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/;
22 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
26 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
30 my $users_rs = $schema->resultset('User');
31 while( $user = $users_rs->next) {
32 print $user->username;
35 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
36 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
40 A ResultSet is an object which stores a set of conditions representing
41 a query. It is the backbone of DBIx::Class (i.e. the really
42 important/useful bit).
44 No SQL is executed on the database when a ResultSet is created, it
45 just stores all the conditions needed to create the query.
47 A basic ResultSet representing the data of an entire table is returned
48 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
49 L<Source|DBIx::Class::Manual::Glossary/Source> name.
51 my $users_rs = $schema->resultset('User');
53 A new ResultSet is returned from calling L</search> on an existing
54 ResultSet. The new one will contain all the conditions of the
55 original, plus any new conditions added in the C<search> call.
57 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
58 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
61 The query that the ResultSet represents is B<only> executed against
62 the database when these methods are called:
63 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
65 If a resultset is used in a numeric context it returns the L</count>.
66 However, if it is used in a boolean context it is B<always> true. So if
67 you want to check if a resultset has any results, you must use C<if $rs
72 =head2 Chaining resultsets
74 Let's say you've got a query that needs to be run to return some data
75 to the user. But, you have an authorization system in place that
76 prevents certain users from seeing certain information. So, you want
77 to construct the basic query in one method, but add constraints to it in
82 my $request = $self->get_request; # Get a request object somehow.
83 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
85 my $cd_rs = $schema->resultset('CD')->search({
86 title => $request->param('title'),
87 year => $request->param('year'),
90 $self->apply_security_policy( $cd_rs );
95 sub apply_security_policy {
104 =head3 Resolving conditions and attributes
106 When a resultset is chained from another resultset, conditions and
107 attributes with the same keys need resolving.
109 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
110 into the existing ones from the original resultset.
112 The L</where> and L</having> attributes, and any search conditions, are
113 merged with an SQL C<AND> to the existing condition from the original
116 All other attributes are overridden by any new ones supplied in the
119 =head2 Multiple queries
121 Since a resultset just defines a query, you can do all sorts of
122 things with it with the same object.
124 # Don't hit the DB yet.
125 my $cd_rs = $schema->resultset('CD')->search({
126 title => 'something',
130 # Each of these hits the DB individually.
131 my $count = $cd_rs->count;
132 my $most_recent = $cd_rs->get_column('date_released')->max();
133 my @records = $cd_rs->all;
135 And it's not just limited to SELECT statements.
141 $cd_rs->create({ artist => 'Fred' });
143 Which is the same as:
145 $schema->resultset('CD')->create({
146 title => 'something',
151 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
159 =item Arguments: $source, \%$attrs
161 =item Return Value: $rs
165 The resultset constructor. Takes a source object (usually a
166 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
167 L</ATTRIBUTES> below). Does not perform any queries -- these are
168 executed as needed by the other methods.
170 Generally you won't need to construct a resultset manually. You'll
171 automatically get one from e.g. a L</search> called in scalar context:
173 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
175 IMPORTANT: If called on an object, proxies to new_result instead so
177 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
179 will return a CD object, not a ResultSet.
185 return $class->new_result(@_) if ref $class;
187 my ($source, $attrs) = @_;
188 $source = $source->handle
189 unless $source->isa('DBIx::Class::ResultSourceHandle');
190 $attrs = { %{$attrs||{}} };
192 if ($attrs->{page}) {
193 $attrs->{rows} ||= 10;
196 $attrs->{alias} ||= 'me';
198 # Creation of {} and bless separated to mitigate RH perl bug
199 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
201 _source_handle => $source,
202 cond => $attrs->{where},
210 $attrs->{result_class} || $source->resolve->result_class
220 =item Arguments: $cond, \%attrs?
222 =item Return Value: $resultset (scalar context), @row_objs (list context)
226 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
227 my $new_rs = $cd_rs->search({ year => 2005 });
229 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
230 # year = 2005 OR year = 2004
232 If you need to pass in additional attributes but no additional condition,
233 call it as C<search(undef, \%attrs)>.
235 # "SELECT name, artistid FROM $artist_table"
236 my @all_artists = $schema->resultset('Artist')->search(undef, {
237 columns => [qw/name artistid/],
240 For a list of attributes that can be passed to C<search>, see
241 L</ATTRIBUTES>. For more examples of using this function, see
242 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
243 documentation for the first argument, see L<SQL::Abstract>.
245 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
251 my $rs = $self->search_rs( @_ );
253 my $want = wantarray;
257 elsif (defined $want) {
261 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense');
269 =item Arguments: $cond, \%attrs?
271 =item Return Value: $resultset
275 This method does the same exact thing as search() except it will
276 always return a resultset, even in list context.
283 # Special-case handling for (undef, undef).
284 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
289 $call_attrs = pop(@_) if @_ > 1 and ref $_[-1] eq 'HASH';
291 # see if we can keep the cache (no $rs changes)
293 my %safe = (alias => 1, cache => 1);
294 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
297 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
299 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
301 $cache = $self->get_cache;
304 my $old_attrs = { %{$self->{attrs}} };
305 my $old_having = delete $old_attrs->{having};
306 my $old_where = delete $old_attrs->{where};
308 # reset the selector list
309 if (List::Util::first { exists $call_attrs->{$_} } qw{columns select as}) {
310 delete @{$old_attrs}{qw{select as columns +select +as +columns include_columns}};
313 my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
315 # merge new attrs into inherited
316 foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
317 next unless exists $call_attrs->{$key};
318 $new_attrs->{$key} = $self->_merge_attr($old_attrs->{$key}, $call_attrs->{$key});
321 # rip apart the rest of @_, parse a condition
324 if (ref $_[0] eq 'HASH') {
325 (keys %{$_[0]}) ? $_[0] : undef
331 $self->throw_exception('Odd number of arguments to search')
339 for ($old_where, $call_cond) {
341 $new_attrs->{where} = $self->_stack_cond (
342 $_, $new_attrs->{where}
347 if (defined $old_having) {
348 $new_attrs->{having} = $self->_stack_cond (
349 $old_having, $new_attrs->{having}
353 my $rs = (ref $self)->new($self->result_source, $new_attrs);
355 $rs->set_cache($cache) if ($cache);
361 my ($self, $left, $right) = @_;
362 if (defined $left xor defined $right) {
363 return defined $left ? $left : $right;
365 elsif (defined $left) {
366 return { -and => [ map
367 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
375 =head2 search_literal
379 =item Arguments: $sql_fragment, @bind_values
381 =item Return Value: $resultset (scalar context), @row_objs (list context)
385 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
386 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
388 Pass a literal chunk of SQL to be added to the conditional part of the
391 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
392 only be used in that context. C<search_literal> is a convenience method.
393 It is equivalent to calling $schema->search(\[]), but if you want to ensure
394 columns are bound correctly, use C<search>.
396 Example of how to use C<search> instead of C<search_literal>
398 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
399 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
402 See L<DBIx::Class::Manual::Cookbook/Searching> and
403 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
404 require C<search_literal>.
409 my ($self, $sql, @bind) = @_;
411 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
414 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
421 =item Arguments: \%columns_values | @pk_values, \%attrs?
423 =item Return Value: $row_object | undef
427 Finds and returns a single row based on supplied criteria. Takes either a
428 hashref with the same format as L</create> (including inference of foreign
429 keys from related objects), or a list of primary key values in the same
430 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
431 declaration on the L</result_source>.
433 In either case an attempt is made to combine conditions already existing on
434 the resultset with the condition passed to this method.
436 To aid with preparing the correct query for the storage you may supply the
437 C<key> attribute, which is the name of a
438 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
439 unique constraint corresponding to the
440 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
441 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
442 to construct a query that satisfies the named unique constraint fully (
443 non-NULL values for each column member of the constraint) an exception is
446 If no C<key> is specified, the search is carried over all unique constraints
447 which are fully defined by the available condition.
449 If no such constraint is found, C<find> currently defaults to a simple
450 C<< search->(\%column_values) >> which may or may not do what you expect.
451 Note that this fallback behavior may be deprecated in further versions. If
452 you need to search with arbitrary conditions - use L</search>. If the query
453 resulting from this fallback produces more than one row, a warning to the
454 effect is issued, though only the first row is constructed and returned as
457 In addition to C<key>, L</find> recognizes and applies standard
458 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
460 Note that if you have extra concerns about the correctness of the resulting
461 query you need to specify the C<key> attribute and supply the entire condition
462 as an argument to find (since it is not always possible to perform the
463 combination of the resultset condition with the supplied one, especially if
464 the resultset condition contains literal sql).
466 For example, to find a row by its primary key:
468 my $cd = $schema->resultset('CD')->find(5);
470 You can also find a row by a specific unique constraint:
472 my $cd = $schema->resultset('CD')->find(
474 artist => 'Massive Attack',
475 title => 'Mezzanine',
477 { key => 'cd_artist_title' }
480 See also L</find_or_create> and L</update_or_create>.
486 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
488 my $rsrc = $self->result_source;
490 # Parse out the condition from input
492 if (ref $_[0] eq 'HASH') {
493 $call_cond = { %{$_[0]} };
496 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
497 my @c_cols = $rsrc->unique_constraint_columns($constraint);
499 $self->throw_exception(
500 "No constraint columns, maybe a malformed '$constraint' constraint?"
503 $self->throw_exception (
504 'find() expects either a column/value hashref, or a list of values '
505 . "corresponding to the columns of the specified unique constraint '$constraint'"
506 ) unless @c_cols == @_;
509 @{$call_cond}{@c_cols} = @_;
513 for my $key (keys %$call_cond) {
515 my $keyref = ref($call_cond->{$key})
517 my $relinfo = $rsrc->relationship_info($key)
519 my $val = delete $call_cond->{$key};
521 next if $keyref eq 'ARRAY'; # has_many for multi_create
523 my $rel_q = $rsrc->_resolve_condition(
524 $relinfo->{cond}, $val, $key
526 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
527 @related{keys %$rel_q} = values %$rel_q;
531 # relationship conditions take precedence (?)
532 @{$call_cond}{keys %related} = values %related;
534 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
536 if (exists $attrs->{key}) {
537 $final_cond = $self->_qualify_cond_columns (
539 $self->_build_unique_cond (
547 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
548 # This means that we got here after a merger of relationship conditions
549 # in ::Relationship::Base::search_related (the row method), and furthermore
550 # the relationship is of the 'single' type. This means that the condition
551 # provided by the relationship (already attached to $self) is sufficient,
552 # as there can be only one row in the database that would satisfy the
556 # no key was specified - fall down to heuristics mode:
557 # run through all unique queries registered on the resultset, and
558 # 'OR' all qualifying queries together
559 my (@unique_queries, %seen_column_combinations);
560 for my $c_name ($rsrc->unique_constraint_names) {
561 next if $seen_column_combinations{
562 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
565 push @unique_queries, try {
566 $self->_build_unique_cond ($c_name, $call_cond)
570 $final_cond = @unique_queries
571 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
572 : $self->_non_unique_find_fallback ($call_cond, $attrs)
576 # Run the query, passing the result_class since it should propagate for find
577 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
578 if (keys %{$rs->_resolved_attrs->{collapse}}) {
580 carp "Query returned more than one row" if $rs->next;
588 # This is a stop-gap method as agreed during the discussion on find() cleanup:
589 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
591 # It is invoked when find() is called in legacy-mode with insufficiently-unique
592 # condition. It is provided for overrides until a saner way forward is devised
594 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
595 # the road. Please adjust your tests accordingly to catch this situation early
596 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
598 # The method will not be removed without an adequately complete replacement
599 # for strict-mode enforcement
600 sub _non_unique_find_fallback {
601 my ($self, $cond, $attrs) = @_;
603 return $self->_qualify_cond_columns(
605 exists $attrs->{alias}
607 : $self->{attrs}{alias}
612 sub _qualify_cond_columns {
613 my ($self, $cond, $alias) = @_;
615 my %aliased = %$cond;
616 for (keys %aliased) {
617 $aliased{"$alias.$_"} = delete $aliased{$_}
624 sub _build_unique_cond {
625 my ($self, $constraint_name, $extra_cond) = @_;
627 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
629 # combination may fail if $self->{cond} is non-trivial
630 my ($final_cond) = try {
631 $self->_merge_with_rscond ($extra_cond)
636 # trim out everything not in $columns
637 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
639 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
640 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
642 join (', ', map { "'$_'" } @missing),
649 =head2 search_related
653 =item Arguments: $rel, $cond, \%attrs?
655 =item Return Value: $new_resultset
659 $new_rs = $cd_rs->search_related('artist', {
663 Searches the specified relationship, optionally specifying a condition and
664 attributes for matching records. See L</ATTRIBUTES> for more information.
669 return shift->related_resultset(shift)->search(@_);
672 =head2 search_related_rs
674 This method works exactly the same as search_related, except that
675 it guarantees a resultset, even in list context.
679 sub search_related_rs {
680 return shift->related_resultset(shift)->search_rs(@_);
687 =item Arguments: none
689 =item Return Value: $cursor
693 Returns a storage-driven cursor to the given resultset. See
694 L<DBIx::Class::Cursor> for more information.
701 my $attrs = $self->_resolved_attrs_copy;
703 return $self->{cursor}
704 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
705 $attrs->{where},$attrs);
712 =item Arguments: $cond?
714 =item Return Value: $row_object | undef
718 my $cd = $schema->resultset('CD')->single({ year => 2001 });
720 Inflates the first result without creating a cursor if the resultset has
721 any records in it; if not returns C<undef>. Used by L</find> as a lean version
724 While this method can take an optional search condition (just like L</search>)
725 being a fast-code-path it does not recognize search attributes. If you need to
726 add extra joins or similar, call L</search> and then chain-call L</single> on the
727 L<DBIx::Class::ResultSet> returned.
733 As of 0.08100, this method enforces the assumption that the preceding
734 query returns only one row. If more than one row is returned, you will receive
737 Query returned more than one row
739 In this case, you should be using L</next> or L</find> instead, or if you really
740 know what you are doing, use the L</rows> attribute to explicitly limit the size
743 This method will also throw an exception if it is called on a resultset prefetching
744 has_many, as such a prefetch implies fetching multiple rows from the database in
745 order to assemble the resulting object.
752 my ($self, $where) = @_;
754 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
757 my $attrs = $self->_resolved_attrs_copy;
759 if (keys %{$attrs->{collapse}}) {
760 $self->throw_exception(
761 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
766 if (defined $attrs->{where}) {
769 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
770 $where, delete $attrs->{where} ]
773 $attrs->{where} = $where;
777 my @data = $self->result_source->storage->select_single(
778 $attrs->{from}, $attrs->{select},
779 $attrs->{where}, $attrs
782 return (@data ? ($self->_construct_object(@data))[0] : undef);
788 # Recursively collapse the query, accumulating values for each column.
790 sub _collapse_query {
791 my ($self, $query, $collapsed) = @_;
795 if (ref $query eq 'ARRAY') {
796 foreach my $subquery (@$query) {
797 next unless ref $subquery; # -or
798 $collapsed = $self->_collapse_query($subquery, $collapsed);
801 elsif (ref $query eq 'HASH') {
802 if (keys %$query and (keys %$query)[0] eq '-and') {
803 foreach my $subquery (@{$query->{-and}}) {
804 $collapsed = $self->_collapse_query($subquery, $collapsed);
808 foreach my $col (keys %$query) {
809 my $value = $query->{$col};
810 $collapsed->{$col}{$value}++;
822 =item Arguments: $cond?
824 =item Return Value: $resultsetcolumn
828 my $max_length = $rs->get_column('length')->max;
830 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
835 my ($self, $column) = @_;
836 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
844 =item Arguments: $cond, \%attrs?
846 =item Return Value: $resultset (scalar context), @row_objs (list context)
850 # WHERE title LIKE '%blue%'
851 $cd_rs = $rs->search_like({ title => '%blue%'});
853 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
854 that this is simply a convenience method retained for ex Class::DBI users.
855 You most likely want to use L</search> with specific operators.
857 For more information, see L<DBIx::Class::Manual::Cookbook>.
859 This method is deprecated and will be removed in 0.09. Use L</search()>
860 instead. An example conversion is:
862 ->search_like({ foo => 'bar' });
866 ->search({ foo => { like => 'bar' } });
873 'search_like() is deprecated and will be removed in DBIC version 0.09.'
874 .' Instead use ->search({ x => { -like => "y%" } })'
875 .' (note the outer pair of {}s - they are important!)'
877 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
878 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
879 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
880 return $class->search($query, { %$attrs });
887 =item Arguments: $first, $last
889 =item Return Value: $resultset (scalar context), @row_objs (list context)
893 Returns a resultset or object list representing a subset of elements from the
894 resultset slice is called on. Indexes are from 0, i.e., to get the first
897 my ($one, $two, $three) = $rs->slice(0, 2);
902 my ($self, $min, $max) = @_;
903 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
904 $attrs->{offset} = $self->{attrs}{offset} || 0;
905 $attrs->{offset} += $min;
906 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
907 return $self->search(undef, $attrs);
908 #my $slice = (ref $self)->new($self->result_source, $attrs);
909 #return (wantarray ? $slice->all : $slice);
916 =item Arguments: none
918 =item Return Value: $result | undef
922 Returns the next element in the resultset (C<undef> is there is none).
924 Can be used to efficiently iterate over records in the resultset:
926 my $rs = $schema->resultset('CD')->search;
927 while (my $cd = $rs->next) {
931 Note that you need to store the resultset object, and call C<next> on it.
932 Calling C<< resultset('Table')->next >> repeatedly will always return the
933 first record from the resultset.
939 if (my $cache = $self->get_cache) {
940 $self->{all_cache_position} ||= 0;
941 return $cache->[$self->{all_cache_position}++];
943 if ($self->{attrs}{cache}) {
944 delete $self->{pager};
945 $self->{all_cache_position} = 1;
946 return ($self->all)[0];
948 if ($self->{stashed_objects}) {
949 my $obj = shift(@{$self->{stashed_objects}});
950 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
954 exists $self->{stashed_row}
955 ? @{delete $self->{stashed_row}}
956 : $self->cursor->next
958 return undef unless (@row);
959 my ($row, @more) = $self->_construct_object(@row);
960 $self->{stashed_objects} = \@more if @more;
964 sub _construct_object {
965 my ($self, @row) = @_;
967 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
969 my @new = $self->result_class->inflate_result($self->result_source, @$info);
970 @new = $self->{_attrs}{record_filter}->(@new)
971 if exists $self->{_attrs}{record_filter};
975 sub _collapse_result {
976 my ($self, $as_proto, $row) = @_;
980 # 'foo' => [ undef, 'foo' ]
981 # 'foo.bar' => [ 'foo', 'bar' ]
982 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
984 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
986 my %collapse = %{$self->{_attrs}{collapse}||{}};
990 # if we're doing collapsing (has_many prefetch) we need to grab records
991 # until the PK changes, so fill @pri_index. if not, we leave it empty so
992 # we know we don't have to bother.
994 # the reason for not using the collapse stuff directly is because if you
995 # had for e.g. two artists in a row with no cds, the collapse info for
996 # both would be NULL (undef) so you'd lose the second artist
998 # store just the index so we can check the array positions from the row
999 # without having to contruct the full hash
1001 if (keys %collapse) {
1002 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1003 foreach my $i (0 .. $#construct_as) {
1004 next if defined($construct_as[$i][0]); # only self table
1005 if (delete $pri{$construct_as[$i][1]}) {
1006 push(@pri_index, $i);
1008 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1012 # no need to do an if, it'll be empty if @pri_index is empty anyway
1014 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1018 do { # no need to check anything at the front, we always want the first row
1022 foreach my $this_as (@construct_as) {
1023 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1026 push(@const_rows, \%const);
1028 } until ( # no pri_index => no collapse => drop straight out
1031 do { # get another row, stash it, drop out if different PK
1033 @copy = $self->cursor->next;
1034 $self->{stashed_row} = \@copy;
1036 # last thing in do block, counts as true if anything doesn't match
1038 # check xor defined first for NULL vs. NOT NULL then if one is
1039 # defined the other must be so check string equality
1042 (defined $pri_vals{$_} ^ defined $copy[$_])
1043 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1048 my $alias = $self->{attrs}{alias};
1055 foreach my $const (@const_rows) {
1056 scalar @const_keys or do {
1057 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1059 foreach my $key (@const_keys) {
1062 my @parts = split(/\./, $key);
1064 my $data = $const->{$key};
1065 foreach my $p (@parts) {
1066 $target = $target->[1]->{$p} ||= [];
1068 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1069 # collapsing at this point and on final part
1070 my $pos = $collapse_pos{$cur};
1071 CK: foreach my $ck (@ckey) {
1072 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1073 $collapse_pos{$cur} = $data;
1074 delete @collapse_pos{ # clear all positioning for sub-entries
1075 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1082 if (exists $collapse{$cur}) {
1083 $target = $target->[-1];
1086 $target->[0] = $data;
1088 $info->[0] = $const->{$key};
1096 =head2 result_source
1100 =item Arguments: $result_source?
1102 =item Return Value: $result_source
1106 An accessor for the primary ResultSource object from which this ResultSet
1113 =item Arguments: $result_class?
1115 =item Return Value: $result_class
1119 An accessor for the class to use when creating row objects. Defaults to
1120 C<< result_source->result_class >> - which in most cases is the name of the
1121 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1123 Note that changing the result_class will also remove any components
1124 that were originally loaded in the source class via
1125 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1126 in the original source class will not run.
1131 my ($self, $result_class) = @_;
1132 if ($result_class) {
1133 unless (ref $result_class) { # don't fire this for an object
1134 $self->ensure_class_loaded($result_class);
1136 $self->_result_class($result_class);
1137 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1138 # permit the user to set result class on one result set only; it only
1139 # chains if provided to search()
1140 #$self->{attrs}{result_class} = $result_class if ref $self;
1142 $self->_result_class;
1149 =item Arguments: $cond, \%attrs??
1151 =item Return Value: $count
1155 Performs an SQL C<COUNT> with the same query as the resultset was built
1156 with to find the number of elements. Passing arguments is equivalent to
1157 C<< $rs->search ($cond, \%attrs)->count >>
1163 return $self->search(@_)->count if @_ and defined $_[0];
1164 return scalar @{ $self->get_cache } if $self->get_cache;
1166 my $attrs = $self->_resolved_attrs_copy;
1168 # this is a little optimization - it is faster to do the limit
1169 # adjustments in software, instead of a subquery
1170 my $rows = delete $attrs->{rows};
1171 my $offset = delete $attrs->{offset};
1174 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1175 $crs = $self->_count_subq_rs ($attrs);
1178 $crs = $self->_count_rs ($attrs);
1180 my $count = $crs->next;
1182 $count -= $offset if $offset;
1183 $count = $rows if $rows and $rows < $count;
1184 $count = 0 if ($count < 0);
1193 =item Arguments: $cond, \%attrs??
1195 =item Return Value: $count_rs
1199 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1200 This can be very handy for subqueries:
1202 ->search( { amount => $some_rs->count_rs->as_query } )
1204 As with regular resultsets the SQL query will be executed only after
1205 the resultset is accessed via L</next> or L</all>. That would return
1206 the same single value obtainable via L</count>.
1212 return $self->search(@_)->count_rs if @_;
1214 # this may look like a lack of abstraction (count() does about the same)
1215 # but in fact an _rs *must* use a subquery for the limits, as the
1216 # software based limiting can not be ported if this $rs is to be used
1217 # in a subquery itself (i.e. ->as_query)
1218 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1219 return $self->_count_subq_rs;
1222 return $self->_count_rs;
1227 # returns a ResultSetColumn object tied to the count query
1230 my ($self, $attrs) = @_;
1232 my $rsrc = $self->result_source;
1233 $attrs ||= $self->_resolved_attrs;
1235 my $tmp_attrs = { %$attrs };
1236 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1237 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1239 # overwrite the selector (supplied by the storage)
1240 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1241 $tmp_attrs->{as} = 'count';
1243 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1249 # same as above but uses a subquery
1251 sub _count_subq_rs {
1252 my ($self, $attrs) = @_;
1254 my $rsrc = $self->result_source;
1255 $attrs ||= $self->_resolved_attrs;
1257 my $sub_attrs = { %$attrs };
1258 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1259 delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
1261 # if we multi-prefetch we group_by primary keys only as this is what we would
1262 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1263 if ( keys %{$attrs->{collapse}} ) {
1264 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1267 # Calculate subquery selector
1268 if (my $g = $sub_attrs->{group_by}) {
1270 my $sql_maker = $rsrc->storage->sql_maker;
1272 # necessary as the group_by may refer to aliased functions
1274 for my $sel (@{$attrs->{select}}) {
1275 $sel_index->{$sel->{-as}} = $sel
1276 if (ref $sel eq 'HASH' and $sel->{-as});
1279 for my $g_part (@$g) {
1280 my $colpiece = $sel_index->{$g_part} || $g_part;
1282 # disqualify join-based group_by's. Arcane but possible query
1283 # also horrible horrible hack to alias a column (not a func.)
1284 # (probably need to introduce SQLA syntax)
1285 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1288 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1290 push @{$sub_attrs->{select}}, $colpiece;
1294 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1295 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1298 return $rsrc->resultset_class
1299 ->new ($rsrc, $sub_attrs)
1301 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1302 ->get_column ('count');
1309 =head2 count_literal
1313 =item Arguments: $sql_fragment, @bind_values
1315 =item Return Value: $count
1319 Counts the results in a literal query. Equivalent to calling L</search_literal>
1320 with the passed arguments, then L</count>.
1324 sub count_literal { shift->search_literal(@_)->count; }
1330 =item Arguments: none
1332 =item Return Value: @objects
1336 Returns all elements in the resultset. Called implicitly if the resultset
1337 is returned in list context.
1344 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1347 return @{ $self->get_cache } if $self->get_cache;
1351 if (keys %{$self->_resolved_attrs->{collapse}}) {
1352 # Using $self->cursor->all is really just an optimisation.
1353 # If we're collapsing has_many prefetches it probably makes
1354 # very little difference, and this is cleaner than hacking
1355 # _construct_object to survive the approach
1356 $self->cursor->reset;
1357 my @row = $self->cursor->next;
1359 push(@obj, $self->_construct_object(@row));
1360 @row = (exists $self->{stashed_row}
1361 ? @{delete $self->{stashed_row}}
1362 : $self->cursor->next);
1365 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1368 $self->set_cache(\@obj) if $self->{attrs}{cache};
1377 =item Arguments: none
1379 =item Return Value: $self
1383 Resets the resultset's cursor, so you can iterate through the elements again.
1384 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1391 delete $self->{_attrs} if exists $self->{_attrs};
1392 $self->{all_cache_position} = 0;
1393 $self->cursor->reset;
1401 =item Arguments: none
1403 =item Return Value: $object | undef
1407 Resets the resultset and returns an object for the first result (or C<undef>
1408 if the resultset is empty).
1413 return $_[0]->reset->next;
1419 # Determines whether and what type of subquery is required for the $rs operation.
1420 # If grouping is necessary either supplies its own, or verifies the current one
1421 # After all is done delegates to the proper storage method.
1423 sub _rs_update_delete {
1424 my ($self, $op, $values) = @_;
1426 my $rsrc = $self->result_source;
1428 # if a condition exists we need to strip all table qualifiers
1429 # if this is not possible we'll force a subquery below
1430 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1432 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1433 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1435 if ($needs_group_by_subq or $needs_subq) {
1437 # make a new $rs selecting only the PKs (that's all we really need)
1438 my $attrs = $self->_resolved_attrs_copy;
1441 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1442 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1444 if ($needs_group_by_subq) {
1445 # make sure no group_by was supplied, or if there is one - make sure it matches
1446 # the columns compiled above perfectly. Anything else can not be sanely executed
1447 # on most databases so croak right then and there
1449 if (my $g = $attrs->{group_by}) {
1450 my @current_group_by = map
1451 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1456 join ("\x00", sort @current_group_by)
1458 join ("\x00", sort @{$attrs->{columns}} )
1460 $self->throw_exception (
1461 "You have just attempted a $op operation on a resultset which does group_by"
1462 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1463 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1464 . ' kind of queries. Please retry the operation with a modified group_by or'
1465 . ' without using one at all.'
1470 $attrs->{group_by} = $attrs->{columns};
1474 my $subrs = (ref $self)->new($rsrc, $attrs);
1475 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1478 return $rsrc->storage->$op(
1480 $op eq 'update' ? $values : (),
1490 =item Arguments: \%values
1492 =item Return Value: $storage_rv
1496 Sets the specified columns in the resultset to the supplied values in a
1497 single query. Note that this will not run any accessor/set_column/update
1498 triggers, nor will it update any row object instances derived from this
1499 resultset (this includes the contents of the L<resultset cache|/set_cache>
1500 if any). See L</update_all> if you need to execute any on-update
1501 triggers or cascades defined either by you or a
1502 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1504 The return value is a pass through of what the underlying
1505 storage backend returned, and may vary. See L<DBI/execute> for the most
1511 my ($self, $values) = @_;
1512 $self->throw_exception('Values for update must be a hash')
1513 unless ref $values eq 'HASH';
1515 return $self->_rs_update_delete ('update', $values);
1522 =item Arguments: \%values
1524 =item Return Value: 1
1528 Fetches all objects and updates them one at a time via
1529 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1530 triggers, while L</update> will not.
1535 my ($self, $values) = @_;
1536 $self->throw_exception('Values for update_all must be a hash')
1537 unless ref $values eq 'HASH';
1539 my $guard = $self->result_source->schema->txn_scope_guard;
1540 $_->update($values) for $self->all;
1549 =item Arguments: none
1551 =item Return Value: $storage_rv
1555 Deletes the rows matching this resultset in a single query. Note that this
1556 will not run any delete triggers, nor will it alter the
1557 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1558 derived from this resultset (this includes the contents of the
1559 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1560 execute any on-delete triggers or cascades defined either by you or a
1561 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1563 The return value is a pass through of what the underlying storage backend
1564 returned, and may vary. See L<DBI/execute> for the most common case.
1570 $self->throw_exception('delete does not accept any arguments')
1573 return $self->_rs_update_delete ('delete');
1580 =item Arguments: none
1582 =item Return Value: 1
1586 Fetches all objects and deletes them one at a time via
1587 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1588 triggers, while L</delete> will not.
1594 $self->throw_exception('delete_all does not accept any arguments')
1597 my $guard = $self->result_source->schema->txn_scope_guard;
1598 $_->delete for $self->all;
1607 =item Arguments: \@data;
1611 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1612 For the arrayref of hashrefs style each hashref should be a structure suitable
1613 forsubmitting to a $resultset->create(...) method.
1615 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1616 to insert the data, as this is a faster method.
1618 Otherwise, each set of data is inserted into the database using
1619 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1620 accumulated into an array. The array itself, or an array reference
1621 is returned depending on scalar or list context.
1623 Example: Assuming an Artist Class that has many CDs Classes relating:
1625 my $Artist_rs = $schema->resultset("Artist");
1627 ## Void Context Example
1628 $Artist_rs->populate([
1629 { artistid => 4, name => 'Manufactured Crap', cds => [
1630 { title => 'My First CD', year => 2006 },
1631 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1634 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1635 { title => 'My parents sold me to a record company', year => 2005 },
1636 { title => 'Why Am I So Ugly?', year => 2006 },
1637 { title => 'I Got Surgery and am now Popular', year => 2007 }
1642 ## Array Context Example
1643 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1644 { name => "Artist One"},
1645 { name => "Artist Two"},
1646 { name => "Artist Three", cds=> [
1647 { title => "First CD", year => 2007},
1648 { title => "Second CD", year => 2008},
1652 print $ArtistOne->name; ## response is 'Artist One'
1653 print $ArtistThree->cds->count ## reponse is '2'
1655 For the arrayref of arrayrefs style, the first element should be a list of the
1656 fieldsnames to which the remaining elements are rows being inserted. For
1659 $Arstist_rs->populate([
1660 [qw/artistid name/],
1661 [100, 'A Formally Unknown Singer'],
1662 [101, 'A singer that jumped the shark two albums ago'],
1663 [102, 'An actually cool singer'],
1666 Please note an important effect on your data when choosing between void and
1667 wantarray context. Since void context goes straight to C<insert_bulk> in
1668 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1669 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1670 create primary keys for you, you will find that your PKs are empty. In this
1671 case you will have to use the wantarray context in order to create those
1679 # cruft placed in standalone method
1680 my $data = $self->_normalize_populate_args(@_);
1682 if(defined wantarray) {
1684 foreach my $item (@$data) {
1685 push(@created, $self->create($item));
1687 return wantarray ? @created : \@created;
1689 my $first = $data->[0];
1691 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1692 # it relationship data
1693 my (@rels, @columns);
1694 for (keys %$first) {
1695 my $ref = ref $first->{$_};
1696 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1702 my @pks = $self->result_source->primary_columns;
1704 ## do the belongs_to relationships
1705 foreach my $index (0..$#$data) {
1707 # delegate to create() for any dataset without primary keys with specified relationships
1708 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1710 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1711 my @ret = $self->populate($data);
1717 foreach my $rel (@rels) {
1718 next unless ref $data->[$index]->{$rel} eq "HASH";
1719 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1720 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1721 my $related = $result->result_source->_resolve_condition(
1722 $result->result_source->relationship_info($reverse)->{cond},
1727 delete $data->[$index]->{$rel};
1728 $data->[$index] = {%{$data->[$index]}, %$related};
1730 push @columns, keys %$related if $index == 0;
1734 ## inherit the data locked in the conditions of the resultset
1735 my ($rs_data) = $self->_merge_with_rscond({});
1736 delete @{$rs_data}{@columns};
1737 my @inherit_cols = keys %$rs_data;
1738 my @inherit_data = values %$rs_data;
1740 ## do bulk insert on current row
1741 $self->result_source->storage->insert_bulk(
1742 $self->result_source,
1743 [@columns, @inherit_cols],
1744 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1747 ## do the has_many relationships
1748 foreach my $item (@$data) {
1750 foreach my $rel (@rels) {
1751 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1753 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1754 || $self->throw_exception('Cannot find the relating object.');
1756 my $child = $parent->$rel;
1758 my $related = $child->result_source->_resolve_condition(
1759 $parent->result_source->relationship_info($rel)->{cond},
1764 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1765 my @populate = map { {%$_, %$related} } @rows_to_add;
1767 $child->populate( \@populate );
1774 # populate() argumnets went over several incarnations
1775 # What we ultimately support is AoH
1776 sub _normalize_populate_args {
1777 my ($self, $arg) = @_;
1779 if (ref $arg eq 'ARRAY') {
1780 if (ref $arg->[0] eq 'HASH') {
1783 elsif (ref $arg->[0] eq 'ARRAY') {
1785 my @colnames = @{$arg->[0]};
1786 foreach my $values (@{$arg}[1 .. $#$arg]) {
1787 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1793 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1800 =item Arguments: none
1802 =item Return Value: $pager
1806 Return Value a L<Data::Page> object for the current resultset. Only makes
1807 sense for queries with a C<page> attribute.
1809 To get the full count of entries for a paged resultset, call
1810 C<total_entries> on the L<Data::Page> object.
1814 # make a wizard good for both a scalar and a hashref
1815 my $mk_lazy_count_wizard = sub {
1816 require Variable::Magic;
1818 my $stash = { total_rs => shift };
1819 my $slot = shift; # only used by the hashref magic
1821 my $magic = Variable::Magic::wizard (
1822 data => sub { $stash },
1828 # set value lazily, and dispell for good
1829 ${$_[0]} = $_[1]{total_rs}->count;
1830 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
1834 # an explicit set implies dispell as well
1835 # the unless() is to work around "fun and giggles" below
1836 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
1837 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1844 if ($_[2] eq $slot and !$_[1]{inactive}) {
1845 my $cnt = $_[1]{total_rs}->count;
1846 $_[0]->{$slot} = $cnt;
1848 # attempting to dispell in a fetch handle (works in store), seems
1849 # to invariable segfault on 5.10, 5.12, 5.13 :(
1850 # so use an inactivator instead
1851 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1857 if (! $_[1]{inactive} and $_[2] eq $slot) {
1858 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1860 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1867 $stash->{magic_selfref} = $magic;
1868 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
1873 # the tie class for 5.8.1
1875 package # hide from pause
1876 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
1877 use base qw/Tie::Hash/;
1879 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
1880 sub NEXTKEY { each %{$_[0]{data}} }
1881 sub EXISTS { exists $_[0]{data}{$_[1]} }
1882 sub DELETE { delete $_[0]{data}{$_[1]} }
1883 sub CLEAR { %{$_[0]{data}} = () }
1884 sub SCALAR { scalar %{$_[0]{data}} }
1887 $_[1]{data} = {%{$_[1]{selfref}}};
1888 %{$_[1]{selfref}} = ();
1889 Scalar::Util::weaken ($_[1]{selfref});
1890 return bless ($_[1], $_[0]);
1894 if ($_[1] eq $_[0]{slot}) {
1895 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
1896 untie %{$_[0]{selfref}};
1897 %{$_[0]{selfref}} = %{$_[0]{data}};
1906 $_[0]{data}{$_[1]} = $_[2];
1907 if ($_[1] eq $_[0]{slot}) {
1908 untie %{$_[0]{selfref}};
1909 %{$_[0]{selfref}} = %{$_[0]{data}};
1918 return $self->{pager} if $self->{pager};
1920 if ($self->get_cache) {
1921 $self->throw_exception ('Pagers on cached resultsets are not supported');
1924 my $attrs = $self->{attrs};
1925 $self->throw_exception("Can't create pager for non-paged rs")
1926 unless $self->{attrs}{page};
1927 $attrs->{rows} ||= 10;
1929 # throw away the paging flags and re-run the count (possibly
1930 # with a subselect) to get the real total count
1931 my $count_attrs = { %$attrs };
1932 delete $count_attrs->{$_} for qw/rows offset page pager/;
1933 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
1936 ### the following may seem awkward and dirty, but it's a thought-experiment
1937 ### necessary for future development of DBIx::DS. Do *NOT* change this code
1938 ### before talking to ribasushi/mst
1940 my $pager = Data::Page->new(
1941 0, #start with an empty set
1943 $self->{attrs}{page},
1946 my $data_slot = 'total_entries';
1948 # Since we are interested in a cached value (once it's set - it's set), every
1949 # technique will detach from the magic-host once the time comes to fire the
1950 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
1952 if ($] < 5.008003) {
1953 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
1954 # to weakref the magic container :(
1956 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
1957 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
1960 elsif ($] < 5.010) {
1961 # We can use magic on the hash value slot. It's interesting that the magic is
1962 # attached to the hash-slot, and does *not* stop working once I do the dummy
1963 # assignments after the cast()
1964 # tested on 5.8.3 and 5.8.9
1965 my $magic = $mk_lazy_count_wizard->($total_rs);
1966 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
1968 # this is for fun and giggles
1969 $pager->{$data_slot} = -1;
1970 $pager->{$data_slot} = 0;
1972 # this does not work for scalars, but works with
1974 #my %vals = %$pager;
1979 # And the uvar magic
1980 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
1981 # however see the wizard maker for more notes
1982 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
1983 Variable::Magic::cast ( %$pager, $magic );
1986 $pager->{$data_slot} = -1;
1987 $pager->{$data_slot} = 0;
1995 return $self->{pager} = $pager;
2002 =item Arguments: $page_number
2004 =item Return Value: $rs
2008 Returns a resultset for the $page_number page of the resultset on which page
2009 is called, where each page contains a number of rows equal to the 'rows'
2010 attribute set on the resultset (10 by default).
2015 my ($self, $page) = @_;
2016 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2023 =item Arguments: \%vals
2025 =item Return Value: $rowobject
2029 Creates a new row object in the resultset's result class and returns
2030 it. The row is not inserted into the database at this point, call
2031 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2032 will tell you whether the row object has been inserted or not.
2034 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2039 my ($self, $values) = @_;
2040 $self->throw_exception( "new_result needs a hash" )
2041 unless (ref $values eq 'HASH');
2043 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2047 @$cols_from_relations
2048 ? (-cols_from_relations => $cols_from_relations)
2050 -source_handle => $self->_source_handle,
2051 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2054 return $self->result_class->new(\%new);
2057 # _merge_with_rscond
2059 # Takes a simple hash of K/V data and returns its copy merged with the
2060 # condition already present on the resultset. Additionally returns an
2061 # arrayref of value/condition names, which were inferred from related
2062 # objects (this is needed for in-memory related objects)
2063 sub _merge_with_rscond {
2064 my ($self, $data) = @_;
2066 my (%new_data, @cols_from_relations);
2068 my $alias = $self->{attrs}{alias};
2070 if (! defined $self->{cond}) {
2071 # just massage $data below
2073 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2074 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2075 @cols_from_relations = keys %new_data;
2077 elsif (ref $self->{cond} ne 'HASH') {
2078 $self->throw_exception(
2079 "Can't abstract implicit construct, resultset condition not a hash"
2083 # precendence must be given to passed values over values inherited from
2084 # the cond, so the order here is important.
2085 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2086 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2088 while ( my($col, $value) = each %implied ) {
2089 my $vref = ref $value;
2090 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2091 $new_data{$col} = $value->{'='};
2093 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2094 $new_data{$col} = $value;
2101 %{ $self->_remove_alias($data, $alias) },
2104 return (\%new_data, \@cols_from_relations);
2107 # _has_resolved_attr
2109 # determines if the resultset defines at least one
2110 # of the attributes supplied
2112 # used to determine if a subquery is neccessary
2114 # supports some virtual attributes:
2116 # This will scan for any joins being present on the resultset.
2117 # It is not a mere key-search but a deep inspection of {from}
2120 sub _has_resolved_attr {
2121 my ($self, @attr_names) = @_;
2123 my $attrs = $self->_resolved_attrs;
2127 for my $n (@attr_names) {
2128 if (grep { $n eq $_ } (qw/-join/) ) {
2129 $extra_checks{$n}++;
2133 my $attr = $attrs->{$n};
2135 next if not defined $attr;
2137 if (ref $attr eq 'HASH') {
2138 return 1 if keys %$attr;
2140 elsif (ref $attr eq 'ARRAY') {
2148 # a resolved join is expressed as a multi-level from
2150 $extra_checks{-join}
2152 ref $attrs->{from} eq 'ARRAY'
2154 @{$attrs->{from}} > 1
2162 # Recursively collapse the condition.
2164 sub _collapse_cond {
2165 my ($self, $cond, $collapsed) = @_;
2169 if (ref $cond eq 'ARRAY') {
2170 foreach my $subcond (@$cond) {
2171 next unless ref $subcond; # -or
2172 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2175 elsif (ref $cond eq 'HASH') {
2176 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2177 foreach my $subcond (@{$cond->{-and}}) {
2178 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2182 foreach my $col (keys %$cond) {
2183 my $value = $cond->{$col};
2184 $collapsed->{$col} = $value;
2194 # Remove the specified alias from the specified query hash. A copy is made so
2195 # the original query is not modified.
2198 my ($self, $query, $alias) = @_;
2200 my %orig = %{ $query || {} };
2203 foreach my $key (keys %orig) {
2205 $unaliased{$key} = $orig{$key};
2208 $unaliased{$1} = $orig{$key}
2209 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2219 =item Arguments: none
2221 =item Return Value: \[ $sql, @bind ]
2225 Returns the SQL query and bind vars associated with the invocant.
2227 This is generally used as the RHS for a subquery.
2234 my $attrs = $self->_resolved_attrs_copy;
2239 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2240 # $sql also has no wrapping parenthesis in list ctx
2242 my $sqlbind = $self->result_source->storage
2243 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2252 =item Arguments: \%vals, \%attrs?
2254 =item Return Value: $rowobject
2258 my $artist = $schema->resultset('Artist')->find_or_new(
2259 { artist => 'fred' }, { key => 'artists' });
2261 $cd->cd_to_producer->find_or_new({ producer => $producer },
2262 { key => 'primary });
2264 Find an existing record from this resultset using L</find>. if none exists,
2265 instantiate a new result object and return it. The object will not be saved
2266 into your storage until you call L<DBIx::Class::Row/insert> on it.
2268 You most likely want this method when looking for existing rows using a unique
2269 constraint that is not the primary key, or looking for related rows.
2271 If you want objects to be saved immediately, use L</find_or_create> instead.
2273 B<Note>: Make sure to read the documentation of L</find> and understand the
2274 significance of the C<key> attribute, as its lack may skew your search, and
2275 subsequently result in spurious new objects.
2277 B<Note>: Take care when using C<find_or_new> with a table having
2278 columns with default values that you intend to be automatically
2279 supplied by the database (e.g. an auto_increment primary key column).
2280 In normal usage, the value of such columns should NOT be included at
2281 all in the call to C<find_or_new>, even when set to C<undef>.
2287 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2288 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2289 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2292 return $self->new_result($hash);
2299 =item Arguments: \%vals
2301 =item Return Value: a L<DBIx::Class::Row> $object
2305 Attempt to create a single new row or a row with multiple related rows
2306 in the table represented by the resultset (and related tables). This
2307 will not check for duplicate rows before inserting, use
2308 L</find_or_create> to do that.
2310 To create one row for this resultset, pass a hashref of key/value
2311 pairs representing the columns of the table and the values you wish to
2312 store. If the appropriate relationships are set up, foreign key fields
2313 can also be passed an object representing the foreign row, and the
2314 value will be set to its primary key.
2316 To create related objects, pass a hashref of related-object column values
2317 B<keyed on the relationship name>. If the relationship is of type C<multi>
2318 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2319 The process will correctly identify columns holding foreign keys, and will
2320 transparently populate them from the keys of the corresponding relation.
2321 This can be applied recursively, and will work correctly for a structure
2322 with an arbitrary depth and width, as long as the relationships actually
2323 exists and the correct column data has been supplied.
2326 Instead of hashrefs of plain related data (key/value pairs), you may
2327 also pass new or inserted objects. New objects (not inserted yet, see
2328 L</new>), will be inserted into their appropriate tables.
2330 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2332 Example of creating a new row.
2334 $person_rs->create({
2335 name=>"Some Person",
2336 email=>"somebody@someplace.com"
2339 Example of creating a new row and also creating rows in a related C<has_many>
2340 or C<has_one> resultset. Note Arrayref.
2343 { artistid => 4, name => 'Manufactured Crap', cds => [
2344 { title => 'My First CD', year => 2006 },
2345 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2350 Example of creating a new row and also creating a row in a related
2351 C<belongs_to> resultset. Note Hashref.
2354 title=>"Music for Silly Walks",
2357 name=>"Silly Musician",
2365 When subclassing ResultSet never attempt to override this method. Since
2366 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2367 lot of the internals simply never call it, so your override will be
2368 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2369 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2370 L</create> process you need to intervene.
2377 my ($self, $attrs) = @_;
2378 $self->throw_exception( "create needs a hashref" )
2379 unless ref $attrs eq 'HASH';
2380 return $self->new_result($attrs)->insert;
2383 =head2 find_or_create
2387 =item Arguments: \%vals, \%attrs?
2389 =item Return Value: $rowobject
2393 $cd->cd_to_producer->find_or_create({ producer => $producer },
2394 { key => 'primary' });
2396 Tries to find a record based on its primary key or unique constraints; if none
2397 is found, creates one and returns that instead.
2399 my $cd = $schema->resultset('CD')->find_or_create({
2401 artist => 'Massive Attack',
2402 title => 'Mezzanine',
2406 Also takes an optional C<key> attribute, to search by a specific key or unique
2407 constraint. For example:
2409 my $cd = $schema->resultset('CD')->find_or_create(
2411 artist => 'Massive Attack',
2412 title => 'Mezzanine',
2414 { key => 'cd_artist_title' }
2417 B<Note>: Make sure to read the documentation of L</find> and understand the
2418 significance of the C<key> attribute, as its lack may skew your search, and
2419 subsequently result in spurious row creation.
2421 B<Note>: Because find_or_create() reads from the database and then
2422 possibly inserts based on the result, this method is subject to a race
2423 condition. Another process could create a record in the table after
2424 the find has completed and before the create has started. To avoid
2425 this problem, use find_or_create() inside a transaction.
2427 B<Note>: Take care when using C<find_or_create> with a table having
2428 columns with default values that you intend to be automatically
2429 supplied by the database (e.g. an auto_increment primary key column).
2430 In normal usage, the value of such columns should NOT be included at
2431 all in the call to C<find_or_create>, even when set to C<undef>.
2433 See also L</find> and L</update_or_create>. For information on how to declare
2434 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2438 sub find_or_create {
2440 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2441 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2442 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2445 return $self->create($hash);
2448 =head2 update_or_create
2452 =item Arguments: \%col_values, { key => $unique_constraint }?
2454 =item Return Value: $row_object
2458 $resultset->update_or_create({ col => $val, ... });
2460 Like L</find_or_create>, but if a row is found it is immediately updated via
2461 C<< $found_row->update (\%col_values) >>.
2464 Takes an optional C<key> attribute to search on a specific unique constraint.
2467 # In your application
2468 my $cd = $schema->resultset('CD')->update_or_create(
2470 artist => 'Massive Attack',
2471 title => 'Mezzanine',
2474 { key => 'cd_artist_title' }
2477 $cd->cd_to_producer->update_or_create({
2478 producer => $producer,
2484 B<Note>: Make sure to read the documentation of L</find> and understand the
2485 significance of the C<key> attribute, as its lack may skew your search, and
2486 subsequently result in spurious row creation.
2488 B<Note>: Take care when using C<update_or_create> with a table having
2489 columns with default values that you intend to be automatically
2490 supplied by the database (e.g. an auto_increment primary key column).
2491 In normal usage, the value of such columns should NOT be included at
2492 all in the call to C<update_or_create>, even when set to C<undef>.
2494 See also L</find> and L</find_or_create>. For information on how to declare
2495 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2499 sub update_or_create {
2501 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2502 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2504 my $row = $self->find($cond, $attrs);
2506 $row->update($cond);
2510 return $self->create($cond);
2513 =head2 update_or_new
2517 =item Arguments: \%col_values, { key => $unique_constraint }?
2519 =item Return Value: $rowobject
2523 $resultset->update_or_new({ col => $val, ... });
2525 Like L</find_or_new> but if a row is found it is immediately updated via
2526 C<< $found_row->update (\%col_values) >>.
2530 # In your application
2531 my $cd = $schema->resultset('CD')->update_or_new(
2533 artist => 'Massive Attack',
2534 title => 'Mezzanine',
2537 { key => 'cd_artist_title' }
2540 if ($cd->in_storage) {
2541 # the cd was updated
2544 # the cd is not yet in the database, let's insert it
2548 B<Note>: Make sure to read the documentation of L</find> and understand the
2549 significance of the C<key> attribute, as its lack may skew your search, and
2550 subsequently result in spurious new objects.
2552 B<Note>: Take care when using C<update_or_new> with a table having
2553 columns with default values that you intend to be automatically
2554 supplied by the database (e.g. an auto_increment primary key column).
2555 In normal usage, the value of such columns should NOT be included at
2556 all in the call to C<update_or_new>, even when set to C<undef>.
2558 See also L</find>, L</find_or_create> and L</find_or_new>.
2564 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2565 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2567 my $row = $self->find( $cond, $attrs );
2568 if ( defined $row ) {
2569 $row->update($cond);
2573 return $self->new_result($cond);
2580 =item Arguments: none
2582 =item Return Value: \@cache_objects | undef
2586 Gets the contents of the cache for the resultset, if the cache is set.
2588 The cache is populated either by using the L</prefetch> attribute to
2589 L</search> or by calling L</set_cache>.
2601 =item Arguments: \@cache_objects
2603 =item Return Value: \@cache_objects
2607 Sets the contents of the cache for the resultset. Expects an arrayref
2608 of objects of the same class as those produced by the resultset. Note that
2609 if the cache is set the resultset will return the cached objects rather
2610 than re-querying the database even if the cache attr is not set.
2612 The contents of the cache can also be populated by using the
2613 L</prefetch> attribute to L</search>.
2618 my ( $self, $data ) = @_;
2619 $self->throw_exception("set_cache requires an arrayref")
2620 if defined($data) && (ref $data ne 'ARRAY');
2621 $self->{all_cache} = $data;
2628 =item Arguments: none
2630 =item Return Value: undef
2634 Clears the cache for the resultset.
2639 shift->set_cache(undef);
2646 =item Arguments: none
2648 =item Return Value: true, if the resultset has been paginated
2656 return !!$self->{attrs}{page};
2663 =item Arguments: none
2665 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2673 return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
2676 =head2 related_resultset
2680 =item Arguments: $relationship_name
2682 =item Return Value: $resultset
2686 Returns a related resultset for the supplied relationship name.
2688 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2692 sub related_resultset {
2693 my ($self, $rel) = @_;
2695 $self->{related_resultsets} ||= {};
2696 return $self->{related_resultsets}{$rel} ||= do {
2697 my $rsrc = $self->result_source;
2698 my $rel_info = $rsrc->relationship_info($rel);
2700 $self->throw_exception(
2701 "search_related: result source '" . $rsrc->source_name .
2702 "' has no such relationship $rel")
2705 my $attrs = $self->_chain_relationship($rel);
2707 my $join_count = $attrs->{seen_join}{$rel};
2709 my $alias = $self->result_source->storage
2710 ->relname_to_table_alias($rel, $join_count);
2712 # since this is search_related, and we already slid the select window inwards
2713 # (the select/as attrs were deleted in the beginning), we need to flip all
2714 # left joins to inner, so we get the expected results
2715 # read the comment on top of the actual function to see what this does
2716 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2719 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2720 delete @{$attrs}{qw(result_class alias)};
2724 if (my $cache = $self->get_cache) {
2725 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2726 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2731 my $rel_source = $rsrc->related_source($rel);
2735 # The reason we do this now instead of passing the alias to the
2736 # search_rs below is that if you wrap/overload resultset on the
2737 # source you need to know what alias it's -going- to have for things
2738 # to work sanely (e.g. RestrictWithObject wants to be able to add
2739 # extra query restrictions, and these may need to be $alias.)
2741 my $rel_attrs = $rel_source->resultset_attributes;
2742 local $rel_attrs->{alias} = $alias;
2744 $rel_source->resultset
2748 where => $attrs->{where},
2751 $new->set_cache($new_cache) if $new_cache;
2756 =head2 current_source_alias
2760 =item Arguments: none
2762 =item Return Value: $source_alias
2766 Returns the current table alias for the result source this resultset is built
2767 on, that will be used in the SQL query. Usually it is C<me>.
2769 Currently the source alias that refers to the result set returned by a
2770 L</search>/L</find> family method depends on how you got to the resultset: it's
2771 C<me> by default, but eg. L</search_related> aliases it to the related result
2772 source name (and keeps C<me> referring to the original result set). The long
2773 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2774 (and make this method unnecessary).
2776 Thus it's currently necessary to use this method in predefined queries (see
2777 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2778 source alias of the current result set:
2780 # in a result set class
2782 my ($self, $user) = @_;
2784 my $me = $self->current_source_alias;
2786 return $self->search(
2787 "$me.modified" => $user->id,
2793 sub current_source_alias {
2796 return ($self->{attrs} || {})->{alias} || 'me';
2799 =head2 as_subselect_rs
2803 =item Arguments: none
2805 =item Return Value: $resultset
2809 Act as a barrier to SQL symbols. The resultset provided will be made into a
2810 "virtual view" by including it as a subquery within the from clause. From this
2811 point on, any joined tables are inaccessible to ->search on the resultset (as if
2812 it were simply where-filtered without joins). For example:
2814 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2816 # 'x' now pollutes the query namespace
2818 # So the following works as expected
2819 my $ok_rs = $rs->search({'x.other' => 1});
2821 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2822 # def) we look for one row with contradictory terms and join in another table
2823 # (aliased 'x_2') which we never use
2824 my $broken_rs = $rs->search({'x.name' => 'def'});
2826 my $rs2 = $rs->as_subselect_rs;
2828 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2829 my $not_joined_rs = $rs2->search({'x.other' => 1});
2831 # works as expected: finds a 'table' row related to two x rows (abc and def)
2832 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2834 Another example of when one might use this would be to select a subset of
2835 columns in a group by clause:
2837 my $rs = $schema->resultset('Bar')->search(undef, {
2838 group_by => [qw{ id foo_id baz_id }],
2839 })->as_subselect_rs->search(undef, {
2840 columns => [qw{ id foo_id }]
2843 In the above example normally columns would have to be equal to the group by,
2844 but because we isolated the group by into a subselect the above works.
2848 sub as_subselect_rs {
2851 my $attrs = $self->_resolved_attrs;
2853 my $fresh_rs = (ref $self)->new (
2854 $self->result_source
2857 # these pieces will be locked in the subquery
2858 delete $fresh_rs->{cond};
2859 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2861 return $fresh_rs->search( {}, {
2863 $attrs->{alias} => $self->as_query,
2864 -alias => $attrs->{alias},
2865 -source_handle => $self->result_source->handle,
2867 alias => $attrs->{alias},
2871 # This code is called by search_related, and makes sure there
2872 # is clear separation between the joins before, during, and
2873 # after the relationship. This information is needed later
2874 # in order to properly resolve prefetch aliases (any alias
2875 # with a relation_chain_depth less than the depth of the
2876 # current prefetch is not considered)
2878 # The increments happen twice per join. An even number means a
2879 # relationship specified via a search_related, whereas an odd
2880 # number indicates a join/prefetch added via attributes
2882 # Also this code will wrap the current resultset (the one we
2883 # chain to) in a subselect IFF it contains limiting attributes
2884 sub _chain_relationship {
2885 my ($self, $rel) = @_;
2886 my $source = $self->result_source;
2887 my $attrs = { %{$self->{attrs}||{}} };
2889 # we need to take the prefetch the attrs into account before we
2890 # ->_resolve_join as otherwise they get lost - captainL
2891 my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2893 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2895 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2898 my @force_subq_attrs = qw/offset rows group_by having/;
2901 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2903 $self->_has_resolved_attr (@force_subq_attrs)
2905 # Nuke the prefetch (if any) before the new $rs attrs
2906 # are resolved (prefetch is useless - we are wrapping
2907 # a subquery anyway).
2908 my $rs_copy = $self->search;
2909 $rs_copy->{attrs}{join} = $self->_merge_attr (
2910 $rs_copy->{attrs}{join},
2911 delete $rs_copy->{attrs}{prefetch},
2915 -source_handle => $source->handle,
2916 -alias => $attrs->{alias},
2917 $attrs->{alias} => $rs_copy->as_query,
2919 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2920 $seen->{-relation_chain_depth} = 0;
2922 elsif ($attrs->{from}) { #shallow copy suffices
2923 $from = [ @{$attrs->{from}} ];
2927 -source_handle => $source->handle,
2928 -alias => $attrs->{alias},
2929 $attrs->{alias} => $source->from,
2933 my $jpath = ($seen->{-relation_chain_depth})
2934 ? $from->[-1][0]{-join_path}
2937 my @requested_joins = $source->_resolve_join(
2944 push @$from, @requested_joins;
2946 $seen->{-relation_chain_depth}++;
2948 # if $self already had a join/prefetch specified on it, the requested
2949 # $rel might very well be already included. What we do in this case
2950 # is effectively a no-op (except that we bump up the chain_depth on
2951 # the join in question so we could tell it *is* the search_related)
2954 # we consider the last one thus reverse
2955 for my $j (reverse @requested_joins) {
2956 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2957 if ($rel eq $last_j) {
2958 $j->[0]{-relation_chain_depth}++;
2964 unless ($already_joined) {
2965 push @$from, $source->_resolve_join(
2973 $seen->{-relation_chain_depth}++;
2975 return {%$attrs, from => $from, seen_join => $seen};
2978 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2979 sub _resolved_attrs_copy {
2981 return { %{$self->_resolved_attrs (@_)} };
2984 sub _resolved_attrs {
2986 return $self->{_attrs} if $self->{_attrs};
2988 my $attrs = { %{ $self->{attrs} || {} } };
2989 my $source = $self->result_source;
2990 my $alias = $attrs->{alias};
2992 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2995 # build columns (as long as select isn't set) into a set of as/select hashes
2996 unless ( $attrs->{select} ) {
2999 if ( ref $attrs->{columns} eq 'ARRAY' ) {
3000 @cols = @{ delete $attrs->{columns}}
3001 } elsif ( defined $attrs->{columns} ) {
3002 @cols = delete $attrs->{columns}
3004 @cols = $source->columns
3008 if ( ref $_ eq 'HASH' ) {
3011 my $key = /^\Q${alias}.\E(.+)$/
3017 push @colbits, { $key => $value };
3022 # add the additional columns on
3023 foreach (qw{include_columns +columns}) {
3024 if ( $attrs->{$_} ) {
3025 my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
3026 ? @{ delete $attrs->{$_} }
3027 : delete $attrs->{$_};
3029 if ( ref($_) eq 'HASH' ) {
3032 my $key = ( split /\./, $_ )[-1];
3033 my $value = ( /\./ ? $_ : "$alias.$_" );
3034 push @colbits, { $key => $value };
3040 # start with initial select items
3041 if ( $attrs->{select} ) {
3043 ( ref $attrs->{select} eq 'ARRAY' )
3044 ? [ @{ $attrs->{select} } ]
3045 : [ $attrs->{select} ];
3047 if ( $attrs->{as} ) {
3050 ref $attrs->{as} eq 'ARRAY'
3051 ? [ @{ $attrs->{as} } ]
3055 $attrs->{as} = [ map {
3056 m/^\Q${alias}.\E(.+)$/
3059 } @{ $attrs->{select} }
3065 # otherwise we intialise select & as to empty
3066 $attrs->{select} = [];
3070 # now add colbits to select/as
3071 push @{ $attrs->{select} }, map values %{$_}, @colbits;
3072 push @{ $attrs->{as} }, map keys %{$_}, @colbits;
3074 if ( my $adds = delete $attrs->{'+select'} ) {
3075 $adds = [$adds] unless ref $adds eq 'ARRAY';
3076 push @{ $attrs->{select} },
3077 map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
3079 if ( my $adds = delete $attrs->{'+as'} ) {
3080 $adds = [$adds] unless ref $adds eq 'ARRAY';
3081 push @{ $attrs->{as} }, @$adds;
3084 $attrs->{from} ||= [{
3085 -source_handle => $source->handle,
3086 -alias => $self->{attrs}{alias},
3087 $self->{attrs}{alias} => $source->from,
3090 if ( $attrs->{join} || $attrs->{prefetch} ) {
3092 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3093 if ref $attrs->{from} ne 'ARRAY';
3095 my $join = delete $attrs->{join} || {};
3097 if ( defined $attrs->{prefetch} ) {
3098 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
3101 $attrs->{from} = # have to copy here to avoid corrupting the original
3103 @{ $attrs->{from} },
3104 $source->_resolve_join(
3107 { %{ $attrs->{seen_join} || {} } },
3108 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3109 ? $attrs->{from}[-1][0]{-join_path}
3116 if ( defined $attrs->{order_by} ) {
3117 $attrs->{order_by} = (
3118 ref( $attrs->{order_by} ) eq 'ARRAY'
3119 ? [ @{ $attrs->{order_by} } ]
3120 : [ $attrs->{order_by} || () ]
3124 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3125 $attrs->{group_by} = [ $attrs->{group_by} ];
3128 # generate the distinct induced group_by early, as prefetch will be carried via a
3129 # subquery (since a group_by is present)
3130 if (delete $attrs->{distinct}) {
3131 if ($attrs->{group_by}) {
3132 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3135 $attrs->{group_by} = $source->storage->_group_over_selection (
3136 @{$attrs}{qw/from select order_by/}
3141 $attrs->{collapse} ||= {};
3142 if ( my $prefetch = delete $attrs->{prefetch} ) {
3143 $prefetch = $self->_merge_attr( {}, $prefetch );
3145 my $prefetch_ordering = [];
3147 # this is a separate structure (we don't look in {from} directly)
3148 # as the resolver needs to shift things off the lists to work
3149 # properly (identical-prefetches on different branches)
3151 if (ref $attrs->{from} eq 'ARRAY') {
3153 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3155 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3156 next unless $j->[0]{-alias};
3157 next unless $j->[0]{-join_path};
3158 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3160 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3163 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3164 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3169 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3171 # we need to somehow mark which columns came from prefetch
3172 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3174 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3175 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3177 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3178 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3181 # if both page and offset are specified, produce a combined offset
3182 # even though it doesn't make much sense, this is what pre 081xx has
3184 if (my $page = delete $attrs->{page}) {
3186 ($attrs->{rows} * ($page - 1))
3188 ($attrs->{offset} || 0)
3192 return $self->{_attrs} = $attrs;
3196 my ($self, $attr) = @_;
3198 if (ref $attr eq 'HASH') {
3199 return $self->_rollout_hash($attr);
3200 } elsif (ref $attr eq 'ARRAY') {
3201 return $self->_rollout_array($attr);
3207 sub _rollout_array {
3208 my ($self, $attr) = @_;
3211 foreach my $element (@{$attr}) {
3212 if (ref $element eq 'HASH') {
3213 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3214 } elsif (ref $element eq 'ARRAY') {
3215 # XXX - should probably recurse here
3216 push( @rolled_array, @{$self->_rollout_array($element)} );
3218 push( @rolled_array, $element );
3221 return \@rolled_array;
3225 my ($self, $attr) = @_;
3228 foreach my $key (keys %{$attr}) {
3229 push( @rolled_array, { $key => $attr->{$key} } );
3231 return \@rolled_array;
3234 sub _calculate_score {
3235 my ($self, $a, $b) = @_;
3237 if (defined $a xor defined $b) {
3240 elsif (not defined $a) {
3244 if (ref $b eq 'HASH') {
3245 my ($b_key) = keys %{$b};
3246 if (ref $a eq 'HASH') {
3247 my ($a_key) = keys %{$a};
3248 if ($a_key eq $b_key) {
3249 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3254 return ($a eq $b_key) ? 1 : 0;
3257 if (ref $a eq 'HASH') {
3258 my ($a_key) = keys %{$a};
3259 return ($b eq $a_key) ? 1 : 0;
3261 return ($b eq $a) ? 1 : 0;
3267 my ($self, $orig, $import) = @_;
3269 return $import unless defined($orig);
3270 return $orig unless defined($import);
3272 $orig = $self->_rollout_attr($orig);
3273 $import = $self->_rollout_attr($import);
3276 foreach my $import_element ( @{$import} ) {
3277 # find best candidate from $orig to merge $b_element into
3278 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3279 foreach my $orig_element ( @{$orig} ) {
3280 my $score = $self->_calculate_score( $orig_element, $import_element );
3281 if ($score > $best_candidate->{score}) {
3282 $best_candidate->{position} = $position;
3283 $best_candidate->{score} = $score;
3287 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3289 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3290 push( @{$orig}, $import_element );
3292 my $orig_best = $orig->[$best_candidate->{position}];
3293 # merge orig_best and b_element together and replace original with merged
3294 if (ref $orig_best ne 'HASH') {
3295 $orig->[$best_candidate->{position}] = $import_element;
3296 } elsif (ref $import_element eq 'HASH') {
3297 my ($key) = keys %{$orig_best};
3298 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
3301 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3311 $self->_source_handle($_[0]->handle);
3313 $self->_source_handle->resolve;
3317 =head2 throw_exception
3319 See L<DBIx::Class::Schema/throw_exception> for details.
3323 sub throw_exception {
3326 if (ref $self && $self->_source_handle->schema) {
3327 $self->_source_handle->schema->throw_exception(@_)
3330 DBIx::Class::Exception->throw(@_);
3334 # XXX: FIXME: Attributes docs need clearing up
3338 Attributes are used to refine a ResultSet in various ways when
3339 searching for data. They can be passed to any method which takes an
3340 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3343 These are in no particular order:
3349 =item Value: ( $order_by | \@order_by | \%order_by )
3353 Which column(s) to order the results by.
3355 [The full list of suitable values is documented in
3356 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3359 If a single column name, or an arrayref of names is supplied, the
3360 argument is passed through directly to SQL. The hashref syntax allows
3361 for connection-agnostic specification of ordering direction:
3363 For descending order:
3365 order_by => { -desc => [qw/col1 col2 col3/] }
3367 For explicit ascending order:
3369 order_by => { -asc => 'col' }
3371 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3372 supported, although you are strongly encouraged to use the hashref
3373 syntax as outlined above.
3379 =item Value: \@columns
3383 Shortcut to request a particular set of columns to be retrieved. Each
3384 column spec may be a string (a table column name), or a hash (in which
3385 case the key is the C<as> value, and the value is used as the C<select>
3386 expression). Adds C<me.> onto the start of any column without a C<.> in
3387 it and sets C<select> from that, then auto-populates C<as> from
3388 C<select> as normal. (You may also use the C<cols> attribute, as in
3389 earlier versions of DBIC.)
3391 Essentially C<columns> does the same as L</select> and L</as>.
3393 columns => [ 'foo', { bar => 'baz' } ]
3397 select => [qw/foo baz/],
3404 =item Value: \@columns
3408 Indicates additional columns to be selected from storage. Works the same
3409 as L</columns> but adds columns to the selection. (You may also use the
3410 C<include_columns> attribute, as in earlier versions of DBIC). For
3413 $schema->resultset('CD')->search(undef, {
3414 '+columns' => ['artist.name'],
3418 would return all CDs and include a 'name' column to the information
3419 passed to object inflation. Note that the 'artist' is the name of the
3420 column (or relationship) accessor, and 'name' is the name of the column
3421 accessor in the related table.
3423 =head2 include_columns
3427 =item Value: \@columns
3431 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3437 =item Value: \@select_columns
3441 Indicates which columns should be selected from the storage. You can use
3442 column names, or in the case of RDBMS back ends, function or stored procedure
3445 $rs = $schema->resultset('Employee')->search(undef, {
3448 { count => 'employeeid' },
3449 { max => { length => 'name' }, -as => 'longest_name' }
3454 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3456 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3457 use L</select>, to instruct DBIx::Class how to store the result of the column.
3458 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3459 identifier aliasing. You can however alias a function, so you can use it in
3460 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3461 attribute> supplied as shown in the example above.
3467 Indicates additional columns to be selected from storage. Works the same as
3468 L</select> but adds columns to the default selection, instead of specifying
3477 Indicates additional column names for those added via L</+select>. See L</as>.
3485 =item Value: \@inflation_names
3489 Indicates column names for object inflation. That is L</as> indicates the
3490 slot name in which the column value will be stored within the
3491 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3492 identifier by the C<get_column> method (or via the object accessor B<if one
3493 with the same name already exists>) as shown below. The L</as> attribute has
3494 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3496 $rs = $schema->resultset('Employee')->search(undef, {
3499 { count => 'employeeid' },
3500 { max => { length => 'name' }, -as => 'longest_name' }
3509 If the object against which the search is performed already has an accessor
3510 matching a column name specified in C<as>, the value can be retrieved using
3511 the accessor as normal:
3513 my $name = $employee->name();
3515 If on the other hand an accessor does not exist in the object, you need to
3516 use C<get_column> instead:
3518 my $employee_count = $employee->get_column('employee_count');
3520 You can create your own accessors if required - see
3521 L<DBIx::Class::Manual::Cookbook> for details.
3527 =item Value: ($rel_name | \@rel_names | \%rel_names)
3531 Contains a list of relationships that should be joined for this query. For
3534 # Get CDs by Nine Inch Nails
3535 my $rs = $schema->resultset('CD')->search(
3536 { 'artist.name' => 'Nine Inch Nails' },
3537 { join => 'artist' }
3540 Can also contain a hash reference to refer to the other relation's relations.
3543 package MyApp::Schema::Track;
3544 use base qw/DBIx::Class/;
3545 __PACKAGE__->table('track');
3546 __PACKAGE__->add_columns(qw/trackid cd position title/);
3547 __PACKAGE__->set_primary_key('trackid');
3548 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3551 # In your application
3552 my $rs = $schema->resultset('Artist')->search(
3553 { 'track.title' => 'Teardrop' },
3555 join => { cd => 'track' },
3556 order_by => 'artist.name',
3560 You need to use the relationship (not the table) name in conditions,
3561 because they are aliased as such. The current table is aliased as "me", so
3562 you need to use me.column_name in order to avoid ambiguity. For example:
3564 # Get CDs from 1984 with a 'Foo' track
3565 my $rs = $schema->resultset('CD')->search(
3568 'tracks.name' => 'Foo'
3570 { join => 'tracks' }
3573 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3574 similarly for a third time). For e.g.
3576 my $rs = $schema->resultset('Artist')->search({
3577 'cds.title' => 'Down to Earth',
3578 'cds_2.title' => 'Popular',
3580 join => [ qw/cds cds/ ],
3583 will return a set of all artists that have both a cd with title 'Down
3584 to Earth' and a cd with title 'Popular'.
3586 If you want to fetch related objects from other tables as well, see C<prefetch>
3589 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3595 =item Value: ($rel_name | \@rel_names | \%rel_names)
3599 Contains one or more relationships that should be fetched along with
3600 the main query (when they are accessed afterwards the data will
3601 already be available, without extra queries to the database). This is
3602 useful for when you know you will need the related objects, because it
3603 saves at least one query:
3605 my $rs = $schema->resultset('Tag')->search(
3614 The initial search results in SQL like the following:
3616 SELECT tag.*, cd.*, artist.* FROM tag
3617 JOIN cd ON tag.cd = cd.cdid
3618 JOIN artist ON cd.artist = artist.artistid
3620 L<DBIx::Class> has no need to go back to the database when we access the
3621 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3624 Simple prefetches will be joined automatically, so there is no need
3625 for a C<join> attribute in the above search.
3627 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3628 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3629 with an accessor type of 'single' or 'filter'). A more complex example that
3630 prefetches an artists cds, the tracks on those cds, and the tags associated
3631 with that artist is given below (assuming many-to-many from artists to tags):
3633 my $rs = $schema->resultset('Artist')->search(
3637 { cds => 'tracks' },
3638 { artist_tags => 'tags' }
3644 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3645 attributes will be ignored.
3647 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3648 exactly as you might expect.
3654 Prefetch uses the L</cache> to populate the prefetched relationships. This
3655 may or may not be what you want.
3659 If you specify a condition on a prefetched relationship, ONLY those
3660 rows that match the prefetched condition will be fetched into that relationship.
3661 This means that adding prefetch to a search() B<may alter> what is returned by
3662 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3664 my $artist_rs = $schema->resultset('Artist')->search({
3670 my $count = $artist_rs->first->cds->count;
3672 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3674 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3676 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3678 that cmp_ok() may or may not pass depending on the datasets involved. This
3679 behavior may or may not survive the 0.09 transition.
3691 Makes the resultset paged and specifies the page to retrieve. Effectively
3692 identical to creating a non-pages resultset and then calling ->page($page)
3695 If L<rows> attribute is not specified it defaults to 10 rows per page.
3697 When you have a paged resultset, L</count> will only return the number
3698 of rows in the page. To get the total, use the L</pager> and call
3699 C<total_entries> on it.
3709 Specifies the maximum number of rows for direct retrieval or the number of
3710 rows per page if the page attribute or method is used.
3716 =item Value: $offset
3720 Specifies the (zero-based) row number for the first row to be returned, or the
3721 of the first row of the first page if paging is used.
3727 =item Value: \@columns
3731 A arrayref of columns to group by. Can include columns of joined tables.
3733 group_by => [qw/ column1 column2 ... /]
3739 =item Value: $condition
3743 HAVING is a select statement attribute that is applied between GROUP BY and
3744 ORDER BY. It is applied to the after the grouping calculations have been
3747 having => { 'count(employee)' => { '>=', 100 } }
3753 =item Value: (0 | 1)
3757 Set to 1 to group by all columns. If the resultset already has a group_by
3758 attribute, this setting is ignored and an appropriate warning is issued.
3764 Adds to the WHERE clause.
3766 # only return rows WHERE deleted IS NULL for all searches
3767 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3769 Can be overridden by passing C<< { where => undef } >> as an attribute
3776 Set to 1 to cache search results. This prevents extra SQL queries if you
3777 revisit rows in your ResultSet:
3779 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3781 while( my $artist = $resultset->next ) {
3785 $rs->first; # without cache, this would issue a query
3787 By default, searches are not cached.
3789 For more examples of using these attributes, see
3790 L<DBIx::Class::Manual::Cookbook>.
3796 =item Value: ( 'update' | 'shared' )
3800 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT