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, $key
688 die "Can't handle complex relationship conditions in find" if ref($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 for submitting 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},
1958 delete $data->[$index]->{$rel};
1959 $data->[$index] = {%{$data->[$index]}, %$related};
1961 push @columns, keys %$related if $index == 0;
1965 ## inherit the data locked in the conditions of the resultset
1966 my ($rs_data) = $self->_merge_with_rscond({});
1967 delete @{$rs_data}{@columns};
1968 my @inherit_cols = keys %$rs_data;
1969 my @inherit_data = values %$rs_data;
1971 ## do bulk insert on current row
1972 $rsrc->storage->insert_bulk(
1974 [@columns, @inherit_cols],
1975 [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
1978 ## do the has_many relationships
1979 foreach my $item (@$data) {
1983 foreach my $rel (@rels) {
1984 next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
1986 $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
1988 my $child = $main_row->$rel;
1990 my $related = $child->result_source->_resolve_condition(
1991 $rels->{$rel}{cond},
1997 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1998 my @populate = map { {%$_, %$related} } @rows_to_add;
2000 $child->populate( \@populate );
2007 # populate() argumnets went over several incarnations
2008 # What we ultimately support is AoH
2009 sub _normalize_populate_args {
2010 my ($self, $arg) = @_;
2012 if (ref $arg eq 'ARRAY') {
2013 if (ref $arg->[0] eq 'HASH') {
2016 elsif (ref $arg->[0] eq 'ARRAY') {
2018 my @colnames = @{$arg->[0]};
2019 foreach my $values (@{$arg}[1 .. $#$arg]) {
2020 push @ret, { map { $colnames[$_] => $values->[$_] } (0 .. $#colnames) };
2026 $self->throw_exception('Populate expects an arrayref of hashrefs or arrayref of arrayrefs');
2033 =item Arguments: none
2035 =item Return Value: $pager
2039 Return Value a L<Data::Page> object for the current resultset. Only makes
2040 sense for queries with a C<page> attribute.
2042 To get the full count of entries for a paged resultset, call
2043 C<total_entries> on the L<Data::Page> object.
2047 # make a wizard good for both a scalar and a hashref
2048 my $mk_lazy_count_wizard = sub {
2049 require Variable::Magic;
2051 my $stash = { total_rs => shift };
2052 my $slot = shift; # only used by the hashref magic
2054 my $magic = Variable::Magic::wizard (
2055 data => sub { $stash },
2061 # set value lazily, and dispell for good
2062 ${$_[0]} = $_[1]{total_rs}->count;
2063 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
2067 # an explicit set implies dispell as well
2068 # the unless() is to work around "fun and giggles" below
2069 Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
2070 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2077 if ($_[2] eq $slot and !$_[1]{inactive}) {
2078 my $cnt = $_[1]{total_rs}->count;
2079 $_[0]->{$slot} = $cnt;
2081 # attempting to dispell in a fetch handle (works in store), seems
2082 # to invariable segfault on 5.10, 5.12, 5.13 :(
2083 # so use an inactivator instead
2084 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2090 if (! $_[1]{inactive} and $_[2] eq $slot) {
2091 #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
2093 unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
2100 $stash->{magic_selfref} = $magic;
2101 weaken ($stash->{magic_selfref}); # this fails on 5.8.1
2106 # the tie class for 5.8.1
2108 package # hide from pause
2109 DBIx::Class::__DBIC_LAZY_RS_COUNT__;
2110 use base qw/Tie::Hash/;
2112 sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
2113 sub NEXTKEY { each %{$_[0]{data}} }
2114 sub EXISTS { exists $_[0]{data}{$_[1]} }
2115 sub DELETE { delete $_[0]{data}{$_[1]} }
2116 sub CLEAR { %{$_[0]{data}} = () }
2117 sub SCALAR { scalar %{$_[0]{data}} }
2120 $_[1]{data} = {%{$_[1]{selfref}}};
2121 %{$_[1]{selfref}} = ();
2122 Scalar::Util::weaken ($_[1]{selfref});
2123 return bless ($_[1], $_[0]);
2127 if ($_[1] eq $_[0]{slot}) {
2128 my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
2129 untie %{$_[0]{selfref}};
2130 %{$_[0]{selfref}} = %{$_[0]{data}};
2139 $_[0]{data}{$_[1]} = $_[2];
2140 if ($_[1] eq $_[0]{slot}) {
2141 untie %{$_[0]{selfref}};
2142 %{$_[0]{selfref}} = %{$_[0]{data}};
2151 return $self->{pager} if $self->{pager};
2153 if ($self->get_cache) {
2154 $self->throw_exception ('Pagers on cached resultsets are not supported');
2157 my $attrs = $self->{attrs};
2158 if (!defined $attrs->{page}) {
2159 $self->throw_exception("Can't create pager for non-paged rs");
2161 elsif ($attrs->{page} <= 0) {
2162 $self->throw_exception('Invalid page number (page-numbers are 1-based)');
2164 $attrs->{rows} ||= 10;
2166 # throw away the paging flags and re-run the count (possibly
2167 # with a subselect) to get the real total count
2168 my $count_attrs = { %$attrs };
2169 delete $count_attrs->{$_} for qw/rows offset page pager/;
2170 my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
2173 ### the following may seem awkward and dirty, but it's a thought-experiment
2174 ### necessary for future development of DBIx::DS. Do *NOT* change this code
2175 ### before talking to ribasushi/mst
2178 my $pager = Data::Page->new(
2179 0, #start with an empty set
2181 $self->{attrs}{page},
2184 my $data_slot = 'total_entries';
2186 # Since we are interested in a cached value (once it's set - it's set), every
2187 # technique will detach from the magic-host once the time comes to fire the
2188 # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
2190 if ($] < 5.008003) {
2191 # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
2192 # to weakref the magic container :(
2194 tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
2195 { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
2198 elsif ($] < 5.010) {
2199 # We can use magic on the hash value slot. It's interesting that the magic is
2200 # attached to the hash-slot, and does *not* stop working once I do the dummy
2201 # assignments after the cast()
2202 # tested on 5.8.3 and 5.8.9
2203 my $magic = $mk_lazy_count_wizard->($total_rs);
2204 Variable::Magic::cast ( $pager->{$data_slot}, $magic );
2206 # this is for fun and giggles
2207 $pager->{$data_slot} = -1;
2208 $pager->{$data_slot} = 0;
2210 # this does not work for scalars, but works with
2212 #my %vals = %$pager;
2217 # And the uvar magic
2218 # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
2219 # however see the wizard maker for more notes
2220 my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
2221 Variable::Magic::cast ( %$pager, $magic );
2224 $pager->{$data_slot} = -1;
2225 $pager->{$data_slot} = 0;
2233 return $self->{pager} = $pager;
2240 =item Arguments: $page_number
2242 =item Return Value: $rs
2246 Returns a resultset for the $page_number page of the resultset on which page
2247 is called, where each page contains a number of rows equal to the 'rows'
2248 attribute set on the resultset (10 by default).
2253 my ($self, $page) = @_;
2254 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
2261 =item Arguments: \%vals
2263 =item Return Value: $rowobject
2267 Creates a new row object in the resultset's result class and returns
2268 it. The row is not inserted into the database at this point, call
2269 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
2270 will tell you whether the row object has been inserted or not.
2272 Passes the hashref of input on to L<DBIx::Class::Row/new>.
2277 my ($self, $values) = @_;
2278 $self->throw_exception( "new_result needs a hash" )
2279 unless (ref $values eq 'HASH');
2281 my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
2285 @$cols_from_relations
2286 ? (-cols_from_relations => $cols_from_relations)
2288 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
2291 return $self->result_class->new(\%new);
2294 # _merge_with_rscond
2296 # Takes a simple hash of K/V data and returns its copy merged with the
2297 # condition already present on the resultset. Additionally returns an
2298 # arrayref of value/condition names, which were inferred from related
2299 # objects (this is needed for in-memory related objects)
2300 sub _merge_with_rscond {
2301 my ($self, $data) = @_;
2303 my (%new_data, @cols_from_relations);
2305 my $alias = $self->{attrs}{alias};
2307 if (! defined $self->{cond}) {
2308 # just massage $data below
2310 elsif ($self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) {
2311 %new_data = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
2312 @cols_from_relations = keys %new_data;
2314 elsif (ref $self->{cond} ne 'HASH') {
2315 $self->throw_exception(
2316 "Can't abstract implicit construct, resultset condition not a hash"
2320 # precendence must be given to passed values over values inherited from
2321 # the cond, so the order here is important.
2322 my $collapsed_cond = $self->_collapse_cond($self->{cond});
2323 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
2325 while ( my($col, $value) = each %implied ) {
2326 my $vref = ref $value;
2332 (keys %$value)[0] eq '='
2334 $new_data{$col} = $value->{'='};
2336 elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
2337 $new_data{$col} = $value;
2344 %{ $self->_remove_alias($data, $alias) },
2347 return (\%new_data, \@cols_from_relations);
2350 # _has_resolved_attr
2352 # determines if the resultset defines at least one
2353 # of the attributes supplied
2355 # used to determine if a subquery is neccessary
2357 # supports some virtual attributes:
2359 # This will scan for any joins being present on the resultset.
2360 # It is not a mere key-search but a deep inspection of {from}
2363 sub _has_resolved_attr {
2364 my ($self, @attr_names) = @_;
2366 my $attrs = $self->_resolved_attrs;
2370 for my $n (@attr_names) {
2371 if (grep { $n eq $_ } (qw/-join/) ) {
2372 $extra_checks{$n}++;
2376 my $attr = $attrs->{$n};
2378 next if not defined $attr;
2380 if (ref $attr eq 'HASH') {
2381 return 1 if keys %$attr;
2383 elsif (ref $attr eq 'ARRAY') {
2391 # a resolved join is expressed as a multi-level from
2393 $extra_checks{-join}
2395 ref $attrs->{from} eq 'ARRAY'
2397 @{$attrs->{from}} > 1
2405 # Recursively collapse the condition.
2407 sub _collapse_cond {
2408 my ($self, $cond, $collapsed) = @_;
2412 if (ref $cond eq 'ARRAY') {
2413 foreach my $subcond (@$cond) {
2414 next unless ref $subcond; # -or
2415 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2418 elsif (ref $cond eq 'HASH') {
2419 if (keys %$cond and (keys %$cond)[0] eq '-and') {
2420 foreach my $subcond (@{$cond->{-and}}) {
2421 $collapsed = $self->_collapse_cond($subcond, $collapsed);
2425 foreach my $col (keys %$cond) {
2426 my $value = $cond->{$col};
2427 $collapsed->{$col} = $value;
2437 # Remove the specified alias from the specified query hash. A copy is made so
2438 # the original query is not modified.
2441 my ($self, $query, $alias) = @_;
2443 my %orig = %{ $query || {} };
2446 foreach my $key (keys %orig) {
2448 $unaliased{$key} = $orig{$key};
2451 $unaliased{$1} = $orig{$key}
2452 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
2462 =item Arguments: none
2464 =item Return Value: \[ $sql, @bind ]
2468 Returns the SQL query and bind vars associated with the invocant.
2470 This is generally used as the RHS for a subquery.
2477 my $attrs = $self->_resolved_attrs_copy;
2482 # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
2483 # $sql also has no wrapping parenthesis in list ctx
2485 my $sqlbind = $self->result_source->storage
2486 ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
2495 =item Arguments: \%vals, \%attrs?
2497 =item Return Value: $rowobject
2501 my $artist = $schema->resultset('Artist')->find_or_new(
2502 { artist => 'fred' }, { key => 'artists' });
2504 $cd->cd_to_producer->find_or_new({ producer => $producer },
2505 { key => 'primary });
2507 Find an existing record from this resultset using L</find>. if none exists,
2508 instantiate a new result object and return it. The object will not be saved
2509 into your storage until you call L<DBIx::Class::Row/insert> on it.
2511 You most likely want this method when looking for existing rows using a unique
2512 constraint that is not the primary key, or looking for related rows.
2514 If you want objects to be saved immediately, use L</find_or_create> instead.
2516 B<Note>: Make sure to read the documentation of L</find> and understand the
2517 significance of the C<key> attribute, as its lack may skew your search, and
2518 subsequently result in spurious new objects.
2520 B<Note>: Take care when using C<find_or_new> with a table having
2521 columns with default values that you intend to be automatically
2522 supplied by the database (e.g. an auto_increment primary key column).
2523 In normal usage, the value of such columns should NOT be included at
2524 all in the call to C<find_or_new>, even when set to C<undef>.
2530 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2531 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2532 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2535 return $self->new_result($hash);
2542 =item Arguments: \%vals
2544 =item Return Value: a L<DBIx::Class::Row> $object
2548 Attempt to create a single new row or a row with multiple related rows
2549 in the table represented by the resultset (and related tables). This
2550 will not check for duplicate rows before inserting, use
2551 L</find_or_create> to do that.
2553 To create one row for this resultset, pass a hashref of key/value
2554 pairs representing the columns of the table and the values you wish to
2555 store. If the appropriate relationships are set up, foreign key fields
2556 can also be passed an object representing the foreign row, and the
2557 value will be set to its primary key.
2559 To create related objects, pass a hashref of related-object column values
2560 B<keyed on the relationship name>. If the relationship is of type C<multi>
2561 (L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
2562 The process will correctly identify columns holding foreign keys, and will
2563 transparently populate them from the keys of the corresponding relation.
2564 This can be applied recursively, and will work correctly for a structure
2565 with an arbitrary depth and width, as long as the relationships actually
2566 exists and the correct column data has been supplied.
2569 Instead of hashrefs of plain related data (key/value pairs), you may
2570 also pass new or inserted objects. New objects (not inserted yet, see
2571 L</new>), will be inserted into their appropriate tables.
2573 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2575 Example of creating a new row.
2577 $person_rs->create({
2578 name=>"Some Person",
2579 email=>"somebody@someplace.com"
2582 Example of creating a new row and also creating rows in a related C<has_many>
2583 or C<has_one> resultset. Note Arrayref.
2586 { artistid => 4, name => 'Manufactured Crap', cds => [
2587 { title => 'My First CD', year => 2006 },
2588 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2593 Example of creating a new row and also creating a row in a related
2594 C<belongs_to> resultset. Note Hashref.
2597 title=>"Music for Silly Walks",
2600 name=>"Silly Musician",
2608 When subclassing ResultSet never attempt to override this method. Since
2609 it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
2610 lot of the internals simply never call it, so your override will be
2611 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
2612 or L<insert|DBIx::Class::Row/insert> depending on how early in the
2613 L</create> process you need to intervene.
2620 my ($self, $attrs) = @_;
2621 $self->throw_exception( "create needs a hashref" )
2622 unless ref $attrs eq 'HASH';
2623 return $self->new_result($attrs)->insert;
2626 =head2 find_or_create
2630 =item Arguments: \%vals, \%attrs?
2632 =item Return Value: $rowobject
2636 $cd->cd_to_producer->find_or_create({ producer => $producer },
2637 { key => 'primary' });
2639 Tries to find a record based on its primary key or unique constraints; if none
2640 is found, creates one and returns that instead.
2642 my $cd = $schema->resultset('CD')->find_or_create({
2644 artist => 'Massive Attack',
2645 title => 'Mezzanine',
2649 Also takes an optional C<key> attribute, to search by a specific key or unique
2650 constraint. For example:
2652 my $cd = $schema->resultset('CD')->find_or_create(
2654 artist => 'Massive Attack',
2655 title => 'Mezzanine',
2657 { key => 'cd_artist_title' }
2660 B<Note>: Make sure to read the documentation of L</find> and understand the
2661 significance of the C<key> attribute, as its lack may skew your search, and
2662 subsequently result in spurious row creation.
2664 B<Note>: Because find_or_create() reads from the database and then
2665 possibly inserts based on the result, this method is subject to a race
2666 condition. Another process could create a record in the table after
2667 the find has completed and before the create has started. To avoid
2668 this problem, use find_or_create() inside a transaction.
2670 B<Note>: Take care when using C<find_or_create> with a table having
2671 columns with default values that you intend to be automatically
2672 supplied by the database (e.g. an auto_increment primary key column).
2673 In normal usage, the value of such columns should NOT be included at
2674 all in the call to C<find_or_create>, even when set to C<undef>.
2676 See also L</find> and L</update_or_create>. For information on how to declare
2677 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2681 sub find_or_create {
2683 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2684 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2685 if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
2688 return $self->create($hash);
2691 =head2 update_or_create
2695 =item Arguments: \%col_values, { key => $unique_constraint }?
2697 =item Return Value: $row_object
2701 $resultset->update_or_create({ col => $val, ... });
2703 Like L</find_or_create>, but if a row is found it is immediately updated via
2704 C<< $found_row->update (\%col_values) >>.
2707 Takes an optional C<key> attribute to search on a specific unique constraint.
2710 # In your application
2711 my $cd = $schema->resultset('CD')->update_or_create(
2713 artist => 'Massive Attack',
2714 title => 'Mezzanine',
2717 { key => 'cd_artist_title' }
2720 $cd->cd_to_producer->update_or_create({
2721 producer => $producer,
2727 B<Note>: Make sure to read the documentation of L</find> and understand the
2728 significance of the C<key> attribute, as its lack may skew your search, and
2729 subsequently result in spurious row creation.
2731 B<Note>: Take care when using C<update_or_create> with a table having
2732 columns with default values that you intend to be automatically
2733 supplied by the database (e.g. an auto_increment primary key column).
2734 In normal usage, the value of such columns should NOT be included at
2735 all in the call to C<update_or_create>, even when set to C<undef>.
2737 See also L</find> and L</find_or_create>. For information on how to declare
2738 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2742 sub update_or_create {
2744 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2745 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2747 my $row = $self->find($cond, $attrs);
2749 $row->update($cond);
2753 return $self->create($cond);
2756 =head2 update_or_new
2760 =item Arguments: \%col_values, { key => $unique_constraint }?
2762 =item Return Value: $rowobject
2766 $resultset->update_or_new({ col => $val, ... });
2768 Like L</find_or_new> but if a row is found it is immediately updated via
2769 C<< $found_row->update (\%col_values) >>.
2773 # In your application
2774 my $cd = $schema->resultset('CD')->update_or_new(
2776 artist => 'Massive Attack',
2777 title => 'Mezzanine',
2780 { key => 'cd_artist_title' }
2783 if ($cd->in_storage) {
2784 # the cd was updated
2787 # the cd is not yet in the database, let's insert it
2791 B<Note>: Make sure to read the documentation of L</find> and understand the
2792 significance of the C<key> attribute, as its lack may skew your search, and
2793 subsequently result in spurious new objects.
2795 B<Note>: Take care when using C<update_or_new> with a table having
2796 columns with default values that you intend to be automatically
2797 supplied by the database (e.g. an auto_increment primary key column).
2798 In normal usage, the value of such columns should NOT be included at
2799 all in the call to C<update_or_new>, even when set to C<undef>.
2801 See also L</find>, L</find_or_create> and L</find_or_new>.
2807 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2808 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2810 my $row = $self->find( $cond, $attrs );
2811 if ( defined $row ) {
2812 $row->update($cond);
2816 return $self->new_result($cond);
2823 =item Arguments: none
2825 =item Return Value: \@cache_objects | undef
2829 Gets the contents of the cache for the resultset, if the cache is set.
2831 The cache is populated either by using the L</prefetch> attribute to
2832 L</search> or by calling L</set_cache>.
2844 =item Arguments: \@cache_objects
2846 =item Return Value: \@cache_objects
2850 Sets the contents of the cache for the resultset. Expects an arrayref
2851 of objects of the same class as those produced by the resultset. Note that
2852 if the cache is set the resultset will return the cached objects rather
2853 than re-querying the database even if the cache attr is not set.
2855 The contents of the cache can also be populated by using the
2856 L</prefetch> attribute to L</search>.
2861 my ( $self, $data ) = @_;
2862 $self->throw_exception("set_cache requires an arrayref")
2863 if defined($data) && (ref $data ne 'ARRAY');
2864 $self->{all_cache} = $data;
2871 =item Arguments: none
2873 =item Return Value: undef
2877 Clears the cache for the resultset.
2882 shift->set_cache(undef);
2889 =item Arguments: none
2891 =item Return Value: true, if the resultset has been paginated
2899 return !!$self->{attrs}{page};
2906 =item Arguments: none
2908 =item Return Value: true, if the resultset has been ordered with C<order_by>.
2916 return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
2919 =head2 related_resultset
2923 =item Arguments: $relationship_name
2925 =item Return Value: $resultset
2929 Returns a related resultset for the supplied relationship name.
2931 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2935 sub related_resultset {
2936 my ($self, $rel) = @_;
2938 $self->{related_resultsets} ||= {};
2939 return $self->{related_resultsets}{$rel} ||= do {
2940 my $rsrc = $self->result_source;
2941 my $rel_info = $rsrc->relationship_info($rel);
2943 $self->throw_exception(
2944 "search_related: result source '" . $rsrc->source_name .
2945 "' has no such relationship $rel")
2948 my $attrs = $self->_chain_relationship($rel);
2950 my $join_count = $attrs->{seen_join}{$rel};
2952 my $alias = $self->result_source->storage
2953 ->relname_to_table_alias($rel, $join_count);
2955 # since this is search_related, and we already slid the select window inwards
2956 # (the select/as attrs were deleted in the beginning), we need to flip all
2957 # left joins to inner, so we get the expected results
2958 # read the comment on top of the actual function to see what this does
2959 $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
2962 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2963 delete @{$attrs}{qw(result_class alias)};
2967 if (my $cache = $self->get_cache) {
2968 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2969 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2974 my $rel_source = $rsrc->related_source($rel);
2978 # The reason we do this now instead of passing the alias to the
2979 # search_rs below is that if you wrap/overload resultset on the
2980 # source you need to know what alias it's -going- to have for things
2981 # to work sanely (e.g. RestrictWithObject wants to be able to add
2982 # extra query restrictions, and these may need to be $alias.)
2984 my $rel_attrs = $rel_source->resultset_attributes;
2985 local $rel_attrs->{alias} = $alias;
2987 $rel_source->resultset
2991 where => $attrs->{where},
2994 $new->set_cache($new_cache) if $new_cache;
2999 =head2 current_source_alias
3003 =item Arguments: none
3005 =item Return Value: $source_alias
3009 Returns the current table alias for the result source this resultset is built
3010 on, that will be used in the SQL query. Usually it is C<me>.
3012 Currently the source alias that refers to the result set returned by a
3013 L</search>/L</find> family method depends on how you got to the resultset: it's
3014 C<me> by default, but eg. L</search_related> aliases it to the related result
3015 source name (and keeps C<me> referring to the original result set). The long
3016 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
3017 (and make this method unnecessary).
3019 Thus it's currently necessary to use this method in predefined queries (see
3020 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
3021 source alias of the current result set:
3023 # in a result set class
3025 my ($self, $user) = @_;
3027 my $me = $self->current_source_alias;
3029 return $self->search(
3030 "$me.modified" => $user->id,
3036 sub current_source_alias {
3039 return ($self->{attrs} || {})->{alias} || 'me';
3042 =head2 as_subselect_rs
3046 =item Arguments: none
3048 =item Return Value: $resultset
3052 Act as a barrier to SQL symbols. The resultset provided will be made into a
3053 "virtual view" by including it as a subquery within the from clause. From this
3054 point on, any joined tables are inaccessible to ->search on the resultset (as if
3055 it were simply where-filtered without joins). For example:
3057 my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
3059 # 'x' now pollutes the query namespace
3061 # So the following works as expected
3062 my $ok_rs = $rs->search({'x.other' => 1});
3064 # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
3065 # def) we look for one row with contradictory terms and join in another table
3066 # (aliased 'x_2') which we never use
3067 my $broken_rs = $rs->search({'x.name' => 'def'});
3069 my $rs2 = $rs->as_subselect_rs;
3071 # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
3072 my $not_joined_rs = $rs2->search({'x.other' => 1});
3074 # works as expected: finds a 'table' row related to two x rows (abc and def)
3075 my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
3077 Another example of when one might use this would be to select a subset of
3078 columns in a group by clause:
3080 my $rs = $schema->resultset('Bar')->search(undef, {
3081 group_by => [qw{ id foo_id baz_id }],
3082 })->as_subselect_rs->search(undef, {
3083 columns => [qw{ id foo_id }]
3086 In the above example normally columns would have to be equal to the group by,
3087 but because we isolated the group by into a subselect the above works.
3091 sub as_subselect_rs {
3094 my $attrs = $self->_resolved_attrs;
3096 my $fresh_rs = (ref $self)->new (
3097 $self->result_source
3100 # these pieces will be locked in the subquery
3101 delete $fresh_rs->{cond};
3102 delete @{$fresh_rs->{attrs}}{qw/where bind/};
3104 return $fresh_rs->search( {}, {
3106 $attrs->{alias} => $self->as_query,
3107 -alias => $attrs->{alias},
3108 -rsrc => $self->result_source,
3110 alias => $attrs->{alias},
3114 # This code is called by search_related, and makes sure there
3115 # is clear separation between the joins before, during, and
3116 # after the relationship. This information is needed later
3117 # in order to properly resolve prefetch aliases (any alias
3118 # with a relation_chain_depth less than the depth of the
3119 # current prefetch is not considered)
3121 # The increments happen twice per join. An even number means a
3122 # relationship specified via a search_related, whereas an odd
3123 # number indicates a join/prefetch added via attributes
3125 # Also this code will wrap the current resultset (the one we
3126 # chain to) in a subselect IFF it contains limiting attributes
3127 sub _chain_relationship {
3128 my ($self, $rel) = @_;
3129 my $source = $self->result_source;
3130 my $attrs = { %{$self->{attrs}||{}} };
3132 # we need to take the prefetch the attrs into account before we
3133 # ->_resolve_join as otherwise they get lost - captainL
3134 my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
3136 delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
3138 my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
3141 my @force_subq_attrs = qw/offset rows group_by having/;
3144 ($attrs->{from} && ref $attrs->{from} ne 'ARRAY')
3146 $self->_has_resolved_attr (@force_subq_attrs)
3148 # Nuke the prefetch (if any) before the new $rs attrs
3149 # are resolved (prefetch is useless - we are wrapping
3150 # a subquery anyway).
3151 my $rs_copy = $self->search;
3152 $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
3153 $rs_copy->{attrs}{join},
3154 delete $rs_copy->{attrs}{prefetch},
3159 -alias => $attrs->{alias},
3160 $attrs->{alias} => $rs_copy->as_query,
3162 delete @{$attrs}{@force_subq_attrs, qw/where bind/};
3163 $seen->{-relation_chain_depth} = 0;
3165 elsif ($attrs->{from}) { #shallow copy suffices
3166 $from = [ @{$attrs->{from}} ];
3171 -alias => $attrs->{alias},
3172 $attrs->{alias} => $source->from,
3176 my $jpath = ($seen->{-relation_chain_depth})
3177 ? $from->[-1][0]{-join_path}
3180 my @requested_joins = $source->_resolve_join(
3187 push @$from, @requested_joins;
3189 $seen->{-relation_chain_depth}++;
3191 # if $self already had a join/prefetch specified on it, the requested
3192 # $rel might very well be already included. What we do in this case
3193 # is effectively a no-op (except that we bump up the chain_depth on
3194 # the join in question so we could tell it *is* the search_related)
3197 # we consider the last one thus reverse
3198 for my $j (reverse @requested_joins) {
3199 my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
3200 if ($rel eq $last_j) {
3201 $j->[0]{-relation_chain_depth}++;
3207 unless ($already_joined) {
3208 push @$from, $source->_resolve_join(
3216 $seen->{-relation_chain_depth}++;
3218 return {%$attrs, from => $from, seen_join => $seen};
3221 # too many times we have to do $attrs = { %{$self->_resolved_attrs} }
3222 sub _resolved_attrs_copy {
3224 return { %{$self->_resolved_attrs (@_)} };
3227 sub _resolved_attrs {
3229 return $self->{_attrs} if $self->{_attrs};
3231 my $attrs = { %{ $self->{attrs} || {} } };
3232 my $source = $self->result_source;
3233 my $alias = $attrs->{alias};
3235 # one last pass of normalization
3236 $self->_normalize_selection($attrs);
3238 # default selection list
3239 $attrs->{columns} = [ $source->columns ]
3240 unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as _trailing_select/;
3242 # merge selectors together
3243 for (qw/columns select as _trailing_select/) {
3244 $attrs->{$_} = $self->_merge_attr($attrs->{$_}, $attrs->{"+$_"})
3245 if $attrs->{$_} or $attrs->{"+$_"};
3248 # disassemble columns
3250 if (my $cols = delete $attrs->{columns}) {
3251 for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
3252 if (ref $c eq 'HASH') {
3253 for my $as (keys %$c) {
3254 push @sel, $c->{$as};
3265 # when trying to weed off duplicates later do not go past this point -
3266 # everything added from here on is unbalanced "anyone's guess" stuff
3267 my $dedup_stop_idx = $#as;
3269 push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
3271 push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
3272 if $attrs->{select};
3274 # assume all unqualified selectors to apply to the current alias (legacy stuff)
3276 $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
3279 # disqualify all $alias.col as-bits (collapser mandated)
3281 $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
3284 # de-duplicate the result (remove *identical* select/as pairs)
3285 # and also die on duplicate {as} pointing to different {select}s
3286 # not using a c-style for as the condition is prone to shrinkage
3289 while ($i <= $dedup_stop_idx) {
3290 if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
3295 elsif ($seen->{$as[$i]}++) {
3296 $self->throw_exception(
3297 "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
3305 $attrs->{select} = \@sel;
3306 $attrs->{as} = \@as;
3308 $attrs->{from} ||= [{
3310 -alias => $self->{attrs}{alias},
3311 $self->{attrs}{alias} => $source->from,
3314 if ( $attrs->{join} || $attrs->{prefetch} ) {
3316 $self->throw_exception ('join/prefetch can not be used with a custom {from}')
3317 if ref $attrs->{from} ne 'ARRAY';
3319 my $join = (delete $attrs->{join}) || {};
3321 if ( defined $attrs->{prefetch} ) {
3322 $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
3325 $attrs->{from} = # have to copy here to avoid corrupting the original
3327 @{ $attrs->{from} },
3328 $source->_resolve_join(
3331 { %{ $attrs->{seen_join} || {} } },
3332 ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
3333 ? $attrs->{from}[-1][0]{-join_path}
3340 if ( defined $attrs->{order_by} ) {
3341 $attrs->{order_by} = (
3342 ref( $attrs->{order_by} ) eq 'ARRAY'
3343 ? [ @{ $attrs->{order_by} } ]
3344 : [ $attrs->{order_by} || () ]
3348 if ($attrs->{group_by} and ref $attrs->{group_by} ne 'ARRAY') {
3349 $attrs->{group_by} = [ $attrs->{group_by} ];
3352 # generate the distinct induced group_by early, as prefetch will be carried via a
3353 # subquery (since a group_by is present)
3354 if (delete $attrs->{distinct}) {
3355 if ($attrs->{group_by}) {
3356 carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
3359 # distinct affects only the main selection part, not what prefetch may
3360 # add below. However trailing is not yet a part of the selection as
3361 # prefetch must insert before it
3362 $attrs->{group_by} = $source->storage->_group_over_selection (
3364 [ @{$attrs->{select}||[]}, @{$attrs->{_trailing_select}||[]} ],
3370 $attrs->{collapse} ||= {};
3371 if ($attrs->{prefetch}) {
3372 my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
3374 my $prefetch_ordering = [];
3376 # this is a separate structure (we don't look in {from} directly)
3377 # as the resolver needs to shift things off the lists to work
3378 # properly (identical-prefetches on different branches)
3380 if (ref $attrs->{from} eq 'ARRAY') {
3382 my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
3384 for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
3385 next unless $j->[0]{-alias};
3386 next unless $j->[0]{-join_path};
3387 next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
3389 my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
3392 $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
3393 push @{$p->{-join_aliases} }, $j->[0]{-alias};
3398 $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
3400 # we need to somehow mark which columns came from prefetch
3402 my $sel_end = $#{$attrs->{select}};
3403 $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
3406 push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
3407 push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
3409 push( @{$attrs->{order_by}}, @$prefetch_ordering );
3410 $attrs->{_collapse_order_by} = \@$prefetch_ordering;
3414 push @{ $attrs->{select} }, @{$attrs->{_trailing_select}}
3415 if $attrs->{_trailing_select};
3417 # if both page and offset are specified, produce a combined offset
3418 # even though it doesn't make much sense, this is what pre 081xx has
3420 if (my $page = delete $attrs->{page}) {
3422 ($attrs->{rows} * ($page - 1))
3424 ($attrs->{offset} || 0)
3428 return $self->{_attrs} = $attrs;
3432 my ($self, $attr) = @_;
3434 if (ref $attr eq 'HASH') {
3435 return $self->_rollout_hash($attr);
3436 } elsif (ref $attr eq 'ARRAY') {
3437 return $self->_rollout_array($attr);
3443 sub _rollout_array {
3444 my ($self, $attr) = @_;
3447 foreach my $element (@{$attr}) {
3448 if (ref $element eq 'HASH') {
3449 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
3450 } elsif (ref $element eq 'ARRAY') {
3451 # XXX - should probably recurse here
3452 push( @rolled_array, @{$self->_rollout_array($element)} );
3454 push( @rolled_array, $element );
3457 return \@rolled_array;
3461 my ($self, $attr) = @_;
3464 foreach my $key (keys %{$attr}) {
3465 push( @rolled_array, { $key => $attr->{$key} } );
3467 return \@rolled_array;
3470 sub _calculate_score {
3471 my ($self, $a, $b) = @_;
3473 if (defined $a xor defined $b) {
3476 elsif (not defined $a) {
3480 if (ref $b eq 'HASH') {
3481 my ($b_key) = keys %{$b};
3482 if (ref $a eq 'HASH') {
3483 my ($a_key) = keys %{$a};
3484 if ($a_key eq $b_key) {
3485 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
3490 return ($a eq $b_key) ? 1 : 0;
3493 if (ref $a eq 'HASH') {
3494 my ($a_key) = keys %{$a};
3495 return ($b eq $a_key) ? 1 : 0;
3497 return ($b eq $a) ? 1 : 0;
3502 sub _merge_joinpref_attr {
3503 my ($self, $orig, $import) = @_;
3505 return $import unless defined($orig);
3506 return $orig unless defined($import);
3508 $orig = $self->_rollout_attr($orig);
3509 $import = $self->_rollout_attr($import);
3512 foreach my $import_element ( @{$import} ) {
3513 # find best candidate from $orig to merge $b_element into
3514 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
3515 foreach my $orig_element ( @{$orig} ) {
3516 my $score = $self->_calculate_score( $orig_element, $import_element );
3517 if ($score > $best_candidate->{score}) {
3518 $best_candidate->{position} = $position;
3519 $best_candidate->{score} = $score;
3523 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
3525 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
3526 push( @{$orig}, $import_element );
3528 my $orig_best = $orig->[$best_candidate->{position}];
3529 # merge orig_best and b_element together and replace original with merged
3530 if (ref $orig_best ne 'HASH') {
3531 $orig->[$best_candidate->{position}] = $import_element;
3532 } elsif (ref $import_element eq 'HASH') {
3533 my ($key) = keys %{$orig_best};
3534 $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
3537 $seen_keys->{$import_key} = 1; # don't merge the same key twice
3548 require Hash::Merge;
3549 my $hm = Hash::Merge->new;
3551 $hm->specify_behavior({
3554 my ($defl, $defr) = map { defined $_ } (@_[0,1]);
3556 if ($defl xor $defr) {
3557 return [ $defl ? $_[0] : $_[1] ];
3562 elsif (__HM_DEDUP and $_[0] eq $_[1]) {
3566 return [$_[0], $_[1]];
3570 return $_[1] if !defined $_[0];
3571 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3572 return [$_[0], @{$_[1]}]
3575 return [] if !defined $_[0] and !keys %{$_[1]};
3576 return [ $_[1] ] if !defined $_[0];
3577 return [ $_[0] ] if !keys %{$_[1]};
3578 return [$_[0], $_[1]]
3583 return $_[0] if !defined $_[1];
3584 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3585 return [@{$_[0]}, $_[1]]
3588 my @ret = @{$_[0]} or return $_[1];
3589 return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
3590 my %idx = map { $_ => 1 } @ret;
3591 push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
3595 return [ $_[1] ] if ! @{$_[0]};
3596 return $_[0] if !keys %{$_[1]};
3597 return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
3598 return [ @{$_[0]}, $_[1] ];
3603 return [] if !keys %{$_[0]} and !defined $_[1];
3604 return [ $_[0] ] if !defined $_[1];
3605 return [ $_[1] ] if !keys %{$_[0]};
3606 return [$_[0], $_[1]]
3609 return [] if !keys %{$_[0]} and !@{$_[1]};
3610 return [ $_[0] ] if !@{$_[1]};
3611 return $_[1] if !keys %{$_[0]};
3612 return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
3613 return [ $_[0], @{$_[1]} ];
3616 return [] if !keys %{$_[0]} and !keys %{$_[1]};
3617 return [ $_[0] ] if !keys %{$_[1]};
3618 return [ $_[1] ] if !keys %{$_[0]};
3619 return [ $_[0] ] if $_[0] eq $_[1];
3620 return [ $_[0], $_[1] ];
3623 } => 'DBIC_RS_ATTR_MERGER');
3627 return $hm->merge ($_[1], $_[2]);
3631 sub STORABLE_freeze {
3632 my ($self, $cloning) = @_;
3633 my $to_serialize = { %$self };
3635 # A cursor in progress can't be serialized (and would make little sense anyway)
3636 delete $to_serialize->{cursor};
3638 Storable::nfreeze($to_serialize);
3641 # need this hook for symmetry
3643 my ($self, $cloning, $serialized) = @_;
3645 %$self = %{ Storable::thaw($serialized) };
3651 =head2 throw_exception
3653 See L<DBIx::Class::Schema/throw_exception> for details.
3657 sub throw_exception {
3660 if (ref $self and my $rsrc = $self->result_source) {
3661 $rsrc->throw_exception(@_)
3664 DBIx::Class::Exception->throw(@_);
3668 # XXX: FIXME: Attributes docs need clearing up
3672 Attributes are used to refine a ResultSet in various ways when
3673 searching for data. They can be passed to any method which takes an
3674 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
3677 These are in no particular order:
3683 =item Value: ( $order_by | \@order_by | \%order_by )
3687 Which column(s) to order the results by.
3689 [The full list of suitable values is documented in
3690 L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
3693 If a single column name, or an arrayref of names is supplied, the
3694 argument is passed through directly to SQL. The hashref syntax allows
3695 for connection-agnostic specification of ordering direction:
3697 For descending order:
3699 order_by => { -desc => [qw/col1 col2 col3/] }
3701 For explicit ascending order:
3703 order_by => { -asc => 'col' }
3705 The old scalarref syntax (i.e. order_by => \'year DESC') is still
3706 supported, although you are strongly encouraged to use the hashref
3707 syntax as outlined above.
3713 =item Value: \@columns
3717 Shortcut to request a particular set of columns to be retrieved. Each
3718 column spec may be a string (a table column name), or a hash (in which
3719 case the key is the C<as> value, and the value is used as the C<select>
3720 expression). Adds C<me.> onto the start of any column without a C<.> in
3721 it and sets C<select> from that, then auto-populates C<as> from
3722 C<select> as normal. (You may also use the C<cols> attribute, as in
3723 earlier versions of DBIC.)
3725 Essentially C<columns> does the same as L</select> and L</as>.
3727 columns => [ 'foo', { bar => 'baz' } ]
3731 select => [qw/foo baz/],
3738 =item Value: \@columns
3742 Indicates additional columns to be selected from storage. Works the same
3743 as L</columns> but adds columns to the selection. (You may also use the
3744 C<include_columns> attribute, as in earlier versions of DBIC). For
3747 $schema->resultset('CD')->search(undef, {
3748 '+columns' => ['artist.name'],
3752 would return all CDs and include a 'name' column to the information
3753 passed to object inflation. Note that the 'artist' is the name of the
3754 column (or relationship) accessor, and 'name' is the name of the column
3755 accessor in the related table.
3757 B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
3758 Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
3759 unary plus operator before it.
3761 =head2 include_columns
3765 =item Value: \@columns
3769 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
3775 =item Value: \@select_columns
3779 Indicates which columns should be selected from the storage. You can use
3780 column names, or in the case of RDBMS back ends, function or stored procedure
3783 $rs = $schema->resultset('Employee')->search(undef, {
3786 { count => 'employeeid' },
3787 { max => { length => 'name' }, -as => 'longest_name' }
3792 SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
3794 B<NOTE:> You will almost always need a corresponding L</as> attribute when you
3795 use L</select>, to instruct DBIx::Class how to store the result of the column.
3796 Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
3797 identifier aliasing. You can however alias a function, so you can use it in
3798 e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
3799 attribute> supplied as shown in the example above.
3801 B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
3802 Not doing so causes Perl to incorrectly interpret them as a bareword with a
3803 unary plus operator before it.
3809 Indicates additional columns to be selected from storage. Works the same as
3810 L</select> but adds columns to the default selection, instead of specifying
3819 Indicates additional column names for those added via L</+select>. See L</as>.
3827 =item Value: \@inflation_names
3831 Indicates column names for object inflation. That is L</as> indicates the
3832 slot name in which the column value will be stored within the
3833 L<Row|DBIx::Class::Row> object. The value will then be accessible via this
3834 identifier by the C<get_column> method (or via the object accessor B<if one
3835 with the same name already exists>) as shown below. The L</as> attribute has
3836 B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
3838 $rs = $schema->resultset('Employee')->search(undef, {
3841 { count => 'employeeid' },
3842 { max => { length => 'name' }, -as => 'longest_name' }
3851 If the object against which the search is performed already has an accessor
3852 matching a column name specified in C<as>, the value can be retrieved using
3853 the accessor as normal:
3855 my $name = $employee->name();
3857 If on the other hand an accessor does not exist in the object, you need to
3858 use C<get_column> instead:
3860 my $employee_count = $employee->get_column('employee_count');
3862 You can create your own accessors if required - see
3863 L<DBIx::Class::Manual::Cookbook> for details.
3869 =item Value: ($rel_name | \@rel_names | \%rel_names)
3873 Contains a list of relationships that should be joined for this query. For
3876 # Get CDs by Nine Inch Nails
3877 my $rs = $schema->resultset('CD')->search(
3878 { 'artist.name' => 'Nine Inch Nails' },
3879 { join => 'artist' }
3882 Can also contain a hash reference to refer to the other relation's relations.
3885 package MyApp::Schema::Track;
3886 use base qw/DBIx::Class/;
3887 __PACKAGE__->table('track');
3888 __PACKAGE__->add_columns(qw/trackid cd position title/);
3889 __PACKAGE__->set_primary_key('trackid');
3890 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3893 # In your application
3894 my $rs = $schema->resultset('Artist')->search(
3895 { 'track.title' => 'Teardrop' },
3897 join => { cd => 'track' },
3898 order_by => 'artist.name',
3902 You need to use the relationship (not the table) name in conditions,
3903 because they are aliased as such. The current table is aliased as "me", so
3904 you need to use me.column_name in order to avoid ambiguity. For example:
3906 # Get CDs from 1984 with a 'Foo' track
3907 my $rs = $schema->resultset('CD')->search(
3910 'tracks.name' => 'Foo'
3912 { join => 'tracks' }
3915 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3916 similarly for a third time). For e.g.
3918 my $rs = $schema->resultset('Artist')->search({
3919 'cds.title' => 'Down to Earth',
3920 'cds_2.title' => 'Popular',
3922 join => [ qw/cds cds/ ],
3925 will return a set of all artists that have both a cd with title 'Down
3926 to Earth' and a cd with title 'Popular'.
3928 If you want to fetch related objects from other tables as well, see C<prefetch>
3931 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3937 =item Value: ($rel_name | \@rel_names | \%rel_names)
3941 Contains one or more relationships that should be fetched along with
3942 the main query (when they are accessed afterwards the data will
3943 already be available, without extra queries to the database). This is
3944 useful for when you know you will need the related objects, because it
3945 saves at least one query:
3947 my $rs = $schema->resultset('Tag')->search(
3956 The initial search results in SQL like the following:
3958 SELECT tag.*, cd.*, artist.* FROM tag
3959 JOIN cd ON tag.cd = cd.cdid
3960 JOIN artist ON cd.artist = artist.artistid
3962 L<DBIx::Class> has no need to go back to the database when we access the
3963 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3966 Simple prefetches will be joined automatically, so there is no need
3967 for a C<join> attribute in the above search.
3969 L</prefetch> can be used with the any of the relationship types and
3970 multiple prefetches can be specified together. Below is a more complex
3971 example that prefetches a CD's artist, its liner notes (if present),
3972 the cover image, the tracks on that cd, and the guests on those
3976 My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
3977 My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
3978 My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
3979 My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
3981 My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
3983 My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
3986 my $rs = $schema->resultset('CD')->search(
3990 { artist => 'record_label'}, # belongs_to => belongs_to
3991 'liner_note', # might_have
3992 'cover_image', # has_one
3993 { tracks => 'guests' }, # has_many => has_many
3998 This will produce SQL like the following:
4000 SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
4004 ON artist.artistid = me.artistid
4005 JOIN record_label record_label
4006 ON record_label.labelid = artist.labelid
4007 LEFT JOIN track tracks
4008 ON tracks.cdid = me.cdid
4009 LEFT JOIN guest guests
4010 ON guests.trackid = track.trackid
4011 LEFT JOIN liner_notes liner_note
4012 ON liner_note.cdid = me.cdid
4013 JOIN cd_artwork cover_image
4014 ON cover_image.cdid = me.cdid
4017 Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
4018 C<tracks>, and C<guests> of the CD will all be available through the
4019 relationship accessors without the need for additional queries to the
4022 However, there is one caveat to be observed: it can be dangerous to
4023 prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
4024 relationship on a given level. e.g.:
4026 my $rs = $schema->resultset('CD')->search(
4030 'tracks', # has_many
4031 { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
4036 In fact, C<DBIx::Class> will emit the following warning:
4038 Prefetching multiple has_many rels tracks and cd_to_producer at top
4039 level will explode the number of row objects retrievable via ->next
4040 or ->all. Use at your own risk.
4042 The collapser currently can't identify duplicate tuples for multiple
4043 L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
4044 result the second L<has_many|DBIx::Class::Relationship/has_many>
4045 relation could contain redundant objects.
4047 =head3 Using L</prefetch> with L</join>
4049 L</prefetch> implies a L</join> with the equivalent argument, and is
4050 properly merged with any existing L</join> specification. So the
4053 my $rs = $schema->resultset('CD')->search(
4054 {'record_label.name' => 'Music Product Ltd.'},
4056 join => {artist => 'record_label'},
4057 prefetch => 'artist',
4061 ... will work, searching on the record label's name, but only
4062 prefetching the C<artist>.
4064 =head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
4066 L</prefetch> implies a L</+select>/L</+as> with the fields of the
4067 prefetched relations. So given:
4069 my $rs = $schema->resultset('CD')->search(
4072 select => ['cd.title'],
4074 prefetch => 'artist',
4078 The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
4079 becomes: C<'cd_title', 'artist.*'>.
4083 Prefetch does a lot of deep magic. As such, it may not behave exactly
4084 as you might expect.
4090 Prefetch uses the L</cache> to populate the prefetched relationships. This
4091 may or may not be what you want.
4095 If you specify a condition on a prefetched relationship, ONLY those
4096 rows that match the prefetched condition will be fetched into that relationship.
4097 This means that adding prefetch to a search() B<may alter> what is returned by
4098 traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
4100 my $artist_rs = $schema->resultset('Artist')->search({
4106 my $count = $artist_rs->first->cds->count;
4108 my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
4110 my $prefetch_count = $artist_rs_prefetch->first->cds->count;
4112 cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
4114 that cmp_ok() may or may not pass depending on the datasets involved. This
4115 behavior may or may not survive the 0.09 transition.
4127 Makes the resultset paged and specifies the page to retrieve. Effectively
4128 identical to creating a non-pages resultset and then calling ->page($page)
4131 If L</rows> attribute is not specified it defaults to 10 rows per page.
4133 When you have a paged resultset, L</count> will only return the number
4134 of rows in the page. To get the total, use the L</pager> and call
4135 C<total_entries> on it.
4145 Specifies the maximum number of rows for direct retrieval or the number of
4146 rows per page if the page attribute or method is used.
4152 =item Value: $offset
4156 Specifies the (zero-based) row number for the first row to be returned, or the
4157 of the first row of the first page if paging is used.
4163 =item Value: \@columns
4167 A arrayref of columns to group by. Can include columns of joined tables.
4169 group_by => [qw/ column1 column2 ... /]
4175 =item Value: $condition
4179 HAVING is a select statement attribute that is applied between GROUP BY and
4180 ORDER BY. It is applied to the after the grouping calculations have been
4183 having => { 'count_employee' => { '>=', 100 } }
4185 or with an in-place function in which case literal SQL is required:
4187 having => \[ 'count(employee) >= ?', [ count => 100 ] ]
4193 =item Value: (0 | 1)
4197 Set to 1 to group by all columns. If the resultset already has a group_by
4198 attribute, this setting is ignored and an appropriate warning is issued.
4204 Adds to the WHERE clause.
4206 # only return rows WHERE deleted IS NULL for all searches
4207 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
4209 Can be overridden by passing C<< { where => undef } >> as an attribute
4216 Set to 1 to cache search results. This prevents extra SQL queries if you
4217 revisit rows in your ResultSet:
4219 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
4221 while( my $artist = $resultset->next ) {
4225 $rs->first; # without cache, this would issue a query
4227 By default, searches are not cached.
4229 For more examples of using these attributes, see
4230 L<DBIx::Class::Manual::Cookbook>.
4236 =item Value: ( 'update' | 'shared' )
4240 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT