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 # default selection list
211 $attrs->{columns} = [ $source->resolve->columns ]
212 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
214 # Creation of {} and bless separated to mitigate RH perl bug
215 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
217 _source_handle => $source,
218 cond => $attrs->{where},
226 $attrs->{result_class} || $source->resolve->result_class
236 =item Arguments: $cond, \%attrs?
238 =item Return Value: $resultset (scalar context), @row_objs (list context)
242 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
243 my $new_rs = $cd_rs->search({ year => 2005 });
245 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
246 # year = 2005 OR year = 2004
248 If you need to pass in additional attributes but no additional condition,
249 call it as C<search(undef, \%attrs)>.
251 # "SELECT name, artistid FROM $artist_table"
252 my @all_artists = $schema->resultset('Artist')->search(undef, {
253 columns => [qw/name artistid/],
256 For a list of attributes that can be passed to C<search>, see
257 L</ATTRIBUTES>. For more examples of using this function, see
258 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
259 documentation for the first argument, see L<SQL::Abstract>.
261 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
265 Note that L</search> does not process/deflate any of the values passed in the
266 L<SQL::Abstract>-compatible search condition structure. This is unlike other
267 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
268 manually that any value passed to this method will stringify to something the
269 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
270 objects, for more info see:
271 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
277 my $rs = $self->search_rs( @_ );
282 elsif (defined wantarray) {
286 # we can be called by a relationship helper, which in
287 # turn may be called in void context due to some braindead
288 # overload or whatever else the user decided to be clever
289 # at this particular day. Thus limit the exception to
290 # external code calls only
291 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
292 if (caller)[0] !~ /^\QDBIx::Class::/;
302 =item Arguments: $cond, \%attrs?
304 =item Return Value: $resultset
308 This method does the same exact thing as search() except it will
309 always return a resultset, even in list context.
313 my $callsites_warned;
317 # Special-case handling for (undef, undef).
318 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
323 $call_attrs = pop(@_) if (
324 @_ > 1 and ( ! defined $_[-1] or ref $_[-1] eq 'HASH' )
327 # see if we can keep the cache (no $rs changes)
329 my %safe = (alias => 1, cache => 1);
330 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
333 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
335 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
337 $cache = $self->get_cache;
340 my $rsrc = $self->result_source;
342 my $old_attrs = { %{$self->{attrs}} };
343 my $old_having = delete $old_attrs->{having};
344 my $old_where = delete $old_attrs->{where};
347 # start with blind overwriting merge
348 my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
350 # join/prefetch use their own crazy merging heuristics
351 foreach my $key (qw/join prefetch/) {
352 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
353 if exists $call_attrs->{$key};
356 # stack binds together
357 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
359 # take care of selects (only if anything changed)
360 if (keys %$call_attrs) {
362 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
363 if exists $call_attrs->{_trailing_select};
365 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
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 # the new/old acrobatics is because of the merger in the next loop
370 for ($new_attrs, $old_attrs) {
371 delete @{$_}{@selector_attrs, '_trailing_select'};
375 for (@selector_attrs) {
376 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
377 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
380 # older deprecated name, use only if {columns} is not there
381 if (my $c = delete $new_attrs->{cols}) {
382 if ($new_attrs->{columns}) {
383 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
386 $new_attrs->{columns} = $c;
390 # Normalize the selector list (operates on the passed-in attr structure)
391 # Need to do it on every chain instead of only once on _resolved_attrs, in
392 # order to separate 'as'-ed from blind 'select's
393 $self->_normalize_selection ($new_attrs);
397 # rip apart the rest of @_, parse a condition
400 if (ref $_[0] eq 'HASH') {
401 (keys %{$_[0]}) ? $_[0] : undef
407 $self->throw_exception('Odd number of arguments to search')
415 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
416 # determine callsite obeying Carp::Clan rules (fucking ugly but don't have better ideas)
419 local $SIG{__WARN__} = sub { $w = shift };
423 carp 'search( %condition ) is deprecated, use search( \%condition ) instead'
424 unless $callsites_warned->{$callsite}++;
427 for ($old_where, $call_cond) {
429 $new_attrs->{where} = $self->_stack_cond (
430 $_, $new_attrs->{where}
435 if (defined $old_having) {
436 $new_attrs->{having} = $self->_stack_cond (
437 $old_having, $new_attrs->{having}
441 my $rs = (ref $self)->new($rsrc, $new_attrs);
443 $rs->set_cache($cache) if ($cache);
448 sub _normalize_selection {
449 my ($self, $attrs) = @_;
451 # merge all balanced selectors into the 'columns' stack, deleting the rest
452 foreach my $key (qw/+columns include_columns/) {
453 $attrs->{columns} = $self->_merge_attr($attrs->{columns}, delete $attrs->{$key})
454 if exists $attrs->{$key};
457 # select/as +select/+as pairs need special handling - the amount of select/as
458 # elements in each pair does *not* have to be equal (think multicolumn
459 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
460 # supplied at all) - try to infer the alias, either from the -as parameter
461 # of the selector spec, or use the parameter whole if it looks like a column
462 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
463 # is ok as well), but transport it over a separate attribute to make sure it is
464 # the last thing in the select list, thus unable to throw off the corresponding
466 for my $pref ('', '+') {
468 my ($sel, $as) = map {
469 my $key = "${pref}${_}";
471 my $val = [ ref $attrs->{$key} eq 'ARRAY'
473 : $attrs->{$key} || ()
475 delete $attrs->{$key};
479 if (! @$as and ! @$sel ) {
482 elsif (@$as and ! @$sel) {
483 $self->throw_exception(
484 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
488 # no as part supplied at all - try to deduce
489 # if any @$as has been supplied we assume the user knows what (s)he is doing
490 # and blindly keep stacking up pieces
491 my (@new_sel, @new_trailing);
493 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
494 push @$as, $_->{-as};
497 # assume any plain no-space, no-parenthesis string to be a column spec
498 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
499 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
503 # if all else fails - shove the selection to the trailing stack and move on
505 push @new_trailing, $_;
510 $attrs->{'_trailing_select'} = $self->_merge_attr($attrs->{'_trailing_select'}, \@new_trailing)
513 elsif (@$as < @$sel) {
514 $self->throw_exception(
515 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
519 # now see what the result for this pair looks like:
522 # if balanced - treat as a columns entry
523 $attrs->{columns} = $self->_merge_attr(
525 { map { $as->[$_] => $sel->[$_] } ( 0 .. $#$as ) }
529 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
530 $attrs->{select} = $self->_merge_attr($attrs->{select}, $sel);
531 $attrs->{as} = $self->_merge_attr($attrs->{as}, $as);
536 delete $attrs->{$_} for grep { $attrs->{$_} and ! @{$attrs->{$_}} } qw/select as columns/;
540 my ($self, $left, $right) = @_;
541 if (defined $left xor defined $right) {
542 return defined $left ? $left : $right;
544 elsif (defined $left) {
545 return { -and => [ map
546 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
554 =head2 search_literal
558 =item Arguments: $sql_fragment, @bind_values
560 =item Return Value: $resultset (scalar context), @row_objs (list context)
564 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
565 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
567 Pass a literal chunk of SQL to be added to the conditional part of the
570 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
571 only be used in that context. C<search_literal> is a convenience method.
572 It is equivalent to calling $schema->search(\[]), but if you want to ensure
573 columns are bound correctly, use C<search>.
575 Example of how to use C<search> instead of C<search_literal>
577 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
578 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
581 See L<DBIx::Class::Manual::Cookbook/Searching> and
582 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
583 require C<search_literal>.
588 my ($self, $sql, @bind) = @_;
590 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
593 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
600 =item Arguments: \%columns_values | @pk_values, \%attrs?
602 =item Return Value: $row_object | undef
606 Finds and returns a single row based on supplied criteria. Takes either a
607 hashref with the same format as L</create> (including inference of foreign
608 keys from related objects), or a list of primary key values in the same
609 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
610 declaration on the L</result_source>.
612 In either case an attempt is made to combine conditions already existing on
613 the resultset with the condition passed to this method.
615 To aid with preparing the correct query for the storage you may supply the
616 C<key> attribute, which is the name of a
617 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
618 unique constraint corresponding to the
619 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
620 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
621 to construct a query that satisfies the named unique constraint fully (
622 non-NULL values for each column member of the constraint) an exception is
625 If no C<key> is specified, the search is carried over all unique constraints
626 which are fully defined by the available condition.
628 If no such constraint is found, C<find> currently defaults to a simple
629 C<< search->(\%column_values) >> which may or may not do what you expect.
630 Note that this fallback behavior may be deprecated in further versions. If
631 you need to search with arbitrary conditions - use L</search>. If the query
632 resulting from this fallback produces more than one row, a warning to the
633 effect is issued, though only the first row is constructed and returned as
636 In addition to C<key>, L</find> recognizes and applies standard
637 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
639 Note that if you have extra concerns about the correctness of the resulting
640 query you need to specify the C<key> attribute and supply the entire condition
641 as an argument to find (since it is not always possible to perform the
642 combination of the resultset condition with the supplied one, especially if
643 the resultset condition contains literal sql).
645 For example, to find a row by its primary key:
647 my $cd = $schema->resultset('CD')->find(5);
649 You can also find a row by a specific unique constraint:
651 my $cd = $schema->resultset('CD')->find(
653 artist => 'Massive Attack',
654 title => 'Mezzanine',
656 { key => 'cd_artist_title' }
659 See also L</find_or_create> and L</update_or_create>.
665 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
667 my $rsrc = $self->result_source;
669 # Parse out the condition from input
671 if (ref $_[0] eq 'HASH') {
672 $call_cond = { %{$_[0]} };
675 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
676 my @c_cols = $rsrc->unique_constraint_columns($constraint);
678 $self->throw_exception(
679 "No constraint columns, maybe a malformed '$constraint' constraint?"
682 $self->throw_exception (
683 'find() expects either a column/value hashref, or a list of values '
684 . "corresponding to the columns of the specified unique constraint '$constraint'"
685 ) unless @c_cols == @_;
688 @{$call_cond}{@c_cols} = @_;
692 for my $key (keys %$call_cond) {
694 my $keyref = ref($call_cond->{$key})
696 my $relinfo = $rsrc->relationship_info($key)
698 my $val = delete $call_cond->{$key};
700 next if $keyref eq 'ARRAY'; # has_many for multi_create
702 my $rel_q = $rsrc->_resolve_condition(
703 $relinfo->{cond}, $val, $key
705 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
706 @related{keys %$rel_q} = values %$rel_q;
710 # relationship conditions take precedence (?)
711 @{$call_cond}{keys %related} = values %related;
713 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
715 if (exists $attrs->{key}) {
716 $final_cond = $self->_qualify_cond_columns (
718 $self->_build_unique_cond (
726 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
727 # This means that we got here after a merger of relationship conditions
728 # in ::Relationship::Base::search_related (the row method), and furthermore
729 # the relationship is of the 'single' type. This means that the condition
730 # provided by the relationship (already attached to $self) is sufficient,
731 # as there can be only one row in the database that would satisfy the
735 # no key was specified - fall down to heuristics mode:
736 # run through all unique queries registered on the resultset, and
737 # 'OR' all qualifying queries together
738 my (@unique_queries, %seen_column_combinations);
739 for my $c_name ($rsrc->unique_constraint_names) {
740 next if $seen_column_combinations{
741 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
744 push @unique_queries, try {
745 $self->_build_unique_cond ($c_name, $call_cond)
749 $final_cond = @unique_queries
750 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
751 : $self->_non_unique_find_fallback ($call_cond, $attrs)
755 # Run the query, passing the result_class since it should propagate for find
756 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
757 if (keys %{$rs->_resolved_attrs->{collapse}}) {
759 carp "Query returned more than one row" if $rs->next;
767 # This is a stop-gap method as agreed during the discussion on find() cleanup:
768 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
770 # It is invoked when find() is called in legacy-mode with insufficiently-unique
771 # condition. It is provided for overrides until a saner way forward is devised
773 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
774 # the road. Please adjust your tests accordingly to catch this situation early
775 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
777 # The method will not be removed without an adequately complete replacement
778 # for strict-mode enforcement
779 sub _non_unique_find_fallback {
780 my ($self, $cond, $attrs) = @_;
782 return $self->_qualify_cond_columns(
784 exists $attrs->{alias}
786 : $self->{attrs}{alias}
791 sub _qualify_cond_columns {
792 my ($self, $cond, $alias) = @_;
794 my %aliased = %$cond;
795 for (keys %aliased) {
796 $aliased{"$alias.$_"} = delete $aliased{$_}
803 sub _build_unique_cond {
804 my ($self, $constraint_name, $extra_cond) = @_;
806 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
808 # combination may fail if $self->{cond} is non-trivial
809 my ($final_cond) = try {
810 $self->_merge_with_rscond ($extra_cond)
815 # trim out everything not in $columns
816 $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
818 if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
819 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
821 join (', ', map { "'$_'" } @missing),
828 =head2 search_related
832 =item Arguments: $rel, $cond, \%attrs?
834 =item Return Value: $new_resultset
838 $new_rs = $cd_rs->search_related('artist', {
842 Searches the specified relationship, optionally specifying a condition and
843 attributes for matching records. See L</ATTRIBUTES> for more information.
848 return shift->related_resultset(shift)->search(@_);
851 =head2 search_related_rs
853 This method works exactly the same as search_related, except that
854 it guarantees a resultset, even in list context.
858 sub search_related_rs {
859 return shift->related_resultset(shift)->search_rs(@_);
866 =item Arguments: none
868 =item Return Value: $cursor
872 Returns a storage-driven cursor to the given resultset. See
873 L<DBIx::Class::Cursor> for more information.
880 my $attrs = $self->_resolved_attrs_copy;
882 return $self->{cursor}
883 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
884 $attrs->{where},$attrs);
891 =item Arguments: $cond?
893 =item Return Value: $row_object | undef
897 my $cd = $schema->resultset('CD')->single({ year => 2001 });
899 Inflates the first result without creating a cursor if the resultset has
900 any records in it; if not returns C<undef>. Used by L</find> as a lean version
903 While this method can take an optional search condition (just like L</search>)
904 being a fast-code-path it does not recognize search attributes. If you need to
905 add extra joins or similar, call L</search> and then chain-call L</single> on the
906 L<DBIx::Class::ResultSet> returned.
912 As of 0.08100, this method enforces the assumption that the preceding
913 query returns only one row. If more than one row is returned, you will receive
916 Query returned more than one row
918 In this case, you should be using L</next> or L</find> instead, or if you really
919 know what you are doing, use the L</rows> attribute to explicitly limit the size
922 This method will also throw an exception if it is called on a resultset prefetching
923 has_many, as such a prefetch implies fetching multiple rows from the database in
924 order to assemble the resulting object.
931 my ($self, $where) = @_;
933 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
936 my $attrs = $self->_resolved_attrs_copy;
938 if (keys %{$attrs->{collapse}}) {
939 $self->throw_exception(
940 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
945 if (defined $attrs->{where}) {
948 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
949 $where, delete $attrs->{where} ]
952 $attrs->{where} = $where;
956 my @data = $self->result_source->storage->select_single(
957 $attrs->{from}, $attrs->{select},
958 $attrs->{where}, $attrs
961 return (@data ? ($self->_construct_object(@data))[0] : undef);
967 # Recursively collapse the query, accumulating values for each column.
969 sub _collapse_query {
970 my ($self, $query, $collapsed) = @_;
974 if (ref $query eq 'ARRAY') {
975 foreach my $subquery (@$query) {
976 next unless ref $subquery; # -or
977 $collapsed = $self->_collapse_query($subquery, $collapsed);
980 elsif (ref $query eq 'HASH') {
981 if (keys %$query and (keys %$query)[0] eq '-and') {
982 foreach my $subquery (@{$query->{-and}}) {
983 $collapsed = $self->_collapse_query($subquery, $collapsed);
987 foreach my $col (keys %$query) {
988 my $value = $query->{$col};
989 $collapsed->{$col}{$value}++;
1001 =item Arguments: $cond?
1003 =item Return Value: $resultsetcolumn
1007 my $max_length = $rs->get_column('length')->max;
1009 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1014 my ($self, $column) = @_;
1015 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1023 =item Arguments: $cond, \%attrs?
1025 =item Return Value: $resultset (scalar context), @row_objs (list context)
1029 # WHERE title LIKE '%blue%'
1030 $cd_rs = $rs->search_like({ title => '%blue%'});
1032 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1033 that this is simply a convenience method retained for ex Class::DBI users.
1034 You most likely want to use L</search> with specific operators.
1036 For more information, see L<DBIx::Class::Manual::Cookbook>.
1038 This method is deprecated and will be removed in 0.09. Use L</search()>
1039 instead. An example conversion is:
1041 ->search_like({ foo => 'bar' });
1045 ->search({ foo => { like => 'bar' } });
1052 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1053 .' Instead use ->search({ x => { -like => "y%" } })'
1054 .' (note the outer pair of {}s - they are important!)'
1056 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1057 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1058 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1059 return $class->search($query, { %$attrs });
1066 =item Arguments: $first, $last
1068 =item Return Value: $resultset (scalar context), @row_objs (list context)
1072 Returns a resultset or object list representing a subset of elements from the
1073 resultset slice is called on. Indexes are from 0, i.e., to get the first
1074 three records, call:
1076 my ($one, $two, $three) = $rs->slice(0, 2);
1081 my ($self, $min, $max) = @_;
1082 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1083 $attrs->{offset} = $self->{attrs}{offset} || 0;
1084 $attrs->{offset} += $min;
1085 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1086 return $self->search(undef, $attrs);
1087 #my $slice = (ref $self)->new($self->result_source, $attrs);
1088 #return (wantarray ? $slice->all : $slice);
1095 =item Arguments: none
1097 =item Return Value: $result | undef
1101 Returns the next element in the resultset (C<undef> is there is none).
1103 Can be used to efficiently iterate over records in the resultset:
1105 my $rs = $schema->resultset('CD')->search;
1106 while (my $cd = $rs->next) {
1110 Note that you need to store the resultset object, and call C<next> on it.
1111 Calling C<< resultset('Table')->next >> repeatedly will always return the
1112 first record from the resultset.
1118 if (my $cache = $self->get_cache) {
1119 $self->{all_cache_position} ||= 0;
1120 return $cache->[$self->{all_cache_position}++];
1122 if ($self->{attrs}{cache}) {
1123 delete $self->{pager};
1124 $self->{all_cache_position} = 1;
1125 return ($self->all)[0];
1127 if ($self->{stashed_objects}) {
1128 my $obj = shift(@{$self->{stashed_objects}});
1129 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1133 exists $self->{stashed_row}
1134 ? @{delete $self->{stashed_row}}
1135 : $self->cursor->next
1137 return undef unless (@row);
1138 my ($row, @more) = $self->_construct_object(@row);
1139 $self->{stashed_objects} = \@more if @more;
1143 sub _construct_object {
1144 my ($self, @row) = @_;
1146 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1148 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1149 @new = $self->{_attrs}{record_filter}->(@new)
1150 if exists $self->{_attrs}{record_filter};
1154 sub _collapse_result {
1155 my ($self, $as_proto, $row) = @_;
1159 # 'foo' => [ undef, 'foo' ]
1160 # 'foo.bar' => [ 'foo', 'bar' ]
1161 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1163 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1165 my %collapse = %{$self->{_attrs}{collapse}||{}};
1169 # if we're doing collapsing (has_many prefetch) we need to grab records
1170 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1171 # we know we don't have to bother.
1173 # the reason for not using the collapse stuff directly is because if you
1174 # had for e.g. two artists in a row with no cds, the collapse info for
1175 # both would be NULL (undef) so you'd lose the second artist
1177 # store just the index so we can check the array positions from the row
1178 # without having to contruct the full hash
1180 if (keys %collapse) {
1181 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1182 foreach my $i (0 .. $#construct_as) {
1183 next if defined($construct_as[$i][0]); # only self table
1184 if (delete $pri{$construct_as[$i][1]}) {
1185 push(@pri_index, $i);
1187 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1191 # no need to do an if, it'll be empty if @pri_index is empty anyway
1193 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1197 do { # no need to check anything at the front, we always want the first row
1201 foreach my $this_as (@construct_as) {
1202 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1205 push(@const_rows, \%const);
1207 } until ( # no pri_index => no collapse => drop straight out
1210 do { # get another row, stash it, drop out if different PK
1212 @copy = $self->cursor->next;
1213 $self->{stashed_row} = \@copy;
1215 # last thing in do block, counts as true if anything doesn't match
1217 # check xor defined first for NULL vs. NOT NULL then if one is
1218 # defined the other must be so check string equality
1221 (defined $pri_vals{$_} ^ defined $copy[$_])
1222 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1227 my $alias = $self->{attrs}{alias};
1234 foreach my $const (@const_rows) {
1235 scalar @const_keys or do {
1236 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1238 foreach my $key (@const_keys) {
1241 my @parts = split(/\./, $key);
1243 my $data = $const->{$key};
1244 foreach my $p (@parts) {
1245 $target = $target->[1]->{$p} ||= [];
1247 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1248 # collapsing at this point and on final part
1249 my $pos = $collapse_pos{$cur};
1250 CK: foreach my $ck (@ckey) {
1251 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1252 $collapse_pos{$cur} = $data;
1253 delete @collapse_pos{ # clear all positioning for sub-entries
1254 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1261 if (exists $collapse{$cur}) {
1262 $target = $target->[-1];
1265 $target->[0] = $data;
1267 $info->[0] = $const->{$key};
1275 =head2 result_source
1279 =item Arguments: $result_source?
1281 =item Return Value: $result_source
1285 An accessor for the primary ResultSource object from which this ResultSet
1292 =item Arguments: $result_class?
1294 =item Return Value: $result_class
1298 An accessor for the class to use when creating row objects. Defaults to
1299 C<< result_source->result_class >> - which in most cases is the name of the
1300 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1302 Note that changing the result_class will also remove any components
1303 that were originally loaded in the source class via
1304 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1305 in the original source class will not run.
1310 my ($self, $result_class) = @_;
1311 if ($result_class) {
1312 unless (ref $result_class) { # don't fire this for an object
1313 $self->ensure_class_loaded($result_class);
1315 $self->_result_class($result_class);
1316 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1317 # permit the user to set result class on one result set only; it only
1318 # chains if provided to search()
1319 #$self->{attrs}{result_class} = $result_class if ref $self;
1321 $self->_result_class;
1328 =item Arguments: $cond, \%attrs??
1330 =item Return Value: $count
1334 Performs an SQL C<COUNT> with the same query as the resultset was built
1335 with to find the number of elements. Passing arguments is equivalent to
1336 C<< $rs->search ($cond, \%attrs)->count >>
1342 return $self->search(@_)->count if @_ and defined $_[0];
1343 return scalar @{ $self->get_cache } if $self->get_cache;
1345 my $attrs = $self->_resolved_attrs_copy;
1347 # this is a little optimization - it is faster to do the limit
1348 # adjustments in software, instead of a subquery
1349 my $rows = delete $attrs->{rows};
1350 my $offset = delete $attrs->{offset};
1353 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1354 $crs = $self->_count_subq_rs ($attrs);
1357 $crs = $self->_count_rs ($attrs);
1359 my $count = $crs->next;
1361 $count -= $offset if $offset;
1362 $count = $rows if $rows and $rows < $count;
1363 $count = 0 if ($count < 0);
1372 =item Arguments: $cond, \%attrs??
1374 =item Return Value: $count_rs
1378 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1379 This can be very handy for subqueries:
1381 ->search( { amount => $some_rs->count_rs->as_query } )
1383 As with regular resultsets the SQL query will be executed only after
1384 the resultset is accessed via L</next> or L</all>. That would return
1385 the same single value obtainable via L</count>.
1391 return $self->search(@_)->count_rs if @_;
1393 # this may look like a lack of abstraction (count() does about the same)
1394 # but in fact an _rs *must* use a subquery for the limits, as the
1395 # software based limiting can not be ported if this $rs is to be used
1396 # in a subquery itself (i.e. ->as_query)
1397 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1398 return $self->_count_subq_rs;
1401 return $self->_count_rs;
1406 # returns a ResultSetColumn object tied to the count query
1409 my ($self, $attrs) = @_;
1411 my $rsrc = $self->result_source;
1412 $attrs ||= $self->_resolved_attrs;
1414 my $tmp_attrs = { %$attrs };
1415 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1416 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1418 # overwrite the selector (supplied by the storage)
1419 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1420 $tmp_attrs->{as} = 'count';
1421 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1423 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1429 # same as above but uses a subquery
1431 sub _count_subq_rs {
1432 my ($self, $attrs) = @_;
1434 my $rsrc = $self->result_source;
1435 $attrs ||= $self->_resolved_attrs;
1437 my $sub_attrs = { %$attrs };
1438 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1439 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1441 # if we multi-prefetch we group_by primary keys only as this is what we would
1442 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1443 if ( keys %{$attrs->{collapse}} ) {
1444 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1447 # Calculate subquery selector
1448 if (my $g = $sub_attrs->{group_by}) {
1450 my $sql_maker = $rsrc->storage->sql_maker;
1452 # necessary as the group_by may refer to aliased functions
1454 for my $sel (@{$attrs->{select}}) {
1455 $sel_index->{$sel->{-as}} = $sel
1456 if (ref $sel eq 'HASH' and $sel->{-as});
1459 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1460 # also look for named aggregates referred in the having clause
1461 # having often contains scalarrefs - thus parse it out entirely
1463 if ($attrs->{having}) {
1464 local $sql_maker->{having_bind};
1465 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1466 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1467 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1468 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1469 # if we don't unset it we screw up retarded but unfortunately working
1470 # 'MAX(foo.bar)' => { '>', 3 }
1471 $sql_maker->{name_sep} = '';
1474 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1476 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1478 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1479 # and if all fails for an utterly naive quoted scalar-with-function
1481 $rquote $sep $lquote (.+?) $rquote
1483 [\s,] \w+ \. (\w+) [\s,]
1485 [\s,] $lquote (.+?) $rquote [\s,]
1487 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1492 my $colpiece = $sel_index->{$_} || $_;
1494 # unqualify join-based group_by's. Arcane but possible query
1495 # also horrible horrible hack to alias a column (not a func.)
1496 # (probably need to introduce SQLA syntax)
1497 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1500 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1502 push @{$sub_attrs->{select}}, $colpiece;
1506 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1507 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1510 return $rsrc->resultset_class
1511 ->new ($rsrc, $sub_attrs)
1513 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1514 ->get_column ('count');
1521 =head2 count_literal
1525 =item Arguments: $sql_fragment, @bind_values
1527 =item Return Value: $count
1531 Counts the results in a literal query. Equivalent to calling L</search_literal>
1532 with the passed arguments, then L</count>.
1536 sub count_literal { shift->search_literal(@_)->count; }
1542 =item Arguments: none
1544 =item Return Value: @objects
1548 Returns all elements in the resultset. Called implicitly if the resultset
1549 is returned in list context.
1556 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1559 return @{ $self->get_cache } if $self->get_cache;
1563 if (keys %{$self->_resolved_attrs->{collapse}}) {
1564 # Using $self->cursor->all is really just an optimisation.
1565 # If we're collapsing has_many prefetches it probably makes
1566 # very little difference, and this is cleaner than hacking
1567 # _construct_object to survive the approach
1568 $self->cursor->reset;
1569 my @row = $self->cursor->next;
1571 push(@obj, $self->_construct_object(@row));
1572 @row = (exists $self->{stashed_row}
1573 ? @{delete $self->{stashed_row}}
1574 : $self->cursor->next);
1577 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1580 $self->set_cache(\@obj) if $self->{attrs}{cache};
1589 =item Arguments: none
1591 =item Return Value: $self
1595 Resets the resultset's cursor, so you can iterate through the elements again.
1596 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1603 delete $self->{_attrs} if exists $self->{_attrs};
1604 $self->{all_cache_position} = 0;
1605 $self->cursor->reset;
1613 =item Arguments: none
1615 =item Return Value: $object | undef
1619 Resets the resultset and returns an object for the first result (or C<undef>
1620 if the resultset is empty).
1625 return $_[0]->reset->next;
1631 # Determines whether and what type of subquery is required for the $rs operation.
1632 # If grouping is necessary either supplies its own, or verifies the current one
1633 # After all is done delegates to the proper storage method.
1635 sub _rs_update_delete {
1636 my ($self, $op, $values) = @_;
1638 my $rsrc = $self->result_source;
1640 # if a condition exists we need to strip all table qualifiers
1641 # if this is not possible we'll force a subquery below
1642 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1644 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1645 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1647 if ($needs_group_by_subq or $needs_subq) {
1649 # make a new $rs selecting only the PKs (that's all we really need)
1650 my $attrs = $self->_resolved_attrs_copy;
1653 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1654 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1656 if ($needs_group_by_subq) {
1657 # make sure no group_by was supplied, or if there is one - make sure it matches
1658 # the columns compiled above perfectly. Anything else can not be sanely executed
1659 # on most databases so croak right then and there
1661 if (my $g = $attrs->{group_by}) {
1662 my @current_group_by = map
1663 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1668 join ("\x00", sort @current_group_by)
1670 join ("\x00", sort @{$attrs->{columns}} )
1672 $self->throw_exception (
1673 "You have just attempted a $op operation on a resultset which does group_by"
1674 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1675 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1676 . ' kind of queries. Please retry the operation with a modified group_by or'
1677 . ' without using one at all.'
1682 $attrs->{group_by} = $attrs->{columns};
1686 my $subrs = (ref $self)->new($rsrc, $attrs);
1687 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1690 return $rsrc->storage->$op(
1692 $op eq 'update' ? $values : (),
1702 =item Arguments: \%values
1704 =item Return Value: $storage_rv
1708 Sets the specified columns in the resultset to the supplied values in a
1709 single query. Note that this will not run any accessor/set_column/update
1710 triggers, nor will it update any row object instances derived from this
1711 resultset (this includes the contents of the L<resultset cache|/set_cache>
1712 if any). See L</update_all> if you need to execute any on-update
1713 triggers or cascades defined either by you or a
1714 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1716 The return value is a pass through of what the underlying
1717 storage backend returned, and may vary. See L<DBI/execute> for the most
1722 Note that L</update> does not process/deflate any of the values passed in.
1723 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1724 ensure manually that any value passed to this method will stringify to
1725 something the RDBMS knows how to deal with. A notable example is the
1726 handling of L<DateTime> objects, for more info see:
1727 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1732 my ($self, $values) = @_;
1733 $self->throw_exception('Values for update must be a hash')
1734 unless ref $values eq 'HASH';
1736 return $self->_rs_update_delete ('update', $values);
1743 =item Arguments: \%values
1745 =item Return Value: 1
1749 Fetches all objects and updates them one at a time via
1750 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1751 triggers, while L</update> will not.
1756 my ($self, $values) = @_;
1757 $self->throw_exception('Values for update_all must be a hash')
1758 unless ref $values eq 'HASH';
1760 my $guard = $self->result_source->schema->txn_scope_guard;
1761 $_->update($values) for $self->all;
1770 =item Arguments: none
1772 =item Return Value: $storage_rv
1776 Deletes the rows matching this resultset in a single query. Note that this
1777 will not run any delete triggers, nor will it alter the
1778 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1779 derived from this resultset (this includes the contents of the
1780 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1781 execute any on-delete triggers or cascades defined either by you or a
1782 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1784 The return value is a pass through of what the underlying storage backend
1785 returned, and may vary. See L<DBI/execute> for the most common case.
1791 $self->throw_exception('delete does not accept any arguments')
1794 return $self->_rs_update_delete ('delete');
1801 =item Arguments: none
1803 =item Return Value: 1
1807 Fetches all objects and deletes them one at a time via
1808 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1809 triggers, while L</delete> will not.
1815 $self->throw_exception('delete_all does not accept any arguments')
1818 my $guard = $self->result_source->schema->txn_scope_guard;
1819 $_->delete for $self->all;
1828 =item Arguments: \@data;
1832 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1833 For the arrayref of hashrefs style each hashref should be a structure suitable
1834 forsubmitting to a $resultset->create(...) method.
1836 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1837 to insert the data, as this is a faster method.
1839 Otherwise, each set of data is inserted into the database using
1840 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1841 accumulated into an array. The array itself, or an array reference
1842 is returned depending on scalar or list context.
1844 Example: Assuming an Artist Class that has many CDs Classes relating:
1846 my $Artist_rs = $schema->resultset("Artist");
1848 ## Void Context Example
1849 $Artist_rs->populate([
1850 { artistid => 4, name => 'Manufactured Crap', cds => [
1851 { title => 'My First CD', year => 2006 },
1852 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1855 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1856 { title => 'My parents sold me to a record company', year => 2005 },
1857 { title => 'Why Am I So Ugly?', year => 2006 },
1858 { title => 'I Got Surgery and am now Popular', year => 2007 }
1863 ## Array Context Example
1864 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1865 { name => "Artist One"},
1866 { name => "Artist Two"},
1867 { name => "Artist Three", cds=> [
1868 { title => "First CD", year => 2007},
1869 { title => "Second CD", year => 2008},
1873 print $ArtistOne->name; ## response is 'Artist One'
1874 print $ArtistThree->cds->count ## reponse is '2'
1876 For the arrayref of arrayrefs style, the first element should be a list of the
1877 fieldsnames to which the remaining elements are rows being inserted. For
1880 $Arstist_rs->populate([
1881 [qw/artistid name/],
1882 [100, 'A Formally Unknown Singer'],
1883 [101, 'A singer that jumped the shark two albums ago'],
1884 [102, 'An actually cool singer'],
1887 Please note an important effect on your data when choosing between void and
1888 wantarray context. Since void context goes straight to C<insert_bulk> in
1889 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1890 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1891 create primary keys for you, you will find that your PKs are empty. In this
1892 case you will have to use the wantarray context in order to create those
1900 # cruft placed in standalone method
1901 my $data = $self->_normalize_populate_args(@_);
1903 if(defined wantarray) {
1905 foreach my $item (@$data) {
1906 push(@created, $self->create($item));
1908 return wantarray ? @created : \@created;
1910 my $first = $data->[0];
1912 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1913 # it relationship data
1914 my (@rels, @columns);
1915 for (keys %$first) {
1916 my $ref = ref $first->{$_};
1917 $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
1923 my @pks = $self->result_source->primary_columns;
1925 ## do the belongs_to relationships
1926 foreach my $index (0..$#$data) {
1928 # delegate to create() for any dataset without primary keys with specified relationships
1929 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1931 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1932 my @ret = $self->populate($data);
1938 foreach my $rel (@rels) {
1939 next unless ref $data->[$index]->{$rel} eq "HASH";
1940 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1941 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1942 my $related = $result->result_source->_resolve_condition(
1943 $result->result_source->relationship_info($reverse)->{cond},
1948 delete $data->[$index]->{$rel};
1949 $data->[$index] = {%{$data->[$index]}, %$related};
1951 push @columns, keys %$related if $index == 0;
1955 ## inherit the data locked in the conditions of the resultset
1956 my ($rs_data) = $self->_merge_with_rscond({});
1957 delete @{$rs_data}{@columns};
1958 my @inherit_cols = keys %$rs_data;
1959 my @inherit_data = values %$rs_data;
1961 ## do bulk insert on current row
1962 $self->result_source->storage->insert_bulk(
1963 $self->result_source,
1964 [@columns, @inherit_cols],
1965 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1968 ## do the has_many relationships
1969 foreach my $item (@$data) {
1971 foreach my $rel (@rels) {
1972 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1974 my $parent = $self->find({map { $_ => $item->{$_} } @pks})
1975 || $self->throw_exception('Cannot find the relating object.');
1977 my $child = $parent->$rel;
1979 my $related = $child->result_source->_resolve_condition(
1980 $parent->result_source->relationship_info($rel)->{cond},
1985 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1986 my @populate = map { {%$_, %$related} } @rows_to_add;
1988 $child->populate( \@populate );
1995 # populate() argumnets went over several incarnations
1996 # What we ultimately support is AoH
1997 sub _normalize_populate_args {
1998 my ($self, $arg) = @_;
2000 if (ref $arg eq 'ARRAY') {
2001 if (ref $arg->[0] eq 'HASH') {
2004 elsif (ref $arg->[0] eq 'ARRAY') {
2006 my @colnames = @{$arg->[0]};
2007 foreach my $values (@{$arg}[1 .. $#$arg]) {
2008 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2014 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2021 =item Arguments: none
2023 =item Return Value: $pager
2027 Return Value a L<Data::Page> object for the current resultset. Only makes
2028 sense for queries with a C<page> attribute.
2030 To get the full count of entries for a paged resultset, call
2031 C<total_entries> on the L<Data::Page> object.
2035 # make a wizard good for both a scalar and a hashref
2036 my $mk_lazy_count_wizard = sub {
2037 require Variable::Magic;
2039 my $stash = { total_rs => shift };
2040 my $slot = shift; # only used by the hashref magic
2042 my $magic = Variable::Magic::wizard (
2043 data => sub { $stash },
2049 # set value lazily, and dispell for good
2050 ${$_[0]} = $_[1]{total_rs}->count;
2051 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2055 # an explicit set implies dispell as well
2056 # the unless() is to work around "fun and giggles" below
2057 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2058 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2065 if ($_[2] eq $slot and !$_[1]{inactive}) {
2066 my $cnt = $_[1]{total_rs}->count;
2067 $_[0]->{$slot} = $cnt;
2069 # attempting to dispell in a fetch handle (works in store), seems
2070 # to invariable segfault on 5.10, 5.12, 5.13 :(
2071 # so use an inactivator instead
2072 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2078 if (! $_[1]{inactive} and $_[2] eq $slot) {
2079 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2081 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2088 $stash->{magic_selfref} = $magic;
2089 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2094 # the tie class for 5.8.1
2096 package # hide from pause
2097 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2098 use base qw/Tie::Hash/;
2100 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2101 sub NEXTKEY { each %{$_[0]{data}} }
2102 sub EXISTS { exists $_[0]{data}{$_[1]} }
2103 sub DELETE { delete $_[0]{data}{$_[1]} }
2104 sub CLEAR { %{$_[0]{data}} = () }
2105 sub SCALAR { scalar %{$_[0]{data}} }
2108 $_[1]{data} = {%{$_[1]{selfref}}};
2109 %{$_[1]{selfref}} = ();
2110 Scalar::Util::weaken ($_[1]{selfref});
2111 return bless ($_[1], $_[0]);
2115 if ($_[1] eq $_[0]{slot}) {
2116 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2117 untie %{$_[0]{selfref}};
2118 %{$_[0]{selfref}} = %{$_[0]{data}};
2127 $_[0]{data}{$_[1]} = $_[2];
2128 if ($_[1] eq $_[0]{slot}) {
2129 untie %{$_[0]{selfref}};
2130 %{$_[0]{selfref}} = %{$_[0]{data}};
2139 return $self->{pager} if $self->{pager};
2141 if ($self->get_cache) {
2142 $self->throw_exception ('Pagers on cached resultsets are not supported');
2145 my $attrs = $self->{attrs};
2146 if (!defined $attrs->{page}) {
2147 $self->throw_exception("Can't create pager for non-paged rs");
2149 elsif ($attrs->{page} <= 0) {
2150 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2152 $attrs->{rows} ||= 10;
2154 # throw away the paging flags and re-run the count (possibly
2155 # with a subselect) to get the real total count
2156 my $count_attrs = { %$attrs };
2157 delete $count_attrs->{$_} for qw/rows offset page pager/;
2158 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2161 ### the following may seem awkward and dirty, but it's a thought-experiment
2162 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2163 ### before talking to ribasushi/mst
2165 my $pager = Data::Page->new(
2166 0, #start with an empty set
2168 $self->{attrs}{page},
2171 my $data_slot = 'total_entries';
2173 # Since we are interested in a cached value (once it's set - it's set), every
2174 # technique will detach from the magic-host once the time comes to fire the
2175 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2177 if ($] < 5.008003) {
2178 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2179 # to weakref the magic container :(
2181 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2182 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2185 elsif ($] < 5.010) {
2186 # We can use magic on the hash value slot. It's interesting that the magic is
2187 # attached to the hash-slot, and does *not* stop working once I do the dummy
2188 # assignments after the cast()
2189 # tested on 5.8.3 and 5.8.9
2190 my $magic = $mk_lazy_count_wizard->($total_rs);
2191 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2193 # this is for fun and giggles
2194 $pager->{$data_slot} = -1;
2195 $pager->{$data_slot} = 0;
2197 # this does not work for scalars, but works with
2199 #my %vals = %$pager;
2204 # And the uvar magic
2205 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2206 # however see the wizard maker for more notes
2207 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2208 Variable::Magic::cast ( %$pager, $magic );
2211 $pager->{$data_slot} = -1;
2212 $pager->{$data_slot} = 0;
2220 return $self->{pager} = $pager;
2227 =item Arguments: $page_number
2229 =item Return Value: $rs
2233 Returns a resultset for the $page_number page of the resultset on which page
2234 is called, where each page contains a number of rows equal to the 'rows'
2235 attribute set on the resultset (10 by default).
2240 my ($self, $page) = @_;
2241 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2248 =item Arguments: \%vals
2250 =item Return Value: $rowobject
2254 Creates a new row object in the resultset's result class and returns
2255 it. The row is not inserted into the database at this point, call
2256 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2257 will tell you whether the row object has been inserted or not.
2259 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2264 my ($self, $values) = @_;
2265 $self->throw_exception( "new_result needs a hash" )
2266 unless (ref $values eq 'HASH');
2268 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2272 @$cols_from_relations
2273 ? (-cols_from_relations => $cols_from_relations)
2275 -source_handle => $self->_source_handle,
2276 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2279 return $self->result_class->new(\%new);
2282 # _merge_with_rscond
2284 # Takes a simple hash of K/V data and returns its copy merged with the
2285 # condition already present on the resultset. Additionally returns an
2286 # arrayref of value/condition names, which were inferred from related
2287 # objects (this is needed for in-memory related objects)
2288 sub _merge_with_rscond {
2289 my ($self, $data) = @_;
2291 my (%new_data, @cols_from_relations);
2293 my $alias = $self->{attrs}{alias};
2295 if (! defined $self->{cond}) {
2296 # just massage $data below
2298 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2299 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2300 @cols_from_relations = keys %new_data;
2302 elsif (ref $self->{cond} ne 'HASH') {
2303 $self->throw_exception(
2304 "Can't abstract implicit construct, resultset condition not a hash"
2308 # precendence must be given to passed values over values inherited from
2309 # the cond, so the order here is important.
2310 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2311 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2313 while ( my($col, $value) = each %implied ) {
2314 my $vref = ref $value;
2315 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2316 $new_data{$col} = $value->{'='};
2318 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2319 $new_data{$col} = $value;
2326 %{ $self->_remove_alias($data, $alias) },
2329 return (\%new_data, \@cols_from_relations);
2332 # _has_resolved_attr
2334 # determines if the resultset defines at least one
2335 # of the attributes supplied
2337 # used to determine if a subquery is neccessary
2339 # supports some virtual attributes:
2341 # This will scan for any joins being present on the resultset.
2342 # It is not a mere key-search but a deep inspection of {from}
2345 sub _has_resolved_attr {
2346 my ($self, @attr_names) = @_;
2348 my $attrs = $self->_resolved_attrs;
2352 for my $n (@attr_names) {
2353 if (grep { $n eq $_ } (qw/-join/) ) {
2354 $extra_checks{$n}++;
2358 my $attr = $attrs->{$n};
2360 next if not defined $attr;
2362 if (ref $attr eq 'HASH') {
2363 return 1 if keys %$attr;
2365 elsif (ref $attr eq 'ARRAY') {
2373 # a resolved join is expressed as a multi-level from
2375 $extra_checks{-join}
2377 ref $attrs->{from} eq 'ARRAY'
2379 @{$attrs->{from}} > 1
2387 # Recursively collapse the condition.
2389 sub _collapse_cond {
2390 my ($self, $cond, $collapsed) = @_;
2394 if (ref $cond eq 'ARRAY') {
2395 foreach my $subcond (@$cond) {
2396 next unless ref $subcond; # -or
2397 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2400 elsif (ref $cond eq 'HASH') {
2401 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2402 foreach my $subcond (@{$cond->{-and}}) {
2403 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2407 foreach my $col (keys %$cond) {
2408 my $value = $cond->{$col};
2409 $collapsed->{$col} = $value;
2419 # Remove the specified alias from the specified query hash. A copy is made so
2420 # the original query is not modified.
2423 my ($self, $query, $alias) = @_;
2425 my %orig = %{ $query || {} };
2428 foreach my $key (keys %orig) {
2430 $unaliased{$key} = $orig{$key};
2433 $unaliased{$1} = $orig{$key}
2434 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2444 =item Arguments: none
2446 =item Return Value: \[ $sql, @bind ]
2450 Returns the SQL query and bind vars associated with the invocant.
2452 This is generally used as the RHS for a subquery.
2459 my $attrs = $self->_resolved_attrs_copy;
2464 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2465 # $sql also has no wrapping parenthesis in list ctx
2467 my $sqlbind = $self->result_source->storage
2468 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2477 =item Arguments: \%vals, \%attrs?
2479 =item Return Value: $rowobject
2483 my $artist = $schema->resultset('Artist')->find_or_new(
2484 { artist => 'fred' }, { key => 'artists' });
2486 $cd->cd_to_producer->find_or_new({ producer => $producer },
2487 { key => 'primary });
2489 Find an existing record from this resultset using L</find>. if none exists,
2490 instantiate a new result object and return it. The object will not be saved
2491 into your storage until you call L<DBIx::Class::Row/insert> on it.
2493 You most likely want this method when looking for existing rows using a unique
2494 constraint that is not the primary key, or looking for related rows.
2496 If you want objects to be saved immediately, use L</find_or_create> instead.
2498 B<Note>: Make sure to read the documentation of L</find> and understand the
2499 significance of the C<key> attribute, as its lack may skew your search, and
2500 subsequently result in spurious new objects.
2502 B<Note>: Take care when using C<find_or_new> with a table having
2503 columns with default values that you intend to be automatically
2504 supplied by the database (e.g. an auto_increment primary key column).
2505 In normal usage, the value of such columns should NOT be included at
2506 all in the call to C<find_or_new>, even when set to C<undef>.
2512 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2513 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2514 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2517 return $self->new_result($hash);
2524 =item Arguments: \%vals
2526 =item Return Value: a L<DBIx::Class::Row> $object
2530 Attempt to create a single new row or a row with multiple related rows
2531 in the table represented by the resultset (and related tables). This
2532 will not check for duplicate rows before inserting, use
2533 L</find_or_create> to do that.
2535 To create one row for this resultset, pass a hashref of key/value
2536 pairs representing the columns of the table and the values you wish to
2537 store. If the appropriate relationships are set up, foreign key fields
2538 can also be passed an object representing the foreign row, and the
2539 value will be set to its primary key.
2541 To create related objects, pass a hashref of related-object column values
2542 B<keyed on the relationship name>. If the relationship is of type C<multi>
2543 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2544 The process will correctly identify columns holding foreign keys, and will
2545 transparently populate them from the keys of the corresponding relation.
2546 This can be applied recursively, and will work correctly for a structure
2547 with an arbitrary depth and width, as long as the relationships actually
2548 exists and the correct column data has been supplied.
2551 Instead of hashrefs of plain related data (key/value pairs), you may
2552 also pass new or inserted objects. New objects (not inserted yet, see
2553 L</new>), will be inserted into their appropriate tables.
2555 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2557 Example of creating a new row.
2559 $person_rs->create({
2560 name=>"Some Person",
2561 email=>"somebody@someplace.com"
2564 Example of creating a new row and also creating rows in a related C<has_many>
2565 or C<has_one> resultset. Note Arrayref.
2568 { artistid => 4, name => 'Manufactured Crap', cds => [
2569 { title => 'My First CD', year => 2006 },
2570 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2575 Example of creating a new row and also creating a row in a related
2576 C<belongs_to> resultset. Note Hashref.
2579 title=>"Music for Silly Walks",
2582 name=>"Silly Musician",
2590 When subclassing ResultSet never attempt to override this method. Since
2591 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2592 lot of the internals simply never call it, so your override will be
2593 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2594 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2595 L</create> process you need to intervene.
2602 my ($self, $attrs) = @_;
2603 $self->throw_exception( "create needs a hashref" )
2604 unless ref $attrs eq 'HASH';
2605 return $self->new_result($attrs)->insert;
2608 =head2 find_or_create
2612 =item Arguments: \%vals, \%attrs?
2614 =item Return Value: $rowobject
2618 $cd->cd_to_producer->find_or_create({ producer => $producer },
2619 { key => 'primary' });
2621 Tries to find a record based on its primary key or unique constraints; if none
2622 is found, creates one and returns that instead.
2624 my $cd = $schema->resultset('CD')->find_or_create({
2626 artist => 'Massive Attack',
2627 title => 'Mezzanine',
2631 Also takes an optional C<key> attribute, to search by a specific key or unique
2632 constraint. For example:
2634 my $cd = $schema->resultset('CD')->find_or_create(
2636 artist => 'Massive Attack',
2637 title => 'Mezzanine',
2639 { key => 'cd_artist_title' }
2642 B<Note>: Make sure to read the documentation of L</find> and understand the
2643 significance of the C<key> attribute, as its lack may skew your search, and
2644 subsequently result in spurious row creation.
2646 B<Note>: Because find_or_create() reads from the database and then
2647 possibly inserts based on the result, this method is subject to a race
2648 condition. Another process could create a record in the table after
2649 the find has completed and before the create has started. To avoid
2650 this problem, use find_or_create() inside a transaction.
2652 B<Note>: Take care when using C<find_or_create> with a table having
2653 columns with default values that you intend to be automatically
2654 supplied by the database (e.g. an auto_increment primary key column).
2655 In normal usage, the value of such columns should NOT be included at
2656 all in the call to C<find_or_create>, even when set to C<undef>.
2658 See also L</find> and L</update_or_create>. For information on how to declare
2659 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2663 sub find_or_create {
2665 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2666 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2667 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2670 return $self->create($hash);
2673 =head2 update_or_create
2677 =item Arguments: \%col_values, { key => $unique_constraint }?
2679 =item Return Value: $row_object
2683 $resultset->update_or_create({ col => $val, ... });
2685 Like L</find_or_create>, but if a row is found it is immediately updated via
2686 C<< $found_row->update (\%col_values) >>.
2689 Takes an optional C<key> attribute to search on a specific unique constraint.
2692 # In your application
2693 my $cd = $schema->resultset('CD')->update_or_create(
2695 artist => 'Massive Attack',
2696 title => 'Mezzanine',
2699 { key => 'cd_artist_title' }
2702 $cd->cd_to_producer->update_or_create({
2703 producer => $producer,
2709 B<Note>: Make sure to read the documentation of L</find> and understand the
2710 significance of the C<key> attribute, as its lack may skew your search, and
2711 subsequently result in spurious row creation.
2713 B<Note>: Take care when using C<update_or_create> with a table having
2714 columns with default values that you intend to be automatically
2715 supplied by the database (e.g. an auto_increment primary key column).
2716 In normal usage, the value of such columns should NOT be included at
2717 all in the call to C<update_or_create>, even when set to C<undef>.
2719 See also L</find> and L</find_or_create>. For information on how to declare
2720 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2724 sub update_or_create {
2726 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2727 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2729 my $row = $self->find($cond, $attrs);
2731 $row->update($cond);
2735 return $self->create($cond);
2738 =head2 update_or_new
2742 =item Arguments: \%col_values, { key => $unique_constraint }?
2744 =item Return Value: $rowobject
2748 $resultset->update_or_new({ col => $val, ... });
2750 Like L</find_or_new> but if a row is found it is immediately updated via
2751 C<< $found_row->update (\%col_values) >>.
2755 # In your application
2756 my $cd = $schema->resultset('CD')->update_or_new(
2758 artist => 'Massive Attack',
2759 title => 'Mezzanine',
2762 { key => 'cd_artist_title' }
2765 if ($cd->in_storage) {
2766 # the cd was updated
2769 # the cd is not yet in the database, let's insert it
2773 B<Note>: Make sure to read the documentation of L</find> and understand the
2774 significance of the C<key> attribute, as its lack may skew your search, and
2775 subsequently result in spurious new objects.
2777 B<Note>: Take care when using C<update_or_new> with a table having
2778 columns with default values that you intend to be automatically
2779 supplied by the database (e.g. an auto_increment primary key column).
2780 In normal usage, the value of such columns should NOT be included at
2781 all in the call to C<update_or_new>, even when set to C<undef>.
2783 See also L</find>, L</find_or_create> and L</find_or_new>.
2789 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2790 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2792 my $row = $self->find( $cond, $attrs );
2793 if ( defined $row ) {
2794 $row->update($cond);
2798 return $self->new_result($cond);
2805 =item Arguments: none
2807 =item Return Value: \@cache_objects | undef
2811 Gets the contents of the cache for the resultset, if the cache is set.
2813 The cache is populated either by using the L</prefetch> attribute to
2814 L</search> or by calling L</set_cache>.
2826 =item Arguments: \@cache_objects
2828 =item Return Value: \@cache_objects
2832 Sets the contents of the cache for the resultset. Expects an arrayref
2833 of objects of the same class as those produced by the resultset. Note that
2834 if the cache is set the resultset will return the cached objects rather
2835 than re-querying the database even if the cache attr is not set.
2837 The contents of the cache can also be populated by using the
2838 L</prefetch> attribute to L</search>.
2843 my ( $self, $data ) = @_;
2844 $self->throw_exception("set_cache requires an arrayref")
2845 if defined($data) && (ref $data ne 'ARRAY');
2846 $self->{all_cache} = $data;
2853 =item Arguments: none
2855 =item Return Value: undef
2859 Clears the cache for the resultset.
2864 shift->set_cache(undef);
2871 =item Arguments: none
2873 =item Return Value: true, if the resultset has been paginated
2881 return !!$self->{attrs}{page};
2888 =item Arguments: none
2890 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2898 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2901 =head2 related_resultset
2905 =item Arguments: $relationship_name
2907 =item Return Value: $resultset
2911 Returns a related resultset for the supplied relationship name.
2913 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2917 sub related_resultset {
2918 my ($self, $rel) = @_;
2920 $self->{related_resultsets} ||= {};
2921 return $self->{related_resultsets}{$rel} ||= do {
2922 my $rsrc = $self->result_source;
2923 my $rel_info = $rsrc->relationship_info($rel);
2925 $self->throw_exception(
2926 "search_related: result source '" . $rsrc->source_name .
2927 "' has no such relationship $rel")
2930 my $attrs = $self->_chain_relationship($rel);
2932 my $join_count = $attrs->{seen_join}{$rel};
2934 my $alias = $self->result_source->storage
2935 ->relname_to_table_alias($rel, $join_count);
2937 # since this is search_related, and we already slid the select window inwards
2938 # (the select/as attrs were deleted in the beginning), we need to flip all
2939 # left joins to inner, so we get the expected results
2940 # read the comment on top of the actual function to see what this does
2941 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2944 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2945 delete @{$attrs}{qw(result_class alias)};
2949 if (my $cache = $self->get_cache) {
2950 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2951 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2956 my $rel_source = $rsrc->related_source($rel);
2960 # The reason we do this now instead of passing the alias to the
2961 # search_rs below is that if you wrap/overload resultset on the
2962 # source you need to know what alias it's -going- to have for things
2963 # to work sanely (e.g. RestrictWithObject wants to be able to add
2964 # extra query restrictions, and these may need to be $alias.)
2966 my $rel_attrs = $rel_source->resultset_attributes;
2967 local $rel_attrs->{alias} = $alias;
2969 $rel_source->resultset
2973 where => $attrs->{where},
2976 $new->set_cache($new_cache) if $new_cache;
2981 =head2 current_source_alias
2985 =item Arguments: none
2987 =item Return Value: $source_alias
2991 Returns the current table alias for the result source this resultset is built
2992 on, that will be used in the SQL query. Usually it is C<me>.
2994 Currently the source alias that refers to the result set returned by a
2995 L</search>/L</find> family method depends on how you got to the resultset: it's
2996 C<me> by default, but eg. L</search_related> aliases it to the related result
2997 source name (and keeps C<me> referring to the original result set). The long
2998 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2999 (and make this method unnecessary).
3001 Thus it's currently necessary to use this method in predefined queries (see
3002 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3003 source alias of the current result set:
3005 # in a result set class
3007 my ($self, $user) = @_;
3009 my $me = $self->current_source_alias;
3011 return $self->search(
3012 "$me.modified" => $user->id,
3018 sub current_source_alias {
3021 return ($self->{attrs} || {})->{alias} || 'me';
3024 =head2 as_subselect_rs
3028 =item Arguments: none
3030 =item Return Value: $resultset
3034 Act as a barrier to SQL symbols. The resultset provided will be made into a
3035 "virtual view" by including it as a subquery within the from clause. From this
3036 point on, any joined tables are inaccessible to ->search on the resultset (as if
3037 it were simply where-filtered without joins). For example:
3039 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3041 # 'x' now pollutes the query namespace
3043 # So the following works as expected
3044 my $ok_rs = $rs->search({'x.other' => 1});
3046 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3047 # def) we look for one row with contradictory terms and join in another table
3048 # (aliased 'x_2') which we never use
3049 my $broken_rs = $rs->search({'x.name' => 'def'});
3051 my $rs2 = $rs->as_subselect_rs;
3053 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3054 my $not_joined_rs = $rs2->search({'x.other' => 1});
3056 # works as expected: finds a 'table' row related to two x rows (abc and def)
3057 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3059 Another example of when one might use this would be to select a subset of
3060 columns in a group by clause:
3062 my $rs = $schema->resultset('Bar')->search(undef, {
3063 group_by => [qw{ id foo_id baz_id }],
3064 })->as_subselect_rs->search(undef, {
3065 columns => [qw{ id foo_id }]
3068 In the above example normally columns would have to be equal to the group by,
3069 but because we isolated the group by into a subselect the above works.
3073 sub as_subselect_rs {
3076 my $attrs = $self->_resolved_attrs;
3078 my $fresh_rs = (ref $self)->new (
3079 $self->result_source
3082 # these pieces will be locked in the subquery
3083 delete $fresh_rs->{cond};
3084 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3086 return $fresh_rs->search( {}, {
3088 $attrs->{alias} => $self->as_query,
3089 -alias => $attrs->{alias},
3090 -source_handle => $self->result_source->handle,
3092 alias => $attrs->{alias},
3096 # This code is called by search_related, and makes sure there
3097 # is clear separation between the joins before, during, and
3098 # after the relationship. This information is needed later
3099 # in order to properly resolve prefetch aliases (any alias
3100 # with a relation_chain_depth less than the depth of the
3101 # current prefetch is not considered)
3103 # The increments happen twice per join. An even number means a
3104 # relationship specified via a search_related, whereas an odd
3105 # number indicates a join/prefetch added via attributes
3107 # Also this code will wrap the current resultset (the one we
3108 # chain to) in a subselect IFF it contains limiting attributes
3109 sub _chain_relationship {
3110 my ($self, $rel) = @_;
3111 my $source = $self->result_source;
3112 my $attrs = { %{$self->{attrs}||{}} };
3114 # we need to take the prefetch the attrs into account before we
3115 # ->_resolve_join as otherwise they get lost - captainL
3116 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3118 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3120 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3123 my @force_subq_attrs = qw/offset rows group_by having/;
3126 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3128 $self->_has_resolved_attr (@force_subq_attrs)
3130 # Nuke the prefetch (if any) before the new $rs attrs
3131 # are resolved (prefetch is useless - we are wrapping
3132 # a subquery anyway).
3133 my $rs_copy = $self->search;
3134 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3135 $rs_copy->{attrs}{join},
3136 delete $rs_copy->{attrs}{prefetch},
3140 -source_handle => $source->handle,
3141 -alias => $attrs->{alias},
3142 $attrs->{alias} => $rs_copy->as_query,
3144 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3145 $seen->{-relation_chain_depth} = 0;
3147 elsif ($attrs->{from}) { #shallow copy suffices
3148 $from = [ @{$attrs->{from}} ];
3152 -source_handle => $source->handle,
3153 -alias => $attrs->{alias},
3154 $attrs->{alias} => $source->from,
3158 my $jpath = ($seen->{-relation_chain_depth})
3159 ? $from->[-1][0]{-join_path}
3162 my @requested_joins = $source->_resolve_join(
3169 push @$from, @requested_joins;
3171 $seen->{-relation_chain_depth}++;
3173 # if $self already had a join/prefetch specified on it, the requested
3174 # $rel might very well be already included. What we do in this case
3175 # is effectively a no-op (except that we bump up the chain_depth on
3176 # the join in question so we could tell it *is* the search_related)
3179 # we consider the last one thus reverse
3180 for my $j (reverse @requested_joins) {
3181 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3182 if ($rel eq $last_j) {
3183 $j->[0]{-relation_chain_depth}++;
3189 unless ($already_joined) {
3190 push @$from, $source->_resolve_join(
3198 $seen->{-relation_chain_depth}++;
3200 return {%$attrs, from => $from, seen_join => $seen};
3203 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3204 sub _resolved_attrs_copy {
3206 return { %{$self->_resolved_attrs (@_)} };
3209 sub _resolved_attrs {
3211 return $self->{_attrs} if $self->{_attrs};
3213 my $attrs = { %{ $self->{attrs} || {} } };
3214 my $source = $self->result_source;
3215 my $alias = $attrs->{alias};
3217 # take care of any selector merging
3218 $self->_normalize_selection ($attrs);
3220 # disassemble columns
3223 ref $attrs->{columns} eq 'ARRAY' ? $attrs->{columns} : [ $attrs->{columns} || () ]
3225 if (ref $c eq 'HASH') {
3226 for my $as (keys %$c) {
3227 push @sel, $c->{$as};
3237 # when trying to weed off duplicates later do not go past this point -
3238 # everything added from here on is unbalanced "anyone's guess" stuff
3239 my $dedup_stop_idx = $#as;
3241 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3243 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3244 if $attrs->{select};
3246 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3248 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3251 # disqualify all $alias.col as-bits (collapser mandated)
3253 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3256 # de-duplicate the result (remove *identical* select/as pairs)
3257 # and also die on duplicate {as} pointing to different {select}s
3258 # not using a c-style for as the condition is prone to shrinkage
3261 while ($i <= $dedup_stop_idx) {
3262 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3267 elsif ($seen->{$as[$i]}++) {
3268 $self->throw_exception(
3269 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3277 $attrs->{select} = \@sel;
3278 $attrs->{as} = \@as;
3280 $attrs->{from} ||= [{
3281 -source_handle => $source->handle,
3282 -alias => $self->{attrs}{alias},
3283 $self->{attrs}{alias} => $source->from,
3286 if ( $attrs->{join} || $attrs->{prefetch} ) {
3288 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3289 if ref $attrs->{from} ne 'ARRAY';
3291 my $join = (delete $attrs->{join}) || {};
3293 if ( defined $attrs->{prefetch} ) {
3294 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3297 $attrs->{from} = # have to copy here to avoid corrupting the original
3299 @{ $attrs->{from} },
3300 $source->_resolve_join(
3303 { %{ $attrs->{seen_join} || {} } },
3304 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3305 ? $attrs->{from}[-1][0]{-join_path}
3312 if ( defined $attrs->{order_by} ) {
3313 $attrs->{order_by} = (
3314 ref( $attrs->{order_by} ) eq 'ARRAY'
3315 ? [ @{ $attrs->{order_by} } ]
3316 : [ $attrs->{order_by} || () ]
3320 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3321 $attrs->{group_by} = [ $attrs->{group_by} ];
3324 # generate the distinct induced group_by early, as prefetch will be carried via a
3325 # subquery (since a group_by is present)
3326 if (delete $attrs->{distinct}) {
3327 if ($attrs->{group_by}) {
3328 carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3331 # distinct affects only the main selection part, not what prefetch may
3332 # add below. However trailing is not yet a part of the selection as
3333 # prefetch must insert before it
3334 $attrs->{group_by} = $source->storage->_group_over_selection (
3336 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3342 $attrs->{collapse} ||= {};
3343 if ($attrs->{prefetch}) {
3344 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3346 my $prefetch_ordering = [];
3348 # this is a separate structure (we don't look in {from} directly)
3349 # as the resolver needs to shift things off the lists to work
3350 # properly (identical-prefetches on different branches)
3352 if (ref $attrs->{from} eq 'ARRAY') {
3354 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3356 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3357 next unless $j->[0]{-alias};
3358 next unless $j->[0]{-join_path};
3359 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3361 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3364 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3365 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3370 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3372 # we need to somehow mark which columns came from prefetch
3374 my $sel_end = $#{$attrs->{select}};
3375 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3378 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3379 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3381 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3382 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3386 push @sel, @{$attrs->{_trailing_select}}
3387 if $attrs->{_trailing_select};
3389 # if both page and offset are specified, produce a combined offset
3390 # even though it doesn't make much sense, this is what pre 081xx has
3392 if (my $page = delete $attrs->{page}) {
3394 ($attrs->{rows} * ($page - 1))
3396 ($attrs->{offset} || 0)
3400 return $self->{_attrs} = $attrs;
3404 my ($self, $attr) = @_;
3406 if (ref $attr eq 'HASH') {
3407 return $self->_rollout_hash($attr);
3408 } elsif (ref $attr eq 'ARRAY') {
3409 return $self->_rollout_array($attr);
3415 sub _rollout_array {
3416 my ($self, $attr) = @_;
3419 foreach my $element (@{$attr}) {
3420 if (ref $element eq 'HASH') {
3421 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3422 } elsif (ref $element eq 'ARRAY') {
3423 # XXX - should probably recurse here
3424 push( @rolled_array, @{$self->_rollout_array($element)} );
3426 push( @rolled_array, $element );
3429 return \@rolled_array;
3433 my ($self, $attr) = @_;
3436 foreach my $key (keys %{$attr}) {
3437 push( @rolled_array, { $key => $attr->{$key} } );
3439 return \@rolled_array;
3442 sub _calculate_score {
3443 my ($self, $a, $b) = @_;
3445 if (defined $a xor defined $b) {
3448 elsif (not defined $a) {
3452 if (ref $b eq 'HASH') {
3453 my ($b_key) = keys %{$b};
3454 if (ref $a eq 'HASH') {
3455 my ($a_key) = keys %{$a};
3456 if ($a_key eq $b_key) {
3457 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3462 return ($a eq $b_key) ? 1 : 0;
3465 if (ref $a eq 'HASH') {
3466 my ($a_key) = keys %{$a};
3467 return ($b eq $a_key) ? 1 : 0;
3469 return ($b eq $a) ? 1 : 0;
3474 sub _merge_joinpref_attr {
3475 my ($self, $orig, $import) = @_;
3477 return $import unless defined($orig);
3478 return $orig unless defined($import);
3480 $orig = $self->_rollout_attr($orig);
3481 $import = $self->_rollout_attr($import);
3484 foreach my $import_element ( @{$import} ) {
3485 # find best candidate from $orig to merge $b_element into
3486 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3487 foreach my $orig_element ( @{$orig} ) {
3488 my $score = $self->_calculate_score( $orig_element, $import_element );
3489 if ($score > $best_candidate->{score}) {
3490 $best_candidate->{position} = $position;
3491 $best_candidate->{score} = $score;
3495 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3497 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3498 push( @{$orig}, $import_element );
3500 my $orig_best = $orig->[$best_candidate->{position}];
3501 # merge orig_best and b_element together and replace original with merged
3502 if (ref $orig_best ne 'HASH') {
3503 $orig->[$best_candidate->{position}] = $import_element;
3504 } elsif (ref $import_element eq 'HASH') {
3505 my ($key) = keys %{$orig_best};
3506 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3509 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3520 my $hm = Hash::Merge->new;
3522 $hm->specify_behavior({
3525 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3527 if ($defl xor $defr) {
3528 return [ $defl ? $_[0] : $_[1] ];
3533 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3537 return [$_[0], $_[1]];
3541 return $_[1] if !defined $_[0];
3542 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3543 return [$_[0], @{$_[1]}]
3546 return [ $_[1] ] if !defined $_[0];
3547 return [ $_[0] ] if !keys %{$_[1]};
3548 return [$_[0], $_[1]]
3553 return $_[0] if !defined $_[1];
3554 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3555 return [@{$_[0]}, $_[1]]
3558 my @ret = @{$_[0]} or return $_[1];
3559 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3560 my %idx = map { $_ => 1 } @ret;
3561 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3565 return [ $_[1] ] if ! @{$_[0]};
3566 return $_[0] if !keys %{$_[1]};
3567 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3568 return [ @{$_[0]}, $_[1] ];
3573 return [ $_[0] ] if !defined $_[1];
3574 return [ $_[1] ] if !keys %{$_[0]};
3575 return [$_[0], $_[1]]
3578 return [ $_[0] ] if !@{$_[1]};
3579 return $_[1] if !keys %{$_[0]};
3580 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3581 return [ $_[0], @{$_[1]} ];
3584 return [ $_[0] ] if !keys %{$_[1]};
3585 return [ $_[1] ] if !keys %{$_[0]};
3586 return [ $_[0] ] if $_[0] eq $_[1];
3587 return [ $_[0], $_[1] ];
3590 } => 'DBIC_RS_ATTR_MERGER');
3594 return $hm->merge ($_[1], $_[2]);
3602 $self->_source_handle($_[0]->handle);
3604 $self->_source_handle->resolve;
3609 sub STORABLE_freeze {
3610 my ($self, $cloning) = @_;
3611 my $to_serialize = { %$self };
3613 # A cursor in progress can't be serialized (and would make little sense anyway)
3614 delete $to_serialize->{cursor};
3616 return nfreeze($to_serialize);
3619 # need this hook for symmetry
3621 my ($self, $cloning, $serialized) = @_;
3623 %$self = %{ thaw($serialized) };
3629 =head2 throw_exception
3631 See L<DBIx::Class::Schema/throw_exception> for details.
3635 sub throw_exception {
3638 if (ref $self && $self->_source_handle->schema) {
3639 $self->_source_handle->schema->throw_exception(@_)
3642 DBIx::Class::Exception->throw(@_);
3646 # XXX: FIXME: Attributes docs need clearing up
3650 Attributes are used to refine a ResultSet in various ways when
3651 searching for data. They can be passed to any method which takes an
3652 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3655 These are in no particular order:
3661 =item Value: ( $order_by | \@order_by | \%order_by )
3665 Which column(s) to order the results by.
3667 [The full list of suitable values is documented in
3668 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3671 If a single column name, or an arrayref of names is supplied, the
3672 argument is passed through directly to SQL. The hashref syntax allows
3673 for connection-agnostic specification of ordering direction:
3675 For descending order:
3677 order_by => { -desc => [qw/col1 col2 col3/] }
3679 For explicit ascending order:
3681 order_by => { -asc => 'col' }
3683 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3684 supported, although you are strongly encouraged to use the hashref
3685 syntax as outlined above.
3691 =item Value: \@columns
3695 Shortcut to request a particular set of columns to be retrieved. Each
3696 column spec may be a string (a table column name), or a hash (in which
3697 case the key is the C<as> value, and the value is used as the C<select>
3698 expression). Adds C<me.> onto the start of any column without a C<.> in
3699 it and sets C<select> from that, then auto-populates C<as> from
3700 C<select> as normal. (You may also use the C<cols> attribute, as in
3701 earlier versions of DBIC.)
3703 Essentially C<columns> does the same as L</select> and L</as>.
3705 columns => [ 'foo', { bar => 'baz' } ]
3709 select => [qw/foo baz/],
3716 =item Value: \@columns
3720 Indicates additional columns to be selected from storage. Works the same
3721 as L</columns> but adds columns to the selection. (You may also use the
3722 C<include_columns> attribute, as in earlier versions of DBIC). For
3725 $schema->resultset('CD')->search(undef, {
3726 '+columns' => ['artist.name'],
3730 would return all CDs and include a 'name' column to the information
3731 passed to object inflation. Note that the 'artist' is the name of the
3732 column (or relationship) accessor, and 'name' is the name of the column
3733 accessor in the related table.
3735 =head2 include_columns
3739 =item Value: \@columns
3743 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3749 =item Value: \@select_columns
3753 Indicates which columns should be selected from the storage. You can use
3754 column names, or in the case of RDBMS back ends, function or stored procedure
3757 $rs = $schema->resultset('Employee')->search(undef, {
3760 { count => 'employeeid' },
3761 { max => { length => 'name' }, -as => 'longest_name' }
3766 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3768 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3769 use L</select>, to instruct DBIx::Class how to store the result of the column.
3770 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3771 identifier aliasing. You can however alias a function, so you can use it in
3772 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3773 attribute> supplied as shown in the example above.
3779 Indicates additional columns to be selected from storage. Works the same as
3780 L</select> but adds columns to the default selection, instead of specifying
3789 Indicates additional column names for those added via L</+select>. See L</as>.
3797 =item Value: \@inflation_names
3801 Indicates column names for object inflation. That is L</as> indicates the
3802 slot name in which the column value will be stored within the
3803 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3804 identifier by the C<get_column> method (or via the object accessor B<if one
3805 with the same name already exists>) as shown below. The L</as> attribute has
3806 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3808 $rs = $schema->resultset('Employee')->search(undef, {
3811 { count => 'employeeid' },
3812 { max => { length => 'name' }, -as => 'longest_name' }
3821 If the object against which the search is performed already has an accessor
3822 matching a column name specified in C<as>, the value can be retrieved using
3823 the accessor as normal:
3825 my $name = $employee->name();
3827 If on the other hand an accessor does not exist in the object, you need to
3828 use C<get_column> instead:
3830 my $employee_count = $employee->get_column('employee_count');
3832 You can create your own accessors if required - see
3833 L<DBIx::Class::Manual::Cookbook> for details.
3839 =item Value: ($rel_name | \@rel_names | \%rel_names)
3843 Contains a list of relationships that should be joined for this query. For
3846 # Get CDs by Nine Inch Nails
3847 my $rs = $schema->resultset('CD')->search(
3848 { 'artist.name' => 'Nine Inch Nails' },
3849 { join => 'artist' }
3852 Can also contain a hash reference to refer to the other relation's relations.
3855 package MyApp::Schema::Track;
3856 use base qw/DBIx::Class/;
3857 __PACKAGE__->table('track');
3858 __PACKAGE__->add_columns(qw/trackid cd position title/);
3859 __PACKAGE__->set_primary_key('trackid');
3860 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3863 # In your application
3864 my $rs = $schema->resultset('Artist')->search(
3865 { 'track.title' => 'Teardrop' },
3867 join => { cd => 'track' },
3868 order_by => 'artist.name',
3872 You need to use the relationship (not the table) name in conditions,
3873 because they are aliased as such. The current table is aliased as "me", so
3874 you need to use me.column_name in order to avoid ambiguity. For example:
3876 # Get CDs from 1984 with a 'Foo' track
3877 my $rs = $schema->resultset('CD')->search(
3880 'tracks.name' => 'Foo'
3882 { join => 'tracks' }
3885 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3886 similarly for a third time). For e.g.
3888 my $rs = $schema->resultset('Artist')->search({
3889 'cds.title' => 'Down to Earth',
3890 'cds_2.title' => 'Popular',
3892 join => [ qw/cds cds/ ],
3895 will return a set of all artists that have both a cd with title 'Down
3896 to Earth' and a cd with title 'Popular'.
3898 If you want to fetch related objects from other tables as well, see C<prefetch>
3901 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3907 =item Value: ($rel_name | \@rel_names | \%rel_names)
3911 Contains one or more relationships that should be fetched along with
3912 the main query (when they are accessed afterwards the data will
3913 already be available, without extra queries to the database). This is
3914 useful for when you know you will need the related objects, because it
3915 saves at least one query:
3917 my $rs = $schema->resultset('Tag')->search(
3926 The initial search results in SQL like the following:
3928 SELECT tag.*, cd.*, artist.* FROM tag
3929 JOIN cd ON tag.cd = cd.cdid
3930 JOIN artist ON cd.artist = artist.artistid
3932 L<DBIx::Class> has no need to go back to the database when we access the
3933 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3936 Simple prefetches will be joined automatically, so there is no need
3937 for a C<join> attribute in the above search.
3939 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3940 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3941 with an accessor type of 'single' or 'filter'). A more complex example that
3942 prefetches an artists cds, the tracks on those cds, and the tags associated
3943 with that artist is given below (assuming many-to-many from artists to tags):
3945 my $rs = $schema->resultset('Artist')->search(
3949 { cds => 'tracks' },
3950 { artist_tags => 'tags' }
3956 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3957 attributes will be ignored.
3959 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3960 exactly as you might expect.
3966 Prefetch uses the L</cache> to populate the prefetched relationships. This
3967 may or may not be what you want.
3971 If you specify a condition on a prefetched relationship, ONLY those
3972 rows that match the prefetched condition will be fetched into that relationship.
3973 This means that adding prefetch to a search() B<may alter> what is returned by
3974 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3976 my $artist_rs = $schema->resultset('Artist')->search({
3982 my $count = $artist_rs->first->cds->count;
3984 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
3986 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
3988 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
3990 that cmp_ok() may or may not pass depending on the datasets involved. This
3991 behavior may or may not survive the 0.09 transition.
4003 Makes the resultset paged and specifies the page to retrieve. Effectively
4004 identical to creating a non-pages resultset and then calling ->page($page)
4007 If L<rows> attribute is not specified it defaults to 10 rows per page.
4009 When you have a paged resultset, L</count> will only return the number
4010 of rows in the page. To get the total, use the L</pager> and call
4011 C<total_entries> on it.
4021 Specifies the maximum number of rows for direct retrieval or the number of
4022 rows per page if the page attribute or method is used.
4028 =item Value: $offset
4032 Specifies the (zero-based) row number for the first row to be returned, or the
4033 of the first row of the first page if paging is used.
4039 =item Value: \@columns
4043 A arrayref of columns to group by. Can include columns of joined tables.
4045 group_by => [qw/ column1 column2 ... /]
4051 =item Value: $condition
4055 HAVING is a select statement attribute that is applied between GROUP BY and
4056 ORDER BY. It is applied to the after the grouping calculations have been
4059 having => { 'count_employee' => { '>=', 100 } }
4061 or with an in-place function in which case literal SQL is required:
4063 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4069 =item Value: (0 | 1)
4073 Set to 1 to group by all columns. If the resultset already has a group_by
4074 attribute, this setting is ignored and an appropriate warning is issued.
4080 Adds to the WHERE clause.
4082 # only return rows WHERE deleted IS NULL for all searches
4083 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4085 Can be overridden by passing C<< { where => undef } >> as an attribute
4092 Set to 1 to cache search results. This prevents extra SQL queries if you
4093 revisit rows in your ResultSet:
4095 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4097 while( my $artist = $resultset->next ) {
4101 $rs->first; # without cache, this would issue a query
4103 By default, searches are not cached.
4105 For more examples of using these attributes, see
4106 L<DBIx::Class::Manual::Cookbook>.
4112 =item Value: ( 'update' | 'shared' )
4116 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT