1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use DBIx::Class::Exception;
10 use DBIx::Class::ResultSetColumn;
11 use DBIx::Class::ResultSourceHandle;
13 use Scalar::Util qw/blessed weaken/;
15 use Storable qw/nfreeze thaw/;
17 # not importing first() as it will clash with our own method
24 # De-duplication in _merge_attr() is disabled, but left in for reference
25 # (the merger is used for other things that ought not to be de-duped)
26 *__HM_DEDUP = sub () { 0 };
34 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
38 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
42 my $users_rs = $schema->resultset('User');
43 while( $user = $users_rs->next) {
44 print $user->username;
47 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
48 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
52 A ResultSet is an object which stores a set of conditions representing
53 a query. It is the backbone of DBIx::Class (i.e. the really
54 important/useful bit).
56 No SQL is executed on the database when a ResultSet is created, it
57 just stores all the conditions needed to create the query.
59 A basic ResultSet representing the data of an entire table is returned
60 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
61 L<Source|DBIx::Class::Manual::Glossary/Source> name.
63 my $users_rs = $schema->resultset('User');
65 A new ResultSet is returned from calling L</search> on an existing
66 ResultSet. The new one will contain all the conditions of the
67 original, plus any new conditions added in the C<search> call.
69 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
70 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
73 The query that the ResultSet represents is B<only> executed against
74 the database when these methods are called:
75 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
77 If a resultset is used in a numeric context it returns the L</count>.
78 However, if it is used in a boolean context it is B<always> true. So if
79 you want to check if a resultset has any results, you must use C<if $rs
84 =head2 Chaining resultsets
86 Let's say you've got a query that needs to be run to return some data
87 to the user. But, you have an authorization system in place that
88 prevents certain users from seeing certain information. So, you want
89 to construct the basic query in one method, but add constraints to it in
94 my $request = $self->get_request; # Get a request object somehow.
95 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
97 my $cd_rs = $schema->resultset('CD')->search({
98 title => $request->param('title'),
99 year => $request->param('year'),
102 $self->apply_security_policy( $cd_rs );
104 return $cd_rs->all();
107 sub apply_security_policy {
116 =head3 Resolving conditions and attributes
118 When a resultset is chained from another resultset, conditions and
119 attributes with the same keys need resolving.
121 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
122 into the existing ones from the original resultset.
124 The L</where> and L</having> attributes, and any search conditions, are
125 merged with an SQL C<AND> to the existing condition from the original
128 All other attributes are overridden by any new ones supplied in the
131 =head2 Multiple queries
133 Since a resultset just defines a query, you can do all sorts of
134 things with it with the same object.
136 # Don't hit the DB yet.
137 my $cd_rs = $schema->resultset('CD')->search({
138 title => 'something',
142 # Each of these hits the DB individually.
143 my $count = $cd_rs->count;
144 my $most_recent = $cd_rs->get_column('date_released')->max();
145 my @records = $cd_rs->all;
147 And it's not just limited to SELECT statements.
153 $cd_rs->create({ artist => 'Fred' });
155 Which is the same as:
157 $schema->resultset('CD')->create({
158 title => 'something',
163 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
171 =item Arguments: $source, \%$attrs
173 =item Return Value: $rs
177 The resultset constructor. Takes a source object (usually a
178 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
179 L</ATTRIBUTES> below). Does not perform any queries -- these are
180 executed as needed by the other methods.
182 Generally you won't need to construct a resultset manually. You'll
183 automatically get one from e.g. a L</search> called in scalar context:
185 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
187 IMPORTANT: If called on an object, proxies to new_result instead so
189 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
191 will return a CD object, not a ResultSet.
197 return $class->new_result(@_) if ref $class;
199 my ($source, $attrs) = @_;
200 $source = $source->handle
201 unless $source->isa('DBIx::Class::ResultSourceHandle');
202 $attrs = { %{$attrs||{}} };
204 if ($attrs->{page}) {
205 $attrs->{rows} ||= 10;
208 $attrs->{alias} ||= 'me';
210 # Creation of {} and bless separated to mitigate RH perl bug
211 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
213 _source_handle => $source,
214 cond => $attrs->{where},
222 $attrs->{result_class} || $source->resolve->result_class
232 =item Arguments: $cond, \%attrs?
234 =item Return Value: $resultset (scalar context), @row_objs (list context)
238 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
239 my $new_rs = $cd_rs->search({ year => 2005 });
241 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
242 # year = 2005 OR year = 2004
244 If you need to pass in additional attributes but no additional condition,
245 call it as C<search(undef, \%attrs)>.
247 # "SELECT name, artistid FROM $artist_table"
248 my @all_artists = $schema->resultset('Artist')->search(undef, {
249 columns => [qw/name artistid/],
252 For a list of attributes that can be passed to C<search>, see
253 L</ATTRIBUTES>. For more examples of using this function, see
254 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
255 documentation for the first argument, see L<SQL::Abstract>.
257 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
261 Note that L</search> does not process/deflate any of the values passed in the
262 L<SQL::Abstract>-compatible search condition structure. This is unlike other
263 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
264 manually that any value passed to this method will stringify to something the
265 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
266 objects, for more info see:
267 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
273 my $rs = $self->search_rs( @_ );
278 elsif (defined wantarray) {
282 # we can be called by a relationship helper, which in
283 # turn may be called in void context due to some braindead
284 # overload or whatever else the user decided to be clever
285 # at this particular day. Thus limit the exception to
286 # external code calls only
287 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
288 if (caller)[0] !~ /^\QDBIx::Class::/;
298 =item Arguments: $cond, \%attrs?
300 =item Return Value: $resultset
304 This method does the same exact thing as search() except it will
305 always return a resultset, even in list context.
309 my $callsites_warned;
313 # Special-case handling for (undef, undef).
314 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
320 if (ref $_[-1] eq 'HASH') {
321 # copy for _normalize_selection
322 $call_attrs = { %{ pop @_ } };
324 elsif (! defined $_[-1] ) {
325 pop @_; # search({}, undef)
329 # see if we can keep the cache (no $rs changes)
331 my %safe = (alias => 1, cache => 1);
332 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
335 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
337 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
339 $cache = $self->get_cache;
342 my $rsrc = $self->result_source;
344 my $old_attrs = { %{$self->{attrs}} };
345 my $old_having = delete $old_attrs->{having};
346 my $old_where = delete $old_attrs->{where};
348 my $new_attrs = { %$old_attrs };
350 # take care of call attrs (only if anything is changing)
351 if (keys %$call_attrs) {
353 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
354 if ( exists $call_attrs->{_trailing_select} or exists $call_attrs->{'+_trailing_select'} );
356 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns _trailing_select +_trailing_select/;
358 # Normalize the selector list (operates on the passed-in attr structure)
359 # Need to do it on every chain instead of only once on _resolved_attrs, in
360 # order to separate 'as'-ed from blind 'select's
361 $self->_normalize_selection ($call_attrs);
363 # start with blind overwriting merge, exclude selector attrs
364 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
365 delete @{$new_attrs}{@selector_attrs};
367 # reset the current selector list if new selectors are supplied
368 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
369 delete @{$old_attrs}{@selector_attrs};
372 for (@selector_attrs) {
373 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
374 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
377 # older deprecated name, use only if {columns} is not there
378 if (my $c = delete $new_attrs->{cols}) {
379 if ($new_attrs->{columns}) {
380 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
383 $new_attrs->{columns} = $c;
388 # join/prefetch use their own crazy merging heuristics
389 foreach my $key (qw/join prefetch/) {
390 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
391 if exists $call_attrs->{$key};
394 # stack binds together
395 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
399 # rip apart the rest of @_, parse a condition
402 if (ref $_[0] eq 'HASH') {
403 (keys %{$_[0]}) ? $_[0] : undef
409 $self->throw_exception('Odd number of arguments to search')
417 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
418 # determine callsite obeying Carp::Clan rules (fucking ugly but don't have better ideas)
421 local $SIG{__WARN__} = sub { $w = shift };
425 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
426 unless $callsites_warned->{$callsite}++;
429 for ($old_where, $call_cond) {
431 $new_attrs->{where} = $self->_stack_cond (
432 $_, $new_attrs->{where}
437 if (defined $old_having) {
438 $new_attrs->{having} = $self->_stack_cond (
439 $old_having, $new_attrs->{having}
443 my $rs = (ref $self)->new($rsrc, $new_attrs);
445 $rs->set_cache($cache) if ($cache);
450 sub _normalize_selection {
451 my ($self, $attrs) = @_;
454 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
455 if exists $attrs->{include_columns};
457 # Keep the X vs +X separation until _resolved_attrs time - this allows to
458 # delay the decision on whether to use a default select list ($rsrc->columns)
459 # allowing stuff like the remove_columns helper to work
461 # select/as +select/+as pairs need special handling - the amount of select/as
462 # elements in each pair does *not* have to be equal (think multicolumn
463 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
464 # supplied at all) - try to infer the alias, either from the -as parameter
465 # of the selector spec, or use the parameter whole if it looks like a column
466 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
467 # is ok as well), but transport it over a separate attribute to make sure it is
468 # the last thing in the select list, thus unable to throw off the corresponding
470 for my $pref ('', '+') {
472 my ($sel, $as) = map {
473 my $key = "${pref}${_}";
475 my $val = [ ref $attrs->{$key} eq 'ARRAY'
477 : $attrs->{$key} || ()
479 delete $attrs->{$key};
483 if (! @$as and ! @$sel ) {
486 elsif (@$as and ! @$sel) {
487 $self->throw_exception(
488 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
492 # no as part supplied at all - try to deduce
493 # if any @$as has been supplied we assume the user knows what (s)he is doing
494 # and blindly keep stacking up pieces
495 my (@new_sel, @new_trailing);
497 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
498 push @$as, $_->{-as};
501 # assume any plain no-space, no-parenthesis string to be a column spec
502 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
503 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
507 # if all else fails - shove the selection to the trailing stack and move on
509 push @new_trailing, $_;
514 $attrs->{"${pref}_trailing_select"} = $self->_merge_attr($attrs->{"${pref}_trailing_select"}, \@new_trailing)
517 elsif (@$as < @$sel) {
518 $self->throw_exception(
519 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
523 # now see what the result for this pair looks like:
526 # if balanced - treat as a columns entry
527 $attrs->{"${pref}columns"} = $self->_merge_attr(
528 $attrs->{"${pref}columns"},
529 { map { $as->[$_] => $sel->[$_] } ( 0 .. $#$as ) }
533 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
534 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
535 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
542 my ($self, $left, $right) = @_;
543 if (defined $left xor defined $right) {
544 return defined $left ? $left : $right;
546 elsif (defined $left) {
547 return { -and => [ map
548 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
556 =head2 search_literal
560 =item Arguments: $sql_fragment, @bind_values
562 =item Return Value: $resultset (scalar context), @row_objs (list context)
566 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
567 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
569 Pass a literal chunk of SQL to be added to the conditional part of the
572 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
573 only be used in that context. C<search_literal> is a convenience method.
574 It is equivalent to calling $schema->search(\[]), but if you want to ensure
575 columns are bound correctly, use C<search>.
577 Example of how to use C<search> instead of C<search_literal>
579 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
580 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
583 See L<DBIx::Class::Manual::Cookbook/Searching> and
584 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
585 require C<search_literal>.
590 my ($self, $sql, @bind) = @_;
592 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
595 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
602 =item Arguments: \%columns_values | @pk_values, \%attrs?
604 =item Return Value: $row_object | undef
608 Finds and returns a single row based on supplied criteria. Takes either a
609 hashref with the same format as L</create> (including inference of foreign
610 keys from related objects), or a list of primary key values in the same
611 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
612 declaration on the L</result_source>.
614 In either case an attempt is made to combine conditions already existing on
615 the resultset with the condition passed to this method.
617 To aid with preparing the correct query for the storage you may supply the
618 C<key> attribute, which is the name of a
619 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
620 unique constraint corresponding to the
621 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
622 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
623 to construct a query that satisfies the named unique constraint fully (
624 non-NULL values for each column member of the constraint) an exception is
627 If no C<key> is specified, the search is carried over all unique constraints
628 which are fully defined by the available condition.
630 If no such constraint is found, C<find> currently defaults to a simple
631 C<< search->(\%column_values) >> which may or may not do what you expect.
632 Note that this fallback behavior may be deprecated in further versions. If
633 you need to search with arbitrary conditions - use L</search>. If the query
634 resulting from this fallback produces more than one row, a warning to the
635 effect is issued, though only the first row is constructed and returned as
638 In addition to C<key>, L</find> recognizes and applies standard
639 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
641 Note that if you have extra concerns about the correctness of the resulting
642 query you need to specify the C<key> attribute and supply the entire condition
643 as an argument to find (since it is not always possible to perform the
644 combination of the resultset condition with the supplied one, especially if
645 the resultset condition contains literal sql).
647 For example, to find a row by its primary key:
649 my $cd = $schema->resultset('CD')->find(5);
651 You can also find a row by a specific unique constraint:
653 my $cd = $schema->resultset('CD')->find(
655 artist => 'Massive Attack',
656 title => 'Mezzanine',
658 { key => 'cd_artist_title' }
661 See also L</find_or_create> and L</update_or_create>.
667 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
669 my $rsrc = $self->result_source;
671 # Parse out the condition from input
673 if (ref $_[0] eq 'HASH') {
674 $call_cond = { %{$_[0]} };
677 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
678 my @c_cols = $rsrc->unique_constraint_columns($constraint);
680 $self->throw_exception(
681 "No constraint columns, maybe a malformed '$constraint' constraint?"
684 $self->throw_exception (
685 'find() expects either a column/value hashref, or a list of values '
686 . "corresponding to the columns of the specified unique constraint '$constraint'"
687 ) unless @c_cols == @_;
690 @{$call_cond}{@c_cols} = @_;
694 for my $key (keys %$call_cond) {
696 my $keyref = ref($call_cond->{$key})
698 my $relinfo = $rsrc->relationship_info($key)
700 my $val = delete $call_cond->{$key};
702 next if $keyref eq 'ARRAY'; # has_many for multi_create
704 my $rel_q = $rsrc->_resolve_condition(
705 $relinfo->{cond}, $val, $key
707 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
708 @related{keys %$rel_q} = values %$rel_q;
712 # relationship conditions take precedence (?)
713 @{$call_cond}{keys %related} = values %related;
715 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
717 if (exists $attrs->{key}) {
718 $final_cond = $self->_qualify_cond_columns (
720 $self->_build_unique_cond (
728 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
729 # This means that we got here after a merger of relationship conditions
730 # in ::Relationship::Base::search_related (the row method), and furthermore
731 # the relationship is of the 'single' type. This means that the condition
732 # provided by the relationship (already attached to $self) is sufficient,
733 # as there can be only one row in the database that would satisfy the
737 # no key was specified - fall down to heuristics mode:
738 # run through all unique queries registered on the resultset, and
739 # 'OR' all qualifying queries together
740 my (@unique_queries, %seen_column_combinations);
741 for my $c_name ($rsrc->unique_constraint_names) {
742 next if $seen_column_combinations{
743 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
746 push @unique_queries, try {
747 $self->_build_unique_cond ($c_name, $call_cond)
751 $final_cond = @unique_queries
752 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
753 : $self->_non_unique_find_fallback ($call_cond, $attrs)
757 # Run the query, passing the result_class since it should propagate for find
758 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
759 if (keys %{$rs->_resolved_attrs->{collapse}}) {
761 carp "Query returned more than one row" if $rs->next;
769 # This is a stop-gap method as agreed during the discussion on find() cleanup:
770 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
772 # It is invoked when find() is called in legacy-mode with insufficiently-unique
773 # condition. It is provided for overrides until a saner way forward is devised
775 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
776 # the road. Please adjust your tests accordingly to catch this situation early
777 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
779 # The method will not be removed without an adequately complete replacement
780 # for strict-mode enforcement
781 sub _non_unique_find_fallback {
782 my ($self, $cond, $attrs) = @_;
784 return $self->_qualify_cond_columns(
786 exists $attrs->{alias}
788 : $self->{attrs}{alias}
793 sub _qualify_cond_columns {
794 my ($self, $cond, $alias) = @_;
796 my %aliased = %$cond;
797 for (keys %aliased) {
798 $aliased{"$alias.$_"} = delete $aliased{$_}
805 sub _build_unique_cond {
806 my ($self, $constraint_name, $extra_cond) = @_;
808 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
810 # combination may fail if $self->{cond} is non-trivial
811 my ($final_cond) = try {
812 $self->_merge_with_rscond ($extra_cond)
817 # trim out everything not in $columns
818 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
820 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
821 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
823 join (', ', map { "'$_'" } @missing),
830 =head2 search_related
834 =item Arguments: $rel, $cond, \%attrs?
836 =item Return Value: $new_resultset
840 $new_rs = $cd_rs->search_related('artist', {
844 Searches the specified relationship, optionally specifying a condition and
845 attributes for matching records. See L</ATTRIBUTES> for more information.
850 return shift->related_resultset(shift)->search(@_);
853 =head2 search_related_rs
855 This method works exactly the same as search_related, except that
856 it guarantees a resultset, even in list context.
860 sub search_related_rs {
861 return shift->related_resultset(shift)->search_rs(@_);
868 =item Arguments: none
870 =item Return Value: $cursor
874 Returns a storage-driven cursor to the given resultset. See
875 L<DBIx::Class::Cursor> for more information.
882 my $attrs = $self->_resolved_attrs_copy;
884 return $self->{cursor}
885 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
886 $attrs->{where},$attrs);
893 =item Arguments: $cond?
895 =item Return Value: $row_object | undef
899 my $cd = $schema->resultset('CD')->single({ year => 2001 });
901 Inflates the first result without creating a cursor if the resultset has
902 any records in it; if not returns C<undef>. Used by L</find> as a lean version
905 While this method can take an optional search condition (just like L</search>)
906 being a fast-code-path it does not recognize search attributes. If you need to
907 add extra joins or similar, call L</search> and then chain-call L</single> on the
908 L<DBIx::Class::ResultSet> returned.
914 As of 0.08100, this method enforces the assumption that the preceding
915 query returns only one row. If more than one row is returned, you will receive
918 Query returned more than one row
920 In this case, you should be using L</next> or L</find> instead, or if you really
921 know what you are doing, use the L</rows> attribute to explicitly limit the size
924 This method will also throw an exception if it is called on a resultset prefetching
925 has_many, as such a prefetch implies fetching multiple rows from the database in
926 order to assemble the resulting object.
933 my ($self, $where) = @_;
935 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
938 my $attrs = $self->_resolved_attrs_copy;
940 if (keys %{$attrs->{collapse}}) {
941 $self->throw_exception(
942 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
947 if (defined $attrs->{where}) {
950 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
951 $where, delete $attrs->{where} ]
954 $attrs->{where} = $where;
958 my @data = $self->result_source->storage->select_single(
959 $attrs->{from}, $attrs->{select},
960 $attrs->{where}, $attrs
963 return (@data ? ($self->_construct_object(@data))[0] : undef);
969 # Recursively collapse the query, accumulating values for each column.
971 sub _collapse_query {
972 my ($self, $query, $collapsed) = @_;
976 if (ref $query eq 'ARRAY') {
977 foreach my $subquery (@$query) {
978 next unless ref $subquery; # -or
979 $collapsed = $self->_collapse_query($subquery, $collapsed);
982 elsif (ref $query eq 'HASH') {
983 if (keys %$query and (keys %$query)[0] eq '-and') {
984 foreach my $subquery (@{$query->{-and}}) {
985 $collapsed = $self->_collapse_query($subquery, $collapsed);
989 foreach my $col (keys %$query) {
990 my $value = $query->{$col};
991 $collapsed->{$col}{$value}++;
1003 =item Arguments: $cond?
1005 =item Return Value: $resultsetcolumn
1009 my $max_length = $rs->get_column('length')->max;
1011 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1016 my ($self, $column) = @_;
1017 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1025 =item Arguments: $cond, \%attrs?
1027 =item Return Value: $resultset (scalar context), @row_objs (list context)
1031 # WHERE title LIKE '%blue%'
1032 $cd_rs = $rs->search_like({ title => '%blue%'});
1034 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1035 that this is simply a convenience method retained for ex Class::DBI users.
1036 You most likely want to use L</search> with specific operators.
1038 For more information, see L<DBIx::Class::Manual::Cookbook>.
1040 This method is deprecated and will be removed in 0.09. Use L</search()>
1041 instead. An example conversion is:
1043 ->search_like({ foo => 'bar' });
1047 ->search({ foo => { like => 'bar' } });
1054 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1055 .' Instead use ->search({ x => { -like => "y%" } })'
1056 .' (note the outer pair of {}s - they are important!)'
1058 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1059 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1060 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1061 return $class->search($query, { %$attrs });
1068 =item Arguments: $first, $last
1070 =item Return Value: $resultset (scalar context), @row_objs (list context)
1074 Returns a resultset or object list representing a subset of elements from the
1075 resultset slice is called on. Indexes are from 0, i.e., to get the first
1076 three records, call:
1078 my ($one, $two, $three) = $rs->slice(0, 2);
1083 my ($self, $min, $max) = @_;
1084 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1085 $attrs->{offset} = $self->{attrs}{offset} || 0;
1086 $attrs->{offset} += $min;
1087 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1088 return $self->search(undef, $attrs);
1089 #my $slice = (ref $self)->new($self->result_source, $attrs);
1090 #return (wantarray ? $slice->all : $slice);
1097 =item Arguments: none
1099 =item Return Value: $result | undef
1103 Returns the next element in the resultset (C<undef> is there is none).
1105 Can be used to efficiently iterate over records in the resultset:
1107 my $rs = $schema->resultset('CD')->search;
1108 while (my $cd = $rs->next) {
1112 Note that you need to store the resultset object, and call C<next> on it.
1113 Calling C<< resultset('Table')->next >> repeatedly will always return the
1114 first record from the resultset.
1120 if (my $cache = $self->get_cache) {
1121 $self->{all_cache_position} ||= 0;
1122 return $cache->[$self->{all_cache_position}++];
1124 if ($self->{attrs}{cache}) {
1125 delete $self->{pager};
1126 $self->{all_cache_position} = 1;
1127 return ($self->all)[0];
1129 if ($self->{stashed_objects}) {
1130 my $obj = shift(@{$self->{stashed_objects}});
1131 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1135 exists $self->{stashed_row}
1136 ? @{delete $self->{stashed_row}}
1137 : $self->cursor->next
1139 return undef unless (@row);
1140 my ($row, @more) = $self->_construct_object(@row);
1141 $self->{stashed_objects} = \@more if @more;
1145 sub _construct_object {
1146 my ($self, @row) = @_;
1148 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1150 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1151 @new = $self->{_attrs}{record_filter}->(@new)
1152 if exists $self->{_attrs}{record_filter};
1156 sub _collapse_result {
1157 my ($self, $as_proto, $row) = @_;
1161 # 'foo' => [ undef, 'foo' ]
1162 # 'foo.bar' => [ 'foo', 'bar' ]
1163 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1165 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1167 my %collapse = %{$self->{_attrs}{collapse}||{}};
1171 # if we're doing collapsing (has_many prefetch) we need to grab records
1172 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1173 # we know we don't have to bother.
1175 # the reason for not using the collapse stuff directly is because if you
1176 # had for e.g. two artists in a row with no cds, the collapse info for
1177 # both would be NULL (undef) so you'd lose the second artist
1179 # store just the index so we can check the array positions from the row
1180 # without having to contruct the full hash
1182 if (keys %collapse) {
1183 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1184 foreach my $i (0 .. $#construct_as) {
1185 next if defined($construct_as[$i][0]); # only self table
1186 if (delete $pri{$construct_as[$i][1]}) {
1187 push(@pri_index, $i);
1189 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1193 # no need to do an if, it'll be empty if @pri_index is empty anyway
1195 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1199 do { # no need to check anything at the front, we always want the first row
1203 foreach my $this_as (@construct_as) {
1204 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1207 push(@const_rows, \%const);
1209 } until ( # no pri_index => no collapse => drop straight out
1212 do { # get another row, stash it, drop out if different PK
1214 @copy = $self->cursor->next;
1215 $self->{stashed_row} = \@copy;
1217 # last thing in do block, counts as true if anything doesn't match
1219 # check xor defined first for NULL vs. NOT NULL then if one is
1220 # defined the other must be so check string equality
1223 (defined $pri_vals{$_} ^ defined $copy[$_])
1224 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1229 my $alias = $self->{attrs}{alias};
1236 foreach my $const (@const_rows) {
1237 scalar @const_keys or do {
1238 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1240 foreach my $key (@const_keys) {
1243 my @parts = split(/\./, $key);
1245 my $data = $const->{$key};
1246 foreach my $p (@parts) {
1247 $target = $target->[1]->{$p} ||= [];
1249 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1250 # collapsing at this point and on final part
1251 my $pos = $collapse_pos{$cur};
1252 CK: foreach my $ck (@ckey) {
1253 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1254 $collapse_pos{$cur} = $data;
1255 delete @collapse_pos{ # clear all positioning for sub-entries
1256 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1263 if (exists $collapse{$cur}) {
1264 $target = $target->[-1];
1267 $target->[0] = $data;
1269 $info->[0] = $const->{$key};
1277 =head2 result_source
1281 =item Arguments: $result_source?
1283 =item Return Value: $result_source
1287 An accessor for the primary ResultSource object from which this ResultSet
1294 =item Arguments: $result_class?
1296 =item Return Value: $result_class
1300 An accessor for the class to use when creating row objects. Defaults to
1301 C<< result_source->result_class >> - which in most cases is the name of the
1302 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1304 Note that changing the result_class will also remove any components
1305 that were originally loaded in the source class via
1306 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1307 in the original source class will not run.
1312 my ($self, $result_class) = @_;
1313 if ($result_class) {
1314 unless (ref $result_class) { # don't fire this for an object
1315 $self->ensure_class_loaded($result_class);
1317 $self->_result_class($result_class);
1318 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1319 # permit the user to set result class on one result set only; it only
1320 # chains if provided to search()
1321 #$self->{attrs}{result_class} = $result_class if ref $self;
1323 $self->_result_class;
1330 =item Arguments: $cond, \%attrs??
1332 =item Return Value: $count
1336 Performs an SQL C<COUNT> with the same query as the resultset was built
1337 with to find the number of elements. Passing arguments is equivalent to
1338 C<< $rs->search ($cond, \%attrs)->count >>
1344 return $self->search(@_)->count if @_ and defined $_[0];
1345 return scalar @{ $self->get_cache } if $self->get_cache;
1347 my $attrs = $self->_resolved_attrs_copy;
1349 # this is a little optimization - it is faster to do the limit
1350 # adjustments in software, instead of a subquery
1351 my $rows = delete $attrs->{rows};
1352 my $offset = delete $attrs->{offset};
1355 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1356 $crs = $self->_count_subq_rs ($attrs);
1359 $crs = $self->_count_rs ($attrs);
1361 my $count = $crs->next;
1363 $count -= $offset if $offset;
1364 $count = $rows if $rows and $rows < $count;
1365 $count = 0 if ($count < 0);
1374 =item Arguments: $cond, \%attrs??
1376 =item Return Value: $count_rs
1380 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1381 This can be very handy for subqueries:
1383 ->search( { amount => $some_rs->count_rs->as_query } )
1385 As with regular resultsets the SQL query will be executed only after
1386 the resultset is accessed via L</next> or L</all>. That would return
1387 the same single value obtainable via L</count>.
1393 return $self->search(@_)->count_rs if @_;
1395 # this may look like a lack of abstraction (count() does about the same)
1396 # but in fact an _rs *must* use a subquery for the limits, as the
1397 # software based limiting can not be ported if this $rs is to be used
1398 # in a subquery itself (i.e. ->as_query)
1399 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1400 return $self->_count_subq_rs;
1403 return $self->_count_rs;
1408 # returns a ResultSetColumn object tied to the count query
1411 my ($self, $attrs) = @_;
1413 my $rsrc = $self->result_source;
1414 $attrs ||= $self->_resolved_attrs;
1416 my $tmp_attrs = { %$attrs };
1417 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1418 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1420 # overwrite the selector (supplied by the storage)
1421 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1422 $tmp_attrs->{as} = 'count';
1423 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1425 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1431 # same as above but uses a subquery
1433 sub _count_subq_rs {
1434 my ($self, $attrs) = @_;
1436 my $rsrc = $self->result_source;
1437 $attrs ||= $self->_resolved_attrs;
1439 my $sub_attrs = { %$attrs };
1440 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1441 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1443 # if we multi-prefetch we group_by primary keys only as this is what we would
1444 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1445 if ( keys %{$attrs->{collapse}} ) {
1446 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1449 # Calculate subquery selector
1450 if (my $g = $sub_attrs->{group_by}) {
1452 my $sql_maker = $rsrc->storage->sql_maker;
1454 # necessary as the group_by may refer to aliased functions
1456 for my $sel (@{$attrs->{select}}) {
1457 $sel_index->{$sel->{-as}} = $sel
1458 if (ref $sel eq 'HASH' and $sel->{-as});
1461 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1462 # also look for named aggregates referred in the having clause
1463 # having often contains scalarrefs - thus parse it out entirely
1465 if ($attrs->{having}) {
1466 local $sql_maker->{having_bind};
1467 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1468 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1469 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1470 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1471 # if we don't unset it we screw up retarded but unfortunately working
1472 # 'MAX(foo.bar)' => { '>', 3 }
1473 $sql_maker->{name_sep} = '';
1476 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1478 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1480 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1481 # and if all fails for an utterly naive quoted scalar-with-function
1483 $rquote $sep $lquote (.+?) $rquote
1485 [\s,] \w+ \. (\w+) [\s,]
1487 [\s,] $lquote (.+?) $rquote [\s,]
1489 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1494 my $colpiece = $sel_index->{$_} || $_;
1496 # unqualify join-based group_by's. Arcane but possible query
1497 # also horrible horrible hack to alias a column (not a func.)
1498 # (probably need to introduce SQLA syntax)
1499 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1502 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1504 push @{$sub_attrs->{select}}, $colpiece;
1508 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1509 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1512 return $rsrc->resultset_class
1513 ->new ($rsrc, $sub_attrs)
1515 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1516 ->get_column ('count');
1523 =head2 count_literal
1527 =item Arguments: $sql_fragment, @bind_values
1529 =item Return Value: $count
1533 Counts the results in a literal query. Equivalent to calling L</search_literal>
1534 with the passed arguments, then L</count>.
1538 sub count_literal { shift->search_literal(@_)->count; }
1544 =item Arguments: none
1546 =item Return Value: @objects
1550 Returns all elements in the resultset. Called implicitly if the resultset
1551 is returned in list context.
1558 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1561 return @{ $self->get_cache } if $self->get_cache;
1565 if (keys %{$self->_resolved_attrs->{collapse}}) {
1566 # Using $self->cursor->all is really just an optimisation.
1567 # If we're collapsing has_many prefetches it probably makes
1568 # very little difference, and this is cleaner than hacking
1569 # _construct_object to survive the approach
1570 $self->cursor->reset;
1571 my @row = $self->cursor->next;
1573 push(@obj, $self->_construct_object(@row));
1574 @row = (exists $self->{stashed_row}
1575 ? @{delete $self->{stashed_row}}
1576 : $self->cursor->next);
1579 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1582 $self->set_cache(\@obj) if $self->{attrs}{cache};
1591 =item Arguments: none
1593 =item Return Value: $self
1597 Resets the resultset's cursor, so you can iterate through the elements again.
1598 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1605 delete $self->{_attrs} if exists $self->{_attrs};
1606 $self->{all_cache_position} = 0;
1607 $self->cursor->reset;
1615 =item Arguments: none
1617 =item Return Value: $object | undef
1621 Resets the resultset and returns an object for the first result (or C<undef>
1622 if the resultset is empty).
1627 return $_[0]->reset->next;
1633 # Determines whether and what type of subquery is required for the $rs operation.
1634 # If grouping is necessary either supplies its own, or verifies the current one
1635 # After all is done delegates to the proper storage method.
1637 sub _rs_update_delete {
1638 my ($self, $op, $values) = @_;
1640 my $rsrc = $self->result_source;
1642 # if a condition exists we need to strip all table qualifiers
1643 # if this is not possible we'll force a subquery below
1644 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1646 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1647 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1649 if ($needs_group_by_subq or $needs_subq) {
1651 # make a new $rs selecting only the PKs (that's all we really need)
1652 my $attrs = $self->_resolved_attrs_copy;
1655 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1656 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1658 if ($needs_group_by_subq) {
1659 # make sure no group_by was supplied, or if there is one - make sure it matches
1660 # the columns compiled above perfectly. Anything else can not be sanely executed
1661 # on most databases so croak right then and there
1663 if (my $g = $attrs->{group_by}) {
1664 my @current_group_by = map
1665 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1670 join ("\x00", sort @current_group_by)
1672 join ("\x00", sort @{$attrs->{columns}} )
1674 $self->throw_exception (
1675 "You have just attempted a $op operation on a resultset which does group_by"
1676 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1677 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1678 . ' kind of queries. Please retry the operation with a modified group_by or'
1679 . ' without using one at all.'
1684 $attrs->{group_by} = $attrs->{columns};
1688 my $subrs = (ref $self)->new($rsrc, $attrs);
1689 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1692 return $rsrc->storage->$op(
1694 $op eq 'update' ? $values : (),
1704 =item Arguments: \%values
1706 =item Return Value: $storage_rv
1710 Sets the specified columns in the resultset to the supplied values in a
1711 single query. Note that this will not run any accessor/set_column/update
1712 triggers, nor will it update any row object instances derived from this
1713 resultset (this includes the contents of the L<resultset cache|/set_cache>
1714 if any). See L</update_all> if you need to execute any on-update
1715 triggers or cascades defined either by you or a
1716 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1718 The return value is a pass through of what the underlying
1719 storage backend returned, and may vary. See L<DBI/execute> for the most
1724 Note that L</update> does not process/deflate any of the values passed in.
1725 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1726 ensure manually that any value passed to this method will stringify to
1727 something the RDBMS knows how to deal with. A notable example is the
1728 handling of L<DateTime> objects, for more info see:
1729 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1734 my ($self, $values) = @_;
1735 $self->throw_exception('Values for update must be a hash')
1736 unless ref $values eq 'HASH';
1738 return $self->_rs_update_delete ('update', $values);
1745 =item Arguments: \%values
1747 =item Return Value: 1
1751 Fetches all objects and updates them one at a time via
1752 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1753 triggers, while L</update> will not.
1758 my ($self, $values) = @_;
1759 $self->throw_exception('Values for update_all must be a hash')
1760 unless ref $values eq 'HASH';
1762 my $guard = $self->result_source->schema->txn_scope_guard;
1763 $_->update($values) for $self->all;
1772 =item Arguments: none
1774 =item Return Value: $storage_rv
1778 Deletes the rows matching this resultset in a single query. Note that this
1779 will not run any delete triggers, nor will it alter the
1780 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1781 derived from this resultset (this includes the contents of the
1782 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1783 execute any on-delete triggers or cascades defined either by you or a
1784 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1786 The return value is a pass through of what the underlying storage backend
1787 returned, and may vary. See L<DBI/execute> for the most common case.
1793 $self->throw_exception('delete does not accept any arguments')
1796 return $self->_rs_update_delete ('delete');
1803 =item Arguments: none
1805 =item Return Value: 1
1809 Fetches all objects and deletes them one at a time via
1810 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1811 triggers, while L</delete> will not.
1817 $self->throw_exception('delete_all does not accept any arguments')
1820 my $guard = $self->result_source->schema->txn_scope_guard;
1821 $_->delete for $self->all;
1830 =item Arguments: \@data;
1834 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1835 For the arrayref of hashrefs style each hashref should be a structure suitable
1836 forsubmitting to a $resultset->create(...) method.
1838 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1839 to insert the data, as this is a faster method.
1841 Otherwise, each set of data is inserted into the database using
1842 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1843 accumulated into an array. The array itself, or an array reference
1844 is returned depending on scalar or list context.
1846 Example: Assuming an Artist Class that has many CDs Classes relating:
1848 my $Artist_rs = $schema->resultset("Artist");
1850 ## Void Context Example
1851 $Artist_rs->populate([
1852 { artistid => 4, name => 'Manufactured Crap', cds => [
1853 { title => 'My First CD', year => 2006 },
1854 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1857 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1858 { title => 'My parents sold me to a record company', year => 2005 },
1859 { title => 'Why Am I So Ugly?', year => 2006 },
1860 { title => 'I Got Surgery and am now Popular', year => 2007 }
1865 ## Array Context Example
1866 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1867 { name => "Artist One"},
1868 { name => "Artist Two"},
1869 { name => "Artist Three", cds=> [
1870 { title => "First CD", year => 2007},
1871 { title => "Second CD", year => 2008},
1875 print $ArtistOne->name; ## response is 'Artist One'
1876 print $ArtistThree->cds->count ## reponse is '2'
1878 For the arrayref of arrayrefs style, the first element should be a list of the
1879 fieldsnames to which the remaining elements are rows being inserted. For
1882 $Arstist_rs->populate([
1883 [qw/artistid name/],
1884 [100, 'A Formally Unknown Singer'],
1885 [101, 'A singer that jumped the shark two albums ago'],
1886 [102, 'An actually cool singer'],
1889 Please note an important effect on your data when choosing between void and
1890 wantarray context. Since void context goes straight to C<insert_bulk> in
1891 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1892 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1893 create primary keys for you, you will find that your PKs are empty. In this
1894 case you will have to use the wantarray context in order to create those
1902 # cruft placed in standalone method
1903 my $data = $self->_normalize_populate_args(@_);
1905 if(defined wantarray) {
1907 foreach my $item (@$data) {
1908 push(@created, $self->create($item));
1910 return wantarray ? @created : \@created;
1912 my $first = $data->[0];
1914 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1915 # it relationship data
1916 my (@rels, @columns);
1917 for (keys %$first) {
1918 my $ref = ref $first->{$_};
1919 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1925 my @pks = $self->result_source->primary_columns;
1927 ## do the belongs_to relationships
1928 foreach my $index (0..$#$data) {
1930 # delegate to create() for any dataset without primary keys with specified relationships
1931 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1933 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1934 my @ret = $self->populate($data);
1940 foreach my $rel (@rels) {
1941 next unless ref $data->[$index]->{$rel} eq "HASH";
1942 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1943 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1944 my $related = $result->result_source->_resolve_condition(
1945 $result->result_source->relationship_info($reverse)->{cond},
1950 delete $data->[$index]->{$rel};
1951 $data->[$index] = {%{$data->[$index]}, %$related};
1953 push @columns, keys %$related if $index == 0;
1957 ## inherit the data locked in the conditions of the resultset
1958 my ($rs_data) = $self->_merge_with_rscond({});
1959 delete @{$rs_data}{@columns};
1960 my @inherit_cols = keys %$rs_data;
1961 my @inherit_data = values %$rs_data;
1963 ## do bulk insert on current row
1964 $self->result_source->storage->insert_bulk(
1965 $self->result_source,
1966 [@columns, @inherit_cols],
1967 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1970 ## do the has_many relationships
1971 foreach my $item (@$data) {
1973 foreach my $rel (@rels) {
1974 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1976 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1977 || $self->throw_exception('Cannot find the relating object.');
1979 my $child = $parent->$rel;
1981 my $related = $child->result_source->_resolve_condition(
1982 $parent->result_source->relationship_info($rel)->{cond},
1987 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1988 my @populate = map { {%$_, %$related} } @rows_to_add;
1990 $child->populate( \@populate );
1997 # populate() argumnets went over several incarnations
1998 # What we ultimately support is AoH
1999 sub _normalize_populate_args {
2000 my ($self, $arg) = @_;
2002 if (ref $arg eq 'ARRAY') {
2003 if (ref $arg->[0] eq 'HASH') {
2006 elsif (ref $arg->[0] eq 'ARRAY') {
2008 my @colnames = @{$arg->[0]};
2009 foreach my $values (@{$arg}[1 .. $#$arg]) {
2010 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2016 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2023 =item Arguments: none
2025 =item Return Value: $pager
2029 Return Value a L<Data::Page> object for the current resultset. Only makes
2030 sense for queries with a C<page> attribute.
2032 To get the full count of entries for a paged resultset, call
2033 C<total_entries> on the L<Data::Page> object.
2037 # make a wizard good for both a scalar and a hashref
2038 my $mk_lazy_count_wizard = sub {
2039 require Variable::Magic;
2041 my $stash = { total_rs => shift };
2042 my $slot = shift; # only used by the hashref magic
2044 my $magic = Variable::Magic::wizard (
2045 data => sub { $stash },
2051 # set value lazily, and dispell for good
2052 ${$_[0]} = $_[1]{total_rs}->count;
2053 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2057 # an explicit set implies dispell as well
2058 # the unless() is to work around "fun and giggles" below
2059 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2060 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2067 if ($_[2] eq $slot and !$_[1]{inactive}) {
2068 my $cnt = $_[1]{total_rs}->count;
2069 $_[0]->{$slot} = $cnt;
2071 # attempting to dispell in a fetch handle (works in store), seems
2072 # to invariable segfault on 5.10, 5.12, 5.13 :(
2073 # so use an inactivator instead
2074 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2080 if (! $_[1]{inactive} and $_[2] eq $slot) {
2081 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2083 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2090 $stash->{magic_selfref} = $magic;
2091 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2096 # the tie class for 5.8.1
2098 package # hide from pause
2099 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2100 use base qw/Tie::Hash/;
2102 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2103 sub NEXTKEY { each %{$_[0]{data}} }
2104 sub EXISTS { exists $_[0]{data}{$_[1]} }
2105 sub DELETE { delete $_[0]{data}{$_[1]} }
2106 sub CLEAR { %{$_[0]{data}} = () }
2107 sub SCALAR { scalar %{$_[0]{data}} }
2110 $_[1]{data} = {%{$_[1]{selfref}}};
2111 %{$_[1]{selfref}} = ();
2112 Scalar::Util::weaken ($_[1]{selfref});
2113 return bless ($_[1], $_[0]);
2117 if ($_[1] eq $_[0]{slot}) {
2118 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2119 untie %{$_[0]{selfref}};
2120 %{$_[0]{selfref}} = %{$_[0]{data}};
2129 $_[0]{data}{$_[1]} = $_[2];
2130 if ($_[1] eq $_[0]{slot}) {
2131 untie %{$_[0]{selfref}};
2132 %{$_[0]{selfref}} = %{$_[0]{data}};
2141 return $self->{pager} if $self->{pager};
2143 if ($self->get_cache) {
2144 $self->throw_exception ('Pagers on cached resultsets are not supported');
2147 my $attrs = $self->{attrs};
2148 if (!defined $attrs->{page}) {
2149 $self->throw_exception("Can't create pager for non-paged rs");
2151 elsif ($attrs->{page} <= 0) {
2152 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2154 $attrs->{rows} ||= 10;
2156 # throw away the paging flags and re-run the count (possibly
2157 # with a subselect) to get the real total count
2158 my $count_attrs = { %$attrs };
2159 delete $count_attrs->{$_} for qw/rows offset page pager/;
2160 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2163 ### the following may seem awkward and dirty, but it's a thought-experiment
2164 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2165 ### before talking to ribasushi/mst
2167 my $pager = Data::Page->new(
2168 0, #start with an empty set
2170 $self->{attrs}{page},
2173 my $data_slot = 'total_entries';
2175 # Since we are interested in a cached value (once it's set - it's set), every
2176 # technique will detach from the magic-host once the time comes to fire the
2177 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2179 if ($] < 5.008003) {
2180 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2181 # to weakref the magic container :(
2183 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2184 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2187 elsif ($] < 5.010) {
2188 # We can use magic on the hash value slot. It's interesting that the magic is
2189 # attached to the hash-slot, and does *not* stop working once I do the dummy
2190 # assignments after the cast()
2191 # tested on 5.8.3 and 5.8.9
2192 my $magic = $mk_lazy_count_wizard->($total_rs);
2193 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2195 # this is for fun and giggles
2196 $pager->{$data_slot} = -1;
2197 $pager->{$data_slot} = 0;
2199 # this does not work for scalars, but works with
2201 #my %vals = %$pager;
2206 # And the uvar magic
2207 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2208 # however see the wizard maker for more notes
2209 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2210 Variable::Magic::cast ( %$pager, $magic );
2213 $pager->{$data_slot} = -1;
2214 $pager->{$data_slot} = 0;
2222 return $self->{pager} = $pager;
2229 =item Arguments: $page_number
2231 =item Return Value: $rs
2235 Returns a resultset for the $page_number page of the resultset on which page
2236 is called, where each page contains a number of rows equal to the 'rows'
2237 attribute set on the resultset (10 by default).
2242 my ($self, $page) = @_;
2243 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2250 =item Arguments: \%vals
2252 =item Return Value: $rowobject
2256 Creates a new row object in the resultset's result class and returns
2257 it. The row is not inserted into the database at this point, call
2258 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2259 will tell you whether the row object has been inserted or not.
2261 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2266 my ($self, $values) = @_;
2267 $self->throw_exception( "new_result needs a hash" )
2268 unless (ref $values eq 'HASH');
2270 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2274 @$cols_from_relations
2275 ? (-cols_from_relations => $cols_from_relations)
2277 -source_handle => $self->_source_handle,
2278 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2281 return $self->result_class->new(\%new);
2284 # _merge_with_rscond
2286 # Takes a simple hash of K/V data and returns its copy merged with the
2287 # condition already present on the resultset. Additionally returns an
2288 # arrayref of value/condition names, which were inferred from related
2289 # objects (this is needed for in-memory related objects)
2290 sub _merge_with_rscond {
2291 my ($self, $data) = @_;
2293 my (%new_data, @cols_from_relations);
2295 my $alias = $self->{attrs}{alias};
2297 if (! defined $self->{cond}) {
2298 # just massage $data below
2300 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2301 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2302 @cols_from_relations = keys %new_data;
2304 elsif (ref $self->{cond} ne 'HASH') {
2305 $self->throw_exception(
2306 "Can't abstract implicit construct, resultset condition not a hash"
2310 # precendence must be given to passed values over values inherited from
2311 # the cond, so the order here is important.
2312 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2313 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2315 while ( my($col, $value) = each %implied ) {
2316 my $vref = ref $value;
2317 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2318 $new_data{$col} = $value->{'='};
2320 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2321 $new_data{$col} = $value;
2328 %{ $self->_remove_alias($data, $alias) },
2331 return (\%new_data, \@cols_from_relations);
2334 # _has_resolved_attr
2336 # determines if the resultset defines at least one
2337 # of the attributes supplied
2339 # used to determine if a subquery is neccessary
2341 # supports some virtual attributes:
2343 # This will scan for any joins being present on the resultset.
2344 # It is not a mere key-search but a deep inspection of {from}
2347 sub _has_resolved_attr {
2348 my ($self, @attr_names) = @_;
2350 my $attrs = $self->_resolved_attrs;
2354 for my $n (@attr_names) {
2355 if (grep { $n eq $_ } (qw/-join/) ) {
2356 $extra_checks{$n}++;
2360 my $attr = $attrs->{$n};
2362 next if not defined $attr;
2364 if (ref $attr eq 'HASH') {
2365 return 1 if keys %$attr;
2367 elsif (ref $attr eq 'ARRAY') {
2375 # a resolved join is expressed as a multi-level from
2377 $extra_checks{-join}
2379 ref $attrs->{from} eq 'ARRAY'
2381 @{$attrs->{from}} > 1
2389 # Recursively collapse the condition.
2391 sub _collapse_cond {
2392 my ($self, $cond, $collapsed) = @_;
2396 if (ref $cond eq 'ARRAY') {
2397 foreach my $subcond (@$cond) {
2398 next unless ref $subcond; # -or
2399 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2402 elsif (ref $cond eq 'HASH') {
2403 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2404 foreach my $subcond (@{$cond->{-and}}) {
2405 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2409 foreach my $col (keys %$cond) {
2410 my $value = $cond->{$col};
2411 $collapsed->{$col} = $value;
2421 # Remove the specified alias from the specified query hash. A copy is made so
2422 # the original query is not modified.
2425 my ($self, $query, $alias) = @_;
2427 my %orig = %{ $query || {} };
2430 foreach my $key (keys %orig) {
2432 $unaliased{$key} = $orig{$key};
2435 $unaliased{$1} = $orig{$key}
2436 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2446 =item Arguments: none
2448 =item Return Value: \[ $sql, @bind ]
2452 Returns the SQL query and bind vars associated with the invocant.
2454 This is generally used as the RHS for a subquery.
2461 my $attrs = $self->_resolved_attrs_copy;
2466 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2467 # $sql also has no wrapping parenthesis in list ctx
2469 my $sqlbind = $self->result_source->storage
2470 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2479 =item Arguments: \%vals, \%attrs?
2481 =item Return Value: $rowobject
2485 my $artist = $schema->resultset('Artist')->find_or_new(
2486 { artist => 'fred' }, { key => 'artists' });
2488 $cd->cd_to_producer->find_or_new({ producer => $producer },
2489 { key => 'primary });
2491 Find an existing record from this resultset using L</find>. if none exists,
2492 instantiate a new result object and return it. The object will not be saved
2493 into your storage until you call L<DBIx::Class::Row/insert> on it.
2495 You most likely want this method when looking for existing rows using a unique
2496 constraint that is not the primary key, or looking for related rows.
2498 If you want objects to be saved immediately, use L</find_or_create> instead.
2500 B<Note>: Make sure to read the documentation of L</find> and understand the
2501 significance of the C<key> attribute, as its lack may skew your search, and
2502 subsequently result in spurious new objects.
2504 B<Note>: Take care when using C<find_or_new> with a table having
2505 columns with default values that you intend to be automatically
2506 supplied by the database (e.g. an auto_increment primary key column).
2507 In normal usage, the value of such columns should NOT be included at
2508 all in the call to C<find_or_new>, even when set to C<undef>.
2514 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2515 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2516 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2519 return $self->new_result($hash);
2526 =item Arguments: \%vals
2528 =item Return Value: a L<DBIx::Class::Row> $object
2532 Attempt to create a single new row or a row with multiple related rows
2533 in the table represented by the resultset (and related tables). This
2534 will not check for duplicate rows before inserting, use
2535 L</find_or_create> to do that.
2537 To create one row for this resultset, pass a hashref of key/value
2538 pairs representing the columns of the table and the values you wish to
2539 store. If the appropriate relationships are set up, foreign key fields
2540 can also be passed an object representing the foreign row, and the
2541 value will be set to its primary key.
2543 To create related objects, pass a hashref of related-object column values
2544 B<keyed on the relationship name>. If the relationship is of type C<multi>
2545 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2546 The process will correctly identify columns holding foreign keys, and will
2547 transparently populate them from the keys of the corresponding relation.
2548 This can be applied recursively, and will work correctly for a structure
2549 with an arbitrary depth and width, as long as the relationships actually
2550 exists and the correct column data has been supplied.
2553 Instead of hashrefs of plain related data (key/value pairs), you may
2554 also pass new or inserted objects. New objects (not inserted yet, see
2555 L</new>), will be inserted into their appropriate tables.
2557 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2559 Example of creating a new row.
2561 $person_rs->create({
2562 name=>"Some Person",
2563 email=>"somebody@someplace.com"
2566 Example of creating a new row and also creating rows in a related C<has_many>
2567 or C<has_one> resultset. Note Arrayref.
2570 { artistid => 4, name => 'Manufactured Crap', cds => [
2571 { title => 'My First CD', year => 2006 },
2572 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2577 Example of creating a new row and also creating a row in a related
2578 C<belongs_to> resultset. Note Hashref.
2581 title=>"Music for Silly Walks",
2584 name=>"Silly Musician",
2592 When subclassing ResultSet never attempt to override this method. Since
2593 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2594 lot of the internals simply never call it, so your override will be
2595 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2596 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2597 L</create> process you need to intervene.
2604 my ($self, $attrs) = @_;
2605 $self->throw_exception( "create needs a hashref" )
2606 unless ref $attrs eq 'HASH';
2607 return $self->new_result($attrs)->insert;
2610 =head2 find_or_create
2614 =item Arguments: \%vals, \%attrs?
2616 =item Return Value: $rowobject
2620 $cd->cd_to_producer->find_or_create({ producer => $producer },
2621 { key => 'primary' });
2623 Tries to find a record based on its primary key or unique constraints; if none
2624 is found, creates one and returns that instead.
2626 my $cd = $schema->resultset('CD')->find_or_create({
2628 artist => 'Massive Attack',
2629 title => 'Mezzanine',
2633 Also takes an optional C<key> attribute, to search by a specific key or unique
2634 constraint. For example:
2636 my $cd = $schema->resultset('CD')->find_or_create(
2638 artist => 'Massive Attack',
2639 title => 'Mezzanine',
2641 { key => 'cd_artist_title' }
2644 B<Note>: Make sure to read the documentation of L</find> and understand the
2645 significance of the C<key> attribute, as its lack may skew your search, and
2646 subsequently result in spurious row creation.
2648 B<Note>: Because find_or_create() reads from the database and then
2649 possibly inserts based on the result, this method is subject to a race
2650 condition. Another process could create a record in the table after
2651 the find has completed and before the create has started. To avoid
2652 this problem, use find_or_create() inside a transaction.
2654 B<Note>: Take care when using C<find_or_create> with a table having
2655 columns with default values that you intend to be automatically
2656 supplied by the database (e.g. an auto_increment primary key column).
2657 In normal usage, the value of such columns should NOT be included at
2658 all in the call to C<find_or_create>, even when set to C<undef>.
2660 See also L</find> and L</update_or_create>. For information on how to declare
2661 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2665 sub find_or_create {
2667 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2668 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2669 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2672 return $self->create($hash);
2675 =head2 update_or_create
2679 =item Arguments: \%col_values, { key => $unique_constraint }?
2681 =item Return Value: $row_object
2685 $resultset->update_or_create({ col => $val, ... });
2687 Like L</find_or_create>, but if a row is found it is immediately updated via
2688 C<< $found_row->update (\%col_values) >>.
2691 Takes an optional C<key> attribute to search on a specific unique constraint.
2694 # In your application
2695 my $cd = $schema->resultset('CD')->update_or_create(
2697 artist => 'Massive Attack',
2698 title => 'Mezzanine',
2701 { key => 'cd_artist_title' }
2704 $cd->cd_to_producer->update_or_create({
2705 producer => $producer,
2711 B<Note>: Make sure to read the documentation of L</find> and understand the
2712 significance of the C<key> attribute, as its lack may skew your search, and
2713 subsequently result in spurious row creation.
2715 B<Note>: Take care when using C<update_or_create> with a table having
2716 columns with default values that you intend to be automatically
2717 supplied by the database (e.g. an auto_increment primary key column).
2718 In normal usage, the value of such columns should NOT be included at
2719 all in the call to C<update_or_create>, even when set to C<undef>.
2721 See also L</find> and L</find_or_create>. For information on how to declare
2722 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2726 sub update_or_create {
2728 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2729 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2731 my $row = $self->find($cond, $attrs);
2733 $row->update($cond);
2737 return $self->create($cond);
2740 =head2 update_or_new
2744 =item Arguments: \%col_values, { key => $unique_constraint }?
2746 =item Return Value: $rowobject
2750 $resultset->update_or_new({ col => $val, ... });
2752 Like L</find_or_new> but if a row is found it is immediately updated via
2753 C<< $found_row->update (\%col_values) >>.
2757 # In your application
2758 my $cd = $schema->resultset('CD')->update_or_new(
2760 artist => 'Massive Attack',
2761 title => 'Mezzanine',
2764 { key => 'cd_artist_title' }
2767 if ($cd->in_storage) {
2768 # the cd was updated
2771 # the cd is not yet in the database, let's insert it
2775 B<Note>: Make sure to read the documentation of L</find> and understand the
2776 significance of the C<key> attribute, as its lack may skew your search, and
2777 subsequently result in spurious new objects.
2779 B<Note>: Take care when using C<update_or_new> with a table having
2780 columns with default values that you intend to be automatically
2781 supplied by the database (e.g. an auto_increment primary key column).
2782 In normal usage, the value of such columns should NOT be included at
2783 all in the call to C<update_or_new>, even when set to C<undef>.
2785 See also L</find>, L</find_or_create> and L</find_or_new>.
2791 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2792 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2794 my $row = $self->find( $cond, $attrs );
2795 if ( defined $row ) {
2796 $row->update($cond);
2800 return $self->new_result($cond);
2807 =item Arguments: none
2809 =item Return Value: \@cache_objects | undef
2813 Gets the contents of the cache for the resultset, if the cache is set.
2815 The cache is populated either by using the L</prefetch> attribute to
2816 L</search> or by calling L</set_cache>.
2828 =item Arguments: \@cache_objects
2830 =item Return Value: \@cache_objects
2834 Sets the contents of the cache for the resultset. Expects an arrayref
2835 of objects of the same class as those produced by the resultset. Note that
2836 if the cache is set the resultset will return the cached objects rather
2837 than re-querying the database even if the cache attr is not set.
2839 The contents of the cache can also be populated by using the
2840 L</prefetch> attribute to L</search>.
2845 my ( $self, $data ) = @_;
2846 $self->throw_exception("set_cache requires an arrayref")
2847 if defined($data) && (ref $data ne 'ARRAY');
2848 $self->{all_cache} = $data;
2855 =item Arguments: none
2857 =item Return Value: undef
2861 Clears the cache for the resultset.
2866 shift->set_cache(undef);
2873 =item Arguments: none
2875 =item Return Value: true, if the resultset has been paginated
2883 return !!$self->{attrs}{page};
2890 =item Arguments: none
2892 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2900 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2903 =head2 related_resultset
2907 =item Arguments: $relationship_name
2909 =item Return Value: $resultset
2913 Returns a related resultset for the supplied relationship name.
2915 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2919 sub related_resultset {
2920 my ($self, $rel) = @_;
2922 $self->{related_resultsets} ||= {};
2923 return $self->{related_resultsets}{$rel} ||= do {
2924 my $rsrc = $self->result_source;
2925 my $rel_info = $rsrc->relationship_info($rel);
2927 $self->throw_exception(
2928 "search_related: result source '" . $rsrc->source_name .
2929 "' has no such relationship $rel")
2932 my $attrs = $self->_chain_relationship($rel);
2934 my $join_count = $attrs->{seen_join}{$rel};
2936 my $alias = $self->result_source->storage
2937 ->relname_to_table_alias($rel, $join_count);
2939 # since this is search_related, and we already slid the select window inwards
2940 # (the select/as attrs were deleted in the beginning), we need to flip all
2941 # left joins to inner, so we get the expected results
2942 # read the comment on top of the actual function to see what this does
2943 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2946 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2947 delete @{$attrs}{qw(result_class alias)};
2951 if (my $cache = $self->get_cache) {
2952 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2953 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2958 my $rel_source = $rsrc->related_source($rel);
2962 # The reason we do this now instead of passing the alias to the
2963 # search_rs below is that if you wrap/overload resultset on the
2964 # source you need to know what alias it's -going- to have for things
2965 # to work sanely (e.g. RestrictWithObject wants to be able to add
2966 # extra query restrictions, and these may need to be $alias.)
2968 my $rel_attrs = $rel_source->resultset_attributes;
2969 local $rel_attrs->{alias} = $alias;
2971 $rel_source->resultset
2975 where => $attrs->{where},
2978 $new->set_cache($new_cache) if $new_cache;
2983 =head2 current_source_alias
2987 =item Arguments: none
2989 =item Return Value: $source_alias
2993 Returns the current table alias for the result source this resultset is built
2994 on, that will be used in the SQL query. Usually it is C<me>.
2996 Currently the source alias that refers to the result set returned by a
2997 L</search>/L</find> family method depends on how you got to the resultset: it's
2998 C<me> by default, but eg. L</search_related> aliases it to the related result
2999 source name (and keeps C<me> referring to the original result set). The long
3000 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3001 (and make this method unnecessary).
3003 Thus it's currently necessary to use this method in predefined queries (see
3004 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3005 source alias of the current result set:
3007 # in a result set class
3009 my ($self, $user) = @_;
3011 my $me = $self->current_source_alias;
3013 return $self->search(
3014 "$me.modified" => $user->id,
3020 sub current_source_alias {
3023 return ($self->{attrs} || {})->{alias} || 'me';
3026 =head2 as_subselect_rs
3030 =item Arguments: none
3032 =item Return Value: $resultset
3036 Act as a barrier to SQL symbols. The resultset provided will be made into a
3037 "virtual view" by including it as a subquery within the from clause. From this
3038 point on, any joined tables are inaccessible to ->search on the resultset (as if
3039 it were simply where-filtered without joins). For example:
3041 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3043 # 'x' now pollutes the query namespace
3045 # So the following works as expected
3046 my $ok_rs = $rs->search({'x.other' => 1});
3048 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3049 # def) we look for one row with contradictory terms and join in another table
3050 # (aliased 'x_2') which we never use
3051 my $broken_rs = $rs->search({'x.name' => 'def'});
3053 my $rs2 = $rs->as_subselect_rs;
3055 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3056 my $not_joined_rs = $rs2->search({'x.other' => 1});
3058 # works as expected: finds a 'table' row related to two x rows (abc and def)
3059 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3061 Another example of when one might use this would be to select a subset of
3062 columns in a group by clause:
3064 my $rs = $schema->resultset('Bar')->search(undef, {
3065 group_by => [qw{ id foo_id baz_id }],
3066 })->as_subselect_rs->search(undef, {
3067 columns => [qw{ id foo_id }]
3070 In the above example normally columns would have to be equal to the group by,
3071 but because we isolated the group by into a subselect the above works.
3075 sub as_subselect_rs {
3078 my $attrs = $self->_resolved_attrs;
3080 my $fresh_rs = (ref $self)->new (
3081 $self->result_source
3084 # these pieces will be locked in the subquery
3085 delete $fresh_rs->{cond};
3086 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3088 return $fresh_rs->search( {}, {
3090 $attrs->{alias} => $self->as_query,
3091 -alias => $attrs->{alias},
3092 -source_handle => $self->result_source->handle,
3094 alias => $attrs->{alias},
3098 # This code is called by search_related, and makes sure there
3099 # is clear separation between the joins before, during, and
3100 # after the relationship. This information is needed later
3101 # in order to properly resolve prefetch aliases (any alias
3102 # with a relation_chain_depth less than the depth of the
3103 # current prefetch is not considered)
3105 # The increments happen twice per join. An even number means a
3106 # relationship specified via a search_related, whereas an odd
3107 # number indicates a join/prefetch added via attributes
3109 # Also this code will wrap the current resultset (the one we
3110 # chain to) in a subselect IFF it contains limiting attributes
3111 sub _chain_relationship {
3112 my ($self, $rel) = @_;
3113 my $source = $self->result_source;
3114 my $attrs = { %{$self->{attrs}||{}} };
3116 # we need to take the prefetch the attrs into account before we
3117 # ->_resolve_join as otherwise they get lost - captainL
3118 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3120 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3122 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3125 my @force_subq_attrs = qw/offset rows group_by having/;
3128 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3130 $self->_has_resolved_attr (@force_subq_attrs)
3132 # Nuke the prefetch (if any) before the new $rs attrs
3133 # are resolved (prefetch is useless - we are wrapping
3134 # a subquery anyway).
3135 my $rs_copy = $self->search;
3136 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3137 $rs_copy->{attrs}{join},
3138 delete $rs_copy->{attrs}{prefetch},
3142 -source_handle => $source->handle,
3143 -alias => $attrs->{alias},
3144 $attrs->{alias} => $rs_copy->as_query,
3146 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3147 $seen->{-relation_chain_depth} = 0;
3149 elsif ($attrs->{from}) { #shallow copy suffices
3150 $from = [ @{$attrs->{from}} ];
3154 -source_handle => $source->handle,
3155 -alias => $attrs->{alias},
3156 $attrs->{alias} => $source->from,
3160 my $jpath = ($seen->{-relation_chain_depth})
3161 ? $from->[-1][0]{-join_path}
3164 my @requested_joins = $source->_resolve_join(
3171 push @$from, @requested_joins;
3173 $seen->{-relation_chain_depth}++;
3175 # if $self already had a join/prefetch specified on it, the requested
3176 # $rel might very well be already included. What we do in this case
3177 # is effectively a no-op (except that we bump up the chain_depth on
3178 # the join in question so we could tell it *is* the search_related)
3181 # we consider the last one thus reverse
3182 for my $j (reverse @requested_joins) {
3183 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3184 if ($rel eq $last_j) {
3185 $j->[0]{-relation_chain_depth}++;
3191 unless ($already_joined) {
3192 push @$from, $source->_resolve_join(
3200 $seen->{-relation_chain_depth}++;
3202 return {%$attrs, from => $from, seen_join => $seen};
3205 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3206 sub _resolved_attrs_copy {
3208 return { %{$self->_resolved_attrs (@_)} };
3211 sub _resolved_attrs {
3213 return $self->{_attrs} if $self->{_attrs};
3215 my $attrs = { %{ $self->{attrs} || {} } };
3216 my $source = $self->result_source;
3217 my $alias = $attrs->{alias};
3219 # one last pass of normalization
3220 $self->_normalize_selection($attrs);
3222 # default selection list
3223 $attrs->{columns} = [ $source->columns ]
3224 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3226 # merge selectors together
3227 for (qw/columns select as _trailing_select/) {
3228 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3229 if $attrs->{$_} or $attrs->{"+$_"};
3232 # disassemble columns
3235 ref $attrs->{columns} eq 'ARRAY' ? $attrs->{columns} : [ $attrs->{columns} || () ]
3237 if (ref $c eq 'HASH') {
3238 for my $as (keys %$c) {
3239 push @sel, $c->{$as};
3249 # when trying to weed off duplicates later do not go past this point -
3250 # everything added from here on is unbalanced "anyone's guess" stuff
3251 my $dedup_stop_idx = $#as;
3253 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3255 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3256 if $attrs->{select};
3258 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3260 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3263 # disqualify all $alias.col as-bits (collapser mandated)
3265 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3268 # de-duplicate the result (remove *identical* select/as pairs)
3269 # and also die on duplicate {as} pointing to different {select}s
3270 # not using a c-style for as the condition is prone to shrinkage
3273 while ($i <= $dedup_stop_idx) {
3274 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3279 elsif ($seen->{$as[$i]}++) {
3280 $self->throw_exception(
3281 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3289 $attrs->{select} = \@sel;
3290 $attrs->{as} = \@as;
3292 $attrs->{from} ||= [{
3293 -source_handle => $source->handle,
3294 -alias => $self->{attrs}{alias},
3295 $self->{attrs}{alias} => $source->from,
3298 if ( $attrs->{join} || $attrs->{prefetch} ) {
3300 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3301 if ref $attrs->{from} ne 'ARRAY';
3303 my $join = (delete $attrs->{join}) || {};
3305 if ( defined $attrs->{prefetch} ) {
3306 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3309 $attrs->{from} = # have to copy here to avoid corrupting the original
3311 @{ $attrs->{from} },
3312 $source->_resolve_join(
3315 { %{ $attrs->{seen_join} || {} } },
3316 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3317 ? $attrs->{from}[-1][0]{-join_path}
3324 if ( defined $attrs->{order_by} ) {
3325 $attrs->{order_by} = (
3326 ref( $attrs->{order_by} ) eq 'ARRAY'
3327 ? [ @{ $attrs->{order_by} } ]
3328 : [ $attrs->{order_by} || () ]
3332 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3333 $attrs->{group_by} = [ $attrs->{group_by} ];
3336 # generate the distinct induced group_by early, as prefetch will be carried via a
3337 # subquery (since a group_by is present)
3338 if (delete $attrs->{distinct}) {
3339 if ($attrs->{group_by}) {
3340 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3343 # distinct affects only the main selection part, not what prefetch may
3344 # add below. However trailing is not yet a part of the selection as
3345 # prefetch must insert before it
3346 $attrs->{group_by} = $source->storage->_group_over_selection (
3348 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3354 $attrs->{collapse} ||= {};
3355 if ($attrs->{prefetch}) {
3356 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3358 my $prefetch_ordering = [];
3360 # this is a separate structure (we don't look in {from} directly)
3361 # as the resolver needs to shift things off the lists to work
3362 # properly (identical-prefetches on different branches)
3364 if (ref $attrs->{from} eq 'ARRAY') {
3366 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3368 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3369 next unless $j->[0]{-alias};
3370 next unless $j->[0]{-join_path};
3371 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3373 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3376 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3377 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3382 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3384 # we need to somehow mark which columns came from prefetch
3386 my $sel_end = $#{$attrs->{select}};
3387 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3390 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3391 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3393 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3394 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3398 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3399 if $attrs->{_trailing_select};
3401 # if both page and offset are specified, produce a combined offset
3402 # even though it doesn't make much sense, this is what pre 081xx has
3404 if (my $page = delete $attrs->{page}) {
3406 ($attrs->{rows} * ($page - 1))
3408 ($attrs->{offset} || 0)
3412 return $self->{_attrs} = $attrs;
3416 my ($self, $attr) = @_;
3418 if (ref $attr eq 'HASH') {
3419 return $self->_rollout_hash($attr);
3420 } elsif (ref $attr eq 'ARRAY') {
3421 return $self->_rollout_array($attr);
3427 sub _rollout_array {
3428 my ($self, $attr) = @_;
3431 foreach my $element (@{$attr}) {
3432 if (ref $element eq 'HASH') {
3433 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3434 } elsif (ref $element eq 'ARRAY') {
3435 # XXX - should probably recurse here
3436 push( @rolled_array, @{$self->_rollout_array($element)} );
3438 push( @rolled_array, $element );
3441 return \@rolled_array;
3445 my ($self, $attr) = @_;
3448 foreach my $key (keys %{$attr}) {
3449 push( @rolled_array, { $key => $attr->{$key} } );
3451 return \@rolled_array;
3454 sub _calculate_score {
3455 my ($self, $a, $b) = @_;
3457 if (defined $a xor defined $b) {
3460 elsif (not defined $a) {
3464 if (ref $b eq 'HASH') {
3465 my ($b_key) = keys %{$b};
3466 if (ref $a eq 'HASH') {
3467 my ($a_key) = keys %{$a};
3468 if ($a_key eq $b_key) {
3469 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3474 return ($a eq $b_key) ? 1 : 0;
3477 if (ref $a eq 'HASH') {
3478 my ($a_key) = keys %{$a};
3479 return ($b eq $a_key) ? 1 : 0;
3481 return ($b eq $a) ? 1 : 0;
3486 sub _merge_joinpref_attr {
3487 my ($self, $orig, $import) = @_;
3489 return $import unless defined($orig);
3490 return $orig unless defined($import);
3492 $orig = $self->_rollout_attr($orig);
3493 $import = $self->_rollout_attr($import);
3496 foreach my $import_element ( @{$import} ) {
3497 # find best candidate from $orig to merge $b_element into
3498 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3499 foreach my $orig_element ( @{$orig} ) {
3500 my $score = $self->_calculate_score( $orig_element, $import_element );
3501 if ($score > $best_candidate->{score}) {
3502 $best_candidate->{position} = $position;
3503 $best_candidate->{score} = $score;
3507 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3509 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3510 push( @{$orig}, $import_element );
3512 my $orig_best = $orig->[$best_candidate->{position}];
3513 # merge orig_best and b_element together and replace original with merged
3514 if (ref $orig_best ne 'HASH') {
3515 $orig->[$best_candidate->{position}] = $import_element;
3516 } elsif (ref $import_element eq 'HASH') {
3517 my ($key) = keys %{$orig_best};
3518 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3521 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3532 my $hm = Hash::Merge->new;
3534 $hm->specify_behavior({
3537 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3539 if ($defl xor $defr) {
3540 return [ $defl ? $_[0] : $_[1] ];
3545 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3549 return [$_[0], $_[1]];
3553 return $_[1] if !defined $_[0];
3554 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3555 return [$_[0], @{$_[1]}]
3558 return [] if !defined $_[0] and !keys %{$_[1]};
3559 return [ $_[1] ] if !defined $_[0];
3560 return [ $_[0] ] if !keys %{$_[1]};
3561 return [$_[0], $_[1]]
3566 return $_[0] if !defined $_[1];
3567 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3568 return [@{$_[0]}, $_[1]]
3571 my @ret = @{$_[0]} or return $_[1];
3572 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3573 my %idx = map { $_ => 1 } @ret;
3574 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3578 return [ $_[1] ] if ! @{$_[0]};
3579 return $_[0] if !keys %{$_[1]};
3580 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3581 return [ @{$_[0]}, $_[1] ];
3586 return [] if !keys %{$_[0]} and !defined $_[1];
3587 return [ $_[0] ] if !defined $_[1];
3588 return [ $_[1] ] if !keys %{$_[0]};
3589 return [$_[0], $_[1]]
3592 return [] if !keys %{$_[0]} and !@{$_[1]};
3593 return [ $_[0] ] if !@{$_[1]};
3594 return $_[1] if !keys %{$_[0]};
3595 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3596 return [ $_[0], @{$_[1]} ];
3599 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3600 return [ $_[0] ] if !keys %{$_[1]};
3601 return [ $_[1] ] if !keys %{$_[0]};
3602 return [ $_[0] ] if $_[0] eq $_[1];
3603 return [ $_[0], $_[1] ];
3606 } => 'DBIC_RS_ATTR_MERGER');
3610 return $hm->merge ($_[1], $_[2]);
3618 $self->_source_handle($_[0]->handle);
3620 $self->_source_handle->resolve;
3625 sub STORABLE_freeze {
3626 my ($self, $cloning) = @_;
3627 my $to_serialize = { %$self };
3629 # A cursor in progress can't be serialized (and would make little sense anyway)
3630 delete $to_serialize->{cursor};
3632 return nfreeze($to_serialize);
3635 # need this hook for symmetry
3637 my ($self, $cloning, $serialized) = @_;
3639 %$self = %{ thaw($serialized) };
3645 =head2 throw_exception
3647 See L<DBIx::Class::Schema/throw_exception> for details.
3651 sub throw_exception {
3654 if (ref $self && $self->_source_handle->schema) {
3655 $self->_source_handle->schema->throw_exception(@_)
3658 DBIx::Class::Exception->throw(@_);
3662 # XXX: FIXME: Attributes docs need clearing up
3666 Attributes are used to refine a ResultSet in various ways when
3667 searching for data. They can be passed to any method which takes an
3668 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3671 These are in no particular order:
3677 =item Value: ( $order_by | \@order_by | \%order_by )
3681 Which column(s) to order the results by.
3683 [The full list of suitable values is documented in
3684 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3687 If a single column name, or an arrayref of names is supplied, the
3688 argument is passed through directly to SQL. The hashref syntax allows
3689 for connection-agnostic specification of ordering direction:
3691 For descending order:
3693 order_by => { -desc => [qw/col1 col2 col3/] }
3695 For explicit ascending order:
3697 order_by => { -asc => 'col' }
3699 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3700 supported, although you are strongly encouraged to use the hashref
3701 syntax as outlined above.
3707 =item Value: \@columns
3711 Shortcut to request a particular set of columns to be retrieved. Each
3712 column spec may be a string (a table column name), or a hash (in which
3713 case the key is the C<as> value, and the value is used as the C<select>
3714 expression). Adds C<me.> onto the start of any column without a C<.> in
3715 it and sets C<select> from that, then auto-populates C<as> from
3716 C<select> as normal. (You may also use the C<cols> attribute, as in
3717 earlier versions of DBIC.)
3719 Essentially C<columns> does the same as L</select> and L</as>.
3721 columns => [ 'foo', { bar => 'baz' } ]
3725 select => [qw/foo baz/],
3732 =item Value: \@columns
3736 Indicates additional columns to be selected from storage. Works the same
3737 as L</columns> but adds columns to the selection. (You may also use the
3738 C<include_columns> attribute, as in earlier versions of DBIC). For
3741 $schema->resultset('CD')->search(undef, {
3742 '+columns' => ['artist.name'],
3746 would return all CDs and include a 'name' column to the information
3747 passed to object inflation. Note that the 'artist' is the name of the
3748 column (or relationship) accessor, and 'name' is the name of the column
3749 accessor in the related table.
3751 =head2 include_columns
3755 =item Value: \@columns
3759 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3765 =item Value: \@select_columns
3769 Indicates which columns should be selected from the storage. You can use
3770 column names, or in the case of RDBMS back ends, function or stored procedure
3773 $rs = $schema->resultset('Employee')->search(undef, {
3776 { count => 'employeeid' },
3777 { max => { length => 'name' }, -as => 'longest_name' }
3782 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3784 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3785 use L</select>, to instruct DBIx::Class how to store the result of the column.
3786 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3787 identifier aliasing. You can however alias a function, so you can use it in
3788 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3789 attribute> supplied as shown in the example above.
3795 Indicates additional columns to be selected from storage. Works the same as
3796 L</select> but adds columns to the default selection, instead of specifying
3805 Indicates additional column names for those added via L</+select>. See L</as>.
3813 =item Value: \@inflation_names
3817 Indicates column names for object inflation. That is L</as> indicates the
3818 slot name in which the column value will be stored within the
3819 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3820 identifier by the C<get_column> method (or via the object accessor B<if one
3821 with the same name already exists>) as shown below. The L</as> attribute has
3822 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3824 $rs = $schema->resultset('Employee')->search(undef, {
3827 { count => 'employeeid' },
3828 { max => { length => 'name' }, -as => 'longest_name' }
3837 If the object against which the search is performed already has an accessor
3838 matching a column name specified in C<as>, the value can be retrieved using
3839 the accessor as normal:
3841 my $name = $employee->name();
3843 If on the other hand an accessor does not exist in the object, you need to
3844 use C<get_column> instead:
3846 my $employee_count = $employee->get_column('employee_count');
3848 You can create your own accessors if required - see
3849 L<DBIx::Class::Manual::Cookbook> for details.
3855 =item Value: ($rel_name | \@rel_names | \%rel_names)
3859 Contains a list of relationships that should be joined for this query. For
3862 # Get CDs by Nine Inch Nails
3863 my $rs = $schema->resultset('CD')->search(
3864 { 'artist.name' => 'Nine Inch Nails' },
3865 { join => 'artist' }
3868 Can also contain a hash reference to refer to the other relation's relations.
3871 package MyApp::Schema::Track;
3872 use base qw/DBIx::Class/;
3873 __PACKAGE__->table('track');
3874 __PACKAGE__->add_columns(qw/trackid cd position title/);
3875 __PACKAGE__->set_primary_key('trackid');
3876 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3879 # In your application
3880 my $rs = $schema->resultset('Artist')->search(
3881 { 'track.title' => 'Teardrop' },
3883 join => { cd => 'track' },
3884 order_by => 'artist.name',
3888 You need to use the relationship (not the table) name in conditions,
3889 because they are aliased as such. The current table is aliased as "me", so
3890 you need to use me.column_name in order to avoid ambiguity. For example:
3892 # Get CDs from 1984 with a 'Foo' track
3893 my $rs = $schema->resultset('CD')->search(
3896 'tracks.name' => 'Foo'
3898 { join => 'tracks' }
3901 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3902 similarly for a third time). For e.g.
3904 my $rs = $schema->resultset('Artist')->search({
3905 'cds.title' => 'Down to Earth',
3906 'cds_2.title' => 'Popular',
3908 join => [ qw/cds cds/ ],
3911 will return a set of all artists that have both a cd with title 'Down
3912 to Earth' and a cd with title 'Popular'.
3914 If you want to fetch related objects from other tables as well, see C<prefetch>
3917 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3923 =item Value: ($rel_name | \@rel_names | \%rel_names)
3927 Contains one or more relationships that should be fetched along with
3928 the main query (when they are accessed afterwards the data will
3929 already be available, without extra queries to the database). This is
3930 useful for when you know you will need the related objects, because it
3931 saves at least one query:
3933 my $rs = $schema->resultset('Tag')->search(
3942 The initial search results in SQL like the following:
3944 SELECT tag.*, cd.*, artist.* FROM tag
3945 JOIN cd ON tag.cd = cd.cdid
3946 JOIN artist ON cd.artist = artist.artistid
3948 L<DBIx::Class> has no need to go back to the database when we access the
3949 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3952 Simple prefetches will be joined automatically, so there is no need
3953 for a C<join> attribute in the above search.
3955 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3956 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3957 with an accessor type of 'single' or 'filter'). A more complex example that
3958 prefetches an artists cds, the tracks on those cds, and the tags associated
3959 with that artist is given below (assuming many-to-many from artists to tags):
3961 my $rs = $schema->resultset('Artist')->search(
3965 { cds => 'tracks' },
3966 { artist_tags => 'tags' }
3972 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3973 attributes will be ignored.
3975 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3976 exactly as you might expect.
3982 Prefetch uses the L</cache> to populate the prefetched relationships. This
3983 may or may not be what you want.
3987 If you specify a condition on a prefetched relationship, ONLY those
3988 rows that match the prefetched condition will be fetched into that relationship.
3989 This means that adding prefetch to a search() B<may alter> what is returned by
3990 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3992 my $artist_rs = $schema->resultset('Artist')->search({
3998 my $count = $artist_rs->first->cds->count;
4000 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4002 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4004 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4006 that cmp_ok() may or may not pass depending on the datasets involved. This
4007 behavior may or may not survive the 0.09 transition.
4019 Makes the resultset paged and specifies the page to retrieve. Effectively
4020 identical to creating a non-pages resultset and then calling ->page($page)
4023 If L<rows> attribute is not specified it defaults to 10 rows per page.
4025 When you have a paged resultset, L</count> will only return the number
4026 of rows in the page. To get the total, use the L</pager> and call
4027 C<total_entries> on it.
4037 Specifies the maximum number of rows for direct retrieval or the number of
4038 rows per page if the page attribute or method is used.
4044 =item Value: $offset
4048 Specifies the (zero-based) row number for the first row to be returned, or the
4049 of the first row of the first page if paging is used.
4055 =item Value: \@columns
4059 A arrayref of columns to group by. Can include columns of joined tables.
4061 group_by => [qw/ column1 column2 ... /]
4067 =item Value: $condition
4071 HAVING is a select statement attribute that is applied between GROUP BY and
4072 ORDER BY. It is applied to the after the grouping calculations have been
4075 having => { 'count_employee' => { '>=', 100 } }
4077 or with an in-place function in which case literal SQL is required:
4079 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4085 =item Value: (0 | 1)
4089 Set to 1 to group by all columns. If the resultset already has a group_by
4090 attribute, this setting is ignored and an appropriate warning is issued.
4096 Adds to the WHERE clause.
4098 # only return rows WHERE deleted IS NULL for all searches
4099 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4101 Can be overridden by passing C<< { where => undef } >> as an attribute
4108 Set to 1 to cache search results. This prevents extra SQL queries if you
4109 revisit rows in your ResultSet:
4111 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4113 while( my $artist = $resultset->next ) {
4117 $rs->first; # without cache, this would issue a query
4119 By default, searches are not cached.
4121 For more examples of using these attributes, see
4122 L<DBIx::Class::Manual::Cookbook>.
4128 =item Value: ( 'update' | 'shared' )
4132 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT