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;
1913 my $first = $data->[0];
1915 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1916 # it relationship data
1917 my (@rels, @columns);
1918 my $rsrc = $self->result_source;
1919 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1920 for (keys %$first) {
1921 my $ref = ref $first->{$_};
1922 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1928 my @pks = $rsrc->primary_columns;
1930 ## do the belongs_to relationships
1931 foreach my $index (0..$#$data) {
1933 # delegate to create() for any dataset without primary keys with specified relationships
1934 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1936 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1937 my @ret = $self->populate($data);
1943 foreach my $rel (@rels) {
1944 next unless ref $data->[$index]->{$rel} eq "HASH";
1945 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1946 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1947 my $related = $result->result_source->_resolve_condition(
1948 $reverse_relinfo->{cond},
1953 delete $data->[$index]->{$rel};
1954 $data->[$index] = {%{$data->[$index]}, %$related};
1956 push @columns, keys %$related if $index == 0;
1960 ## inherit the data locked in the conditions of the resultset
1961 my ($rs_data) = $self->_merge_with_rscond({});
1962 delete @{$rs_data}{@columns};
1963 my @inherit_cols = keys %$rs_data;
1964 my @inherit_data = values %$rs_data;
1966 ## do bulk insert on current row
1967 $rsrc->storage->insert_bulk(
1969 [@columns, @inherit_cols],
1970 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1973 ## do the has_many relationships
1974 foreach my $item (@$data) {
1978 foreach my $rel (@rels) {
1979 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
1981 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
1983 my $child = $main_row->$rel;
1985 my $related = $child->result_source->_resolve_condition(
1986 $rels->{$rel}{cond},
1991 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1992 my @populate = map { {%$_, %$related} } @rows_to_add;
1994 $child->populate( \@populate );
2001 # populate() argumnets went over several incarnations
2002 # What we ultimately support is AoH
2003 sub _normalize_populate_args {
2004 my ($self, $arg) = @_;
2006 if (ref $arg eq 'ARRAY') {
2007 if (ref $arg->[0] eq 'HASH') {
2010 elsif (ref $arg->[0] eq 'ARRAY') {
2012 my @colnames = @{$arg->[0]};
2013 foreach my $values (@{$arg}[1 .. $#$arg]) {
2014 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2020 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2027 =item Arguments: none
2029 =item Return Value: $pager
2033 Return Value a L<Data::Page> object for the current resultset. Only makes
2034 sense for queries with a C<page> attribute.
2036 To get the full count of entries for a paged resultset, call
2037 C<total_entries> on the L<Data::Page> object.
2041 # make a wizard good for both a scalar and a hashref
2042 my $mk_lazy_count_wizard = sub {
2043 require Variable::Magic;
2045 my $stash = { total_rs => shift };
2046 my $slot = shift; # only used by the hashref magic
2048 my $magic = Variable::Magic::wizard (
2049 data => sub { $stash },
2055 # set value lazily, and dispell for good
2056 ${$_[0]} = $_[1]{total_rs}->count;
2057 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2061 # an explicit set implies dispell as well
2062 # the unless() is to work around "fun and giggles" below
2063 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2064 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2071 if ($_[2] eq $slot and !$_[1]{inactive}) {
2072 my $cnt = $_[1]{total_rs}->count;
2073 $_[0]->{$slot} = $cnt;
2075 # attempting to dispell in a fetch handle (works in store), seems
2076 # to invariable segfault on 5.10, 5.12, 5.13 :(
2077 # so use an inactivator instead
2078 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2084 if (! $_[1]{inactive} and $_[2] eq $slot) {
2085 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2087 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2094 $stash->{magic_selfref} = $magic;
2095 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2100 # the tie class for 5.8.1
2102 package # hide from pause
2103 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2104 use base qw/Tie::Hash/;
2106 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2107 sub NEXTKEY { each %{$_[0]{data}} }
2108 sub EXISTS { exists $_[0]{data}{$_[1]} }
2109 sub DELETE { delete $_[0]{data}{$_[1]} }
2110 sub CLEAR { %{$_[0]{data}} = () }
2111 sub SCALAR { scalar %{$_[0]{data}} }
2114 $_[1]{data} = {%{$_[1]{selfref}}};
2115 %{$_[1]{selfref}} = ();
2116 Scalar::Util::weaken ($_[1]{selfref});
2117 return bless ($_[1], $_[0]);
2121 if ($_[1] eq $_[0]{slot}) {
2122 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2123 untie %{$_[0]{selfref}};
2124 %{$_[0]{selfref}} = %{$_[0]{data}};
2133 $_[0]{data}{$_[1]} = $_[2];
2134 if ($_[1] eq $_[0]{slot}) {
2135 untie %{$_[0]{selfref}};
2136 %{$_[0]{selfref}} = %{$_[0]{data}};
2145 return $self->{pager} if $self->{pager};
2147 if ($self->get_cache) {
2148 $self->throw_exception ('Pagers on cached resultsets are not supported');
2151 my $attrs = $self->{attrs};
2152 if (!defined $attrs->{page}) {
2153 $self->throw_exception("Can't create pager for non-paged rs");
2155 elsif ($attrs->{page} <= 0) {
2156 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2158 $attrs->{rows} ||= 10;
2160 # throw away the paging flags and re-run the count (possibly
2161 # with a subselect) to get the real total count
2162 my $count_attrs = { %$attrs };
2163 delete $count_attrs->{$_} for qw/rows offset page pager/;
2164 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2167 ### the following may seem awkward and dirty, but it's a thought-experiment
2168 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2169 ### before talking to ribasushi/mst
2171 my $pager = Data::Page->new(
2172 0, #start with an empty set
2174 $self->{attrs}{page},
2177 my $data_slot = 'total_entries';
2179 # Since we are interested in a cached value (once it's set - it's set), every
2180 # technique will detach from the magic-host once the time comes to fire the
2181 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2183 if ($] < 5.008003) {
2184 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2185 # to weakref the magic container :(
2187 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2188 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2191 elsif ($] < 5.010) {
2192 # We can use magic on the hash value slot. It's interesting that the magic is
2193 # attached to the hash-slot, and does *not* stop working once I do the dummy
2194 # assignments after the cast()
2195 # tested on 5.8.3 and 5.8.9
2196 my $magic = $mk_lazy_count_wizard->($total_rs);
2197 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2199 # this is for fun and giggles
2200 $pager->{$data_slot} = -1;
2201 $pager->{$data_slot} = 0;
2203 # this does not work for scalars, but works with
2205 #my %vals = %$pager;
2210 # And the uvar magic
2211 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2212 # however see the wizard maker for more notes
2213 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2214 Variable::Magic::cast ( %$pager, $magic );
2217 $pager->{$data_slot} = -1;
2218 $pager->{$data_slot} = 0;
2226 return $self->{pager} = $pager;
2233 =item Arguments: $page_number
2235 =item Return Value: $rs
2239 Returns a resultset for the $page_number page of the resultset on which page
2240 is called, where each page contains a number of rows equal to the 'rows'
2241 attribute set on the resultset (10 by default).
2246 my ($self, $page) = @_;
2247 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2254 =item Arguments: \%vals
2256 =item Return Value: $rowobject
2260 Creates a new row object in the resultset's result class and returns
2261 it. The row is not inserted into the database at this point, call
2262 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2263 will tell you whether the row object has been inserted or not.
2265 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2270 my ($self, $values) = @_;
2271 $self->throw_exception( "new_result needs a hash" )
2272 unless (ref $values eq 'HASH');
2274 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2278 @$cols_from_relations
2279 ? (-cols_from_relations => $cols_from_relations)
2281 -source_handle => $self->_source_handle,
2282 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2285 return $self->result_class->new(\%new);
2288 # _merge_with_rscond
2290 # Takes a simple hash of K/V data and returns its copy merged with the
2291 # condition already present on the resultset. Additionally returns an
2292 # arrayref of value/condition names, which were inferred from related
2293 # objects (this is needed for in-memory related objects)
2294 sub _merge_with_rscond {
2295 my ($self, $data) = @_;
2297 my (%new_data, @cols_from_relations);
2299 my $alias = $self->{attrs}{alias};
2301 if (! defined $self->{cond}) {
2302 # just massage $data below
2304 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2305 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2306 @cols_from_relations = keys %new_data;
2308 elsif (ref $self->{cond} ne 'HASH') {
2309 $self->throw_exception(
2310 "Can't abstract implicit construct, resultset condition not a hash"
2314 # precendence must be given to passed values over values inherited from
2315 # the cond, so the order here is important.
2316 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2317 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2319 while ( my($col, $value) = each %implied ) {
2320 my $vref = ref $value;
2321 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2322 $new_data{$col} = $value->{'='};
2324 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2325 $new_data{$col} = $value;
2332 %{ $self->_remove_alias($data, $alias) },
2335 return (\%new_data, \@cols_from_relations);
2338 # _has_resolved_attr
2340 # determines if the resultset defines at least one
2341 # of the attributes supplied
2343 # used to determine if a subquery is neccessary
2345 # supports some virtual attributes:
2347 # This will scan for any joins being present on the resultset.
2348 # It is not a mere key-search but a deep inspection of {from}
2351 sub _has_resolved_attr {
2352 my ($self, @attr_names) = @_;
2354 my $attrs = $self->_resolved_attrs;
2358 for my $n (@attr_names) {
2359 if (grep { $n eq $_ } (qw/-join/) ) {
2360 $extra_checks{$n}++;
2364 my $attr = $attrs->{$n};
2366 next if not defined $attr;
2368 if (ref $attr eq 'HASH') {
2369 return 1 if keys %$attr;
2371 elsif (ref $attr eq 'ARRAY') {
2379 # a resolved join is expressed as a multi-level from
2381 $extra_checks{-join}
2383 ref $attrs->{from} eq 'ARRAY'
2385 @{$attrs->{from}} > 1
2393 # Recursively collapse the condition.
2395 sub _collapse_cond {
2396 my ($self, $cond, $collapsed) = @_;
2400 if (ref $cond eq 'ARRAY') {
2401 foreach my $subcond (@$cond) {
2402 next unless ref $subcond; # -or
2403 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2406 elsif (ref $cond eq 'HASH') {
2407 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2408 foreach my $subcond (@{$cond->{-and}}) {
2409 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2413 foreach my $col (keys %$cond) {
2414 my $value = $cond->{$col};
2415 $collapsed->{$col} = $value;
2425 # Remove the specified alias from the specified query hash. A copy is made so
2426 # the original query is not modified.
2429 my ($self, $query, $alias) = @_;
2431 my %orig = %{ $query || {} };
2434 foreach my $key (keys %orig) {
2436 $unaliased{$key} = $orig{$key};
2439 $unaliased{$1} = $orig{$key}
2440 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2450 =item Arguments: none
2452 =item Return Value: \[ $sql, @bind ]
2456 Returns the SQL query and bind vars associated with the invocant.
2458 This is generally used as the RHS for a subquery.
2465 my $attrs = $self->_resolved_attrs_copy;
2470 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2471 # $sql also has no wrapping parenthesis in list ctx
2473 my $sqlbind = $self->result_source->storage
2474 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2483 =item Arguments: \%vals, \%attrs?
2485 =item Return Value: $rowobject
2489 my $artist = $schema->resultset('Artist')->find_or_new(
2490 { artist => 'fred' }, { key => 'artists' });
2492 $cd->cd_to_producer->find_or_new({ producer => $producer },
2493 { key => 'primary });
2495 Find an existing record from this resultset using L</find>. if none exists,
2496 instantiate a new result object and return it. The object will not be saved
2497 into your storage until you call L<DBIx::Class::Row/insert> on it.
2499 You most likely want this method when looking for existing rows using a unique
2500 constraint that is not the primary key, or looking for related rows.
2502 If you want objects to be saved immediately, use L</find_or_create> instead.
2504 B<Note>: Make sure to read the documentation of L</find> and understand the
2505 significance of the C<key> attribute, as its lack may skew your search, and
2506 subsequently result in spurious new objects.
2508 B<Note>: Take care when using C<find_or_new> with a table having
2509 columns with default values that you intend to be automatically
2510 supplied by the database (e.g. an auto_increment primary key column).
2511 In normal usage, the value of such columns should NOT be included at
2512 all in the call to C<find_or_new>, even when set to C<undef>.
2518 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2519 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2520 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2523 return $self->new_result($hash);
2530 =item Arguments: \%vals
2532 =item Return Value: a L<DBIx::Class::Row> $object
2536 Attempt to create a single new row or a row with multiple related rows
2537 in the table represented by the resultset (and related tables). This
2538 will not check for duplicate rows before inserting, use
2539 L</find_or_create> to do that.
2541 To create one row for this resultset, pass a hashref of key/value
2542 pairs representing the columns of the table and the values you wish to
2543 store. If the appropriate relationships are set up, foreign key fields
2544 can also be passed an object representing the foreign row, and the
2545 value will be set to its primary key.
2547 To create related objects, pass a hashref of related-object column values
2548 B<keyed on the relationship name>. If the relationship is of type C<multi>
2549 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2550 The process will correctly identify columns holding foreign keys, and will
2551 transparently populate them from the keys of the corresponding relation.
2552 This can be applied recursively, and will work correctly for a structure
2553 with an arbitrary depth and width, as long as the relationships actually
2554 exists and the correct column data has been supplied.
2557 Instead of hashrefs of plain related data (key/value pairs), you may
2558 also pass new or inserted objects. New objects (not inserted yet, see
2559 L</new>), will be inserted into their appropriate tables.
2561 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2563 Example of creating a new row.
2565 $person_rs->create({
2566 name=>"Some Person",
2567 email=>"somebody@someplace.com"
2570 Example of creating a new row and also creating rows in a related C<has_many>
2571 or C<has_one> resultset. Note Arrayref.
2574 { artistid => 4, name => 'Manufactured Crap', cds => [
2575 { title => 'My First CD', year => 2006 },
2576 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2581 Example of creating a new row and also creating a row in a related
2582 C<belongs_to> resultset. Note Hashref.
2585 title=>"Music for Silly Walks",
2588 name=>"Silly Musician",
2596 When subclassing ResultSet never attempt to override this method. Since
2597 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2598 lot of the internals simply never call it, so your override will be
2599 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2600 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2601 L</create> process you need to intervene.
2608 my ($self, $attrs) = @_;
2609 $self->throw_exception( "create needs a hashref" )
2610 unless ref $attrs eq 'HASH';
2611 return $self->new_result($attrs)->insert;
2614 =head2 find_or_create
2618 =item Arguments: \%vals, \%attrs?
2620 =item Return Value: $rowobject
2624 $cd->cd_to_producer->find_or_create({ producer => $producer },
2625 { key => 'primary' });
2627 Tries to find a record based on its primary key or unique constraints; if none
2628 is found, creates one and returns that instead.
2630 my $cd = $schema->resultset('CD')->find_or_create({
2632 artist => 'Massive Attack',
2633 title => 'Mezzanine',
2637 Also takes an optional C<key> attribute, to search by a specific key or unique
2638 constraint. For example:
2640 my $cd = $schema->resultset('CD')->find_or_create(
2642 artist => 'Massive Attack',
2643 title => 'Mezzanine',
2645 { key => 'cd_artist_title' }
2648 B<Note>: Make sure to read the documentation of L</find> and understand the
2649 significance of the C<key> attribute, as its lack may skew your search, and
2650 subsequently result in spurious row creation.
2652 B<Note>: Because find_or_create() reads from the database and then
2653 possibly inserts based on the result, this method is subject to a race
2654 condition. Another process could create a record in the table after
2655 the find has completed and before the create has started. To avoid
2656 this problem, use find_or_create() inside a transaction.
2658 B<Note>: Take care when using C<find_or_create> with a table having
2659 columns with default values that you intend to be automatically
2660 supplied by the database (e.g. an auto_increment primary key column).
2661 In normal usage, the value of such columns should NOT be included at
2662 all in the call to C<find_or_create>, even when set to C<undef>.
2664 See also L</find> and L</update_or_create>. For information on how to declare
2665 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2669 sub find_or_create {
2671 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2672 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2673 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2676 return $self->create($hash);
2679 =head2 update_or_create
2683 =item Arguments: \%col_values, { key => $unique_constraint }?
2685 =item Return Value: $row_object
2689 $resultset->update_or_create({ col => $val, ... });
2691 Like L</find_or_create>, but if a row is found it is immediately updated via
2692 C<< $found_row->update (\%col_values) >>.
2695 Takes an optional C<key> attribute to search on a specific unique constraint.
2698 # In your application
2699 my $cd = $schema->resultset('CD')->update_or_create(
2701 artist => 'Massive Attack',
2702 title => 'Mezzanine',
2705 { key => 'cd_artist_title' }
2708 $cd->cd_to_producer->update_or_create({
2709 producer => $producer,
2715 B<Note>: Make sure to read the documentation of L</find> and understand the
2716 significance of the C<key> attribute, as its lack may skew your search, and
2717 subsequently result in spurious row creation.
2719 B<Note>: Take care when using C<update_or_create> with a table having
2720 columns with default values that you intend to be automatically
2721 supplied by the database (e.g. an auto_increment primary key column).
2722 In normal usage, the value of such columns should NOT be included at
2723 all in the call to C<update_or_create>, even when set to C<undef>.
2725 See also L</find> and L</find_or_create>. For information on how to declare
2726 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2730 sub update_or_create {
2732 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2733 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2735 my $row = $self->find($cond, $attrs);
2737 $row->update($cond);
2741 return $self->create($cond);
2744 =head2 update_or_new
2748 =item Arguments: \%col_values, { key => $unique_constraint }?
2750 =item Return Value: $rowobject
2754 $resultset->update_or_new({ col => $val, ... });
2756 Like L</find_or_new> but if a row is found it is immediately updated via
2757 C<< $found_row->update (\%col_values) >>.
2761 # In your application
2762 my $cd = $schema->resultset('CD')->update_or_new(
2764 artist => 'Massive Attack',
2765 title => 'Mezzanine',
2768 { key => 'cd_artist_title' }
2771 if ($cd->in_storage) {
2772 # the cd was updated
2775 # the cd is not yet in the database, let's insert it
2779 B<Note>: Make sure to read the documentation of L</find> and understand the
2780 significance of the C<key> attribute, as its lack may skew your search, and
2781 subsequently result in spurious new objects.
2783 B<Note>: Take care when using C<update_or_new> with a table having
2784 columns with default values that you intend to be automatically
2785 supplied by the database (e.g. an auto_increment primary key column).
2786 In normal usage, the value of such columns should NOT be included at
2787 all in the call to C<update_or_new>, even when set to C<undef>.
2789 See also L</find>, L</find_or_create> and L</find_or_new>.
2795 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2796 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2798 my $row = $self->find( $cond, $attrs );
2799 if ( defined $row ) {
2800 $row->update($cond);
2804 return $self->new_result($cond);
2811 =item Arguments: none
2813 =item Return Value: \@cache_objects | undef
2817 Gets the contents of the cache for the resultset, if the cache is set.
2819 The cache is populated either by using the L</prefetch> attribute to
2820 L</search> or by calling L</set_cache>.
2832 =item Arguments: \@cache_objects
2834 =item Return Value: \@cache_objects
2838 Sets the contents of the cache for the resultset. Expects an arrayref
2839 of objects of the same class as those produced by the resultset. Note that
2840 if the cache is set the resultset will return the cached objects rather
2841 than re-querying the database even if the cache attr is not set.
2843 The contents of the cache can also be populated by using the
2844 L</prefetch> attribute to L</search>.
2849 my ( $self, $data ) = @_;
2850 $self->throw_exception("set_cache requires an arrayref")
2851 if defined($data) && (ref $data ne 'ARRAY');
2852 $self->{all_cache} = $data;
2859 =item Arguments: none
2861 =item Return Value: undef
2865 Clears the cache for the resultset.
2870 shift->set_cache(undef);
2877 =item Arguments: none
2879 =item Return Value: true, if the resultset has been paginated
2887 return !!$self->{attrs}{page};
2894 =item Arguments: none
2896 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2904 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2907 =head2 related_resultset
2911 =item Arguments: $relationship_name
2913 =item Return Value: $resultset
2917 Returns a related resultset for the supplied relationship name.
2919 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2923 sub related_resultset {
2924 my ($self, $rel) = @_;
2926 $self->{related_resultsets} ||= {};
2927 return $self->{related_resultsets}{$rel} ||= do {
2928 my $rsrc = $self->result_source;
2929 my $rel_info = $rsrc->relationship_info($rel);
2931 $self->throw_exception(
2932 "search_related: result source '" . $rsrc->source_name .
2933 "' has no such relationship $rel")
2936 my $attrs = $self->_chain_relationship($rel);
2938 my $join_count = $attrs->{seen_join}{$rel};
2940 my $alias = $self->result_source->storage
2941 ->relname_to_table_alias($rel, $join_count);
2943 # since this is search_related, and we already slid the select window inwards
2944 # (the select/as attrs were deleted in the beginning), we need to flip all
2945 # left joins to inner, so we get the expected results
2946 # read the comment on top of the actual function to see what this does
2947 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2950 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2951 delete @{$attrs}{qw(result_class alias)};
2955 if (my $cache = $self->get_cache) {
2956 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2957 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2962 my $rel_source = $rsrc->related_source($rel);
2966 # The reason we do this now instead of passing the alias to the
2967 # search_rs below is that if you wrap/overload resultset on the
2968 # source you need to know what alias it's -going- to have for things
2969 # to work sanely (e.g. RestrictWithObject wants to be able to add
2970 # extra query restrictions, and these may need to be $alias.)
2972 my $rel_attrs = $rel_source->resultset_attributes;
2973 local $rel_attrs->{alias} = $alias;
2975 $rel_source->resultset
2979 where => $attrs->{where},
2982 $new->set_cache($new_cache) if $new_cache;
2987 =head2 current_source_alias
2991 =item Arguments: none
2993 =item Return Value: $source_alias
2997 Returns the current table alias for the result source this resultset is built
2998 on, that will be used in the SQL query. Usually it is C<me>.
3000 Currently the source alias that refers to the result set returned by a
3001 L</search>/L</find> family method depends on how you got to the resultset: it's
3002 C<me> by default, but eg. L</search_related> aliases it to the related result
3003 source name (and keeps C<me> referring to the original result set). The long
3004 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3005 (and make this method unnecessary).
3007 Thus it's currently necessary to use this method in predefined queries (see
3008 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3009 source alias of the current result set:
3011 # in a result set class
3013 my ($self, $user) = @_;
3015 my $me = $self->current_source_alias;
3017 return $self->search(
3018 "$me.modified" => $user->id,
3024 sub current_source_alias {
3027 return ($self->{attrs} || {})->{alias} || 'me';
3030 =head2 as_subselect_rs
3034 =item Arguments: none
3036 =item Return Value: $resultset
3040 Act as a barrier to SQL symbols. The resultset provided will be made into a
3041 "virtual view" by including it as a subquery within the from clause. From this
3042 point on, any joined tables are inaccessible to ->search on the resultset (as if
3043 it were simply where-filtered without joins). For example:
3045 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3047 # 'x' now pollutes the query namespace
3049 # So the following works as expected
3050 my $ok_rs = $rs->search({'x.other' => 1});
3052 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3053 # def) we look for one row with contradictory terms and join in another table
3054 # (aliased 'x_2') which we never use
3055 my $broken_rs = $rs->search({'x.name' => 'def'});
3057 my $rs2 = $rs->as_subselect_rs;
3059 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3060 my $not_joined_rs = $rs2->search({'x.other' => 1});
3062 # works as expected: finds a 'table' row related to two x rows (abc and def)
3063 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3065 Another example of when one might use this would be to select a subset of
3066 columns in a group by clause:
3068 my $rs = $schema->resultset('Bar')->search(undef, {
3069 group_by => [qw{ id foo_id baz_id }],
3070 })->as_subselect_rs->search(undef, {
3071 columns => [qw{ id foo_id }]
3074 In the above example normally columns would have to be equal to the group by,
3075 but because we isolated the group by into a subselect the above works.
3079 sub as_subselect_rs {
3082 my $attrs = $self->_resolved_attrs;
3084 my $fresh_rs = (ref $self)->new (
3085 $self->result_source
3088 # these pieces will be locked in the subquery
3089 delete $fresh_rs->{cond};
3090 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3092 return $fresh_rs->search( {}, {
3094 $attrs->{alias} => $self->as_query,
3095 -alias => $attrs->{alias},
3096 -source_handle => $self->result_source->handle,
3098 alias => $attrs->{alias},
3102 # This code is called by search_related, and makes sure there
3103 # is clear separation between the joins before, during, and
3104 # after the relationship. This information is needed later
3105 # in order to properly resolve prefetch aliases (any alias
3106 # with a relation_chain_depth less than the depth of the
3107 # current prefetch is not considered)
3109 # The increments happen twice per join. An even number means a
3110 # relationship specified via a search_related, whereas an odd
3111 # number indicates a join/prefetch added via attributes
3113 # Also this code will wrap the current resultset (the one we
3114 # chain to) in a subselect IFF it contains limiting attributes
3115 sub _chain_relationship {
3116 my ($self, $rel) = @_;
3117 my $source = $self->result_source;
3118 my $attrs = { %{$self->{attrs}||{}} };
3120 # we need to take the prefetch the attrs into account before we
3121 # ->_resolve_join as otherwise they get lost - captainL
3122 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3124 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3126 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3129 my @force_subq_attrs = qw/offset rows group_by having/;
3132 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3134 $self->_has_resolved_attr (@force_subq_attrs)
3136 # Nuke the prefetch (if any) before the new $rs attrs
3137 # are resolved (prefetch is useless - we are wrapping
3138 # a subquery anyway).
3139 my $rs_copy = $self->search;
3140 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3141 $rs_copy->{attrs}{join},
3142 delete $rs_copy->{attrs}{prefetch},
3146 -source_handle => $source->handle,
3147 -alias => $attrs->{alias},
3148 $attrs->{alias} => $rs_copy->as_query,
3150 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3151 $seen->{-relation_chain_depth} = 0;
3153 elsif ($attrs->{from}) { #shallow copy suffices
3154 $from = [ @{$attrs->{from}} ];
3158 -source_handle => $source->handle,
3159 -alias => $attrs->{alias},
3160 $attrs->{alias} => $source->from,
3164 my $jpath = ($seen->{-relation_chain_depth})
3165 ? $from->[-1][0]{-join_path}
3168 my @requested_joins = $source->_resolve_join(
3175 push @$from, @requested_joins;
3177 $seen->{-relation_chain_depth}++;
3179 # if $self already had a join/prefetch specified on it, the requested
3180 # $rel might very well be already included. What we do in this case
3181 # is effectively a no-op (except that we bump up the chain_depth on
3182 # the join in question so we could tell it *is* the search_related)
3185 # we consider the last one thus reverse
3186 for my $j (reverse @requested_joins) {
3187 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3188 if ($rel eq $last_j) {
3189 $j->[0]{-relation_chain_depth}++;
3195 unless ($already_joined) {
3196 push @$from, $source->_resolve_join(
3204 $seen->{-relation_chain_depth}++;
3206 return {%$attrs, from => $from, seen_join => $seen};
3209 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3210 sub _resolved_attrs_copy {
3212 return { %{$self->_resolved_attrs (@_)} };
3215 sub _resolved_attrs {
3217 return $self->{_attrs} if $self->{_attrs};
3219 my $attrs = { %{ $self->{attrs} || {} } };
3220 my $source = $self->result_source;
3221 my $alias = $attrs->{alias};
3223 # one last pass of normalization
3224 $self->_normalize_selection($attrs);
3226 # default selection list
3227 $attrs->{columns} = [ $source->columns ]
3228 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3230 # merge selectors together
3231 for (qw/columns select as _trailing_select/) {
3232 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3233 if $attrs->{$_} or $attrs->{"+$_"};
3236 # disassemble columns
3239 ref $attrs->{columns} eq 'ARRAY' ? $attrs->{columns} : [ $attrs->{columns} || () ]
3241 if (ref $c eq 'HASH') {
3242 for my $as (keys %$c) {
3243 push @sel, $c->{$as};
3253 # when trying to weed off duplicates later do not go past this point -
3254 # everything added from here on is unbalanced "anyone's guess" stuff
3255 my $dedup_stop_idx = $#as;
3257 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3259 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3260 if $attrs->{select};
3262 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3264 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3267 # disqualify all $alias.col as-bits (collapser mandated)
3269 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3272 # de-duplicate the result (remove *identical* select/as pairs)
3273 # and also die on duplicate {as} pointing to different {select}s
3274 # not using a c-style for as the condition is prone to shrinkage
3277 while ($i <= $dedup_stop_idx) {
3278 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3283 elsif ($seen->{$as[$i]}++) {
3284 $self->throw_exception(
3285 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3293 $attrs->{select} = \@sel;
3294 $attrs->{as} = \@as;
3296 $attrs->{from} ||= [{
3297 -source_handle => $source->handle,
3298 -alias => $self->{attrs}{alias},
3299 $self->{attrs}{alias} => $source->from,
3302 if ( $attrs->{join} || $attrs->{prefetch} ) {
3304 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3305 if ref $attrs->{from} ne 'ARRAY';
3307 my $join = (delete $attrs->{join}) || {};
3309 if ( defined $attrs->{prefetch} ) {
3310 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3313 $attrs->{from} = # have to copy here to avoid corrupting the original
3315 @{ $attrs->{from} },
3316 $source->_resolve_join(
3319 { %{ $attrs->{seen_join} || {} } },
3320 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3321 ? $attrs->{from}[-1][0]{-join_path}
3328 if ( defined $attrs->{order_by} ) {
3329 $attrs->{order_by} = (
3330 ref( $attrs->{order_by} ) eq 'ARRAY'
3331 ? [ @{ $attrs->{order_by} } ]
3332 : [ $attrs->{order_by} || () ]
3336 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3337 $attrs->{group_by} = [ $attrs->{group_by} ];
3340 # generate the distinct induced group_by early, as prefetch will be carried via a
3341 # subquery (since a group_by is present)
3342 if (delete $attrs->{distinct}) {
3343 if ($attrs->{group_by}) {
3344 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3347 # distinct affects only the main selection part, not what prefetch may
3348 # add below. However trailing is not yet a part of the selection as
3349 # prefetch must insert before it
3350 $attrs->{group_by} = $source->storage->_group_over_selection (
3352 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3358 $attrs->{collapse} ||= {};
3359 if ($attrs->{prefetch}) {
3360 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3362 my $prefetch_ordering = [];
3364 # this is a separate structure (we don't look in {from} directly)
3365 # as the resolver needs to shift things off the lists to work
3366 # properly (identical-prefetches on different branches)
3368 if (ref $attrs->{from} eq 'ARRAY') {
3370 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3372 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3373 next unless $j->[0]{-alias};
3374 next unless $j->[0]{-join_path};
3375 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3377 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3380 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3381 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3386 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3388 # we need to somehow mark which columns came from prefetch
3390 my $sel_end = $#{$attrs->{select}};
3391 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3394 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3395 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3397 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3398 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3402 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3403 if $attrs->{_trailing_select};
3405 # if both page and offset are specified, produce a combined offset
3406 # even though it doesn't make much sense, this is what pre 081xx has
3408 if (my $page = delete $attrs->{page}) {
3410 ($attrs->{rows} * ($page - 1))
3412 ($attrs->{offset} || 0)
3416 return $self->{_attrs} = $attrs;
3420 my ($self, $attr) = @_;
3422 if (ref $attr eq 'HASH') {
3423 return $self->_rollout_hash($attr);
3424 } elsif (ref $attr eq 'ARRAY') {
3425 return $self->_rollout_array($attr);
3431 sub _rollout_array {
3432 my ($self, $attr) = @_;
3435 foreach my $element (@{$attr}) {
3436 if (ref $element eq 'HASH') {
3437 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3438 } elsif (ref $element eq 'ARRAY') {
3439 # XXX - should probably recurse here
3440 push( @rolled_array, @{$self->_rollout_array($element)} );
3442 push( @rolled_array, $element );
3445 return \@rolled_array;
3449 my ($self, $attr) = @_;
3452 foreach my $key (keys %{$attr}) {
3453 push( @rolled_array, { $key => $attr->{$key} } );
3455 return \@rolled_array;
3458 sub _calculate_score {
3459 my ($self, $a, $b) = @_;
3461 if (defined $a xor defined $b) {
3464 elsif (not defined $a) {
3468 if (ref $b eq 'HASH') {
3469 my ($b_key) = keys %{$b};
3470 if (ref $a eq 'HASH') {
3471 my ($a_key) = keys %{$a};
3472 if ($a_key eq $b_key) {
3473 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3478 return ($a eq $b_key) ? 1 : 0;
3481 if (ref $a eq 'HASH') {
3482 my ($a_key) = keys %{$a};
3483 return ($b eq $a_key) ? 1 : 0;
3485 return ($b eq $a) ? 1 : 0;
3490 sub _merge_joinpref_attr {
3491 my ($self, $orig, $import) = @_;
3493 return $import unless defined($orig);
3494 return $orig unless defined($import);
3496 $orig = $self->_rollout_attr($orig);
3497 $import = $self->_rollout_attr($import);
3500 foreach my $import_element ( @{$import} ) {
3501 # find best candidate from $orig to merge $b_element into
3502 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3503 foreach my $orig_element ( @{$orig} ) {
3504 my $score = $self->_calculate_score( $orig_element, $import_element );
3505 if ($score > $best_candidate->{score}) {
3506 $best_candidate->{position} = $position;
3507 $best_candidate->{score} = $score;
3511 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3513 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3514 push( @{$orig}, $import_element );
3516 my $orig_best = $orig->[$best_candidate->{position}];
3517 # merge orig_best and b_element together and replace original with merged
3518 if (ref $orig_best ne 'HASH') {
3519 $orig->[$best_candidate->{position}] = $import_element;
3520 } elsif (ref $import_element eq 'HASH') {
3521 my ($key) = keys %{$orig_best};
3522 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3525 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3536 my $hm = Hash::Merge->new;
3538 $hm->specify_behavior({
3541 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3543 if ($defl xor $defr) {
3544 return [ $defl ? $_[0] : $_[1] ];
3549 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3553 return [$_[0], $_[1]];
3557 return $_[1] if !defined $_[0];
3558 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3559 return [$_[0], @{$_[1]}]
3562 return [] if !defined $_[0] and !keys %{$_[1]};
3563 return [ $_[1] ] if !defined $_[0];
3564 return [ $_[0] ] if !keys %{$_[1]};
3565 return [$_[0], $_[1]]
3570 return $_[0] if !defined $_[1];
3571 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3572 return [@{$_[0]}, $_[1]]
3575 my @ret = @{$_[0]} or return $_[1];
3576 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3577 my %idx = map { $_ => 1 } @ret;
3578 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3582 return [ $_[1] ] if ! @{$_[0]};
3583 return $_[0] if !keys %{$_[1]};
3584 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3585 return [ @{$_[0]}, $_[1] ];
3590 return [] if !keys %{$_[0]} and !defined $_[1];
3591 return [ $_[0] ] if !defined $_[1];
3592 return [ $_[1] ] if !keys %{$_[0]};
3593 return [$_[0], $_[1]]
3596 return [] if !keys %{$_[0]} and !@{$_[1]};
3597 return [ $_[0] ] if !@{$_[1]};
3598 return $_[1] if !keys %{$_[0]};
3599 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3600 return [ $_[0], @{$_[1]} ];
3603 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3604 return [ $_[0] ] if !keys %{$_[1]};
3605 return [ $_[1] ] if !keys %{$_[0]};
3606 return [ $_[0] ] if $_[0] eq $_[1];
3607 return [ $_[0], $_[1] ];
3610 } => 'DBIC_RS_ATTR_MERGER');
3614 return $hm->merge ($_[1], $_[2]);
3622 $self->_source_handle($_[0]->handle);
3624 $self->_source_handle->resolve;
3629 sub STORABLE_freeze {
3630 my ($self, $cloning) = @_;
3631 my $to_serialize = { %$self };
3633 # A cursor in progress can't be serialized (and would make little sense anyway)
3634 delete $to_serialize->{cursor};
3636 return nfreeze($to_serialize);
3639 # need this hook for symmetry
3641 my ($self, $cloning, $serialized) = @_;
3643 %$self = %{ thaw($serialized) };
3649 =head2 throw_exception
3651 See L<DBIx::Class::Schema/throw_exception> for details.
3655 sub throw_exception {
3658 if (ref $self && $self->_source_handle->schema) {
3659 $self->_source_handle->schema->throw_exception(@_)
3662 DBIx::Class::Exception->throw(@_);
3666 # XXX: FIXME: Attributes docs need clearing up
3670 Attributes are used to refine a ResultSet in various ways when
3671 searching for data. They can be passed to any method which takes an
3672 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3675 These are in no particular order:
3681 =item Value: ( $order_by | \@order_by | \%order_by )
3685 Which column(s) to order the results by.
3687 [The full list of suitable values is documented in
3688 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3691 If a single column name, or an arrayref of names is supplied, the
3692 argument is passed through directly to SQL. The hashref syntax allows
3693 for connection-agnostic specification of ordering direction:
3695 For descending order:
3697 order_by => { -desc => [qw/col1 col2 col3/] }
3699 For explicit ascending order:
3701 order_by => { -asc => 'col' }
3703 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3704 supported, although you are strongly encouraged to use the hashref
3705 syntax as outlined above.
3711 =item Value: \@columns
3715 Shortcut to request a particular set of columns to be retrieved. Each
3716 column spec may be a string (a table column name), or a hash (in which
3717 case the key is the C<as> value, and the value is used as the C<select>
3718 expression). Adds C<me.> onto the start of any column without a C<.> in
3719 it and sets C<select> from that, then auto-populates C<as> from
3720 C<select> as normal. (You may also use the C<cols> attribute, as in
3721 earlier versions of DBIC.)
3723 Essentially C<columns> does the same as L</select> and L</as>.
3725 columns => [ 'foo', { bar => 'baz' } ]
3729 select => [qw/foo baz/],
3736 =item Value: \@columns
3740 Indicates additional columns to be selected from storage. Works the same
3741 as L</columns> but adds columns to the selection. (You may also use the
3742 C<include_columns> attribute, as in earlier versions of DBIC). For
3745 $schema->resultset('CD')->search(undef, {
3746 '+columns' => ['artist.name'],
3750 would return all CDs and include a 'name' column to the information
3751 passed to object inflation. Note that the 'artist' is the name of the
3752 column (or relationship) accessor, and 'name' is the name of the column
3753 accessor in the related table.
3755 =head2 include_columns
3759 =item Value: \@columns
3763 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3769 =item Value: \@select_columns
3773 Indicates which columns should be selected from the storage. You can use
3774 column names, or in the case of RDBMS back ends, function or stored procedure
3777 $rs = $schema->resultset('Employee')->search(undef, {
3780 { count => 'employeeid' },
3781 { max => { length => 'name' }, -as => 'longest_name' }
3786 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3788 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3789 use L</select>, to instruct DBIx::Class how to store the result of the column.
3790 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3791 identifier aliasing. You can however alias a function, so you can use it in
3792 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3793 attribute> supplied as shown in the example above.
3799 Indicates additional columns to be selected from storage. Works the same as
3800 L</select> but adds columns to the default selection, instead of specifying
3809 Indicates additional column names for those added via L</+select>. See L</as>.
3817 =item Value: \@inflation_names
3821 Indicates column names for object inflation. That is L</as> indicates the
3822 slot name in which the column value will be stored within the
3823 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3824 identifier by the C<get_column> method (or via the object accessor B<if one
3825 with the same name already exists>) as shown below. The L</as> attribute has
3826 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3828 $rs = $schema->resultset('Employee')->search(undef, {
3831 { count => 'employeeid' },
3832 { max => { length => 'name' }, -as => 'longest_name' }
3841 If the object against which the search is performed already has an accessor
3842 matching a column name specified in C<as>, the value can be retrieved using
3843 the accessor as normal:
3845 my $name = $employee->name();
3847 If on the other hand an accessor does not exist in the object, you need to
3848 use C<get_column> instead:
3850 my $employee_count = $employee->get_column('employee_count');
3852 You can create your own accessors if required - see
3853 L<DBIx::Class::Manual::Cookbook> for details.
3859 =item Value: ($rel_name | \@rel_names | \%rel_names)
3863 Contains a list of relationships that should be joined for this query. For
3866 # Get CDs by Nine Inch Nails
3867 my $rs = $schema->resultset('CD')->search(
3868 { 'artist.name' => 'Nine Inch Nails' },
3869 { join => 'artist' }
3872 Can also contain a hash reference to refer to the other relation's relations.
3875 package MyApp::Schema::Track;
3876 use base qw/DBIx::Class/;
3877 __PACKAGE__->table('track');
3878 __PACKAGE__->add_columns(qw/trackid cd position title/);
3879 __PACKAGE__->set_primary_key('trackid');
3880 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3883 # In your application
3884 my $rs = $schema->resultset('Artist')->search(
3885 { 'track.title' => 'Teardrop' },
3887 join => { cd => 'track' },
3888 order_by => 'artist.name',
3892 You need to use the relationship (not the table) name in conditions,
3893 because they are aliased as such. The current table is aliased as "me", so
3894 you need to use me.column_name in order to avoid ambiguity. For example:
3896 # Get CDs from 1984 with a 'Foo' track
3897 my $rs = $schema->resultset('CD')->search(
3900 'tracks.name' => 'Foo'
3902 { join => 'tracks' }
3905 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3906 similarly for a third time). For e.g.
3908 my $rs = $schema->resultset('Artist')->search({
3909 'cds.title' => 'Down to Earth',
3910 'cds_2.title' => 'Popular',
3912 join => [ qw/cds cds/ ],
3915 will return a set of all artists that have both a cd with title 'Down
3916 to Earth' and a cd with title 'Popular'.
3918 If you want to fetch related objects from other tables as well, see C<prefetch>
3921 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3927 =item Value: ($rel_name | \@rel_names | \%rel_names)
3931 Contains one or more relationships that should be fetched along with
3932 the main query (when they are accessed afterwards the data will
3933 already be available, without extra queries to the database). This is
3934 useful for when you know you will need the related objects, because it
3935 saves at least one query:
3937 my $rs = $schema->resultset('Tag')->search(
3946 The initial search results in SQL like the following:
3948 SELECT tag.*, cd.*, artist.* FROM tag
3949 JOIN cd ON tag.cd = cd.cdid
3950 JOIN artist ON cd.artist = artist.artistid
3952 L<DBIx::Class> has no need to go back to the database when we access the
3953 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3956 Simple prefetches will be joined automatically, so there is no need
3957 for a C<join> attribute in the above search.
3959 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3960 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3961 with an accessor type of 'single' or 'filter'). A more complex example that
3962 prefetches an artists cds, the tracks on those cds, and the tags associated
3963 with that artist is given below (assuming many-to-many from artists to tags):
3965 my $rs = $schema->resultset('Artist')->search(
3969 { cds => 'tracks' },
3970 { artist_tags => 'tags' }
3976 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3977 attributes will be ignored.
3979 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3980 exactly as you might expect.
3986 Prefetch uses the L</cache> to populate the prefetched relationships. This
3987 may or may not be what you want.
3991 If you specify a condition on a prefetched relationship, ONLY those
3992 rows that match the prefetched condition will be fetched into that relationship.
3993 This means that adding prefetch to a search() B<may alter> what is returned by
3994 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3996 my $artist_rs = $schema->resultset('Artist')->search({
4002 my $count = $artist_rs->first->cds->count;
4004 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4006 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4008 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4010 that cmp_ok() may or may not pass depending on the datasets involved. This
4011 behavior may or may not survive the 0.09 transition.
4023 Makes the resultset paged and specifies the page to retrieve. Effectively
4024 identical to creating a non-pages resultset and then calling ->page($page)
4027 If L<rows> attribute is not specified it defaults to 10 rows per page.
4029 When you have a paged resultset, L</count> will only return the number
4030 of rows in the page. To get the total, use the L</pager> and call
4031 C<total_entries> on it.
4041 Specifies the maximum number of rows for direct retrieval or the number of
4042 rows per page if the page attribute or method is used.
4048 =item Value: $offset
4052 Specifies the (zero-based) row number for the first row to be returned, or the
4053 of the first row of the first page if paging is used.
4059 =item Value: \@columns
4063 A arrayref of columns to group by. Can include columns of joined tables.
4065 group_by => [qw/ column1 column2 ... /]
4071 =item Value: $condition
4075 HAVING is a select statement attribute that is applied between GROUP BY and
4076 ORDER BY. It is applied to the after the grouping calculations have been
4079 having => { 'count_employee' => { '>=', 100 } }
4081 or with an in-place function in which case literal SQL is required:
4083 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4089 =item Value: (0 | 1)
4093 Set to 1 to group by all columns. If the resultset already has a group_by
4094 attribute, this setting is ignored and an appropriate warning is issued.
4100 Adds to the WHERE clause.
4102 # only return rows WHERE deleted IS NULL for all searches
4103 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4105 Can be overridden by passing C<< { where => undef } >> as an attribute
4112 Set to 1 to cache search results. This prevents extra SQL queries if you
4113 revisit rows in your ResultSet:
4115 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4117 while( my $artist = $resultset->next ) {
4121 $rs->first; # without cache, this would issue a query
4123 By default, searches are not cached.
4125 For more examples of using these attributes, see
4126 L<DBIx::Class::Manual::Cookbook>.
4132 =item Value: ( 'update' | 'shared' )
4136 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT