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 'blessed';
21 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
25 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
29 my $users_rs = $schema->resultset('User');
30 while( $user = $users_rs->next) {
31 print $user->username;
34 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
35 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
39 A ResultSet is an object which stores a set of conditions representing
40 a query. It is the backbone of DBIx::Class (i.e. the really
41 important/useful bit).
43 No SQL is executed on the database when a ResultSet is created, it
44 just stores all the conditions needed to create the query.
46 A basic ResultSet representing the data of an entire table is returned
47 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
48 L<Source|DBIx::Class::Manual::Glossary/Source> name.
50 my $users_rs = $schema->resultset('User');
52 A new ResultSet is returned from calling L</search> on an existing
53 ResultSet. The new one will contain all the conditions of the
54 original, plus any new conditions added in the C<search> call.
56 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
57 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
60 The query that the ResultSet represents is B<only> executed against
61 the database when these methods are called:
62 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
64 If a resultset is used in a numeric context it returns the L</count>.
65 However, if it is used in a boolean context it is B<always> true. So if
66 you want to check if a resultset has any results, you must use C<if $rs
71 =head2 Chaining resultsets
73 Let's say you've got a query that needs to be run to return some data
74 to the user. But, you have an authorization system in place that
75 prevents certain users from seeing certain information. So, you want
76 to construct the basic query in one method, but add constraints to it in
81 my $request = $self->get_request; # Get a request object somehow.
82 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
84 my $cd_rs = $schema->resultset('CD')->search({
85 title => $request->param('title'),
86 year => $request->param('year'),
89 $self->apply_security_policy( $cd_rs );
94 sub apply_security_policy {
103 =head3 Resolving conditions and attributes
105 When a resultset is chained from another resultset, conditions and
106 attributes with the same keys need resolving.
108 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
109 into the existing ones from the original resultset.
111 The L</where> and L</having> attributes, and any search conditions, are
112 merged with an SQL C<AND> to the existing condition from the original
115 All other attributes are overridden by any new ones supplied in the
118 =head2 Multiple queries
120 Since a resultset just defines a query, you can do all sorts of
121 things with it with the same object.
123 # Don't hit the DB yet.
124 my $cd_rs = $schema->resultset('CD')->search({
125 title => 'something',
129 # Each of these hits the DB individually.
130 my $count = $cd_rs->count;
131 my $most_recent = $cd_rs->get_column('date_released')->max();
132 my @records = $cd_rs->all;
134 And it's not just limited to SELECT statements.
140 $cd_rs->create({ artist => 'Fred' });
142 Which is the same as:
144 $schema->resultset('CD')->create({
145 title => 'something',
150 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
158 =item Arguments: $source, \%$attrs
160 =item Return Value: $rs
164 The resultset constructor. Takes a source object (usually a
165 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
166 L</ATTRIBUTES> below). Does not perform any queries -- these are
167 executed as needed by the other methods.
169 Generally you won't need to construct a resultset manually. You'll
170 automatically get one from e.g. a L</search> called in scalar context:
172 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
174 IMPORTANT: If called on an object, proxies to new_result instead so
176 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
178 will return a CD object, not a ResultSet.
184 return $class->new_result(@_) if ref $class;
186 my ($source, $attrs) = @_;
187 $source = $source->handle
188 unless $source->isa('DBIx::Class::ResultSourceHandle');
189 $attrs = { %{$attrs||{}} };
191 if ($attrs->{page}) {
192 $attrs->{rows} ||= 10;
195 $attrs->{alias} ||= 'me';
197 # Creation of {} and bless separated to mitigate RH perl bug
198 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
200 _source_handle => $source,
201 cond => $attrs->{where},
209 $attrs->{result_class} || $source->resolve->result_class
219 =item Arguments: $cond, \%attrs?
221 =item Return Value: $resultset (scalar context), @row_objs (list context)
225 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
226 my $new_rs = $cd_rs->search({ year => 2005 });
228 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
229 # year = 2005 OR year = 2004
231 If you need to pass in additional attributes but no additional condition,
232 call it as C<search(undef, \%attrs)>.
234 # "SELECT name, artistid FROM $artist_table"
235 my @all_artists = $schema->resultset('Artist')->search(undef, {
236 columns => [qw/name artistid/],
239 For a list of attributes that can be passed to C<search>, see
240 L</ATTRIBUTES>. For more examples of using this function, see
241 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
242 documentation for the first argument, see L<SQL::Abstract>.
244 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
250 my $rs = $self->search_rs( @_ );
251 return (wantarray ? $rs->all : $rs);
258 =item Arguments: $cond, \%attrs?
260 =item Return Value: $resultset
264 This method does the same exact thing as search() except it will
265 always return a resultset, even in list context.
272 # Special-case handling for (undef, undef).
273 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
278 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
279 my $our_attrs = { %{$self->{attrs}} };
280 my $having = delete $our_attrs->{having};
281 my $where = delete $our_attrs->{where};
285 my %safe = (alias => 1, cache => 1);
288 (@_ && defined($_[0])) # @_ == () or (undef)
290 (keys %$attrs # empty attrs or only 'safe' attrs
291 && List::Util::first { !$safe{$_} } keys %$attrs)
293 # no search, effectively just a clone
294 $rows = $self->get_cache;
297 # reset the selector list
298 if (List::Util::first { exists $attrs->{$_} } qw{columns select as}) {
299 delete @{$our_attrs}{qw{select as columns +select +as +columns include_columns}};
302 my $new_attrs = { %{$our_attrs}, %{$attrs} };
304 # merge new attrs into inherited
305 foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
306 next unless exists $attrs->{$key};
307 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
312 (@_ == 1 || ref $_[0] eq "HASH")
314 (ref $_[0] eq 'HASH')
316 (keys %{ $_[0] } > 0)
324 ? $self->throw_exception("Odd number of arguments to search")
331 if (defined $where) {
332 $new_attrs->{where} = (
333 defined $new_attrs->{where}
336 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
337 } $where, $new_attrs->{where}
344 $new_attrs->{where} = (
345 defined $new_attrs->{where}
348 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
349 } $cond, $new_attrs->{where}
355 if (defined $having) {
356 $new_attrs->{having} = (
357 defined $new_attrs->{having}
360 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
361 } $having, $new_attrs->{having}
367 my $rs = (ref $self)->new($self->result_source, $new_attrs);
369 $rs->set_cache($rows) if ($rows);
374 =head2 search_literal
378 =item Arguments: $sql_fragment, @bind_values
380 =item Return Value: $resultset (scalar context), @row_objs (list context)
384 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
385 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
387 Pass a literal chunk of SQL to be added to the conditional part of the
390 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
391 only be used in that context. C<search_literal> is a convenience method.
392 It is equivalent to calling $schema->search(\[]), but if you want to ensure
393 columns are bound correctly, use C<search>.
395 Example of how to use C<search> instead of C<search_literal>
397 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
398 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
401 See L<DBIx::Class::Manual::Cookbook/Searching> and
402 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
403 require C<search_literal>.
408 my ($self, $sql, @bind) = @_;
410 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
413 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
420 =item Arguments: @values | \%cols, \%attrs?
422 =item Return Value: $row_object | undef
426 Finds a row based on its primary key or unique constraint. For example, to find
427 a row by its primary key:
429 my $cd = $schema->resultset('CD')->find(5);
431 You can also find a row by a specific unique constraint using the C<key>
432 attribute. For example:
434 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
435 key => 'cd_artist_title'
438 Additionally, you can specify the columns explicitly by name:
440 my $cd = $schema->resultset('CD')->find(
442 artist => 'Massive Attack',
443 title => 'Mezzanine',
445 { key => 'cd_artist_title' }
448 If the C<key> is specified as C<primary>, it searches only on the primary key.
450 If no C<key> is specified, it searches on all unique constraints defined on the
451 source for which column data is provided, including the primary key.
453 If your table does not have a primary key, you B<must> provide a value for the
454 C<key> attribute matching one of the unique constraints on the source.
456 In addition to C<key>, L</find> recognizes and applies standard
457 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
459 Note: If your query does not return only one row, a warning is generated:
461 Query returned more than one row
463 See also L</find_or_create> and L</update_or_create>. For information on how to
464 declare unique constraints, see
465 L<DBIx::Class::ResultSource/add_unique_constraint>.
471 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
473 # Default to the primary key, but allow a specific key
474 my @cols = exists $attrs->{key}
475 ? $self->result_source->unique_constraint_columns($attrs->{key})
476 : $self->result_source->primary_columns;
477 $self->throw_exception(
478 "Can't find unless a primary key is defined or unique constraint is specified"
481 # Parse out a hashref from input
483 if (ref $_[0] eq 'HASH') {
484 $input_query = { %{$_[0]} };
486 elsif (@_ == @cols) {
488 @{$input_query}{@cols} = @_;
491 # Compatibility: Allow e.g. find(id => $value)
492 carp "Find by key => value deprecated; please use a hashref instead";
496 my (%related, $info);
498 KEY: foreach my $key (keys %$input_query) {
499 if (ref($input_query->{$key})
500 && ($info = $self->result_source->relationship_info($key))) {
501 my $val = delete $input_query->{$key};
502 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
503 my $rel_q = $self->result_source->_resolve_condition(
504 $info->{cond}, $val, $key
506 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
507 @related{keys %$rel_q} = values %$rel_q;
510 if (my @keys = keys %related) {
511 @{$input_query}{@keys} = values %related;
515 # Build the final query: Default to the disjunction of the unique queries,
516 # but allow the input query in case the ResultSet defines the query or the
517 # user is abusing find
518 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
520 if (exists $attrs->{key}) {
521 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
522 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
523 $query = $self->_add_alias($unique_query, $alias);
525 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
526 # This means that we got here after a merger of relationship conditions
527 # in ::Relationship::Base::search_related (the row method), and furthermore
528 # the relationship is of the 'single' type. This means that the condition
529 # provided by the relationship (already attached to $self) is sufficient,
530 # as there can be only one row in the database that would satisfy the
534 my @unique_queries = $self->_unique_queries($input_query, $attrs);
535 $query = @unique_queries
536 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
537 : $self->_add_alias($input_query, $alias);
540 # Run the query, passing the result_class since it should propagate for find
541 my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs});
542 if (keys %{$rs->_resolved_attrs->{collapse}}) {
544 carp "Query returned more than one row" if $rs->next;
554 # Add the specified alias to the specified query hash. A copy is made so the
555 # original query is not modified.
558 my ($self, $query, $alias) = @_;
560 my %aliased = %$query;
561 foreach my $col (grep { ! m/\./ } keys %aliased) {
562 $aliased{"$alias.$col"} = delete $aliased{$col};
570 # Build a list of queries which satisfy unique constraints.
572 sub _unique_queries {
573 my ($self, $query, $attrs) = @_;
575 my @constraint_names = exists $attrs->{key}
577 : $self->result_source->unique_constraint_names;
579 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
580 my $num_where = scalar keys %$where;
582 my (@unique_queries, %seen_column_combinations);
583 foreach my $name (@constraint_names) {
584 my @constraint_cols = $self->result_source->unique_constraint_columns($name);
586 my $constraint_sig = join "\x00", sort @constraint_cols;
587 next if $seen_column_combinations{$constraint_sig}++;
589 my $unique_query = $self->_build_unique_query($query, \@constraint_cols);
591 my $num_cols = scalar @constraint_cols;
592 my $num_query = scalar keys %$unique_query;
594 my $total = $num_query + $num_where;
595 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
596 # The query is either unique on its own or is unique in combination with
597 # the existing where clause
598 push @unique_queries, $unique_query;
602 return @unique_queries;
605 # _build_unique_query
607 # Constrain the specified query hash based on the specified column names.
609 sub _build_unique_query {
610 my ($self, $query, $unique_cols) = @_;
613 map { $_ => $query->{$_} }
614 grep { exists $query->{$_} }
619 =head2 search_related
623 =item Arguments: $rel, $cond, \%attrs?
625 =item Return Value: $new_resultset
629 $new_rs = $cd_rs->search_related('artist', {
633 Searches the specified relationship, optionally specifying a condition and
634 attributes for matching records. See L</ATTRIBUTES> for more information.
639 return shift->related_resultset(shift)->search(@_);
642 =head2 search_related_rs
644 This method works exactly the same as search_related, except that
645 it guarantees a resultset, even in list context.
649 sub search_related_rs {
650 return shift->related_resultset(shift)->search_rs(@_);
657 =item Arguments: none
659 =item Return Value: $cursor
663 Returns a storage-driven cursor to the given resultset. See
664 L<DBIx::Class::Cursor> for more information.
671 my $attrs = $self->_resolved_attrs_copy;
673 return $self->{cursor}
674 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
675 $attrs->{where},$attrs);
682 =item Arguments: $cond?
684 =item Return Value: $row_object?
688 my $cd = $schema->resultset('CD')->single({ year => 2001 });
690 Inflates the first result without creating a cursor if the resultset has
691 any records in it; if not returns nothing. Used by L</find> as a lean version of
694 While this method can take an optional search condition (just like L</search>)
695 being a fast-code-path it does not recognize search attributes. If you need to
696 add extra joins or similar, call L</search> and then chain-call L</single> on the
697 L<DBIx::Class::ResultSet> returned.
703 As of 0.08100, this method enforces the assumption that the preceding
704 query returns only one row. If more than one row is returned, you will receive
707 Query returned more than one row
709 In this case, you should be using L</next> or L</find> instead, or if you really
710 know what you are doing, use the L</rows> attribute to explicitly limit the size
713 This method will also throw an exception if it is called on a resultset prefetching
714 has_many, as such a prefetch implies fetching multiple rows from the database in
715 order to assemble the resulting object.
722 my ($self, $where) = @_;
724 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
727 my $attrs = $self->_resolved_attrs_copy;
729 if (keys %{$attrs->{collapse}}) {
730 $self->throw_exception(
731 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
736 if (defined $attrs->{where}) {
739 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
740 $where, delete $attrs->{where} ]
743 $attrs->{where} = $where;
747 # XXX: Disabled since it doesn't infer uniqueness in all cases
748 # unless ($self->_is_unique_query($attrs->{where})) {
749 # carp "Query not guaranteed to return a single row"
750 # . "; please declare your unique constraints or use search instead";
753 my @data = $self->result_source->storage->select_single(
754 $attrs->{from}, $attrs->{select},
755 $attrs->{where}, $attrs
758 return (@data ? ($self->_construct_object(@data))[0] : undef);
764 # Try to determine if the specified query is guaranteed to be unique, based on
765 # the declared unique constraints.
767 sub _is_unique_query {
768 my ($self, $query) = @_;
770 my $collapsed = $self->_collapse_query($query);
771 my $alias = $self->{attrs}{alias};
773 foreach my $name ($self->result_source->unique_constraint_names) {
774 my @unique_cols = map {
776 } $self->result_source->unique_constraint_columns($name);
778 # Count the values for each unique column
779 my %seen = map { $_ => 0 } @unique_cols;
781 foreach my $key (keys %$collapsed) {
782 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
783 next unless exists $seen{$aliased}; # Additional constraints are okay
784 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
787 # If we get 0 or more than 1 value for a column, it's not necessarily unique
788 return 1 unless grep { $_ != 1 } values %seen;
796 # Recursively collapse the query, accumulating values for each column.
798 sub _collapse_query {
799 my ($self, $query, $collapsed) = @_;
803 if (ref $query eq 'ARRAY') {
804 foreach my $subquery (@$query) {
805 next unless ref $subquery; # -or
806 $collapsed = $self->_collapse_query($subquery, $collapsed);
809 elsif (ref $query eq 'HASH') {
810 if (keys %$query and (keys %$query)[0] eq '-and') {
811 foreach my $subquery (@{$query->{-and}}) {
812 $collapsed = $self->_collapse_query($subquery, $collapsed);
816 foreach my $col (keys %$query) {
817 my $value = $query->{$col};
818 $collapsed->{$col}{$value}++;
830 =item Arguments: $cond?
832 =item Return Value: $resultsetcolumn
836 my $max_length = $rs->get_column('length')->max;
838 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
843 my ($self, $column) = @_;
844 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
852 =item Arguments: $cond, \%attrs?
854 =item Return Value: $resultset (scalar context), @row_objs (list context)
858 # WHERE title LIKE '%blue%'
859 $cd_rs = $rs->search_like({ title => '%blue%'});
861 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
862 that this is simply a convenience method retained for ex Class::DBI users.
863 You most likely want to use L</search> with specific operators.
865 For more information, see L<DBIx::Class::Manual::Cookbook>.
867 This method is deprecated and will be removed in 0.09. Use L</search()>
868 instead. An example conversion is:
870 ->search_like({ foo => 'bar' });
874 ->search({ foo => { like => 'bar' } });
881 'search_like() is deprecated and will be removed in DBIC version 0.09.'
882 .' Instead use ->search({ x => { -like => "y%" } })'
883 .' (note the outer pair of {}s - they are important!)'
885 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
886 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
887 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
888 return $class->search($query, { %$attrs });
895 =item Arguments: $first, $last
897 =item Return Value: $resultset (scalar context), @row_objs (list context)
901 Returns a resultset or object list representing a subset of elements from the
902 resultset slice is called on. Indexes are from 0, i.e., to get the first
905 my ($one, $two, $three) = $rs->slice(0, 2);
910 my ($self, $min, $max) = @_;
911 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
912 $attrs->{offset} = $self->{attrs}{offset} || 0;
913 $attrs->{offset} += $min;
914 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
915 return $self->search(undef(), $attrs);
916 #my $slice = (ref $self)->new($self->result_source, $attrs);
917 #return (wantarray ? $slice->all : $slice);
924 =item Arguments: none
926 =item Return Value: $result?
930 Returns the next element in the resultset (C<undef> is there is none).
932 Can be used to efficiently iterate over records in the resultset:
934 my $rs = $schema->resultset('CD')->search;
935 while (my $cd = $rs->next) {
939 Note that you need to store the resultset object, and call C<next> on it.
940 Calling C<< resultset('Table')->next >> repeatedly will always return the
941 first record from the resultset.
947 if (my $cache = $self->get_cache) {
948 $self->{all_cache_position} ||= 0;
949 return $cache->[$self->{all_cache_position}++];
951 if ($self->{attrs}{cache}) {
952 $self->{all_cache_position} = 1;
953 return ($self->all)[0];
955 if ($self->{stashed_objects}) {
956 my $obj = shift(@{$self->{stashed_objects}});
957 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
961 exists $self->{stashed_row}
962 ? @{delete $self->{stashed_row}}
963 : $self->cursor->next
965 return undef unless (@row);
966 my ($row, @more) = $self->_construct_object(@row);
967 $self->{stashed_objects} = \@more if @more;
971 sub _construct_object {
972 my ($self, @row) = @_;
974 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
976 my @new = $self->result_class->inflate_result($self->result_source, @$info);
977 @new = $self->{_attrs}{record_filter}->(@new)
978 if exists $self->{_attrs}{record_filter};
982 sub _collapse_result {
983 my ($self, $as_proto, $row) = @_;
987 # 'foo' => [ undef, 'foo' ]
988 # 'foo.bar' => [ 'foo', 'bar' ]
989 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
991 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
993 my %collapse = %{$self->{_attrs}{collapse}||{}};
997 # if we're doing collapsing (has_many prefetch) we need to grab records
998 # until the PK changes, so fill @pri_index. if not, we leave it empty so
999 # we know we don't have to bother.
1001 # the reason for not using the collapse stuff directly is because if you
1002 # had for e.g. two artists in a row with no cds, the collapse info for
1003 # both would be NULL (undef) so you'd lose the second artist
1005 # store just the index so we can check the array positions from the row
1006 # without having to contruct the full hash
1008 if (keys %collapse) {
1009 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1010 foreach my $i (0 .. $#construct_as) {
1011 next if defined($construct_as[$i][0]); # only self table
1012 if (delete $pri{$construct_as[$i][1]}) {
1013 push(@pri_index, $i);
1015 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1019 # no need to do an if, it'll be empty if @pri_index is empty anyway
1021 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1025 do { # no need to check anything at the front, we always want the first row
1029 foreach my $this_as (@construct_as) {
1030 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1033 push(@const_rows, \%const);
1035 } until ( # no pri_index => no collapse => drop straight out
1038 do { # get another row, stash it, drop out if different PK
1040 @copy = $self->cursor->next;
1041 $self->{stashed_row} = \@copy;
1043 # last thing in do block, counts as true if anything doesn't match
1045 # check xor defined first for NULL vs. NOT NULL then if one is
1046 # defined the other must be so check string equality
1049 (defined $pri_vals{$_} ^ defined $copy[$_])
1050 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1055 my $alias = $self->{attrs}{alias};
1062 foreach my $const (@const_rows) {
1063 scalar @const_keys or do {
1064 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1066 foreach my $key (@const_keys) {
1069 my @parts = split(/\./, $key);
1071 my $data = $const->{$key};
1072 foreach my $p (@parts) {
1073 $target = $target->[1]->{$p} ||= [];
1075 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1076 # collapsing at this point and on final part
1077 my $pos = $collapse_pos{$cur};
1078 CK: foreach my $ck (@ckey) {
1079 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1080 $collapse_pos{$cur} = $data;
1081 delete @collapse_pos{ # clear all positioning for sub-entries
1082 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1089 if (exists $collapse{$cur}) {
1090 $target = $target->[-1];
1093 $target->[0] = $data;
1095 $info->[0] = $const->{$key};
1103 =head2 result_source
1107 =item Arguments: $result_source?
1109 =item Return Value: $result_source
1113 An accessor for the primary ResultSource object from which this ResultSet
1120 =item Arguments: $result_class?
1122 =item Return Value: $result_class
1126 An accessor for the class to use when creating row objects. Defaults to
1127 C<< result_source->result_class >> - which in most cases is the name of the
1128 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1130 Note that changing the result_class will also remove any components
1131 that were originally loaded in the source class via
1132 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1133 in the original source class will not run.
1138 my ($self, $result_class) = @_;
1139 if ($result_class) {
1140 unless (ref $result_class) { # don't fire this for an object
1141 $self->ensure_class_loaded($result_class);
1143 $self->_result_class($result_class);
1144 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1145 # permit the user to set result class on one result set only; it only
1146 # chains if provided to search()
1147 #$self->{attrs}{result_class} = $result_class if ref $self;
1149 $self->_result_class;
1156 =item Arguments: $cond, \%attrs??
1158 =item Return Value: $count
1162 Performs an SQL C<COUNT> with the same query as the resultset was built
1163 with to find the number of elements. Passing arguments is equivalent to
1164 C<< $rs->search ($cond, \%attrs)->count >>
1170 return $self->search(@_)->count if @_ and defined $_[0];
1171 return scalar @{ $self->get_cache } if $self->get_cache;
1173 my $attrs = $self->_resolved_attrs_copy;
1175 # this is a little optimization - it is faster to do the limit
1176 # adjustments in software, instead of a subquery
1177 my $rows = delete $attrs->{rows};
1178 my $offset = delete $attrs->{offset};
1181 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1182 $crs = $self->_count_subq_rs ($attrs);
1185 $crs = $self->_count_rs ($attrs);
1187 my $count = $crs->next;
1189 $count -= $offset if $offset;
1190 $count = $rows if $rows and $rows < $count;
1191 $count = 0 if ($count < 0);
1200 =item Arguments: $cond, \%attrs??
1202 =item Return Value: $count_rs
1206 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1207 This can be very handy for subqueries:
1209 ->search( { amount => $some_rs->count_rs->as_query } )
1211 As with regular resultsets the SQL query will be executed only after
1212 the resultset is accessed via L</next> or L</all>. That would return
1213 the same single value obtainable via L</count>.
1219 return $self->search(@_)->count_rs if @_;
1221 # this may look like a lack of abstraction (count() does about the same)
1222 # but in fact an _rs *must* use a subquery for the limits, as the
1223 # software based limiting can not be ported if this $rs is to be used
1224 # in a subquery itself (i.e. ->as_query)
1225 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1226 return $self->_count_subq_rs;
1229 return $self->_count_rs;
1234 # returns a ResultSetColumn object tied to the count query
1237 my ($self, $attrs) = @_;
1239 my $rsrc = $self->result_source;
1240 $attrs ||= $self->_resolved_attrs;
1242 # only take pieces we need for a simple count
1243 my $tmp_attrs = { map
1244 { $_ => $attrs->{$_} }
1245 qw/ alias from where bind join /
1248 # overwrite the selector (supplied by the storage)
1249 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $tmp_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 = { map
1267 { $_ => $attrs->{$_} }
1268 qw/ alias from where bind join group_by having rows offset /
1271 # if we multi-prefetch we group_by primary keys only as this is what we would
1272 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1273 if ( keys %{$attrs->{collapse}} ) {
1274 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1277 # Calculate subquery selector
1278 if (my $g = $sub_attrs->{group_by}) {
1280 # necessary as the group_by may refer to aliased functions
1282 for my $sel (@{$attrs->{select}}) {
1283 $sel_index->{$sel->{-as}} = $sel
1284 if (ref $sel eq 'HASH' and $sel->{-as});
1287 for my $g_part (@$g) {
1288 push @{$sub_attrs->{select}}, $sel_index->{$g_part} || $g_part;
1292 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1293 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1296 return $rsrc->resultset_class
1297 ->new ($rsrc, $sub_attrs)
1299 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1300 -> get_column ('count');
1307 =head2 count_literal
1311 =item Arguments: $sql_fragment, @bind_values
1313 =item Return Value: $count
1317 Counts the results in a literal query. Equivalent to calling L</search_literal>
1318 with the passed arguments, then L</count>.
1322 sub count_literal { shift->search_literal(@_)->count; }
1328 =item Arguments: none
1330 =item Return Value: @objects
1334 Returns all elements in the resultset. Called implicitly if the resultset
1335 is returned in list context.
1342 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1345 return @{ $self->get_cache } if $self->get_cache;
1349 if (keys %{$self->_resolved_attrs->{collapse}}) {
1350 # Using $self->cursor->all is really just an optimisation.
1351 # If we're collapsing has_many prefetches it probably makes
1352 # very little difference, and this is cleaner than hacking
1353 # _construct_object to survive the approach
1354 $self->cursor->reset;
1355 my @row = $self->cursor->next;
1357 push(@obj, $self->_construct_object(@row));
1358 @row = (exists $self->{stashed_row}
1359 ? @{delete $self->{stashed_row}}
1360 : $self->cursor->next);
1363 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1366 $self->set_cache(\@obj) if $self->{attrs}{cache};
1375 =item Arguments: none
1377 =item Return Value: $self
1381 Resets the resultset's cursor, so you can iterate through the elements again.
1382 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1389 delete $self->{_attrs} if exists $self->{_attrs};
1390 $self->{all_cache_position} = 0;
1391 $self->cursor->reset;
1399 =item Arguments: none
1401 =item Return Value: $object?
1405 Resets the resultset and returns an object for the first result (if the
1406 resultset returns anything).
1411 return $_[0]->reset->next;
1417 # Determines whether and what type of subquery is required for the $rs operation.
1418 # If grouping is necessary either supplies its own, or verifies the current one
1419 # After all is done delegates to the proper storage method.
1421 sub _rs_update_delete {
1422 my ($self, $op, $values) = @_;
1424 my $rsrc = $self->result_source;
1426 # if a condition exists we need to strip all table qualifiers
1427 # if this is not possible we'll force a subquery below
1428 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1430 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1431 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1433 if ($needs_group_by_subq or $needs_subq) {
1435 # make a new $rs selecting only the PKs (that's all we really need)
1436 my $attrs = $self->_resolved_attrs_copy;
1439 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
1440 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1442 if ($needs_group_by_subq) {
1443 # make sure no group_by was supplied, or if there is one - make sure it matches
1444 # the columns compiled above perfectly. Anything else can not be sanely executed
1445 # on most databases so croak right then and there
1447 if (my $g = $attrs->{group_by}) {
1448 my @current_group_by = map
1449 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1454 join ("\x00", sort @current_group_by)
1456 join ("\x00", sort @{$attrs->{columns}} )
1458 $self->throw_exception (
1459 "You have just attempted a $op operation on a resultset which does group_by"
1460 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1461 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1462 . ' kind of queries. Please retry the operation with a modified group_by or'
1463 . ' without using one at all.'
1468 $attrs->{group_by} = $attrs->{columns};
1472 my $subrs = (ref $self)->new($rsrc, $attrs);
1473 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1476 return $rsrc->storage->$op(
1478 $op eq 'update' ? $values : (),
1488 =item Arguments: \%values
1490 =item Return Value: $storage_rv
1494 Sets the specified columns in the resultset to the supplied values in a
1495 single query. Return value will be true if the update succeeded or false
1496 if no records were updated; exact type of success value is storage-dependent.
1501 my ($self, $values) = @_;
1502 $self->throw_exception('Values for update must be a hash')
1503 unless ref $values eq 'HASH';
1505 return $self->_rs_update_delete ('update', $values);
1512 =item Arguments: \%values
1514 =item Return Value: 1
1518 Fetches all objects and updates them one at a time. Note that C<update_all>
1519 will run DBIC cascade triggers, while L</update> will not.
1524 my ($self, $values) = @_;
1525 $self->throw_exception('Values for update_all must be a hash')
1526 unless ref $values eq 'HASH';
1528 my $guard = $self->result_source->schema->txn_scope_guard;
1529 $_->update($values) for $self->all;
1538 =item Arguments: none
1540 =item Return Value: $storage_rv
1544 Deletes the contents of the resultset from its result source. Note that this
1545 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1546 to run. See also L<DBIx::Class::Row/delete>.
1548 Return value will be the number of rows deleted; exact type of return value
1549 is storage-dependent.
1555 $self->throw_exception('delete does not accept any arguments')
1558 return $self->_rs_update_delete ('delete');
1565 =item Arguments: none
1567 =item Return Value: 1
1571 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1572 will run DBIC cascade triggers, while L</delete> will not.
1578 $self->throw_exception('delete_all does not accept any arguments')
1581 my $guard = $self->result_source->schema->txn_scope_guard;
1582 $_->delete for $self->all;
1591 =item Arguments: \@data;
1595 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1596 For the arrayref of hashrefs style each hashref should be a structure suitable
1597 forsubmitting to a $resultset->create(...) method.
1599 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1600 to insert the data, as this is a faster method.
1602 Otherwise, each set of data is inserted into the database using
1603 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1604 accumulated into an array. The array itself, or an array reference
1605 is returned depending on scalar or list context.
1607 Example: Assuming an Artist Class that has many CDs Classes relating:
1609 my $Artist_rs = $schema->resultset("Artist");
1611 ## Void Context Example
1612 $Artist_rs->populate([
1613 { artistid => 4, name => 'Manufactured Crap', cds => [
1614 { title => 'My First CD', year => 2006 },
1615 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1618 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1619 { title => 'My parents sold me to a record company', year => 2005 },
1620 { title => 'Why Am I So Ugly?', year => 2006 },
1621 { title => 'I Got Surgery and am now Popular', year => 2007 }
1626 ## Array Context Example
1627 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1628 { name => "Artist One"},
1629 { name => "Artist Two"},
1630 { name => "Artist Three", cds=> [
1631 { title => "First CD", year => 2007},
1632 { title => "Second CD", year => 2008},
1636 print $ArtistOne->name; ## response is 'Artist One'
1637 print $ArtistThree->cds->count ## reponse is '2'
1639 For the arrayref of arrayrefs style, the first element should be a list of the
1640 fieldsnames to which the remaining elements are rows being inserted. For
1643 $Arstist_rs->populate([
1644 [qw/artistid name/],
1645 [100, 'A Formally Unknown Singer'],
1646 [101, 'A singer that jumped the shark two albums ago'],
1647 [102, 'An actually cool singer'],
1650 Please note an important effect on your data when choosing between void and
1651 wantarray context. Since void context goes straight to C<insert_bulk> in
1652 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1653 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1654 create primary keys for you, you will find that your PKs are empty. In this
1655 case you will have to use the wantarray context in order to create those
1663 # cruft placed in standalone method
1664 my $data = $self->_normalize_populate_args(@_);
1666 if(defined wantarray) {
1668 foreach my $item (@$data) {
1669 push(@created, $self->create($item));
1671 return wantarray ? @created : \@created;
1673 my $first = $data->[0];
1675 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1676 # it relationship data
1677 my (@rels, @columns);
1678 for (keys %$first) {
1679 my $ref = ref $first->{$_};
1680 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1686 my @pks = $self->result_source->primary_columns;
1688 ## do the belongs_to relationships
1689 foreach my $index (0..$#$data) {
1691 # delegate to create() for any dataset without primary keys with specified relationships
1692 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1694 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1695 my @ret = $self->populate($data);
1701 foreach my $rel (@rels) {
1702 next unless ref $data->[$index]->{$rel} eq "HASH";
1703 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1704 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1705 my $related = $result->result_source->_resolve_condition(
1706 $result->result_source->relationship_info($reverse)->{cond},
1711 delete $data->[$index]->{$rel};
1712 $data->[$index] = {%{$data->[$index]}, %$related};
1714 push @columns, keys %$related if $index == 0;
1718 ## inherit the data locked in the conditions of the resultset
1719 my ($rs_data) = $self->_merge_cond_with_data({});
1720 delete @{$rs_data}{@columns};
1721 my @inherit_cols = keys %$rs_data;
1722 my @inherit_data = values %$rs_data;
1724 ## do bulk insert on current row
1725 $self->result_source->storage->insert_bulk(
1726 $self->result_source,
1727 [@columns, @inherit_cols],
1728 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1731 ## do the has_many relationships
1732 foreach my $item (@$data) {
1734 foreach my $rel (@rels) {
1735 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1737 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1738 || $self->throw_exception('Cannot find the relating object.');
1740 my $child = $parent->$rel;
1742 my $related = $child->result_source->_resolve_condition(
1743 $parent->result_source->relationship_info($rel)->{cond},
1748 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1749 my @populate = map { {%$_, %$related} } @rows_to_add;
1751 $child->populate( \@populate );
1758 # populate() argumnets went over several incarnations
1759 # What we ultimately support is AoH
1760 sub _normalize_populate_args {
1761 my ($self, $arg) = @_;
1763 if (ref $arg eq 'ARRAY') {
1764 if (ref $arg->[0] eq 'HASH') {
1767 elsif (ref $arg->[0] eq 'ARRAY') {
1769 my @colnames = @{$arg->[0]};
1770 foreach my $values (@{$arg}[1 .. $#$arg]) {
1771 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1777 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1784 =item Arguments: none
1786 =item Return Value: $pager
1790 Return Value a L<Data::Page> object for the current resultset. Only makes
1791 sense for queries with a C<page> attribute.
1793 To get the full count of entries for a paged resultset, call
1794 C<total_entries> on the L<Data::Page> object.
1801 return $self->{pager} if $self->{pager};
1803 my $attrs = $self->{attrs};
1804 $self->throw_exception("Can't create pager for non-paged rs")
1805 unless $self->{attrs}{page};
1806 $attrs->{rows} ||= 10;
1808 # throw away the paging flags and re-run the count (possibly
1809 # with a subselect) to get the real total count
1810 my $count_attrs = { %$attrs };
1811 delete $count_attrs->{$_} for qw/rows offset page pager/;
1812 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1814 return $self->{pager} = Data::Page->new(
1817 $self->{attrs}{page}
1825 =item Arguments: $page_number
1827 =item Return Value: $rs
1831 Returns a resultset for the $page_number page of the resultset on which page
1832 is called, where each page contains a number of rows equal to the 'rows'
1833 attribute set on the resultset (10 by default).
1838 my ($self, $page) = @_;
1839 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1846 =item Arguments: \%vals
1848 =item Return Value: $rowobject
1852 Creates a new row object in the resultset's result class and returns
1853 it. The row is not inserted into the database at this point, call
1854 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1855 will tell you whether the row object has been inserted or not.
1857 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1862 my ($self, $values) = @_;
1863 $self->throw_exception( "new_result needs a hash" )
1864 unless (ref $values eq 'HASH');
1866 my ($merged_cond, $cols_from_relations) = $self->_merge_cond_with_data($values);
1870 @$cols_from_relations
1871 ? (-cols_from_relations => $cols_from_relations)
1873 -source_handle => $self->_source_handle,
1874 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1877 return $self->result_class->new(\%new);
1880 # _merge_cond_with_data
1882 # Takes a simple hash of K/V data and returns its copy merged with the
1883 # condition already present on the resultset. Additionally returns an
1884 # arrayref of value/condition names, which were inferred from related
1885 # objects (this is needed for in-memory related objects)
1886 sub _merge_cond_with_data {
1887 my ($self, $data) = @_;
1889 my (%new_data, @cols_from_relations);
1891 my $alias = $self->{attrs}{alias};
1893 if (! defined $self->{cond}) {
1894 # just massage $data below
1896 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
1897 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1898 @cols_from_relations = keys %new_data;
1900 elsif (ref $self->{cond} ne 'HASH') {
1901 $self->throw_exception(
1902 "Can't abstract implicit construct, resultset condition not a hash"
1906 # precendence must be given to passed values over values inherited from
1907 # the cond, so the order here is important.
1908 my $collapsed_cond = $self->_collapse_cond($self->{cond});
1909 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1911 while ( my($col, $value) = each %implied ) {
1912 if (ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
1913 $new_data{$col} = $value->{'='};
1916 $new_data{$col} = $value if $self->_is_deterministic_value($value);
1922 %{ $self->_remove_alias($data, $alias) },
1925 return (\%new_data, \@cols_from_relations);
1928 # _is_deterministic_value
1930 # Make an effor to strip non-deterministic values from the condition,
1931 # to make sure new_result chokes less
1933 sub _is_deterministic_value {
1936 my $ref_type = ref $value;
1937 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1938 return 1 if blessed $value;
1942 # _has_resolved_attr
1944 # determines if the resultset defines at least one
1945 # of the attributes supplied
1947 # used to determine if a subquery is neccessary
1949 # supports some virtual attributes:
1951 # This will scan for any joins being present on the resultset.
1952 # It is not a mere key-search but a deep inspection of {from}
1955 sub _has_resolved_attr {
1956 my ($self, @attr_names) = @_;
1958 my $attrs = $self->_resolved_attrs;
1962 for my $n (@attr_names) {
1963 if (grep { $n eq $_ } (qw/-join/) ) {
1964 $extra_checks{$n}++;
1968 my $attr = $attrs->{$n};
1970 next if not defined $attr;
1972 if (ref $attr eq 'HASH') {
1973 return 1 if keys %$attr;
1975 elsif (ref $attr eq 'ARRAY') {
1983 # a resolved join is expressed as a multi-level from
1985 $extra_checks{-join}
1987 ref $attrs->{from} eq 'ARRAY'
1989 @{$attrs->{from}} > 1
1997 # Recursively collapse the condition.
1999 sub _collapse_cond {
2000 my ($self, $cond, $collapsed) = @_;
2004 if (ref $cond eq 'ARRAY') {
2005 foreach my $subcond (@$cond) {
2006 next unless ref $subcond; # -or
2007 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2010 elsif (ref $cond eq 'HASH') {
2011 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2012 foreach my $subcond (@{$cond->{-and}}) {
2013 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2017 foreach my $col (keys %$cond) {
2018 my $value = $cond->{$col};
2019 $collapsed->{$col} = $value;
2029 # Remove the specified alias from the specified query hash. A copy is made so
2030 # the original query is not modified.
2033 my ($self, $query, $alias) = @_;
2035 my %orig = %{ $query || {} };
2038 foreach my $key (keys %orig) {
2040 $unaliased{$key} = $orig{$key};
2043 $unaliased{$1} = $orig{$key}
2044 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2054 =item Arguments: none
2056 =item Return Value: \[ $sql, @bind ]
2060 Returns the SQL query and bind vars associated with the invocant.
2062 This is generally used as the RHS for a subquery.
2069 my $attrs = $self->_resolved_attrs_copy;
2074 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2075 # $sql also has no wrapping parenthesis in list ctx
2077 my $sqlbind = $self->result_source->storage
2078 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2087 =item Arguments: \%vals, \%attrs?
2089 =item Return Value: $rowobject
2093 my $artist = $schema->resultset('Artist')->find_or_new(
2094 { artist => 'fred' }, { key => 'artists' });
2096 $cd->cd_to_producer->find_or_new({ producer => $producer },
2097 { key => 'primary });
2099 Find an existing record from this resultset, based on its primary
2100 key, or a unique constraint. If none exists, instantiate a new result
2101 object and return it. The object will not be saved into your storage
2102 until you call L<DBIx::Class::Row/insert> on it.
2104 You most likely want this method when looking for existing rows using
2105 a unique constraint that is not the primary key, or looking for
2108 If you want objects to be saved immediately, use L</find_or_create>
2111 B<Note>: Take care when using C<find_or_new> with a table having
2112 columns with default values that you intend to be automatically
2113 supplied by the database (e.g. an auto_increment primary key column).
2114 In normal usage, the value of such columns should NOT be included at
2115 all in the call to C<find_or_new>, even when set to C<undef>.
2121 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2122 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2123 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2126 return $self->new_result($hash);
2133 =item Arguments: \%vals
2135 =item Return Value: a L<DBIx::Class::Row> $object
2139 Attempt to create a single new row or a row with multiple related rows
2140 in the table represented by the resultset (and related tables). This
2141 will not check for duplicate rows before inserting, use
2142 L</find_or_create> to do that.
2144 To create one row for this resultset, pass a hashref of key/value
2145 pairs representing the columns of the table and the values you wish to
2146 store. If the appropriate relationships are set up, foreign key fields
2147 can also be passed an object representing the foreign row, and the
2148 value will be set to its primary key.
2150 To create related objects, pass a hashref of related-object column values
2151 B<keyed on the relationship name>. If the relationship is of type C<multi>
2152 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2153 The process will correctly identify columns holding foreign keys, and will
2154 transparently populate them from the keys of the corresponding relation.
2155 This can be applied recursively, and will work correctly for a structure
2156 with an arbitrary depth and width, as long as the relationships actually
2157 exists and the correct column data has been supplied.
2160 Instead of hashrefs of plain related data (key/value pairs), you may
2161 also pass new or inserted objects. New objects (not inserted yet, see
2162 L</new>), will be inserted into their appropriate tables.
2164 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2166 Example of creating a new row.
2168 $person_rs->create({
2169 name=>"Some Person",
2170 email=>"somebody@someplace.com"
2173 Example of creating a new row and also creating rows in a related C<has_many>
2174 or C<has_one> resultset. Note Arrayref.
2177 { artistid => 4, name => 'Manufactured Crap', cds => [
2178 { title => 'My First CD', year => 2006 },
2179 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2184 Example of creating a new row and also creating a row in a related
2185 C<belongs_to>resultset. Note Hashref.
2188 title=>"Music for Silly Walks",
2191 name=>"Silly Musician",
2199 When subclassing ResultSet never attempt to override this method. Since
2200 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2201 lot of the internals simply never call it, so your override will be
2202 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2203 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2204 L</create> process you need to intervene.
2211 my ($self, $attrs) = @_;
2212 $self->throw_exception( "create needs a hashref" )
2213 unless ref $attrs eq 'HASH';
2214 return $self->new_result($attrs)->insert;
2217 =head2 find_or_create
2221 =item Arguments: \%vals, \%attrs?
2223 =item Return Value: $rowobject
2227 $cd->cd_to_producer->find_or_create({ producer => $producer },
2228 { key => 'primary' });
2230 Tries to find a record based on its primary key or unique constraints; if none
2231 is found, creates one and returns that instead.
2233 my $cd = $schema->resultset('CD')->find_or_create({
2235 artist => 'Massive Attack',
2236 title => 'Mezzanine',
2240 Also takes an optional C<key> attribute, to search by a specific key or unique
2241 constraint. For example:
2243 my $cd = $schema->resultset('CD')->find_or_create(
2245 artist => 'Massive Attack',
2246 title => 'Mezzanine',
2248 { key => 'cd_artist_title' }
2251 B<Note>: Because find_or_create() reads from the database and then
2252 possibly inserts based on the result, this method is subject to a race
2253 condition. Another process could create a record in the table after
2254 the find has completed and before the create has started. To avoid
2255 this problem, use find_or_create() inside a transaction.
2257 B<Note>: Take care when using C<find_or_create> with a table having
2258 columns with default values that you intend to be automatically
2259 supplied by the database (e.g. an auto_increment primary key column).
2260 In normal usage, the value of such columns should NOT be included at
2261 all in the call to C<find_or_create>, even when set to C<undef>.
2263 See also L</find> and L</update_or_create>. For information on how to declare
2264 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2268 sub find_or_create {
2270 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2271 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2272 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2275 return $self->create($hash);
2278 =head2 update_or_create
2282 =item Arguments: \%col_values, { key => $unique_constraint }?
2284 =item Return Value: $rowobject
2288 $resultset->update_or_create({ col => $val, ... });
2290 First, searches for an existing row matching one of the unique constraints
2291 (including the primary key) on the source of this resultset. If a row is
2292 found, updates it with the other given column values. Otherwise, creates a new
2295 Takes an optional C<key> attribute to search on a specific unique constraint.
2298 # In your application
2299 my $cd = $schema->resultset('CD')->update_or_create(
2301 artist => 'Massive Attack',
2302 title => 'Mezzanine',
2305 { key => 'cd_artist_title' }
2308 $cd->cd_to_producer->update_or_create({
2309 producer => $producer,
2316 If no C<key> is specified, it searches on all unique constraints defined on the
2317 source, including the primary key.
2319 If the C<key> is specified as C<primary>, it searches only on the primary key.
2321 See also L</find> and L</find_or_create>. For information on how to declare
2322 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2324 B<Note>: Take care when using C<update_or_create> with a table having
2325 columns with default values that you intend to be automatically
2326 supplied by the database (e.g. an auto_increment primary key column).
2327 In normal usage, the value of such columns should NOT be included at
2328 all in the call to C<update_or_create>, even when set to C<undef>.
2332 sub update_or_create {
2334 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2335 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2337 my $row = $self->find($cond, $attrs);
2339 $row->update($cond);
2343 return $self->create($cond);
2346 =head2 update_or_new
2350 =item Arguments: \%col_values, { key => $unique_constraint }?
2352 =item Return Value: $rowobject
2356 $resultset->update_or_new({ col => $val, ... });
2358 First, searches for an existing row matching one of the unique constraints
2359 (including the primary key) on the source of this resultset. If a row is
2360 found, updates it with the other given column values. Otherwise, instantiate
2361 a new result object and return it. The object will not be saved into your storage
2362 until you call L<DBIx::Class::Row/insert> on it.
2364 Takes an optional C<key> attribute to search on a specific unique constraint.
2367 # In your application
2368 my $cd = $schema->resultset('CD')->update_or_new(
2370 artist => 'Massive Attack',
2371 title => 'Mezzanine',
2374 { key => 'cd_artist_title' }
2377 if ($cd->in_storage) {
2378 # the cd was updated
2381 # the cd is not yet in the database, let's insert it
2385 B<Note>: Take care when using C<update_or_new> with a table having
2386 columns with default values that you intend to be automatically
2387 supplied by the database (e.g. an auto_increment primary key column).
2388 In normal usage, the value of such columns should NOT be included at
2389 all in the call to C<update_or_new>, even when set to C<undef>.
2391 See also L</find>, L</find_or_create> and L</find_or_new>.
2397 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2398 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2400 my $row = $self->find( $cond, $attrs );
2401 if ( defined $row ) {
2402 $row->update($cond);
2406 return $self->new_result($cond);
2413 =item Arguments: none
2415 =item Return Value: \@cache_objects?
2419 Gets the contents of the cache for the resultset, if the cache is set.
2421 The cache is populated either by using the L</prefetch> attribute to
2422 L</search> or by calling L</set_cache>.
2434 =item Arguments: \@cache_objects
2436 =item Return Value: \@cache_objects
2440 Sets the contents of the cache for the resultset. Expects an arrayref
2441 of objects of the same class as those produced by the resultset. Note that
2442 if the cache is set the resultset will return the cached objects rather
2443 than re-querying the database even if the cache attr is not set.
2445 The contents of the cache can also be populated by using the
2446 L</prefetch> attribute to L</search>.
2451 my ( $self, $data ) = @_;
2452 $self->throw_exception("set_cache requires an arrayref")
2453 if defined($data) && (ref $data ne 'ARRAY');
2454 $self->{all_cache} = $data;
2461 =item Arguments: none
2463 =item Return Value: []
2467 Clears the cache for the resultset.
2472 shift->set_cache(undef);
2479 =item Arguments: none
2481 =item Return Value: true, if the resultset has been paginated
2489 return !!$self->{attrs}{page};
2496 =item Arguments: none
2498 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2506 return scalar $self->result_source->storage->_parse_order_by($self->{attrs}{order_by});
2509 =head2 related_resultset
2513 =item Arguments: $relationship_name
2515 =item Return Value: $resultset
2519 Returns a related resultset for the supplied relationship name.
2521 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2525 sub related_resultset {
2526 my ($self, $rel) = @_;
2528 $self->{related_resultsets} ||= {};
2529 return $self->{related_resultsets}{$rel} ||= do {
2530 my $rsrc = $self->result_source;
2531 my $rel_info = $rsrc->relationship_info($rel);
2533 $self->throw_exception(
2534 "search_related: result source '" . $rsrc->source_name .
2535 "' has no such relationship $rel")
2538 my $attrs = $self->_chain_relationship($rel);
2540 my $join_count = $attrs->{seen_join}{$rel};
2542 my $alias = $self->result_source->storage
2543 ->relname_to_table_alias($rel, $join_count);
2545 # since this is search_related, and we already slid the select window inwards
2546 # (the select/as attrs were deleted in the beginning), we need to flip all
2547 # left joins to inner, so we get the expected results
2548 # read the comment on top of the actual function to see what this does
2549 $attrs->{from} = $rsrc->schema->storage->_straight_join_to_node ($attrs->{from}, $alias);
2552 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2553 delete @{$attrs}{qw(result_class alias)};
2557 if (my $cache = $self->get_cache) {
2558 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2559 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2564 my $rel_source = $rsrc->related_source($rel);
2568 # The reason we do this now instead of passing the alias to the
2569 # search_rs below is that if you wrap/overload resultset on the
2570 # source you need to know what alias it's -going- to have for things
2571 # to work sanely (e.g. RestrictWithObject wants to be able to add
2572 # extra query restrictions, and these may need to be $alias.)
2574 my $rel_attrs = $rel_source->resultset_attributes;
2575 local $rel_attrs->{alias} = $alias;
2577 $rel_source->resultset
2581 where => $attrs->{where},
2584 $new->set_cache($new_cache) if $new_cache;
2589 =head2 current_source_alias
2593 =item Arguments: none
2595 =item Return Value: $source_alias
2599 Returns the current table alias for the result source this resultset is built
2600 on, that will be used in the SQL query. Usually it is C<me>.
2602 Currently the source alias that refers to the result set returned by a
2603 L</search>/L</find> family method depends on how you got to the resultset: it's
2604 C<me> by default, but eg. L</search_related> aliases it to the related result
2605 source name (and keeps C<me> referring to the original result set). The long
2606 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2607 (and make this method unnecessary).
2609 Thus it's currently necessary to use this method in predefined queries (see
2610 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2611 source alias of the current result set:
2613 # in a result set class
2615 my ($self, $user) = @_;
2617 my $me = $self->current_source_alias;
2619 return $self->search(
2620 "$me.modified" => $user->id,
2626 sub current_source_alias {
2629 return ($self->{attrs} || {})->{alias} || 'me';
2632 =head2 as_subselect_rs
2636 =item Arguments: none
2638 =item Return Value: $resultset
2642 Act as a barrier to SQL symbols. The resultset provided will be made into a
2643 "virtual view" by including it as a subquery within the from clause. From this
2644 point on, any joined tables are inaccessible to ->search on the resultset (as if
2645 it were simply where-filtered without joins). For example:
2647 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2649 # 'x' now pollutes the query namespace
2651 # So the following works as expected
2652 my $ok_rs = $rs->search({'x.other' => 1});
2654 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2655 # def) we look for one row with contradictory terms and join in another table
2656 # (aliased 'x_2') which we never use
2657 my $broken_rs = $rs->search({'x.name' => 'def'});
2659 my $rs2 = $rs->as_subselect_rs;
2661 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2662 my $not_joined_rs = $rs2->search({'x.other' => 1});
2664 # works as expected: finds a 'table' row related to two x rows (abc and def)
2665 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2667 Another example of when one might use this would be to select a subset of
2668 columns in a group by clause:
2670 my $rs = $schema->resultset('Bar')->search(undef, {
2671 group_by => [qw{ id foo_id baz_id }],
2672 })->as_subselect_rs->search(undef, {
2673 columns => [qw{ id foo_id }]
2676 In the above example normally columns would have to be equal to the group by,
2677 but because we isolated the group by into a subselect the above works.
2681 sub as_subselect_rs {
2684 my $attrs = $self->_resolved_attrs;
2686 my $fresh_rs = (ref $self)->new (
2687 $self->result_source
2690 # these pieces will be locked in the subquery
2691 delete $fresh_rs->{cond};
2692 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2694 return $fresh_rs->search( {}, {
2696 $attrs->{alias} => $self->as_query,
2697 -alias => $attrs->{alias},
2698 -source_handle => $self->result_source->handle,
2700 alias => $attrs->{alias},
2704 # This code is called by search_related, and makes sure there
2705 # is clear separation between the joins before, during, and
2706 # after the relationship. This information is needed later
2707 # in order to properly resolve prefetch aliases (any alias
2708 # with a relation_chain_depth less than the depth of the
2709 # current prefetch is not considered)
2711 # The increments happen twice per join. An even number means a
2712 # relationship specified via a search_related, whereas an odd
2713 # number indicates a join/prefetch added via attributes
2715 # Also this code will wrap the current resultset (the one we
2716 # chain to) in a subselect IFF it contains limiting attributes
2717 sub _chain_relationship {
2718 my ($self, $rel) = @_;
2719 my $source = $self->result_source;
2720 my $attrs = { %{$self->{attrs}||{}} };
2722 # we need to take the prefetch the attrs into account before we
2723 # ->_resolve_join as otherwise they get lost - captainL
2724 my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2726 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2728 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2731 my @force_subq_attrs = qw/offset rows group_by having/;
2734 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2736 $self->_has_resolved_attr (@force_subq_attrs)
2738 # Nuke the prefetch (if any) before the new $rs attrs
2739 # are resolved (prefetch is useless - we are wrapping
2740 # a subquery anyway).
2741 my $rs_copy = $self->search;
2742 $rs_copy->{attrs}{join} = $self->_merge_attr (
2743 $rs_copy->{attrs}{join},
2744 delete $rs_copy->{attrs}{prefetch},
2748 -source_handle => $source->handle,
2749 -alias => $attrs->{alias},
2750 $attrs->{alias} => $rs_copy->as_query,
2752 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2753 $seen->{-relation_chain_depth} = 0;
2755 elsif ($attrs->{from}) { #shallow copy suffices
2756 $from = [ @{$attrs->{from}} ];
2760 -source_handle => $source->handle,
2761 -alias => $attrs->{alias},
2762 $attrs->{alias} => $source->from,
2766 my $jpath = ($seen->{-relation_chain_depth})
2767 ? $from->[-1][0]{-join_path}
2770 my @requested_joins = $source->_resolve_join(
2777 push @$from, @requested_joins;
2779 $seen->{-relation_chain_depth}++;
2781 # if $self already had a join/prefetch specified on it, the requested
2782 # $rel might very well be already included. What we do in this case
2783 # is effectively a no-op (except that we bump up the chain_depth on
2784 # the join in question so we could tell it *is* the search_related)
2787 # we consider the last one thus reverse
2788 for my $j (reverse @requested_joins) {
2789 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2790 if ($rel eq $last_j) {
2791 $j->[0]{-relation_chain_depth}++;
2797 unless ($already_joined) {
2798 push @$from, $source->_resolve_join(
2806 $seen->{-relation_chain_depth}++;
2808 return {%$attrs, from => $from, seen_join => $seen};
2811 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2812 sub _resolved_attrs_copy {
2814 return { %{$self->_resolved_attrs (@_)} };
2817 sub _resolved_attrs {
2819 return $self->{_attrs} if $self->{_attrs};
2821 my $attrs = { %{ $self->{attrs} || {} } };
2822 my $source = $self->result_source;
2823 my $alias = $attrs->{alias};
2825 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2828 # build columns (as long as select isn't set) into a set of as/select hashes
2829 unless ( $attrs->{select} ) {
2832 if ( ref $attrs->{columns} eq 'ARRAY' ) {
2833 @cols = @{ delete $attrs->{columns}}
2834 } elsif ( defined $attrs->{columns} ) {
2835 @cols = delete $attrs->{columns}
2837 @cols = $source->columns
2841 if ( ref $_ eq 'HASH' ) {
2844 my $key = /^\Q${alias}.\E(.+)$/
2850 push @colbits, { $key => $value };
2855 # add the additional columns on
2856 foreach (qw{include_columns +columns}) {
2857 if ( $attrs->{$_} ) {
2858 my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
2859 ? @{ delete $attrs->{$_} }
2860 : delete $attrs->{$_};
2862 if ( ref($_) eq 'HASH' ) {
2865 my $key = ( split /\./, $_ )[-1];
2866 my $value = ( /\./ ? $_ : "$alias.$_" );
2867 push @colbits, { $key => $value };
2873 # start with initial select items
2874 if ( $attrs->{select} ) {
2876 ( ref $attrs->{select} eq 'ARRAY' )
2877 ? [ @{ $attrs->{select} } ]
2878 : [ $attrs->{select} ];
2880 if ( $attrs->{as} ) {
2883 ref $attrs->{as} eq 'ARRAY'
2884 ? [ @{ $attrs->{as} } ]
2888 $attrs->{as} = [ map {
2889 m/^\Q${alias}.\E(.+)$/
2892 } @{ $attrs->{select} }
2898 # otherwise we intialise select & as to empty
2899 $attrs->{select} = [];
2903 # now add colbits to select/as
2904 push @{ $attrs->{select} }, map values %{$_}, @colbits;
2905 push @{ $attrs->{as} }, map keys %{$_}, @colbits;
2907 if ( my $adds = delete $attrs->{'+select'} ) {
2908 $adds = [$adds] unless ref $adds eq 'ARRAY';
2909 push @{ $attrs->{select} },
2910 map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
2912 if ( my $adds = delete $attrs->{'+as'} ) {
2913 $adds = [$adds] unless ref $adds eq 'ARRAY';
2914 push @{ $attrs->{as} }, @$adds;
2917 $attrs->{from} ||= [{
2918 -source_handle => $source->handle,
2919 -alias => $self->{attrs}{alias},
2920 $self->{attrs}{alias} => $source->from,
2923 if ( $attrs->{join} || $attrs->{prefetch} ) {
2925 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
2926 if ref $attrs->{from} ne 'ARRAY';
2928 my $join = delete $attrs->{join} || {};
2930 if ( defined $attrs->{prefetch} ) {
2931 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2934 $attrs->{from} = # have to copy here to avoid corrupting the original
2936 @{ $attrs->{from} },
2937 $source->_resolve_join(
2940 { %{ $attrs->{seen_join} || {} } },
2941 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
2942 ? $attrs->{from}[-1][0]{-join_path}
2949 if ( defined $attrs->{order_by} ) {
2950 $attrs->{order_by} = (
2951 ref( $attrs->{order_by} ) eq 'ARRAY'
2952 ? [ @{ $attrs->{order_by} } ]
2953 : [ $attrs->{order_by} || () ]
2957 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
2958 $attrs->{group_by} = [ $attrs->{group_by} ];
2961 # generate the distinct induced group_by early, as prefetch will be carried via a
2962 # subquery (since a group_by is present)
2963 if (delete $attrs->{distinct}) {
2964 if ($attrs->{group_by}) {
2965 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
2968 $attrs->{group_by} = [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2970 # add any order_by parts that are not already present in the group_by
2971 # we need to be careful not to add any named functions/aggregates
2972 # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
2973 my %already_grouped = map { $_ => 1 } (@{$attrs->{group_by}});
2975 my $storage = $self->result_source->schema->storage;
2977 my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
2979 for my $chunk ($storage->_parse_order_by($attrs->{order_by})) {
2980 if ($rs_column_list->{$chunk} && not $already_grouped{$chunk}++) {
2981 push @{$attrs->{group_by}}, $chunk;
2987 $attrs->{collapse} ||= {};
2988 if ( my $prefetch = delete $attrs->{prefetch} ) {
2989 $prefetch = $self->_merge_attr( {}, $prefetch );
2991 my $prefetch_ordering = [];
2993 # this is a separate structure (we don't look in {from} directly)
2994 # as the resolver needs to shift things off the lists to work
2995 # properly (identical-prefetches on different branches)
2997 if (ref $attrs->{from} eq 'ARRAY') {
2999 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3001 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3002 next unless $j->[0]{-alias};
3003 next unless $j->[0]{-join_path};
3004 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3006 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3009 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3010 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3015 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3017 # we need to somehow mark which columns came from prefetch
3018 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3020 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3021 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3023 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3024 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3027 # if both page and offset are specified, produce a combined offset
3028 # even though it doesn't make much sense, this is what pre 081xx has
3030 if (my $page = delete $attrs->{page}) {
3032 ($attrs->{rows} * ($page - 1))
3034 ($attrs->{offset} || 0)
3038 return $self->{_attrs} = $attrs;
3042 my ($self, $attr) = @_;
3044 if (ref $attr eq 'HASH') {
3045 return $self->_rollout_hash($attr);
3046 } elsif (ref $attr eq 'ARRAY') {
3047 return $self->_rollout_array($attr);
3053 sub _rollout_array {
3054 my ($self, $attr) = @_;
3057 foreach my $element (@{$attr}) {
3058 if (ref $element eq 'HASH') {
3059 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3060 } elsif (ref $element eq 'ARRAY') {
3061 # XXX - should probably recurse here
3062 push( @rolled_array, @{$self->_rollout_array($element)} );
3064 push( @rolled_array, $element );
3067 return \@rolled_array;
3071 my ($self, $attr) = @_;
3074 foreach my $key (keys %{$attr}) {
3075 push( @rolled_array, { $key => $attr->{$key} } );
3077 return \@rolled_array;
3080 sub _calculate_score {
3081 my ($self, $a, $b) = @_;
3083 if (defined $a xor defined $b) {
3086 elsif (not defined $a) {
3090 if (ref $b eq 'HASH') {
3091 my ($b_key) = keys %{$b};
3092 if (ref $a eq 'HASH') {
3093 my ($a_key) = keys %{$a};
3094 if ($a_key eq $b_key) {
3095 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3100 return ($a eq $b_key) ? 1 : 0;
3103 if (ref $a eq 'HASH') {
3104 my ($a_key) = keys %{$a};
3105 return ($b eq $a_key) ? 1 : 0;
3107 return ($b eq $a) ? 1 : 0;
3113 my ($self, $orig, $import) = @_;
3115 return $import unless defined($orig);
3116 return $orig unless defined($import);
3118 $orig = $self->_rollout_attr($orig);
3119 $import = $self->_rollout_attr($import);
3122 foreach my $import_element ( @{$import} ) {
3123 # find best candidate from $orig to merge $b_element into
3124 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3125 foreach my $orig_element ( @{$orig} ) {
3126 my $score = $self->_calculate_score( $orig_element, $import_element );
3127 if ($score > $best_candidate->{score}) {
3128 $best_candidate->{position} = $position;
3129 $best_candidate->{score} = $score;
3133 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3135 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3136 push( @{$orig}, $import_element );
3138 my $orig_best = $orig->[$best_candidate->{position}];
3139 # merge orig_best and b_element together and replace original with merged
3140 if (ref $orig_best ne 'HASH') {
3141 $orig->[$best_candidate->{position}] = $import_element;
3142 } elsif (ref $import_element eq 'HASH') {
3143 my ($key) = keys %{$orig_best};
3144 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
3147 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3157 $self->_source_handle($_[0]->handle);
3159 $self->_source_handle->resolve;
3163 =head2 throw_exception
3165 See L<DBIx::Class::Schema/throw_exception> for details.
3169 sub throw_exception {
3172 if (ref $self && $self->_source_handle->schema) {
3173 $self->_source_handle->schema->throw_exception(@_)
3176 DBIx::Class::Exception->throw(@_);
3180 # XXX: FIXME: Attributes docs need clearing up
3184 Attributes are used to refine a ResultSet in various ways when
3185 searching for data. They can be passed to any method which takes an
3186 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3189 These are in no particular order:
3195 =item Value: ( $order_by | \@order_by | \%order_by )
3199 Which column(s) to order the results by.
3201 [The full list of suitable values is documented in
3202 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3205 If a single column name, or an arrayref of names is supplied, the
3206 argument is passed through directly to SQL. The hashref syntax allows
3207 for connection-agnostic specification of ordering direction:
3209 For descending order:
3211 order_by => { -desc => [qw/col1 col2 col3/] }
3213 For explicit ascending order:
3215 order_by => { -asc => 'col' }
3217 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3218 supported, although you are strongly encouraged to use the hashref
3219 syntax as outlined above.
3225 =item Value: \@columns
3229 Shortcut to request a particular set of columns to be retrieved. Each
3230 column spec may be a string (a table column name), or a hash (in which
3231 case the key is the C<as> value, and the value is used as the C<select>
3232 expression). Adds C<me.> onto the start of any column without a C<.> in
3233 it and sets C<select> from that, then auto-populates C<as> from
3234 C<select> as normal. (You may also use the C<cols> attribute, as in
3235 earlier versions of DBIC.)
3241 =item Value: \@columns
3245 Indicates additional columns to be selected from storage. Works the same
3246 as L</columns> but adds columns to the selection. (You may also use the
3247 C<include_columns> attribute, as in earlier versions of DBIC). For
3250 $schema->resultset('CD')->search(undef, {
3251 '+columns' => ['artist.name'],
3255 would return all CDs and include a 'name' column to the information
3256 passed to object inflation. Note that the 'artist' is the name of the
3257 column (or relationship) accessor, and 'name' is the name of the column
3258 accessor in the related table.
3260 =head2 include_columns
3264 =item Value: \@columns
3268 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3274 =item Value: \@select_columns
3278 Indicates which columns should be selected from the storage. You can use
3279 column names, or in the case of RDBMS back ends, function or stored procedure
3282 $rs = $schema->resultset('Employee')->search(undef, {
3285 { count => 'employeeid' },
3286 { max => { length => 'name' }, -as => 'longest_name' }
3291 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3293 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3294 use L</select>, to instruct DBIx::Class how to store the result of the column.
3295 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3296 identifier aliasing. You can however alias a function, so you can use it in
3297 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3298 attribute> supplied as shown in the example above.
3304 Indicates additional columns to be selected from storage. Works the same as
3305 L</select> but adds columns to the default selection, instead of specifying
3314 Indicates additional column names for those added via L</+select>. See L</as>.
3322 =item Value: \@inflation_names
3326 Indicates column names for object inflation. That is L</as> indicates the
3327 slot name in which the column value will be stored within the
3328 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3329 identifier by the C<get_column> method (or via the object accessor B<if one
3330 with the same name already exists>) as shown below. The L</as> attribute has
3331 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3333 $rs = $schema->resultset('Employee')->search(undef, {
3336 { count => 'employeeid' },
3337 { max => { length => 'name' }, -as => 'longest_name' }
3346 If the object against which the search is performed already has an accessor
3347 matching a column name specified in C<as>, the value can be retrieved using
3348 the accessor as normal:
3350 my $name = $employee->name();
3352 If on the other hand an accessor does not exist in the object, you need to
3353 use C<get_column> instead:
3355 my $employee_count = $employee->get_column('employee_count');
3357 You can create your own accessors if required - see
3358 L<DBIx::Class::Manual::Cookbook> for details.
3364 =item Value: ($rel_name | \@rel_names | \%rel_names)
3368 Contains a list of relationships that should be joined for this query. For
3371 # Get CDs by Nine Inch Nails
3372 my $rs = $schema->resultset('CD')->search(
3373 { 'artist.name' => 'Nine Inch Nails' },
3374 { join => 'artist' }
3377 Can also contain a hash reference to refer to the other relation's relations.
3380 package MyApp::Schema::Track;
3381 use base qw/DBIx::Class/;
3382 __PACKAGE__->table('track');
3383 __PACKAGE__->add_columns(qw/trackid cd position title/);
3384 __PACKAGE__->set_primary_key('trackid');
3385 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3388 # In your application
3389 my $rs = $schema->resultset('Artist')->search(
3390 { 'track.title' => 'Teardrop' },
3392 join => { cd => 'track' },
3393 order_by => 'artist.name',
3397 You need to use the relationship (not the table) name in conditions,
3398 because they are aliased as such. The current table is aliased as "me", so
3399 you need to use me.column_name in order to avoid ambiguity. For example:
3401 # Get CDs from 1984 with a 'Foo' track
3402 my $rs = $schema->resultset('CD')->search(
3405 'tracks.name' => 'Foo'
3407 { join => 'tracks' }
3410 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3411 similarly for a third time). For e.g.
3413 my $rs = $schema->resultset('Artist')->search({
3414 'cds.title' => 'Down to Earth',
3415 'cds_2.title' => 'Popular',
3417 join => [ qw/cds cds/ ],
3420 will return a set of all artists that have both a cd with title 'Down
3421 to Earth' and a cd with title 'Popular'.
3423 If you want to fetch related objects from other tables as well, see C<prefetch>
3426 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3432 =item Value: ($rel_name | \@rel_names | \%rel_names)
3436 Contains one or more relationships that should be fetched along with
3437 the main query (when they are accessed afterwards the data will
3438 already be available, without extra queries to the database). This is
3439 useful for when you know you will need the related objects, because it
3440 saves at least one query:
3442 my $rs = $schema->resultset('Tag')->search(
3451 The initial search results in SQL like the following:
3453 SELECT tag.*, cd.*, artist.* FROM tag
3454 JOIN cd ON tag.cd = cd.cdid
3455 JOIN artist ON cd.artist = artist.artistid
3457 L<DBIx::Class> has no need to go back to the database when we access the
3458 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3461 Simple prefetches will be joined automatically, so there is no need
3462 for a C<join> attribute in the above search.
3464 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3465 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3466 with an accessor type of 'single' or 'filter'). A more complex example that
3467 prefetches an artists cds, the tracks on those cds, and the tags associated
3468 with that artist is given below (assuming many-to-many from artists to tags):
3470 my $rs = $schema->resultset('Artist')->search(
3474 { cds => 'tracks' },
3475 { artist_tags => 'tags' }
3481 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3482 attributes will be ignored.
3484 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3485 exactly as you might expect.
3491 Prefetch uses the L</cache> to populate the prefetched relationships. This
3492 may or may not be what you want.
3496 If you specify a condition on a prefetched relationship, ONLY those
3497 rows that match the prefetched condition will be fetched into that relationship.
3498 This means that adding prefetch to a search() B<may alter> what is returned by
3499 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3501 my $artist_rs = $schema->resultset('Artist')->search({
3507 my $count = $artist_rs->first->cds->count;
3509 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3511 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3513 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3515 that cmp_ok() may or may not pass depending on the datasets involved. This
3516 behavior may or may not survive the 0.09 transition.
3528 Makes the resultset paged and specifies the page to retrieve. Effectively
3529 identical to creating a non-pages resultset and then calling ->page($page)
3532 If L<rows> attribute is not specified it defaults to 10 rows per page.
3534 When you have a paged resultset, L</count> will only return the number
3535 of rows in the page. To get the total, use the L</pager> and call
3536 C<total_entries> on it.
3546 Specifies the maximum number of rows for direct retrieval or the number of
3547 rows per page if the page attribute or method is used.
3553 =item Value: $offset
3557 Specifies the (zero-based) row number for the first row to be returned, or the
3558 of the first row of the first page if paging is used.
3564 =item Value: \@columns
3568 A arrayref of columns to group by. Can include columns of joined tables.
3570 group_by => [qw/ column1 column2 ... /]
3576 =item Value: $condition
3580 HAVING is a select statement attribute that is applied between GROUP BY and
3581 ORDER BY. It is applied to the after the grouping calculations have been
3584 having => { 'count(employee)' => { '>=', 100 } }
3590 =item Value: (0 | 1)
3594 Set to 1 to group by all columns. If the resultset already has a group_by
3595 attribute, this setting is ignored and an appropriate warning is issued.
3601 Adds to the WHERE clause.
3603 # only return rows WHERE deleted IS NULL for all searches
3604 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3606 Can be overridden by passing C<< { where => undef } >> as an attribute
3613 Set to 1 to cache search results. This prevents extra SQL queries if you
3614 revisit rows in your ResultSet:
3616 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3618 while( my $artist = $resultset->next ) {
3622 $rs->first; # without cache, this would issue a query
3624 By default, searches are not cached.
3626 For more examples of using these attributes, see
3627 L<DBIx::Class::Manual::Cookbook>.
3633 =item Value: ( 'update' | 'shared' )
3637 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT