1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
50 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
53 The query that the ResultSet represents is B<only> executed against
54 the database when these methods are called:
55 L</find> L</next> L</all> L</first> L</single> L</count>
59 =head2 Chaining resultsets
61 Let's say you've got a query that needs to be run to return some data
62 to the user. But, you have an authorization system in place that
63 prevents certain users from seeing certain information. So, you want
64 to construct the basic query in one method, but add constraints to it in
69 my $request = $self->get_request; # Get a request object somehow.
70 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
72 my $cd_rs = $schema->resultset('CD')->search({
73 title => $request->param('title'),
74 year => $request->param('year'),
77 $self->apply_security_policy( $cd_rs );
82 sub apply_security_policy {
91 =head3 Resolving conditions and attributes
93 When a resultset is chained from another resultset, conditions and
94 attributes with the same keys need resolving.
96 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
97 into the existing ones from the original resultset.
99 The L</where>, L</having> attribute, and any search conditions are
100 merged with an SQL C<AND> to the existing condition from the original
103 All other attributes are overridden by any new ones supplied in the
106 =head2 Multiple queries
108 Since a resultset just defines a query, you can do all sorts of
109 things with it with the same object.
111 # Don't hit the DB yet.
112 my $cd_rs = $schema->resultset('CD')->search({
113 title => 'something',
117 # Each of these hits the DB individually.
118 my $count = $cd_rs->count;
119 my $most_recent = $cd_rs->get_column('date_released')->max();
120 my @records = $cd_rs->all;
122 And it's not just limited to SELECT statements.
128 $cd_rs->create({ artist => 'Fred' });
130 Which is the same as:
132 $schema->resultset('CD')->create({
133 title => 'something',
138 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
142 If a resultset is used in a numeric context it returns the L</count>.
143 However, if it is used in a booleand context it is always true. So if
144 you want to check if a resultset has any results use C<if $rs != 0>.
145 C<if $rs> will always be true.
153 =item Arguments: $source, \%$attrs
155 =item Return Value: $rs
159 The resultset constructor. Takes a source object (usually a
160 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
161 L</ATTRIBUTES> below). Does not perform any queries -- these are
162 executed as needed by the other methods.
164 Generally you won't need to construct a resultset manually. You'll
165 automatically get one from e.g. a L</search> called in scalar context:
167 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
169 IMPORTANT: If called on an object, proxies to new_result instead so
171 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
173 will return a CD object, not a ResultSet.
179 return $class->new_result(@_) if ref $class;
181 my ($source, $attrs) = @_;
182 $source = $source->handle
183 unless $source->isa('DBIx::Class::ResultSourceHandle');
184 $attrs = { %{$attrs||{}} };
186 if ($attrs->{page}) {
187 $attrs->{rows} ||= 10;
190 $attrs->{alias} ||= 'me';
192 # Creation of {} and bless separated to mitigate RH perl bug
193 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
195 _source_handle => $source,
196 cond => $attrs->{where},
205 $attrs->{result_class} || $source->resolve->result_class
215 =item Arguments: $cond, \%attrs?
217 =item Return Value: $resultset (scalar context), @row_objs (list context)
221 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
222 my $new_rs = $cd_rs->search({ year => 2005 });
224 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
225 # year = 2005 OR year = 2004
227 If you need to pass in additional attributes but no additional condition,
228 call it as C<search(undef, \%attrs)>.
230 # "SELECT name, artistid FROM $artist_table"
231 my @all_artists = $schema->resultset('Artist')->search(undef, {
232 columns => [qw/name artistid/],
235 For a list of attributes that can be passed to C<search>, see
236 L</ATTRIBUTES>. For more examples of using this function, see
237 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
238 documentation for the first argument, see L<SQL::Abstract>.
240 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
246 my $rs = $self->search_rs( @_ );
247 return (wantarray ? $rs->all : $rs);
254 =item Arguments: $cond, \%attrs?
256 =item Return Value: $resultset
260 This method does the same exact thing as search() except it will
261 always return a resultset, even in list context.
268 # Special-case handling for (undef, undef).
269 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
274 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
275 my $our_attrs = { %{$self->{attrs}} };
276 my $having = delete $our_attrs->{having};
277 my $where = delete $our_attrs->{where};
281 my %safe = (alias => 1, cache => 1);
284 (@_ && defined($_[0])) # @_ == () or (undef)
286 (keys %$attrs # empty attrs or only 'safe' attrs
287 && List::Util::first { !$safe{$_} } keys %$attrs)
289 # no search, effectively just a clone
290 $rows = $self->get_cache;
293 my $new_attrs = { %{$our_attrs}, %{$attrs} };
295 # merge new attrs into inherited
296 foreach my $key (qw/join prefetch +select +as bind/) {
297 next unless exists $attrs->{$key};
298 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
303 (@_ == 1 || ref $_[0] eq "HASH")
305 (ref $_[0] eq 'HASH')
307 (keys %{ $_[0] } > 0)
315 ? $self->throw_exception("Odd number of arguments to search")
322 if (defined $where) {
323 $new_attrs->{where} = (
324 defined $new_attrs->{where}
327 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
328 } $where, $new_attrs->{where}
335 $new_attrs->{where} = (
336 defined $new_attrs->{where}
339 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
340 } $cond, $new_attrs->{where}
346 if (defined $having) {
347 $new_attrs->{having} = (
348 defined $new_attrs->{having}
351 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
352 } $having, $new_attrs->{having}
358 my $rs = (ref $self)->new($self->result_source, $new_attrs);
360 $rs->set_cache($rows);
365 =head2 search_literal
369 =item Arguments: $sql_fragment, @bind_values
371 =item Return Value: $resultset (scalar context), @row_objs (list context)
375 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
376 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
378 Pass a literal chunk of SQL to be added to the conditional part of the
381 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
382 only be used in that context. C<search_literal> is a convenience method.
383 It is equivalent to calling $schema->search(\[]), but if you want to ensure
384 columns are bound correctly, use C<search>.
386 Example of how to use C<search> instead of C<search_literal>
388 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
389 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
392 See L<DBIx::Class::Manual::Cookbook/Searching> and
393 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
394 require C<search_literal>.
399 my ($self, $sql, @bind) = @_;
401 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
404 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
411 =item Arguments: @values | \%cols, \%attrs?
413 =item Return Value: $row_object | undef
417 Finds a row based on its primary key or unique constraint. For example, to find
418 a row by its primary key:
420 my $cd = $schema->resultset('CD')->find(5);
422 You can also find a row by a specific unique constraint using the C<key>
423 attribute. For example:
425 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
426 key => 'cd_artist_title'
429 Additionally, you can specify the columns explicitly by name:
431 my $cd = $schema->resultset('CD')->find(
433 artist => 'Massive Attack',
434 title => 'Mezzanine',
436 { key => 'cd_artist_title' }
439 If the C<key> is specified as C<primary>, it searches only on the primary key.
441 If no C<key> is specified, it searches on all unique constraints defined on the
442 source for which column data is provided, including the primary key.
444 If your table does not have a primary key, you B<must> provide a value for the
445 C<key> attribute matching one of the unique constraints on the source.
447 In addition to C<key>, L</find> recognizes and applies standard
448 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
450 Note: If your query does not return only one row, a warning is generated:
452 Query returned more than one row
454 See also L</find_or_create> and L</update_or_create>. For information on how to
455 declare unique constraints, see
456 L<DBIx::Class::ResultSource/add_unique_constraint>.
462 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
464 # Default to the primary key, but allow a specific key
465 my @cols = exists $attrs->{key}
466 ? $self->result_source->unique_constraint_columns($attrs->{key})
467 : $self->result_source->primary_columns;
468 $self->throw_exception(
469 "Can't find unless a primary key is defined or unique constraint is specified"
472 # Parse out a hashref from input
474 if (ref $_[0] eq 'HASH') {
475 $input_query = { %{$_[0]} };
477 elsif (@_ == @cols) {
479 @{$input_query}{@cols} = @_;
482 # Compatibility: Allow e.g. find(id => $value)
483 carp "Find by key => value deprecated; please use a hashref instead";
487 my (%related, $info);
489 KEY: foreach my $key (keys %$input_query) {
490 if (ref($input_query->{$key})
491 && ($info = $self->result_source->relationship_info($key))) {
492 my $val = delete $input_query->{$key};
493 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
494 my $rel_q = $self->result_source->_resolve_condition(
495 $info->{cond}, $val, $key
497 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
498 @related{keys %$rel_q} = values %$rel_q;
501 if (my @keys = keys %related) {
502 @{$input_query}{@keys} = values %related;
506 # Build the final query: Default to the disjunction of the unique queries,
507 # but allow the input query in case the ResultSet defines the query or the
508 # user is abusing find
509 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
511 if (exists $attrs->{key}) {
512 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
513 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
514 $query = $self->_add_alias($unique_query, $alias);
517 my @unique_queries = $self->_unique_queries($input_query, $attrs);
518 $query = @unique_queries
519 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
520 : $self->_add_alias($input_query, $alias);
525 my $rs = $self->search($query, $attrs);
526 if (keys %{$rs->_resolved_attrs->{collapse}}) {
528 carp "Query returned more than one row" if $rs->next;
536 if (keys %{$self->_resolved_attrs->{collapse}}) {
537 my $rs = $self->search($query);
539 carp "Query returned more than one row" if $rs->next;
543 return $self->single($query);
550 # Add the specified alias to the specified query hash. A copy is made so the
551 # original query is not modified.
554 my ($self, $query, $alias) = @_;
556 my %aliased = %$query;
557 foreach my $col (grep { ! m/\./ } keys %aliased) {
558 $aliased{"$alias.$col"} = delete $aliased{$col};
566 # Build a list of queries which satisfy unique constraints.
568 sub _unique_queries {
569 my ($self, $query, $attrs) = @_;
571 my @constraint_names = exists $attrs->{key}
573 : $self->result_source->unique_constraint_names;
575 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
576 my $num_where = scalar keys %$where;
579 foreach my $name (@constraint_names) {
580 my @unique_cols = $self->result_source->unique_constraint_columns($name);
581 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
583 my $num_cols = scalar @unique_cols;
584 my $num_query = scalar keys %$unique_query;
586 my $total = $num_query + $num_where;
587 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
588 # The query is either unique on its own or is unique in combination with
589 # the existing where clause
590 push @unique_queries, $unique_query;
594 return @unique_queries;
597 # _build_unique_query
599 # Constrain the specified query hash based on the specified column names.
601 sub _build_unique_query {
602 my ($self, $query, $unique_cols) = @_;
605 map { $_ => $query->{$_} }
606 grep { exists $query->{$_} }
611 =head2 search_related
615 =item Arguments: $rel, $cond, \%attrs?
617 =item Return Value: $new_resultset
621 $new_rs = $cd_rs->search_related('artist', {
625 Searches the specified relationship, optionally specifying a condition and
626 attributes for matching records. See L</ATTRIBUTES> for more information.
631 return shift->related_resultset(shift)->search(@_);
634 =head2 search_related_rs
636 This method works exactly the same as search_related, except that
637 it guarantees a restultset, even in list context.
641 sub search_related_rs {
642 return shift->related_resultset(shift)->search_rs(@_);
649 =item Arguments: none
651 =item Return Value: $cursor
655 Returns a storage-driven cursor to the given resultset. See
656 L<DBIx::Class::Cursor> for more information.
663 my $attrs = $self->_resolved_attrs_copy;
664 $attrs->{_virtual_order_by} = $self->_gen_virtual_order;
666 return $self->{cursor}
667 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
668 $attrs->{where},$attrs);
675 =item Arguments: $cond?
677 =item Return Value: $row_object?
681 my $cd = $schema->resultset('CD')->single({ year => 2001 });
683 Inflates the first result without creating a cursor if the resultset has
684 any records in it; if not returns nothing. Used by L</find> as a lean version of
687 While this method can take an optional search condition (just like L</search>)
688 being a fast-code-path it does not recognize search attributes. If you need to
689 add extra joins or similar, call L</search> and then chain-call L</single> on the
690 L<DBIx::Class::ResultSet> returned.
696 As of 0.08100, this method enforces the assumption that the preceeding
697 query returns only one row. If more than one row is returned, you will receive
700 Query returned more than one row
702 In this case, you should be using L</first> or L</find> instead, or if you really
703 know what you are doing, use the L</rows> attribute to explicitly limit the size
711 my ($self, $where) = @_;
713 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
716 my $attrs = $self->_resolved_attrs_copy;
717 $attrs->{_virtual_order_by} = $self->_gen_virtual_order;
720 if (defined $attrs->{where}) {
723 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
724 $where, delete $attrs->{where} ]
727 $attrs->{where} = $where;
731 # XXX: Disabled since it doesn't infer uniqueness in all cases
732 # unless ($self->_is_unique_query($attrs->{where})) {
733 # carp "Query not guaranteed to return a single row"
734 # . "; please declare your unique constraints or use search instead";
737 my @data = $self->result_source->storage->select_single(
738 $attrs->{from}, $attrs->{select},
739 $attrs->{where}, $attrs
742 return (@data ? ($self->_construct_object(@data))[0] : undef);
747 # This is a horrble hack, but seems like the best we can do at this point
748 # Some limit emulations (Top) require an ordered resultset in order to
749 # function at all. So supply a PK order to be used if necessary
751 sub _gen_virtual_order {
752 return [ shift->result_source->primary_columns ];
757 # Try to determine if the specified query is guaranteed to be unique, based on
758 # the declared unique constraints.
760 sub _is_unique_query {
761 my ($self, $query) = @_;
763 my $collapsed = $self->_collapse_query($query);
764 my $alias = $self->{attrs}{alias};
766 foreach my $name ($self->result_source->unique_constraint_names) {
767 my @unique_cols = map {
769 } $self->result_source->unique_constraint_columns($name);
771 # Count the values for each unique column
772 my %seen = map { $_ => 0 } @unique_cols;
774 foreach my $key (keys %$collapsed) {
775 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
776 next unless exists $seen{$aliased}; # Additional constraints are okay
777 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
780 # If we get 0 or more than 1 value for a column, it's not necessarily unique
781 return 1 unless grep { $_ != 1 } values %seen;
789 # Recursively collapse the query, accumulating values for each column.
791 sub _collapse_query {
792 my ($self, $query, $collapsed) = @_;
796 if (ref $query eq 'ARRAY') {
797 foreach my $subquery (@$query) {
798 next unless ref $subquery; # -or
799 $collapsed = $self->_collapse_query($subquery, $collapsed);
802 elsif (ref $query eq 'HASH') {
803 if (keys %$query and (keys %$query)[0] eq '-and') {
804 foreach my $subquery (@{$query->{-and}}) {
805 $collapsed = $self->_collapse_query($subquery, $collapsed);
809 foreach my $col (keys %$query) {
810 my $value = $query->{$col};
811 $collapsed->{$col}{$value}++;
823 =item Arguments: $cond?
825 =item Return Value: $resultsetcolumn
829 my $max_length = $rs->get_column('length')->max;
831 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
836 my ($self, $column) = @_;
837 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
845 =item Arguments: $cond, \%attrs?
847 =item Return Value: $resultset (scalar context), @row_objs (list context)
851 # WHERE title LIKE '%blue%'
852 $cd_rs = $rs->search_like({ title => '%blue%'});
854 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
855 that this is simply a convenience method retained for ex Class::DBI users.
856 You most likely want to use L</search> with specific operators.
858 For more information, see L<DBIx::Class::Manual::Cookbook>.
860 This method is deprecated and will be removed in 0.09. Use L</search()>
861 instead. An example conversion is:
863 ->search_like({ foo => 'bar' });
867 ->search({ foo => { like => 'bar' } });
874 'search_like() is deprecated and will be removed in DBIC version 0.09.'
875 .' Instead use ->search({ x => { -like => "y%" } })'
876 .' (note the outer pair of {}s - they are important!)'
878 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
879 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
880 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
881 return $class->search($query, { %$attrs });
888 =item Arguments: $first, $last
890 =item Return Value: $resultset (scalar context), @row_objs (list context)
894 Returns a resultset or object list representing a subset of elements from the
895 resultset slice is called on. Indexes are from 0, i.e., to get the first
898 my ($one, $two, $three) = $rs->slice(0, 2);
903 my ($self, $min, $max) = @_;
904 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
905 $attrs->{offset} = $self->{attrs}{offset} || 0;
906 $attrs->{offset} += $min;
907 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
908 return $self->search(undef(), $attrs);
909 #my $slice = (ref $self)->new($self->result_source, $attrs);
910 #return (wantarray ? $slice->all : $slice);
917 =item Arguments: none
919 =item Return Value: $result?
923 Returns the next element in the resultset (C<undef> is there is none).
925 Can be used to efficiently iterate over records in the resultset:
927 my $rs = $schema->resultset('CD')->search;
928 while (my $cd = $rs->next) {
932 Note that you need to store the resultset object, and call C<next> on it.
933 Calling C<< resultset('Table')->next >> repeatedly will always return the
934 first record from the resultset.
940 if (my $cache = $self->get_cache) {
941 $self->{all_cache_position} ||= 0;
942 return $cache->[$self->{all_cache_position}++];
944 if ($self->{attrs}{cache}) {
945 $self->{all_cache_position} = 1;
946 return ($self->all)[0];
948 if ($self->{stashed_objects}) {
949 my $obj = shift(@{$self->{stashed_objects}});
950 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
954 exists $self->{stashed_row}
955 ? @{delete $self->{stashed_row}}
956 : $self->cursor->next
958 return undef unless (@row);
959 my ($row, @more) = $self->_construct_object(@row);
960 $self->{stashed_objects} = \@more if @more;
964 sub _construct_object {
965 my ($self, @row) = @_;
966 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
967 my @new = $self->result_class->inflate_result($self->result_source, @$info);
968 @new = $self->{_attrs}{record_filter}->(@new)
969 if exists $self->{_attrs}{record_filter};
973 sub _collapse_result {
974 my ($self, $as_proto, $row) = @_;
978 # 'foo' => [ undef, 'foo' ]
979 # 'foo.bar' => [ 'foo', 'bar' ]
980 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
982 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
984 my %collapse = %{$self->{_attrs}{collapse}||{}};
988 # if we're doing collapsing (has_many prefetch) we need to grab records
989 # until the PK changes, so fill @pri_index. if not, we leave it empty so
990 # we know we don't have to bother.
992 # the reason for not using the collapse stuff directly is because if you
993 # had for e.g. two artists in a row with no cds, the collapse info for
994 # both would be NULL (undef) so you'd lose the second artist
996 # store just the index so we can check the array positions from the row
997 # without having to contruct the full hash
999 if (keys %collapse) {
1000 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
1001 foreach my $i (0 .. $#construct_as) {
1002 next if defined($construct_as[$i][0]); # only self table
1003 if (delete $pri{$construct_as[$i][1]}) {
1004 push(@pri_index, $i);
1006 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1010 # no need to do an if, it'll be empty if @pri_index is empty anyway
1012 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1016 do { # no need to check anything at the front, we always want the first row
1020 foreach my $this_as (@construct_as) {
1021 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1024 push(@const_rows, \%const);
1026 } until ( # no pri_index => no collapse => drop straight out
1029 do { # get another row, stash it, drop out if different PK
1031 @copy = $self->cursor->next;
1032 $self->{stashed_row} = \@copy;
1034 # last thing in do block, counts as true if anything doesn't match
1036 # check xor defined first for NULL vs. NOT NULL then if one is
1037 # defined the other must be so check string equality
1040 (defined $pri_vals{$_} ^ defined $copy[$_])
1041 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1046 my $alias = $self->{attrs}{alias};
1053 foreach my $const (@const_rows) {
1054 scalar @const_keys or do {
1055 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1057 foreach my $key (@const_keys) {
1060 my @parts = split(/\./, $key);
1062 my $data = $const->{$key};
1063 foreach my $p (@parts) {
1064 $target = $target->[1]->{$p} ||= [];
1066 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1067 # collapsing at this point and on final part
1068 my $pos = $collapse_pos{$cur};
1069 CK: foreach my $ck (@ckey) {
1070 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1071 $collapse_pos{$cur} = $data;
1072 delete @collapse_pos{ # clear all positioning for sub-entries
1073 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1080 if (exists $collapse{$cur}) {
1081 $target = $target->[-1];
1084 $target->[0] = $data;
1086 $info->[0] = $const->{$key};
1094 =head2 result_source
1098 =item Arguments: $result_source?
1100 =item Return Value: $result_source
1104 An accessor for the primary ResultSource object from which this ResultSet
1111 =item Arguments: $result_class?
1113 =item Return Value: $result_class
1117 An accessor for the class to use when creating row objects. Defaults to
1118 C<< result_source->result_class >> - which in most cases is the name of the
1119 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1121 Note that changing the result_class will also remove any components
1122 that were originally loaded in the source class via
1123 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1124 in the original source class will not run.
1129 my ($self, $result_class) = @_;
1130 if ($result_class) {
1131 $self->ensure_class_loaded($result_class);
1132 $self->_result_class($result_class);
1134 $self->_result_class;
1141 =item Arguments: $cond, \%attrs??
1143 =item Return Value: $count
1147 Performs an SQL C<COUNT> with the same query as the resultset was built
1148 with to find the number of elements. Passing arguments is equivalent to
1149 C<< $rs->search ($cond, \%attrs)->count >>
1155 return $self->search(@_)->count if @_ and defined $_[0];
1156 return scalar @{ $self->get_cache } if $self->get_cache;
1158 my @grouped_subq_attrs = qw/prefetch collapse distinct group_by having/;
1159 my @subq_attrs = ();
1161 my $attrs = $self->_resolved_attrs;
1162 # if we are not paged - we are simply asking for a limit
1163 if (not $attrs->{page} and not $attrs->{software_limit}) {
1164 push @subq_attrs, qw/rows offset/;
1167 my $need_subq = $self->_has_attr (@subq_attrs);
1168 my $need_group_subq = $self->_has_attr (@grouped_subq_attrs);
1170 return ($need_subq || $need_group_subq)
1171 ? $self->_count_subq ($need_group_subq)
1172 : $self->_count_simple
1176 my ($self, $add_group_by) = @_;
1178 my $attrs = $self->_resolved_attrs_copy;
1180 # copy for the subquery, we need to do some adjustments to it too
1181 my $sub_attrs = { %$attrs };
1183 # these can not go in the subquery, and there is no point of ordering it
1184 delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns order_by/;
1186 # if needed force a group_by and the same set of columns (most databases require this)
1187 if ($add_group_by) {
1189 # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
1190 # simply deleting group_by suffices, as the code below will re-fill it
1191 # Note: we check $attrs, as $sub_attrs has collapse deleted
1192 if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
1193 delete $sub_attrs->{group_by};
1196 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1200 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1203 # the subquery replaces this
1204 delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind/;
1206 return $self->__count ($attrs);
1212 my $count = $self->__count;
1213 return 0 unless $count;
1215 # need to take offset from resolved attrs
1217 my $attrs = $self->_resolved_attrs;
1219 $count -= $attrs->{offset} if $attrs->{offset};
1220 $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
1221 $count = 0 if ($count < 0);
1226 my ($self, $attrs) = @_;
1228 $attrs ||= $self->_resolved_attrs_copy;
1230 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1231 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1233 $attrs->{select} = { count => '*' };
1234 $attrs->{as} = [qw/count/];
1236 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1237 my ($count) = $tmp_rs->cursor->next;
1246 =head2 count_literal
1250 =item Arguments: $sql_fragment, @bind_values
1252 =item Return Value: $count
1256 Counts the results in a literal query. Equivalent to calling L</search_literal>
1257 with the passed arguments, then L</count>.
1261 sub count_literal { shift->search_literal(@_)->count; }
1267 =item Arguments: none
1269 =item Return Value: @objects
1273 Returns all elements in the resultset. Called implicitly if the resultset
1274 is returned in list context.
1281 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1284 return @{ $self->get_cache } if $self->get_cache;
1288 # TODO: don't call resolve here
1289 if (keys %{$self->_resolved_attrs->{collapse}}) {
1290 # if ($self->{attrs}{prefetch}) {
1291 # Using $self->cursor->all is really just an optimisation.
1292 # If we're collapsing has_many prefetches it probably makes
1293 # very little difference, and this is cleaner than hacking
1294 # _construct_object to survive the approach
1295 my @row = $self->cursor->next;
1297 push(@obj, $self->_construct_object(@row));
1298 @row = (exists $self->{stashed_row}
1299 ? @{delete $self->{stashed_row}}
1300 : $self->cursor->next);
1303 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1306 $self->set_cache(\@obj) if $self->{attrs}{cache};
1314 =item Arguments: none
1316 =item Return Value: $self
1320 Resets the resultset's cursor, so you can iterate through the elements again.
1326 delete $self->{_attrs} if exists $self->{_attrs};
1327 $self->{all_cache_position} = 0;
1328 $self->cursor->reset;
1336 =item Arguments: none
1338 =item Return Value: $object?
1342 Resets the resultset and returns an object for the first result (if the
1343 resultset returns anything).
1348 return $_[0]->reset->next;
1354 # Determines whether and what type of subquery is required for the $rs operation.
1355 # If grouping is necessary either supplies its own, or verifies the current one
1356 # After all is done delegates to the proper storage method.
1358 sub _rs_update_delete {
1359 my ($self, $op, $values) = @_;
1361 my $rsrc = $self->result_source;
1363 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1364 my $needs_subq = $self->_has_attr (qw/row offset page/);
1366 if ($needs_group_by_subq or $needs_subq) {
1368 # make a new $rs selecting only the PKs (that's all we really need)
1369 my $attrs = $self->_resolved_attrs_copy;
1371 delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
1372 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1374 if ($needs_group_by_subq) {
1375 # make sure no group_by was supplied, or if there is one - make sure it matches
1376 # the columns compiled above perfectly. Anything else can not be sanely executed
1377 # on most databases so croak right then and there
1379 if (my $g = $attrs->{group_by}) {
1380 my @current_group_by = map
1381 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1382 (ref $g eq 'ARRAY' ? @$g : $g );
1385 join ("\x00", sort @current_group_by)
1387 join ("\x00", sort @{$attrs->{columns}} )
1389 $self->throw_exception (
1390 "You have just attempted a $op operation on a resultset which does group_by"
1391 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1392 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1393 . ' kind of queries. Please retry the operation with a modified group_by or'
1394 . ' without using one at all.'
1399 $attrs->{group_by} = $attrs->{columns};
1403 my $subrs = (ref $self)->new($rsrc, $attrs);
1405 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1408 return $rsrc->storage->$op(
1410 $op eq 'update' ? $values : (),
1411 $self->_cond_for_update_delete,
1417 # _cond_for_update_delete
1419 # update/delete require the condition to be modified to handle
1420 # the differing SQL syntax available. This transforms the $self->{cond}
1421 # appropriately, returning the new condition.
1423 sub _cond_for_update_delete {
1424 my ($self, $full_cond) = @_;
1427 $full_cond ||= $self->{cond};
1428 # No-op. No condition, we're updating/deleting everything
1429 return $cond unless ref $full_cond;
1431 if (ref $full_cond eq 'ARRAY') {
1435 foreach my $key (keys %{$_}) {
1437 $hash{$1} = $_->{$key};
1443 elsif (ref $full_cond eq 'HASH') {
1444 if ((keys %{$full_cond})[0] eq '-and') {
1446 my @cond = @{$full_cond->{-and}};
1447 for (my $i = 0; $i < @cond; $i++) {
1448 my $entry = $cond[$i];
1450 if (ref $entry eq 'HASH') {
1451 $hash = $self->_cond_for_update_delete($entry);
1454 $entry =~ /([^.]+)$/;
1455 $hash->{$1} = $cond[++$i];
1457 push @{$cond->{-and}}, $hash;
1461 foreach my $key (keys %{$full_cond}) {
1463 $cond->{$1} = $full_cond->{$key};
1468 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1479 =item Arguments: \%values
1481 =item Return Value: $storage_rv
1485 Sets the specified columns in the resultset to the supplied values in a
1486 single query. Return value will be true if the update succeeded or false
1487 if no records were updated; exact type of success value is storage-dependent.
1492 my ($self, $values) = @_;
1493 $self->throw_exception('Values for update must be a hash')
1494 unless ref $values eq 'HASH';
1496 return $self->_rs_update_delete ('update', $values);
1503 =item Arguments: \%values
1505 =item Return Value: 1
1509 Fetches all objects and updates them one at a time. Note that C<update_all>
1510 will run DBIC cascade triggers, while L</update> will not.
1515 my ($self, $values) = @_;
1516 $self->throw_exception('Values for update_all must be a hash')
1517 unless ref $values eq 'HASH';
1518 foreach my $obj ($self->all) {
1519 $obj->set_columns($values)->update;
1528 =item Arguments: none
1530 =item Return Value: 1
1534 Deletes the contents of the resultset from its result source. Note that this
1535 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1536 to run. See also L<DBIx::Class::Row/delete>.
1538 delete may not generate correct SQL for a query with joins or a resultset
1539 chained from a related resultset. In this case it will generate a warning:-
1541 In these cases you may find that delete_all is more appropriate, or you
1542 need to respecify your query in a way that can be expressed without a join.
1548 $self->throw_exception('delete does not accept any arguments')
1551 return $self->_rs_update_delete ('delete');
1558 =item Arguments: none
1560 =item Return Value: 1
1564 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1565 will run DBIC cascade triggers, while L</delete> will not.
1571 $self->throw_exception('delete_all does not accept any arguments')
1574 $_->delete for $self->all;
1582 =item Arguments: \@data;
1586 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1587 For the arrayref of hashrefs style each hashref should be a structure suitable
1588 forsubmitting to a $resultset->create(...) method.
1590 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1591 to insert the data, as this is a faster method.
1593 Otherwise, each set of data is inserted into the database using
1594 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1595 objects is returned.
1597 Example: Assuming an Artist Class that has many CDs Classes relating:
1599 my $Artist_rs = $schema->resultset("Artist");
1601 ## Void Context Example
1602 $Artist_rs->populate([
1603 { artistid => 4, name => 'Manufactured Crap', cds => [
1604 { title => 'My First CD', year => 2006 },
1605 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1608 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1609 { title => 'My parents sold me to a record company' ,year => 2005 },
1610 { title => 'Why Am I So Ugly?', year => 2006 },
1611 { title => 'I Got Surgery and am now Popular', year => 2007 }
1616 ## Array Context Example
1617 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1618 { name => "Artist One"},
1619 { name => "Artist Two"},
1620 { name => "Artist Three", cds=> [
1621 { title => "First CD", year => 2007},
1622 { title => "Second CD", year => 2008},
1626 print $ArtistOne->name; ## response is 'Artist One'
1627 print $ArtistThree->cds->count ## reponse is '2'
1629 For the arrayref of arrayrefs style, the first element should be a list of the
1630 fieldsnames to which the remaining elements are rows being inserted. For
1633 $Arstist_rs->populate([
1634 [qw/artistid name/],
1635 [100, 'A Formally Unknown Singer'],
1636 [101, 'A singer that jumped the shark two albums ago'],
1637 [102, 'An actually cool singer.'],
1640 Please note an important effect on your data when choosing between void and
1641 wantarray context. Since void context goes straight to C<insert_bulk> in
1642 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1643 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1644 create primary keys for you, you will find that your PKs are empty. In this
1645 case you will have to use the wantarray context in order to create those
1651 my $self = shift @_;
1652 my $data = ref $_[0][0] eq 'HASH'
1653 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1654 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1656 if(defined wantarray) {
1658 foreach my $item (@$data) {
1659 push(@created, $self->create($item));
1663 my ($first, @rest) = @$data;
1665 my @names = grep {!ref $first->{$_}} keys %$first;
1666 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1667 my @pks = $self->result_source->primary_columns;
1669 ## do the belongs_to relationships
1670 foreach my $index (0..$#$data) {
1671 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1672 my @ret = $self->populate($data);
1676 foreach my $rel (@rels) {
1677 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1678 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1679 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1680 my $related = $result->result_source->_resolve_condition(
1681 $result->result_source->relationship_info($reverse)->{cond},
1686 delete $data->[$index]->{$rel};
1687 $data->[$index] = {%{$data->[$index]}, %$related};
1689 push @names, keys %$related if $index == 0;
1693 ## do bulk insert on current row
1694 my @values = map { [ @$_{@names} ] } @$data;
1696 $self->result_source->storage->insert_bulk(
1697 $self->result_source,
1702 ## do the has_many relationships
1703 foreach my $item (@$data) {
1705 foreach my $rel (@rels) {
1706 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1708 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1709 || $self->throw_exception('Cannot find the relating object.');
1711 my $child = $parent->$rel;
1713 my $related = $child->result_source->_resolve_condition(
1714 $parent->result_source->relationship_info($rel)->{cond},
1719 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1720 my @populate = map { {%$_, %$related} } @rows_to_add;
1722 $child->populate( \@populate );
1728 =head2 _normalize_populate_args ($args)
1730 Private method used by L</populate> to normalize its incoming arguments. Factored
1731 out in case you want to subclass and accept new argument structures to the
1732 L</populate> method.
1736 sub _normalize_populate_args {
1737 my ($self, $data) = @_;
1738 my @names = @{shift(@$data)};
1739 my @results_to_create;
1740 foreach my $datum (@$data) {
1741 my %result_to_create;
1742 foreach my $index (0..$#names) {
1743 $result_to_create{$names[$index]} = $$datum[$index];
1745 push @results_to_create, \%result_to_create;
1747 return \@results_to_create;
1754 =item Arguments: none
1756 =item Return Value: $pager
1760 Return Value a L<Data::Page> object for the current resultset. Only makes
1761 sense for queries with a C<page> attribute.
1763 To get the full count of entries for a paged resultset, call
1764 C<total_entries> on the L<Data::Page> object.
1771 return $self->{pager} if $self->{pager};
1773 my $attrs = $self->{attrs};
1774 $self->throw_exception("Can't create pager for non-paged rs")
1775 unless $self->{attrs}{page};
1776 $attrs->{rows} ||= 10;
1778 # throw away the paging flags and re-run the count (possibly
1779 # with a subselect) to get the real total count
1780 my $count_attrs = { %$attrs };
1781 delete $count_attrs->{$_} for qw/rows offset page pager/;
1782 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1784 return $self->{pager} = Data::Page->new(
1787 $self->{attrs}{page}
1795 =item Arguments: $page_number
1797 =item Return Value: $rs
1801 Returns a resultset for the $page_number page of the resultset on which page
1802 is called, where each page contains a number of rows equal to the 'rows'
1803 attribute set on the resultset (10 by default).
1808 my ($self, $page) = @_;
1809 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1816 =item Arguments: \%vals
1818 =item Return Value: $rowobject
1822 Creates a new row object in the resultset's result class and returns
1823 it. The row is not inserted into the database at this point, call
1824 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1825 will tell you whether the row object has been inserted or not.
1827 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1832 my ($self, $values) = @_;
1833 $self->throw_exception( "new_result needs a hash" )
1834 unless (ref $values eq 'HASH');
1837 my $alias = $self->{attrs}{alias};
1840 defined $self->{cond}
1841 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1843 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1844 $new{-from_resultset} = [ keys %new ] if keys %new;
1846 $self->throw_exception(
1847 "Can't abstract implicit construct, condition not a hash"
1848 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1850 my $collapsed_cond = (
1852 ? $self->_collapse_cond($self->{cond})
1856 # precendence must be given to passed values over values inherited from
1857 # the cond, so the order here is important.
1858 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1859 while( my($col,$value) = each %implied ){
1860 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1861 $new{$col} = $value->{'='};
1864 $new{$col} = $value if $self->_is_deterministic_value($value);
1870 %{ $self->_remove_alias($values, $alias) },
1871 -source_handle => $self->_source_handle,
1872 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1875 return $self->result_class->new(\%new);
1878 # _is_deterministic_value
1880 # Make an effor to strip non-deterministic values from the condition,
1881 # to make sure new_result chokes less
1883 sub _is_deterministic_value {
1886 my $ref_type = ref $value;
1887 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1888 return 1 if Scalar::Util::blessed($value);
1894 # determines if the resultset defines at least one
1895 # of the attributes supplied
1897 # used to determine if a subquery is neccessary
1900 my ($self, @attr_names) = @_;
1902 my $attrs = $self->_resolved_attrs;
1906 for my $n (@attr_names) {
1907 ++$join_check_req if $n =~ /join/;
1909 my $attr = $attrs->{$n};
1911 next if not defined $attr;
1913 if (ref $attr eq 'HASH') {
1914 return 1 if keys %$attr;
1916 elsif (ref $attr eq 'ARRAY') {
1924 # a join can be expressed as a multi-level from
1928 ref $attrs->{from} eq 'ARRAY'
1930 @{$attrs->{from}} > 1
1938 # Recursively collapse the condition.
1940 sub _collapse_cond {
1941 my ($self, $cond, $collapsed) = @_;
1945 if (ref $cond eq 'ARRAY') {
1946 foreach my $subcond (@$cond) {
1947 next unless ref $subcond; # -or
1948 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1951 elsif (ref $cond eq 'HASH') {
1952 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1953 foreach my $subcond (@{$cond->{-and}}) {
1954 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1958 foreach my $col (keys %$cond) {
1959 my $value = $cond->{$col};
1960 $collapsed->{$col} = $value;
1970 # Remove the specified alias from the specified query hash. A copy is made so
1971 # the original query is not modified.
1974 my ($self, $query, $alias) = @_;
1976 my %orig = %{ $query || {} };
1979 foreach my $key (keys %orig) {
1981 $unaliased{$key} = $orig{$key};
1984 $unaliased{$1} = $orig{$key}
1985 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1991 =head2 as_query (EXPERIMENTAL)
1995 =item Arguments: none
1997 =item Return Value: \[ $sql, @bind ]
2001 Returns the SQL query and bind vars associated with the invocant.
2003 This is generally used as the RHS for a subquery.
2005 B<NOTE>: This feature is still experimental.
2009 sub as_query { return shift->cursor->as_query(@_) }
2015 =item Arguments: \%vals, \%attrs?
2017 =item Return Value: $rowobject
2021 my $artist = $schema->resultset('Artist')->find_or_new(
2022 { artist => 'fred' }, { key => 'artists' });
2024 $cd->cd_to_producer->find_or_new({ producer => $producer },
2025 { key => 'primary });
2027 Find an existing record from this resultset, based on its primary
2028 key, or a unique constraint. If none exists, instantiate a new result
2029 object and return it. The object will not be saved into your storage
2030 until you call L<DBIx::Class::Row/insert> on it.
2032 You most likely want this method when looking for existing rows using
2033 a unique constraint that is not the primary key, or looking for
2036 If you want objects to be saved immediately, use L</find_or_create> instead.
2038 B<Note>: C<find_or_new> is probably not what you want when creating a
2039 new row in a table that uses primary keys supplied by the
2040 database. Passing in a primary key column with a value of I<undef>
2041 will cause L</find> to attempt to search for a row with a value of
2048 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2049 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2050 my $exists = $self->find($hash, $attrs);
2051 return defined $exists ? $exists : $self->new_result($hash);
2058 =item Arguments: \%vals
2060 =item Return Value: a L<DBIx::Class::Row> $object
2064 Attempt to create a single new row or a row with multiple related rows
2065 in the table represented by the resultset (and related tables). This
2066 will not check for duplicate rows before inserting, use
2067 L</find_or_create> to do that.
2069 To create one row for this resultset, pass a hashref of key/value
2070 pairs representing the columns of the table and the values you wish to
2071 store. If the appropriate relationships are set up, foreign key fields
2072 can also be passed an object representing the foreign row, and the
2073 value will be set to its primary key.
2075 To create related objects, pass a hashref for the value if the related
2076 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2077 and use the name of the relationship as the key. (NOT the name of the field,
2078 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2079 of hashrefs containing the data for each of the rows to create in the foreign
2080 tables, again using the relationship name as the key.
2082 Instead of hashrefs of plain related data (key/value pairs), you may
2083 also pass new or inserted objects. New objects (not inserted yet, see
2084 L</new>), will be inserted into their appropriate tables.
2086 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2088 Example of creating a new row.
2090 $person_rs->create({
2091 name=>"Some Person",
2092 email=>"somebody@someplace.com"
2095 Example of creating a new row and also creating rows in a related C<has_many>
2096 or C<has_one> resultset. Note Arrayref.
2099 { artistid => 4, name => 'Manufactured Crap', cds => [
2100 { title => 'My First CD', year => 2006 },
2101 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2106 Example of creating a new row and also creating a row in a related
2107 C<belongs_to>resultset. Note Hashref.
2110 title=>"Music for Silly Walks",
2113 name=>"Silly Musician",
2120 my ($self, $attrs) = @_;
2121 $self->throw_exception( "create needs a hashref" )
2122 unless ref $attrs eq 'HASH';
2123 return $self->new_result($attrs)->insert;
2126 =head2 find_or_create
2130 =item Arguments: \%vals, \%attrs?
2132 =item Return Value: $rowobject
2136 $cd->cd_to_producer->find_or_create({ producer => $producer },
2137 { key => 'primary });
2139 Tries to find a record based on its primary key or unique constraints; if none
2140 is found, creates one and returns that instead.
2142 my $cd = $schema->resultset('CD')->find_or_create({
2144 artist => 'Massive Attack',
2145 title => 'Mezzanine',
2149 Also takes an optional C<key> attribute, to search by a specific key or unique
2150 constraint. For example:
2152 my $cd = $schema->resultset('CD')->find_or_create(
2154 artist => 'Massive Attack',
2155 title => 'Mezzanine',
2157 { key => 'cd_artist_title' }
2160 B<Note>: Because find_or_create() reads from the database and then
2161 possibly inserts based on the result, this method is subject to a race
2162 condition. Another process could create a record in the table after
2163 the find has completed and before the create has started. To avoid
2164 this problem, use find_or_create() inside a transaction.
2166 B<Note>: C<find_or_create> is probably not what you want when creating
2167 a new row in a table that uses primary keys supplied by the
2168 database. Passing in a primary key column with a value of I<undef>
2169 will cause L</find> to attempt to search for a row with a value of
2172 See also L</find> and L</update_or_create>. For information on how to declare
2173 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2177 sub find_or_create {
2179 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2180 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2181 my $exists = $self->find($hash, $attrs);
2182 return defined $exists ? $exists : $self->create($hash);
2185 =head2 update_or_create
2189 =item Arguments: \%col_values, { key => $unique_constraint }?
2191 =item Return Value: $rowobject
2195 $resultset->update_or_create({ col => $val, ... });
2197 First, searches for an existing row matching one of the unique constraints
2198 (including the primary key) on the source of this resultset. If a row is
2199 found, updates it with the other given column values. Otherwise, creates a new
2202 Takes an optional C<key> attribute to search on a specific unique constraint.
2205 # In your application
2206 my $cd = $schema->resultset('CD')->update_or_create(
2208 artist => 'Massive Attack',
2209 title => 'Mezzanine',
2212 { key => 'cd_artist_title' }
2215 $cd->cd_to_producer->update_or_create({
2216 producer => $producer,
2223 If no C<key> is specified, it searches on all unique constraints defined on the
2224 source, including the primary key.
2226 If the C<key> is specified as C<primary>, it searches only on the primary key.
2228 See also L</find> and L</find_or_create>. For information on how to declare
2229 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2231 B<Note>: C<update_or_create> is probably not what you want when
2232 looking for a row in a table that uses primary keys supplied by the
2233 database, unless you actually have a key value. Passing in a primary
2234 key column with a value of I<undef> will cause L</find> to attempt to
2235 search for a row with a value of I<NULL>.
2239 sub update_or_create {
2241 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2242 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2244 my $row = $self->find($cond, $attrs);
2246 $row->update($cond);
2250 return $self->create($cond);
2253 =head2 update_or_new
2257 =item Arguments: \%col_values, { key => $unique_constraint }?
2259 =item Return Value: $rowobject
2263 $resultset->update_or_new({ col => $val, ... });
2265 First, searches for an existing row matching one of the unique constraints
2266 (including the primary key) on the source of this resultset. If a row is
2267 found, updates it with the other given column values. Otherwise, instantiate
2268 a new result object and return it. The object will not be saved into your storage
2269 until you call L<DBIx::Class::Row/insert> on it.
2271 Takes an optional C<key> attribute to search on a specific unique constraint.
2274 # In your application
2275 my $cd = $schema->resultset('CD')->update_or_new(
2277 artist => 'Massive Attack',
2278 title => 'Mezzanine',
2281 { key => 'cd_artist_title' }
2284 if ($cd->in_storage) {
2285 # the cd was updated
2288 # the cd is not yet in the database, let's insert it
2292 See also L</find>, L</find_or_create> and L<find_or_new>.
2298 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2299 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2301 my $row = $self->find( $cond, $attrs );
2302 if ( defined $row ) {
2303 $row->update($cond);
2307 return $self->new_result($cond);
2314 =item Arguments: none
2316 =item Return Value: \@cache_objects?
2320 Gets the contents of the cache for the resultset, if the cache is set.
2322 The cache is populated either by using the L</prefetch> attribute to
2323 L</search> or by calling L</set_cache>.
2335 =item Arguments: \@cache_objects
2337 =item Return Value: \@cache_objects
2341 Sets the contents of the cache for the resultset. Expects an arrayref
2342 of objects of the same class as those produced by the resultset. Note that
2343 if the cache is set the resultset will return the cached objects rather
2344 than re-querying the database even if the cache attr is not set.
2346 The contents of the cache can also be populated by using the
2347 L</prefetch> attribute to L</search>.
2352 my ( $self, $data ) = @_;
2353 $self->throw_exception("set_cache requires an arrayref")
2354 if defined($data) && (ref $data ne 'ARRAY');
2355 $self->{all_cache} = $data;
2362 =item Arguments: none
2364 =item Return Value: []
2368 Clears the cache for the resultset.
2373 shift->set_cache(undef);
2376 =head2 related_resultset
2380 =item Arguments: $relationship_name
2382 =item Return Value: $resultset
2386 Returns a related resultset for the supplied relationship name.
2388 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2392 sub related_resultset {
2393 my ($self, $rel) = @_;
2395 $self->{related_resultsets} ||= {};
2396 return $self->{related_resultsets}{$rel} ||= do {
2397 my $rel_obj = $self->result_source->relationship_info($rel);
2399 $self->throw_exception(
2400 "search_related: result source '" . $self->result_source->source_name .
2401 "' has no such relationship $rel")
2404 my ($from,$seen) = $self->_resolve_from($rel);
2406 my $join_count = $seen->{$rel};
2407 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2409 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2410 my %attrs = %{$self->{attrs}||{}};
2411 delete @attrs{qw(result_class alias)};
2415 if (my $cache = $self->get_cache) {
2416 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2417 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2422 my $rel_source = $self->result_source->related_source($rel);
2426 # The reason we do this now instead of passing the alias to the
2427 # search_rs below is that if you wrap/overload resultset on the
2428 # source you need to know what alias it's -going- to have for things
2429 # to work sanely (e.g. RestrictWithObject wants to be able to add
2430 # extra query restrictions, and these may need to be $alias.)
2432 my $attrs = $rel_source->resultset_attributes;
2433 local $attrs->{alias} = $alias;
2435 $rel_source->resultset
2443 where => $self->{cond},
2448 $new->set_cache($new_cache) if $new_cache;
2453 =head2 current_source_alias
2457 =item Arguments: none
2459 =item Return Value: $source_alias
2463 Returns the current table alias for the result source this resultset is built
2464 on, that will be used in the SQL query. Usually it is C<me>.
2466 Currently the source alias that refers to the result set returned by a
2467 L</search>/L</find> family method depends on how you got to the resultset: it's
2468 C<me> by default, but eg. L</search_related> aliases it to the related result
2469 source name (and keeps C<me> referring to the original result set). The long
2470 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2471 (and make this method unnecessary).
2473 Thus it's currently necessary to use this method in predefined queries (see
2474 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2475 source alias of the current result set:
2477 # in a result set class
2479 my ($self, $user) = @_;
2481 my $me = $self->current_source_alias;
2483 return $self->search(
2484 "$me.modified" => $user->id,
2490 sub current_source_alias {
2493 return ($self->{attrs} || {})->{alias} || 'me';
2496 # This code is called by search_related, and makes sure there
2497 # is clear separation between the joins before, during, and
2498 # after the relationship. This information is needed later
2499 # in order to properly resolve prefetch aliases (any alias
2500 # with a relation_chain_depth less than the depth of the
2501 # current prefetch is not considered)
2503 my ($self, $extra_join) = @_;
2504 my $source = $self->result_source;
2505 my $attrs = $self->{attrs};
2507 my $from = $attrs->{from}
2508 || [ { $attrs->{alias} => $source->from } ];
2510 my $seen = { %{$attrs->{seen_join}||{}} };
2512 # we need to take the prefetch the attrs into account before we
2513 # ->_resolve_join as otherwise they get lost - captainL
2514 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2516 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2518 ++$seen->{-relation_chain_depth};
2520 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2522 ++$seen->{-relation_chain_depth};
2524 return ($from,$seen);
2527 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2528 sub _resolved_attrs_copy {
2530 return { %{$self->_resolved_attrs (@_)} };
2533 sub _resolved_attrs {
2535 return $self->{_attrs} if $self->{_attrs};
2537 my $attrs = { %{ $self->{attrs} || {} } };
2538 my $source = $self->result_source;
2539 my $alias = $attrs->{alias};
2541 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2544 # build columns (as long as select isn't set) into a set of as/select hashes
2545 unless ( $attrs->{select} ) {
2547 ( ref($_) eq 'HASH' )
2551 /^\Q${alias}.\E(.+)$/
2562 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2564 # add the additional columns on
2565 foreach ( 'include_columns', '+columns' ) {
2566 push @colbits, map {
2567 ( ref($_) eq 'HASH' )
2569 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2570 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2573 # start with initial select items
2574 if ( $attrs->{select} ) {
2576 ( ref $attrs->{select} eq 'ARRAY' )
2577 ? [ @{ $attrs->{select} } ]
2578 : [ $attrs->{select} ];
2582 ref $attrs->{as} eq 'ARRAY'
2583 ? [ @{ $attrs->{as} } ]
2586 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2591 # otherwise we intialise select & as to empty
2592 $attrs->{select} = [];
2596 # now add colbits to select/as
2597 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2598 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2601 if ( $adds = delete $attrs->{'+select'} ) {
2602 $adds = [$adds] unless ref $adds eq 'ARRAY';
2604 @{ $attrs->{select} },
2605 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2608 if ( $adds = delete $attrs->{'+as'} ) {
2609 $adds = [$adds] unless ref $adds eq 'ARRAY';
2610 push( @{ $attrs->{as} }, @$adds );
2613 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2615 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2616 my $join = delete $attrs->{join} || {};
2618 if ( defined $attrs->{prefetch} ) {
2619 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2623 $attrs->{from} = # have to copy here to avoid corrupting the original
2625 @{ $attrs->{from} },
2626 $source->_resolve_join(
2627 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2633 if ( $attrs->{order_by} ) {
2634 $attrs->{order_by} = (
2635 ref( $attrs->{order_by} ) eq 'ARRAY'
2636 ? [ @{ $attrs->{order_by} } ]
2637 : [ $attrs->{order_by} ]
2641 $attrs->{order_by} = [];
2644 my $collapse = $attrs->{collapse} || {};
2645 if ( my $prefetch = delete $attrs->{prefetch} ) {
2646 $prefetch = $self->_merge_attr( {}, $prefetch );
2648 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2650 # bring joins back to level of current class
2651 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2653 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2654 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2655 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2657 push( @{ $attrs->{order_by} }, @pre_order );
2660 if (delete $attrs->{distinct}) {
2661 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2664 $attrs->{collapse} = $collapse;
2666 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2667 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2670 return $self->{_attrs} = $attrs;
2673 sub _joinpath_aliases {
2674 my ($self, $fromspec, $seen) = @_;
2677 return $paths unless ref $fromspec eq 'ARRAY';
2679 for my $j (@$fromspec) {
2681 next if ref $j ne 'ARRAY';
2682 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2685 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2686 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2693 my ($self, $attr) = @_;
2695 if (ref $attr eq 'HASH') {
2696 return $self->_rollout_hash($attr);
2697 } elsif (ref $attr eq 'ARRAY') {
2698 return $self->_rollout_array($attr);
2704 sub _rollout_array {
2705 my ($self, $attr) = @_;
2708 foreach my $element (@{$attr}) {
2709 if (ref $element eq 'HASH') {
2710 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2711 } elsif (ref $element eq 'ARRAY') {
2712 # XXX - should probably recurse here
2713 push( @rolled_array, @{$self->_rollout_array($element)} );
2715 push( @rolled_array, $element );
2718 return \@rolled_array;
2722 my ($self, $attr) = @_;
2725 foreach my $key (keys %{$attr}) {
2726 push( @rolled_array, { $key => $attr->{$key} } );
2728 return \@rolled_array;
2731 sub _calculate_score {
2732 my ($self, $a, $b) = @_;
2734 if (ref $b eq 'HASH') {
2735 my ($b_key) = keys %{$b};
2736 if (ref $a eq 'HASH') {
2737 my ($a_key) = keys %{$a};
2738 if ($a_key eq $b_key) {
2739 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2744 return ($a eq $b_key) ? 1 : 0;
2747 if (ref $a eq 'HASH') {
2748 my ($a_key) = keys %{$a};
2749 return ($b eq $a_key) ? 1 : 0;
2751 return ($b eq $a) ? 1 : 0;
2757 my ($self, $orig, $import) = @_;
2759 return $import unless defined($orig);
2760 return $orig unless defined($import);
2762 $orig = $self->_rollout_attr($orig);
2763 $import = $self->_rollout_attr($import);
2766 foreach my $import_element ( @{$import} ) {
2767 # find best candidate from $orig to merge $b_element into
2768 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2769 foreach my $orig_element ( @{$orig} ) {
2770 my $score = $self->_calculate_score( $orig_element, $import_element );
2771 if ($score > $best_candidate->{score}) {
2772 $best_candidate->{position} = $position;
2773 $best_candidate->{score} = $score;
2777 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2779 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2780 push( @{$orig}, $import_element );
2782 my $orig_best = $orig->[$best_candidate->{position}];
2783 # merge orig_best and b_element together and replace original with merged
2784 if (ref $orig_best ne 'HASH') {
2785 $orig->[$best_candidate->{position}] = $import_element;
2786 } elsif (ref $import_element eq 'HASH') {
2787 my ($key) = keys %{$orig_best};
2788 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2791 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2801 $self->_source_handle($_[0]->handle);
2803 $self->_source_handle->resolve;
2807 =head2 throw_exception
2809 See L<DBIx::Class::Schema/throw_exception> for details.
2813 sub throw_exception {
2815 if (ref $self && $self->_source_handle->schema) {
2816 $self->_source_handle->schema->throw_exception(@_)
2823 # XXX: FIXME: Attributes docs need clearing up
2827 Attributes are used to refine a ResultSet in various ways when
2828 searching for data. They can be passed to any method which takes an
2829 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2832 These are in no particular order:
2838 =item Value: ( $order_by | \@order_by | \%order_by )
2842 Which column(s) to order the results by. If a single column name, or
2843 an arrayref of names is supplied, the argument is passed through
2844 directly to SQL. The hashref syntax allows for connection-agnostic
2845 specification of ordering direction:
2847 For descending order:
2849 order_by => { -desc => [qw/col1 col2 col3/] }
2851 For explicit ascending order:
2853 order_by => { -asc => 'col' }
2855 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2856 supported, although you are strongly encouraged to use the hashref
2857 syntax as outlined above.
2863 =item Value: \@columns
2867 Shortcut to request a particular set of columns to be retrieved. Each
2868 column spec may be a string (a table column name), or a hash (in which
2869 case the key is the C<as> value, and the value is used as the C<select>
2870 expression). Adds C<me.> onto the start of any column without a C<.> in
2871 it and sets C<select> from that, then auto-populates C<as> from
2872 C<select> as normal. (You may also use the C<cols> attribute, as in
2873 earlier versions of DBIC.)
2879 =item Value: \@columns
2883 Indicates additional columns to be selected from storage. Works the same
2884 as L</columns> but adds columns to the selection. (You may also use the
2885 C<include_columns> attribute, as in earlier versions of DBIC). For
2888 $schema->resultset('CD')->search(undef, {
2889 '+columns' => ['artist.name'],
2893 would return all CDs and include a 'name' column to the information
2894 passed to object inflation. Note that the 'artist' is the name of the
2895 column (or relationship) accessor, and 'name' is the name of the column
2896 accessor in the related table.
2898 =head2 include_columns
2902 =item Value: \@columns
2906 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2912 =item Value: \@select_columns
2916 Indicates which columns should be selected from the storage. You can use
2917 column names, or in the case of RDBMS back ends, function or stored procedure
2920 $rs = $schema->resultset('Employee')->search(undef, {
2923 { count => 'employeeid' },
2928 When you use function/stored procedure names and do not supply an C<as>
2929 attribute, the column names returned are storage-dependent. E.g. MySQL would
2930 return a column named C<count(employeeid)> in the above example.
2936 Indicates additional columns to be selected from storage. Works the same as
2937 L</select> but adds columns to the selection.
2945 Indicates additional column names for those added via L</+select>. See L</as>.
2953 =item Value: \@inflation_names
2957 Indicates column names for object inflation. That is, C<as>
2958 indicates the name that the column can be accessed as via the
2959 C<get_column> method (or via the object accessor, B<if one already
2960 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2962 The C<as> attribute is used in conjunction with C<select>,
2963 usually when C<select> contains one or more function or stored
2966 $rs = $schema->resultset('Employee')->search(undef, {
2969 { count => 'employeeid' }
2971 as => ['name', 'employee_count'],
2974 my $employee = $rs->first(); # get the first Employee
2976 If the object against which the search is performed already has an accessor
2977 matching a column name specified in C<as>, the value can be retrieved using
2978 the accessor as normal:
2980 my $name = $employee->name();
2982 If on the other hand an accessor does not exist in the object, you need to
2983 use C<get_column> instead:
2985 my $employee_count = $employee->get_column('employee_count');
2987 You can create your own accessors if required - see
2988 L<DBIx::Class::Manual::Cookbook> for details.
2990 Please note: This will NOT insert an C<AS employee_count> into the SQL
2991 statement produced, it is used for internal access only. Thus
2992 attempting to use the accessor in an C<order_by> clause or similar
2993 will fail miserably.
2995 To get around this limitation, you can supply literal SQL to your
2996 C<select> attibute that contains the C<AS alias> text, eg:
2998 select => [\'myfield AS alias']
3004 =item Value: ($rel_name | \@rel_names | \%rel_names)
3008 Contains a list of relationships that should be joined for this query. For
3011 # Get CDs by Nine Inch Nails
3012 my $rs = $schema->resultset('CD')->search(
3013 { 'artist.name' => 'Nine Inch Nails' },
3014 { join => 'artist' }
3017 Can also contain a hash reference to refer to the other relation's relations.
3020 package MyApp::Schema::Track;
3021 use base qw/DBIx::Class/;
3022 __PACKAGE__->table('track');
3023 __PACKAGE__->add_columns(qw/trackid cd position title/);
3024 __PACKAGE__->set_primary_key('trackid');
3025 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3028 # In your application
3029 my $rs = $schema->resultset('Artist')->search(
3030 { 'track.title' => 'Teardrop' },
3032 join => { cd => 'track' },
3033 order_by => 'artist.name',
3037 You need to use the relationship (not the table) name in conditions,
3038 because they are aliased as such. The current table is aliased as "me", so
3039 you need to use me.column_name in order to avoid ambiguity. For example:
3041 # Get CDs from 1984 with a 'Foo' track
3042 my $rs = $schema->resultset('CD')->search(
3045 'tracks.name' => 'Foo'
3047 { join => 'tracks' }
3050 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3051 similarly for a third time). For e.g.
3053 my $rs = $schema->resultset('Artist')->search({
3054 'cds.title' => 'Down to Earth',
3055 'cds_2.title' => 'Popular',
3057 join => [ qw/cds cds/ ],
3060 will return a set of all artists that have both a cd with title 'Down
3061 to Earth' and a cd with title 'Popular'.
3063 If you want to fetch related objects from other tables as well, see C<prefetch>
3066 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3072 =item Value: ($rel_name | \@rel_names | \%rel_names)
3076 Contains one or more relationships that should be fetched along with
3077 the main query (when they are accessed afterwards the data will
3078 already be available, without extra queries to the database). This is
3079 useful for when you know you will need the related objects, because it
3080 saves at least one query:
3082 my $rs = $schema->resultset('Tag')->search(
3091 The initial search results in SQL like the following:
3093 SELECT tag.*, cd.*, artist.* FROM tag
3094 JOIN cd ON tag.cd = cd.cdid
3095 JOIN artist ON cd.artist = artist.artistid
3097 L<DBIx::Class> has no need to go back to the database when we access the
3098 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3101 Simple prefetches will be joined automatically, so there is no need
3102 for a C<join> attribute in the above search.
3104 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3105 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3106 with an accessor type of 'single' or 'filter'). A more complex example that
3107 prefetches an artists cds, the tracks on those cds, and the tags associted
3108 with that artist is given below (assuming many-to-many from artists to tags):
3110 my $rs = $schema->resultset('Artist')->search(
3114 { cds => 'tracks' },
3115 { artist_tags => 'tags' }
3121 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3122 attributes will be ignored.
3132 Makes the resultset paged and specifies the page to retrieve. Effectively
3133 identical to creating a non-pages resultset and then calling ->page($page)
3136 If L<rows> attribute is not specified it defualts to 10 rows per page.
3138 When you have a paged resultset, L</count> will only return the number
3139 of rows in the page. To get the total, use the L</pager> and call
3140 C<total_entries> on it.
3150 Specifes the maximum number of rows for direct retrieval or the number of
3151 rows per page if the page attribute or method is used.
3157 =item Value: $offset
3161 Specifies the (zero-based) row number for the first row to be returned, or the
3162 of the first row of the first page if paging is used.
3168 =item Value: \@columns
3172 A arrayref of columns to group by. Can include columns of joined tables.
3174 group_by => [qw/ column1 column2 ... /]
3180 =item Value: $condition
3184 HAVING is a select statement attribute that is applied between GROUP BY and
3185 ORDER BY. It is applied to the after the grouping calculations have been
3188 having => { 'count(employee)' => { '>=', 100 } }
3194 =item Value: (0 | 1)
3198 Set to 1 to group by all columns.
3204 Adds to the WHERE clause.
3206 # only return rows WHERE deleted IS NULL for all searches
3207 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3209 Can be overridden by passing C<{ where => undef }> as an attribute
3216 Set to 1 to cache search results. This prevents extra SQL queries if you
3217 revisit rows in your ResultSet:
3219 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3221 while( my $artist = $resultset->next ) {
3225 $rs->first; # without cache, this would issue a query
3227 By default, searches are not cached.
3229 For more examples of using these attributes, see
3230 L<DBIx::Class::Manual::Cookbook>.
3236 =item Value: \@from_clause
3240 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3241 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3244 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3246 C<join> will usually do what you need and it is strongly recommended that you
3247 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3248 And we really do mean "cannot", not just tried and failed. Attempting to use
3249 this because you're having problems with C<join> is like trying to use x86
3250 ASM because you've got a syntax error in your C. Trust us on this.
3252 Now, if you're still really, really sure you need to use this (and if you're
3253 not 100% sure, ask the mailing list first), here's an explanation of how this
3256 The syntax is as follows -
3259 { <alias1> => <table1> },
3261 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3262 [], # nested JOIN (optional)
3263 { <table1.column1> => <table2.column2>, ... (more conditions) },
3265 # More of the above [ ] may follow for additional joins
3272 ON <table1.column1> = <table2.column2>
3273 <more joins may follow>
3275 An easy way to follow the examples below is to remember the following:
3277 Anything inside "[]" is a JOIN
3278 Anything inside "{}" is a condition for the enclosing JOIN
3280 The following examples utilize a "person" table in a family tree application.
3281 In order to express parent->child relationships, this table is self-joined:
3283 # Person->belongs_to('father' => 'Person');
3284 # Person->belongs_to('mother' => 'Person');
3286 C<from> can be used to nest joins. Here we return all children with a father,
3287 then search against all mothers of those children:
3289 $rs = $schema->resultset('Person')->search(
3292 alias => 'mother', # alias columns in accordance with "from"
3294 { mother => 'person' },
3297 { child => 'person' },
3299 { father => 'person' },
3300 { 'father.person_id' => 'child.father_id' }
3303 { 'mother.person_id' => 'child.mother_id' }
3310 # SELECT mother.* FROM person mother
3313 # JOIN person father
3314 # ON ( father.person_id = child.father_id )
3316 # ON ( mother.person_id = child.mother_id )
3318 The type of any join can be controlled manually. To search against only people
3319 with a father in the person table, we could explicitly use C<INNER JOIN>:
3321 $rs = $schema->resultset('Person')->search(
3324 alias => 'child', # alias columns in accordance with "from"
3326 { child => 'person' },
3328 { father => 'person', -join_type => 'inner' },
3329 { 'father.id' => 'child.father_id' }
3336 # SELECT child.* FROM person child
3337 # INNER JOIN person father ON child.father_id = father.id
3339 If you need to express really complex joins or you need a subselect, you
3340 can supply literal SQL to C<from> via a scalar reference. In this case
3341 the contents of the scalar will replace the table name asscoiated with the
3344 WARNING: This technique might very well not work as expected on chained
3345 searches - you have been warned.
3347 # Assuming the Event resultsource is defined as:
3349 MySchema::Event->add_columns (
3352 is_auto_increment => 1,
3361 MySchema::Event->set_primary_key ('sequence');
3363 # This will get back the latest event for every location. The column
3364 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3365 # combo to limit the resultset
3367 $rs = $schema->resultset('Event');
3368 $table = $rs->result_source->name;
3369 $latest = $rs->search (
3372 (SELECT e1.* FROM $table e1
3374 ON e1.location = e2.location
3375 AND e1.sequence < e2.sequence
3376 WHERE e2.sequence is NULL
3381 # Equivalent SQL (with the DBIC chunks added):
3383 SELECT me.sequence, me.location, me.type FROM
3384 (SELECT e1.* FROM events e1
3386 ON e1.location = e2.location
3387 AND e1.sequence < e2.sequence
3388 WHERE e2.sequence is NULL
3395 =item Value: ( 'update' | 'shared' )
3399 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT