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 group_by having having_bind/;
1160 # if we are not paged - we are simply asking for a limit
1161 if (not $self->{attrs}{page} and not $self->{attrs}{software_limit}) {
1162 push @subq_attrs, qw/rows offset/;
1165 return $self->_has_attr (@subq_attrs)
1166 ? $self->_count_subq
1167 : $self->_count_simple
1173 my $attrs = { %{$self->_resolved_attrs} };
1175 # copy for the subquery, we need to do some adjustments to it too
1176 my $sub_attrs = { %$attrs };
1178 # these can not go in the subquery either
1179 delete $sub_attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
1181 # force a group_by and the same set of columns (most databases require this)
1182 $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1185 count_subq => (ref $self)->new ($self->result_source, $sub_attrs )->as_query
1188 # the subquery replaces this
1189 delete $attrs->{$_} for qw/where bind prefetch collapse group_by having/;
1191 return $self->__count ($attrs);
1197 my $count = $self->__count;
1198 return 0 unless $count;
1200 # need to take offset from resolved attrs
1202 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1203 $count = $self->{attrs}{rows} if
1204 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1205 $count = 0 if ($count < 0);
1210 my ($self, $attrs) = @_;
1212 $attrs ||= { %{$self->{attrs}} };
1214 # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
1215 delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/);
1217 $attrs->{select} = { count => '*' };
1218 $attrs->{as} = [qw/count/];
1220 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1221 my ($count) = $tmp_rs->cursor->next;
1230 =head2 count_literal
1234 =item Arguments: $sql_fragment, @bind_values
1236 =item Return Value: $count
1240 Counts the results in a literal query. Equivalent to calling L</search_literal>
1241 with the passed arguments, then L</count>.
1245 sub count_literal { shift->search_literal(@_)->count; }
1251 =item Arguments: none
1253 =item Return Value: @objects
1257 Returns all elements in the resultset. Called implicitly if the resultset
1258 is returned in list context.
1265 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1268 return @{ $self->get_cache } if $self->get_cache;
1272 # TODO: don't call resolve here
1273 if (keys %{$self->_resolved_attrs->{collapse}}) {
1274 # if ($self->{attrs}{prefetch}) {
1275 # Using $self->cursor->all is really just an optimisation.
1276 # If we're collapsing has_many prefetches it probably makes
1277 # very little difference, and this is cleaner than hacking
1278 # _construct_object to survive the approach
1279 my @row = $self->cursor->next;
1281 push(@obj, $self->_construct_object(@row));
1282 @row = (exists $self->{stashed_row}
1283 ? @{delete $self->{stashed_row}}
1284 : $self->cursor->next);
1287 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1290 $self->set_cache(\@obj) if $self->{attrs}{cache};
1298 =item Arguments: none
1300 =item Return Value: $self
1304 Resets the resultset's cursor, so you can iterate through the elements again.
1310 delete $self->{_attrs} if exists $self->{_attrs};
1311 $self->{all_cache_position} = 0;
1312 $self->cursor->reset;
1320 =item Arguments: none
1322 =item Return Value: $object?
1326 Resets the resultset and returns an object for the first result (if the
1327 resultset returns anything).
1332 return $_[0]->reset->next;
1336 # _update_delete_via_subq
1338 # Presence of some rs attributes requires a subquery to reliably
1342 sub _update_delete_via_subq {
1343 return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
1347 # _cond_for_update_delete
1349 # update/delete require the condition to be modified to handle
1350 # the differing SQL syntax available. This transforms the $self->{cond}
1351 # appropriately, returning the new condition.
1353 sub _cond_for_update_delete {
1354 my ($self, $full_cond) = @_;
1357 $full_cond ||= $self->{cond};
1358 # No-op. No condition, we're updating/deleting everything
1359 return $cond unless ref $full_cond;
1361 if (ref $full_cond eq 'ARRAY') {
1365 foreach my $key (keys %{$_}) {
1367 $hash{$1} = $_->{$key};
1373 elsif (ref $full_cond eq 'HASH') {
1374 if ((keys %{$full_cond})[0] eq '-and') {
1376 my @cond = @{$full_cond->{-and}};
1377 for (my $i = 0; $i < @cond; $i++) {
1378 my $entry = $cond[$i];
1380 if (ref $entry eq 'HASH') {
1381 $hash = $self->_cond_for_update_delete($entry);
1384 $entry =~ /([^.]+)$/;
1385 $hash->{$1} = $cond[++$i];
1387 push @{$cond->{-and}}, $hash;
1391 foreach my $key (keys %{$full_cond}) {
1393 $cond->{$1} = $full_cond->{$key};
1398 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1409 =item Arguments: \%values
1411 =item Return Value: $storage_rv
1415 Sets the specified columns in the resultset to the supplied values in a
1416 single query. Return value will be true if the update succeeded or false
1417 if no records were updated; exact type of success value is storage-dependent.
1422 my ($self, $values) = @_;
1423 $self->throw_exception('Values for update must be a hash')
1424 unless ref $values eq 'HASH';
1426 # rs operations with subqueries are Storage dependent - delegate
1427 if ($self->_update_delete_via_subq) {
1428 return $self->result_source->storage->subq_update_delete($self, 'update', $values);
1431 my $cond = $self->_cond_for_update_delete;
1433 return $self->result_source->storage->update(
1434 $self->result_source, $values, $cond
1442 =item Arguments: \%values
1444 =item Return Value: 1
1448 Fetches all objects and updates them one at a time. Note that C<update_all>
1449 will run DBIC cascade triggers, while L</update> will not.
1454 my ($self, $values) = @_;
1455 $self->throw_exception('Values for update_all must be a hash')
1456 unless ref $values eq 'HASH';
1457 foreach my $obj ($self->all) {
1458 $obj->set_columns($values)->update;
1467 =item Arguments: none
1469 =item Return Value: 1
1473 Deletes the contents of the resultset from its result source. Note that this
1474 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1475 to run. See also L<DBIx::Class::Row/delete>.
1477 delete may not generate correct SQL for a query with joins or a resultset
1478 chained from a related resultset. In this case it will generate a warning:-
1480 In these cases you may find that delete_all is more appropriate, or you
1481 need to respecify your query in a way that can be expressed without a join.
1487 $self->throw_exception('delete does not accept any arguments')
1490 # rs operations with subqueries are Storage dependent - delegate
1491 if ($self->_update_delete_via_subq) {
1492 return $self->result_source->storage->subq_update_delete($self, 'delete');
1495 my $cond = $self->_cond_for_update_delete;
1497 $self->result_source->storage->delete($self->result_source, $cond);
1505 =item Arguments: none
1507 =item Return Value: 1
1511 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1512 will run DBIC cascade triggers, while L</delete> will not.
1518 $self->throw_exception('delete_all does not accept any arguments')
1521 $_->delete for $self->all;
1529 =item Arguments: \@data;
1533 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1534 For the arrayref of hashrefs style each hashref should be a structure suitable
1535 forsubmitting to a $resultset->create(...) method.
1537 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1538 to insert the data, as this is a faster method.
1540 Otherwise, each set of data is inserted into the database using
1541 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1542 objects is returned.
1544 Example: Assuming an Artist Class that has many CDs Classes relating:
1546 my $Artist_rs = $schema->resultset("Artist");
1548 ## Void Context Example
1549 $Artist_rs->populate([
1550 { artistid => 4, name => 'Manufactured Crap', cds => [
1551 { title => 'My First CD', year => 2006 },
1552 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1555 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1556 { title => 'My parents sold me to a record company' ,year => 2005 },
1557 { title => 'Why Am I So Ugly?', year => 2006 },
1558 { title => 'I Got Surgery and am now Popular', year => 2007 }
1563 ## Array Context Example
1564 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1565 { name => "Artist One"},
1566 { name => "Artist Two"},
1567 { name => "Artist Three", cds=> [
1568 { title => "First CD", year => 2007},
1569 { title => "Second CD", year => 2008},
1573 print $ArtistOne->name; ## response is 'Artist One'
1574 print $ArtistThree->cds->count ## reponse is '2'
1576 For the arrayref of arrayrefs style, the first element should be a list of the
1577 fieldsnames to which the remaining elements are rows being inserted. For
1580 $Arstist_rs->populate([
1581 [qw/artistid name/],
1582 [100, 'A Formally Unknown Singer'],
1583 [101, 'A singer that jumped the shark two albums ago'],
1584 [102, 'An actually cool singer.'],
1587 Please note an important effect on your data when choosing between void and
1588 wantarray context. Since void context goes straight to C<insert_bulk> in
1589 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1590 C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1591 create primary keys for you, you will find that your PKs are empty. In this
1592 case you will have to use the wantarray context in order to create those
1598 my $self = shift @_;
1599 my $data = ref $_[0][0] eq 'HASH'
1600 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1601 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1603 if(defined wantarray) {
1605 foreach my $item (@$data) {
1606 push(@created, $self->create($item));
1610 my ($first, @rest) = @$data;
1612 my @names = grep {!ref $first->{$_}} keys %$first;
1613 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1614 my @pks = $self->result_source->primary_columns;
1616 ## do the belongs_to relationships
1617 foreach my $index (0..$#$data) {
1618 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1619 my @ret = $self->populate($data);
1623 foreach my $rel (@rels) {
1624 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1625 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1626 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1627 my $related = $result->result_source->_resolve_condition(
1628 $result->result_source->relationship_info($reverse)->{cond},
1633 delete $data->[$index]->{$rel};
1634 $data->[$index] = {%{$data->[$index]}, %$related};
1636 push @names, keys %$related if $index == 0;
1640 ## do bulk insert on current row
1641 my @values = map { [ @$_{@names} ] } @$data;
1643 $self->result_source->storage->insert_bulk(
1644 $self->result_source,
1649 ## do the has_many relationships
1650 foreach my $item (@$data) {
1652 foreach my $rel (@rels) {
1653 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1655 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1656 || $self->throw_exception('Cannot find the relating object.');
1658 my $child = $parent->$rel;
1660 my $related = $child->result_source->_resolve_condition(
1661 $parent->result_source->relationship_info($rel)->{cond},
1666 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1667 my @populate = map { {%$_, %$related} } @rows_to_add;
1669 $child->populate( \@populate );
1675 =head2 _normalize_populate_args ($args)
1677 Private method used by L</populate> to normalize its incoming arguments. Factored
1678 out in case you want to subclass and accept new argument structures to the
1679 L</populate> method.
1683 sub _normalize_populate_args {
1684 my ($self, $data) = @_;
1685 my @names = @{shift(@$data)};
1686 my @results_to_create;
1687 foreach my $datum (@$data) {
1688 my %result_to_create;
1689 foreach my $index (0..$#names) {
1690 $result_to_create{$names[$index]} = $$datum[$index];
1692 push @results_to_create, \%result_to_create;
1694 return \@results_to_create;
1701 =item Arguments: none
1703 =item Return Value: $pager
1707 Return Value a L<Data::Page> object for the current resultset. Only makes
1708 sense for queries with a C<page> attribute.
1710 To get the full count of entries for a paged resultset, call
1711 C<total_entries> on the L<Data::Page> object.
1718 return $self->{pager} if $self->{pager};
1720 my $attrs = $self->{attrs};
1721 $self->throw_exception("Can't create pager for non-paged rs")
1722 unless $self->{attrs}{page};
1723 $attrs->{rows} ||= 10;
1725 # throw away the paging flags and re-run the count (possibly
1726 # with a subselect) to get the real total count
1727 my $count_attrs = { %$attrs };
1728 delete $count_attrs->{$_} for qw/rows offset page pager/;
1729 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1731 return $self->{pager} = Data::Page->new(
1734 $self->{attrs}{page}
1742 =item Arguments: $page_number
1744 =item Return Value: $rs
1748 Returns a resultset for the $page_number page of the resultset on which page
1749 is called, where each page contains a number of rows equal to the 'rows'
1750 attribute set on the resultset (10 by default).
1755 my ($self, $page) = @_;
1756 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1763 =item Arguments: \%vals
1765 =item Return Value: $rowobject
1769 Creates a new row object in the resultset's result class and returns
1770 it. The row is not inserted into the database at this point, call
1771 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1772 will tell you whether the row object has been inserted or not.
1774 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1779 my ($self, $values) = @_;
1780 $self->throw_exception( "new_result needs a hash" )
1781 unless (ref $values eq 'HASH');
1784 my $alias = $self->{attrs}{alias};
1787 defined $self->{cond}
1788 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1790 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1791 $new{-from_resultset} = [ keys %new ] if keys %new;
1793 $self->throw_exception(
1794 "Can't abstract implicit construct, condition not a hash"
1795 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1797 my $collapsed_cond = (
1799 ? $self->_collapse_cond($self->{cond})
1803 # precendence must be given to passed values over values inherited from
1804 # the cond, so the order here is important.
1805 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1806 while( my($col,$value) = each %implied ){
1807 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1808 $new{$col} = $value->{'='};
1811 $new{$col} = $value if $self->_is_deterministic_value($value);
1817 %{ $self->_remove_alias($values, $alias) },
1818 -source_handle => $self->_source_handle,
1819 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1822 return $self->result_class->new(\%new);
1825 # _is_deterministic_value
1827 # Make an effor to strip non-deterministic values from the condition,
1828 # to make sure new_result chokes less
1830 sub _is_deterministic_value {
1833 my $ref_type = ref $value;
1834 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1835 return 1 if Scalar::Util::blessed($value);
1841 # determines if the resultset defines at least one
1842 # of the attributes supplied
1844 # used to determine if a subquery is neccessary
1847 my ($self, @attr_names) = @_;
1849 my $attrs = $self->_resolved_attrs;
1853 for my $n (@attr_names) {
1854 ++$join_check_req if $n =~ /join/;
1856 my $attr = $attrs->{$n};
1858 next if not defined $attr;
1860 if (ref $attr eq 'HASH') {
1861 return 1 if keys %$attr;
1863 elsif (ref $attr eq 'ARRAY') {
1871 # a join can be expressed as a multi-level from
1875 ref $attrs->{from} eq 'ARRAY'
1877 @{$attrs->{from}} > 1
1885 # Recursively collapse the condition.
1887 sub _collapse_cond {
1888 my ($self, $cond, $collapsed) = @_;
1892 if (ref $cond eq 'ARRAY') {
1893 foreach my $subcond (@$cond) {
1894 next unless ref $subcond; # -or
1895 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1898 elsif (ref $cond eq 'HASH') {
1899 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1900 foreach my $subcond (@{$cond->{-and}}) {
1901 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1905 foreach my $col (keys %$cond) {
1906 my $value = $cond->{$col};
1907 $collapsed->{$col} = $value;
1917 # Remove the specified alias from the specified query hash. A copy is made so
1918 # the original query is not modified.
1921 my ($self, $query, $alias) = @_;
1923 my %orig = %{ $query || {} };
1926 foreach my $key (keys %orig) {
1928 $unaliased{$key} = $orig{$key};
1931 $unaliased{$1} = $orig{$key}
1932 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1938 =head2 as_query (EXPERIMENTAL)
1942 =item Arguments: none
1944 =item Return Value: \[ $sql, @bind ]
1948 Returns the SQL query and bind vars associated with the invocant.
1950 This is generally used as the RHS for a subquery.
1952 B<NOTE>: This feature is still experimental.
1956 sub as_query { return shift->cursor->as_query(@_) }
1962 =item Arguments: \%vals, \%attrs?
1964 =item Return Value: $rowobject
1968 my $artist = $schema->resultset('Artist')->find_or_new(
1969 { artist => 'fred' }, { key => 'artists' });
1971 $cd->cd_to_producer->find_or_new({ producer => $producer },
1972 { key => 'primary });
1974 Find an existing record from this resultset, based on its primary
1975 key, or a unique constraint. If none exists, instantiate a new result
1976 object and return it. The object will not be saved into your storage
1977 until you call L<DBIx::Class::Row/insert> on it.
1979 You most likely want this method when looking for existing rows using
1980 a unique constraint that is not the primary key, or looking for
1983 If you want objects to be saved immediately, use L</find_or_create> instead.
1985 B<Note>: C<find_or_new> is probably not what you want when creating a
1986 new row in a table that uses primary keys supplied by the
1987 database. Passing in a primary key column with a value of I<undef>
1988 will cause L</find> to attempt to search for a row with a value of
1995 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1996 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1997 my $exists = $self->find($hash, $attrs);
1998 return defined $exists ? $exists : $self->new_result($hash);
2005 =item Arguments: \%vals
2007 =item Return Value: a L<DBIx::Class::Row> $object
2011 Attempt to create a single new row or a row with multiple related rows
2012 in the table represented by the resultset (and related tables). This
2013 will not check for duplicate rows before inserting, use
2014 L</find_or_create> to do that.
2016 To create one row for this resultset, pass a hashref of key/value
2017 pairs representing the columns of the table and the values you wish to
2018 store. If the appropriate relationships are set up, foreign key fields
2019 can also be passed an object representing the foreign row, and the
2020 value will be set to its primary key.
2022 To create related objects, pass a hashref for the value if the related
2023 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2024 and use the name of the relationship as the key. (NOT the name of the field,
2025 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2026 of hashrefs containing the data for each of the rows to create in the foreign
2027 tables, again using the relationship name as the key.
2029 Instead of hashrefs of plain related data (key/value pairs), you may
2030 also pass new or inserted objects. New objects (not inserted yet, see
2031 L</new>), will be inserted into their appropriate tables.
2033 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2035 Example of creating a new row.
2037 $person_rs->create({
2038 name=>"Some Person",
2039 email=>"somebody@someplace.com"
2042 Example of creating a new row and also creating rows in a related C<has_many>
2043 or C<has_one> resultset. Note Arrayref.
2046 { artistid => 4, name => 'Manufactured Crap', cds => [
2047 { title => 'My First CD', year => 2006 },
2048 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2053 Example of creating a new row and also creating a row in a related
2054 C<belongs_to>resultset. Note Hashref.
2057 title=>"Music for Silly Walks",
2060 name=>"Silly Musician",
2067 my ($self, $attrs) = @_;
2068 $self->throw_exception( "create needs a hashref" )
2069 unless ref $attrs eq 'HASH';
2070 return $self->new_result($attrs)->insert;
2073 =head2 find_or_create
2077 =item Arguments: \%vals, \%attrs?
2079 =item Return Value: $rowobject
2083 $cd->cd_to_producer->find_or_create({ producer => $producer },
2084 { key => 'primary });
2086 Tries to find a record based on its primary key or unique constraints; if none
2087 is found, creates one and returns that instead.
2089 my $cd = $schema->resultset('CD')->find_or_create({
2091 artist => 'Massive Attack',
2092 title => 'Mezzanine',
2096 Also takes an optional C<key> attribute, to search by a specific key or unique
2097 constraint. For example:
2099 my $cd = $schema->resultset('CD')->find_or_create(
2101 artist => 'Massive Attack',
2102 title => 'Mezzanine',
2104 { key => 'cd_artist_title' }
2107 B<Note>: Because find_or_create() reads from the database and then
2108 possibly inserts based on the result, this method is subject to a race
2109 condition. Another process could create a record in the table after
2110 the find has completed and before the create has started. To avoid
2111 this problem, use find_or_create() inside a transaction.
2113 B<Note>: C<find_or_create> is probably not what you want when creating
2114 a new row in a table that uses primary keys supplied by the
2115 database. Passing in a primary key column with a value of I<undef>
2116 will cause L</find> to attempt to search for a row with a value of
2119 See also L</find> and L</update_or_create>. For information on how to declare
2120 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2124 sub find_or_create {
2126 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2127 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2128 my $exists = $self->find($hash, $attrs);
2129 return defined $exists ? $exists : $self->create($hash);
2132 =head2 update_or_create
2136 =item Arguments: \%col_values, { key => $unique_constraint }?
2138 =item Return Value: $rowobject
2142 $resultset->update_or_create({ col => $val, ... });
2144 First, searches for an existing row matching one of the unique constraints
2145 (including the primary key) on the source of this resultset. If a row is
2146 found, updates it with the other given column values. Otherwise, creates a new
2149 Takes an optional C<key> attribute to search on a specific unique constraint.
2152 # In your application
2153 my $cd = $schema->resultset('CD')->update_or_create(
2155 artist => 'Massive Attack',
2156 title => 'Mezzanine',
2159 { key => 'cd_artist_title' }
2162 $cd->cd_to_producer->update_or_create({
2163 producer => $producer,
2170 If no C<key> is specified, it searches on all unique constraints defined on the
2171 source, including the primary key.
2173 If the C<key> is specified as C<primary>, it searches only on the primary key.
2175 See also L</find> and L</find_or_create>. For information on how to declare
2176 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2178 B<Note>: C<update_or_create> is probably not what you want when
2179 looking for a row in a table that uses primary keys supplied by the
2180 database, unless you actually have a key value. Passing in a primary
2181 key column with a value of I<undef> will cause L</find> to attempt to
2182 search for a row with a value of I<NULL>.
2186 sub update_or_create {
2188 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2189 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2191 my $row = $self->find($cond, $attrs);
2193 $row->update($cond);
2197 return $self->create($cond);
2200 =head2 update_or_new
2204 =item Arguments: \%col_values, { key => $unique_constraint }?
2206 =item Return Value: $rowobject
2210 $resultset->update_or_new({ col => $val, ... });
2212 First, searches for an existing row matching one of the unique constraints
2213 (including the primary key) on the source of this resultset. If a row is
2214 found, updates it with the other given column values. Otherwise, instantiate
2215 a new result object and return it. The object will not be saved into your storage
2216 until you call L<DBIx::Class::Row/insert> on it.
2218 Takes an optional C<key> attribute to search on a specific unique constraint.
2221 # In your application
2222 my $cd = $schema->resultset('CD')->update_or_new(
2224 artist => 'Massive Attack',
2225 title => 'Mezzanine',
2228 { key => 'cd_artist_title' }
2231 if ($cd->in_storage) {
2232 # the cd was updated
2235 # the cd is not yet in the database, let's insert it
2239 See also L</find>, L</find_or_create> and L<find_or_new>.
2245 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2246 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2248 my $row = $self->find( $cond, $attrs );
2249 if ( defined $row ) {
2250 $row->update($cond);
2254 return $self->new_result($cond);
2261 =item Arguments: none
2263 =item Return Value: \@cache_objects?
2267 Gets the contents of the cache for the resultset, if the cache is set.
2269 The cache is populated either by using the L</prefetch> attribute to
2270 L</search> or by calling L</set_cache>.
2282 =item Arguments: \@cache_objects
2284 =item Return Value: \@cache_objects
2288 Sets the contents of the cache for the resultset. Expects an arrayref
2289 of objects of the same class as those produced by the resultset. Note that
2290 if the cache is set the resultset will return the cached objects rather
2291 than re-querying the database even if the cache attr is not set.
2293 The contents of the cache can also be populated by using the
2294 L</prefetch> attribute to L</search>.
2299 my ( $self, $data ) = @_;
2300 $self->throw_exception("set_cache requires an arrayref")
2301 if defined($data) && (ref $data ne 'ARRAY');
2302 $self->{all_cache} = $data;
2309 =item Arguments: none
2311 =item Return Value: []
2315 Clears the cache for the resultset.
2320 shift->set_cache(undef);
2323 =head2 related_resultset
2327 =item Arguments: $relationship_name
2329 =item Return Value: $resultset
2333 Returns a related resultset for the supplied relationship name.
2335 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2339 sub related_resultset {
2340 my ($self, $rel) = @_;
2342 $self->{related_resultsets} ||= {};
2343 return $self->{related_resultsets}{$rel} ||= do {
2344 my $rel_obj = $self->result_source->relationship_info($rel);
2346 $self->throw_exception(
2347 "search_related: result source '" . $self->result_source->source_name .
2348 "' has no such relationship $rel")
2351 my ($from,$seen) = $self->_resolve_from($rel);
2353 my $join_count = $seen->{$rel};
2354 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2356 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2357 my %attrs = %{$self->{attrs}||{}};
2358 delete @attrs{qw(result_class alias)};
2362 if (my $cache = $self->get_cache) {
2363 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2364 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2369 my $rel_source = $self->result_source->related_source($rel);
2373 # The reason we do this now instead of passing the alias to the
2374 # search_rs below is that if you wrap/overload resultset on the
2375 # source you need to know what alias it's -going- to have for things
2376 # to work sanely (e.g. RestrictWithObject wants to be able to add
2377 # extra query restrictions, and these may need to be $alias.)
2379 my $attrs = $rel_source->resultset_attributes;
2380 local $attrs->{alias} = $alias;
2382 $rel_source->resultset
2390 where => $self->{cond},
2395 $new->set_cache($new_cache) if $new_cache;
2400 =head2 current_source_alias
2404 =item Arguments: none
2406 =item Return Value: $source_alias
2410 Returns the current table alias for the result source this resultset is built
2411 on, that will be used in the SQL query. Usually it is C<me>.
2413 Currently the source alias that refers to the result set returned by a
2414 L</search>/L</find> family method depends on how you got to the resultset: it's
2415 C<me> by default, but eg. L</search_related> aliases it to the related result
2416 source name (and keeps C<me> referring to the original result set). The long
2417 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2418 (and make this method unnecessary).
2420 Thus it's currently necessary to use this method in predefined queries (see
2421 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2422 source alias of the current result set:
2424 # in a result set class
2426 my ($self, $user) = @_;
2428 my $me = $self->current_source_alias;
2430 return $self->search(
2431 "$me.modified" => $user->id,
2437 sub current_source_alias {
2440 return ($self->{attrs} || {})->{alias} || 'me';
2443 # This code is called by search_related, and makes sure there
2444 # is clear separation between the joins before, during, and
2445 # after the relationship. This information is needed later
2446 # in order to properly resolve prefetch aliases (any alias
2447 # with a relation_chain_depth less than the depth of the
2448 # current prefetch is not considered)
2450 my ($self, $extra_join) = @_;
2451 my $source = $self->result_source;
2452 my $attrs = $self->{attrs};
2454 my $from = $attrs->{from}
2455 || [ { $attrs->{alias} => $source->from } ];
2457 my $seen = { %{$attrs->{seen_join}||{}} };
2459 # we need to take the prefetch the attrs into account before we
2460 # ->_resolve_join as otherwise they get lost - captainL
2461 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2463 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2465 ++$seen->{-relation_chain_depth};
2467 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2469 ++$seen->{-relation_chain_depth};
2471 return ($from,$seen);
2474 sub _resolved_attrs {
2476 return $self->{_attrs} if $self->{_attrs};
2478 my $attrs = { %{ $self->{attrs} || {} } };
2479 my $source = $self->result_source;
2480 my $alias = $attrs->{alias};
2482 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2485 # build columns (as long as select isn't set) into a set of as/select hashes
2486 unless ( $attrs->{select} ) {
2488 ( ref($_) eq 'HASH' )
2492 /^\Q${alias}.\E(.+)$/
2503 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2505 # add the additional columns on
2506 foreach ( 'include_columns', '+columns' ) {
2507 push @colbits, map {
2508 ( ref($_) eq 'HASH' )
2510 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2511 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2514 # start with initial select items
2515 if ( $attrs->{select} ) {
2517 ( ref $attrs->{select} eq 'ARRAY' )
2518 ? [ @{ $attrs->{select} } ]
2519 : [ $attrs->{select} ];
2523 ref $attrs->{as} eq 'ARRAY'
2524 ? [ @{ $attrs->{as} } ]
2527 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2532 # otherwise we intialise select & as to empty
2533 $attrs->{select} = [];
2537 # now add colbits to select/as
2538 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2539 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2542 if ( $adds = delete $attrs->{'+select'} ) {
2543 $adds = [$adds] unless ref $adds eq 'ARRAY';
2545 @{ $attrs->{select} },
2546 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2549 if ( $adds = delete $attrs->{'+as'} ) {
2550 $adds = [$adds] unless ref $adds eq 'ARRAY';
2551 push( @{ $attrs->{as} }, @$adds );
2554 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2556 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2557 my $join = delete $attrs->{join} || {};
2559 if ( defined $attrs->{prefetch} ) {
2560 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2564 $attrs->{from} = # have to copy here to avoid corrupting the original
2566 @{ $attrs->{from} },
2567 $source->_resolve_join(
2568 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2574 $attrs->{group_by} ||= $attrs->{select}
2575 if delete $attrs->{distinct};
2576 if ( $attrs->{order_by} ) {
2577 $attrs->{order_by} = (
2578 ref( $attrs->{order_by} ) eq 'ARRAY'
2579 ? [ @{ $attrs->{order_by} } ]
2580 : [ $attrs->{order_by} ]
2584 $attrs->{order_by} = [];
2587 my $collapse = $attrs->{collapse} || {};
2588 if ( my $prefetch = delete $attrs->{prefetch} ) {
2589 $prefetch = $self->_merge_attr( {}, $prefetch );
2591 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2593 # bring joins back to level of current class
2594 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2596 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2597 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2598 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2600 push( @{ $attrs->{order_by} }, @pre_order );
2602 $attrs->{collapse} = $collapse;
2604 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2605 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2608 return $self->{_attrs} = $attrs;
2611 sub _joinpath_aliases {
2612 my ($self, $fromspec, $seen) = @_;
2615 return $paths unless ref $fromspec eq 'ARRAY';
2617 for my $j (@$fromspec) {
2619 next if ref $j ne 'ARRAY';
2620 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2623 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2624 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2631 my ($self, $attr) = @_;
2633 if (ref $attr eq 'HASH') {
2634 return $self->_rollout_hash($attr);
2635 } elsif (ref $attr eq 'ARRAY') {
2636 return $self->_rollout_array($attr);
2642 sub _rollout_array {
2643 my ($self, $attr) = @_;
2646 foreach my $element (@{$attr}) {
2647 if (ref $element eq 'HASH') {
2648 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2649 } elsif (ref $element eq 'ARRAY') {
2650 # XXX - should probably recurse here
2651 push( @rolled_array, @{$self->_rollout_array($element)} );
2653 push( @rolled_array, $element );
2656 return \@rolled_array;
2660 my ($self, $attr) = @_;
2663 foreach my $key (keys %{$attr}) {
2664 push( @rolled_array, { $key => $attr->{$key} } );
2666 return \@rolled_array;
2669 sub _calculate_score {
2670 my ($self, $a, $b) = @_;
2672 if (ref $b eq 'HASH') {
2673 my ($b_key) = keys %{$b};
2674 if (ref $a eq 'HASH') {
2675 my ($a_key) = keys %{$a};
2676 if ($a_key eq $b_key) {
2677 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2682 return ($a eq $b_key) ? 1 : 0;
2685 if (ref $a eq 'HASH') {
2686 my ($a_key) = keys %{$a};
2687 return ($b eq $a_key) ? 1 : 0;
2689 return ($b eq $a) ? 1 : 0;
2695 my ($self, $orig, $import) = @_;
2697 return $import unless defined($orig);
2698 return $orig unless defined($import);
2700 $orig = $self->_rollout_attr($orig);
2701 $import = $self->_rollout_attr($import);
2704 foreach my $import_element ( @{$import} ) {
2705 # find best candidate from $orig to merge $b_element into
2706 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2707 foreach my $orig_element ( @{$orig} ) {
2708 my $score = $self->_calculate_score( $orig_element, $import_element );
2709 if ($score > $best_candidate->{score}) {
2710 $best_candidate->{position} = $position;
2711 $best_candidate->{score} = $score;
2715 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2717 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2718 push( @{$orig}, $import_element );
2720 my $orig_best = $orig->[$best_candidate->{position}];
2721 # merge orig_best and b_element together and replace original with merged
2722 if (ref $orig_best ne 'HASH') {
2723 $orig->[$best_candidate->{position}] = $import_element;
2724 } elsif (ref $import_element eq 'HASH') {
2725 my ($key) = keys %{$orig_best};
2726 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2729 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2739 $self->_source_handle($_[0]->handle);
2741 $self->_source_handle->resolve;
2745 =head2 throw_exception
2747 See L<DBIx::Class::Schema/throw_exception> for details.
2751 sub throw_exception {
2753 if (ref $self && $self->_source_handle->schema) {
2754 $self->_source_handle->schema->throw_exception(@_)
2761 # XXX: FIXME: Attributes docs need clearing up
2765 Attributes are used to refine a ResultSet in various ways when
2766 searching for data. They can be passed to any method which takes an
2767 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2770 These are in no particular order:
2776 =item Value: ( $order_by | \@order_by | \%order_by )
2780 Which column(s) to order the results by. If a single column name, or
2781 an arrayref of names is supplied, the argument is passed through
2782 directly to SQL. The hashref syntax allows for connection-agnostic
2783 specification of ordering direction:
2785 For descending order:
2787 order_by => { -desc => [qw/col1 col2 col3/] }
2789 For explicit ascending order:
2791 order_by => { -asc => 'col' }
2793 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2794 supported, although you are strongly encouraged to use the hashref
2795 syntax as outlined above.
2801 =item Value: \@columns
2805 Shortcut to request a particular set of columns to be retrieved. Each
2806 column spec may be a string (a table column name), or a hash (in which
2807 case the key is the C<as> value, and the value is used as the C<select>
2808 expression). Adds C<me.> onto the start of any column without a C<.> in
2809 it and sets C<select> from that, then auto-populates C<as> from
2810 C<select> as normal. (You may also use the C<cols> attribute, as in
2811 earlier versions of DBIC.)
2817 =item Value: \@columns
2821 Indicates additional columns to be selected from storage. Works the same
2822 as L</columns> but adds columns to the selection. (You may also use the
2823 C<include_columns> attribute, as in earlier versions of DBIC). For
2826 $schema->resultset('CD')->search(undef, {
2827 '+columns' => ['artist.name'],
2831 would return all CDs and include a 'name' column to the information
2832 passed to object inflation. Note that the 'artist' is the name of the
2833 column (or relationship) accessor, and 'name' is the name of the column
2834 accessor in the related table.
2836 =head2 include_columns
2840 =item Value: \@columns
2844 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2850 =item Value: \@select_columns
2854 Indicates which columns should be selected from the storage. You can use
2855 column names, or in the case of RDBMS back ends, function or stored procedure
2858 $rs = $schema->resultset('Employee')->search(undef, {
2861 { count => 'employeeid' },
2866 When you use function/stored procedure names and do not supply an C<as>
2867 attribute, the column names returned are storage-dependent. E.g. MySQL would
2868 return a column named C<count(employeeid)> in the above example.
2874 Indicates additional columns to be selected from storage. Works the same as
2875 L</select> but adds columns to the selection.
2883 Indicates additional column names for those added via L</+select>. See L</as>.
2891 =item Value: \@inflation_names
2895 Indicates column names for object inflation. That is, C<as>
2896 indicates the name that the column can be accessed as via the
2897 C<get_column> method (or via the object accessor, B<if one already
2898 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2900 The C<as> attribute is used in conjunction with C<select>,
2901 usually when C<select> contains one or more function or stored
2904 $rs = $schema->resultset('Employee')->search(undef, {
2907 { count => 'employeeid' }
2909 as => ['name', 'employee_count'],
2912 my $employee = $rs->first(); # get the first Employee
2914 If the object against which the search is performed already has an accessor
2915 matching a column name specified in C<as>, the value can be retrieved using
2916 the accessor as normal:
2918 my $name = $employee->name();
2920 If on the other hand an accessor does not exist in the object, you need to
2921 use C<get_column> instead:
2923 my $employee_count = $employee->get_column('employee_count');
2925 You can create your own accessors if required - see
2926 L<DBIx::Class::Manual::Cookbook> for details.
2928 Please note: This will NOT insert an C<AS employee_count> into the SQL
2929 statement produced, it is used for internal access only. Thus
2930 attempting to use the accessor in an C<order_by> clause or similar
2931 will fail miserably.
2933 To get around this limitation, you can supply literal SQL to your
2934 C<select> attibute that contains the C<AS alias> text, eg:
2936 select => [\'myfield AS alias']
2942 =item Value: ($rel_name | \@rel_names | \%rel_names)
2946 Contains a list of relationships that should be joined for this query. For
2949 # Get CDs by Nine Inch Nails
2950 my $rs = $schema->resultset('CD')->search(
2951 { 'artist.name' => 'Nine Inch Nails' },
2952 { join => 'artist' }
2955 Can also contain a hash reference to refer to the other relation's relations.
2958 package MyApp::Schema::Track;
2959 use base qw/DBIx::Class/;
2960 __PACKAGE__->table('track');
2961 __PACKAGE__->add_columns(qw/trackid cd position title/);
2962 __PACKAGE__->set_primary_key('trackid');
2963 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2966 # In your application
2967 my $rs = $schema->resultset('Artist')->search(
2968 { 'track.title' => 'Teardrop' },
2970 join => { cd => 'track' },
2971 order_by => 'artist.name',
2975 You need to use the relationship (not the table) name in conditions,
2976 because they are aliased as such. The current table is aliased as "me", so
2977 you need to use me.column_name in order to avoid ambiguity. For example:
2979 # Get CDs from 1984 with a 'Foo' track
2980 my $rs = $schema->resultset('CD')->search(
2983 'tracks.name' => 'Foo'
2985 { join => 'tracks' }
2988 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2989 similarly for a third time). For e.g.
2991 my $rs = $schema->resultset('Artist')->search({
2992 'cds.title' => 'Down to Earth',
2993 'cds_2.title' => 'Popular',
2995 join => [ qw/cds cds/ ],
2998 will return a set of all artists that have both a cd with title 'Down
2999 to Earth' and a cd with title 'Popular'.
3001 If you want to fetch related objects from other tables as well, see C<prefetch>
3004 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
3010 =item Value: ($rel_name | \@rel_names | \%rel_names)
3014 Contains one or more relationships that should be fetched along with
3015 the main query (when they are accessed afterwards the data will
3016 already be available, without extra queries to the database). This is
3017 useful for when you know you will need the related objects, because it
3018 saves at least one query:
3020 my $rs = $schema->resultset('Tag')->search(
3029 The initial search results in SQL like the following:
3031 SELECT tag.*, cd.*, artist.* FROM tag
3032 JOIN cd ON tag.cd = cd.cdid
3033 JOIN artist ON cd.artist = artist.artistid
3035 L<DBIx::Class> has no need to go back to the database when we access the
3036 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3039 Simple prefetches will be joined automatically, so there is no need
3040 for a C<join> attribute in the above search.
3042 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3043 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3044 with an accessor type of 'single' or 'filter'). A more complex example that
3045 prefetches an artists cds, the tracks on those cds, and the tags associted
3046 with that artist is given below (assuming many-to-many from artists to tags):
3048 my $rs = $schema->resultset('Artist')->search(
3052 { cds => 'tracks' },
3053 { artist_tags => 'tags' }
3059 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3060 attributes will be ignored.
3070 Makes the resultset paged and specifies the page to retrieve. Effectively
3071 identical to creating a non-pages resultset and then calling ->page($page)
3074 If L<rows> attribute is not specified it defualts to 10 rows per page.
3076 When you have a paged resultset, L</count> will only return the number
3077 of rows in the page. To get the total, use the L</pager> and call
3078 C<total_entries> on it.
3088 Specifes the maximum number of rows for direct retrieval or the number of
3089 rows per page if the page attribute or method is used.
3095 =item Value: $offset
3099 Specifies the (zero-based) row number for the first row to be returned, or the
3100 of the first row of the first page if paging is used.
3106 =item Value: \@columns
3110 A arrayref of columns to group by. Can include columns of joined tables.
3112 group_by => [qw/ column1 column2 ... /]
3118 =item Value: $condition
3122 HAVING is a select statement attribute that is applied between GROUP BY and
3123 ORDER BY. It is applied to the after the grouping calculations have been
3126 having => { 'count(employee)' => { '>=', 100 } }
3132 =item Value: (0 | 1)
3136 Set to 1 to group by all columns.
3142 Adds to the WHERE clause.
3144 # only return rows WHERE deleted IS NULL for all searches
3145 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3147 Can be overridden by passing C<{ where => undef }> as an attribute
3154 Set to 1 to cache search results. This prevents extra SQL queries if you
3155 revisit rows in your ResultSet:
3157 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3159 while( my $artist = $resultset->next ) {
3163 $rs->first; # without cache, this would issue a query
3165 By default, searches are not cached.
3167 For more examples of using these attributes, see
3168 L<DBIx::Class::Manual::Cookbook>.
3174 =item Value: \@from_clause
3178 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3179 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3182 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3184 C<join> will usually do what you need and it is strongly recommended that you
3185 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3186 And we really do mean "cannot", not just tried and failed. Attempting to use
3187 this because you're having problems with C<join> is like trying to use x86
3188 ASM because you've got a syntax error in your C. Trust us on this.
3190 Now, if you're still really, really sure you need to use this (and if you're
3191 not 100% sure, ask the mailing list first), here's an explanation of how this
3194 The syntax is as follows -
3197 { <alias1> => <table1> },
3199 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3200 [], # nested JOIN (optional)
3201 { <table1.column1> => <table2.column2>, ... (more conditions) },
3203 # More of the above [ ] may follow for additional joins
3210 ON <table1.column1> = <table2.column2>
3211 <more joins may follow>
3213 An easy way to follow the examples below is to remember the following:
3215 Anything inside "[]" is a JOIN
3216 Anything inside "{}" is a condition for the enclosing JOIN
3218 The following examples utilize a "person" table in a family tree application.
3219 In order to express parent->child relationships, this table is self-joined:
3221 # Person->belongs_to('father' => 'Person');
3222 # Person->belongs_to('mother' => 'Person');
3224 C<from> can be used to nest joins. Here we return all children with a father,
3225 then search against all mothers of those children:
3227 $rs = $schema->resultset('Person')->search(
3230 alias => 'mother', # alias columns in accordance with "from"
3232 { mother => 'person' },
3235 { child => 'person' },
3237 { father => 'person' },
3238 { 'father.person_id' => 'child.father_id' }
3241 { 'mother.person_id' => 'child.mother_id' }
3248 # SELECT mother.* FROM person mother
3251 # JOIN person father
3252 # ON ( father.person_id = child.father_id )
3254 # ON ( mother.person_id = child.mother_id )
3256 The type of any join can be controlled manually. To search against only people
3257 with a father in the person table, we could explicitly use C<INNER JOIN>:
3259 $rs = $schema->resultset('Person')->search(
3262 alias => 'child', # alias columns in accordance with "from"
3264 { child => 'person' },
3266 { father => 'person', -join_type => 'inner' },
3267 { 'father.id' => 'child.father_id' }
3274 # SELECT child.* FROM person child
3275 # INNER JOIN person father ON child.father_id = father.id
3277 If you need to express really complex joins or you need a subselect, you
3278 can supply literal SQL to C<from> via a scalar reference. In this case
3279 the contents of the scalar will replace the table name asscoiated with the
3282 WARNING: This technique might very well not work as expected on chained
3283 searches - you have been warned.
3285 # Assuming the Event resultsource is defined as:
3287 MySchema::Event->add_columns (
3290 is_auto_increment => 1,
3299 MySchema::Event->set_primary_key ('sequence');
3301 # This will get back the latest event for every location. The column
3302 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3303 # combo to limit the resultset
3305 $rs = $schema->resultset('Event');
3306 $table = $rs->result_source->name;
3307 $latest = $rs->search (
3310 (SELECT e1.* FROM $table e1
3312 ON e1.location = e2.location
3313 AND e1.sequence < e2.sequence
3314 WHERE e2.sequence is NULL
3319 # Equivalent SQL (with the DBIC chunks added):
3321 SELECT me.sequence, me.location, me.type FROM
3322 (SELECT e1.* FROM events e1
3324 ON e1.location = e2.location
3325 AND e1.sequence < e2.sequence
3326 WHERE e2.sequence is NULL
3333 =item Value: ( 'update' | 'shared' )
3337 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT