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( @_ );
252 return (wantarray ? $rs->all : $rs);
259 =item Arguments: $cond, \%attrs?
261 =item Return Value: $resultset
265 This method does the same exact thing as search() except it will
266 always return a resultset, even in list context.
273 # Special-case handling for (undef, undef).
274 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
279 $call_attrs = pop(@_) if @_ > 1 and ref $_[-1] eq 'HASH';
281 # see if we can keep the cache (no $rs changes)
283 my %safe = (alias => 1, cache => 1);
284 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
287 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
289 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
291 $cache = $self->get_cache;
294 my $old_attrs = { %{$self->{attrs}} };
295 my $old_having = delete $old_attrs->{having};
296 my $old_where = delete $old_attrs->{where};
298 # reset the selector list
299 if (List::Util::first { exists $call_attrs->{$_} } qw{columns select as}) {
300 delete @{$old_attrs}{qw{select as columns +select +as +columns include_columns}};
303 my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
305 # merge new attrs into inherited
306 foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
307 next unless exists $call_attrs->{$key};
308 $new_attrs->{$key} = $self->_merge_attr($old_attrs->{$key}, $call_attrs->{$key});
311 # rip apart the rest of @_, parse a condition
314 if (ref $_[0] eq 'HASH') {
315 (keys %{$_[0]}) ? $_[0] : undef
321 $self->throw_exception('Odd number of arguments to search')
329 for ($old_where, $call_cond) {
331 $new_attrs->{where} = $self->_stack_cond (
332 $_, $new_attrs->{where}
337 if (defined $old_having) {
338 $new_attrs->{having} = $self->_stack_cond (
339 $old_having, $new_attrs->{having}
343 my $rs = (ref $self)->new($self->result_source, $new_attrs);
345 $rs->set_cache($cache) if ($cache);
351 my ($self, $left, $right) = @_;
352 if (defined $left xor defined $right) {
353 return defined $left ? $left : $right;
355 elsif (defined $left) {
356 return { -and => [ map
357 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
365 =head2 search_literal
369 =item Arguments: $sql_fragment, @bind_values
371 =item Return Value: $resultset (scalar context), @row_objs (list context)
375 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
376 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
378 Pass a literal chunk of SQL to be added to the conditional part of the
381 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
382 only be used in that context. C<search_literal> is a convenience method.
383 It is equivalent to calling $schema->search(\[]), but if you want to ensure
384 columns are bound correctly, use C<search>.
386 Example of how to use C<search> instead of C<search_literal>
388 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
389 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
392 See L<DBIx::Class::Manual::Cookbook/Searching> and
393 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
394 require C<search_literal>.
399 my ($self, $sql, @bind) = @_;
401 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
404 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
411 =item Arguments: \%columns_values | @pk_values, \%attrs?
413 =item Return Value: $row_object | undef
417 Finds and returns a single row based on supplied criteria. Takes either a
418 hashref with the same format as L</create> (including inference of foreign
419 keys from related objects), or a list of primary key values in the same
420 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
421 declaration on the L</result_source>.
423 In either case an attempt is made to combine conditions already existing on
424 the resultset with the condition passed to this method.
426 To aid with preparing the correct query for the storage you may supply the
427 C<key> attribute, which is the name of a
428 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
429 unique constraint corresponding to the
430 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
431 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
432 to construct a query that satisfies the named unique constraint fully (
433 non-NULL values for each column member of the constraint) an exception is
436 If no C<key> is specified, the search is carried over all unique constraints
437 which are fully defined by the available condition.
439 If no such constraint is found, C<find> currently defaults to a simple
440 C<< search->(\%column_values) >> which may or may not do what you expect.
441 Note that this fallback behavior may be deprecated in further versions. If
442 you need to search with arbitrary conditions - use L</search>. If the query
443 resulting from this fallback produces more than one row, a warning to the
444 effect is issued, though only the first row is constructed and returned as
447 In addition to C<key>, L</find> recognizes and applies standard
448 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
450 Note that if you have extra concerns about the correctness of the resulting
451 query you need to specify the C<key> attribute and supply the entire condition
452 as an argument to find (since it is not always possible to perform the
453 combination of the resultset condition with the supplied one, especially if
454 the resultset condition contains literal sql).
456 For example, to find a row by its primary key:
458 my $cd = $schema->resultset('CD')->find(5);
460 You can also find a row by a specific unique constraint:
462 my $cd = $schema->resultset('CD')->find(
464 artist => 'Massive Attack',
465 title => 'Mezzanine',
467 { key => 'cd_artist_title' }
470 See also L</find_or_create> and L</update_or_create>.
476 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
478 my $rsrc = $self->result_source;
480 # Parse out the condition from input
482 if (ref $_[0] eq 'HASH') {
483 $call_cond = { %{$_[0]} };
486 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
487 my @c_cols = $rsrc->unique_constraint_columns($constraint);
489 $self->throw_exception(
490 "No constraint columns, maybe a malformed '$constraint' constraint?"
493 $self->throw_exception (
494 'find() expects either a column/value hashref, or a list of values '
495 . "corresponding to the columns of the specified unique constraint '$constraint'"
496 ) unless @c_cols == @_;
499 @{$call_cond}{@c_cols} = @_;
503 for my $key (keys %$call_cond) {
505 my $keyref = ref($call_cond->{$key})
507 my $relinfo = $rsrc->relationship_info($key)
509 my $val = delete $call_cond->{$key};
511 next if $keyref eq 'ARRAY'; # has_many for multi_create
513 my $rel_q = $rsrc->_resolve_condition(
514 $relinfo->{cond}, $val, $key
516 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
517 @related{keys %$rel_q} = values %$rel_q;
521 # relationship conditions take precedence (?)
522 @{$call_cond}{keys %related} = values %related;
524 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
526 if (exists $attrs->{key}) {
527 $final_cond = $self->_qualify_cond_columns (
529 $self->_build_unique_cond (
537 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
538 # This means that we got here after a merger of relationship conditions
539 # in ::Relationship::Base::search_related (the row method), and furthermore
540 # the relationship is of the 'single' type. This means that the condition
541 # provided by the relationship (already attached to $self) is sufficient,
542 # as there can be only one row in the database that would satisfy the
546 # no key was specified - fall down to heuristics mode:
547 # run through all unique queries registered on the resultset, and
548 # 'OR' all qualifying queries together
549 my (@unique_queries, %seen_column_combinations);
550 for my $c_name ($rsrc->unique_constraint_names) {
551 next if $seen_column_combinations{
552 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
555 push @unique_queries, try {
556 $self->_build_unique_cond ($c_name, $call_cond)
560 $final_cond = @unique_queries
561 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
562 : $self->_non_unique_find_fallback ($call_cond, $attrs)
566 # Run the query, passing the result_class since it should propagate for find
567 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
568 if (keys %{$rs->_resolved_attrs->{collapse}}) {
570 carp "Query returned more than one row" if $rs->next;
578 # This is a stop-gap method as agreed during the discussion on find() cleanup:
579 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
581 # It is invoked when find() is called in legacy-mode with insufficiently-unique
582 # condition. It is provided for overrides until a saner way forward is devised
584 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
585 # the road. Please adjust your tests accordingly to catch this situation early
586 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
588 # The method will not be removed without an adequately complete replacement
589 # for strict-mode enforcement
590 sub _non_unique_find_fallback {
591 my ($self, $cond, $attrs) = @_;
593 return $self->_qualify_cond_columns(
595 exists $attrs->{alias}
597 : $self->{attrs}{alias}
602 sub _qualify_cond_columns {
603 my ($self, $cond, $alias) = @_;
605 my %aliased = %$cond;
606 for (keys %aliased) {
607 $aliased{"$alias.$_"} = delete $aliased{$_}
614 sub _build_unique_cond {
615 my ($self, $constraint_name, $extra_cond) = @_;
617 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
619 # combination may fail if $self->{cond} is non-trivial
620 my ($final_cond) = try {
621 $self->_merge_with_rscond ($extra_cond)
626 # trim out everything not in $columns
627 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
629 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
630 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
632 join (', ', map { "'$_'" } @missing),
639 =head2 search_related
643 =item Arguments: $rel, $cond, \%attrs?
645 =item Return Value: $new_resultset
649 $new_rs = $cd_rs->search_related('artist', {
653 Searches the specified relationship, optionally specifying a condition and
654 attributes for matching records. See L</ATTRIBUTES> for more information.
659 return shift->related_resultset(shift)->search(@_);
662 =head2 search_related_rs
664 This method works exactly the same as search_related, except that
665 it guarantees a resultset, even in list context.
669 sub search_related_rs {
670 return shift->related_resultset(shift)->search_rs(@_);
677 =item Arguments: none
679 =item Return Value: $cursor
683 Returns a storage-driven cursor to the given resultset. See
684 L<DBIx::Class::Cursor> for more information.
691 my $attrs = $self->_resolved_attrs_copy;
693 return $self->{cursor}
694 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
695 $attrs->{where},$attrs);
702 =item Arguments: $cond?
704 =item Return Value: $row_object | undef
708 my $cd = $schema->resultset('CD')->single({ year => 2001 });
710 Inflates the first result without creating a cursor if the resultset has
711 any records in it; if not returns C<undef>. Used by L</find> as a lean version
714 While this method can take an optional search condition (just like L</search>)
715 being a fast-code-path it does not recognize search attributes. If you need to
716 add extra joins or similar, call L</search> and then chain-call L</single> on the
717 L<DBIx::Class::ResultSet> returned.
723 As of 0.08100, this method enforces the assumption that the preceding
724 query returns only one row. If more than one row is returned, you will receive
727 Query returned more than one row
729 In this case, you should be using L</next> or L</find> instead, or if you really
730 know what you are doing, use the L</rows> attribute to explicitly limit the size
733 This method will also throw an exception if it is called on a resultset prefetching
734 has_many, as such a prefetch implies fetching multiple rows from the database in
735 order to assemble the resulting object.
742 my ($self, $where) = @_;
744 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
747 my $attrs = $self->_resolved_attrs_copy;
749 if (keys %{$attrs->{collapse}}) {
750 $self->throw_exception(
751 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
756 if (defined $attrs->{where}) {
759 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
760 $where, delete $attrs->{where} ]
763 $attrs->{where} = $where;
767 my @data = $self->result_source->storage->select_single(
768 $attrs->{from}, $attrs->{select},
769 $attrs->{where}, $attrs
772 return (@data ? ($self->_construct_object(@data))[0] : undef);
778 # Recursively collapse the query, accumulating values for each column.
780 sub _collapse_query {
781 my ($self, $query, $collapsed) = @_;
785 if (ref $query eq 'ARRAY') {
786 foreach my $subquery (@$query) {
787 next unless ref $subquery; # -or
788 $collapsed = $self->_collapse_query($subquery, $collapsed);
791 elsif (ref $query eq 'HASH') {
792 if (keys %$query and (keys %$query)[0] eq '-and') {
793 foreach my $subquery (@{$query->{-and}}) {
794 $collapsed = $self->_collapse_query($subquery, $collapsed);
798 foreach my $col (keys %$query) {
799 my $value = $query->{$col};
800 $collapsed->{$col}{$value}++;
812 =item Arguments: $cond?
814 =item Return Value: $resultsetcolumn
818 my $max_length = $rs->get_column('length')->max;
820 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
825 my ($self, $column) = @_;
826 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
834 =item Arguments: $cond, \%attrs?
836 =item Return Value: $resultset (scalar context), @row_objs (list context)
840 # WHERE title LIKE '%blue%'
841 $cd_rs = $rs->search_like({ title => '%blue%'});
843 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
844 that this is simply a convenience method retained for ex Class::DBI users.
845 You most likely want to use L</search> with specific operators.
847 For more information, see L<DBIx::Class::Manual::Cookbook>.
849 This method is deprecated and will be removed in 0.09. Use L</search()>
850 instead. An example conversion is:
852 ->search_like({ foo => 'bar' });
856 ->search({ foo => { like => 'bar' } });
863 'search_like() is deprecated and will be removed in DBIC version 0.09.'
864 .' Instead use ->search({ x => { -like => "y%" } })'
865 .' (note the outer pair of {}s - they are important!)'
867 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
868 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
869 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
870 return $class->search($query, { %$attrs });
877 =item Arguments: $first, $last
879 =item Return Value: $resultset (scalar context), @row_objs (list context)
883 Returns a resultset or object list representing a subset of elements from the
884 resultset slice is called on. Indexes are from 0, i.e., to get the first
887 my ($one, $two, $three) = $rs->slice(0, 2);
892 my ($self, $min, $max) = @_;
893 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
894 $attrs->{offset} = $self->{attrs}{offset} || 0;
895 $attrs->{offset} += $min;
896 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
897 return $self->search(undef, $attrs);
898 #my $slice = (ref $self)->new($self->result_source, $attrs);
899 #return (wantarray ? $slice->all : $slice);
906 =item Arguments: none
908 =item Return Value: $result | undef
912 Returns the next element in the resultset (C<undef> is there is none).
914 Can be used to efficiently iterate over records in the resultset:
916 my $rs = $schema->resultset('CD')->search;
917 while (my $cd = $rs->next) {
921 Note that you need to store the resultset object, and call C<next> on it.
922 Calling C<< resultset('Table')->next >> repeatedly will always return the
923 first record from the resultset.
929 if (my $cache = $self->get_cache) {
930 $self->{all_cache_position} ||= 0;
931 return $cache->[$self->{all_cache_position}++];
933 if ($self->{attrs}{cache}) {
934 delete $self->{pager};
935 $self->{all_cache_position} = 1;
936 return ($self->all)[0];
938 if ($self->{stashed_objects}) {
939 my $obj = shift(@{$self->{stashed_objects}});
940 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
944 exists $self->{stashed_row}
945 ? @{delete $self->{stashed_row}}
946 : $self->cursor->next
948 return undef unless (@row);
949 my ($row, @more) = $self->_construct_object(@row);
950 $self->{stashed_objects} = \@more if @more;
954 sub _construct_object {
955 my ($self, @row) = @_;
957 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
959 my @new = $self->result_class->inflate_result($self->result_source, @$info);
960 @new = $self->{_attrs}{record_filter}->(@new)
961 if exists $self->{_attrs}{record_filter};
965 sub _collapse_result {
966 my ($self, $as_proto, $row) = @_;
970 # 'foo' => [ undef, 'foo' ]
971 # 'foo.bar' => [ 'foo', 'bar' ]
972 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
974 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
976 my %collapse = %{$self->{_attrs}{collapse}||{}};
980 # if we're doing collapsing (has_many prefetch) we need to grab records
981 # until the PK changes, so fill @pri_index. if not, we leave it empty so
982 # we know we don't have to bother.
984 # the reason for not using the collapse stuff directly is because if you
985 # had for e.g. two artists in a row with no cds, the collapse info for
986 # both would be NULL (undef) so you'd lose the second artist
988 # store just the index so we can check the array positions from the row
989 # without having to contruct the full hash
991 if (keys %collapse) {
992 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
993 foreach my $i (0 .. $#construct_as) {
994 next if defined($construct_as[$i][0]); # only self table
995 if (delete $pri{$construct_as[$i][1]}) {
996 push(@pri_index, $i);
998 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1002 # no need to do an if, it'll be empty if @pri_index is empty anyway
1004 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1008 do { # no need to check anything at the front, we always want the first row
1012 foreach my $this_as (@construct_as) {
1013 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1016 push(@const_rows, \%const);
1018 } until ( # no pri_index => no collapse => drop straight out
1021 do { # get another row, stash it, drop out if different PK
1023 @copy = $self->cursor->next;
1024 $self->{stashed_row} = \@copy;
1026 # last thing in do block, counts as true if anything doesn't match
1028 # check xor defined first for NULL vs. NOT NULL then if one is
1029 # defined the other must be so check string equality
1032 (defined $pri_vals{$_} ^ defined $copy[$_])
1033 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1038 my $alias = $self->{attrs}{alias};
1045 foreach my $const (@const_rows) {
1046 scalar @const_keys or do {
1047 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1049 foreach my $key (@const_keys) {
1052 my @parts = split(/\./, $key);
1054 my $data = $const->{$key};
1055 foreach my $p (@parts) {
1056 $target = $target->[1]->{$p} ||= [];
1058 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1059 # collapsing at this point and on final part
1060 my $pos = $collapse_pos{$cur};
1061 CK: foreach my $ck (@ckey) {
1062 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1063 $collapse_pos{$cur} = $data;
1064 delete @collapse_pos{ # clear all positioning for sub-entries
1065 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1072 if (exists $collapse{$cur}) {
1073 $target = $target->[-1];
1076 $target->[0] = $data;
1078 $info->[0] = $const->{$key};
1086 =head2 result_source
1090 =item Arguments: $result_source?
1092 =item Return Value: $result_source
1096 An accessor for the primary ResultSource object from which this ResultSet
1103 =item Arguments: $result_class?
1105 =item Return Value: $result_class
1109 An accessor for the class to use when creating row objects. Defaults to
1110 C<< result_source->result_class >> - which in most cases is the name of the
1111 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1113 Note that changing the result_class will also remove any components
1114 that were originally loaded in the source class via
1115 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1116 in the original source class will not run.
1121 my ($self, $result_class) = @_;
1122 if ($result_class) {
1123 unless (ref $result_class) { # don't fire this for an object
1124 $self->ensure_class_loaded($result_class);
1126 $self->_result_class($result_class);
1127 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1128 # permit the user to set result class on one result set only; it only
1129 # chains if provided to search()
1130 #$self->{attrs}{result_class} = $result_class if ref $self;
1132 $self->_result_class;
1139 =item Arguments: $cond, \%attrs??
1141 =item Return Value: $count
1145 Performs an SQL C<COUNT> with the same query as the resultset was built
1146 with to find the number of elements. Passing arguments is equivalent to
1147 C<< $rs->search ($cond, \%attrs)->count >>
1153 return $self->search(@_)->count if @_ and defined $_[0];
1154 return scalar @{ $self->get_cache } if $self->get_cache;
1156 my $attrs = $self->_resolved_attrs_copy;
1158 # this is a little optimization - it is faster to do the limit
1159 # adjustments in software, instead of a subquery
1160 my $rows = delete $attrs->{rows};
1161 my $offset = delete $attrs->{offset};
1164 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1165 $crs = $self->_count_subq_rs ($attrs);
1168 $crs = $self->_count_rs ($attrs);
1170 my $count = $crs->next;
1172 $count -= $offset if $offset;
1173 $count = $rows if $rows and $rows < $count;
1174 $count = 0 if ($count < 0);
1183 =item Arguments: $cond, \%attrs??
1185 =item Return Value: $count_rs
1189 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1190 This can be very handy for subqueries:
1192 ->search( { amount => $some_rs->count_rs->as_query } )
1194 As with regular resultsets the SQL query will be executed only after
1195 the resultset is accessed via L</next> or L</all>. That would return
1196 the same single value obtainable via L</count>.
1202 return $self->search(@_)->count_rs if @_;
1204 # this may look like a lack of abstraction (count() does about the same)
1205 # but in fact an _rs *must* use a subquery for the limits, as the
1206 # software based limiting can not be ported if this $rs is to be used
1207 # in a subquery itself (i.e. ->as_query)
1208 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1209 return $self->_count_subq_rs;
1212 return $self->_count_rs;
1217 # returns a ResultSetColumn object tied to the count query
1220 my ($self, $attrs) = @_;
1222 my $rsrc = $self->result_source;
1223 $attrs ||= $self->_resolved_attrs;
1225 my $tmp_attrs = { %$attrs };
1226 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1227 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1229 # overwrite the selector (supplied by the storage)
1230 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1231 $tmp_attrs->{as} = 'count';
1233 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1239 # same as above but uses a subquery
1241 sub _count_subq_rs {
1242 my ($self, $attrs) = @_;
1244 my $rsrc = $self->result_source;
1245 $attrs ||= $self->_resolved_attrs;
1247 my $sub_attrs = { %$attrs };
1248 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1249 delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
1251 # if we multi-prefetch we group_by primary keys only as this is what we would
1252 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1253 if ( keys %{$attrs->{collapse}} ) {
1254 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1257 # Calculate subquery selector
1258 if (my $g = $sub_attrs->{group_by}) {
1260 my $sql_maker = $rsrc->storage->sql_maker;
1262 # necessary as the group_by may refer to aliased functions
1264 for my $sel (@{$attrs->{select}}) {
1265 $sel_index->{$sel->{-as}} = $sel
1266 if (ref $sel eq 'HASH' and $sel->{-as});
1269 for my $g_part (@$g) {
1270 my $colpiece = $sel_index->{$g_part} || $g_part;
1272 # disqualify join-based group_by's. Arcane but possible query
1273 # also horrible horrible hack to alias a column (not a func.)
1274 # (probably need to introduce SQLA syntax)
1275 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1278 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1280 push @{$sub_attrs->{select}}, $colpiece;
1284 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1285 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1288 return $rsrc->resultset_class
1289 ->new ($rsrc, $sub_attrs)
1291 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1292 ->get_column ('count');
1299 =head2 count_literal
1303 =item Arguments: $sql_fragment, @bind_values
1305 =item Return Value: $count
1309 Counts the results in a literal query. Equivalent to calling L</search_literal>
1310 with the passed arguments, then L</count>.
1314 sub count_literal { shift->search_literal(@_)->count; }
1320 =item Arguments: none
1322 =item Return Value: @objects
1326 Returns all elements in the resultset. Called implicitly if the resultset
1327 is returned in list context.
1334 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1337 return @{ $self->get_cache } if $self->get_cache;
1341 if (keys %{$self->_resolved_attrs->{collapse}}) {
1342 # Using $self->cursor->all is really just an optimisation.
1343 # If we're collapsing has_many prefetches it probably makes
1344 # very little difference, and this is cleaner than hacking
1345 # _construct_object to survive the approach
1346 $self->cursor->reset;
1347 my @row = $self->cursor->next;
1349 push(@obj, $self->_construct_object(@row));
1350 @row = (exists $self->{stashed_row}
1351 ? @{delete $self->{stashed_row}}
1352 : $self->cursor->next);
1355 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1358 $self->set_cache(\@obj) if $self->{attrs}{cache};
1367 =item Arguments: none
1369 =item Return Value: $self
1373 Resets the resultset's cursor, so you can iterate through the elements again.
1374 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1381 delete $self->{_attrs} if exists $self->{_attrs};
1382 $self->{all_cache_position} = 0;
1383 $self->cursor->reset;
1391 =item Arguments: none
1393 =item Return Value: $object | undef
1397 Resets the resultset and returns an object for the first result (or C<undef>
1398 if the resultset is empty).
1403 return $_[0]->reset->next;
1409 # Determines whether and what type of subquery is required for the $rs operation.
1410 # If grouping is necessary either supplies its own, or verifies the current one
1411 # After all is done delegates to the proper storage method.
1413 sub _rs_update_delete {
1414 my ($self, $op, $values) = @_;
1416 my $rsrc = $self->result_source;
1418 # if a condition exists we need to strip all table qualifiers
1419 # if this is not possible we'll force a subquery below
1420 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1422 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1423 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1425 if ($needs_group_by_subq or $needs_subq) {
1427 # make a new $rs selecting only the PKs (that's all we really need)
1428 my $attrs = $self->_resolved_attrs_copy;
1431 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1432 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1434 if ($needs_group_by_subq) {
1435 # make sure no group_by was supplied, or if there is one - make sure it matches
1436 # the columns compiled above perfectly. Anything else can not be sanely executed
1437 # on most databases so croak right then and there
1439 if (my $g = $attrs->{group_by}) {
1440 my @current_group_by = map
1441 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1446 join ("\x00", sort @current_group_by)
1448 join ("\x00", sort @{$attrs->{columns}} )
1450 $self->throw_exception (
1451 "You have just attempted a $op operation on a resultset which does group_by"
1452 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1453 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1454 . ' kind of queries. Please retry the operation with a modified group_by or'
1455 . ' without using one at all.'
1460 $attrs->{group_by} = $attrs->{columns};
1464 my $subrs = (ref $self)->new($rsrc, $attrs);
1465 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1468 return $rsrc->storage->$op(
1470 $op eq 'update' ? $values : (),
1480 =item Arguments: \%values
1482 =item Return Value: $storage_rv
1486 Sets the specified columns in the resultset to the supplied values in a
1487 single query. Note that this will not run any accessor/set_column/update
1488 triggers, nor will it update any row object instances derived from this
1489 resultset (this includes the contents of the L<resultset cache|/set_cache>
1490 if any). See L</update_all> if you need to execute any on-update
1491 triggers or cascades defined either by you or a
1492 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1494 The return value is a pass through of what the underlying
1495 storage backend returned, and may vary. See L<DBI/execute> for the most
1501 my ($self, $values) = @_;
1502 $self->throw_exception('Values for update must be a hash')
1503 unless ref $values eq 'HASH';
1505 return $self->_rs_update_delete ('update', $values);
1512 =item Arguments: \%values
1514 =item Return Value: 1
1518 Fetches all objects and updates them one at a time via
1519 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1520 triggers, while L</update> will not.
1525 my ($self, $values) = @_;
1526 $self->throw_exception('Values for update_all must be a hash')
1527 unless ref $values eq 'HASH';
1529 my $guard = $self->result_source->schema->txn_scope_guard;
1530 $_->update($values) for $self->all;
1539 =item Arguments: none
1541 =item Return Value: $storage_rv
1545 Deletes the rows matching this resultset in a single query. Note that this
1546 will not run any delete triggers, nor will it alter the
1547 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1548 derived from this resultset (this includes the contents of the
1549 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1550 execute any on-delete triggers or cascades defined either by you or a
1551 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1553 The return value is a pass through of what the underlying storage backend
1554 returned, and may vary. See L<DBI/execute> for the most common case.
1560 $self->throw_exception('delete does not accept any arguments')
1563 return $self->_rs_update_delete ('delete');
1570 =item Arguments: none
1572 =item Return Value: 1
1576 Fetches all objects and deletes them one at a time via
1577 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1578 triggers, while L</delete> will not.
1584 $self->throw_exception('delete_all does not accept any arguments')
1587 my $guard = $self->result_source->schema->txn_scope_guard;
1588 $_->delete for $self->all;
1597 =item Arguments: \@data;
1601 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1602 For the arrayref of hashrefs style each hashref should be a structure suitable
1603 forsubmitting to a $resultset->create(...) method.
1605 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1606 to insert the data, as this is a faster method.
1608 Otherwise, each set of data is inserted into the database using
1609 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1610 accumulated into an array. The array itself, or an array reference
1611 is returned depending on scalar or list context.
1613 Example: Assuming an Artist Class that has many CDs Classes relating:
1615 my $Artist_rs = $schema->resultset("Artist");
1617 ## Void Context Example
1618 $Artist_rs->populate([
1619 { artistid => 4, name => 'Manufactured Crap', cds => [
1620 { title => 'My First CD', year => 2006 },
1621 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1624 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1625 { title => 'My parents sold me to a record company', year => 2005 },
1626 { title => 'Why Am I So Ugly?', year => 2006 },
1627 { title => 'I Got Surgery and am now Popular', year => 2007 }
1632 ## Array Context Example
1633 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1634 { name => "Artist One"},
1635 { name => "Artist Two"},
1636 { name => "Artist Three", cds=> [
1637 { title => "First CD", year => 2007},
1638 { title => "Second CD", year => 2008},
1642 print $ArtistOne->name; ## response is 'Artist One'
1643 print $ArtistThree->cds->count ## reponse is '2'
1645 For the arrayref of arrayrefs style, the first element should be a list of the
1646 fieldsnames to which the remaining elements are rows being inserted. For
1649 $Arstist_rs->populate([
1650 [qw/artistid name/],
1651 [100, 'A Formally Unknown Singer'],
1652 [101, 'A singer that jumped the shark two albums ago'],
1653 [102, 'An actually cool singer'],
1656 Please note an important effect on your data when choosing between void and
1657 wantarray context. Since void context goes straight to C<insert_bulk> in
1658 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1659 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1660 create primary keys for you, you will find that your PKs are empty. In this
1661 case you will have to use the wantarray context in order to create those
1669 # cruft placed in standalone method
1670 my $data = $self->_normalize_populate_args(@_);
1672 if(defined wantarray) {
1674 foreach my $item (@$data) {
1675 push(@created, $self->create($item));
1677 return wantarray ? @created : \@created;
1679 my $first = $data->[0];
1681 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1682 # it relationship data
1683 my (@rels, @columns);
1684 for (keys %$first) {
1685 my $ref = ref $first->{$_};
1686 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1692 my @pks = $self->result_source->primary_columns;
1694 ## do the belongs_to relationships
1695 foreach my $index (0..$#$data) {
1697 # delegate to create() for any dataset without primary keys with specified relationships
1698 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1700 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1701 my @ret = $self->populate($data);
1707 foreach my $rel (@rels) {
1708 next unless ref $data->[$index]->{$rel} eq "HASH";
1709 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1710 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1711 my $related = $result->result_source->_resolve_condition(
1712 $result->result_source->relationship_info($reverse)->{cond},
1717 delete $data->[$index]->{$rel};
1718 $data->[$index] = {%{$data->[$index]}, %$related};
1720 push @columns, keys %$related if $index == 0;
1724 ## inherit the data locked in the conditions of the resultset
1725 my ($rs_data) = $self->_merge_with_rscond({});
1726 delete @{$rs_data}{@columns};
1727 my @inherit_cols = keys %$rs_data;
1728 my @inherit_data = values %$rs_data;
1730 ## do bulk insert on current row
1731 $self->result_source->storage->insert_bulk(
1732 $self->result_source,
1733 [@columns, @inherit_cols],
1734 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1737 ## do the has_many relationships
1738 foreach my $item (@$data) {
1740 foreach my $rel (@rels) {
1741 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1743 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1744 || $self->throw_exception('Cannot find the relating object.');
1746 my $child = $parent->$rel;
1748 my $related = $child->result_source->_resolve_condition(
1749 $parent->result_source->relationship_info($rel)->{cond},
1754 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1755 my @populate = map { {%$_, %$related} } @rows_to_add;
1757 $child->populate( \@populate );
1764 # populate() argumnets went over several incarnations
1765 # What we ultimately support is AoH
1766 sub _normalize_populate_args {
1767 my ($self, $arg) = @_;
1769 if (ref $arg eq 'ARRAY') {
1770 if (ref $arg->[0] eq 'HASH') {
1773 elsif (ref $arg->[0] eq 'ARRAY') {
1775 my @colnames = @{$arg->[0]};
1776 foreach my $values (@{$arg}[1 .. $#$arg]) {
1777 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1783 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1790 =item Arguments: none
1792 =item Return Value: $pager
1796 Return Value a L<Data::Page> object for the current resultset. Only makes
1797 sense for queries with a C<page> attribute.
1799 To get the full count of entries for a paged resultset, call
1800 C<total_entries> on the L<Data::Page> object.
1804 # make a wizard good for both a scalar and a hashref
1805 my $mk_lazy_count_wizard = sub {
1806 require Variable::Magic;
1808 my $stash = { total_rs => shift };
1809 my $slot = shift; # only used by the hashref magic
1811 my $magic = Variable::Magic::wizard (
1812 data => sub { $stash },
1818 # set value lazily, and dispell for good
1819 ${$_[0]} = $_[1]{total_rs}->count;
1820 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
1824 # an explicit set implies dispell as well
1825 # the unless() is to work around "fun and giggles" below
1826 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
1827 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1834 if ($_[2] eq $slot and !$_[1]{inactive}) {
1835 my $cnt = $_[1]{total_rs}->count;
1836 $_[0]->{$slot} = $cnt;
1838 # attempting to dispell in a fetch handle (works in store), seems
1839 # to invariable segfault on 5.10, 5.12, 5.13 :(
1840 # so use an inactivator instead
1841 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1847 if (! $_[1]{inactive} and $_[2] eq $slot) {
1848 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1850 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1857 $stash->{magic_selfref} = $magic;
1858 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
1863 # the tie class for 5.8.1
1865 package DBIx::Class::__DBIC_LAZY_RS_COUNT__;
1866 use base qw/Tie::Hash/;
1868 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
1869 sub NEXTKEY { each %{$_[0]{data}} }
1870 sub EXISTS { exists $_[0]{data}{$_[1]} }
1871 sub DELETE { delete $_[0]{data}{$_[1]} }
1872 sub CLEAR { %{$_[0]{data}} = () }
1873 sub SCALAR { scalar %{$_[0]{data}} }
1876 $_[1]{data} = {%{$_[1]{selfref}}};
1877 %{$_[1]{selfref}} = ();
1878 Scalar::Util::weaken ($_[1]{selfref});
1879 return bless ($_[1], $_[0]);
1883 if ($_[1] eq $_[0]{slot}) {
1884 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
1885 untie %{$_[0]{selfref}};
1886 %{$_[0]{selfref}} = %{$_[0]{data}};
1895 $_[0]{data}{$_[1]} = $_[2];
1896 if ($_[1] eq $_[0]{slot}) {
1897 untie %{$_[0]{selfref}};
1898 %{$_[0]{selfref}} = %{$_[0]{data}};
1907 return $self->{pager} if $self->{pager};
1909 if ($self->get_cache) {
1910 $self->throw_exception ('Pagers on cached resultsets are not supported');
1913 my $attrs = $self->{attrs};
1914 $self->throw_exception("Can't create pager for non-paged rs")
1915 unless $self->{attrs}{page};
1916 $attrs->{rows} ||= 10;
1918 # throw away the paging flags and re-run the count (possibly
1919 # with a subselect) to get the real total count
1920 my $count_attrs = { %$attrs };
1921 delete $count_attrs->{$_} for qw/rows offset page pager/;
1922 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
1925 ### the following may seem awkward and dirty, but it's a thought-experiment
1926 ### necessary for future development of DBIx::DS. Do *NOT* change this code
1927 ### before talking to ribasushi/mst
1929 my $pager = Data::Page->new(
1930 0, #start with an empty set
1932 $self->{attrs}{page},
1935 my $data_slot = 'total_entries';
1937 # Since we are interested in a cached value (once it's set - it's set), every
1938 # technique will detach from the magic-host once the time comes to fire the
1939 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
1941 if ($] < 5.008003) {
1942 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
1943 # to weakref the magic container :(
1945 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
1946 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
1949 elsif ($] < 5.010) {
1950 # We can use magic on the hash value slot. It's interesting that the magic is
1951 # attached to the hash-slot, and does *not* stop working once I do the dummy
1952 # assignments after the cast()
1953 # tested on 5.8.3 and 5.8.9
1954 my $magic = $mk_lazy_count_wizard->($total_rs);
1955 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
1957 # this is for fun and giggles
1958 $pager->{$data_slot} = -1;
1959 $pager->{$data_slot} = 0;
1961 # this does not work for scalars, but works with
1963 #my %vals = %$pager;
1968 # And the uvar magic
1969 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
1970 # however see the wizard maker for more notes
1971 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
1972 Variable::Magic::cast ( %$pager, $magic );
1975 $pager->{$data_slot} = -1;
1976 $pager->{$data_slot} = 0;
1984 return $self->{pager} = $pager;
1991 =item Arguments: $page_number
1993 =item Return Value: $rs
1997 Returns a resultset for the $page_number page of the resultset on which page
1998 is called, where each page contains a number of rows equal to the 'rows'
1999 attribute set on the resultset (10 by default).
2004 my ($self, $page) = @_;
2005 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2012 =item Arguments: \%vals
2014 =item Return Value: $rowobject
2018 Creates a new row object in the resultset's result class and returns
2019 it. The row is not inserted into the database at this point, call
2020 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2021 will tell you whether the row object has been inserted or not.
2023 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2028 my ($self, $values) = @_;
2029 $self->throw_exception( "new_result needs a hash" )
2030 unless (ref $values eq 'HASH');
2032 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2036 @$cols_from_relations
2037 ? (-cols_from_relations => $cols_from_relations)
2039 -source_handle => $self->_source_handle,
2040 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2043 return $self->result_class->new(\%new);
2046 # _merge_with_rscond
2048 # Takes a simple hash of K/V data and returns its copy merged with the
2049 # condition already present on the resultset. Additionally returns an
2050 # arrayref of value/condition names, which were inferred from related
2051 # objects (this is needed for in-memory related objects)
2052 sub _merge_with_rscond {
2053 my ($self, $data) = @_;
2055 my (%new_data, @cols_from_relations);
2057 my $alias = $self->{attrs}{alias};
2059 if (! defined $self->{cond}) {
2060 # just massage $data below
2062 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2063 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2064 @cols_from_relations = keys %new_data;
2066 elsif (ref $self->{cond} ne 'HASH') {
2067 $self->throw_exception(
2068 "Can't abstract implicit construct, resultset condition not a hash"
2072 # precendence must be given to passed values over values inherited from
2073 # the cond, so the order here is important.
2074 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2075 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2077 while ( my($col, $value) = each %implied ) {
2078 my $vref = ref $value;
2079 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2080 $new_data{$col} = $value->{'='};
2082 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2083 $new_data{$col} = $value;
2090 %{ $self->_remove_alias($data, $alias) },
2093 return (\%new_data, \@cols_from_relations);
2096 # _has_resolved_attr
2098 # determines if the resultset defines at least one
2099 # of the attributes supplied
2101 # used to determine if a subquery is neccessary
2103 # supports some virtual attributes:
2105 # This will scan for any joins being present on the resultset.
2106 # It is not a mere key-search but a deep inspection of {from}
2109 sub _has_resolved_attr {
2110 my ($self, @attr_names) = @_;
2112 my $attrs = $self->_resolved_attrs;
2116 for my $n (@attr_names) {
2117 if (grep { $n eq $_ } (qw/-join/) ) {
2118 $extra_checks{$n}++;
2122 my $attr = $attrs->{$n};
2124 next if not defined $attr;
2126 if (ref $attr eq 'HASH') {
2127 return 1 if keys %$attr;
2129 elsif (ref $attr eq 'ARRAY') {
2137 # a resolved join is expressed as a multi-level from
2139 $extra_checks{-join}
2141 ref $attrs->{from} eq 'ARRAY'
2143 @{$attrs->{from}} > 1
2151 # Recursively collapse the condition.
2153 sub _collapse_cond {
2154 my ($self, $cond, $collapsed) = @_;
2158 if (ref $cond eq 'ARRAY') {
2159 foreach my $subcond (@$cond) {
2160 next unless ref $subcond; # -or
2161 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2164 elsif (ref $cond eq 'HASH') {
2165 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2166 foreach my $subcond (@{$cond->{-and}}) {
2167 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2171 foreach my $col (keys %$cond) {
2172 my $value = $cond->{$col};
2173 $collapsed->{$col} = $value;
2183 # Remove the specified alias from the specified query hash. A copy is made so
2184 # the original query is not modified.
2187 my ($self, $query, $alias) = @_;
2189 my %orig = %{ $query || {} };
2192 foreach my $key (keys %orig) {
2194 $unaliased{$key} = $orig{$key};
2197 $unaliased{$1} = $orig{$key}
2198 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2208 =item Arguments: none
2210 =item Return Value: \[ $sql, @bind ]
2214 Returns the SQL query and bind vars associated with the invocant.
2216 This is generally used as the RHS for a subquery.
2223 my $attrs = $self->_resolved_attrs_copy;
2228 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2229 # $sql also has no wrapping parenthesis in list ctx
2231 my $sqlbind = $self->result_source->storage
2232 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2241 =item Arguments: \%vals, \%attrs?
2243 =item Return Value: $rowobject
2247 my $artist = $schema->resultset('Artist')->find_or_new(
2248 { artist => 'fred' }, { key => 'artists' });
2250 $cd->cd_to_producer->find_or_new({ producer => $producer },
2251 { key => 'primary });
2253 Find an existing record from this resultset using L</find>. if none exists,
2254 instantiate a new result object and return it. The object will not be saved
2255 into your storage until you call L<DBIx::Class::Row/insert> on it.
2257 You most likely want this method when looking for existing rows using a unique
2258 constraint that is not the primary key, or looking for related rows.
2260 If you want objects to be saved immediately, use L</find_or_create> instead.
2262 B<Note>: Make sure to read the documentation of L</find> and understand the
2263 significance of the C<key> attribute, as its lack may skew your search, and
2264 subsequently result in spurious new objects.
2266 B<Note>: Take care when using C<find_or_new> with a table having
2267 columns with default values that you intend to be automatically
2268 supplied by the database (e.g. an auto_increment primary key column).
2269 In normal usage, the value of such columns should NOT be included at
2270 all in the call to C<find_or_new>, even when set to C<undef>.
2276 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2277 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2278 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2281 return $self->new_result($hash);
2288 =item Arguments: \%vals
2290 =item Return Value: a L<DBIx::Class::Row> $object
2294 Attempt to create a single new row or a row with multiple related rows
2295 in the table represented by the resultset (and related tables). This
2296 will not check for duplicate rows before inserting, use
2297 L</find_or_create> to do that.
2299 To create one row for this resultset, pass a hashref of key/value
2300 pairs representing the columns of the table and the values you wish to
2301 store. If the appropriate relationships are set up, foreign key fields
2302 can also be passed an object representing the foreign row, and the
2303 value will be set to its primary key.
2305 To create related objects, pass a hashref of related-object column values
2306 B<keyed on the relationship name>. If the relationship is of type C<multi>
2307 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2308 The process will correctly identify columns holding foreign keys, and will
2309 transparently populate them from the keys of the corresponding relation.
2310 This can be applied recursively, and will work correctly for a structure
2311 with an arbitrary depth and width, as long as the relationships actually
2312 exists and the correct column data has been supplied.
2315 Instead of hashrefs of plain related data (key/value pairs), you may
2316 also pass new or inserted objects. New objects (not inserted yet, see
2317 L</new>), will be inserted into their appropriate tables.
2319 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2321 Example of creating a new row.
2323 $person_rs->create({
2324 name=>"Some Person",
2325 email=>"somebody@someplace.com"
2328 Example of creating a new row and also creating rows in a related C<has_many>
2329 or C<has_one> resultset. Note Arrayref.
2332 { artistid => 4, name => 'Manufactured Crap', cds => [
2333 { title => 'My First CD', year => 2006 },
2334 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2339 Example of creating a new row and also creating a row in a related
2340 C<belongs_to> resultset. Note Hashref.
2343 title=>"Music for Silly Walks",
2346 name=>"Silly Musician",
2354 When subclassing ResultSet never attempt to override this method. Since
2355 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2356 lot of the internals simply never call it, so your override will be
2357 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2358 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2359 L</create> process you need to intervene.
2366 my ($self, $attrs) = @_;
2367 $self->throw_exception( "create needs a hashref" )
2368 unless ref $attrs eq 'HASH';
2369 return $self->new_result($attrs)->insert;
2372 =head2 find_or_create
2376 =item Arguments: \%vals, \%attrs?
2378 =item Return Value: $rowobject
2382 $cd->cd_to_producer->find_or_create({ producer => $producer },
2383 { key => 'primary' });
2385 Tries to find a record based on its primary key or unique constraints; if none
2386 is found, creates one and returns that instead.
2388 my $cd = $schema->resultset('CD')->find_or_create({
2390 artist => 'Massive Attack',
2391 title => 'Mezzanine',
2395 Also takes an optional C<key> attribute, to search by a specific key or unique
2396 constraint. For example:
2398 my $cd = $schema->resultset('CD')->find_or_create(
2400 artist => 'Massive Attack',
2401 title => 'Mezzanine',
2403 { key => 'cd_artist_title' }
2406 B<Note>: Make sure to read the documentation of L</find> and understand the
2407 significance of the C<key> attribute, as its lack may skew your search, and
2408 subsequently result in spurious row creation.
2410 B<Note>: Because find_or_create() reads from the database and then
2411 possibly inserts based on the result, this method is subject to a race
2412 condition. Another process could create a record in the table after
2413 the find has completed and before the create has started. To avoid
2414 this problem, use find_or_create() inside a transaction.
2416 B<Note>: Take care when using C<find_or_create> with a table having
2417 columns with default values that you intend to be automatically
2418 supplied by the database (e.g. an auto_increment primary key column).
2419 In normal usage, the value of such columns should NOT be included at
2420 all in the call to C<find_or_create>, even when set to C<undef>.
2422 See also L</find> and L</update_or_create>. For information on how to declare
2423 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2427 sub find_or_create {
2429 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2430 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2431 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2434 return $self->create($hash);
2437 =head2 update_or_create
2441 =item Arguments: \%col_values, { key => $unique_constraint }?
2443 =item Return Value: $row_object
2447 $resultset->update_or_create({ col => $val, ... });
2449 Like L</find_or_create>, but if a row is found it is immediately updated via
2450 C<< $found_row->update (\%col_values) >>.
2453 Takes an optional C<key> attribute to search on a specific unique constraint.
2456 # In your application
2457 my $cd = $schema->resultset('CD')->update_or_create(
2459 artist => 'Massive Attack',
2460 title => 'Mezzanine',
2463 { key => 'cd_artist_title' }
2466 $cd->cd_to_producer->update_or_create({
2467 producer => $producer,
2473 B<Note>: Make sure to read the documentation of L</find> and understand the
2474 significance of the C<key> attribute, as its lack may skew your search, and
2475 subsequently result in spurious row creation.
2477 B<Note>: Take care when using C<update_or_create> with a table having
2478 columns with default values that you intend to be automatically
2479 supplied by the database (e.g. an auto_increment primary key column).
2480 In normal usage, the value of such columns should NOT be included at
2481 all in the call to C<update_or_create>, even when set to C<undef>.
2483 See also L</find> and L</find_or_create>. For information on how to declare
2484 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2488 sub update_or_create {
2490 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2491 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2493 my $row = $self->find($cond, $attrs);
2495 $row->update($cond);
2499 return $self->create($cond);
2502 =head2 update_or_new
2506 =item Arguments: \%col_values, { key => $unique_constraint }?
2508 =item Return Value: $rowobject
2512 $resultset->update_or_new({ col => $val, ... });
2514 Like L</find_or_new> but if a row is found it is immediately updated via
2515 C<< $found_row->update (\%col_values) >>.
2519 # In your application
2520 my $cd = $schema->resultset('CD')->update_or_new(
2522 artist => 'Massive Attack',
2523 title => 'Mezzanine',
2526 { key => 'cd_artist_title' }
2529 if ($cd->in_storage) {
2530 # the cd was updated
2533 # the cd is not yet in the database, let's insert it
2537 B<Note>: Make sure to read the documentation of L</find> and understand the
2538 significance of the C<key> attribute, as its lack may skew your search, and
2539 subsequently result in spurious new objects.
2541 B<Note>: Take care when using C<update_or_new> with a table having
2542 columns with default values that you intend to be automatically
2543 supplied by the database (e.g. an auto_increment primary key column).
2544 In normal usage, the value of such columns should NOT be included at
2545 all in the call to C<update_or_new>, even when set to C<undef>.
2547 See also L</find>, L</find_or_create> and L</find_or_new>.
2553 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2554 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2556 my $row = $self->find( $cond, $attrs );
2557 if ( defined $row ) {
2558 $row->update($cond);
2562 return $self->new_result($cond);
2569 =item Arguments: none
2571 =item Return Value: \@cache_objects | undef
2575 Gets the contents of the cache for the resultset, if the cache is set.
2577 The cache is populated either by using the L</prefetch> attribute to
2578 L</search> or by calling L</set_cache>.
2590 =item Arguments: \@cache_objects
2592 =item Return Value: \@cache_objects
2596 Sets the contents of the cache for the resultset. Expects an arrayref
2597 of objects of the same class as those produced by the resultset. Note that
2598 if the cache is set the resultset will return the cached objects rather
2599 than re-querying the database even if the cache attr is not set.
2601 The contents of the cache can also be populated by using the
2602 L</prefetch> attribute to L</search>.
2607 my ( $self, $data ) = @_;
2608 $self->throw_exception("set_cache requires an arrayref")
2609 if defined($data) && (ref $data ne 'ARRAY');
2610 $self->{all_cache} = $data;
2617 =item Arguments: none
2619 =item Return Value: undef
2623 Clears the cache for the resultset.
2628 shift->set_cache(undef);
2635 =item Arguments: none
2637 =item Return Value: true, if the resultset has been paginated
2645 return !!$self->{attrs}{page};
2652 =item Arguments: none
2654 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2662 return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
2665 =head2 related_resultset
2669 =item Arguments: $relationship_name
2671 =item Return Value: $resultset
2675 Returns a related resultset for the supplied relationship name.
2677 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2681 sub related_resultset {
2682 my ($self, $rel) = @_;
2684 $self->{related_resultsets} ||= {};
2685 return $self->{related_resultsets}{$rel} ||= do {
2686 my $rsrc = $self->result_source;
2687 my $rel_info = $rsrc->relationship_info($rel);
2689 $self->throw_exception(
2690 "search_related: result source '" . $rsrc->source_name .
2691 "' has no such relationship $rel")
2694 my $attrs = $self->_chain_relationship($rel);
2696 my $join_count = $attrs->{seen_join}{$rel};
2698 my $alias = $self->result_source->storage
2699 ->relname_to_table_alias($rel, $join_count);
2701 # since this is search_related, and we already slid the select window inwards
2702 # (the select/as attrs were deleted in the beginning), we need to flip all
2703 # left joins to inner, so we get the expected results
2704 # read the comment on top of the actual function to see what this does
2705 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2708 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2709 delete @{$attrs}{qw(result_class alias)};
2713 if (my $cache = $self->get_cache) {
2714 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2715 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2720 my $rel_source = $rsrc->related_source($rel);
2724 # The reason we do this now instead of passing the alias to the
2725 # search_rs below is that if you wrap/overload resultset on the
2726 # source you need to know what alias it's -going- to have for things
2727 # to work sanely (e.g. RestrictWithObject wants to be able to add
2728 # extra query restrictions, and these may need to be $alias.)
2730 my $rel_attrs = $rel_source->resultset_attributes;
2731 local $rel_attrs->{alias} = $alias;
2733 $rel_source->resultset
2737 where => $attrs->{where},
2740 $new->set_cache($new_cache) if $new_cache;
2745 =head2 current_source_alias
2749 =item Arguments: none
2751 =item Return Value: $source_alias
2755 Returns the current table alias for the result source this resultset is built
2756 on, that will be used in the SQL query. Usually it is C<me>.
2758 Currently the source alias that refers to the result set returned by a
2759 L</search>/L</find> family method depends on how you got to the resultset: it's
2760 C<me> by default, but eg. L</search_related> aliases it to the related result
2761 source name (and keeps C<me> referring to the original result set). The long
2762 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2763 (and make this method unnecessary).
2765 Thus it's currently necessary to use this method in predefined queries (see
2766 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2767 source alias of the current result set:
2769 # in a result set class
2771 my ($self, $user) = @_;
2773 my $me = $self->current_source_alias;
2775 return $self->search(
2776 "$me.modified" => $user->id,
2782 sub current_source_alias {
2785 return ($self->{attrs} || {})->{alias} || 'me';
2788 =head2 as_subselect_rs
2792 =item Arguments: none
2794 =item Return Value: $resultset
2798 Act as a barrier to SQL symbols. The resultset provided will be made into a
2799 "virtual view" by including it as a subquery within the from clause. From this
2800 point on, any joined tables are inaccessible to ->search on the resultset (as if
2801 it were simply where-filtered without joins). For example:
2803 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2805 # 'x' now pollutes the query namespace
2807 # So the following works as expected
2808 my $ok_rs = $rs->search({'x.other' => 1});
2810 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2811 # def) we look for one row with contradictory terms and join in another table
2812 # (aliased 'x_2') which we never use
2813 my $broken_rs = $rs->search({'x.name' => 'def'});
2815 my $rs2 = $rs->as_subselect_rs;
2817 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2818 my $not_joined_rs = $rs2->search({'x.other' => 1});
2820 # works as expected: finds a 'table' row related to two x rows (abc and def)
2821 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2823 Another example of when one might use this would be to select a subset of
2824 columns in a group by clause:
2826 my $rs = $schema->resultset('Bar')->search(undef, {
2827 group_by => [qw{ id foo_id baz_id }],
2828 })->as_subselect_rs->search(undef, {
2829 columns => [qw{ id foo_id }]
2832 In the above example normally columns would have to be equal to the group by,
2833 but because we isolated the group by into a subselect the above works.
2837 sub as_subselect_rs {
2840 my $attrs = $self->_resolved_attrs;
2842 my $fresh_rs = (ref $self)->new (
2843 $self->result_source
2846 # these pieces will be locked in the subquery
2847 delete $fresh_rs->{cond};
2848 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2850 return $fresh_rs->search( {}, {
2852 $attrs->{alias} => $self->as_query,
2853 -alias => $attrs->{alias},
2854 -source_handle => $self->result_source->handle,
2856 alias => $attrs->{alias},
2860 # This code is called by search_related, and makes sure there
2861 # is clear separation between the joins before, during, and
2862 # after the relationship. This information is needed later
2863 # in order to properly resolve prefetch aliases (any alias
2864 # with a relation_chain_depth less than the depth of the
2865 # current prefetch is not considered)
2867 # The increments happen twice per join. An even number means a
2868 # relationship specified via a search_related, whereas an odd
2869 # number indicates a join/prefetch added via attributes
2871 # Also this code will wrap the current resultset (the one we
2872 # chain to) in a subselect IFF it contains limiting attributes
2873 sub _chain_relationship {
2874 my ($self, $rel) = @_;
2875 my $source = $self->result_source;
2876 my $attrs = { %{$self->{attrs}||{}} };
2878 # we need to take the prefetch the attrs into account before we
2879 # ->_resolve_join as otherwise they get lost - captainL
2880 my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2882 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2884 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2887 my @force_subq_attrs = qw/offset rows group_by having/;
2890 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2892 $self->_has_resolved_attr (@force_subq_attrs)
2894 # Nuke the prefetch (if any) before the new $rs attrs
2895 # are resolved (prefetch is useless - we are wrapping
2896 # a subquery anyway).
2897 my $rs_copy = $self->search;
2898 $rs_copy->{attrs}{join} = $self->_merge_attr (
2899 $rs_copy->{attrs}{join},
2900 delete $rs_copy->{attrs}{prefetch},
2904 -source_handle => $source->handle,
2905 -alias => $attrs->{alias},
2906 $attrs->{alias} => $rs_copy->as_query,
2908 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2909 $seen->{-relation_chain_depth} = 0;
2911 elsif ($attrs->{from}) { #shallow copy suffices
2912 $from = [ @{$attrs->{from}} ];
2916 -source_handle => $source->handle,
2917 -alias => $attrs->{alias},
2918 $attrs->{alias} => $source->from,
2922 my $jpath = ($seen->{-relation_chain_depth})
2923 ? $from->[-1][0]{-join_path}
2926 my @requested_joins = $source->_resolve_join(
2933 push @$from, @requested_joins;
2935 $seen->{-relation_chain_depth}++;
2937 # if $self already had a join/prefetch specified on it, the requested
2938 # $rel might very well be already included. What we do in this case
2939 # is effectively a no-op (except that we bump up the chain_depth on
2940 # the join in question so we could tell it *is* the search_related)
2943 # we consider the last one thus reverse
2944 for my $j (reverse @requested_joins) {
2945 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2946 if ($rel eq $last_j) {
2947 $j->[0]{-relation_chain_depth}++;
2953 unless ($already_joined) {
2954 push @$from, $source->_resolve_join(
2962 $seen->{-relation_chain_depth}++;
2964 return {%$attrs, from => $from, seen_join => $seen};
2967 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2968 sub _resolved_attrs_copy {
2970 return { %{$self->_resolved_attrs (@_)} };
2973 sub _resolved_attrs {
2975 return $self->{_attrs} if $self->{_attrs};
2977 my $attrs = { %{ $self->{attrs} || {} } };
2978 my $source = $self->result_source;
2979 my $alias = $attrs->{alias};
2981 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2984 # build columns (as long as select isn't set) into a set of as/select hashes
2985 unless ( $attrs->{select} ) {
2988 if ( ref $attrs->{columns} eq 'ARRAY' ) {
2989 @cols = @{ delete $attrs->{columns}}
2990 } elsif ( defined $attrs->{columns} ) {
2991 @cols = delete $attrs->{columns}
2993 @cols = $source->columns
2997 if ( ref $_ eq 'HASH' ) {
3000 my $key = /^\Q${alias}.\E(.+)$/
3006 push @colbits, { $key => $value };
3011 # add the additional columns on
3012 foreach (qw{include_columns +columns}) {
3013 if ( $attrs->{$_} ) {
3014 my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
3015 ? @{ delete $attrs->{$_} }
3016 : delete $attrs->{$_};
3018 if ( ref($_) eq 'HASH' ) {
3021 my $key = ( split /\./, $_ )[-1];
3022 my $value = ( /\./ ? $_ : "$alias.$_" );
3023 push @colbits, { $key => $value };
3029 # start with initial select items
3030 if ( $attrs->{select} ) {
3032 ( ref $attrs->{select} eq 'ARRAY' )
3033 ? [ @{ $attrs->{select} } ]
3034 : [ $attrs->{select} ];
3036 if ( $attrs->{as} ) {
3039 ref $attrs->{as} eq 'ARRAY'
3040 ? [ @{ $attrs->{as} } ]
3044 $attrs->{as} = [ map {
3045 m/^\Q${alias}.\E(.+)$/
3048 } @{ $attrs->{select} }
3054 # otherwise we intialise select & as to empty
3055 $attrs->{select} = [];
3059 # now add colbits to select/as
3060 push @{ $attrs->{select} }, map values %{$_}, @colbits;
3061 push @{ $attrs->{as} }, map keys %{$_}, @colbits;
3063 if ( my $adds = delete $attrs->{'+select'} ) {
3064 $adds = [$adds] unless ref $adds eq 'ARRAY';
3065 push @{ $attrs->{select} },
3066 map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
3068 if ( my $adds = delete $attrs->{'+as'} ) {
3069 $adds = [$adds] unless ref $adds eq 'ARRAY';
3070 push @{ $attrs->{as} }, @$adds;
3073 $attrs->{from} ||= [{
3074 -source_handle => $source->handle,
3075 -alias => $self->{attrs}{alias},
3076 $self->{attrs}{alias} => $source->from,
3079 if ( $attrs->{join} || $attrs->{prefetch} ) {
3081 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3082 if ref $attrs->{from} ne 'ARRAY';
3084 my $join = delete $attrs->{join} || {};
3086 if ( defined $attrs->{prefetch} ) {
3087 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
3090 $attrs->{from} = # have to copy here to avoid corrupting the original
3092 @{ $attrs->{from} },
3093 $source->_resolve_join(
3096 { %{ $attrs->{seen_join} || {} } },
3097 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3098 ? $attrs->{from}[-1][0]{-join_path}
3105 if ( defined $attrs->{order_by} ) {
3106 $attrs->{order_by} = (
3107 ref( $attrs->{order_by} ) eq 'ARRAY'
3108 ? [ @{ $attrs->{order_by} } ]
3109 : [ $attrs->{order_by} || () ]
3113 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3114 $attrs->{group_by} = [ $attrs->{group_by} ];
3117 # generate the distinct induced group_by early, as prefetch will be carried via a
3118 # subquery (since a group_by is present)
3119 if (delete $attrs->{distinct}) {
3120 if ($attrs->{group_by}) {
3121 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3124 $attrs->{group_by} = $source->storage->_group_over_selection (
3125 @{$attrs}{qw/from select order_by/}
3130 $attrs->{collapse} ||= {};
3131 if ( my $prefetch = delete $attrs->{prefetch} ) {
3132 $prefetch = $self->_merge_attr( {}, $prefetch );
3134 my $prefetch_ordering = [];
3136 # this is a separate structure (we don't look in {from} directly)
3137 # as the resolver needs to shift things off the lists to work
3138 # properly (identical-prefetches on different branches)
3140 if (ref $attrs->{from} eq 'ARRAY') {
3142 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3144 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3145 next unless $j->[0]{-alias};
3146 next unless $j->[0]{-join_path};
3147 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3149 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3152 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3153 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3158 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3160 # we need to somehow mark which columns came from prefetch
3161 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3163 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3164 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3166 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3167 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3170 # if both page and offset are specified, produce a combined offset
3171 # even though it doesn't make much sense, this is what pre 081xx has
3173 if (my $page = delete $attrs->{page}) {
3175 ($attrs->{rows} * ($page - 1))
3177 ($attrs->{offset} || 0)
3181 return $self->{_attrs} = $attrs;
3185 my ($self, $attr) = @_;
3187 if (ref $attr eq 'HASH') {
3188 return $self->_rollout_hash($attr);
3189 } elsif (ref $attr eq 'ARRAY') {
3190 return $self->_rollout_array($attr);
3196 sub _rollout_array {
3197 my ($self, $attr) = @_;
3200 foreach my $element (@{$attr}) {
3201 if (ref $element eq 'HASH') {
3202 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3203 } elsif (ref $element eq 'ARRAY') {
3204 # XXX - should probably recurse here
3205 push( @rolled_array, @{$self->_rollout_array($element)} );
3207 push( @rolled_array, $element );
3210 return \@rolled_array;
3214 my ($self, $attr) = @_;
3217 foreach my $key (keys %{$attr}) {
3218 push( @rolled_array, { $key => $attr->{$key} } );
3220 return \@rolled_array;
3223 sub _calculate_score {
3224 my ($self, $a, $b) = @_;
3226 if (defined $a xor defined $b) {
3229 elsif (not defined $a) {
3233 if (ref $b eq 'HASH') {
3234 my ($b_key) = keys %{$b};
3235 if (ref $a eq 'HASH') {
3236 my ($a_key) = keys %{$a};
3237 if ($a_key eq $b_key) {
3238 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3243 return ($a eq $b_key) ? 1 : 0;
3246 if (ref $a eq 'HASH') {
3247 my ($a_key) = keys %{$a};
3248 return ($b eq $a_key) ? 1 : 0;
3250 return ($b eq $a) ? 1 : 0;
3256 my ($self, $orig, $import) = @_;
3258 return $import unless defined($orig);
3259 return $orig unless defined($import);
3261 $orig = $self->_rollout_attr($orig);
3262 $import = $self->_rollout_attr($import);
3265 foreach my $import_element ( @{$import} ) {
3266 # find best candidate from $orig to merge $b_element into
3267 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3268 foreach my $orig_element ( @{$orig} ) {
3269 my $score = $self->_calculate_score( $orig_element, $import_element );
3270 if ($score > $best_candidate->{score}) {
3271 $best_candidate->{position} = $position;
3272 $best_candidate->{score} = $score;
3276 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3278 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3279 push( @{$orig}, $import_element );
3281 my $orig_best = $orig->[$best_candidate->{position}];
3282 # merge orig_best and b_element together and replace original with merged
3283 if (ref $orig_best ne 'HASH') {
3284 $orig->[$best_candidate->{position}] = $import_element;
3285 } elsif (ref $import_element eq 'HASH') {
3286 my ($key) = keys %{$orig_best};
3287 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
3290 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3300 $self->_source_handle($_[0]->handle);
3302 $self->_source_handle->resolve;
3306 =head2 throw_exception
3308 See L<DBIx::Class::Schema/throw_exception> for details.
3312 sub throw_exception {
3315 if (ref $self && $self->_source_handle->schema) {
3316 $self->_source_handle->schema->throw_exception(@_)
3319 DBIx::Class::Exception->throw(@_);
3323 # XXX: FIXME: Attributes docs need clearing up
3327 Attributes are used to refine a ResultSet in various ways when
3328 searching for data. They can be passed to any method which takes an
3329 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3332 These are in no particular order:
3338 =item Value: ( $order_by | \@order_by | \%order_by )
3342 Which column(s) to order the results by.
3344 [The full list of suitable values is documented in
3345 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3348 If a single column name, or an arrayref of names is supplied, the
3349 argument is passed through directly to SQL. The hashref syntax allows
3350 for connection-agnostic specification of ordering direction:
3352 For descending order:
3354 order_by => { -desc => [qw/col1 col2 col3/] }
3356 For explicit ascending order:
3358 order_by => { -asc => 'col' }
3360 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3361 supported, although you are strongly encouraged to use the hashref
3362 syntax as outlined above.
3368 =item Value: \@columns
3372 Shortcut to request a particular set of columns to be retrieved. Each
3373 column spec may be a string (a table column name), or a hash (in which
3374 case the key is the C<as> value, and the value is used as the C<select>
3375 expression). Adds C<me.> onto the start of any column without a C<.> in
3376 it and sets C<select> from that, then auto-populates C<as> from
3377 C<select> as normal. (You may also use the C<cols> attribute, as in
3378 earlier versions of DBIC.)
3380 Essentially C<columns> does the same as L</select> and L</as>.
3382 columns => [ 'foo', { bar => 'baz' } ]
3386 select => [qw/foo baz/],
3393 =item Value: \@columns
3397 Indicates additional columns to be selected from storage. Works the same
3398 as L</columns> but adds columns to the selection. (You may also use the
3399 C<include_columns> attribute, as in earlier versions of DBIC). For
3402 $schema->resultset('CD')->search(undef, {
3403 '+columns' => ['artist.name'],
3407 would return all CDs and include a 'name' column to the information
3408 passed to object inflation. Note that the 'artist' is the name of the
3409 column (or relationship) accessor, and 'name' is the name of the column
3410 accessor in the related table.
3412 =head2 include_columns
3416 =item Value: \@columns
3420 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3426 =item Value: \@select_columns
3430 Indicates which columns should be selected from the storage. You can use
3431 column names, or in the case of RDBMS back ends, function or stored procedure
3434 $rs = $schema->resultset('Employee')->search(undef, {
3437 { count => 'employeeid' },
3438 { max => { length => 'name' }, -as => 'longest_name' }
3443 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3445 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3446 use L</select>, to instruct DBIx::Class how to store the result of the column.
3447 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3448 identifier aliasing. You can however alias a function, so you can use it in
3449 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3450 attribute> supplied as shown in the example above.
3456 Indicates additional columns to be selected from storage. Works the same as
3457 L</select> but adds columns to the default selection, instead of specifying
3466 Indicates additional column names for those added via L</+select>. See L</as>.
3474 =item Value: \@inflation_names
3478 Indicates column names for object inflation. That is L</as> indicates the
3479 slot name in which the column value will be stored within the
3480 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3481 identifier by the C<get_column> method (or via the object accessor B<if one
3482 with the same name already exists>) as shown below. The L</as> attribute has
3483 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3485 $rs = $schema->resultset('Employee')->search(undef, {
3488 { count => 'employeeid' },
3489 { max => { length => 'name' }, -as => 'longest_name' }
3498 If the object against which the search is performed already has an accessor
3499 matching a column name specified in C<as>, the value can be retrieved using
3500 the accessor as normal:
3502 my $name = $employee->name();
3504 If on the other hand an accessor does not exist in the object, you need to
3505 use C<get_column> instead:
3507 my $employee_count = $employee->get_column('employee_count');
3509 You can create your own accessors if required - see
3510 L<DBIx::Class::Manual::Cookbook> for details.
3516 =item Value: ($rel_name | \@rel_names | \%rel_names)
3520 Contains a list of relationships that should be joined for this query. For
3523 # Get CDs by Nine Inch Nails
3524 my $rs = $schema->resultset('CD')->search(
3525 { 'artist.name' => 'Nine Inch Nails' },
3526 { join => 'artist' }
3529 Can also contain a hash reference to refer to the other relation's relations.
3532 package MyApp::Schema::Track;
3533 use base qw/DBIx::Class/;
3534 __PACKAGE__->table('track');
3535 __PACKAGE__->add_columns(qw/trackid cd position title/);
3536 __PACKAGE__->set_primary_key('trackid');
3537 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3540 # In your application
3541 my $rs = $schema->resultset('Artist')->search(
3542 { 'track.title' => 'Teardrop' },
3544 join => { cd => 'track' },
3545 order_by => 'artist.name',
3549 You need to use the relationship (not the table) name in conditions,
3550 because they are aliased as such. The current table is aliased as "me", so
3551 you need to use me.column_name in order to avoid ambiguity. For example:
3553 # Get CDs from 1984 with a 'Foo' track
3554 my $rs = $schema->resultset('CD')->search(
3557 'tracks.name' => 'Foo'
3559 { join => 'tracks' }
3562 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3563 similarly for a third time). For e.g.
3565 my $rs = $schema->resultset('Artist')->search({
3566 'cds.title' => 'Down to Earth',
3567 'cds_2.title' => 'Popular',
3569 join => [ qw/cds cds/ ],
3572 will return a set of all artists that have both a cd with title 'Down
3573 to Earth' and a cd with title 'Popular'.
3575 If you want to fetch related objects from other tables as well, see C<prefetch>
3578 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3584 =item Value: ($rel_name | \@rel_names | \%rel_names)
3588 Contains one or more relationships that should be fetched along with
3589 the main query (when they are accessed afterwards the data will
3590 already be available, without extra queries to the database). This is
3591 useful for when you know you will need the related objects, because it
3592 saves at least one query:
3594 my $rs = $schema->resultset('Tag')->search(
3603 The initial search results in SQL like the following:
3605 SELECT tag.*, cd.*, artist.* FROM tag
3606 JOIN cd ON tag.cd = cd.cdid
3607 JOIN artist ON cd.artist = artist.artistid
3609 L<DBIx::Class> has no need to go back to the database when we access the
3610 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3613 Simple prefetches will be joined automatically, so there is no need
3614 for a C<join> attribute in the above search.
3616 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3617 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3618 with an accessor type of 'single' or 'filter'). A more complex example that
3619 prefetches an artists cds, the tracks on those cds, and the tags associated
3620 with that artist is given below (assuming many-to-many from artists to tags):
3622 my $rs = $schema->resultset('Artist')->search(
3626 { cds => 'tracks' },
3627 { artist_tags => 'tags' }
3633 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3634 attributes will be ignored.
3636 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3637 exactly as you might expect.
3643 Prefetch uses the L</cache> to populate the prefetched relationships. This
3644 may or may not be what you want.
3648 If you specify a condition on a prefetched relationship, ONLY those
3649 rows that match the prefetched condition will be fetched into that relationship.
3650 This means that adding prefetch to a search() B<may alter> what is returned by
3651 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3653 my $artist_rs = $schema->resultset('Artist')->search({
3659 my $count = $artist_rs->first->cds->count;
3661 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3663 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3665 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3667 that cmp_ok() may or may not pass depending on the datasets involved. This
3668 behavior may or may not survive the 0.09 transition.
3680 Makes the resultset paged and specifies the page to retrieve. Effectively
3681 identical to creating a non-pages resultset and then calling ->page($page)
3684 If L<rows> attribute is not specified it defaults to 10 rows per page.
3686 When you have a paged resultset, L</count> will only return the number
3687 of rows in the page. To get the total, use the L</pager> and call
3688 C<total_entries> on it.
3698 Specifies the maximum number of rows for direct retrieval or the number of
3699 rows per page if the page attribute or method is used.
3705 =item Value: $offset
3709 Specifies the (zero-based) row number for the first row to be returned, or the
3710 of the first row of the first page if paging is used.
3716 =item Value: \@columns
3720 A arrayref of columns to group by. Can include columns of joined tables.
3722 group_by => [qw/ column1 column2 ... /]
3728 =item Value: $condition
3732 HAVING is a select statement attribute that is applied between GROUP BY and
3733 ORDER BY. It is applied to the after the grouping calculations have been
3736 having => { 'count(employee)' => { '>=', 100 } }
3742 =item Value: (0 | 1)
3746 Set to 1 to group by all columns. If the resultset already has a group_by
3747 attribute, this setting is ignored and an appropriate warning is issued.
3753 Adds to the WHERE clause.
3755 # only return rows WHERE deleted IS NULL for all searches
3756 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3758 Can be overridden by passing C<< { where => undef } >> as an attribute
3765 Set to 1 to cache search results. This prevents extra SQL queries if you
3766 revisit rows in your ResultSet:
3768 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3770 while( my $artist = $resultset->next ) {
3774 $rs->first; # without cache, this would issue a query
3776 By default, searches are not cached.
3778 For more examples of using these attributes, see
3779 L<DBIx::Class::Manual::Cookbook>.
3785 =item Value: ( 'update' | 'shared' )
3789 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT