whereas an odd
2955 # number indicates a join/prefetch added via attributes
2957 # Also this code will wrap the current resultset (the one we
2958 # chain to) in a subselect IFF it contains limiting attributes
2959 sub _chain_relationship {
2960 my ($self, $rel) = @_;
2961 my $source = $self->result_source;
2962 my $attrs = { %{$self->{attrs}||{}} };
2964 # we need to take the prefetch the attrs into account before we
2965 # ->_resolve_join as otherwise they get lost - captainL
2966 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
2968 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2970 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2973 my @force_subq_attrs = qw/offset rows group_by having/;
2976 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2978 $self->_has_resolved_attr (@force_subq_attrs)
2980 # Nuke the prefetch (if any) before the new $rs attrs
2981 # are resolved (prefetch is useless - we are wrapping
2982 # a subquery anyway).
2983 my $rs_copy = $self->search;
2984 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
2985 $rs_copy->{attrs}{join},
2986 delete $rs_copy->{attrs}{prefetch},
2990 -source_handle => $source->handle,
2991 -alias => $attrs->{alias},
2992 $attrs->{alias} => $rs_copy->as_query,
2994 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2995 $seen->{-relation_chain_depth} = 0;
2997 elsif ($attrs->{from}) { #shallow copy suffices
2998 $from = [ @{$attrs->{from}} ];
3002 -source_handle => $source->handle,
3003 -alias => $attrs->{alias},
3004 $attrs->{alias} => $source->from,
3008 my $jpath = ($seen->{-relation_chain_depth})
3009 ? $from->[-1][0]{-join_path}
3012 my @requested_joins = $source->_resolve_join(
3019 push @$from, @requested_joins;
3021 $seen->{-relation_chain_depth}++;
3023 # if $self already had a join/prefetch specified on it, the requested
3024 # $rel might very well be already included. What we do in this case
3025 # is effectively a no-op (except that we bump up the chain_depth on
3026 # the join in question so we could tell it *is* the search_related)
3029 # we consider the last one thus reverse
3030 for my $j (reverse @requested_joins) {
3031 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3032 if ($rel eq $last_j) {
3033 $j->[0]{-relation_chain_depth}++;
3039 unless ($already_joined) {
3040 push @$from, $source->_resolve_join(
3048 $seen->{-relation_chain_depth}++;
3050 return {%$attrs, from => $from, seen_join => $seen};
3053 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3054 sub _resolved_attrs_copy {
3056 return { %{$self->_resolved_attrs (@_)} };
3059 sub _resolved_attrs {
3061 return $self->{_attrs} if $self->{_attrs};
3063 my $attrs = { %{ $self->{attrs} || {} } };
3064 my $source = $self->result_source;
3065 my $alias = $attrs->{alias};
3068 # resolve selectors, this one is quite hairy
3070 my $selection_pieces;
3072 $attrs->{columns} ||= delete $attrs->{cols}
3073 if exists $attrs->{cols};
3075 # disassemble columns / +columns
3077 $selection_pieces->{columns}{select},
3078 $selection_pieces->{columns}{as},
3079 $selection_pieces->{'+columns'}{select},
3080 $selection_pieces->{'+columns'}{as},
3085 for my $colbit (@$_) {
3087 if (ref $colbit eq 'HASH') {
3088 for my $as (keys %$colbit) {
3089 push @sel, $colbit->{$as};
3102 (ref $attrs->{columns} eq 'ARRAY' ? delete $attrs->{columns} : [ delete $attrs->{columns} ]),
3103 # include_columns is a legacy add-on to +columns
3104 [ map { ref $_ eq 'ARRAY' ? @$_ : ($_ || () ) } delete @{$attrs}{qw/+columns include_columns/} ] )
3107 # make copies of select/as and +select/+as
3109 $selection_pieces->{'select/as'}{select},
3110 $selection_pieces->{'select/as'}{as},
3111 $selection_pieces->{'+select/+as'}{select},
3112 $selection_pieces->{'+select/+as'}{as},
3114 { $_ ? [ ref $_ eq 'ARRAY' ? @$_ : $_ ] : [] }
3115 ( delete @{$attrs}{qw/select as +select +as/} )
3118 # default to * only when neither no non-plus selectors are available
3120 ! @{$selection_pieces->{'select/as'}{select}}
3122 ! @{$selection_pieces->{'columns'}{select}}
3124 for ($source->columns) {
3125 push @{$selection_pieces->{'select/as'}{select}}, $_;
3126 push @{$selection_pieces->{'select/as'}{as}}, $_;
3130 # final composition order (important)
3131 my @sel_pairs = grep {
3132 $selection_pieces->{$_}
3135 ( $selection_pieces->{$_}{select} && @{$selection_pieces->{$_}{select}} )
3137 ( $selection_pieces->{$_}{as} && @{$selection_pieces->{$_}{as}} )
3139 } qw|columns select/as +columns +select/+as|;
3141 # fill in missing as bits for each pair
3142 # if it's the last pair we can let things slide ( bare +select is sadly popular)
3145 for my $i (0 .. $#sel_pairs) {
3147 my $pairname = $sel_pairs[$i];
3149 my ($sel, $as) = @{$selection_pieces->{$pairname}}{qw/select as/};
3151 $self->throw_exception(
3152 "Unable to assemble final selection list: $pairname specified in addition to unbalanced $sel_pairs[$i-1]"
3153 ) if ($out_of_sync);
3155 if (@$sel == @$as) {
3158 elsif (@$sel < @$as) {
3159 $self->throw_exception(
3160 "More 'as' elements than 'select' elements for $pairname, unable to continue"
3164 # try to deduce the 'as' part, will work only if all the selectors are "plain", or contain an explicit -as
3165 # if we can not deduce something - stop right there and leave the rest of the selector un-as'ed
3166 # if there is an extra selection pair coming after that - it will die due to out_of_sync being set
3167 for my $j ($#$as+1 .. $#$sel) {
3168 if (my $ref = ref $sel->[$j]) {
3169 if ($ref eq 'HASH' and exists $sel->[$j]{-as}) {
3170 push @$as, $sel->[$j]{-as};
3178 push @$as, $sel->[$j];
3184 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3185 # disqualify all $alias.col as-bits (collapser mandated)
3186 for (values %$selection_pieces) {
3187 $_->{select} = [ map { (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" } @{$_->{select}} ];
3188 $_->{as} = [ map { $_ =~ /^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$_->{as}} ];
3193 $attrs->{select} = $self->_merge_attr ($attrs->{select}, $selection_pieces->{$_}{select});
3194 $attrs->{as} = $self->_merge_attr ($attrs->{as}, $selection_pieces->{$_}{as});
3197 # de-duplicate the result (remove *identical* select/as pairs)
3198 # and also die on duplicate {as} pointing to different {select}s
3199 # not using a c-style for as the condition is prone to shrinkage
3202 while ($i <= $#{$attrs->{as}} ) {
3203 my ($sel, $as) = map { $attrs->{$_}[$i] } (qw/select as/);
3205 if ($seen->{"$sel \x00\x00 $as"}++) {
3207 for @{$attrs}{qw/select as/};
3209 elsif ($seen->{$as}++) {
3210 $self->throw_exception(
3211 "inflate_result() alias '$as' specified twice with different SQL-side {select}-ors"
3219 ## selector resolution done
3223 $attrs->{from} ||= [{
3224 -source_handle => $source->handle,
3225 -alias => $self->{attrs}{alias},
3226 $self->{attrs}{alias} => $source->from,
3229 if ( $attrs->{join} || $attrs->{prefetch} ) {
3231 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3232 if ref $attrs->{from} ne 'ARRAY';
3234 my $join = delete $attrs->{join} || {};
3236 if ( defined $attrs->{prefetch} ) {
3237 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3240 $attrs->{from} = # have to copy here to avoid corrupting the original
3242 @{ $attrs->{from} },
3243 $source->_resolve_join(
3246 { %{ $attrs->{seen_join} || {} } },
3247 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3248 ? $attrs->{from}[-1][0]{-join_path}
3255 if ( defined $attrs->{order_by} ) {
3256 $attrs->{order_by} = (
3257 ref( $attrs->{order_by} ) eq 'ARRAY'
3258 ? [ @{ $attrs->{order_by} } ]
3259 : [ $attrs->{order_by} || () ]
3263 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3264 $attrs->{group_by} = [ $attrs->{group_by} ];
3267 # generate the distinct induced group_by early, as prefetch will be carried via a
3268 # subquery (since a group_by is present)
3269 if (delete $attrs->{distinct}) {
3270 if ($attrs->{group_by}) {
3271 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3274 $attrs->{group_by} = $source->storage->_group_over_selection (
3275 @{$attrs}{qw/from select order_by/}
3280 $attrs->{collapse} ||= {};
3281 if ( my $prefetch = delete $attrs->{prefetch} ) {
3282 $prefetch = $self->_merge_joinpref_attr( {}, $prefetch );
3284 my $prefetch_ordering = [];
3286 # this is a separate structure (we don't look in {from} directly)
3287 # as the resolver needs to shift things off the lists to work
3288 # properly (identical-prefetches on different branches)
3290 if (ref $attrs->{from} eq 'ARRAY') {
3292 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3294 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3295 next unless $j->[0]{-alias};
3296 next unless $j->[0]{-join_path};
3297 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3299 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3302 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3303 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3308 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3310 # we need to somehow mark which columns came from prefetch
3311 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3313 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3314 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3316 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3317 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3320 # if both page and offset are specified, produce a combined offset
3321 # even though it doesn't make much sense, this is what pre 081xx has
3323 if (my $page = delete $attrs->{page}) {
3325 ($attrs->{rows} * ($page - 1))
3327 ($attrs->{offset} || 0)
3331 return $self->{_attrs} = $attrs;
3335 my ($self, $attr) = @_;
3337 if (ref $attr eq 'HASH') {
3338 return $self->_rollout_hash($attr);
3339 } elsif (ref $attr eq 'ARRAY') {
3340 return $self->_rollout_array($attr);
3346 sub _rollout_array {
3347 my ($self, $attr) = @_;
3350 foreach my $element (@{$attr}) {
3351 if (ref $element eq 'HASH') {
3352 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3353 } elsif (ref $element eq 'ARRAY') {
3354 # XXX - should probably recurse here
3355 push( @rolled_array, @{$self->_rollout_array($element)} );
3357 push( @rolled_array, $element );
3360 return \@rolled_array;
3364 my ($self, $attr) = @_;
3367 foreach my $key (keys %{$attr}) {
3368 push( @rolled_array, { $key => $attr->{$key} } );
3370 return \@rolled_array;
3373 sub _calculate_score {
3374 my ($self, $a, $b) = @_;
3376 if (defined $a xor defined $b) {
3379 elsif (not defined $a) {
3383 if (ref $b eq 'HASH') {
3384 my ($b_key) = keys %{$b};
3385 if (ref $a eq 'HASH') {
3386 my ($a_key) = keys %{$a};
3387 if ($a_key eq $b_key) {
3388 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3393 return ($a eq $b_key) ? 1 : 0;
3396 if (ref $a eq 'HASH') {
3397 my ($a_key) = keys %{$a};
3398 return ($b eq $a_key) ? 1 : 0;
3400 return ($b eq $a) ? 1 : 0;
3405 sub _merge_joinpref_attr {
3406 my ($self, $orig, $import) = @_;
3408 return $import unless defined($orig);
3409 return $orig unless defined($import);
3411 $orig = $self->_rollout_attr($orig);
3412 $import = $self->_rollout_attr($import);
3415 foreach my $import_element ( @{$import} ) {
3416 # find best candidate from $orig to merge $b_element into
3417 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3418 foreach my $orig_element ( @{$orig} ) {
3419 my $score = $self->_calculate_score( $orig_element, $import_element );
3420 if ($score > $best_candidate->{score}) {
3421 $best_candidate->{position} = $position;
3422 $best_candidate->{score} = $score;
3426 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3428 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3429 push( @{$orig}, $import_element );
3431 my $orig_best = $orig->[$best_candidate->{position}];
3432 # merge orig_best and b_element together and replace original with merged
3433 if (ref $orig_best ne 'HASH') {
3434 $orig->[$best_candidate->{position}] = $import_element;
3435 } elsif (ref $import_element eq 'HASH') {
3436 my ($key) = keys %{$orig_best};
3437 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3440 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3451 my $hm = Hash::Merge->new;
3453 $hm->specify_behavior({
3456 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3458 if ($defl xor $defr) {
3459 return $defl ? $_[0] : $_[1];
3464 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3468 return [$_[0], $_[1]];
3472 return $_[1] if !defined $_[0];
3473 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3474 return [$_[0], @{$_[1]}]
3477 return $_[1] if !defined $_[0];
3478 return $_[0] if !keys %{$_[1]};
3479 return [$_[0], $_[1]]
3484 return $_[0] if !defined $_[1];
3485 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3486 return [@{$_[0]}, $_[1]]
3489 my @ret = @{$_[0]} or return $_[1];
3490 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3491 my %idx = map { $_ => 1 } @ret;
3492 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3496 return [ $_[1] ] if ! @{$_[0]};
3497 return $_[0] if !keys %{$_[1]};
3498 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3499 return [ @{$_[0]}, $_[1] ];
3504 return $_[0] if !defined $_[1];
3505 return $_[1] if !keys %{$_[0]};
3506 return [$_[0], $_[1]]
3509 return $_[0] if !@{$_[1]};
3510 return $_[1] if !keys %{$_[0]};
3511 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3512 return [ $_[0], @{$_[1]} ];
3515 return $_[0] if !keys %{$_[1]};
3516 return $_[1] if !keys %{$_[0]};
3517 return $_[0] if $_[0] eq $_[1];
3518 return [ $_[0], $_[1] ];
3521 } => 'DBIC_RS_ATTR_MERGER');
3525 return $hm->merge ($_[1], $_[2]);
3533 $self->_source_handle($_[0]->handle);
3535 $self->_source_handle->resolve;
3540 sub STORABLE_freeze {
3541 my ($self, $cloning) = @_;
3542 my $to_serialize = { %$self };
3544 # A cursor in progress can't be serialized (and would make little sense anyway)
3545 delete $to_serialize->{cursor};
3547 return nfreeze($to_serialize);
3550 # need this hook for symmetry
3552 my ($self, $cloning, $serialized) = @_;
3554 %$self = %{ thaw($serialized) };
3560 =head2 throw_exception
3562 See L<DBIx::Class::Schema/throw_exception> for details.
3566 sub throw_exception {
3569 if (ref $self && $self->_source_handle->schema) {
3570 $self->_source_handle->schema->throw_exception(@_)
3573 DBIx::Class::Exception->throw(@_);
3577 # XXX: FIXME: Attributes docs need clearing up
3581 Attributes are used to refine a ResultSet in various ways when
3582 searching for data. They can be passed to any method which takes an
3583 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3586 These are in no particular order:
3592 =item Value: ( $order_by | \@order_by | \%order_by )
3596 Which column(s) to order the results by.
3598 [The full list of suitable values is documented in
3599 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3602 If a single column name, or an arrayref of names is supplied, the
3603 argument is passed through directly to SQL. The hashref syntax allows
3604 for connection-agnostic specification of ordering direction:
3606 For descending order:
3608 order_by => { -desc => [qw/col1 col2 col3/] }
3610 For explicit ascending order:
3612 order_by => { -asc => 'col' }
3614 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3615 supported, although you are strongly encouraged to use the hashref
3616 syntax as outlined above.
3622 =item Value: \@columns
3626 Shortcut to request a particular set of columns to be retrieved. Each
3627 column spec may be a string (a table column name), or a hash (in which
3628 case the key is the C<as> value, and the value is used as the C<select>
3629 expression). Adds C<me.> onto the start of any column without a C<.> in
3630 it and sets C<select> from that, then auto-populates C<as> from
3631 C<select> as normal. (You may also use the C<cols> attribute, as in
3632 earlier versions of DBIC.)
3634 Essentially C<columns> does the same as L</select> and L</as>.
3636 columns => [ 'foo', { bar => 'baz' } ]
3640 select => [qw/foo baz/],
3647 =item Value: \@columns
3651 Indicates additional columns to be selected from storage. Works the same
3652 as L</columns> but adds columns to the selection. (You may also use the
3653 C<include_columns> attribute, as in earlier versions of DBIC). For
3656 $schema->resultset('CD')->search(undef, {
3657 '+columns' => ['artist.name'],
3661 would return all CDs and include a 'name' column to the information
3662 passed to object inflation. Note that the 'artist' is the name of the
3663 column (or relationship) accessor, and 'name' is the name of the column
3664 accessor in the related table.
3666 =head2 include_columns
3670 =item Value: \@columns
3674 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3680 =item Value: \@select_columns
3684 Indicates which columns should be selected from the storage. You can use
3685 column names, or in the case of RDBMS back ends, function or stored procedure
3688 $rs = $schema->resultset('Employee')->search(undef, {
3691 { count => 'employeeid' },
3692 { max => { length => 'name' }, -as => 'longest_name' }
3697 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3699 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3700 use L</select>, to instruct DBIx::Class how to store the result of the column.
3701 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3702 identifier aliasing. You can however alias a function, so you can use it in
3703 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3704 attribute> supplied as shown in the example above.
3710 Indicates additional columns to be selected from storage. Works the same as
3711 L</select> but adds columns to the default selection, instead of specifying
3720 Indicates additional column names for those added via L</+select>. See L</as>.
3728 =item Value: \@inflation_names
3732 Indicates column names for object inflation. That is L</as> indicates the
3733 slot name in which the column value will be stored within the
3734 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3735 identifier by the C<get_column> method (or via the object accessor B<if one
3736 with the same name already exists>) as shown below. The L</as> attribute has
3737 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3739 $rs = $schema->resultset('Employee')->search(undef, {
3742 { count => 'employeeid' },
3743 { max => { length => 'name' }, -as => 'longest_name' }
3752 If the object against which the search is performed already has an accessor
3753 matching a column name specified in C<as>, the value can be retrieved using
3754 the accessor as normal:
3756 my $name = $employee->name();
3758 If on the other hand an accessor does not exist in the object, you need to
3759 use C<get_column> instead:
3761 my $employee_count = $employee->get_column('employee_count');
3763 You can create your own accessors if required - see
3764 L<DBIx::Class::Manual::Cookbook> for details.
3770 =item Value: ($rel_name | \@rel_names | \%rel_names)
3774 Contains a list of relationships that should be joined for this query. For
3777 # Get CDs by Nine Inch Nails
3778 my $rs = $schema->resultset('CD')->search(
3779 { 'artist.name' => 'Nine Inch Nails' },
3780 { join => 'artist' }
3783 Can also contain a hash reference to refer to the other relation's relations.
3786 package MyApp::Schema::Track;
3787 use base qw/DBIx::Class/;
3788 __PACKAGE__->table('track');
3789 __PACKAGE__->add_columns(qw/trackid cd position title/);
3790 __PACKAGE__->set_primary_key('trackid');
3791 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3794 # In your application
3795 my $rs = $schema->resultset('Artist')->search(
3796 { 'track.title' => 'Teardrop' },
3798 join => { cd => 'track' },
3799 order_by => 'artist.name',
3803 You need to use the relationship (not the table) name in conditions,
3804 because they are aliased as such. The current table is aliased as "me", so
3805 you need to use me.column_name in order to avoid ambiguity. For example:
3807 # Get CDs from 1984 with a 'Foo' track
3808 my $rs = $schema->resultset('CD')->search(
3811 'tracks.name' => 'Foo'
3813 { join => 'tracks' }
3816 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3817 similarly for a third time). For e.g.
3819 my $rs = $schema->resultset('Artist')->search({
3820 'cds.title' => 'Down to Earth',
3821 'cds_2.title' => 'Popular',
3823 join => [ qw/cds cds/ ],
3826 will return a set of all artists that have both a cd with title 'Down
3827 to Earth' and a cd with title 'Popular'.
3829 If you want to fetch related objects from other tables as well, see C<prefetch>
3832 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3838 =item Value: ($rel_name | \@rel_names | \%rel_names)
3842 Contains one or more relationships that should be fetched along with
3843 the main query (when they are accessed afterwards the data will
3844 already be available, without extra queries to the database). This is
3845 useful for when you know you will need the related objects, because it
3846 saves at least one query:
3848 my $rs = $schema->resultset('Tag')->search(
3857 The initial search results in SQL like the following:
3859 SELECT tag.*, cd.*, artist.* FROM tag
3860 JOIN cd ON tag.cd = cd.cdid
3861 JOIN artist ON cd.artist = artist.artistid
3863 L<DBIx::Class> has no need to go back to the database when we access the
3864 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3867 Simple prefetches will be joined automatically, so there is no need
3868 for a C<join> attribute in the above search.
3870 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3871 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3872 with an accessor type of 'single' or 'filter'). A more complex example that
3873 prefetches an artists cds, the tracks on those cds, and the tags associated
3874 with that artist is given below (assuming many-to-many from artists to tags):
3876 my $rs = $schema->resultset('Artist')->search(
3880 { cds => 'tracks' },
3881 { artist_tags => 'tags' }
3887 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3888 attributes will be ignored.
3890 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3891 exactly as you might expect.
3897 Prefetch uses the L</cache> to populate the prefetched relationships. This
3898 may or may not be what you want.
3902 If you specify a condition on a prefetched relationship, ONLY those
3903 rows that match the prefetched condition will be fetched into that relationship.
3904 This means that adding prefetch to a search() B<may alter> what is returned by
3905 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3907 my $artist_rs = $schema->resultset('Artist')->search({
3913 my $count = $artist_rs->first->cds->count;
3915 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3917 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3919 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3921 that cmp_ok() may or may not pass depending on the datasets involved. This
3922 behavior may or may not survive the 0.09 transition.
3934 Makes the resultset paged and specifies the page to retrieve. Effectively
3935 identical to creating a non-pages resultset and then calling ->page($page)
3938 If L<rows> attribute is not specified it defaults to 10 rows per page.
3940 When you have a paged resultset, L</count> will only return the number
3941 of rows in the page. To get the total, use the L</pager> and call
3942 C<total_entries> on it.
3952 Specifies the maximum number of rows for direct retrieval or the number of
3953 rows per page if the page attribute or method is used.
3959 =item Value: $offset
3963 Specifies the (zero-based) row number for the first row to be returned, or the
3964 of the first row of the first page if paging is used.
3970 =item Value: \@columns
3974 A arrayref of columns to group by. Can include columns of joined tables.
3976 group_by => [qw/ column1 column2 ... /]
3982 =item Value: $condition
3986 HAVING is a select statement attribute that is applied between GROUP BY and
3987 ORDER BY. It is applied to the after the grouping calculations have been
3990 having => { 'count(employee)' => { '>=', 100 } }
3996 =item Value: (0 | 1)
4000 Set to 1 to group by all columns. If the resultset already has a group_by
4001 attribute, this setting is ignored and an appropriate warning is issued.
4007 Adds to the WHERE clause.
4009 # only return rows WHERE deleted IS NULL for all searches
4010 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4012 Can be overridden by passing C<< { where => undef } >> as an attribute
4019 Set to 1 to cache search results. This prevents extra SQL queries if you
4020 revisit rows in your ResultSet:
4022 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4024 while( my $artist = $resultset->next ) {
4028 $rs->first; # without cache, this would issue a query
4030 By default, searches are not cached.
4032 For more examples of using these attributes, see
4033 L<DBIx::Class::Manual::Cookbook>.
4039 =item Value: ( 'update' | 'shared' )
4043 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT