1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
10 use DBIx::Class::Exception;
13 use DBIx::Class::ResultSetColumn;
14 use DBIx::Class::ResultSourceHandle;
17 use base qw/DBIx::Class/;
19 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
23 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
27 my $users_rs = $schema->resultset('User');
28 while( $user = $users_rs->next) {
29 print $user->username;
32 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
33 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
37 A ResultSet is an object which stores a set of conditions representing
38 a query. It is the backbone of DBIx::Class (i.e. the really
39 important/useful bit).
41 No SQL is executed on the database when a ResultSet is created, it
42 just stores all the conditions needed to create the query.
44 A basic ResultSet representing the data of an entire table is returned
45 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
46 L<Source|DBIx::Class::Manual::Glossary/Source> name.
48 my $users_rs = $schema->resultset('User');
50 A new ResultSet is returned from calling L</search> on an existing
51 ResultSet. The new one will contain all the conditions of the
52 original, plus any new conditions added in the C<search> call.
54 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
55 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
58 The query that the ResultSet represents is B<only> executed against
59 the database when these methods are called:
60 L</find> L</next> L</all> L</first> L</single> L</count>
64 =head2 Chaining resultsets
66 Let's say you've got a query that needs to be run to return some data
67 to the user. But, you have an authorization system in place that
68 prevents certain users from seeing certain information. So, you want
69 to construct the basic query in one method, but add constraints to it in
74 my $request = $self->get_request; # Get a request object somehow.
75 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
77 my $cd_rs = $schema->resultset('CD')->search({
78 title => $request->param('title'),
79 year => $request->param('year'),
82 $self->apply_security_policy( $cd_rs );
87 sub apply_security_policy {
96 =head3 Resolving conditions and attributes
98 When a resultset is chained from another resultset, conditions and
99 attributes with the same keys need resolving.
101 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
102 into the existing ones from the original resultset.
104 The L</where>, L</having> attribute, and any search conditions are
105 merged with an SQL C<AND> to the existing condition from the original
108 All other attributes are overridden by any new ones supplied in the
111 =head2 Multiple queries
113 Since a resultset just defines a query, you can do all sorts of
114 things with it with the same object.
116 # Don't hit the DB yet.
117 my $cd_rs = $schema->resultset('CD')->search({
118 title => 'something',
122 # Each of these hits the DB individually.
123 my $count = $cd_rs->count;
124 my $most_recent = $cd_rs->get_column('date_released')->max();
125 my @records = $cd_rs->all;
127 And it's not just limited to SELECT statements.
133 $cd_rs->create({ artist => 'Fred' });
135 Which is the same as:
137 $schema->resultset('CD')->create({
138 title => 'something',
143 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
147 If a resultset is used in a numeric context it returns the L</count>.
148 However, if it is used in a boolean context it is always true. So if
149 you want to check if a resultset has any results use C<if $rs != 0>.
150 C<if $rs> will always be true.
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},
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?
689 my $cd = $schema->resultset('CD')->single({ year => 2001 });
691 Inflates the first result without creating a cursor if the resultset has
692 any records in it; if not returns nothing. Used by L</find> as a lean version of
695 While this method can take an optional search condition (just like L</search>)
696 being a fast-code-path it does not recognize search attributes. If you need to
697 add extra joins or similar, call L</search> and then chain-call L</single> on the
698 L<DBIx::Class::ResultSet> returned.
704 As of 0.08100, this method enforces the assumption that the preceding
705 query returns only one row. If more than one row is returned, you will receive
708 Query returned more than one row
710 In this case, you should be using L</next> or L</find> instead, or if you really
711 know what you are doing, use the L</rows> attribute to explicitly limit the size
714 This method will also throw an exception if it is called on a resultset prefetching
715 has_many, as such a prefetch implies fetching multiple rows from the database in
716 order to assemble the resulting object.
723 my ($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?
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 $self->{all_cache_position} = 1;
954 return ($self->all)[0];
956 if ($self->{stashed_objects}) {
957 my $obj = shift(@{$self->{stashed_objects}});
958 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
962 exists $self->{stashed_row}
963 ? @{delete $self->{stashed_row}}
964 : $self->cursor->next
966 return undef unless (@row);
967 my ($row, @more) = $self->_construct_object(@row);
968 $self->{stashed_objects} = \@more if @more;
972 sub _construct_object {
973 my ($self, @row) = @_;
975 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
977 my @new = $self->result_class->inflate_result($self->result_source, @$info);
978 @new = $self->{_attrs}{record_filter}->(@new)
979 if exists $self->{_attrs}{record_filter};
983 sub _collapse_result {
984 my ($self, $as_proto, $row) = @_;
988 # 'foo' => [ undef, 'foo' ]
989 # 'foo.bar' => [ 'foo', 'bar' ]
990 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
992 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
994 my %collapse = %{$self->{_attrs}{collapse}||{}};
998 # if we're doing collapsing (has_many prefetch) we need to grab records
999 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1000 # we know we don't have to bother.
1002 # the reason for not using the collapse stuff directly is because if you
1003 # had for e.g. two artists in a row with no cds, the collapse info for
1004 # both would be NULL (undef) so you'd lose the second artist
1006 # store just the index so we can check the array positions from the row
1007 # without having to contruct the full hash
1009 if (keys %collapse) {
1010 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1011 foreach my $i (0 .. $#construct_as) {
1012 next if defined($construct_as[$i][0]); # only self table
1013 if (delete $pri{$construct_as[$i][1]}) {
1014 push(@pri_index, $i);
1016 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1020 # no need to do an if, it'll be empty if @pri_index is empty anyway
1022 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1026 do { # no need to check anything at the front, we always want the first row
1030 foreach my $this_as (@construct_as) {
1031 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1034 push(@const_rows, \%const);
1036 } until ( # no pri_index => no collapse => drop straight out
1039 do { # get another row, stash it, drop out if different PK
1041 @copy = $self->cursor->next;
1042 $self->{stashed_row} = \@copy;
1044 # last thing in do block, counts as true if anything doesn't match
1046 # check xor defined first for NULL vs. NOT NULL then if one is
1047 # defined the other must be so check string equality
1050 (defined $pri_vals{$_} ^ defined $copy[$_])
1051 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1056 my $alias = $self->{attrs}{alias};
1063 foreach my $const (@const_rows) {
1064 scalar @const_keys or do {
1065 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1067 foreach my $key (@const_keys) {
1070 my @parts = split(/\./, $key);
1072 my $data = $const->{$key};
1073 foreach my $p (@parts) {
1074 $target = $target->[1]->{$p} ||= [];
1076 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1077 # collapsing at this point and on final part
1078 my $pos = $collapse_pos{$cur};
1079 CK: foreach my $ck (@ckey) {
1080 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1081 $collapse_pos{$cur} = $data;
1082 delete @collapse_pos{ # clear all positioning for sub-entries
1083 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1090 if (exists $collapse{$cur}) {
1091 $target = $target->[-1];
1094 $target->[0] = $data;
1096 $info->[0] = $const->{$key};
1104 =head2 result_source
1108 =item Arguments: $result_source?
1110 =item Return Value: $result_source
1114 An accessor for the primary ResultSource object from which this ResultSet
1121 =item Arguments: $result_class?
1123 =item Return Value: $result_class
1127 An accessor for the class to use when creating row objects. Defaults to
1128 C<< result_source->result_class >> - which in most cases is the name of the
1129 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1131 Note that changing the result_class will also remove any components
1132 that were originally loaded in the source class via
1133 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1134 in the original source class will not run.
1139 my ($self, $result_class) = @_;
1140 if ($result_class) {
1141 unless (ref $result_class) { # don't fire this for an object
1142 $self->ensure_class_loaded($result_class);
1144 $self->_result_class($result_class);
1145 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1146 # permit the user to set result class on one result set only; it only
1147 # chains if provided to search()
1148 #$self->{attrs}{result_class} = $result_class if ref $self;
1150 $self->_result_class;
1157 =item Arguments: $cond, \%attrs??
1159 =item Return Value: $count
1163 Performs an SQL C<COUNT> with the same query as the resultset was built
1164 with to find the number of elements. Passing arguments is equivalent to
1165 C<< $rs->search ($cond, \%attrs)->count >>
1171 return $self->search(@_)->count if @_ and defined $_[0];
1172 return scalar @{ $self->get_cache } if $self->get_cache;
1174 my $attrs = $self->_resolved_attrs_copy;
1176 # this is a little optimization - it is faster to do the limit
1177 # adjustments in software, instead of a subquery
1178 my $rows = delete $attrs->{rows};
1179 my $offset = delete $attrs->{offset};
1182 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1183 $crs = $self->_count_subq_rs ($attrs);
1186 $crs = $self->_count_rs ($attrs);
1188 my $count = $crs->next;
1190 $count -= $offset if $offset;
1191 $count = $rows if $rows and $rows < $count;
1192 $count = 0 if ($count < 0);
1201 =item Arguments: $cond, \%attrs??
1203 =item Return Value: $count_rs
1207 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1208 This can be very handy for subqueries:
1210 ->search( { amount => $some_rs->count_rs->as_query } )
1212 As with regular resultsets the SQL query will be executed only after
1213 the resultset is accessed via L</next> or L</all>. That would return
1214 the same single value obtainable via L</count>.
1220 return $self->search(@_)->count_rs if @_;
1222 # this may look like a lack of abstraction (count() does about the same)
1223 # but in fact an _rs *must* use a subquery for the limits, as the
1224 # software based limiting can not be ported if this $rs is to be used
1225 # in a subquery itself (i.e. ->as_query)
1226 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1227 return $self->_count_subq_rs;
1230 return $self->_count_rs;
1235 # returns a ResultSetColumn object tied to the count query
1238 my ($self, $attrs) = @_;
1240 my $rsrc = $self->result_source;
1241 $attrs ||= $self->_resolved_attrs;
1243 # only take pieces we need for a simple count
1244 my $tmp_attrs = { map
1245 { $_ => $attrs->{$_} }
1246 qw/ alias from where bind join /
1249 # overwrite the selector (supplied by the storage)
1250 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $tmp_attrs);
1251 $tmp_attrs->{as} = 'count';
1253 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1259 # same as above but uses a subquery
1261 sub _count_subq_rs {
1262 my ($self, $attrs) = @_;
1264 my $rsrc = $self->result_source;
1265 $attrs ||= $self->_resolved_attrs;
1267 my $sub_attrs = { map
1268 { $_ => $attrs->{$_} }
1269 qw/ alias from where bind join group_by having rows offset /
1272 # if we multi-prefetch we group_by primary keys only as this is what we would
1273 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1274 if ( keys %{$attrs->{collapse}} ) {
1275 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1278 # Calculate subquery selector
1279 if (my $g = $sub_attrs->{group_by}) {
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 push @{$sub_attrs->{select}}, $sel_index->{$g_part} || $g_part;
1293 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1294 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1297 return $rsrc->resultset_class
1298 ->new ($rsrc, $sub_attrs)
1300 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1301 -> get_column ('count');
1308 =head2 count_literal
1312 =item Arguments: $sql_fragment, @bind_values
1314 =item Return Value: $count
1318 Counts the results in a literal query. Equivalent to calling L</search_literal>
1319 with the passed arguments, then L</count>.
1323 sub count_literal { shift->search_literal(@_)->count; }
1329 =item Arguments: none
1331 =item Return Value: @objects
1335 Returns all elements in the resultset. Called implicitly if the resultset
1336 is returned in list context.
1343 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1346 return @{ $self->get_cache } if $self->get_cache;
1350 if (keys %{$self->_resolved_attrs->{collapse}}) {
1351 # Using $self->cursor->all is really just an optimisation.
1352 # If we're collapsing has_many prefetches it probably makes
1353 # very little difference, and this is cleaner than hacking
1354 # _construct_object to survive the approach
1355 $self->cursor->reset;
1356 my @row = $self->cursor->next;
1358 push(@obj, $self->_construct_object(@row));
1359 @row = (exists $self->{stashed_row}
1360 ? @{delete $self->{stashed_row}}
1361 : $self->cursor->next);
1364 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1367 $self->set_cache(\@obj) if $self->{attrs}{cache};
1376 =item Arguments: none
1378 =item Return Value: $self
1382 Resets the resultset's cursor, so you can iterate through the elements again.
1383 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1390 delete $self->{_attrs} if exists $self->{_attrs};
1391 $self->{all_cache_position} = 0;
1392 $self->cursor->reset;
1400 =item Arguments: none
1402 =item Return Value: $object?
1406 Resets the resultset and returns an object for the first result (if the
1407 resultset returns anything).
1412 return $_[0]->reset->next;
1418 # Determines whether and what type of subquery is required for the $rs operation.
1419 # If grouping is necessary either supplies its own, or verifies the current one
1420 # After all is done delegates to the proper storage method.
1422 sub _rs_update_delete {
1423 my ($self, $op, $values) = @_;
1425 my $rsrc = $self->result_source;
1427 # if a condition exists we need to strip all table qualifiers
1428 # if this is not possible we'll force a subquery below
1429 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1431 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1432 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1434 if ($needs_group_by_subq or $needs_subq) {
1436 # make a new $rs selecting only the PKs (that's all we really need)
1437 my $attrs = $self->_resolved_attrs_copy;
1439 delete $attrs->{$_} for qw/collapse 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);
1474 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1477 return $rsrc->storage->$op(
1479 $op eq 'update' ? $values : (),
1489 =item Arguments: \%values
1491 =item Return Value: $storage_rv
1495 Sets the specified columns in the resultset to the supplied values in a
1496 single query. Return value will be true if the update succeeded or false
1497 if no records were updated; exact type of success value is storage-dependent.
1502 my ($self, $values) = @_;
1503 $self->throw_exception('Values for update must be a hash')
1504 unless ref $values eq 'HASH';
1506 return $self->_rs_update_delete ('update', $values);
1513 =item Arguments: \%values
1515 =item Return Value: 1
1519 Fetches all objects and updates them one at a time. Note that C<update_all>
1520 will run DBIC cascade triggers, while L</update> will not.
1525 my ($self, $values) = @_;
1526 $self->throw_exception('Values for update_all must be a hash')
1527 unless ref $values eq 'HASH';
1529 my $guard = $self->result_source->schema->txn_scope_guard;
1530 $_->update($values) for $self->all;
1539 =item Arguments: none
1541 =item Return Value: $storage_rv
1545 Deletes the contents of the resultset from its result source. Note that this
1546 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1547 to run. See also L<DBIx::Class::Row/delete>.
1549 Return value will be the number of rows deleted; exact type of return value
1550 is storage-dependent.
1556 $self->throw_exception('delete does not accept any arguments')
1559 return $self->_rs_update_delete ('delete');
1566 =item Arguments: none
1568 =item Return Value: 1
1572 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1573 will run DBIC cascade triggers, while L</delete> will not.
1579 $self->throw_exception('delete_all does not accept any arguments')
1582 my $guard = $self->result_source->schema->txn_scope_guard;
1583 $_->delete for $self->all;
1592 =item Arguments: \@data;
1596 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1597 For the arrayref of hashrefs style each hashref should be a structure suitable
1598 forsubmitting to a $resultset->create(...) method.
1600 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1601 to insert the data, as this is a faster method.
1603 Otherwise, each set of data is inserted into the database using
1604 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1605 accumulated into an array. The array itself, or an array reference
1606 is returned depending on scalar or list context.
1608 Example: Assuming an Artist Class that has many CDs Classes relating:
1610 my $Artist_rs = $schema->resultset("Artist");
1612 ## Void Context Example
1613 $Artist_rs->populate([
1614 { artistid => 4, name => 'Manufactured Crap', cds => [
1615 { title => 'My First CD', year => 2006 },
1616 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1619 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1620 { title => 'My parents sold me to a record company', year => 2005 },
1621 { title => 'Why Am I So Ugly?', year => 2006 },
1622 { title => 'I Got Surgery and am now Popular', year => 2007 }
1627 ## Array Context Example
1628 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1629 { name => "Artist One"},
1630 { name => "Artist Two"},
1631 { name => "Artist Three", cds=> [
1632 { title => "First CD", year => 2007},
1633 { title => "Second CD", year => 2008},
1637 print $ArtistOne->name; ## response is 'Artist One'
1638 print $ArtistThree->cds->count ## reponse is '2'
1640 For the arrayref of arrayrefs style, the first element should be a list of the
1641 fieldsnames to which the remaining elements are rows being inserted. For
1644 $Arstist_rs->populate([
1645 [qw/artistid name/],
1646 [100, 'A Formally Unknown Singer'],
1647 [101, 'A singer that jumped the shark two albums ago'],
1648 [102, 'An actually cool singer'],
1651 Please note an important effect on your data when choosing between void and
1652 wantarray context. Since void context goes straight to C<insert_bulk> in
1653 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1654 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1655 create primary keys for you, you will find that your PKs are empty. In this
1656 case you will have to use the wantarray context in order to create those
1664 # cruft placed in standalone method
1665 my $data = $self->_normalize_populate_args(@_);
1667 if(defined wantarray) {
1669 foreach my $item (@$data) {
1670 push(@created, $self->create($item));
1672 return wantarray ? @created : \@created;
1674 my $first = $data->[0];
1676 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1677 # it relationship data
1678 my (@rels, @columns);
1679 for (keys %$first) {
1680 my $ref = ref $first->{$_};
1681 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1687 my @pks = $self->result_source->primary_columns;
1689 ## do the belongs_to relationships
1690 foreach my $index (0..$#$data) {
1692 # delegate to create() for any dataset without primary keys with specified relationships
1693 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1695 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1696 my @ret = $self->populate($data);
1702 foreach my $rel (@rels) {
1703 next unless ref $data->[$index]->{$rel} eq "HASH";
1704 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1705 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1706 my $related = $result->result_source->_resolve_condition(
1707 $result->result_source->relationship_info($reverse)->{cond},
1712 delete $data->[$index]->{$rel};
1713 $data->[$index] = {%{$data->[$index]}, %$related};
1715 push @columns, keys %$related if $index == 0;
1719 ## inherit the data locked in the conditions of the resultset
1720 my ($rs_data) = $self->_merge_cond_with_data({});
1721 delete @{$rs_data}{@columns};
1722 my @inherit_cols = keys %$rs_data;
1723 my @inherit_data = values %$rs_data;
1725 ## do bulk insert on current row
1726 $self->result_source->storage->insert_bulk(
1727 $self->result_source,
1728 [@columns, @inherit_cols],
1729 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1732 ## do the has_many relationships
1733 foreach my $item (@$data) {
1735 foreach my $rel (@rels) {
1736 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1738 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1739 || $self->throw_exception('Cannot find the relating object.');
1741 my $child = $parent->$rel;
1743 my $related = $child->result_source->_resolve_condition(
1744 $parent->result_source->relationship_info($rel)->{cond},
1749 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1750 my @populate = map { {%$_, %$related} } @rows_to_add;
1752 $child->populate( \@populate );
1759 # populate() argumnets went over several incarnations
1760 # What we ultimately support is AoH
1761 sub _normalize_populate_args {
1762 my ($self, $arg) = @_;
1764 if (ref $arg eq 'ARRAY') {
1765 if (ref $arg->[0] eq 'HASH') {
1768 elsif (ref $arg->[0] eq 'ARRAY') {
1770 my @colnames = @{$arg->[0]};
1771 foreach my $values (@{$arg}[1 .. $#$arg]) {
1772 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
1778 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
1785 =item Arguments: none
1787 =item Return Value: $pager
1791 Return Value a L<Data::Page> object for the current resultset. Only makes
1792 sense for queries with a C<page> attribute.
1794 To get the full count of entries for a paged resultset, call
1795 C<total_entries> on the L<Data::Page> object.
1802 return $self->{pager} if $self->{pager};
1804 my $attrs = $self->{attrs};
1805 $self->throw_exception("Can't create pager for non-paged rs")
1806 unless $self->{attrs}{page};
1807 $attrs->{rows} ||= 10;
1809 # throw away the paging flags and re-run the count (possibly
1810 # with a subselect) to get the real total count
1811 my $count_attrs = { %$attrs };
1812 delete $count_attrs->{$_} for qw/rows offset page pager/;
1813 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1815 return $self->{pager} = Data::Page->new(
1818 $self->{attrs}{page}
1826 =item Arguments: $page_number
1828 =item Return Value: $rs
1832 Returns a resultset for the $page_number page of the resultset on which page
1833 is called, where each page contains a number of rows equal to the 'rows'
1834 attribute set on the resultset (10 by default).
1839 my ($self, $page) = @_;
1840 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1847 =item Arguments: \%vals
1849 =item Return Value: $rowobject
1853 Creates a new row object in the resultset's result class and returns
1854 it. The row is not inserted into the database at this point, call
1855 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1856 will tell you whether the row object has been inserted or not.
1858 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1863 my ($self, $values) = @_;
1864 $self->throw_exception( "new_result needs a hash" )
1865 unless (ref $values eq 'HASH');
1867 my ($merged_cond, $cols_from_relations) = $self->_merge_cond_with_data($values);
1871 @$cols_from_relations
1872 ? (-cols_from_relations => $cols_from_relations)
1874 -source_handle => $self->_source_handle,
1875 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1878 return $self->result_class->new(\%new);
1881 # _merge_cond_with_data
1883 # Takes a simple hash of K/V data and returns its copy merged with the
1884 # condition already present on the resultset. Additionally returns an
1885 # arrayref of value/condition names, which were inferred from related
1886 # objects (this is needed for in-memory related objects)
1887 sub _merge_cond_with_data {
1888 my ($self, $data) = @_;
1890 my (%new_data, @cols_from_relations);
1892 my $alias = $self->{attrs}{alias};
1894 if (! defined $self->{cond}) {
1895 # just massage $data below
1897 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
1898 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1899 @cols_from_relations = keys %new_data;
1901 elsif (ref $self->{cond} ne 'HASH') {
1902 $self->throw_exception(
1903 "Can't abstract implicit construct, resultset condition not a hash"
1907 # precendence must be given to passed values over values inherited from
1908 # the cond, so the order here is important.
1909 my $collapsed_cond = $self->_collapse_cond($self->{cond});
1910 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1912 while ( my($col, $value) = each %implied ) {
1913 if (ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
1914 $new_data{$col} = $value->{'='};
1917 $new_data{$col} = $value if $self->_is_deterministic_value($value);
1923 %{ $self->_remove_alias($data, $alias) },
1926 return (\%new_data, \@cols_from_relations);
1929 # _is_deterministic_value
1931 # Make an effor to strip non-deterministic values from the condition,
1932 # to make sure new_result chokes less
1934 sub _is_deterministic_value {
1937 my $ref_type = ref $value;
1938 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1939 return 1 if Scalar::Util::blessed($value);
1943 # _has_resolved_attr
1945 # determines if the resultset defines at least one
1946 # of the attributes supplied
1948 # used to determine if a subquery is neccessary
1950 # supports some virtual attributes:
1952 # This will scan for any joins being present on the resultset.
1953 # It is not a mere key-search but a deep inspection of {from}
1956 sub _has_resolved_attr {
1957 my ($self, @attr_names) = @_;
1959 my $attrs = $self->_resolved_attrs;
1963 for my $n (@attr_names) {
1964 if (grep { $n eq $_ } (qw/-join/) ) {
1965 $extra_checks{$n}++;
1969 my $attr = $attrs->{$n};
1971 next if not defined $attr;
1973 if (ref $attr eq 'HASH') {
1974 return 1 if keys %$attr;
1976 elsif (ref $attr eq 'ARRAY') {
1984 # a resolved join is expressed as a multi-level from
1986 $extra_checks{-join}
1988 ref $attrs->{from} eq 'ARRAY'
1990 @{$attrs->{from}} > 1
1998 # Recursively collapse the condition.
2000 sub _collapse_cond {
2001 my ($self, $cond, $collapsed) = @_;
2005 if (ref $cond eq 'ARRAY') {
2006 foreach my $subcond (@$cond) {
2007 next unless ref $subcond; # -or
2008 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2011 elsif (ref $cond eq 'HASH') {
2012 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2013 foreach my $subcond (@{$cond->{-and}}) {
2014 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2018 foreach my $col (keys %$cond) {
2019 my $value = $cond->{$col};
2020 $collapsed->{$col} = $value;
2030 # Remove the specified alias from the specified query hash. A copy is made so
2031 # the original query is not modified.
2034 my ($self, $query, $alias) = @_;
2036 my %orig = %{ $query || {} };
2039 foreach my $key (keys %orig) {
2041 $unaliased{$key} = $orig{$key};
2044 $unaliased{$1} = $orig{$key}
2045 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2055 =item Arguments: none
2057 =item Return Value: \[ $sql, @bind ]
2061 Returns the SQL query and bind vars associated with the invocant.
2063 This is generally used as the RHS for a subquery.
2070 my $attrs = $self->_resolved_attrs_copy;
2075 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2076 # $sql also has no wrapping parenthesis in list ctx
2078 my $sqlbind = $self->result_source->storage
2079 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2088 =item Arguments: \%vals, \%attrs?
2090 =item Return Value: $rowobject
2094 my $artist = $schema->resultset('Artist')->find_or_new(
2095 { artist => 'fred' }, { key => 'artists' });
2097 $cd->cd_to_producer->find_or_new({ producer => $producer },
2098 { key => 'primary });
2100 Find an existing record from this resultset, based on its primary
2101 key, or a unique constraint. If none exists, instantiate a new result
2102 object and return it. The object will not be saved into your storage
2103 until you call L<DBIx::Class::Row/insert> on it.
2105 You most likely want this method when looking for existing rows using
2106 a unique constraint that is not the primary key, or looking for
2109 If you want objects to be saved immediately, use L</find_or_create>
2112 B<Note>: Take care when using C<find_or_new> with a table having
2113 columns with default values that you intend to be automatically
2114 supplied by the database (e.g. an auto_increment primary key column).
2115 In normal usage, the value of such columns should NOT be included at
2116 all in the call to C<find_or_new>, even when set to C<undef>.
2122 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2123 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2124 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2127 return $self->new_result($hash);
2134 =item Arguments: \%vals
2136 =item Return Value: a L<DBIx::Class::Row> $object
2140 Attempt to create a single new row or a row with multiple related rows
2141 in the table represented by the resultset (and related tables). This
2142 will not check for duplicate rows before inserting, use
2143 L</find_or_create> to do that.
2145 To create one row for this resultset, pass a hashref of key/value
2146 pairs representing the columns of the table and the values you wish to
2147 store. If the appropriate relationships are set up, foreign key fields
2148 can also be passed an object representing the foreign row, and the
2149 value will be set to its primary key.
2151 To create related objects, pass a hashref of related-object column values
2152 B<keyed on the relationship name>. If the relationship is of type C<multi>
2153 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2154 The process will correctly identify columns holding foreign keys, and will
2155 transparently populate them from the keys of the corresponding relation.
2156 This can be applied recursively, and will work correctly for a structure
2157 with an arbitrary depth and width, as long as the relationships actually
2158 exists and the correct column data has been supplied.
2161 Instead of hashrefs of plain related data (key/value pairs), you may
2162 also pass new or inserted objects. New objects (not inserted yet, see
2163 L</new>), will be inserted into their appropriate tables.
2165 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2167 Example of creating a new row.
2169 $person_rs->create({
2170 name=>"Some Person",
2171 email=>"somebody@someplace.com"
2174 Example of creating a new row and also creating rows in a related C<has_many>
2175 or C<has_one> resultset. Note Arrayref.
2178 { artistid => 4, name => 'Manufactured Crap', cds => [
2179 { title => 'My First CD', year => 2006 },
2180 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2185 Example of creating a new row and also creating a row in a related
2186 C<belongs_to>resultset. Note Hashref.
2189 title=>"Music for Silly Walks",
2192 name=>"Silly Musician",
2200 When subclassing ResultSet never attempt to override this method. Since
2201 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2202 lot of the internals simply never call it, so your override will be
2203 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2204 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2205 L</create> process you need to intervene.
2212 my ($self, $attrs) = @_;
2213 $self->throw_exception( "create needs a hashref" )
2214 unless ref $attrs eq 'HASH';
2215 return $self->new_result($attrs)->insert;
2218 =head2 find_or_create
2222 =item Arguments: \%vals, \%attrs?
2224 =item Return Value: $rowobject
2228 $cd->cd_to_producer->find_or_create({ producer => $producer },
2229 { key => 'primary' });
2231 Tries to find a record based on its primary key or unique constraints; if none
2232 is found, creates one and returns that instead.
2234 my $cd = $schema->resultset('CD')->find_or_create({
2236 artist => 'Massive Attack',
2237 title => 'Mezzanine',
2241 Also takes an optional C<key> attribute, to search by a specific key or unique
2242 constraint. For example:
2244 my $cd = $schema->resultset('CD')->find_or_create(
2246 artist => 'Massive Attack',
2247 title => 'Mezzanine',
2249 { key => 'cd_artist_title' }
2252 B<Note>: Because find_or_create() reads from the database and then
2253 possibly inserts based on the result, this method is subject to a race
2254 condition. Another process could create a record in the table after
2255 the find has completed and before the create has started. To avoid
2256 this problem, use find_or_create() inside a transaction.
2258 B<Note>: Take care when using C<find_or_create> with a table having
2259 columns with default values that you intend to be automatically
2260 supplied by the database (e.g. an auto_increment primary key column).
2261 In normal usage, the value of such columns should NOT be included at
2262 all in the call to C<find_or_create>, even when set to C<undef>.
2264 See also L</find> and L</update_or_create>. For information on how to declare
2265 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2269 sub find_or_create {
2271 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2272 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2273 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2276 return $self->create($hash);
2279 =head2 update_or_create
2283 =item Arguments: \%col_values, { key => $unique_constraint }?
2285 =item Return Value: $rowobject
2289 $resultset->update_or_create({ col => $val, ... });
2291 First, searches for an existing row matching one of the unique constraints
2292 (including the primary key) on the source of this resultset. If a row is
2293 found, updates it with the other given column values. Otherwise, creates a new
2296 Takes an optional C<key> attribute to search on a specific unique constraint.
2299 # In your application
2300 my $cd = $schema->resultset('CD')->update_or_create(
2302 artist => 'Massive Attack',
2303 title => 'Mezzanine',
2306 { key => 'cd_artist_title' }
2309 $cd->cd_to_producer->update_or_create({
2310 producer => $producer,
2317 If no C<key> is specified, it searches on all unique constraints defined on the
2318 source, including the primary key.
2320 If the C<key> is specified as C<primary>, it searches only on the primary key.
2322 See also L</find> and L</find_or_create>. For information on how to declare
2323 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2325 B<Note>: Take care when using C<update_or_create> with a table having
2326 columns with default values that you intend to be automatically
2327 supplied by the database (e.g. an auto_increment primary key column).
2328 In normal usage, the value of such columns should NOT be included at
2329 all in the call to C<update_or_create>, even when set to C<undef>.
2333 sub update_or_create {
2335 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2336 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2338 my $row = $self->find($cond, $attrs);
2340 $row->update($cond);
2344 return $self->create($cond);
2347 =head2 update_or_new
2351 =item Arguments: \%col_values, { key => $unique_constraint }?
2353 =item Return Value: $rowobject
2357 $resultset->update_or_new({ col => $val, ... });
2359 First, searches for an existing row matching one of the unique constraints
2360 (including the primary key) on the source of this resultset. If a row is
2361 found, updates it with the other given column values. Otherwise, instantiate
2362 a new result object and return it. The object will not be saved into your storage
2363 until you call L<DBIx::Class::Row/insert> on it.
2365 Takes an optional C<key> attribute to search on a specific unique constraint.
2368 # In your application
2369 my $cd = $schema->resultset('CD')->update_or_new(
2371 artist => 'Massive Attack',
2372 title => 'Mezzanine',
2375 { key => 'cd_artist_title' }
2378 if ($cd->in_storage) {
2379 # the cd was updated
2382 # the cd is not yet in the database, let's insert it
2386 B<Note>: Take care when using C<update_or_new> with a table having
2387 columns with default values that you intend to be automatically
2388 supplied by the database (e.g. an auto_increment primary key column).
2389 In normal usage, the value of such columns should NOT be included at
2390 all in the call to C<update_or_new>, even when set to C<undef>.
2392 See also L</find>, L</find_or_create> and L</find_or_new>.
2398 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2399 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2401 my $row = $self->find( $cond, $attrs );
2402 if ( defined $row ) {
2403 $row->update($cond);
2407 return $self->new_result($cond);
2414 =item Arguments: none
2416 =item Return Value: \@cache_objects?
2420 Gets the contents of the cache for the resultset, if the cache is set.
2422 The cache is populated either by using the L</prefetch> attribute to
2423 L</search> or by calling L</set_cache>.
2435 =item Arguments: \@cache_objects
2437 =item Return Value: \@cache_objects
2441 Sets the contents of the cache for the resultset. Expects an arrayref
2442 of objects of the same class as those produced by the resultset. Note that
2443 if the cache is set the resultset will return the cached objects rather
2444 than re-querying the database even if the cache attr is not set.
2446 The contents of the cache can also be populated by using the
2447 L</prefetch> attribute to L</search>.
2452 my ( $self, $data ) = @_;
2453 $self->throw_exception("set_cache requires an arrayref")
2454 if defined($data) && (ref $data ne 'ARRAY');
2455 $self->{all_cache} = $data;
2462 =item Arguments: none
2464 =item Return Value: []
2468 Clears the cache for the resultset.
2473 shift->set_cache(undef);
2480 =item Arguments: none
2482 =item Return Value: true, if the resultset has been paginated
2490 return !!$self->{attrs}{page};
2497 =item Arguments: none
2499 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2507 return scalar $self->result_source->storage->_parse_order_by($self->{attrs}{order_by});
2510 =head2 related_resultset
2514 =item Arguments: $relationship_name
2516 =item Return Value: $resultset
2520 Returns a related resultset for the supplied relationship name.
2522 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2526 sub related_resultset {
2527 my ($self, $rel) = @_;
2529 $self->{related_resultsets} ||= {};
2530 return $self->{related_resultsets}{$rel} ||= do {
2531 my $rsrc = $self->result_source;
2532 my $rel_info = $rsrc->relationship_info($rel);
2534 $self->throw_exception(
2535 "search_related: result source '" . $rsrc->source_name .
2536 "' has no such relationship $rel")
2539 my $attrs = $self->_chain_relationship($rel);
2541 my $join_count = $attrs->{seen_join}{$rel};
2543 my $alias = $self->result_source->storage
2544 ->relname_to_table_alias($rel, $join_count);
2546 # since this is search_related, and we already slid the select window inwards
2547 # (the select/as attrs were deleted in the beginning), we need to flip all
2548 # left joins to inner, so we get the expected results
2549 # read the comment on top of the actual function to see what this does
2550 $attrs->{from} = $rsrc->schema->storage->_straight_join_to_node ($attrs->{from}, $alias);
2553 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2554 delete @{$attrs}{qw(result_class alias)};
2558 if (my $cache = $self->get_cache) {
2559 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2560 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2565 my $rel_source = $rsrc->related_source($rel);
2569 # The reason we do this now instead of passing the alias to the
2570 # search_rs below is that if you wrap/overload resultset on the
2571 # source you need to know what alias it's -going- to have for things
2572 # to work sanely (e.g. RestrictWithObject wants to be able to add
2573 # extra query restrictions, and these may need to be $alias.)
2575 my $rel_attrs = $rel_source->resultset_attributes;
2576 local $rel_attrs->{alias} = $alias;
2578 $rel_source->resultset
2582 where => $attrs->{where},
2585 $new->set_cache($new_cache) if $new_cache;
2590 =head2 current_source_alias
2594 =item Arguments: none
2596 =item Return Value: $source_alias
2600 Returns the current table alias for the result source this resultset is built
2601 on, that will be used in the SQL query. Usually it is C<me>.
2603 Currently the source alias that refers to the result set returned by a
2604 L</search>/L</find> family method depends on how you got to the resultset: it's
2605 C<me> by default, but eg. L</search_related> aliases it to the related result
2606 source name (and keeps C<me> referring to the original result set). The long
2607 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2608 (and make this method unnecessary).
2610 Thus it's currently necessary to use this method in predefined queries (see
2611 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2612 source alias of the current result set:
2614 # in a result set class
2616 my ($self, $user) = @_;
2618 my $me = $self->current_source_alias;
2620 return $self->search(
2621 "$me.modified" => $user->id,
2627 sub current_source_alias {
2630 return ($self->{attrs} || {})->{alias} || 'me';
2633 =head2 as_subselect_rs
2637 =item Arguments: none
2639 =item Return Value: $resultset
2643 Act as a barrier to SQL symbols. The resultset provided will be made into a
2644 "virtual view" by including it as a subquery within the from clause. From this
2645 point on, any joined tables are inaccessible to ->search on the resultset (as if
2646 it were simply where-filtered without joins). For example:
2648 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
2650 # 'x' now pollutes the query namespace
2652 # So the following works as expected
2653 my $ok_rs = $rs->search({'x.other' => 1});
2655 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
2656 # def) we look for one row with contradictory terms and join in another table
2657 # (aliased 'x_2') which we never use
2658 my $broken_rs = $rs->search({'x.name' => 'def'});
2660 my $rs2 = $rs->as_subselect_rs;
2662 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
2663 my $not_joined_rs = $rs2->search({'x.other' => 1});
2665 # works as expected: finds a 'table' row related to two x rows (abc and def)
2666 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
2668 Another example of when one might use this would be to select a subset of
2669 columns in a group by clause:
2671 my $rs = $schema->resultset('Bar')->search(undef, {
2672 group_by => [qw{ id foo_id baz_id }],
2673 })->as_subselect_rs->search(undef, {
2674 columns => [qw{ id foo_id }]
2677 In the above example normally columns would have to be equal to the group by,
2678 but because we isolated the group by into a subselect the above works.
2682 sub as_subselect_rs {
2685 my $attrs = $self->_resolved_attrs;
2687 my $fresh_rs = (ref $self)->new (
2688 $self->result_source
2691 # these pieces will be locked in the subquery
2692 delete $fresh_rs->{cond};
2693 delete @{$fresh_rs->{attrs}}{qw/where bind/};
2695 return $fresh_rs->search( {}, {
2697 $attrs->{alias} => $self->as_query,
2698 -alias => $attrs->{alias},
2699 -source_handle => $self->result_source->handle,
2701 alias => $attrs->{alias},
2705 # This code is called by search_related, and makes sure there
2706 # is clear separation between the joins before, during, and
2707 # after the relationship. This information is needed later
2708 # in order to properly resolve prefetch aliases (any alias
2709 # with a relation_chain_depth less than the depth of the
2710 # current prefetch is not considered)
2712 # The increments happen twice per join. An even number means a
2713 # relationship specified via a search_related, whereas an odd
2714 # number indicates a join/prefetch added via attributes
2716 # Also this code will wrap the current resultset (the one we
2717 # chain to) in a subselect IFF it contains limiting attributes
2718 sub _chain_relationship {
2719 my ($self, $rel) = @_;
2720 my $source = $self->result_source;
2721 my $attrs = { %{$self->{attrs}||{}} };
2723 # we need to take the prefetch the attrs into account before we
2724 # ->_resolve_join as otherwise they get lost - captainL
2725 my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2727 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
2729 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
2732 my @force_subq_attrs = qw/offset rows group_by having/;
2735 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
2737 $self->_has_resolved_attr (@force_subq_attrs)
2739 # Nuke the prefetch (if any) before the new $rs attrs
2740 # are resolved (prefetch is useless - we are wrapping
2741 # a subquery anyway).
2742 my $rs_copy = $self->search;
2743 $rs_copy->{attrs}{join} = $self->_merge_attr (
2744 $rs_copy->{attrs}{join},
2745 delete $rs_copy->{attrs}{prefetch},
2749 -source_handle => $source->handle,
2750 -alias => $attrs->{alias},
2751 $attrs->{alias} => $rs_copy->as_query,
2753 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
2754 $seen->{-relation_chain_depth} = 0;
2756 elsif ($attrs->{from}) { #shallow copy suffices
2757 $from = [ @{$attrs->{from}} ];
2761 -source_handle => $source->handle,
2762 -alias => $attrs->{alias},
2763 $attrs->{alias} => $source->from,
2767 my $jpath = ($seen->{-relation_chain_depth})
2768 ? $from->[-1][0]{-join_path}
2771 my @requested_joins = $source->_resolve_join(
2778 push @$from, @requested_joins;
2780 $seen->{-relation_chain_depth}++;
2782 # if $self already had a join/prefetch specified on it, the requested
2783 # $rel might very well be already included. What we do in this case
2784 # is effectively a no-op (except that we bump up the chain_depth on
2785 # the join in question so we could tell it *is* the search_related)
2788 # we consider the last one thus reverse
2789 for my $j (reverse @requested_joins) {
2790 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
2791 if ($rel eq $last_j) {
2792 $j->[0]{-relation_chain_depth}++;
2798 unless ($already_joined) {
2799 push @$from, $source->_resolve_join(
2807 $seen->{-relation_chain_depth}++;
2809 return {%$attrs, from => $from, seen_join => $seen};
2812 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2813 sub _resolved_attrs_copy {
2815 return { %{$self->_resolved_attrs (@_)} };
2818 sub _resolved_attrs {
2820 return $self->{_attrs} if $self->{_attrs};
2822 my $attrs = { %{ $self->{attrs} || {} } };
2823 my $source = $self->result_source;
2824 my $alias = $attrs->{alias};
2826 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2829 # build columns (as long as select isn't set) into a set of as/select hashes
2830 unless ( $attrs->{select} ) {
2833 if ( ref $attrs->{columns} eq 'ARRAY' ) {
2834 @cols = @{ delete $attrs->{columns}}
2835 } elsif ( defined $attrs->{columns} ) {
2836 @cols = delete $attrs->{columns}
2838 @cols = $source->columns
2842 if ( ref $_ eq 'HASH' ) {
2845 my $key = /^\Q${alias}.\E(.+)$/
2851 push @colbits, { $key => $value };
2856 # add the additional columns on
2857 foreach (qw{include_columns +columns}) {
2858 if ( $attrs->{$_} ) {
2859 my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
2860 ? @{ delete $attrs->{$_} }
2861 : delete $attrs->{$_};
2863 if ( ref($_) eq 'HASH' ) {
2866 my $key = ( split /\./, $_ )[-1];
2867 my $value = ( /\./ ? $_ : "$alias.$_" );
2868 push @colbits, { $key => $value };
2874 # start with initial select items
2875 if ( $attrs->{select} ) {
2877 ( ref $attrs->{select} eq 'ARRAY' )
2878 ? [ @{ $attrs->{select} } ]
2879 : [ $attrs->{select} ];
2881 if ( $attrs->{as} ) {
2884 ref $attrs->{as} eq 'ARRAY'
2885 ? [ @{ $attrs->{as} } ]
2889 $attrs->{as} = [ map {
2890 m/^\Q${alias}.\E(.+)$/
2893 } @{ $attrs->{select} }
2899 # otherwise we intialise select & as to empty
2900 $attrs->{select} = [];
2904 # now add colbits to select/as
2905 push @{ $attrs->{select} }, map values %{$_}, @colbits;
2906 push @{ $attrs->{as} }, map keys %{$_}, @colbits;
2908 if ( my $adds = delete $attrs->{'+select'} ) {
2909 $adds = [$adds] unless ref $adds eq 'ARRAY';
2910 push @{ $attrs->{select} },
2911 map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
2913 if ( my $adds = delete $attrs->{'+as'} ) {
2914 $adds = [$adds] unless ref $adds eq 'ARRAY';
2915 push @{ $attrs->{as} }, @$adds;
2918 $attrs->{from} ||= [{
2919 -source_handle => $source->handle,
2920 -alias => $self->{attrs}{alias},
2921 $self->{attrs}{alias} => $source->from,
2924 if ( $attrs->{join} || $attrs->{prefetch} ) {
2926 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
2927 if ref $attrs->{from} ne 'ARRAY';
2929 my $join = delete $attrs->{join} || {};
2931 if ( defined $attrs->{prefetch} ) {
2932 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2935 $attrs->{from} = # have to copy here to avoid corrupting the original
2937 @{ $attrs->{from} },
2938 $source->_resolve_join(
2941 { %{ $attrs->{seen_join} || {} } },
2942 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
2943 ? $attrs->{from}[-1][0]{-join_path}
2950 if ( defined $attrs->{order_by} ) {
2951 $attrs->{order_by} = (
2952 ref( $attrs->{order_by} ) eq 'ARRAY'
2953 ? [ @{ $attrs->{order_by} } ]
2954 : [ $attrs->{order_by} || () ]
2958 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
2959 $attrs->{group_by} = [ $attrs->{group_by} ];
2962 # generate the distinct induced group_by early, as prefetch will be carried via a
2963 # subquery (since a group_by is present)
2964 if (delete $attrs->{distinct}) {
2965 if ($attrs->{group_by}) {
2966 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
2969 $attrs->{group_by} = [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2971 # add any order_by parts that are not already present in the group_by
2972 # we need to be careful not to add any named functions/aggregates
2973 # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
2974 my %already_grouped = map { $_ => 1 } (@{$attrs->{group_by}});
2976 my $storage = $self->result_source->schema->storage;
2978 my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
2980 for my $chunk ($storage->_parse_order_by($attrs->{order_by})) {
2981 if ($rs_column_list->{$chunk} && not $already_grouped{$chunk}++) {
2982 push @{$attrs->{group_by}}, $chunk;
2988 $attrs->{collapse} ||= {};
2989 if ( my $prefetch = delete $attrs->{prefetch} ) {
2990 $prefetch = $self->_merge_attr( {}, $prefetch );
2992 my $prefetch_ordering = [];
2994 # this is a separate structure (we don't look in {from} directly)
2995 # as the resolver needs to shift things off the lists to work
2996 # properly (identical-prefetches on different branches)
2998 if (ref $attrs->{from} eq 'ARRAY') {
3000 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3002 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3003 next unless $j->[0]{-alias};
3004 next unless $j->[0]{-join_path};
3005 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3007 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3010 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3011 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3016 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3018 # we need to somehow mark which columns came from prefetch
3019 $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
3021 push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
3022 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3024 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3025 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3028 # if both page and offset are specified, produce a combined offset
3029 # even though it doesn't make much sense, this is what pre 081xx has
3031 if (my $page = delete $attrs->{page}) {
3033 ($attrs->{rows} * ($page - 1))
3035 ($attrs->{offset} || 0)
3039 return $self->{_attrs} = $attrs;
3043 my ($self, $attr) = @_;
3045 if (ref $attr eq 'HASH') {
3046 return $self->_rollout_hash($attr);
3047 } elsif (ref $attr eq 'ARRAY') {
3048 return $self->_rollout_array($attr);
3054 sub _rollout_array {
3055 my ($self, $attr) = @_;
3058 foreach my $element (@{$attr}) {
3059 if (ref $element eq 'HASH') {
3060 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3061 } elsif (ref $element eq 'ARRAY') {
3062 # XXX - should probably recurse here
3063 push( @rolled_array, @{$self->_rollout_array($element)} );
3065 push( @rolled_array, $element );
3068 return \@rolled_array;
3072 my ($self, $attr) = @_;
3075 foreach my $key (keys %{$attr}) {
3076 push( @rolled_array, { $key => $attr->{$key} } );
3078 return \@rolled_array;
3081 sub _calculate_score {
3082 my ($self, $a, $b) = @_;
3084 if (defined $a xor defined $b) {
3087 elsif (not defined $a) {
3091 if (ref $b eq 'HASH') {
3092 my ($b_key) = keys %{$b};
3093 if (ref $a eq 'HASH') {
3094 my ($a_key) = keys %{$a};
3095 if ($a_key eq $b_key) {
3096 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3101 return ($a eq $b_key) ? 1 : 0;
3104 if (ref $a eq 'HASH') {
3105 my ($a_key) = keys %{$a};
3106 return ($b eq $a_key) ? 1 : 0;
3108 return ($b eq $a) ? 1 : 0;
3114 my ($self, $orig, $import) = @_;
3116 return $import unless defined($orig);
3117 return $orig unless defined($import);
3119 $orig = $self->_rollout_attr($orig);
3120 $import = $self->_rollout_attr($import);
3123 foreach my $import_element ( @{$import} ) {
3124 # find best candidate from $orig to merge $b_element into
3125 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3126 foreach my $orig_element ( @{$orig} ) {
3127 my $score = $self->_calculate_score( $orig_element, $import_element );
3128 if ($score > $best_candidate->{score}) {
3129 $best_candidate->{position} = $position;
3130 $best_candidate->{score} = $score;
3134 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3136 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3137 push( @{$orig}, $import_element );
3139 my $orig_best = $orig->[$best_candidate->{position}];
3140 # merge orig_best and b_element together and replace original with merged
3141 if (ref $orig_best ne 'HASH') {
3142 $orig->[$best_candidate->{position}] = $import_element;
3143 } elsif (ref $import_element eq 'HASH') {
3144 my ($key) = keys %{$orig_best};
3145 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
3148 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3158 $self->_source_handle($_[0]->handle);
3160 $self->_source_handle->resolve;
3164 =head2 throw_exception
3166 See L<DBIx::Class::Schema/throw_exception> for details.
3170 sub throw_exception {
3173 if (ref $self && $self->_source_handle->schema) {
3174 $self->_source_handle->schema->throw_exception(@_)
3177 DBIx::Class::Exception->throw(@_);
3181 # XXX: FIXME: Attributes docs need clearing up
3185 Attributes are used to refine a ResultSet in various ways when
3186 searching for data. They can be passed to any method which takes an
3187 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3190 These are in no particular order:
3196 =item Value: ( $order_by | \@order_by | \%order_by )
3200 Which column(s) to order the results by.
3202 [The full list of suitable values is documented in
3203 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3206 If a single column name, or an arrayref of names is supplied, the
3207 argument is passed through directly to SQL. The hashref syntax allows
3208 for connection-agnostic specification of ordering direction:
3210 For descending order:
3212 order_by => { -desc => [qw/col1 col2 col3/] }
3214 For explicit ascending order:
3216 order_by => { -asc => 'col' }
3218 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3219 supported, although you are strongly encouraged to use the hashref
3220 syntax as outlined above.
3226 =item Value: \@columns
3230 Shortcut to request a particular set of columns to be retrieved. Each
3231 column spec may be a string (a table column name), or a hash (in which
3232 case the key is the C<as> value, and the value is used as the C<select>
3233 expression). Adds C<me.> onto the start of any column without a C<.> in
3234 it and sets C<select> from that, then auto-populates C<as> from
3235 C<select> as normal. (You may also use the C<cols> attribute, as in
3236 earlier versions of DBIC.)
3242 =item Value: \@columns
3246 Indicates additional columns to be selected from storage. Works the same
3247 as L</columns> but adds columns to the selection. (You may also use the
3248 C<include_columns> attribute, as in earlier versions of DBIC). For
3251 $schema->resultset('CD')->search(undef, {
3252 '+columns' => ['artist.name'],
3256 would return all CDs and include a 'name' column to the information
3257 passed to object inflation. Note that the 'artist' is the name of the
3258 column (or relationship) accessor, and 'name' is the name of the column
3259 accessor in the related table.
3261 =head2 include_columns
3265 =item Value: \@columns
3269 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3275 =item Value: \@select_columns
3279 Indicates which columns should be selected from the storage. You can use
3280 column names, or in the case of RDBMS back ends, function or stored procedure
3283 $rs = $schema->resultset('Employee')->search(undef, {
3286 { count => 'employeeid' },
3287 { max => { length => 'name' }, -as => 'longest_name' }
3292 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3294 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3295 use L</select>, to instruct DBIx::Class how to store the result of the column.
3296 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3297 identifier aliasing. You can however alias a function, so you can use it in
3298 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3299 attribute> supplied as shown in the example above.
3305 Indicates additional columns to be selected from storage. Works the same as
3306 L</select> but adds columns to the default selection, instead of specifying
3315 Indicates additional column names for those added via L</+select>. See L</as>.
3323 =item Value: \@inflation_names
3327 Indicates column names for object inflation. That is L</as> indicates the
3328 slot name in which the column value will be stored within the
3329 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3330 identifier by the C<get_column> method (or via the object accessor B<if one
3331 with the same name already exists>) as shown below. The L</as> attribute has
3332 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3334 $rs = $schema->resultset('Employee')->search(undef, {
3337 { count => 'employeeid' },
3338 { max => { length => 'name' }, -as => 'longest_name' }
3347 If the object against which the search is performed already has an accessor
3348 matching a column name specified in C<as>, the value can be retrieved using
3349 the accessor as normal:
3351 my $name = $employee->name();
3353 If on the other hand an accessor does not exist in the object, you need to
3354 use C<get_column> instead:
3356 my $employee_count = $employee->get_column('employee_count');
3358 You can create your own accessors if required - see
3359 L<DBIx::Class::Manual::Cookbook> for details.
3365 =item Value: ($rel_name | \@rel_names | \%rel_names)
3369 Contains a list of relationships that should be joined for this query. For
3372 # Get CDs by Nine Inch Nails
3373 my $rs = $schema->resultset('CD')->search(
3374 { 'artist.name' => 'Nine Inch Nails' },
3375 { join => 'artist' }
3378 Can also contain a hash reference to refer to the other relation's relations.
3381 package MyApp::Schema::Track;
3382 use base qw/DBIx::Class/;
3383 __PACKAGE__->table('track');
3384 __PACKAGE__->add_columns(qw/trackid cd position title/);
3385 __PACKAGE__->set_primary_key('trackid');
3386 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3389 # In your application
3390 my $rs = $schema->resultset('Artist')->search(
3391 { 'track.title' => 'Teardrop' },
3393 join => { cd => 'track' },
3394 order_by => 'artist.name',
3398 You need to use the relationship (not the table) name in conditions,
3399 because they are aliased as such. The current table is aliased as "me", so
3400 you need to use me.column_name in order to avoid ambiguity. For example:
3402 # Get CDs from 1984 with a 'Foo' track
3403 my $rs = $schema->resultset('CD')->search(
3406 'tracks.name' => 'Foo'
3408 { join => 'tracks' }
3411 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3412 similarly for a third time). For e.g.
3414 my $rs = $schema->resultset('Artist')->search({
3415 'cds.title' => 'Down to Earth',
3416 'cds_2.title' => 'Popular',
3418 join => [ qw/cds cds/ ],
3421 will return a set of all artists that have both a cd with title 'Down
3422 to Earth' and a cd with title 'Popular'.
3424 If you want to fetch related objects from other tables as well, see C<prefetch>
3427 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3433 =item Value: ($rel_name | \@rel_names | \%rel_names)
3437 Contains one or more relationships that should be fetched along with
3438 the main query (when they are accessed afterwards the data will
3439 already be available, without extra queries to the database). This is
3440 useful for when you know you will need the related objects, because it
3441 saves at least one query:
3443 my $rs = $schema->resultset('Tag')->search(
3452 The initial search results in SQL like the following:
3454 SELECT tag.*, cd.*, artist.* FROM tag
3455 JOIN cd ON tag.cd = cd.cdid
3456 JOIN artist ON cd.artist = artist.artistid
3458 L<DBIx::Class> has no need to go back to the database when we access the
3459 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3462 Simple prefetches will be joined automatically, so there is no need
3463 for a C<join> attribute in the above search.
3465 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3466 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3467 with an accessor type of 'single' or 'filter'). A more complex example that
3468 prefetches an artists cds, the tracks on those cds, and the tags associated
3469 with that artist is given below (assuming many-to-many from artists to tags):
3471 my $rs = $schema->resultset('Artist')->search(
3475 { cds => 'tracks' },
3476 { artist_tags => 'tags' }
3482 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3483 attributes will be ignored.
3485 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3486 exactly as you might expect.
3492 Prefetch uses the L</cache> to populate the prefetched relationships. This
3493 may or may not be what you want.
3497 If you specify a condition on a prefetched relationship, ONLY those
3498 rows that match the prefetched condition will be fetched into that relationship.
3499 This means that adding prefetch to a search() B<may alter> what is returned by
3500 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3502 my $artist_rs = $schema->resultset('Artist')->search({
3508 my $count = $artist_rs->first->cds->count;
3510 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3512 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3514 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3516 that cmp_ok() may or may not pass depending on the datasets involved. This
3517 behavior may or may not survive the 0.09 transition.
3529 Makes the resultset paged and specifies the page to retrieve. Effectively
3530 identical to creating a non-pages resultset and then calling ->page($page)
3533 If L<rows> attribute is not specified it defaults to 10 rows per page.
3535 When you have a paged resultset, L</count> will only return the number
3536 of rows in the page. To get the total, use the L</pager> and call
3537 C<total_entries> on it.
3547 Specifies the maximum number of rows for direct retrieval or the number of
3548 rows per page if the page attribute or method is used.
3554 =item Value: $offset
3558 Specifies the (zero-based) row number for the first row to be returned, or the
3559 of the first row of the first page if paging is used.
3565 =item Value: \@columns
3569 A arrayref of columns to group by. Can include columns of joined tables.
3571 group_by => [qw/ column1 column2 ... /]
3577 =item Value: $condition
3581 HAVING is a select statement attribute that is applied between GROUP BY and
3582 ORDER BY. It is applied to the after the grouping calculations have been
3585 having => { 'count(employee)' => { '>=', 100 } }
3591 =item Value: (0 | 1)
3595 Set to 1 to group by all columns. If the resultset already has a group_by
3596 attribute, this setting is ignored and an appropriate warning is issued.
3602 Adds to the WHERE clause.
3604 # only return rows WHERE deleted IS NULL for all searches
3605 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3607 Can be overridden by passing C<< { where => undef } >> as an attribute
3614 Set to 1 to cache search results. This prevents extra SQL queries if you
3615 revisit rows in your ResultSet:
3617 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3619 while( my $artist = $resultset->next ) {
3623 $rs->first; # without cache, this would issue a query
3625 By default, searches are not cached.
3627 For more examples of using these attributes, see
3628 L<DBIx::Class::Manual::Cookbook>.
3634 =item Value: ( 'update' | 'shared' )
3638 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT