1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet is also an iterator. L</next> is used to return all the
50 L<DBIx::Class::Row>s the ResultSet represents.
52 The query that the ResultSet represents is B<only> executed against
53 the database when these methods are called:
73 =head2 Chaining resultsets
75 Let's say you've got a query that needs to be run to return some data
76 to the user. But, you have an authorization system in place that
77 prevents certain users from seeing certain information. So, you want
78 to construct the basic query in one method, but add constraints to it in
83 my $request = $self->get_request; # Get a request object somehow.
84 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
86 my $cd_rs = $schema->resultset('CD')->search({
87 title => $request->param('title'),
88 year => $request->param('year'),
91 $self->apply_security_policy( $cd_rs );
96 sub apply_security_policy {
105 =head3 Resolving conditions and attributes
107 When a resultset is chained from another resultset, conditions and
108 attributes with the same keys need resolving.
110 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
111 into the existing ones from the original resultset.
113 The L</where>, L</having> attribute, and any search conditions are
114 merged with an SQL C<AND> to the existing condition from the original
117 All other attributes are overridden by any new ones supplied in the
120 =head2 Multiple queries
122 Since a resultset just defines a query, you can do all sorts of
123 things with it with the same object.
125 # Don't hit the DB yet.
126 my $cd_rs = $schema->resultset('CD')->search({
127 title => 'something',
131 # Each of these hits the DB individually.
132 my $count = $cd_rs->count;
133 my $most_recent = $cd_rs->get_column('date_released')->max();
134 my @records = $cd_rs->all;
136 And it's not just limited to SELECT statements.
142 $cd_rs->create({ artist => 'Fred' });
144 Which is the same as:
146 $schema->resultset('CD')->create({
147 title => 'something',
152 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
156 If a resultset is used in a numeric context it returns the L</count>.
157 However, if it is used in a booleand context it is always true. So if
158 you want to check if a resultset has any results use C<if $rs != 0>.
159 C<if $rs> will always be true.
167 =item Arguments: $source, \%$attrs
169 =item Return Value: $rs
173 The resultset constructor. Takes a source object (usually a
174 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
175 L</ATTRIBUTES> below). Does not perform any queries -- these are
176 executed as needed by the other methods.
178 Generally you won't need to construct a resultset manually. You'll
179 automatically get one from e.g. a L</search> called in scalar context:
181 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
183 IMPORTANT: If called on an object, proxies to new_result instead so
185 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
187 will return a CD object, not a ResultSet.
193 return $class->new_result(@_) if ref $class;
195 my ($source, $attrs) = @_;
196 $source = $source->handle
197 unless $source->isa('DBIx::Class::ResultSourceHandle');
198 $attrs = { %{$attrs||{}} };
200 if ($attrs->{page}) {
201 $attrs->{rows} ||= 10;
204 $attrs->{alias} ||= 'me';
206 # Creation of {} and bless separated to mitigate RH perl bug
207 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
209 _source_handle => $source,
210 cond => $attrs->{where},
219 $attrs->{result_class} || $source->resolve->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context), @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 If you need to pass in additional attributes but no additional condition,
242 call it as C<search(undef, \%attrs)>.
244 # "SELECT name, artistid FROM $artist_table"
245 my @all_artists = $schema->resultset('Artist')->search(undef, {
246 columns => [qw/name artistid/],
249 For a list of attributes that can be passed to C<search>, see
250 L</ATTRIBUTES>. For more examples of using this function, see
251 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
252 documentation for the first argument, see L<SQL::Abstract>.
254 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 my $rs = $self->search_rs( @_ );
261 return (wantarray ? $rs->all : $rs);
268 =item Arguments: $cond, \%attrs?
270 =item Return Value: $resultset
274 This method does the same exact thing as search() except it will
275 always return a resultset, even in list context.
283 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
284 my $our_attrs = { %{$self->{attrs}} };
285 my $having = delete $our_attrs->{having};
286 my $where = delete $our_attrs->{where};
290 my %safe = (alias => 1, cache => 1);
293 (@_ && defined($_[0])) # @_ == () or (undef)
295 (keys %$attrs # empty attrs or only 'safe' attrs
296 && List::Util::first { !$safe{$_} } keys %$attrs)
298 # no search, effectively just a clone
299 $rows = $self->get_cache;
302 my $new_attrs = { %{$our_attrs}, %{$attrs} };
304 # merge new attrs into inherited
305 foreach my $key (qw/join prefetch +select +as/) {
306 next unless exists $attrs->{$key};
307 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
312 (@_ == 1 || ref $_[0] eq "HASH")
314 (ref $_[0] eq 'HASH')
316 (keys %{ $_[0] } > 0)
324 ? $self->throw_exception("Odd number of arguments to search")
331 if (defined $where) {
332 $new_attrs->{where} = (
333 defined $new_attrs->{where}
336 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
337 } $where, $new_attrs->{where}
344 $new_attrs->{where} = (
345 defined $new_attrs->{where}
348 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
349 } $cond, $new_attrs->{where}
355 if (defined $having) {
356 $new_attrs->{having} = (
357 defined $new_attrs->{having}
360 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
361 } $having, $new_attrs->{having}
367 my $rs = (ref $self)->new($self->result_source, $new_attrs);
369 $rs->set_cache($rows);
374 =head2 search_literal
378 =item Arguments: $sql_fragment, @bind_values
380 =item Return Value: $resultset (scalar context), @row_objs (list context)
384 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
385 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
387 Pass a literal chunk of SQL to be added to the conditional part of the
390 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
391 only be used in that context. There are known problems using C<search_literal>
392 in chained queries; it can result in bind values in the wrong order. See
393 L<DBIx::Class::Manual::Cookbook/Searching> and
394 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
395 require C<search_literal>.
400 my ($self, $cond, @vals) = @_;
401 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
402 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
403 return $self->search(\$cond, $attrs);
410 =item Arguments: @values | \%cols, \%attrs?
412 =item Return Value: $row_object | undef
416 Finds a row based on its primary key or unique constraint. For example, to find
417 a row by its primary key:
419 my $cd = $schema->resultset('CD')->find(5);
421 You can also find a row by a specific unique constraint using the C<key>
422 attribute. For example:
424 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
425 key => 'cd_artist_title'
428 Additionally, you can specify the columns explicitly by name:
430 my $cd = $schema->resultset('CD')->find(
432 artist => 'Massive Attack',
433 title => 'Mezzanine',
435 { key => 'cd_artist_title' }
438 If the C<key> is specified as C<primary>, it searches only on the primary key.
440 If no C<key> is specified, it searches on all unique constraints defined on the
441 source for which column data is provided, including the primary key.
443 If your table does not have a primary key, you B<must> provide a value for the
444 C<key> attribute matching one of the unique constraints on the source.
446 In addition to C<key>, L</find> recognizes and applies standard
447 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
449 Note: If your query does not return only one row, a warning is generated:
451 Query returned more than one row
453 See also L</find_or_create> and L</update_or_create>. For information on how to
454 declare unique constraints, see
455 L<DBIx::Class::ResultSource/add_unique_constraint>.
461 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
463 # Default to the primary key, but allow a specific key
464 my @cols = exists $attrs->{key}
465 ? $self->result_source->unique_constraint_columns($attrs->{key})
466 : $self->result_source->primary_columns;
467 $self->throw_exception(
468 "Can't find unless a primary key is defined or unique constraint is specified"
471 # Parse out a hashref from input
473 if (ref $_[0] eq 'HASH') {
474 $input_query = { %{$_[0]} };
476 elsif (@_ == @cols) {
478 @{$input_query}{@cols} = @_;
481 # Compatibility: Allow e.g. find(id => $value)
482 carp "Find by key => value deprecated; please use a hashref instead";
486 my (%related, $info);
488 KEY: foreach my $key (keys %$input_query) {
489 if (ref($input_query->{$key})
490 && ($info = $self->result_source->relationship_info($key))) {
491 my $val = delete $input_query->{$key};
492 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
493 my $rel_q = $self->result_source->resolve_condition(
494 $info->{cond}, $val, $key
496 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
497 @related{keys %$rel_q} = values %$rel_q;
500 if (my @keys = keys %related) {
501 @{$input_query}{@keys} = values %related;
505 # Build the final query: Default to the disjunction of the unique queries,
506 # but allow the input query in case the ResultSet defines the query or the
507 # user is abusing find
508 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
510 if (exists $attrs->{key}) {
511 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
512 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
513 $query = $self->_add_alias($unique_query, $alias);
516 my @unique_queries = $self->_unique_queries($input_query, $attrs);
517 $query = @unique_queries
518 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
519 : $self->_add_alias($input_query, $alias);
524 my $rs = $self->search($query, $attrs);
525 if (keys %{$rs->_resolved_attrs->{collapse}}) {
527 carp "Query returned more than one row" if $rs->next;
535 if (keys %{$self->_resolved_attrs->{collapse}}) {
536 my $rs = $self->search($query);
538 carp "Query returned more than one row" if $rs->next;
542 return $self->single($query);
549 # Add the specified alias to the specified query hash. A copy is made so the
550 # original query is not modified.
553 my ($self, $query, $alias) = @_;
555 my %aliased = %$query;
556 foreach my $col (grep { ! m/\./ } keys %aliased) {
557 $aliased{"$alias.$col"} = delete $aliased{$col};
565 # Build a list of queries which satisfy unique constraints.
567 sub _unique_queries {
568 my ($self, $query, $attrs) = @_;
570 my @constraint_names = exists $attrs->{key}
572 : $self->result_source->unique_constraint_names;
574 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
575 my $num_where = scalar keys %$where;
578 foreach my $name (@constraint_names) {
579 my @unique_cols = $self->result_source->unique_constraint_columns($name);
580 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
582 my $num_cols = scalar @unique_cols;
583 my $num_query = scalar keys %$unique_query;
585 my $total = $num_query + $num_where;
586 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
587 # The query is either unique on its own or is unique in combination with
588 # the existing where clause
589 push @unique_queries, $unique_query;
593 return @unique_queries;
596 # _build_unique_query
598 # Constrain the specified query hash based on the specified column names.
600 sub _build_unique_query {
601 my ($self, $query, $unique_cols) = @_;
604 map { $_ => $query->{$_} }
605 grep { exists $query->{$_} }
610 =head2 search_related
614 =item Arguments: $rel, $cond, \%attrs?
616 =item Return Value: $new_resultset
620 $new_rs = $cd_rs->search_related('artist', {
624 Searches the specified relationship, optionally specifying a condition and
625 attributes for matching records. See L</ATTRIBUTES> for more information.
630 return shift->related_resultset(shift)->search(@_);
633 =head2 search_related_rs
635 This method works exactly the same as search_related, except that
636 it guarantees a restultset, even in list context.
640 sub search_related_rs {
641 return shift->related_resultset(shift)->search_rs(@_);
648 =item Arguments: none
650 =item Return Value: $cursor
654 Returns a storage-driven cursor to the given resultset. See
655 L<DBIx::Class::Cursor> for more information.
662 my $attrs = { %{$self->_resolved_attrs} };
663 return $self->{cursor}
664 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
665 $attrs->{where},$attrs);
672 =item Arguments: $cond?
674 =item Return Value: $row_object?
678 my $cd = $schema->resultset('CD')->single({ year => 2001 });
680 Inflates the first result without creating a cursor if the resultset has
681 any records in it; if not returns nothing. Used by L</find> as a lean version of
684 While this method can take an optional search condition (just like L</search>)
685 being a fast-code-path it does not recognize search attributes. If you need to
686 add extra joins or similar, call L</search> and then chain-call L</single> on the
687 L<DBIx::Class::ResultSet> returned.
693 As of 0.08100, this method enforces the assumption that the preceeding
694 query returns only one row. If more than one row is returned, you will receive
697 Query returned more than one row
699 In this case, you should be using L</first> or L</find> instead, or if you really
700 know what you are doing, use the L</rows> attribute to explicitly limit the size
708 my ($self, $where) = @_;
710 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
713 my $attrs = { %{$self->_resolved_attrs} };
715 if (defined $attrs->{where}) {
718 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
719 $where, delete $attrs->{where} ]
722 $attrs->{where} = $where;
726 # XXX: Disabled since it doesn't infer uniqueness in all cases
727 # unless ($self->_is_unique_query($attrs->{where})) {
728 # carp "Query not guaranteed to return a single row"
729 # . "; please declare your unique constraints or use search instead";
732 my @data = $self->result_source->storage->select_single(
733 $attrs->{from}, $attrs->{select},
734 $attrs->{where}, $attrs
737 return (@data ? ($self->_construct_object(@data))[0] : undef);
742 # Try to determine if the specified query is guaranteed to be unique, based on
743 # the declared unique constraints.
745 sub _is_unique_query {
746 my ($self, $query) = @_;
748 my $collapsed = $self->_collapse_query($query);
749 my $alias = $self->{attrs}{alias};
751 foreach my $name ($self->result_source->unique_constraint_names) {
752 my @unique_cols = map {
754 } $self->result_source->unique_constraint_columns($name);
756 # Count the values for each unique column
757 my %seen = map { $_ => 0 } @unique_cols;
759 foreach my $key (keys %$collapsed) {
760 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
761 next unless exists $seen{$aliased}; # Additional constraints are okay
762 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
765 # If we get 0 or more than 1 value for a column, it's not necessarily unique
766 return 1 unless grep { $_ != 1 } values %seen;
774 # Recursively collapse the query, accumulating values for each column.
776 sub _collapse_query {
777 my ($self, $query, $collapsed) = @_;
781 if (ref $query eq 'ARRAY') {
782 foreach my $subquery (@$query) {
783 next unless ref $subquery; # -or
784 # warn "ARRAY: " . Dumper $subquery;
785 $collapsed = $self->_collapse_query($subquery, $collapsed);
788 elsif (ref $query eq 'HASH') {
789 if (keys %$query and (keys %$query)[0] eq '-and') {
790 foreach my $subquery (@{$query->{-and}}) {
791 # warn "HASH: " . Dumper $subquery;
792 $collapsed = $self->_collapse_query($subquery, $collapsed);
796 # warn "LEAF: " . Dumper $query;
797 foreach my $col (keys %$query) {
798 my $value = $query->{$col};
799 $collapsed->{$col}{$value}++;
811 =item Arguments: $cond?
813 =item Return Value: $resultsetcolumn
817 my $max_length = $rs->get_column('length')->max;
819 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
824 my ($self, $column) = @_;
825 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
833 =item Arguments: $cond, \%attrs?
835 =item Return Value: $resultset (scalar context), @row_objs (list context)
839 # WHERE title LIKE '%blue%'
840 $cd_rs = $rs->search_like({ title => '%blue%'});
842 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
843 that this is simply a convenience method retained for ex Class::DBI users.
844 You most likely want to use L</search> with specific operators.
846 For more information, see L<DBIx::Class::Manual::Cookbook>.
852 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
853 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
854 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
855 return $class->search($query, { %$attrs });
862 =item Arguments: $first, $last
864 =item Return Value: $resultset (scalar context), @row_objs (list context)
868 Returns a resultset or object list representing a subset of elements from the
869 resultset slice is called on. Indexes are from 0, i.e., to get the first
872 my ($one, $two, $three) = $rs->slice(0, 2);
877 my ($self, $min, $max) = @_;
878 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
879 $attrs->{offset} = $self->{attrs}{offset} || 0;
880 $attrs->{offset} += $min;
881 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
882 return $self->search(undef(), $attrs);
883 #my $slice = (ref $self)->new($self->result_source, $attrs);
884 #return (wantarray ? $slice->all : $slice);
891 =item Arguments: none
893 =item Return Value: $result?
897 Returns the next element in the resultset (C<undef> is there is none).
899 Can be used to efficiently iterate over records in the resultset:
901 my $rs = $schema->resultset('CD')->search;
902 while (my $cd = $rs->next) {
906 Note that you need to store the resultset object, and call C<next> on it.
907 Calling C<< resultset('Table')->next >> repeatedly will always return the
908 first record from the resultset.
914 if (my $cache = $self->get_cache) {
915 $self->{all_cache_position} ||= 0;
916 return $cache->[$self->{all_cache_position}++];
918 if ($self->{attrs}{cache}) {
919 $self->{all_cache_position} = 1;
920 return ($self->all)[0];
922 if ($self->{stashed_objects}) {
923 my $obj = shift(@{$self->{stashed_objects}});
924 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
928 exists $self->{stashed_row}
929 ? @{delete $self->{stashed_row}}
930 : $self->cursor->next
932 return undef unless (@row);
933 my ($row, @more) = $self->_construct_object(@row);
934 $self->{stashed_objects} = \@more if @more;
938 sub _construct_object {
939 my ($self, @row) = @_;
940 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
941 my @new = $self->result_class->inflate_result($self->result_source, @$info);
942 @new = $self->{_attrs}{record_filter}->(@new)
943 if exists $self->{_attrs}{record_filter};
947 sub _collapse_result {
948 my ($self, $as_proto, $row) = @_;
952 # 'foo' => [ undef, 'foo' ]
953 # 'foo.bar' => [ 'foo', 'bar' ]
954 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
956 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
958 my %collapse = %{$self->{_attrs}{collapse}||{}};
962 # if we're doing collapsing (has_many prefetch) we need to grab records
963 # until the PK changes, so fill @pri_index. if not, we leave it empty so
964 # we know we don't have to bother.
966 # the reason for not using the collapse stuff directly is because if you
967 # had for e.g. two artists in a row with no cds, the collapse info for
968 # both would be NULL (undef) so you'd lose the second artist
970 # store just the index so we can check the array positions from the row
971 # without having to contruct the full hash
973 if (keys %collapse) {
974 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
975 foreach my $i (0 .. $#construct_as) {
976 next if defined($construct_as[$i][0]); # only self table
977 if (delete $pri{$construct_as[$i][1]}) {
978 push(@pri_index, $i);
980 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
984 # no need to do an if, it'll be empty if @pri_index is empty anyway
986 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
990 do { # no need to check anything at the front, we always want the first row
994 foreach my $this_as (@construct_as) {
995 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
998 push(@const_rows, \%const);
1000 } until ( # no pri_index => no collapse => drop straight out
1003 do { # get another row, stash it, drop out if different PK
1005 @copy = $self->cursor->next;
1006 $self->{stashed_row} = \@copy;
1008 # last thing in do block, counts as true if anything doesn't match
1010 # check xor defined first for NULL vs. NOT NULL then if one is
1011 # defined the other must be so check string equality
1014 (defined $pri_vals{$_} ^ defined $copy[$_])
1015 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1020 my $alias = $self->{attrs}{alias};
1027 foreach my $const (@const_rows) {
1028 scalar @const_keys or do {
1029 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1031 foreach my $key (@const_keys) {
1034 my @parts = split(/\./, $key);
1036 my $data = $const->{$key};
1037 foreach my $p (@parts) {
1038 $target = $target->[1]->{$p} ||= [];
1040 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1041 # collapsing at this point and on final part
1042 my $pos = $collapse_pos{$cur};
1043 CK: foreach my $ck (@ckey) {
1044 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1045 $collapse_pos{$cur} = $data;
1046 delete @collapse_pos{ # clear all positioning for sub-entries
1047 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1054 if (exists $collapse{$cur}) {
1055 $target = $target->[-1];
1058 $target->[0] = $data;
1060 $info->[0] = $const->{$key};
1068 =head2 result_source
1072 =item Arguments: $result_source?
1074 =item Return Value: $result_source
1078 An accessor for the primary ResultSource object from which this ResultSet
1085 =item Arguments: $result_class?
1087 =item Return Value: $result_class
1091 An accessor for the class to use when creating row objects. Defaults to
1092 C<< result_source->result_class >> - which in most cases is the name of the
1093 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1098 my ($self, $result_class) = @_;
1099 if ($result_class) {
1100 $self->ensure_class_loaded($result_class);
1101 $self->_result_class($result_class);
1103 $self->_result_class;
1110 =item Arguments: $cond, \%attrs??
1112 =item Return Value: $count
1116 Performs an SQL C<COUNT> with the same query as the resultset was built
1117 with to find the number of elements. If passed arguments, does a search
1118 on the resultset and counts the results of that.
1120 Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
1121 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
1122 not support C<DISTINCT> with multiple columns. If you are using such a
1123 database, you should only use columns from the main table in your C<group_by>
1130 return $self->search(@_)->count if @_ and defined $_[0];
1131 return scalar @{ $self->get_cache } if $self->get_cache;
1132 my $count = $self->_count;
1133 return 0 unless $count;
1135 # need to take offset from resolved attrs
1137 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1138 $count = $self->{attrs}{rows} if
1139 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1140 $count = 0 if ($count < 0);
1144 sub _count { # Separated out so pager can get the full count
1146 my $select = { count => '*' };
1148 my $attrs = { %{$self->_resolved_attrs} };
1149 if (my $group_by = delete $attrs->{group_by}) {
1150 delete $attrs->{having};
1151 my @distinct = (ref $group_by ? @$group_by : ($group_by));
1152 # todo: try CONCAT for multi-column pk
1153 my @pk = $self->result_source->primary_columns;
1155 my $alias = $attrs->{alias};
1156 foreach my $column (@distinct) {
1157 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
1158 @distinct = ($column);
1164 $select = { count => { distinct => \@distinct } };
1167 $attrs->{select} = $select;
1168 $attrs->{as} = [qw/count/];
1170 # offset, order by and page are not needed to count. record_filter is cdbi
1171 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
1173 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1174 my ($count) = $tmp_rs->cursor->next;
1182 =head2 count_literal
1186 =item Arguments: $sql_fragment, @bind_values
1188 =item Return Value: $count
1192 Counts the results in a literal query. Equivalent to calling L</search_literal>
1193 with the passed arguments, then L</count>.
1197 sub count_literal { shift->search_literal(@_)->count; }
1203 =item Arguments: none
1205 =item Return Value: @objects
1209 Returns all elements in the resultset. Called implicitly if the resultset
1210 is returned in list context.
1217 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1220 return @{ $self->get_cache } if $self->get_cache;
1224 # TODO: don't call resolve here
1225 if (keys %{$self->_resolved_attrs->{collapse}}) {
1226 # if ($self->{attrs}{prefetch}) {
1227 # Using $self->cursor->all is really just an optimisation.
1228 # If we're collapsing has_many prefetches it probably makes
1229 # very little difference, and this is cleaner than hacking
1230 # _construct_object to survive the approach
1231 my @row = $self->cursor->next;
1233 push(@obj, $self->_construct_object(@row));
1234 @row = (exists $self->{stashed_row}
1235 ? @{delete $self->{stashed_row}}
1236 : $self->cursor->next);
1239 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1242 $self->set_cache(\@obj) if $self->{attrs}{cache};
1250 =item Arguments: none
1252 =item Return Value: $self
1256 Resets the resultset's cursor, so you can iterate through the elements again.
1262 delete $self->{_attrs} if exists $self->{_attrs};
1263 $self->{all_cache_position} = 0;
1264 $self->cursor->reset;
1272 =item Arguments: none
1274 =item Return Value: $object?
1278 Resets the resultset and returns an object for the first result (if the
1279 resultset returns anything).
1284 return $_[0]->reset->next;
1287 # _cond_for_update_delete
1289 # update/delete require the condition to be modified to handle
1290 # the differing SQL syntax available. This transforms the $self->{cond}
1291 # appropriately, returning the new condition.
1293 sub _cond_for_update_delete {
1294 my ($self, $full_cond) = @_;
1297 $full_cond ||= $self->{cond};
1298 # No-op. No condition, we're updating/deleting everything
1299 return $cond unless ref $full_cond;
1301 if (ref $full_cond eq 'ARRAY') {
1305 foreach my $key (keys %{$_}) {
1307 $hash{$1} = $_->{$key};
1313 elsif (ref $full_cond eq 'HASH') {
1314 if ((keys %{$full_cond})[0] eq '-and') {
1317 my @cond = @{$full_cond->{-and}};
1318 for (my $i = 0; $i < @cond; $i++) {
1319 my $entry = $cond[$i];
1322 if (ref $entry eq 'HASH') {
1323 $hash = $self->_cond_for_update_delete($entry);
1326 $entry =~ /([^.]+)$/;
1327 $hash->{$1} = $cond[++$i];
1330 push @{$cond->{-and}}, $hash;
1334 foreach my $key (keys %{$full_cond}) {
1336 $cond->{$1} = $full_cond->{$key};
1341 $self->throw_exception(
1342 "Can't update/delete on resultset with condition unless hash or array"
1354 =item Arguments: \%values
1356 =item Return Value: $storage_rv
1360 Sets the specified columns in the resultset to the supplied values in a
1361 single query. Return value will be true if the update succeeded or false
1362 if no records were updated; exact type of success value is storage-dependent.
1367 my ($self, $values) = @_;
1368 $self->throw_exception("Values for update must be a hash")
1369 unless ref $values eq 'HASH';
1371 carp( 'WARNING! Currently $rs->update() does not generate proper SQL'
1372 . ' on joined resultsets, and may affect rows well outside of the'
1373 . ' contents of $rs. Use at your own risk' )
1374 if ( $self->{attrs}{seen_join} );
1376 my $cond = $self->_cond_for_update_delete;
1378 return $self->result_source->storage->update(
1379 $self->result_source, $values, $cond
1387 =item Arguments: \%values
1389 =item Return Value: 1
1393 Fetches all objects and updates them one at a time. Note that C<update_all>
1394 will run DBIC cascade triggers, while L</update> will not.
1399 my ($self, $values) = @_;
1400 $self->throw_exception("Values for update must be a hash")
1401 unless ref $values eq 'HASH';
1402 foreach my $obj ($self->all) {
1403 $obj->set_columns($values)->update;
1412 =item Arguments: none
1414 =item Return Value: 1
1418 Deletes the contents of the resultset from its result source. Note that this
1419 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1420 to run. See also L<DBIx::Class::Row/delete>.
1422 delete may not generate correct SQL for a query with joins or a resultset
1423 chained from a related resultset. In this case it will generate a warning:-
1425 WARNING! Currently $rs->delete() does not generate proper SQL on
1426 joined resultsets, and may delete rows well outside of the contents
1427 of $rs. Use at your own risk
1429 In these cases you may find that delete_all is more appropriate, or you
1430 need to respecify your query in a way that can be expressed without a join.
1436 $self->throw_exception("Delete should not be passed any arguments")
1438 carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
1439 . ' on joined resultsets, and may delete rows well outside of the'
1440 . ' contents of $rs. Use at your own risk' )
1441 if ( $self->{attrs}{seen_join} );
1442 my $cond = $self->_cond_for_update_delete;
1444 $self->result_source->storage->delete($self->result_source, $cond);
1452 =item Arguments: none
1454 =item Return Value: 1
1458 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1459 will run DBIC cascade triggers, while L</delete> will not.
1465 $_->delete for $self->all;
1473 =item Arguments: \@data;
1477 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1478 For the arrayref of hashrefs style each hashref should be a structure suitable
1479 forsubmitting to a $resultset->create(...) method.
1481 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1482 to insert the data, as this is a faster method.
1484 Otherwise, each set of data is inserted into the database using
1485 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1486 objects is returned.
1488 Example: Assuming an Artist Class that has many CDs Classes relating:
1490 my $Artist_rs = $schema->resultset("Artist");
1492 ## Void Context Example
1493 $Artist_rs->populate([
1494 { artistid => 4, name => 'Manufactured Crap', cds => [
1495 { title => 'My First CD', year => 2006 },
1496 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1499 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1500 { title => 'My parents sold me to a record company' ,year => 2005 },
1501 { title => 'Why Am I So Ugly?', year => 2006 },
1502 { title => 'I Got Surgery and am now Popular', year => 2007 }
1507 ## Array Context Example
1508 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1509 { name => "Artist One"},
1510 { name => "Artist Two"},
1511 { name => "Artist Three", cds=> [
1512 { title => "First CD", year => 2007},
1513 { title => "Second CD", year => 2008},
1517 print $ArtistOne->name; ## response is 'Artist One'
1518 print $ArtistThree->cds->count ## reponse is '2'
1520 For the arrayref of arrayrefs style, the first element should be a list of the
1521 fieldsnames to which the remaining elements are rows being inserted. For
1524 $Arstist_rs->populate([
1525 [qw/artistid name/],
1526 [100, 'A Formally Unknown Singer'],
1527 [101, 'A singer that jumped the shark two albums ago'],
1528 [102, 'An actually cool singer.'],
1531 Please note an important effect on your data when choosing between void and
1532 wantarray context. Since void context goes straight to C<insert_bulk> in
1533 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1534 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1535 create primary keys for you, you will find that your PKs are empty. In this
1536 case you will have to use the wantarray context in order to create those
1542 my $self = shift @_;
1543 my $data = ref $_[0][0] eq 'HASH'
1544 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1545 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1547 if(defined wantarray) {
1549 foreach my $item (@$data) {
1550 push(@created, $self->create($item));
1554 my ($first, @rest) = @$data;
1556 my @names = grep {!ref $first->{$_}} keys %$first;
1557 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1558 my @pks = $self->result_source->primary_columns;
1560 ## do the belongs_to relationships
1561 foreach my $index (0..$#$data) {
1562 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1563 my @ret = $self->populate($data);
1567 foreach my $rel (@rels) {
1568 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1569 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1570 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1571 my $related = $result->result_source->resolve_condition(
1572 $result->result_source->relationship_info($reverse)->{cond},
1577 delete $data->[$index]->{$rel};
1578 $data->[$index] = {%{$data->[$index]}, %$related};
1580 push @names, keys %$related if $index == 0;
1584 ## do bulk insert on current row
1585 my @values = map { [ @$_{@names} ] } @$data;
1587 $self->result_source->storage->insert_bulk(
1588 $self->result_source,
1593 ## do the has_many relationships
1594 foreach my $item (@$data) {
1596 foreach my $rel (@rels) {
1597 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1599 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1600 || $self->throw_exception('Cannot find the relating object.');
1602 my $child = $parent->$rel;
1604 my $related = $child->result_source->resolve_condition(
1605 $parent->result_source->relationship_info($rel)->{cond},
1610 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1611 my @populate = map { {%$_, %$related} } @rows_to_add;
1613 $child->populate( \@populate );
1619 =head2 _normalize_populate_args ($args)
1621 Private method used by L</populate> to normalize its incoming arguments. Factored
1622 out in case you want to subclass and accept new argument structures to the
1623 L</populate> method.
1627 sub _normalize_populate_args {
1628 my ($self, $data) = @_;
1629 my @names = @{shift(@$data)};
1630 my @results_to_create;
1631 foreach my $datum (@$data) {
1632 my %result_to_create;
1633 foreach my $index (0..$#names) {
1634 $result_to_create{$names[$index]} = $$datum[$index];
1636 push @results_to_create, \%result_to_create;
1638 return \@results_to_create;
1645 =item Arguments: none
1647 =item Return Value: $pager
1651 Return Value a L<Data::Page> object for the current resultset. Only makes
1652 sense for queries with a C<page> attribute.
1654 To get the full count of entries for a paged resultset, call
1655 C<total_entries> on the L<Data::Page> object.
1661 my $attrs = $self->{attrs};
1662 $self->throw_exception("Can't create pager for non-paged rs")
1663 unless $self->{attrs}{page};
1664 $attrs->{rows} ||= 10;
1665 return $self->{pager} ||= Data::Page->new(
1666 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1673 =item Arguments: $page_number
1675 =item Return Value: $rs
1679 Returns a resultset for the $page_number page of the resultset on which page
1680 is called, where each page contains a number of rows equal to the 'rows'
1681 attribute set on the resultset (10 by default).
1686 my ($self, $page) = @_;
1687 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1694 =item Arguments: \%vals
1696 =item Return Value: $rowobject
1700 Creates a new row object in the resultset's result class and returns
1701 it. The row is not inserted into the database at this point, call
1702 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1703 will tell you whether the row object has been inserted or not.
1705 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1710 my ($self, $values) = @_;
1711 $self->throw_exception( "new_result needs a hash" )
1712 unless (ref $values eq 'HASH');
1715 my $alias = $self->{attrs}{alias};
1718 defined $self->{cond}
1719 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1721 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1722 $new{-from_resultset} = [ keys %new ] if keys %new;
1724 $self->throw_exception(
1725 "Can't abstract implicit construct, condition not a hash"
1726 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1728 my $collapsed_cond = (
1730 ? $self->_collapse_cond($self->{cond})
1734 # precendence must be given to passed values over values inherited from
1735 # the cond, so the order here is important.
1736 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1737 while( my($col,$value) = each %implied ){
1738 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1739 $new{$col} = $value->{'='};
1742 $new{$col} = $value if $self->_is_deterministic_value($value);
1748 %{ $self->_remove_alias($values, $alias) },
1749 -source_handle => $self->_source_handle,
1750 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1753 return $self->result_class->new(\%new);
1756 # _is_deterministic_value
1758 # Make an effor to strip non-deterministic values from the condition,
1759 # to make sure new_result chokes less
1761 sub _is_deterministic_value {
1764 my $ref_type = ref $value;
1765 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1766 return 1 if Scalar::Util::blessed($value);
1772 # Recursively collapse the condition.
1774 sub _collapse_cond {
1775 my ($self, $cond, $collapsed) = @_;
1779 if (ref $cond eq 'ARRAY') {
1780 foreach my $subcond (@$cond) {
1781 next unless ref $subcond; # -or
1782 # warn "ARRAY: " . Dumper $subcond;
1783 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1786 elsif (ref $cond eq 'HASH') {
1787 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1788 foreach my $subcond (@{$cond->{-and}}) {
1789 # warn "HASH: " . Dumper $subcond;
1790 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1794 # warn "LEAF: " . Dumper $cond;
1795 foreach my $col (keys %$cond) {
1796 my $value = $cond->{$col};
1797 $collapsed->{$col} = $value;
1807 # Remove the specified alias from the specified query hash. A copy is made so
1808 # the original query is not modified.
1811 my ($self, $query, $alias) = @_;
1813 my %orig = %{ $query || {} };
1816 foreach my $key (keys %orig) {
1818 $unaliased{$key} = $orig{$key};
1821 $unaliased{$1} = $orig{$key}
1822 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1828 =head2 as_query (EXPERIMENTAL)
1832 =item Arguments: none
1834 =item Return Value: \[ $sql, @bind ]
1838 Returns the SQL query and bind vars associated with the invocant.
1840 This is generally used as the RHS for a subquery.
1842 B<NOTE>: This feature is still experimental.
1846 sub as_query { return shift->cursor->as_query(@_) }
1852 =item Arguments: \%vals, \%attrs?
1854 =item Return Value: $rowobject
1858 my $artist = $schema->resultset('Artist')->find_or_new(
1859 { artist => 'fred' }, { key => 'artists' });
1861 $cd->cd_to_producer->find_or_new({ producer => $producer },
1862 { key => 'primary });
1864 Find an existing record from this resultset, based on its primary
1865 key, or a unique constraint. If none exists, instantiate a new result
1866 object and return it. The object will not be saved into your storage
1867 until you call L<DBIx::Class::Row/insert> on it.
1869 You most likely want this method when looking for existing rows using
1870 a unique constraint that is not the primary key, or looking for
1873 If you want objects to be saved immediately, use L</find_or_create> instead.
1875 B<Note>: C<find_or_new> is probably not what you want when creating a
1876 new row in a table that uses primary keys supplied by the
1877 database. Passing in a primary key column with a value of I<undef>
1878 will cause L</find> to attempt to search for a row with a value of
1885 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1886 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1887 my $exists = $self->find($hash, $attrs);
1888 return defined $exists ? $exists : $self->new_result($hash);
1895 =item Arguments: \%vals
1897 =item Return Value: a L<DBIx::Class::Row> $object
1901 Attempt to create a single new row or a row with multiple related rows
1902 in the table represented by the resultset (and related tables). This
1903 will not check for duplicate rows before inserting, use
1904 L</find_or_create> to do that.
1906 To create one row for this resultset, pass a hashref of key/value
1907 pairs representing the columns of the table and the values you wish to
1908 store. If the appropriate relationships are set up, foreign key fields
1909 can also be passed an object representing the foreign row, and the
1910 value will be set to its primary key.
1912 To create related objects, pass a hashref for the value if the related
1913 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1914 and use the name of the relationship as the key. (NOT the name of the field,
1915 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
1916 of hashrefs containing the data for each of the rows to create in the foreign
1917 tables, again using the relationship name as the key.
1919 Instead of hashrefs of plain related data (key/value pairs), you may
1920 also pass new or inserted objects. New objects (not inserted yet, see
1921 L</new>), will be inserted into their appropriate tables.
1923 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1925 Example of creating a new row.
1927 $person_rs->create({
1928 name=>"Some Person",
1929 email=>"somebody@someplace.com"
1932 Example of creating a new row and also creating rows in a related C<has_many>
1933 or C<has_one> resultset. Note Arrayref.
1936 { artistid => 4, name => 'Manufactured Crap', cds => [
1937 { title => 'My First CD', year => 2006 },
1938 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1943 Example of creating a new row and also creating a row in a related
1944 C<belongs_to>resultset. Note Hashref.
1947 title=>"Music for Silly Walks",
1950 name=>"Silly Musician",
1957 my ($self, $attrs) = @_;
1958 $self->throw_exception( "create needs a hashref" )
1959 unless ref $attrs eq 'HASH';
1960 return $self->new_result($attrs)->insert;
1963 =head2 find_or_create
1967 =item Arguments: \%vals, \%attrs?
1969 =item Return Value: $rowobject
1973 $cd->cd_to_producer->find_or_create({ producer => $producer },
1974 { key => 'primary });
1976 Tries to find a record based on its primary key or unique constraints; if none
1977 is found, creates one and returns that instead.
1979 my $cd = $schema->resultset('CD')->find_or_create({
1981 artist => 'Massive Attack',
1982 title => 'Mezzanine',
1986 Also takes an optional C<key> attribute, to search by a specific key or unique
1987 constraint. For example:
1989 my $cd = $schema->resultset('CD')->find_or_create(
1991 artist => 'Massive Attack',
1992 title => 'Mezzanine',
1994 { key => 'cd_artist_title' }
1997 B<Note>: Because find_or_create() reads from the database and then
1998 possibly inserts based on the result, this method is subject to a race
1999 condition. Another process could create a record in the table after
2000 the find has completed and before the create has started. To avoid
2001 this problem, use find_or_create() inside a transaction.
2003 B<Note>: C<find_or_create> is probably not what you want when creating
2004 a new row in a table that uses primary keys supplied by the
2005 database. Passing in a primary key column with a value of I<undef>
2006 will cause L</find> to attempt to search for a row with a value of
2009 See also L</find> and L</update_or_create>. For information on how to declare
2010 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2014 sub find_or_create {
2016 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2017 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2018 my $exists = $self->find($hash, $attrs);
2019 return defined $exists ? $exists : $self->create($hash);
2022 =head2 update_or_create
2026 =item Arguments: \%col_values, { key => $unique_constraint }?
2028 =item Return Value: $rowobject
2032 $resultset->update_or_create({ col => $val, ... });
2034 First, searches for an existing row matching one of the unique constraints
2035 (including the primary key) on the source of this resultset. If a row is
2036 found, updates it with the other given column values. Otherwise, creates a new
2039 Takes an optional C<key> attribute to search on a specific unique constraint.
2042 # In your application
2043 my $cd = $schema->resultset('CD')->update_or_create(
2045 artist => 'Massive Attack',
2046 title => 'Mezzanine',
2049 { key => 'cd_artist_title' }
2052 $cd->cd_to_producer->update_or_create({
2053 producer => $producer,
2060 If no C<key> is specified, it searches on all unique constraints defined on the
2061 source, including the primary key.
2063 If the C<key> is specified as C<primary>, it searches only on the primary key.
2065 See also L</find> and L</find_or_create>. For information on how to declare
2066 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2068 B<Note>: C<update_or_create> is probably not what you want when
2069 looking for a row in a table that uses primary keys supplied by the
2070 database, unless you actually have a key value. Passing in a primary
2071 key column with a value of I<undef> will cause L</find> to attempt to
2072 search for a row with a value of I<NULL>.
2076 sub update_or_create {
2078 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2079 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2081 my $row = $self->find($cond, $attrs);
2083 $row->update($cond);
2087 return $self->create($cond);
2094 =item Arguments: none
2096 =item Return Value: \@cache_objects?
2100 Gets the contents of the cache for the resultset, if the cache is set.
2102 The cache is populated either by using the L</prefetch> attribute to
2103 L</search> or by calling L</set_cache>.
2115 =item Arguments: \@cache_objects
2117 =item Return Value: \@cache_objects
2121 Sets the contents of the cache for the resultset. Expects an arrayref
2122 of objects of the same class as those produced by the resultset. Note that
2123 if the cache is set the resultset will return the cached objects rather
2124 than re-querying the database even if the cache attr is not set.
2126 The contents of the cache can also be populated by using the
2127 L</prefetch> attribute to L</search>.
2132 my ( $self, $data ) = @_;
2133 $self->throw_exception("set_cache requires an arrayref")
2134 if defined($data) && (ref $data ne 'ARRAY');
2135 $self->{all_cache} = $data;
2142 =item Arguments: none
2144 =item Return Value: []
2148 Clears the cache for the resultset.
2153 shift->set_cache(undef);
2156 =head2 related_resultset
2160 =item Arguments: $relationship_name
2162 =item Return Value: $resultset
2166 Returns a related resultset for the supplied relationship name.
2168 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2172 sub related_resultset {
2173 my ($self, $rel) = @_;
2175 $self->{related_resultsets} ||= {};
2176 return $self->{related_resultsets}{$rel} ||= do {
2177 my $rel_obj = $self->result_source->relationship_info($rel);
2179 $self->throw_exception(
2180 "search_related: result source '" . $self->result_source->source_name .
2181 "' has no such relationship $rel")
2184 my ($from,$seen) = $self->_resolve_from($rel);
2186 my $join_count = $seen->{$rel};
2187 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2189 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2190 my %attrs = %{$self->{attrs}||{}};
2191 delete @attrs{qw(result_class alias)};
2195 if (my $cache = $self->get_cache) {
2196 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2197 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2202 my $rel_source = $self->result_source->related_source($rel);
2206 # The reason we do this now instead of passing the alias to the
2207 # search_rs below is that if you wrap/overload resultset on the
2208 # source you need to know what alias it's -going- to have for things
2209 # to work sanely (e.g. RestrictWithObject wants to be able to add
2210 # extra query restrictions, and these may need to be $alias.)
2212 my $attrs = $rel_source->resultset_attributes;
2213 local $attrs->{alias} = $alias;
2215 $rel_source->resultset
2223 where => $self->{cond},
2228 $new->set_cache($new_cache) if $new_cache;
2233 =head2 current_source_alias
2237 =item Arguments: none
2239 =item Return Value: $source_alias
2243 Returns the current table alias for the result source this resultset is built
2244 on, that will be used in the SQL query. Usually it is C<me>.
2246 Currently the source alias that refers to the result set returned by a
2247 L</search>/L</find> family method depends on how you got to the resultset: it's
2248 C<me> by default, but eg. L</search_related> aliases it to the related result
2249 source name (and keeps C<me> referring to the original result set). The long
2250 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2251 (and make this method unnecessary).
2253 Thus it's currently necessary to use this method in predefined queries (see
2254 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2255 source alias of the current result set:
2257 # in a result set class
2259 my ($self, $user) = @_;
2261 my $me = $self->current_source_alias;
2263 return $self->search(
2264 "$me.modified" => $user->id,
2270 sub current_source_alias {
2273 return ($self->{attrs} || {})->{alias} || 'me';
2277 my ($self, $extra_join) = @_;
2278 my $source = $self->result_source;
2279 my $attrs = $self->{attrs};
2281 my $from = $attrs->{from}
2282 || [ { $attrs->{alias} => $source->from } ];
2284 my $seen = { %{$attrs->{seen_join}||{}} };
2286 my $join = ($attrs->{join}
2287 ? [ $attrs->{join}, $extra_join ]
2290 # we need to take the prefetch the attrs into account before we
2291 # ->resolve_join as otherwise they get lost - captainL
2292 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2296 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2299 return ($from,$seen);
2302 sub _resolved_attrs {
2304 return $self->{_attrs} if $self->{_attrs};
2306 my $attrs = { %{ $self->{attrs} || {} } };
2307 my $source = $self->result_source;
2308 my $alias = $attrs->{alias};
2310 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2313 # build columns (as long as select isn't set) into a set of as/select hashes
2314 unless ( $attrs->{select} ) {
2316 ( ref($_) eq 'HASH' ) ? $_
2319 /^\Q${alias}.\E(.+)$/ ? $1
2321 ) => ( /\./ ? $_ : "${alias}.$_" )
2323 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2325 # add the additional columns on
2326 foreach ( 'include_columns', '+columns' ) {
2327 push @colbits, map {
2328 ( ref($_) eq 'HASH' )
2330 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2331 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2334 # start with initial select items
2335 if ( $attrs->{select} ) {
2337 ( ref $attrs->{select} eq 'ARRAY' )
2338 ? [ @{ $attrs->{select} } ]
2339 : [ $attrs->{select} ];
2343 ref $attrs->{as} eq 'ARRAY'
2344 ? [ @{ $attrs->{as} } ]
2347 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2352 # otherwise we intialise select & as to empty
2353 $attrs->{select} = [];
2357 # now add colbits to select/as
2358 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2359 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2362 if ( $adds = delete $attrs->{'+select'} ) {
2363 $adds = [$adds] unless ref $adds eq 'ARRAY';
2365 @{ $attrs->{select} },
2366 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2369 if ( $adds = delete $attrs->{'+as'} ) {
2370 $adds = [$adds] unless ref $adds eq 'ARRAY';
2371 push( @{ $attrs->{as} }, @$adds );
2374 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2376 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2377 my $join = delete $attrs->{join} || {};
2379 if ( defined $attrs->{prefetch} ) {
2380 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2384 $attrs->{from} = # have to copy here to avoid corrupting the original
2386 @{ $attrs->{from} },
2387 $source->resolve_join(
2388 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2394 $attrs->{group_by} ||= $attrs->{select}
2395 if delete $attrs->{distinct};
2396 if ( $attrs->{order_by} ) {
2397 $attrs->{order_by} = (
2398 ref( $attrs->{order_by} ) eq 'ARRAY'
2399 ? [ @{ $attrs->{order_by} } ]
2400 : [ $attrs->{order_by} ]
2404 $attrs->{order_by} = [];
2407 my $collapse = $attrs->{collapse} || {};
2408 if ( my $prefetch = delete $attrs->{prefetch} ) {
2409 $prefetch = $self->_merge_attr( {}, $prefetch );
2411 my $seen = { %{ $attrs->{seen_join} || {} } };
2412 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2414 # bring joins back to level of current class
2416 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2417 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2418 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2420 push( @{ $attrs->{order_by} }, @pre_order );
2422 $attrs->{collapse} = $collapse;
2424 if ( $attrs->{page} ) {
2425 $attrs->{offset} ||= 0;
2426 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2429 return $self->{_attrs} = $attrs;
2433 my ($self, $attr) = @_;
2435 if (ref $attr eq 'HASH') {
2436 return $self->_rollout_hash($attr);
2437 } elsif (ref $attr eq 'ARRAY') {
2438 return $self->_rollout_array($attr);
2444 sub _rollout_array {
2445 my ($self, $attr) = @_;
2448 foreach my $element (@{$attr}) {
2449 if (ref $element eq 'HASH') {
2450 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2451 } elsif (ref $element eq 'ARRAY') {
2452 # XXX - should probably recurse here
2453 push( @rolled_array, @{$self->_rollout_array($element)} );
2455 push( @rolled_array, $element );
2458 return \@rolled_array;
2462 my ($self, $attr) = @_;
2465 foreach my $key (keys %{$attr}) {
2466 push( @rolled_array, { $key => $attr->{$key} } );
2468 return \@rolled_array;
2471 sub _calculate_score {
2472 my ($self, $a, $b) = @_;
2474 if (ref $b eq 'HASH') {
2475 my ($b_key) = keys %{$b};
2476 if (ref $a eq 'HASH') {
2477 my ($a_key) = keys %{$a};
2478 if ($a_key eq $b_key) {
2479 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2484 return ($a eq $b_key) ? 1 : 0;
2487 if (ref $a eq 'HASH') {
2488 my ($a_key) = keys %{$a};
2489 return ($b eq $a_key) ? 1 : 0;
2491 return ($b eq $a) ? 1 : 0;
2497 my ($self, $orig, $import) = @_;
2499 return $import unless defined($orig);
2500 return $orig unless defined($import);
2502 $orig = $self->_rollout_attr($orig);
2503 $import = $self->_rollout_attr($import);
2506 foreach my $import_element ( @{$import} ) {
2507 # find best candidate from $orig to merge $b_element into
2508 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2509 foreach my $orig_element ( @{$orig} ) {
2510 my $score = $self->_calculate_score( $orig_element, $import_element );
2511 if ($score > $best_candidate->{score}) {
2512 $best_candidate->{position} = $position;
2513 $best_candidate->{score} = $score;
2517 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2519 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2520 push( @{$orig}, $import_element );
2522 my $orig_best = $orig->[$best_candidate->{position}];
2523 # merge orig_best and b_element together and replace original with merged
2524 if (ref $orig_best ne 'HASH') {
2525 $orig->[$best_candidate->{position}] = $import_element;
2526 } elsif (ref $import_element eq 'HASH') {
2527 my ($key) = keys %{$orig_best};
2528 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2531 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2541 $self->_source_handle($_[0]->handle);
2543 $self->_source_handle->resolve;
2547 =head2 throw_exception
2549 See L<DBIx::Class::Schema/throw_exception> for details.
2553 sub throw_exception {
2555 if (ref $self && $self->_source_handle->schema) {
2556 $self->_source_handle->schema->throw_exception(@_)
2563 # XXX: FIXME: Attributes docs need clearing up
2567 Attributes are used to refine a ResultSet in various ways when
2568 searching for data. They can be passed to any method which takes an
2569 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2572 These are in no particular order:
2578 =item Value: ( $order_by | \@order_by | \%order_by )
2582 Which column(s) to order the results by. If a single column name, or
2583 an arrayref of names is supplied, the argument is passed through
2584 directly to SQL. The hashref syntax allows for connection-agnostic
2585 specification of ordering direction:
2587 For descending order:
2589 order_by => { -desc => [qw/col1 col2 col3/] }
2591 For explicit ascending order:
2593 order_by => { -asc => 'col' }
2595 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2596 supported, although you are strongly encouraged to use the hashref
2597 syntax as outlined above.
2603 =item Value: \@columns
2607 Shortcut to request a particular set of columns to be retrieved. Each
2608 column spec may be a string (a table column name), or a hash (in which
2609 case the key is the C<as> value, and the value is used as the C<select>
2610 expression). Adds C<me.> onto the start of any column without a C<.> in
2611 it and sets C<select> from that, then auto-populates C<as> from
2612 C<select> as normal. (You may also use the C<cols> attribute, as in
2613 earlier versions of DBIC.)
2619 =item Value: \@columns
2623 Indicates additional columns to be selected from storage. Works the same
2624 as L</columns> but adds columns to the selection. (You may also use the
2625 C<include_columns> attribute, as in earlier versions of DBIC). For
2628 $schema->resultset('CD')->search(undef, {
2629 '+columns' => ['artist.name'],
2633 would return all CDs and include a 'name' column to the information
2634 passed to object inflation. Note that the 'artist' is the name of the
2635 column (or relationship) accessor, and 'name' is the name of the column
2636 accessor in the related table.
2638 =head2 include_columns
2642 =item Value: \@columns
2646 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2652 =item Value: \@select_columns
2656 Indicates which columns should be selected from the storage. You can use
2657 column names, or in the case of RDBMS back ends, function or stored procedure
2660 $rs = $schema->resultset('Employee')->search(undef, {
2663 { count => 'employeeid' },
2668 When you use function/stored procedure names and do not supply an C<as>
2669 attribute, the column names returned are storage-dependent. E.g. MySQL would
2670 return a column named C<count(employeeid)> in the above example.
2676 Indicates additional columns to be selected from storage. Works the same as
2677 L</select> but adds columns to the selection.
2685 Indicates additional column names for those added via L</+select>. See L</as>.
2693 =item Value: \@inflation_names
2697 Indicates column names for object inflation. That is, C<as>
2698 indicates the name that the column can be accessed as via the
2699 C<get_column> method (or via the object accessor, B<if one already
2700 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2702 The C<as> attribute is used in conjunction with C<select>,
2703 usually when C<select> contains one or more function or stored
2706 $rs = $schema->resultset('Employee')->search(undef, {
2709 { count => 'employeeid' }
2711 as => ['name', 'employee_count'],
2714 my $employee = $rs->first(); # get the first Employee
2716 If the object against which the search is performed already has an accessor
2717 matching a column name specified in C<as>, the value can be retrieved using
2718 the accessor as normal:
2720 my $name = $employee->name();
2722 If on the other hand an accessor does not exist in the object, you need to
2723 use C<get_column> instead:
2725 my $employee_count = $employee->get_column('employee_count');
2727 You can create your own accessors if required - see
2728 L<DBIx::Class::Manual::Cookbook> for details.
2730 Please note: This will NOT insert an C<AS employee_count> into the SQL
2731 statement produced, it is used for internal access only. Thus
2732 attempting to use the accessor in an C<order_by> clause or similar
2733 will fail miserably.
2735 To get around this limitation, you can supply literal SQL to your
2736 C<select> attibute that contains the C<AS alias> text, eg:
2738 select => [\'myfield AS alias']
2744 =item Value: ($rel_name | \@rel_names | \%rel_names)
2748 Contains a list of relationships that should be joined for this query. For
2751 # Get CDs by Nine Inch Nails
2752 my $rs = $schema->resultset('CD')->search(
2753 { 'artist.name' => 'Nine Inch Nails' },
2754 { join => 'artist' }
2757 Can also contain a hash reference to refer to the other relation's relations.
2760 package MyApp::Schema::Track;
2761 use base qw/DBIx::Class/;
2762 __PACKAGE__->table('track');
2763 __PACKAGE__->add_columns(qw/trackid cd position title/);
2764 __PACKAGE__->set_primary_key('trackid');
2765 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2768 # In your application
2769 my $rs = $schema->resultset('Artist')->search(
2770 { 'track.title' => 'Teardrop' },
2772 join => { cd => 'track' },
2773 order_by => 'artist.name',
2777 You need to use the relationship (not the table) name in conditions,
2778 because they are aliased as such. The current table is aliased as "me", so
2779 you need to use me.column_name in order to avoid ambiguity. For example:
2781 # Get CDs from 1984 with a 'Foo' track
2782 my $rs = $schema->resultset('CD')->search(
2785 'tracks.name' => 'Foo'
2787 { join => 'tracks' }
2790 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2791 similarly for a third time). For e.g.
2793 my $rs = $schema->resultset('Artist')->search({
2794 'cds.title' => 'Down to Earth',
2795 'cds_2.title' => 'Popular',
2797 join => [ qw/cds cds/ ],
2800 will return a set of all artists that have both a cd with title 'Down
2801 to Earth' and a cd with title 'Popular'.
2803 If you want to fetch related objects from other tables as well, see C<prefetch>
2806 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2812 =item Value: ($rel_name | \@rel_names | \%rel_names)
2816 Contains one or more relationships that should be fetched along with
2817 the main query (when they are accessed afterwards the data will
2818 already be available, without extra queries to the database). This is
2819 useful for when you know you will need the related objects, because it
2820 saves at least one query:
2822 my $rs = $schema->resultset('Tag')->search(
2831 The initial search results in SQL like the following:
2833 SELECT tag.*, cd.*, artist.* FROM tag
2834 JOIN cd ON tag.cd = cd.cdid
2835 JOIN artist ON cd.artist = artist.artistid
2837 L<DBIx::Class> has no need to go back to the database when we access the
2838 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2841 Simple prefetches will be joined automatically, so there is no need
2842 for a C<join> attribute in the above search.
2844 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2845 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2846 with an accessor type of 'single' or 'filter'). A more complex example that
2847 prefetches an artists cds, the tracks on those cds, and the tags associted
2848 with that artist is given below (assuming many-to-many from artists to tags):
2850 my $rs = $schema->resultset('Artist')->search(
2854 { cds => 'tracks' },
2855 { artist_tags => 'tags' }
2861 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
2862 attributes will be ignored.
2872 Makes the resultset paged and specifies the page to retrieve. Effectively
2873 identical to creating a non-pages resultset and then calling ->page($page)
2876 If L<rows> attribute is not specified it defualts to 10 rows per page.
2878 When you have a paged resultset, L</count> will only return the number
2879 of rows in the page. To get the total, use the L</pager> and call
2880 C<total_entries> on it.
2890 Specifes the maximum number of rows for direct retrieval or the number of
2891 rows per page if the page attribute or method is used.
2897 =item Value: $offset
2901 Specifies the (zero-based) row number for the first row to be returned, or the
2902 of the first row of the first page if paging is used.
2908 =item Value: \@columns
2912 A arrayref of columns to group by. Can include columns of joined tables.
2914 group_by => [qw/ column1 column2 ... /]
2920 =item Value: $condition
2924 HAVING is a select statement attribute that is applied between GROUP BY and
2925 ORDER BY. It is applied to the after the grouping calculations have been
2928 having => { 'count(employee)' => { '>=', 100 } }
2934 =item Value: (0 | 1)
2938 Set to 1 to group by all columns.
2944 Adds to the WHERE clause.
2946 # only return rows WHERE deleted IS NULL for all searches
2947 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2949 Can be overridden by passing C<{ where => undef }> as an attribute
2956 Set to 1 to cache search results. This prevents extra SQL queries if you
2957 revisit rows in your ResultSet:
2959 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2961 while( my $artist = $resultset->next ) {
2965 $rs->first; # without cache, this would issue a query
2967 By default, searches are not cached.
2969 For more examples of using these attributes, see
2970 L<DBIx::Class::Manual::Cookbook>.
2976 =item Value: \@from_clause
2980 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2981 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2984 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2986 C<join> will usually do what you need and it is strongly recommended that you
2987 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2988 And we really do mean "cannot", not just tried and failed. Attempting to use
2989 this because you're having problems with C<join> is like trying to use x86
2990 ASM because you've got a syntax error in your C. Trust us on this.
2992 Now, if you're still really, really sure you need to use this (and if you're
2993 not 100% sure, ask the mailing list first), here's an explanation of how this
2996 The syntax is as follows -
2999 { <alias1> => <table1> },
3001 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3002 [], # nested JOIN (optional)
3003 { <table1.column1> => <table2.column2>, ... (more conditions) },
3005 # More of the above [ ] may follow for additional joins
3012 ON <table1.column1> = <table2.column2>
3013 <more joins may follow>
3015 An easy way to follow the examples below is to remember the following:
3017 Anything inside "[]" is a JOIN
3018 Anything inside "{}" is a condition for the enclosing JOIN
3020 The following examples utilize a "person" table in a family tree application.
3021 In order to express parent->child relationships, this table is self-joined:
3023 # Person->belongs_to('father' => 'Person');
3024 # Person->belongs_to('mother' => 'Person');
3026 C<from> can be used to nest joins. Here we return all children with a father,
3027 then search against all mothers of those children:
3029 $rs = $schema->resultset('Person')->search(
3032 alias => 'mother', # alias columns in accordance with "from"
3034 { mother => 'person' },
3037 { child => 'person' },
3039 { father => 'person' },
3040 { 'father.person_id' => 'child.father_id' }
3043 { 'mother.person_id' => 'child.mother_id' }
3050 # SELECT mother.* FROM person mother
3053 # JOIN person father
3054 # ON ( father.person_id = child.father_id )
3056 # ON ( mother.person_id = child.mother_id )
3058 The type of any join can be controlled manually. To search against only people
3059 with a father in the person table, we could explicitly use C<INNER JOIN>:
3061 $rs = $schema->resultset('Person')->search(
3064 alias => 'child', # alias columns in accordance with "from"
3066 { child => 'person' },
3068 { father => 'person', -join_type => 'inner' },
3069 { 'father.id' => 'child.father_id' }
3076 # SELECT child.* FROM person child
3077 # INNER JOIN person father ON child.father_id = father.id
3079 If you need to express really complex joins or you need a subselect, you
3080 can supply literal SQL to C<from> via a scalar reference. In this case
3081 the contents of the scalar will replace the table name asscoiated with the
3084 WARNING: This technique might very well not work as expected on chained
3085 searches - you have been warned.
3087 # Assuming the Event resultsource is defined as:
3089 MySchema::Event->add_columns (
3092 is_auto_increment => 1,
3101 MySchema::Event->set_primary_key ('sequence');
3103 # This will get back the latest event for every location. The column
3104 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3105 # combo to limit the resultset
3107 $rs = $schema->resultset('Event');
3108 $table = $rs->result_source->name;
3109 $latest = $rs->search (
3112 (SELECT e1.* FROM $table e1
3114 ON e1.location = e2.location
3115 AND e1.sequence < e2.sequence
3116 WHERE e2.sequence is NULL
3121 # Equivalent SQL (with the DBIC chunks added):
3123 SELECT me.sequence, me.location, me.type FROM
3124 (SELECT e1.* FROM events e1
3126 ON e1.location = e2.location
3127 AND e1.sequence < e2.sequence
3128 WHERE e2.sequence is NULL
3135 =item Value: ( 'update' | 'shared' )
3139 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT