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;
665 return $self->{cursor}
666 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
667 $attrs->{where},$attrs);
674 =item Arguments: $cond?
676 =item Return Value: $row_object?
680 my $cd = $schema->resultset('CD')->single({ year => 2001 });
682 Inflates the first result without creating a cursor if the resultset has
683 any records in it; if not returns nothing. Used by L</find> as a lean version of
686 While this method can take an optional search condition (just like L</search>)
687 being a fast-code-path it does not recognize search attributes. If you need to
688 add extra joins or similar, call L</search> and then chain-call L</single> on the
689 L<DBIx::Class::ResultSet> returned.
695 As of 0.08100, this method enforces the assumption that the preceeding
696 query returns only one row. If more than one row is returned, you will receive
699 Query returned more than one row
701 In this case, you should be using L</next> or L</find> instead, or if you really
702 know what you are doing, use the L</rows> attribute to explicitly limit the size
705 This method will also throw an exception if it is called on a resultset prefetching
706 has_many, as such a prefetch implies fetching multiple rows from the database in
707 order to assemble the resulting object.
714 my ($self, $where) = @_;
716 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
719 my $attrs = $self->_resolved_attrs_copy;
721 if (keys %{$attrs->{collapse}}) {
722 $self->throw_exception(
723 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
728 if (defined $attrs->{where}) {
731 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
732 $where, delete $attrs->{where} ]
735 $attrs->{where} = $where;
739 # XXX: Disabled since it doesn't infer uniqueness in all cases
740 # unless ($self->_is_unique_query($attrs->{where})) {
741 # carp "Query not guaranteed to return a single row"
742 # . "; please declare your unique constraints or use search instead";
745 my @data = $self->result_source->storage->select_single(
746 $attrs->{from}, $attrs->{select},
747 $attrs->{where}, $attrs
750 return (@data ? ($self->_construct_object(@data))[0] : undef);
756 # Try to determine if the specified query is guaranteed to be unique, based on
757 # the declared unique constraints.
759 sub _is_unique_query {
760 my ($self, $query) = @_;
762 my $collapsed = $self->_collapse_query($query);
763 my $alias = $self->{attrs}{alias};
765 foreach my $name ($self->result_source->unique_constraint_names) {
766 my @unique_cols = map {
768 } $self->result_source->unique_constraint_columns($name);
770 # Count the values for each unique column
771 my %seen = map { $_ => 0 } @unique_cols;
773 foreach my $key (keys %$collapsed) {
774 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
775 next unless exists $seen{$aliased}; # Additional constraints are okay
776 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
779 # If we get 0 or more than 1 value for a column, it's not necessarily unique
780 return 1 unless grep { $_ != 1 } values %seen;
788 # Recursively collapse the query, accumulating values for each column.
790 sub _collapse_query {
791 my ($self, $query, $collapsed) = @_;
795 if (ref $query eq 'ARRAY') {
796 foreach my $subquery (@$query) {
797 next unless ref $subquery; # -or
798 $collapsed = $self->_collapse_query($subquery, $collapsed);
801 elsif (ref $query eq 'HASH') {
802 if (keys %$query and (keys %$query)[0] eq '-and') {
803 foreach my $subquery (@{$query->{-and}}) {
804 $collapsed = $self->_collapse_query($subquery, $collapsed);
808 foreach my $col (keys %$query) {
809 my $value = $query->{$col};
810 $collapsed->{$col}{$value}++;
822 =item Arguments: $cond?
824 =item Return Value: $resultsetcolumn
828 my $max_length = $rs->get_column('length')->max;
830 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
835 my ($self, $column) = @_;
836 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
844 =item Arguments: $cond, \%attrs?
846 =item Return Value: $resultset (scalar context), @row_objs (list context)
850 # WHERE title LIKE '%blue%'
851 $cd_rs = $rs->search_like({ title => '%blue%'});
853 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
854 that this is simply a convenience method retained for ex Class::DBI users.
855 You most likely want to use L</search> with specific operators.
857 For more information, see L<DBIx::Class::Manual::Cookbook>.
859 This method is deprecated and will be removed in 0.09. Use L</search()>
860 instead. An example conversion is:
862 ->search_like({ foo => 'bar' });
866 ->search({ foo => { like => 'bar' } });
873 'search_like() is deprecated and will be removed in DBIC version 0.09.'
874 .' Instead use ->search({ x => { -like => "y%" } })'
875 .' (note the outer pair of {}s - they are important!)'
877 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
878 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
879 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
880 return $class->search($query, { %$attrs });
887 =item Arguments: $first, $last
889 =item Return Value: $resultset (scalar context), @row_objs (list context)
893 Returns a resultset or object list representing a subset of elements from the
894 resultset slice is called on. Indexes are from 0, i.e., to get the first
897 my ($one, $two, $three) = $rs->slice(0, 2);
902 my ($self, $min, $max) = @_;
903 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
904 $attrs->{offset} = $self->{attrs}{offset} || 0;
905 $attrs->{offset} += $min;
906 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
907 return $self->search(undef(), $attrs);
908 #my $slice = (ref $self)->new($self->result_source, $attrs);
909 #return (wantarray ? $slice->all : $slice);
916 =item Arguments: none
918 =item Return Value: $result?
922 Returns the next element in the resultset (C<undef> is there is none).
924 Can be used to efficiently iterate over records in the resultset:
926 my $rs = $schema->resultset('CD')->search;
927 while (my $cd = $rs->next) {
931 Note that you need to store the resultset object, and call C<next> on it.
932 Calling C<< resultset('Table')->next >> repeatedly will always return the
933 first record from the resultset.
939 if (my $cache = $self->get_cache) {
940 $self->{all_cache_position} ||= 0;
941 return $cache->[$self->{all_cache_position}++];
943 if ($self->{attrs}{cache}) {
944 $self->{all_cache_position} = 1;
945 return ($self->all)[0];
947 if ($self->{stashed_objects}) {
948 my $obj = shift(@{$self->{stashed_objects}});
949 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
953 exists $self->{stashed_row}
954 ? @{delete $self->{stashed_row}}
955 : $self->cursor->next
957 return undef unless (@row);
958 my ($row, @more) = $self->_construct_object(@row);
959 $self->{stashed_objects} = \@more if @more;
963 sub _construct_object {
964 my ($self, @row) = @_;
965 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
966 my @new = $self->result_class->inflate_result($self->result_source, @$info);
967 @new = $self->{_attrs}{record_filter}->(@new)
968 if exists $self->{_attrs}{record_filter};
972 sub _collapse_result {
973 my ($self, $as_proto, $row) = @_;
977 # 'foo' => [ undef, 'foo' ]
978 # 'foo.bar' => [ 'foo', 'bar' ]
979 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
981 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
983 my %collapse = %{$self->{_attrs}{collapse}||{}};
987 # if we're doing collapsing (has_many prefetch) we need to grab records
988 # until the PK changes, so fill @pri_index. if not, we leave it empty so
989 # we know we don't have to bother.
991 # the reason for not using the collapse stuff directly is because if you
992 # had for e.g. two artists in a row with no cds, the collapse info for
993 # both would be NULL (undef) so you'd lose the second artist
995 # store just the index so we can check the array positions from the row
996 # without having to contruct the full hash
998 if (keys %collapse) {
999 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
1000 foreach my $i (0 .. $#construct_as) {
1001 next if defined($construct_as[$i][0]); # only self table
1002 if (delete $pri{$construct_as[$i][1]}) {
1003 push(@pri_index, $i);
1005 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1009 # no need to do an if, it'll be empty if @pri_index is empty anyway
1011 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1015 do { # no need to check anything at the front, we always want the first row
1019 foreach my $this_as (@construct_as) {
1020 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1023 push(@const_rows, \%const);
1025 } until ( # no pri_index => no collapse => drop straight out
1028 do { # get another row, stash it, drop out if different PK
1030 @copy = $self->cursor->next;
1031 $self->{stashed_row} = \@copy;
1033 # last thing in do block, counts as true if anything doesn't match
1035 # check xor defined first for NULL vs. NOT NULL then if one is
1036 # defined the other must be so check string equality
1039 (defined $pri_vals{$_} ^ defined $copy[$_])
1040 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1045 my $alias = $self->{attrs}{alias};
1052 foreach my $const (@const_rows) {
1053 scalar @const_keys or do {
1054 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1056 foreach my $key (@const_keys) {
1059 my @parts = split(/\./, $key);
1061 my $data = $const->{$key};
1062 foreach my $p (@parts) {
1063 $target = $target->[1]->{$p} ||= [];
1065 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1066 # collapsing at this point and on final part
1067 my $pos = $collapse_pos{$cur};
1068 CK: foreach my $ck (@ckey) {
1069 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1070 $collapse_pos{$cur} = $data;
1071 delete @collapse_pos{ # clear all positioning for sub-entries
1072 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1079 if (exists $collapse{$cur}) {
1080 $target = $target->[-1];
1083 $target->[0] = $data;
1085 $info->[0] = $const->{$key};
1093 =head2 result_source
1097 =item Arguments: $result_source?
1099 =item Return Value: $result_source
1103 An accessor for the primary ResultSource object from which this ResultSet
1110 =item Arguments: $result_class?
1112 =item Return Value: $result_class
1116 An accessor for the class to use when creating row objects. Defaults to
1117 C<< result_source->result_class >> - which in most cases is the name of the
1118 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1120 Note that changing the result_class will also remove any components
1121 that were originally loaded in the source class via
1122 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1123 in the original source class will not run.
1128 my ($self, $result_class) = @_;
1129 if ($result_class) {
1130 $self->ensure_class_loaded($result_class);
1131 $self->_result_class($result_class);
1133 $self->_result_class;
1140 =item Arguments: $cond, \%attrs??
1142 =item Return Value: $count
1146 Performs an SQL C<COUNT> with the same query as the resultset was built
1147 with to find the number of elements. Passing arguments is equivalent to
1148 C<< $rs->search ($cond, \%attrs)->count >>
1154 return $self->search(@_)->count if @_ and defined $_[0];
1155 return scalar @{ $self->get_cache } if $self->get_cache;
1157 my $meth = $self->_has_resolved_attr (qw/collapse group_by/)
1162 my $attrs = $self->_resolved_attrs_copy;
1163 my $rsrc = $self->result_source;
1165 return $rsrc->storage->$meth ($rsrc, $attrs);
1172 =head2 count_literal
1176 =item Arguments: $sql_fragment, @bind_values
1178 =item Return Value: $count
1182 Counts the results in a literal query. Equivalent to calling L</search_literal>
1183 with the passed arguments, then L</count>.
1187 sub count_literal { shift->search_literal(@_)->count; }
1193 =item Arguments: none
1195 =item Return Value: @objects
1199 Returns all elements in the resultset. Called implicitly if the resultset
1200 is returned in list context.
1207 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1210 return @{ $self->get_cache } if $self->get_cache;
1214 # TODO: don't call resolve here
1215 if (keys %{$self->_resolved_attrs->{collapse}}) {
1216 # if ($self->{attrs}{prefetch}) {
1217 # Using $self->cursor->all is really just an optimisation.
1218 # If we're collapsing has_many prefetches it probably makes
1219 # very little difference, and this is cleaner than hacking
1220 # _construct_object to survive the approach
1221 my @row = $self->cursor->next;
1223 push(@obj, $self->_construct_object(@row));
1224 @row = (exists $self->{stashed_row}
1225 ? @{delete $self->{stashed_row}}
1226 : $self->cursor->next);
1229 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1232 $self->set_cache(\@obj) if $self->{attrs}{cache};
1240 =item Arguments: none
1242 =item Return Value: $self
1246 Resets the resultset's cursor, so you can iterate through the elements again.
1252 delete $self->{_attrs} if exists $self->{_attrs};
1253 $self->{all_cache_position} = 0;
1254 $self->cursor->reset;
1262 =item Arguments: none
1264 =item Return Value: $object?
1268 Resets the resultset and returns an object for the first result (if the
1269 resultset returns anything).
1274 return $_[0]->reset->next;
1280 # Determines whether and what type of subquery is required for the $rs operation.
1281 # If grouping is necessary either supplies its own, or verifies the current one
1282 # After all is done delegates to the proper storage method.
1284 sub _rs_update_delete {
1285 my ($self, $op, $values) = @_;
1287 my $rsrc = $self->result_source;
1289 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1290 my $needs_subq = $self->_has_resolved_attr (qw/row offset/);
1292 if ($needs_group_by_subq or $needs_subq) {
1294 # make a new $rs selecting only the PKs (that's all we really need)
1295 my $attrs = $self->_resolved_attrs_copy;
1297 delete $attrs->{$_} for qw/collapse select as/;
1298 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1300 if ($needs_group_by_subq) {
1301 # make sure no group_by was supplied, or if there is one - make sure it matches
1302 # the columns compiled above perfectly. Anything else can not be sanely executed
1303 # on most databases so croak right then and there
1305 if (my $g = $attrs->{group_by}) {
1306 my @current_group_by = map
1307 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1308 (ref $g eq 'ARRAY' ? @$g : $g );
1311 join ("\x00", sort @current_group_by)
1313 join ("\x00", sort @{$attrs->{columns}} )
1315 $self->throw_exception (
1316 "You have just attempted a $op operation on a resultset which does group_by"
1317 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1318 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1319 . ' kind of queries. Please retry the operation with a modified group_by or'
1320 . ' without using one at all.'
1325 $attrs->{group_by} = $attrs->{columns};
1329 my $subrs = (ref $self)->new($rsrc, $attrs);
1331 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1334 return $rsrc->storage->$op(
1336 $op eq 'update' ? $values : (),
1337 $self->_cond_for_update_delete,
1343 # _cond_for_update_delete
1345 # update/delete require the condition to be modified to handle
1346 # the differing SQL syntax available. This transforms the $self->{cond}
1347 # appropriately, returning the new condition.
1349 sub _cond_for_update_delete {
1350 my ($self, $full_cond) = @_;
1353 $full_cond ||= $self->{cond};
1354 # No-op. No condition, we're updating/deleting everything
1355 return $cond unless ref $full_cond;
1357 if (ref $full_cond eq 'ARRAY') {
1361 foreach my $key (keys %{$_}) {
1363 $hash{$1} = $_->{$key};
1369 elsif (ref $full_cond eq 'HASH') {
1370 if ((keys %{$full_cond})[0] eq '-and') {
1372 my @cond = @{$full_cond->{-and}};
1373 for (my $i = 0; $i < @cond; $i++) {
1374 my $entry = $cond[$i];
1376 if (ref $entry eq 'HASH') {
1377 $hash = $self->_cond_for_update_delete($entry);
1380 $entry =~ /([^.]+)$/;
1381 $hash->{$1} = $cond[++$i];
1383 push @{$cond->{-and}}, $hash;
1387 foreach my $key (keys %{$full_cond}) {
1389 $cond->{$1} = $full_cond->{$key};
1394 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1405 =item Arguments: \%values
1407 =item Return Value: $storage_rv
1411 Sets the specified columns in the resultset to the supplied values in a
1412 single query. Return value will be true if the update succeeded or false
1413 if no records were updated; exact type of success value is storage-dependent.
1418 my ($self, $values) = @_;
1419 $self->throw_exception('Values for update must be a hash')
1420 unless ref $values eq 'HASH';
1422 return $self->_rs_update_delete ('update', $values);
1429 =item Arguments: \%values
1431 =item Return Value: 1
1435 Fetches all objects and updates them one at a time. Note that C<update_all>
1436 will run DBIC cascade triggers, while L</update> will not.
1441 my ($self, $values) = @_;
1442 $self->throw_exception('Values for update_all must be a hash')
1443 unless ref $values eq 'HASH';
1444 foreach my $obj ($self->all) {
1445 $obj->set_columns($values)->update;
1454 =item Arguments: none
1456 =item Return Value: $storage_rv
1460 Deletes the contents of the resultset from its result source. Note that this
1461 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1462 to run. See also L<DBIx::Class::Row/delete>.
1464 Return value will be the amount of rows deleted; exact type of return value
1465 is storage-dependent.
1471 $self->throw_exception('delete does not accept any arguments')
1474 return $self->_rs_update_delete ('delete');
1481 =item Arguments: none
1483 =item Return Value: 1
1487 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1488 will run DBIC cascade triggers, while L</delete> will not.
1494 $self->throw_exception('delete_all does not accept any arguments')
1497 $_->delete for $self->all;
1505 =item Arguments: \@data;
1509 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1510 For the arrayref of hashrefs style each hashref should be a structure suitable
1511 forsubmitting to a $resultset->create(...) method.
1513 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1514 to insert the data, as this is a faster method.
1516 Otherwise, each set of data is inserted into the database using
1517 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1518 accumulated into an array. The array itself, or an array reference
1519 is returned depending on scalar or list context.
1521 Example: Assuming an Artist Class that has many CDs Classes relating:
1523 my $Artist_rs = $schema->resultset("Artist");
1525 ## Void Context Example
1526 $Artist_rs->populate([
1527 { artistid => 4, name => 'Manufactured Crap', cds => [
1528 { title => 'My First CD', year => 2006 },
1529 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1532 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1533 { title => 'My parents sold me to a record company' ,year => 2005 },
1534 { title => 'Why Am I So Ugly?', year => 2006 },
1535 { title => 'I Got Surgery and am now Popular', year => 2007 }
1540 ## Array Context Example
1541 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1542 { name => "Artist One"},
1543 { name => "Artist Two"},
1544 { name => "Artist Three", cds=> [
1545 { title => "First CD", year => 2007},
1546 { title => "Second CD", year => 2008},
1550 print $ArtistOne->name; ## response is 'Artist One'
1551 print $ArtistThree->cds->count ## reponse is '2'
1553 For the arrayref of arrayrefs style, the first element should be a list of the
1554 fieldsnames to which the remaining elements are rows being inserted. For
1557 $Arstist_rs->populate([
1558 [qw/artistid name/],
1559 [100, 'A Formally Unknown Singer'],
1560 [101, 'A singer that jumped the shark two albums ago'],
1561 [102, 'An actually cool singer.'],
1564 Please note an important effect on your data when choosing between void and
1565 wantarray context. Since void context goes straight to C<insert_bulk> in
1566 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1567 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1568 create primary keys for you, you will find that your PKs are empty. In this
1569 case you will have to use the wantarray context in order to create those
1575 my $self = shift @_;
1576 my $data = ref $_[0][0] eq 'HASH'
1577 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1578 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1580 if(defined wantarray) {
1582 foreach my $item (@$data) {
1583 push(@created, $self->create($item));
1585 return wantarray ? @created : \@created;
1587 my ($first, @rest) = @$data;
1589 my @names = grep {!ref $first->{$_}} keys %$first;
1590 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1591 my @pks = $self->result_source->primary_columns;
1593 ## do the belongs_to relationships
1594 foreach my $index (0..$#$data) {
1596 # delegate to create() for any dataset without primary keys with specified relationships
1597 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1599 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1600 my @ret = $self->populate($data);
1606 foreach my $rel (@rels) {
1607 next unless ref $data->[$index]->{$rel} eq "HASH";
1608 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1609 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1610 my $related = $result->result_source->_resolve_condition(
1611 $result->result_source->relationship_info($reverse)->{cond},
1616 delete $data->[$index]->{$rel};
1617 $data->[$index] = {%{$data->[$index]}, %$related};
1619 push @names, keys %$related if $index == 0;
1623 ## do bulk insert on current row
1624 my @values = map { [ @$_{@names} ] } @$data;
1626 $self->result_source->storage->insert_bulk(
1627 $self->result_source,
1632 ## do the has_many relationships
1633 foreach my $item (@$data) {
1635 foreach my $rel (@rels) {
1636 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1638 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1639 || $self->throw_exception('Cannot find the relating object.');
1641 my $child = $parent->$rel;
1643 my $related = $child->result_source->_resolve_condition(
1644 $parent->result_source->relationship_info($rel)->{cond},
1649 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1650 my @populate = map { {%$_, %$related} } @rows_to_add;
1652 $child->populate( \@populate );
1658 =head2 _normalize_populate_args ($args)
1660 Private method used by L</populate> to normalize its incoming arguments. Factored
1661 out in case you want to subclass and accept new argument structures to the
1662 L</populate> method.
1666 sub _normalize_populate_args {
1667 my ($self, $data) = @_;
1668 my @names = @{shift(@$data)};
1669 my @results_to_create;
1670 foreach my $datum (@$data) {
1671 my %result_to_create;
1672 foreach my $index (0..$#names) {
1673 $result_to_create{$names[$index]} = $$datum[$index];
1675 push @results_to_create, \%result_to_create;
1677 return \@results_to_create;
1684 =item Arguments: none
1686 =item Return Value: $pager
1690 Return Value a L<Data::Page> object for the current resultset. Only makes
1691 sense for queries with a C<page> attribute.
1693 To get the full count of entries for a paged resultset, call
1694 C<total_entries> on the L<Data::Page> object.
1701 return $self->{pager} if $self->{pager};
1703 my $attrs = $self->{attrs};
1704 $self->throw_exception("Can't create pager for non-paged rs")
1705 unless $self->{attrs}{page};
1706 $attrs->{rows} ||= 10;
1708 # throw away the paging flags and re-run the count (possibly
1709 # with a subselect) to get the real total count
1710 my $count_attrs = { %$attrs };
1711 delete $count_attrs->{$_} for qw/rows offset page pager/;
1712 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1714 return $self->{pager} = Data::Page->new(
1717 $self->{attrs}{page}
1725 =item Arguments: $page_number
1727 =item Return Value: $rs
1731 Returns a resultset for the $page_number page of the resultset on which page
1732 is called, where each page contains a number of rows equal to the 'rows'
1733 attribute set on the resultset (10 by default).
1738 my ($self, $page) = @_;
1739 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1746 =item Arguments: \%vals
1748 =item Return Value: $rowobject
1752 Creates a new row object in the resultset's result class and returns
1753 it. The row is not inserted into the database at this point, call
1754 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1755 will tell you whether the row object has been inserted or not.
1757 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1762 my ($self, $values) = @_;
1763 $self->throw_exception( "new_result needs a hash" )
1764 unless (ref $values eq 'HASH');
1767 my $alias = $self->{attrs}{alias};
1770 defined $self->{cond}
1771 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1773 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1774 $new{-from_resultset} = [ keys %new ] if keys %new;
1776 $self->throw_exception(
1777 "Can't abstract implicit construct, condition not a hash"
1778 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1780 my $collapsed_cond = (
1782 ? $self->_collapse_cond($self->{cond})
1786 # precendence must be given to passed values over values inherited from
1787 # the cond, so the order here is important.
1788 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1789 while( my($col,$value) = each %implied ){
1790 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1791 $new{$col} = $value->{'='};
1794 $new{$col} = $value if $self->_is_deterministic_value($value);
1800 %{ $self->_remove_alias($values, $alias) },
1801 -source_handle => $self->_source_handle,
1802 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1805 return $self->result_class->new(\%new);
1808 # _is_deterministic_value
1810 # Make an effor to strip non-deterministic values from the condition,
1811 # to make sure new_result chokes less
1813 sub _is_deterministic_value {
1816 my $ref_type = ref $value;
1817 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1818 return 1 if Scalar::Util::blessed($value);
1822 # _has_resolved_attr
1824 # determines if the resultset defines at least one
1825 # of the attributes supplied
1827 # used to determine if a subquery is neccessary
1829 sub _has_resolved_attr {
1830 my ($self, @attr_names) = @_;
1832 my $attrs = $self->_resolved_attrs;
1836 for my $n (@attr_names) {
1837 ++$join_check_req if $n eq '-join';
1839 my $attr = $attrs->{$n};
1841 next if not defined $attr;
1843 if (ref $attr eq 'HASH') {
1844 return 1 if keys %$attr;
1846 elsif (ref $attr eq 'ARRAY') {
1854 # a resolved join is expressed as a multi-level from
1858 ref $attrs->{from} eq 'ARRAY'
1860 @{$attrs->{from}} > 1
1868 # Recursively collapse the condition.
1870 sub _collapse_cond {
1871 my ($self, $cond, $collapsed) = @_;
1875 if (ref $cond eq 'ARRAY') {
1876 foreach my $subcond (@$cond) {
1877 next unless ref $subcond; # -or
1878 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1881 elsif (ref $cond eq 'HASH') {
1882 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1883 foreach my $subcond (@{$cond->{-and}}) {
1884 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1888 foreach my $col (keys %$cond) {
1889 my $value = $cond->{$col};
1890 $collapsed->{$col} = $value;
1900 # Remove the specified alias from the specified query hash. A copy is made so
1901 # the original query is not modified.
1904 my ($self, $query, $alias) = @_;
1906 my %orig = %{ $query || {} };
1909 foreach my $key (keys %orig) {
1911 $unaliased{$key} = $orig{$key};
1914 $unaliased{$1} = $orig{$key}
1915 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1921 =head2 as_query (EXPERIMENTAL)
1925 =item Arguments: none
1927 =item Return Value: \[ $sql, @bind ]
1931 Returns the SQL query and bind vars associated with the invocant.
1933 This is generally used as the RHS for a subquery.
1935 B<NOTE>: This feature is still experimental.
1942 my $attrs = $self->_resolved_attrs_copy;
1947 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
1948 # $sql also has no wrapping parenthesis in list ctx
1950 my $sqlbind = $self->result_source->storage
1951 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
1960 =item Arguments: \%vals, \%attrs?
1962 =item Return Value: $rowobject
1966 my $artist = $schema->resultset('Artist')->find_or_new(
1967 { artist => 'fred' }, { key => 'artists' });
1969 $cd->cd_to_producer->find_or_new({ producer => $producer },
1970 { key => 'primary });
1972 Find an existing record from this resultset, based on its primary
1973 key, or a unique constraint. If none exists, instantiate a new result
1974 object and return it. The object will not be saved into your storage
1975 until you call L<DBIx::Class::Row/insert> on it.
1977 You most likely want this method when looking for existing rows using
1978 a unique constraint that is not the primary key, or looking for
1981 If you want objects to be saved immediately, use L</find_or_create> instead.
1983 B<Note>: C<find_or_new> is probably not what you want when creating a
1984 new row in a table that uses primary keys supplied by the
1985 database. Passing in a primary key column with a value of I<undef>
1986 will cause L</find> to attempt to search for a row with a value of
1993 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1994 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1995 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
1998 return $self->new_result($hash);
2005 =item Arguments: \%vals
2007 =item Return Value: a L<DBIx::Class::Row> $object
2011 Attempt to create a single new row or a row with multiple related rows
2012 in the table represented by the resultset (and related tables). This
2013 will not check for duplicate rows before inserting, use
2014 L</find_or_create> to do that.
2016 To create one row for this resultset, pass a hashref of key/value
2017 pairs representing the columns of the table and the values you wish to
2018 store. If the appropriate relationships are set up, foreign key fields
2019 can also be passed an object representing the foreign row, and the
2020 value will be set to its primary key.
2022 To create related objects, pass a hashref for the value if the related
2023 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2024 and use the name of the relationship as the key. (NOT the name of the field,
2025 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2026 of hashrefs containing the data for each of the rows to create in the foreign
2027 tables, again using the relationship name as the key.
2029 Instead of hashrefs of plain related data (key/value pairs), you may
2030 also pass new or inserted objects. New objects (not inserted yet, see
2031 L</new>), will be inserted into their appropriate tables.
2033 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2035 Example of creating a new row.
2037 $person_rs->create({
2038 name=>"Some Person",
2039 email=>"somebody@someplace.com"
2042 Example of creating a new row and also creating rows in a related C<has_many>
2043 or C<has_one> resultset. Note Arrayref.
2046 { artistid => 4, name => 'Manufactured Crap', cds => [
2047 { title => 'My First CD', year => 2006 },
2048 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2053 Example of creating a new row and also creating a row in a related
2054 C<belongs_to>resultset. Note Hashref.
2057 title=>"Music for Silly Walks",
2060 name=>"Silly Musician",
2067 my ($self, $attrs) = @_;
2068 $self->throw_exception( "create needs a hashref" )
2069 unless ref $attrs eq 'HASH';
2070 return $self->new_result($attrs)->insert;
2073 =head2 find_or_create
2077 =item Arguments: \%vals, \%attrs?
2079 =item Return Value: $rowobject
2083 $cd->cd_to_producer->find_or_create({ producer => $producer },
2084 { key => 'primary });
2086 Tries to find a record based on its primary key or unique constraints; if none
2087 is found, creates one and returns that instead.
2089 my $cd = $schema->resultset('CD')->find_or_create({
2091 artist => 'Massive Attack',
2092 title => 'Mezzanine',
2096 Also takes an optional C<key> attribute, to search by a specific key or unique
2097 constraint. For example:
2099 my $cd = $schema->resultset('CD')->find_or_create(
2101 artist => 'Massive Attack',
2102 title => 'Mezzanine',
2104 { key => 'cd_artist_title' }
2107 B<Note>: Because find_or_create() reads from the database and then
2108 possibly inserts based on the result, this method is subject to a race
2109 condition. Another process could create a record in the table after
2110 the find has completed and before the create has started. To avoid
2111 this problem, use find_or_create() inside a transaction.
2113 B<Note>: C<find_or_create> is probably not what you want when creating
2114 a new row in a table that uses primary keys supplied by the
2115 database. Passing in a primary key column with a value of I<undef>
2116 will cause L</find> to attempt to search for a row with a value of
2119 See also L</find> and L</update_or_create>. For information on how to declare
2120 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2124 sub find_or_create {
2126 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2127 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2128 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2131 return $self->create($hash);
2134 =head2 update_or_create
2138 =item Arguments: \%col_values, { key => $unique_constraint }?
2140 =item Return Value: $rowobject
2144 $resultset->update_or_create({ col => $val, ... });
2146 First, searches for an existing row matching one of the unique constraints
2147 (including the primary key) on the source of this resultset. If a row is
2148 found, updates it with the other given column values. Otherwise, creates a new
2151 Takes an optional C<key> attribute to search on a specific unique constraint.
2154 # In your application
2155 my $cd = $schema->resultset('CD')->update_or_create(
2157 artist => 'Massive Attack',
2158 title => 'Mezzanine',
2161 { key => 'cd_artist_title' }
2164 $cd->cd_to_producer->update_or_create({
2165 producer => $producer,
2172 If no C<key> is specified, it searches on all unique constraints defined on the
2173 source, including the primary key.
2175 If the C<key> is specified as C<primary>, it searches only on the primary key.
2177 See also L</find> and L</find_or_create>. For information on how to declare
2178 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2180 B<Note>: C<update_or_create> is probably not what you want when
2181 looking for a row in a table that uses primary keys supplied by the
2182 database, unless you actually have a key value. Passing in a primary
2183 key column with a value of I<undef> will cause L</find> to attempt to
2184 search for a row with a value of I<NULL>.
2188 sub update_or_create {
2190 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2191 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2193 my $row = $self->find($cond, $attrs);
2195 $row->update($cond);
2199 return $self->create($cond);
2202 =head2 update_or_new
2206 =item Arguments: \%col_values, { key => $unique_constraint }?
2208 =item Return Value: $rowobject
2212 $resultset->update_or_new({ col => $val, ... });
2214 First, searches for an existing row matching one of the unique constraints
2215 (including the primary key) on the source of this resultset. If a row is
2216 found, updates it with the other given column values. Otherwise, instantiate
2217 a new result object and return it. The object will not be saved into your storage
2218 until you call L<DBIx::Class::Row/insert> on it.
2220 Takes an optional C<key> attribute to search on a specific unique constraint.
2223 # In your application
2224 my $cd = $schema->resultset('CD')->update_or_new(
2226 artist => 'Massive Attack',
2227 title => 'Mezzanine',
2230 { key => 'cd_artist_title' }
2233 if ($cd->in_storage) {
2234 # the cd was updated
2237 # the cd is not yet in the database, let's insert it
2241 See also L</find>, L</find_or_create> and L<find_or_new>.
2247 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2248 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2250 my $row = $self->find( $cond, $attrs );
2251 if ( defined $row ) {
2252 $row->update($cond);
2256 return $self->new_result($cond);
2263 =item Arguments: none
2265 =item Return Value: \@cache_objects?
2269 Gets the contents of the cache for the resultset, if the cache is set.
2271 The cache is populated either by using the L</prefetch> attribute to
2272 L</search> or by calling L</set_cache>.
2284 =item Arguments: \@cache_objects
2286 =item Return Value: \@cache_objects
2290 Sets the contents of the cache for the resultset. Expects an arrayref
2291 of objects of the same class as those produced by the resultset. Note that
2292 if the cache is set the resultset will return the cached objects rather
2293 than re-querying the database even if the cache attr is not set.
2295 The contents of the cache can also be populated by using the
2296 L</prefetch> attribute to L</search>.
2301 my ( $self, $data ) = @_;
2302 $self->throw_exception("set_cache requires an arrayref")
2303 if defined($data) && (ref $data ne 'ARRAY');
2304 $self->{all_cache} = $data;
2311 =item Arguments: none
2313 =item Return Value: []
2317 Clears the cache for the resultset.
2322 shift->set_cache(undef);
2325 =head2 related_resultset
2329 =item Arguments: $relationship_name
2331 =item Return Value: $resultset
2335 Returns a related resultset for the supplied relationship name.
2337 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2341 sub related_resultset {
2342 my ($self, $rel) = @_;
2344 $self->{related_resultsets} ||= {};
2345 return $self->{related_resultsets}{$rel} ||= do {
2346 my $rel_obj = $self->result_source->relationship_info($rel);
2348 $self->throw_exception(
2349 "search_related: result source '" . $self->result_source->source_name .
2350 "' has no such relationship $rel")
2353 my ($from,$seen) = $self->_resolve_from($rel);
2355 my $join_count = $seen->{$rel};
2356 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2358 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2359 my %attrs = %{$self->{attrs}||{}};
2360 delete @attrs{qw(result_class alias)};
2364 if (my $cache = $self->get_cache) {
2365 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2366 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2371 my $rel_source = $self->result_source->related_source($rel);
2375 # The reason we do this now instead of passing the alias to the
2376 # search_rs below is that if you wrap/overload resultset on the
2377 # source you need to know what alias it's -going- to have for things
2378 # to work sanely (e.g. RestrictWithObject wants to be able to add
2379 # extra query restrictions, and these may need to be $alias.)
2381 my $attrs = $rel_source->resultset_attributes;
2382 local $attrs->{alias} = $alias;
2384 $rel_source->resultset
2392 where => $self->{cond},
2397 $new->set_cache($new_cache) if $new_cache;
2402 =head2 current_source_alias
2406 =item Arguments: none
2408 =item Return Value: $source_alias
2412 Returns the current table alias for the result source this resultset is built
2413 on, that will be used in the SQL query. Usually it is C<me>.
2415 Currently the source alias that refers to the result set returned by a
2416 L</search>/L</find> family method depends on how you got to the resultset: it's
2417 C<me> by default, but eg. L</search_related> aliases it to the related result
2418 source name (and keeps C<me> referring to the original result set). The long
2419 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2420 (and make this method unnecessary).
2422 Thus it's currently necessary to use this method in predefined queries (see
2423 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2424 source alias of the current result set:
2426 # in a result set class
2428 my ($self, $user) = @_;
2430 my $me = $self->current_source_alias;
2432 return $self->search(
2433 "$me.modified" => $user->id,
2439 sub current_source_alias {
2442 return ($self->{attrs} || {})->{alias} || 'me';
2445 # This code is called by search_related, and makes sure there
2446 # is clear separation between the joins before, during, and
2447 # after the relationship. This information is needed later
2448 # in order to properly resolve prefetch aliases (any alias
2449 # with a relation_chain_depth less than the depth of the
2450 # current prefetch is not considered)
2452 my ($self, $extra_join) = @_;
2453 my $source = $self->result_source;
2454 my $attrs = $self->{attrs};
2460 -source_handle => $source->handle,
2461 -alias => $attrs->{alias},
2462 $attrs->{alias} => $source->from,
2466 my $seen = { %{$attrs->{seen_join} || {} } };
2468 # we need to take the prefetch the attrs into account before we
2469 # ->_resolve_join as otherwise they get lost - captainL
2470 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2472 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2474 ++$seen->{-relation_chain_depth};
2476 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2478 ++$seen->{-relation_chain_depth};
2480 return ($from,$seen);
2483 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2484 sub _resolved_attrs_copy {
2486 return { %{$self->_resolved_attrs (@_)} };
2489 sub _resolved_attrs {
2491 return $self->{_attrs} if $self->{_attrs};
2493 my $attrs = { %{ $self->{attrs} || {} } };
2494 my $source = $self->result_source;
2495 my $alias = $attrs->{alias};
2497 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2500 # build columns (as long as select isn't set) into a set of as/select hashes
2501 unless ( $attrs->{select} ) {
2503 ( ref($_) eq 'HASH' )
2507 /^\Q${alias}.\E(.+)$/
2518 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2520 # add the additional columns on
2521 foreach ( 'include_columns', '+columns' ) {
2522 push @colbits, map {
2523 ( ref($_) eq 'HASH' )
2525 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2526 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2529 # start with initial select items
2530 if ( $attrs->{select} ) {
2532 ( ref $attrs->{select} eq 'ARRAY' )
2533 ? [ @{ $attrs->{select} } ]
2534 : [ $attrs->{select} ];
2538 ref $attrs->{as} eq 'ARRAY'
2539 ? [ @{ $attrs->{as} } ]
2542 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2547 # otherwise we intialise select & as to empty
2548 $attrs->{select} = [];
2552 # now add colbits to select/as
2553 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2554 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2557 if ( $adds = delete $attrs->{'+select'} ) {
2558 $adds = [$adds] unless ref $adds eq 'ARRAY';
2560 @{ $attrs->{select} },
2561 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2564 if ( $adds = delete $attrs->{'+as'} ) {
2565 $adds = [$adds] unless ref $adds eq 'ARRAY';
2566 push( @{ $attrs->{as} }, @$adds );
2569 $attrs->{from} ||= [ {
2570 -source_handle => $source->handle,
2571 -alias => $self->{attrs}{alias},
2572 $self->{attrs}{alias} => $source->from,
2575 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2576 my $join = delete $attrs->{join} || {};
2578 if ( defined $attrs->{prefetch} ) {
2579 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2583 $attrs->{from} = # have to copy here to avoid corrupting the original
2585 @{ $attrs->{from} },
2586 $source->_resolve_join(
2587 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2593 if ( $attrs->{order_by} ) {
2594 $attrs->{order_by} = (
2595 ref( $attrs->{order_by} ) eq 'ARRAY'
2596 ? [ @{ $attrs->{order_by} } ]
2597 : [ $attrs->{order_by} ]
2601 $attrs->{order_by} = [];
2604 # If the order_by is otherwise empty - we will use this for TOP limit
2605 # emulation and the like.
2606 # Although this is needed only if the order_by is not defined, it is
2607 # actually cheaper to just populate this rather than properly examining
2608 # order_by (stuf like [ {} ] and the like)
2609 $attrs->{_virtual_order_by} = [ $self->result_source->primary_columns ];
2612 $attrs->{collapse} ||= {};
2613 if ( my $prefetch = delete $attrs->{prefetch} ) {
2614 $prefetch = $self->_merge_attr( {}, $prefetch );
2616 my $prefetch_ordering = [];
2618 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2621 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
2623 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2624 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2626 push( @{ $attrs->{order_by} }, @$prefetch_ordering );
2627 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
2631 if (delete $attrs->{distinct}) {
2632 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2635 # if both page and offset are specified, produce a combined offset
2636 # even though it doesn't make much sense, this is what pre 081xx has
2638 if (my $page = delete $attrs->{page}) {
2639 $attrs->{offset} = ($attrs->{rows} * ($page - 1)) +
2640 ($attrs->{offset} || 0);
2643 return $self->{_attrs} = $attrs;
2646 sub _joinpath_aliases {
2647 my ($self, $fromspec, $seen) = @_;
2650 return $paths unless ref $fromspec eq 'ARRAY';
2652 for my $j (@$fromspec) {
2654 next if ref $j ne 'ARRAY';
2655 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2658 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2659 push @{$p->{-join_aliases} }, $j->[0]{-alias};
2666 my ($self, $attr) = @_;
2668 if (ref $attr eq 'HASH') {
2669 return $self->_rollout_hash($attr);
2670 } elsif (ref $attr eq 'ARRAY') {
2671 return $self->_rollout_array($attr);
2677 sub _rollout_array {
2678 my ($self, $attr) = @_;
2681 foreach my $element (@{$attr}) {
2682 if (ref $element eq 'HASH') {
2683 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2684 } elsif (ref $element eq 'ARRAY') {
2685 # XXX - should probably recurse here
2686 push( @rolled_array, @{$self->_rollout_array($element)} );
2688 push( @rolled_array, $element );
2691 return \@rolled_array;
2695 my ($self, $attr) = @_;
2698 foreach my $key (keys %{$attr}) {
2699 push( @rolled_array, { $key => $attr->{$key} } );
2701 return \@rolled_array;
2704 sub _calculate_score {
2705 my ($self, $a, $b) = @_;
2707 if (ref $b eq 'HASH') {
2708 my ($b_key) = keys %{$b};
2709 if (ref $a eq 'HASH') {
2710 my ($a_key) = keys %{$a};
2711 if ($a_key eq $b_key) {
2712 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2717 return ($a eq $b_key) ? 1 : 0;
2720 if (ref $a eq 'HASH') {
2721 my ($a_key) = keys %{$a};
2722 return ($b eq $a_key) ? 1 : 0;
2724 return ($b eq $a) ? 1 : 0;
2730 my ($self, $orig, $import) = @_;
2732 return $import unless defined($orig);
2733 return $orig unless defined($import);
2735 $orig = $self->_rollout_attr($orig);
2736 $import = $self->_rollout_attr($import);
2739 foreach my $import_element ( @{$import} ) {
2740 # find best candidate from $orig to merge $b_element into
2741 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2742 foreach my $orig_element ( @{$orig} ) {
2743 my $score = $self->_calculate_score( $orig_element, $import_element );
2744 if ($score > $best_candidate->{score}) {
2745 $best_candidate->{position} = $position;
2746 $best_candidate->{score} = $score;
2750 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2752 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2753 push( @{$orig}, $import_element );
2755 my $orig_best = $orig->[$best_candidate->{position}];
2756 # merge orig_best and b_element together and replace original with merged
2757 if (ref $orig_best ne 'HASH') {
2758 $orig->[$best_candidate->{position}] = $import_element;
2759 } elsif (ref $import_element eq 'HASH') {
2760 my ($key) = keys %{$orig_best};
2761 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2764 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2774 $self->_source_handle($_[0]->handle);
2776 $self->_source_handle->resolve;
2780 =head2 throw_exception
2782 See L<DBIx::Class::Schema/throw_exception> for details.
2786 sub throw_exception {
2788 if (ref $self && $self->_source_handle->schema) {
2789 $self->_source_handle->schema->throw_exception(@_)
2796 # XXX: FIXME: Attributes docs need clearing up
2800 Attributes are used to refine a ResultSet in various ways when
2801 searching for data. They can be passed to any method which takes an
2802 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2805 These are in no particular order:
2811 =item Value: ( $order_by | \@order_by | \%order_by )
2815 Which column(s) to order the results by. If a single column name, or
2816 an arrayref of names is supplied, the argument is passed through
2817 directly to SQL. The hashref syntax allows for connection-agnostic
2818 specification of ordering direction:
2820 For descending order:
2822 order_by => { -desc => [qw/col1 col2 col3/] }
2824 For explicit ascending order:
2826 order_by => { -asc => 'col' }
2828 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2829 supported, although you are strongly encouraged to use the hashref
2830 syntax as outlined above.
2836 =item Value: \@columns
2840 Shortcut to request a particular set of columns to be retrieved. Each
2841 column spec may be a string (a table column name), or a hash (in which
2842 case the key is the C<as> value, and the value is used as the C<select>
2843 expression). Adds C<me.> onto the start of any column without a C<.> in
2844 it and sets C<select> from that, then auto-populates C<as> from
2845 C<select> as normal. (You may also use the C<cols> attribute, as in
2846 earlier versions of DBIC.)
2852 =item Value: \@columns
2856 Indicates additional columns to be selected from storage. Works the same
2857 as L</columns> but adds columns to the selection. (You may also use the
2858 C<include_columns> attribute, as in earlier versions of DBIC). For
2861 $schema->resultset('CD')->search(undef, {
2862 '+columns' => ['artist.name'],
2866 would return all CDs and include a 'name' column to the information
2867 passed to object inflation. Note that the 'artist' is the name of the
2868 column (or relationship) accessor, and 'name' is the name of the column
2869 accessor in the related table.
2871 =head2 include_columns
2875 =item Value: \@columns
2879 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2885 =item Value: \@select_columns
2889 Indicates which columns should be selected from the storage. You can use
2890 column names, or in the case of RDBMS back ends, function or stored procedure
2893 $rs = $schema->resultset('Employee')->search(undef, {
2896 { count => 'employeeid' },
2901 When you use function/stored procedure names and do not supply an C<as>
2902 attribute, the column names returned are storage-dependent. E.g. MySQL would
2903 return a column named C<count(employeeid)> in the above example.
2909 Indicates additional columns to be selected from storage. Works the same as
2910 L</select> but adds columns to the selection.
2918 Indicates additional column names for those added via L</+select>. See L</as>.
2926 =item Value: \@inflation_names
2930 Indicates column names for object inflation. That is, C<as>
2931 indicates the name that the column can be accessed as via the
2932 C<get_column> method (or via the object accessor, B<if one already
2933 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2935 The C<as> attribute is used in conjunction with C<select>,
2936 usually when C<select> contains one or more function or stored
2939 $rs = $schema->resultset('Employee')->search(undef, {
2942 { count => 'employeeid' }
2944 as => ['name', 'employee_count'],
2947 my $employee = $rs->first(); # get the first Employee
2949 If the object against which the search is performed already has an accessor
2950 matching a column name specified in C<as>, the value can be retrieved using
2951 the accessor as normal:
2953 my $name = $employee->name();
2955 If on the other hand an accessor does not exist in the object, you need to
2956 use C<get_column> instead:
2958 my $employee_count = $employee->get_column('employee_count');
2960 You can create your own accessors if required - see
2961 L<DBIx::Class::Manual::Cookbook> for details.
2963 Please note: This will NOT insert an C<AS employee_count> into the SQL
2964 statement produced, it is used for internal access only. Thus
2965 attempting to use the accessor in an C<order_by> clause or similar
2966 will fail miserably.
2968 To get around this limitation, you can supply literal SQL to your
2969 C<select> attibute that contains the C<AS alias> text, eg:
2971 select => [\'myfield AS alias']
2977 =item Value: ($rel_name | \@rel_names | \%rel_names)
2981 Contains a list of relationships that should be joined for this query. For
2984 # Get CDs by Nine Inch Nails
2985 my $rs = $schema->resultset('CD')->search(
2986 { 'artist.name' => 'Nine Inch Nails' },
2987 { join => 'artist' }
2990 Can also contain a hash reference to refer to the other relation's relations.
2993 package MyApp::Schema::Track;
2994 use base qw/DBIx::Class/;
2995 __PACKAGE__->table('track');
2996 __PACKAGE__->add_columns(qw/trackid cd position title/);
2997 __PACKAGE__->set_primary_key('trackid');
2998 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3001 # In your application
3002 my $rs = $schema->resultset('Artist')->search(
3003 { 'track.title' => 'Teardrop' },
3005 join => { cd => 'track' },
3006 order_by => 'artist.name',
3010 You need to use the relationship (not the table) name in conditions,
3011 because they are aliased as such. The current table is aliased as "me", so
3012 you need to use me.column_name in order to avoid ambiguity. For example:
3014 # Get CDs from 1984 with a 'Foo' track
3015 my $rs = $schema->resultset('CD')->search(
3018 'tracks.name' => 'Foo'
3020 { join => 'tracks' }
3023 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3024 similarly for a third time). For e.g.
3026 my $rs = $schema->resultset('Artist')->search({
3027 'cds.title' => 'Down to Earth',
3028 'cds_2.title' => 'Popular',
3030 join => [ qw/cds cds/ ],
3033 will return a set of all artists that have both a cd with title 'Down
3034 to Earth' and a cd with title 'Popular'.
3036 If you want to fetch related objects from other tables as well, see C<prefetch>
3039 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3045 =item Value: ($rel_name | \@rel_names | \%rel_names)
3049 Contains one or more relationships that should be fetched along with
3050 the main query (when they are accessed afterwards the data will
3051 already be available, without extra queries to the database). This is
3052 useful for when you know you will need the related objects, because it
3053 saves at least one query:
3055 my $rs = $schema->resultset('Tag')->search(
3064 The initial search results in SQL like the following:
3066 SELECT tag.*, cd.*, artist.* FROM tag
3067 JOIN cd ON tag.cd = cd.cdid
3068 JOIN artist ON cd.artist = artist.artistid
3070 L<DBIx::Class> has no need to go back to the database when we access the
3071 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3074 Simple prefetches will be joined automatically, so there is no need
3075 for a C<join> attribute in the above search.
3077 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3078 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3079 with an accessor type of 'single' or 'filter'). A more complex example that
3080 prefetches an artists cds, the tracks on those cds, and the tags associted
3081 with that artist is given below (assuming many-to-many from artists to tags):
3083 my $rs = $schema->resultset('Artist')->search(
3087 { cds => 'tracks' },
3088 { artist_tags => 'tags' }
3094 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3095 attributes will be ignored.
3105 Makes the resultset paged and specifies the page to retrieve. Effectively
3106 identical to creating a non-pages resultset and then calling ->page($page)
3109 If L<rows> attribute is not specified it defualts to 10 rows per page.
3111 When you have a paged resultset, L</count> will only return the number
3112 of rows in the page. To get the total, use the L</pager> and call
3113 C<total_entries> on it.
3123 Specifes the maximum number of rows for direct retrieval or the number of
3124 rows per page if the page attribute or method is used.
3130 =item Value: $offset
3134 Specifies the (zero-based) row number for the first row to be returned, or the
3135 of the first row of the first page if paging is used.
3141 =item Value: \@columns
3145 A arrayref of columns to group by. Can include columns of joined tables.
3147 group_by => [qw/ column1 column2 ... /]
3153 =item Value: $condition
3157 HAVING is a select statement attribute that is applied between GROUP BY and
3158 ORDER BY. It is applied to the after the grouping calculations have been
3161 having => { 'count(employee)' => { '>=', 100 } }
3167 =item Value: (0 | 1)
3171 Set to 1 to group by all columns.
3177 Adds to the WHERE clause.
3179 # only return rows WHERE deleted IS NULL for all searches
3180 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3182 Can be overridden by passing C<{ where => undef }> as an attribute
3189 Set to 1 to cache search results. This prevents extra SQL queries if you
3190 revisit rows in your ResultSet:
3192 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3194 while( my $artist = $resultset->next ) {
3198 $rs->first; # without cache, this would issue a query
3200 By default, searches are not cached.
3202 For more examples of using these attributes, see
3203 L<DBIx::Class::Manual::Cookbook>.
3209 =item Value: \@from_clause
3213 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3214 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3217 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3219 C<join> will usually do what you need and it is strongly recommended that you
3220 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3221 And we really do mean "cannot", not just tried and failed. Attempting to use
3222 this because you're having problems with C<join> is like trying to use x86
3223 ASM because you've got a syntax error in your C. Trust us on this.
3225 Now, if you're still really, really sure you need to use this (and if you're
3226 not 100% sure, ask the mailing list first), here's an explanation of how this
3229 The syntax is as follows -
3232 { <alias1> => <table1> },
3234 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3235 [], # nested JOIN (optional)
3236 { <table1.column1> => <table2.column2>, ... (more conditions) },
3238 # More of the above [ ] may follow for additional joins
3245 ON <table1.column1> = <table2.column2>
3246 <more joins may follow>
3248 An easy way to follow the examples below is to remember the following:
3250 Anything inside "[]" is a JOIN
3251 Anything inside "{}" is a condition for the enclosing JOIN
3253 The following examples utilize a "person" table in a family tree application.
3254 In order to express parent->child relationships, this table is self-joined:
3256 # Person->belongs_to('father' => 'Person');
3257 # Person->belongs_to('mother' => 'Person');
3259 C<from> can be used to nest joins. Here we return all children with a father,
3260 then search against all mothers of those children:
3262 $rs = $schema->resultset('Person')->search(
3265 alias => 'mother', # alias columns in accordance with "from"
3267 { mother => 'person' },
3270 { child => 'person' },
3272 { father => 'person' },
3273 { 'father.person_id' => 'child.father_id' }
3276 { 'mother.person_id' => 'child.mother_id' }
3283 # SELECT mother.* FROM person mother
3286 # JOIN person father
3287 # ON ( father.person_id = child.father_id )
3289 # ON ( mother.person_id = child.mother_id )
3291 The type of any join can be controlled manually. To search against only people
3292 with a father in the person table, we could explicitly use C<INNER JOIN>:
3294 $rs = $schema->resultset('Person')->search(
3297 alias => 'child', # alias columns in accordance with "from"
3299 { child => 'person' },
3301 { father => 'person', -join_type => 'inner' },
3302 { 'father.id' => 'child.father_id' }
3309 # SELECT child.* FROM person child
3310 # INNER JOIN person father ON child.father_id = father.id
3312 You can select from a subquery by passing a resultset to from as follows.
3314 $schema->resultset('Artist')->search(
3316 { alias => 'artist2',
3317 from => [ { artist2 => $artist_rs->as_query } ],
3320 # and you'll get sql like this..
3321 # SELECT artist2.artistid, artist2.name, artist2.rank, artist2.charfield FROM
3322 # ( SELECT me.artistid, me.name, me.rank, me.charfield FROM artists me ) artist2
3324 If you need to express really complex joins, you
3325 can supply literal SQL to C<from> via a scalar reference. In this case
3326 the contents of the scalar will replace the table name associated with the
3329 WARNING: This technique might very well not work as expected on chained
3330 searches - you have been warned.
3332 # Assuming the Event resultsource is defined as:
3334 MySchema::Event->add_columns (
3337 is_auto_increment => 1,
3346 MySchema::Event->set_primary_key ('sequence');
3348 # This will get back the latest event for every location. The column
3349 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3350 # combo to limit the resultset
3352 $rs = $schema->resultset('Event');
3353 $table = $rs->result_source->name;
3354 $latest = $rs->search (
3357 (SELECT e1.* FROM $table e1
3359 ON e1.location = e2.location
3360 AND e1.sequence < e2.sequence
3361 WHERE e2.sequence is NULL
3366 # Equivalent SQL (with the DBIC chunks added):
3368 SELECT me.sequence, me.location, me.type FROM
3369 (SELECT e1.* FROM events e1
3371 ON e1.location = e2.location
3372 AND e1.sequence < e2.sequence
3373 WHERE e2.sequence is NULL
3380 =item Value: ( 'update' | 'shared' )
3384 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT