1 package DBIx::Class::ResultSet;
5 use base qw/DBIx::Class/;
7 use DBIx::Class::Exception;
8 use DBIx::Class::ResultSetColumn;
9 use Scalar::Util qw/blessed weaken/;
12 # not importing first() as it will clash with our own method
16 # De-duplication in _merge_attr() is disabled, but left in for reference
17 # (the merger is used for other things that ought not to be de-duped)
18 *__HM_DEDUP = sub () { 0 };
28 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
32 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
36 my $users_rs = $schema->resultset('User');
37 while( $user = $users_rs->next) {
38 print $user->username;
41 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
42 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
46 A ResultSet is an object which stores a set of conditions representing
47 a query. It is the backbone of DBIx::Class (i.e. the really
48 important/useful bit).
50 No SQL is executed on the database when a ResultSet is created, it
51 just stores all the conditions needed to create the query.
53 A basic ResultSet representing the data of an entire table is returned
54 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
55 L<Source|DBIx::Class::Manual::Glossary/Source> name.
57 my $users_rs = $schema->resultset('User');
59 A new ResultSet is returned from calling L</search> on an existing
60 ResultSet. The new one will contain all the conditions of the
61 original, plus any new conditions added in the C<search> call.
63 A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
64 can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
67 The query that the ResultSet represents is B<only> executed against
68 the database when these methods are called:
69 L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
71 If a resultset is used in a numeric context it returns the L</count>.
72 However, if it is used in a boolean context it is B<always> true. So if
73 you want to check if a resultset has any results, you must use C<if $rs
78 =head2 Chaining resultsets
80 Let's say you've got a query that needs to be run to return some data
81 to the user. But, you have an authorization system in place that
82 prevents certain users from seeing certain information. So, you want
83 to construct the basic query in one method, but add constraints to it in
88 my $request = $self->get_request; # Get a request object somehow.
89 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
91 my $cd_rs = $schema->resultset('CD')->search({
92 title => $request->param('title'),
93 year => $request->param('year'),
96 $cd_rs = $self->apply_security_policy( $cd_rs );
101 sub apply_security_policy {
110 =head3 Resolving conditions and attributes
112 When a resultset is chained from another resultset, conditions and
113 attributes with the same keys need resolving.
115 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
116 into the existing ones from the original resultset.
118 The L</where> and L</having> attributes, and any search conditions, are
119 merged with an SQL C<AND> to the existing condition from the original
122 All other attributes are overridden by any new ones supplied in the
125 =head2 Multiple queries
127 Since a resultset just defines a query, you can do all sorts of
128 things with it with the same object.
130 # Don't hit the DB yet.
131 my $cd_rs = $schema->resultset('CD')->search({
132 title => 'something',
136 # Each of these hits the DB individually.
137 my $count = $cd_rs->count;
138 my $most_recent = $cd_rs->get_column('date_released')->max();
139 my @records = $cd_rs->all;
141 And it's not just limited to SELECT statements.
147 $cd_rs->create({ artist => 'Fred' });
149 Which is the same as:
151 $schema->resultset('CD')->create({
152 title => 'something',
157 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
165 =item Arguments: $source, \%$attrs
167 =item Return Value: $rs
171 The resultset constructor. Takes a source object (usually a
172 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
173 L</ATTRIBUTES> below). Does not perform any queries -- these are
174 executed as needed by the other methods.
176 Generally you won't need to construct a resultset manually. You'll
177 automatically get one from e.g. a L</search> called in scalar context:
179 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
181 IMPORTANT: If called on an object, proxies to new_result instead so
183 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
185 will return a CD object, not a ResultSet.
191 return $class->new_result(@_) if ref $class;
193 my ($source, $attrs) = @_;
194 $source = $source->resolve
195 if $source->isa('DBIx::Class::ResultSourceHandle');
196 $attrs = { %{$attrs||{}} };
198 if ($attrs->{page}) {
199 $attrs->{rows} ||= 10;
202 $attrs->{alias} ||= 'me';
205 result_source => $source,
206 cond => $attrs->{where},
212 $attrs->{result_class} || $source->result_class
222 =item Arguments: $cond, \%attrs?
224 =item Return Value: $resultset (scalar context), @row_objs (list context)
228 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
229 my $new_rs = $cd_rs->search({ year => 2005 });
231 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
232 # year = 2005 OR year = 2004
234 If you need to pass in additional attributes but no additional condition,
235 call it as C<search(undef, \%attrs)>.
237 # "SELECT name, artistid FROM $artist_table"
238 my @all_artists = $schema->resultset('Artist')->search(undef, {
239 columns => [qw/name artistid/],
242 For a list of attributes that can be passed to C<search>, see
243 L</ATTRIBUTES>. For more examples of using this function, see
244 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
245 documentation for the first argument, see L<SQL::Abstract>.
247 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
251 Note that L</search> does not process/deflate any of the values passed in the
252 L<SQL::Abstract>-compatible search condition structure. This is unlike other
253 condition-bound methods L</new>, L</create> and L</find>. The user must ensure
254 manually that any value passed to this method will stringify to something the
255 RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
256 objects, for more info see:
257 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
263 my $rs = $self->search_rs( @_ );
268 elsif (defined wantarray) {
272 # we can be called by a relationship helper, which in
273 # turn may be called in void context due to some braindead
274 # overload or whatever else the user decided to be clever
275 # at this particular day. Thus limit the exception to
276 # external code calls only
277 $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
278 if (caller)[0] !~ /^\QDBIx::Class::/;
288 =item Arguments: $cond, \%attrs?
290 =item Return Value: $resultset
294 This method does the same exact thing as search() except it will
295 always return a resultset, even in list context.
302 # Special-case handling for (undef, undef).
303 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
309 if (ref $_[-1] eq 'HASH') {
310 # copy for _normalize_selection
311 $call_attrs = { %{ pop @_ } };
313 elsif (! defined $_[-1] ) {
314 pop @_; # search({}, undef)
318 # see if we can keep the cache (no $rs changes)
320 my %safe = (alias => 1, cache => 1);
321 if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
324 ref $_[0] eq 'HASH' && ! keys %{$_[0]}
326 ref $_[0] eq 'ARRAY' && ! @{$_[0]}
328 $cache = $self->get_cache;
331 my $rsrc = $self->result_source;
333 my $old_attrs = { %{$self->{attrs}} };
334 my $old_having = delete $old_attrs->{having};
335 my $old_where = delete $old_attrs->{where};
337 my $new_attrs = { %$old_attrs };
339 # take care of call attrs (only if anything is changing)
340 if (keys %$call_attrs) {
342 $self->throw_exception ('_trailing_select is not a public attribute - do not use it in search()')
343 if ( exists $call_attrs->{_trailing_select} or exists $call_attrs->{'+_trailing_select'} );
345 my @selector_attrs = qw/select as columns cols +select +as +columns include_columns _trailing_select +_trailing_select/;
347 # Normalize the selector list (operates on the passed-in attr structure)
348 # Need to do it on every chain instead of only once on _resolved_attrs, in
349 # order to separate 'as'-ed from blind 'select's
350 $self->_normalize_selection ($call_attrs);
352 # start with blind overwriting merge, exclude selector attrs
353 $new_attrs = { %{$old_attrs}, %{$call_attrs} };
354 delete @{$new_attrs}{@selector_attrs};
356 # reset the current selector list if new selectors are supplied
357 if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
358 delete @{$old_attrs}{@selector_attrs};
361 for (@selector_attrs) {
362 $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
363 if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
366 # older deprecated name, use only if {columns} is not there
367 if (my $c = delete $new_attrs->{cols}) {
368 if ($new_attrs->{columns}) {
369 carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
372 $new_attrs->{columns} = $c;
377 # join/prefetch use their own crazy merging heuristics
378 foreach my $key (qw/join prefetch/) {
379 $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
380 if exists $call_attrs->{$key};
383 # stack binds together
384 $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
388 # rip apart the rest of @_, parse a condition
391 if (ref $_[0] eq 'HASH') {
392 (keys %{$_[0]}) ? $_[0] : undef
398 $self->throw_exception('Odd number of arguments to search')
406 if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
407 carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
410 for ($old_where, $call_cond) {
412 $new_attrs->{where} = $self->_stack_cond (
413 $_, $new_attrs->{where}
418 if (defined $old_having) {
419 $new_attrs->{having} = $self->_stack_cond (
420 $old_having, $new_attrs->{having}
424 my $rs = (ref $self)->new($rsrc, $new_attrs);
426 $rs->set_cache($cache) if ($cache);
431 sub _normalize_selection {
432 my ($self, $attrs) = @_;
435 $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
436 if exists $attrs->{include_columns};
438 # Keep the X vs +X separation until _resolved_attrs time - this allows to
439 # delay the decision on whether to use a default select list ($rsrc->columns)
440 # allowing stuff like the remove_columns helper to work
442 # select/as +select/+as pairs need special handling - the amount of select/as
443 # elements in each pair does *not* have to be equal (think multicolumn
444 # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
445 # supplied at all) - try to infer the alias, either from the -as parameter
446 # of the selector spec, or use the parameter whole if it looks like a column
447 # name (ugly legacy heuristic). If all fails - leave the selector bare (which
448 # is ok as well), but transport it over a separate attribute to make sure it is
449 # the last thing in the select list, thus unable to throw off the corresponding
451 for my $pref ('', '+') {
453 my ($sel, $as) = map {
454 my $key = "${pref}${_}";
456 my $val = [ ref $attrs->{$key} eq 'ARRAY'
458 : $attrs->{$key} || ()
460 delete $attrs->{$key};
464 if (! @$as and ! @$sel ) {
467 elsif (@$as and ! @$sel) {
468 $self->throw_exception(
469 "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
473 # no as part supplied at all - try to deduce
474 # if any @$as has been supplied we assume the user knows what (s)he is doing
475 # and blindly keep stacking up pieces
476 my (@new_sel, @new_trailing);
478 if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
479 push @$as, $_->{-as};
482 # assume any plain no-space, no-parenthesis string to be a column spec
483 # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
484 elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
488 # if all else fails - shove the selection to the trailing stack and move on
490 push @new_trailing, $_;
495 $attrs->{"${pref}_trailing_select"} = $self->_merge_attr($attrs->{"${pref}_trailing_select"}, \@new_trailing)
498 elsif (@$as < @$sel) {
499 $self->throw_exception(
500 "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
504 # now see what the result for this pair looks like:
507 # if balanced - treat as a columns entry
508 $attrs->{"${pref}columns"} = $self->_merge_attr(
509 $attrs->{"${pref}columns"},
510 [ map { +{ $as->[$_] => $sel->[$_] } } ( 0 .. $#$as ) ]
514 # unbalanced - shove in select/as, not subject to deduplication in _resolved_attrs
515 $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
516 $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
523 my ($self, $left, $right) = @_;
524 if (defined $left xor defined $right) {
525 return defined $left ? $left : $right;
527 elsif (defined $left) {
528 return { -and => [ map
529 { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
537 =head2 search_literal
541 =item Arguments: $sql_fragment, @bind_values
543 =item Return Value: $resultset (scalar context), @row_objs (list context)
547 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
548 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
550 Pass a literal chunk of SQL to be added to the conditional part of the
553 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
554 only be used in that context. C<search_literal> is a convenience method.
555 It is equivalent to calling $schema->search(\[]), but if you want to ensure
556 columns are bound correctly, use C<search>.
558 Example of how to use C<search> instead of C<search_literal>
560 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
561 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
564 See L<DBIx::Class::Manual::Cookbook/Searching> and
565 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
566 require C<search_literal>.
571 my ($self, $sql, @bind) = @_;
573 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
576 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
583 =item Arguments: \%columns_values | @pk_values, \%attrs?
585 =item Return Value: $row_object | undef
589 Finds and returns a single row based on supplied criteria. Takes either a
590 hashref with the same format as L</create> (including inference of foreign
591 keys from related objects), or a list of primary key values in the same
592 order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
593 declaration on the L</result_source>.
595 In either case an attempt is made to combine conditions already existing on
596 the resultset with the condition passed to this method.
598 To aid with preparing the correct query for the storage you may supply the
599 C<key> attribute, which is the name of a
600 L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
601 unique constraint corresponding to the
602 L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
603 C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
604 to construct a query that satisfies the named unique constraint fully (
605 non-NULL values for each column member of the constraint) an exception is
608 If no C<key> is specified, the search is carried over all unique constraints
609 which are fully defined by the available condition.
611 If no such constraint is found, C<find> currently defaults to a simple
612 C<< search->(\%column_values) >> which may or may not do what you expect.
613 Note that this fallback behavior may be deprecated in further versions. If
614 you need to search with arbitrary conditions - use L</search>. If the query
615 resulting from this fallback produces more than one row, a warning to the
616 effect is issued, though only the first row is constructed and returned as
619 In addition to C<key>, L</find> recognizes and applies standard
620 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
622 Note that if you have extra concerns about the correctness of the resulting
623 query you need to specify the C<key> attribute and supply the entire condition
624 as an argument to find (since it is not always possible to perform the
625 combination of the resultset condition with the supplied one, especially if
626 the resultset condition contains literal sql).
628 For example, to find a row by its primary key:
630 my $cd = $schema->resultset('CD')->find(5);
632 You can also find a row by a specific unique constraint:
634 my $cd = $schema->resultset('CD')->find(
636 artist => 'Massive Attack',
637 title => 'Mezzanine',
639 { key => 'cd_artist_title' }
642 See also L</find_or_create> and L</update_or_create>.
648 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
650 my $rsrc = $self->result_source;
652 # Parse out the condition from input
654 if (ref $_[0] eq 'HASH') {
655 $call_cond = { %{$_[0]} };
658 my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
659 my @c_cols = $rsrc->unique_constraint_columns($constraint);
661 $self->throw_exception(
662 "No constraint columns, maybe a malformed '$constraint' constraint?"
665 $self->throw_exception (
666 'find() expects either a column/value hashref, or a list of values '
667 . "corresponding to the columns of the specified unique constraint '$constraint'"
668 ) unless @c_cols == @_;
671 @{$call_cond}{@c_cols} = @_;
675 for my $key (keys %$call_cond) {
677 my $keyref = ref($call_cond->{$key})
679 my $relinfo = $rsrc->relationship_info($key)
681 my $val = delete $call_cond->{$key};
683 next if $keyref eq 'ARRAY'; # has_many for multi_create
685 my $rel_q = $rsrc->_resolve_condition(
686 $relinfo->{cond}, $val, $key
688 die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
689 @related{keys %$rel_q} = values %$rel_q;
693 # relationship conditions take precedence (?)
694 @{$call_cond}{keys %related} = values %related;
696 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
698 if (exists $attrs->{key}) {
699 $final_cond = $self->_qualify_cond_columns (
701 $self->_build_unique_cond (
709 elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
710 # This means that we got here after a merger of relationship conditions
711 # in ::Relationship::Base::search_related (the row method), and furthermore
712 # the relationship is of the 'single' type. This means that the condition
713 # provided by the relationship (already attached to $self) is sufficient,
714 # as there can be only one row in the database that would satisfy the
718 # no key was specified - fall down to heuristics mode:
719 # run through all unique queries registered on the resultset, and
720 # 'OR' all qualifying queries together
721 my (@unique_queries, %seen_column_combinations);
722 for my $c_name ($rsrc->unique_constraint_names) {
723 next if $seen_column_combinations{
724 join "\x00", sort $rsrc->unique_constraint_columns($c_name)
727 push @unique_queries, try {
728 $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
732 $final_cond = @unique_queries
733 ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
734 : $self->_non_unique_find_fallback ($call_cond, $attrs)
738 # Run the query, passing the result_class since it should propagate for find
739 my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
740 if (keys %{$rs->_resolved_attrs->{collapse}}) {
742 carp "Query returned more than one row" if $rs->next;
750 # This is a stop-gap method as agreed during the discussion on find() cleanup:
751 # http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
753 # It is invoked when find() is called in legacy-mode with insufficiently-unique
754 # condition. It is provided for overrides until a saner way forward is devised
756 # *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
757 # the road. Please adjust your tests accordingly to catch this situation early
758 # DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
760 # The method will not be removed without an adequately complete replacement
761 # for strict-mode enforcement
762 sub _non_unique_find_fallback {
763 my ($self, $cond, $attrs) = @_;
765 return $self->_qualify_cond_columns(
767 exists $attrs->{alias}
769 : $self->{attrs}{alias}
774 sub _qualify_cond_columns {
775 my ($self, $cond, $alias) = @_;
777 my %aliased = %$cond;
778 for (keys %aliased) {
779 $aliased{"$alias.$_"} = delete $aliased{$_}
786 sub _build_unique_cond {
787 my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
789 my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
791 # combination may fail if $self->{cond} is non-trivial
792 my ($final_cond) = try {
793 $self->_merge_with_rscond ($extra_cond)
798 # trim out everything not in $columns
799 $final_cond = { map {
800 exists $final_cond->{$_}
801 ? ( $_ => $final_cond->{$_} )
805 if (my @missing = grep
806 { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
809 $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
811 join (', ', map { "'$_'" } @missing),
818 !$ENV{DBIC_NULLABLE_KEY_NOWARN}
820 my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
822 carp_unique ( sprintf (
823 "NULL/undef values supplied for requested unique constraint '%s' (NULL "
824 . 'values in column(s): %s). This is almost certainly not what you wanted, '
825 . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
827 join (', ', map { "'$_'" } @undefs),
834 =head2 search_related
838 =item Arguments: $rel, $cond, \%attrs?
840 =item Return Value: $new_resultset
844 $new_rs = $cd_rs->search_related('artist', {
848 Searches the specified relationship, optionally specifying a condition and
849 attributes for matching records. See L</ATTRIBUTES> for more information.
854 return shift->related_resultset(shift)->search(@_);
857 =head2 search_related_rs
859 This method works exactly the same as search_related, except that
860 it guarantees a resultset, even in list context.
864 sub search_related_rs {
865 return shift->related_resultset(shift)->search_rs(@_);
872 =item Arguments: none
874 =item Return Value: $cursor
878 Returns a storage-driven cursor to the given resultset. See
879 L<DBIx::Class::Cursor> for more information.
886 my $attrs = $self->_resolved_attrs_copy;
888 return $self->{cursor}
889 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
890 $attrs->{where},$attrs);
897 =item Arguments: $cond?
899 =item Return Value: $row_object | undef
903 my $cd = $schema->resultset('CD')->single({ year => 2001 });
905 Inflates the first result without creating a cursor if the resultset has
906 any records in it; if not returns C<undef>. Used by L</find> as a lean version
909 While this method can take an optional search condition (just like L</search>)
910 being a fast-code-path it does not recognize search attributes. If you need to
911 add extra joins or similar, call L</search> and then chain-call L</single> on the
912 L<DBIx::Class::ResultSet> returned.
918 As of 0.08100, this method enforces the assumption that the preceding
919 query returns only one row. If more than one row is returned, you will receive
922 Query returned more than one row
924 In this case, you should be using L</next> or L</find> instead, or if you really
925 know what you are doing, use the L</rows> attribute to explicitly limit the size
928 This method will also throw an exception if it is called on a resultset prefetching
929 has_many, as such a prefetch implies fetching multiple rows from the database in
930 order to assemble the resulting object.
937 my ($self, $where) = @_;
939 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
942 my $attrs = $self->_resolved_attrs_copy;
944 if (keys %{$attrs->{collapse}}) {
945 $self->throw_exception(
946 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
951 if (defined $attrs->{where}) {
954 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
955 $where, delete $attrs->{where} ]
958 $attrs->{where} = $where;
962 my @data = $self->result_source->storage->select_single(
963 $attrs->{from}, $attrs->{select},
964 $attrs->{where}, $attrs
967 return (@data ? ($self->_construct_object(@data))[0] : undef);
973 # Recursively collapse the query, accumulating values for each column.
975 sub _collapse_query {
976 my ($self, $query, $collapsed) = @_;
980 if (ref $query eq 'ARRAY') {
981 foreach my $subquery (@$query) {
982 next unless ref $subquery; # -or
983 $collapsed = $self->_collapse_query($subquery, $collapsed);
986 elsif (ref $query eq 'HASH') {
987 if (keys %$query and (keys %$query)[0] eq '-and') {
988 foreach my $subquery (@{$query->{-and}}) {
989 $collapsed = $self->_collapse_query($subquery, $collapsed);
993 foreach my $col (keys %$query) {
994 my $value = $query->{$col};
995 $collapsed->{$col}{$value}++;
1007 =item Arguments: $cond?
1009 =item Return Value: $resultsetcolumn
1013 my $max_length = $rs->get_column('length')->max;
1015 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
1020 my ($self, $column) = @_;
1021 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
1029 =item Arguments: $cond, \%attrs?
1031 =item Return Value: $resultset (scalar context), @row_objs (list context)
1035 # WHERE title LIKE '%blue%'
1036 $cd_rs = $rs->search_like({ title => '%blue%'});
1038 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
1039 that this is simply a convenience method retained for ex Class::DBI users.
1040 You most likely want to use L</search> with specific operators.
1042 For more information, see L<DBIx::Class::Manual::Cookbook>.
1044 This method is deprecated and will be removed in 0.09. Use L</search()>
1045 instead. An example conversion is:
1047 ->search_like({ foo => 'bar' });
1051 ->search({ foo => { like => 'bar' } });
1058 'search_like() is deprecated and will be removed in DBIC version 0.09.'
1059 .' Instead use ->search({ x => { -like => "y%" } })'
1060 .' (note the outer pair of {}s - they are important!)'
1062 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1063 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
1064 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
1065 return $class->search($query, { %$attrs });
1072 =item Arguments: $first, $last
1074 =item Return Value: $resultset (scalar context), @row_objs (list context)
1078 Returns a resultset or object list representing a subset of elements from the
1079 resultset slice is called on. Indexes are from 0, i.e., to get the first
1080 three records, call:
1082 my ($one, $two, $three) = $rs->slice(0, 2);
1087 my ($self, $min, $max) = @_;
1088 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
1089 $attrs->{offset} = $self->{attrs}{offset} || 0;
1090 $attrs->{offset} += $min;
1091 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
1092 return $self->search(undef, $attrs);
1093 #my $slice = (ref $self)->new($self->result_source, $attrs);
1094 #return (wantarray ? $slice->all : $slice);
1101 =item Arguments: none
1103 =item Return Value: $result | undef
1107 Returns the next element in the resultset (C<undef> is there is none).
1109 Can be used to efficiently iterate over records in the resultset:
1111 my $rs = $schema->resultset('CD')->search;
1112 while (my $cd = $rs->next) {
1116 Note that you need to store the resultset object, and call C<next> on it.
1117 Calling C<< resultset('Table')->next >> repeatedly will always return the
1118 first record from the resultset.
1124 if (my $cache = $self->get_cache) {
1125 $self->{all_cache_position} ||= 0;
1126 return $cache->[$self->{all_cache_position}++];
1128 if ($self->{attrs}{cache}) {
1129 delete $self->{pager};
1130 $self->{all_cache_position} = 1;
1131 return ($self->all)[0];
1133 if ($self->{stashed_objects}) {
1134 my $obj = shift(@{$self->{stashed_objects}});
1135 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
1139 exists $self->{stashed_row}
1140 ? @{delete $self->{stashed_row}}
1141 : $self->cursor->next
1143 return undef unless (@row);
1144 my ($row, @more) = $self->_construct_object(@row);
1145 $self->{stashed_objects} = \@more if @more;
1149 sub _construct_object {
1150 my ($self, @row) = @_;
1152 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
1154 my @new = $self->result_class->inflate_result($self->result_source, @$info);
1155 @new = $self->{_attrs}{record_filter}->(@new)
1156 if exists $self->{_attrs}{record_filter};
1160 sub _collapse_result {
1161 my ($self, $as_proto, $row) = @_;
1165 # 'foo' => [ undef, 'foo' ]
1166 # 'foo.bar' => [ 'foo', 'bar' ]
1167 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
1169 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
1171 my %collapse = %{$self->{_attrs}{collapse}||{}};
1175 # if we're doing collapsing (has_many prefetch) we need to grab records
1176 # until the PK changes, so fill @pri_index. if not, we leave it empty so
1177 # we know we don't have to bother.
1179 # the reason for not using the collapse stuff directly is because if you
1180 # had for e.g. two artists in a row with no cds, the collapse info for
1181 # both would be NULL (undef) so you'd lose the second artist
1183 # store just the index so we can check the array positions from the row
1184 # without having to contruct the full hash
1186 if (keys %collapse) {
1187 my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
1188 foreach my $i (0 .. $#construct_as) {
1189 next if defined($construct_as[$i][0]); # only self table
1190 if (delete $pri{$construct_as[$i][1]}) {
1191 push(@pri_index, $i);
1193 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1197 # no need to do an if, it'll be empty if @pri_index is empty anyway
1199 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1203 do { # no need to check anything at the front, we always want the first row
1207 foreach my $this_as (@construct_as) {
1208 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1211 push(@const_rows, \%const);
1213 } until ( # no pri_index => no collapse => drop straight out
1216 do { # get another row, stash it, drop out if different PK
1218 @copy = $self->cursor->next;
1219 $self->{stashed_row} = \@copy;
1221 # last thing in do block, counts as true if anything doesn't match
1223 # check xor defined first for NULL vs. NOT NULL then if one is
1224 # defined the other must be so check string equality
1227 (defined $pri_vals{$_} ^ defined $copy[$_])
1228 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1233 my $alias = $self->{attrs}{alias};
1240 foreach my $const (@const_rows) {
1241 scalar @const_keys or do {
1242 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1244 foreach my $key (@const_keys) {
1247 my @parts = split(/\./, $key);
1249 my $data = $const->{$key};
1250 foreach my $p (@parts) {
1251 $target = $target->[1]->{$p} ||= [];
1253 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1254 # collapsing at this point and on final part
1255 my $pos = $collapse_pos{$cur};
1256 CK: foreach my $ck (@ckey) {
1257 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1258 $collapse_pos{$cur} = $data;
1259 delete @collapse_pos{ # clear all positioning for sub-entries
1260 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1267 if (exists $collapse{$cur}) {
1268 $target = $target->[-1];
1271 $target->[0] = $data;
1273 $info->[0] = $const->{$key};
1281 =head2 result_source
1285 =item Arguments: $result_source?
1287 =item Return Value: $result_source
1291 An accessor for the primary ResultSource object from which this ResultSet
1298 =item Arguments: $result_class?
1300 =item Return Value: $result_class
1304 An accessor for the class to use when creating row objects. Defaults to
1305 C<< result_source->result_class >> - which in most cases is the name of the
1306 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1308 Note that changing the result_class will also remove any components
1309 that were originally loaded in the source class via
1310 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1311 in the original source class will not run.
1316 my ($self, $result_class) = @_;
1317 if ($result_class) {
1318 unless (ref $result_class) { # don't fire this for an object
1319 $self->ensure_class_loaded($result_class);
1321 $self->_result_class($result_class);
1322 # THIS LINE WOULD BE A BUG - this accessor specifically exists to
1323 # permit the user to set result class on one result set only; it only
1324 # chains if provided to search()
1325 #$self->{attrs}{result_class} = $result_class if ref $self;
1327 $self->_result_class;
1334 =item Arguments: $cond, \%attrs??
1336 =item Return Value: $count
1340 Performs an SQL C<COUNT> with the same query as the resultset was built
1341 with to find the number of elements. Passing arguments is equivalent to
1342 C<< $rs->search ($cond, \%attrs)->count >>
1348 return $self->search(@_)->count if @_ and defined $_[0];
1349 return scalar @{ $self->get_cache } if $self->get_cache;
1351 my $attrs = $self->_resolved_attrs_copy;
1353 # this is a little optimization - it is faster to do the limit
1354 # adjustments in software, instead of a subquery
1355 my $rows = delete $attrs->{rows};
1356 my $offset = delete $attrs->{offset};
1359 if ($self->_has_resolved_attr (qw/collapse group_by/)) {
1360 $crs = $self->_count_subq_rs ($attrs);
1363 $crs = $self->_count_rs ($attrs);
1365 my $count = $crs->next;
1367 $count -= $offset if $offset;
1368 $count = $rows if $rows and $rows < $count;
1369 $count = 0 if ($count < 0);
1378 =item Arguments: $cond, \%attrs??
1380 =item Return Value: $count_rs
1384 Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
1385 This can be very handy for subqueries:
1387 ->search( { amount => $some_rs->count_rs->as_query } )
1389 As with regular resultsets the SQL query will be executed only after
1390 the resultset is accessed via L</next> or L</all>. That would return
1391 the same single value obtainable via L</count>.
1397 return $self->search(@_)->count_rs if @_;
1399 # this may look like a lack of abstraction (count() does about the same)
1400 # but in fact an _rs *must* use a subquery for the limits, as the
1401 # software based limiting can not be ported if this $rs is to be used
1402 # in a subquery itself (i.e. ->as_query)
1403 if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
1404 return $self->_count_subq_rs;
1407 return $self->_count_rs;
1412 # returns a ResultSetColumn object tied to the count query
1415 my ($self, $attrs) = @_;
1417 my $rsrc = $self->result_source;
1418 $attrs ||= $self->_resolved_attrs;
1420 my $tmp_attrs = { %$attrs };
1421 # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
1422 delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
1424 # overwrite the selector (supplied by the storage)
1425 $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
1426 $tmp_attrs->{as} = 'count';
1427 delete @{$tmp_attrs}{qw/columns _trailing_select/};
1429 my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
1435 # same as above but uses a subquery
1437 sub _count_subq_rs {
1438 my ($self, $attrs) = @_;
1440 my $rsrc = $self->result_source;
1441 $attrs ||= $self->_resolved_attrs;
1443 my $sub_attrs = { %$attrs };
1444 # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
1445 delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range _trailing_select order_by for/};
1447 # if we multi-prefetch we group_by primary keys only as this is what we would
1448 # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
1449 if ( keys %{$attrs->{collapse}} ) {
1450 $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
1453 # Calculate subquery selector
1454 if (my $g = $sub_attrs->{group_by}) {
1456 my $sql_maker = $rsrc->storage->sql_maker;
1458 # necessary as the group_by may refer to aliased functions
1460 for my $sel (@{$attrs->{select}}) {
1461 $sel_index->{$sel->{-as}} = $sel
1462 if (ref $sel eq 'HASH' and $sel->{-as});
1465 # anything from the original select mentioned on the group-by needs to make it to the inner selector
1466 # also look for named aggregates referred in the having clause
1467 # having often contains scalarrefs - thus parse it out entirely
1469 if ($attrs->{having}) {
1470 local $sql_maker->{having_bind};
1471 local $sql_maker->{quote_char} = $sql_maker->{quote_char};
1472 local $sql_maker->{name_sep} = $sql_maker->{name_sep};
1473 unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
1474 $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
1475 # if we don't unset it we screw up retarded but unfortunately working
1476 # 'MAX(foo.bar)' => { '>', 3 }
1477 $sql_maker->{name_sep} = '';
1480 my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
1482 my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
1484 # search for both a proper quoted qualified string, for a naive unquoted scalarref
1485 # and if all fails for an utterly naive quoted scalar-with-function
1487 $rquote $sep $lquote (.+?) $rquote
1489 [\s,] \w+ \. (\w+) [\s,]
1491 [\s,] $lquote (.+?) $rquote [\s,]
1493 push @parts, ($1 || $2 || $3); # one of them matched if we got here
1498 my $colpiece = $sel_index->{$_} || $_;
1500 # unqualify join-based group_by's. Arcane but possible query
1501 # also horrible horrible hack to alias a column (not a func.)
1502 # (probably need to introduce SQLA syntax)
1503 if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
1506 $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
1508 push @{$sub_attrs->{select}}, $colpiece;
1512 my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
1513 $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
1516 return $rsrc->resultset_class
1517 ->new ($rsrc, $sub_attrs)
1519 ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
1520 ->get_column ('count');
1527 =head2 count_literal
1531 =item Arguments: $sql_fragment, @bind_values
1533 =item Return Value: $count
1537 Counts the results in a literal query. Equivalent to calling L</search_literal>
1538 with the passed arguments, then L</count>.
1542 sub count_literal { shift->search_literal(@_)->count; }
1548 =item Arguments: none
1550 =item Return Value: @objects
1554 Returns all elements in the resultset. Called implicitly if the resultset
1555 is returned in list context.
1562 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1565 return @{ $self->get_cache } if $self->get_cache;
1569 if (keys %{$self->_resolved_attrs->{collapse}}) {
1570 # Using $self->cursor->all is really just an optimisation.
1571 # If we're collapsing has_many prefetches it probably makes
1572 # very little difference, and this is cleaner than hacking
1573 # _construct_object to survive the approach
1574 $self->cursor->reset;
1575 my @row = $self->cursor->next;
1577 push(@obj, $self->_construct_object(@row));
1578 @row = (exists $self->{stashed_row}
1579 ? @{delete $self->{stashed_row}}
1580 : $self->cursor->next);
1583 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1586 $self->set_cache(\@obj) if $self->{attrs}{cache};
1595 =item Arguments: none
1597 =item Return Value: $self
1601 Resets the resultset's cursor, so you can iterate through the elements again.
1602 Implicitly resets the storage cursor, so a subsequent L</next> will trigger
1609 delete $self->{_attrs} if exists $self->{_attrs};
1610 $self->{all_cache_position} = 0;
1611 $self->cursor->reset;
1619 =item Arguments: none
1621 =item Return Value: $object | undef
1625 Resets the resultset and returns an object for the first result (or C<undef>
1626 if the resultset is empty).
1631 return $_[0]->reset->next;
1637 # Determines whether and what type of subquery is required for the $rs operation.
1638 # If grouping is necessary either supplies its own, or verifies the current one
1639 # After all is done delegates to the proper storage method.
1641 sub _rs_update_delete {
1642 my ($self, $op, $values) = @_;
1644 my $rsrc = $self->result_source;
1646 # if a condition exists we need to strip all table qualifiers
1647 # if this is not possible we'll force a subquery below
1648 my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
1650 my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
1651 my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/rows offset/);
1653 if ($needs_group_by_subq or $needs_subq) {
1655 # make a new $rs selecting only the PKs (that's all we really need)
1656 my $attrs = $self->_resolved_attrs_copy;
1659 delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
1660 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
1662 if ($needs_group_by_subq) {
1663 # make sure no group_by was supplied, or if there is one - make sure it matches
1664 # the columns compiled above perfectly. Anything else can not be sanely executed
1665 # on most databases so croak right then and there
1667 if (my $g = $attrs->{group_by}) {
1668 my @current_group_by = map
1669 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1674 join ("\x00", sort @current_group_by)
1676 join ("\x00", sort @{$attrs->{columns}} )
1678 $self->throw_exception (
1679 "You have just attempted a $op operation on a resultset which does group_by"
1680 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1681 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1682 . ' kind of queries. Please retry the operation with a modified group_by or'
1683 . ' without using one at all.'
1688 $attrs->{group_by} = $attrs->{columns};
1692 my $subrs = (ref $self)->new($rsrc, $attrs);
1693 return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
1696 return $rsrc->storage->$op(
1698 $op eq 'update' ? $values : (),
1708 =item Arguments: \%values
1710 =item Return Value: $storage_rv
1714 Sets the specified columns in the resultset to the supplied values in a
1715 single query. Note that this will not run any accessor/set_column/update
1716 triggers, nor will it update any row object instances derived from this
1717 resultset (this includes the contents of the L<resultset cache|/set_cache>
1718 if any). See L</update_all> if you need to execute any on-update
1719 triggers or cascades defined either by you or a
1720 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1722 The return value is a pass through of what the underlying
1723 storage backend returned, and may vary. See L<DBI/execute> for the most
1728 Note that L</update> does not process/deflate any of the values passed in.
1729 This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
1730 ensure manually that any value passed to this method will stringify to
1731 something the RDBMS knows how to deal with. A notable example is the
1732 handling of L<DateTime> objects, for more info see:
1733 L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
1738 my ($self, $values) = @_;
1739 $self->throw_exception('Values for update must be a hash')
1740 unless ref $values eq 'HASH';
1742 return $self->_rs_update_delete ('update', $values);
1749 =item Arguments: \%values
1751 =item Return Value: 1
1755 Fetches all objects and updates them one at a time via
1756 L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
1757 triggers, while L</update> will not.
1762 my ($self, $values) = @_;
1763 $self->throw_exception('Values for update_all must be a hash')
1764 unless ref $values eq 'HASH';
1766 my $guard = $self->result_source->schema->txn_scope_guard;
1767 $_->update($values) for $self->all;
1776 =item Arguments: none
1778 =item Return Value: $storage_rv
1782 Deletes the rows matching this resultset in a single query. Note that this
1783 will not run any delete triggers, nor will it alter the
1784 L<in_storage|DBIx::Class::Row/in_storage> status of any row object instances
1785 derived from this resultset (this includes the contents of the
1786 L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
1787 execute any on-delete triggers or cascades defined either by you or a
1788 L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
1790 The return value is a pass through of what the underlying storage backend
1791 returned, and may vary. See L<DBI/execute> for the most common case.
1797 $self->throw_exception('delete does not accept any arguments')
1800 return $self->_rs_update_delete ('delete');
1807 =item Arguments: none
1809 =item Return Value: 1
1813 Fetches all objects and deletes them one at a time via
1814 L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
1815 triggers, while L</delete> will not.
1821 $self->throw_exception('delete_all does not accept any arguments')
1824 my $guard = $self->result_source->schema->txn_scope_guard;
1825 $_->delete for $self->all;
1834 =item Arguments: \@data;
1838 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1839 For the arrayref of hashrefs style each hashref should be a structure suitable
1840 forsubmitting to a $resultset->create(...) method.
1842 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1843 to insert the data, as this is a faster method.
1845 Otherwise, each set of data is inserted into the database using
1846 L<DBIx::Class::ResultSet/create>, and the resulting objects are
1847 accumulated into an array. The array itself, or an array reference
1848 is returned depending on scalar or list context.
1850 Example: Assuming an Artist Class that has many CDs Classes relating:
1852 my $Artist_rs = $schema->resultset("Artist");
1854 ## Void Context Example
1855 $Artist_rs->populate([
1856 { artistid => 4, name => 'Manufactured Crap', cds => [
1857 { title => 'My First CD', year => 2006 },
1858 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1861 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1862 { title => 'My parents sold me to a record company', year => 2005 },
1863 { title => 'Why Am I So Ugly?', year => 2006 },
1864 { title => 'I Got Surgery and am now Popular', year => 2007 }
1869 ## Array Context Example
1870 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1871 { name => "Artist One"},
1872 { name => "Artist Two"},
1873 { name => "Artist Three", cds=> [
1874 { title => "First CD", year => 2007},
1875 { title => "Second CD", year => 2008},
1879 print $ArtistOne->name; ## response is 'Artist One'
1880 print $ArtistThree->cds->count ## reponse is '2'
1882 For the arrayref of arrayrefs style, the first element should be a list of the
1883 fieldsnames to which the remaining elements are rows being inserted. For
1886 $Arstist_rs->populate([
1887 [qw/artistid name/],
1888 [100, 'A Formally Unknown Singer'],
1889 [101, 'A singer that jumped the shark two albums ago'],
1890 [102, 'An actually cool singer'],
1893 Please note an important effect on your data when choosing between void and
1894 wantarray context. Since void context goes straight to C<insert_bulk> in
1895 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1896 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1897 create primary keys for you, you will find that your PKs are empty. In this
1898 case you will have to use the wantarray context in order to create those
1906 # cruft placed in standalone method
1907 my $data = $self->_normalize_populate_args(@_);
1909 if(defined wantarray) {
1911 foreach my $item (@$data) {
1912 push(@created, $self->create($item));
1914 return wantarray ? @created : \@created;
1917 my $first = $data->[0];
1919 # if a column is a registered relationship, and is a non-blessed hash/array, consider
1920 # it relationship data
1921 my (@rels, @columns);
1922 my $rsrc = $self->result_source;
1923 my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
1924 for (keys %$first) {
1925 my $ref = ref $first->{$_};
1926 $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
1932 my @pks = $rsrc->primary_columns;
1934 ## do the belongs_to relationships
1935 foreach my $index (0..$#$data) {
1937 # delegate to create() for any dataset without primary keys with specified relationships
1938 if (grep { !defined $data->[$index]->{$_} } @pks ) {
1940 if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
1941 my @ret = $self->populate($data);
1947 foreach my $rel (@rels) {
1948 next unless ref $data->[$index]->{$rel} eq "HASH";
1949 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1950 my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
1951 my $related = $result->result_source->_resolve_condition(
1952 $reverse_relinfo->{cond},
1957 delete $data->[$index]->{$rel};
1958 $data->[$index] = {%{$data->[$index]}, %$related};
1960 push @columns, keys %$related if $index == 0;
1964 ## inherit the data locked in the conditions of the resultset
1965 my ($rs_data) = $self->_merge_with_rscond({});
1966 delete @{$rs_data}{@columns};
1967 my @inherit_cols = keys %$rs_data;
1968 my @inherit_data = values %$rs_data;
1970 ## do bulk insert on current row
1971 $rsrc->storage->insert_bulk(
1973 [@columns, @inherit_cols],
1974 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1977 ## do the has_many relationships
1978 foreach my $item (@$data) {
1982 foreach my $rel (@rels) {
1983 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
1985 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
1987 my $child = $main_row->$rel;
1989 my $related = $child->result_source->_resolve_condition(
1990 $rels->{$rel}{cond},
1995 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1996 my @populate = map { {%$_, %$related} } @rows_to_add;
1998 $child->populate( \@populate );
2005 # populate() argumnets went over several incarnations
2006 # What we ultimately support is AoH
2007 sub _normalize_populate_args {
2008 my ($self, $arg) = @_;
2010 if (ref $arg eq 'ARRAY') {
2011 if (ref $arg->[0] eq 'HASH') {
2014 elsif (ref $arg->[0] eq 'ARRAY') {
2016 my @colnames = @{$arg->[0]};
2017 foreach my $values (@{$arg}[1 .. $#$arg]) {
2018 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2024 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2031 =item Arguments: none
2033 =item Return Value: $pager
2037 Return Value a L<Data::Page> object for the current resultset. Only makes
2038 sense for queries with a C<page> attribute.
2040 To get the full count of entries for a paged resultset, call
2041 C<total_entries> on the L<Data::Page> object.
2045 # make a wizard good for both a scalar and a hashref
2046 my $mk_lazy_count_wizard = sub {
2047 require Variable::Magic;
2049 my $stash = { total_rs => shift };
2050 my $slot = shift; # only used by the hashref magic
2052 my $magic = Variable::Magic::wizard (
2053 data => sub { $stash },
2059 # set value lazily, and dispell for good
2060 ${$_[0]} = $_[1]{total_rs}->count;
2061 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2065 # an explicit set implies dispell as well
2066 # the unless() is to work around "fun and giggles" below
2067 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2068 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2075 if ($_[2] eq $slot and !$_[1]{inactive}) {
2076 my $cnt = $_[1]{total_rs}->count;
2077 $_[0]->{$slot} = $cnt;
2079 # attempting to dispell in a fetch handle (works in store), seems
2080 # to invariable segfault on 5.10, 5.12, 5.13 :(
2081 # so use an inactivator instead
2082 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2088 if (! $_[1]{inactive} and $_[2] eq $slot) {
2089 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2091 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2098 $stash->{magic_selfref} = $magic;
2099 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2104 # the tie class for 5.8.1
2106 package # hide from pause
2107 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2108 use base qw/Tie::Hash/;
2110 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2111 sub NEXTKEY { each %{$_[0]{data}} }
2112 sub EXISTS { exists $_[0]{data}{$_[1]} }
2113 sub DELETE { delete $_[0]{data}{$_[1]} }
2114 sub CLEAR { %{$_[0]{data}} = () }
2115 sub SCALAR { scalar %{$_[0]{data}} }
2118 $_[1]{data} = {%{$_[1]{selfref}}};
2119 %{$_[1]{selfref}} = ();
2120 Scalar::Util::weaken ($_[1]{selfref});
2121 return bless ($_[1], $_[0]);
2125 if ($_[1] eq $_[0]{slot}) {
2126 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2127 untie %{$_[0]{selfref}};
2128 %{$_[0]{selfref}} = %{$_[0]{data}};
2137 $_[0]{data}{$_[1]} = $_[2];
2138 if ($_[1] eq $_[0]{slot}) {
2139 untie %{$_[0]{selfref}};
2140 %{$_[0]{selfref}} = %{$_[0]{data}};
2149 return $self->{pager} if $self->{pager};
2151 if ($self->get_cache) {
2152 $self->throw_exception ('Pagers on cached resultsets are not supported');
2155 my $attrs = $self->{attrs};
2156 if (!defined $attrs->{page}) {
2157 $self->throw_exception("Can't create pager for non-paged rs");
2159 elsif ($attrs->{page} <= 0) {
2160 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2162 $attrs->{rows} ||= 10;
2164 # throw away the paging flags and re-run the count (possibly
2165 # with a subselect) to get the real total count
2166 my $count_attrs = { %$attrs };
2167 delete $count_attrs->{$_} for qw/rows offset page pager/;
2168 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2171 ### the following may seem awkward and dirty, but it's a thought-experiment
2172 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2173 ### before talking to ribasushi/mst
2176 my $pager = Data::Page->new(
2177 0, #start with an empty set
2179 $self->{attrs}{page},
2182 my $data_slot = 'total_entries';
2184 # Since we are interested in a cached value (once it's set - it's set), every
2185 # technique will detach from the magic-host once the time comes to fire the
2186 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2188 if ($] < 5.008003) {
2189 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2190 # to weakref the magic container :(
2192 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2193 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2196 elsif ($] < 5.010) {
2197 # We can use magic on the hash value slot. It's interesting that the magic is
2198 # attached to the hash-slot, and does *not* stop working once I do the dummy
2199 # assignments after the cast()
2200 # tested on 5.8.3 and 5.8.9
2201 my $magic = $mk_lazy_count_wizard->($total_rs);
2202 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2204 # this is for fun and giggles
2205 $pager->{$data_slot} = -1;
2206 $pager->{$data_slot} = 0;
2208 # this does not work for scalars, but works with
2210 #my %vals = %$pager;
2215 # And the uvar magic
2216 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2217 # however see the wizard maker for more notes
2218 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2219 Variable::Magic::cast ( %$pager, $magic );
2222 $pager->{$data_slot} = -1;
2223 $pager->{$data_slot} = 0;
2231 return $self->{pager} = $pager;
2238 =item Arguments: $page_number
2240 =item Return Value: $rs
2244 Returns a resultset for the $page_number page of the resultset on which page
2245 is called, where each page contains a number of rows equal to the 'rows'
2246 attribute set on the resultset (10 by default).
2251 my ($self, $page) = @_;
2252 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2259 =item Arguments: \%vals
2261 =item Return Value: $rowobject
2265 Creates a new row object in the resultset's result class and returns
2266 it. The row is not inserted into the database at this point, call
2267 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2268 will tell you whether the row object has been inserted or not.
2270 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2275 my ($self, $values) = @_;
2276 $self->throw_exception( "new_result needs a hash" )
2277 unless (ref $values eq 'HASH');
2279 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2283 @$cols_from_relations
2284 ? (-cols_from_relations => $cols_from_relations)
2286 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2289 return $self->result_class->new(\%new);
2292 # _merge_with_rscond
2294 # Takes a simple hash of K/V data and returns its copy merged with the
2295 # condition already present on the resultset. Additionally returns an
2296 # arrayref of value/condition names, which were inferred from related
2297 # objects (this is needed for in-memory related objects)
2298 sub _merge_with_rscond {
2299 my ($self, $data) = @_;
2301 my (%new_data, @cols_from_relations);
2303 my $alias = $self->{attrs}{alias};
2305 if (! defined $self->{cond}) {
2306 # just massage $data below
2308 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2309 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2310 @cols_from_relations = keys %new_data;
2312 elsif (ref $self->{cond} ne 'HASH') {
2313 $self->throw_exception(
2314 "Can't abstract implicit construct, resultset condition not a hash"
2318 # precendence must be given to passed values over values inherited from
2319 # the cond, so the order here is important.
2320 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2321 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2323 while ( my($col, $value) = each %implied ) {
2324 my $vref = ref $value;
2325 if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
2326 $new_data{$col} = $value->{'='};
2328 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2329 $new_data{$col} = $value;
2336 %{ $self->_remove_alias($data, $alias) },
2339 return (\%new_data, \@cols_from_relations);
2342 # _has_resolved_attr
2344 # determines if the resultset defines at least one
2345 # of the attributes supplied
2347 # used to determine if a subquery is neccessary
2349 # supports some virtual attributes:
2351 # This will scan for any joins being present on the resultset.
2352 # It is not a mere key-search but a deep inspection of {from}
2355 sub _has_resolved_attr {
2356 my ($self, @attr_names) = @_;
2358 my $attrs = $self->_resolved_attrs;
2362 for my $n (@attr_names) {
2363 if (grep { $n eq $_ } (qw/-join/) ) {
2364 $extra_checks{$n}++;
2368 my $attr = $attrs->{$n};
2370 next if not defined $attr;
2372 if (ref $attr eq 'HASH') {
2373 return 1 if keys %$attr;
2375 elsif (ref $attr eq 'ARRAY') {
2383 # a resolved join is expressed as a multi-level from
2385 $extra_checks{-join}
2387 ref $attrs->{from} eq 'ARRAY'
2389 @{$attrs->{from}} > 1
2397 # Recursively collapse the condition.
2399 sub _collapse_cond {
2400 my ($self, $cond, $collapsed) = @_;
2404 if (ref $cond eq 'ARRAY') {
2405 foreach my $subcond (@$cond) {
2406 next unless ref $subcond; # -or
2407 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2410 elsif (ref $cond eq 'HASH') {
2411 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2412 foreach my $subcond (@{$cond->{-and}}) {
2413 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2417 foreach my $col (keys %$cond) {
2418 my $value = $cond->{$col};
2419 $collapsed->{$col} = $value;
2429 # Remove the specified alias from the specified query hash. A copy is made so
2430 # the original query is not modified.
2433 my ($self, $query, $alias) = @_;
2435 my %orig = %{ $query || {} };
2438 foreach my $key (keys %orig) {
2440 $unaliased{$key} = $orig{$key};
2443 $unaliased{$1} = $orig{$key}
2444 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2454 =item Arguments: none
2456 =item Return Value: \[ $sql, @bind ]
2460 Returns the SQL query and bind vars associated with the invocant.
2462 This is generally used as the RHS for a subquery.
2469 my $attrs = $self->_resolved_attrs_copy;
2474 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2475 # $sql also has no wrapping parenthesis in list ctx
2477 my $sqlbind = $self->result_source->storage
2478 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2487 =item Arguments: \%vals, \%attrs?
2489 =item Return Value: $rowobject
2493 my $artist = $schema->resultset('Artist')->find_or_new(
2494 { artist => 'fred' }, { key => 'artists' });
2496 $cd->cd_to_producer->find_or_new({ producer => $producer },
2497 { key => 'primary });
2499 Find an existing record from this resultset using L</find>. if none exists,
2500 instantiate a new result object and return it. The object will not be saved
2501 into your storage until you call L<DBIx::Class::Row/insert> on it.
2503 You most likely want this method when looking for existing rows using a unique
2504 constraint that is not the primary key, or looking for related rows.
2506 If you want objects to be saved immediately, use L</find_or_create> instead.
2508 B<Note>: Make sure to read the documentation of L</find> and understand the
2509 significance of the C<key> attribute, as its lack may skew your search, and
2510 subsequently result in spurious new objects.
2512 B<Note>: Take care when using C<find_or_new> with a table having
2513 columns with default values that you intend to be automatically
2514 supplied by the database (e.g. an auto_increment primary key column).
2515 In normal usage, the value of such columns should NOT be included at
2516 all in the call to C<find_or_new>, even when set to C<undef>.
2522 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2523 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2524 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2527 return $self->new_result($hash);
2534 =item Arguments: \%vals
2536 =item Return Value: a L<DBIx::Class::Row> $object
2540 Attempt to create a single new row or a row with multiple related rows
2541 in the table represented by the resultset (and related tables). This
2542 will not check for duplicate rows before inserting, use
2543 L</find_or_create> to do that.
2545 To create one row for this resultset, pass a hashref of key/value
2546 pairs representing the columns of the table and the values you wish to
2547 store. If the appropriate relationships are set up, foreign key fields
2548 can also be passed an object representing the foreign row, and the
2549 value will be set to its primary key.
2551 To create related objects, pass a hashref of related-object column values
2552 B<keyed on the relationship name>. If the relationship is of type C<multi>
2553 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2554 The process will correctly identify columns holding foreign keys, and will
2555 transparently populate them from the keys of the corresponding relation.
2556 This can be applied recursively, and will work correctly for a structure
2557 with an arbitrary depth and width, as long as the relationships actually
2558 exists and the correct column data has been supplied.
2561 Instead of hashrefs of plain related data (key/value pairs), you may
2562 also pass new or inserted objects. New objects (not inserted yet, see
2563 L</new>), will be inserted into their appropriate tables.
2565 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2567 Example of creating a new row.
2569 $person_rs->create({
2570 name=>"Some Person",
2571 email=>"somebody@someplace.com"
2574 Example of creating a new row and also creating rows in a related C<has_many>
2575 or C<has_one> resultset. Note Arrayref.
2578 { artistid => 4, name => 'Manufactured Crap', cds => [
2579 { title => 'My First CD', year => 2006 },
2580 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2585 Example of creating a new row and also creating a row in a related
2586 C<belongs_to> resultset. Note Hashref.
2589 title=>"Music for Silly Walks",
2592 name=>"Silly Musician",
2600 When subclassing ResultSet never attempt to override this method. Since
2601 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2602 lot of the internals simply never call it, so your override will be
2603 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2604 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2605 L</create> process you need to intervene.
2612 my ($self, $attrs) = @_;
2613 $self->throw_exception( "create needs a hashref" )
2614 unless ref $attrs eq 'HASH';
2615 return $self->new_result($attrs)->insert;
2618 =head2 find_or_create
2622 =item Arguments: \%vals, \%attrs?
2624 =item Return Value: $rowobject
2628 $cd->cd_to_producer->find_or_create({ producer => $producer },
2629 { key => 'primary' });
2631 Tries to find a record based on its primary key or unique constraints; if none
2632 is found, creates one and returns that instead.
2634 my $cd = $schema->resultset('CD')->find_or_create({
2636 artist => 'Massive Attack',
2637 title => 'Mezzanine',
2641 Also takes an optional C<key> attribute, to search by a specific key or unique
2642 constraint. For example:
2644 my $cd = $schema->resultset('CD')->find_or_create(
2646 artist => 'Massive Attack',
2647 title => 'Mezzanine',
2649 { key => 'cd_artist_title' }
2652 B<Note>: Make sure to read the documentation of L</find> and understand the
2653 significance of the C<key> attribute, as its lack may skew your search, and
2654 subsequently result in spurious row creation.
2656 B<Note>: Because find_or_create() reads from the database and then
2657 possibly inserts based on the result, this method is subject to a race
2658 condition. Another process could create a record in the table after
2659 the find has completed and before the create has started. To avoid
2660 this problem, use find_or_create() inside a transaction.
2662 B<Note>: Take care when using C<find_or_create> with a table having
2663 columns with default values that you intend to be automatically
2664 supplied by the database (e.g. an auto_increment primary key column).
2665 In normal usage, the value of such columns should NOT be included at
2666 all in the call to C<find_or_create>, even when set to C<undef>.
2668 See also L</find> and L</update_or_create>. For information on how to declare
2669 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2673 sub find_or_create {
2675 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2676 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2677 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2680 return $self->create($hash);
2683 =head2 update_or_create
2687 =item Arguments: \%col_values, { key => $unique_constraint }?
2689 =item Return Value: $row_object
2693 $resultset->update_or_create({ col => $val, ... });
2695 Like L</find_or_create>, but if a row is found it is immediately updated via
2696 C<< $found_row->update (\%col_values) >>.
2699 Takes an optional C<key> attribute to search on a specific unique constraint.
2702 # In your application
2703 my $cd = $schema->resultset('CD')->update_or_create(
2705 artist => 'Massive Attack',
2706 title => 'Mezzanine',
2709 { key => 'cd_artist_title' }
2712 $cd->cd_to_producer->update_or_create({
2713 producer => $producer,
2719 B<Note>: Make sure to read the documentation of L</find> and understand the
2720 significance of the C<key> attribute, as its lack may skew your search, and
2721 subsequently result in spurious row creation.
2723 B<Note>: Take care when using C<update_or_create> with a table having
2724 columns with default values that you intend to be automatically
2725 supplied by the database (e.g. an auto_increment primary key column).
2726 In normal usage, the value of such columns should NOT be included at
2727 all in the call to C<update_or_create>, even when set to C<undef>.
2729 See also L</find> and L</find_or_create>. For information on how to declare
2730 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2734 sub update_or_create {
2736 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2737 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2739 my $row = $self->find($cond, $attrs);
2741 $row->update($cond);
2745 return $self->create($cond);
2748 =head2 update_or_new
2752 =item Arguments: \%col_values, { key => $unique_constraint }?
2754 =item Return Value: $rowobject
2758 $resultset->update_or_new({ col => $val, ... });
2760 Like L</find_or_new> but if a row is found it is immediately updated via
2761 C<< $found_row->update (\%col_values) >>.
2765 # In your application
2766 my $cd = $schema->resultset('CD')->update_or_new(
2768 artist => 'Massive Attack',
2769 title => 'Mezzanine',
2772 { key => 'cd_artist_title' }
2775 if ($cd->in_storage) {
2776 # the cd was updated
2779 # the cd is not yet in the database, let's insert it
2783 B<Note>: Make sure to read the documentation of L</find> and understand the
2784 significance of the C<key> attribute, as its lack may skew your search, and
2785 subsequently result in spurious new objects.
2787 B<Note>: Take care when using C<update_or_new> with a table having
2788 columns with default values that you intend to be automatically
2789 supplied by the database (e.g. an auto_increment primary key column).
2790 In normal usage, the value of such columns should NOT be included at
2791 all in the call to C<update_or_new>, even when set to C<undef>.
2793 See also L</find>, L</find_or_create> and L</find_or_new>.
2799 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2800 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2802 my $row = $self->find( $cond, $attrs );
2803 if ( defined $row ) {
2804 $row->update($cond);
2808 return $self->new_result($cond);
2815 =item Arguments: none
2817 =item Return Value: \@cache_objects | undef
2821 Gets the contents of the cache for the resultset, if the cache is set.
2823 The cache is populated either by using the L</prefetch> attribute to
2824 L</search> or by calling L</set_cache>.
2836 =item Arguments: \@cache_objects
2838 =item Return Value: \@cache_objects
2842 Sets the contents of the cache for the resultset. Expects an arrayref
2843 of objects of the same class as those produced by the resultset. Note that
2844 if the cache is set the resultset will return the cached objects rather
2845 than re-querying the database even if the cache attr is not set.
2847 The contents of the cache can also be populated by using the
2848 L</prefetch> attribute to L</search>.
2853 my ( $self, $data ) = @_;
2854 $self->throw_exception("set_cache requires an arrayref")
2855 if defined($data) && (ref $data ne 'ARRAY');
2856 $self->{all_cache} = $data;
2863 =item Arguments: none
2865 =item Return Value: undef
2869 Clears the cache for the resultset.
2874 shift->set_cache(undef);
2881 =item Arguments: none
2883 =item Return Value: true, if the resultset has been paginated
2891 return !!$self->{attrs}{page};
2898 =item Arguments: none
2900 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2908 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2911 =head2 related_resultset
2915 =item Arguments: $relationship_name
2917 =item Return Value: $resultset
2921 Returns a related resultset for the supplied relationship name.
2923 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2927 sub related_resultset {
2928 my ($self, $rel) = @_;
2930 $self->{related_resultsets} ||= {};
2931 return $self->{related_resultsets}{$rel} ||= do {
2932 my $rsrc = $self->result_source;
2933 my $rel_info = $rsrc->relationship_info($rel);
2935 $self->throw_exception(
2936 "search_related: result source '" . $rsrc->source_name .
2937 "' has no such relationship $rel")
2940 my $attrs = $self->_chain_relationship($rel);
2942 my $join_count = $attrs->{seen_join}{$rel};
2944 my $alias = $self->result_source->storage
2945 ->relname_to_table_alias($rel, $join_count);
2947 # since this is search_related, and we already slid the select window inwards
2948 # (the select/as attrs were deleted in the beginning), we need to flip all
2949 # left joins to inner, so we get the expected results
2950 # read the comment on top of the actual function to see what this does
2951 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2954 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2955 delete @{$attrs}{qw(result_class alias)};
2959 if (my $cache = $self->get_cache) {
2960 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2961 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2966 my $rel_source = $rsrc->related_source($rel);
2970 # The reason we do this now instead of passing the alias to the
2971 # search_rs below is that if you wrap/overload resultset on the
2972 # source you need to know what alias it's -going- to have for things
2973 # to work sanely (e.g. RestrictWithObject wants to be able to add
2974 # extra query restrictions, and these may need to be $alias.)
2976 my $rel_attrs = $rel_source->resultset_attributes;
2977 local $rel_attrs->{alias} = $alias;
2979 $rel_source->resultset
2983 where => $attrs->{where},
2986 $new->set_cache($new_cache) if $new_cache;
2991 =head2 current_source_alias
2995 =item Arguments: none
2997 =item Return Value: $source_alias
3001 Returns the current table alias for the result source this resultset is built
3002 on, that will be used in the SQL query. Usually it is C<me>.
3004 Currently the source alias that refers to the result set returned by a
3005 L</search>/L</find> family method depends on how you got to the resultset: it's
3006 C<me> by default, but eg. L</search_related> aliases it to the related result
3007 source name (and keeps C<me> referring to the original result set). The long
3008 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3009 (and make this method unnecessary).
3011 Thus it's currently necessary to use this method in predefined queries (see
3012 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3013 source alias of the current result set:
3015 # in a result set class
3017 my ($self, $user) = @_;
3019 my $me = $self->current_source_alias;
3021 return $self->search(
3022 "$me.modified" => $user->id,
3028 sub current_source_alias {
3031 return ($self->{attrs} || {})->{alias} || 'me';
3034 =head2 as_subselect_rs
3038 =item Arguments: none
3040 =item Return Value: $resultset
3044 Act as a barrier to SQL symbols. The resultset provided will be made into a
3045 "virtual view" by including it as a subquery within the from clause. From this
3046 point on, any joined tables are inaccessible to ->search on the resultset (as if
3047 it were simply where-filtered without joins). For example:
3049 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3051 # 'x' now pollutes the query namespace
3053 # So the following works as expected
3054 my $ok_rs = $rs->search({'x.other' => 1});
3056 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3057 # def) we look for one row with contradictory terms and join in another table
3058 # (aliased 'x_2') which we never use
3059 my $broken_rs = $rs->search({'x.name' => 'def'});
3061 my $rs2 = $rs->as_subselect_rs;
3063 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3064 my $not_joined_rs = $rs2->search({'x.other' => 1});
3066 # works as expected: finds a 'table' row related to two x rows (abc and def)
3067 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3069 Another example of when one might use this would be to select a subset of
3070 columns in a group by clause:
3072 my $rs = $schema->resultset('Bar')->search(undef, {
3073 group_by => [qw{ id foo_id baz_id }],
3074 })->as_subselect_rs->search(undef, {
3075 columns => [qw{ id foo_id }]
3078 In the above example normally columns would have to be equal to the group by,
3079 but because we isolated the group by into a subselect the above works.
3083 sub as_subselect_rs {
3086 my $attrs = $self->_resolved_attrs;
3088 my $fresh_rs = (ref $self)->new (
3089 $self->result_source
3092 # these pieces will be locked in the subquery
3093 delete $fresh_rs->{cond};
3094 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3096 return $fresh_rs->search( {}, {
3098 $attrs->{alias} => $self->as_query,
3099 -alias => $attrs->{alias},
3100 -rsrc => $self->result_source,
3102 alias => $attrs->{alias},
3106 # This code is called by search_related, and makes sure there
3107 # is clear separation between the joins before, during, and
3108 # after the relationship. This information is needed later
3109 # in order to properly resolve prefetch aliases (any alias
3110 # with a relation_chain_depth less than the depth of the
3111 # current prefetch is not considered)
3113 # The increments happen twice per join. An even number means a
3114 # relationship specified via a search_related, whereas an odd
3115 # number indicates a join/prefetch added via attributes
3117 # Also this code will wrap the current resultset (the one we
3118 # chain to) in a subselect IFF it contains limiting attributes
3119 sub _chain_relationship {
3120 my ($self, $rel) = @_;
3121 my $source = $self->result_source;
3122 my $attrs = { %{$self->{attrs}||{}} };
3124 # we need to take the prefetch the attrs into account before we
3125 # ->_resolve_join as otherwise they get lost - captainL
3126 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3128 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3130 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3133 my @force_subq_attrs = qw/offset rows group_by having/;
3136 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3138 $self->_has_resolved_attr (@force_subq_attrs)
3140 # Nuke the prefetch (if any) before the new $rs attrs
3141 # are resolved (prefetch is useless - we are wrapping
3142 # a subquery anyway).
3143 my $rs_copy = $self->search;
3144 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3145 $rs_copy->{attrs}{join},
3146 delete $rs_copy->{attrs}{prefetch},
3151 -alias => $attrs->{alias},
3152 $attrs->{alias} => $rs_copy->as_query,
3154 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3155 $seen->{-relation_chain_depth} = 0;
3157 elsif ($attrs->{from}) { #shallow copy suffices
3158 $from = [ @{$attrs->{from}} ];
3163 -alias => $attrs->{alias},
3164 $attrs->{alias} => $source->from,
3168 my $jpath = ($seen->{-relation_chain_depth})
3169 ? $from->[-1][0]{-join_path}
3172 my @requested_joins = $source->_resolve_join(
3179 push @$from, @requested_joins;
3181 $seen->{-relation_chain_depth}++;
3183 # if $self already had a join/prefetch specified on it, the requested
3184 # $rel might very well be already included. What we do in this case
3185 # is effectively a no-op (except that we bump up the chain_depth on
3186 # the join in question so we could tell it *is* the search_related)
3189 # we consider the last one thus reverse
3190 for my $j (reverse @requested_joins) {
3191 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3192 if ($rel eq $last_j) {
3193 $j->[0]{-relation_chain_depth}++;
3199 unless ($already_joined) {
3200 push @$from, $source->_resolve_join(
3208 $seen->{-relation_chain_depth}++;
3210 return {%$attrs, from => $from, seen_join => $seen};
3213 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3214 sub _resolved_attrs_copy {
3216 return { %{$self->_resolved_attrs (@_)} };
3219 sub _resolved_attrs {
3221 return $self->{_attrs} if $self->{_attrs};
3223 my $attrs = { %{ $self->{attrs} || {} } };
3224 my $source = $self->result_source;
3225 my $alias = $attrs->{alias};
3227 # one last pass of normalization
3228 $self->_normalize_selection($attrs);
3230 # default selection list
3231 $attrs->{columns} = [ $source->columns ]
3232 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3234 # merge selectors together
3235 for (qw/columns select as _trailing_select/) {
3236 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3237 if $attrs->{$_} or $attrs->{"+$_"};
3240 # disassemble columns
3242 if (my $cols = delete $attrs->{columns}) {
3243 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3244 if (ref $c eq 'HASH') {
3245 for my $as (keys %$c) {
3246 push @sel, $c->{$as};
3257 # when trying to weed off duplicates later do not go past this point -
3258 # everything added from here on is unbalanced "anyone's guess" stuff
3259 my $dedup_stop_idx = $#as;
3261 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3263 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3264 if $attrs->{select};
3266 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3268 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3271 # disqualify all $alias.col as-bits (collapser mandated)
3273 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3276 # de-duplicate the result (remove *identical* select/as pairs)
3277 # and also die on duplicate {as} pointing to different {select}s
3278 # not using a c-style for as the condition is prone to shrinkage
3281 while ($i <= $dedup_stop_idx) {
3282 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3287 elsif ($seen->{$as[$i]}++) {
3288 $self->throw_exception(
3289 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3297 $attrs->{select} = \@sel;
3298 $attrs->{as} = \@as;
3300 $attrs->{from} ||= [{
3302 -alias => $self->{attrs}{alias},
3303 $self->{attrs}{alias} => $source->from,
3306 if ( $attrs->{join} || $attrs->{prefetch} ) {
3308 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3309 if ref $attrs->{from} ne 'ARRAY';
3311 my $join = (delete $attrs->{join}) || {};
3313 if ( defined $attrs->{prefetch} ) {
3314 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3317 $attrs->{from} = # have to copy here to avoid corrupting the original
3319 @{ $attrs->{from} },
3320 $source->_resolve_join(
3323 { %{ $attrs->{seen_join} || {} } },
3324 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3325 ? $attrs->{from}[-1][0]{-join_path}
3332 if ( defined $attrs->{order_by} ) {
3333 $attrs->{order_by} = (
3334 ref( $attrs->{order_by} ) eq 'ARRAY'
3335 ? [ @{ $attrs->{order_by} } ]
3336 : [ $attrs->{order_by} || () ]
3340 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3341 $attrs->{group_by} = [ $attrs->{group_by} ];
3344 # generate the distinct induced group_by early, as prefetch will be carried via a
3345 # subquery (since a group_by is present)
3346 if (delete $attrs->{distinct}) {
3347 if ($attrs->{group_by}) {
3348 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3351 # distinct affects only the main selection part, not what prefetch may
3352 # add below. However trailing is not yet a part of the selection as
3353 # prefetch must insert before it
3354 $attrs->{group_by} = $source->storage->_group_over_selection (
3356 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3362 $attrs->{collapse} ||= {};
3363 if ($attrs->{prefetch}) {
3364 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3366 my $prefetch_ordering = [];
3368 # this is a separate structure (we don't look in {from} directly)
3369 # as the resolver needs to shift things off the lists to work
3370 # properly (identical-prefetches on different branches)
3372 if (ref $attrs->{from} eq 'ARRAY') {
3374 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3376 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3377 next unless $j->[0]{-alias};
3378 next unless $j->[0]{-join_path};
3379 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3381 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3384 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3385 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3390 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3392 # we need to somehow mark which columns came from prefetch
3394 my $sel_end = $#{$attrs->{select}};
3395 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3398 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3399 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3401 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3402 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3406 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3407 if $attrs->{_trailing_select};
3409 # if both page and offset are specified, produce a combined offset
3410 # even though it doesn't make much sense, this is what pre 081xx has
3412 if (my $page = delete $attrs->{page}) {
3414 ($attrs->{rows} * ($page - 1))
3416 ($attrs->{offset} || 0)
3420 return $self->{_attrs} = $attrs;
3424 my ($self, $attr) = @_;
3426 if (ref $attr eq 'HASH') {
3427 return $self->_rollout_hash($attr);
3428 } elsif (ref $attr eq 'ARRAY') {
3429 return $self->_rollout_array($attr);
3435 sub _rollout_array {
3436 my ($self, $attr) = @_;
3439 foreach my $element (@{$attr}) {
3440 if (ref $element eq 'HASH') {
3441 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3442 } elsif (ref $element eq 'ARRAY') {
3443 # XXX - should probably recurse here
3444 push( @rolled_array, @{$self->_rollout_array($element)} );
3446 push( @rolled_array, $element );
3449 return \@rolled_array;
3453 my ($self, $attr) = @_;
3456 foreach my $key (keys %{$attr}) {
3457 push( @rolled_array, { $key => $attr->{$key} } );
3459 return \@rolled_array;
3462 sub _calculate_score {
3463 my ($self, $a, $b) = @_;
3465 if (defined $a xor defined $b) {
3468 elsif (not defined $a) {
3472 if (ref $b eq 'HASH') {
3473 my ($b_key) = keys %{$b};
3474 if (ref $a eq 'HASH') {
3475 my ($a_key) = keys %{$a};
3476 if ($a_key eq $b_key) {
3477 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3482 return ($a eq $b_key) ? 1 : 0;
3485 if (ref $a eq 'HASH') {
3486 my ($a_key) = keys %{$a};
3487 return ($b eq $a_key) ? 1 : 0;
3489 return ($b eq $a) ? 1 : 0;
3494 sub _merge_joinpref_attr {
3495 my ($self, $orig, $import) = @_;
3497 return $import unless defined($orig);
3498 return $orig unless defined($import);
3500 $orig = $self->_rollout_attr($orig);
3501 $import = $self->_rollout_attr($import);
3504 foreach my $import_element ( @{$import} ) {
3505 # find best candidate from $orig to merge $b_element into
3506 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3507 foreach my $orig_element ( @{$orig} ) {
3508 my $score = $self->_calculate_score( $orig_element, $import_element );
3509 if ($score > $best_candidate->{score}) {
3510 $best_candidate->{position} = $position;
3511 $best_candidate->{score} = $score;
3515 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3517 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3518 push( @{$orig}, $import_element );
3520 my $orig_best = $orig->[$best_candidate->{position}];
3521 # merge orig_best and b_element together and replace original with merged
3522 if (ref $orig_best ne 'HASH') {
3523 $orig->[$best_candidate->{position}] = $import_element;
3524 } elsif (ref $import_element eq 'HASH') {
3525 my ($key) = keys %{$orig_best};
3526 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3529 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3540 require Hash::Merge;
3541 my $hm = Hash::Merge->new;
3543 $hm->specify_behavior({
3546 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3548 if ($defl xor $defr) {
3549 return [ $defl ? $_[0] : $_[1] ];
3554 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3558 return [$_[0], $_[1]];
3562 return $_[1] if !defined $_[0];
3563 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3564 return [$_[0], @{$_[1]}]
3567 return [] if !defined $_[0] and !keys %{$_[1]};
3568 return [ $_[1] ] if !defined $_[0];
3569 return [ $_[0] ] if !keys %{$_[1]};
3570 return [$_[0], $_[1]]
3575 return $_[0] if !defined $_[1];
3576 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3577 return [@{$_[0]}, $_[1]]
3580 my @ret = @{$_[0]} or return $_[1];
3581 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3582 my %idx = map { $_ => 1 } @ret;
3583 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3587 return [ $_[1] ] if ! @{$_[0]};
3588 return $_[0] if !keys %{$_[1]};
3589 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3590 return [ @{$_[0]}, $_[1] ];
3595 return [] if !keys %{$_[0]} and !defined $_[1];
3596 return [ $_[0] ] if !defined $_[1];
3597 return [ $_[1] ] if !keys %{$_[0]};
3598 return [$_[0], $_[1]]
3601 return [] if !keys %{$_[0]} and !@{$_[1]};
3602 return [ $_[0] ] if !@{$_[1]};
3603 return $_[1] if !keys %{$_[0]};
3604 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3605 return [ $_[0], @{$_[1]} ];
3608 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3609 return [ $_[0] ] if !keys %{$_[1]};
3610 return [ $_[1] ] if !keys %{$_[0]};
3611 return [ $_[0] ] if $_[0] eq $_[1];
3612 return [ $_[0], $_[1] ];
3615 } => 'DBIC_RS_ATTR_MERGER');
3619 return $hm->merge ($_[1], $_[2]);
3623 sub STORABLE_freeze {
3624 my ($self, $cloning) = @_;
3625 my $to_serialize = { %$self };
3627 # A cursor in progress can't be serialized (and would make little sense anyway)
3628 delete $to_serialize->{cursor};
3630 Storable::nfreeze($to_serialize);
3633 # need this hook for symmetry
3635 my ($self, $cloning, $serialized) = @_;
3637 %$self = %{ Storable::thaw($serialized) };
3643 =head2 throw_exception
3645 See L<DBIx::Class::Schema/throw_exception> for details.
3649 sub throw_exception {
3652 if (ref $self and my $rsrc = $self->result_source) {
3653 $rsrc->throw_exception(@_)
3656 DBIx::Class::Exception->throw(@_);
3660 # XXX: FIXME: Attributes docs need clearing up
3664 Attributes are used to refine a ResultSet in various ways when
3665 searching for data. They can be passed to any method which takes an
3666 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3669 These are in no particular order:
3675 =item Value: ( $order_by | \@order_by | \%order_by )
3679 Which column(s) to order the results by.
3681 [The full list of suitable values is documented in
3682 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3685 If a single column name, or an arrayref of names is supplied, the
3686 argument is passed through directly to SQL. The hashref syntax allows
3687 for connection-agnostic specification of ordering direction:
3689 For descending order:
3691 order_by => { -desc => [qw/col1 col2 col3/] }
3693 For explicit ascending order:
3695 order_by => { -asc => 'col' }
3697 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3698 supported, although you are strongly encouraged to use the hashref
3699 syntax as outlined above.
3705 =item Value: \@columns
3709 Shortcut to request a particular set of columns to be retrieved. Each
3710 column spec may be a string (a table column name), or a hash (in which
3711 case the key is the C<as> value, and the value is used as the C<select>
3712 expression). Adds C<me.> onto the start of any column without a C<.> in
3713 it and sets C<select> from that, then auto-populates C<as> from
3714 C<select> as normal. (You may also use the C<cols> attribute, as in
3715 earlier versions of DBIC.)
3717 Essentially C<columns> does the same as L</select> and L</as>.
3719 columns => [ 'foo', { bar => 'baz' } ]
3723 select => [qw/foo baz/],
3730 =item Value: \@columns
3734 Indicates additional columns to be selected from storage. Works the same
3735 as L</columns> but adds columns to the selection. (You may also use the
3736 C<include_columns> attribute, as in earlier versions of DBIC). For
3739 $schema->resultset('CD')->search(undef, {
3740 '+columns' => ['artist.name'],
3744 would return all CDs and include a 'name' column to the information
3745 passed to object inflation. Note that the 'artist' is the name of the
3746 column (or relationship) accessor, and 'name' is the name of the column
3747 accessor in the related table.
3749 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3750 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3751 unary plus operator before it.
3753 =head2 include_columns
3757 =item Value: \@columns
3761 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3767 =item Value: \@select_columns
3771 Indicates which columns should be selected from the storage. You can use
3772 column names, or in the case of RDBMS back ends, function or stored procedure
3775 $rs = $schema->resultset('Employee')->search(undef, {
3778 { count => 'employeeid' },
3779 { max => { length => 'name' }, -as => 'longest_name' }
3784 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3786 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3787 use L</select>, to instruct DBIx::Class how to store the result of the column.
3788 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3789 identifier aliasing. You can however alias a function, so you can use it in
3790 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3791 attribute> supplied as shown in the example above.
3793 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3794 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3795 unary plus operator before it.
3801 Indicates additional columns to be selected from storage. Works the same as
3802 L</select> but adds columns to the default selection, instead of specifying
3811 Indicates additional column names for those added via L</+select>. See L</as>.
3819 =item Value: \@inflation_names
3823 Indicates column names for object inflation. That is L</as> indicates the
3824 slot name in which the column value will be stored within the
3825 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3826 identifier by the C<get_column> method (or via the object accessor B<if one
3827 with the same name already exists>) as shown below. The L</as> attribute has
3828 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3830 $rs = $schema->resultset('Employee')->search(undef, {
3833 { count => 'employeeid' },
3834 { max => { length => 'name' }, -as => 'longest_name' }
3843 If the object against which the search is performed already has an accessor
3844 matching a column name specified in C<as>, the value can be retrieved using
3845 the accessor as normal:
3847 my $name = $employee->name();
3849 If on the other hand an accessor does not exist in the object, you need to
3850 use C<get_column> instead:
3852 my $employee_count = $employee->get_column('employee_count');
3854 You can create your own accessors if required - see
3855 L<DBIx::Class::Manual::Cookbook> for details.
3861 =item Value: ($rel_name | \@rel_names | \%rel_names)
3865 Contains a list of relationships that should be joined for this query. For
3868 # Get CDs by Nine Inch Nails
3869 my $rs = $schema->resultset('CD')->search(
3870 { 'artist.name' => 'Nine Inch Nails' },
3871 { join => 'artist' }
3874 Can also contain a hash reference to refer to the other relation's relations.
3877 package MyApp::Schema::Track;
3878 use base qw/DBIx::Class/;
3879 __PACKAGE__->table('track');
3880 __PACKAGE__->add_columns(qw/trackid cd position title/);
3881 __PACKAGE__->set_primary_key('trackid');
3882 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3885 # In your application
3886 my $rs = $schema->resultset('Artist')->search(
3887 { 'track.title' => 'Teardrop' },
3889 join => { cd => 'track' },
3890 order_by => 'artist.name',
3894 You need to use the relationship (not the table) name in conditions,
3895 because they are aliased as such. The current table is aliased as "me", so
3896 you need to use me.column_name in order to avoid ambiguity. For example:
3898 # Get CDs from 1984 with a 'Foo' track
3899 my $rs = $schema->resultset('CD')->search(
3902 'tracks.name' => 'Foo'
3904 { join => 'tracks' }
3907 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3908 similarly for a third time). For e.g.
3910 my $rs = $schema->resultset('Artist')->search({
3911 'cds.title' => 'Down to Earth',
3912 'cds_2.title' => 'Popular',
3914 join => [ qw/cds cds/ ],
3917 will return a set of all artists that have both a cd with title 'Down
3918 to Earth' and a cd with title 'Popular'.
3920 If you want to fetch related objects from other tables as well, see C<prefetch>
3923 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3929 =item Value: ($rel_name | \@rel_names | \%rel_names)
3933 Contains one or more relationships that should be fetched along with
3934 the main query (when they are accessed afterwards the data will
3935 already be available, without extra queries to the database). This is
3936 useful for when you know you will need the related objects, because it
3937 saves at least one query:
3939 my $rs = $schema->resultset('Tag')->search(
3948 The initial search results in SQL like the following:
3950 SELECT tag.*, cd.*, artist.* FROM tag
3951 JOIN cd ON tag.cd = cd.cdid
3952 JOIN artist ON cd.artist = artist.artistid
3954 L<DBIx::Class> has no need to go back to the database when we access the
3955 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3958 Simple prefetches will be joined automatically, so there is no need
3959 for a C<join> attribute in the above search.
3961 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3962 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3963 with an accessor type of 'single' or 'filter'). A more complex example that
3964 prefetches an artists cds, the tracks on those cds, and the tags associated
3965 with that artist is given below (assuming many-to-many from artists to tags):
3967 my $rs = $schema->resultset('Artist')->search(
3971 { cds => 'tracks' },
3972 { artist_tags => 'tags' }
3978 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3979 attributes will be ignored.
3981 B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
3982 exactly as you might expect.
3988 Prefetch uses the L</cache> to populate the prefetched relationships. This
3989 may or may not be what you want.
3993 If you specify a condition on a prefetched relationship, ONLY those
3994 rows that match the prefetched condition will be fetched into that relationship.
3995 This means that adding prefetch to a search() B<may alter> what is returned by
3996 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
3998 my $artist_rs = $schema->resultset('Artist')->search({
4004 my $count = $artist_rs->first->cds->count;
4006 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4008 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4010 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4012 that cmp_ok() may or may not pass depending on the datasets involved. This
4013 behavior may or may not survive the 0.09 transition.
4025 Makes the resultset paged and specifies the page to retrieve. Effectively
4026 identical to creating a non-pages resultset and then calling ->page($page)
4029 If L</rows> attribute is not specified it defaults to 10 rows per page.
4031 When you have a paged resultset, L</count> will only return the number
4032 of rows in the page. To get the total, use the L</pager> and call
4033 C<total_entries> on it.
4043 Specifies the maximum number of rows for direct retrieval or the number of
4044 rows per page if the page attribute or method is used.
4050 =item Value: $offset
4054 Specifies the (zero-based) row number for the first row to be returned, or the
4055 of the first row of the first page if paging is used.
4061 =item Value: \@columns
4065 A arrayref of columns to group by. Can include columns of joined tables.
4067 group_by => [qw/ column1 column2 ... /]
4073 =item Value: $condition
4077 HAVING is a select statement attribute that is applied between GROUP BY and
4078 ORDER BY. It is applied to the after the grouping calculations have been
4081 having => { 'count_employee' => { '>=', 100 } }
4083 or with an in-place function in which case literal SQL is required:
4085 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4091 =item Value: (0 | 1)
4095 Set to 1 to group by all columns. If the resultset already has a group_by
4096 attribute, this setting is ignored and an appropriate warning is issued.
4102 Adds to the WHERE clause.
4104 # only return rows WHERE deleted IS NULL for all searches
4105 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4107 Can be overridden by passing C<< { where => undef } >> as an attribute
4114 Set to 1 to cache search results. This prevents extra SQL queries if you
4115 revisit rows in your ResultSet:
4117 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4119 while( my $artist = $resultset->next ) {
4123 $rs->first; # without cache, this would issue a query
4125 By default, searches are not cached.
4127 For more examples of using these attributes, see
4128 L<DBIx::Class::Manual::Cookbook>.
4134 =item Value: ( 'update' | 'shared' )
4138 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT