1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
50 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
53 The query that the ResultSet represents is B<only> executed against
54 the database when these methods are called:
55 L</find> L</next> L</all> L</first> L</single> L</count>
59 =head2 Chaining resultsets
61 Let's say you've got a query that needs to be run to return some data
62 to the user. But, you have an authorization system in place that
63 prevents certain users from seeing certain information. So, you want
64 to construct the basic query in one method, but add constraints to it in
69 my $request = $self->get_request; # Get a request object somehow.
70 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
72 my $cd_rs = $schema->resultset('CD')->search({
73 title => $request->param('title'),
74 year => $request->param('year'),
77 $self->apply_security_policy( $cd_rs );
82 sub apply_security_policy {
91 =head3 Resolving conditions and attributes
93 When a resultset is chained from another resultset, conditions and
94 attributes with the same keys need resolving.
96 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
97 into the existing ones from the original resultset.
99 The L</where>, L</having> attribute, and any search conditions are
100 merged with an SQL C<AND> to the existing condition from the original
103 All other attributes are overridden by any new ones supplied in the
106 =head2 Multiple queries
108 Since a resultset just defines a query, you can do all sorts of
109 things with it with the same object.
111 # Don't hit the DB yet.
112 my $cd_rs = $schema->resultset('CD')->search({
113 title => 'something',
117 # Each of these hits the DB individually.
118 my $count = $cd_rs->count;
119 my $most_recent = $cd_rs->get_column('date_released')->max();
120 my @records = $cd_rs->all;
122 And it's not just limited to SELECT statements.
128 $cd_rs->create({ artist => 'Fred' });
130 Which is the same as:
132 $schema->resultset('CD')->create({
133 title => 'something',
138 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
142 If a resultset is used in a numeric context it returns the L</count>.
143 However, if it is used in a booleand context it is always true. So if
144 you want to check if a resultset has any results use C<if $rs != 0>.
145 C<if $rs> will always be true.
153 =item Arguments: $source, \%$attrs
155 =item Return Value: $rs
159 The resultset constructor. Takes a source object (usually a
160 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
161 L</ATTRIBUTES> below). Does not perform any queries -- these are
162 executed as needed by the other methods.
164 Generally you won't need to construct a resultset manually. You'll
165 automatically get one from e.g. a L</search> called in scalar context:
167 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
169 IMPORTANT: If called on an object, proxies to new_result instead so
171 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
173 will return a CD object, not a ResultSet.
179 return $class->new_result(@_) if ref $class;
181 my ($source, $attrs) = @_;
182 $source = $source->handle
183 unless $source->isa('DBIx::Class::ResultSourceHandle');
184 $attrs = { %{$attrs||{}} };
186 if ($attrs->{page}) {
187 $attrs->{rows} ||= 10;
190 $attrs->{alias} ||= 'me';
192 # Creation of {} and bless separated to mitigate RH perl bug
193 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
195 _source_handle => $source,
196 cond => $attrs->{where},
205 $attrs->{result_class} || $source->resolve->result_class
215 =item Arguments: $cond, \%attrs?
217 =item Return Value: $resultset (scalar context), @row_objs (list context)
221 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
222 my $new_rs = $cd_rs->search({ year => 2005 });
224 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
225 # year = 2005 OR year = 2004
227 If you need to pass in additional attributes but no additional condition,
228 call it as C<search(undef, \%attrs)>.
230 # "SELECT name, artistid FROM $artist_table"
231 my @all_artists = $schema->resultset('Artist')->search(undef, {
232 columns => [qw/name artistid/],
235 For a list of attributes that can be passed to C<search>, see
236 L</ATTRIBUTES>. For more examples of using this function, see
237 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
238 documentation for the first argument, see L<SQL::Abstract>.
240 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
246 my $rs = $self->search_rs( @_ );
247 return (wantarray ? $rs->all : $rs);
254 =item Arguments: $cond, \%attrs?
256 =item Return Value: $resultset
260 This method does the same exact thing as search() except it will
261 always return a resultset, even in list context.
268 # Special-case handling for (undef, undef).
269 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
274 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
275 my $our_attrs = { %{$self->{attrs}} };
276 my $having = delete $our_attrs->{having};
277 my $where = delete $our_attrs->{where};
281 my %safe = (alias => 1, cache => 1);
284 (@_ && defined($_[0])) # @_ == () or (undef)
286 (keys %$attrs # empty attrs or only 'safe' attrs
287 && List::Util::first { !$safe{$_} } keys %$attrs)
289 # no search, effectively just a clone
290 $rows = $self->get_cache;
293 my $new_attrs = { %{$our_attrs}, %{$attrs} };
295 # merge new attrs into inherited
296 foreach my $key (qw/join prefetch +select +as bind/) {
297 next unless exists $attrs->{$key};
298 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
303 (@_ == 1 || ref $_[0] eq "HASH")
305 (ref $_[0] eq 'HASH')
307 (keys %{ $_[0] } > 0)
315 ? $self->throw_exception("Odd number of arguments to search")
322 if (defined $where) {
323 $new_attrs->{where} = (
324 defined $new_attrs->{where}
327 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
328 } $where, $new_attrs->{where}
335 $new_attrs->{where} = (
336 defined $new_attrs->{where}
339 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
340 } $cond, $new_attrs->{where}
346 if (defined $having) {
347 $new_attrs->{having} = (
348 defined $new_attrs->{having}
351 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
352 } $having, $new_attrs->{having}
358 my $rs = (ref $self)->new($self->result_source, $new_attrs);
360 $rs->set_cache($rows);
365 =head2 search_literal
369 =item Arguments: $sql_fragment, @bind_values
371 =item Return Value: $resultset (scalar context), @row_objs (list context)
375 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
376 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
378 Pass a literal chunk of SQL to be added to the conditional part of the
381 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
382 only be used in that context. C<search_literal> is a convenience method.
383 It is equivalent to calling $schema->search(\[]), but if you want to ensure
384 columns are bound correctly, use C<search>.
386 Example of how to use C<search> instead of C<search_literal>
388 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
389 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
392 See L<DBIx::Class::Manual::Cookbook/Searching> and
393 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
394 require C<search_literal>.
399 my ($self, $sql, @bind) = @_;
401 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
404 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
411 =item Arguments: @values | \%cols, \%attrs?
413 =item Return Value: $row_object | undef
417 Finds a row based on its primary key or unique constraint. For example, to find
418 a row by its primary key:
420 my $cd = $schema->resultset('CD')->find(5);
422 You can also find a row by a specific unique constraint using the C<key>
423 attribute. For example:
425 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
426 key => 'cd_artist_title'
429 Additionally, you can specify the columns explicitly by name:
431 my $cd = $schema->resultset('CD')->find(
433 artist => 'Massive Attack',
434 title => 'Mezzanine',
436 { key => 'cd_artist_title' }
439 If the C<key> is specified as C<primary>, it searches only on the primary key.
441 If no C<key> is specified, it searches on all unique constraints defined on the
442 source for which column data is provided, including the primary key.
444 If your table does not have a primary key, you B<must> provide a value for the
445 C<key> attribute matching one of the unique constraints on the source.
447 In addition to C<key>, L</find> recognizes and applies standard
448 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
450 Note: If your query does not return only one row, a warning is generated:
452 Query returned more than one row
454 See also L</find_or_create> and L</update_or_create>. For information on how to
455 declare unique constraints, see
456 L<DBIx::Class::ResultSource/add_unique_constraint>.
462 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
464 # Default to the primary key, but allow a specific key
465 my @cols = exists $attrs->{key}
466 ? $self->result_source->unique_constraint_columns($attrs->{key})
467 : $self->result_source->primary_columns;
468 $self->throw_exception(
469 "Can't find unless a primary key is defined or unique constraint is specified"
472 # Parse out a hashref from input
474 if (ref $_[0] eq 'HASH') {
475 $input_query = { %{$_[0]} };
477 elsif (@_ == @cols) {
479 @{$input_query}{@cols} = @_;
482 # Compatibility: Allow e.g. find(id => $value)
483 carp "Find by key => value deprecated; please use a hashref instead";
487 my (%related, $info);
489 KEY: foreach my $key (keys %$input_query) {
490 if (ref($input_query->{$key})
491 && ($info = $self->result_source->relationship_info($key))) {
492 my $val = delete $input_query->{$key};
493 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
494 my $rel_q = $self->result_source->_resolve_condition(
495 $info->{cond}, $val, $key
497 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
498 @related{keys %$rel_q} = values %$rel_q;
501 if (my @keys = keys %related) {
502 @{$input_query}{@keys} = values %related;
506 # Build the final query: Default to the disjunction of the unique queries,
507 # but allow the input query in case the ResultSet defines the query or the
508 # user is abusing find
509 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
511 if (exists $attrs->{key}) {
512 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
513 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
514 $query = $self->_add_alias($unique_query, $alias);
517 my @unique_queries = $self->_unique_queries($input_query, $attrs);
518 $query = @unique_queries
519 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
520 : $self->_add_alias($input_query, $alias);
525 my $rs = $self->search($query, $attrs);
526 if (keys %{$rs->_resolved_attrs->{collapse}}) {
528 carp "Query returned more than one row" if $rs->next;
536 if (keys %{$self->_resolved_attrs->{collapse}}) {
537 my $rs = $self->search($query);
539 carp "Query returned more than one row" if $rs->next;
543 return $self->single($query);
550 # Add the specified alias to the specified query hash. A copy is made so the
551 # original query is not modified.
554 my ($self, $query, $alias) = @_;
556 my %aliased = %$query;
557 foreach my $col (grep { ! m/\./ } keys %aliased) {
558 $aliased{"$alias.$col"} = delete $aliased{$col};
566 # Build a list of queries which satisfy unique constraints.
568 sub _unique_queries {
569 my ($self, $query, $attrs) = @_;
571 my @constraint_names = exists $attrs->{key}
573 : $self->result_source->unique_constraint_names;
575 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
576 my $num_where = scalar keys %$where;
579 foreach my $name (@constraint_names) {
580 my @unique_cols = $self->result_source->unique_constraint_columns($name);
581 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
583 my $num_cols = scalar @unique_cols;
584 my $num_query = scalar keys %$unique_query;
586 my $total = $num_query + $num_where;
587 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
588 # The query is either unique on its own or is unique in combination with
589 # the existing where clause
590 push @unique_queries, $unique_query;
594 return @unique_queries;
597 # _build_unique_query
599 # Constrain the specified query hash based on the specified column names.
601 sub _build_unique_query {
602 my ($self, $query, $unique_cols) = @_;
605 map { $_ => $query->{$_} }
606 grep { exists $query->{$_} }
611 =head2 search_related
615 =item Arguments: $rel, $cond, \%attrs?
617 =item Return Value: $new_resultset
621 $new_rs = $cd_rs->search_related('artist', {
625 Searches the specified relationship, optionally specifying a condition and
626 attributes for matching records. See L</ATTRIBUTES> for more information.
631 return shift->related_resultset(shift)->search(@_);
634 =head2 search_related_rs
636 This method works exactly the same as search_related, except that
637 it guarantees a restultset, even in list context.
641 sub search_related_rs {
642 return shift->related_resultset(shift)->search_rs(@_);
649 =item Arguments: none
651 =item Return Value: $cursor
655 Returns a storage-driven cursor to the given resultset. See
656 L<DBIx::Class::Cursor> for more information.
663 my $attrs = $self->_resolved_attrs_copy;
664 $attrs->{_virtual_order_by} = $self->_gen_virtual_order;
666 return $self->{cursor}
667 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
668 $attrs->{where},$attrs);
675 =item Arguments: $cond?
677 =item Return Value: $row_object?
681 my $cd = $schema->resultset('CD')->single({ year => 2001 });
683 Inflates the first result without creating a cursor if the resultset has
684 any records in it; if not returns nothing. Used by L</find> as a lean version of
687 While this method can take an optional search condition (just like L</search>)
688 being a fast-code-path it does not recognize search attributes. If you need to
689 add extra joins or similar, call L</search> and then chain-call L</single> on the
690 L<DBIx::Class::ResultSet> returned.
696 As of 0.08100, this method enforces the assumption that the preceeding
697 query returns only one row. If more than one row is returned, you will receive
700 Query returned more than one row
702 In this case, you should be using L</first> or L</find> instead, or if you really
703 know what you are doing, use the L</rows> attribute to explicitly limit the size
711 my ($self, $where) = @_;
713 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
716 my $attrs = $self->_resolved_attrs_copy;
717 $attrs->{_virtual_order_by} = $self->_gen_virtual_order;
720 if (defined $attrs->{where}) {
723 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
724 $where, delete $attrs->{where} ]
727 $attrs->{where} = $where;
731 # XXX: Disabled since it doesn't infer uniqueness in all cases
732 # unless ($self->_is_unique_query($attrs->{where})) {
733 # carp "Query not guaranteed to return a single row"
734 # . "; please declare your unique constraints or use search instead";
737 my @data = $self->result_source->storage->select_single(
738 $attrs->{from}, $attrs->{select},
739 $attrs->{where}, $attrs
742 return (@data ? ($self->_construct_object(@data))[0] : undef);
747 # This is a horrble hack, but seems like the best we can do at this point
748 # Some limit emulations (Top) require an ordered resultset in order to
749 # function at all. So supply a PK order to be used if necessary
751 sub _gen_virtual_order {
752 return [ shift->result_source->primary_columns ];
757 # Try to determine if the specified query is guaranteed to be unique, based on
758 # the declared unique constraints.
760 sub _is_unique_query {
761 my ($self, $query) = @_;
763 my $collapsed = $self->_collapse_query($query);
764 my $alias = $self->{attrs}{alias};
766 foreach my $name ($self->result_source->unique_constraint_names) {
767 my @unique_cols = map {
769 } $self->result_source->unique_constraint_columns($name);
771 # Count the values for each unique column
772 my %seen = map { $_ => 0 } @unique_cols;
774 foreach my $key (keys %$collapsed) {
775 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
776 next unless exists $seen{$aliased}; # Additional constraints are okay
777 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
780 # If we get 0 or more than 1 value for a column, it's not necessarily unique
781 return 1 unless grep { $_ != 1 } values %seen;
789 # Recursively collapse the query, accumulating values for each column.
791 sub _collapse_query {
792 my ($self, $query, $collapsed) = @_;
796 if (ref $query eq 'ARRAY') {
797 foreach my $subquery (@$query) {
798 next unless ref $subquery; # -or
799 $collapsed = $self->_collapse_query($subquery, $collapsed);
802 elsif (ref $query eq 'HASH') {
803 if (keys %$query and (keys %$query)[0] eq '-and') {
804 foreach my $subquery (@{$query->{-and}}) {
805 $collapsed = $self->_collapse_query($subquery, $collapsed);
809 foreach my $col (keys %$query) {
810 my $value = $query->{$col};
811 $collapsed->{$col}{$value}++;
823 =item Arguments: $cond?
825 =item Return Value: $resultsetcolumn
829 my $max_length = $rs->get_column('length')->max;
831 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
836 my ($self, $column) = @_;
837 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
845 =item Arguments: $cond, \%attrs?
847 =item Return Value: $resultset (scalar context), @row_objs (list context)
851 # WHERE title LIKE '%blue%'
852 $cd_rs = $rs->search_like({ title => '%blue%'});
854 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
855 that this is simply a convenience method retained for ex Class::DBI users.
856 You most likely want to use L</search> with specific operators.
858 For more information, see L<DBIx::Class::Manual::Cookbook>.
860 This method is deprecated and will be removed in 0.09. Use L</search()>
861 instead. An example conversion is:
863 ->search_like({ foo => 'bar' });
867 ->search({ foo => { like => 'bar' } });
874 'search_like() is deprecated and will be removed in DBIC version 0.09.'
875 .' Instead use ->search({ x => { -like => "y%" } })'
876 .' (note the outer pair of {}s - they are important!)'
878 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
879 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
880 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
881 return $class->search($query, { %$attrs });
888 =item Arguments: $first, $last
890 =item Return Value: $resultset (scalar context), @row_objs (list context)
894 Returns a resultset or object list representing a subset of elements from the
895 resultset slice is called on. Indexes are from 0, i.e., to get the first
898 my ($one, $two, $three) = $rs->slice(0, 2);
903 my ($self, $min, $max) = @_;
904 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
905 $attrs->{offset} = $self->{attrs}{offset} || 0;
906 $attrs->{offset} += $min;
907 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
908 return $self->search(undef(), $attrs);
909 #my $slice = (ref $self)->new($self->result_source, $attrs);
910 #return (wantarray ? $slice->all : $slice);
917 =item Arguments: none
919 =item Return Value: $result?
923 Returns the next element in the resultset (C<undef> is there is none).
925 Can be used to efficiently iterate over records in the resultset:
927 my $rs = $schema->resultset('CD')->search;
928 while (my $cd = $rs->next) {
932 Note that you need to store the resultset object, and call C<next> on it.
933 Calling C<< resultset('Table')->next >> repeatedly will always return the
934 first record from the resultset.
940 if (my $cache = $self->get_cache) {
941 $self->{all_cache_position} ||= 0;
942 return $cache->[$self->{all_cache_position}++];
944 if ($self->{attrs}{cache}) {
945 $self->{all_cache_position} = 1;
946 return ($self->all)[0];
948 if ($self->{stashed_objects}) {
949 my $obj = shift(@{$self->{stashed_objects}});
950 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
954 exists $self->{stashed_row}
955 ? @{delete $self->{stashed_row}}
956 : $self->cursor->next
958 return undef unless (@row);
959 my ($row, @more) = $self->_construct_object(@row);
960 $self->{stashed_objects} = \@more if @more;
964 sub _construct_object {
965 my ($self, @row) = @_;
966 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
967 my @new = $self->result_class->inflate_result($self->result_source, @$info);
968 @new = $self->{_attrs}{record_filter}->(@new)
969 if exists $self->{_attrs}{record_filter};
973 sub _collapse_result {
974 my ($self, $as_proto, $row) = @_;
978 # 'foo' => [ undef, 'foo' ]
979 # 'foo.bar' => [ 'foo', 'bar' ]
980 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
982 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
984 my %collapse = %{$self->{_attrs}{collapse}||{}};
988 # if we're doing collapsing (has_many prefetch) we need to grab records
989 # until the PK changes, so fill @pri_index. if not, we leave it empty so
990 # we know we don't have to bother.
992 # the reason for not using the collapse stuff directly is because if you
993 # had for e.g. two artists in a row with no cds, the collapse info for
994 # both would be NULL (undef) so you'd lose the second artist
996 # store just the index so we can check the array positions from the row
997 # without having to contruct the full hash
999 if (keys %collapse) {
1000 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
1001 foreach my $i (0 .. $#construct_as) {
1002 next if defined($construct_as[$i][0]); # only self table
1003 if (delete $pri{$construct_as[$i][1]}) {
1004 push(@pri_index, $i);
1006 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1010 # no need to do an if, it'll be empty if @pri_index is empty anyway
1012 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1016 do { # no need to check anything at the front, we always want the first row
1020 foreach my $this_as (@construct_as) {
1021 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1024 push(@const_rows, \%const);
1026 } until ( # no pri_index => no collapse => drop straight out
1029 do { # get another row, stash it, drop out if different PK
1031 @copy = $self->cursor->next;
1032 $self->{stashed_row} = \@copy;
1034 # last thing in do block, counts as true if anything doesn't match
1036 # check xor defined first for NULL vs. NOT NULL then if one is
1037 # defined the other must be so check string equality
1040 (defined $pri_vals{$_} ^ defined $copy[$_])
1041 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1046 my $alias = $self->{attrs}{alias};
1053 foreach my $const (@const_rows) {
1054 scalar @const_keys or do {
1055 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1057 foreach my $key (@const_keys) {
1060 my @parts = split(/\./, $key);
1062 my $data = $const->{$key};
1063 foreach my $p (@parts) {
1064 $target = $target->[1]->{$p} ||= [];
1066 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1067 # collapsing at this point and on final part
1068 my $pos = $collapse_pos{$cur};
1069 CK: foreach my $ck (@ckey) {
1070 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1071 $collapse_pos{$cur} = $data;
1072 delete @collapse_pos{ # clear all positioning for sub-entries
1073 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1080 if (exists $collapse{$cur}) {
1081 $target = $target->[-1];
1084 $target->[0] = $data;
1086 $info->[0] = $const->{$key};
1094 =head2 result_source
1098 =item Arguments: $result_source?
1100 =item Return Value: $result_source
1104 An accessor for the primary ResultSource object from which this ResultSet
1111 =item Arguments: $result_class?
1113 =item Return Value: $result_class
1117 An accessor for the class to use when creating row objects. Defaults to
1118 C<< result_source->result_class >> - which in most cases is the name of the
1119 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1121 Note that changing the result_class will also remove any components
1122 that were originally loaded in the source class via
1123 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1124 in the original source class will not run.
1129 my ($self, $result_class) = @_;
1130 if ($result_class) {
1131 $self->ensure_class_loaded($result_class);
1132 $self->_result_class($result_class);
1134 $self->_result_class;
1141 =item Arguments: $cond, \%attrs??
1143 =item Return Value: $count
1147 Performs an SQL C<COUNT> with the same query as the resultset was built
1148 with to find the number of elements. Passing arguments is equivalent to
1149 C<< $rs->search ($cond, \%attrs)->count >>
1155 return $self->search(@_)->count if @_ and defined $_[0];
1156 return scalar @{ $self->get_cache } if $self->get_cache;
1158 my @grouped_subq_attrs = qw/prefetch collapse distinct group_by having/;
1159 my @subq_attrs = ();
1161 my $attrs = $self->_resolved_attrs;
1162 # if we are not paged - we are simply asking for a limit
1163 if (not $attrs->{page} and not $attrs->{software_limit}) {
1164 push @subq_attrs, qw/rows offset/;
1167 my $need_subq = $self->_has_attr (@subq_attrs);
1168 my $need_group_subq = $self->_has_attr (@grouped_subq_attrs);
1170 return ($need_subq || $need_group_subq)
1171 ? $self->_count_subq ($need_group_subq)
1172 : $self->_count_simple
1176 my ($self, $add_group_by) = @_;
1178 my $attrs = $self->_resolved_attrs_copy;
1179 my $rsrc = $self->result_source;
1181 # copy for the subquery, we need to do some adjustments to it too
1182 my $sub_attrs = { %$attrs };
1184 # these can not go in the subquery, and there is no point of ordering it
1185 delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns order_by/;
1187 # if needed force a group_by and the same set of columns (most databases require this)
1188 if ($add_group_by) {
1190 # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
1191 # simply deleting group_by suffices, as the code below will re-fill it
1192 # Note: we check $attrs, as $sub_attrs has collapse deleted
1193 if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
1194 delete $sub_attrs->{group_by};
1197 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($rsrc->primary_columns) ];
1201 count_subq => (ref $self)->new ($rsrc, $sub_attrs )->as_query
1204 # the subquery replaces this
1205 delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind/;
1207 return $rsrc->storage->count ($rsrc, $attrs);
1213 my $rsrc = $self->result_source;
1215 # the attrs supplied here are getting modified, do not reuse below
1216 my $count = $rsrc->storage->count ($rsrc, $self->_resolved_attrs_copy);
1217 return 0 unless $count;
1219 # need to take offset from resolved attrs
1220 my $attrs = $self->_resolved_attrs;
1222 $count -= $attrs->{offset} if $attrs->{offset};
1223 $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
1224 $count = 0 if ($count < 0);
1232 =head2 count_literal
1236 =item Arguments: $sql_fragment, @bind_values
1238 =item Return Value: $count
1242 Counts the results in a literal query. Equivalent to calling L</search_literal>
1243 with the passed arguments, then L</count>.
1247 sub count_literal { shift->search_literal(@_)->count; }
1253 =item Arguments: none
1255 =item Return Value: @objects
1259 Returns all elements in the resultset. Called implicitly if the resultset
1260 is returned in list context.
1267 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1270 return @{ $self->get_cache } if $self->get_cache;
1274 # TODO: don't call resolve here
1275 if (keys %{$self->_resolved_attrs->{collapse}}) {
1276 # if ($self->{attrs}{prefetch}) {
1277 # Using $self->cursor->all is really just an optimisation.
1278 # If we're collapsing has_many prefetches it probably makes
1279 # very little difference, and this is cleaner than hacking
1280 # _construct_object to survive the approach
1281 my @row = $self->cursor->next;
1283 push(@obj, $self->_construct_object(@row));
1284 @row = (exists $self->{stashed_row}
1285 ? @{delete $self->{stashed_row}}
1286 : $self->cursor->next);
1289 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1292 $self->set_cache(\@obj) if $self->{attrs}{cache};
1300 =item Arguments: none
1302 =item Return Value: $self
1306 Resets the resultset's cursor, so you can iterate through the elements again.
1312 delete $self->{_attrs} if exists $self->{_attrs};
1313 $self->{all_cache_position} = 0;
1314 $self->cursor->reset;
1322 =item Arguments: none
1324 =item Return Value: $object?
1328 Resets the resultset and returns an object for the first result (if the
1329 resultset returns anything).
1334 return $_[0]->reset->next;
1340 # Determines whether and what type of subquery is required for the $rs operation.
1341 # If grouping is necessary either supplies its own, or verifies the current one
1342 # After all is done delegates to the proper storage method.
1344 sub _rs_update_delete {
1345 my ($self, $op, $values) = @_;
1347 my $rsrc = $self->result_source;
1349 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1350 my $needs_subq = $self->_has_attr (qw/row offset page/);
1352 if ($needs_group_by_subq or $needs_subq) {
1354 # make a new $rs selecting only the PKs (that's all we really need)
1355 my $attrs = $self->_resolved_attrs_copy;
1357 delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
1358 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1360 if ($needs_group_by_subq) {
1361 # make sure no group_by was supplied, or if there is one - make sure it matches
1362 # the columns compiled above perfectly. Anything else can not be sanely executed
1363 # on most databases so croak right then and there
1365 if (my $g = $attrs->{group_by}) {
1366 my @current_group_by = map
1367 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1368 (ref $g eq 'ARRAY' ? @$g : $g );
1371 join ("\x00", sort @current_group_by)
1373 join ("\x00", sort @{$attrs->{columns}} )
1375 $self->throw_exception (
1376 "You have just attempted a $op operation on a resultset which does group_by"
1377 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1378 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1379 . ' kind of queries. Please retry the operation with a modified group_by or'
1380 . ' without using one at all.'
1385 $attrs->{group_by} = $attrs->{columns};
1389 my $subrs = (ref $self)->new($rsrc, $attrs);
1391 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1394 return $rsrc->storage->$op(
1396 $op eq 'update' ? $values : (),
1397 $self->_cond_for_update_delete,
1403 # _cond_for_update_delete
1405 # update/delete require the condition to be modified to handle
1406 # the differing SQL syntax available. This transforms the $self->{cond}
1407 # appropriately, returning the new condition.
1409 sub _cond_for_update_delete {
1410 my ($self, $full_cond) = @_;
1413 $full_cond ||= $self->{cond};
1414 # No-op. No condition, we're updating/deleting everything
1415 return $cond unless ref $full_cond;
1417 if (ref $full_cond eq 'ARRAY') {
1421 foreach my $key (keys %{$_}) {
1423 $hash{$1} = $_->{$key};
1429 elsif (ref $full_cond eq 'HASH') {
1430 if ((keys %{$full_cond})[0] eq '-and') {
1432 my @cond = @{$full_cond->{-and}};
1433 for (my $i = 0; $i < @cond; $i++) {
1434 my $entry = $cond[$i];
1436 if (ref $entry eq 'HASH') {
1437 $hash = $self->_cond_for_update_delete($entry);
1440 $entry =~ /([^.]+)$/;
1441 $hash->{$1} = $cond[++$i];
1443 push @{$cond->{-and}}, $hash;
1447 foreach my $key (keys %{$full_cond}) {
1449 $cond->{$1} = $full_cond->{$key};
1454 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1465 =item Arguments: \%values
1467 =item Return Value: $storage_rv
1471 Sets the specified columns in the resultset to the supplied values in a
1472 single query. Return value will be true if the update succeeded or false
1473 if no records were updated; exact type of success value is storage-dependent.
1478 my ($self, $values) = @_;
1479 $self->throw_exception('Values for update must be a hash')
1480 unless ref $values eq 'HASH';
1482 return $self->_rs_update_delete ('update', $values);
1489 =item Arguments: \%values
1491 =item Return Value: 1
1495 Fetches all objects and updates them one at a time. Note that C<update_all>
1496 will run DBIC cascade triggers, while L</update> will not.
1501 my ($self, $values) = @_;
1502 $self->throw_exception('Values for update_all must be a hash')
1503 unless ref $values eq 'HASH';
1504 foreach my $obj ($self->all) {
1505 $obj->set_columns($values)->update;
1514 =item Arguments: none
1516 =item Return Value: $storage_rv
1520 Deletes the contents of the resultset from its result source. Note that this
1521 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1522 to run. See also L<DBIx::Class::Row/delete>.
1524 Return value will be the amount of rows deleted; exact type of return value
1525 is storage-dependent.
1531 $self->throw_exception('delete does not accept any arguments')
1534 return $self->_rs_update_delete ('delete');
1541 =item Arguments: none
1543 =item Return Value: 1
1547 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1548 will run DBIC cascade triggers, while L</delete> will not.
1554 $self->throw_exception('delete_all does not accept any arguments')
1557 $_->delete for $self->all;
1565 =item Arguments: \@data;
1569 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1570 For the arrayref of hashrefs style each hashref should be a structure suitable
1571 forsubmitting to a $resultset->create(...) method.
1573 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1574 to insert the data, as this is a faster method.
1576 Otherwise, each set of data is inserted into the database using
1577 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1578 objects is returned.
1580 Example: Assuming an Artist Class that has many CDs Classes relating:
1582 my $Artist_rs = $schema->resultset("Artist");
1584 ## Void Context Example
1585 $Artist_rs->populate([
1586 { artistid => 4, name => 'Manufactured Crap', cds => [
1587 { title => 'My First CD', year => 2006 },
1588 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1591 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1592 { title => 'My parents sold me to a record company' ,year => 2005 },
1593 { title => 'Why Am I So Ugly?', year => 2006 },
1594 { title => 'I Got Surgery and am now Popular', year => 2007 }
1599 ## Array Context Example
1600 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1601 { name => "Artist One"},
1602 { name => "Artist Two"},
1603 { name => "Artist Three", cds=> [
1604 { title => "First CD", year => 2007},
1605 { title => "Second CD", year => 2008},
1609 print $ArtistOne->name; ## response is 'Artist One'
1610 print $ArtistThree->cds->count ## reponse is '2'
1612 For the arrayref of arrayrefs style, the first element should be a list of the
1613 fieldsnames to which the remaining elements are rows being inserted. For
1616 $Arstist_rs->populate([
1617 [qw/artistid name/],
1618 [100, 'A Formally Unknown Singer'],
1619 [101, 'A singer that jumped the shark two albums ago'],
1620 [102, 'An actually cool singer.'],
1623 Please note an important effect on your data when choosing between void and
1624 wantarray context. Since void context goes straight to C<insert_bulk> in
1625 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1626 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1627 create primary keys for you, you will find that your PKs are empty. In this
1628 case you will have to use the wantarray context in order to create those
1634 my $self = shift @_;
1635 my $data = ref $_[0][0] eq 'HASH'
1636 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1637 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1639 if(defined wantarray) {
1641 foreach my $item (@$data) {
1642 push(@created, $self->create($item));
1646 my ($first, @rest) = @$data;
1648 my @names = grep {!ref $first->{$_}} keys %$first;
1649 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1650 my @pks = $self->result_source->primary_columns;
1652 ## do the belongs_to relationships
1653 foreach my $index (0..$#$data) {
1655 # delegate to create() for any dataset without primary keys with specified relationships
1656 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1658 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1659 my @ret = $self->populate($data);
1665 foreach my $rel (@rels) {
1666 next unless ref $data->[$index]->{$rel} eq "HASH";
1667 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1668 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1669 my $related = $result->result_source->_resolve_condition(
1670 $result->result_source->relationship_info($reverse)->{cond},
1675 delete $data->[$index]->{$rel};
1676 $data->[$index] = {%{$data->[$index]}, %$related};
1678 push @names, keys %$related if $index == 0;
1682 ## do bulk insert on current row
1683 my @values = map { [ @$_{@names} ] } @$data;
1685 $self->result_source->storage->insert_bulk(
1686 $self->result_source,
1691 ## do the has_many relationships
1692 foreach my $item (@$data) {
1694 foreach my $rel (@rels) {
1695 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1697 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1698 || $self->throw_exception('Cannot find the relating object.');
1700 my $child = $parent->$rel;
1702 my $related = $child->result_source->_resolve_condition(
1703 $parent->result_source->relationship_info($rel)->{cond},
1708 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1709 my @populate = map { {%$_, %$related} } @rows_to_add;
1711 $child->populate( \@populate );
1717 =head2 _normalize_populate_args ($args)
1719 Private method used by L</populate> to normalize its incoming arguments. Factored
1720 out in case you want to subclass and accept new argument structures to the
1721 L</populate> method.
1725 sub _normalize_populate_args {
1726 my ($self, $data) = @_;
1727 my @names = @{shift(@$data)};
1728 my @results_to_create;
1729 foreach my $datum (@$data) {
1730 my %result_to_create;
1731 foreach my $index (0..$#names) {
1732 $result_to_create{$names[$index]} = $$datum[$index];
1734 push @results_to_create, \%result_to_create;
1736 return \@results_to_create;
1743 =item Arguments: none
1745 =item Return Value: $pager
1749 Return Value a L<Data::Page> object for the current resultset. Only makes
1750 sense for queries with a C<page> attribute.
1752 To get the full count of entries for a paged resultset, call
1753 C<total_entries> on the L<Data::Page> object.
1760 return $self->{pager} if $self->{pager};
1762 my $attrs = $self->{attrs};
1763 $self->throw_exception("Can't create pager for non-paged rs")
1764 unless $self->{attrs}{page};
1765 $attrs->{rows} ||= 10;
1767 # throw away the paging flags and re-run the count (possibly
1768 # with a subselect) to get the real total count
1769 my $count_attrs = { %$attrs };
1770 delete $count_attrs->{$_} for qw/rows offset page pager/;
1771 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1773 return $self->{pager} = Data::Page->new(
1776 $self->{attrs}{page}
1784 =item Arguments: $page_number
1786 =item Return Value: $rs
1790 Returns a resultset for the $page_number page of the resultset on which page
1791 is called, where each page contains a number of rows equal to the 'rows'
1792 attribute set on the resultset (10 by default).
1797 my ($self, $page) = @_;
1798 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1805 =item Arguments: \%vals
1807 =item Return Value: $rowobject
1811 Creates a new row object in the resultset's result class and returns
1812 it. The row is not inserted into the database at this point, call
1813 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1814 will tell you whether the row object has been inserted or not.
1816 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1821 my ($self, $values) = @_;
1822 $self->throw_exception( "new_result needs a hash" )
1823 unless (ref $values eq 'HASH');
1826 my $alias = $self->{attrs}{alias};
1829 defined $self->{cond}
1830 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1832 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1833 $new{-from_resultset} = [ keys %new ] if keys %new;
1835 $self->throw_exception(
1836 "Can't abstract implicit construct, condition not a hash"
1837 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1839 my $collapsed_cond = (
1841 ? $self->_collapse_cond($self->{cond})
1845 # precendence must be given to passed values over values inherited from
1846 # the cond, so the order here is important.
1847 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1848 while( my($col,$value) = each %implied ){
1849 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1850 $new{$col} = $value->{'='};
1853 $new{$col} = $value if $self->_is_deterministic_value($value);
1859 %{ $self->_remove_alias($values, $alias) },
1860 -source_handle => $self->_source_handle,
1861 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1864 return $self->result_class->new(\%new);
1867 # _is_deterministic_value
1869 # Make an effor to strip non-deterministic values from the condition,
1870 # to make sure new_result chokes less
1872 sub _is_deterministic_value {
1875 my $ref_type = ref $value;
1876 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1877 return 1 if Scalar::Util::blessed($value);
1883 # determines if the resultset defines at least one
1884 # of the attributes supplied
1886 # used to determine if a subquery is neccessary
1889 my ($self, @attr_names) = @_;
1891 my $attrs = $self->_resolved_attrs;
1895 for my $n (@attr_names) {
1896 ++$join_check_req if $n =~ /join/;
1898 my $attr = $attrs->{$n};
1900 next if not defined $attr;
1902 if (ref $attr eq 'HASH') {
1903 return 1 if keys %$attr;
1905 elsif (ref $attr eq 'ARRAY') {
1913 # a join can be expressed as a multi-level from
1917 ref $attrs->{from} eq 'ARRAY'
1919 @{$attrs->{from}} > 1
1927 # Recursively collapse the condition.
1929 sub _collapse_cond {
1930 my ($self, $cond, $collapsed) = @_;
1934 if (ref $cond eq 'ARRAY') {
1935 foreach my $subcond (@$cond) {
1936 next unless ref $subcond; # -or
1937 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1940 elsif (ref $cond eq 'HASH') {
1941 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1942 foreach my $subcond (@{$cond->{-and}}) {
1943 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1947 foreach my $col (keys %$cond) {
1948 my $value = $cond->{$col};
1949 $collapsed->{$col} = $value;
1959 # Remove the specified alias from the specified query hash. A copy is made so
1960 # the original query is not modified.
1963 my ($self, $query, $alias) = @_;
1965 my %orig = %{ $query || {} };
1968 foreach my $key (keys %orig) {
1970 $unaliased{$key} = $orig{$key};
1973 $unaliased{$1} = $orig{$key}
1974 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1980 =head2 as_query (EXPERIMENTAL)
1984 =item Arguments: none
1986 =item Return Value: \[ $sql, @bind ]
1990 Returns the SQL query and bind vars associated with the invocant.
1992 This is generally used as the RHS for a subquery.
1994 B<NOTE>: This feature is still experimental.
1998 sub as_query { return shift->cursor->as_query(@_) }
2004 =item Arguments: \%vals, \%attrs?
2006 =item Return Value: $rowobject
2010 my $artist = $schema->resultset('Artist')->find_or_new(
2011 { artist => 'fred' }, { key => 'artists' });
2013 $cd->cd_to_producer->find_or_new({ producer => $producer },
2014 { key => 'primary });
2016 Find an existing record from this resultset, based on its primary
2017 key, or a unique constraint. If none exists, instantiate a new result
2018 object and return it. The object will not be saved into your storage
2019 until you call L<DBIx::Class::Row/insert> on it.
2021 You most likely want this method when looking for existing rows using
2022 a unique constraint that is not the primary key, or looking for
2025 If you want objects to be saved immediately, use L</find_or_create> instead.
2027 B<Note>: C<find_or_new> is probably not what you want when creating a
2028 new row in a table that uses primary keys supplied by the
2029 database. Passing in a primary key column with a value of I<undef>
2030 will cause L</find> to attempt to search for a row with a value of
2037 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2038 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2039 my $exists = $self->find($hash, $attrs);
2040 return defined $exists ? $exists : $self->new_result($hash);
2047 =item Arguments: \%vals
2049 =item Return Value: a L<DBIx::Class::Row> $object
2053 Attempt to create a single new row or a row with multiple related rows
2054 in the table represented by the resultset (and related tables). This
2055 will not check for duplicate rows before inserting, use
2056 L</find_or_create> to do that.
2058 To create one row for this resultset, pass a hashref of key/value
2059 pairs representing the columns of the table and the values you wish to
2060 store. If the appropriate relationships are set up, foreign key fields
2061 can also be passed an object representing the foreign row, and the
2062 value will be set to its primary key.
2064 To create related objects, pass a hashref for the value if the related
2065 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2066 and use the name of the relationship as the key. (NOT the name of the field,
2067 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2068 of hashrefs containing the data for each of the rows to create in the foreign
2069 tables, again using the relationship name as the key.
2071 Instead of hashrefs of plain related data (key/value pairs), you may
2072 also pass new or inserted objects. New objects (not inserted yet, see
2073 L</new>), will be inserted into their appropriate tables.
2075 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2077 Example of creating a new row.
2079 $person_rs->create({
2080 name=>"Some Person",
2081 email=>"somebody@someplace.com"
2084 Example of creating a new row and also creating rows in a related C<has_many>
2085 or C<has_one> resultset. Note Arrayref.
2088 { artistid => 4, name => 'Manufactured Crap', cds => [
2089 { title => 'My First CD', year => 2006 },
2090 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2095 Example of creating a new row and also creating a row in a related
2096 C<belongs_to>resultset. Note Hashref.
2099 title=>"Music for Silly Walks",
2102 name=>"Silly Musician",
2109 my ($self, $attrs) = @_;
2110 $self->throw_exception( "create needs a hashref" )
2111 unless ref $attrs eq 'HASH';
2112 return $self->new_result($attrs)->insert;
2115 =head2 find_or_create
2119 =item Arguments: \%vals, \%attrs?
2121 =item Return Value: $rowobject
2125 $cd->cd_to_producer->find_or_create({ producer => $producer },
2126 { key => 'primary });
2128 Tries to find a record based on its primary key or unique constraints; if none
2129 is found, creates one and returns that instead.
2131 my $cd = $schema->resultset('CD')->find_or_create({
2133 artist => 'Massive Attack',
2134 title => 'Mezzanine',
2138 Also takes an optional C<key> attribute, to search by a specific key or unique
2139 constraint. For example:
2141 my $cd = $schema->resultset('CD')->find_or_create(
2143 artist => 'Massive Attack',
2144 title => 'Mezzanine',
2146 { key => 'cd_artist_title' }
2149 B<Note>: Because find_or_create() reads from the database and then
2150 possibly inserts based on the result, this method is subject to a race
2151 condition. Another process could create a record in the table after
2152 the find has completed and before the create has started. To avoid
2153 this problem, use find_or_create() inside a transaction.
2155 B<Note>: C<find_or_create> is probably not what you want when creating
2156 a new row in a table that uses primary keys supplied by the
2157 database. Passing in a primary key column with a value of I<undef>
2158 will cause L</find> to attempt to search for a row with a value of
2161 See also L</find> and L</update_or_create>. For information on how to declare
2162 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2166 sub find_or_create {
2168 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2169 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2170 my $exists = $self->find($hash, $attrs);
2171 return defined $exists ? $exists : $self->create($hash);
2174 =head2 update_or_create
2178 =item Arguments: \%col_values, { key => $unique_constraint }?
2180 =item Return Value: $rowobject
2184 $resultset->update_or_create({ col => $val, ... });
2186 First, searches for an existing row matching one of the unique constraints
2187 (including the primary key) on the source of this resultset. If a row is
2188 found, updates it with the other given column values. Otherwise, creates a new
2191 Takes an optional C<key> attribute to search on a specific unique constraint.
2194 # In your application
2195 my $cd = $schema->resultset('CD')->update_or_create(
2197 artist => 'Massive Attack',
2198 title => 'Mezzanine',
2201 { key => 'cd_artist_title' }
2204 $cd->cd_to_producer->update_or_create({
2205 producer => $producer,
2212 If no C<key> is specified, it searches on all unique constraints defined on the
2213 source, including the primary key.
2215 If the C<key> is specified as C<primary>, it searches only on the primary key.
2217 See also L</find> and L</find_or_create>. For information on how to declare
2218 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2220 B<Note>: C<update_or_create> is probably not what you want when
2221 looking for a row in a table that uses primary keys supplied by the
2222 database, unless you actually have a key value. Passing in a primary
2223 key column with a value of I<undef> will cause L</find> to attempt to
2224 search for a row with a value of I<NULL>.
2228 sub update_or_create {
2230 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2231 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2233 my $row = $self->find($cond, $attrs);
2235 $row->update($cond);
2239 return $self->create($cond);
2242 =head2 update_or_new
2246 =item Arguments: \%col_values, { key => $unique_constraint }?
2248 =item Return Value: $rowobject
2252 $resultset->update_or_new({ col => $val, ... });
2254 First, searches for an existing row matching one of the unique constraints
2255 (including the primary key) on the source of this resultset. If a row is
2256 found, updates it with the other given column values. Otherwise, instantiate
2257 a new result object and return it. The object will not be saved into your storage
2258 until you call L<DBIx::Class::Row/insert> on it.
2260 Takes an optional C<key> attribute to search on a specific unique constraint.
2263 # In your application
2264 my $cd = $schema->resultset('CD')->update_or_new(
2266 artist => 'Massive Attack',
2267 title => 'Mezzanine',
2270 { key => 'cd_artist_title' }
2273 if ($cd->in_storage) {
2274 # the cd was updated
2277 # the cd is not yet in the database, let's insert it
2281 See also L</find>, L</find_or_create> and L<find_or_new>.
2287 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2288 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2290 my $row = $self->find( $cond, $attrs );
2291 if ( defined $row ) {
2292 $row->update($cond);
2296 return $self->new_result($cond);
2303 =item Arguments: none
2305 =item Return Value: \@cache_objects?
2309 Gets the contents of the cache for the resultset, if the cache is set.
2311 The cache is populated either by using the L</prefetch> attribute to
2312 L</search> or by calling L</set_cache>.
2324 =item Arguments: \@cache_objects
2326 =item Return Value: \@cache_objects
2330 Sets the contents of the cache for the resultset. Expects an arrayref
2331 of objects of the same class as those produced by the resultset. Note that
2332 if the cache is set the resultset will return the cached objects rather
2333 than re-querying the database even if the cache attr is not set.
2335 The contents of the cache can also be populated by using the
2336 L</prefetch> attribute to L</search>.
2341 my ( $self, $data ) = @_;
2342 $self->throw_exception("set_cache requires an arrayref")
2343 if defined($data) && (ref $data ne 'ARRAY');
2344 $self->{all_cache} = $data;
2351 =item Arguments: none
2353 =item Return Value: []
2357 Clears the cache for the resultset.
2362 shift->set_cache(undef);
2365 =head2 related_resultset
2369 =item Arguments: $relationship_name
2371 =item Return Value: $resultset
2375 Returns a related resultset for the supplied relationship name.
2377 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2381 sub related_resultset {
2382 my ($self, $rel) = @_;
2384 $self->{related_resultsets} ||= {};
2385 return $self->{related_resultsets}{$rel} ||= do {
2386 my $rel_obj = $self->result_source->relationship_info($rel);
2388 $self->throw_exception(
2389 "search_related: result source '" . $self->result_source->source_name .
2390 "' has no such relationship $rel")
2393 my ($from,$seen) = $self->_resolve_from($rel);
2395 my $join_count = $seen->{$rel};
2396 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2398 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2399 my %attrs = %{$self->{attrs}||{}};
2400 delete @attrs{qw(result_class alias)};
2404 if (my $cache = $self->get_cache) {
2405 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2406 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2411 my $rel_source = $self->result_source->related_source($rel);
2415 # The reason we do this now instead of passing the alias to the
2416 # search_rs below is that if you wrap/overload resultset on the
2417 # source you need to know what alias it's -going- to have for things
2418 # to work sanely (e.g. RestrictWithObject wants to be able to add
2419 # extra query restrictions, and these may need to be $alias.)
2421 my $attrs = $rel_source->resultset_attributes;
2422 local $attrs->{alias} = $alias;
2424 $rel_source->resultset
2432 where => $self->{cond},
2437 $new->set_cache($new_cache) if $new_cache;
2442 =head2 current_source_alias
2446 =item Arguments: none
2448 =item Return Value: $source_alias
2452 Returns the current table alias for the result source this resultset is built
2453 on, that will be used in the SQL query. Usually it is C<me>.
2455 Currently the source alias that refers to the result set returned by a
2456 L</search>/L</find> family method depends on how you got to the resultset: it's
2457 C<me> by default, but eg. L</search_related> aliases it to the related result
2458 source name (and keeps C<me> referring to the original result set). The long
2459 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2460 (and make this method unnecessary).
2462 Thus it's currently necessary to use this method in predefined queries (see
2463 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2464 source alias of the current result set:
2466 # in a result set class
2468 my ($self, $user) = @_;
2470 my $me = $self->current_source_alias;
2472 return $self->search(
2473 "$me.modified" => $user->id,
2479 sub current_source_alias {
2482 return ($self->{attrs} || {})->{alias} || 'me';
2485 # This code is called by search_related, and makes sure there
2486 # is clear separation between the joins before, during, and
2487 # after the relationship. This information is needed later
2488 # in order to properly resolve prefetch aliases (any alias
2489 # with a relation_chain_depth less than the depth of the
2490 # current prefetch is not considered)
2492 my ($self, $extra_join) = @_;
2493 my $source = $self->result_source;
2494 my $attrs = $self->{attrs};
2496 my $from = $attrs->{from}
2497 || [ { $attrs->{alias} => $source->from } ];
2499 my $seen = { %{$attrs->{seen_join}||{}} };
2501 # we need to take the prefetch the attrs into account before we
2502 # ->_resolve_join as otherwise they get lost - captainL
2503 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2505 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2507 ++$seen->{-relation_chain_depth};
2509 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2511 ++$seen->{-relation_chain_depth};
2513 return ($from,$seen);
2516 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2517 sub _resolved_attrs_copy {
2519 return { %{$self->_resolved_attrs (@_)} };
2522 sub _resolved_attrs {
2524 return $self->{_attrs} if $self->{_attrs};
2526 my $attrs = { %{ $self->{attrs} || {} } };
2527 my $source = $self->result_source;
2528 my $alias = $attrs->{alias};
2530 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2533 # build columns (as long as select isn't set) into a set of as/select hashes
2534 unless ( $attrs->{select} ) {
2536 ( ref($_) eq 'HASH' )
2540 /^\Q${alias}.\E(.+)$/
2551 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2553 # add the additional columns on
2554 foreach ( 'include_columns', '+columns' ) {
2555 push @colbits, map {
2556 ( ref($_) eq 'HASH' )
2558 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2559 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2562 # start with initial select items
2563 if ( $attrs->{select} ) {
2565 ( ref $attrs->{select} eq 'ARRAY' )
2566 ? [ @{ $attrs->{select} } ]
2567 : [ $attrs->{select} ];
2571 ref $attrs->{as} eq 'ARRAY'
2572 ? [ @{ $attrs->{as} } ]
2575 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2580 # otherwise we intialise select & as to empty
2581 $attrs->{select} = [];
2585 # now add colbits to select/as
2586 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2587 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2590 if ( $adds = delete $attrs->{'+select'} ) {
2591 $adds = [$adds] unless ref $adds eq 'ARRAY';
2593 @{ $attrs->{select} },
2594 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2597 if ( $adds = delete $attrs->{'+as'} ) {
2598 $adds = [$adds] unless ref $adds eq 'ARRAY';
2599 push( @{ $attrs->{as} }, @$adds );
2602 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2604 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2605 my $join = delete $attrs->{join} || {};
2607 if ( defined $attrs->{prefetch} ) {
2608 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2612 $attrs->{from} = # have to copy here to avoid corrupting the original
2614 @{ $attrs->{from} },
2615 $source->_resolve_join(
2616 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2622 if ( $attrs->{order_by} ) {
2623 $attrs->{order_by} = (
2624 ref( $attrs->{order_by} ) eq 'ARRAY'
2625 ? [ @{ $attrs->{order_by} } ]
2626 : [ $attrs->{order_by} ]
2630 $attrs->{order_by} = [];
2633 my $collapse = $attrs->{collapse} || {};
2634 if ( my $prefetch = delete $attrs->{prefetch} ) {
2635 $prefetch = $self->_merge_attr( {}, $prefetch );
2637 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2639 # bring joins back to level of current class
2640 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2642 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2643 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2644 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2646 push( @{ $attrs->{order_by} }, @pre_order );
2649 if (delete $attrs->{distinct}) {
2650 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2653 $attrs->{collapse} = $collapse;
2655 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2656 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2659 return $self->{_attrs} = $attrs;
2662 sub _joinpath_aliases {
2663 my ($self, $fromspec, $seen) = @_;
2666 return $paths unless ref $fromspec eq 'ARRAY';
2668 for my $j (@$fromspec) {
2670 next if ref $j ne 'ARRAY';
2671 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2674 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2675 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2682 my ($self, $attr) = @_;
2684 if (ref $attr eq 'HASH') {
2685 return $self->_rollout_hash($attr);
2686 } elsif (ref $attr eq 'ARRAY') {
2687 return $self->_rollout_array($attr);
2693 sub _rollout_array {
2694 my ($self, $attr) = @_;
2697 foreach my $element (@{$attr}) {
2698 if (ref $element eq 'HASH') {
2699 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2700 } elsif (ref $element eq 'ARRAY') {
2701 # XXX - should probably recurse here
2702 push( @rolled_array, @{$self->_rollout_array($element)} );
2704 push( @rolled_array, $element );
2707 return \@rolled_array;
2711 my ($self, $attr) = @_;
2714 foreach my $key (keys %{$attr}) {
2715 push( @rolled_array, { $key => $attr->{$key} } );
2717 return \@rolled_array;
2720 sub _calculate_score {
2721 my ($self, $a, $b) = @_;
2723 if (ref $b eq 'HASH') {
2724 my ($b_key) = keys %{$b};
2725 if (ref $a eq 'HASH') {
2726 my ($a_key) = keys %{$a};
2727 if ($a_key eq $b_key) {
2728 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2733 return ($a eq $b_key) ? 1 : 0;
2736 if (ref $a eq 'HASH') {
2737 my ($a_key) = keys %{$a};
2738 return ($b eq $a_key) ? 1 : 0;
2740 return ($b eq $a) ? 1 : 0;
2746 my ($self, $orig, $import) = @_;
2748 return $import unless defined($orig);
2749 return $orig unless defined($import);
2751 $orig = $self->_rollout_attr($orig);
2752 $import = $self->_rollout_attr($import);
2755 foreach my $import_element ( @{$import} ) {
2756 # find best candidate from $orig to merge $b_element into
2757 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2758 foreach my $orig_element ( @{$orig} ) {
2759 my $score = $self->_calculate_score( $orig_element, $import_element );
2760 if ($score > $best_candidate->{score}) {
2761 $best_candidate->{position} = $position;
2762 $best_candidate->{score} = $score;
2766 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2768 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2769 push( @{$orig}, $import_element );
2771 my $orig_best = $orig->[$best_candidate->{position}];
2772 # merge orig_best and b_element together and replace original with merged
2773 if (ref $orig_best ne 'HASH') {
2774 $orig->[$best_candidate->{position}] = $import_element;
2775 } elsif (ref $import_element eq 'HASH') {
2776 my ($key) = keys %{$orig_best};
2777 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2780 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2790 $self->_source_handle($_[0]->handle);
2792 $self->_source_handle->resolve;
2796 =head2 throw_exception
2798 See L<DBIx::Class::Schema/throw_exception> for details.
2802 sub throw_exception {
2804 if (ref $self && $self->_source_handle->schema) {
2805 $self->_source_handle->schema->throw_exception(@_)
2812 # XXX: FIXME: Attributes docs need clearing up
2816 Attributes are used to refine a ResultSet in various ways when
2817 searching for data. They can be passed to any method which takes an
2818 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2821 These are in no particular order:
2827 =item Value: ( $order_by | \@order_by | \%order_by )
2831 Which column(s) to order the results by. If a single column name, or
2832 an arrayref of names is supplied, the argument is passed through
2833 directly to SQL. The hashref syntax allows for connection-agnostic
2834 specification of ordering direction:
2836 For descending order:
2838 order_by => { -desc => [qw/col1 col2 col3/] }
2840 For explicit ascending order:
2842 order_by => { -asc => 'col' }
2844 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2845 supported, although you are strongly encouraged to use the hashref
2846 syntax as outlined above.
2852 =item Value: \@columns
2856 Shortcut to request a particular set of columns to be retrieved. Each
2857 column spec may be a string (a table column name), or a hash (in which
2858 case the key is the C<as> value, and the value is used as the C<select>
2859 expression). Adds C<me.> onto the start of any column without a C<.> in
2860 it and sets C<select> from that, then auto-populates C<as> from
2861 C<select> as normal. (You may also use the C<cols> attribute, as in
2862 earlier versions of DBIC.)
2868 =item Value: \@columns
2872 Indicates additional columns to be selected from storage. Works the same
2873 as L</columns> but adds columns to the selection. (You may also use the
2874 C<include_columns> attribute, as in earlier versions of DBIC). For
2877 $schema->resultset('CD')->search(undef, {
2878 '+columns' => ['artist.name'],
2882 would return all CDs and include a 'name' column to the information
2883 passed to object inflation. Note that the 'artist' is the name of the
2884 column (or relationship) accessor, and 'name' is the name of the column
2885 accessor in the related table.
2887 =head2 include_columns
2891 =item Value: \@columns
2895 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2901 =item Value: \@select_columns
2905 Indicates which columns should be selected from the storage. You can use
2906 column names, or in the case of RDBMS back ends, function or stored procedure
2909 $rs = $schema->resultset('Employee')->search(undef, {
2912 { count => 'employeeid' },
2917 When you use function/stored procedure names and do not supply an C<as>
2918 attribute, the column names returned are storage-dependent. E.g. MySQL would
2919 return a column named C<count(employeeid)> in the above example.
2925 Indicates additional columns to be selected from storage. Works the same as
2926 L</select> but adds columns to the selection.
2934 Indicates additional column names for those added via L</+select>. See L</as>.
2942 =item Value: \@inflation_names
2946 Indicates column names for object inflation. That is, C<as>
2947 indicates the name that the column can be accessed as via the
2948 C<get_column> method (or via the object accessor, B<if one already
2949 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2951 The C<as> attribute is used in conjunction with C<select>,
2952 usually when C<select> contains one or more function or stored
2955 $rs = $schema->resultset('Employee')->search(undef, {
2958 { count => 'employeeid' }
2960 as => ['name', 'employee_count'],
2963 my $employee = $rs->first(); # get the first Employee
2965 If the object against which the search is performed already has an accessor
2966 matching a column name specified in C<as>, the value can be retrieved using
2967 the accessor as normal:
2969 my $name = $employee->name();
2971 If on the other hand an accessor does not exist in the object, you need to
2972 use C<get_column> instead:
2974 my $employee_count = $employee->get_column('employee_count');
2976 You can create your own accessors if required - see
2977 L<DBIx::Class::Manual::Cookbook> for details.
2979 Please note: This will NOT insert an C<AS employee_count> into the SQL
2980 statement produced, it is used for internal access only. Thus
2981 attempting to use the accessor in an C<order_by> clause or similar
2982 will fail miserably.
2984 To get around this limitation, you can supply literal SQL to your
2985 C<select> attibute that contains the C<AS alias> text, eg:
2987 select => [\'myfield AS alias']
2993 =item Value: ($rel_name | \@rel_names | \%rel_names)
2997 Contains a list of relationships that should be joined for this query. For
3000 # Get CDs by Nine Inch Nails
3001 my $rs = $schema->resultset('CD')->search(
3002 { 'artist.name' => 'Nine Inch Nails' },
3003 { join => 'artist' }
3006 Can also contain a hash reference to refer to the other relation's relations.
3009 package MyApp::Schema::Track;
3010 use base qw/DBIx::Class/;
3011 __PACKAGE__->table('track');
3012 __PACKAGE__->add_columns(qw/trackid cd position title/);
3013 __PACKAGE__->set_primary_key('trackid');
3014 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3017 # In your application
3018 my $rs = $schema->resultset('Artist')->search(
3019 { 'track.title' => 'Teardrop' },
3021 join => { cd => 'track' },
3022 order_by => 'artist.name',
3026 You need to use the relationship (not the table) name in conditions,
3027 because they are aliased as such. The current table is aliased as "me", so
3028 you need to use me.column_name in order to avoid ambiguity. For example:
3030 # Get CDs from 1984 with a 'Foo' track
3031 my $rs = $schema->resultset('CD')->search(
3034 'tracks.name' => 'Foo'
3036 { join => 'tracks' }
3039 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3040 similarly for a third time). For e.g.
3042 my $rs = $schema->resultset('Artist')->search({
3043 'cds.title' => 'Down to Earth',
3044 'cds_2.title' => 'Popular',
3046 join => [ qw/cds cds/ ],
3049 will return a set of all artists that have both a cd with title 'Down
3050 to Earth' and a cd with title 'Popular'.
3052 If you want to fetch related objects from other tables as well, see C<prefetch>
3055 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3061 =item Value: ($rel_name | \@rel_names | \%rel_names)
3065 Contains one or more relationships that should be fetched along with
3066 the main query (when they are accessed afterwards the data will
3067 already be available, without extra queries to the database). This is
3068 useful for when you know you will need the related objects, because it
3069 saves at least one query:
3071 my $rs = $schema->resultset('Tag')->search(
3080 The initial search results in SQL like the following:
3082 SELECT tag.*, cd.*, artist.* FROM tag
3083 JOIN cd ON tag.cd = cd.cdid
3084 JOIN artist ON cd.artist = artist.artistid
3086 L<DBIx::Class> has no need to go back to the database when we access the
3087 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3090 Simple prefetches will be joined automatically, so there is no need
3091 for a C<join> attribute in the above search.
3093 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3094 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3095 with an accessor type of 'single' or 'filter'). A more complex example that
3096 prefetches an artists cds, the tracks on those cds, and the tags associted
3097 with that artist is given below (assuming many-to-many from artists to tags):
3099 my $rs = $schema->resultset('Artist')->search(
3103 { cds => 'tracks' },
3104 { artist_tags => 'tags' }
3110 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3111 attributes will be ignored.
3121 Makes the resultset paged and specifies the page to retrieve. Effectively
3122 identical to creating a non-pages resultset and then calling ->page($page)
3125 If L<rows> attribute is not specified it defualts to 10 rows per page.
3127 When you have a paged resultset, L</count> will only return the number
3128 of rows in the page. To get the total, use the L</pager> and call
3129 C<total_entries> on it.
3139 Specifes the maximum number of rows for direct retrieval or the number of
3140 rows per page if the page attribute or method is used.
3146 =item Value: $offset
3150 Specifies the (zero-based) row number for the first row to be returned, or the
3151 of the first row of the first page if paging is used.
3157 =item Value: \@columns
3161 A arrayref of columns to group by. Can include columns of joined tables.
3163 group_by => [qw/ column1 column2 ... /]
3169 =item Value: $condition
3173 HAVING is a select statement attribute that is applied between GROUP BY and
3174 ORDER BY. It is applied to the after the grouping calculations have been
3177 having => { 'count(employee)' => { '>=', 100 } }
3183 =item Value: (0 | 1)
3187 Set to 1 to group by all columns.
3193 Adds to the WHERE clause.
3195 # only return rows WHERE deleted IS NULL for all searches
3196 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3198 Can be overridden by passing C<{ where => undef }> as an attribute
3205 Set to 1 to cache search results. This prevents extra SQL queries if you
3206 revisit rows in your ResultSet:
3208 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3210 while( my $artist = $resultset->next ) {
3214 $rs->first; # without cache, this would issue a query
3216 By default, searches are not cached.
3218 For more examples of using these attributes, see
3219 L<DBIx::Class::Manual::Cookbook>.
3225 =item Value: \@from_clause
3229 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3230 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3233 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3235 C<join> will usually do what you need and it is strongly recommended that you
3236 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3237 And we really do mean "cannot", not just tried and failed. Attempting to use
3238 this because you're having problems with C<join> is like trying to use x86
3239 ASM because you've got a syntax error in your C. Trust us on this.
3241 Now, if you're still really, really sure you need to use this (and if you're
3242 not 100% sure, ask the mailing list first), here's an explanation of how this
3245 The syntax is as follows -
3248 { <alias1> => <table1> },
3250 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3251 [], # nested JOIN (optional)
3252 { <table1.column1> => <table2.column2>, ... (more conditions) },
3254 # More of the above [ ] may follow for additional joins
3261 ON <table1.column1> = <table2.column2>
3262 <more joins may follow>
3264 An easy way to follow the examples below is to remember the following:
3266 Anything inside "[]" is a JOIN
3267 Anything inside "{}" is a condition for the enclosing JOIN
3269 The following examples utilize a "person" table in a family tree application.
3270 In order to express parent->child relationships, this table is self-joined:
3272 # Person->belongs_to('father' => 'Person');
3273 # Person->belongs_to('mother' => 'Person');
3275 C<from> can be used to nest joins. Here we return all children with a father,
3276 then search against all mothers of those children:
3278 $rs = $schema->resultset('Person')->search(
3281 alias => 'mother', # alias columns in accordance with "from"
3283 { mother => 'person' },
3286 { child => 'person' },
3288 { father => 'person' },
3289 { 'father.person_id' => 'child.father_id' }
3292 { 'mother.person_id' => 'child.mother_id' }
3299 # SELECT mother.* FROM person mother
3302 # JOIN person father
3303 # ON ( father.person_id = child.father_id )
3305 # ON ( mother.person_id = child.mother_id )
3307 The type of any join can be controlled manually. To search against only people
3308 with a father in the person table, we could explicitly use C<INNER JOIN>:
3310 $rs = $schema->resultset('Person')->search(
3313 alias => 'child', # alias columns in accordance with "from"
3315 { child => 'person' },
3317 { father => 'person', -join_type => 'inner' },
3318 { 'father.id' => 'child.father_id' }
3325 # SELECT child.* FROM person child
3326 # INNER JOIN person father ON child.father_id = father.id
3328 If you need to express really complex joins or you need a subselect, you
3329 can supply literal SQL to C<from> via a scalar reference. In this case
3330 the contents of the scalar will replace the table name asscoiated with the
3333 WARNING: This technique might very well not work as expected on chained
3334 searches - you have been warned.
3336 # Assuming the Event resultsource is defined as:
3338 MySchema::Event->add_columns (
3341 is_auto_increment => 1,
3350 MySchema::Event->set_primary_key ('sequence');
3352 # This will get back the latest event for every location. The column
3353 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3354 # combo to limit the resultset
3356 $rs = $schema->resultset('Event');
3357 $table = $rs->result_source->name;
3358 $latest = $rs->search (
3361 (SELECT e1.* FROM $table e1
3363 ON e1.location = e2.location
3364 AND e1.sequence < e2.sequence
3365 WHERE e2.sequence is NULL
3370 # Equivalent SQL (with the DBIC chunks added):
3372 SELECT me.sequence, me.location, me.type FROM
3373 (SELECT e1.* FROM events e1
3375 ON e1.location = e2.location
3376 AND e1.sequence < e2.sequence
3377 WHERE e2.sequence is NULL
3384 =item Value: ( 'update' | 'shared' )
3388 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT