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/;
1159 my $attrs = $self->_resolved_attrs;
1161 # if we are not paged - we are simply asking for a limit
1162 if (not $attrs->{page} and not $attrs->{software_limit}) {
1163 push @subq_attrs, qw/rows offset/;
1166 return $self->_has_attr (@subq_attrs)
1167 ? $self->_count_subq
1168 : $self->_count_simple
1174 my $attrs = { %{$self->_resolved_attrs} };
1176 # copy for the subquery, we need to do some adjustments to it too
1177 my $sub_attrs = { %$attrs };
1179 # these can not go in the subquery either
1180 delete $sub_attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
1182 # force a group_by and the same set of columns (most databases require this)
1183 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1186 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1189 # the subquery replaces this
1190 delete $attrs->{$_} for qw/where bind prefetch collapse group_by having/;
1192 return $self->__count ($attrs);
1198 my $count = $self->__count;
1199 return 0 unless $count;
1201 # need to take offset from resolved attrs
1203 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1204 $count = $self->{attrs}{rows} if
1205 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1206 $count = 0 if ($count < 0);
1211 my ($self, $attrs) = @_;
1213 $attrs ||= { %{$self->_resolved_attrs} };
1215 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1216 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1218 $attrs->{select} = { count => '*' };
1219 $attrs->{as} = [qw/count/];
1221 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1222 my ($count) = $tmp_rs->cursor->next;
1231 =head2 count_literal
1235 =item Arguments: $sql_fragment, @bind_values
1237 =item Return Value: $count
1241 Counts the results in a literal query. Equivalent to calling L</search_literal>
1242 with the passed arguments, then L</count>.
1246 sub count_literal { shift->search_literal(@_)->count; }
1252 =item Arguments: none
1254 =item Return Value: @objects
1258 Returns all elements in the resultset. Called implicitly if the resultset
1259 is returned in list context.
1266 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1269 return @{ $self->get_cache } if $self->get_cache;
1273 # TODO: don't call resolve here
1274 if (keys %{$self->_resolved_attrs->{collapse}}) {
1275 # if ($self->{attrs}{prefetch}) {
1276 # Using $self->cursor->all is really just an optimisation.
1277 # If we're collapsing has_many prefetches it probably makes
1278 # very little difference, and this is cleaner than hacking
1279 # _construct_object to survive the approach
1280 my @row = $self->cursor->next;
1282 push(@obj, $self->_construct_object(@row));
1283 @row = (exists $self->{stashed_row}
1284 ? @{delete $self->{stashed_row}}
1285 : $self->cursor->next);
1288 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1291 $self->set_cache(\@obj) if $self->{attrs}{cache};
1299 =item Arguments: none
1301 =item Return Value: $self
1305 Resets the resultset's cursor, so you can iterate through the elements again.
1311 delete $self->{_attrs} if exists $self->{_attrs};
1312 $self->{all_cache_position} = 0;
1313 $self->cursor->reset;
1321 =item Arguments: none
1323 =item Return Value: $object?
1327 Resets the resultset and returns an object for the first result (if the
1328 resultset returns anything).
1333 return $_[0]->reset->next;
1339 # Determines whether and what type of subquery is required for the $rs operation.
1340 # If grouping is necessary either supplies its own, or verifies the current one
1341 # After all is done delegates to the proper storage method.
1343 sub _rs_update_delete {
1344 my ($self, $op, $values) = @_;
1346 my $rsrc = $self->result_source;
1348 my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
1349 my $needs_subq = $self->_has_attr (qw/row offset page/);
1351 if ($needs_group_by_subq or $needs_subq) {
1353 # make a new $rs selecting only the PKs (that's all we really need)
1354 my $attrs = $self->_resolved_attrs;
1356 delete $attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
1357 $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1359 if ($needs_group_by_subq) {
1360 # make sure no group_by was supplied, or if there is one - make sure it matches
1361 # the columns compiled above perfectly. Anything else can not be sanely executed
1362 # on most databases so croak right then and there
1364 if (my $g = $attrs->{group_by}) {
1365 my @current_group_by = map
1366 { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
1367 (ref $g eq 'ARRAY' ? @$g : $g );
1370 join ("\x00", sort @current_group_by)
1372 join ("\x00", sort @{$attrs->{columns}} )
1374 $self->throw_exception (
1375 "You have just attempted a $op operation on a resultset which does group_by"
1376 . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
1377 . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
1378 . ' kind of queries. Please retry the operation with a modified group_by or'
1379 . ' without using one at all.'
1384 $attrs->{group_by} = $attrs->{columns};
1388 my $subrs = (ref $self)->new($rsrc, $attrs);
1390 return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
1393 return $rsrc->storage->$op(
1395 $op eq 'update' ? $values : (),
1396 $self->_cond_for_update_delete,
1402 # _cond_for_update_delete
1404 # update/delete require the condition to be modified to handle
1405 # the differing SQL syntax available. This transforms the $self->{cond}
1406 # appropriately, returning the new condition.
1408 sub _cond_for_update_delete {
1409 my ($self, $full_cond) = @_;
1412 $full_cond ||= $self->{cond};
1413 # No-op. No condition, we're updating/deleting everything
1414 return $cond unless ref $full_cond;
1416 if (ref $full_cond eq 'ARRAY') {
1420 foreach my $key (keys %{$_}) {
1422 $hash{$1} = $_->{$key};
1428 elsif (ref $full_cond eq 'HASH') {
1429 if ((keys %{$full_cond})[0] eq '-and') {
1431 my @cond = @{$full_cond->{-and}};
1432 for (my $i = 0; $i < @cond; $i++) {
1433 my $entry = $cond[$i];
1435 if (ref $entry eq 'HASH') {
1436 $hash = $self->_cond_for_update_delete($entry);
1439 $entry =~ /([^.]+)$/;
1440 $hash->{$1} = $cond[++$i];
1442 push @{$cond->{-and}}, $hash;
1446 foreach my $key (keys %{$full_cond}) {
1448 $cond->{$1} = $full_cond->{$key};
1453 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1464 =item Arguments: \%values
1466 =item Return Value: $storage_rv
1470 Sets the specified columns in the resultset to the supplied values in a
1471 single query. Return value will be true if the update succeeded or false
1472 if no records were updated; exact type of success value is storage-dependent.
1477 my ($self, $values) = @_;
1478 $self->throw_exception('Values for update must be a hash')
1479 unless ref $values eq 'HASH';
1481 return $self->_rs_update_delete ('update', $values);
1488 =item Arguments: \%values
1490 =item Return Value: 1
1494 Fetches all objects and updates them one at a time. Note that C<update_all>
1495 will run DBIC cascade triggers, while L</update> will not.
1500 my ($self, $values) = @_;
1501 $self->throw_exception('Values for update_all must be a hash')
1502 unless ref $values eq 'HASH';
1503 foreach my $obj ($self->all) {
1504 $obj->set_columns($values)->update;
1513 =item Arguments: none
1515 =item Return Value: 1
1519 Deletes the contents of the resultset from its result source. Note that this
1520 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1521 to run. See also L<DBIx::Class::Row/delete>.
1523 delete may not generate correct SQL for a query with joins or a resultset
1524 chained from a related resultset. In this case it will generate a warning:-
1526 In these cases you may find that delete_all is more appropriate, or you
1527 need to respecify your query in a way that can be expressed without a join.
1533 $self->throw_exception('delete does not accept any arguments')
1536 return $self->_rs_update_delete ('delete');
1543 =item Arguments: none
1545 =item Return Value: 1
1549 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1550 will run DBIC cascade triggers, while L</delete> will not.
1556 $self->throw_exception('delete_all does not accept any arguments')
1559 $_->delete for $self->all;
1567 =item Arguments: \@data;
1571 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1572 For the arrayref of hashrefs style each hashref should be a structure suitable
1573 forsubmitting to a $resultset->create(...) method.
1575 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1576 to insert the data, as this is a faster method.
1578 Otherwise, each set of data is inserted into the database using
1579 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1580 objects is returned.
1582 Example: Assuming an Artist Class that has many CDs Classes relating:
1584 my $Artist_rs = $schema->resultset("Artist");
1586 ## Void Context Example
1587 $Artist_rs->populate([
1588 { artistid => 4, name => 'Manufactured Crap', cds => [
1589 { title => 'My First CD', year => 2006 },
1590 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1593 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1594 { title => 'My parents sold me to a record company' ,year => 2005 },
1595 { title => 'Why Am I So Ugly?', year => 2006 },
1596 { title => 'I Got Surgery and am now Popular', year => 2007 }
1601 ## Array Context Example
1602 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1603 { name => "Artist One"},
1604 { name => "Artist Two"},
1605 { name => "Artist Three", cds=> [
1606 { title => "First CD", year => 2007},
1607 { title => "Second CD", year => 2008},
1611 print $ArtistOne->name; ## response is 'Artist One'
1612 print $ArtistThree->cds->count ## reponse is '2'
1614 For the arrayref of arrayrefs style, the first element should be a list of the
1615 fieldsnames to which the remaining elements are rows being inserted. For
1618 $Arstist_rs->populate([
1619 [qw/artistid name/],
1620 [100, 'A Formally Unknown Singer'],
1621 [101, 'A singer that jumped the shark two albums ago'],
1622 [102, 'An actually cool singer.'],
1625 Please note an important effect on your data when choosing between void and
1626 wantarray context. Since void context goes straight to C<insert_bulk> in
1627 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1628 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1629 create primary keys for you, you will find that your PKs are empty. In this
1630 case you will have to use the wantarray context in order to create those
1636 my $self = shift @_;
1637 my $data = ref $_[0][0] eq 'HASH'
1638 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1639 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1641 if(defined wantarray) {
1643 foreach my $item (@$data) {
1644 push(@created, $self->create($item));
1648 my ($first, @rest) = @$data;
1650 my @names = grep {!ref $first->{$_}} keys %$first;
1651 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1652 my @pks = $self->result_source->primary_columns;
1654 ## do the belongs_to relationships
1655 foreach my $index (0..$#$data) {
1656 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1657 my @ret = $self->populate($data);
1661 foreach my $rel (@rels) {
1662 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1663 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1664 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1665 my $related = $result->result_source->_resolve_condition(
1666 $result->result_source->relationship_info($reverse)->{cond},
1671 delete $data->[$index]->{$rel};
1672 $data->[$index] = {%{$data->[$index]}, %$related};
1674 push @names, keys %$related if $index == 0;
1678 ## do bulk insert on current row
1679 my @values = map { [ @$_{@names} ] } @$data;
1681 $self->result_source->storage->insert_bulk(
1682 $self->result_source,
1687 ## do the has_many relationships
1688 foreach my $item (@$data) {
1690 foreach my $rel (@rels) {
1691 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1693 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1694 || $self->throw_exception('Cannot find the relating object.');
1696 my $child = $parent->$rel;
1698 my $related = $child->result_source->_resolve_condition(
1699 $parent->result_source->relationship_info($rel)->{cond},
1704 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1705 my @populate = map { {%$_, %$related} } @rows_to_add;
1707 $child->populate( \@populate );
1713 =head2 _normalize_populate_args ($args)
1715 Private method used by L</populate> to normalize its incoming arguments. Factored
1716 out in case you want to subclass and accept new argument structures to the
1717 L</populate> method.
1721 sub _normalize_populate_args {
1722 my ($self, $data) = @_;
1723 my @names = @{shift(@$data)};
1724 my @results_to_create;
1725 foreach my $datum (@$data) {
1726 my %result_to_create;
1727 foreach my $index (0..$#names) {
1728 $result_to_create{$names[$index]} = $$datum[$index];
1730 push @results_to_create, \%result_to_create;
1732 return \@results_to_create;
1739 =item Arguments: none
1741 =item Return Value: $pager
1745 Return Value a L<Data::Page> object for the current resultset. Only makes
1746 sense for queries with a C<page> attribute.
1748 To get the full count of entries for a paged resultset, call
1749 C<total_entries> on the L<Data::Page> object.
1756 return $self->{pager} if $self->{pager};
1758 my $attrs = $self->{attrs};
1759 $self->throw_exception("Can't create pager for non-paged rs")
1760 unless $self->{attrs}{page};
1761 $attrs->{rows} ||= 10;
1763 # throw away the paging flags and re-run the count (possibly
1764 # with a subselect) to get the real total count
1765 my $count_attrs = { %$attrs };
1766 delete $count_attrs->{$_} for qw/rows offset page pager/;
1767 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1769 return $self->{pager} = Data::Page->new(
1772 $self->{attrs}{page}
1780 =item Arguments: $page_number
1782 =item Return Value: $rs
1786 Returns a resultset for the $page_number page of the resultset on which page
1787 is called, where each page contains a number of rows equal to the 'rows'
1788 attribute set on the resultset (10 by default).
1793 my ($self, $page) = @_;
1794 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1801 =item Arguments: \%vals
1803 =item Return Value: $rowobject
1807 Creates a new row object in the resultset's result class and returns
1808 it. The row is not inserted into the database at this point, call
1809 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1810 will tell you whether the row object has been inserted or not.
1812 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1817 my ($self, $values) = @_;
1818 $self->throw_exception( "new_result needs a hash" )
1819 unless (ref $values eq 'HASH');
1822 my $alias = $self->{attrs}{alias};
1825 defined $self->{cond}
1826 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1828 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1829 $new{-from_resultset} = [ keys %new ] if keys %new;
1831 $self->throw_exception(
1832 "Can't abstract implicit construct, condition not a hash"
1833 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1835 my $collapsed_cond = (
1837 ? $self->_collapse_cond($self->{cond})
1841 # precendence must be given to passed values over values inherited from
1842 # the cond, so the order here is important.
1843 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1844 while( my($col,$value) = each %implied ){
1845 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1846 $new{$col} = $value->{'='};
1849 $new{$col} = $value if $self->_is_deterministic_value($value);
1855 %{ $self->_remove_alias($values, $alias) },
1856 -source_handle => $self->_source_handle,
1857 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1860 return $self->result_class->new(\%new);
1863 # _is_deterministic_value
1865 # Make an effor to strip non-deterministic values from the condition,
1866 # to make sure new_result chokes less
1868 sub _is_deterministic_value {
1871 my $ref_type = ref $value;
1872 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1873 return 1 if Scalar::Util::blessed($value);
1879 # determines if the resultset defines at least one
1880 # of the attributes supplied
1882 # used to determine if a subquery is neccessary
1885 my ($self, @attr_names) = @_;
1887 my $attrs = $self->_resolved_attrs;
1891 for my $n (@attr_names) {
1892 ++$join_check_req if $n =~ /join/;
1894 my $attr = $attrs->{$n};
1896 next if not defined $attr;
1898 if (ref $attr eq 'HASH') {
1899 return 1 if keys %$attr;
1901 elsif (ref $attr eq 'ARRAY') {
1909 # a join can be expressed as a multi-level from
1913 ref $attrs->{from} eq 'ARRAY'
1915 @{$attrs->{from}} > 1
1923 # Recursively collapse the condition.
1925 sub _collapse_cond {
1926 my ($self, $cond, $collapsed) = @_;
1930 if (ref $cond eq 'ARRAY') {
1931 foreach my $subcond (@$cond) {
1932 next unless ref $subcond; # -or
1933 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1936 elsif (ref $cond eq 'HASH') {
1937 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1938 foreach my $subcond (@{$cond->{-and}}) {
1939 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1943 foreach my $col (keys %$cond) {
1944 my $value = $cond->{$col};
1945 $collapsed->{$col} = $value;
1955 # Remove the specified alias from the specified query hash. A copy is made so
1956 # the original query is not modified.
1959 my ($self, $query, $alias) = @_;
1961 my %orig = %{ $query || {} };
1964 foreach my $key (keys %orig) {
1966 $unaliased{$key} = $orig{$key};
1969 $unaliased{$1} = $orig{$key}
1970 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1976 =head2 as_query (EXPERIMENTAL)
1980 =item Arguments: none
1982 =item Return Value: \[ $sql, @bind ]
1986 Returns the SQL query and bind vars associated with the invocant.
1988 This is generally used as the RHS for a subquery.
1990 B<NOTE>: This feature is still experimental.
1994 sub as_query { return shift->cursor->as_query(@_) }
2000 =item Arguments: \%vals, \%attrs?
2002 =item Return Value: $rowobject
2006 my $artist = $schema->resultset('Artist')->find_or_new(
2007 { artist => 'fred' }, { key => 'artists' });
2009 $cd->cd_to_producer->find_or_new({ producer => $producer },
2010 { key => 'primary });
2012 Find an existing record from this resultset, based on its primary
2013 key, or a unique constraint. If none exists, instantiate a new result
2014 object and return it. The object will not be saved into your storage
2015 until you call L<DBIx::Class::Row/insert> on it.
2017 You most likely want this method when looking for existing rows using
2018 a unique constraint that is not the primary key, or looking for
2021 If you want objects to be saved immediately, use L</find_or_create> instead.
2023 B<Note>: C<find_or_new> is probably not what you want when creating a
2024 new row in a table that uses primary keys supplied by the
2025 database. Passing in a primary key column with a value of I<undef>
2026 will cause L</find> to attempt to search for a row with a value of
2033 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2034 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2035 my $exists = $self->find($hash, $attrs);
2036 return defined $exists ? $exists : $self->new_result($hash);
2043 =item Arguments: \%vals
2045 =item Return Value: a L<DBIx::Class::Row> $object
2049 Attempt to create a single new row or a row with multiple related rows
2050 in the table represented by the resultset (and related tables). This
2051 will not check for duplicate rows before inserting, use
2052 L</find_or_create> to do that.
2054 To create one row for this resultset, pass a hashref of key/value
2055 pairs representing the columns of the table and the values you wish to
2056 store. If the appropriate relationships are set up, foreign key fields
2057 can also be passed an object representing the foreign row, and the
2058 value will be set to its primary key.
2060 To create related objects, pass a hashref for the value if the related
2061 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2062 and use the name of the relationship as the key. (NOT the name of the field,
2063 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2064 of hashrefs containing the data for each of the rows to create in the foreign
2065 tables, again using the relationship name as the key.
2067 Instead of hashrefs of plain related data (key/value pairs), you may
2068 also pass new or inserted objects. New objects (not inserted yet, see
2069 L</new>), will be inserted into their appropriate tables.
2071 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2073 Example of creating a new row.
2075 $person_rs->create({
2076 name=>"Some Person",
2077 email=>"somebody@someplace.com"
2080 Example of creating a new row and also creating rows in a related C<has_many>
2081 or C<has_one> resultset. Note Arrayref.
2084 { artistid => 4, name => 'Manufactured Crap', cds => [
2085 { title => 'My First CD', year => 2006 },
2086 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2091 Example of creating a new row and also creating a row in a related
2092 C<belongs_to>resultset. Note Hashref.
2095 title=>"Music for Silly Walks",
2098 name=>"Silly Musician",
2105 my ($self, $attrs) = @_;
2106 $self->throw_exception( "create needs a hashref" )
2107 unless ref $attrs eq 'HASH';
2108 return $self->new_result($attrs)->insert;
2111 =head2 find_or_create
2115 =item Arguments: \%vals, \%attrs?
2117 =item Return Value: $rowobject
2121 $cd->cd_to_producer->find_or_create({ producer => $producer },
2122 { key => 'primary });
2124 Tries to find a record based on its primary key or unique constraints; if none
2125 is found, creates one and returns that instead.
2127 my $cd = $schema->resultset('CD')->find_or_create({
2129 artist => 'Massive Attack',
2130 title => 'Mezzanine',
2134 Also takes an optional C<key> attribute, to search by a specific key or unique
2135 constraint. For example:
2137 my $cd = $schema->resultset('CD')->find_or_create(
2139 artist => 'Massive Attack',
2140 title => 'Mezzanine',
2142 { key => 'cd_artist_title' }
2145 B<Note>: Because find_or_create() reads from the database and then
2146 possibly inserts based on the result, this method is subject to a race
2147 condition. Another process could create a record in the table after
2148 the find has completed and before the create has started. To avoid
2149 this problem, use find_or_create() inside a transaction.
2151 B<Note>: C<find_or_create> is probably not what you want when creating
2152 a new row in a table that uses primary keys supplied by the
2153 database. Passing in a primary key column with a value of I<undef>
2154 will cause L</find> to attempt to search for a row with a value of
2157 See also L</find> and L</update_or_create>. For information on how to declare
2158 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2162 sub find_or_create {
2164 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2165 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2166 my $exists = $self->find($hash, $attrs);
2167 return defined $exists ? $exists : $self->create($hash);
2170 =head2 update_or_create
2174 =item Arguments: \%col_values, { key => $unique_constraint }?
2176 =item Return Value: $rowobject
2180 $resultset->update_or_create({ col => $val, ... });
2182 First, searches for an existing row matching one of the unique constraints
2183 (including the primary key) on the source of this resultset. If a row is
2184 found, updates it with the other given column values. Otherwise, creates a new
2187 Takes an optional C<key> attribute to search on a specific unique constraint.
2190 # In your application
2191 my $cd = $schema->resultset('CD')->update_or_create(
2193 artist => 'Massive Attack',
2194 title => 'Mezzanine',
2197 { key => 'cd_artist_title' }
2200 $cd->cd_to_producer->update_or_create({
2201 producer => $producer,
2208 If no C<key> is specified, it searches on all unique constraints defined on the
2209 source, including the primary key.
2211 If the C<key> is specified as C<primary>, it searches only on the primary key.
2213 See also L</find> and L</find_or_create>. For information on how to declare
2214 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2216 B<Note>: C<update_or_create> is probably not what you want when
2217 looking for a row in a table that uses primary keys supplied by the
2218 database, unless you actually have a key value. Passing in a primary
2219 key column with a value of I<undef> will cause L</find> to attempt to
2220 search for a row with a value of I<NULL>.
2224 sub update_or_create {
2226 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2227 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2229 my $row = $self->find($cond, $attrs);
2231 $row->update($cond);
2235 return $self->create($cond);
2238 =head2 update_or_new
2242 =item Arguments: \%col_values, { key => $unique_constraint }?
2244 =item Return Value: $rowobject
2248 $resultset->update_or_new({ col => $val, ... });
2250 First, searches for an existing row matching one of the unique constraints
2251 (including the primary key) on the source of this resultset. If a row is
2252 found, updates it with the other given column values. Otherwise, instantiate
2253 a new result object and return it. The object will not be saved into your storage
2254 until you call L<DBIx::Class::Row/insert> on it.
2256 Takes an optional C<key> attribute to search on a specific unique constraint.
2259 # In your application
2260 my $cd = $schema->resultset('CD')->update_or_new(
2262 artist => 'Massive Attack',
2263 title => 'Mezzanine',
2266 { key => 'cd_artist_title' }
2269 if ($cd->in_storage) {
2270 # the cd was updated
2273 # the cd is not yet in the database, let's insert it
2277 See also L</find>, L</find_or_create> and L<find_or_new>.
2283 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2284 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2286 my $row = $self->find( $cond, $attrs );
2287 if ( defined $row ) {
2288 $row->update($cond);
2292 return $self->new_result($cond);
2299 =item Arguments: none
2301 =item Return Value: \@cache_objects?
2305 Gets the contents of the cache for the resultset, if the cache is set.
2307 The cache is populated either by using the L</prefetch> attribute to
2308 L</search> or by calling L</set_cache>.
2320 =item Arguments: \@cache_objects
2322 =item Return Value: \@cache_objects
2326 Sets the contents of the cache for the resultset. Expects an arrayref
2327 of objects of the same class as those produced by the resultset. Note that
2328 if the cache is set the resultset will return the cached objects rather
2329 than re-querying the database even if the cache attr is not set.
2331 The contents of the cache can also be populated by using the
2332 L</prefetch> attribute to L</search>.
2337 my ( $self, $data ) = @_;
2338 $self->throw_exception("set_cache requires an arrayref")
2339 if defined($data) && (ref $data ne 'ARRAY');
2340 $self->{all_cache} = $data;
2347 =item Arguments: none
2349 =item Return Value: []
2353 Clears the cache for the resultset.
2358 shift->set_cache(undef);
2361 =head2 related_resultset
2365 =item Arguments: $relationship_name
2367 =item Return Value: $resultset
2371 Returns a related resultset for the supplied relationship name.
2373 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2377 sub related_resultset {
2378 my ($self, $rel) = @_;
2380 $self->{related_resultsets} ||= {};
2381 return $self->{related_resultsets}{$rel} ||= do {
2382 my $rel_obj = $self->result_source->relationship_info($rel);
2384 $self->throw_exception(
2385 "search_related: result source '" . $self->result_source->source_name .
2386 "' has no such relationship $rel")
2389 my ($from,$seen) = $self->_resolve_from($rel);
2391 my $join_count = $seen->{$rel};
2392 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2394 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2395 my %attrs = %{$self->{attrs}||{}};
2396 delete @attrs{qw(result_class alias)};
2400 if (my $cache = $self->get_cache) {
2401 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2402 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2407 my $rel_source = $self->result_source->related_source($rel);
2411 # The reason we do this now instead of passing the alias to the
2412 # search_rs below is that if you wrap/overload resultset on the
2413 # source you need to know what alias it's -going- to have for things
2414 # to work sanely (e.g. RestrictWithObject wants to be able to add
2415 # extra query restrictions, and these may need to be $alias.)
2417 my $attrs = $rel_source->resultset_attributes;
2418 local $attrs->{alias} = $alias;
2420 $rel_source->resultset
2428 where => $self->{cond},
2433 $new->set_cache($new_cache) if $new_cache;
2438 =head2 current_source_alias
2442 =item Arguments: none
2444 =item Return Value: $source_alias
2448 Returns the current table alias for the result source this resultset is built
2449 on, that will be used in the SQL query. Usually it is C<me>.
2451 Currently the source alias that refers to the result set returned by a
2452 L</search>/L</find> family method depends on how you got to the resultset: it's
2453 C<me> by default, but eg. L</search_related> aliases it to the related result
2454 source name (and keeps C<me> referring to the original result set). The long
2455 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2456 (and make this method unnecessary).
2458 Thus it's currently necessary to use this method in predefined queries (see
2459 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2460 source alias of the current result set:
2462 # in a result set class
2464 my ($self, $user) = @_;
2466 my $me = $self->current_source_alias;
2468 return $self->search(
2469 "$me.modified" => $user->id,
2475 sub current_source_alias {
2478 return ($self->{attrs} || {})->{alias} || 'me';
2481 # This code is called by search_related, and makes sure there
2482 # is clear separation between the joins before, during, and
2483 # after the relationship. This information is needed later
2484 # in order to properly resolve prefetch aliases (any alias
2485 # with a relation_chain_depth less than the depth of the
2486 # current prefetch is not considered)
2488 my ($self, $extra_join) = @_;
2489 my $source = $self->result_source;
2490 my $attrs = $self->{attrs};
2492 my $from = $attrs->{from}
2493 || [ { $attrs->{alias} => $source->from } ];
2495 my $seen = { %{$attrs->{seen_join}||{}} };
2497 # we need to take the prefetch the attrs into account before we
2498 # ->_resolve_join as otherwise they get lost - captainL
2499 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2501 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2503 ++$seen->{-relation_chain_depth};
2505 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2507 ++$seen->{-relation_chain_depth};
2509 return ($from,$seen);
2512 sub _resolved_attrs {
2514 return $self->{_attrs} if $self->{_attrs};
2516 my $attrs = { %{ $self->{attrs} || {} } };
2517 my $source = $self->result_source;
2518 my $alias = $attrs->{alias};
2520 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2523 # build columns (as long as select isn't set) into a set of as/select hashes
2524 unless ( $attrs->{select} ) {
2526 ( ref($_) eq 'HASH' )
2530 /^\Q${alias}.\E(.+)$/
2541 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2543 # add the additional columns on
2544 foreach ( 'include_columns', '+columns' ) {
2545 push @colbits, map {
2546 ( ref($_) eq 'HASH' )
2548 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2549 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2552 # start with initial select items
2553 if ( $attrs->{select} ) {
2555 ( ref $attrs->{select} eq 'ARRAY' )
2556 ? [ @{ $attrs->{select} } ]
2557 : [ $attrs->{select} ];
2561 ref $attrs->{as} eq 'ARRAY'
2562 ? [ @{ $attrs->{as} } ]
2565 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2570 # otherwise we intialise select & as to empty
2571 $attrs->{select} = [];
2575 # now add colbits to select/as
2576 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2577 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2580 if ( $adds = delete $attrs->{'+select'} ) {
2581 $adds = [$adds] unless ref $adds eq 'ARRAY';
2583 @{ $attrs->{select} },
2584 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2587 if ( $adds = delete $attrs->{'+as'} ) {
2588 $adds = [$adds] unless ref $adds eq 'ARRAY';
2589 push( @{ $attrs->{as} }, @$adds );
2592 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2594 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2595 my $join = delete $attrs->{join} || {};
2597 if ( defined $attrs->{prefetch} ) {
2598 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2602 $attrs->{from} = # have to copy here to avoid corrupting the original
2604 @{ $attrs->{from} },
2605 $source->_resolve_join(
2606 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2612 $attrs->{group_by} ||= $attrs->{select}
2613 if delete $attrs->{distinct};
2614 if ( $attrs->{order_by} ) {
2615 $attrs->{order_by} = (
2616 ref( $attrs->{order_by} ) eq 'ARRAY'
2617 ? [ @{ $attrs->{order_by} } ]
2618 : [ $attrs->{order_by} ]
2622 $attrs->{order_by} = [];
2625 my $collapse = $attrs->{collapse} || {};
2626 if ( my $prefetch = delete $attrs->{prefetch} ) {
2627 $prefetch = $self->_merge_attr( {}, $prefetch );
2629 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2631 # bring joins back to level of current class
2632 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2634 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2635 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2636 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2638 push( @{ $attrs->{order_by} }, @pre_order );
2640 $attrs->{collapse} = $collapse;
2642 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2643 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2646 return $self->{_attrs} = $attrs;
2649 sub _joinpath_aliases {
2650 my ($self, $fromspec, $seen) = @_;
2653 return $paths unless ref $fromspec eq 'ARRAY';
2655 for my $j (@$fromspec) {
2657 next if ref $j ne 'ARRAY';
2658 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2661 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2662 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2669 my ($self, $attr) = @_;
2671 if (ref $attr eq 'HASH') {
2672 return $self->_rollout_hash($attr);
2673 } elsif (ref $attr eq 'ARRAY') {
2674 return $self->_rollout_array($attr);
2680 sub _rollout_array {
2681 my ($self, $attr) = @_;
2684 foreach my $element (@{$attr}) {
2685 if (ref $element eq 'HASH') {
2686 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2687 } elsif (ref $element eq 'ARRAY') {
2688 # XXX - should probably recurse here
2689 push( @rolled_array, @{$self->_rollout_array($element)} );
2691 push( @rolled_array, $element );
2694 return \@rolled_array;
2698 my ($self, $attr) = @_;
2701 foreach my $key (keys %{$attr}) {
2702 push( @rolled_array, { $key => $attr->{$key} } );
2704 return \@rolled_array;
2707 sub _calculate_score {
2708 my ($self, $a, $b) = @_;
2710 if (ref $b eq 'HASH') {
2711 my ($b_key) = keys %{$b};
2712 if (ref $a eq 'HASH') {
2713 my ($a_key) = keys %{$a};
2714 if ($a_key eq $b_key) {
2715 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2720 return ($a eq $b_key) ? 1 : 0;
2723 if (ref $a eq 'HASH') {
2724 my ($a_key) = keys %{$a};
2725 return ($b eq $a_key) ? 1 : 0;
2727 return ($b eq $a) ? 1 : 0;
2733 my ($self, $orig, $import) = @_;
2735 return $import unless defined($orig);
2736 return $orig unless defined($import);
2738 $orig = $self->_rollout_attr($orig);
2739 $import = $self->_rollout_attr($import);
2742 foreach my $import_element ( @{$import} ) {
2743 # find best candidate from $orig to merge $b_element into
2744 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2745 foreach my $orig_element ( @{$orig} ) {
2746 my $score = $self->_calculate_score( $orig_element, $import_element );
2747 if ($score > $best_candidate->{score}) {
2748 $best_candidate->{position} = $position;
2749 $best_candidate->{score} = $score;
2753 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2755 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2756 push( @{$orig}, $import_element );
2758 my $orig_best = $orig->[$best_candidate->{position}];
2759 # merge orig_best and b_element together and replace original with merged
2760 if (ref $orig_best ne 'HASH') {
2761 $orig->[$best_candidate->{position}] = $import_element;
2762 } elsif (ref $import_element eq 'HASH') {
2763 my ($key) = keys %{$orig_best};
2764 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2767 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2777 $self->_source_handle($_[0]->handle);
2779 $self->_source_handle->resolve;
2783 =head2 throw_exception
2785 See L<DBIx::Class::Schema/throw_exception> for details.
2789 sub throw_exception {
2791 if (ref $self && $self->_source_handle->schema) {
2792 $self->_source_handle->schema->throw_exception(@_)
2799 # XXX: FIXME: Attributes docs need clearing up
2803 Attributes are used to refine a ResultSet in various ways when
2804 searching for data. They can be passed to any method which takes an
2805 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2808 These are in no particular order:
2814 =item Value: ( $order_by | \@order_by | \%order_by )
2818 Which column(s) to order the results by. If a single column name, or
2819 an arrayref of names is supplied, the argument is passed through
2820 directly to SQL. The hashref syntax allows for connection-agnostic
2821 specification of ordering direction:
2823 For descending order:
2825 order_by => { -desc => [qw/col1 col2 col3/] }
2827 For explicit ascending order:
2829 order_by => { -asc => 'col' }
2831 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2832 supported, although you are strongly encouraged to use the hashref
2833 syntax as outlined above.
2839 =item Value: \@columns
2843 Shortcut to request a particular set of columns to be retrieved. Each
2844 column spec may be a string (a table column name), or a hash (in which
2845 case the key is the C<as> value, and the value is used as the C<select>
2846 expression). Adds C<me.> onto the start of any column without a C<.> in
2847 it and sets C<select> from that, then auto-populates C<as> from
2848 C<select> as normal. (You may also use the C<cols> attribute, as in
2849 earlier versions of DBIC.)
2855 =item Value: \@columns
2859 Indicates additional columns to be selected from storage. Works the same
2860 as L</columns> but adds columns to the selection. (You may also use the
2861 C<include_columns> attribute, as in earlier versions of DBIC). For
2864 $schema->resultset('CD')->search(undef, {
2865 '+columns' => ['artist.name'],
2869 would return all CDs and include a 'name' column to the information
2870 passed to object inflation. Note that the 'artist' is the name of the
2871 column (or relationship) accessor, and 'name' is the name of the column
2872 accessor in the related table.
2874 =head2 include_columns
2878 =item Value: \@columns
2882 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2888 =item Value: \@select_columns
2892 Indicates which columns should be selected from the storage. You can use
2893 column names, or in the case of RDBMS back ends, function or stored procedure
2896 $rs = $schema->resultset('Employee')->search(undef, {
2899 { count => 'employeeid' },
2904 When you use function/stored procedure names and do not supply an C<as>
2905 attribute, the column names returned are storage-dependent. E.g. MySQL would
2906 return a column named C<count(employeeid)> in the above example.
2912 Indicates additional columns to be selected from storage. Works the same as
2913 L</select> but adds columns to the selection.
2921 Indicates additional column names for those added via L</+select>. See L</as>.
2929 =item Value: \@inflation_names
2933 Indicates column names for object inflation. That is, C<as>
2934 indicates the name that the column can be accessed as via the
2935 C<get_column> method (or via the object accessor, B<if one already
2936 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2938 The C<as> attribute is used in conjunction with C<select>,
2939 usually when C<select> contains one or more function or stored
2942 $rs = $schema->resultset('Employee')->search(undef, {
2945 { count => 'employeeid' }
2947 as => ['name', 'employee_count'],
2950 my $employee = $rs->first(); # get the first Employee
2952 If the object against which the search is performed already has an accessor
2953 matching a column name specified in C<as>, the value can be retrieved using
2954 the accessor as normal:
2956 my $name = $employee->name();
2958 If on the other hand an accessor does not exist in the object, you need to
2959 use C<get_column> instead:
2961 my $employee_count = $employee->get_column('employee_count');
2963 You can create your own accessors if required - see
2964 L<DBIx::Class::Manual::Cookbook> for details.
2966 Please note: This will NOT insert an C<AS employee_count> into the SQL
2967 statement produced, it is used for internal access only. Thus
2968 attempting to use the accessor in an C<order_by> clause or similar
2969 will fail miserably.
2971 To get around this limitation, you can supply literal SQL to your
2972 C<select> attibute that contains the C<AS alias> text, eg:
2974 select => [\'myfield AS alias']
2980 =item Value: ($rel_name | \@rel_names | \%rel_names)
2984 Contains a list of relationships that should be joined for this query. For
2987 # Get CDs by Nine Inch Nails
2988 my $rs = $schema->resultset('CD')->search(
2989 { 'artist.name' => 'Nine Inch Nails' },
2990 { join => 'artist' }
2993 Can also contain a hash reference to refer to the other relation's relations.
2996 package MyApp::Schema::Track;
2997 use base qw/DBIx::Class/;
2998 __PACKAGE__->table('track');
2999 __PACKAGE__->add_columns(qw/trackid cd position title/);
3000 __PACKAGE__->set_primary_key('trackid');
3001 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
3004 # In your application
3005 my $rs = $schema->resultset('Artist')->search(
3006 { 'track.title' => 'Teardrop' },
3008 join => { cd => 'track' },
3009 order_by => 'artist.name',
3013 You need to use the relationship (not the table) name in conditions,
3014 because they are aliased as such. The current table is aliased as "me", so
3015 you need to use me.column_name in order to avoid ambiguity. For example:
3017 # Get CDs from 1984 with a 'Foo' track
3018 my $rs = $schema->resultset('CD')->search(
3021 'tracks.name' => 'Foo'
3023 { join => 'tracks' }
3026 If the same join is supplied twice, it will be aliased to <rel>_2 (and
3027 similarly for a third time). For e.g.
3029 my $rs = $schema->resultset('Artist')->search({
3030 'cds.title' => 'Down to Earth',
3031 'cds_2.title' => 'Popular',
3033 join => [ qw/cds cds/ ],
3036 will return a set of all artists that have both a cd with title 'Down
3037 to Earth' and a cd with title 'Popular'.
3039 If you want to fetch related objects from other tables as well, see C<prefetch>
3042 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3048 =item Value: ($rel_name | \@rel_names | \%rel_names)
3052 Contains one or more relationships that should be fetched along with
3053 the main query (when they are accessed afterwards the data will
3054 already be available, without extra queries to the database). This is
3055 useful for when you know you will need the related objects, because it
3056 saves at least one query:
3058 my $rs = $schema->resultset('Tag')->search(
3067 The initial search results in SQL like the following:
3069 SELECT tag.*, cd.*, artist.* FROM tag
3070 JOIN cd ON tag.cd = cd.cdid
3071 JOIN artist ON cd.artist = artist.artistid
3073 L<DBIx::Class> has no need to go back to the database when we access the
3074 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3077 Simple prefetches will be joined automatically, so there is no need
3078 for a C<join> attribute in the above search.
3080 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3081 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3082 with an accessor type of 'single' or 'filter'). A more complex example that
3083 prefetches an artists cds, the tracks on those cds, and the tags associted
3084 with that artist is given below (assuming many-to-many from artists to tags):
3086 my $rs = $schema->resultset('Artist')->search(
3090 { cds => 'tracks' },
3091 { artist_tags => 'tags' }
3097 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3098 attributes will be ignored.
3108 Makes the resultset paged and specifies the page to retrieve. Effectively
3109 identical to creating a non-pages resultset and then calling ->page($page)
3112 If L<rows> attribute is not specified it defualts to 10 rows per page.
3114 When you have a paged resultset, L</count> will only return the number
3115 of rows in the page. To get the total, use the L</pager> and call
3116 C<total_entries> on it.
3126 Specifes the maximum number of rows for direct retrieval or the number of
3127 rows per page if the page attribute or method is used.
3133 =item Value: $offset
3137 Specifies the (zero-based) row number for the first row to be returned, or the
3138 of the first row of the first page if paging is used.
3144 =item Value: \@columns
3148 A arrayref of columns to group by. Can include columns of joined tables.
3150 group_by => [qw/ column1 column2 ... /]
3156 =item Value: $condition
3160 HAVING is a select statement attribute that is applied between GROUP BY and
3161 ORDER BY. It is applied to the after the grouping calculations have been
3164 having => { 'count(employee)' => { '>=', 100 } }
3170 =item Value: (0 | 1)
3174 Set to 1 to group by all columns.
3180 Adds to the WHERE clause.
3182 # only return rows WHERE deleted IS NULL for all searches
3183 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3185 Can be overridden by passing C<{ where => undef }> as an attribute
3192 Set to 1 to cache search results. This prevents extra SQL queries if you
3193 revisit rows in your ResultSet:
3195 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3197 while( my $artist = $resultset->next ) {
3201 $rs->first; # without cache, this would issue a query
3203 By default, searches are not cached.
3205 For more examples of using these attributes, see
3206 L<DBIx::Class::Manual::Cookbook>.
3212 =item Value: \@from_clause
3216 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3217 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3220 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3222 C<join> will usually do what you need and it is strongly recommended that you
3223 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3224 And we really do mean "cannot", not just tried and failed. Attempting to use
3225 this because you're having problems with C<join> is like trying to use x86
3226 ASM because you've got a syntax error in your C. Trust us on this.
3228 Now, if you're still really, really sure you need to use this (and if you're
3229 not 100% sure, ask the mailing list first), here's an explanation of how this
3232 The syntax is as follows -
3235 { <alias1> => <table1> },
3237 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3238 [], # nested JOIN (optional)
3239 { <table1.column1> => <table2.column2>, ... (more conditions) },
3241 # More of the above [ ] may follow for additional joins
3248 ON <table1.column1> = <table2.column2>
3249 <more joins may follow>
3251 An easy way to follow the examples below is to remember the following:
3253 Anything inside "[]" is a JOIN
3254 Anything inside "{}" is a condition for the enclosing JOIN
3256 The following examples utilize a "person" table in a family tree application.
3257 In order to express parent->child relationships, this table is self-joined:
3259 # Person->belongs_to('father' => 'Person');
3260 # Person->belongs_to('mother' => 'Person');
3262 C<from> can be used to nest joins. Here we return all children with a father,
3263 then search against all mothers of those children:
3265 $rs = $schema->resultset('Person')->search(
3268 alias => 'mother', # alias columns in accordance with "from"
3270 { mother => 'person' },
3273 { child => 'person' },
3275 { father => 'person' },
3276 { 'father.person_id' => 'child.father_id' }
3279 { 'mother.person_id' => 'child.mother_id' }
3286 # SELECT mother.* FROM person mother
3289 # JOIN person father
3290 # ON ( father.person_id = child.father_id )
3292 # ON ( mother.person_id = child.mother_id )
3294 The type of any join can be controlled manually. To search against only people
3295 with a father in the person table, we could explicitly use C<INNER JOIN>:
3297 $rs = $schema->resultset('Person')->search(
3300 alias => 'child', # alias columns in accordance with "from"
3302 { child => 'person' },
3304 { father => 'person', -join_type => 'inner' },
3305 { 'father.id' => 'child.father_id' }
3312 # SELECT child.* FROM person child
3313 # INNER JOIN person father ON child.father_id = father.id
3315 If you need to express really complex joins or you need a subselect, you
3316 can supply literal SQL to C<from> via a scalar reference. In this case
3317 the contents of the scalar will replace the table name asscoiated with the
3320 WARNING: This technique might very well not work as expected on chained
3321 searches - you have been warned.
3323 # Assuming the Event resultsource is defined as:
3325 MySchema::Event->add_columns (
3328 is_auto_increment => 1,
3337 MySchema::Event->set_primary_key ('sequence');
3339 # This will get back the latest event for every location. The column
3340 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3341 # combo to limit the resultset
3343 $rs = $schema->resultset('Event');
3344 $table = $rs->result_source->name;
3345 $latest = $rs->search (
3348 (SELECT e1.* FROM $table e1
3350 ON e1.location = e2.location
3351 AND e1.sequence < e2.sequence
3352 WHERE e2.sequence is NULL
3357 # Equivalent SQL (with the DBIC chunks added):
3359 SELECT me.sequence, me.location, me.type FROM
3360 (SELECT e1.* FROM events e1
3362 ON e1.location = e2.location
3363 AND e1.sequence < e2.sequence
3364 WHERE e2.sequence is NULL
3371 =item Value: ( 'update' | 'shared' )
3375 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT