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 a arrayref of the resulting row
1518 objects is returned.
1520 Example: Assuming an Artist Class that has many CDs Classes relating:
1522 my $Artist_rs = $schema->resultset("Artist");
1524 ## Void Context Example
1525 $Artist_rs->populate([
1526 { artistid => 4, name => 'Manufactured Crap', cds => [
1527 { title => 'My First CD', year => 2006 },
1528 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1531 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1532 { title => 'My parents sold me to a record company' ,year => 2005 },
1533 { title => 'Why Am I So Ugly?', year => 2006 },
1534 { title => 'I Got Surgery and am now Popular', year => 2007 }
1539 ## Array Context Example
1540 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1541 { name => "Artist One"},
1542 { name => "Artist Two"},
1543 { name => "Artist Three", cds=> [
1544 { title => "First CD", year => 2007},
1545 { title => "Second CD", year => 2008},
1549 print $ArtistOne->name; ## response is 'Artist One'
1550 print $ArtistThree->cds->count ## reponse is '2'
1552 For the arrayref of arrayrefs style, the first element should be a list of the
1553 fieldsnames to which the remaining elements are rows being inserted. For
1556 $Arstist_rs->populate([
1557 [qw/artistid name/],
1558 [100, 'A Formally Unknown Singer'],
1559 [101, 'A singer that jumped the shark two albums ago'],
1560 [102, 'An actually cool singer.'],
1563 Please note an important effect on your data when choosing between void and
1564 wantarray context. Since void context goes straight to C<insert_bulk> in
1565 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1566 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1567 create primary keys for you, you will find that your PKs are empty. In this
1568 case you will have to use the wantarray context in order to create those
1574 my $self = shift @_;
1575 my $data = ref $_[0][0] eq 'HASH'
1576 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1577 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1579 if(defined wantarray) {
1581 foreach my $item (@$data) {
1582 push(@created, $self->create($item));
1586 my ($first, @rest) = @$data;
1588 my @names = grep {!ref $first->{$_}} keys %$first;
1589 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1590 my @pks = $self->result_source->primary_columns;
1592 ## do the belongs_to relationships
1593 foreach my $index (0..$#$data) {
1595 # delegate to create() for any dataset without primary keys with specified relationships
1596 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1598 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1599 my @ret = $self->populate($data);
1605 foreach my $rel (@rels) {
1606 next unless ref $data->[$index]->{$rel} eq "HASH";
1607 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1608 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1609 my $related = $result->result_source->_resolve_condition(
1610 $result->result_source->relationship_info($reverse)->{cond},
1615 delete $data->[$index]->{$rel};
1616 $data->[$index] = {%{$data->[$index]}, %$related};
1618 push @names, keys %$related if $index == 0;
1622 ## do bulk insert on current row
1623 my @values = map { [ @$_{@names} ] } @$data;
1625 $self->result_source->storage->insert_bulk(
1626 $self->result_source,
1631 ## do the has_many relationships
1632 foreach my $item (@$data) {
1634 foreach my $rel (@rels) {
1635 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1637 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1638 || $self->throw_exception('Cannot find the relating object.');
1640 my $child = $parent->$rel;
1642 my $related = $child->result_source->_resolve_condition(
1643 $parent->result_source->relationship_info($rel)->{cond},
1648 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1649 my @populate = map { {%$_, %$related} } @rows_to_add;
1651 $child->populate( \@populate );
1657 =head2 _normalize_populate_args ($args)
1659 Private method used by L</populate> to normalize its incoming arguments. Factored
1660 out in case you want to subclass and accept new argument structures to the
1661 L</populate> method.
1665 sub _normalize_populate_args {
1666 my ($self, $data) = @_;
1667 my @names = @{shift(@$data)};
1668 my @results_to_create;
1669 foreach my $datum (@$data) {
1670 my %result_to_create;
1671 foreach my $index (0..$#names) {
1672 $result_to_create{$names[$index]} = $$datum[$index];
1674 push @results_to_create, \%result_to_create;
1676 return \@results_to_create;
1683 =item Arguments: none
1685 =item Return Value: $pager
1689 Return Value a L<Data::Page> object for the current resultset. Only makes
1690 sense for queries with a C<page> attribute.
1692 To get the full count of entries for a paged resultset, call
1693 C<total_entries> on the L<Data::Page> object.
1700 return $self->{pager} if $self->{pager};
1702 my $attrs = $self->{attrs};
1703 $self->throw_exception("Can't create pager for non-paged rs")
1704 unless $self->{attrs}{page};
1705 $attrs->{rows} ||= 10;
1707 # throw away the paging flags and re-run the count (possibly
1708 # with a subselect) to get the real total count
1709 my $count_attrs = { %$attrs };
1710 delete $count_attrs->{$_} for qw/rows offset page pager/;
1711 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1713 return $self->{pager} = Data::Page->new(
1716 $self->{attrs}{page}
1724 =item Arguments: $page_number
1726 =item Return Value: $rs
1730 Returns a resultset for the $page_number page of the resultset on which page
1731 is called, where each page contains a number of rows equal to the 'rows'
1732 attribute set on the resultset (10 by default).
1737 my ($self, $page) = @_;
1738 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1745 =item Arguments: \%vals
1747 =item Return Value: $rowobject
1751 Creates a new row object in the resultset's result class and returns
1752 it. The row is not inserted into the database at this point, call
1753 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1754 will tell you whether the row object has been inserted or not.
1756 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1761 my ($self, $values) = @_;
1762 $self->throw_exception( "new_result needs a hash" )
1763 unless (ref $values eq 'HASH');
1766 my $alias = $self->{attrs}{alias};
1769 defined $self->{cond}
1770 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1772 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1773 $new{-from_resultset} = [ keys %new ] if keys %new;
1775 $self->throw_exception(
1776 "Can't abstract implicit construct, condition not a hash"
1777 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1779 my $collapsed_cond = (
1781 ? $self->_collapse_cond($self->{cond})
1785 # precendence must be given to passed values over values inherited from
1786 # the cond, so the order here is important.
1787 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1788 while( my($col,$value) = each %implied ){
1789 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1790 $new{$col} = $value->{'='};
1793 $new{$col} = $value if $self->_is_deterministic_value($value);
1799 %{ $self->_remove_alias($values, $alias) },
1800 -source_handle => $self->_source_handle,
1801 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1804 return $self->result_class->new(\%new);
1807 # _is_deterministic_value
1809 # Make an effor to strip non-deterministic values from the condition,
1810 # to make sure new_result chokes less
1812 sub _is_deterministic_value {
1815 my $ref_type = ref $value;
1816 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1817 return 1 if Scalar::Util::blessed($value);
1821 # _has_resolved_attr
1823 # determines if the resultset defines at least one
1824 # of the attributes supplied
1826 # used to determine if a subquery is neccessary
1828 sub _has_resolved_attr {
1829 my ($self, @attr_names) = @_;
1831 my $attrs = $self->_resolved_attrs;
1835 for my $n (@attr_names) {
1836 ++$join_check_req if $n eq '-join';
1838 my $attr = $attrs->{$n};
1840 next if not defined $attr;
1842 if (ref $attr eq 'HASH') {
1843 return 1 if keys %$attr;
1845 elsif (ref $attr eq 'ARRAY') {
1853 # a resolved join is expressed as a multi-level from
1857 ref $attrs->{from} eq 'ARRAY'
1859 @{$attrs->{from}} > 1
1867 # Recursively collapse the condition.
1869 sub _collapse_cond {
1870 my ($self, $cond, $collapsed) = @_;
1874 if (ref $cond eq 'ARRAY') {
1875 foreach my $subcond (@$cond) {
1876 next unless ref $subcond; # -or
1877 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1880 elsif (ref $cond eq 'HASH') {
1881 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1882 foreach my $subcond (@{$cond->{-and}}) {
1883 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1887 foreach my $col (keys %$cond) {
1888 my $value = $cond->{$col};
1889 $collapsed->{$col} = $value;
1899 # Remove the specified alias from the specified query hash. A copy is made so
1900 # the original query is not modified.
1903 my ($self, $query, $alias) = @_;
1905 my %orig = %{ $query || {} };
1908 foreach my $key (keys %orig) {
1910 $unaliased{$key} = $orig{$key};
1913 $unaliased{$1} = $orig{$key}
1914 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1920 =head2 as_query (EXPERIMENTAL)
1924 =item Arguments: none
1926 =item Return Value: \[ $sql, @bind ]
1930 Returns the SQL query and bind vars associated with the invocant.
1932 This is generally used as the RHS for a subquery.
1934 B<NOTE>: This feature is still experimental.
1941 my $attrs = $self->_resolved_attrs_copy;
1946 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
1947 # $sql also has no wrapping parenthesis in list ctx
1949 my $sqlbind = $self->result_source->storage
1950 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
1959 =item Arguments: \%vals, \%attrs?
1961 =item Return Value: $rowobject
1965 my $artist = $schema->resultset('Artist')->find_or_new(
1966 { artist => 'fred' }, { key => 'artists' });
1968 $cd->cd_to_producer->find_or_new({ producer => $producer },
1969 { key => 'primary });
1971 Find an existing record from this resultset, based on its primary
1972 key, or a unique constraint. If none exists, instantiate a new result
1973 object and return it. The object will not be saved into your storage
1974 until you call L<DBIx::Class::Row/insert> on it.
1976 You most likely want this method when looking for existing rows using
1977 a unique constraint that is not the primary key, or looking for
1980 If you want objects to be saved immediately, use L</find_or_create> instead.
1982 B<Note>: C<find_or_new> is probably not what you want when creating a
1983 new row in a table that uses primary keys supplied by the
1984 database. Passing in a primary key column with a value of I<undef>
1985 will cause L</find> to attempt to search for a row with a value of
1992 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1993 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1994 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
1997 return $self->new_result($hash);
2004 =item Arguments: \%vals
2006 =item Return Value: a L<DBIx::Class::Row> $object
2010 Attempt to create a single new row or a row with multiple related rows
2011 in the table represented by the resultset (and related tables). This
2012 will not check for duplicate rows before inserting, use
2013 L</find_or_create> to do that.
2015 To create one row for this resultset, pass a hashref of key/value
2016 pairs representing the columns of the table and the values you wish to
2017 store. If the appropriate relationships are set up, foreign key fields
2018 can also be passed an object representing the foreign row, and the
2019 value will be set to its primary key.
2021 To create related objects, pass a hashref for the value if the related
2022 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2023 and use the name of the relationship as the key. (NOT the name of the field,
2024 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2025 of hashrefs containing the data for each of the rows to create in the foreign
2026 tables, again using the relationship name as the key.
2028 Instead of hashrefs of plain related data (key/value pairs), you may
2029 also pass new or inserted objects. New objects (not inserted yet, see
2030 L</new>), will be inserted into their appropriate tables.
2032 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2034 Example of creating a new row.
2036 $person_rs->create({
2037 name=>"Some Person",
2038 email=>"somebody@someplace.com"
2041 Example of creating a new row and also creating rows in a related C<has_many>
2042 or C<has_one> resultset. Note Arrayref.
2045 { artistid => 4, name => 'Manufactured Crap', cds => [
2046 { title => 'My First CD', year => 2006 },
2047 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2052 Example of creating a new row and also creating a row in a related
2053 C<belongs_to>resultset. Note Hashref.
2056 title=>"Music for Silly Walks",
2059 name=>"Silly Musician",
2066 my ($self, $attrs) = @_;
2067 $self->throw_exception( "create needs a hashref" )
2068 unless ref $attrs eq 'HASH';
2069 return $self->new_result($attrs)->insert;
2072 =head2 find_or_create
2076 =item Arguments: \%vals, \%attrs?
2078 =item Return Value: $rowobject
2082 $cd->cd_to_producer->find_or_create({ producer => $producer },
2083 { key => 'primary });
2085 Tries to find a record based on its primary key or unique constraints; if none
2086 is found, creates one and returns that instead.
2088 my $cd = $schema->resultset('CD')->find_or_create({
2090 artist => 'Massive Attack',
2091 title => 'Mezzanine',
2095 Also takes an optional C<key> attribute, to search by a specific key or unique
2096 constraint. For example:
2098 my $cd = $schema->resultset('CD')->find_or_create(
2100 artist => 'Massive Attack',
2101 title => 'Mezzanine',
2103 { key => 'cd_artist_title' }
2106 B<Note>: Because find_or_create() reads from the database and then
2107 possibly inserts based on the result, this method is subject to a race
2108 condition. Another process could create a record in the table after
2109 the find has completed and before the create has started. To avoid
2110 this problem, use find_or_create() inside a transaction.
2112 B<Note>: C<find_or_create> is probably not what you want when creating
2113 a new row in a table that uses primary keys supplied by the
2114 database. Passing in a primary key column with a value of I<undef>
2115 will cause L</find> to attempt to search for a row with a value of
2118 See also L</find> and L</update_or_create>. For information on how to declare
2119 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2123 sub find_or_create {
2125 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2126 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2127 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2130 return $self->create($hash);
2133 =head2 update_or_create
2137 =item Arguments: \%col_values, { key => $unique_constraint }?
2139 =item Return Value: $rowobject
2143 $resultset->update_or_create({ col => $val, ... });
2145 First, searches for an existing row matching one of the unique constraints
2146 (including the primary key) on the source of this resultset. If a row is
2147 found, updates it with the other given column values. Otherwise, creates a new
2150 Takes an optional C<key> attribute to search on a specific unique constraint.
2153 # In your application
2154 my $cd = $schema->resultset('CD')->update_or_create(
2156 artist => 'Massive Attack',
2157 title => 'Mezzanine',
2160 { key => 'cd_artist_title' }
2163 $cd->cd_to_producer->update_or_create({
2164 producer => $producer,
2171 If no C<key> is specified, it searches on all unique constraints defined on the
2172 source, including the primary key.
2174 If the C<key> is specified as C<primary>, it searches only on the primary key.
2176 See also L</find> and L</find_or_create>. For information on how to declare
2177 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2179 B<Note>: C<update_or_create> is probably not what you want when
2180 looking for a row in a table that uses primary keys supplied by the
2181 database, unless you actually have a key value. Passing in a primary
2182 key column with a value of I<undef> will cause L</find> to attempt to
2183 search for a row with a value of I<NULL>.
2187 sub update_or_create {
2189 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2190 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2192 my $row = $self->find($cond, $attrs);
2194 $row->update($cond);
2198 return $self->create($cond);
2201 =head2 update_or_new
2205 =item Arguments: \%col_values, { key => $unique_constraint }?
2207 =item Return Value: $rowobject
2211 $resultset->update_or_new({ col => $val, ... });
2213 First, searches for an existing row matching one of the unique constraints
2214 (including the primary key) on the source of this resultset. If a row is
2215 found, updates it with the other given column values. Otherwise, instantiate
2216 a new result object and return it. The object will not be saved into your storage
2217 until you call L<DBIx::Class::Row/insert> on it.
2219 Takes an optional C<key> attribute to search on a specific unique constraint.
2222 # In your application
2223 my $cd = $schema->resultset('CD')->update_or_new(
2225 artist => 'Massive Attack',
2226 title => 'Mezzanine',
2229 { key => 'cd_artist_title' }
2232 if ($cd->in_storage) {
2233 # the cd was updated
2236 # the cd is not yet in the database, let's insert it
2240 See also L</find>, L</find_or_create> and L<find_or_new>.
2246 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2247 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2249 my $row = $self->find( $cond, $attrs );
2250 if ( defined $row ) {
2251 $row->update($cond);
2255 return $self->new_result($cond);
2262 =item Arguments: none
2264 =item Return Value: \@cache_objects?
2268 Gets the contents of the cache for the resultset, if the cache is set.
2270 The cache is populated either by using the L</prefetch> attribute to
2271 L</search> or by calling L</set_cache>.
2283 =item Arguments: \@cache_objects
2285 =item Return Value: \@cache_objects
2289 Sets the contents of the cache for the resultset. Expects an arrayref
2290 of objects of the same class as those produced by the resultset. Note that
2291 if the cache is set the resultset will return the cached objects rather
2292 than re-querying the database even if the cache attr is not set.
2294 The contents of the cache can also be populated by using the
2295 L</prefetch> attribute to L</search>.
2300 my ( $self, $data ) = @_;
2301 $self->throw_exception("set_cache requires an arrayref")
2302 if defined($data) && (ref $data ne 'ARRAY');
2303 $self->{all_cache} = $data;
2310 =item Arguments: none
2312 =item Return Value: []
2316 Clears the cache for the resultset.
2321 shift->set_cache(undef);
2324 =head2 related_resultset
2328 =item Arguments: $relationship_name
2330 =item Return Value: $resultset
2334 Returns a related resultset for the supplied relationship name.
2336 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2340 sub related_resultset {
2341 my ($self, $rel) = @_;
2343 $self->{related_resultsets} ||= {};
2344 return $self->{related_resultsets}{$rel} ||= do {
2345 my $rel_obj = $self->result_source->relationship_info($rel);
2347 $self->throw_exception(
2348 "search_related: result source '" . $self->result_source->source_name .
2349 "' has no such relationship $rel")
2352 my ($from,$seen) = $self->_resolve_from($rel);
2354 my $join_count = $seen->{$rel};
2355 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2357 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2358 my %attrs = %{$self->{attrs}||{}};
2359 delete @attrs{qw(result_class alias)};
2363 if (my $cache = $self->get_cache) {
2364 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2365 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2370 my $rel_source = $self->result_source->related_source($rel);
2374 # The reason we do this now instead of passing the alias to the
2375 # search_rs below is that if you wrap/overload resultset on the
2376 # source you need to know what alias it's -going- to have for things
2377 # to work sanely (e.g. RestrictWithObject wants to be able to add
2378 # extra query restrictions, and these may need to be $alias.)
2380 my $attrs = $rel_source->resultset_attributes;
2381 local $attrs->{alias} = $alias;
2383 $rel_source->resultset
2391 where => $self->{cond},
2396 $new->set_cache($new_cache) if $new_cache;
2401 =head2 current_source_alias
2405 =item Arguments: none
2407 =item Return Value: $source_alias
2411 Returns the current table alias for the result source this resultset is built
2412 on, that will be used in the SQL query. Usually it is C<me>.
2414 Currently the source alias that refers to the result set returned by a
2415 L</search>/L</find> family method depends on how you got to the resultset: it's
2416 C<me> by default, but eg. L</search_related> aliases it to the related result
2417 source name (and keeps C<me> referring to the original result set). The long
2418 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2419 (and make this method unnecessary).
2421 Thus it's currently necessary to use this method in predefined queries (see
2422 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2423 source alias of the current result set:
2425 # in a result set class
2427 my ($self, $user) = @_;
2429 my $me = $self->current_source_alias;
2431 return $self->search(
2432 "$me.modified" => $user->id,
2438 sub current_source_alias {
2441 return ($self->{attrs} || {})->{alias} || 'me';
2444 # This code is called by search_related, and makes sure there
2445 # is clear separation between the joins before, during, and
2446 # after the relationship. This information is needed later
2447 # in order to properly resolve prefetch aliases (any alias
2448 # with a relation_chain_depth less than the depth of the
2449 # current prefetch is not considered)
2451 my ($self, $extra_join) = @_;
2452 my $source = $self->result_source;
2453 my $attrs = $self->{attrs};
2459 -source_handle => $source->handle,
2460 -alias => $attrs->{alias},
2461 $attrs->{alias} => $source->from,
2465 my $seen = { %{$attrs->{seen_join} || {} } };
2467 # we need to take the prefetch the attrs into account before we
2468 # ->_resolve_join as otherwise they get lost - captainL
2469 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2471 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2473 ++$seen->{-relation_chain_depth};
2475 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2477 ++$seen->{-relation_chain_depth};
2479 return ($from,$seen);
2482 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2483 sub _resolved_attrs_copy {
2485 return { %{$self->_resolved_attrs (@_)} };
2488 sub _resolved_attrs {
2490 return $self->{_attrs} if $self->{_attrs};
2492 my $attrs = { %{ $self->{attrs} || {} } };
2493 my $source = $self->result_source;
2494 my $alias = $attrs->{alias};
2496 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2499 # build columns (as long as select isn't set) into a set of as/select hashes
2500 unless ( $attrs->{select} ) {
2502 ( ref($_) eq 'HASH' )
2506 /^\Q${alias}.\E(.+)$/
2517 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2519 # add the additional columns on
2520 foreach ( 'include_columns', '+columns' ) {
2521 push @colbits, map {
2522 ( ref($_) eq 'HASH' )
2524 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2525 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2528 # start with initial select items
2529 if ( $attrs->{select} ) {
2531 ( ref $attrs->{select} eq 'ARRAY' )
2532 ? [ @{ $attrs->{select} } ]
2533 : [ $attrs->{select} ];
2537 ref $attrs->{as} eq 'ARRAY'
2538 ? [ @{ $attrs->{as} } ]
2541 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2546 # otherwise we intialise select & as to empty
2547 $attrs->{select} = [];
2551 # now add colbits to select/as
2552 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2553 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2556 if ( $adds = delete $attrs->{'+select'} ) {
2557 $adds = [$adds] unless ref $adds eq 'ARRAY';
2559 @{ $attrs->{select} },
2560 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2563 if ( $adds = delete $attrs->{'+as'} ) {
2564 $adds = [$adds] unless ref $adds eq 'ARRAY';
2565 push( @{ $attrs->{as} }, @$adds );
2568 $attrs->{from} ||= [ {
2569 -source_handle => $source->handle,
2570 -alias => $self->{attrs}{alias},
2571 $self->{attrs}{alias} => $source->from,
2574 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2575 my $join = delete $attrs->{join} || {};
2577 if ( defined $attrs->{prefetch} ) {
2578 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2582 $attrs->{from} = # have to copy here to avoid corrupting the original
2584 @{ $attrs->{from} },
2585 $source->_resolve_join(
2586 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2592 if ( $attrs->{order_by} ) {
2593 $attrs->{order_by} = (
2594 ref( $attrs->{order_by} ) eq 'ARRAY'
2595 ? [ @{ $attrs->{order_by} } ]
2596 : [ $attrs->{order_by} ]
2600 $attrs->{order_by} = [];
2603 # If the order_by is otherwise empty - we will use this for TOP limit
2604 # emulation and the like.
2605 # Although this is needed only if the order_by is not defined, it is
2606 # actually cheaper to just populate this rather than properly examining
2607 # order_by (stuf like [ {} ] and the like)
2608 my $prefix = $alias . ($source->schema->storage->_sql_maker_opts->{name_sep} || '.');
2609 $attrs->{_virtual_order_by} = [
2610 map { $prefix . $_ } ($source->primary_columns)
2613 $attrs->{collapse} ||= {};
2614 if ( my $prefetch = delete $attrs->{prefetch} ) {
2615 $prefetch = $self->_merge_attr( {}, $prefetch );
2617 my $prefetch_ordering = [];
2619 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2622 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
2624 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2625 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2627 push( @{ $attrs->{order_by} }, @$prefetch_ordering );
2628 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
2632 if (delete $attrs->{distinct}) {
2633 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2636 # if both page and offset are specified, produce a combined offset
2637 # even though it doesn't make much sense, this is what pre 081xx has
2639 if (my $page = delete $attrs->{page}) {
2640 $attrs->{offset} = ($attrs->{rows} * ($page - 1)) +
2641 ($attrs->{offset} || 0);
2644 return $self->{_attrs} = $attrs;
2647 sub _joinpath_aliases {
2648 my ($self, $fromspec, $seen) = @_;
2651 return $paths unless ref $fromspec eq 'ARRAY';
2653 for my $j (@$fromspec) {
2655 next if ref $j ne 'ARRAY';
2656 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2659 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2660 push @{$p->{-join_aliases} }, $j->[0]{-alias};
2667 my ($self, $attr) = @_;
2669 if (ref $attr eq 'HASH') {
2670 return $self->_rollout_hash($attr);
2671 } elsif (ref $attr eq 'ARRAY') {
2672 return $self->_rollout_array($attr);
2678 sub _rollout_array {
2679 my ($self, $attr) = @_;
2682 foreach my $element (@{$attr}) {
2683 if (ref $element eq 'HASH') {
2684 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2685 } elsif (ref $element eq 'ARRAY') {
2686 # XXX - should probably recurse here
2687 push( @rolled_array, @{$self->_rollout_array($element)} );
2689 push( @rolled_array, $element );
2692 return \@rolled_array;
2696 my ($self, $attr) = @_;
2699 foreach my $key (keys %{$attr}) {
2700 push( @rolled_array, { $key => $attr->{$key} } );
2702 return \@rolled_array;
2705 sub _calculate_score {
2706 my ($self, $a, $b) = @_;
2708 if (ref $b eq 'HASH') {
2709 my ($b_key) = keys %{$b};
2710 if (ref $a eq 'HASH') {
2711 my ($a_key) = keys %{$a};
2712 if ($a_key eq $b_key) {
2713 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2718 return ($a eq $b_key) ? 1 : 0;
2721 if (ref $a eq 'HASH') {
2722 my ($a_key) = keys %{$a};
2723 return ($b eq $a_key) ? 1 : 0;
2725 return ($b eq $a) ? 1 : 0;
2731 my ($self, $orig, $import) = @_;
2733 return $import unless defined($orig);
2734 return $orig unless defined($import);
2736 $orig = $self->_rollout_attr($orig);
2737 $import = $self->_rollout_attr($import);
2740 foreach my $import_element ( @{$import} ) {
2741 # find best candidate from $orig to merge $b_element into
2742 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2743 foreach my $orig_element ( @{$orig} ) {
2744 my $score = $self->_calculate_score( $orig_element, $import_element );
2745 if ($score > $best_candidate->{score}) {
2746 $best_candidate->{position} = $position;
2747 $best_candidate->{score} = $score;
2751 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2753 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2754 push( @{$orig}, $import_element );
2756 my $orig_best = $orig->[$best_candidate->{position}];
2757 # merge orig_best and b_element together and replace original with merged
2758 if (ref $orig_best ne 'HASH') {
2759 $orig->[$best_candidate->{position}] = $import_element;
2760 } elsif (ref $import_element eq 'HASH') {
2761 my ($key) = keys %{$orig_best};
2762 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2765 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2775 $self->_source_handle($_[0]->handle);
2777 $self->_source_handle->resolve;
2781 =head2 throw_exception
2783 See L<DBIx::Class::Schema/throw_exception> for details.
2787 sub throw_exception {
2789 if (ref $self && $self->_source_handle->schema) {
2790 $self->_source_handle->schema->throw_exception(@_)
2797 # XXX: FIXME: Attributes docs need clearing up
2801 Attributes are used to refine a ResultSet in various ways when
2802 searching for data. They can be passed to any method which takes an
2803 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2806 These are in no particular order:
2812 =item Value: ( $order_by | \@order_by | \%order_by )
2816 Which column(s) to order the results by. If a single column name, or
2817 an arrayref of names is supplied, the argument is passed through
2818 directly to SQL. The hashref syntax allows for connection-agnostic
2819 specification of ordering direction:
2821 For descending order:
2823 order_by => { -desc => [qw/col1 col2 col3/] }
2825 For explicit ascending order:
2827 order_by => { -asc => 'col' }
2829 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2830 supported, although you are strongly encouraged to use the hashref
2831 syntax as outlined above.
2837 =item Value: \@columns
2841 Shortcut to request a particular set of columns to be retrieved. Each
2842 column spec may be a string (a table column name), or a hash (in which
2843 case the key is the C<as> value, and the value is used as the C<select>
2844 expression). Adds C<me.> onto the start of any column without a C<.> in
2845 it and sets C<select> from that, then auto-populates C<as> from
2846 C<select> as normal. (You may also use the C<cols> attribute, as in
2847 earlier versions of DBIC.)
2853 =item Value: \@columns
2857 Indicates additional columns to be selected from storage. Works the same
2858 as L</columns> but adds columns to the selection. (You may also use the
2859 C<include_columns> attribute, as in earlier versions of DBIC). For
2862 $schema->resultset('CD')->search(undef, {
2863 '+columns' => ['artist.name'],
2867 would return all CDs and include a 'name' column to the information
2868 passed to object inflation. Note that the 'artist' is the name of the
2869 column (or relationship) accessor, and 'name' is the name of the column
2870 accessor in the related table.
2872 =head2 include_columns
2876 =item Value: \@columns
2880 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2886 =item Value: \@select_columns
2890 Indicates which columns should be selected from the storage. You can use
2891 column names, or in the case of RDBMS back ends, function or stored procedure
2894 $rs = $schema->resultset('Employee')->search(undef, {
2897 { count => 'employeeid' },
2902 When you use function/stored procedure names and do not supply an C<as>
2903 attribute, the column names returned are storage-dependent. E.g. MySQL would
2904 return a column named C<count(employeeid)> in the above example.
2910 Indicates additional columns to be selected from storage. Works the same as
2911 L</select> but adds columns to the selection.
2919 Indicates additional column names for those added via L</+select>. See L</as>.
2927 =item Value: \@inflation_names
2931 Indicates column names for object inflation. That is, C<as>
2932 indicates the name that the column can be accessed as via the
2933 C<get_column> method (or via the object accessor, B<if one already
2934 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2936 The C<as> attribute is used in conjunction with C<select>,
2937 usually when C<select> contains one or more function or stored
2940 $rs = $schema->resultset('Employee')->search(undef, {
2943 { count => 'employeeid' }
2945 as => ['name', 'employee_count'],
2948 my $employee = $rs->first(); # get the first Employee
2950 If the object against which the search is performed already has an accessor
2951 matching a column name specified in C<as>, the value can be retrieved using
2952 the accessor as normal:
2954 my $name = $employee->name();
2956 If on the other hand an accessor does not exist in the object, you need to
2957 use C<get_column> instead:
2959 my $employee_count = $employee->get_column('employee_count');
2961 You can create your own accessors if required - see
2962 L<DBIx::Class::Manual::Cookbook> for details.
2964 Please note: This will NOT insert an C<AS employee_count> into the SQL
2965 statement produced, it is used for internal access only. Thus
2966 attempting to use the accessor in an C<order_by> clause or similar
2967 will fail miserably.
2969 To get around this limitation, you can supply literal SQL to your
2970 C<select> attibute that contains the C<AS alias> text, eg:
2972 select => [\'myfield AS alias']
2978 =item Value: ($rel_name | \@rel_names | \%rel_names)
2982 Contains a list of relationships that should be joined for this query. For
2985 # Get CDs by Nine Inch Nails
2986 my $rs = $schema->resultset('CD')->search(
2987 { 'artist.name' => 'Nine Inch Nails' },
2988 { join => 'artist' }
2991 Can also contain a hash reference to refer to the other relation's relations.
2994 package MyApp::Schema::Track;
2995 use base qw/DBIx::Class/;
2996 __PACKAGE__->table('track');
2997 __PACKAGE__->add_columns(qw/trackid cd position title/);
2998 __PACKAGE__->set_primary_key('trackid');
2999 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3002 # In your application
3003 my $rs = $schema->resultset('Artist')->search(
3004 { 'track.title' => 'Teardrop' },
3006 join => { cd => 'track' },
3007 order_by => 'artist.name',
3011 You need to use the relationship (not the table) name in conditions,
3012 because they are aliased as such. The current table is aliased as "me", so
3013 you need to use me.column_name in order to avoid ambiguity. For example:
3015 # Get CDs from 1984 with a 'Foo' track
3016 my $rs = $schema->resultset('CD')->search(
3019 'tracks.name' => 'Foo'
3021 { join => 'tracks' }
3024 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3025 similarly for a third time). For e.g.
3027 my $rs = $schema->resultset('Artist')->search({
3028 'cds.title' => 'Down to Earth',
3029 'cds_2.title' => 'Popular',
3031 join => [ qw/cds cds/ ],
3034 will return a set of all artists that have both a cd with title 'Down
3035 to Earth' and a cd with title 'Popular'.
3037 If you want to fetch related objects from other tables as well, see C<prefetch>
3040 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3046 =item Value: ($rel_name | \@rel_names | \%rel_names)
3050 Contains one or more relationships that should be fetched along with
3051 the main query (when they are accessed afterwards the data will
3052 already be available, without extra queries to the database). This is
3053 useful for when you know you will need the related objects, because it
3054 saves at least one query:
3056 my $rs = $schema->resultset('Tag')->search(
3065 The initial search results in SQL like the following:
3067 SELECT tag.*, cd.*, artist.* FROM tag
3068 JOIN cd ON tag.cd = cd.cdid
3069 JOIN artist ON cd.artist = artist.artistid
3071 L<DBIx::Class> has no need to go back to the database when we access the
3072 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3075 Simple prefetches will be joined automatically, so there is no need
3076 for a C<join> attribute in the above search.
3078 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3079 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3080 with an accessor type of 'single' or 'filter'). A more complex example that
3081 prefetches an artists cds, the tracks on those cds, and the tags associted
3082 with that artist is given below (assuming many-to-many from artists to tags):
3084 my $rs = $schema->resultset('Artist')->search(
3088 { cds => 'tracks' },
3089 { artist_tags => 'tags' }
3095 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3096 attributes will be ignored.
3106 Makes the resultset paged and specifies the page to retrieve. Effectively
3107 identical to creating a non-pages resultset and then calling ->page($page)
3110 If L<rows> attribute is not specified it defualts to 10 rows per page.
3112 When you have a paged resultset, L</count> will only return the number
3113 of rows in the page. To get the total, use the L</pager> and call
3114 C<total_entries> on it.
3124 Specifes the maximum number of rows for direct retrieval or the number of
3125 rows per page if the page attribute or method is used.
3131 =item Value: $offset
3135 Specifies the (zero-based) row number for the first row to be returned, or the
3136 of the first row of the first page if paging is used.
3142 =item Value: \@columns
3146 A arrayref of columns to group by. Can include columns of joined tables.
3148 group_by => [qw/ column1 column2 ... /]
3154 =item Value: $condition
3158 HAVING is a select statement attribute that is applied between GROUP BY and
3159 ORDER BY. It is applied to the after the grouping calculations have been
3162 having => { 'count(employee)' => { '>=', 100 } }
3168 =item Value: (0 | 1)
3172 Set to 1 to group by all columns.
3178 Adds to the WHERE clause.
3180 # only return rows WHERE deleted IS NULL for all searches
3181 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3183 Can be overridden by passing C<{ where => undef }> as an attribute
3190 Set to 1 to cache search results. This prevents extra SQL queries if you
3191 revisit rows in your ResultSet:
3193 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3195 while( my $artist = $resultset->next ) {
3199 $rs->first; # without cache, this would issue a query
3201 By default, searches are not cached.
3203 For more examples of using these attributes, see
3204 L<DBIx::Class::Manual::Cookbook>.
3210 =item Value: \@from_clause
3214 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3215 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3218 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3220 C<join> will usually do what you need and it is strongly recommended that you
3221 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3222 And we really do mean "cannot", not just tried and failed. Attempting to use
3223 this because you're having problems with C<join> is like trying to use x86
3224 ASM because you've got a syntax error in your C. Trust us on this.
3226 Now, if you're still really, really sure you need to use this (and if you're
3227 not 100% sure, ask the mailing list first), here's an explanation of how this
3230 The syntax is as follows -
3233 { <alias1> => <table1> },
3235 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3236 [], # nested JOIN (optional)
3237 { <table1.column1> => <table2.column2>, ... (more conditions) },
3239 # More of the above [ ] may follow for additional joins
3246 ON <table1.column1> = <table2.column2>
3247 <more joins may follow>
3249 An easy way to follow the examples below is to remember the following:
3251 Anything inside "[]" is a JOIN
3252 Anything inside "{}" is a condition for the enclosing JOIN
3254 The following examples utilize a "person" table in a family tree application.
3255 In order to express parent->child relationships, this table is self-joined:
3257 # Person->belongs_to('father' => 'Person');
3258 # Person->belongs_to('mother' => 'Person');
3260 C<from> can be used to nest joins. Here we return all children with a father,
3261 then search against all mothers of those children:
3263 $rs = $schema->resultset('Person')->search(
3266 alias => 'mother', # alias columns in accordance with "from"
3268 { mother => 'person' },
3271 { child => 'person' },
3273 { father => 'person' },
3274 { 'father.person_id' => 'child.father_id' }
3277 { 'mother.person_id' => 'child.mother_id' }
3284 # SELECT mother.* FROM person mother
3287 # JOIN person father
3288 # ON ( father.person_id = child.father_id )
3290 # ON ( mother.person_id = child.mother_id )
3292 The type of any join can be controlled manually. To search against only people
3293 with a father in the person table, we could explicitly use C<INNER JOIN>:
3295 $rs = $schema->resultset('Person')->search(
3298 alias => 'child', # alias columns in accordance with "from"
3300 { child => 'person' },
3302 { father => 'person', -join_type => 'inner' },
3303 { 'father.id' => 'child.father_id' }
3310 # SELECT child.* FROM person child
3311 # INNER JOIN person father ON child.father_id = father.id
3313 You can select from a subquery by passing a resultset to from as follows.
3315 $schema->resultset('Artist')->search(
3317 { alias => 'artist2',
3318 from => [ { artist2 => $artist_rs->as_query } ],
3321 # and you'll get sql like this..
3322 # SELECT artist2.artistid, artist2.name, artist2.rank, artist2.charfield FROM
3323 # ( SELECT me.artistid, me.name, me.rank, me.charfield FROM artists me ) artist2
3325 If you need to express really complex joins, you
3326 can supply literal SQL to C<from> via a scalar reference. In this case
3327 the contents of the scalar will replace the table name associated with the
3330 WARNING: This technique might very well not work as expected on chained
3331 searches - you have been warned.
3333 # Assuming the Event resultsource is defined as:
3335 MySchema::Event->add_columns (
3338 is_auto_increment => 1,
3347 MySchema::Event->set_primary_key ('sequence');
3349 # This will get back the latest event for every location. The column
3350 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3351 # combo to limit the resultset
3353 $rs = $schema->resultset('Event');
3354 $table = $rs->result_source->name;
3355 $latest = $rs->search (
3358 (SELECT e1.* FROM $table e1
3360 ON e1.location = e2.location
3361 AND e1.sequence < e2.sequence
3362 WHERE e2.sequence is NULL
3367 # Equivalent SQL (with the DBIC chunks added):
3369 SELECT me.sequence, me.location, me.type FROM
3370 (SELECT e1.* FROM events e1
3372 ON e1.location = e2.location
3373 AND e1.sequence < e2.sequence
3374 WHERE e2.sequence is NULL
3381 =item Value: ( 'update' | 'shared' )
3385 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT