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 $attrs = { %{$self->_resolved_attrs} };
1148 if (my $group_by = $attrs->{group_by}) {
1149 delete $attrs->{having};
1150 delete $attrs->{order_by};
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 $attrs->{select} = $group_by;
1165 $attrs->{from} = [ { 'mesub' => (ref $self)->new($self->result_source, $attrs)->cursor->as_query } ];
1168 $attrs->{select} = { count => '*' };
1169 $attrs->{as} = [qw/count/];
1171 # offset, order by, group by, where and page are not needed to count. record_filter is cdbi
1172 delete $attrs->{$_} for qw/rows offset order_by group_by where page pager record_filter/;
1174 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1175 my ($count) = $tmp_rs->cursor->next;
1183 =head2 count_literal
1187 =item Arguments: $sql_fragment, @bind_values
1189 =item Return Value: $count
1193 Counts the results in a literal query. Equivalent to calling L</search_literal>
1194 with the passed arguments, then L</count>.
1198 sub count_literal { shift->search_literal(@_)->count; }
1204 =item Arguments: none
1206 =item Return Value: @objects
1210 Returns all elements in the resultset. Called implicitly if the resultset
1211 is returned in list context.
1218 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1221 return @{ $self->get_cache } if $self->get_cache;
1225 # TODO: don't call resolve here
1226 if (keys %{$self->_resolved_attrs->{collapse}}) {
1227 # if ($self->{attrs}{prefetch}) {
1228 # Using $self->cursor->all is really just an optimisation.
1229 # If we're collapsing has_many prefetches it probably makes
1230 # very little difference, and this is cleaner than hacking
1231 # _construct_object to survive the approach
1232 my @row = $self->cursor->next;
1234 push(@obj, $self->_construct_object(@row));
1235 @row = (exists $self->{stashed_row}
1236 ? @{delete $self->{stashed_row}}
1237 : $self->cursor->next);
1240 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1243 $self->set_cache(\@obj) if $self->{attrs}{cache};
1251 =item Arguments: none
1253 =item Return Value: $self
1257 Resets the resultset's cursor, so you can iterate through the elements again.
1263 delete $self->{_attrs} if exists $self->{_attrs};
1264 $self->{all_cache_position} = 0;
1265 $self->cursor->reset;
1273 =item Arguments: none
1275 =item Return Value: $object?
1279 Resets the resultset and returns an object for the first result (if the
1280 resultset returns anything).
1285 return $_[0]->reset->next;
1288 # _cond_for_update_delete
1290 # update/delete require the condition to be modified to handle
1291 # the differing SQL syntax available. This transforms the $self->{cond}
1292 # appropriately, returning the new condition.
1294 sub _cond_for_update_delete {
1295 my ($self, $full_cond) = @_;
1298 $full_cond ||= $self->{cond};
1299 # No-op. No condition, we're updating/deleting everything
1300 return $cond unless ref $full_cond;
1302 if (ref $full_cond eq 'ARRAY') {
1306 foreach my $key (keys %{$_}) {
1308 $hash{$1} = $_->{$key};
1314 elsif (ref $full_cond eq 'HASH') {
1315 if ((keys %{$full_cond})[0] eq '-and') {
1318 my @cond = @{$full_cond->{-and}};
1319 for (my $i = 0; $i < @cond; $i++) {
1320 my $entry = $cond[$i];
1323 if (ref $entry eq 'HASH') {
1324 $hash = $self->_cond_for_update_delete($entry);
1327 $entry =~ /([^.]+)$/;
1328 $hash->{$1} = $cond[++$i];
1331 push @{$cond->{-and}}, $hash;
1335 foreach my $key (keys %{$full_cond}) {
1337 $cond->{$1} = $full_cond->{$key};
1342 $self->throw_exception(
1343 "Can't update/delete on resultset with condition unless hash or array"
1355 =item Arguments: \%values
1357 =item Return Value: $storage_rv
1361 Sets the specified columns in the resultset to the supplied values in a
1362 single query. Return value will be true if the update succeeded or false
1363 if no records were updated; exact type of success value is storage-dependent.
1368 my ($self, $values) = @_;
1369 $self->throw_exception("Values for update must be a hash")
1370 unless ref $values eq 'HASH';
1372 carp( 'WARNING! Currently $rs->update() does not generate proper SQL'
1373 . ' on joined resultsets, and may affect rows well outside of the'
1374 . ' contents of $rs. Use at your own risk' )
1375 if ( $self->{attrs}{seen_join} );
1377 my $cond = $self->_cond_for_update_delete;
1379 return $self->result_source->storage->update(
1380 $self->result_source, $values, $cond
1388 =item Arguments: \%values
1390 =item Return Value: 1
1394 Fetches all objects and updates them one at a time. Note that C<update_all>
1395 will run DBIC cascade triggers, while L</update> will not.
1400 my ($self, $values) = @_;
1401 $self->throw_exception("Values for update must be a hash")
1402 unless ref $values eq 'HASH';
1403 foreach my $obj ($self->all) {
1404 $obj->set_columns($values)->update;
1413 =item Arguments: none
1415 =item Return Value: 1
1419 Deletes the contents of the resultset from its result source. Note that this
1420 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1421 to run. See also L<DBIx::Class::Row/delete>.
1423 delete may not generate correct SQL for a query with joins or a resultset
1424 chained from a related resultset. In this case it will generate a warning:-
1426 WARNING! Currently $rs->delete() does not generate proper SQL on
1427 joined resultsets, and may delete rows well outside of the contents
1428 of $rs. Use at your own risk
1430 In these cases you may find that delete_all is more appropriate, or you
1431 need to respecify your query in a way that can be expressed without a join.
1437 $self->throw_exception("Delete should not be passed any arguments")
1439 carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
1440 . ' on joined resultsets, and may delete rows well outside of the'
1441 . ' contents of $rs. Use at your own risk' )
1442 if ( $self->{attrs}{seen_join} );
1443 my $cond = $self->_cond_for_update_delete;
1445 $self->result_source->storage->delete($self->result_source, $cond);
1453 =item Arguments: none
1455 =item Return Value: 1
1459 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1460 will run DBIC cascade triggers, while L</delete> will not.
1466 $_->delete for $self->all;
1474 =item Arguments: \@data;
1478 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1479 For the arrayref of hashrefs style each hashref should be a structure suitable
1480 forsubmitting to a $resultset->create(...) method.
1482 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1483 to insert the data, as this is a faster method.
1485 Otherwise, each set of data is inserted into the database using
1486 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1487 objects is returned.
1489 Example: Assuming an Artist Class that has many CDs Classes relating:
1491 my $Artist_rs = $schema->resultset("Artist");
1493 ## Void Context Example
1494 $Artist_rs->populate([
1495 { artistid => 4, name => 'Manufactured Crap', cds => [
1496 { title => 'My First CD', year => 2006 },
1497 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1500 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1501 { title => 'My parents sold me to a record company' ,year => 2005 },
1502 { title => 'Why Am I So Ugly?', year => 2006 },
1503 { title => 'I Got Surgery and am now Popular', year => 2007 }
1508 ## Array Context Example
1509 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1510 { name => "Artist One"},
1511 { name => "Artist Two"},
1512 { name => "Artist Three", cds=> [
1513 { title => "First CD", year => 2007},
1514 { title => "Second CD", year => 2008},
1518 print $ArtistOne->name; ## response is 'Artist One'
1519 print $ArtistThree->cds->count ## reponse is '2'
1521 For the arrayref of arrayrefs style, the first element should be a list of the
1522 fieldsnames to which the remaining elements are rows being inserted. For
1525 $Arstist_rs->populate([
1526 [qw/artistid name/],
1527 [100, 'A Formally Unknown Singer'],
1528 [101, 'A singer that jumped the shark two albums ago'],
1529 [102, 'An actually cool singer.'],
1532 Please note an important effect on your data when choosing between void and
1533 wantarray context. Since void context goes straight to C<insert_bulk> in
1534 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1535 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1536 create primary keys for you, you will find that your PKs are empty. In this
1537 case you will have to use the wantarray context in order to create those
1543 my $self = shift @_;
1544 my $data = ref $_[0][0] eq 'HASH'
1545 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1546 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1548 if(defined wantarray) {
1550 foreach my $item (@$data) {
1551 push(@created, $self->create($item));
1555 my ($first, @rest) = @$data;
1557 my @names = grep {!ref $first->{$_}} keys %$first;
1558 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1559 my @pks = $self->result_source->primary_columns;
1561 ## do the belongs_to relationships
1562 foreach my $index (0..$#$data) {
1563 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1564 my @ret = $self->populate($data);
1568 foreach my $rel (@rels) {
1569 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1570 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1571 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1572 my $related = $result->result_source->resolve_condition(
1573 $result->result_source->relationship_info($reverse)->{cond},
1578 delete $data->[$index]->{$rel};
1579 $data->[$index] = {%{$data->[$index]}, %$related};
1581 push @names, keys %$related if $index == 0;
1585 ## do bulk insert on current row
1586 my @values = map { [ @$_{@names} ] } @$data;
1588 $self->result_source->storage->insert_bulk(
1589 $self->result_source,
1594 ## do the has_many relationships
1595 foreach my $item (@$data) {
1597 foreach my $rel (@rels) {
1598 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1600 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1601 || $self->throw_exception('Cannot find the relating object.');
1603 my $child = $parent->$rel;
1605 my $related = $child->result_source->resolve_condition(
1606 $parent->result_source->relationship_info($rel)->{cond},
1611 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1612 my @populate = map { {%$_, %$related} } @rows_to_add;
1614 $child->populate( \@populate );
1620 =head2 _normalize_populate_args ($args)
1622 Private method used by L</populate> to normalize its incoming arguments. Factored
1623 out in case you want to subclass and accept new argument structures to the
1624 L</populate> method.
1628 sub _normalize_populate_args {
1629 my ($self, $data) = @_;
1630 my @names = @{shift(@$data)};
1631 my @results_to_create;
1632 foreach my $datum (@$data) {
1633 my %result_to_create;
1634 foreach my $index (0..$#names) {
1635 $result_to_create{$names[$index]} = $$datum[$index];
1637 push @results_to_create, \%result_to_create;
1639 return \@results_to_create;
1646 =item Arguments: none
1648 =item Return Value: $pager
1652 Return Value a L<Data::Page> object for the current resultset. Only makes
1653 sense for queries with a C<page> attribute.
1655 To get the full count of entries for a paged resultset, call
1656 C<total_entries> on the L<Data::Page> object.
1662 my $attrs = $self->{attrs};
1663 $self->throw_exception("Can't create pager for non-paged rs")
1664 unless $self->{attrs}{page};
1665 $attrs->{rows} ||= 10;
1666 return $self->{pager} ||= Data::Page->new(
1667 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1674 =item Arguments: $page_number
1676 =item Return Value: $rs
1680 Returns a resultset for the $page_number page of the resultset on which page
1681 is called, where each page contains a number of rows equal to the 'rows'
1682 attribute set on the resultset (10 by default).
1687 my ($self, $page) = @_;
1688 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1695 =item Arguments: \%vals
1697 =item Return Value: $rowobject
1701 Creates a new row object in the resultset's result class and returns
1702 it. The row is not inserted into the database at this point, call
1703 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1704 will tell you whether the row object has been inserted or not.
1706 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1711 my ($self, $values) = @_;
1712 $self->throw_exception( "new_result needs a hash" )
1713 unless (ref $values eq 'HASH');
1716 my $alias = $self->{attrs}{alias};
1719 defined $self->{cond}
1720 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1722 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1723 $new{-from_resultset} = [ keys %new ] if keys %new;
1725 $self->throw_exception(
1726 "Can't abstract implicit construct, condition not a hash"
1727 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1729 my $collapsed_cond = (
1731 ? $self->_collapse_cond($self->{cond})
1735 # precendence must be given to passed values over values inherited from
1736 # the cond, so the order here is important.
1737 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1738 while( my($col,$value) = each %implied ){
1739 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1740 $new{$col} = $value->{'='};
1743 $new{$col} = $value if $self->_is_deterministic_value($value);
1749 %{ $self->_remove_alias($values, $alias) },
1750 -source_handle => $self->_source_handle,
1751 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1754 return $self->result_class->new(\%new);
1757 # _is_deterministic_value
1759 # Make an effor to strip non-deterministic values from the condition,
1760 # to make sure new_result chokes less
1762 sub _is_deterministic_value {
1765 my $ref_type = ref $value;
1766 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1767 return 1 if Scalar::Util::blessed($value);
1773 # Recursively collapse the condition.
1775 sub _collapse_cond {
1776 my ($self, $cond, $collapsed) = @_;
1780 if (ref $cond eq 'ARRAY') {
1781 foreach my $subcond (@$cond) {
1782 next unless ref $subcond; # -or
1783 # warn "ARRAY: " . Dumper $subcond;
1784 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1787 elsif (ref $cond eq 'HASH') {
1788 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1789 foreach my $subcond (@{$cond->{-and}}) {
1790 # warn "HASH: " . Dumper $subcond;
1791 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1795 # warn "LEAF: " . Dumper $cond;
1796 foreach my $col (keys %$cond) {
1797 my $value = $cond->{$col};
1798 $collapsed->{$col} = $value;
1808 # Remove the specified alias from the specified query hash. A copy is made so
1809 # the original query is not modified.
1812 my ($self, $query, $alias) = @_;
1814 my %orig = %{ $query || {} };
1817 foreach my $key (keys %orig) {
1819 $unaliased{$key} = $orig{$key};
1822 $unaliased{$1} = $orig{$key}
1823 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1829 =head2 as_query (EXPERIMENTAL)
1833 =item Arguments: none
1835 =item Return Value: \[ $sql, @bind ]
1839 Returns the SQL query and bind vars associated with the invocant.
1841 This is generally used as the RHS for a subquery.
1843 B<NOTE>: This feature is still experimental.
1847 sub as_query { return shift->cursor->as_query(@_) }
1853 =item Arguments: \%vals, \%attrs?
1855 =item Return Value: $rowobject
1859 my $artist = $schema->resultset('Artist')->find_or_new(
1860 { artist => 'fred' }, { key => 'artists' });
1862 $cd->cd_to_producer->find_or_new({ producer => $producer },
1863 { key => 'primary });
1865 Find an existing record from this resultset, based on its primary
1866 key, or a unique constraint. If none exists, instantiate a new result
1867 object and return it. The object will not be saved into your storage
1868 until you call L<DBIx::Class::Row/insert> on it.
1870 You most likely want this method when looking for existing rows using
1871 a unique constraint that is not the primary key, or looking for
1874 If you want objects to be saved immediately, use L</find_or_create> instead.
1876 B<Note>: C<find_or_new> is probably not what you want when creating a
1877 new row in a table that uses primary keys supplied by the
1878 database. Passing in a primary key column with a value of I<undef>
1879 will cause L</find> to attempt to search for a row with a value of
1886 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1887 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1888 my $exists = $self->find($hash, $attrs);
1889 return defined $exists ? $exists : $self->new_result($hash);
1896 =item Arguments: \%vals
1898 =item Return Value: a L<DBIx::Class::Row> $object
1902 Attempt to create a single new row or a row with multiple related rows
1903 in the table represented by the resultset (and related tables). This
1904 will not check for duplicate rows before inserting, use
1905 L</find_or_create> to do that.
1907 To create one row for this resultset, pass a hashref of key/value
1908 pairs representing the columns of the table and the values you wish to
1909 store. If the appropriate relationships are set up, foreign key fields
1910 can also be passed an object representing the foreign row, and the
1911 value will be set to its primary key.
1913 To create related objects, pass a hashref for the value if the related
1914 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1915 and use the name of the relationship as the key. (NOT the name of the field,
1916 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
1917 of hashrefs containing the data for each of the rows to create in the foreign
1918 tables, again using the relationship name as the key.
1920 Instead of hashrefs of plain related data (key/value pairs), you may
1921 also pass new or inserted objects. New objects (not inserted yet, see
1922 L</new>), will be inserted into their appropriate tables.
1924 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1926 Example of creating a new row.
1928 $person_rs->create({
1929 name=>"Some Person",
1930 email=>"somebody@someplace.com"
1933 Example of creating a new row and also creating rows in a related C<has_many>
1934 or C<has_one> resultset. Note Arrayref.
1937 { artistid => 4, name => 'Manufactured Crap', cds => [
1938 { title => 'My First CD', year => 2006 },
1939 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1944 Example of creating a new row and also creating a row in a related
1945 C<belongs_to>resultset. Note Hashref.
1948 title=>"Music for Silly Walks",
1951 name=>"Silly Musician",
1958 my ($self, $attrs) = @_;
1959 $self->throw_exception( "create needs a hashref" )
1960 unless ref $attrs eq 'HASH';
1961 return $self->new_result($attrs)->insert;
1964 =head2 find_or_create
1968 =item Arguments: \%vals, \%attrs?
1970 =item Return Value: $rowobject
1974 $cd->cd_to_producer->find_or_create({ producer => $producer },
1975 { key => 'primary });
1977 Tries to find a record based on its primary key or unique constraints; if none
1978 is found, creates one and returns that instead.
1980 my $cd = $schema->resultset('CD')->find_or_create({
1982 artist => 'Massive Attack',
1983 title => 'Mezzanine',
1987 Also takes an optional C<key> attribute, to search by a specific key or unique
1988 constraint. For example:
1990 my $cd = $schema->resultset('CD')->find_or_create(
1992 artist => 'Massive Attack',
1993 title => 'Mezzanine',
1995 { key => 'cd_artist_title' }
1998 B<Note>: Because find_or_create() reads from the database and then
1999 possibly inserts based on the result, this method is subject to a race
2000 condition. Another process could create a record in the table after
2001 the find has completed and before the create has started. To avoid
2002 this problem, use find_or_create() inside a transaction.
2004 B<Note>: C<find_or_create> is probably not what you want when creating
2005 a new row in a table that uses primary keys supplied by the
2006 database. Passing in a primary key column with a value of I<undef>
2007 will cause L</find> to attempt to search for a row with a value of
2010 See also L</find> and L</update_or_create>. For information on how to declare
2011 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2015 sub find_or_create {
2017 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2018 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2019 my $exists = $self->find($hash, $attrs);
2020 return defined $exists ? $exists : $self->create($hash);
2023 =head2 update_or_create
2027 =item Arguments: \%col_values, { key => $unique_constraint }?
2029 =item Return Value: $rowobject
2033 $resultset->update_or_create({ col => $val, ... });
2035 First, searches for an existing row matching one of the unique constraints
2036 (including the primary key) on the source of this resultset. If a row is
2037 found, updates it with the other given column values. Otherwise, creates a new
2040 Takes an optional C<key> attribute to search on a specific unique constraint.
2043 # In your application
2044 my $cd = $schema->resultset('CD')->update_or_create(
2046 artist => 'Massive Attack',
2047 title => 'Mezzanine',
2050 { key => 'cd_artist_title' }
2053 $cd->cd_to_producer->update_or_create({
2054 producer => $producer,
2061 If no C<key> is specified, it searches on all unique constraints defined on the
2062 source, including the primary key.
2064 If the C<key> is specified as C<primary>, it searches only on the primary key.
2066 See also L</find> and L</find_or_create>. For information on how to declare
2067 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2069 B<Note>: C<update_or_create> is probably not what you want when
2070 looking for a row in a table that uses primary keys supplied by the
2071 database, unless you actually have a key value. Passing in a primary
2072 key column with a value of I<undef> will cause L</find> to attempt to
2073 search for a row with a value of I<NULL>.
2077 sub update_or_create {
2079 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2080 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2082 my $row = $self->find($cond, $attrs);
2084 $row->update($cond);
2088 return $self->create($cond);
2095 =item Arguments: none
2097 =item Return Value: \@cache_objects?
2101 Gets the contents of the cache for the resultset, if the cache is set.
2103 The cache is populated either by using the L</prefetch> attribute to
2104 L</search> or by calling L</set_cache>.
2116 =item Arguments: \@cache_objects
2118 =item Return Value: \@cache_objects
2122 Sets the contents of the cache for the resultset. Expects an arrayref
2123 of objects of the same class as those produced by the resultset. Note that
2124 if the cache is set the resultset will return the cached objects rather
2125 than re-querying the database even if the cache attr is not set.
2127 The contents of the cache can also be populated by using the
2128 L</prefetch> attribute to L</search>.
2133 my ( $self, $data ) = @_;
2134 $self->throw_exception("set_cache requires an arrayref")
2135 if defined($data) && (ref $data ne 'ARRAY');
2136 $self->{all_cache} = $data;
2143 =item Arguments: none
2145 =item Return Value: []
2149 Clears the cache for the resultset.
2154 shift->set_cache(undef);
2157 =head2 related_resultset
2161 =item Arguments: $relationship_name
2163 =item Return Value: $resultset
2167 Returns a related resultset for the supplied relationship name.
2169 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2173 sub related_resultset {
2174 my ($self, $rel) = @_;
2176 $self->{related_resultsets} ||= {};
2177 return $self->{related_resultsets}{$rel} ||= do {
2178 my $rel_obj = $self->result_source->relationship_info($rel);
2180 $self->throw_exception(
2181 "search_related: result source '" . $self->result_source->source_name .
2182 "' has no such relationship $rel")
2185 my ($from,$seen) = $self->_resolve_from($rel);
2187 my $join_count = $seen->{$rel};
2188 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2190 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2191 my %attrs = %{$self->{attrs}||{}};
2192 delete @attrs{qw(result_class alias)};
2196 if (my $cache = $self->get_cache) {
2197 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2198 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2203 my $rel_source = $self->result_source->related_source($rel);
2207 # The reason we do this now instead of passing the alias to the
2208 # search_rs below is that if you wrap/overload resultset on the
2209 # source you need to know what alias it's -going- to have for things
2210 # to work sanely (e.g. RestrictWithObject wants to be able to add
2211 # extra query restrictions, and these may need to be $alias.)
2213 my $attrs = $rel_source->resultset_attributes;
2214 local $attrs->{alias} = $alias;
2216 $rel_source->resultset
2224 where => $self->{cond},
2229 $new->set_cache($new_cache) if $new_cache;
2234 =head2 current_source_alias
2238 =item Arguments: none
2240 =item Return Value: $source_alias
2244 Returns the current table alias for the result source this resultset is built
2245 on, that will be used in the SQL query. Usually it is C<me>.
2247 Currently the source alias that refers to the result set returned by a
2248 L</search>/L</find> family method depends on how you got to the resultset: it's
2249 C<me> by default, but eg. L</search_related> aliases it to the related result
2250 source name (and keeps C<me> referring to the original result set). The long
2251 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2252 (and make this method unnecessary).
2254 Thus it's currently necessary to use this method in predefined queries (see
2255 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2256 source alias of the current result set:
2258 # in a result set class
2260 my ($self, $user) = @_;
2262 my $me = $self->current_source_alias;
2264 return $self->search(
2265 "$me.modified" => $user->id,
2271 sub current_source_alias {
2274 return ($self->{attrs} || {})->{alias} || 'me';
2278 my ($self, $extra_join) = @_;
2279 my $source = $self->result_source;
2280 my $attrs = $self->{attrs};
2282 my $from = $attrs->{from}
2283 || [ { $attrs->{alias} => $source->from } ];
2285 my $seen = { %{$attrs->{seen_join}||{}} };
2287 my $join = ($attrs->{join}
2288 ? [ $attrs->{join}, $extra_join ]
2291 # we need to take the prefetch the attrs into account before we
2292 # ->resolve_join as otherwise they get lost - captainL
2293 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2297 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2300 return ($from,$seen);
2303 sub _resolved_attrs {
2305 return $self->{_attrs} if $self->{_attrs};
2307 my $attrs = { %{ $self->{attrs} || {} } };
2308 my $source = $self->result_source;
2309 my $alias = $attrs->{alias};
2311 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2314 # build columns (as long as select isn't set) into a set of as/select hashes
2315 unless ( $attrs->{select} ) {
2317 ( ref($_) eq 'HASH' ) ? $_
2320 /^\Q${alias}.\E(.+)$/ ? $1
2322 ) => ( /\./ ? $_ : "${alias}.$_" )
2324 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2326 # add the additional columns on
2327 foreach ( 'include_columns', '+columns' ) {
2328 push @colbits, map {
2329 ( ref($_) eq 'HASH' )
2331 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2332 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2335 # start with initial select items
2336 if ( $attrs->{select} ) {
2338 ( ref $attrs->{select} eq 'ARRAY' )
2339 ? [ @{ $attrs->{select} } ]
2340 : [ $attrs->{select} ];
2344 ref $attrs->{as} eq 'ARRAY'
2345 ? [ @{ $attrs->{as} } ]
2348 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2353 # otherwise we intialise select & as to empty
2354 $attrs->{select} = [];
2358 # now add colbits to select/as
2359 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2360 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2363 if ( $adds = delete $attrs->{'+select'} ) {
2364 $adds = [$adds] unless ref $adds eq 'ARRAY';
2366 @{ $attrs->{select} },
2367 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2370 if ( $adds = delete $attrs->{'+as'} ) {
2371 $adds = [$adds] unless ref $adds eq 'ARRAY';
2372 push( @{ $attrs->{as} }, @$adds );
2375 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2377 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2378 my $join = delete $attrs->{join} || {};
2380 if ( defined $attrs->{prefetch} ) {
2381 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2385 $attrs->{from} = # have to copy here to avoid corrupting the original
2387 @{ $attrs->{from} },
2388 $source->resolve_join(
2389 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2395 $attrs->{group_by} ||= $attrs->{select}
2396 if delete $attrs->{distinct};
2397 if ( $attrs->{order_by} ) {
2398 $attrs->{order_by} = (
2399 ref( $attrs->{order_by} ) eq 'ARRAY'
2400 ? [ @{ $attrs->{order_by} } ]
2401 : [ $attrs->{order_by} ]
2405 $attrs->{order_by} = [];
2408 my $collapse = $attrs->{collapse} || {};
2409 if ( my $prefetch = delete $attrs->{prefetch} ) {
2410 $prefetch = $self->_merge_attr( {}, $prefetch );
2412 my $seen = { %{ $attrs->{seen_join} || {} } };
2413 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2415 # bring joins back to level of current class
2417 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2418 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2419 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2421 push( @{ $attrs->{order_by} }, @pre_order );
2423 $attrs->{collapse} = $collapse;
2425 if ( $attrs->{page} ) {
2426 $attrs->{offset} ||= 0;
2427 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2430 return $self->{_attrs} = $attrs;
2434 my ($self, $attr) = @_;
2436 if (ref $attr eq 'HASH') {
2437 return $self->_rollout_hash($attr);
2438 } elsif (ref $attr eq 'ARRAY') {
2439 return $self->_rollout_array($attr);
2445 sub _rollout_array {
2446 my ($self, $attr) = @_;
2449 foreach my $element (@{$attr}) {
2450 if (ref $element eq 'HASH') {
2451 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2452 } elsif (ref $element eq 'ARRAY') {
2453 # XXX - should probably recurse here
2454 push( @rolled_array, @{$self->_rollout_array($element)} );
2456 push( @rolled_array, $element );
2459 return \@rolled_array;
2463 my ($self, $attr) = @_;
2466 foreach my $key (keys %{$attr}) {
2467 push( @rolled_array, { $key => $attr->{$key} } );
2469 return \@rolled_array;
2472 sub _calculate_score {
2473 my ($self, $a, $b) = @_;
2475 if (ref $b eq 'HASH') {
2476 my ($b_key) = keys %{$b};
2477 if (ref $a eq 'HASH') {
2478 my ($a_key) = keys %{$a};
2479 if ($a_key eq $b_key) {
2480 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2485 return ($a eq $b_key) ? 1 : 0;
2488 if (ref $a eq 'HASH') {
2489 my ($a_key) = keys %{$a};
2490 return ($b eq $a_key) ? 1 : 0;
2492 return ($b eq $a) ? 1 : 0;
2498 my ($self, $orig, $import) = @_;
2500 return $import unless defined($orig);
2501 return $orig unless defined($import);
2503 $orig = $self->_rollout_attr($orig);
2504 $import = $self->_rollout_attr($import);
2507 foreach my $import_element ( @{$import} ) {
2508 # find best candidate from $orig to merge $b_element into
2509 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2510 foreach my $orig_element ( @{$orig} ) {
2511 my $score = $self->_calculate_score( $orig_element, $import_element );
2512 if ($score > $best_candidate->{score}) {
2513 $best_candidate->{position} = $position;
2514 $best_candidate->{score} = $score;
2518 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2520 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2521 push( @{$orig}, $import_element );
2523 my $orig_best = $orig->[$best_candidate->{position}];
2524 # merge orig_best and b_element together and replace original with merged
2525 if (ref $orig_best ne 'HASH') {
2526 $orig->[$best_candidate->{position}] = $import_element;
2527 } elsif (ref $import_element eq 'HASH') {
2528 my ($key) = keys %{$orig_best};
2529 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2532 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2542 $self->_source_handle($_[0]->handle);
2544 $self->_source_handle->resolve;
2548 =head2 throw_exception
2550 See L<DBIx::Class::Schema/throw_exception> for details.
2554 sub throw_exception {
2556 if (ref $self && $self->_source_handle->schema) {
2557 $self->_source_handle->schema->throw_exception(@_)
2564 # XXX: FIXME: Attributes docs need clearing up
2568 Attributes are used to refine a ResultSet in various ways when
2569 searching for data. They can be passed to any method which takes an
2570 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2573 These are in no particular order:
2579 =item Value: ( $order_by | \@order_by | \%order_by )
2583 Which column(s) to order the results by. If a single column name, or
2584 an arrayref of names is supplied, the argument is passed through
2585 directly to SQL. The hashref syntax allows for connection-agnostic
2586 specification of ordering direction:
2588 For descending order:
2590 order_by => { -desc => [qw/col1 col2 col3/] }
2592 For explicit ascending order:
2594 order_by => { -asc => 'col' }
2596 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2597 supported, although you are strongly encouraged to use the hashref
2598 syntax as outlined above.
2604 =item Value: \@columns
2608 Shortcut to request a particular set of columns to be retrieved. Each
2609 column spec may be a string (a table column name), or a hash (in which
2610 case the key is the C<as> value, and the value is used as the C<select>
2611 expression). Adds C<me.> onto the start of any column without a C<.> in
2612 it and sets C<select> from that, then auto-populates C<as> from
2613 C<select> as normal. (You may also use the C<cols> attribute, as in
2614 earlier versions of DBIC.)
2620 =item Value: \@columns
2624 Indicates additional columns to be selected from storage. Works the same
2625 as L</columns> but adds columns to the selection. (You may also use the
2626 C<include_columns> attribute, as in earlier versions of DBIC). For
2629 $schema->resultset('CD')->search(undef, {
2630 '+columns' => ['artist.name'],
2634 would return all CDs and include a 'name' column to the information
2635 passed to object inflation. Note that the 'artist' is the name of the
2636 column (or relationship) accessor, and 'name' is the name of the column
2637 accessor in the related table.
2639 =head2 include_columns
2643 =item Value: \@columns
2647 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2653 =item Value: \@select_columns
2657 Indicates which columns should be selected from the storage. You can use
2658 column names, or in the case of RDBMS back ends, function or stored procedure
2661 $rs = $schema->resultset('Employee')->search(undef, {
2664 { count => 'employeeid' },
2669 When you use function/stored procedure names and do not supply an C<as>
2670 attribute, the column names returned are storage-dependent. E.g. MySQL would
2671 return a column named C<count(employeeid)> in the above example.
2677 Indicates additional columns to be selected from storage. Works the same as
2678 L</select> but adds columns to the selection.
2686 Indicates additional column names for those added via L</+select>. See L</as>.
2694 =item Value: \@inflation_names
2698 Indicates column names for object inflation. That is, C<as>
2699 indicates the name that the column can be accessed as via the
2700 C<get_column> method (or via the object accessor, B<if one already
2701 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2703 The C<as> attribute is used in conjunction with C<select>,
2704 usually when C<select> contains one or more function or stored
2707 $rs = $schema->resultset('Employee')->search(undef, {
2710 { count => 'employeeid' }
2712 as => ['name', 'employee_count'],
2715 my $employee = $rs->first(); # get the first Employee
2717 If the object against which the search is performed already has an accessor
2718 matching a column name specified in C<as>, the value can be retrieved using
2719 the accessor as normal:
2721 my $name = $employee->name();
2723 If on the other hand an accessor does not exist in the object, you need to
2724 use C<get_column> instead:
2726 my $employee_count = $employee->get_column('employee_count');
2728 You can create your own accessors if required - see
2729 L<DBIx::Class::Manual::Cookbook> for details.
2731 Please note: This will NOT insert an C<AS employee_count> into the SQL
2732 statement produced, it is used for internal access only. Thus
2733 attempting to use the accessor in an C<order_by> clause or similar
2734 will fail miserably.
2736 To get around this limitation, you can supply literal SQL to your
2737 C<select> attibute that contains the C<AS alias> text, eg:
2739 select => [\'myfield AS alias']
2745 =item Value: ($rel_name | \@rel_names | \%rel_names)
2749 Contains a list of relationships that should be joined for this query. For
2752 # Get CDs by Nine Inch Nails
2753 my $rs = $schema->resultset('CD')->search(
2754 { 'artist.name' => 'Nine Inch Nails' },
2755 { join => 'artist' }
2758 Can also contain a hash reference to refer to the other relation's relations.
2761 package MyApp::Schema::Track;
2762 use base qw/DBIx::Class/;
2763 __PACKAGE__->table('track');
2764 __PACKAGE__->add_columns(qw/trackid cd position title/);
2765 __PACKAGE__->set_primary_key('trackid');
2766 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2769 # In your application
2770 my $rs = $schema->resultset('Artist')->search(
2771 { 'track.title' => 'Teardrop' },
2773 join => { cd => 'track' },
2774 order_by => 'artist.name',
2778 You need to use the relationship (not the table) name in conditions,
2779 because they are aliased as such. The current table is aliased as "me", so
2780 you need to use me.column_name in order to avoid ambiguity. For example:
2782 # Get CDs from 1984 with a 'Foo' track
2783 my $rs = $schema->resultset('CD')->search(
2786 'tracks.name' => 'Foo'
2788 { join => 'tracks' }
2791 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2792 similarly for a third time). For e.g.
2794 my $rs = $schema->resultset('Artist')->search({
2795 'cds.title' => 'Down to Earth',
2796 'cds_2.title' => 'Popular',
2798 join => [ qw/cds cds/ ],
2801 will return a set of all artists that have both a cd with title 'Down
2802 to Earth' and a cd with title 'Popular'.
2804 If you want to fetch related objects from other tables as well, see C<prefetch>
2807 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2813 =item Value: ($rel_name | \@rel_names | \%rel_names)
2817 Contains one or more relationships that should be fetched along with
2818 the main query (when they are accessed afterwards the data will
2819 already be available, without extra queries to the database). This is
2820 useful for when you know you will need the related objects, because it
2821 saves at least one query:
2823 my $rs = $schema->resultset('Tag')->search(
2832 The initial search results in SQL like the following:
2834 SELECT tag.*, cd.*, artist.* FROM tag
2835 JOIN cd ON tag.cd = cd.cdid
2836 JOIN artist ON cd.artist = artist.artistid
2838 L<DBIx::Class> has no need to go back to the database when we access the
2839 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2842 Simple prefetches will be joined automatically, so there is no need
2843 for a C<join> attribute in the above search.
2845 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2846 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2847 with an accessor type of 'single' or 'filter'). A more complex example that
2848 prefetches an artists cds, the tracks on those cds, and the tags associted
2849 with that artist is given below (assuming many-to-many from artists to tags):
2851 my $rs = $schema->resultset('Artist')->search(
2855 { cds => 'tracks' },
2856 { artist_tags => 'tags' }
2862 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
2863 attributes will be ignored.
2873 Makes the resultset paged and specifies the page to retrieve. Effectively
2874 identical to creating a non-pages resultset and then calling ->page($page)
2877 If L<rows> attribute is not specified it defualts to 10 rows per page.
2879 When you have a paged resultset, L</count> will only return the number
2880 of rows in the page. To get the total, use the L</pager> and call
2881 C<total_entries> on it.
2891 Specifes the maximum number of rows for direct retrieval or the number of
2892 rows per page if the page attribute or method is used.
2898 =item Value: $offset
2902 Specifies the (zero-based) row number for the first row to be returned, or the
2903 of the first row of the first page if paging is used.
2909 =item Value: \@columns
2913 A arrayref of columns to group by. Can include columns of joined tables.
2915 group_by => [qw/ column1 column2 ... /]
2921 =item Value: $condition
2925 HAVING is a select statement attribute that is applied between GROUP BY and
2926 ORDER BY. It is applied to the after the grouping calculations have been
2929 having => { 'count(employee)' => { '>=', 100 } }
2935 =item Value: (0 | 1)
2939 Set to 1 to group by all columns.
2945 Adds to the WHERE clause.
2947 # only return rows WHERE deleted IS NULL for all searches
2948 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2950 Can be overridden by passing C<{ where => undef }> as an attribute
2957 Set to 1 to cache search results. This prevents extra SQL queries if you
2958 revisit rows in your ResultSet:
2960 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2962 while( my $artist = $resultset->next ) {
2966 $rs->first; # without cache, this would issue a query
2968 By default, searches are not cached.
2970 For more examples of using these attributes, see
2971 L<DBIx::Class::Manual::Cookbook>.
2977 =item Value: \@from_clause
2981 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2982 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2985 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2987 C<join> will usually do what you need and it is strongly recommended that you
2988 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2989 And we really do mean "cannot", not just tried and failed. Attempting to use
2990 this because you're having problems with C<join> is like trying to use x86
2991 ASM because you've got a syntax error in your C. Trust us on this.
2993 Now, if you're still really, really sure you need to use this (and if you're
2994 not 100% sure, ask the mailing list first), here's an explanation of how this
2997 The syntax is as follows -
3000 { <alias1> => <table1> },
3002 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3003 [], # nested JOIN (optional)
3004 { <table1.column1> => <table2.column2>, ... (more conditions) },
3006 # More of the above [ ] may follow for additional joins
3013 ON <table1.column1> = <table2.column2>
3014 <more joins may follow>
3016 An easy way to follow the examples below is to remember the following:
3018 Anything inside "[]" is a JOIN
3019 Anything inside "{}" is a condition for the enclosing JOIN
3021 The following examples utilize a "person" table in a family tree application.
3022 In order to express parent->child relationships, this table is self-joined:
3024 # Person->belongs_to('father' => 'Person');
3025 # Person->belongs_to('mother' => 'Person');
3027 C<from> can be used to nest joins. Here we return all children with a father,
3028 then search against all mothers of those children:
3030 $rs = $schema->resultset('Person')->search(
3033 alias => 'mother', # alias columns in accordance with "from"
3035 { mother => 'person' },
3038 { child => 'person' },
3040 { father => 'person' },
3041 { 'father.person_id' => 'child.father_id' }
3044 { 'mother.person_id' => 'child.mother_id' }
3051 # SELECT mother.* FROM person mother
3054 # JOIN person father
3055 # ON ( father.person_id = child.father_id )
3057 # ON ( mother.person_id = child.mother_id )
3059 The type of any join can be controlled manually. To search against only people
3060 with a father in the person table, we could explicitly use C<INNER JOIN>:
3062 $rs = $schema->resultset('Person')->search(
3065 alias => 'child', # alias columns in accordance with "from"
3067 { child => 'person' },
3069 { father => 'person', -join_type => 'inner' },
3070 { 'father.id' => 'child.father_id' }
3077 # SELECT child.* FROM person child
3078 # INNER JOIN person father ON child.father_id = father.id
3080 If you need to express really complex joins or you need a subselect, you
3081 can supply literal SQL to C<from> via a scalar reference. In this case
3082 the contents of the scalar will replace the table name asscoiated with the
3085 WARNING: This technique might very well not work as expected on chained
3086 searches - you have been warned.
3088 # Assuming the Event resultsource is defined as:
3090 MySchema::Event->add_columns (
3093 is_auto_increment => 1,
3102 MySchema::Event->set_primary_key ('sequence');
3104 # This will get back the latest event for every location. The column
3105 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3106 # combo to limit the resultset
3108 $rs = $schema->resultset('Event');
3109 $table = $rs->result_source->name;
3110 $latest = $rs->search (
3113 (SELECT e1.* FROM $table e1
3115 ON e1.location = e2.location
3116 AND e1.sequence < e2.sequence
3117 WHERE e2.sequence is NULL
3122 # Equivalent SQL (with the DBIC chunks added):
3124 SELECT me.sequence, me.location, me.type FROM
3125 (SELECT e1.* FROM events e1
3127 ON e1.location = e2.location
3128 AND e1.sequence < e2.sequence
3129 WHERE e2.sequence is NULL
3136 =item Value: ( 'update' | 'shared' )
3140 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT