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.
1711 my $attrs = $self->{attrs};
1712 $self->throw_exception("Can't create pager for non-paged rs")
1713 unless $self->{attrs}{page};
1714 $attrs->{rows} ||= 10;
1716 # throw away the paging flags and re-run the count (possibly
1717 # with a subselect) to get the real total count
1718 my $count_attrs = { %$attrs };
1719 delete $count_attrs->{$_} for qw/rows offset page pager/;
1720 my $total_count = (ref $self)->new($self->result_source, $count_attrs);
1722 return $self->{pager} ||= Data::Page->new(
1723 $total_count, $attrs->{rows}, $self->{attrs}{page});
1730 =item Arguments: $page_number
1732 =item Return Value: $rs
1736 Returns a resultset for the $page_number page of the resultset on which page
1737 is called, where each page contains a number of rows equal to the 'rows'
1738 attribute set on the resultset (10 by default).
1743 my ($self, $page) = @_;
1744 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1751 =item Arguments: \%vals
1753 =item Return Value: $rowobject
1757 Creates a new row object in the resultset's result class and returns
1758 it. The row is not inserted into the database at this point, call
1759 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1760 will tell you whether the row object has been inserted or not.
1762 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1767 my ($self, $values) = @_;
1768 $self->throw_exception( "new_result needs a hash" )
1769 unless (ref $values eq 'HASH');
1772 my $alias = $self->{attrs}{alias};
1775 defined $self->{cond}
1776 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1778 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1779 $new{-from_resultset} = [ keys %new ] if keys %new;
1781 $self->throw_exception(
1782 "Can't abstract implicit construct, condition not a hash"
1783 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1785 my $collapsed_cond = (
1787 ? $self->_collapse_cond($self->{cond})
1791 # precendence must be given to passed values over values inherited from
1792 # the cond, so the order here is important.
1793 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1794 while( my($col,$value) = each %implied ){
1795 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1796 $new{$col} = $value->{'='};
1799 $new{$col} = $value if $self->_is_deterministic_value($value);
1805 %{ $self->_remove_alias($values, $alias) },
1806 -source_handle => $self->_source_handle,
1807 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1810 return $self->result_class->new(\%new);
1813 # _is_deterministic_value
1815 # Make an effor to strip non-deterministic values from the condition,
1816 # to make sure new_result chokes less
1818 sub _is_deterministic_value {
1821 my $ref_type = ref $value;
1822 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1823 return 1 if Scalar::Util::blessed($value);
1829 # determines if the resultset defines at least one
1830 # of the attributes supplied
1832 # used to determine if a subquery is neccessary
1835 my ($self, @attr_names) = @_;
1837 my $attrs = $self->_resolved_attrs;
1841 for my $n (@attr_names) {
1842 return 1 if defined $attrs->{$n};
1843 ++$join_check_req if $n =~ /join/;
1846 # a join can be expressed as a multi-level from
1850 ref $attrs->{from} eq 'ARRAY'
1852 @{$attrs->{from}} > 1
1860 # Recursively collapse the condition.
1862 sub _collapse_cond {
1863 my ($self, $cond, $collapsed) = @_;
1867 if (ref $cond eq 'ARRAY') {
1868 foreach my $subcond (@$cond) {
1869 next unless ref $subcond; # -or
1870 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1873 elsif (ref $cond eq 'HASH') {
1874 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1875 foreach my $subcond (@{$cond->{-and}}) {
1876 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1880 foreach my $col (keys %$cond) {
1881 my $value = $cond->{$col};
1882 $collapsed->{$col} = $value;
1892 # Remove the specified alias from the specified query hash. A copy is made so
1893 # the original query is not modified.
1896 my ($self, $query, $alias) = @_;
1898 my %orig = %{ $query || {} };
1901 foreach my $key (keys %orig) {
1903 $unaliased{$key} = $orig{$key};
1906 $unaliased{$1} = $orig{$key}
1907 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1913 =head2 as_query (EXPERIMENTAL)
1917 =item Arguments: none
1919 =item Return Value: \[ $sql, @bind ]
1923 Returns the SQL query and bind vars associated with the invocant.
1925 This is generally used as the RHS for a subquery.
1927 B<NOTE>: This feature is still experimental.
1931 sub as_query { return shift->cursor->as_query(@_) }
1937 =item Arguments: \%vals, \%attrs?
1939 =item Return Value: $rowobject
1943 my $artist = $schema->resultset('Artist')->find_or_new(
1944 { artist => 'fred' }, { key => 'artists' });
1946 $cd->cd_to_producer->find_or_new({ producer => $producer },
1947 { key => 'primary });
1949 Find an existing record from this resultset, based on its primary
1950 key, or a unique constraint. If none exists, instantiate a new result
1951 object and return it. The object will not be saved into your storage
1952 until you call L<DBIx::Class::Row/insert> on it.
1954 You most likely want this method when looking for existing rows using
1955 a unique constraint that is not the primary key, or looking for
1958 If you want objects to be saved immediately, use L</find_or_create> instead.
1960 B<Note>: C<find_or_new> is probably not what you want when creating a
1961 new row in a table that uses primary keys supplied by the
1962 database. Passing in a primary key column with a value of I<undef>
1963 will cause L</find> to attempt to search for a row with a value of
1970 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1971 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1972 my $exists = $self->find($hash, $attrs);
1973 return defined $exists ? $exists : $self->new_result($hash);
1980 =item Arguments: \%vals
1982 =item Return Value: a L<DBIx::Class::Row> $object
1986 Attempt to create a single new row or a row with multiple related rows
1987 in the table represented by the resultset (and related tables). This
1988 will not check for duplicate rows before inserting, use
1989 L</find_or_create> to do that.
1991 To create one row for this resultset, pass a hashref of key/value
1992 pairs representing the columns of the table and the values you wish to
1993 store. If the appropriate relationships are set up, foreign key fields
1994 can also be passed an object representing the foreign row, and the
1995 value will be set to its primary key.
1997 To create related objects, pass a hashref for the value if the related
1998 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1999 and use the name of the relationship as the key. (NOT the name of the field,
2000 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
2001 of hashrefs containing the data for each of the rows to create in the foreign
2002 tables, again using the relationship name as the key.
2004 Instead of hashrefs of plain related data (key/value pairs), you may
2005 also pass new or inserted objects. New objects (not inserted yet, see
2006 L</new>), will be inserted into their appropriate tables.
2008 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
2010 Example of creating a new row.
2012 $person_rs->create({
2013 name=>"Some Person",
2014 email=>"somebody@someplace.com"
2017 Example of creating a new row and also creating rows in a related C<has_many>
2018 or C<has_one> resultset. Note Arrayref.
2021 { artistid => 4, name => 'Manufactured Crap', cds => [
2022 { title => 'My First CD', year => 2006 },
2023 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
2028 Example of creating a new row and also creating a row in a related
2029 C<belongs_to>resultset. Note Hashref.
2032 title=>"Music for Silly Walks",
2035 name=>"Silly Musician",
2042 my ($self, $attrs) = @_;
2043 $self->throw_exception( "create needs a hashref" )
2044 unless ref $attrs eq 'HASH';
2045 return $self->new_result($attrs)->insert;
2048 =head2 find_or_create
2052 =item Arguments: \%vals, \%attrs?
2054 =item Return Value: $rowobject
2058 $cd->cd_to_producer->find_or_create({ producer => $producer },
2059 { key => 'primary });
2061 Tries to find a record based on its primary key or unique constraints; if none
2062 is found, creates one and returns that instead.
2064 my $cd = $schema->resultset('CD')->find_or_create({
2066 artist => 'Massive Attack',
2067 title => 'Mezzanine',
2071 Also takes an optional C<key> attribute, to search by a specific key or unique
2072 constraint. For example:
2074 my $cd = $schema->resultset('CD')->find_or_create(
2076 artist => 'Massive Attack',
2077 title => 'Mezzanine',
2079 { key => 'cd_artist_title' }
2082 B<Note>: Because find_or_create() reads from the database and then
2083 possibly inserts based on the result, this method is subject to a race
2084 condition. Another process could create a record in the table after
2085 the find has completed and before the create has started. To avoid
2086 this problem, use find_or_create() inside a transaction.
2088 B<Note>: C<find_or_create> is probably not what you want when creating
2089 a new row in a table that uses primary keys supplied by the
2090 database. Passing in a primary key column with a value of I<undef>
2091 will cause L</find> to attempt to search for a row with a value of
2094 See also L</find> and L</update_or_create>. For information on how to declare
2095 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2099 sub find_or_create {
2101 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2102 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
2103 my $exists = $self->find($hash, $attrs);
2104 return defined $exists ? $exists : $self->create($hash);
2107 =head2 update_or_create
2111 =item Arguments: \%col_values, { key => $unique_constraint }?
2113 =item Return Value: $rowobject
2117 $resultset->update_or_create({ col => $val, ... });
2119 First, searches for an existing row matching one of the unique constraints
2120 (including the primary key) on the source of this resultset. If a row is
2121 found, updates it with the other given column values. Otherwise, creates a new
2124 Takes an optional C<key> attribute to search on a specific unique constraint.
2127 # In your application
2128 my $cd = $schema->resultset('CD')->update_or_create(
2130 artist => 'Massive Attack',
2131 title => 'Mezzanine',
2134 { key => 'cd_artist_title' }
2137 $cd->cd_to_producer->update_or_create({
2138 producer => $producer,
2145 If no C<key> is specified, it searches on all unique constraints defined on the
2146 source, including the primary key.
2148 If the C<key> is specified as C<primary>, it searches only on the primary key.
2150 See also L</find> and L</find_or_create>. For information on how to declare
2151 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2153 B<Note>: C<update_or_create> is probably not what you want when
2154 looking for a row in a table that uses primary keys supplied by the
2155 database, unless you actually have a key value. Passing in a primary
2156 key column with a value of I<undef> will cause L</find> to attempt to
2157 search for a row with a value of I<NULL>.
2161 sub update_or_create {
2163 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2164 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2166 my $row = $self->find($cond, $attrs);
2168 $row->update($cond);
2172 return $self->create($cond);
2175 =head2 update_or_new
2179 =item Arguments: \%col_values, { key => $unique_constraint }?
2181 =item Return Value: $rowobject
2185 $resultset->update_or_new({ col => $val, ... });
2187 First, searches for an existing row matching one of the unique constraints
2188 (including the primary key) on the source of this resultset. If a row is
2189 found, updates it with the other given column values. Otherwise, instantiate
2190 a new result object and return it. The object will not be saved into your storage
2191 until you call L<DBIx::Class::Row/insert> on it.
2193 Takes an optional C<key> attribute to search on a specific unique constraint.
2196 # In your application
2197 my $cd = $schema->resultset('CD')->update_or_new(
2199 artist => 'Massive Attack',
2200 title => 'Mezzanine',
2203 { key => 'cd_artist_title' }
2206 if ($cd->in_storage) {
2207 # the cd was updated
2210 # the cd is not yet in the database, let's insert it
2214 See also L</find>, L</find_or_create> and L<find_or_new>.
2220 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2221 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2223 my $row = $self->find( $cond, $attrs );
2224 if ( defined $row ) {
2225 $row->update($cond);
2229 return $self->new_result($cond);
2236 =item Arguments: none
2238 =item Return Value: \@cache_objects?
2242 Gets the contents of the cache for the resultset, if the cache is set.
2244 The cache is populated either by using the L</prefetch> attribute to
2245 L</search> or by calling L</set_cache>.
2257 =item Arguments: \@cache_objects
2259 =item Return Value: \@cache_objects
2263 Sets the contents of the cache for the resultset. Expects an arrayref
2264 of objects of the same class as those produced by the resultset. Note that
2265 if the cache is set the resultset will return the cached objects rather
2266 than re-querying the database even if the cache attr is not set.
2268 The contents of the cache can also be populated by using the
2269 L</prefetch> attribute to L</search>.
2274 my ( $self, $data ) = @_;
2275 $self->throw_exception("set_cache requires an arrayref")
2276 if defined($data) && (ref $data ne 'ARRAY');
2277 $self->{all_cache} = $data;
2284 =item Arguments: none
2286 =item Return Value: []
2290 Clears the cache for the resultset.
2295 shift->set_cache(undef);
2298 =head2 related_resultset
2302 =item Arguments: $relationship_name
2304 =item Return Value: $resultset
2308 Returns a related resultset for the supplied relationship name.
2310 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2314 sub related_resultset {
2315 my ($self, $rel) = @_;
2317 $self->{related_resultsets} ||= {};
2318 return $self->{related_resultsets}{$rel} ||= do {
2319 my $rel_obj = $self->result_source->relationship_info($rel);
2321 $self->throw_exception(
2322 "search_related: result source '" . $self->result_source->source_name .
2323 "' has no such relationship $rel")
2326 my ($from,$seen) = $self->_resolve_from($rel);
2328 my $join_count = $seen->{$rel};
2329 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2331 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2332 my %attrs = %{$self->{attrs}||{}};
2333 delete @attrs{qw(result_class alias)};
2337 if (my $cache = $self->get_cache) {
2338 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2339 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2344 my $rel_source = $self->result_source->related_source($rel);
2348 # The reason we do this now instead of passing the alias to the
2349 # search_rs below is that if you wrap/overload resultset on the
2350 # source you need to know what alias it's -going- to have for things
2351 # to work sanely (e.g. RestrictWithObject wants to be able to add
2352 # extra query restrictions, and these may need to be $alias.)
2354 my $attrs = $rel_source->resultset_attributes;
2355 local $attrs->{alias} = $alias;
2357 $rel_source->resultset
2365 where => $self->{cond},
2370 $new->set_cache($new_cache) if $new_cache;
2375 =head2 current_source_alias
2379 =item Arguments: none
2381 =item Return Value: $source_alias
2385 Returns the current table alias for the result source this resultset is built
2386 on, that will be used in the SQL query. Usually it is C<me>.
2388 Currently the source alias that refers to the result set returned by a
2389 L</search>/L</find> family method depends on how you got to the resultset: it's
2390 C<me> by default, but eg. L</search_related> aliases it to the related result
2391 source name (and keeps C<me> referring to the original result set). The long
2392 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2393 (and make this method unnecessary).
2395 Thus it's currently necessary to use this method in predefined queries (see
2396 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2397 source alias of the current result set:
2399 # in a result set class
2401 my ($self, $user) = @_;
2403 my $me = $self->current_source_alias;
2405 return $self->search(
2406 "$me.modified" => $user->id,
2412 sub current_source_alias {
2415 return ($self->{attrs} || {})->{alias} || 'me';
2419 my ($self, $extra_join) = @_;
2420 my $source = $self->result_source;
2421 my $attrs = $self->{attrs};
2423 my $from = $attrs->{from}
2424 || [ { $attrs->{alias} => $source->from } ];
2426 my $seen = { %{$attrs->{seen_join}||{}} };
2428 my $join = ($attrs->{join}
2429 ? [ $attrs->{join}, $extra_join ]
2432 # we need to take the prefetch the attrs into account before we
2433 # ->resolve_join as otherwise they get lost - captainL
2434 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2438 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2441 return ($from,$seen);
2444 sub _resolved_attrs {
2446 return $self->{_attrs} if $self->{_attrs};
2448 my $attrs = { %{ $self->{attrs} || {} } };
2449 my $source = $self->result_source;
2450 my $alias = $attrs->{alias};
2452 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2455 # build columns (as long as select isn't set) into a set of as/select hashes
2456 unless ( $attrs->{select} ) {
2458 ( ref($_) eq 'HASH' )
2462 /^\Q${alias}.\E(.+)$/
2473 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2475 # add the additional columns on
2476 foreach ( 'include_columns', '+columns' ) {
2477 push @colbits, map {
2478 ( ref($_) eq 'HASH' )
2480 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2481 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2484 # start with initial select items
2485 if ( $attrs->{select} ) {
2487 ( ref $attrs->{select} eq 'ARRAY' )
2488 ? [ @{ $attrs->{select} } ]
2489 : [ $attrs->{select} ];
2493 ref $attrs->{as} eq 'ARRAY'
2494 ? [ @{ $attrs->{as} } ]
2497 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2502 # otherwise we intialise select & as to empty
2503 $attrs->{select} = [];
2507 # now add colbits to select/as
2508 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2509 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2512 if ( $adds = delete $attrs->{'+select'} ) {
2513 $adds = [$adds] unless ref $adds eq 'ARRAY';
2515 @{ $attrs->{select} },
2516 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2519 if ( $adds = delete $attrs->{'+as'} ) {
2520 $adds = [$adds] unless ref $adds eq 'ARRAY';
2521 push( @{ $attrs->{as} }, @$adds );
2524 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2526 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2527 my $join = delete $attrs->{join} || {};
2529 if ( defined $attrs->{prefetch} ) {
2530 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2534 $attrs->{from} = # have to copy here to avoid corrupting the original
2536 @{ $attrs->{from} },
2537 $source->resolve_join(
2538 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2544 $attrs->{group_by} ||= $attrs->{select}
2545 if delete $attrs->{distinct};
2546 if ( $attrs->{order_by} ) {
2547 $attrs->{order_by} = (
2548 ref( $attrs->{order_by} ) eq 'ARRAY'
2549 ? [ @{ $attrs->{order_by} } ]
2550 : [ $attrs->{order_by} ]
2554 $attrs->{order_by} = [];
2557 my $collapse = $attrs->{collapse} || {};
2558 if ( my $prefetch = delete $attrs->{prefetch} ) {
2559 $prefetch = $self->_merge_attr( {}, $prefetch );
2561 my $seen = { %{ $attrs->{seen_join} || {} } };
2562 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2564 # bring joins back to level of current class
2566 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2567 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2568 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2570 push( @{ $attrs->{order_by} }, @pre_order );
2572 $attrs->{collapse} = $collapse;
2574 if ( $attrs->{page} ) {
2575 $attrs->{offset} ||= 0;
2576 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2579 return $self->{_attrs} = $attrs;
2583 my ($self, $attr) = @_;
2585 if (ref $attr eq 'HASH') {
2586 return $self->_rollout_hash($attr);
2587 } elsif (ref $attr eq 'ARRAY') {
2588 return $self->_rollout_array($attr);
2594 sub _rollout_array {
2595 my ($self, $attr) = @_;
2598 foreach my $element (@{$attr}) {
2599 if (ref $element eq 'HASH') {
2600 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2601 } elsif (ref $element eq 'ARRAY') {
2602 # XXX - should probably recurse here
2603 push( @rolled_array, @{$self->_rollout_array($element)} );
2605 push( @rolled_array, $element );
2608 return \@rolled_array;
2612 my ($self, $attr) = @_;
2615 foreach my $key (keys %{$attr}) {
2616 push( @rolled_array, { $key => $attr->{$key} } );
2618 return \@rolled_array;
2621 sub _calculate_score {
2622 my ($self, $a, $b) = @_;
2624 if (ref $b eq 'HASH') {
2625 my ($b_key) = keys %{$b};
2626 if (ref $a eq 'HASH') {
2627 my ($a_key) = keys %{$a};
2628 if ($a_key eq $b_key) {
2629 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2634 return ($a eq $b_key) ? 1 : 0;
2637 if (ref $a eq 'HASH') {
2638 my ($a_key) = keys %{$a};
2639 return ($b eq $a_key) ? 1 : 0;
2641 return ($b eq $a) ? 1 : 0;
2647 my ($self, $orig, $import) = @_;
2649 return $import unless defined($orig);
2650 return $orig unless defined($import);
2652 $orig = $self->_rollout_attr($orig);
2653 $import = $self->_rollout_attr($import);
2656 foreach my $import_element ( @{$import} ) {
2657 # find best candidate from $orig to merge $b_element into
2658 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2659 foreach my $orig_element ( @{$orig} ) {
2660 my $score = $self->_calculate_score( $orig_element, $import_element );
2661 if ($score > $best_candidate->{score}) {
2662 $best_candidate->{position} = $position;
2663 $best_candidate->{score} = $score;
2667 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2669 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2670 push( @{$orig}, $import_element );
2672 my $orig_best = $orig->[$best_candidate->{position}];
2673 # merge orig_best and b_element together and replace original with merged
2674 if (ref $orig_best ne 'HASH') {
2675 $orig->[$best_candidate->{position}] = $import_element;
2676 } elsif (ref $import_element eq 'HASH') {
2677 my ($key) = keys %{$orig_best};
2678 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2681 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2691 $self->_source_handle($_[0]->handle);
2693 $self->_source_handle->resolve;
2697 =head2 throw_exception
2699 See L<DBIx::Class::Schema/throw_exception> for details.
2703 sub throw_exception {
2705 if (ref $self && $self->_source_handle->schema) {
2706 $self->_source_handle->schema->throw_exception(@_)
2713 # XXX: FIXME: Attributes docs need clearing up
2717 Attributes are used to refine a ResultSet in various ways when
2718 searching for data. They can be passed to any method which takes an
2719 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2722 These are in no particular order:
2728 =item Value: ( $order_by | \@order_by | \%order_by )
2732 Which column(s) to order the results by. If a single column name, or
2733 an arrayref of names is supplied, the argument is passed through
2734 directly to SQL. The hashref syntax allows for connection-agnostic
2735 specification of ordering direction:
2737 For descending order:
2739 order_by => { -desc => [qw/col1 col2 col3/] }
2741 For explicit ascending order:
2743 order_by => { -asc => 'col' }
2745 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2746 supported, although you are strongly encouraged to use the hashref
2747 syntax as outlined above.
2753 =item Value: \@columns
2757 Shortcut to request a particular set of columns to be retrieved. Each
2758 column spec may be a string (a table column name), or a hash (in which
2759 case the key is the C<as> value, and the value is used as the C<select>
2760 expression). Adds C<me.> onto the start of any column without a C<.> in
2761 it and sets C<select> from that, then auto-populates C<as> from
2762 C<select> as normal. (You may also use the C<cols> attribute, as in
2763 earlier versions of DBIC.)
2769 =item Value: \@columns
2773 Indicates additional columns to be selected from storage. Works the same
2774 as L</columns> but adds columns to the selection. (You may also use the
2775 C<include_columns> attribute, as in earlier versions of DBIC). For
2778 $schema->resultset('CD')->search(undef, {
2779 '+columns' => ['artist.name'],
2783 would return all CDs and include a 'name' column to the information
2784 passed to object inflation. Note that the 'artist' is the name of the
2785 column (or relationship) accessor, and 'name' is the name of the column
2786 accessor in the related table.
2788 =head2 include_columns
2792 =item Value: \@columns
2796 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2802 =item Value: \@select_columns
2806 Indicates which columns should be selected from the storage. You can use
2807 column names, or in the case of RDBMS back ends, function or stored procedure
2810 $rs = $schema->resultset('Employee')->search(undef, {
2813 { count => 'employeeid' },
2818 When you use function/stored procedure names and do not supply an C<as>
2819 attribute, the column names returned are storage-dependent. E.g. MySQL would
2820 return a column named C<count(employeeid)> in the above example.
2826 Indicates additional columns to be selected from storage. Works the same as
2827 L</select> but adds columns to the selection.
2835 Indicates additional column names for those added via L</+select>. See L</as>.
2843 =item Value: \@inflation_names
2847 Indicates column names for object inflation. That is, C<as>
2848 indicates the name that the column can be accessed as via the
2849 C<get_column> method (or via the object accessor, B<if one already
2850 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2852 The C<as> attribute is used in conjunction with C<select>,
2853 usually when C<select> contains one or more function or stored
2856 $rs = $schema->resultset('Employee')->search(undef, {
2859 { count => 'employeeid' }
2861 as => ['name', 'employee_count'],
2864 my $employee = $rs->first(); # get the first Employee
2866 If the object against which the search is performed already has an accessor
2867 matching a column name specified in C<as>, the value can be retrieved using
2868 the accessor as normal:
2870 my $name = $employee->name();
2872 If on the other hand an accessor does not exist in the object, you need to
2873 use C<get_column> instead:
2875 my $employee_count = $employee->get_column('employee_count');
2877 You can create your own accessors if required - see
2878 L<DBIx::Class::Manual::Cookbook> for details.
2880 Please note: This will NOT insert an C<AS employee_count> into the SQL
2881 statement produced, it is used for internal access only. Thus
2882 attempting to use the accessor in an C<order_by> clause or similar
2883 will fail miserably.
2885 To get around this limitation, you can supply literal SQL to your
2886 C<select> attibute that contains the C<AS alias> text, eg:
2888 select => [\'myfield AS alias']
2894 =item Value: ($rel_name | \@rel_names | \%rel_names)
2898 Contains a list of relationships that should be joined for this query. For
2901 # Get CDs by Nine Inch Nails
2902 my $rs = $schema->resultset('CD')->search(
2903 { 'artist.name' => 'Nine Inch Nails' },
2904 { join => 'artist' }
2907 Can also contain a hash reference to refer to the other relation's relations.
2910 package MyApp::Schema::Track;
2911 use base qw/DBIx::Class/;
2912 __PACKAGE__->table('track');
2913 __PACKAGE__->add_columns(qw/trackid cd position title/);
2914 __PACKAGE__->set_primary_key('trackid');
2915 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2918 # In your application
2919 my $rs = $schema->resultset('Artist')->search(
2920 { 'track.title' => 'Teardrop' },
2922 join => { cd => 'track' },
2923 order_by => 'artist.name',
2927 You need to use the relationship (not the table) name in conditions,
2928 because they are aliased as such. The current table is aliased as "me", so
2929 you need to use me.column_name in order to avoid ambiguity. For example:
2931 # Get CDs from 1984 with a 'Foo' track
2932 my $rs = $schema->resultset('CD')->search(
2935 'tracks.name' => 'Foo'
2937 { join => 'tracks' }
2940 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2941 similarly for a third time). For e.g.
2943 my $rs = $schema->resultset('Artist')->search({
2944 'cds.title' => 'Down to Earth',
2945 'cds_2.title' => 'Popular',
2947 join => [ qw/cds cds/ ],
2950 will return a set of all artists that have both a cd with title 'Down
2951 to Earth' and a cd with title 'Popular'.
2953 If you want to fetch related objects from other tables as well, see C<prefetch>
2956 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2962 =item Value: ($rel_name | \@rel_names | \%rel_names)
2966 Contains one or more relationships that should be fetched along with
2967 the main query (when they are accessed afterwards the data will
2968 already be available, without extra queries to the database). This is
2969 useful for when you know you will need the related objects, because it
2970 saves at least one query:
2972 my $rs = $schema->resultset('Tag')->search(
2981 The initial search results in SQL like the following:
2983 SELECT tag.*, cd.*, artist.* FROM tag
2984 JOIN cd ON tag.cd = cd.cdid
2985 JOIN artist ON cd.artist = artist.artistid
2987 L<DBIx::Class> has no need to go back to the database when we access the
2988 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2991 Simple prefetches will be joined automatically, so there is no need
2992 for a C<join> attribute in the above search.
2994 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2995 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2996 with an accessor type of 'single' or 'filter'). A more complex example that
2997 prefetches an artists cds, the tracks on those cds, and the tags associted
2998 with that artist is given below (assuming many-to-many from artists to tags):
3000 my $rs = $schema->resultset('Artist')->search(
3004 { cds => 'tracks' },
3005 { artist_tags => 'tags' }
3011 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
3012 attributes will be ignored.
3022 Makes the resultset paged and specifies the page to retrieve. Effectively
3023 identical to creating a non-pages resultset and then calling ->page($page)
3026 If L<rows> attribute is not specified it defualts to 10 rows per page.
3028 When you have a paged resultset, L</count> will only return the number
3029 of rows in the page. To get the total, use the L</pager> and call
3030 C<total_entries> on it.
3040 Specifes the maximum number of rows for direct retrieval or the number of
3041 rows per page if the page attribute or method is used.
3047 =item Value: $offset
3051 Specifies the (zero-based) row number for the first row to be returned, or the
3052 of the first row of the first page if paging is used.
3058 =item Value: \@columns
3062 A arrayref of columns to group by. Can include columns of joined tables.
3064 group_by => [qw/ column1 column2 ... /]
3070 =item Value: $condition
3074 HAVING is a select statement attribute that is applied between GROUP BY and
3075 ORDER BY. It is applied to the after the grouping calculations have been
3078 having => { 'count(employee)' => { '>=', 100 } }
3084 =item Value: (0 | 1)
3088 Set to 1 to group by all columns.
3094 Adds to the WHERE clause.
3096 # only return rows WHERE deleted IS NULL for all searches
3097 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
3099 Can be overridden by passing C<{ where => undef }> as an attribute
3106 Set to 1 to cache search results. This prevents extra SQL queries if you
3107 revisit rows in your ResultSet:
3109 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
3111 while( my $artist = $resultset->next ) {
3115 $rs->first; # without cache, this would issue a query
3117 By default, searches are not cached.
3119 For more examples of using these attributes, see
3120 L<DBIx::Class::Manual::Cookbook>.
3126 =item Value: \@from_clause
3130 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3131 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3134 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3136 C<join> will usually do what you need and it is strongly recommended that you
3137 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3138 And we really do mean "cannot", not just tried and failed. Attempting to use
3139 this because you're having problems with C<join> is like trying to use x86
3140 ASM because you've got a syntax error in your C. Trust us on this.
3142 Now, if you're still really, really sure you need to use this (and if you're
3143 not 100% sure, ask the mailing list first), here's an explanation of how this
3146 The syntax is as follows -
3149 { <alias1> => <table1> },
3151 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3152 [], # nested JOIN (optional)
3153 { <table1.column1> => <table2.column2>, ... (more conditions) },
3155 # More of the above [ ] may follow for additional joins
3162 ON <table1.column1> = <table2.column2>
3163 <more joins may follow>
3165 An easy way to follow the examples below is to remember the following:
3167 Anything inside "[]" is a JOIN
3168 Anything inside "{}" is a condition for the enclosing JOIN
3170 The following examples utilize a "person" table in a family tree application.
3171 In order to express parent->child relationships, this table is self-joined:
3173 # Person->belongs_to('father' => 'Person');
3174 # Person->belongs_to('mother' => 'Person');
3176 C<from> can be used to nest joins. Here we return all children with a father,
3177 then search against all mothers of those children:
3179 $rs = $schema->resultset('Person')->search(
3182 alias => 'mother', # alias columns in accordance with "from"
3184 { mother => 'person' },
3187 { child => 'person' },
3189 { father => 'person' },
3190 { 'father.person_id' => 'child.father_id' }
3193 { 'mother.person_id' => 'child.mother_id' }
3200 # SELECT mother.* FROM person mother
3203 # JOIN person father
3204 # ON ( father.person_id = child.father_id )
3206 # ON ( mother.person_id = child.mother_id )
3208 The type of any join can be controlled manually. To search against only people
3209 with a father in the person table, we could explicitly use C<INNER JOIN>:
3211 $rs = $schema->resultset('Person')->search(
3214 alias => 'child', # alias columns in accordance with "from"
3216 { child => 'person' },
3218 { father => 'person', -join_type => 'inner' },
3219 { 'father.id' => 'child.father_id' }
3226 # SELECT child.* FROM person child
3227 # INNER JOIN person father ON child.father_id = father.id
3229 If you need to express really complex joins or you need a subselect, you
3230 can supply literal SQL to C<from> via a scalar reference. In this case
3231 the contents of the scalar will replace the table name asscoiated with the
3234 WARNING: This technique might very well not work as expected on chained
3235 searches - you have been warned.
3237 # Assuming the Event resultsource is defined as:
3239 MySchema::Event->add_columns (
3242 is_auto_increment => 1,
3251 MySchema::Event->set_primary_key ('sequence');
3253 # This will get back the latest event for every location. The column
3254 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3255 # combo to limit the resultset
3257 $rs = $schema->resultset('Event');
3258 $table = $rs->result_source->name;
3259 $latest = $rs->search (
3262 (SELECT e1.* FROM $table e1
3264 ON e1.location = e2.location
3265 AND e1.sequence < e2.sequence
3266 WHERE e2.sequence is NULL
3271 # Equivalent SQL (with the DBIC chunks added):
3273 SELECT me.sequence, me.location, me.type FROM
3274 (SELECT e1.* FROM events e1
3276 ON e1.location = e2.location
3277 AND e1.sequence < e2.sequence
3278 WHERE e2.sequence is NULL
3285 =item Value: ( 'update' | 'shared' )
3289 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT