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 group_by/;
1156 return $self->search(@_)->count if @_ and defined $_[0];
1157 return scalar @{ $self->get_cache } if $self->get_cache;
1159 my @check_attrs = @count_via_subq_attrs;
1161 # if we are not paged - we are simply asking for a limit
1162 if (not $self->{attrs}{page} and not $self->{attrs}{software_limit}) {
1163 push @check_attrs, qw/rows offset/;
1166 return $self->_has_attr (@check_attrs)
1167 ? $self->_count_subq
1168 : $self->_count_simple
1174 my $attrs = { %{$self->_resolved_attrs} };
1176 my $select_cols = $attrs->{group_by} || [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
1178 count_subq => $self->search ({}, { columns => $select_cols, group_by => $select_cols })
1182 # the subquery above will integrate everything, including 'where' and any pagers
1183 delete $attrs->{$_} for (@count_via_subq_attrs, qw/where rows offset pager page/ );
1185 return $self->__count ($attrs);
1191 my $count = $self->__count;
1192 return 0 unless $count;
1194 # need to take offset from resolved attrs
1196 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1197 $count = $self->{attrs}{rows} if
1198 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1199 $count = 0 if ($count < 0);
1204 my ($self, $attrs) = @_;
1206 $attrs ||= { %{$self->{attrs}} };
1208 $attrs->{select} = { count => '*' };
1209 $attrs->{as} = [qw/count/];
1211 # take off any pagers, record_filter is cdbi, and no point of ordering a count
1212 delete $attrs->{$_} for qw/rows offset page pager order_by record_filter/;
1214 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1215 my ($count) = $tmp_rs->cursor->next;
1224 =head2 count_literal
1228 =item Arguments: $sql_fragment, @bind_values
1230 =item Return Value: $count
1234 Counts the results in a literal query. Equivalent to calling L</search_literal>
1235 with the passed arguments, then L</count>.
1239 sub count_literal { shift->search_literal(@_)->count; }
1245 =item Arguments: none
1247 =item Return Value: @objects
1251 Returns all elements in the resultset. Called implicitly if the resultset
1252 is returned in list context.
1259 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1262 return @{ $self->get_cache } if $self->get_cache;
1266 # TODO: don't call resolve here
1267 if (keys %{$self->_resolved_attrs->{collapse}}) {
1268 # if ($self->{attrs}{prefetch}) {
1269 # Using $self->cursor->all is really just an optimisation.
1270 # If we're collapsing has_many prefetches it probably makes
1271 # very little difference, and this is cleaner than hacking
1272 # _construct_object to survive the approach
1273 my @row = $self->cursor->next;
1275 push(@obj, $self->_construct_object(@row));
1276 @row = (exists $self->{stashed_row}
1277 ? @{delete $self->{stashed_row}}
1278 : $self->cursor->next);
1281 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1284 $self->set_cache(\@obj) if $self->{attrs}{cache};
1292 =item Arguments: none
1294 =item Return Value: $self
1298 Resets the resultset's cursor, so you can iterate through the elements again.
1304 delete $self->{_attrs} if exists $self->{_attrs};
1305 $self->{all_cache_position} = 0;
1306 $self->cursor->reset;
1314 =item Arguments: none
1316 =item Return Value: $object?
1320 Resets the resultset and returns an object for the first result (if the
1321 resultset returns anything).
1326 return $_[0]->reset->next;
1330 # _update_delete_via_subq
1332 # Presence of some rs attributes requires a subquery to reliably
1336 sub _update_delete_via_subq {
1337 return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
1341 # _cond_for_update_delete
1343 # update/delete require the condition to be modified to handle
1344 # the differing SQL syntax available. This transforms the $self->{cond}
1345 # appropriately, returning the new condition.
1347 sub _cond_for_update_delete {
1348 my ($self, $full_cond) = @_;
1351 $full_cond ||= $self->{cond};
1352 # No-op. No condition, we're updating/deleting everything
1353 return $cond unless ref $full_cond;
1355 if (ref $full_cond eq 'ARRAY') {
1359 foreach my $key (keys %{$_}) {
1361 $hash{$1} = $_->{$key};
1367 elsif (ref $full_cond eq 'HASH') {
1368 if ((keys %{$full_cond})[0] eq '-and') {
1370 my @cond = @{$full_cond->{-and}};
1371 for (my $i = 0; $i < @cond; $i++) {
1372 my $entry = $cond[$i];
1374 if (ref $entry eq 'HASH') {
1375 $hash = $self->_cond_for_update_delete($entry);
1378 $entry =~ /([^.]+)$/;
1379 $hash->{$1} = $cond[++$i];
1381 push @{$cond->{-and}}, $hash;
1385 foreach my $key (keys %{$full_cond}) {
1387 $cond->{$1} = $full_cond->{$key};
1392 $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
1403 =item Arguments: \%values
1405 =item Return Value: $storage_rv
1409 Sets the specified columns in the resultset to the supplied values in a
1410 single query. Return value will be true if the update succeeded or false
1411 if no records were updated; exact type of success value is storage-dependent.
1416 my ($self, $values) = @_;
1417 $self->throw_exception('Values for update must be a hash')
1418 unless ref $values eq 'HASH';
1420 # rs operations with subqueries are Storage dependent - delegate
1421 if ($self->_update_delete_via_subq) {
1422 return $self->result_source->storage->subq_update_delete($self, 'update', $values);
1425 my $cond = $self->_cond_for_update_delete;
1427 return $self->result_source->storage->update(
1428 $self->result_source, $values, $cond
1436 =item Arguments: \%values
1438 =item Return Value: 1
1442 Fetches all objects and updates them one at a time. Note that C<update_all>
1443 will run DBIC cascade triggers, while L</update> will not.
1448 my ($self, $values) = @_;
1449 $self->throw_exception('Values for update_all must be a hash')
1450 unless ref $values eq 'HASH';
1451 foreach my $obj ($self->all) {
1452 $obj->set_columns($values)->update;
1461 =item Arguments: none
1463 =item Return Value: 1
1467 Deletes the contents of the resultset from its result source. Note that this
1468 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1469 to run. See also L<DBIx::Class::Row/delete>.
1471 delete may not generate correct SQL for a query with joins or a resultset
1472 chained from a related resultset. In this case it will generate a warning:-
1474 In these cases you may find that delete_all is more appropriate, or you
1475 need to respecify your query in a way that can be expressed without a join.
1481 $self->throw_exception('delete does not accept any arguments')
1484 # rs operations with subqueries are Storage dependent - delegate
1485 if ($self->_update_delete_via_subq) {
1486 return $self->result_source->storage->subq_update_delete($self, 'delete');
1489 my $cond = $self->_cond_for_update_delete;
1491 $self->result_source->storage->delete($self->result_source, $cond);
1499 =item Arguments: none
1501 =item Return Value: 1
1505 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1506 will run DBIC cascade triggers, while L</delete> will not.
1512 $self->throw_exception('delete_all does not accept any arguments')
1515 $_->delete for $self->all;
1523 =item Arguments: \@data;
1527 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1528 For the arrayref of hashrefs style each hashref should be a structure suitable
1529 forsubmitting to a $resultset->create(...) method.
1531 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1532 to insert the data, as this is a faster method.
1534 Otherwise, each set of data is inserted into the database using
1535 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1536 objects is returned.
1538 Example: Assuming an Artist Class that has many CDs Classes relating:
1540 my $Artist_rs = $schema->resultset("Artist");
1542 ## Void Context Example
1543 $Artist_rs->populate([
1544 { artistid => 4, name => 'Manufactured Crap', cds => [
1545 { title => 'My First CD', year => 2006 },
1546 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1549 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1550 { title => 'My parents sold me to a record company' ,year => 2005 },
1551 { title => 'Why Am I So Ugly?', year => 2006 },
1552 { title => 'I Got Surgery and am now Popular', year => 2007 }
1557 ## Array Context Example
1558 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1559 { name => "Artist One"},
1560 { name => "Artist Two"},
1561 { name => "Artist Three", cds=> [
1562 { title => "First CD", year => 2007},
1563 { title => "Second CD", year => 2008},
1567 print $ArtistOne->name; ## response is 'Artist One'
1568 print $ArtistThree->cds->count ## reponse is '2'
1570 For the arrayref of arrayrefs style, the first element should be a list of the
1571 fieldsnames to which the remaining elements are rows being inserted. For
1574 $Arstist_rs->populate([
1575 [qw/artistid name/],
1576 [100, 'A Formally Unknown Singer'],
1577 [101, 'A singer that jumped the shark two albums ago'],
1578 [102, 'An actually cool singer.'],
1581 Please note an important effect on your data when choosing between void and
1582 wantarray context. Since void context goes straight to C<insert_bulk> in
1583 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1584 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1585 create primary keys for you, you will find that your PKs are empty. In this
1586 case you will have to use the wantarray context in order to create those
1592 my $self = shift @_;
1593 my $data = ref $_[0][0] eq 'HASH'
1594 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1595 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1597 if(defined wantarray) {
1599 foreach my $item (@$data) {
1600 push(@created, $self->create($item));
1604 my ($first, @rest) = @$data;
1606 my @names = grep {!ref $first->{$_}} keys %$first;
1607 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1608 my @pks = $self->result_source->primary_columns;
1610 ## do the belongs_to relationships
1611 foreach my $index (0..$#$data) {
1612 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1613 my @ret = $self->populate($data);
1617 foreach my $rel (@rels) {
1618 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1619 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1620 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1621 my $related = $result->result_source->resolve_condition(
1622 $result->result_source->relationship_info($reverse)->{cond},
1627 delete $data->[$index]->{$rel};
1628 $data->[$index] = {%{$data->[$index]}, %$related};
1630 push @names, keys %$related if $index == 0;
1634 ## do bulk insert on current row
1635 my @values = map { [ @$_{@names} ] } @$data;
1637 $self->result_source->storage->insert_bulk(
1638 $self->result_source,
1643 ## do the has_many relationships
1644 foreach my $item (@$data) {
1646 foreach my $rel (@rels) {
1647 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1649 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1650 || $self->throw_exception('Cannot find the relating object.');
1652 my $child = $parent->$rel;
1654 my $related = $child->result_source->resolve_condition(
1655 $parent->result_source->relationship_info($rel)->{cond},
1660 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1661 my @populate = map { {%$_, %$related} } @rows_to_add;
1663 $child->populate( \@populate );
1669 =head2 _normalize_populate_args ($args)
1671 Private method used by L</populate> to normalize its incoming arguments. Factored
1672 out in case you want to subclass and accept new argument structures to the
1673 L</populate> method.
1677 sub _normalize_populate_args {
1678 my ($self, $data) = @_;
1679 my @names = @{shift(@$data)};
1680 my @results_to_create;
1681 foreach my $datum (@$data) {
1682 my %result_to_create;
1683 foreach my $index (0..$#names) {
1684 $result_to_create{$names[$index]} = $$datum[$index];
1686 push @results_to_create, \%result_to_create;
1688 return \@results_to_create;
1695 =item Arguments: none
1697 =item Return Value: $pager
1701 Return Value a L<Data::Page> object for the current resultset. Only makes
1702 sense for queries with a C<page> attribute.
1704 To get the full count of entries for a paged resultset, call
1705 C<total_entries> on the L<Data::Page> object.
1712 return $self->{pager} if $self->{pager};
1714 my $attrs = $self->{attrs};
1715 $self->throw_exception("Can't create pager for non-paged rs")
1716 unless $self->{attrs}{page};
1717 $attrs->{rows} ||= 10;
1719 # throw away the paging flags and re-run the count (possibly
1720 # with a subselect) to get the real total count
1721 my $count_attrs = { %$attrs };
1722 delete $count_attrs->{$_} for qw/rows offset page pager/;
1723 my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
1725 return $self->{pager} = Data::Page->new(
1728 $self->{attrs}{page}
1736 =item Arguments: $page_number
1738 =item Return Value: $rs
1742 Returns a resultset for the $page_number page of the resultset on which page
1743 is called, where each page contains a number of rows equal to the 'rows'
1744 attribute set on the resultset (10 by default).
1749 my ($self, $page) = @_;
1750 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1757 =item Arguments: \%vals
1759 =item Return Value: $rowobject
1763 Creates a new row object in the resultset's result class and returns
1764 it. The row is not inserted into the database at this point, call
1765 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1766 will tell you whether the row object has been inserted or not.
1768 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1773 my ($self, $values) = @_;
1774 $self->throw_exception( "new_result needs a hash" )
1775 unless (ref $values eq 'HASH');
1778 my $alias = $self->{attrs}{alias};
1781 defined $self->{cond}
1782 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1784 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1785 $new{-from_resultset} = [ keys %new ] if keys %new;
1787 $self->throw_exception(
1788 "Can't abstract implicit construct, condition not a hash"
1789 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1791 my $collapsed_cond = (
1793 ? $self->_collapse_cond($self->{cond})
1797 # precendence must be given to passed values over values inherited from
1798 # the cond, so the order here is important.
1799 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1800 while( my($col,$value) = each %implied ){
1801 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1802 $new{$col} = $value->{'='};
1805 $new{$col} = $value if $self->_is_deterministic_value($value);
1811 %{ $self->_remove_alias($values, $alias) },
1812 -source_handle => $self->_source_handle,
1813 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1816 return $self->result_class->new(\%new);
1819 # _is_deterministic_value
1821 # Make an effor to strip non-deterministic values from the condition,
1822 # to make sure new_result chokes less
1824 sub _is_deterministic_value {
1827 my $ref_type = ref $value;
1828 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1829 return 1 if Scalar::Util::blessed($value);
1835 # determines if the resultset defines at least one
1836 # of the attributes supplied
1838 # used to determine if a subquery is neccessary
1841 my ($self, @attr_names) = @_;
1843 my $attrs = $self->_resolved_attrs;
1847 for my $n (@attr_names) {
1848 return 1 if defined $attrs->{$n};
1849 ++$join_check_req if $n =~ /join/;
1852 # a join can be expressed as a multi-level from
1856 ref $attrs->{from} eq 'ARRAY'
1858 @{$attrs->{from}} > 1
1866 # Recursively collapse the condition.
1868 sub _collapse_cond {
1869 my ($self, $cond, $collapsed) = @_;
1873 if (ref $cond eq 'ARRAY') {
1874 foreach my $subcond (@$cond) {
1875 next unless ref $subcond; # -or
1876 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1879 elsif (ref $cond eq 'HASH') {
1880 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1881 foreach my $subcond (@{$cond->{-and}}) {
1882 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1886 foreach my $col (keys %$cond) {
1887 my $value = $cond->{$col};
1888 $collapsed->{$col} = $value;
1898 # Remove the specified alias from the specified query hash. A copy is made so
1899 # the original query is not modified.
1902 my ($self, $query, $alias) = @_;
1904 my %orig = %{ $query || {} };
1907 foreach my $key (keys %orig) {
1909 $unaliased{$key} = $orig{$key};
1912 $unaliased{$1} = $orig{$key}
1913 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1919 =head2 as_query (EXPERIMENTAL)
1923 =item Arguments: none
1925 =item Return Value: \[ $sql, @bind ]
1929 Returns the SQL query and bind vars associated with the invocant.
1931 This is generally used as the RHS for a subquery.
1933 B<NOTE>: This feature is still experimental.
1937 sub as_query { return shift->cursor->as_query(@_) }
1943 =item Arguments: \%vals, \%attrs?
1945 =item Return Value: $rowobject
1949 my $artist = $schema->resultset('Artist')->find_or_new(
1950 { artist => 'fred' }, { key => 'artists' });
1952 $cd->cd_to_producer->find_or_new({ producer => $producer },
1953 { key => 'primary });
1955 Find an existing record from this resultset, based on its primary
1956 key, or a unique constraint. If none exists, instantiate a new result
1957 object and return it. The object will not be saved into your storage
1958 until you call L<DBIx::Class::Row/insert> on it.
1960 You most likely want this method when looking for existing rows using
1961 a unique constraint that is not the primary key, or looking for
1964 If you want objects to be saved immediately, use L</find_or_create> instead.
1966 B<Note>: C<find_or_new> is probably not what you want when creating a
1967 new row in a table that uses primary keys supplied by the
1968 database. Passing in a primary key column with a value of I<undef>
1969 will cause L</find> to attempt to search for a row with a value of
1976 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1977 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1978 my $exists = $self->find($hash, $attrs);
1979 return defined $exists ? $exists : $self->new_result($hash);
1986 =item Arguments: \%vals
1988 =item Return Value: a L<DBIx::Class::Row> $object
1992 Attempt to create a single new row or a row with multiple related rows
1993 in the table represented by the resultset (and related tables). This
1994 will not check for duplicate rows before inserting, use
1995 L</find_or_create> to do that.
1997 To create one row for this resultset, pass a hashref of key/value
1998 pairs representing the columns of the table and the values you wish to
1999 store. If the appropriate relationships are set up, foreign key fields
2000 can also be passed an object representing the foreign row, and the
2001 value will be set to its primary key.
2003 To create related objects, pass a hashref for the value if the related
2004 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
2005 and use the name of the relationship as the key. (NOT the name of the field,
2006 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2007 of hashrefs containing the data for each of the rows to create in the foreign
2008 tables, again using the relationship name as the key.
2010 Instead of hashrefs of plain related data (key/value pairs), you may
2011 also pass new or inserted objects. New objects (not inserted yet, see
2012 L</new>), will be inserted into their appropriate tables.
2014 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2016 Example of creating a new row.
2018 $person_rs->create({
2019 name=>"Some Person",
2020 email=>"somebody@someplace.com"
2023 Example of creating a new row and also creating rows in a related C<has_many>
2024 or C<has_one> resultset. Note Arrayref.
2027 { artistid => 4, name => 'Manufactured Crap', cds => [
2028 { title => 'My First CD', year => 2006 },
2029 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2034 Example of creating a new row and also creating a row in a related
2035 C<belongs_to>resultset. Note Hashref.
2038 title=>"Music for Silly Walks",
2041 name=>"Silly Musician",
2048 my ($self, $attrs) = @_;
2049 $self->throw_exception( "create needs a hashref" )
2050 unless ref $attrs eq 'HASH';
2051 return $self->new_result($attrs)->insert;
2054 =head2 find_or_create
2058 =item Arguments: \%vals, \%attrs?
2060 =item Return Value: $rowobject
2064 $cd->cd_to_producer->find_or_create({ producer => $producer },
2065 { key => 'primary });
2067 Tries to find a record based on its primary key or unique constraints; if none
2068 is found, creates one and returns that instead.
2070 my $cd = $schema->resultset('CD')->find_or_create({
2072 artist => 'Massive Attack',
2073 title => 'Mezzanine',
2077 Also takes an optional C<key> attribute, to search by a specific key or unique
2078 constraint. For example:
2080 my $cd = $schema->resultset('CD')->find_or_create(
2082 artist => 'Massive Attack',
2083 title => 'Mezzanine',
2085 { key => 'cd_artist_title' }
2088 B<Note>: Because find_or_create() reads from the database and then
2089 possibly inserts based on the result, this method is subject to a race
2090 condition. Another process could create a record in the table after
2091 the find has completed and before the create has started. To avoid
2092 this problem, use find_or_create() inside a transaction.
2094 B<Note>: C<find_or_create> is probably not what you want when creating
2095 a new row in a table that uses primary keys supplied by the
2096 database. Passing in a primary key column with a value of I<undef>
2097 will cause L</find> to attempt to search for a row with a value of
2100 See also L</find> and L</update_or_create>. For information on how to declare
2101 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2105 sub find_or_create {
2107 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2108 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2109 my $exists = $self->find($hash, $attrs);
2110 return defined $exists ? $exists : $self->create($hash);
2113 =head2 update_or_create
2117 =item Arguments: \%col_values, { key => $unique_constraint }?
2119 =item Return Value: $rowobject
2123 $resultset->update_or_create({ col => $val, ... });
2125 First, searches for an existing row matching one of the unique constraints
2126 (including the primary key) on the source of this resultset. If a row is
2127 found, updates it with the other given column values. Otherwise, creates a new
2130 Takes an optional C<key> attribute to search on a specific unique constraint.
2133 # In your application
2134 my $cd = $schema->resultset('CD')->update_or_create(
2136 artist => 'Massive Attack',
2137 title => 'Mezzanine',
2140 { key => 'cd_artist_title' }
2143 $cd->cd_to_producer->update_or_create({
2144 producer => $producer,
2151 If no C<key> is specified, it searches on all unique constraints defined on the
2152 source, including the primary key.
2154 If the C<key> is specified as C<primary>, it searches only on the primary key.
2156 See also L</find> and L</find_or_create>. For information on how to declare
2157 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2159 B<Note>: C<update_or_create> is probably not what you want when
2160 looking for a row in a table that uses primary keys supplied by the
2161 database, unless you actually have a key value. Passing in a primary
2162 key column with a value of I<undef> will cause L</find> to attempt to
2163 search for a row with a value of I<NULL>.
2167 sub update_or_create {
2169 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2170 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2172 my $row = $self->find($cond, $attrs);
2174 $row->update($cond);
2178 return $self->create($cond);
2181 =head2 update_or_new
2185 =item Arguments: \%col_values, { key => $unique_constraint }?
2187 =item Return Value: $rowobject
2191 $resultset->update_or_new({ col => $val, ... });
2193 First, searches for an existing row matching one of the unique constraints
2194 (including the primary key) on the source of this resultset. If a row is
2195 found, updates it with the other given column values. Otherwise, instantiate
2196 a new result object and return it. The object will not be saved into your storage
2197 until you call L<DBIx::Class::Row/insert> on it.
2199 Takes an optional C<key> attribute to search on a specific unique constraint.
2202 # In your application
2203 my $cd = $schema->resultset('CD')->update_or_new(
2205 artist => 'Massive Attack',
2206 title => 'Mezzanine',
2209 { key => 'cd_artist_title' }
2212 if ($cd->in_storage) {
2213 # the cd was updated
2216 # the cd is not yet in the database, let's insert it
2220 See also L</find>, L</find_or_create> and L<find_or_new>.
2226 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2227 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2229 my $row = $self->find( $cond, $attrs );
2230 if ( defined $row ) {
2231 $row->update($cond);
2235 return $self->new_result($cond);
2242 =item Arguments: none
2244 =item Return Value: \@cache_objects?
2248 Gets the contents of the cache for the resultset, if the cache is set.
2250 The cache is populated either by using the L</prefetch> attribute to
2251 L</search> or by calling L</set_cache>.
2263 =item Arguments: \@cache_objects
2265 =item Return Value: \@cache_objects
2269 Sets the contents of the cache for the resultset. Expects an arrayref
2270 of objects of the same class as those produced by the resultset. Note that
2271 if the cache is set the resultset will return the cached objects rather
2272 than re-querying the database even if the cache attr is not set.
2274 The contents of the cache can also be populated by using the
2275 L</prefetch> attribute to L</search>.
2280 my ( $self, $data ) = @_;
2281 $self->throw_exception("set_cache requires an arrayref")
2282 if defined($data) && (ref $data ne 'ARRAY');
2283 $self->{all_cache} = $data;
2290 =item Arguments: none
2292 =item Return Value: []
2296 Clears the cache for the resultset.
2301 shift->set_cache(undef);
2304 =head2 related_resultset
2308 =item Arguments: $relationship_name
2310 =item Return Value: $resultset
2314 Returns a related resultset for the supplied relationship name.
2316 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2320 sub related_resultset {
2321 my ($self, $rel) = @_;
2323 $self->{related_resultsets} ||= {};
2324 return $self->{related_resultsets}{$rel} ||= do {
2325 my $rel_obj = $self->result_source->relationship_info($rel);
2327 $self->throw_exception(
2328 "search_related: result source '" . $self->result_source->source_name .
2329 "' has no such relationship $rel")
2332 my ($from,$seen) = $self->_resolve_from($rel);
2334 my $join_count = $seen->{$rel};
2335 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2337 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2338 my %attrs = %{$self->{attrs}||{}};
2339 delete @attrs{qw(result_class alias)};
2343 if (my $cache = $self->get_cache) {
2344 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2345 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2350 my $rel_source = $self->result_source->related_source($rel);
2354 # The reason we do this now instead of passing the alias to the
2355 # search_rs below is that if you wrap/overload resultset on the
2356 # source you need to know what alias it's -going- to have for things
2357 # to work sanely (e.g. RestrictWithObject wants to be able to add
2358 # extra query restrictions, and these may need to be $alias.)
2360 my $attrs = $rel_source->resultset_attributes;
2361 local $attrs->{alias} = $alias;
2363 $rel_source->resultset
2371 where => $self->{cond},
2376 $new->set_cache($new_cache) if $new_cache;
2381 =head2 current_source_alias
2385 =item Arguments: none
2387 =item Return Value: $source_alias
2391 Returns the current table alias for the result source this resultset is built
2392 on, that will be used in the SQL query. Usually it is C<me>.
2394 Currently the source alias that refers to the result set returned by a
2395 L</search>/L</find> family method depends on how you got to the resultset: it's
2396 C<me> by default, but eg. L</search_related> aliases it to the related result
2397 source name (and keeps C<me> referring to the original result set). The long
2398 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2399 (and make this method unnecessary).
2401 Thus it's currently necessary to use this method in predefined queries (see
2402 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2403 source alias of the current result set:
2405 # in a result set class
2407 my ($self, $user) = @_;
2409 my $me = $self->current_source_alias;
2411 return $self->search(
2412 "$me.modified" => $user->id,
2418 sub current_source_alias {
2421 return ($self->{attrs} || {})->{alias} || 'me';
2425 my ($self, $extra_join) = @_;
2426 my $source = $self->result_source;
2427 my $attrs = $self->{attrs};
2429 my $from = $attrs->{from}
2430 || [ { $attrs->{alias} => $source->from } ];
2432 my $seen = { %{$attrs->{seen_join}||{}} };
2434 my $join = ($attrs->{join}
2435 ? [ $attrs->{join}, $extra_join ]
2438 # we need to take the prefetch the attrs into account before we
2439 # ->resolve_join as otherwise they get lost - captainL
2440 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2444 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2447 return ($from,$seen);
2450 sub _resolved_attrs {
2452 return $self->{_attrs} if $self->{_attrs};
2454 my $attrs = { %{ $self->{attrs} || {} } };
2455 my $source = $self->result_source;
2456 my $alias = $attrs->{alias};
2458 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2461 # build columns (as long as select isn't set) into a set of as/select hashes
2462 unless ( $attrs->{select} ) {
2464 ( ref($_) eq 'HASH' )
2468 /^\Q${alias}.\E(.+)$/
2479 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2481 # add the additional columns on
2482 foreach ( 'include_columns', '+columns' ) {
2483 push @colbits, map {
2484 ( ref($_) eq 'HASH' )
2486 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2487 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2490 # start with initial select items
2491 if ( $attrs->{select} ) {
2493 ( ref $attrs->{select} eq 'ARRAY' )
2494 ? [ @{ $attrs->{select} } ]
2495 : [ $attrs->{select} ];
2499 ref $attrs->{as} eq 'ARRAY'
2500 ? [ @{ $attrs->{as} } ]
2503 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2508 # otherwise we intialise select & as to empty
2509 $attrs->{select} = [];
2513 # now add colbits to select/as
2514 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2515 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2518 if ( $adds = delete $attrs->{'+select'} ) {
2519 $adds = [$adds] unless ref $adds eq 'ARRAY';
2521 @{ $attrs->{select} },
2522 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2525 if ( $adds = delete $attrs->{'+as'} ) {
2526 $adds = [$adds] unless ref $adds eq 'ARRAY';
2527 push( @{ $attrs->{as} }, @$adds );
2530 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2532 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2533 my $join = delete $attrs->{join} || {};
2535 if ( defined $attrs->{prefetch} ) {
2536 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2540 $attrs->{from} = # have to copy here to avoid corrupting the original
2542 @{ $attrs->{from} },
2543 $source->resolve_join(
2544 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2550 $attrs->{group_by} ||= $attrs->{select}
2551 if delete $attrs->{distinct};
2552 if ( $attrs->{order_by} ) {
2553 $attrs->{order_by} = (
2554 ref( $attrs->{order_by} ) eq 'ARRAY'
2555 ? [ @{ $attrs->{order_by} } ]
2556 : [ $attrs->{order_by} ]
2560 $attrs->{order_by} = [];
2563 my $collapse = $attrs->{collapse} || {};
2564 if ( my $prefetch = delete $attrs->{prefetch} ) {
2565 $prefetch = $self->_merge_attr( {}, $prefetch );
2567 my $seen = { %{ $attrs->{seen_join} || {} } };
2568 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2570 # bring joins back to level of current class
2572 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2573 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2574 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2576 push( @{ $attrs->{order_by} }, @pre_order );
2578 $attrs->{collapse} = $collapse;
2580 if ( $attrs->{page} ) {
2581 $attrs->{offset} ||= 0;
2582 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2585 return $self->{_attrs} = $attrs;
2589 my ($self, $attr) = @_;
2591 if (ref $attr eq 'HASH') {
2592 return $self->_rollout_hash($attr);
2593 } elsif (ref $attr eq 'ARRAY') {
2594 return $self->_rollout_array($attr);
2600 sub _rollout_array {
2601 my ($self, $attr) = @_;
2604 foreach my $element (@{$attr}) {
2605 if (ref $element eq 'HASH') {
2606 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2607 } elsif (ref $element eq 'ARRAY') {
2608 # XXX - should probably recurse here
2609 push( @rolled_array, @{$self->_rollout_array($element)} );
2611 push( @rolled_array, $element );
2614 return \@rolled_array;
2618 my ($self, $attr) = @_;
2621 foreach my $key (keys %{$attr}) {
2622 push( @rolled_array, { $key => $attr->{$key} } );
2624 return \@rolled_array;
2627 sub _calculate_score {
2628 my ($self, $a, $b) = @_;
2630 if (ref $b eq 'HASH') {
2631 my ($b_key) = keys %{$b};
2632 if (ref $a eq 'HASH') {
2633 my ($a_key) = keys %{$a};
2634 if ($a_key eq $b_key) {
2635 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2640 return ($a eq $b_key) ? 1 : 0;
2643 if (ref $a eq 'HASH') {
2644 my ($a_key) = keys %{$a};
2645 return ($b eq $a_key) ? 1 : 0;
2647 return ($b eq $a) ? 1 : 0;
2653 my ($self, $orig, $import) = @_;
2655 return $import unless defined($orig);
2656 return $orig unless defined($import);
2658 $orig = $self->_rollout_attr($orig);
2659 $import = $self->_rollout_attr($import);
2662 foreach my $import_element ( @{$import} ) {
2663 # find best candidate from $orig to merge $b_element into
2664 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2665 foreach my $orig_element ( @{$orig} ) {
2666 my $score = $self->_calculate_score( $orig_element, $import_element );
2667 if ($score > $best_candidate->{score}) {
2668 $best_candidate->{position} = $position;
2669 $best_candidate->{score} = $score;
2673 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2675 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2676 push( @{$orig}, $import_element );
2678 my $orig_best = $orig->[$best_candidate->{position}];
2679 # merge orig_best and b_element together and replace original with merged
2680 if (ref $orig_best ne 'HASH') {
2681 $orig->[$best_candidate->{position}] = $import_element;
2682 } elsif (ref $import_element eq 'HASH') {
2683 my ($key) = keys %{$orig_best};
2684 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2687 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2697 $self->_source_handle($_[0]->handle);
2699 $self->_source_handle->resolve;
2703 =head2 throw_exception
2705 See L<DBIx::Class::Schema/throw_exception> for details.
2709 sub throw_exception {
2711 if (ref $self && $self->_source_handle->schema) {
2712 $self->_source_handle->schema->throw_exception(@_)
2719 # XXX: FIXME: Attributes docs need clearing up
2723 Attributes are used to refine a ResultSet in various ways when
2724 searching for data. They can be passed to any method which takes an
2725 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2728 These are in no particular order:
2734 =item Value: ( $order_by | \@order_by | \%order_by )
2738 Which column(s) to order the results by. If a single column name, or
2739 an arrayref of names is supplied, the argument is passed through
2740 directly to SQL. The hashref syntax allows for connection-agnostic
2741 specification of ordering direction:
2743 For descending order:
2745 order_by => { -desc => [qw/col1 col2 col3/] }
2747 For explicit ascending order:
2749 order_by => { -asc => 'col' }
2751 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2752 supported, although you are strongly encouraged to use the hashref
2753 syntax as outlined above.
2759 =item Value: \@columns
2763 Shortcut to request a particular set of columns to be retrieved. Each
2764 column spec may be a string (a table column name), or a hash (in which
2765 case the key is the C<as> value, and the value is used as the C<select>
2766 expression). Adds C<me.> onto the start of any column without a C<.> in
2767 it and sets C<select> from that, then auto-populates C<as> from
2768 C<select> as normal. (You may also use the C<cols> attribute, as in
2769 earlier versions of DBIC.)
2775 =item Value: \@columns
2779 Indicates additional columns to be selected from storage. Works the same
2780 as L</columns> but adds columns to the selection. (You may also use the
2781 C<include_columns> attribute, as in earlier versions of DBIC). For
2784 $schema->resultset('CD')->search(undef, {
2785 '+columns' => ['artist.name'],
2789 would return all CDs and include a 'name' column to the information
2790 passed to object inflation. Note that the 'artist' is the name of the
2791 column (or relationship) accessor, and 'name' is the name of the column
2792 accessor in the related table.
2794 =head2 include_columns
2798 =item Value: \@columns
2802 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2808 =item Value: \@select_columns
2812 Indicates which columns should be selected from the storage. You can use
2813 column names, or in the case of RDBMS back ends, function or stored procedure
2816 $rs = $schema->resultset('Employee')->search(undef, {
2819 { count => 'employeeid' },
2824 When you use function/stored procedure names and do not supply an C<as>
2825 attribute, the column names returned are storage-dependent. E.g. MySQL would
2826 return a column named C<count(employeeid)> in the above example.
2832 Indicates additional columns to be selected from storage. Works the same as
2833 L</select> but adds columns to the selection.
2841 Indicates additional column names for those added via L</+select>. See L</as>.
2849 =item Value: \@inflation_names
2853 Indicates column names for object inflation. That is, C<as>
2854 indicates the name that the column can be accessed as via the
2855 C<get_column> method (or via the object accessor, B<if one already
2856 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2858 The C<as> attribute is used in conjunction with C<select>,
2859 usually when C<select> contains one or more function or stored
2862 $rs = $schema->resultset('Employee')->search(undef, {
2865 { count => 'employeeid' }
2867 as => ['name', 'employee_count'],
2870 my $employee = $rs->first(); # get the first Employee
2872 If the object against which the search is performed already has an accessor
2873 matching a column name specified in C<as>, the value can be retrieved using
2874 the accessor as normal:
2876 my $name = $employee->name();
2878 If on the other hand an accessor does not exist in the object, you need to
2879 use C<get_column> instead:
2881 my $employee_count = $employee->get_column('employee_count');
2883 You can create your own accessors if required - see
2884 L<DBIx::Class::Manual::Cookbook> for details.
2886 Please note: This will NOT insert an C<AS employee_count> into the SQL
2887 statement produced, it is used for internal access only. Thus
2888 attempting to use the accessor in an C<order_by> clause or similar
2889 will fail miserably.
2891 To get around this limitation, you can supply literal SQL to your
2892 C<select> attibute that contains the C<AS alias> text, eg:
2894 select => [\'myfield AS alias']
2900 =item Value: ($rel_name | \@rel_names | \%rel_names)
2904 Contains a list of relationships that should be joined for this query. For
2907 # Get CDs by Nine Inch Nails
2908 my $rs = $schema->resultset('CD')->search(
2909 { 'artist.name' => 'Nine Inch Nails' },
2910 { join => 'artist' }
2913 Can also contain a hash reference to refer to the other relation's relations.
2916 package MyApp::Schema::Track;
2917 use base qw/DBIx::Class/;
2918 __PACKAGE__->table('track');
2919 __PACKAGE__->add_columns(qw/trackid cd position title/);
2920 __PACKAGE__->set_primary_key('trackid');
2921 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2924 # In your application
2925 my $rs = $schema->resultset('Artist')->search(
2926 { 'track.title' => 'Teardrop' },
2928 join => { cd => 'track' },
2929 order_by => 'artist.name',
2933 You need to use the relationship (not the table) name in conditions,
2934 because they are aliased as such. The current table is aliased as "me", so
2935 you need to use me.column_name in order to avoid ambiguity. For example:
2937 # Get CDs from 1984 with a 'Foo' track
2938 my $rs = $schema->resultset('CD')->search(
2941 'tracks.name' => 'Foo'
2943 { join => 'tracks' }
2946 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2947 similarly for a third time). For e.g.
2949 my $rs = $schema->resultset('Artist')->search({
2950 'cds.title' => 'Down to Earth',
2951 'cds_2.title' => 'Popular',
2953 join => [ qw/cds cds/ ],
2956 will return a set of all artists that have both a cd with title 'Down
2957 to Earth' and a cd with title 'Popular'.
2959 If you want to fetch related objects from other tables as well, see C<prefetch>
2962 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2968 =item Value: ($rel_name | \@rel_names | \%rel_names)
2972 Contains one or more relationships that should be fetched along with
2973 the main query (when they are accessed afterwards the data will
2974 already be available, without extra queries to the database). This is
2975 useful for when you know you will need the related objects, because it
2976 saves at least one query:
2978 my $rs = $schema->resultset('Tag')->search(
2987 The initial search results in SQL like the following:
2989 SELECT tag.*, cd.*, artist.* FROM tag
2990 JOIN cd ON tag.cd = cd.cdid
2991 JOIN artist ON cd.artist = artist.artistid
2993 L<DBIx::Class> has no need to go back to the database when we access the
2994 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2997 Simple prefetches will be joined automatically, so there is no need
2998 for a C<join> attribute in the above search.
3000 C<prefetch> can be used with the following relationship types: C<belongs_to>,
3001 C<has_one> (or if you're using C<add_relationship>, any relationship declared
3002 with an accessor type of 'single' or 'filter'). A more complex example that
3003 prefetches an artists cds, the tracks on those cds, and the tags associted
3004 with that artist is given below (assuming many-to-many from artists to tags):
3006 my $rs = $schema->resultset('Artist')->search(
3010 { cds => 'tracks' },
3011 { artist_tags => 'tags' }
3017 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3018 attributes will be ignored.
3028 Makes the resultset paged and specifies the page to retrieve. Effectively
3029 identical to creating a non-pages resultset and then calling ->page($page)
3032 If L<rows> attribute is not specified it defualts to 10 rows per page.
3034 When you have a paged resultset, L</count> will only return the number
3035 of rows in the page. To get the total, use the L</pager> and call
3036 C<total_entries> on it.
3046 Specifes the maximum number of rows for direct retrieval or the number of
3047 rows per page if the page attribute or method is used.
3053 =item Value: $offset
3057 Specifies the (zero-based) row number for the first row to be returned, or the
3058 of the first row of the first page if paging is used.
3064 =item Value: \@columns
3068 A arrayref of columns to group by. Can include columns of joined tables.
3070 group_by => [qw/ column1 column2 ... /]
3076 =item Value: $condition
3080 HAVING is a select statement attribute that is applied between GROUP BY and
3081 ORDER BY. It is applied to the after the grouping calculations have been
3084 having => { 'count(employee)' => { '>=', 100 } }
3090 =item Value: (0 | 1)
3094 Set to 1 to group by all columns.
3100 Adds to the WHERE clause.
3102 # only return rows WHERE deleted IS NULL for all searches
3103 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3105 Can be overridden by passing C<{ where => undef }> as an attribute
3112 Set to 1 to cache search results. This prevents extra SQL queries if you
3113 revisit rows in your ResultSet:
3115 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3117 while( my $artist = $resultset->next ) {
3121 $rs->first; # without cache, this would issue a query
3123 By default, searches are not cached.
3125 For more examples of using these attributes, see
3126 L<DBIx::Class::Manual::Cookbook>.
3132 =item Value: \@from_clause
3136 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3137 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3140 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3142 C<join> will usually do what you need and it is strongly recommended that you
3143 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3144 And we really do mean "cannot", not just tried and failed. Attempting to use
3145 this because you're having problems with C<join> is like trying to use x86
3146 ASM because you've got a syntax error in your C. Trust us on this.
3148 Now, if you're still really, really sure you need to use this (and if you're
3149 not 100% sure, ask the mailing list first), here's an explanation of how this
3152 The syntax is as follows -
3155 { <alias1> => <table1> },
3157 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3158 [], # nested JOIN (optional)
3159 { <table1.column1> => <table2.column2>, ... (more conditions) },
3161 # More of the above [ ] may follow for additional joins
3168 ON <table1.column1> = <table2.column2>
3169 <more joins may follow>
3171 An easy way to follow the examples below is to remember the following:
3173 Anything inside "[]" is a JOIN
3174 Anything inside "{}" is a condition for the enclosing JOIN
3176 The following examples utilize a "person" table in a family tree application.
3177 In order to express parent->child relationships, this table is self-joined:
3179 # Person->belongs_to('father' => 'Person');
3180 # Person->belongs_to('mother' => 'Person');
3182 C<from> can be used to nest joins. Here we return all children with a father,
3183 then search against all mothers of those children:
3185 $rs = $schema->resultset('Person')->search(
3188 alias => 'mother', # alias columns in accordance with "from"
3190 { mother => 'person' },
3193 { child => 'person' },
3195 { father => 'person' },
3196 { 'father.person_id' => 'child.father_id' }
3199 { 'mother.person_id' => 'child.mother_id' }
3206 # SELECT mother.* FROM person mother
3209 # JOIN person father
3210 # ON ( father.person_id = child.father_id )
3212 # ON ( mother.person_id = child.mother_id )
3214 The type of any join can be controlled manually. To search against only people
3215 with a father in the person table, we could explicitly use C<INNER JOIN>:
3217 $rs = $schema->resultset('Person')->search(
3220 alias => 'child', # alias columns in accordance with "from"
3222 { child => 'person' },
3224 { father => 'person', -join_type => 'inner' },
3225 { 'father.id' => 'child.father_id' }
3232 # SELECT child.* FROM person child
3233 # INNER JOIN person father ON child.father_id = father.id
3235 If you need to express really complex joins or you need a subselect, you
3236 can supply literal SQL to C<from> via a scalar reference. In this case
3237 the contents of the scalar will replace the table name asscoiated with the
3240 WARNING: This technique might very well not work as expected on chained
3241 searches - you have been warned.
3243 # Assuming the Event resultsource is defined as:
3245 MySchema::Event->add_columns (
3248 is_auto_increment => 1,
3257 MySchema::Event->set_primary_key ('sequence');
3259 # This will get back the latest event for every location. The column
3260 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3261 # combo to limit the resultset
3263 $rs = $schema->resultset('Event');
3264 $table = $rs->result_source->name;
3265 $latest = $rs->search (
3268 (SELECT e1.* FROM $table e1
3270 ON e1.location = e2.location
3271 AND e1.sequence < e2.sequence
3272 WHERE e2.sequence is NULL
3277 # Equivalent SQL (with the DBIC chunks added):
3279 SELECT me.sequence, me.location, me.type FROM
3280 (SELECT e1.* FROM events e1
3282 ON e1.location = e2.location
3283 AND e1.sequence < e2.sequence
3284 WHERE e2.sequence is NULL
3291 =item Value: ( 'update' | 'shared' )
3295 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT