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.
282 # Special-case handling for (undef, undef).
283 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
288 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
289 my $our_attrs = { %{$self->{attrs}} };
290 my $having = delete $our_attrs->{having};
291 my $where = delete $our_attrs->{where};
295 my %safe = (alias => 1, cache => 1);
298 (@_ && defined($_[0])) # @_ == () or (undef)
300 (keys %$attrs # empty attrs or only 'safe' attrs
301 && List::Util::first { !$safe{$_} } keys %$attrs)
303 # no search, effectively just a clone
304 $rows = $self->get_cache;
307 my $new_attrs = { %{$our_attrs}, %{$attrs} };
309 # merge new attrs into inherited
310 foreach my $key (qw/join prefetch +select +as bind/) {
311 next unless exists $attrs->{$key};
312 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
317 (@_ == 1 || ref $_[0] eq "HASH")
319 (ref $_[0] eq 'HASH')
321 (keys %{ $_[0] } > 0)
329 ? $self->throw_exception("Odd number of arguments to search")
336 if (defined $where) {
337 $new_attrs->{where} = (
338 defined $new_attrs->{where}
341 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
342 } $where, $new_attrs->{where}
349 $new_attrs->{where} = (
350 defined $new_attrs->{where}
353 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
354 } $cond, $new_attrs->{where}
360 if (defined $having) {
361 $new_attrs->{having} = (
362 defined $new_attrs->{having}
365 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
366 } $having, $new_attrs->{having}
372 my $rs = (ref $self)->new($self->result_source, $new_attrs);
374 $rs->set_cache($rows);
379 =head2 search_literal
383 =item Arguments: $sql_fragment, @bind_values
385 =item Return Value: $resultset (scalar context), @row_objs (list context)
389 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
390 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
392 Pass a literal chunk of SQL to be added to the conditional part of the
395 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
396 only be used in that context. C<search_literal> is a convenience method.
397 It is equivalent to calling $schema->search(\[]), but if you want to ensure
398 columns are bound correctly, use C<search>.
400 Example of how to use C<search> instead of C<search_literal>
402 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
403 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
406 See L<DBIx::Class::Manual::Cookbook/Searching> and
407 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
408 require C<search_literal>.
413 my ($self, $sql, @bind) = @_;
415 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
418 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
425 =item Arguments: @values | \%cols, \%attrs?
427 =item Return Value: $row_object | undef
431 Finds a row based on its primary key or unique constraint. For example, to find
432 a row by its primary key:
434 my $cd = $schema->resultset('CD')->find(5);
436 You can also find a row by a specific unique constraint using the C<key>
437 attribute. For example:
439 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
440 key => 'cd_artist_title'
443 Additionally, you can specify the columns explicitly by name:
445 my $cd = $schema->resultset('CD')->find(
447 artist => 'Massive Attack',
448 title => 'Mezzanine',
450 { key => 'cd_artist_title' }
453 If the C<key> is specified as C<primary>, it searches only on the primary key.
455 If no C<key> is specified, it searches on all unique constraints defined on the
456 source for which column data is provided, including the primary key.
458 If your table does not have a primary key, you B<must> provide a value for the
459 C<key> attribute matching one of the unique constraints on the source.
461 In addition to C<key>, L</find> recognizes and applies standard
462 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
464 Note: If your query does not return only one row, a warning is generated:
466 Query returned more than one row
468 See also L</find_or_create> and L</update_or_create>. For information on how to
469 declare unique constraints, see
470 L<DBIx::Class::ResultSource/add_unique_constraint>.
476 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
478 # Default to the primary key, but allow a specific key
479 my @cols = exists $attrs->{key}
480 ? $self->result_source->unique_constraint_columns($attrs->{key})
481 : $self->result_source->primary_columns;
482 $self->throw_exception(
483 "Can't find unless a primary key is defined or unique constraint is specified"
486 # Parse out a hashref from input
488 if (ref $_[0] eq 'HASH') {
489 $input_query = { %{$_[0]} };
491 elsif (@_ == @cols) {
493 @{$input_query}{@cols} = @_;
496 # Compatibility: Allow e.g. find(id => $value)
497 carp "Find by key => value deprecated; please use a hashref instead";
501 my (%related, $info);
503 KEY: foreach my $key (keys %$input_query) {
504 if (ref($input_query->{$key})
505 && ($info = $self->result_source->relationship_info($key))) {
506 my $val = delete $input_query->{$key};
507 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
508 my $rel_q = $self->result_source->_resolve_condition(
509 $info->{cond}, $val, $key
511 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
512 @related{keys %$rel_q} = values %$rel_q;
515 if (my @keys = keys %related) {
516 @{$input_query}{@keys} = values %related;
520 # Build the final query: Default to the disjunction of the unique queries,
521 # but allow the input query in case the ResultSet defines the query or the
522 # user is abusing find
523 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
525 if (exists $attrs->{key}) {
526 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
527 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
528 $query = $self->_add_alias($unique_query, $alias);
531 my @unique_queries = $self->_unique_queries($input_query, $attrs);
532 $query = @unique_queries
533 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
534 : $self->_add_alias($input_query, $alias);
539 my $rs = $self->search($query, $attrs);
540 if (keys %{$rs->_resolved_attrs->{collapse}}) {
542 carp "Query returned more than one row" if $rs->next;
550 if (keys %{$self->_resolved_attrs->{collapse}}) {
551 my $rs = $self->search($query);
553 carp "Query returned more than one row" if $rs->next;
557 return $self->single($query);
564 # Add the specified alias to the specified query hash. A copy is made so the
565 # original query is not modified.
568 my ($self, $query, $alias) = @_;
570 my %aliased = %$query;
571 foreach my $col (grep { ! m/\./ } keys %aliased) {
572 $aliased{"$alias.$col"} = delete $aliased{$col};
580 # Build a list of queries which satisfy unique constraints.
582 sub _unique_queries {
583 my ($self, $query, $attrs) = @_;
585 my @constraint_names = exists $attrs->{key}
587 : $self->result_source->unique_constraint_names;
589 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
590 my $num_where = scalar keys %$where;
593 foreach my $name (@constraint_names) {
594 my @unique_cols = $self->result_source->unique_constraint_columns($name);
595 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
597 my $num_cols = scalar @unique_cols;
598 my $num_query = scalar keys %$unique_query;
600 my $total = $num_query + $num_where;
601 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
602 # The query is either unique on its own or is unique in combination with
603 # the existing where clause
604 push @unique_queries, $unique_query;
608 return @unique_queries;
611 # _build_unique_query
613 # Constrain the specified query hash based on the specified column names.
615 sub _build_unique_query {
616 my ($self, $query, $unique_cols) = @_;
619 map { $_ => $query->{$_} }
620 grep { exists $query->{$_} }
625 =head2 search_related
629 =item Arguments: $rel, $cond, \%attrs?
631 =item Return Value: $new_resultset
635 $new_rs = $cd_rs->search_related('artist', {
639 Searches the specified relationship, optionally specifying a condition and
640 attributes for matching records. See L</ATTRIBUTES> for more information.
645 return shift->related_resultset(shift)->search(@_);
648 =head2 search_related_rs
650 This method works exactly the same as search_related, except that
651 it guarantees a restultset, even in list context.
655 sub search_related_rs {
656 return shift->related_resultset(shift)->search_rs(@_);
663 =item Arguments: none
665 =item Return Value: $cursor
669 Returns a storage-driven cursor to the given resultset. See
670 L<DBIx::Class::Cursor> for more information.
677 my $attrs = { %{$self->_resolved_attrs} };
678 return $self->{cursor}
679 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
680 $attrs->{where},$attrs);
687 =item Arguments: $cond?
689 =item Return Value: $row_object?
693 my $cd = $schema->resultset('CD')->single({ year => 2001 });
695 Inflates the first result without creating a cursor if the resultset has
696 any records in it; if not returns nothing. Used by L</find> as a lean version of
699 While this method can take an optional search condition (just like L</search>)
700 being a fast-code-path it does not recognize search attributes. If you need to
701 add extra joins or similar, call L</search> and then chain-call L</single> on the
702 L<DBIx::Class::ResultSet> returned.
708 As of 0.08100, this method enforces the assumption that the preceeding
709 query returns only one row. If more than one row is returned, you will receive
712 Query returned more than one row
714 In this case, you should be using L</first> or L</find> instead, or if you really
715 know what you are doing, use the L</rows> attribute to explicitly limit the size
723 my ($self, $where) = @_;
725 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
728 my $attrs = { %{$self->_resolved_attrs} };
730 if (defined $attrs->{where}) {
733 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
734 $where, delete $attrs->{where} ]
737 $attrs->{where} = $where;
741 # XXX: Disabled since it doesn't infer uniqueness in all cases
742 # unless ($self->_is_unique_query($attrs->{where})) {
743 # carp "Query not guaranteed to return a single row"
744 # . "; please declare your unique constraints or use search instead";
747 my @data = $self->result_source->storage->select_single(
748 $attrs->{from}, $attrs->{select},
749 $attrs->{where}, $attrs
752 return (@data ? ($self->_construct_object(@data))[0] : undef);
757 # Try to determine if the specified query is guaranteed to be unique, based on
758 # the declared unique constraints.
760 sub _is_unique_query {
761 my ($self, $query) = @_;
763 my $collapsed = $self->_collapse_query($query);
764 my $alias = $self->{attrs}{alias};
766 foreach my $name ($self->result_source->unique_constraint_names) {
767 my @unique_cols = map {
769 } $self->result_source->unique_constraint_columns($name);
771 # Count the values for each unique column
772 my %seen = map { $_ => 0 } @unique_cols;
774 foreach my $key (keys %$collapsed) {
775 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
776 next unless exists $seen{$aliased}; # Additional constraints are okay
777 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
780 # If we get 0 or more than 1 value for a column, it's not necessarily unique
781 return 1 unless grep { $_ != 1 } values %seen;
789 # Recursively collapse the query, accumulating values for each column.
791 sub _collapse_query {
792 my ($self, $query, $collapsed) = @_;
796 if (ref $query eq 'ARRAY') {
797 foreach my $subquery (@$query) {
798 next unless ref $subquery; # -or
799 $collapsed = $self->_collapse_query($subquery, $collapsed);
802 elsif (ref $query eq 'HASH') {
803 if (keys %$query and (keys %$query)[0] eq '-and') {
804 foreach my $subquery (@{$query->{-and}}) {
805 $collapsed = $self->_collapse_query($subquery, $collapsed);
809 foreach my $col (keys %$query) {
810 my $value = $query->{$col};
811 $collapsed->{$col}{$value}++;
823 =item Arguments: $cond?
825 =item Return Value: $resultsetcolumn
829 my $max_length = $rs->get_column('length')->max;
831 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
836 my ($self, $column) = @_;
837 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
845 =item Arguments: $cond, \%attrs?
847 =item Return Value: $resultset (scalar context), @row_objs (list context)
851 # WHERE title LIKE '%blue%'
852 $cd_rs = $rs->search_like({ title => '%blue%'});
854 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
855 that this is simply a convenience method retained for ex Class::DBI users.
856 You most likely want to use L</search> with specific operators.
858 For more information, see L<DBIx::Class::Manual::Cookbook>.
860 This method is deprecated and will be removed in 0.09. Use L</search()>
861 instead. An example conversion is:
863 ->search_like({ foo => 'bar' });
867 ->search({ foo => { like => 'bar' } });
874 'search_like() is deprecated and will be removed in 0.09.',
875 'Instead use ->search({ x => { -like => "y%" } })',
876 '(note the outer pair of {}s - they are important!)'
878 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
879 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
880 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
881 return $class->search($query, { %$attrs });
888 =item Arguments: $first, $last
890 =item Return Value: $resultset (scalar context), @row_objs (list context)
894 Returns a resultset or object list representing a subset of elements from the
895 resultset slice is called on. Indexes are from 0, i.e., to get the first
898 my ($one, $two, $three) = $rs->slice(0, 2);
903 my ($self, $min, $max) = @_;
904 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
905 $attrs->{offset} = $self->{attrs}{offset} || 0;
906 $attrs->{offset} += $min;
907 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
908 return $self->search(undef(), $attrs);
909 #my $slice = (ref $self)->new($self->result_source, $attrs);
910 #return (wantarray ? $slice->all : $slice);
917 =item Arguments: none
919 =item Return Value: $result?
923 Returns the next element in the resultset (C<undef> is there is none).
925 Can be used to efficiently iterate over records in the resultset:
927 my $rs = $schema->resultset('CD')->search;
928 while (my $cd = $rs->next) {
932 Note that you need to store the resultset object, and call C<next> on it.
933 Calling C<< resultset('Table')->next >> repeatedly will always return the
934 first record from the resultset.
940 if (my $cache = $self->get_cache) {
941 $self->{all_cache_position} ||= 0;
942 return $cache->[$self->{all_cache_position}++];
944 if ($self->{attrs}{cache}) {
945 $self->{all_cache_position} = 1;
946 return ($self->all)[0];
948 if ($self->{stashed_objects}) {
949 my $obj = shift(@{$self->{stashed_objects}});
950 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
954 exists $self->{stashed_row}
955 ? @{delete $self->{stashed_row}}
956 : $self->cursor->next
958 return undef unless (@row);
959 my ($row, @more) = $self->_construct_object(@row);
960 $self->{stashed_objects} = \@more if @more;
964 sub _construct_object {
965 my ($self, @row) = @_;
966 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
967 my @new = $self->result_class->inflate_result($self->result_source, @$info);
968 @new = $self->{_attrs}{record_filter}->(@new)
969 if exists $self->{_attrs}{record_filter};
973 sub _collapse_result {
974 my ($self, $as_proto, $row) = @_;
978 # 'foo' => [ undef, 'foo' ]
979 # 'foo.bar' => [ 'foo', 'bar' ]
980 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
982 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
984 my %collapse = %{$self->{_attrs}{collapse}||{}};
988 # if we're doing collapsing (has_many prefetch) we need to grab records
989 # until the PK changes, so fill @pri_index. if not, we leave it empty so
990 # we know we don't have to bother.
992 # the reason for not using the collapse stuff directly is because if you
993 # had for e.g. two artists in a row with no cds, the collapse info for
994 # both would be NULL (undef) so you'd lose the second artist
996 # store just the index so we can check the array positions from the row
997 # without having to contruct the full hash
999 if (keys %collapse) {
1000 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
1001 foreach my $i (0 .. $#construct_as) {
1002 next if defined($construct_as[$i][0]); # only self table
1003 if (delete $pri{$construct_as[$i][1]}) {
1004 push(@pri_index, $i);
1006 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1010 # no need to do an if, it'll be empty if @pri_index is empty anyway
1012 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1016 do { # no need to check anything at the front, we always want the first row
1020 foreach my $this_as (@construct_as) {
1021 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1024 push(@const_rows, \%const);
1026 } until ( # no pri_index => no collapse => drop straight out
1029 do { # get another row, stash it, drop out if different PK
1031 @copy = $self->cursor->next;
1032 $self->{stashed_row} = \@copy;
1034 # last thing in do block, counts as true if anything doesn't match
1036 # check xor defined first for NULL vs. NOT NULL then if one is
1037 # defined the other must be so check string equality
1040 (defined $pri_vals{$_} ^ defined $copy[$_])
1041 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1046 my $alias = $self->{attrs}{alias};
1053 foreach my $const (@const_rows) {
1054 scalar @const_keys or do {
1055 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1057 foreach my $key (@const_keys) {
1060 my @parts = split(/\./, $key);
1062 my $data = $const->{$key};
1063 foreach my $p (@parts) {
1064 $target = $target->[1]->{$p} ||= [];
1066 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1067 # collapsing at this point and on final part
1068 my $pos = $collapse_pos{$cur};
1069 CK: foreach my $ck (@ckey) {
1070 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1071 $collapse_pos{$cur} = $data;
1072 delete @collapse_pos{ # clear all positioning for sub-entries
1073 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1080 if (exists $collapse{$cur}) {
1081 $target = $target->[-1];
1084 $target->[0] = $data;
1086 $info->[0] = $const->{$key};
1094 =head2 result_source
1098 =item Arguments: $result_source?
1100 =item Return Value: $result_source
1104 An accessor for the primary ResultSource object from which this ResultSet
1111 =item Arguments: $result_class?
1113 =item Return Value: $result_class
1117 An accessor for the class to use when creating row objects. Defaults to
1118 C<< result_source->result_class >> - which in most cases is the name of the
1119 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1121 Note that changing the result_class will also remove any components
1122 that were originally loaded in the source class via
1123 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1124 in the original source class will not run.
1129 my ($self, $result_class) = @_;
1130 if ($result_class) {
1131 $self->ensure_class_loaded($result_class);
1132 $self->_result_class($result_class);
1134 $self->_result_class;
1141 =item Arguments: $cond, \%attrs??
1143 =item Return Value: $count
1147 Performs an SQL C<COUNT> with the same query as the resultset was built
1148 with to find the number of elements. If passed arguments, does a search
1149 on the resultset and counts the results of that.
1155 return $self->search(@_)->count if @_ and defined $_[0];
1156 return scalar @{ $self->get_cache } if $self->get_cache;
1158 my @subq_attrs = qw/prefetch collapse distinct group_by having having_bind/;
1160 # if we are not paged - we are simply asking for a limit
1161 if (not $self->{attrs}{page} and not $self->{attrs}{software_limit}) {
1162 push @subq_attrs, qw/rows offset/;
1165 return $self->_has_attr (@subq_attrs)
1166 ? $self->_count_subq
1167 : $self->_count_simple
1173 my $attrs = { %{$self->_resolved_attrs} };
1175 # copy for the subquery, we need to do some adjustments to it too
1176 my $sub_attrs = { %$attrs };
1178 # these can not go in the subquery either
1179 delete $sub_attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
1181 # force a group_by and the same set of columns (most databases require this)
1182 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1185 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1188 # the subquery replaces this
1189 delete $attrs->{$_} for qw/where bind prefetch collapse group_by having/;
1191 return $self->__count ($attrs);
1197 my $count = $self->__count;
1198 return 0 unless $count;
1200 # need to take offset from resolved attrs
1202 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1203 $count = $self->{attrs}{rows} if
1204 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1205 $count = 0 if ($count < 0);
1210 my ($self, $attrs) = @_;
1212 $attrs ||= { %{$self->{attrs}} };
1214 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1215 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1217 $attrs->{select} = { count => '*' };
1218 $attrs->{as} = [qw/count/];
1220 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1221 my ($count) = $tmp_rs->cursor->next;
1230 =head2 count_literal
1234 =item Arguments: $sql_fragment, @bind_values
1236 =item Return Value: $count
1240 Counts the results in a literal query. Equivalent to calling L</search_literal>
1241 with the passed arguments, then L</count>.
1245 sub count_literal { shift->search_literal(@_)->count; }
1251 =item Arguments: none
1253 =item Return Value: @objects
1257 Returns all elements in the resultset. Called implicitly if the resultset
1258 is returned in list context.
1265 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1268 return @{ $self->get_cache } if $self->get_cache;
1272 # TODO: don't call resolve here
1273 if (keys %{$self->_resolved_attrs->{collapse}}) {
1274 # if ($self->{attrs}{prefetch}) {
1275 # Using $self->cursor->all is really just an optimisation.
1276 # If we're collapsing has_many prefetches it probably makes
1277 # very little difference, and this is cleaner than hacking
1278 # _construct_object to survive the approach
1279 my @row = $self->cursor->next;
1281 push(@obj, $self->_construct_object(@row));
1282 @row = (exists $self->{stashed_row}
1283 ? @{delete $self->{stashed_row}}
1284 : $self->cursor->next);
1287 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1290 $self->set_cache(\@obj) if $self->{attrs}{cache};
1298 =item Arguments: none
1300 =item Return Value: $self
1304 Resets the resultset's cursor, so you can iterate through the elements again.
1310 delete $self->{_attrs} if exists $self->{_attrs};
1311 $self->{all_cache_position} = 0;
1312 $self->cursor->reset;
1320 =item Arguments: none
1322 =item Return Value: $object?
1326 Resets the resultset and returns an object for the first result (if the
1327 resultset returns anything).
1332 return $_[0]->reset->next;
1338 # Determines whether and what type of subquery is required for the $rs operation.
1339 # If grouping is necessary either supplies its own, or verifies the current one
1340 # After all is done delegates to the proper storage method.
1342 sub _rs_update_delete {
1343 my ($self, $op, $values) = @_;
1345 my $rsrc = $self->result_source;
1347 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1348 my $needs_subq = $self->_has_attr (qw/row offset page/);
1350 if ($needs_group_by_subq or $needs_subq) {
1352 # make a new $rs selecting only the PKs (that's all we really need)
1353 my $attrs = $self->_resolved_attrs;
1355 delete $attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
1356 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1358 if ($needs_group_by_subq) {
1359 # make sure no group_by was supplied, or if there is one - make sure it matches
1360 # the columns compiled above perfectly. Anything else can not be sanely executed
1361 # on most databases so croak right then and there
1363 if (my $g = $attrs->{group_by}) {
1364 my @current_group_by = map
1365 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1366 (ref $g eq 'ARRAY' ? @$g : $g );
1369 join ("\x00", sort @current_group_by)
1371 join ("\x00", sort @{$attrs->{columns}} )
1373 $self->throw_exception (
1374 "You have just attempted a $op operation on a resultset which does group_by"
1375 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1376 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1377 . ' kind of queries. Please retry the operation with a modified group_by or'
1378 . ' without using one at all.'
1383 $attrs->{group_by} = $attrs->{columns};
1387 my $subrs = (ref $self)->new($rsrc, $attrs);
1389 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1392 return $rsrc->storage->$op(
1394 $op eq 'update' ? $values : (),
1395 $self->_cond_for_update_delete,
1401 # _cond_for_update_delete
1403 # update/delete require the condition to be modified to handle
1404 # the differing SQL syntax available. This transforms the $self->{cond}
1405 # appropriately, returning the new condition.
1407 sub _cond_for_update_delete {
1408 my ($self, $full_cond) = @_;
1411 $full_cond ||= $self->{cond};
1412 # No-op. No condition, we're updating/deleting everything
1413 return $cond unless ref $full_cond;
1415 if (ref $full_cond eq 'ARRAY') {
1419 foreach my $key (keys %{$_}) {
1421 $hash{$1} = $_->{$key};
1427 elsif (ref $full_cond eq 'HASH') {
1428 if ((keys %{$full_cond})[0] eq '-and') {
1430 my @cond = @{$full_cond->{-and}};
1431 for (my $i = 0; $i < @cond; $i++) {
1432 my $entry = $cond[$i];
1434 if (ref $entry eq 'HASH') {
1435 $hash = $self->_cond_for_update_delete($entry);
1438 $entry =~ /([^.]+)$/;
1439 $hash->{$1} = $cond[++$i];
1441 push @{$cond->{-and}}, $hash;
1445 foreach my $key (keys %{$full_cond}) {
1447 $cond->{$1} = $full_cond->{$key};
1452 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1463 =item Arguments: \%values
1465 =item Return Value: $storage_rv
1469 Sets the specified columns in the resultset to the supplied values in a
1470 single query. Return value will be true if the update succeeded or false
1471 if no records were updated; exact type of success value is storage-dependent.
1476 my ($self, $values) = @_;
1477 $self->throw_exception('Values for update must be a hash')
1478 unless ref $values eq 'HASH';
1480 return $self->_rs_update_delete ('update', $values);
1487 =item Arguments: \%values
1489 =item Return Value: 1
1493 Fetches all objects and updates them one at a time. Note that C<update_all>
1494 will run DBIC cascade triggers, while L</update> will not.
1499 my ($self, $values) = @_;
1500 $self->throw_exception('Values for update_all must be a hash')
1501 unless ref $values eq 'HASH';
1502 foreach my $obj ($self->all) {
1503 $obj->set_columns($values)->update;
1512 =item Arguments: none
1514 =item Return Value: 1
1518 Deletes the contents of the resultset from its result source. Note that this
1519 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1520 to run. See also L<DBIx::Class::Row/delete>.
1522 delete may not generate correct SQL for a query with joins or a resultset
1523 chained from a related resultset. In this case it will generate a warning:-
1525 In these cases you may find that delete_all is more appropriate, or you
1526 need to respecify your query in a way that can be expressed without a join.
1532 $self->throw_exception('delete does not accept any arguments')
1535 return $self->_rs_update_delete ('delete');
1542 =item Arguments: none
1544 =item Return Value: 1
1548 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1549 will run DBIC cascade triggers, while L</delete> will not.
1555 $self->throw_exception('delete_all does not accept any arguments')
1558 $_->delete for $self->all;
1566 =item Arguments: \@data;
1570 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1571 For the arrayref of hashrefs style each hashref should be a structure suitable
1572 forsubmitting to a $resultset->create(...) method.
1574 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1575 to insert the data, as this is a faster method.
1577 Otherwise, each set of data is inserted into the database using
1578 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1579 objects is returned.
1581 Example: Assuming an Artist Class that has many CDs Classes relating:
1583 my $Artist_rs = $schema->resultset("Artist");
1585 ## Void Context Example
1586 $Artist_rs->populate([
1587 { artistid => 4, name => 'Manufactured Crap', cds => [
1588 { title => 'My First CD', year => 2006 },
1589 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1592 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1593 { title => 'My parents sold me to a record company' ,year => 2005 },
1594 { title => 'Why Am I So Ugly?', year => 2006 },
1595 { title => 'I Got Surgery and am now Popular', year => 2007 }
1600 ## Array Context Example
1601 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1602 { name => "Artist One"},
1603 { name => "Artist Two"},
1604 { name => "Artist Three", cds=> [
1605 { title => "First CD", year => 2007},
1606 { title => "Second CD", year => 2008},
1610 print $ArtistOne->name; ## response is 'Artist One'
1611 print $ArtistThree->cds->count ## reponse is '2'
1613 For the arrayref of arrayrefs style, the first element should be a list of the
1614 fieldsnames to which the remaining elements are rows being inserted. For
1617 $Arstist_rs->populate([
1618 [qw/artistid name/],
1619 [100, 'A Formally Unknown Singer'],
1620 [101, 'A singer that jumped the shark two albums ago'],
1621 [102, 'An actually cool singer.'],
1624 Please note an important effect on your data when choosing between void and
1625 wantarray context. Since void context goes straight to C<insert_bulk> in
1626 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1627 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1628 create primary keys for you, you will find that your PKs are empty. In this
1629 case you will have to use the wantarray context in order to create those
1635 my $self = shift @_;
1636 my $data = ref $_[0][0] eq 'HASH'
1637 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1638 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1640 if(defined wantarray) {
1642 foreach my $item (@$data) {
1643 push(@created, $self->create($item));
1647 my ($first, @rest) = @$data;
1649 my @names = grep {!ref $first->{$_}} keys %$first;
1650 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1651 my @pks = $self->result_source->primary_columns;
1653 ## do the belongs_to relationships
1654 foreach my $index (0..$#$data) {
1655 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1656 my @ret = $self->populate($data);
1660 foreach my $rel (@rels) {
1661 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1662 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1663 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1664 my $related = $result->result_source->_resolve_condition(
1665 $result->result_source->relationship_info($reverse)->{cond},
1670 delete $data->[$index]->{$rel};
1671 $data->[$index] = {%{$data->[$index]}, %$related};
1673 push @names, keys %$related if $index == 0;
1677 ## do bulk insert on current row
1678 my @values = map { [ @$_{@names} ] } @$data;
1680 $self->result_source->storage->insert_bulk(
1681 $self->result_source,
1686 ## do the has_many relationships
1687 foreach my $item (@$data) {
1689 foreach my $rel (@rels) {
1690 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1692 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1693 || $self->throw_exception('Cannot find the relating object.');
1695 my $child = $parent->$rel;
1697 my $related = $child->result_source->_resolve_condition(
1698 $parent->result_source->relationship_info($rel)->{cond},
1703 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1704 my @populate = map { {%$_, %$related} } @rows_to_add;
1706 $child->populate( \@populate );
1712 =head2 _normalize_populate_args ($args)
1714 Private method used by L</populate> to normalize its incoming arguments. Factored
1715 out in case you want to subclass and accept new argument structures to the
1716 L</populate> method.
1720 sub _normalize_populate_args {
1721 my ($self, $data) = @_;
1722 my @names = @{shift(@$data)};
1723 my @results_to_create;
1724 foreach my $datum (@$data) {
1725 my %result_to_create;
1726 foreach my $index (0..$#names) {
1727 $result_to_create{$names[$index]} = $$datum[$index];
1729 push @results_to_create, \%result_to_create;
1731 return \@results_to_create;
1738 =item Arguments: none
1740 =item Return Value: $pager
1744 Return Value a L<Data::Page> object for the current resultset. Only makes
1745 sense for queries with a C<page> attribute.
1747 To get the full count of entries for a paged resultset, call
1748 C<total_entries> on the L<Data::Page> object.
1755 return $self->{pager} if $self->{pager};
1757 my $attrs = $self->{attrs};
1758 $self->throw_exception("Can't create pager for non-paged rs")
1759 unless $self->{attrs}{page};
1760 $attrs->{rows} ||= 10;
1762 # throw away the paging flags and re-run the count (possibly
1763 # with a subselect) to get the real total count
1764 my $count_attrs = { %$attrs };
1765 delete $count_attrs->{$_} for qw/rows offset page pager/;
1766 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1768 return $self->{pager} = Data::Page->new(
1771 $self->{attrs}{page}
1779 =item Arguments: $page_number
1781 =item Return Value: $rs
1785 Returns a resultset for the $page_number page of the resultset on which page
1786 is called, where each page contains a number of rows equal to the 'rows'
1787 attribute set on the resultset (10 by default).
1792 my ($self, $page) = @_;
1793 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1800 =item Arguments: \%vals
1802 =item Return Value: $rowobject
1806 Creates a new row object in the resultset's result class and returns
1807 it. The row is not inserted into the database at this point, call
1808 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1809 will tell you whether the row object has been inserted or not.
1811 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1816 my ($self, $values) = @_;
1817 $self->throw_exception( "new_result needs a hash" )
1818 unless (ref $values eq 'HASH');
1821 my $alias = $self->{attrs}{alias};
1824 defined $self->{cond}
1825 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1827 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1828 $new{-from_resultset} = [ keys %new ] if keys %new;
1830 $self->throw_exception(
1831 "Can't abstract implicit construct, condition not a hash"
1832 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1834 my $collapsed_cond = (
1836 ? $self->_collapse_cond($self->{cond})
1840 # precendence must be given to passed values over values inherited from
1841 # the cond, so the order here is important.
1842 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1843 while( my($col,$value) = each %implied ){
1844 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1845 $new{$col} = $value->{'='};
1848 $new{$col} = $value if $self->_is_deterministic_value($value);
1854 %{ $self->_remove_alias($values, $alias) },
1855 -source_handle => $self->_source_handle,
1856 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1859 return $self->result_class->new(\%new);
1862 # _is_deterministic_value
1864 # Make an effor to strip non-deterministic values from the condition,
1865 # to make sure new_result chokes less
1867 sub _is_deterministic_value {
1870 my $ref_type = ref $value;
1871 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1872 return 1 if Scalar::Util::blessed($value);
1878 # determines if the resultset defines at least one
1879 # of the attributes supplied
1881 # used to determine if a subquery is neccessary
1884 my ($self, @attr_names) = @_;
1886 my $attrs = $self->_resolved_attrs;
1890 for my $n (@attr_names) {
1891 ++$join_check_req if $n =~ /join/;
1893 my $attr = $attrs->{$n};
1895 next if not defined $attr;
1897 if (ref $attr eq 'HASH') {
1898 return 1 if keys %$attr;
1900 elsif (ref $attr eq 'ARRAY') {
1908 # a join can be expressed as a multi-level from
1912 ref $attrs->{from} eq 'ARRAY'
1914 @{$attrs->{from}} > 1
1922 # Recursively collapse the condition.
1924 sub _collapse_cond {
1925 my ($self, $cond, $collapsed) = @_;
1929 if (ref $cond eq 'ARRAY') {
1930 foreach my $subcond (@$cond) {
1931 next unless ref $subcond; # -or
1932 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1935 elsif (ref $cond eq 'HASH') {
1936 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1937 foreach my $subcond (@{$cond->{-and}}) {
1938 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1942 foreach my $col (keys %$cond) {
1943 my $value = $cond->{$col};
1944 $collapsed->{$col} = $value;
1954 # Remove the specified alias from the specified query hash. A copy is made so
1955 # the original query is not modified.
1958 my ($self, $query, $alias) = @_;
1960 my %orig = %{ $query || {} };
1963 foreach my $key (keys %orig) {
1965 $unaliased{$key} = $orig{$key};
1968 $unaliased{$1} = $orig{$key}
1969 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1975 =head2 as_query (EXPERIMENTAL)
1979 =item Arguments: none
1981 =item Return Value: \[ $sql, @bind ]
1985 Returns the SQL query and bind vars associated with the invocant.
1987 This is generally used as the RHS for a subquery.
1989 B<NOTE>: This feature is still experimental.
1993 sub as_query { return shift->cursor->as_query(@_) }
1999 =item Arguments: \%vals, \%attrs?
2001 =item Return Value: $rowobject
2005 my $artist = $schema->resultset('Artist')->find_or_new(
2006 { artist => 'fred' }, { key => 'artists' });
2008 $cd->cd_to_producer->find_or_new({ producer => $producer },
2009 { key => 'primary });
2011 Find an existing record from this resultset, based on its primary
2012 key, or a unique constraint. If none exists, instantiate a new result
2013 object and return it. The object will not be saved into your storage
2014 until you call L<DBIx::Class::Row/insert> on it.
2016 You most likely want this method when looking for existing rows using
2017 a unique constraint that is not the primary key, or looking for
2020 If you want objects to be saved immediately, use L</find_or_create> instead.
2022 B<Note>: C<find_or_new> is probably not what you want when creating a
2023 new row in a table that uses primary keys supplied by the
2024 database. Passing in a primary key column with a value of I<undef>
2025 will cause L</find> to attempt to search for a row with a value of
2032 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2033 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2034 my $exists = $self->find($hash, $attrs);
2035 return defined $exists ? $exists : $self->new_result($hash);
2042 =item Arguments: \%vals
2044 =item Return Value: a L<DBIx::Class::Row> $object
2048 Attempt to create a single new row or a row with multiple related rows
2049 in the table represented by the resultset (and related tables). This
2050 will not check for duplicate rows before inserting, use
2051 L</find_or_create> to do that.
2053 To create one row for this resultset, pass a hashref of key/value
2054 pairs representing the columns of the table and the values you wish to
2055 store. If the appropriate relationships are set up, foreign key fields
2056 can also be passed an object representing the foreign row, and the
2057 value will be set to its primary key.
2059 To create related objects, pass a hashref for the value if the related
2060 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2061 and use the name of the relationship as the key. (NOT the name of the field,
2062 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2063 of hashrefs containing the data for each of the rows to create in the foreign
2064 tables, again using the relationship name as the key.
2066 Instead of hashrefs of plain related data (key/value pairs), you may
2067 also pass new or inserted objects. New objects (not inserted yet, see
2068 L</new>), will be inserted into their appropriate tables.
2070 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2072 Example of creating a new row.
2074 $person_rs->create({
2075 name=>"Some Person",
2076 email=>"somebody@someplace.com"
2079 Example of creating a new row and also creating rows in a related C<has_many>
2080 or C<has_one> resultset. Note Arrayref.
2083 { artistid => 4, name => 'Manufactured Crap', cds => [
2084 { title => 'My First CD', year => 2006 },
2085 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2090 Example of creating a new row and also creating a row in a related
2091 C<belongs_to>resultset. Note Hashref.
2094 title=>"Music for Silly Walks",
2097 name=>"Silly Musician",
2104 my ($self, $attrs) = @_;
2105 $self->throw_exception( "create needs a hashref" )
2106 unless ref $attrs eq 'HASH';
2107 return $self->new_result($attrs)->insert;
2110 =head2 find_or_create
2114 =item Arguments: \%vals, \%attrs?
2116 =item Return Value: $rowobject
2120 $cd->cd_to_producer->find_or_create({ producer => $producer },
2121 { key => 'primary });
2123 Tries to find a record based on its primary key or unique constraints; if none
2124 is found, creates one and returns that instead.
2126 my $cd = $schema->resultset('CD')->find_or_create({
2128 artist => 'Massive Attack',
2129 title => 'Mezzanine',
2133 Also takes an optional C<key> attribute, to search by a specific key or unique
2134 constraint. For example:
2136 my $cd = $schema->resultset('CD')->find_or_create(
2138 artist => 'Massive Attack',
2139 title => 'Mezzanine',
2141 { key => 'cd_artist_title' }
2144 B<Note>: Because find_or_create() reads from the database and then
2145 possibly inserts based on the result, this method is subject to a race
2146 condition. Another process could create a record in the table after
2147 the find has completed and before the create has started. To avoid
2148 this problem, use find_or_create() inside a transaction.
2150 B<Note>: C<find_or_create> is probably not what you want when creating
2151 a new row in a table that uses primary keys supplied by the
2152 database. Passing in a primary key column with a value of I<undef>
2153 will cause L</find> to attempt to search for a row with a value of
2156 See also L</find> and L</update_or_create>. For information on how to declare
2157 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2161 sub find_or_create {
2163 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2164 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2165 my $exists = $self->find($hash, $attrs);
2166 return defined $exists ? $exists : $self->create($hash);
2169 =head2 update_or_create
2173 =item Arguments: \%col_values, { key => $unique_constraint }?
2175 =item Return Value: $rowobject
2179 $resultset->update_or_create({ col => $val, ... });
2181 First, searches for an existing row matching one of the unique constraints
2182 (including the primary key) on the source of this resultset. If a row is
2183 found, updates it with the other given column values. Otherwise, creates a new
2186 Takes an optional C<key> attribute to search on a specific unique constraint.
2189 # In your application
2190 my $cd = $schema->resultset('CD')->update_or_create(
2192 artist => 'Massive Attack',
2193 title => 'Mezzanine',
2196 { key => 'cd_artist_title' }
2199 $cd->cd_to_producer->update_or_create({
2200 producer => $producer,
2207 If no C<key> is specified, it searches on all unique constraints defined on the
2208 source, including the primary key.
2210 If the C<key> is specified as C<primary>, it searches only on the primary key.
2212 See also L</find> and L</find_or_create>. For information on how to declare
2213 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2215 B<Note>: C<update_or_create> is probably not what you want when
2216 looking for a row in a table that uses primary keys supplied by the
2217 database, unless you actually have a key value. Passing in a primary
2218 key column with a value of I<undef> will cause L</find> to attempt to
2219 search for a row with a value of I<NULL>.
2223 sub update_or_create {
2225 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2226 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2228 my $row = $self->find($cond, $attrs);
2230 $row->update($cond);
2234 return $self->create($cond);
2237 =head2 update_or_new
2241 =item Arguments: \%col_values, { key => $unique_constraint }?
2243 =item Return Value: $rowobject
2247 $resultset->update_or_new({ col => $val, ... });
2249 First, searches for an existing row matching one of the unique constraints
2250 (including the primary key) on the source of this resultset. If a row is
2251 found, updates it with the other given column values. Otherwise, instantiate
2252 a new result object and return it. The object will not be saved into your storage
2253 until you call L<DBIx::Class::Row/insert> on it.
2255 Takes an optional C<key> attribute to search on a specific unique constraint.
2258 # In your application
2259 my $cd = $schema->resultset('CD')->update_or_new(
2261 artist => 'Massive Attack',
2262 title => 'Mezzanine',
2265 { key => 'cd_artist_title' }
2268 if ($cd->in_storage) {
2269 # the cd was updated
2272 # the cd is not yet in the database, let's insert it
2276 See also L</find>, L</find_or_create> and L<find_or_new>.
2282 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2283 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2285 my $row = $self->find( $cond, $attrs );
2286 if ( defined $row ) {
2287 $row->update($cond);
2291 return $self->new_result($cond);
2298 =item Arguments: none
2300 =item Return Value: \@cache_objects?
2304 Gets the contents of the cache for the resultset, if the cache is set.
2306 The cache is populated either by using the L</prefetch> attribute to
2307 L</search> or by calling L</set_cache>.
2319 =item Arguments: \@cache_objects
2321 =item Return Value: \@cache_objects
2325 Sets the contents of the cache for the resultset. Expects an arrayref
2326 of objects of the same class as those produced by the resultset. Note that
2327 if the cache is set the resultset will return the cached objects rather
2328 than re-querying the database even if the cache attr is not set.
2330 The contents of the cache can also be populated by using the
2331 L</prefetch> attribute to L</search>.
2336 my ( $self, $data ) = @_;
2337 $self->throw_exception("set_cache requires an arrayref")
2338 if defined($data) && (ref $data ne 'ARRAY');
2339 $self->{all_cache} = $data;
2346 =item Arguments: none
2348 =item Return Value: []
2352 Clears the cache for the resultset.
2357 shift->set_cache(undef);
2360 =head2 related_resultset
2364 =item Arguments: $relationship_name
2366 =item Return Value: $resultset
2370 Returns a related resultset for the supplied relationship name.
2372 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2376 sub related_resultset {
2377 my ($self, $rel) = @_;
2379 $self->{related_resultsets} ||= {};
2380 return $self->{related_resultsets}{$rel} ||= do {
2381 my $rel_obj = $self->result_source->relationship_info($rel);
2383 $self->throw_exception(
2384 "search_related: result source '" . $self->result_source->source_name .
2385 "' has no such relationship $rel")
2388 my ($from,$seen) = $self->_resolve_from($rel);
2390 my $join_count = $seen->{$rel};
2391 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2393 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2394 my %attrs = %{$self->{attrs}||{}};
2395 delete @attrs{qw(result_class alias)};
2399 if (my $cache = $self->get_cache) {
2400 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2401 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2406 my $rel_source = $self->result_source->related_source($rel);
2410 # The reason we do this now instead of passing the alias to the
2411 # search_rs below is that if you wrap/overload resultset on the
2412 # source you need to know what alias it's -going- to have for things
2413 # to work sanely (e.g. RestrictWithObject wants to be able to add
2414 # extra query restrictions, and these may need to be $alias.)
2416 my $attrs = $rel_source->resultset_attributes;
2417 local $attrs->{alias} = $alias;
2419 $rel_source->resultset
2427 where => $self->{cond},
2432 $new->set_cache($new_cache) if $new_cache;
2437 =head2 current_source_alias
2441 =item Arguments: none
2443 =item Return Value: $source_alias
2447 Returns the current table alias for the result source this resultset is built
2448 on, that will be used in the SQL query. Usually it is C<me>.
2450 Currently the source alias that refers to the result set returned by a
2451 L</search>/L</find> family method depends on how you got to the resultset: it's
2452 C<me> by default, but eg. L</search_related> aliases it to the related result
2453 source name (and keeps C<me> referring to the original result set). The long
2454 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2455 (and make this method unnecessary).
2457 Thus it's currently necessary to use this method in predefined queries (see
2458 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2459 source alias of the current result set:
2461 # in a result set class
2463 my ($self, $user) = @_;
2465 my $me = $self->current_source_alias;
2467 return $self->search(
2468 "$me.modified" => $user->id,
2474 sub current_source_alias {
2477 return ($self->{attrs} || {})->{alias} || 'me';
2480 # This code is called by search_related, and makes sure there
2481 # is clear separation between the joins before, during, and
2482 # after the relationship. This information is needed later
2483 # in order to properly resolve prefetch aliases (any alias
2484 # with a relation_chain_depth less than the depth of the
2485 # current prefetch is not considered)
2487 my ($self, $extra_join) = @_;
2488 my $source = $self->result_source;
2489 my $attrs = $self->{attrs};
2491 my $from = $attrs->{from}
2492 || [ { $attrs->{alias} => $source->from } ];
2494 my $seen = { %{$attrs->{seen_join}||{}} };
2496 # we need to take the prefetch the attrs into account before we
2497 # ->_resolve_join as otherwise they get lost - captainL
2498 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2500 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2502 ++$seen->{-relation_chain_depth};
2504 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2506 ++$seen->{-relation_chain_depth};
2508 return ($from,$seen);
2511 sub _resolved_attrs {
2513 return $self->{_attrs} if $self->{_attrs};
2515 my $attrs = { %{ $self->{attrs} || {} } };
2516 my $source = $self->result_source;
2517 my $alias = $attrs->{alias};
2519 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2522 # build columns (as long as select isn't set) into a set of as/select hashes
2523 unless ( $attrs->{select} ) {
2525 ( ref($_) eq 'HASH' )
2529 /^\Q${alias}.\E(.+)$/
2540 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2542 # add the additional columns on
2543 foreach ( 'include_columns', '+columns' ) {
2544 push @colbits, map {
2545 ( ref($_) eq 'HASH' )
2547 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2548 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2551 # start with initial select items
2552 if ( $attrs->{select} ) {
2554 ( ref $attrs->{select} eq 'ARRAY' )
2555 ? [ @{ $attrs->{select} } ]
2556 : [ $attrs->{select} ];
2560 ref $attrs->{as} eq 'ARRAY'
2561 ? [ @{ $attrs->{as} } ]
2564 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2569 # otherwise we intialise select & as to empty
2570 $attrs->{select} = [];
2574 # now add colbits to select/as
2575 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2576 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2579 if ( $adds = delete $attrs->{'+select'} ) {
2580 $adds = [$adds] unless ref $adds eq 'ARRAY';
2582 @{ $attrs->{select} },
2583 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2586 if ( $adds = delete $attrs->{'+as'} ) {
2587 $adds = [$adds] unless ref $adds eq 'ARRAY';
2588 push( @{ $attrs->{as} }, @$adds );
2591 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2593 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2594 my $join = delete $attrs->{join} || {};
2596 if ( defined $attrs->{prefetch} ) {
2597 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2601 $attrs->{from} = # have to copy here to avoid corrupting the original
2603 @{ $attrs->{from} },
2604 $source->_resolve_join(
2605 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2611 $attrs->{group_by} ||= $attrs->{select}
2612 if delete $attrs->{distinct};
2613 if ( $attrs->{order_by} ) {
2614 $attrs->{order_by} = (
2615 ref( $attrs->{order_by} ) eq 'ARRAY'
2616 ? [ @{ $attrs->{order_by} } ]
2617 : [ $attrs->{order_by} ]
2621 $attrs->{order_by} = [];
2624 my $collapse = $attrs->{collapse} || {};
2625 if ( my $prefetch = delete $attrs->{prefetch} ) {
2626 $prefetch = $self->_merge_attr( {}, $prefetch );
2628 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2630 # bring joins back to level of current class
2631 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2633 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2634 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2635 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2637 push( @{ $attrs->{order_by} }, @pre_order );
2639 $attrs->{collapse} = $collapse;
2641 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2642 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2645 return $self->{_attrs} = $attrs;
2648 sub _joinpath_aliases {
2649 my ($self, $fromspec, $seen) = @_;
2652 return $paths unless ref $fromspec eq 'ARRAY';
2654 for my $j (@$fromspec) {
2656 next if ref $j ne 'ARRAY';
2657 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2660 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2661 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2668 my ($self, $attr) = @_;
2670 if (ref $attr eq 'HASH') {
2671 return $self->_rollout_hash($attr);
2672 } elsif (ref $attr eq 'ARRAY') {
2673 return $self->_rollout_array($attr);
2679 sub _rollout_array {
2680 my ($self, $attr) = @_;
2683 foreach my $element (@{$attr}) {
2684 if (ref $element eq 'HASH') {
2685 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2686 } elsif (ref $element eq 'ARRAY') {
2687 # XXX - should probably recurse here
2688 push( @rolled_array, @{$self->_rollout_array($element)} );
2690 push( @rolled_array, $element );
2693 return \@rolled_array;
2697 my ($self, $attr) = @_;
2700 foreach my $key (keys %{$attr}) {
2701 push( @rolled_array, { $key => $attr->{$key} } );
2703 return \@rolled_array;
2706 sub _calculate_score {
2707 my ($self, $a, $b) = @_;
2709 if (ref $b eq 'HASH') {
2710 my ($b_key) = keys %{$b};
2711 if (ref $a eq 'HASH') {
2712 my ($a_key) = keys %{$a};
2713 if ($a_key eq $b_key) {
2714 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2719 return ($a eq $b_key) ? 1 : 0;
2722 if (ref $a eq 'HASH') {
2723 my ($a_key) = keys %{$a};
2724 return ($b eq $a_key) ? 1 : 0;
2726 return ($b eq $a) ? 1 : 0;
2732 my ($self, $orig, $import) = @_;
2734 return $import unless defined($orig);
2735 return $orig unless defined($import);
2737 $orig = $self->_rollout_attr($orig);
2738 $import = $self->_rollout_attr($import);
2741 foreach my $import_element ( @{$import} ) {
2742 # find best candidate from $orig to merge $b_element into
2743 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2744 foreach my $orig_element ( @{$orig} ) {
2745 my $score = $self->_calculate_score( $orig_element, $import_element );
2746 if ($score > $best_candidate->{score}) {
2747 $best_candidate->{position} = $position;
2748 $best_candidate->{score} = $score;
2752 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2754 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2755 push( @{$orig}, $import_element );
2757 my $orig_best = $orig->[$best_candidate->{position}];
2758 # merge orig_best and b_element together and replace original with merged
2759 if (ref $orig_best ne 'HASH') {
2760 $orig->[$best_candidate->{position}] = $import_element;
2761 } elsif (ref $import_element eq 'HASH') {
2762 my ($key) = keys %{$orig_best};
2763 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2766 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2776 $self->_source_handle($_[0]->handle);
2778 $self->_source_handle->resolve;
2782 =head2 throw_exception
2784 See L<DBIx::Class::Schema/throw_exception> for details.
2788 sub throw_exception {
2790 if (ref $self && $self->_source_handle->schema) {
2791 $self->_source_handle->schema->throw_exception(@_)
2798 # XXX: FIXME: Attributes docs need clearing up
2802 Attributes are used to refine a ResultSet in various ways when
2803 searching for data. They can be passed to any method which takes an
2804 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2807 These are in no particular order:
2813 =item Value: ( $order_by | \@order_by | \%order_by )
2817 Which column(s) to order the results by. If a single column name, or
2818 an arrayref of names is supplied, the argument is passed through
2819 directly to SQL. The hashref syntax allows for connection-agnostic
2820 specification of ordering direction:
2822 For descending order:
2824 order_by => { -desc => [qw/col1 col2 col3/] }
2826 For explicit ascending order:
2828 order_by => { -asc => 'col' }
2830 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2831 supported, although you are strongly encouraged to use the hashref
2832 syntax as outlined above.
2838 =item Value: \@columns
2842 Shortcut to request a particular set of columns to be retrieved. Each
2843 column spec may be a string (a table column name), or a hash (in which
2844 case the key is the C<as> value, and the value is used as the C<select>
2845 expression). Adds C<me.> onto the start of any column without a C<.> in
2846 it and sets C<select> from that, then auto-populates C<as> from
2847 C<select> as normal. (You may also use the C<cols> attribute, as in
2848 earlier versions of DBIC.)
2854 =item Value: \@columns
2858 Indicates additional columns to be selected from storage. Works the same
2859 as L</columns> but adds columns to the selection. (You may also use the
2860 C<include_columns> attribute, as in earlier versions of DBIC). For
2863 $schema->resultset('CD')->search(undef, {
2864 '+columns' => ['artist.name'],
2868 would return all CDs and include a 'name' column to the information
2869 passed to object inflation. Note that the 'artist' is the name of the
2870 column (or relationship) accessor, and 'name' is the name of the column
2871 accessor in the related table.
2873 =head2 include_columns
2877 =item Value: \@columns
2881 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2887 =item Value: \@select_columns
2891 Indicates which columns should be selected from the storage. You can use
2892 column names, or in the case of RDBMS back ends, function or stored procedure
2895 $rs = $schema->resultset('Employee')->search(undef, {
2898 { count => 'employeeid' },
2903 When you use function/stored procedure names and do not supply an C<as>
2904 attribute, the column names returned are storage-dependent. E.g. MySQL would
2905 return a column named C<count(employeeid)> in the above example.
2911 Indicates additional columns to be selected from storage. Works the same as
2912 L</select> but adds columns to the selection.
2920 Indicates additional column names for those added via L</+select>. See L</as>.
2928 =item Value: \@inflation_names
2932 Indicates column names for object inflation. That is, C<as>
2933 indicates the name that the column can be accessed as via the
2934 C<get_column> method (or via the object accessor, B<if one already
2935 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2937 The C<as> attribute is used in conjunction with C<select>,
2938 usually when C<select> contains one or more function or stored
2941 $rs = $schema->resultset('Employee')->search(undef, {
2944 { count => 'employeeid' }
2946 as => ['name', 'employee_count'],
2949 my $employee = $rs->first(); # get the first Employee
2951 If the object against which the search is performed already has an accessor
2952 matching a column name specified in C<as>, the value can be retrieved using
2953 the accessor as normal:
2955 my $name = $employee->name();
2957 If on the other hand an accessor does not exist in the object, you need to
2958 use C<get_column> instead:
2960 my $employee_count = $employee->get_column('employee_count');
2962 You can create your own accessors if required - see
2963 L<DBIx::Class::Manual::Cookbook> for details.
2965 Please note: This will NOT insert an C<AS employee_count> into the SQL
2966 statement produced, it is used for internal access only. Thus
2967 attempting to use the accessor in an C<order_by> clause or similar
2968 will fail miserably.
2970 To get around this limitation, you can supply literal SQL to your
2971 C<select> attibute that contains the C<AS alias> text, eg:
2973 select => [\'myfield AS alias']
2979 =item Value: ($rel_name | \@rel_names | \%rel_names)
2983 Contains a list of relationships that should be joined for this query. For
2986 # Get CDs by Nine Inch Nails
2987 my $rs = $schema->resultset('CD')->search(
2988 { 'artist.name' => 'Nine Inch Nails' },
2989 { join => 'artist' }
2992 Can also contain a hash reference to refer to the other relation's relations.
2995 package MyApp::Schema::Track;
2996 use base qw/DBIx::Class/;
2997 __PACKAGE__->table('track');
2998 __PACKAGE__->add_columns(qw/trackid cd position title/);
2999 __PACKAGE__->set_primary_key('trackid');
3000 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3003 # In your application
3004 my $rs = $schema->resultset('Artist')->search(
3005 { 'track.title' => 'Teardrop' },
3007 join => { cd => 'track' },
3008 order_by => 'artist.name',
3012 You need to use the relationship (not the table) name in conditions,
3013 because they are aliased as such. The current table is aliased as "me", so
3014 you need to use me.column_name in order to avoid ambiguity. For example:
3016 # Get CDs from 1984 with a 'Foo' track
3017 my $rs = $schema->resultset('CD')->search(
3020 'tracks.name' => 'Foo'
3022 { join => 'tracks' }
3025 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3026 similarly for a third time). For e.g.
3028 my $rs = $schema->resultset('Artist')->search({
3029 'cds.title' => 'Down to Earth',
3030 'cds_2.title' => 'Popular',
3032 join => [ qw/cds cds/ ],
3035 will return a set of all artists that have both a cd with title 'Down
3036 to Earth' and a cd with title 'Popular'.
3038 If you want to fetch related objects from other tables as well, see C<prefetch>
3041 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3047 =item Value: ($rel_name | \@rel_names | \%rel_names)
3051 Contains one or more relationships that should be fetched along with
3052 the main query (when they are accessed afterwards the data will
3053 already be available, without extra queries to the database). This is
3054 useful for when you know you will need the related objects, because it
3055 saves at least one query:
3057 my $rs = $schema->resultset('Tag')->search(
3066 The initial search results in SQL like the following:
3068 SELECT tag.*, cd.*, artist.* FROM tag
3069 JOIN cd ON tag.cd = cd.cdid
3070 JOIN artist ON cd.artist = artist.artistid
3072 L<DBIx::Class> has no need to go back to the database when we access the
3073 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3076 Simple prefetches will be joined automatically, so there is no need
3077 for a C<join> attribute in the above search.
3079 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3080 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3081 with an accessor type of 'single' or 'filter'). A more complex example that
3082 prefetches an artists cds, the tracks on those cds, and the tags associted
3083 with that artist is given below (assuming many-to-many from artists to tags):
3085 my $rs = $schema->resultset('Artist')->search(
3089 { cds => 'tracks' },
3090 { artist_tags => 'tags' }
3096 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3097 attributes will be ignored.
3107 Makes the resultset paged and specifies the page to retrieve. Effectively
3108 identical to creating a non-pages resultset and then calling ->page($page)
3111 If L<rows> attribute is not specified it defualts to 10 rows per page.
3113 When you have a paged resultset, L</count> will only return the number
3114 of rows in the page. To get the total, use the L</pager> and call
3115 C<total_entries> on it.
3125 Specifes the maximum number of rows for direct retrieval or the number of
3126 rows per page if the page attribute or method is used.
3132 =item Value: $offset
3136 Specifies the (zero-based) row number for the first row to be returned, or the
3137 of the first row of the first page if paging is used.
3143 =item Value: \@columns
3147 A arrayref of columns to group by. Can include columns of joined tables.
3149 group_by => [qw/ column1 column2 ... /]
3155 =item Value: $condition
3159 HAVING is a select statement attribute that is applied between GROUP BY and
3160 ORDER BY. It is applied to the after the grouping calculations have been
3163 having => { 'count(employee)' => { '>=', 100 } }
3169 =item Value: (0 | 1)
3173 Set to 1 to group by all columns.
3179 Adds to the WHERE clause.
3181 # only return rows WHERE deleted IS NULL for all searches
3182 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3184 Can be overridden by passing C<{ where => undef }> as an attribute
3191 Set to 1 to cache search results. This prevents extra SQL queries if you
3192 revisit rows in your ResultSet:
3194 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3196 while( my $artist = $resultset->next ) {
3200 $rs->first; # without cache, this would issue a query
3202 By default, searches are not cached.
3204 For more examples of using these attributes, see
3205 L<DBIx::Class::Manual::Cookbook>.
3211 =item Value: \@from_clause
3215 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3216 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3219 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3221 C<join> will usually do what you need and it is strongly recommended that you
3222 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3223 And we really do mean "cannot", not just tried and failed. Attempting to use
3224 this because you're having problems with C<join> is like trying to use x86
3225 ASM because you've got a syntax error in your C. Trust us on this.
3227 Now, if you're still really, really sure you need to use this (and if you're
3228 not 100% sure, ask the mailing list first), here's an explanation of how this
3231 The syntax is as follows -
3234 { <alias1> => <table1> },
3236 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3237 [], # nested JOIN (optional)
3238 { <table1.column1> => <table2.column2>, ... (more conditions) },
3240 # More of the above [ ] may follow for additional joins
3247 ON <table1.column1> = <table2.column2>
3248 <more joins may follow>
3250 An easy way to follow the examples below is to remember the following:
3252 Anything inside "[]" is a JOIN
3253 Anything inside "{}" is a condition for the enclosing JOIN
3255 The following examples utilize a "person" table in a family tree application.
3256 In order to express parent->child relationships, this table is self-joined:
3258 # Person->belongs_to('father' => 'Person');
3259 # Person->belongs_to('mother' => 'Person');
3261 C<from> can be used to nest joins. Here we return all children with a father,
3262 then search against all mothers of those children:
3264 $rs = $schema->resultset('Person')->search(
3267 alias => 'mother', # alias columns in accordance with "from"
3269 { mother => 'person' },
3272 { child => 'person' },
3274 { father => 'person' },
3275 { 'father.person_id' => 'child.father_id' }
3278 { 'mother.person_id' => 'child.mother_id' }
3285 # SELECT mother.* FROM person mother
3288 # JOIN person father
3289 # ON ( father.person_id = child.father_id )
3291 # ON ( mother.person_id = child.mother_id )
3293 The type of any join can be controlled manually. To search against only people
3294 with a father in the person table, we could explicitly use C<INNER JOIN>:
3296 $rs = $schema->resultset('Person')->search(
3299 alias => 'child', # alias columns in accordance with "from"
3301 { child => 'person' },
3303 { father => 'person', -join_type => 'inner' },
3304 { 'father.id' => 'child.father_id' }
3311 # SELECT child.* FROM person child
3312 # INNER JOIN person father ON child.father_id = father.id
3314 If you need to express really complex joins or you need a subselect, you
3315 can supply literal SQL to C<from> via a scalar reference. In this case
3316 the contents of the scalar will replace the table name asscoiated with the
3319 WARNING: This technique might very well not work as expected on chained
3320 searches - you have been warned.
3322 # Assuming the Event resultsource is defined as:
3324 MySchema::Event->add_columns (
3327 is_auto_increment => 1,
3336 MySchema::Event->set_primary_key ('sequence');
3338 # This will get back the latest event for every location. The column
3339 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3340 # combo to limit the resultset
3342 $rs = $schema->resultset('Event');
3343 $table = $rs->result_source->name;
3344 $latest = $rs->search (
3347 (SELECT e1.* FROM $table e1
3349 ON e1.location = e2.location
3350 AND e1.sequence < e2.sequence
3351 WHERE e2.sequence is NULL
3356 # Equivalent SQL (with the DBIC chunks added):
3358 SELECT me.sequence, me.location, me.type FROM
3359 (SELECT e1.* FROM events e1
3361 ON e1.location = e2.location
3362 AND e1.sequence < e2.sequence
3363 WHERE e2.sequence is NULL
3370 =item Value: ( 'update' | 'shared' )
3374 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT