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 having/;
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 # these are the only attributes that actually matter for count
1216 $attrs = { map { exists $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () } qw/where bind alias from from_bind/ };
1218 $attrs->{select} = { count => '*' };
1219 $attrs->{as} = [qw/count/];
1221 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1222 my ($count) = $tmp_rs->cursor->next;
1231 =head2 count_literal
1235 =item Arguments: $sql_fragment, @bind_values
1237 =item Return Value: $count
1241 Counts the results in a literal query. Equivalent to calling L</search_literal>
1242 with the passed arguments, then L</count>.
1246 sub count_literal { shift->search_literal(@_)->count; }
1252 =item Arguments: none
1254 =item Return Value: @objects
1258 Returns all elements in the resultset. Called implicitly if the resultset
1259 is returned in list context.
1266 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1269 return @{ $self->get_cache } if $self->get_cache;
1273 # TODO: don't call resolve here
1274 if (keys %{$self->_resolved_attrs->{collapse}}) {
1275 # if ($self->{attrs}{prefetch}) {
1276 # Using $self->cursor->all is really just an optimisation.
1277 # If we're collapsing has_many prefetches it probably makes
1278 # very little difference, and this is cleaner than hacking
1279 # _construct_object to survive the approach
1280 my @row = $self->cursor->next;
1282 push(@obj, $self->_construct_object(@row));
1283 @row = (exists $self->{stashed_row}
1284 ? @{delete $self->{stashed_row}}
1285 : $self->cursor->next);
1288 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1291 $self->set_cache(\@obj) if $self->{attrs}{cache};
1299 =item Arguments: none
1301 =item Return Value: $self
1305 Resets the resultset's cursor, so you can iterate through the elements again.
1311 delete $self->{_attrs} if exists $self->{_attrs};
1312 $self->{all_cache_position} = 0;
1313 $self->cursor->reset;
1321 =item Arguments: none
1323 =item Return Value: $object?
1327 Resets the resultset and returns an object for the first result (if the
1328 resultset returns anything).
1333 return $_[0]->reset->next;
1337 # _update_delete_via_subq
1339 # Presence of some rs attributes requires a subquery to reliably
1343 sub _update_delete_via_subq {
1344 return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
1348 # _cond_for_update_delete
1350 # update/delete require the condition to be modified to handle
1351 # the differing SQL syntax available. This transforms the $self->{cond}
1352 # appropriately, returning the new condition.
1354 sub _cond_for_update_delete {
1355 my ($self, $full_cond) = @_;
1358 $full_cond ||= $self->{cond};
1359 # No-op. No condition, we're updating/deleting everything
1360 return $cond unless ref $full_cond;
1362 if (ref $full_cond eq 'ARRAY') {
1366 foreach my $key (keys %{$_}) {
1368 $hash{$1} = $_->{$key};
1374 elsif (ref $full_cond eq 'HASH') {
1375 if ((keys %{$full_cond})[0] eq '-and') {
1377 my @cond = @{$full_cond->{-and}};
1378 for (my $i = 0; $i < @cond; $i++) {
1379 my $entry = $cond[$i];
1381 if (ref $entry eq 'HASH') {
1382 $hash = $self->_cond_for_update_delete($entry);
1385 $entry =~ /([^.]+)$/;
1386 $hash->{$1} = $cond[++$i];
1388 push @{$cond->{-and}}, $hash;
1392 foreach my $key (keys %{$full_cond}) {
1394 $cond->{$1} = $full_cond->{$key};
1399 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1410 =item Arguments: \%values
1412 =item Return Value: $storage_rv
1416 Sets the specified columns in the resultset to the supplied values in a
1417 single query. Return value will be true if the update succeeded or false
1418 if no records were updated; exact type of success value is storage-dependent.
1423 my ($self, $values) = @_;
1424 $self->throw_exception('Values for update must be a hash')
1425 unless ref $values eq 'HASH';
1427 # rs operations with subqueries are Storage dependent - delegate
1428 if ($self->_update_delete_via_subq) {
1429 return $self->result_source->storage->subq_update_delete($self, 'update', $values);
1432 my $cond = $self->_cond_for_update_delete;
1434 return $self->result_source->storage->update(
1435 $self->result_source, $values, $cond
1443 =item Arguments: \%values
1445 =item Return Value: 1
1449 Fetches all objects and updates them one at a time. Note that C<update_all>
1450 will run DBIC cascade triggers, while L</update> will not.
1455 my ($self, $values) = @_;
1456 $self->throw_exception('Values for update_all must be a hash')
1457 unless ref $values eq 'HASH';
1458 foreach my $obj ($self->all) {
1459 $obj->set_columns($values)->update;
1468 =item Arguments: none
1470 =item Return Value: 1
1474 Deletes the contents of the resultset from its result source. Note that this
1475 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1476 to run. See also L<DBIx::Class::Row/delete>.
1478 delete may not generate correct SQL for a query with joins or a resultset
1479 chained from a related resultset. In this case it will generate a warning:-
1481 In these cases you may find that delete_all is more appropriate, or you
1482 need to respecify your query in a way that can be expressed without a join.
1488 $self->throw_exception('delete does not accept any arguments')
1491 # rs operations with subqueries are Storage dependent - delegate
1492 if ($self->_update_delete_via_subq) {
1493 return $self->result_source->storage->subq_update_delete($self, 'delete');
1496 my $cond = $self->_cond_for_update_delete;
1498 $self->result_source->storage->delete($self->result_source, $cond);
1506 =item Arguments: none
1508 =item Return Value: 1
1512 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1513 will run DBIC cascade triggers, while L</delete> will not.
1519 $self->throw_exception('delete_all does not accept any arguments')
1522 $_->delete for $self->all;
1530 =item Arguments: \@data;
1534 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1535 For the arrayref of hashrefs style each hashref should be a structure suitable
1536 forsubmitting to a $resultset->create(...) method.
1538 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1539 to insert the data, as this is a faster method.
1541 Otherwise, each set of data is inserted into the database using
1542 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1543 objects is returned.
1545 Example: Assuming an Artist Class that has many CDs Classes relating:
1547 my $Artist_rs = $schema->resultset("Artist");
1549 ## Void Context Example
1550 $Artist_rs->populate([
1551 { artistid => 4, name => 'Manufactured Crap', cds => [
1552 { title => 'My First CD', year => 2006 },
1553 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1556 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1557 { title => 'My parents sold me to a record company' ,year => 2005 },
1558 { title => 'Why Am I So Ugly?', year => 2006 },
1559 { title => 'I Got Surgery and am now Popular', year => 2007 }
1564 ## Array Context Example
1565 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1566 { name => "Artist One"},
1567 { name => "Artist Two"},
1568 { name => "Artist Three", cds=> [
1569 { title => "First CD", year => 2007},
1570 { title => "Second CD", year => 2008},
1574 print $ArtistOne->name; ## response is 'Artist One'
1575 print $ArtistThree->cds->count ## reponse is '2'
1577 For the arrayref of arrayrefs style, the first element should be a list of the
1578 fieldsnames to which the remaining elements are rows being inserted. For
1581 $Arstist_rs->populate([
1582 [qw/artistid name/],
1583 [100, 'A Formally Unknown Singer'],
1584 [101, 'A singer that jumped the shark two albums ago'],
1585 [102, 'An actually cool singer.'],
1588 Please note an important effect on your data when choosing between void and
1589 wantarray context. Since void context goes straight to C<insert_bulk> in
1590 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1591 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1592 create primary keys for you, you will find that your PKs are empty. In this
1593 case you will have to use the wantarray context in order to create those
1599 my $self = shift @_;
1600 my $data = ref $_[0][0] eq 'HASH'
1601 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1602 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1604 if(defined wantarray) {
1606 foreach my $item (@$data) {
1607 push(@created, $self->create($item));
1611 my ($first, @rest) = @$data;
1613 my @names = grep {!ref $first->{$_}} keys %$first;
1614 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1615 my @pks = $self->result_source->primary_columns;
1617 ## do the belongs_to relationships
1618 foreach my $index (0..$#$data) {
1619 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1620 my @ret = $self->populate($data);
1624 foreach my $rel (@rels) {
1625 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1626 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1627 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1628 my $related = $result->result_source->_resolve_condition(
1629 $result->result_source->relationship_info($reverse)->{cond},
1634 delete $data->[$index]->{$rel};
1635 $data->[$index] = {%{$data->[$index]}, %$related};
1637 push @names, keys %$related if $index == 0;
1641 ## do bulk insert on current row
1642 my @values = map { [ @$_{@names} ] } @$data;
1644 $self->result_source->storage->insert_bulk(
1645 $self->result_source,
1650 ## do the has_many relationships
1651 foreach my $item (@$data) {
1653 foreach my $rel (@rels) {
1654 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1656 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1657 || $self->throw_exception('Cannot find the relating object.');
1659 my $child = $parent->$rel;
1661 my $related = $child->result_source->_resolve_condition(
1662 $parent->result_source->relationship_info($rel)->{cond},
1667 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1668 my @populate = map { {%$_, %$related} } @rows_to_add;
1670 $child->populate( \@populate );
1676 =head2 _normalize_populate_args ($args)
1678 Private method used by L</populate> to normalize its incoming arguments. Factored
1679 out in case you want to subclass and accept new argument structures to the
1680 L</populate> method.
1684 sub _normalize_populate_args {
1685 my ($self, $data) = @_;
1686 my @names = @{shift(@$data)};
1687 my @results_to_create;
1688 foreach my $datum (@$data) {
1689 my %result_to_create;
1690 foreach my $index (0..$#names) {
1691 $result_to_create{$names[$index]} = $$datum[$index];
1693 push @results_to_create, \%result_to_create;
1695 return \@results_to_create;
1702 =item Arguments: none
1704 =item Return Value: $pager
1708 Return Value a L<Data::Page> object for the current resultset. Only makes
1709 sense for queries with a C<page> attribute.
1711 To get the full count of entries for a paged resultset, call
1712 C<total_entries> on the L<Data::Page> object.
1719 return $self->{pager} if $self->{pager};
1721 my $attrs = $self->{attrs};
1722 $self->throw_exception("Can't create pager for non-paged rs")
1723 unless $self->{attrs}{page};
1724 $attrs->{rows} ||= 10;
1726 # throw away the paging flags and re-run the count (possibly
1727 # with a subselect) to get the real total count
1728 my $count_attrs = { %$attrs };
1729 delete $count_attrs->{$_} for qw/rows offset page pager/;
1730 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1732 return $self->{pager} = Data::Page->new(
1735 $self->{attrs}{page}
1743 =item Arguments: $page_number
1745 =item Return Value: $rs
1749 Returns a resultset for the $page_number page of the resultset on which page
1750 is called, where each page contains a number of rows equal to the 'rows'
1751 attribute set on the resultset (10 by default).
1756 my ($self, $page) = @_;
1757 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1764 =item Arguments: \%vals
1766 =item Return Value: $rowobject
1770 Creates a new row object in the resultset's result class and returns
1771 it. The row is not inserted into the database at this point, call
1772 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1773 will tell you whether the row object has been inserted or not.
1775 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1780 my ($self, $values) = @_;
1781 $self->throw_exception( "new_result needs a hash" )
1782 unless (ref $values eq 'HASH');
1785 my $alias = $self->{attrs}{alias};
1788 defined $self->{cond}
1789 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1791 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1792 $new{-from_resultset} = [ keys %new ] if keys %new;
1794 $self->throw_exception(
1795 "Can't abstract implicit construct, condition not a hash"
1796 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1798 my $collapsed_cond = (
1800 ? $self->_collapse_cond($self->{cond})
1804 # precendence must be given to passed values over values inherited from
1805 # the cond, so the order here is important.
1806 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1807 while( my($col,$value) = each %implied ){
1808 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1809 $new{$col} = $value->{'='};
1812 $new{$col} = $value if $self->_is_deterministic_value($value);
1818 %{ $self->_remove_alias($values, $alias) },
1819 -source_handle => $self->_source_handle,
1820 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1823 return $self->result_class->new(\%new);
1826 # _is_deterministic_value
1828 # Make an effor to strip non-deterministic values from the condition,
1829 # to make sure new_result chokes less
1831 sub _is_deterministic_value {
1834 my $ref_type = ref $value;
1835 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1836 return 1 if Scalar::Util::blessed($value);
1842 # determines if the resultset defines at least one
1843 # of the attributes supplied
1845 # used to determine if a subquery is neccessary
1848 my ($self, @attr_names) = @_;
1850 my $attrs = $self->_resolved_attrs;
1854 for my $n (@attr_names) {
1855 return 1 if defined $attrs->{$n};
1856 ++$join_check_req if $n =~ /join/;
1859 # a join can be expressed as a multi-level from
1863 ref $attrs->{from} eq 'ARRAY'
1865 @{$attrs->{from}} > 1
1873 # Recursively collapse the condition.
1875 sub _collapse_cond {
1876 my ($self, $cond, $collapsed) = @_;
1880 if (ref $cond eq 'ARRAY') {
1881 foreach my $subcond (@$cond) {
1882 next unless ref $subcond; # -or
1883 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1886 elsif (ref $cond eq 'HASH') {
1887 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1888 foreach my $subcond (@{$cond->{-and}}) {
1889 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1893 foreach my $col (keys %$cond) {
1894 my $value = $cond->{$col};
1895 $collapsed->{$col} = $value;
1905 # Remove the specified alias from the specified query hash. A copy is made so
1906 # the original query is not modified.
1909 my ($self, $query, $alias) = @_;
1911 my %orig = %{ $query || {} };
1914 foreach my $key (keys %orig) {
1916 $unaliased{$key} = $orig{$key};
1919 $unaliased{$1} = $orig{$key}
1920 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1926 =head2 as_query (EXPERIMENTAL)
1930 =item Arguments: none
1932 =item Return Value: \[ $sql, @bind ]
1936 Returns the SQL query and bind vars associated with the invocant.
1938 This is generally used as the RHS for a subquery.
1940 B<NOTE>: This feature is still experimental.
1944 sub as_query { return shift->cursor->as_query(@_) }
1950 =item Arguments: \%vals, \%attrs?
1952 =item Return Value: $rowobject
1956 my $artist = $schema->resultset('Artist')->find_or_new(
1957 { artist => 'fred' }, { key => 'artists' });
1959 $cd->cd_to_producer->find_or_new({ producer => $producer },
1960 { key => 'primary });
1962 Find an existing record from this resultset, based on its primary
1963 key, or a unique constraint. If none exists, instantiate a new result
1964 object and return it. The object will not be saved into your storage
1965 until you call L<DBIx::Class::Row/insert> on it.
1967 You most likely want this method when looking for existing rows using
1968 a unique constraint that is not the primary key, or looking for
1971 If you want objects to be saved immediately, use L</find_or_create> instead.
1973 B<Note>: C<find_or_new> is probably not what you want when creating a
1974 new row in a table that uses primary keys supplied by the
1975 database. Passing in a primary key column with a value of I<undef>
1976 will cause L</find> to attempt to search for a row with a value of
1983 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1984 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1985 my $exists = $self->find($hash, $attrs);
1986 return defined $exists ? $exists : $self->new_result($hash);
1993 =item Arguments: \%vals
1995 =item Return Value: a L<DBIx::Class::Row> $object
1999 Attempt to create a single new row or a row with multiple related rows
2000 in the table represented by the resultset (and related tables). This
2001 will not check for duplicate rows before inserting, use
2002 L</find_or_create> to do that.
2004 To create one row for this resultset, pass a hashref of key/value
2005 pairs representing the columns of the table and the values you wish to
2006 store. If the appropriate relationships are set up, foreign key fields
2007 can also be passed an object representing the foreign row, and the
2008 value will be set to its primary key.
2010 To create related objects, pass a hashref for the value if the related
2011 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2012 and use the name of the relationship as the key. (NOT the name of the field,
2013 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2014 of hashrefs containing the data for each of the rows to create in the foreign
2015 tables, again using the relationship name as the key.
2017 Instead of hashrefs of plain related data (key/value pairs), you may
2018 also pass new or inserted objects. New objects (not inserted yet, see
2019 L</new>), will be inserted into their appropriate tables.
2021 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2023 Example of creating a new row.
2025 $person_rs->create({
2026 name=>"Some Person",
2027 email=>"somebody@someplace.com"
2030 Example of creating a new row and also creating rows in a related C<has_many>
2031 or C<has_one> resultset. Note Arrayref.
2034 { artistid => 4, name => 'Manufactured Crap', cds => [
2035 { title => 'My First CD', year => 2006 },
2036 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2041 Example of creating a new row and also creating a row in a related
2042 C<belongs_to>resultset. Note Hashref.
2045 title=>"Music for Silly Walks",
2048 name=>"Silly Musician",
2055 my ($self, $attrs) = @_;
2056 $self->throw_exception( "create needs a hashref" )
2057 unless ref $attrs eq 'HASH';
2058 return $self->new_result($attrs)->insert;
2061 =head2 find_or_create
2065 =item Arguments: \%vals, \%attrs?
2067 =item Return Value: $rowobject
2071 $cd->cd_to_producer->find_or_create({ producer => $producer },
2072 { key => 'primary });
2074 Tries to find a record based on its primary key or unique constraints; if none
2075 is found, creates one and returns that instead.
2077 my $cd = $schema->resultset('CD')->find_or_create({
2079 artist => 'Massive Attack',
2080 title => 'Mezzanine',
2084 Also takes an optional C<key> attribute, to search by a specific key or unique
2085 constraint. For example:
2087 my $cd = $schema->resultset('CD')->find_or_create(
2089 artist => 'Massive Attack',
2090 title => 'Mezzanine',
2092 { key => 'cd_artist_title' }
2095 B<Note>: Because find_or_create() reads from the database and then
2096 possibly inserts based on the result, this method is subject to a race
2097 condition. Another process could create a record in the table after
2098 the find has completed and before the create has started. To avoid
2099 this problem, use find_or_create() inside a transaction.
2101 B<Note>: C<find_or_create> is probably not what you want when creating
2102 a new row in a table that uses primary keys supplied by the
2103 database. Passing in a primary key column with a value of I<undef>
2104 will cause L</find> to attempt to search for a row with a value of
2107 See also L</find> and L</update_or_create>. For information on how to declare
2108 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2112 sub find_or_create {
2114 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2115 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2116 my $exists = $self->find($hash, $attrs);
2117 return defined $exists ? $exists : $self->create($hash);
2120 =head2 update_or_create
2124 =item Arguments: \%col_values, { key => $unique_constraint }?
2126 =item Return Value: $rowobject
2130 $resultset->update_or_create({ col => $val, ... });
2132 First, searches for an existing row matching one of the unique constraints
2133 (including the primary key) on the source of this resultset. If a row is
2134 found, updates it with the other given column values. Otherwise, creates a new
2137 Takes an optional C<key> attribute to search on a specific unique constraint.
2140 # In your application
2141 my $cd = $schema->resultset('CD')->update_or_create(
2143 artist => 'Massive Attack',
2144 title => 'Mezzanine',
2147 { key => 'cd_artist_title' }
2150 $cd->cd_to_producer->update_or_create({
2151 producer => $producer,
2158 If no C<key> is specified, it searches on all unique constraints defined on the
2159 source, including the primary key.
2161 If the C<key> is specified as C<primary>, it searches only on the primary key.
2163 See also L</find> and L</find_or_create>. For information on how to declare
2164 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2166 B<Note>: C<update_or_create> is probably not what you want when
2167 looking for a row in a table that uses primary keys supplied by the
2168 database, unless you actually have a key value. Passing in a primary
2169 key column with a value of I<undef> will cause L</find> to attempt to
2170 search for a row with a value of I<NULL>.
2174 sub update_or_create {
2176 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2177 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2179 my $row = $self->find($cond, $attrs);
2181 $row->update($cond);
2185 return $self->create($cond);
2188 =head2 update_or_new
2192 =item Arguments: \%col_values, { key => $unique_constraint }?
2194 =item Return Value: $rowobject
2198 $resultset->update_or_new({ col => $val, ... });
2200 First, searches for an existing row matching one of the unique constraints
2201 (including the primary key) on the source of this resultset. If a row is
2202 found, updates it with the other given column values. Otherwise, instantiate
2203 a new result object and return it. The object will not be saved into your storage
2204 until you call L<DBIx::Class::Row/insert> on it.
2206 Takes an optional C<key> attribute to search on a specific unique constraint.
2209 # In your application
2210 my $cd = $schema->resultset('CD')->update_or_new(
2212 artist => 'Massive Attack',
2213 title => 'Mezzanine',
2216 { key => 'cd_artist_title' }
2219 if ($cd->in_storage) {
2220 # the cd was updated
2223 # the cd is not yet in the database, let's insert it
2227 See also L</find>, L</find_or_create> and L<find_or_new>.
2233 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2234 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2236 my $row = $self->find( $cond, $attrs );
2237 if ( defined $row ) {
2238 $row->update($cond);
2242 return $self->new_result($cond);
2249 =item Arguments: none
2251 =item Return Value: \@cache_objects?
2255 Gets the contents of the cache for the resultset, if the cache is set.
2257 The cache is populated either by using the L</prefetch> attribute to
2258 L</search> or by calling L</set_cache>.
2270 =item Arguments: \@cache_objects
2272 =item Return Value: \@cache_objects
2276 Sets the contents of the cache for the resultset. Expects an arrayref
2277 of objects of the same class as those produced by the resultset. Note that
2278 if the cache is set the resultset will return the cached objects rather
2279 than re-querying the database even if the cache attr is not set.
2281 The contents of the cache can also be populated by using the
2282 L</prefetch> attribute to L</search>.
2287 my ( $self, $data ) = @_;
2288 $self->throw_exception("set_cache requires an arrayref")
2289 if defined($data) && (ref $data ne 'ARRAY');
2290 $self->{all_cache} = $data;
2297 =item Arguments: none
2299 =item Return Value: []
2303 Clears the cache for the resultset.
2308 shift->set_cache(undef);
2311 =head2 related_resultset
2315 =item Arguments: $relationship_name
2317 =item Return Value: $resultset
2321 Returns a related resultset for the supplied relationship name.
2323 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2327 sub related_resultset {
2328 my ($self, $rel) = @_;
2330 $self->{related_resultsets} ||= {};
2331 return $self->{related_resultsets}{$rel} ||= do {
2332 my $rel_obj = $self->result_source->relationship_info($rel);
2334 $self->throw_exception(
2335 "search_related: result source '" . $self->result_source->source_name .
2336 "' has no such relationship $rel")
2339 my ($from,$seen) = $self->_resolve_from($rel);
2341 my $join_count = $seen->{$rel};
2342 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2344 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2345 my %attrs = %{$self->{attrs}||{}};
2346 delete @attrs{qw(result_class alias)};
2350 if (my $cache = $self->get_cache) {
2351 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2352 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2357 my $rel_source = $self->result_source->related_source($rel);
2361 # The reason we do this now instead of passing the alias to the
2362 # search_rs below is that if you wrap/overload resultset on the
2363 # source you need to know what alias it's -going- to have for things
2364 # to work sanely (e.g. RestrictWithObject wants to be able to add
2365 # extra query restrictions, and these may need to be $alias.)
2367 my $attrs = $rel_source->resultset_attributes;
2368 local $attrs->{alias} = $alias;
2370 $rel_source->resultset
2378 where => $self->{cond},
2383 $new->set_cache($new_cache) if $new_cache;
2388 =head2 current_source_alias
2392 =item Arguments: none
2394 =item Return Value: $source_alias
2398 Returns the current table alias for the result source this resultset is built
2399 on, that will be used in the SQL query. Usually it is C<me>.
2401 Currently the source alias that refers to the result set returned by a
2402 L</search>/L</find> family method depends on how you got to the resultset: it's
2403 C<me> by default, but eg. L</search_related> aliases it to the related result
2404 source name (and keeps C<me> referring to the original result set). The long
2405 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2406 (and make this method unnecessary).
2408 Thus it's currently necessary to use this method in predefined queries (see
2409 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2410 source alias of the current result set:
2412 # in a result set class
2414 my ($self, $user) = @_;
2416 my $me = $self->current_source_alias;
2418 return $self->search(
2419 "$me.modified" => $user->id,
2425 sub current_source_alias {
2428 return ($self->{attrs} || {})->{alias} || 'me';
2431 # This code is called by search_related, and makes sure there
2432 # is clear separation between the joins before, during, and
2433 # after the relationship. This information is needed later
2434 # in order to properly resolve prefetch aliases (any alias
2435 # with a relation_chain_depth less than the depth of the
2436 # current prefetch is not considered)
2438 my ($self, $extra_join) = @_;
2439 my $source = $self->result_source;
2440 my $attrs = $self->{attrs};
2442 my $from = $attrs->{from}
2443 || [ { $attrs->{alias} => $source->from } ];
2445 my $seen = { %{$attrs->{seen_join}||{}} };
2447 # we need to take the prefetch the attrs into account before we
2448 # ->_resolve_join as otherwise they get lost - captainL
2449 my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
2451 push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
2453 ++$seen->{-relation_chain_depth};
2455 push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
2457 ++$seen->{-relation_chain_depth};
2459 return ($from,$seen);
2462 sub _resolved_attrs {
2464 return $self->{_attrs} if $self->{_attrs};
2466 my $attrs = { %{ $self->{attrs} || {} } };
2467 my $source = $self->result_source;
2468 my $alias = $attrs->{alias};
2470 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2473 # build columns (as long as select isn't set) into a set of as/select hashes
2474 unless ( $attrs->{select} ) {
2476 ( ref($_) eq 'HASH' )
2480 /^\Q${alias}.\E(.+)$/
2491 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2493 # add the additional columns on
2494 foreach ( 'include_columns', '+columns' ) {
2495 push @colbits, map {
2496 ( ref($_) eq 'HASH' )
2498 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2499 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2502 # start with initial select items
2503 if ( $attrs->{select} ) {
2505 ( ref $attrs->{select} eq 'ARRAY' )
2506 ? [ @{ $attrs->{select} } ]
2507 : [ $attrs->{select} ];
2511 ref $attrs->{as} eq 'ARRAY'
2512 ? [ @{ $attrs->{as} } ]
2515 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2520 # otherwise we intialise select & as to empty
2521 $attrs->{select} = [];
2525 # now add colbits to select/as
2526 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2527 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2530 if ( $adds = delete $attrs->{'+select'} ) {
2531 $adds = [$adds] unless ref $adds eq 'ARRAY';
2533 @{ $attrs->{select} },
2534 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2537 if ( $adds = delete $attrs->{'+as'} ) {
2538 $adds = [$adds] unless ref $adds eq 'ARRAY';
2539 push( @{ $attrs->{as} }, @$adds );
2542 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2544 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2545 my $join = delete $attrs->{join} || {};
2547 if ( defined $attrs->{prefetch} ) {
2548 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2552 $attrs->{from} = # have to copy here to avoid corrupting the original
2554 @{ $attrs->{from} },
2555 $source->_resolve_join(
2556 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2562 $attrs->{group_by} ||= $attrs->{select}
2563 if delete $attrs->{distinct};
2564 if ( $attrs->{order_by} ) {
2565 $attrs->{order_by} = (
2566 ref( $attrs->{order_by} ) eq 'ARRAY'
2567 ? [ @{ $attrs->{order_by} } ]
2568 : [ $attrs->{order_by} ]
2572 $attrs->{order_by} = [];
2575 my $collapse = $attrs->{collapse} || {};
2576 if ( my $prefetch = delete $attrs->{prefetch} ) {
2577 $prefetch = $self->_merge_attr( {}, $prefetch );
2579 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2581 # bring joins back to level of current class
2582 my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
2584 $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
2585 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2586 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2588 push( @{ $attrs->{order_by} }, @pre_order );
2590 $attrs->{collapse} = $collapse;
2592 if ( $attrs->{page} and not defined $attrs->{offset} ) {
2593 $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2596 return $self->{_attrs} = $attrs;
2599 sub _joinpath_aliases {
2600 my ($self, $fromspec, $seen) = @_;
2603 return $paths unless ref $fromspec eq 'ARRAY';
2605 for my $j (@$fromspec) {
2607 next if ref $j ne 'ARRAY';
2608 next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
2611 $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
2612 push @{$p->{-join_aliases} }, $j->[0]{-join_alias};
2619 my ($self, $attr) = @_;
2621 if (ref $attr eq 'HASH') {
2622 return $self->_rollout_hash($attr);
2623 } elsif (ref $attr eq 'ARRAY') {
2624 return $self->_rollout_array($attr);
2630 sub _rollout_array {
2631 my ($self, $attr) = @_;
2634 foreach my $element (@{$attr}) {
2635 if (ref $element eq 'HASH') {
2636 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2637 } elsif (ref $element eq 'ARRAY') {
2638 # XXX - should probably recurse here
2639 push( @rolled_array, @{$self->_rollout_array($element)} );
2641 push( @rolled_array, $element );
2644 return \@rolled_array;
2648 my ($self, $attr) = @_;
2651 foreach my $key (keys %{$attr}) {
2652 push( @rolled_array, { $key => $attr->{$key} } );
2654 return \@rolled_array;
2657 sub _calculate_score {
2658 my ($self, $a, $b) = @_;
2660 if (ref $b eq 'HASH') {
2661 my ($b_key) = keys %{$b};
2662 if (ref $a eq 'HASH') {
2663 my ($a_key) = keys %{$a};
2664 if ($a_key eq $b_key) {
2665 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2670 return ($a eq $b_key) ? 1 : 0;
2673 if (ref $a eq 'HASH') {
2674 my ($a_key) = keys %{$a};
2675 return ($b eq $a_key) ? 1 : 0;
2677 return ($b eq $a) ? 1 : 0;
2683 my ($self, $orig, $import) = @_;
2685 return $import unless defined($orig);
2686 return $orig unless defined($import);
2688 $orig = $self->_rollout_attr($orig);
2689 $import = $self->_rollout_attr($import);
2692 foreach my $import_element ( @{$import} ) {
2693 # find best candidate from $orig to merge $b_element into
2694 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2695 foreach my $orig_element ( @{$orig} ) {
2696 my $score = $self->_calculate_score( $orig_element, $import_element );
2697 if ($score > $best_candidate->{score}) {
2698 $best_candidate->{position} = $position;
2699 $best_candidate->{score} = $score;
2703 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2705 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2706 push( @{$orig}, $import_element );
2708 my $orig_best = $orig->[$best_candidate->{position}];
2709 # merge orig_best and b_element together and replace original with merged
2710 if (ref $orig_best ne 'HASH') {
2711 $orig->[$best_candidate->{position}] = $import_element;
2712 } elsif (ref $import_element eq 'HASH') {
2713 my ($key) = keys %{$orig_best};
2714 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2717 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2727 $self->_source_handle($_[0]->handle);
2729 $self->_source_handle->resolve;
2733 =head2 throw_exception
2735 See L<DBIx::Class::Schema/throw_exception> for details.
2739 sub throw_exception {
2741 if (ref $self && $self->_source_handle->schema) {
2742 $self->_source_handle->schema->throw_exception(@_)
2749 # XXX: FIXME: Attributes docs need clearing up
2753 Attributes are used to refine a ResultSet in various ways when
2754 searching for data. They can be passed to any method which takes an
2755 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2758 These are in no particular order:
2764 =item Value: ( $order_by | \@order_by | \%order_by )
2768 Which column(s) to order the results by. If a single column name, or
2769 an arrayref of names is supplied, the argument is passed through
2770 directly to SQL. The hashref syntax allows for connection-agnostic
2771 specification of ordering direction:
2773 For descending order:
2775 order_by => { -desc => [qw/col1 col2 col3/] }
2777 For explicit ascending order:
2779 order_by => { -asc => 'col' }
2781 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2782 supported, although you are strongly encouraged to use the hashref
2783 syntax as outlined above.
2789 =item Value: \@columns
2793 Shortcut to request a particular set of columns to be retrieved. Each
2794 column spec may be a string (a table column name), or a hash (in which
2795 case the key is the C<as> value, and the value is used as the C<select>
2796 expression). Adds C<me.> onto the start of any column without a C<.> in
2797 it and sets C<select> from that, then auto-populates C<as> from
2798 C<select> as normal. (You may also use the C<cols> attribute, as in
2799 earlier versions of DBIC.)
2805 =item Value: \@columns
2809 Indicates additional columns to be selected from storage. Works the same
2810 as L</columns> but adds columns to the selection. (You may also use the
2811 C<include_columns> attribute, as in earlier versions of DBIC). For
2814 $schema->resultset('CD')->search(undef, {
2815 '+columns' => ['artist.name'],
2819 would return all CDs and include a 'name' column to the information
2820 passed to object inflation. Note that the 'artist' is the name of the
2821 column (or relationship) accessor, and 'name' is the name of the column
2822 accessor in the related table.
2824 =head2 include_columns
2828 =item Value: \@columns
2832 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2838 =item Value: \@select_columns
2842 Indicates which columns should be selected from the storage. You can use
2843 column names, or in the case of RDBMS back ends, function or stored procedure
2846 $rs = $schema->resultset('Employee')->search(undef, {
2849 { count => 'employeeid' },
2854 When you use function/stored procedure names and do not supply an C<as>
2855 attribute, the column names returned are storage-dependent. E.g. MySQL would
2856 return a column named C<count(employeeid)> in the above example.
2862 Indicates additional columns to be selected from storage. Works the same as
2863 L</select> but adds columns to the selection.
2871 Indicates additional column names for those added via L</+select>. See L</as>.
2879 =item Value: \@inflation_names
2883 Indicates column names for object inflation. That is, C<as>
2884 indicates the name that the column can be accessed as via the
2885 C<get_column> method (or via the object accessor, B<if one already
2886 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2888 The C<as> attribute is used in conjunction with C<select>,
2889 usually when C<select> contains one or more function or stored
2892 $rs = $schema->resultset('Employee')->search(undef, {
2895 { count => 'employeeid' }
2897 as => ['name', 'employee_count'],
2900 my $employee = $rs->first(); # get the first Employee
2902 If the object against which the search is performed already has an accessor
2903 matching a column name specified in C<as>, the value can be retrieved using
2904 the accessor as normal:
2906 my $name = $employee->name();
2908 If on the other hand an accessor does not exist in the object, you need to
2909 use C<get_column> instead:
2911 my $employee_count = $employee->get_column('employee_count');
2913 You can create your own accessors if required - see
2914 L<DBIx::Class::Manual::Cookbook> for details.
2916 Please note: This will NOT insert an C<AS employee_count> into the SQL
2917 statement produced, it is used for internal access only. Thus
2918 attempting to use the accessor in an C<order_by> clause or similar
2919 will fail miserably.
2921 To get around this limitation, you can supply literal SQL to your
2922 C<select> attibute that contains the C<AS alias> text, eg:
2924 select => [\'myfield AS alias']
2930 =item Value: ($rel_name | \@rel_names | \%rel_names)
2934 Contains a list of relationships that should be joined for this query. For
2937 # Get CDs by Nine Inch Nails
2938 my $rs = $schema->resultset('CD')->search(
2939 { 'artist.name' => 'Nine Inch Nails' },
2940 { join => 'artist' }
2943 Can also contain a hash reference to refer to the other relation's relations.
2946 package MyApp::Schema::Track;
2947 use base qw/DBIx::Class/;
2948 __PACKAGE__->table('track');
2949 __PACKAGE__->add_columns(qw/trackid cd position title/);
2950 __PACKAGE__->set_primary_key('trackid');
2951 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2954 # In your application
2955 my $rs = $schema->resultset('Artist')->search(
2956 { 'track.title' => 'Teardrop' },
2958 join => { cd => 'track' },
2959 order_by => 'artist.name',
2963 You need to use the relationship (not the table) name in conditions,
2964 because they are aliased as such. The current table is aliased as "me", so
2965 you need to use me.column_name in order to avoid ambiguity. For example:
2967 # Get CDs from 1984 with a 'Foo' track
2968 my $rs = $schema->resultset('CD')->search(
2971 'tracks.name' => 'Foo'
2973 { join => 'tracks' }
2976 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2977 similarly for a third time). For e.g.
2979 my $rs = $schema->resultset('Artist')->search({
2980 'cds.title' => 'Down to Earth',
2981 'cds_2.title' => 'Popular',
2983 join => [ qw/cds cds/ ],
2986 will return a set of all artists that have both a cd with title 'Down
2987 to Earth' and a cd with title 'Popular'.
2989 If you want to fetch related objects from other tables as well, see C<prefetch>
2992 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2998 =item Value: ($rel_name | \@rel_names | \%rel_names)
3002 Contains one or more relationships that should be fetched along with
3003 the main query (when they are accessed afterwards the data will
3004 already be available, without extra queries to the database). This is
3005 useful for when you know you will need the related objects, because it
3006 saves at least one query:
3008 my $rs = $schema->resultset('Tag')->search(
3017 The initial search results in SQL like the following:
3019 SELECT tag.*, cd.*, artist.* FROM tag
3020 JOIN cd ON tag.cd = cd.cdid
3021 JOIN artist ON cd.artist = artist.artistid
3023 L<DBIx::Class> has no need to go back to the database when we access the
3024 C<cd> or C<artist> relationships, which saves us two SQL statements in this
3027 Simple prefetches will be joined automatically, so there is no need
3028 for a C<join> attribute in the above search.
3030 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3031 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3032 with an accessor type of 'single' or 'filter'). A more complex example that
3033 prefetches an artists cds, the tracks on those cds, and the tags associted
3034 with that artist is given below (assuming many-to-many from artists to tags):
3036 my $rs = $schema->resultset('Artist')->search(
3040 { cds => 'tracks' },
3041 { artist_tags => 'tags' }
3047 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3048 attributes will be ignored.
3058 Makes the resultset paged and specifies the page to retrieve. Effectively
3059 identical to creating a non-pages resultset and then calling ->page($page)
3062 If L<rows> attribute is not specified it defualts to 10 rows per page.
3064 When you have a paged resultset, L</count> will only return the number
3065 of rows in the page. To get the total, use the L</pager> and call
3066 C<total_entries> on it.
3076 Specifes the maximum number of rows for direct retrieval or the number of
3077 rows per page if the page attribute or method is used.
3083 =item Value: $offset
3087 Specifies the (zero-based) row number for the first row to be returned, or the
3088 of the first row of the first page if paging is used.
3094 =item Value: \@columns
3098 A arrayref of columns to group by. Can include columns of joined tables.
3100 group_by => [qw/ column1 column2 ... /]
3106 =item Value: $condition
3110 HAVING is a select statement attribute that is applied between GROUP BY and
3111 ORDER BY. It is applied to the after the grouping calculations have been
3114 having => { 'count(employee)' => { '>=', 100 } }
3120 =item Value: (0 | 1)
3124 Set to 1 to group by all columns.
3130 Adds to the WHERE clause.
3132 # only return rows WHERE deleted IS NULL for all searches
3133 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3135 Can be overridden by passing C<{ where => undef }> as an attribute
3142 Set to 1 to cache search results. This prevents extra SQL queries if you
3143 revisit rows in your ResultSet:
3145 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3147 while( my $artist = $resultset->next ) {
3151 $rs->first; # without cache, this would issue a query
3153 By default, searches are not cached.
3155 For more examples of using these attributes, see
3156 L<DBIx::Class::Manual::Cookbook>.
3162 =item Value: \@from_clause
3166 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3167 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3170 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3172 C<join> will usually do what you need and it is strongly recommended that you
3173 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3174 And we really do mean "cannot", not just tried and failed. Attempting to use
3175 this because you're having problems with C<join> is like trying to use x86
3176 ASM because you've got a syntax error in your C. Trust us on this.
3178 Now, if you're still really, really sure you need to use this (and if you're
3179 not 100% sure, ask the mailing list first), here's an explanation of how this
3182 The syntax is as follows -
3185 { <alias1> => <table1> },
3187 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3188 [], # nested JOIN (optional)
3189 { <table1.column1> => <table2.column2>, ... (more conditions) },
3191 # More of the above [ ] may follow for additional joins
3198 ON <table1.column1> = <table2.column2>
3199 <more joins may follow>
3201 An easy way to follow the examples below is to remember the following:
3203 Anything inside "[]" is a JOIN
3204 Anything inside "{}" is a condition for the enclosing JOIN
3206 The following examples utilize a "person" table in a family tree application.
3207 In order to express parent->child relationships, this table is self-joined:
3209 # Person->belongs_to('father' => 'Person');
3210 # Person->belongs_to('mother' => 'Person');
3212 C<from> can be used to nest joins. Here we return all children with a father,
3213 then search against all mothers of those children:
3215 $rs = $schema->resultset('Person')->search(
3218 alias => 'mother', # alias columns in accordance with "from"
3220 { mother => 'person' },
3223 { child => 'person' },
3225 { father => 'person' },
3226 { 'father.person_id' => 'child.father_id' }
3229 { 'mother.person_id' => 'child.mother_id' }
3236 # SELECT mother.* FROM person mother
3239 # JOIN person father
3240 # ON ( father.person_id = child.father_id )
3242 # ON ( mother.person_id = child.mother_id )
3244 The type of any join can be controlled manually. To search against only people
3245 with a father in the person table, we could explicitly use C<INNER JOIN>:
3247 $rs = $schema->resultset('Person')->search(
3250 alias => 'child', # alias columns in accordance with "from"
3252 { child => 'person' },
3254 { father => 'person', -join_type => 'inner' },
3255 { 'father.id' => 'child.father_id' }
3262 # SELECT child.* FROM person child
3263 # INNER JOIN person father ON child.father_id = father.id
3265 If you need to express really complex joins or you need a subselect, you
3266 can supply literal SQL to C<from> via a scalar reference. In this case
3267 the contents of the scalar will replace the table name asscoiated with the
3270 WARNING: This technique might very well not work as expected on chained
3271 searches - you have been warned.
3273 # Assuming the Event resultsource is defined as:
3275 MySchema::Event->add_columns (
3278 is_auto_increment => 1,
3287 MySchema::Event->set_primary_key ('sequence');
3289 # This will get back the latest event for every location. The column
3290 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3291 # combo to limit the resultset
3293 $rs = $schema->resultset('Event');
3294 $table = $rs->result_source->name;
3295 $latest = $rs->search (
3298 (SELECT e1.* FROM $table e1
3300 ON e1.location = e2.location
3301 AND e1.sequence < e2.sequence
3302 WHERE e2.sequence is NULL
3307 # Equivalent SQL (with the DBIC chunks added):
3309 SELECT me.sequence, me.location, me.type FROM
3310 (SELECT e1.* FROM events e1
3312 ON e1.location = e2.location
3313 AND e1.sequence < e2.sequence
3314 WHERE e2.sequence is NULL
3321 =item Value: ( 'update' | 'shared' )
3325 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT