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 @grouped_subq_attrs = qw/prefetch collapse distinct group_by having/;
1145 my @subq_attrs = ();
1147 my $attrs = $self->_resolved_attrs;
1148 # if we are not paged - we are simply asking for a limit
1149 if (not $attrs->{page} and not $attrs->{software_limit}) {
1150 push @subq_attrs, qw/rows offset/;
1153 my $need_subq = $self->_has_attr (@subq_attrs);
1154 my $need_group_subq = $self->_has_attr (@grouped_subq_attrs);
1156 return ($need_subq || $need_group_subq)
1157 ? $self->_count_subq ($need_group_subq)
1158 : $self->_count_simple
1162 my ($self, $add_group_by) = @_;
1164 my $attrs = $self->_resolved_attrs_copy;
1166 # copy for the subquery, we need to do some adjustments to it too
1167 my $sub_attrs = { %$attrs };
1169 # these can not go in the subquery, and there is no point of ordering it
1170 delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns order_by/;
1172 # if needed force a group_by and the same set of columns (most databases require this)
1173 if ($add_group_by) {
1174 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1178 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1181 # the subquery replaces this
1182 delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind/;
1184 return $self->__count ($attrs);
1190 my $count = $self->__count;
1191 return 0 unless $count;
1193 # need to take offset from resolved attrs
1195 my $attrs = $self->_resolved_attrs;
1197 $count -= $attrs->{offset} if $attrs->{offset};
1198 $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
1199 $count = 0 if ($count < 0);
1204 my ($self, $attrs) = @_;
1206 $attrs ||= $self->_resolved_attrs_copy;
1208 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1209 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1211 $attrs->{select} = { count => '*' };
1212 $attrs->{as} = [qw/count/];
1214 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1215 my ($count) = $tmp_rs->cursor->next;
1224 =head2 count_literal
1228 =item Arguments: $sql_fragment, @bind_values
1230 =item Return Value: $count
1234 Counts the results in a literal query. Equivalent to calling L</search_literal>
1235 with the passed arguments, then L</count>.
1239 sub count_literal { shift->search_literal(@_)->count; }
1245 =item Arguments: none
1247 =item Return Value: @objects
1251 Returns all elements in the resultset. Called implicitly if the resultset
1252 is returned in list context.
1259 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1262 return @{ $self->get_cache } if $self->get_cache;
1266 # TODO: don't call resolve here
1267 if (keys %{$self->_resolved_attrs->{collapse}}) {
1268 # if ($self->{attrs}{prefetch}) {
1269 # Using $self->cursor->all is really just an optimisation.
1270 # If we're collapsing has_many prefetches it probably makes
1271 # very little difference, and this is cleaner than hacking
1272 # _construct_object to survive the approach
1273 my @row = $self->cursor->next;
1275 push(@obj, $self->_construct_object(@row));
1276 @row = (exists $self->{stashed_row}
1277 ? @{delete $self->{stashed_row}}
1278 : $self->cursor->next);
1281 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1284 $self->set_cache(\@obj) if $self->{attrs}{cache};
1292 =item Arguments: none
1294 =item Return Value: $self
1298 Resets the resultset's cursor, so you can iterate through the elements again.
1304 delete $self->{_attrs} if exists $self->{_attrs};
1305 $self->{all_cache_position} = 0;
1306 $self->cursor->reset;
1314 =item Arguments: none
1316 =item Return Value: $object?
1320 Resets the resultset and returns an object for the first result (if the
1321 resultset returns anything).
1326 return $_[0]->reset->next;
1332 # Determines whether and what type of subquery is required for the $rs operation.
1333 # If grouping is necessary either supplies its own, or verifies the current one
1334 # After all is done delegates to the proper storage method.
1336 sub _rs_update_delete {
1337 my ($self, $op, $values) = @_;
1339 my $rsrc = $self->result_source;
1341 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1342 my $needs_subq = $self->_has_attr (qw/row offset page/);
1344 if ($needs_group_by_subq or $needs_subq) {
1346 # make a new $rs selecting only the PKs (that's all we really need)
1347 my $attrs = $self->_resolved_attrs_copy;
1349 delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
1350 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1352 if ($needs_group_by_subq) {
1353 # make sure no group_by was supplied, or if there is one - make sure it matches
1354 # the columns compiled above perfectly. Anything else can not be sanely executed
1355 # on most databases so croak right then and there
1357 if (my $g = $attrs->{group_by}) {
1358 my @current_group_by = map
1359 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1360 (ref $g eq 'ARRAY' ? @$g : $g );
1363 join ("\x00", sort @current_group_by)
1365 join ("\x00", sort @{$attrs->{columns}} )
1367 $self->throw_exception (
1368 "You have just attempted a $op operation on a resultset which does group_by"
1369 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1370 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1371 . ' kind of queries. Please retry the operation with a modified group_by or'
1372 . ' without using one at all.'
1377 $attrs->{group_by} = $attrs->{columns};
1381 my $subrs = (ref $self)->new($rsrc, $attrs);
1383 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1386 return $rsrc->storage->$op(
1388 $op eq 'update' ? $values : (),
1389 $self->_cond_for_update_delete,
1395 # _cond_for_update_delete
1397 # update/delete require the condition to be modified to handle
1398 # the differing SQL syntax available. This transforms the $self->{cond}
1399 # appropriately, returning the new condition.
1401 sub _cond_for_update_delete {
1402 my ($self, $full_cond) = @_;
1405 $full_cond ||= $self->{cond};
1406 # No-op. No condition, we're updating/deleting everything
1407 return $cond unless ref $full_cond;
1409 if (ref $full_cond eq 'ARRAY') {
1413 foreach my $key (keys %{$_}) {
1415 $hash{$1} = $_->{$key};
1421 elsif (ref $full_cond eq 'HASH') {
1422 if ((keys %{$full_cond})[0] eq '-and') {
1424 my @cond = @{$full_cond->{-and}};
1425 for (my $i = 0; $i < @cond; $i++) {
1426 my $entry = $cond[$i];
1428 if (ref $entry eq 'HASH') {
1429 $hash = $self->_cond_for_update_delete($entry);
1432 $entry =~ /([^.]+)$/;
1433 $hash->{$1} = $cond[++$i];
1435 push @{$cond->{-and}}, $hash;
1439 foreach my $key (keys %{$full_cond}) {
1441 $cond->{$1} = $full_cond->{$key};
1446 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1457 =item Arguments: \%values
1459 =item Return Value: $storage_rv
1463 Sets the specified columns in the resultset to the supplied values in a
1464 single query. Return value will be true if the update succeeded or false
1465 if no records were updated; exact type of success value is storage-dependent.
1470 my ($self, $values) = @_;
1471 $self->throw_exception('Values for update must be a hash')
1472 unless ref $values eq 'HASH';
1474 return $self->_rs_update_delete ('update', $values);
1481 =item Arguments: \%values
1483 =item Return Value: 1
1487 Fetches all objects and updates them one at a time. Note that C<update_all>
1488 will run DBIC cascade triggers, while L</update> will not.
1493 my ($self, $values) = @_;
1494 $self->throw_exception('Values for update_all must be a hash')
1495 unless ref $values eq 'HASH';
1496 foreach my $obj ($self->all) {
1497 $obj->set_columns($values)->update;
1506 =item Arguments: none
1508 =item Return Value: 1
1512 Deletes the contents of the resultset from its result source. Note that this
1513 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1514 to run. See also L<DBIx::Class::Row/delete>.
1516 delete may not generate correct SQL for a query with joins or a resultset
1517 chained from a related resultset. In this case it will generate a warning:-
1519 In these cases you may find that delete_all is more appropriate, or you
1520 need to respecify your query in a way that can be expressed without a join.
1526 $self->throw_exception('delete does not accept any arguments')
1529 return $self->_rs_update_delete ('delete');
1536 =item Arguments: none
1538 =item Return Value: 1
1542 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1543 will run DBIC cascade triggers, while L</delete> will not.
1549 $self->throw_exception('delete_all does not accept any arguments')
1552 $_->delete for $self->all;
1560 =item Arguments: \@data;
1564 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1565 For the arrayref of hashrefs style each hashref should be a structure suitable
1566 forsubmitting to a $resultset->create(...) method.
1568 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1569 to insert the data, as this is a faster method.
1571 Otherwise, each set of data is inserted into the database using
1572 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1573 objects is returned.
1575 Example: Assuming an Artist Class that has many CDs Classes relating:
1577 my $Artist_rs = $schema->resultset("Artist");
1579 ## Void Context Example
1580 $Artist_rs->populate([
1581 { artistid => 4, name => 'Manufactured Crap', cds => [
1582 { title => 'My First CD', year => 2006 },
1583 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1586 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1587 { title => 'My parents sold me to a record company' ,year => 2005 },
1588 { title => 'Why Am I So Ugly?', year => 2006 },
1589 { title => 'I Got Surgery and am now Popular', year => 2007 }
1594 ## Array Context Example
1595 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1596 { name => "Artist One"},
1597 { name => "Artist Two"},
1598 { name => "Artist Three", cds=> [
1599 { title => "First CD", year => 2007},
1600 { title => "Second CD", year => 2008},
1604 print $ArtistOne->name; ## response is 'Artist One'
1605 print $ArtistThree->cds->count ## reponse is '2'
1607 For the arrayref of arrayrefs style, the first element should be a list of the
1608 fieldsnames to which the remaining elements are rows being inserted. For
1611 $Arstist_rs->populate([
1612 [qw/artistid name/],
1613 [100, 'A Formally Unknown Singer'],
1614 [101, 'A singer that jumped the shark two albums ago'],
1615 [102, 'An actually cool singer.'],
1618 Please note an important effect on your data when choosing between void and
1619 wantarray context. Since void context goes straight to C<insert_bulk> in
1620 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1621 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1622 create primary keys for you, you will find that your PKs are empty. In this
1623 case you will have to use the wantarray context in order to create those
1629 my $self = shift @_;
1630 my $data = ref $_[0][0] eq 'HASH'
1631 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1632 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1634 if(defined wantarray) {
1636 foreach my $item (@$data) {
1637 push(@created, $self->create($item));
1641 my ($first, @rest) = @$data;
1643 my @names = grep {!ref $first->{$_}} keys %$first;
1644 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1645 my @pks = $self->result_source->primary_columns;
1647 ## do the belongs_to relationships
1648 foreach my $index (0..$#$data) {
1649 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1650 my @ret = $self->populate($data);
1654 foreach my $rel (@rels) {
1655 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1656 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1657 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1658 my $related = $result->result_source->_resolve_condition(
1659 $result->result_source->relationship_info($reverse)->{cond},
1664 delete $data->[$index]->{$rel};
1665 $data->[$index] = {%{$data->[$index]}, %$related};
1667 push @names, keys %$related if $index == 0;
1671 ## do bulk insert on current row
1672 my @values = map { [ @$_{@names} ] } @$data;
1674 $self->result_source->storage->insert_bulk(
1675 $self->result_source,
1680 ## do the has_many relationships
1681 foreach my $item (@$data) {
1683 foreach my $rel (@rels) {
1684 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1686 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1687 || $self->throw_exception('Cannot find the relating object.');
1689 my $child = $parent->$rel;
1691 my $related = $child->result_source->_resolve_condition(
1692 $parent->result_source->relationship_info($rel)->{cond},
1697 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1698 my @populate = map { {%$_, %$related} } @rows_to_add;
1700 $child->populate( \@populate );
1706 =head2 _normalize_populate_args ($args)
1708 Private method used by L</populate> to normalize its incoming arguments. Factored
1709 out in case you want to subclass and accept new argument structures to the
1710 L</populate> method.
1714 sub _normalize_populate_args {
1715 my ($self, $data) = @_;
1716 my @names = @{shift(@$data)};
1717 my @results_to_create;
1718 foreach my $datum (@$data) {
1719 my %result_to_create;
1720 foreach my $index (0..$#names) {
1721 $result_to_create{$names[$index]} = $$datum[$index];
1723 push @results_to_create, \%result_to_create;
1725 return \@results_to_create;
1732 =item Arguments: none
1734 =item Return Value: $pager
1738 Return Value a L<Data::Page> object for the current resultset. Only makes
1739 sense for queries with a C<page> attribute.
1741 To get the full count of entries for a paged resultset, call
1742 C<total_entries> on the L<Data::Page> object.
1749 return $self->{pager} if $self->{pager};
1751 my $attrs = $self->{attrs};
1752 $self->throw_exception("Can't create pager for non-paged rs")
1753 unless $self->{attrs}{page};
1754 $attrs->{rows} ||= 10;
1756 # throw away the paging flags and re-run the count (possibly
1757 # with a subselect) to get the real total count
1758 my $count_attrs = { %$attrs };
1759 delete $count_attrs->{$_} for qw/rows offset page pager/;
1760 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1762 return $self->{pager} = Data::Page->new(
1765 $self->{attrs}{page}
1773 =item Arguments: $page_number
1775 =item Return Value: $rs
1779 Returns a resultset for the $page_number page of the resultset on which page
1780 is called, where each page contains a number of rows equal to the 'rows'
1781 attribute set on the resultset (10 by default).
1786 my ($self, $page) = @_;
1787 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1794 =item Arguments: \%vals
1796 =item Return Value: $rowobject
1800 Creates a new row object in the resultset's result class and returns
1801 it. The row is not inserted into the database at this point, call
1802 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1803 will tell you whether the row object has been inserted or not.
1805 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1810 my ($self, $values) = @_;
1811 $self->throw_exception( "new_result needs a hash" )
1812 unless (ref $values eq 'HASH');
1815 my $alias = $self->{attrs}{alias};
1818 defined $self->{cond}
1819 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1821 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1822 $new{-from_resultset} = [ keys %new ] if keys %new;
1824 $self->throw_exception(
1825 "Can't abstract implicit construct, condition not a hash"
1826 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1828 my $collapsed_cond = (
1830 ? $self->_collapse_cond($self->{cond})
1834 # precendence must be given to passed values over values inherited from
1835 # the cond, so the order here is important.
1836 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1837 while( my($col,$value) = each %implied ){
1838 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1839 $new{$col} = $value->{'='};
1842 $new{$col} = $value if $self->_is_deterministic_value($value);
1848 %{ $self->_remove_alias($values, $alias) },
1849 -source_handle => $self->_source_handle,
1850 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1853 return $self->result_class->new(\%new);
1856 # _is_deterministic_value
1858 # Make an effor to strip non-deterministic values from the condition,
1859 # to make sure new_result chokes less
1861 sub _is_deterministic_value {
1864 my $ref_type = ref $value;
1865 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1866 return 1 if Scalar::Util::blessed($value);
1872 # determines if the resultset defines at least one
1873 # of the attributes supplied
1875 # used to determine if a subquery is neccessary
1878 my ($self, @attr_names) = @_;
1880 my $attrs = $self->_resolved_attrs;
1884 for my $n (@attr_names) {
1885 ++$join_check_req if $n =~ /join/;
1887 my $attr = $attrs->{$n};
1889 next if not defined $attr;
1891 if (ref $attr eq 'HASH') {
1892 return 1 if keys %$attr;
1894 elsif (ref $attr eq 'ARRAY') {
1902 # a join can be expressed as a multi-level from
1906 ref $attrs->{from} eq 'ARRAY'
1908 @{$attrs->{from}} > 1
1916 # Recursively collapse the condition.
1918 sub _collapse_cond {
1919 my ($self, $cond, $collapsed) = @_;
1923 if (ref $cond eq 'ARRAY') {
1924 foreach my $subcond (@$cond) {
1925 next unless ref $subcond; # -or
1926 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1929 elsif (ref $cond eq 'HASH') {
1930 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1931 foreach my $subcond (@{$cond->{-and}}) {
1932 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1936 foreach my $col (keys %$cond) {
1937 my $value = $cond->{$col};
1938 $collapsed->{$col} = $value;
1948 # Remove the specified alias from the specified query hash. A copy is made so
1949 # the original query is not modified.
1952 my ($self, $query, $alias) = @_;
1954 my %orig = %{ $query || {} };
1957 foreach my $key (keys %orig) {
1959 $unaliased{$key} = $orig{$key};
1962 $unaliased{$1} = $orig{$key}
1963 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1969 =head2 as_query (EXPERIMENTAL)
1973 =item Arguments: none
1975 =item Return Value: \[ $sql, @bind ]
1979 Returns the SQL query and bind vars associated with the invocant.
1981 This is generally used as the RHS for a subquery.
1983 B<NOTE>: This feature is still experimental.
1987 sub as_query { return shift->cursor->as_query(@_) }
1993 =item Arguments: \%vals, \%attrs?
1995 =item Return Value: $rowobject
1999 my $artist = $schema->resultset('Artist')->find_or_new(
2000 { artist => 'fred' }, { key => 'artists' });
2002 $cd->cd_to_producer->find_or_new({ producer => $producer },
2003 { key => 'primary });
2005 Find an existing record from this resultset, based on its primary
2006 key, or a unique constraint. If none exists, instantiate a new result
2007 object and return it. The object will not be saved into your storage
2008 until you call L<DBIx::Class::Row/insert> on it.
2010 You most likely want this method when looking for existing rows using
2011 a unique constraint that is not the primary key, or looking for
2014 If you want objects to be saved immediately, use L</find_or_create> instead.
2016 B<Note>: C<find_or_new> is probably not what you want when creating a
2017 new row in a table that uses primary keys supplied by the
2018 database. Passing in a primary key column with a value of I<undef>
2019 will cause L</find> to attempt to search for a row with a value of
2026 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2027 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2028 my $exists = $self->find($hash, $attrs);
2029 return defined $exists ? $exists : $self->new_result($hash);
2036 =item Arguments: \%vals
2038 =item Return Value: a L<DBIx::Class::Row> $object
2042 Attempt to create a single new row or a row with multiple related rows
2043 in the table represented by the resultset (and related tables). This
2044 will not check for duplicate rows before inserting, use
2045 L</find_or_create> to do that.
2047 To create one row for this resultset, pass a hashref of key/value
2048 pairs representing the columns of the table and the values you wish to
2049 store. If the appropriate relationships are set up, foreign key fields
2050 can also be passed an object representing the foreign row, and the
2051 value will be set to its primary key.
2053 To create related objects, pass a hashref for the value if the related
2054 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2055 and use the name of the relationship as the key. (NOT the name of the field,
2056 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2057 of hashrefs containing the data for each of the rows to create in the foreign
2058 tables, again using the relationship name as the key.
2060 Instead of hashrefs of plain related data (key/value pairs), you may
2061 also pass new or inserted objects. New objects (not inserted yet, see
2062 L</new>), will be inserted into their appropriate tables.
2064 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2066 Example of creating a new row.
2068 $person_rs->create({
2069 name=>"Some Person",
2070 email=>"somebody@someplace.com"
2073 Example of creating a new row and also creating rows in a related C<has_many>
2074 or C<has_one> resultset. Note Arrayref.
2077 { artistid => 4, name => 'Manufactured Crap', cds => [
2078 { title => 'My First CD', year => 2006 },
2079 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2084 Example of creating a new row and also creating a row in a related
2085 C<belongs_to>resultset. Note Hashref.
2088 title=>"Music for Silly Walks",
2091 name=>"Silly Musician",
2098 my ($self, $attrs) = @_;
2099 $self->throw_exception( "create needs a hashref" )
2100 unless ref $attrs eq 'HASH';
2101 return $self->new_result($attrs)->insert;
2104 =head2 find_or_create
2108 =item Arguments: \%vals, \%attrs?
2110 =item Return Value: $rowobject
2114 $cd->cd_to_producer->find_or_create({ producer => $producer },
2115 { key => 'primary });
2117 Tries to find a record based on its primary key or unique constraints; if none
2118 is found, creates one and returns that instead.
2120 my $cd = $schema->resultset('CD')->find_or_create({
2122 artist => 'Massive Attack',
2123 title => 'Mezzanine',
2127 Also takes an optional C<key> attribute, to search by a specific key or unique
2128 constraint. For example:
2130 my $cd = $schema->resultset('CD')->find_or_create(
2132 artist => 'Massive Attack',
2133 title => 'Mezzanine',
2135 { key => 'cd_artist_title' }
2138 B<Note>: Because find_or_create() reads from the database and then
2139 possibly inserts based on the result, this method is subject to a race
2140 condition. Another process could create a record in the table after
2141 the find has completed and before the create has started. To avoid
2142 this problem, use find_or_create() inside a transaction.
2144 B<Note>: C<find_or_create> is probably not what you want when creating
2145 a new row in a table that uses primary keys supplied by the
2146 database. Passing in a primary key column with a value of I<undef>
2147 will cause L</find> to attempt to search for a row with a value of
2150 See also L</find> and L</update_or_create>. For information on how to declare
2151 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2155 sub find_or_create {
2157 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2158 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2159 my $exists = $self->find($hash, $attrs);
2160 return defined $exists ? $exists : $self->create($hash);
2163 =head2 update_or_create
2167 =item Arguments: \%col_values, { key => $unique_constraint }?
2169 =item Return Value: $rowobject
2173 $resultset->update_or_create({ col => $val, ... });
2175 First, searches for an existing row matching one of the unique constraints
2176 (including the primary key) on the source of this resultset. If a row is
2177 found, updates it with the other given column values. Otherwise, creates a new
2180 Takes an optional C<key> attribute to search on a specific unique constraint.
2183 # In your application
2184 my $cd = $schema->resultset('CD')->update_or_create(
2186 artist => 'Massive Attack',
2187 title => 'Mezzanine',
2190 { key => 'cd_artist_title' }
2193 $cd->cd_to_producer->update_or_create({
2194 producer => $producer,
2201 If no C<key> is specified, it searches on all unique constraints defined on the
2202 source, including the primary key.
2204 If the C<key> is specified as C<primary>, it searches only on the primary key.
2206 See also L</find> and L</find_or_create>. For information on how to declare
2207 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2209 B<Note>: C<update_or_create> is probably not what you want when
2210 looking for a row in a table that uses primary keys supplied by the
2211 database, unless you actually have a key value. Passing in a primary
2212 key column with a value of I<undef> will cause L</find> to attempt to
2213 search for a row with a value of I<NULL>.
2217 sub update_or_create {
2219 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2220 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2222 my $row = $self->find($cond, $attrs);
2224 $row->update($cond);
2228 return $self->create($cond);
2231 =head2 update_or_new
2235 =item Arguments: \%col_values, { key => $unique_constraint }?
2237 =item Return Value: $rowobject
2241 $resultset->update_or_new({ col => $val, ... });
2243 First, searches for an existing row matching one of the unique constraints
2244 (including the primary key) on the source of this resultset. If a row is
2245 found, updates it with the other given column values. Otherwise, instantiate
2246 a new result object and return it. The object will not be saved into your storage
2247 until you call L<DBIx::Class::Row/insert> on it.
2249 Takes an optional C<key> attribute to search on a specific unique constraint.
2252 # In your application
2253 my $cd = $schema->resultset('CD')->update_or_new(
2255 artist => 'Massive Attack',
2256 title => 'Mezzanine',
2259 { key => 'cd_artist_title' }
2262 if ($cd->in_storage) {
2263 # the cd was updated
2266 # the cd is not yet in the database, let's insert it
2270 See also L</find>, L</find_or_create> and L<find_or_new>.
2276 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2277 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2279 my $row = $self->find( $cond, $attrs );
2280 if ( defined $row ) {
2281 $row->update($cond);
2285 return $self->new_result($cond);
2292 =item Arguments: none
2294 =item Return Value: \@cache_objects?
2298 Gets the contents of the cache for the resultset, if the cache is set.
2300 The cache is populated either by using the L</prefetch> attribute to
2301 L</search> or by calling L</set_cache>.
2313 =item Arguments: \@cache_objects
2315 =item Return Value: \@cache_objects
2319 Sets the contents of the cache for the resultset. Expects an arrayref
2320 of objects of the same class as those produced by the resultset. Note that
2321 if the cache is set the resultset will return the cached objects rather
2322 than re-querying the database even if the cache attr is not set.
2324 The contents of the cache can also be populated by using the
2325 L</prefetch> attribute to L</search>.
2330 my ( $self, $data ) = @_;
2331 $self->throw_exception("set_cache requires an arrayref")
2332 if defined($data) && (ref $data ne 'ARRAY');
2333 $self->{all_cache} = $data;
2340 =item Arguments: none
2342 =item Return Value: []
2346 Clears the cache for the resultset.
2351 shift->set_cache(undef);
2354 =head2 related_resultset
2358 =item Arguments: $relationship_name
2360 =item Return Value: $resultset
2364 Returns a related resultset for the supplied relationship name.
2366 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2370 sub related_resultset {
2371 my ($self, $rel) = @_;
2373 $self->{related_resultsets} ||= {};
2374 return $self->{related_resultsets}{$rel} ||= do {
2375 my $rel_obj = $self->result_source->relationship_info($rel);
2377 $self->throw_exception(
2378 "search_related: result source '" . $self->result_source->source_name .
2379 "' has no such relationship $rel")
2382 my ($from,$seen) = $self->_resolve_from($rel);
2384 my $join_count = $seen->{$rel};
2385 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2387 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2388 my %attrs = %{$self->{attrs}||{}};
2389 delete @attrs{qw(result_class alias)};
2393 if (my $cache = $self->get_cache) {
2394 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2395 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2400 my $rel_source = $self->result_source->related_source($rel);
2404 # The reason we do this now instead of passing the alias to the
2405 # search_rs below is that if you wrap/overload resultset on the
2406 # source you need to know what alias it's -going- to have for things
2407 # to work sanely (e.g. RestrictWithObject wants to be able to add
2408 # extra query restrictions, and these may need to be $alias.)
2410 my $attrs = $rel_source->resultset_attributes;
2411 local $attrs->{alias} = $alias;
2413 $rel_source->resultset
2421 where => $self->{cond},
2426 $new->set_cache($new_cache) if $new_cache;
2431 =head2 current_source_alias
2435 =item Arguments: none
2437 =item Return Value: $source_alias
2441 Returns the current table alias for the result source this resultset is built
2442 on, that will be used in the SQL query. Usually it is C<me>.
2444 Currently the source alias that refers to the result set returned by a
2445 L</search>/L</find> family method depends on how you got to the resultset: it's
2446 C<me> by default, but eg. L</search_related> aliases it to the related result
2447 source name (and keeps C<me> referring to the original result set). The long
2448 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2449 (and make this method unnecessary).
2451 Thus it's currently necessary to use this method in predefined queries (see
2452 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2453 source alias of the current result set:
2455 # in a result set class
2457 my ($self, $user) = @_;
2459 my $me = $self->current_source_alias;
2461 return $self->search(
2462 "$me.modified" => $user->id,
2468 sub current_source_alias {
2471 return ($self->{attrs} || {})->{alias} || 'me';
2474 # This code is called by search_related, and makes sure there
2475 # is clear separation between the joins before, during, and
2476 # after the relationship. This information is needed later
2477 # in order to properly resolve prefetch aliases (any alias
2478 # with a relation_chain_depth less than the depth of the
2479 # current prefetch is not considered)
2481 my ($self, $extra_join) = @_;
2482 my $source = $self->result_source;
2483 my $attrs = $self->{attrs};
2485 my $from = $attrs->{from}
2486 || [ { $attrs->{alias} => $source->from } ];
2488 my $seen = { %{$attrs->{seen_join}||{}} };
2490 # we need to take the prefetch the attrs into account before we
2491 # ->_resolve_join as otherwise they get lost - captainL
2492 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2494 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2496 ++$seen->{-relation_chain_depth};
2498 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2500 ++$seen->{-relation_chain_depth};
2502 return ($from,$seen);
2505 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
2506 sub _resolved_attrs_copy {
2508 return { %{$self->_resolved_attrs (@_)} };
2511 sub _resolved_attrs {
2513 return $self->{_attrs} if $self->{_attrs};
2515 my $attrs = { %{ $self->{attrs} || {} } };
2516 my $source = $self->result_source;
2517 my $alias = $attrs->{alias};
2519 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2522 # build columns (as long as select isn't set) into a set of as/select hashes
2523 unless ( $attrs->{select} ) {
2525 ( ref($_) eq 'HASH' )
2529 /^\Q${alias}.\E(.+)$/
2540 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2542 # add the additional columns on
2543 foreach ( 'include_columns', '+columns' ) {
2544 push @colbits, map {
2545 ( ref($_) eq 'HASH' )
2547 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2548 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2551 # start with initial select items
2552 if ( $attrs->{select} ) {
2554 ( ref $attrs->{select} eq 'ARRAY' )
2555 ? [ @{ $attrs->{select} } ]
2556 : [ $attrs->{select} ];
2560 ref $attrs->{as} eq 'ARRAY'
2561 ? [ @{ $attrs->{as} } ]
2564 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2569 # otherwise we intialise select & as to empty
2570 $attrs->{select} = [];
2574 # now add colbits to select/as
2575 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2576 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2579 if ( $adds = delete $attrs->{'+select'} ) {
2580 $adds = [$adds] unless ref $adds eq 'ARRAY';
2582 @{ $attrs->{select} },
2583 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2586 if ( $adds = delete $attrs->{'+as'} ) {
2587 $adds = [$adds] unless ref $adds eq 'ARRAY';
2588 push( @{ $attrs->{as} }, @$adds );
2591 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2593 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2594 my $join = delete $attrs->{join} || {};
2596 if ( defined $attrs->{prefetch} ) {
2597 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2601 $attrs->{from} = # have to copy here to avoid corrupting the original
2603 @{ $attrs->{from} },
2604 $source->_resolve_join(
2605 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2611 if ( $attrs->{order_by} ) {
2612 $attrs->{order_by} = (
2613 ref( $attrs->{order_by} ) eq 'ARRAY'
2614 ? [ @{ $attrs->{order_by} } ]
2615 : [ $attrs->{order_by} ]
2619 $attrs->{order_by} = [];
2622 my $collapse = $attrs->{collapse} || {};
2623 if ( my $prefetch = delete $attrs->{prefetch} ) {
2624 $prefetch = $self->_merge_attr( {}, $prefetch );
2626 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2628 # bring joins back to level of current class
2629 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2631 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2632 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2633 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2635 push( @{ $attrs->{order_by} }, @pre_order );
2638 if (delete $attrs->{distinct}) {
2639 $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
2642 $attrs->{collapse} = $collapse;
2644 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2645 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2648 return $self->{_attrs} = $attrs;
2651 sub _joinpath_aliases {
2652 my ($self, $fromspec, $seen) = @_;
2655 return $paths unless ref $fromspec eq 'ARRAY';
2657 for my $j (@$fromspec) {
2659 next if ref $j ne 'ARRAY';
2660 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2663 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2664 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2671 my ($self, $attr) = @_;
2673 if (ref $attr eq 'HASH') {
2674 return $self->_rollout_hash($attr);
2675 } elsif (ref $attr eq 'ARRAY') {
2676 return $self->_rollout_array($attr);
2682 sub _rollout_array {
2683 my ($self, $attr) = @_;
2686 foreach my $element (@{$attr}) {
2687 if (ref $element eq 'HASH') {
2688 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2689 } elsif (ref $element eq 'ARRAY') {
2690 # XXX - should probably recurse here
2691 push( @rolled_array, @{$self->_rollout_array($element)} );
2693 push( @rolled_array, $element );
2696 return \@rolled_array;
2700 my ($self, $attr) = @_;
2703 foreach my $key (keys %{$attr}) {
2704 push( @rolled_array, { $key => $attr->{$key} } );
2706 return \@rolled_array;
2709 sub _calculate_score {
2710 my ($self, $a, $b) = @_;
2712 if (ref $b eq 'HASH') {
2713 my ($b_key) = keys %{$b};
2714 if (ref $a eq 'HASH') {
2715 my ($a_key) = keys %{$a};
2716 if ($a_key eq $b_key) {
2717 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2722 return ($a eq $b_key) ? 1 : 0;
2725 if (ref $a eq 'HASH') {
2726 my ($a_key) = keys %{$a};
2727 return ($b eq $a_key) ? 1 : 0;
2729 return ($b eq $a) ? 1 : 0;
2735 my ($self, $orig, $import) = @_;
2737 return $import unless defined($orig);
2738 return $orig unless defined($import);
2740 $orig = $self->_rollout_attr($orig);
2741 $import = $self->_rollout_attr($import);
2744 foreach my $import_element ( @{$import} ) {
2745 # find best candidate from $orig to merge $b_element into
2746 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2747 foreach my $orig_element ( @{$orig} ) {
2748 my $score = $self->_calculate_score( $orig_element, $import_element );
2749 if ($score > $best_candidate->{score}) {
2750 $best_candidate->{position} = $position;
2751 $best_candidate->{score} = $score;
2755 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2757 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2758 push( @{$orig}, $import_element );
2760 my $orig_best = $orig->[$best_candidate->{position}];
2761 # merge orig_best and b_element together and replace original with merged
2762 if (ref $orig_best ne 'HASH') {
2763 $orig->[$best_candidate->{position}] = $import_element;
2764 } elsif (ref $import_element eq 'HASH') {
2765 my ($key) = keys %{$orig_best};
2766 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2769 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2779 $self->_source_handle($_[0]->handle);
2781 $self->_source_handle->resolve;
2785 =head2 throw_exception
2787 See L<DBIx::Class::Schema/throw_exception> for details.
2791 sub throw_exception {
2793 if (ref $self && $self->_source_handle->schema) {
2794 $self->_source_handle->schema->throw_exception(@_)
2801 # XXX: FIXME: Attributes docs need clearing up
2805 Attributes are used to refine a ResultSet in various ways when
2806 searching for data. They can be passed to any method which takes an
2807 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2810 These are in no particular order:
2816 =item Value: ( $order_by | \@order_by | \%order_by )
2820 Which column(s) to order the results by. If a single column name, or
2821 an arrayref of names is supplied, the argument is passed through
2822 directly to SQL. The hashref syntax allows for connection-agnostic
2823 specification of ordering direction:
2825 For descending order:
2827 order_by => { -desc => [qw/col1 col2 col3/] }
2829 For explicit ascending order:
2831 order_by => { -asc => 'col' }
2833 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2834 supported, although you are strongly encouraged to use the hashref
2835 syntax as outlined above.
2841 =item Value: \@columns
2845 Shortcut to request a particular set of columns to be retrieved. Each
2846 column spec may be a string (a table column name), or a hash (in which
2847 case the key is the C<as> value, and the value is used as the C<select>
2848 expression). Adds C<me.> onto the start of any column without a C<.> in
2849 it and sets C<select> from that, then auto-populates C<as> from
2850 C<select> as normal. (You may also use the C<cols> attribute, as in
2851 earlier versions of DBIC.)
2857 =item Value: \@columns
2861 Indicates additional columns to be selected from storage. Works the same
2862 as L</columns> but adds columns to the selection. (You may also use the
2863 C<include_columns> attribute, as in earlier versions of DBIC). For
2866 $schema->resultset('CD')->search(undef, {
2867 '+columns' => ['artist.name'],
2871 would return all CDs and include a 'name' column to the information
2872 passed to object inflation. Note that the 'artist' is the name of the
2873 column (or relationship) accessor, and 'name' is the name of the column
2874 accessor in the related table.
2876 =head2 include_columns
2880 =item Value: \@columns
2884 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2890 =item Value: \@select_columns
2894 Indicates which columns should be selected from the storage. You can use
2895 column names, or in the case of RDBMS back ends, function or stored procedure
2898 $rs = $schema->resultset('Employee')->search(undef, {
2901 { count => 'employeeid' },
2906 When you use function/stored procedure names and do not supply an C<as>
2907 attribute, the column names returned are storage-dependent. E.g. MySQL would
2908 return a column named C<count(employeeid)> in the above example.
2914 Indicates additional columns to be selected from storage. Works the same as
2915 L</select> but adds columns to the selection.
2923 Indicates additional column names for those added via L</+select>. See L</as>.
2931 =item Value: \@inflation_names
2935 Indicates column names for object inflation. That is, C<as>
2936 indicates the name that the column can be accessed as via the
2937 C<get_column> method (or via the object accessor, B<if one already
2938 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2940 The C<as> attribute is used in conjunction with C<select>,
2941 usually when C<select> contains one or more function or stored
2944 $rs = $schema->resultset('Employee')->search(undef, {
2947 { count => 'employeeid' }
2949 as => ['name', 'employee_count'],
2952 my $employee = $rs->first(); # get the first Employee
2954 If the object against which the search is performed already has an accessor
2955 matching a column name specified in C<as>, the value can be retrieved using
2956 the accessor as normal:
2958 my $name = $employee->name();
2960 If on the other hand an accessor does not exist in the object, you need to
2961 use C<get_column> instead:
2963 my $employee_count = $employee->get_column('employee_count');
2965 You can create your own accessors if required - see
2966 L<DBIx::Class::Manual::Cookbook> for details.
2968 Please note: This will NOT insert an C<AS employee_count> into the SQL
2969 statement produced, it is used for internal access only. Thus
2970 attempting to use the accessor in an C<order_by> clause or similar
2971 will fail miserably.
2973 To get around this limitation, you can supply literal SQL to your
2974 C<select> attibute that contains the C<AS alias> text, eg:
2976 select => [\'myfield AS alias']
2982 =item Value: ($rel_name | \@rel_names | \%rel_names)
2986 Contains a list of relationships that should be joined for this query. For
2989 # Get CDs by Nine Inch Nails
2990 my $rs = $schema->resultset('CD')->search(
2991 { 'artist.name' => 'Nine Inch Nails' },
2992 { join => 'artist' }
2995 Can also contain a hash reference to refer to the other relation's relations.
2998 package MyApp::Schema::Track;
2999 use base qw/DBIx::Class/;
3000 __PACKAGE__->table('track');
3001 __PACKAGE__->add_columns(qw/trackid cd position title/);
3002 __PACKAGE__->set_primary_key('trackid');
3003 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3006 # In your application
3007 my $rs = $schema->resultset('Artist')->search(
3008 { 'track.title' => 'Teardrop' },
3010 join => { cd => 'track' },
3011 order_by => 'artist.name',
3015 You need to use the relationship (not the table) name in conditions,
3016 because they are aliased as such. The current table is aliased as "me", so
3017 you need to use me.column_name in order to avoid ambiguity. For example:
3019 # Get CDs from 1984 with a 'Foo' track
3020 my $rs = $schema->resultset('CD')->search(
3023 'tracks.name' => 'Foo'
3025 { join => 'tracks' }
3028 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3029 similarly for a third time). For e.g.
3031 my $rs = $schema->resultset('Artist')->search({
3032 'cds.title' => 'Down to Earth',
3033 'cds_2.title' => 'Popular',
3035 join => [ qw/cds cds/ ],
3038 will return a set of all artists that have both a cd with title 'Down
3039 to Earth' and a cd with title 'Popular'.
3041 If you want to fetch related objects from other tables as well, see C<prefetch>
3044 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3050 =item Value: ($rel_name | \@rel_names | \%rel_names)
3054 Contains one or more relationships that should be fetched along with
3055 the main query (when they are accessed afterwards the data will
3056 already be available, without extra queries to the database). This is
3057 useful for when you know you will need the related objects, because it
3058 saves at least one query:
3060 my $rs = $schema->resultset('Tag')->search(
3069 The initial search results in SQL like the following:
3071 SELECT tag.*, cd.*, artist.* FROM tag
3072 JOIN cd ON tag.cd = cd.cdid
3073 JOIN artist ON cd.artist = artist.artistid
3075 L<DBIx::Class> has no need to go back to the database when we access the
3076 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3079 Simple prefetches will be joined automatically, so there is no need
3080 for a C<join> attribute in the above search.
3082 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3083 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3084 with an accessor type of 'single' or 'filter'). A more complex example that
3085 prefetches an artists cds, the tracks on those cds, and the tags associted
3086 with that artist is given below (assuming many-to-many from artists to tags):
3088 my $rs = $schema->resultset('Artist')->search(
3092 { cds => 'tracks' },
3093 { artist_tags => 'tags' }
3099 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3100 attributes will be ignored.
3110 Makes the resultset paged and specifies the page to retrieve. Effectively
3111 identical to creating a non-pages resultset and then calling ->page($page)
3114 If L<rows> attribute is not specified it defualts to 10 rows per page.
3116 When you have a paged resultset, L</count> will only return the number
3117 of rows in the page. To get the total, use the L</pager> and call
3118 C<total_entries> on it.
3128 Specifes the maximum number of rows for direct retrieval or the number of
3129 rows per page if the page attribute or method is used.
3135 =item Value: $offset
3139 Specifies the (zero-based) row number for the first row to be returned, or the
3140 of the first row of the first page if paging is used.
3146 =item Value: \@columns
3150 A arrayref of columns to group by. Can include columns of joined tables.
3152 group_by => [qw/ column1 column2 ... /]
3158 =item Value: $condition
3162 HAVING is a select statement attribute that is applied between GROUP BY and
3163 ORDER BY. It is applied to the after the grouping calculations have been
3166 having => { 'count(employee)' => { '>=', 100 } }
3172 =item Value: (0 | 1)
3176 Set to 1 to group by all columns.
3182 Adds to the WHERE clause.
3184 # only return rows WHERE deleted IS NULL for all searches
3185 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3187 Can be overridden by passing C<{ where => undef }> as an attribute
3194 Set to 1 to cache search results. This prevents extra SQL queries if you
3195 revisit rows in your ResultSet:
3197 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3199 while( my $artist = $resultset->next ) {
3203 $rs->first; # without cache, this would issue a query
3205 By default, searches are not cached.
3207 For more examples of using these attributes, see
3208 L<DBIx::Class::Manual::Cookbook>.
3214 =item Value: \@from_clause
3218 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3219 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3222 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3224 C<join> will usually do what you need and it is strongly recommended that you
3225 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3226 And we really do mean "cannot", not just tried and failed. Attempting to use
3227 this because you're having problems with C<join> is like trying to use x86
3228 ASM because you've got a syntax error in your C. Trust us on this.
3230 Now, if you're still really, really sure you need to use this (and if you're
3231 not 100% sure, ask the mailing list first), here's an explanation of how this
3234 The syntax is as follows -
3237 { <alias1> => <table1> },
3239 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3240 [], # nested JOIN (optional)
3241 { <table1.column1> => <table2.column2>, ... (more conditions) },
3243 # More of the above [ ] may follow for additional joins
3250 ON <table1.column1> = <table2.column2>
3251 <more joins may follow>
3253 An easy way to follow the examples below is to remember the following:
3255 Anything inside "[]" is a JOIN
3256 Anything inside "{}" is a condition for the enclosing JOIN
3258 The following examples utilize a "person" table in a family tree application.
3259 In order to express parent->child relationships, this table is self-joined:
3261 # Person->belongs_to('father' => 'Person');
3262 # Person->belongs_to('mother' => 'Person');
3264 C<from> can be used to nest joins. Here we return all children with a father,
3265 then search against all mothers of those children:
3267 $rs = $schema->resultset('Person')->search(
3270 alias => 'mother', # alias columns in accordance with "from"
3272 { mother => 'person' },
3275 { child => 'person' },
3277 { father => 'person' },
3278 { 'father.person_id' => 'child.father_id' }
3281 { 'mother.person_id' => 'child.mother_id' }
3288 # SELECT mother.* FROM person mother
3291 # JOIN person father
3292 # ON ( father.person_id = child.father_id )
3294 # ON ( mother.person_id = child.mother_id )
3296 The type of any join can be controlled manually. To search against only people
3297 with a father in the person table, we could explicitly use C<INNER JOIN>:
3299 $rs = $schema->resultset('Person')->search(
3302 alias => 'child', # alias columns in accordance with "from"
3304 { child => 'person' },
3306 { father => 'person', -join_type => 'inner' },
3307 { 'father.id' => 'child.father_id' }
3314 # SELECT child.* FROM person child
3315 # INNER JOIN person father ON child.father_id = father.id
3317 If you need to express really complex joins or you need a subselect, you
3318 can supply literal SQL to C<from> via a scalar reference. In this case
3319 the contents of the scalar will replace the table name asscoiated with the
3322 WARNING: This technique might very well not work as expected on chained
3323 searches - you have been warned.
3325 # Assuming the Event resultsource is defined as:
3327 MySchema::Event->add_columns (
3330 is_auto_increment => 1,
3339 MySchema::Event->set_primary_key ('sequence');
3341 # This will get back the latest event for every location. The column
3342 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3343 # combo to limit the resultset
3345 $rs = $schema->resultset('Event');
3346 $table = $rs->result_source->name;
3347 $latest = $rs->search (
3350 (SELECT e1.* FROM $table e1
3352 ON e1.location = e2.location
3353 AND e1.sequence < e2.sequence
3354 WHERE e2.sequence is NULL
3359 # Equivalent SQL (with the DBIC chunks added):
3361 SELECT me.sequence, me.location, me.type FROM
3362 (SELECT e1.* FROM events e1
3364 ON e1.location = e2.location
3365 AND e1.sequence < e2.sequence
3366 WHERE e2.sequence is NULL
3373 =item Value: ( 'update' | 'shared' )
3377 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT