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.
1153 my @count_via_subq_attrs = qw/join seen_join prefetch group_by/;
1156 return $self->search(@_)->count if @_ and defined $_[0];
1157 return scalar @{ $self->get_cache } if $self->get_cache;
1159 my @check_attrs = @count_via_subq_attrs;
1161 # if we are not paged - we are simply asking for a limit
1162 if (not $self->{attrs}{page} and not $self->{attrs}{software_limit}) {
1163 push @check_attrs, qw/rows offset/;
1166 return $self->_has_attr (@check_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->{where};
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->{attrs}} };
1215 # take off any subquery attrs (they'd be incorporated in the subquery),
1216 # any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1217 delete $attrs->{$_} for (@count_via_subq_attrs, qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1219 $attrs->{select} = { count => '*' };
1220 $attrs->{as} = [qw/count/];
1222 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1223 my ($count) = $tmp_rs->cursor->next;
1232 =head2 count_literal
1236 =item Arguments: $sql_fragment, @bind_values
1238 =item Return Value: $count
1242 Counts the results in a literal query. Equivalent to calling L</search_literal>
1243 with the passed arguments, then L</count>.
1247 sub count_literal { shift->search_literal(@_)->count; }
1253 =item Arguments: none
1255 =item Return Value: @objects
1259 Returns all elements in the resultset. Called implicitly if the resultset
1260 is returned in list context.
1267 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1270 return @{ $self->get_cache } if $self->get_cache;
1274 # TODO: don't call resolve here
1275 if (keys %{$self->_resolved_attrs->{collapse}}) {
1276 # if ($self->{attrs}{prefetch}) {
1277 # Using $self->cursor->all is really just an optimisation.
1278 # If we're collapsing has_many prefetches it probably makes
1279 # very little difference, and this is cleaner than hacking
1280 # _construct_object to survive the approach
1281 my @row = $self->cursor->next;
1283 push(@obj, $self->_construct_object(@row));
1284 @row = (exists $self->{stashed_row}
1285 ? @{delete $self->{stashed_row}}
1286 : $self->cursor->next);
1289 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1292 $self->set_cache(\@obj) if $self->{attrs}{cache};
1300 =item Arguments: none
1302 =item Return Value: $self
1306 Resets the resultset's cursor, so you can iterate through the elements again.
1312 delete $self->{_attrs} if exists $self->{_attrs};
1313 $self->{all_cache_position} = 0;
1314 $self->cursor->reset;
1322 =item Arguments: none
1324 =item Return Value: $object?
1328 Resets the resultset and returns an object for the first result (if the
1329 resultset returns anything).
1334 return $_[0]->reset->next;
1338 # _update_delete_via_subq
1340 # Presence of some rs attributes requires a subquery to reliably
1344 sub _update_delete_via_subq {
1345 return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
1349 # _cond_for_update_delete
1351 # update/delete require the condition to be modified to handle
1352 # the differing SQL syntax available. This transforms the $self->{cond}
1353 # appropriately, returning the new condition.
1355 sub _cond_for_update_delete {
1356 my ($self, $full_cond) = @_;
1359 $full_cond ||= $self->{cond};
1360 # No-op. No condition, we're updating/deleting everything
1361 return $cond unless ref $full_cond;
1363 if (ref $full_cond eq 'ARRAY') {
1367 foreach my $key (keys %{$_}) {
1369 $hash{$1} = $_->{$key};
1375 elsif (ref $full_cond eq 'HASH') {
1376 if ((keys %{$full_cond})[0] eq '-and') {
1378 my @cond = @{$full_cond->{-and}};
1379 for (my $i = 0; $i < @cond; $i++) {
1380 my $entry = $cond[$i];
1382 if (ref $entry eq 'HASH') {
1383 $hash = $self->_cond_for_update_delete($entry);
1386 $entry =~ /([^.]+)$/;
1387 $hash->{$1} = $cond[++$i];
1389 push @{$cond->{-and}}, $hash;
1393 foreach my $key (keys %{$full_cond}) {
1395 $cond->{$1} = $full_cond->{$key};
1400 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1411 =item Arguments: \%values
1413 =item Return Value: $storage_rv
1417 Sets the specified columns in the resultset to the supplied values in a
1418 single query. Return value will be true if the update succeeded or false
1419 if no records were updated; exact type of success value is storage-dependent.
1424 my ($self, $values) = @_;
1425 $self->throw_exception('Values for update must be a hash')
1426 unless ref $values eq 'HASH';
1428 # rs operations with subqueries are Storage dependent - delegate
1429 if ($self->_update_delete_via_subq) {
1430 return $self->result_source->storage->subq_update_delete($self, 'update', $values);
1433 my $cond = $self->_cond_for_update_delete;
1435 return $self->result_source->storage->update(
1436 $self->result_source, $values, $cond
1444 =item Arguments: \%values
1446 =item Return Value: 1
1450 Fetches all objects and updates them one at a time. Note that C<update_all>
1451 will run DBIC cascade triggers, while L</update> will not.
1456 my ($self, $values) = @_;
1457 $self->throw_exception('Values for update_all must be a hash')
1458 unless ref $values eq 'HASH';
1459 foreach my $obj ($self->all) {
1460 $obj->set_columns($values)->update;
1469 =item Arguments: none
1471 =item Return Value: 1
1475 Deletes the contents of the resultset from its result source. Note that this
1476 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1477 to run. See also L<DBIx::Class::Row/delete>.
1479 delete may not generate correct SQL for a query with joins or a resultset
1480 chained from a related resultset. In this case it will generate a warning:-
1482 In these cases you may find that delete_all is more appropriate, or you
1483 need to respecify your query in a way that can be expressed without a join.
1489 $self->throw_exception('delete does not accept any arguments')
1492 # rs operations with subqueries are Storage dependent - delegate
1493 if ($self->_update_delete_via_subq) {
1494 return $self->result_source->storage->subq_update_delete($self, 'delete');
1497 my $cond = $self->_cond_for_update_delete;
1499 $self->result_source->storage->delete($self->result_source, $cond);
1507 =item Arguments: none
1509 =item Return Value: 1
1513 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1514 will run DBIC cascade triggers, while L</delete> will not.
1520 $self->throw_exception('delete_all does not accept any arguments')
1523 $_->delete for $self->all;
1531 =item Arguments: \@data;
1535 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1536 For the arrayref of hashrefs style each hashref should be a structure suitable
1537 forsubmitting to a $resultset->create(...) method.
1539 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1540 to insert the data, as this is a faster method.
1542 Otherwise, each set of data is inserted into the database using
1543 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1544 objects is returned.
1546 Example: Assuming an Artist Class that has many CDs Classes relating:
1548 my $Artist_rs = $schema->resultset("Artist");
1550 ## Void Context Example
1551 $Artist_rs->populate([
1552 { artistid => 4, name => 'Manufactured Crap', cds => [
1553 { title => 'My First CD', year => 2006 },
1554 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1557 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1558 { title => 'My parents sold me to a record company' ,year => 2005 },
1559 { title => 'Why Am I So Ugly?', year => 2006 },
1560 { title => 'I Got Surgery and am now Popular', year => 2007 }
1565 ## Array Context Example
1566 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1567 { name => "Artist One"},
1568 { name => "Artist Two"},
1569 { name => "Artist Three", cds=> [
1570 { title => "First CD", year => 2007},
1571 { title => "Second CD", year => 2008},
1575 print $ArtistOne->name; ## response is 'Artist One'
1576 print $ArtistThree->cds->count ## reponse is '2'
1578 For the arrayref of arrayrefs style, the first element should be a list of the
1579 fieldsnames to which the remaining elements are rows being inserted. For
1582 $Arstist_rs->populate([
1583 [qw/artistid name/],
1584 [100, 'A Formally Unknown Singer'],
1585 [101, 'A singer that jumped the shark two albums ago'],
1586 [102, 'An actually cool singer.'],
1589 Please note an important effect on your data when choosing between void and
1590 wantarray context. Since void context goes straight to C<insert_bulk> in
1591 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1592 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1593 create primary keys for you, you will find that your PKs are empty. In this
1594 case you will have to use the wantarray context in order to create those
1600 my $self = shift @_;
1601 my $data = ref $_[0][0] eq 'HASH'
1602 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1603 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1605 if(defined wantarray) {
1607 foreach my $item (@$data) {
1608 push(@created, $self->create($item));
1612 my ($first, @rest) = @$data;
1614 my @names = grep {!ref $first->{$_}} keys %$first;
1615 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1616 my @pks = $self->result_source->primary_columns;
1618 ## do the belongs_to relationships
1619 foreach my $index (0..$#$data) {
1620 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1621 my @ret = $self->populate($data);
1625 foreach my $rel (@rels) {
1626 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1627 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1628 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1629 my $related = $result->result_source->resolve_condition(
1630 $result->result_source->relationship_info($reverse)->{cond},
1635 delete $data->[$index]->{$rel};
1636 $data->[$index] = {%{$data->[$index]}, %$related};
1638 push @names, keys %$related if $index == 0;
1642 ## do bulk insert on current row
1643 my @values = map { [ @$_{@names} ] } @$data;
1645 $self->result_source->storage->insert_bulk(
1646 $self->result_source,
1651 ## do the has_many relationships
1652 foreach my $item (@$data) {
1654 foreach my $rel (@rels) {
1655 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1657 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1658 || $self->throw_exception('Cannot find the relating object.');
1660 my $child = $parent->$rel;
1662 my $related = $child->result_source->resolve_condition(
1663 $parent->result_source->relationship_info($rel)->{cond},
1668 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1669 my @populate = map { {%$_, %$related} } @rows_to_add;
1671 $child->populate( \@populate );
1677 =head2 _normalize_populate_args ($args)
1679 Private method used by L</populate> to normalize its incoming arguments. Factored
1680 out in case you want to subclass and accept new argument structures to the
1681 L</populate> method.
1685 sub _normalize_populate_args {
1686 my ($self, $data) = @_;
1687 my @names = @{shift(@$data)};
1688 my @results_to_create;
1689 foreach my $datum (@$data) {
1690 my %result_to_create;
1691 foreach my $index (0..$#names) {
1692 $result_to_create{$names[$index]} = $$datum[$index];
1694 push @results_to_create, \%result_to_create;
1696 return \@results_to_create;
1703 =item Arguments: none
1705 =item Return Value: $pager
1709 Return Value a L<Data::Page> object for the current resultset. Only makes
1710 sense for queries with a C<page> attribute.
1712 To get the full count of entries for a paged resultset, call
1713 C<total_entries> on the L<Data::Page> object.
1720 return $self->{pager} if $self->{pager};
1722 my $attrs = $self->{attrs};
1723 $self->throw_exception("Can't create pager for non-paged rs")
1724 unless $self->{attrs}{page};
1725 $attrs->{rows} ||= 10;
1727 # throw away the paging flags and re-run the count (possibly
1728 # with a subselect) to get the real total count
1729 my $count_attrs = { %$attrs };
1730 delete $count_attrs->{$_} for qw/rows offset page pager/;
1731 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1733 return $self->{pager} = Data::Page->new(
1736 $self->{attrs}{page}
1744 =item Arguments: $page_number
1746 =item Return Value: $rs
1750 Returns a resultset for the $page_number page of the resultset on which page
1751 is called, where each page contains a number of rows equal to the 'rows'
1752 attribute set on the resultset (10 by default).
1757 my ($self, $page) = @_;
1758 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1765 =item Arguments: \%vals
1767 =item Return Value: $rowobject
1771 Creates a new row object in the resultset's result class and returns
1772 it. The row is not inserted into the database at this point, call
1773 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1774 will tell you whether the row object has been inserted or not.
1776 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1781 my ($self, $values) = @_;
1782 $self->throw_exception( "new_result needs a hash" )
1783 unless (ref $values eq 'HASH');
1786 my $alias = $self->{attrs}{alias};
1789 defined $self->{cond}
1790 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1792 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1793 $new{-from_resultset} = [ keys %new ] if keys %new;
1795 $self->throw_exception(
1796 "Can't abstract implicit construct, condition not a hash"
1797 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1799 my $collapsed_cond = (
1801 ? $self->_collapse_cond($self->{cond})
1805 # precendence must be given to passed values over values inherited from
1806 # the cond, so the order here is important.
1807 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1808 while( my($col,$value) = each %implied ){
1809 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1810 $new{$col} = $value->{'='};
1813 $new{$col} = $value if $self->_is_deterministic_value($value);
1819 %{ $self->_remove_alias($values, $alias) },
1820 -source_handle => $self->_source_handle,
1821 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1824 return $self->result_class->new(\%new);
1827 # _is_deterministic_value
1829 # Make an effor to strip non-deterministic values from the condition,
1830 # to make sure new_result chokes less
1832 sub _is_deterministic_value {
1835 my $ref_type = ref $value;
1836 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1837 return 1 if Scalar::Util::blessed($value);
1843 # determines if the resultset defines at least one
1844 # of the attributes supplied
1846 # used to determine if a subquery is neccessary
1849 my ($self, @attr_names) = @_;
1851 my $attrs = $self->_resolved_attrs;
1855 for my $n (@attr_names) {
1856 return 1 if defined $attrs->{$n};
1857 ++$join_check_req if $n =~ /join/;
1860 # a join can be expressed as a multi-level from
1864 ref $attrs->{from} eq 'ARRAY'
1866 @{$attrs->{from}} > 1
1874 # Recursively collapse the condition.
1876 sub _collapse_cond {
1877 my ($self, $cond, $collapsed) = @_;
1881 if (ref $cond eq 'ARRAY') {
1882 foreach my $subcond (@$cond) {
1883 next unless ref $subcond; # -or
1884 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1887 elsif (ref $cond eq 'HASH') {
1888 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1889 foreach my $subcond (@{$cond->{-and}}) {
1890 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1894 foreach my $col (keys %$cond) {
1895 my $value = $cond->{$col};
1896 $collapsed->{$col} = $value;
1906 # Remove the specified alias from the specified query hash. A copy is made so
1907 # the original query is not modified.
1910 my ($self, $query, $alias) = @_;
1912 my %orig = %{ $query || {} };
1915 foreach my $key (keys %orig) {
1917 $unaliased{$key} = $orig{$key};
1920 $unaliased{$1} = $orig{$key}
1921 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1927 =head2 as_query (EXPERIMENTAL)
1931 =item Arguments: none
1933 =item Return Value: \[ $sql, @bind ]
1937 Returns the SQL query and bind vars associated with the invocant.
1939 This is generally used as the RHS for a subquery.
1941 B<NOTE>: This feature is still experimental.
1945 sub as_query { return shift->cursor->as_query(@_) }
1951 =item Arguments: \%vals, \%attrs?
1953 =item Return Value: $rowobject
1957 my $artist = $schema->resultset('Artist')->find_or_new(
1958 { artist => 'fred' }, { key => 'artists' });
1960 $cd->cd_to_producer->find_or_new({ producer => $producer },
1961 { key => 'primary });
1963 Find an existing record from this resultset, based on its primary
1964 key, or a unique constraint. If none exists, instantiate a new result
1965 object and return it. The object will not be saved into your storage
1966 until you call L<DBIx::Class::Row/insert> on it.
1968 You most likely want this method when looking for existing rows using
1969 a unique constraint that is not the primary key, or looking for
1972 If you want objects to be saved immediately, use L</find_or_create> instead.
1974 B<Note>: C<find_or_new> is probably not what you want when creating a
1975 new row in a table that uses primary keys supplied by the
1976 database. Passing in a primary key column with a value of I<undef>
1977 will cause L</find> to attempt to search for a row with a value of
1984 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1985 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1986 my $exists = $self->find($hash, $attrs);
1987 return defined $exists ? $exists : $self->new_result($hash);
1994 =item Arguments: \%vals
1996 =item Return Value: a L<DBIx::Class::Row> $object
2000 Attempt to create a single new row or a row with multiple related rows
2001 in the table represented by the resultset (and related tables). This
2002 will not check for duplicate rows before inserting, use
2003 L</find_or_create> to do that.
2005 To create one row for this resultset, pass a hashref of key/value
2006 pairs representing the columns of the table and the values you wish to
2007 store. If the appropriate relationships are set up, foreign key fields
2008 can also be passed an object representing the foreign row, and the
2009 value will be set to its primary key.
2011 To create related objects, pass a hashref for the value if the related
2012 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2013 and use the name of the relationship as the key. (NOT the name of the field,
2014 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2015 of hashrefs containing the data for each of the rows to create in the foreign
2016 tables, again using the relationship name as the key.
2018 Instead of hashrefs of plain related data (key/value pairs), you may
2019 also pass new or inserted objects. New objects (not inserted yet, see
2020 L</new>), will be inserted into their appropriate tables.
2022 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2024 Example of creating a new row.
2026 $person_rs->create({
2027 name=>"Some Person",
2028 email=>"somebody@someplace.com"
2031 Example of creating a new row and also creating rows in a related C<has_many>
2032 or C<has_one> resultset. Note Arrayref.
2035 { artistid => 4, name => 'Manufactured Crap', cds => [
2036 { title => 'My First CD', year => 2006 },
2037 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2042 Example of creating a new row and also creating a row in a related
2043 C<belongs_to>resultset. Note Hashref.
2046 title=>"Music for Silly Walks",
2049 name=>"Silly Musician",
2056 my ($self, $attrs) = @_;
2057 $self->throw_exception( "create needs a hashref" )
2058 unless ref $attrs eq 'HASH';
2059 return $self->new_result($attrs)->insert;
2062 =head2 find_or_create
2066 =item Arguments: \%vals, \%attrs?
2068 =item Return Value: $rowobject
2072 $cd->cd_to_producer->find_or_create({ producer => $producer },
2073 { key => 'primary });
2075 Tries to find a record based on its primary key or unique constraints; if none
2076 is found, creates one and returns that instead.
2078 my $cd = $schema->resultset('CD')->find_or_create({
2080 artist => 'Massive Attack',
2081 title => 'Mezzanine',
2085 Also takes an optional C<key> attribute, to search by a specific key or unique
2086 constraint. For example:
2088 my $cd = $schema->resultset('CD')->find_or_create(
2090 artist => 'Massive Attack',
2091 title => 'Mezzanine',
2093 { key => 'cd_artist_title' }
2096 B<Note>: Because find_or_create() reads from the database and then
2097 possibly inserts based on the result, this method is subject to a race
2098 condition. Another process could create a record in the table after
2099 the find has completed and before the create has started. To avoid
2100 this problem, use find_or_create() inside a transaction.
2102 B<Note>: C<find_or_create> is probably not what you want when creating
2103 a new row in a table that uses primary keys supplied by the
2104 database. Passing in a primary key column with a value of I<undef>
2105 will cause L</find> to attempt to search for a row with a value of
2108 See also L</find> and L</update_or_create>. For information on how to declare
2109 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2113 sub find_or_create {
2115 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2116 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2117 my $exists = $self->find($hash, $attrs);
2118 return defined $exists ? $exists : $self->create($hash);
2121 =head2 update_or_create
2125 =item Arguments: \%col_values, { key => $unique_constraint }?
2127 =item Return Value: $rowobject
2131 $resultset->update_or_create({ col => $val, ... });
2133 First, searches for an existing row matching one of the unique constraints
2134 (including the primary key) on the source of this resultset. If a row is
2135 found, updates it with the other given column values. Otherwise, creates a new
2138 Takes an optional C<key> attribute to search on a specific unique constraint.
2141 # In your application
2142 my $cd = $schema->resultset('CD')->update_or_create(
2144 artist => 'Massive Attack',
2145 title => 'Mezzanine',
2148 { key => 'cd_artist_title' }
2151 $cd->cd_to_producer->update_or_create({
2152 producer => $producer,
2159 If no C<key> is specified, it searches on all unique constraints defined on the
2160 source, including the primary key.
2162 If the C<key> is specified as C<primary>, it searches only on the primary key.
2164 See also L</find> and L</find_or_create>. For information on how to declare
2165 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2167 B<Note>: C<update_or_create> is probably not what you want when
2168 looking for a row in a table that uses primary keys supplied by the
2169 database, unless you actually have a key value. Passing in a primary
2170 key column with a value of I<undef> will cause L</find> to attempt to
2171 search for a row with a value of I<NULL>.
2175 sub update_or_create {
2177 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2178 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2180 my $row = $self->find($cond, $attrs);
2182 $row->update($cond);
2186 return $self->create($cond);
2189 =head2 update_or_new
2193 =item Arguments: \%col_values, { key => $unique_constraint }?
2195 =item Return Value: $rowobject
2199 $resultset->update_or_new({ col => $val, ... });
2201 First, searches for an existing row matching one of the unique constraints
2202 (including the primary key) on the source of this resultset. If a row is
2203 found, updates it with the other given column values. Otherwise, instantiate
2204 a new result object and return it. The object will not be saved into your storage
2205 until you call L<DBIx::Class::Row/insert> on it.
2207 Takes an optional C<key> attribute to search on a specific unique constraint.
2210 # In your application
2211 my $cd = $schema->resultset('CD')->update_or_new(
2213 artist => 'Massive Attack',
2214 title => 'Mezzanine',
2217 { key => 'cd_artist_title' }
2220 if ($cd->in_storage) {
2221 # the cd was updated
2224 # the cd is not yet in the database, let's insert it
2228 See also L</find>, L</find_or_create> and L<find_or_new>.
2234 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2235 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2237 my $row = $self->find( $cond, $attrs );
2238 if ( defined $row ) {
2239 $row->update($cond);
2243 return $self->new_result($cond);
2250 =item Arguments: none
2252 =item Return Value: \@cache_objects?
2256 Gets the contents of the cache for the resultset, if the cache is set.
2258 The cache is populated either by using the L</prefetch> attribute to
2259 L</search> or by calling L</set_cache>.
2271 =item Arguments: \@cache_objects
2273 =item Return Value: \@cache_objects
2277 Sets the contents of the cache for the resultset. Expects an arrayref
2278 of objects of the same class as those produced by the resultset. Note that
2279 if the cache is set the resultset will return the cached objects rather
2280 than re-querying the database even if the cache attr is not set.
2282 The contents of the cache can also be populated by using the
2283 L</prefetch> attribute to L</search>.
2288 my ( $self, $data ) = @_;
2289 $self->throw_exception("set_cache requires an arrayref")
2290 if defined($data) && (ref $data ne 'ARRAY');
2291 $self->{all_cache} = $data;
2298 =item Arguments: none
2300 =item Return Value: []
2304 Clears the cache for the resultset.
2309 shift->set_cache(undef);
2312 =head2 related_resultset
2316 =item Arguments: $relationship_name
2318 =item Return Value: $resultset
2322 Returns a related resultset for the supplied relationship name.
2324 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2328 sub related_resultset {
2329 my ($self, $rel) = @_;
2331 $self->{related_resultsets} ||= {};
2332 return $self->{related_resultsets}{$rel} ||= do {
2333 my $rel_obj = $self->result_source->relationship_info($rel);
2335 $self->throw_exception(
2336 "search_related: result source '" . $self->result_source->source_name .
2337 "' has no such relationship $rel")
2340 my ($from,$seen) = $self->_resolve_from($rel);
2342 my $join_count = $seen->{$rel};
2343 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2345 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2346 my %attrs = %{$self->{attrs}||{}};
2347 delete @attrs{qw(result_class alias)};
2351 if (my $cache = $self->get_cache) {
2352 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2353 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2358 my $rel_source = $self->result_source->related_source($rel);
2362 # The reason we do this now instead of passing the alias to the
2363 # search_rs below is that if you wrap/overload resultset on the
2364 # source you need to know what alias it's -going- to have for things
2365 # to work sanely (e.g. RestrictWithObject wants to be able to add
2366 # extra query restrictions, and these may need to be $alias.)
2368 my $attrs = $rel_source->resultset_attributes;
2369 local $attrs->{alias} = $alias;
2371 $rel_source->resultset
2379 where => $self->{cond},
2384 $new->set_cache($new_cache) if $new_cache;
2389 =head2 current_source_alias
2393 =item Arguments: none
2395 =item Return Value: $source_alias
2399 Returns the current table alias for the result source this resultset is built
2400 on, that will be used in the SQL query. Usually it is C<me>.
2402 Currently the source alias that refers to the result set returned by a
2403 L</search>/L</find> family method depends on how you got to the resultset: it's
2404 C<me> by default, but eg. L</search_related> aliases it to the related result
2405 source name (and keeps C<me> referring to the original result set). The long
2406 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2407 (and make this method unnecessary).
2409 Thus it's currently necessary to use this method in predefined queries (see
2410 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2411 source alias of the current result set:
2413 # in a result set class
2415 my ($self, $user) = @_;
2417 my $me = $self->current_source_alias;
2419 return $self->search(
2420 "$me.modified" => $user->id,
2426 sub current_source_alias {
2429 return ($self->{attrs} || {})->{alias} || 'me';
2432 # This code is called by search_related, and makes sure there
2433 # is clear separation between the joins before, during, and
2434 # after the relationship. This information is needed later
2435 # in order to properly resolve prefetch aliases (any alias
2436 # with a relation_chain_depth less than the depth of the
2437 # current prefetch is not considered)
2439 my ($self, $extra_join) = @_;
2440 my $source = $self->result_source;
2441 my $attrs = $self->{attrs};
2443 my $from = $attrs->{from}
2444 || [ { $attrs->{alias} => $source->from } ];
2446 my $seen = { %{$attrs->{seen_join}||{}} };
2448 # we need to take the prefetch the attrs into account before we
2449 # ->resolve_join as otherwise they get lost - captainL
2450 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2452 push @$from, $source->resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2454 ++$seen->{-relation_chain_depth};
2456 push @$from, $source->resolve_join($extra_join, $attrs->{alias}, $seen);
2458 ++$seen->{-relation_chain_depth};
2460 return ($from,$seen);
2463 sub _resolved_attrs {
2465 return $self->{_attrs} if $self->{_attrs};
2467 my $attrs = { %{ $self->{attrs} || {} } };
2468 my $source = $self->result_source;
2469 my $alias = $attrs->{alias};
2471 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2474 # build columns (as long as select isn't set) into a set of as/select hashes
2475 unless ( $attrs->{select} ) {
2477 ( ref($_) eq 'HASH' )
2481 /^\Q${alias}.\E(.+)$/
2492 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2494 # add the additional columns on
2495 foreach ( 'include_columns', '+columns' ) {
2496 push @colbits, map {
2497 ( ref($_) eq 'HASH' )
2499 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2500 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2503 # start with initial select items
2504 if ( $attrs->{select} ) {
2506 ( ref $attrs->{select} eq 'ARRAY' )
2507 ? [ @{ $attrs->{select} } ]
2508 : [ $attrs->{select} ];
2512 ref $attrs->{as} eq 'ARRAY'
2513 ? [ @{ $attrs->{as} } ]
2516 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2521 # otherwise we intialise select & as to empty
2522 $attrs->{select} = [];
2526 # now add colbits to select/as
2527 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2528 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2531 if ( $adds = delete $attrs->{'+select'} ) {
2532 $adds = [$adds] unless ref $adds eq 'ARRAY';
2534 @{ $attrs->{select} },
2535 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2538 if ( $adds = delete $attrs->{'+as'} ) {
2539 $adds = [$adds] unless ref $adds eq 'ARRAY';
2540 push( @{ $attrs->{as} }, @$adds );
2543 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2545 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2546 my $join = delete $attrs->{join} || {};
2548 if ( defined $attrs->{prefetch} ) {
2549 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2553 $attrs->{from} = # have to copy here to avoid corrupting the original
2555 @{ $attrs->{from} },
2556 $source->resolve_join(
2557 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2563 $attrs->{group_by} ||= $attrs->{select}
2564 if delete $attrs->{distinct};
2565 if ( $attrs->{order_by} ) {
2566 $attrs->{order_by} = (
2567 ref( $attrs->{order_by} ) eq 'ARRAY'
2568 ? [ @{ $attrs->{order_by} } ]
2569 : [ $attrs->{order_by} ]
2573 $attrs->{order_by} = [];
2576 my $collapse = $attrs->{collapse} || {};
2577 if ( my $prefetch = delete $attrs->{prefetch} ) {
2578 $prefetch = $self->_merge_attr( {}, $prefetch );
2580 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2582 # bring joins back to level of current class
2583 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2585 $source->resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2586 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2587 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2589 push( @{ $attrs->{order_by} }, @pre_order );
2591 $attrs->{collapse} = $collapse;
2593 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2594 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2597 return $self->{_attrs} = $attrs;
2600 sub _joinpath_aliases {
2601 my ($self, $fromspec, $seen) = @_;
2604 return $paths unless ref $fromspec eq 'ARRAY';
2606 for my $j (@$fromspec) {
2608 next if ref $j ne 'ARRAY';
2609 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2612 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2613 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2620 my ($self, $attr) = @_;
2622 if (ref $attr eq 'HASH') {
2623 return $self->_rollout_hash($attr);
2624 } elsif (ref $attr eq 'ARRAY') {
2625 return $self->_rollout_array($attr);
2631 sub _rollout_array {
2632 my ($self, $attr) = @_;
2635 foreach my $element (@{$attr}) {
2636 if (ref $element eq 'HASH') {
2637 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2638 } elsif (ref $element eq 'ARRAY') {
2639 # XXX - should probably recurse here
2640 push( @rolled_array, @{$self->_rollout_array($element)} );
2642 push( @rolled_array, $element );
2645 return \@rolled_array;
2649 my ($self, $attr) = @_;
2652 foreach my $key (keys %{$attr}) {
2653 push( @rolled_array, { $key => $attr->{$key} } );
2655 return \@rolled_array;
2658 sub _calculate_score {
2659 my ($self, $a, $b) = @_;
2661 if (ref $b eq 'HASH') {
2662 my ($b_key) = keys %{$b};
2663 if (ref $a eq 'HASH') {
2664 my ($a_key) = keys %{$a};
2665 if ($a_key eq $b_key) {
2666 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2671 return ($a eq $b_key) ? 1 : 0;
2674 if (ref $a eq 'HASH') {
2675 my ($a_key) = keys %{$a};
2676 return ($b eq $a_key) ? 1 : 0;
2678 return ($b eq $a) ? 1 : 0;
2684 my ($self, $orig, $import) = @_;
2686 return $import unless defined($orig);
2687 return $orig unless defined($import);
2689 $orig = $self->_rollout_attr($orig);
2690 $import = $self->_rollout_attr($import);
2693 foreach my $import_element ( @{$import} ) {
2694 # find best candidate from $orig to merge $b_element into
2695 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2696 foreach my $orig_element ( @{$orig} ) {
2697 my $score = $self->_calculate_score( $orig_element, $import_element );
2698 if ($score > $best_candidate->{score}) {
2699 $best_candidate->{position} = $position;
2700 $best_candidate->{score} = $score;
2704 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2706 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2707 push( @{$orig}, $import_element );
2709 my $orig_best = $orig->[$best_candidate->{position}];
2710 # merge orig_best and b_element together and replace original with merged
2711 if (ref $orig_best ne 'HASH') {
2712 $orig->[$best_candidate->{position}] = $import_element;
2713 } elsif (ref $import_element eq 'HASH') {
2714 my ($key) = keys %{$orig_best};
2715 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2718 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2728 $self->_source_handle($_[0]->handle);
2730 $self->_source_handle->resolve;
2734 =head2 throw_exception
2736 See L<DBIx::Class::Schema/throw_exception> for details.
2740 sub throw_exception {
2742 if (ref $self && $self->_source_handle->schema) {
2743 $self->_source_handle->schema->throw_exception(@_)
2750 # XXX: FIXME: Attributes docs need clearing up
2754 Attributes are used to refine a ResultSet in various ways when
2755 searching for data. They can be passed to any method which takes an
2756 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2759 These are in no particular order:
2765 =item Value: ( $order_by | \@order_by | \%order_by )
2769 Which column(s) to order the results by. If a single column name, or
2770 an arrayref of names is supplied, the argument is passed through
2771 directly to SQL. The hashref syntax allows for connection-agnostic
2772 specification of ordering direction:
2774 For descending order:
2776 order_by => { -desc => [qw/col1 col2 col3/] }
2778 For explicit ascending order:
2780 order_by => { -asc => 'col' }
2782 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2783 supported, although you are strongly encouraged to use the hashref
2784 syntax as outlined above.
2790 =item Value: \@columns
2794 Shortcut to request a particular set of columns to be retrieved. Each
2795 column spec may be a string (a table column name), or a hash (in which
2796 case the key is the C<as> value, and the value is used as the C<select>
2797 expression). Adds C<me.> onto the start of any column without a C<.> in
2798 it and sets C<select> from that, then auto-populates C<as> from
2799 C<select> as normal. (You may also use the C<cols> attribute, as in
2800 earlier versions of DBIC.)
2806 =item Value: \@columns
2810 Indicates additional columns to be selected from storage. Works the same
2811 as L</columns> but adds columns to the selection. (You may also use the
2812 C<include_columns> attribute, as in earlier versions of DBIC). For
2815 $schema->resultset('CD')->search(undef, {
2816 '+columns' => ['artist.name'],
2820 would return all CDs and include a 'name' column to the information
2821 passed to object inflation. Note that the 'artist' is the name of the
2822 column (or relationship) accessor, and 'name' is the name of the column
2823 accessor in the related table.
2825 =head2 include_columns
2829 =item Value: \@columns
2833 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2839 =item Value: \@select_columns
2843 Indicates which columns should be selected from the storage. You can use
2844 column names, or in the case of RDBMS back ends, function or stored procedure
2847 $rs = $schema->resultset('Employee')->search(undef, {
2850 { count => 'employeeid' },
2855 When you use function/stored procedure names and do not supply an C<as>
2856 attribute, the column names returned are storage-dependent. E.g. MySQL would
2857 return a column named C<count(employeeid)> in the above example.
2863 Indicates additional columns to be selected from storage. Works the same as
2864 L</select> but adds columns to the selection.
2872 Indicates additional column names for those added via L</+select>. See L</as>.
2880 =item Value: \@inflation_names
2884 Indicates column names for object inflation. That is, C<as>
2885 indicates the name that the column can be accessed as via the
2886 C<get_column> method (or via the object accessor, B<if one already
2887 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2889 The C<as> attribute is used in conjunction with C<select>,
2890 usually when C<select> contains one or more function or stored
2893 $rs = $schema->resultset('Employee')->search(undef, {
2896 { count => 'employeeid' }
2898 as => ['name', 'employee_count'],
2901 my $employee = $rs->first(); # get the first Employee
2903 If the object against which the search is performed already has an accessor
2904 matching a column name specified in C<as>, the value can be retrieved using
2905 the accessor as normal:
2907 my $name = $employee->name();
2909 If on the other hand an accessor does not exist in the object, you need to
2910 use C<get_column> instead:
2912 my $employee_count = $employee->get_column('employee_count');
2914 You can create your own accessors if required - see
2915 L<DBIx::Class::Manual::Cookbook> for details.
2917 Please note: This will NOT insert an C<AS employee_count> into the SQL
2918 statement produced, it is used for internal access only. Thus
2919 attempting to use the accessor in an C<order_by> clause or similar
2920 will fail miserably.
2922 To get around this limitation, you can supply literal SQL to your
2923 C<select> attibute that contains the C<AS alias> text, eg:
2925 select => [\'myfield AS alias']
2931 =item Value: ($rel_name | \@rel_names | \%rel_names)
2935 Contains a list of relationships that should be joined for this query. For
2938 # Get CDs by Nine Inch Nails
2939 my $rs = $schema->resultset('CD')->search(
2940 { 'artist.name' => 'Nine Inch Nails' },
2941 { join => 'artist' }
2944 Can also contain a hash reference to refer to the other relation's relations.
2947 package MyApp::Schema::Track;
2948 use base qw/DBIx::Class/;
2949 __PACKAGE__->table('track');
2950 __PACKAGE__->add_columns(qw/trackid cd position title/);
2951 __PACKAGE__->set_primary_key('trackid');
2952 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2955 # In your application
2956 my $rs = $schema->resultset('Artist')->search(
2957 { 'track.title' => 'Teardrop' },
2959 join => { cd => 'track' },
2960 order_by => 'artist.name',
2964 You need to use the relationship (not the table) name in conditions,
2965 because they are aliased as such. The current table is aliased as "me", so
2966 you need to use me.column_name in order to avoid ambiguity. For example:
2968 # Get CDs from 1984 with a 'Foo' track
2969 my $rs = $schema->resultset('CD')->search(
2972 'tracks.name' => 'Foo'
2974 { join => 'tracks' }
2977 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2978 similarly for a third time). For e.g.
2980 my $rs = $schema->resultset('Artist')->search({
2981 'cds.title' => 'Down to Earth',
2982 'cds_2.title' => 'Popular',
2984 join => [ qw/cds cds/ ],
2987 will return a set of all artists that have both a cd with title 'Down
2988 to Earth' and a cd with title 'Popular'.
2990 If you want to fetch related objects from other tables as well, see C<prefetch>
2993 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2999 =item Value: ($rel_name | \@rel_names | \%rel_names)
3003 Contains one or more relationships that should be fetched along with
3004 the main query (when they are accessed afterwards the data will
3005 already be available, without extra queries to the database). This is
3006 useful for when you know you will need the related objects, because it
3007 saves at least one query:
3009 my $rs = $schema->resultset('Tag')->search(
3018 The initial search results in SQL like the following:
3020 SELECT tag.*, cd.*, artist.* FROM tag
3021 JOIN cd ON tag.cd = cd.cdid
3022 JOIN artist ON cd.artist = artist.artistid
3024 L<DBIx::Class> has no need to go back to the database when we access the
3025 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3028 Simple prefetches will be joined automatically, so there is no need
3029 for a C<join> attribute in the above search.
3031 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3032 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3033 with an accessor type of 'single' or 'filter'). A more complex example that
3034 prefetches an artists cds, the tracks on those cds, and the tags associted
3035 with that artist is given below (assuming many-to-many from artists to tags):
3037 my $rs = $schema->resultset('Artist')->search(
3041 { cds => 'tracks' },
3042 { artist_tags => 'tags' }
3048 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3049 attributes will be ignored.
3059 Makes the resultset paged and specifies the page to retrieve. Effectively
3060 identical to creating a non-pages resultset and then calling ->page($page)
3063 If L<rows> attribute is not specified it defualts to 10 rows per page.
3065 When you have a paged resultset, L</count> will only return the number
3066 of rows in the page. To get the total, use the L</pager> and call
3067 C<total_entries> on it.
3077 Specifes the maximum number of rows for direct retrieval or the number of
3078 rows per page if the page attribute or method is used.
3084 =item Value: $offset
3088 Specifies the (zero-based) row number for the first row to be returned, or the
3089 of the first row of the first page if paging is used.
3095 =item Value: \@columns
3099 A arrayref of columns to group by. Can include columns of joined tables.
3101 group_by => [qw/ column1 column2 ... /]
3107 =item Value: $condition
3111 HAVING is a select statement attribute that is applied between GROUP BY and
3112 ORDER BY. It is applied to the after the grouping calculations have been
3115 having => { 'count(employee)' => { '>=', 100 } }
3121 =item Value: (0 | 1)
3125 Set to 1 to group by all columns.
3131 Adds to the WHERE clause.
3133 # only return rows WHERE deleted IS NULL for all searches
3134 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3136 Can be overridden by passing C<{ where => undef }> as an attribute
3143 Set to 1 to cache search results. This prevents extra SQL queries if you
3144 revisit rows in your ResultSet:
3146 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3148 while( my $artist = $resultset->next ) {
3152 $rs->first; # without cache, this would issue a query
3154 By default, searches are not cached.
3156 For more examples of using these attributes, see
3157 L<DBIx::Class::Manual::Cookbook>.
3163 =item Value: \@from_clause
3167 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3168 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3171 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3173 C<join> will usually do what you need and it is strongly recommended that you
3174 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3175 And we really do mean "cannot", not just tried and failed. Attempting to use
3176 this because you're having problems with C<join> is like trying to use x86
3177 ASM because you've got a syntax error in your C. Trust us on this.
3179 Now, if you're still really, really sure you need to use this (and if you're
3180 not 100% sure, ask the mailing list first), here's an explanation of how this
3183 The syntax is as follows -
3186 { <alias1> => <table1> },
3188 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3189 [], # nested JOIN (optional)
3190 { <table1.column1> => <table2.column2>, ... (more conditions) },
3192 # More of the above [ ] may follow for additional joins
3199 ON <table1.column1> = <table2.column2>
3200 <more joins may follow>
3202 An easy way to follow the examples below is to remember the following:
3204 Anything inside "[]" is a JOIN
3205 Anything inside "{}" is a condition for the enclosing JOIN
3207 The following examples utilize a "person" table in a family tree application.
3208 In order to express parent->child relationships, this table is self-joined:
3210 # Person->belongs_to('father' => 'Person');
3211 # Person->belongs_to('mother' => 'Person');
3213 C<from> can be used to nest joins. Here we return all children with a father,
3214 then search against all mothers of those children:
3216 $rs = $schema->resultset('Person')->search(
3219 alias => 'mother', # alias columns in accordance with "from"
3221 { mother => 'person' },
3224 { child => 'person' },
3226 { father => 'person' },
3227 { 'father.person_id' => 'child.father_id' }
3230 { 'mother.person_id' => 'child.mother_id' }
3237 # SELECT mother.* FROM person mother
3240 # JOIN person father
3241 # ON ( father.person_id = child.father_id )
3243 # ON ( mother.person_id = child.mother_id )
3245 The type of any join can be controlled manually. To search against only people
3246 with a father in the person table, we could explicitly use C<INNER JOIN>:
3248 $rs = $schema->resultset('Person')->search(
3251 alias => 'child', # alias columns in accordance with "from"
3253 { child => 'person' },
3255 { father => 'person', -join_type => 'inner' },
3256 { 'father.id' => 'child.father_id' }
3263 # SELECT child.* FROM person child
3264 # INNER JOIN person father ON child.father_id = father.id
3266 If you need to express really complex joins or you need a subselect, you
3267 can supply literal SQL to C<from> via a scalar reference. In this case
3268 the contents of the scalar will replace the table name asscoiated with the
3271 WARNING: This technique might very well not work as expected on chained
3272 searches - you have been warned.
3274 # Assuming the Event resultsource is defined as:
3276 MySchema::Event->add_columns (
3279 is_auto_increment => 1,
3288 MySchema::Event->set_primary_key ('sequence');
3290 # This will get back the latest event for every location. The column
3291 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3292 # combo to limit the resultset
3294 $rs = $schema->resultset('Event');
3295 $table = $rs->result_source->name;
3296 $latest = $rs->search (
3299 (SELECT e1.* FROM $table e1
3301 ON e1.location = e2.location
3302 AND e1.sequence < e2.sequence
3303 WHERE e2.sequence is NULL
3308 # Equivalent SQL (with the DBIC chunks added):
3310 SELECT me.sequence, me.location, me.type FROM
3311 (SELECT e1.* FROM events e1
3313 ON e1.location = e2.location
3314 AND e1.sequence < e2.sequence
3315 WHERE e2.sequence is NULL
3322 =item Value: ( 'update' | 'shared' )
3326 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT