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 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
280 my $our_attrs = { %{$self->{attrs}} };
281 my $having = delete $our_attrs->{having};
282 my $where = delete $our_attrs->{where};
286 my %safe = (alias => 1, cache => 1);
289 (@_ && defined($_[0])) # @_ == () or (undef)
291 (keys %$attrs # empty attrs or only 'safe' attrs
292 && List::Util::first { !$safe{$_} } keys %$attrs)
294 # no search, effectively just a clone
295 $rows = $self->get_cache;
298 # reset the selector list
299 if (List::Util::first { exists $attrs->{$_} } qw{columns select as}) {
300 delete @{$our_attrs}{qw{select as columns +select +as +columns include_columns}};
303 my $new_attrs = { %{$our_attrs}, %{$attrs} };
305 # merge new attrs into inherited
306 foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
307 next unless exists $attrs->{$key};
308 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
313 (@_ == 1 || ref $_[0] eq "HASH")
315 (ref $_[0] eq 'HASH')
317 (keys %{ $_[0] } > 0)
325 ? $self->throw_exception("Odd number of arguments to search")
332 if (defined $where) {
333 $new_attrs->{where} = (
334 defined $new_attrs->{where}
337 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
338 } $where, $new_attrs->{where}
345 $new_attrs->{where} = (
346 defined $new_attrs->{where}
349 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
350 } $cond, $new_attrs->{where}
356 if (defined $having) {
357 $new_attrs->{having} = (
358 defined $new_attrs->{having}
361 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
362 } $having, $new_attrs->{having}
368 my $rs = (ref $self)->new($self->result_source, $new_attrs);
370 $rs->set_cache($rows) if ($rows);
375 =head2 search_literal
379 =item Arguments: $sql_fragment, @bind_values
381 =item Return Value: $resultset (scalar context), @row_objs (list context)
385 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
386 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
388 Pass a literal chunk of SQL to be added to the conditional part of the
391 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
392 only be used in that context. C<search_literal> is a convenience method.
393 It is equivalent to calling $schema->search(\[]), but if you want to ensure
394 columns are bound correctly, use C<search>.
396 Example of how to use C<search> instead of C<search_literal>
398 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
399 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
402 See L<DBIx::Class::Manual::Cookbook/Searching> and
403 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
404 require C<search_literal>.
409 my ($self, $sql, @bind) = @_;
411 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
414 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
421 =item Arguments: @values | \%cols, \%attrs?
423 =item Return Value: $row_object | undef
427 Finds a row based on its primary key or unique constraint. For example, to find
428 a row by its primary key:
430 my $cd = $schema->resultset('CD')->find(5);
432 You can also find a row by a specific unique constraint using the C<key>
433 attribute. For example:
435 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
436 key => 'cd_artist_title'
439 Additionally, you can specify the columns explicitly by name:
441 my $cd = $schema->resultset('CD')->find(
443 artist => 'Massive Attack',
444 title => 'Mezzanine',
446 { key => 'cd_artist_title' }
449 If the C<key> is specified as C<primary>, it searches only on the primary key.
451 If no C<key> is specified, it searches on all unique constraints defined on the
452 source for which column data is provided, including the primary key.
454 If your table does not have a primary key, you B<must> provide a value for the
455 C<key> attribute matching one of the unique constraints on the source.
457 In addition to C<key>, L</find> recognizes and applies standard
458 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
460 Note: If your query does not return only one row, a warning is generated:
462 Query returned more than one row
464 See also L</find_or_create> and L</update_or_create>. For information on how to
465 declare unique constraints, see
466 L<DBIx::Class::ResultSource/add_unique_constraint>.
472 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
474 # Default to the primary key, but allow a specific key
475 my @cols = exists $attrs->{key}
476 ? $self->result_source->unique_constraint_columns($attrs->{key})
477 : $self->result_source->primary_columns;
478 $self->throw_exception(
479 "Can't find unless a primary key is defined or unique constraint is specified"
482 # Parse out a hashref from input
484 if (ref $_[0] eq 'HASH') {
485 $input_query = { %{$_[0]} };
487 elsif (@_ == @cols) {
489 @{$input_query}{@cols} = @_;
492 # Compatibility: Allow e.g. find(id => $value)
493 carp "Find by key => value deprecated; please use a hashref instead";
497 my (%related, $info);
499 KEY: foreach my $key (keys %$input_query) {
500 if (ref($input_query->{$key})
501 && ($info = $self->result_source->relationship_info($key))) {
502 my $val = delete $input_query->{$key};
503 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
504 my $rel_q = $self->result_source->_resolve_condition(
505 $info->{cond}, $val, $key
507 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
508 @related{keys %$rel_q} = values %$rel_q;
511 if (my @keys = keys %related) {
512 @{$input_query}{@keys} = values %related;
516 # Build the final query: Default to the disjunction of the unique queries,
517 # but allow the input query in case the ResultSet defines the query or the
518 # user is abusing find
519 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
521 if (exists $attrs->{key}) {
522 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
523 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
524 $query = $self->_add_alias($unique_query, $alias);
526 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
527 # This means that we got here after a merger of relationship conditions
528 # in ::Relationship::Base::search_related (the row method), and furthermore
529 # the relationship is of the 'single' type. This means that the condition
530 # provided by the relationship (already attached to $self) is sufficient,
531 # as there can be only one row in the database that would satisfy the
535 my @unique_queries = $self->_unique_queries($input_query, $attrs);
536 $query = @unique_queries
537 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
538 : $self->_add_alias($input_query, $alias);
541 # Run the query, passing the result_class since it should propagate for find
542 my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs});
543 if (keys %{$rs->_resolved_attrs->{collapse}}) {
545 carp "Query returned more than one row" if $rs->next;
555 # Add the specified alias to the specified query hash. A copy is made so the
556 # original query is not modified.
559 my ($self, $query, $alias) = @_;
561 my %aliased = %$query;
562 foreach my $col (grep { ! m/\./ } keys %aliased) {
563 $aliased{"$alias.$col"} = delete $aliased{$col};
571 # Build a list of queries which satisfy unique constraints.
573 sub _unique_queries {
574 my ($self, $query, $attrs) = @_;
576 my @constraint_names = exists $attrs->{key}
578 : $self->result_source->unique_constraint_names;
580 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
581 my $num_where = scalar keys %$where;
583 my (@unique_queries, %seen_column_combinations);
584 foreach my $name (@constraint_names) {
585 my @constraint_cols = $self->result_source->unique_constraint_columns($name);
587 my $constraint_sig = join "\x00", sort @constraint_cols;
588 next if $seen_column_combinations{$constraint_sig}++;
590 my $unique_query = $self->_build_unique_query($query, \@constraint_cols);
592 my $num_cols = scalar @constraint_cols;
593 my $num_query = scalar keys %$unique_query;
595 my $total = $num_query + $num_where;
596 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
597 # The query is either unique on its own or is unique in combination with
598 # the existing where clause
599 push @unique_queries, $unique_query;
603 return @unique_queries;
606 # _build_unique_query
608 # Constrain the specified query hash based on the specified column names.
610 sub _build_unique_query {
611 my ($self, $query, $unique_cols) = @_;
614 map { $_ => $query->{$_} }
615 grep { exists $query->{$_} }
620 =head2 search_related
624 =item Arguments: $rel, $cond, \%attrs?
626 =item Return Value: $new_resultset
630 $new_rs = $cd_rs->search_related('artist', {
634 Searches the specified relationship, optionally specifying a condition and
635 attributes for matching records. See L</ATTRIBUTES> for more information.
640 return shift->related_resultset(shift)->search(@_);
643 =head2 search_related_rs
645 This method works exactly the same as search_related, except that
646 it guarantees a resultset, even in list context.
650 sub search_related_rs {
651 return shift->related_resultset(shift)->search_rs(@_);
658 =item Arguments: none
660 =item Return Value: $cursor
664 Returns a storage-driven cursor to the given resultset. See
665 L<DBIx::Class::Cursor> for more information.
672 my $attrs = $self->_resolved_attrs_copy;
674 return $self->{cursor}
675 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
676 $attrs->{where},$attrs);
683 =item Arguments: $cond?
685 =item Return Value: $row_object | undef
689 my $cd = $schema->resultset('CD')->single({ year => 2001 });
691 Inflates the first result without creating a cursor if the resultset has
692 any records in it; if not returns C<undef>. Used by L</find> as a lean version
695 While this method can take an optional search condition (just like L</search>)
696 being a fast-code-path it does not recognize search attributes. If you need to
697 add extra joins or similar, call L</search> and then chain-call L</single> on the
698 L<DBIx::Class::ResultSet> returned.
704 As of 0.08100, this method enforces the assumption that the preceding
705 query returns only one row. If more than one row is returned, you will receive
708 Query returned more than one row
710 In this case, you should be using L</next> or L</find> instead, or if you really
711 know what you are doing, use the L</rows> attribute to explicitly limit the size
714 This method will also throw an exception if it is called on a resultset prefetching
715 has_many, as such a prefetch implies fetching multiple rows from the database in
716 order to assemble the resulting object.
723 my ($self, $where) = @_;
725 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
728 my $attrs = $self->_resolved_attrs_copy;
730 if (keys %{$attrs->{collapse}}) {
731 $self->throw_exception(
732 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
737 if (defined $attrs->{where}) {
740 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
741 $where, delete $attrs->{where} ]
744 $attrs->{where} = $where;
748 # XXX: Disabled since it doesn't infer uniqueness in all cases
749 # unless ($self->_is_unique_query($attrs->{where})) {
750 # carp "Query not guaranteed to return a single row"
751 # . "; please declare your unique constraints or use search instead";
754 my @data = $self->result_source->storage->select_single(
755 $attrs->{from}, $attrs->{select},
756 $attrs->{where}, $attrs
759 return (@data ? ($self->_construct_object(@data))[0] : undef);
765 # Try to determine if the specified query is guaranteed to be unique, based on
766 # the declared unique constraints.
768 sub _is_unique_query {
769 my ($self, $query) = @_;
771 my $collapsed = $self->_collapse_query($query);
772 my $alias = $self->{attrs}{alias};
774 foreach my $name ($self->result_source->unique_constraint_names) {
775 my @unique_cols = map {
777 } $self->result_source->unique_constraint_columns($name);
779 # Count the values for each unique column
780 my %seen = map { $_ => 0 } @unique_cols;
782 foreach my $key (keys %$collapsed) {
783 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
784 next unless exists $seen{$aliased}; # Additional constraints are okay
785 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
788 # If we get 0 or more than 1 value for a column, it's not necessarily unique
789 return 1 unless grep { $_ != 1 } values %seen;
797 # Recursively collapse the query, accumulating values for each column.
799 sub _collapse_query {
800 my ($self, $query, $collapsed) = @_;
804 if (ref $query eq 'ARRAY') {
805 foreach my $subquery (@$query) {
806 next unless ref $subquery; # -or
807 $collapsed = $self->_collapse_query($subquery, $collapsed);
810 elsif (ref $query eq 'HASH') {
811 if (keys %$query and (keys %$query)[0] eq '-and') {
812 foreach my $subquery (@{$query->{-and}}) {
813 $collapsed = $self->_collapse_query($subquery, $collapsed);
817 foreach my $col (keys %$query) {
818 my $value = $query->{$col};
819 $collapsed->{$col}{$value}++;
831 =item Arguments: $cond?
833 =item Return Value: $resultsetcolumn
837 my $max_length = $rs->get_column('length')->max;
839 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
844 my ($self, $column) = @_;
845 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
853 =item Arguments: $cond, \%attrs?
855 =item Return Value: $resultset (scalar context), @row_objs (list context)
859 # WHERE title LIKE '%blue%'
860 $cd_rs = $rs->search_like({ title => '%blue%'});
862 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
863 that this is simply a convenience method retained for ex Class::DBI users.
864 You most likely want to use L</search> with specific operators.
866 For more information, see L<DBIx::Class::Manual::Cookbook>.
868 This method is deprecated and will be removed in 0.09. Use L</search()>
869 instead. An example conversion is:
871 ->search_like({ foo => 'bar' });
875 ->search({ foo => { like => 'bar' } });
882 'search_like() is deprecated and will be removed in DBIC version 0.09.'
883 .' Instead use ->search({ x => { -like => "y%" } })'
884 .' (note the outer pair of {}s - they are important!)'
886 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
887 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
888 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
889 return $class->search($query, { %$attrs });
896 =item Arguments: $first, $last
898 =item Return Value: $resultset (scalar context), @row_objs (list context)
902 Returns a resultset or object list representing a subset of elements from the
903 resultset slice is called on. Indexes are from 0, i.e., to get the first
906 my ($one, $two, $three) = $rs->slice(0, 2);
911 my ($self, $min, $max) = @_;
912 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
913 $attrs->{offset} = $self->{attrs}{offset} || 0;
914 $attrs->{offset} += $min;
915 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
916 return $self->search(undef, $attrs);
917 #my $slice = (ref $self)->new($self->result_source, $attrs);
918 #return (wantarray ? $slice->all : $slice);
925 =item Arguments: none
927 =item Return Value: $result | undef
931 Returns the next element in the resultset (C<undef> is there is none).
933 Can be used to efficiently iterate over records in the resultset:
935 my $rs = $schema->resultset('CD')->search;
936 while (my $cd = $rs->next) {
940 Note that you need to store the resultset object, and call C<next> on it.
941 Calling C<< resultset('Table')->next >> repeatedly will always return the
942 first record from the resultset.
948 if (my $cache = $self->get_cache) {
949 $self->{all_cache_position} ||= 0;
950 return $cache->[$self->{all_cache_position}++];
952 if ($self->{attrs}{cache}) {
953 delete $self->{pager};
954 $self->{all_cache_position} = 1;
955 return ($self->all)[0];
957 if ($self->{stashed_objects}) {
958 my $obj = shift(@{$self->{stashed_objects}});
959 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
963 exists $self->{stashed_row}
964 ? @{delete $self->{stashed_row}}
965 : $self->cursor->next
967 return undef unless (@row);
968 my ($row, @more) = $self->_construct_object(@row);
969 $self->{stashed_objects} = \@more if @more;
973 sub _construct_object {
974 my ($self, @row) = @_;
976 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
978 my @new = $self->result_class->inflate_result($self->result_source, @$info);
979 @new = $self->{_attrs}{record_filter}->(@new)
980 if exists $self->{_attrs}{record_filter};
984 sub _collapse_result {
985 my ($self, $as_proto, $row) = @_;
989 # 'foo' => [ undef, 'foo' ]
990 # 'foo.bar' => [ 'foo', 'bar' ]
991 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
993 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
995 my %collapse = %{$self->{_attrs}{collapse}||{}};
999 # if we're doing collapsing (has_many prefetch) we need to grab records
1000 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1001 # we know we don't have to bother.
1003 # the reason for not using the collapse stuff directly is because if you
1004 # had for e.g. two artists in a row with no cds, the collapse info for
1005 # both would be NULL (undef) so you'd lose the second artist
1007 # store just the index so we can check the array positions from the row
1008 # without having to contruct the full hash
1010 if (keys %collapse) {
1011 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1012 foreach my $i (0 .. $#construct_as) {
1013 next if defined($construct_as[$i][0]); # only self table
1014 if (delete $pri{$construct_as[$i][1]}) {
1015 push(@pri_index, $i);
1017 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1021 # no need to do an if, it'll be empty if @pri_index is empty anyway
1023 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1027 do { # no need to check anything at the front, we always want the first row
1031 foreach my $this_as (@construct_as) {
1032 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1035 push(@const_rows, \%const);
1037 } until ( # no pri_index => no collapse => drop straight out
1040 do { # get another row, stash it, drop out if different PK
1042 @copy = $self->cursor->next;
1043 $self->{stashed_row} = \@copy;
1045 # last thing in do block, counts as true if anything doesn't match
1047 # check xor defined first for NULL vs. NOT NULL then if one is
1048 # defined the other must be so check string equality
1051 (defined $pri_vals{$_} ^ defined $copy[$_])
1052 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1057 my $alias = $self->{attrs}{alias};
1064 foreach my $const (@const_rows) {
1065 scalar @const_keys or do {
1066 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1068 foreach my $key (@const_keys) {
1071 my @parts = split(/\./, $key);
1073 my $data = $const->{$key};
1074 foreach my $p (@parts) {
1075 $target = $target->[1]->{$p} ||= [];
1077 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1078 # collapsing at this point and on final part
1079 my $pos = $collapse_pos{$cur};
1080 CK: foreach my $ck (@ckey) {
1081 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1082 $collapse_pos{$cur} = $data;
1083 delete @collapse_pos{ # clear all positioning for sub-entries
1084 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1091 if (exists $collapse{$cur}) {
1092 $target = $target->[-1];
1095 $target->[0] = $data;
1097 $info->[0] = $const->{$key};
1105 =head2 result_source
1109 =item Arguments: $result_source?
1111 =item Return Value: $result_source
1115 An accessor for the primary ResultSource object from which this ResultSet
1122 =item Arguments: $result_class?
1124 =item Return Value: $result_class
1128 An accessor for the class to use when creating row objects. Defaults to
1129 C<< result_source->result_class >> - which in most cases is the name of the
1130 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1132 Note that changing the result_class will also remove any components
1133 that were originally loaded in the source class via
1134 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1135 in the original source class will not run.
1140 my ($self, $result_class) = @_;
1141 if ($result_class) {
1142 unless (ref $result_class) { # don't fire this for an object
1143 $self->ensure_class_loaded($result_class);
1145 $self->_result_class($result_class);
1146 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1147 # permit the user to set result class on one result set only; it only
1148 # chains if provided to search()
1149 #$self->{attrs}{result_class} = $result_class if ref $self;
1151 $self->_result_class;
1158 =item Arguments: $cond, \%attrs??
1160 =item Return Value: $count
1164 Performs an SQL C<COUNT> with the same query as the resultset was built
1165 with to find the number of elements. Passing arguments is equivalent to
1166 C<< $rs->search ($cond, \%attrs)->count >>
1172 return $self->search(@_)->count if @_ and defined $_[0];
1173 return scalar @{ $self->get_cache } if $self->get_cache;
1175 my $attrs = $self->_resolved_attrs_copy;
1177 # this is a little optimization - it is faster to do the limit
1178 # adjustments in software, instead of a subquery
1179 my $rows = delete $attrs->{rows};
1180 my $offset = delete $attrs->{offset};
1183 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1184 $crs = $self->_count_subq_rs ($attrs);
1187 $crs = $self->_count_rs ($attrs);
1189 my $count = $crs->next;
1191 $count -= $offset if $offset;
1192 $count = $rows if $rows and $rows < $count;
1193 $count = 0 if ($count < 0);
1202 =item Arguments: $cond, \%attrs??
1204 =item Return Value: $count_rs
1208 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1209 This can be very handy for subqueries:
1211 ->search( { amount => $some_rs->count_rs->as_query } )
1213 As with regular resultsets the SQL query will be executed only after
1214 the resultset is accessed via L</next> or L</all>. That would return
1215 the same single value obtainable via L</count>.
1221 return $self->search(@_)->count_rs if @_;
1223 # this may look like a lack of abstraction (count() does about the same)
1224 # but in fact an _rs *must* use a subquery for the limits, as the
1225 # software based limiting can not be ported if this $rs is to be used
1226 # in a subquery itself (i.e. ->as_query)
1227 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1228 return $self->_count_subq_rs;
1231 return $self->_count_rs;
1236 # returns a ResultSetColumn object tied to the count query
1239 my ($self, $attrs) = @_;
1241 my $rsrc = $self->result_source;
1242 $attrs ||= $self->_resolved_attrs;
1244 my $tmp_attrs = { %$attrs };
1245 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1246 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1248 # overwrite the selector (supplied by the storage)
1249 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1250 $tmp_attrs->{as} = 'count';
1252 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1258 # same as above but uses a subquery
1260 sub _count_subq_rs {
1261 my ($self, $attrs) = @_;
1263 my $rsrc = $self->result_source;
1264 $attrs ||= $self->_resolved_attrs;
1266 my $sub_attrs = { %$attrs };
1267 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1268 delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
1270 # if we multi-prefetch we group_by primary keys only as this is what we would
1271 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1272 if ( keys %{$attrs->{collapse}} ) {
1273 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1276 # Calculate subquery selector
1277 if (my $g = $sub_attrs->{group_by}) {
1279 my $sql_maker = $rsrc->storage->sql_maker;
1281 # necessary as the group_by may refer to aliased functions
1283 for my $sel (@{$attrs->{select}}) {
1284 $sel_index->{$sel->{-as}} = $sel
1285 if (ref $sel eq 'HASH' and $sel->{-as});
1288 for my $g_part (@$g) {
1289 my $colpiece = $sel_index->{$g_part} || $g_part;
1291 # disqualify join-based group_by's. Arcane but possible query
1292 # also horrible horrible hack to alias a column (not a func.)
1293 # (probably need to introduce SQLA syntax)
1294 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1297 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1299 push @{$sub_attrs->{select}}, $colpiece;
1303 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1304 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1307 return $rsrc->resultset_class
1308 ->new ($rsrc, $sub_attrs)
1310 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1311 ->get_column ('count');
1318 =head2 count_literal
1322 =item Arguments: $sql_fragment, @bind_values
1324 =item Return Value: $count
1328 Counts the results in a literal query. Equivalent to calling L</search_literal>
1329 with the passed arguments, then L</count>.
1333 sub count_literal { shift->search_literal(@_)->count; }
1339 =item Arguments: none
1341 =item Return Value: @objects
1345 Returns all elements in the resultset. Called implicitly if the resultset
1346 is returned in list context.
1353 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1356 return @{ $self->get_cache } if $self->get_cache;
1360 if (keys %{$self->_resolved_attrs->{collapse}}) {
1361 # Using $self->cursor->all is really just an optimisation.
1362 # If we're collapsing has_many prefetches it probably makes
1363 # very little difference, and this is cleaner than hacking
1364 # _construct_object to survive the approach
1365 $self->cursor->reset;
1366 my @row = $self->cursor->next;
1368 push(@obj, $self->_construct_object(@row));
1369 @row = (exists $self->{stashed_row}
1370 ? @{delete $self->{stashed_row}}
1371 : $self->cursor->next);
1374 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1377 $self->set_cache(\@obj) if $self->{attrs}{cache};
1386 =item Arguments: none
1388 =item Return Value: $self
1392 Resets the resultset's cursor, so you can iterate through the elements again.
1393 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1400 delete $self->{_attrs} if exists $self->{_attrs};
1401 $self->{all_cache_position} = 0;
1402 $self->cursor->reset;
1410 =item Arguments: none
1412 =item Return Value: $object | undef
1416 Resets the resultset and returns an object for the first result (or C<undef>
1417 if the resultset is empty).
1422 return $_[0]->reset->next;
1428 # Determines whether and what type of subquery is required for the $rs operation.
1429 # If grouping is necessary either supplies its own, or verifies the current one
1430 # After all is done delegates to the proper storage method.
1432 sub _rs_update_delete {
1433 my ($self, $op, $values) = @_;
1435 my $rsrc = $self->result_source;
1437 # if a condition exists we need to strip all table qualifiers
1438 # if this is not possible we'll force a subquery below
1439 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1441 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1442 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1444 if ($needs_group_by_subq or $needs_subq) {
1446 # make a new $rs selecting only the PKs (that's all we really need)
1447 my $attrs = $self->_resolved_attrs_copy;
1450 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1451 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1453 if ($needs_group_by_subq) {
1454 # make sure no group_by was supplied, or if there is one - make sure it matches
1455 # the columns compiled above perfectly. Anything else can not be sanely executed
1456 # on most databases so croak right then and there
1458 if (my $g = $attrs->{group_by}) {
1459 my @current_group_by = map
1460 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1465 join ("\x00", sort @current_group_by)
1467 join ("\x00", sort @{$attrs->{columns}} )
1469 $self->throw_exception (
1470 "You have just attempted a $op operation on a resultset which does group_by"
1471 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1472 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1473 . ' kind of queries. Please retry the operation with a modified group_by or'
1474 . ' without using one at all.'
1479 $attrs->{group_by} = $attrs->{columns};
1483 my $subrs = (ref $self)->new($rsrc, $attrs);
1484 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1487 return $rsrc->storage->$op(
1489 $op eq 'update' ? $values : (),
1499 =item Arguments: \%values
1501 =item Return Value: $storage_rv
1505 Sets the specified columns in the resultset to the supplied values in a
1506 single query. Note that this will not run any accessor/set_column/update
1507 triggers, nor will it update any row object instances derived from this
1508 resultset (this includes the contents of the L<resultset cache|/set_cache>
1509 if any). See L</update_all> if you need to execute any on-update
1510 triggers or cascades defined either by you or a
1511 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1513 The return value is a pass through of what the underlying
1514 storage backend returned, and may vary. See L<DBI/execute> for the most
1520 my ($self, $values) = @_;
1521 $self->throw_exception('Values for update must be a hash')
1522 unless ref $values eq 'HASH';
1524 return $self->_rs_update_delete ('update', $values);
1531 =item Arguments: \%values
1533 =item Return Value: 1
1537 Fetches all objects and updates them one at a time via
1538 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1539 triggers, while L</update> will not.
1544 my ($self, $values) = @_;
1545 $self->throw_exception('Values for update_all must be a hash')
1546 unless ref $values eq 'HASH';
1548 my $guard = $self->result_source->schema->txn_scope_guard;
1549 $_->update($values) for $self->all;
1558 =item Arguments: none
1560 =item Return Value: $storage_rv
1564 Deletes the rows matching this resultset in a single query. Note that this
1565 will not run any delete triggers, nor will it alter the
1566 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1567 derived from this resultset (this includes the contents of the
1568 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1569 execute any on-delete triggers or cascades defined either by you or a
1570 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1572 The return value is a pass through of what the underlying storage backend
1573 returned, and may vary. See L<DBI/execute> for the most common case.
1579 $self->throw_exception('delete does not accept any arguments')
1582 return $self->_rs_update_delete ('delete');
1589 =item Arguments: none
1591 =item Return Value: 1
1595 Fetches all objects and deletes them one at a time via
1596 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1597 triggers, while L</delete> will not.
1603 $self->throw_exception('delete_all does not accept any arguments')
1606 my $guard = $self->result_source->schema->txn_scope_guard;
1607 $_->delete for $self->all;
1616 =item Arguments: \@data;
1620 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1621 For the arrayref of hashrefs style each hashref should be a structure suitable
1622 forsubmitting to a $resultset->create(...) method.
1624 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1625 to insert the data, as this is a faster method.
1627 Otherwise, each set of data is inserted into the database using
1628 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1629 accumulated into an array. The array itself, or an array reference
1630 is returned depending on scalar or list context.
1632 Example: Assuming an Artist Class that has many CDs Classes relating:
1634 my $Artist_rs = $schema->resultset("Artist");
1636 ## Void Context Example
1637 $Artist_rs->populate([
1638 { artistid => 4, name => 'Manufactured Crap', cds => [
1639 { title => 'My First CD', year => 2006 },
1640 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1643 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1644 { title => 'My parents sold me to a record company', year => 2005 },
1645 { title => 'Why Am I So Ugly?', year => 2006 },
1646 { title => 'I Got Surgery and am now Popular', year => 2007 }
1651 ## Array Context Example
1652 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1653 { name => "Artist One"},
1654 { name => "Artist Two"},
1655 { name => "Artist Three", cds=> [
1656 { title => "First CD", year => 2007},
1657 { title => "Second CD", year => 2008},
1661 print $ArtistOne->name; ## response is 'Artist One'
1662 print $ArtistThree->cds->count ## reponse is '2'
1664 For the arrayref of arrayrefs style, the first element should be a list of the
1665 fieldsnames to which the remaining elements are rows being inserted. For
1668 $Arstist_rs->populate([
1669 [qw/artistid name/],
1670 [100, 'A Formally Unknown Singer'],
1671 [101, 'A singer that jumped the shark two albums ago'],
1672 [102, 'An actually cool singer'],
1675 Please note an important effect on your data when choosing between void and
1676 wantarray context. Since void context goes straight to C<insert_bulk> in
1677 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1678 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1679 create primary keys for you, you will find that your PKs are empty. In this
1680 case you will have to use the wantarray context in order to create those
1688 # cruft placed in standalone method
1689 my $data = $self->_normalize_populate_args(@_);
1691 if(defined wantarray) {
1693 foreach my $item (@$data) {
1694 push(@created, $self->create($item));
1696 return wantarray ? @created : \@created;
1698 my $first = $data->[0];
1700 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1701 # it relationship data
1702 my (@rels, @columns);
1703 for (keys %$first) {
1704 my $ref = ref $first->{$_};
1705 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1711 my @pks = $self->result_source->primary_columns;
1713 ## do the belongs_to relationships
1714 foreach my $index (0..$#$data) {
1716 # delegate to create() for any dataset without primary keys with specified relationships
1717 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1719 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1720 my @ret = $self->populate($data);
1726 foreach my $rel (@rels) {
1727 next unless ref $data->[$index]->{$rel} eq "HASH";
1728 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1729 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1730 my $related = $result->result_source->_resolve_condition(
1731 $result->result_source->relationship_info($reverse)->{cond},
1736 delete $data->[$index]->{$rel};
1737 $data->[$index] = {%{$data->[$index]}, %$related};
1739 push @columns, keys %$related if $index == 0;
1743 ## inherit the data locked in the conditions of the resultset
1744 my ($rs_data) = $self->_merge_cond_with_data({});
1745 delete @{$rs_data}{@columns};
1746 my @inherit_cols = keys %$rs_data;
1747 my @inherit_data = values %$rs_data;
1749 ## do bulk insert on current row
1750 $self->result_source->storage->insert_bulk(
1751 $self->result_source,
1752 [@columns, @inherit_cols],
1753 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1756 ## do the has_many relationships
1757 foreach my $item (@$data) {
1759 foreach my $rel (@rels) {
1760 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1762 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1763 || $self->throw_exception('Cannot find the relating object.');
1765 my $child = $parent->$rel;
1767 my $related = $child->result_source->_resolve_condition(
1768 $parent->result_source->relationship_info($rel)->{cond},
1773 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1774 my @populate = map { {%$_, %$related} } @rows_to_add;
1776 $child->populate( \@populate );
1783 # populate() argumnets went over several incarnations
1784 # What we ultimately support is AoH
1785 sub _normalize_populate_args {
1786 my ($self, $arg) = @_;
1788 if (ref $arg eq 'ARRAY') {
1789 if (ref $arg->[0] eq 'HASH') {
1792 elsif (ref $arg->[0] eq 'ARRAY') {
1794 my @colnames = @{$arg->[0]};
1795 foreach my $values (@{$arg}[1 .. $#$arg]) {
1796 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1802 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1809 =item Arguments: none
1811 =item Return Value: $pager
1815 Return Value a L<Data::Page> object for the current resultset. Only makes
1816 sense for queries with a C<page> attribute.
1818 To get the full count of entries for a paged resultset, call
1819 C<total_entries> on the L<Data::Page> object.
1823 # make a wizard good for both a scalar and a hashref
1824 my $mk_lazy_count_wizard = sub {
1825 require Variable::Magic;
1827 my $stash = { total_rs => shift };
1828 my $slot = shift; # only used by the hashref magic
1830 my $magic = Variable::Magic::wizard (
1831 data => sub { $stash },
1837 # set value lazily, and dispell for good
1838 ${$_[0]} = $_[1]{total_rs}->count;
1839 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
1843 # an explicit set implies dispell as well
1844 # the unless() is to work around "fun and giggles" below
1845 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
1846 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1853 if ($_[2] eq $slot and !$_[1]{inactive}) {
1854 my $cnt = $_[1]{total_rs}->count;
1855 $_[0]->{$slot} = $cnt;
1857 # attempting to dispell in a fetch handle (works in store), seems
1858 # to invariable segfault on 5.10, 5.12, 5.13 :(
1859 # so use an inactivator instead
1860 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1866 if (! $_[1]{inactive} and $_[2] eq $slot) {
1867 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
1869 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
1876 $stash->{magic_selfref} = $magic;
1877 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
1882 # the tie class for 5.8.1
1884 package DBIx::Class::__DBIC_LAZY_RS_COUNT__;
1885 use base qw/Tie::Hash/;
1887 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
1888 sub NEXTKEY { each %{$_[0]{data}} }
1889 sub EXISTS { exists $_[0]{data}{$_[1]} }
1890 sub DELETE { delete $_[0]{data}{$_[1]} }
1891 sub CLEAR { %{$_[0]{data}} = () }
1892 sub SCALAR { scalar %{$_[0]{data}} }
1895 $_[1]{data} = {%{$_[1]{selfref}}};
1896 %{$_[1]{selfref}} = ();
1897 Scalar::Util::weaken ($_[1]{selfref});
1898 return bless ($_[1], $_[0]);
1902 if ($_[1] eq $_[0]{slot}) {
1903 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
1904 untie %{$_[0]{selfref}};
1905 %{$_[0]{selfref}} = %{$_[0]{data}};
1914 $_[0]{data}{$_[1]} = $_[2];
1915 if ($_[1] eq $_[0]{slot}) {
1916 untie %{$_[0]{selfref}};
1917 %{$_[0]{selfref}} = %{$_[0]{data}};
1926 return $self->{pager} if $self->{pager};
1928 if ($self->get_cache) {
1929 $self->throw_exception ('Pagers on cached resultsets are not supported');
1932 my $attrs = $self->{attrs};
1933 $self->throw_exception("Can't create pager for non-paged rs")
1934 unless $self->{attrs}{page};
1935 $attrs->{rows} ||= 10;
1937 # throw away the paging flags and re-run the count (possibly
1938 # with a subselect) to get the real total count
1939 my $count_attrs = { %$attrs };
1940 delete $count_attrs->{$_} for qw/rows offset page pager/;
1941 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
1944 ### the following may seem awkward and dirty, but it's a thought-experiment
1945 ### necessary for future development of DBIx::DS. Do *NOT* change this code
1946 ### before talking to ribasushi/mst
1948 my $pager = Data::Page->new(
1949 0, #start with an empty set
1951 $self->{attrs}{page},
1954 my $data_slot = 'total_entries';
1956 # Since we are interested in a cached value (once it's set - it's set), every
1957 # technique will detach from the magic-host once the time comes to fire the
1958 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
1960 if ($] < 5.008003) {
1961 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
1962 # to weakref the magic container :(
1964 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
1965 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
1968 elsif ($] < 5.010) {
1969 # We can use magic on the hash value slot. It's interesting that the magic is
1970 # attached to the hash-slot, and does *not* stop working once I do the dummy
1971 # assignments after the cast()
1972 # tested on 5.8.3 and 5.8.9
1973 my $magic = $mk_lazy_count_wizard->($total_rs);
1974 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
1976 # this is for fun and giggles
1977 $pager->{$data_slot} = -1;
1978 $pager->{$data_slot} = 0;
1980 # this does not work for scalars, but works with
1982 #my %vals = %$pager;
1987 # And the uvar magic
1988 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
1989 # however see the wizard maker for more notes
1990 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
1991 Variable::Magic::cast ( %$pager, $magic );
1994 $pager->{$data_slot} = -1;
1995 $pager->{$data_slot} = 0;
2003 return $self->{pager} = $pager;
2010 =item Arguments: $page_number
2012 =item Return Value: $rs
2016 Returns a resultset for the $page_number page of the resultset on which page
2017 is called, where each page contains a number of rows equal to the 'rows'
2018 attribute set on the resultset (10 by default).
2023 my ($self, $page) = @_;
2024 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2031 =item Arguments: \%vals
2033 =item Return Value: $rowobject
2037 Creates a new row object in the resultset's result class and returns
2038 it. The row is not inserted into the database at this point, call
2039 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2040 will tell you whether the row object has been inserted or not.
2042 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2047 my ($self, $values) = @_;
2048 $self->throw_exception( "new_result needs a hash" )
2049 unless (ref $values eq 'HASH');
2051 my ($merged_cond, $cols_from_relations) = $self->_merge_cond_with_data($values);
2055 @$cols_from_relations
2056 ? (-cols_from_relations => $cols_from_relations)
2058 -source_handle => $self->_source_handle,
2059 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2062 return $self->result_class->new(\%new);
2065 # _merge_cond_with_data
2067 # Takes a simple hash of K/V data and returns its copy merged with the
2068 # condition already present on the resultset. Additionally returns an
2069 # arrayref of value/condition names, which were inferred from related
2070 # objects (this is needed for in-memory related objects)
2071 sub _merge_cond_with_data {
2072 my ($self, $data) = @_;
2074 my (%new_data, @cols_from_relations);
2076 my $alias = $self->{attrs}{alias};
2078 if (! defined $self->{cond}) {
2079 # just massage $data below
2081 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2082 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2083 @cols_from_relations = keys %new_data;
2085 elsif (ref $self->{cond} ne 'HASH') {
2086 $self->throw_exception(
2087 "Can't abstract implicit construct, resultset condition not a hash"
2091 # precendence must be given to passed values over values inherited from
2092 # the cond, so the order here is important.
2093 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2094 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2096 while ( my($col, $value) = each %implied ) {
2097 if (ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2098 $new_data{$col} = $value->{'='};
2101 $new_data{$col} = $value if $self->_is_deterministic_value($value);
2107 %{ $self->_remove_alias($data, $alias) },
2110 return (\%new_data, \@cols_from_relations);
2113 # _is_deterministic_value
2115 # Make an effor to strip non-deterministic values from the condition,
2116 # to make sure new_result chokes less
2118 sub _is_deterministic_value {
2121 my $ref_type = ref $value;
2122 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
2123 return 1 if blessed $value;
2127 # _has_resolved_attr
2129 # determines if the resultset defines at least one
2130 # of the attributes supplied
2132 # used to determine if a subquery is neccessary
2134 # supports some virtual attributes:
2136 # This will scan for any joins being present on the resultset.
2137 # It is not a mere key-search but a deep inspection of {from}
2140 sub _has_resolved_attr {
2141 my ($self, @attr_names) = @_;
2143 my $attrs = $self->_resolved_attrs;
2147 for my $n (@attr_names) {
2148 if (grep { $n eq $_ } (qw/-join/) ) {
2149 $extra_checks{$n}++;
2153 my $attr = $attrs->{$n};
2155 next if not defined $attr;
2157 if (ref $attr eq 'HASH') {
2158 return 1 if keys %$attr;
2160 elsif (ref $attr eq 'ARRAY') {
2168 # a resolved join is expressed as a multi-level from
2170 $extra_checks{-join}
2172 ref $attrs->{from} eq 'ARRAY'
2174 @{$attrs->{from}} > 1
2182 # Recursively collapse the condition.
2184 sub _collapse_cond {
2185 my ($self, $cond, $collapsed) = @_;
2189 if (ref $cond eq 'ARRAY') {
2190 foreach my $subcond (@$cond) {
2191 next unless ref $subcond; # -or
2192 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2195 elsif (ref $cond eq 'HASH') {
2196 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2197 foreach my $subcond (@{$cond->{-and}}) {
2198 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2202 foreach my $col (keys %$cond) {
2203 my $value = $cond->{$col};
2204 $collapsed->{$col} = $value;
2214 # Remove the specified alias from the specified query hash. A copy is made so
2215 # the original query is not modified.
2218 my ($self, $query, $alias) = @_;
2220 my %orig = %{ $query || {} };
2223 foreach my $key (keys %orig) {
2225 $unaliased{$key} = $orig{$key};
2228 $unaliased{$1} = $orig{$key}
2229 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2239 =item Arguments: none
2241 =item Return Value: \[ $sql, @bind ]
2245 Returns the SQL query and bind vars associated with the invocant.
2247 This is generally used as the RHS for a subquery.
2254 my $attrs = $self->_resolved_attrs_copy;
2259 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2260 # $sql also has no wrapping parenthesis in list ctx
2262 my $sqlbind = $self->result_source->storage
2263 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2272 =item Arguments: \%vals, \%attrs?
2274 =item Return Value: $rowobject
2278 my $artist = $schema->resultset('Artist')->find_or_new(
2279 { artist => 'fred' }, { key => 'artists' });
2281 $cd->cd_to_producer->find_or_new({ producer => $producer },
2282 { key => 'primary });
2284 Find an existing record from this resultset, based on its primary
2285 key, or a unique constraint. If none exists, instantiate a new result
2286 object and return it. The object will not be saved into your storage
2287 until you call L<DBIx::Class::Row/insert> on it.
2289 You most likely want this method when looking for existing rows using
2290 a unique constraint that is not the primary key, or looking for
2293 If you want objects to be saved immediately, use L</find_or_create>
2296 B<Note>: Take care when using C<find_or_new> with a table having
2297 columns with default values that you intend to be automatically
2298 supplied by the database (e.g. an auto_increment primary key column).
2299 In normal usage, the value of such columns should NOT be included at
2300 all in the call to C<find_or_new>, even when set to C<undef>.
2306 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2307 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2308 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2311 return $self->new_result($hash);
2318 =item Arguments: \%vals
2320 =item Return Value: a L<DBIx::Class::Row> $object
2324 Attempt to create a single new row or a row with multiple related rows
2325 in the table represented by the resultset (and related tables). This
2326 will not check for duplicate rows before inserting, use
2327 L</find_or_create> to do that.
2329 To create one row for this resultset, pass a hashref of key/value
2330 pairs representing the columns of the table and the values you wish to
2331 store. If the appropriate relationships are set up, foreign key fields
2332 can also be passed an object representing the foreign row, and the
2333 value will be set to its primary key.
2335 To create related objects, pass a hashref of related-object column values
2336 B<keyed on the relationship name>. If the relationship is of type C<multi>
2337 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2338 The process will correctly identify columns holding foreign keys, and will
2339 transparently populate them from the keys of the corresponding relation.
2340 This can be applied recursively, and will work correctly for a structure
2341 with an arbitrary depth and width, as long as the relationships actually
2342 exists and the correct column data has been supplied.
2345 Instead of hashrefs of plain related data (key/value pairs), you may
2346 also pass new or inserted objects. New objects (not inserted yet, see
2347 L</new>), will be inserted into their appropriate tables.
2349 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2351 Example of creating a new row.
2353 $person_rs->create({
2354 name=>"Some Person",
2355 email=>"somebody@someplace.com"
2358 Example of creating a new row and also creating rows in a related C<has_many>
2359 or C<has_one> resultset. Note Arrayref.
2362 { artistid => 4, name => 'Manufactured Crap', cds => [
2363 { title => 'My First CD', year => 2006 },
2364 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2369 Example of creating a new row and also creating a row in a related
2370 C<belongs_to> resultset. Note Hashref.
2373 title=>"Music for Silly Walks",
2376 name=>"Silly Musician",
2384 When subclassing ResultSet never attempt to override this method. Since
2385 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2386 lot of the internals simply never call it, so your override will be
2387 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2388 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2389 L</create> process you need to intervene.
2396 my ($self, $attrs) = @_;
2397 $self->throw_exception( "create needs a hashref" )
2398 unless ref $attrs eq 'HASH';
2399 return $self->new_result($attrs)->insert;
2402 =head2 find_or_create
2406 =item Arguments: \%vals, \%attrs?
2408 =item Return Value: $rowobject
2412 $cd->cd_to_producer->find_or_create({ producer => $producer },
2413 { key => 'primary' });
2415 Tries to find a record based on its primary key or unique constraints; if none
2416 is found, creates one and returns that instead.
2418 my $cd = $schema->resultset('CD')->find_or_create({
2420 artist => 'Massive Attack',
2421 title => 'Mezzanine',
2425 Also takes an optional C<key> attribute, to search by a specific key or unique
2426 constraint. For example:
2428 my $cd = $schema->resultset('CD')->find_or_create(
2430 artist => 'Massive Attack',
2431 title => 'Mezzanine',
2433 { key => 'cd_artist_title' }
2436 B<Note>: Because find_or_create() reads from the database and then
2437 possibly inserts based on the result, this method is subject to a race
2438 condition. Another process could create a record in the table after
2439 the find has completed and before the create has started. To avoid
2440 this problem, use find_or_create() inside a transaction.
2442 B<Note>: Take care when using C<find_or_create> with a table having
2443 columns with default values that you intend to be automatically
2444 supplied by the database (e.g. an auto_increment primary key column).
2445 In normal usage, the value of such columns should NOT be included at
2446 all in the call to C<find_or_create>, even when set to C<undef>.
2448 See also L</find> and L</update_or_create>. For information on how to declare
2449 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2453 sub find_or_create {
2455 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2456 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2457 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2460 return $self->create($hash);
2463 =head2 update_or_create
2467 =item Arguments: \%col_values, { key => $unique_constraint }?
2469 =item Return Value: $rowobject
2473 $resultset->update_or_create({ col => $val, ... });
2475 First, searches for an existing row matching one of the unique constraints
2476 (including the primary key) on the source of this resultset. If a row is
2477 found, updates it with the other given column values. Otherwise, creates a new
2480 Takes an optional C<key> attribute to search on a specific unique constraint.
2483 # In your application
2484 my $cd = $schema->resultset('CD')->update_or_create(
2486 artist => 'Massive Attack',
2487 title => 'Mezzanine',
2490 { key => 'cd_artist_title' }
2493 $cd->cd_to_producer->update_or_create({
2494 producer => $producer,
2501 If no C<key> is specified, it searches on all unique constraints defined on the
2502 source, including the primary key.
2504 If the C<key> is specified as C<primary>, it searches only on the primary key.
2506 See also L</find> and L</find_or_create>. For information on how to declare
2507 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2509 B<Note>: Take care when using C<update_or_create> with a table having
2510 columns with default values that you intend to be automatically
2511 supplied by the database (e.g. an auto_increment primary key column).
2512 In normal usage, the value of such columns should NOT be included at
2513 all in the call to C<update_or_create>, even when set to C<undef>.
2517 sub update_or_create {
2519 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2520 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2522 my $row = $self->find($cond, $attrs);
2524 $row->update($cond);
2528 return $self->create($cond);
2531 =head2 update_or_new
2535 =item Arguments: \%col_values, { key => $unique_constraint }?
2537 =item Return Value: $rowobject
2541 $resultset->update_or_new({ col => $val, ... });
2543 First, searches for an existing row matching one of the unique constraints
2544 (including the primary key) on the source of this resultset. If a row is
2545 found, updates it with the other given column values. Otherwise, instantiate
2546 a new result object and return it. The object will not be saved into your storage
2547 until you call L<DBIx::Class::Row/insert> on it.
2549 Takes an optional C<key> attribute to search on a specific unique constraint.
2552 # In your application
2553 my $cd = $schema->resultset('CD')->update_or_new(
2555 artist => 'Massive Attack',
2556 title => 'Mezzanine',
2559 { key => 'cd_artist_title' }
2562 if ($cd->in_storage) {
2563 # the cd was updated
2566 # the cd is not yet in the database, let's insert it
2570 B<Note>: Take care when using C<update_or_new> with a table having
2571 columns with default values that you intend to be automatically
2572 supplied by the database (e.g. an auto_increment primary key column).
2573 In normal usage, the value of such columns should NOT be included at
2574 all in the call to C<update_or_new>, even when set to C<undef>.
2576 See also L</find>, L</find_or_create> and L</find_or_new>.
2582 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2583 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2585 my $row = $self->find( $cond, $attrs );
2586 if ( defined $row ) {
2587 $row->update($cond);
2591 return $self->new_result($cond);
2598 =item Arguments: none
2600 =item Return Value: \@cache_objects | undef
2604 Gets the contents of the cache for the resultset, if the cache is set.
2606 The cache is populated either by using the L</prefetch> attribute to
2607 L</search> or by calling L</set_cache>.
2619 =item Arguments: \@cache_objects
2621 =item Return Value: \@cache_objects
2625 Sets the contents of the cache for the resultset. Expects an arrayref
2626 of objects of the same class as those produced by the resultset. Note that
2627 if the cache is set the resultset will return the cached objects rather
2628 than re-querying the database even if the cache attr is not set.
2630 The contents of the cache can also be populated by using the
2631 L</prefetch> attribute to L</search>.
2636 my ( $self, $data ) = @_;
2637 $self->throw_exception("set_cache requires an arrayref")
2638 if defined($data) && (ref $data ne 'ARRAY');
2639 $self->{all_cache} = $data;
2646 =item Arguments: none
2648 =item Return Value: undef
2652 Clears the cache for the resultset.
2657 shift->set_cache(undef);
2664 =item Arguments: none
2666 =item Return Value: true, if the resultset has been paginated
2674 return !!$self->{attrs}{page};
2681 =item Arguments: none
2683 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2691 return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
2694 =head2 related_resultset
2698 =item Arguments: $relationship_name
2700 =item Return Value: $resultset
2704 Returns a related resultset for the supplied relationship name.
2706 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2710 sub related_resultset {
2711 my ($self, $rel) = @_;
2713 $self->{related_resultsets} ||= {};
2714 return $self->{related_resultsets}{$rel} ||= do {
2715 my $rsrc = $self->result_source;
2716 my $rel_info = $rsrc->relationship_info($rel);
2718 $self->throw_exception(
2719 "search_related: result source '" . $rsrc->source_name .
2720 "' has no such relationship $rel")
2723 my $attrs = $self->_chain_relationship($rel);
2725 my $join_count = $attrs->{seen_join}{$rel};
2727 my $alias = $self->result_source->storage
2728 ->relname_to_table_alias($rel, $join_count);
2730 # since this is search_related, and we already slid the select window inwards
2731 # (the select/as attrs were deleted in the beginning), we need to flip all
2732 # left joins to inner, so we get the expected results
2733 # read the comment on top of the actual function to see what this does
2734 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2737 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2738 delete @{$attrs}{qw(result_class alias)};
2742 if (my $cache = $self->get_cache) {
2743 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2744 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2749 my $rel_source = $rsrc->related_source($rel);
2753 # The reason we do this now instead of passing the alias to the
2754 # search_rs below is that if you wrap/overload resultset on the
2755 # source you need to know what alias it's -going- to have for things
2756 # to work sanely (e.g. RestrictWithObject wants to be able to add
2757 # extra query restrictions, and these may need to be $alias.)
2759 my $rel_attrs = $rel_source->resultset_attributes;
2760 local $rel_attrs->{alias} = $alias;
2762 $rel_source->resultset
2766 where => $attrs->{where},
2769 $new->set_cache($new_cache) if $new_cache;
2774 =head2 current_source_alias
2778 =item Arguments: none
2780 =item Return Value: $source_alias
2784 Returns the current table alias for the result source this resultset is built
2785 on, that will be used in the SQL query. Usually it is C<me>.
2787 Currently the source alias that refers to the result set returned by a
2788 L</search>/L</find> family method depends on how you got to the resultset: it's
2789 C<me> by default, but eg. L</search_related> aliases it to the related result
2790 source name (and keeps C<me> referring to the original result set). The long
2791 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2792 (and make this method unnecessary).
2794 Thus it's currently necessary to use this method in predefined queries (see
2795 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2796 source alias of the current result set:
2798 # in a result set class
2800 my ($self, $user) = @_;
2802 my $me = $self->current_source_alias;
2804 return $self->search(
2805 "$me.modified" => $user->id,
2811 sub current_source_alias {
2814 return ($self->{attrs} || {})->{alias} || 'me';
2817 =head2 as_subselect_rs
2821 =item Arguments: none
2823 =item Return Value: $resultset
2827 Act as a barrier to SQL symbols. The resultset provided will be made into a
2828 "virtual view" by including it as a subquery within the from clause. From this
2829 point on, any joined tables are inaccessible to ->search on the resultset (as if
2830 it were simply where-filtered without joins). For example:
2832 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2834 # 'x' now pollutes the query namespace
2836 # So the following works as expected
2837 my $ok_rs = $rs->search({'x.other' => 1});
2839 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2840 # def) we look for one row with contradictory terms and join in another table
2841 # (aliased 'x_2') which we never use
2842 my $broken_rs = $rs->search({'x.name' => 'def'});
2844 my $rs2 = $rs->as_subselect_rs;
2846 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2847 my $not_joined_rs = $rs2->search({'x.other' => 1});
2849 # works as expected: finds a 'table' row related to two x rows (abc and def)
2850 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2852 Another example of when one might use this would be to select a subset of
2853 columns in a group by clause:
2855 my $rs = $schema->resultset('Bar')->search(undef, {
2856 group_by => [qw{ id foo_id baz_id }],
2857 })->as_subselect_rs->search(undef, {
2858 columns => [qw{ id foo_id }]
2861 In the above example normally columns would have to be equal to the group by,
2862 but because we isolated the group by into a subselect the above works.
2866 sub as_subselect_rs {
2869 my $attrs = $self->_resolved_attrs;
2871 my $fresh_rs = (ref $self)->new (
2872 $self->result_source
2875 # these pieces will be locked in the subquery
2876 delete $fresh_rs->{cond};
2877 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2879 return $fresh_rs->search( {}, {
2881 $attrs->{alias} => $self->as_query,
2882 -alias => $attrs->{alias},
2883 -source_handle => $self->result_source->handle,
2885 alias => $attrs->{alias},
2889 # This code is called by search_related, and makes sure there
2890 # is clear separation between the joins before, during, and
2891 # after the relationship. This information is needed later
2892 # in order to properly resolve prefetch aliases (any alias
2893 # with a relation_chain_depth less than the depth of the
2894 # current prefetch is not considered)
2896 # The increments happen twice per join. An even number means a
2897 # relationship specified via a search_related, whereas an odd
2898 # number indicates a join/prefetch added via attributes
2900 # Also this code will wrap the current resultset (the one we
2901 # chain to) in a subselect IFF it contains limiting attributes
2902 sub _chain_relationship {
2903 my ($self, $rel) = @_;
2904 my $source = $self->result_source;
2905 my $attrs = { %{$self->{attrs}||{}} };
2907 # we need to take the prefetch the attrs into account before we
2908 # ->_resolve_join as otherwise they get lost - captainL
2909 my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2911 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2913 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2916 my @force_subq_attrs = qw/offset rows group_by having/;
2919 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2921 $self->_has_resolved_attr (@force_subq_attrs)
2923 # Nuke the prefetch (if any) before the new $rs attrs
2924 # are resolved (prefetch is useless - we are wrapping
2925 # a subquery anyway).
2926 my $rs_copy = $self->search;
2927 $rs_copy->{attrs}{join} = $self->_merge_attr (
2928 $rs_copy->{attrs}{join},
2929 delete $rs_copy->{attrs}{prefetch},
2933 -source_handle => $source->handle,
2934 -alias => $attrs->{alias},
2935 $attrs->{alias} => $rs_copy->as_query,
2937 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2938 $seen->{-relation_chain_depth} = 0;
2940 elsif ($attrs->{from}) { #shallow copy suffices
2941 $from = [ @{$attrs->{from}} ];
2945 -source_handle => $source->handle,
2946 -alias => $attrs->{alias},
2947 $attrs->{alias} => $source->from,
2951 my $jpath = ($seen->{-relation_chain_depth})
2952 ? $from->[-1][0]{-join_path}
2955 my @requested_joins = $source->_resolve_join(
2962 push @$from, @requested_joins;
2964 $seen->{-relation_chain_depth}++;
2966 # if $self already had a join/prefetch specified on it, the requested
2967 # $rel might very well be already included. What we do in this case
2968 # is effectively a no-op (except that we bump up the chain_depth on
2969 # the join in question so we could tell it *is* the search_related)
2972 # we consider the last one thus reverse
2973 for my $j (reverse @requested_joins) {
2974 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2975 if ($rel eq $last_j) {
2976 $j->[0]{-relation_chain_depth}++;
2982 unless ($already_joined) {
2983 push @$from, $source->_resolve_join(
2991 $seen->{-relation_chain_depth}++;
2993 return {%$attrs, from => $from, seen_join => $seen};
2996 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2997 sub _resolved_attrs_copy {
2999 return { %{$self->_resolved_attrs (@_)} };
3002 sub _resolved_attrs {
3004 return $self->{_attrs} if $self->{_attrs};
3006 my $attrs = { %{ $self->{attrs} || {} } };
3007 my $source = $self->result_source;
3008 my $alias = $attrs->{alias};
3010 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
3013 # build columns (as long as select isn't set) into a set of as/select hashes
3014 unless ( $attrs->{select} ) {
3017 if ( ref $attrs->{columns} eq 'ARRAY' ) {
3018 @cols = @{ delete $attrs->{columns}}
3019 } elsif ( defined $attrs->{columns} ) {
3020 @cols = delete $attrs->{columns}
3022 @cols = $source->columns
3026 if ( ref $_ eq 'HASH' ) {
3029 my $key = /^\Q${alias}.\E(.+)$/
3035 push @colbits, { $key => $value };
3040 # add the additional columns on
3041 foreach (qw{include_columns +columns}) {
3042 if ( $attrs->{$_} ) {
3043 my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
3044 ? @{ delete $attrs->{$_} }
3045 : delete $attrs->{$_};
3047 if ( ref($_) eq 'HASH' ) {
3050 my $key = ( split /\./, $_ )[-1];
3051 my $value = ( /\./ ? $_ : "$alias.$_" );
3052 push @colbits, { $key => $value };
3058 # start with initial select items
3059 if ( $attrs->{select} ) {
3061 ( ref $attrs->{select} eq 'ARRAY' )
3062 ? [ @{ $attrs->{select} } ]
3063 : [ $attrs->{select} ];
3065 if ( $attrs->{as} ) {
3068 ref $attrs->{as} eq 'ARRAY'
3069 ? [ @{ $attrs->{as} } ]
3073 $attrs->{as} = [ map {
3074 m/^\Q${alias}.\E(.+)$/
3077 } @{ $attrs->{select} }
3083 # otherwise we intialise select & as to empty
3084 $attrs->{select} = [];
3088 # now add colbits to select/as
3089 push @{ $attrs->{select} }, map values %{$_}, @colbits;
3090 push @{ $attrs->{as} }, map keys %{$_}, @colbits;
3092 if ( my $adds = delete $attrs->{'+select'} ) {
3093 $adds = [$adds] unless ref $adds eq 'ARRAY';
3094 push @{ $attrs->{select} },
3095 map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
3097 if ( my $adds = delete $attrs->{'+as'} ) {
3098 $adds = [$adds] unless ref $adds eq 'ARRAY';
3099 push @{ $attrs->{as} }, @$adds;
3102 $attrs->{from} ||= [{
3103 -source_handle => $source->handle,
3104 -alias => $self->{attrs}{alias},
3105 $self->{attrs}{alias} => $source->from,
3108 if ( $attrs->{join} || $attrs->{prefetch} ) {
3110 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3111 if ref $attrs->{from} ne 'ARRAY';
3113 my $join = delete $attrs->{join} || {};
3115 if ( defined $attrs->{prefetch} ) {
3116 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
3119 $attrs->{from} = # have to copy here to avoid corrupting the original
3121 @{ $attrs->{from} },
3122 $source->_resolve_join(
3125 { %{ $attrs->{seen_join} || {} } },
3126 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3127 ? $attrs->{from}[-1][0]{-join_path}
3134 if ( defined $attrs->{order_by} ) {
3135 $attrs->{order_by} = (
3136 ref( $attrs->{order_by} ) eq 'ARRAY'
3137 ? [ @{ $attrs->{order_by} } ]
3138 : [ $attrs->{order_by} || () ]
3142 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3143 $attrs->{group_by} = [ $attrs->{group_by} ];
3146 # generate the distinct induced group_by early, as prefetch will be carried via a
3147 # subquery (since a group_by is present)
3148 if (delete $attrs->{distinct}) {
3149 if ($attrs->{group_by}) {
3150 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3153 my $storage = $self->result_source->schema->storage;
3154 my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
3156 my $group_spec = $attrs->{group_by} = [];
3159 for (@{$attrs->{select}}) {
3160 if (! ref($_) or ref ($_) ne 'HASH' ) {
3161 push @$group_spec, $_;
3163 if ($rs_column_list->{$_} and $_ !~ /\./ ) {
3164 # add a fully qualified version as well
3165 $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
3169 # add any order_by parts that are not already present in the group_by
3170 # we need to be careful not to add any named functions/aggregates
3171 # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
3172 for my $chunk ($storage->_extract_order_columns($attrs->{order_by})) {
3174 # only consider real columns (for functions the user got to do an explicit group_by)
3175 my $colinfo = $rs_column_list->{$chunk}
3178 $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
3179 push @$group_spec, $chunk unless $group_index{$chunk}++;
3184 $attrs->{collapse} ||= {};
3185 if ( my $prefetch = delete $attrs->{prefetch} ) {
3186 $prefetch = $self->_merge_attr( {}, $prefetch );
3188 my $prefetch_ordering = [];
3190 # this is a separate structure (we don't look in {from} directly)
3191 # as the resolver needs to shift things off the lists to work
3192 # properly (identical-prefetches on different branches)
3194 if (ref $attrs->{from} eq 'ARRAY') {
3196 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3198 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3199 next unless $j->[0]{-alias};
3200 next unless $j->[0]{-join_path};
3201 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3203 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3206 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3207 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3212 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3214 # we need to somehow mark which columns came from prefetch
3215 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3217 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3218 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3220 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3221 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3224 # if both page and offset are specified, produce a combined offset
3225 # even though it doesn't make much sense, this is what pre 081xx has
3227 if (my $page = delete $attrs->{page}) {
3229 ($attrs->{rows} * ($page - 1))
3231 ($attrs->{offset} || 0)
3235 return $self->{_attrs} = $attrs;
3239 my ($self, $attr) = @_;
3241 if (ref $attr eq 'HASH') {
3242 return $self->_rollout_hash($attr);
3243 } elsif (ref $attr eq 'ARRAY') {
3244 return $self->_rollout_array($attr);
3250 sub _rollout_array {
3251 my ($self, $attr) = @_;
3254 foreach my $element (@{$attr}) {
3255 if (ref $element eq 'HASH') {
3256 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3257 } elsif (ref $element eq 'ARRAY') {
3258 # XXX - should probably recurse here
3259 push( @rolled_array, @{$self->_rollout_array($element)} );
3261 push( @rolled_array, $element );
3264 return \@rolled_array;
3268 my ($self, $attr) = @_;
3271 foreach my $key (keys %{$attr}) {
3272 push( @rolled_array, { $key => $attr->{$key} } );
3274 return \@rolled_array;
3277 sub _calculate_score {
3278 my ($self, $a, $b) = @_;
3280 if (defined $a xor defined $b) {
3283 elsif (not defined $a) {
3287 if (ref $b eq 'HASH') {
3288 my ($b_key) = keys %{$b};
3289 if (ref $a eq 'HASH') {
3290 my ($a_key) = keys %{$a};
3291 if ($a_key eq $b_key) {
3292 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3297 return ($a eq $b_key) ? 1 : 0;
3300 if (ref $a eq 'HASH') {
3301 my ($a_key) = keys %{$a};
3302 return ($b eq $a_key) ? 1 : 0;
3304 return ($b eq $a) ? 1 : 0;
3310 my ($self, $orig, $import) = @_;
3312 return $import unless defined($orig);
3313 return $orig unless defined($import);
3315 $orig = $self->_rollout_attr($orig);
3316 $import = $self->_rollout_attr($import);
3319 foreach my $import_element ( @{$import} ) {
3320 # find best candidate from $orig to merge $b_element into
3321 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3322 foreach my $orig_element ( @{$orig} ) {
3323 my $score = $self->_calculate_score( $orig_element, $import_element );
3324 if ($score > $best_candidate->{score}) {
3325 $best_candidate->{position} = $position;
3326 $best_candidate->{score} = $score;
3330 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3332 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3333 push( @{$orig}, $import_element );
3335 my $orig_best = $orig->[$best_candidate->{position}];
3336 # merge orig_best and b_element together and replace original with merged
3337 if (ref $orig_best ne 'HASH') {
3338 $orig->[$best_candidate->{position}] = $import_element;
3339 } elsif (ref $import_element eq 'HASH') {
3340 my ($key) = keys %{$orig_best};
3341 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
3344 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3354 $self->_source_handle($_[0]->handle);
3356 $self->_source_handle->resolve;
3360 =head2 throw_exception
3362 See L<DBIx::Class::Schema/throw_exception> for details.
3366 sub throw_exception {
3369 if (ref $self && $self->_source_handle->schema) {
3370 $self->_source_handle->schema->throw_exception(@_)
3373 DBIx::Class::Exception->throw(@_);
3377 # XXX: FIXME: Attributes docs need clearing up
3381 Attributes are used to refine a ResultSet in various ways when
3382 searching for data. They can be passed to any method which takes an
3383 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3386 These are in no particular order:
3392 =item Value: ( $order_by | \@order_by | \%order_by )
3396 Which column(s) to order the results by.
3398 [The full list of suitable values is documented in
3399 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3402 If a single column name, or an arrayref of names is supplied, the
3403 argument is passed through directly to SQL. The hashref syntax allows
3404 for connection-agnostic specification of ordering direction:
3406 For descending order:
3408 order_by => { -desc => [qw/col1 col2 col3/] }
3410 For explicit ascending order:
3412 order_by => { -asc => 'col' }
3414 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3415 supported, although you are strongly encouraged to use the hashref
3416 syntax as outlined above.
3422 =item Value: \@columns
3426 Shortcut to request a particular set of columns to be retrieved. Each
3427 column spec may be a string (a table column name), or a hash (in which
3428 case the key is the C<as> value, and the value is used as the C<select>
3429 expression). Adds C<me.> onto the start of any column without a C<.> in
3430 it and sets C<select> from that, then auto-populates C<as> from
3431 C<select> as normal. (You may also use the C<cols> attribute, as in
3432 earlier versions of DBIC.)
3434 Essentially C<columns> does the same as L</select> and L</as>.
3436 columns => [ 'foo', { bar => 'baz' } ]
3440 select => [qw/foo baz/],
3447 =item Value: \@columns
3451 Indicates additional columns to be selected from storage. Works the same
3452 as L</columns> but adds columns to the selection. (You may also use the
3453 C<include_columns> attribute, as in earlier versions of DBIC). For
3456 $schema->resultset('CD')->search(undef, {
3457 '+columns' => ['artist.name'],
3461 would return all CDs and include a 'name' column to the information
3462 passed to object inflation. Note that the 'artist' is the name of the
3463 column (or relationship) accessor, and 'name' is the name of the column
3464 accessor in the related table.
3466 =head2 include_columns
3470 =item Value: \@columns
3474 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3480 =item Value: \@select_columns
3484 Indicates which columns should be selected from the storage. You can use
3485 column names, or in the case of RDBMS back ends, function or stored procedure
3488 $rs = $schema->resultset('Employee')->search(undef, {
3491 { count => 'employeeid' },
3492 { max => { length => 'name' }, -as => 'longest_name' }
3497 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3499 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3500 use L</select>, to instruct DBIx::Class how to store the result of the column.
3501 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3502 identifier aliasing. You can however alias a function, so you can use it in
3503 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3504 attribute> supplied as shown in the example above.
3510 Indicates additional columns to be selected from storage. Works the same as
3511 L</select> but adds columns to the default selection, instead of specifying
3520 Indicates additional column names for those added via L</+select>. See L</as>.
3528 =item Value: \@inflation_names
3532 Indicates column names for object inflation. That is L</as> indicates the
3533 slot name in which the column value will be stored within the
3534 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3535 identifier by the C<get_column> method (or via the object accessor B<if one
3536 with the same name already exists>) as shown below. The L</as> attribute has
3537 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3539 $rs = $schema->resultset('Employee')->search(undef, {
3542 { count => 'employeeid' },
3543 { max => { length => 'name' }, -as => 'longest_name' }
3552 If the object against which the search is performed already has an accessor
3553 matching a column name specified in C<as>, the value can be retrieved using
3554 the accessor as normal:
3556 my $name = $employee->name();
3558 If on the other hand an accessor does not exist in the object, you need to
3559 use C<get_column> instead:
3561 my $employee_count = $employee->get_column('employee_count');
3563 You can create your own accessors if required - see
3564 L<DBIx::Class::Manual::Cookbook> for details.
3570 =item Value: ($rel_name | \@rel_names | \%rel_names)
3574 Contains a list of relationships that should be joined for this query. For
3577 # Get CDs by Nine Inch Nails
3578 my $rs = $schema->resultset('CD')->search(
3579 { 'artist.name' => 'Nine Inch Nails' },
3580 { join => 'artist' }
3583 Can also contain a hash reference to refer to the other relation's relations.
3586 package MyApp::Schema::Track;
3587 use base qw/DBIx::Class/;
3588 __PACKAGE__->table('track');
3589 __PACKAGE__->add_columns(qw/trackid cd position title/);
3590 __PACKAGE__->set_primary_key('trackid');
3591 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3594 # In your application
3595 my $rs = $schema->resultset('Artist')->search(
3596 { 'track.title' => 'Teardrop' },
3598 join => { cd => 'track' },
3599 order_by => 'artist.name',
3603 You need to use the relationship (not the table) name in conditions,
3604 because they are aliased as such. The current table is aliased as "me", so
3605 you need to use me.column_name in order to avoid ambiguity. For example:
3607 # Get CDs from 1984 with a 'Foo' track
3608 my $rs = $schema->resultset('CD')->search(
3611 'tracks.name' => 'Foo'
3613 { join => 'tracks' }
3616 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3617 similarly for a third time). For e.g.
3619 my $rs = $schema->resultset('Artist')->search({
3620 'cds.title' => 'Down to Earth',
3621 'cds_2.title' => 'Popular',
3623 join => [ qw/cds cds/ ],
3626 will return a set of all artists that have both a cd with title 'Down
3627 to Earth' and a cd with title 'Popular'.
3629 If you want to fetch related objects from other tables as well, see C<prefetch>
3632 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3638 =item Value: ($rel_name | \@rel_names | \%rel_names)
3642 Contains one or more relationships that should be fetched along with
3643 the main query (when they are accessed afterwards the data will
3644 already be available, without extra queries to the database). This is
3645 useful for when you know you will need the related objects, because it
3646 saves at least one query:
3648 my $rs = $schema->resultset('Tag')->search(
3657 The initial search results in SQL like the following:
3659 SELECT tag.*, cd.*, artist.* FROM tag
3660 JOIN cd ON tag.cd = cd.cdid
3661 JOIN artist ON cd.artist = artist.artistid
3663 L<DBIx::Class> has no need to go back to the database when we access the
3664 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3667 Simple prefetches will be joined automatically, so there is no need
3668 for a C<join> attribute in the above search.
3670 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3671 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3672 with an accessor type of 'single' or 'filter'). A more complex example that
3673 prefetches an artists cds, the tracks on those cds, and the tags associated
3674 with that artist is given below (assuming many-to-many from artists to tags):
3676 my $rs = $schema->resultset('Artist')->search(
3680 { cds => 'tracks' },
3681 { artist_tags => 'tags' }
3687 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3688 attributes will be ignored.
3690 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3691 exactly as you might expect.
3697 Prefetch uses the L</cache> to populate the prefetched relationships. This
3698 may or may not be what you want.
3702 If you specify a condition on a prefetched relationship, ONLY those
3703 rows that match the prefetched condition will be fetched into that relationship.
3704 This means that adding prefetch to a search() B<may alter> what is returned by
3705 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3707 my $artist_rs = $schema->resultset('Artist')->search({
3713 my $count = $artist_rs->first->cds->count;
3715 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3717 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3719 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3721 that cmp_ok() may or may not pass depending on the datasets involved. This
3722 behavior may or may not survive the 0.09 transition.
3734 Makes the resultset paged and specifies the page to retrieve. Effectively
3735 identical to creating a non-pages resultset and then calling ->page($page)
3738 If L<rows> attribute is not specified it defaults to 10 rows per page.
3740 When you have a paged resultset, L</count> will only return the number
3741 of rows in the page. To get the total, use the L</pager> and call
3742 C<total_entries> on it.
3752 Specifies the maximum number of rows for direct retrieval or the number of
3753 rows per page if the page attribute or method is used.
3759 =item Value: $offset
3763 Specifies the (zero-based) row number for the first row to be returned, or the
3764 of the first row of the first page if paging is used.
3770 =item Value: \@columns
3774 A arrayref of columns to group by. Can include columns of joined tables.
3776 group_by => [qw/ column1 column2 ... /]
3782 =item Value: $condition
3786 HAVING is a select statement attribute that is applied between GROUP BY and
3787 ORDER BY. It is applied to the after the grouping calculations have been
3790 having => { 'count(employee)' => { '>=', 100 } }
3796 =item Value: (0 | 1)
3800 Set to 1 to group by all columns. If the resultset already has a group_by
3801 attribute, this setting is ignored and an appropriate warning is issued.
3807 Adds to the WHERE clause.
3809 # only return rows WHERE deleted IS NULL for all searches
3810 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3812 Can be overridden by passing C<< { where => undef } >> as an attribute
3819 Set to 1 to cache search results. This prevents extra SQL queries if you
3820 revisit rows in your ResultSet:
3822 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3824 while( my $artist = $resultset->next ) {
3828 $rs->first; # without cache, this would issue a query
3830 By default, searches are not cached.
3832 For more examples of using these attributes, see
3833 L<DBIx::Class::Manual::Cookbook>.
3839 =item Value: ( 'update' | 'shared' )
3843 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT