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 return $self->{cursor}
665 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
666 $attrs->{where},$attrs);
673 =item Arguments: $cond?
675 =item Return Value: $row_object?
679 my $cd = $schema->resultset('CD')->single({ year => 2001 });
681 Inflates the first result without creating a cursor if the resultset has
682 any records in it; if not returns nothing. Used by L</find> as a lean version of
685 While this method can take an optional search condition (just like L</search>)
686 being a fast-code-path it does not recognize search attributes. If you need to
687 add extra joins or similar, call L</search> and then chain-call L</single> on the
688 L<DBIx::Class::ResultSet> returned.
694 As of 0.08100, this method enforces the assumption that the preceeding
695 query returns only one row. If more than one row is returned, you will receive
698 Query returned more than one row
700 In this case, you should be using L</first> or L</find> instead, or if you really
701 know what you are doing, use the L</rows> attribute to explicitly limit the size
709 my ($self, $where) = @_;
711 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
714 my $attrs = $self->_resolved_attrs_copy;
716 if (defined $attrs->{where}) {
719 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
720 $where, delete $attrs->{where} ]
723 $attrs->{where} = $where;
727 # XXX: Disabled since it doesn't infer uniqueness in all cases
728 # unless ($self->_is_unique_query($attrs->{where})) {
729 # carp "Query not guaranteed to return a single row"
730 # . "; please declare your unique constraints or use search instead";
733 my @data = $self->result_source->storage->select_single(
734 $attrs->{from}, $attrs->{select},
735 $attrs->{where}, $attrs
738 return (@data ? ($self->_construct_object(@data))[0] : undef);
743 # Try to determine if the specified query is guaranteed to be unique, based on
744 # the declared unique constraints.
746 sub _is_unique_query {
747 my ($self, $query) = @_;
749 my $collapsed = $self->_collapse_query($query);
750 my $alias = $self->{attrs}{alias};
752 foreach my $name ($self->result_source->unique_constraint_names) {
753 my @unique_cols = map {
755 } $self->result_source->unique_constraint_columns($name);
757 # Count the values for each unique column
758 my %seen = map { $_ => 0 } @unique_cols;
760 foreach my $key (keys %$collapsed) {
761 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
762 next unless exists $seen{$aliased}; # Additional constraints are okay
763 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
766 # If we get 0 or more than 1 value for a column, it's not necessarily unique
767 return 1 unless grep { $_ != 1 } values %seen;
775 # Recursively collapse the query, accumulating values for each column.
777 sub _collapse_query {
778 my ($self, $query, $collapsed) = @_;
782 if (ref $query eq 'ARRAY') {
783 foreach my $subquery (@$query) {
784 next unless ref $subquery; # -or
785 $collapsed = $self->_collapse_query($subquery, $collapsed);
788 elsif (ref $query eq 'HASH') {
789 if (keys %$query and (keys %$query)[0] eq '-and') {
790 foreach my $subquery (@{$query->{-and}}) {
791 $collapsed = $self->_collapse_query($subquery, $collapsed);
795 foreach my $col (keys %$query) {
796 my $value = $query->{$col};
797 $collapsed->{$col}{$value}++;
809 =item Arguments: $cond?
811 =item Return Value: $resultsetcolumn
815 my $max_length = $rs->get_column('length')->max;
817 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
822 my ($self, $column) = @_;
823 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
831 =item Arguments: $cond, \%attrs?
833 =item Return Value: $resultset (scalar context), @row_objs (list context)
837 # WHERE title LIKE '%blue%'
838 $cd_rs = $rs->search_like({ title => '%blue%'});
840 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
841 that this is simply a convenience method retained for ex Class::DBI users.
842 You most likely want to use L</search> with specific operators.
844 For more information, see L<DBIx::Class::Manual::Cookbook>.
846 This method is deprecated and will be removed in 0.09. Use L</search()>
847 instead. An example conversion is:
849 ->search_like({ foo => 'bar' });
853 ->search({ foo => { like => 'bar' } });
860 'search_like() is deprecated and will be removed in 0.09.',
861 'Instead use ->search({ x => { -like => "y%" } })',
862 '(note the outer pair of {}s - they are important!)'
864 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
865 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
866 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
867 return $class->search($query, { %$attrs });
874 =item Arguments: $first, $last
876 =item Return Value: $resultset (scalar context), @row_objs (list context)
880 Returns a resultset or object list representing a subset of elements from the
881 resultset slice is called on. Indexes are from 0, i.e., to get the first
884 my ($one, $two, $three) = $rs->slice(0, 2);
889 my ($self, $min, $max) = @_;
890 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
891 $attrs->{offset} = $self->{attrs}{offset} || 0;
892 $attrs->{offset} += $min;
893 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
894 return $self->search(undef(), $attrs);
895 #my $slice = (ref $self)->new($self->result_source, $attrs);
896 #return (wantarray ? $slice->all : $slice);
903 =item Arguments: none
905 =item Return Value: $result?
909 Returns the next element in the resultset (C<undef> is there is none).
911 Can be used to efficiently iterate over records in the resultset:
913 my $rs = $schema->resultset('CD')->search;
914 while (my $cd = $rs->next) {
918 Note that you need to store the resultset object, and call C<next> on it.
919 Calling C<< resultset('Table')->next >> repeatedly will always return the
920 first record from the resultset.
926 if (my $cache = $self->get_cache) {
927 $self->{all_cache_position} ||= 0;
928 return $cache->[$self->{all_cache_position}++];
930 if ($self->{attrs}{cache}) {
931 $self->{all_cache_position} = 1;
932 return ($self->all)[0];
934 if ($self->{stashed_objects}) {
935 my $obj = shift(@{$self->{stashed_objects}});
936 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
940 exists $self->{stashed_row}
941 ? @{delete $self->{stashed_row}}
942 : $self->cursor->next
944 return undef unless (@row);
945 my ($row, @more) = $self->_construct_object(@row);
946 $self->{stashed_objects} = \@more if @more;
950 sub _construct_object {
951 my ($self, @row) = @_;
952 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
953 my @new = $self->result_class->inflate_result($self->result_source, @$info);
954 @new = $self->{_attrs}{record_filter}->(@new)
955 if exists $self->{_attrs}{record_filter};
959 sub _collapse_result {
960 my ($self, $as_proto, $row) = @_;
964 # 'foo' => [ undef, 'foo' ]
965 # 'foo.bar' => [ 'foo', 'bar' ]
966 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
968 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
970 my %collapse = %{$self->{_attrs}{collapse}||{}};
974 # if we're doing collapsing (has_many prefetch) we need to grab records
975 # until the PK changes, so fill @pri_index. if not, we leave it empty so
976 # we know we don't have to bother.
978 # the reason for not using the collapse stuff directly is because if you
979 # had for e.g. two artists in a row with no cds, the collapse info for
980 # both would be NULL (undef) so you'd lose the second artist
982 # store just the index so we can check the array positions from the row
983 # without having to contruct the full hash
985 if (keys %collapse) {
986 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
987 foreach my $i (0 .. $#construct_as) {
988 next if defined($construct_as[$i][0]); # only self table
989 if (delete $pri{$construct_as[$i][1]}) {
990 push(@pri_index, $i);
992 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
996 # no need to do an if, it'll be empty if @pri_index is empty anyway
998 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1002 do { # no need to check anything at the front, we always want the first row
1006 foreach my $this_as (@construct_as) {
1007 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1010 push(@const_rows, \%const);
1012 } until ( # no pri_index => no collapse => drop straight out
1015 do { # get another row, stash it, drop out if different PK
1017 @copy = $self->cursor->next;
1018 $self->{stashed_row} = \@copy;
1020 # last thing in do block, counts as true if anything doesn't match
1022 # check xor defined first for NULL vs. NOT NULL then if one is
1023 # defined the other must be so check string equality
1026 (defined $pri_vals{$_} ^ defined $copy[$_])
1027 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1032 my $alias = $self->{attrs}{alias};
1039 foreach my $const (@const_rows) {
1040 scalar @const_keys or do {
1041 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1043 foreach my $key (@const_keys) {
1046 my @parts = split(/\./, $key);
1048 my $data = $const->{$key};
1049 foreach my $p (@parts) {
1050 $target = $target->[1]->{$p} ||= [];
1052 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1053 # collapsing at this point and on final part
1054 my $pos = $collapse_pos{$cur};
1055 CK: foreach my $ck (@ckey) {
1056 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1057 $collapse_pos{$cur} = $data;
1058 delete @collapse_pos{ # clear all positioning for sub-entries
1059 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1066 if (exists $collapse{$cur}) {
1067 $target = $target->[-1];
1070 $target->[0] = $data;
1072 $info->[0] = $const->{$key};
1080 =head2 result_source
1084 =item Arguments: $result_source?
1086 =item Return Value: $result_source
1090 An accessor for the primary ResultSource object from which this ResultSet
1097 =item Arguments: $result_class?
1099 =item Return Value: $result_class
1103 An accessor for the class to use when creating row objects. Defaults to
1104 C<< result_source->result_class >> - which in most cases is the name of the
1105 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1107 Note that changing the result_class will also remove any components
1108 that were originally loaded in the source class via
1109 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1110 in the original source class will not run.
1115 my ($self, $result_class) = @_;
1116 if ($result_class) {
1117 $self->ensure_class_loaded($result_class);
1118 $self->_result_class($result_class);
1120 $self->_result_class;
1127 =item Arguments: $cond, \%attrs??
1129 =item Return Value: $count
1133 Performs an SQL C<COUNT> with the same query as the resultset was built
1134 with to find the number of elements. Passing arguments is equivalent to
1135 C<< $rs->search ($cond, \%attrs)->count >>
1141 return $self->search(@_)->count if @_ and defined $_[0];
1142 return scalar @{ $self->get_cache } if $self->get_cache;
1144 my @subq_attrs = qw/prefetch collapse distinct group_by having/;
1145 my $attrs = $self->_resolved_attrs;
1147 # if we are not paged - we are simply asking for a limit
1148 if (not $attrs->{page} and not $attrs->{software_limit}) {
1149 push @subq_attrs, qw/rows offset/;
1152 return $self->_has_attr (@subq_attrs)
1153 ? $self->_count_subq
1154 : $self->_count_simple
1160 my $attrs = $self->_resolved_attrs_copy;
1162 # copy for the subquery, we need to do some adjustments to it too
1163 my $sub_attrs = { %$attrs };
1165 # these can not go in the subquery either
1166 delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
1168 # force a group_by and the same set of columns (most databases require this)
1169 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1172 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1175 # the subquery replaces this
1176 delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind/;
1178 return $self->__count ($attrs);
1184 my $count = $self->__count;
1185 return 0 unless $count;
1187 # need to take offset from resolved attrs
1189 my $attrs = $self->_resolved_attrs;
1191 $count -= $attrs->{offset} if $attrs->{offset};
1192 $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
1193 $count = 0 if ($count < 0);
1198 my ($self, $attrs) = @_;
1200 $attrs ||= $self->_resolved_attrs_copy;
1202 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1203 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1205 $attrs->{select} = { count => '*' };
1206 $attrs->{as} = [qw/count/];
1208 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1209 my ($count) = $tmp_rs->cursor->next;
1218 =head2 count_literal
1222 =item Arguments: $sql_fragment, @bind_values
1224 =item Return Value: $count
1228 Counts the results in a literal query. Equivalent to calling L</search_literal>
1229 with the passed arguments, then L</count>.
1233 sub count_literal { shift->search_literal(@_)->count; }
1239 =item Arguments: none
1241 =item Return Value: @objects
1245 Returns all elements in the resultset. Called implicitly if the resultset
1246 is returned in list context.
1253 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1256 return @{ $self->get_cache } if $self->get_cache;
1260 # TODO: don't call resolve here
1261 if (keys %{$self->_resolved_attrs->{collapse}}) {
1262 # if ($self->{attrs}{prefetch}) {
1263 # Using $self->cursor->all is really just an optimisation.
1264 # If we're collapsing has_many prefetches it probably makes
1265 # very little difference, and this is cleaner than hacking
1266 # _construct_object to survive the approach
1267 my @row = $self->cursor->next;
1269 push(@obj, $self->_construct_object(@row));
1270 @row = (exists $self->{stashed_row}
1271 ? @{delete $self->{stashed_row}}
1272 : $self->cursor->next);
1275 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1278 $self->set_cache(\@obj) if $self->{attrs}{cache};
1286 =item Arguments: none
1288 =item Return Value: $self
1292 Resets the resultset's cursor, so you can iterate through the elements again.
1298 delete $self->{_attrs} if exists $self->{_attrs};
1299 $self->{all_cache_position} = 0;
1300 $self->cursor->reset;
1308 =item Arguments: none
1310 =item Return Value: $object?
1314 Resets the resultset and returns an object for the first result (if the
1315 resultset returns anything).
1320 return $_[0]->reset->next;
1326 # Determines whether and what type of subquery is required for the $rs operation.
1327 # If grouping is necessary either supplies its own, or verifies the current one
1328 # After all is done delegates to the proper storage method.
1330 sub _rs_update_delete {
1331 my ($self, $op, $values) = @_;
1333 my $rsrc = $self->result_source;
1335 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1336 my $needs_subq = $self->_has_attr (qw/row offset page/);
1338 if ($needs_group_by_subq or $needs_subq) {
1340 # make a new $rs selecting only the PKs (that's all we really need)
1341 my $attrs = $self->_resolved_attrs_copy;
1343 delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
1344 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1346 if ($needs_group_by_subq) {
1347 # make sure no group_by was supplied, or if there is one - make sure it matches
1348 # the columns compiled above perfectly. Anything else can not be sanely executed
1349 # on most databases so croak right then and there
1351 if (my $g = $attrs->{group_by}) {
1352 my @current_group_by = map
1353 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1354 (ref $g eq 'ARRAY' ? @$g : $g );
1357 join ("\x00", sort @current_group_by)
1359 join ("\x00", sort @{$attrs->{columns}} )
1361 $self->throw_exception (
1362 "You have just attempted a $op operation on a resultset which does group_by"
1363 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1364 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1365 . ' kind of queries. Please retry the operation with a modified group_by or'
1366 . ' without using one at all.'
1371 $attrs->{group_by} = $attrs->{columns};
1375 my $subrs = (ref $self)->new($rsrc, $attrs);
1377 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1380 return $rsrc->storage->$op(
1382 $op eq 'update' ? $values : (),
1383 $self->_cond_for_update_delete,
1389 # _cond_for_update_delete
1391 # update/delete require the condition to be modified to handle
1392 # the differing SQL syntax available. This transforms the $self->{cond}
1393 # appropriately, returning the new condition.
1395 sub _cond_for_update_delete {
1396 my ($self, $full_cond) = @_;
1399 $full_cond ||= $self->{cond};
1400 # No-op. No condition, we're updating/deleting everything
1401 return $cond unless ref $full_cond;
1403 if (ref $full_cond eq 'ARRAY') {
1407 foreach my $key (keys %{$_}) {
1409 $hash{$1} = $_->{$key};
1415 elsif (ref $full_cond eq 'HASH') {
1416 if ((keys %{$full_cond})[0] eq '-and') {
1418 my @cond = @{$full_cond->{-and}};
1419 for (my $i = 0; $i < @cond; $i++) {
1420 my $entry = $cond[$i];
1422 if (ref $entry eq 'HASH') {
1423 $hash = $self->_cond_for_update_delete($entry);
1426 $entry =~ /([^.]+)$/;
1427 $hash->{$1} = $cond[++$i];
1429 push @{$cond->{-and}}, $hash;
1433 foreach my $key (keys %{$full_cond}) {
1435 $cond->{$1} = $full_cond->{$key};
1440 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1451 =item Arguments: \%values
1453 =item Return Value: $storage_rv
1457 Sets the specified columns in the resultset to the supplied values in a
1458 single query. Return value will be true if the update succeeded or false
1459 if no records were updated; exact type of success value is storage-dependent.
1464 my ($self, $values) = @_;
1465 $self->throw_exception('Values for update must be a hash')
1466 unless ref $values eq 'HASH';
1468 return $self->_rs_update_delete ('update', $values);
1475 =item Arguments: \%values
1477 =item Return Value: 1
1481 Fetches all objects and updates them one at a time. Note that C<update_all>
1482 will run DBIC cascade triggers, while L</update> will not.
1487 my ($self, $values) = @_;
1488 $self->throw_exception('Values for update_all must be a hash')
1489 unless ref $values eq 'HASH';
1490 foreach my $obj ($self->all) {
1491 $obj->set_columns($values)->update;
1500 =item Arguments: none
1502 =item Return Value: 1
1506 Deletes the contents of the resultset from its result source. Note that this
1507 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1508 to run. See also L<DBIx::Class::Row/delete>.
1510 delete may not generate correct SQL for a query with joins or a resultset
1511 chained from a related resultset. In this case it will generate a warning:-
1513 In these cases you may find that delete_all is more appropriate, or you
1514 need to respecify your query in a way that can be expressed without a join.
1520 $self->throw_exception('delete does not accept any arguments')
1523 return $self->_rs_update_delete ('delete');
1530 =item Arguments: none
1532 =item Return Value: 1
1536 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1537 will run DBIC cascade triggers, while L</delete> will not.
1543 $self->throw_exception('delete_all does not accept any arguments')
1546 $_->delete for $self->all;
1554 =item Arguments: \@data;
1558 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1559 For the arrayref of hashrefs style each hashref should be a structure suitable
1560 forsubmitting to a $resultset->create(...) method.
1562 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1563 to insert the data, as this is a faster method.
1565 Otherwise, each set of data is inserted into the database using
1566 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1567 objects is returned.
1569 Example: Assuming an Artist Class that has many CDs Classes relating:
1571 my $Artist_rs = $schema->resultset("Artist");
1573 ## Void Context Example
1574 $Artist_rs->populate([
1575 { artistid => 4, name => 'Manufactured Crap', cds => [
1576 { title => 'My First CD', year => 2006 },
1577 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1580 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1581 { title => 'My parents sold me to a record company' ,year => 2005 },
1582 { title => 'Why Am I So Ugly?', year => 2006 },
1583 { title => 'I Got Surgery and am now Popular', year => 2007 }
1588 ## Array Context Example
1589 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1590 { name => "Artist One"},
1591 { name => "Artist Two"},
1592 { name => "Artist Three", cds=> [
1593 { title => "First CD", year => 2007},
1594 { title => "Second CD", year => 2008},
1598 print $ArtistOne->name; ## response is 'Artist One'
1599 print $ArtistThree->cds->count ## reponse is '2'
1601 For the arrayref of arrayrefs style, the first element should be a list of the
1602 fieldsnames to which the remaining elements are rows being inserted. For
1605 $Arstist_rs->populate([
1606 [qw/artistid name/],
1607 [100, 'A Formally Unknown Singer'],
1608 [101, 'A singer that jumped the shark two albums ago'],
1609 [102, 'An actually cool singer.'],
1612 Please note an important effect on your data when choosing between void and
1613 wantarray context. Since void context goes straight to C<insert_bulk> in
1614 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1615 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1616 create primary keys for you, you will find that your PKs are empty. In this
1617 case you will have to use the wantarray context in order to create those
1623 my $self = shift @_;
1624 my $data = ref $_[0][0] eq 'HASH'
1625 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1626 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1628 if(defined wantarray) {
1630 foreach my $item (@$data) {
1631 push(@created, $self->create($item));
1635 my ($first, @rest) = @$data;
1637 my @names = grep {!ref $first->{$_}} keys %$first;
1638 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1639 my @pks = $self->result_source->primary_columns;
1641 ## do the belongs_to relationships
1642 foreach my $index (0..$#$data) {
1643 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1644 my @ret = $self->populate($data);
1648 foreach my $rel (@rels) {
1649 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1650 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1651 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1652 my $related = $result->result_source->_resolve_condition(
1653 $result->result_source->relationship_info($reverse)->{cond},
1658 delete $data->[$index]->{$rel};
1659 $data->[$index] = {%{$data->[$index]}, %$related};
1661 push @names, keys %$related if $index == 0;
1665 ## do bulk insert on current row
1666 my @values = map { [ @$_{@names} ] } @$data;
1668 $self->result_source->storage->insert_bulk(
1669 $self->result_source,
1674 ## do the has_many relationships
1675 foreach my $item (@$data) {
1677 foreach my $rel (@rels) {
1678 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1680 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1681 || $self->throw_exception('Cannot find the relating object.');
1683 my $child = $parent->$rel;
1685 my $related = $child->result_source->_resolve_condition(
1686 $parent->result_source->relationship_info($rel)->{cond},
1691 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1692 my @populate = map { {%$_, %$related} } @rows_to_add;
1694 $child->populate( \@populate );
1700 =head2 _normalize_populate_args ($args)
1702 Private method used by L</populate> to normalize its incoming arguments. Factored
1703 out in case you want to subclass and accept new argument structures to the
1704 L</populate> method.
1708 sub _normalize_populate_args {
1709 my ($self, $data) = @_;
1710 my @names = @{shift(@$data)};
1711 my @results_to_create;
1712 foreach my $datum (@$data) {
1713 my %result_to_create;
1714 foreach my $index (0..$#names) {
1715 $result_to_create{$names[$index]} = $$datum[$index];
1717 push @results_to_create, \%result_to_create;
1719 return \@results_to_create;
1726 =item Arguments: none
1728 =item Return Value: $pager
1732 Return Value a L<Data::Page> object for the current resultset. Only makes
1733 sense for queries with a C<page> attribute.
1735 To get the full count of entries for a paged resultset, call
1736 C<total_entries> on the L<Data::Page> object.
1743 return $self->{pager} if $self->{pager};
1745 my $attrs = $self->{attrs};
1746 $self->throw_exception("Can't create pager for non-paged rs")
1747 unless $self->{attrs}{page};
1748 $attrs->{rows} ||= 10;
1750 # throw away the paging flags and re-run the count (possibly
1751 # with a subselect) to get the real total count
1752 my $count_attrs = { %$attrs };
1753 delete $count_attrs->{$_} for qw/rows offset page pager/;
1754 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1756 return $self->{pager} = Data::Page->new(
1759 $self->{attrs}{page}
1767 =item Arguments: $page_number
1769 =item Return Value: $rs
1773 Returns a resultset for the $page_number page of the resultset on which page
1774 is called, where each page contains a number of rows equal to the 'rows'
1775 attribute set on the resultset (10 by default).
1780 my ($self, $page) = @_;
1781 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1788 =item Arguments: \%vals
1790 =item Return Value: $rowobject
1794 Creates a new row object in the resultset's result class and returns
1795 it. The row is not inserted into the database at this point, call
1796 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1797 will tell you whether the row object has been inserted or not.
1799 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1804 my ($self, $values) = @_;
1805 $self->throw_exception( "new_result needs a hash" )
1806 unless (ref $values eq 'HASH');
1809 my $alias = $self->{attrs}{alias};
1812 defined $self->{cond}
1813 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1815 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1816 $new{-from_resultset} = [ keys %new ] if keys %new;
1818 $self->throw_exception(
1819 "Can't abstract implicit construct, condition not a hash"
1820 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1822 my $collapsed_cond = (
1824 ? $self->_collapse_cond($self->{cond})
1828 # precendence must be given to passed values over values inherited from
1829 # the cond, so the order here is important.
1830 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1831 while( my($col,$value) = each %implied ){
1832 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1833 $new{$col} = $value->{'='};
1836 $new{$col} = $value if $self->_is_deterministic_value($value);
1842 %{ $self->_remove_alias($values, $alias) },
1843 -source_handle => $self->_source_handle,
1844 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1847 return $self->result_class->new(\%new);
1850 # _is_deterministic_value
1852 # Make an effor to strip non-deterministic values from the condition,
1853 # to make sure new_result chokes less
1855 sub _is_deterministic_value {
1858 my $ref_type = ref $value;
1859 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1860 return 1 if Scalar::Util::blessed($value);
1866 # determines if the resultset defines at least one
1867 # of the attributes supplied
1869 # used to determine if a subquery is neccessary
1872 my ($self, @attr_names) = @_;
1874 my $attrs = $self->_resolved_attrs;
1878 for my $n (@attr_names) {
1879 ++$join_check_req if $n =~ /join/;
1881 my $attr = $attrs->{$n};
1883 next if not defined $attr;
1885 if (ref $attr eq 'HASH') {
1886 return 1 if keys %$attr;
1888 elsif (ref $attr eq 'ARRAY') {
1896 # a join can be expressed as a multi-level from
1900 ref $attrs->{from} eq 'ARRAY'
1902 @{$attrs->{from}} > 1
1910 # Recursively collapse the condition.
1912 sub _collapse_cond {
1913 my ($self, $cond, $collapsed) = @_;
1917 if (ref $cond eq 'ARRAY') {
1918 foreach my $subcond (@$cond) {
1919 next unless ref $subcond; # -or
1920 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1923 elsif (ref $cond eq 'HASH') {
1924 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1925 foreach my $subcond (@{$cond->{-and}}) {
1926 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1930 foreach my $col (keys %$cond) {
1931 my $value = $cond->{$col};
1932 $collapsed->{$col} = $value;
1942 # Remove the specified alias from the specified query hash. A copy is made so
1943 # the original query is not modified.
1946 my ($self, $query, $alias) = @_;
1948 my %orig = %{ $query || {} };
1951 foreach my $key (keys %orig) {
1953 $unaliased{$key} = $orig{$key};
1956 $unaliased{$1} = $orig{$key}
1957 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1963 =head2 as_query (EXPERIMENTAL)
1967 =item Arguments: none
1969 =item Return Value: \[ $sql, @bind ]
1973 Returns the SQL query and bind vars associated with the invocant.
1975 This is generally used as the RHS for a subquery.
1977 B<NOTE>: This feature is still experimental.
1981 sub as_query { return shift->cursor->as_query(@_) }
1987 =item Arguments: \%vals, \%attrs?
1989 =item Return Value: $rowobject
1993 my $artist = $schema->resultset('Artist')->find_or_new(
1994 { artist => 'fred' }, { key => 'artists' });
1996 $cd->cd_to_producer->find_or_new({ producer => $producer },
1997 { key => 'primary });
1999 Find an existing record from this resultset, based on its primary
2000 key, or a unique constraint. If none exists, instantiate a new result
2001 object and return it. The object will not be saved into your storage
2002 until you call L<DBIx::Class::Row/insert> on it.
2004 You most likely want this method when looking for existing rows using
2005 a unique constraint that is not the primary key, or looking for
2008 If you want objects to be saved immediately, use L</find_or_create> instead.
2010 B<Note>: C<find_or_new> is probably not what you want when creating a
2011 new row in a table that uses primary keys supplied by the
2012 database. Passing in a primary key column with a value of I<undef>
2013 will cause L</find> to attempt to search for a row with a value of
2020 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2021 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2022 my $exists = $self->find($hash, $attrs);
2023 return defined $exists ? $exists : $self->new_result($hash);
2030 =item Arguments: \%vals
2032 =item Return Value: a L<DBIx::Class::Row> $object
2036 Attempt to create a single new row or a row with multiple related rows
2037 in the table represented by the resultset (and related tables). This
2038 will not check for duplicate rows before inserting, use
2039 L</find_or_create> to do that.
2041 To create one row for this resultset, pass a hashref of key/value
2042 pairs representing the columns of the table and the values you wish to
2043 store. If the appropriate relationships are set up, foreign key fields
2044 can also be passed an object representing the foreign row, and the
2045 value will be set to its primary key.
2047 To create related objects, pass a hashref for the value if the related
2048 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2049 and use the name of the relationship as the key. (NOT the name of the field,
2050 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2051 of hashrefs containing the data for each of the rows to create in the foreign
2052 tables, again using the relationship name as the key.
2054 Instead of hashrefs of plain related data (key/value pairs), you may
2055 also pass new or inserted objects. New objects (not inserted yet, see
2056 L</new>), will be inserted into their appropriate tables.
2058 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2060 Example of creating a new row.
2062 $person_rs->create({
2063 name=>"Some Person",
2064 email=>"somebody@someplace.com"
2067 Example of creating a new row and also creating rows in a related C<has_many>
2068 or C<has_one> resultset. Note Arrayref.
2071 { artistid => 4, name => 'Manufactured Crap', cds => [
2072 { title => 'My First CD', year => 2006 },
2073 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2078 Example of creating a new row and also creating a row in a related
2079 C<belongs_to>resultset. Note Hashref.
2082 title=>"Music for Silly Walks",
2085 name=>"Silly Musician",
2092 my ($self, $attrs) = @_;
2093 $self->throw_exception( "create needs a hashref" )
2094 unless ref $attrs eq 'HASH';
2095 return $self->new_result($attrs)->insert;
2098 =head2 find_or_create
2102 =item Arguments: \%vals, \%attrs?
2104 =item Return Value: $rowobject
2108 $cd->cd_to_producer->find_or_create({ producer => $producer },
2109 { key => 'primary });
2111 Tries to find a record based on its primary key or unique constraints; if none
2112 is found, creates one and returns that instead.
2114 my $cd = $schema->resultset('CD')->find_or_create({
2116 artist => 'Massive Attack',
2117 title => 'Mezzanine',
2121 Also takes an optional C<key> attribute, to search by a specific key or unique
2122 constraint. For example:
2124 my $cd = $schema->resultset('CD')->find_or_create(
2126 artist => 'Massive Attack',
2127 title => 'Mezzanine',
2129 { key => 'cd_artist_title' }
2132 B<Note>: Because find_or_create() reads from the database and then
2133 possibly inserts based on the result, this method is subject to a race
2134 condition. Another process could create a record in the table after
2135 the find has completed and before the create has started. To avoid
2136 this problem, use find_or_create() inside a transaction.
2138 B<Note>: C<find_or_create> is probably not what you want when creating
2139 a new row in a table that uses primary keys supplied by the
2140 database. Passing in a primary key column with a value of I<undef>
2141 will cause L</find> to attempt to search for a row with a value of
2144 See also L</find> and L</update_or_create>. For information on how to declare
2145 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2149 sub find_or_create {
2151 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2152 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2153 my $exists = $self->find($hash, $attrs);
2154 return defined $exists ? $exists : $self->create($hash);
2157 =head2 update_or_create
2161 =item Arguments: \%col_values, { key => $unique_constraint }?
2163 =item Return Value: $rowobject
2167 $resultset->update_or_create({ col => $val, ... });
2169 First, searches for an existing row matching one of the unique constraints
2170 (including the primary key) on the source of this resultset. If a row is
2171 found, updates it with the other given column values. Otherwise, creates a new
2174 Takes an optional C<key> attribute to search on a specific unique constraint.
2177 # In your application
2178 my $cd = $schema->resultset('CD')->update_or_create(
2180 artist => 'Massive Attack',
2181 title => 'Mezzanine',
2184 { key => 'cd_artist_title' }
2187 $cd->cd_to_producer->update_or_create({
2188 producer => $producer,
2195 If no C<key> is specified, it searches on all unique constraints defined on the
2196 source, including the primary key.
2198 If the C<key> is specified as C<primary>, it searches only on the primary key.
2200 See also L</find> and L</find_or_create>. For information on how to declare
2201 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2203 B<Note>: C<update_or_create> is probably not what you want when
2204 looking for a row in a table that uses primary keys supplied by the
2205 database, unless you actually have a key value. Passing in a primary
2206 key column with a value of I<undef> will cause L</find> to attempt to
2207 search for a row with a value of I<NULL>.
2211 sub update_or_create {
2213 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2214 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2216 my $row = $self->find($cond, $attrs);
2218 $row->update($cond);
2222 return $self->create($cond);
2225 =head2 update_or_new
2229 =item Arguments: \%col_values, { key => $unique_constraint }?
2231 =item Return Value: $rowobject
2235 $resultset->update_or_new({ col => $val, ... });
2237 First, searches for an existing row matching one of the unique constraints
2238 (including the primary key) on the source of this resultset. If a row is
2239 found, updates it with the other given column values. Otherwise, instantiate
2240 a new result object and return it. The object will not be saved into your storage
2241 until you call L<DBIx::Class::Row/insert> on it.
2243 Takes an optional C<key> attribute to search on a specific unique constraint.
2246 # In your application
2247 my $cd = $schema->resultset('CD')->update_or_new(
2249 artist => 'Massive Attack',
2250 title => 'Mezzanine',
2253 { key => 'cd_artist_title' }
2256 if ($cd->in_storage) {
2257 # the cd was updated
2260 # the cd is not yet in the database, let's insert it
2264 See also L</find>, L</find_or_create> and L<find_or_new>.
2270 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2271 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2273 my $row = $self->find( $cond, $attrs );
2274 if ( defined $row ) {
2275 $row->update($cond);
2279 return $self->new_result($cond);
2286 =item Arguments: none
2288 =item Return Value: \@cache_objects?
2292 Gets the contents of the cache for the resultset, if the cache is set.
2294 The cache is populated either by using the L</prefetch> attribute to
2295 L</search> or by calling L</set_cache>.
2307 =item Arguments: \@cache_objects
2309 =item Return Value: \@cache_objects
2313 Sets the contents of the cache for the resultset. Expects an arrayref
2314 of objects of the same class as those produced by the resultset. Note that
2315 if the cache is set the resultset will return the cached objects rather
2316 than re-querying the database even if the cache attr is not set.
2318 The contents of the cache can also be populated by using the
2319 L</prefetch> attribute to L</search>.
2324 my ( $self, $data ) = @_;
2325 $self->throw_exception("set_cache requires an arrayref")
2326 if defined($data) && (ref $data ne 'ARRAY');
2327 $self->{all_cache} = $data;
2334 =item Arguments: none
2336 =item Return Value: []
2340 Clears the cache for the resultset.
2345 shift->set_cache(undef);
2348 =head2 related_resultset
2352 =item Arguments: $relationship_name
2354 =item Return Value: $resultset
2358 Returns a related resultset for the supplied relationship name.
2360 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2364 sub related_resultset {
2365 my ($self, $rel) = @_;
2367 $self->{related_resultsets} ||= {};
2368 return $self->{related_resultsets}{$rel} ||= do {
2369 my $rel_obj = $self->result_source->relationship_info($rel);
2371 $self->throw_exception(
2372 "search_related: result source '" . $self->result_source->source_name .
2373 "' has no such relationship $rel")
2376 my ($from,$seen) = $self->_resolve_from($rel);
2378 my $join_count = $seen->{$rel};
2379 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2381 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2382 my %attrs = %{$self->{attrs}||{}};
2383 delete @attrs{qw(result_class alias)};
2387 if (my $cache = $self->get_cache) {
2388 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2389 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2394 my $rel_source = $self->result_source->related_source($rel);
2398 # The reason we do this now instead of passing the alias to the
2399 # search_rs below is that if you wrap/overload resultset on the
2400 # source you need to know what alias it's -going- to have for things
2401 # to work sanely (e.g. RestrictWithObject wants to be able to add
2402 # extra query restrictions, and these may need to be $alias.)
2404 my $attrs = $rel_source->resultset_attributes;
2405 local $attrs->{alias} = $alias;
2407 $rel_source->resultset
2415 where => $self->{cond},
2420 $new->set_cache($new_cache) if $new_cache;
2425 =head2 current_source_alias
2429 =item Arguments: none
2431 =item Return Value: $source_alias
2435 Returns the current table alias for the result source this resultset is built
2436 on, that will be used in the SQL query. Usually it is C<me>.
2438 Currently the source alias that refers to the result set returned by a
2439 L</search>/L</find> family method depends on how you got to the resultset: it's
2440 C<me> by default, but eg. L</search_related> aliases it to the related result
2441 source name (and keeps C<me> referring to the original result set). The long
2442 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2443 (and make this method unnecessary).
2445 Thus it's currently necessary to use this method in predefined queries (see
2446 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2447 source alias of the current result set:
2449 # in a result set class
2451 my ($self, $user) = @_;
2453 my $me = $self->current_source_alias;
2455 return $self->search(
2456 "$me.modified" => $user->id,
2462 sub current_source_alias {
2465 return ($self->{attrs} || {})->{alias} || 'me';
2468 # This code is called by search_related, and makes sure there
2469 # is clear separation between the joins before, during, and
2470 # after the relationship. This information is needed later
2471 # in order to properly resolve prefetch aliases (any alias
2472 # with a relation_chain_depth less than the depth of the
2473 # current prefetch is not considered)
2475 my ($self, $extra_join) = @_;
2476 my $source = $self->result_source;
2477 my $attrs = $self->{attrs};
2479 my $from = $attrs->{from}
2480 || [ { $attrs->{alias} => $source->from } ];
2482 my $seen = { %{$attrs->{seen_join}||{}} };
2484 # we need to take the prefetch the attrs into account before we
2485 # ->_resolve_join as otherwise they get lost - captainL
2486 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2488 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2490 ++$seen->{-relation_chain_depth};
2492 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2494 ++$seen->{-relation_chain_depth};
2496 return ($from,$seen);
2499 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2500 sub _resolved_attrs_copy {
2502 return { %{$self->_resolved_attrs (@_)} };
2505 sub _resolved_attrs {
2507 return $self->{_attrs} if $self->{_attrs};
2509 my $attrs = { %{ $self->{attrs} || {} } };
2510 my $source = $self->result_source;
2511 my $alias = $attrs->{alias};
2513 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2516 # build columns (as long as select isn't set) into a set of as/select hashes
2517 unless ( $attrs->{select} ) {
2519 ( ref($_) eq 'HASH' )
2523 /^\Q${alias}.\E(.+)$/
2534 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2536 # add the additional columns on
2537 foreach ( 'include_columns', '+columns' ) {
2538 push @colbits, map {
2539 ( ref($_) eq 'HASH' )
2541 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2542 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2545 # start with initial select items
2546 if ( $attrs->{select} ) {
2548 ( ref $attrs->{select} eq 'ARRAY' )
2549 ? [ @{ $attrs->{select} } ]
2550 : [ $attrs->{select} ];
2554 ref $attrs->{as} eq 'ARRAY'
2555 ? [ @{ $attrs->{as} } ]
2558 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2563 # otherwise we intialise select & as to empty
2564 $attrs->{select} = [];
2568 # now add colbits to select/as
2569 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2570 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2573 if ( $adds = delete $attrs->{'+select'} ) {
2574 $adds = [$adds] unless ref $adds eq 'ARRAY';
2576 @{ $attrs->{select} },
2577 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2580 if ( $adds = delete $attrs->{'+as'} ) {
2581 $adds = [$adds] unless ref $adds eq 'ARRAY';
2582 push( @{ $attrs->{as} }, @$adds );
2585 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2587 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2588 my $join = delete $attrs->{join} || {};
2590 if ( defined $attrs->{prefetch} ) {
2591 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2595 $attrs->{from} = # have to copy here to avoid corrupting the original
2597 @{ $attrs->{from} },
2598 $source->_resolve_join(
2599 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2605 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ]
2606 if delete $attrs->{distinct};
2607 if ( $attrs->{order_by} ) {
2608 $attrs->{order_by} = (
2609 ref( $attrs->{order_by} ) eq 'ARRAY'
2610 ? [ @{ $attrs->{order_by} } ]
2611 : [ $attrs->{order_by} ]
2615 $attrs->{order_by} = [];
2618 my $collapse = $attrs->{collapse} || {};
2619 if ( my $prefetch = delete $attrs->{prefetch} ) {
2620 $prefetch = $self->_merge_attr( {}, $prefetch );
2622 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2624 # bring joins back to level of current class
2625 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2627 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2628 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2629 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2631 push( @{ $attrs->{order_by} }, @pre_order );
2633 $attrs->{collapse} = $collapse;
2635 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2636 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2639 return $self->{_attrs} = $attrs;
2642 sub _joinpath_aliases {
2643 my ($self, $fromspec, $seen) = @_;
2646 return $paths unless ref $fromspec eq 'ARRAY';
2648 for my $j (@$fromspec) {
2650 next if ref $j ne 'ARRAY';
2651 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2654 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2655 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2662 my ($self, $attr) = @_;
2664 if (ref $attr eq 'HASH') {
2665 return $self->_rollout_hash($attr);
2666 } elsif (ref $attr eq 'ARRAY') {
2667 return $self->_rollout_array($attr);
2673 sub _rollout_array {
2674 my ($self, $attr) = @_;
2677 foreach my $element (@{$attr}) {
2678 if (ref $element eq 'HASH') {
2679 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2680 } elsif (ref $element eq 'ARRAY') {
2681 # XXX - should probably recurse here
2682 push( @rolled_array, @{$self->_rollout_array($element)} );
2684 push( @rolled_array, $element );
2687 return \@rolled_array;
2691 my ($self, $attr) = @_;
2694 foreach my $key (keys %{$attr}) {
2695 push( @rolled_array, { $key => $attr->{$key} } );
2697 return \@rolled_array;
2700 sub _calculate_score {
2701 my ($self, $a, $b) = @_;
2703 if (ref $b eq 'HASH') {
2704 my ($b_key) = keys %{$b};
2705 if (ref $a eq 'HASH') {
2706 my ($a_key) = keys %{$a};
2707 if ($a_key eq $b_key) {
2708 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2713 return ($a eq $b_key) ? 1 : 0;
2716 if (ref $a eq 'HASH') {
2717 my ($a_key) = keys %{$a};
2718 return ($b eq $a_key) ? 1 : 0;
2720 return ($b eq $a) ? 1 : 0;
2726 my ($self, $orig, $import) = @_;
2728 return $import unless defined($orig);
2729 return $orig unless defined($import);
2731 $orig = $self->_rollout_attr($orig);
2732 $import = $self->_rollout_attr($import);
2735 foreach my $import_element ( @{$import} ) {
2736 # find best candidate from $orig to merge $b_element into
2737 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2738 foreach my $orig_element ( @{$orig} ) {
2739 my $score = $self->_calculate_score( $orig_element, $import_element );
2740 if ($score > $best_candidate->{score}) {
2741 $best_candidate->{position} = $position;
2742 $best_candidate->{score} = $score;
2746 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2748 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2749 push( @{$orig}, $import_element );
2751 my $orig_best = $orig->[$best_candidate->{position}];
2752 # merge orig_best and b_element together and replace original with merged
2753 if (ref $orig_best ne 'HASH') {
2754 $orig->[$best_candidate->{position}] = $import_element;
2755 } elsif (ref $import_element eq 'HASH') {
2756 my ($key) = keys %{$orig_best};
2757 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2760 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2770 $self->_source_handle($_[0]->handle);
2772 $self->_source_handle->resolve;
2776 =head2 throw_exception
2778 See L<DBIx::Class::Schema/throw_exception> for details.
2782 sub throw_exception {
2784 if (ref $self && $self->_source_handle->schema) {
2785 $self->_source_handle->schema->throw_exception(@_)
2792 # XXX: FIXME: Attributes docs need clearing up
2796 Attributes are used to refine a ResultSet in various ways when
2797 searching for data. They can be passed to any method which takes an
2798 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2801 These are in no particular order:
2807 =item Value: ( $order_by | \@order_by | \%order_by )
2811 Which column(s) to order the results by. If a single column name, or
2812 an arrayref of names is supplied, the argument is passed through
2813 directly to SQL. The hashref syntax allows for connection-agnostic
2814 specification of ordering direction:
2816 For descending order:
2818 order_by => { -desc => [qw/col1 col2 col3/] }
2820 For explicit ascending order:
2822 order_by => { -asc => 'col' }
2824 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2825 supported, although you are strongly encouraged to use the hashref
2826 syntax as outlined above.
2832 =item Value: \@columns
2836 Shortcut to request a particular set of columns to be retrieved. Each
2837 column spec may be a string (a table column name), or a hash (in which
2838 case the key is the C<as> value, and the value is used as the C<select>
2839 expression). Adds C<me.> onto the start of any column without a C<.> in
2840 it and sets C<select> from that, then auto-populates C<as> from
2841 C<select> as normal. (You may also use the C<cols> attribute, as in
2842 earlier versions of DBIC.)
2848 =item Value: \@columns
2852 Indicates additional columns to be selected from storage. Works the same
2853 as L</columns> but adds columns to the selection. (You may also use the
2854 C<include_columns> attribute, as in earlier versions of DBIC). For
2857 $schema->resultset('CD')->search(undef, {
2858 '+columns' => ['artist.name'],
2862 would return all CDs and include a 'name' column to the information
2863 passed to object inflation. Note that the 'artist' is the name of the
2864 column (or relationship) accessor, and 'name' is the name of the column
2865 accessor in the related table.
2867 =head2 include_columns
2871 =item Value: \@columns
2875 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2881 =item Value: \@select_columns
2885 Indicates which columns should be selected from the storage. You can use
2886 column names, or in the case of RDBMS back ends, function or stored procedure
2889 $rs = $schema->resultset('Employee')->search(undef, {
2892 { count => 'employeeid' },
2897 When you use function/stored procedure names and do not supply an C<as>
2898 attribute, the column names returned are storage-dependent. E.g. MySQL would
2899 return a column named C<count(employeeid)> in the above example.
2905 Indicates additional columns to be selected from storage. Works the same as
2906 L</select> but adds columns to the selection.
2914 Indicates additional column names for those added via L</+select>. See L</as>.
2922 =item Value: \@inflation_names
2926 Indicates column names for object inflation. That is, C<as>
2927 indicates the name that the column can be accessed as via the
2928 C<get_column> method (or via the object accessor, B<if one already
2929 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2931 The C<as> attribute is used in conjunction with C<select>,
2932 usually when C<select> contains one or more function or stored
2935 $rs = $schema->resultset('Employee')->search(undef, {
2938 { count => 'employeeid' }
2940 as => ['name', 'employee_count'],
2943 my $employee = $rs->first(); # get the first Employee
2945 If the object against which the search is performed already has an accessor
2946 matching a column name specified in C<as>, the value can be retrieved using
2947 the accessor as normal:
2949 my $name = $employee->name();
2951 If on the other hand an accessor does not exist in the object, you need to
2952 use C<get_column> instead:
2954 my $employee_count = $employee->get_column('employee_count');
2956 You can create your own accessors if required - see
2957 L<DBIx::Class::Manual::Cookbook> for details.
2959 Please note: This will NOT insert an C<AS employee_count> into the SQL
2960 statement produced, it is used for internal access only. Thus
2961 attempting to use the accessor in an C<order_by> clause or similar
2962 will fail miserably.
2964 To get around this limitation, you can supply literal SQL to your
2965 C<select> attibute that contains the C<AS alias> text, eg:
2967 select => [\'myfield AS alias']
2973 =item Value: ($rel_name | \@rel_names | \%rel_names)
2977 Contains a list of relationships that should be joined for this query. For
2980 # Get CDs by Nine Inch Nails
2981 my $rs = $schema->resultset('CD')->search(
2982 { 'artist.name' => 'Nine Inch Nails' },
2983 { join => 'artist' }
2986 Can also contain a hash reference to refer to the other relation's relations.
2989 package MyApp::Schema::Track;
2990 use base qw/DBIx::Class/;
2991 __PACKAGE__->table('track');
2992 __PACKAGE__->add_columns(qw/trackid cd position title/);
2993 __PACKAGE__->set_primary_key('trackid');
2994 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2997 # In your application
2998 my $rs = $schema->resultset('Artist')->search(
2999 { 'track.title' => 'Teardrop' },
3001 join => { cd => 'track' },
3002 order_by => 'artist.name',
3006 You need to use the relationship (not the table) name in conditions,
3007 because they are aliased as such. The current table is aliased as "me", so
3008 you need to use me.column_name in order to avoid ambiguity. For example:
3010 # Get CDs from 1984 with a 'Foo' track
3011 my $rs = $schema->resultset('CD')->search(
3014 'tracks.name' => 'Foo'
3016 { join => 'tracks' }
3019 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3020 similarly for a third time). For e.g.
3022 my $rs = $schema->resultset('Artist')->search({
3023 'cds.title' => 'Down to Earth',
3024 'cds_2.title' => 'Popular',
3026 join => [ qw/cds cds/ ],
3029 will return a set of all artists that have both a cd with title 'Down
3030 to Earth' and a cd with title 'Popular'.
3032 If you want to fetch related objects from other tables as well, see C<prefetch>
3035 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3041 =item Value: ($rel_name | \@rel_names | \%rel_names)
3045 Contains one or more relationships that should be fetched along with
3046 the main query (when they are accessed afterwards the data will
3047 already be available, without extra queries to the database). This is
3048 useful for when you know you will need the related objects, because it
3049 saves at least one query:
3051 my $rs = $schema->resultset('Tag')->search(
3060 The initial search results in SQL like the following:
3062 SELECT tag.*, cd.*, artist.* FROM tag
3063 JOIN cd ON tag.cd = cd.cdid
3064 JOIN artist ON cd.artist = artist.artistid
3066 L<DBIx::Class> has no need to go back to the database when we access the
3067 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3070 Simple prefetches will be joined automatically, so there is no need
3071 for a C<join> attribute in the above search.
3073 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3074 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3075 with an accessor type of 'single' or 'filter'). A more complex example that
3076 prefetches an artists cds, the tracks on those cds, and the tags associted
3077 with that artist is given below (assuming many-to-many from artists to tags):
3079 my $rs = $schema->resultset('Artist')->search(
3083 { cds => 'tracks' },
3084 { artist_tags => 'tags' }
3090 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3091 attributes will be ignored.
3101 Makes the resultset paged and specifies the page to retrieve. Effectively
3102 identical to creating a non-pages resultset and then calling ->page($page)
3105 If L<rows> attribute is not specified it defualts to 10 rows per page.
3107 When you have a paged resultset, L</count> will only return the number
3108 of rows in the page. To get the total, use the L</pager> and call
3109 C<total_entries> on it.
3119 Specifes the maximum number of rows for direct retrieval or the number of
3120 rows per page if the page attribute or method is used.
3126 =item Value: $offset
3130 Specifies the (zero-based) row number for the first row to be returned, or the
3131 of the first row of the first page if paging is used.
3137 =item Value: \@columns
3141 A arrayref of columns to group by. Can include columns of joined tables.
3143 group_by => [qw/ column1 column2 ... /]
3149 =item Value: $condition
3153 HAVING is a select statement attribute that is applied between GROUP BY and
3154 ORDER BY. It is applied to the after the grouping calculations have been
3157 having => { 'count(employee)' => { '>=', 100 } }
3163 =item Value: (0 | 1)
3167 Set to 1 to group by all columns.
3173 Adds to the WHERE clause.
3175 # only return rows WHERE deleted IS NULL for all searches
3176 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3178 Can be overridden by passing C<{ where => undef }> as an attribute
3185 Set to 1 to cache search results. This prevents extra SQL queries if you
3186 revisit rows in your ResultSet:
3188 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3190 while( my $artist = $resultset->next ) {
3194 $rs->first; # without cache, this would issue a query
3196 By default, searches are not cached.
3198 For more examples of using these attributes, see
3199 L<DBIx::Class::Manual::Cookbook>.
3205 =item Value: \@from_clause
3209 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3210 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3213 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3215 C<join> will usually do what you need and it is strongly recommended that you
3216 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3217 And we really do mean "cannot", not just tried and failed. Attempting to use
3218 this because you're having problems with C<join> is like trying to use x86
3219 ASM because you've got a syntax error in your C. Trust us on this.
3221 Now, if you're still really, really sure you need to use this (and if you're
3222 not 100% sure, ask the mailing list first), here's an explanation of how this
3225 The syntax is as follows -
3228 { <alias1> => <table1> },
3230 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3231 [], # nested JOIN (optional)
3232 { <table1.column1> => <table2.column2>, ... (more conditions) },
3234 # More of the above [ ] may follow for additional joins
3241 ON <table1.column1> = <table2.column2>
3242 <more joins may follow>
3244 An easy way to follow the examples below is to remember the following:
3246 Anything inside "[]" is a JOIN
3247 Anything inside "{}" is a condition for the enclosing JOIN
3249 The following examples utilize a "person" table in a family tree application.
3250 In order to express parent->child relationships, this table is self-joined:
3252 # Person->belongs_to('father' => 'Person');
3253 # Person->belongs_to('mother' => 'Person');
3255 C<from> can be used to nest joins. Here we return all children with a father,
3256 then search against all mothers of those children:
3258 $rs = $schema->resultset('Person')->search(
3261 alias => 'mother', # alias columns in accordance with "from"
3263 { mother => 'person' },
3266 { child => 'person' },
3268 { father => 'person' },
3269 { 'father.person_id' => 'child.father_id' }
3272 { 'mother.person_id' => 'child.mother_id' }
3279 # SELECT mother.* FROM person mother
3282 # JOIN person father
3283 # ON ( father.person_id = child.father_id )
3285 # ON ( mother.person_id = child.mother_id )
3287 The type of any join can be controlled manually. To search against only people
3288 with a father in the person table, we could explicitly use C<INNER JOIN>:
3290 $rs = $schema->resultset('Person')->search(
3293 alias => 'child', # alias columns in accordance with "from"
3295 { child => 'person' },
3297 { father => 'person', -join_type => 'inner' },
3298 { 'father.id' => 'child.father_id' }
3305 # SELECT child.* FROM person child
3306 # INNER JOIN person father ON child.father_id = father.id
3308 If you need to express really complex joins or you need a subselect, you
3309 can supply literal SQL to C<from> via a scalar reference. In this case
3310 the contents of the scalar will replace the table name asscoiated with the
3313 WARNING: This technique might very well not work as expected on chained
3314 searches - you have been warned.
3316 # Assuming the Event resultsource is defined as:
3318 MySchema::Event->add_columns (
3321 is_auto_increment => 1,
3330 MySchema::Event->set_primary_key ('sequence');
3332 # This will get back the latest event for every location. The column
3333 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3334 # combo to limit the resultset
3336 $rs = $schema->resultset('Event');
3337 $table = $rs->result_source->name;
3338 $latest = $rs->search (
3341 (SELECT e1.* FROM $table e1
3343 ON e1.location = e2.location
3344 AND e1.sequence < e2.sequence
3345 WHERE e2.sequence is NULL
3350 # Equivalent SQL (with the DBIC chunks added):
3352 SELECT me.sequence, me.location, me.type FROM
3353 (SELECT e1.* FROM events e1
3355 ON e1.location = e2.location
3356 AND e1.sequence < e2.sequence
3357 WHERE e2.sequence is NULL
3364 =item Value: ( 'update' | 'shared' )
3368 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT