1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
16 use base qw/DBIx::Class/;
18 __PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
22 DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
26 my $users_rs = $schema->resultset('User');
27 my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
28 my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
32 A ResultSet is an object which stores a set of conditions representing
33 a query. It is the backbone of DBIx::Class (i.e. the really
34 important/useful bit).
36 No SQL is executed on the database when a ResultSet is created, it
37 just stores all the conditions needed to create the query.
39 A basic ResultSet representing the data of an entire table is returned
40 by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
41 L<Source|DBIx::Class::Manual::Glossary/Source> name.
43 my $users_rs = $schema->resultset('User');
45 A new ResultSet is returned from calling L</search> on an existing
46 ResultSet. The new one will contain all the conditions of the
47 original, plus any new conditions added in the C<search> call.
49 A ResultSet is also an iterator. L</next> is used to return all the
50 L<DBIx::Class::Row>s the ResultSet represents.
52 The query that the ResultSet represents is B<only> executed against
53 the database when these methods are called:
73 =head2 Chaining resultsets
75 Let's say you've got a query that needs to be run to return some data
76 to the user. But, you have an authorization system in place that
77 prevents certain users from seeing certain information. So, you want
78 to construct the basic query in one method, but add constraints to it in
83 my $request = $self->get_request; # Get a request object somehow.
84 my $schema = $self->get_schema; # Get the DBIC schema object somehow.
86 my $cd_rs = $schema->resultset('CD')->search({
87 title => $request->param('title'),
88 year => $request->param('year'),
91 $self->apply_security_policy( $cd_rs );
96 sub apply_security_policy {
105 =head3 Resolving conditions and attributes
107 When a resultset is chained from another resultset, conditions and
108 attributes with the same keys need resolving.
110 L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
111 into the existing ones from the original resultset.
113 The L</where>, L</having> attribute, and any search conditions are
114 merged with an SQL C<AND> to the existing condition from the original
117 All other attributes are overridden by any new ones supplied in the
120 =head2 Multiple queries
122 Since a resultset just defines a query, you can do all sorts of
123 things with it with the same object.
125 # Don't hit the DB yet.
126 my $cd_rs = $schema->resultset('CD')->search({
127 title => 'something',
131 # Each of these hits the DB individually.
132 my $count = $cd_rs->count;
133 my $most_recent = $cd_rs->get_column('date_released')->max();
134 my @records = $cd_rs->all;
136 And it's not just limited to SELECT statements.
142 $cd_rs->create({ artist => 'Fred' });
144 Which is the same as:
146 $schema->resultset('CD')->create({
147 title => 'something',
152 See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
156 If a resultset is used in a numeric context it returns the L</count>.
157 However, if it is used in a booleand context it is always true. So if
158 you want to check if a resultset has any results use C<if $rs != 0>.
159 C<if $rs> will always be true.
167 =item Arguments: $source, \%$attrs
169 =item Return Value: $rs
173 The resultset constructor. Takes a source object (usually a
174 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
175 L</ATTRIBUTES> below). Does not perform any queries -- these are
176 executed as needed by the other methods.
178 Generally you won't need to construct a resultset manually. You'll
179 automatically get one from e.g. a L</search> called in scalar context:
181 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
183 IMPORTANT: If called on an object, proxies to new_result instead so
185 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
187 will return a CD object, not a ResultSet.
193 return $class->new_result(@_) if ref $class;
195 my ($source, $attrs) = @_;
196 $source = $source->handle
197 unless $source->isa('DBIx::Class::ResultSourceHandle');
198 $attrs = { %{$attrs||{}} };
200 if ($attrs->{page}) {
201 $attrs->{rows} ||= 10;
204 $attrs->{alias} ||= 'me';
206 # Creation of {} and bless separated to mitigate RH perl bug
207 # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
209 _source_handle => $source,
210 cond => $attrs->{where},
219 $attrs->{result_class} || $source->resolve->result_class
229 =item Arguments: $cond, \%attrs?
231 =item Return Value: $resultset (scalar context), @row_objs (list context)
235 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
236 my $new_rs = $cd_rs->search({ year => 2005 });
238 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
239 # year = 2005 OR year = 2004
241 If you need to pass in additional attributes but no additional condition,
242 call it as C<search(undef, \%attrs)>.
244 # "SELECT name, artistid FROM $artist_table"
245 my @all_artists = $schema->resultset('Artist')->search(undef, {
246 columns => [qw/name artistid/],
249 For a list of attributes that can be passed to C<search>, see
250 L</ATTRIBUTES>. For more examples of using this function, see
251 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
252 documentation for the first argument, see L<SQL::Abstract>.
254 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
260 my $rs = $self->search_rs( @_ );
261 return (wantarray ? $rs->all : $rs);
268 =item Arguments: $cond, \%attrs?
270 =item Return Value: $resultset
274 This method does the same exact thing as search() except it will
275 always return a resultset, even in list context.
282 # Special-case handling for (undef, undef).
283 if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
288 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
289 my $our_attrs = { %{$self->{attrs}} };
290 my $having = delete $our_attrs->{having};
291 my $where = delete $our_attrs->{where};
295 my %safe = (alias => 1, cache => 1);
298 (@_ && defined($_[0])) # @_ == () or (undef)
300 (keys %$attrs # empty attrs or only 'safe' attrs
301 && List::Util::first { !$safe{$_} } keys %$attrs)
303 # no search, effectively just a clone
304 $rows = $self->get_cache;
307 my $new_attrs = { %{$our_attrs}, %{$attrs} };
309 # merge new attrs into inherited
310 foreach my $key (qw/join prefetch +select +as bind/) {
311 next unless exists $attrs->{$key};
312 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
317 (@_ == 1 || ref $_[0] eq "HASH")
319 (ref $_[0] eq 'HASH')
321 (keys %{ $_[0] } > 0)
329 ? $self->throw_exception("Odd number of arguments to search")
336 if (defined $where) {
337 $new_attrs->{where} = (
338 defined $new_attrs->{where}
341 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
342 } $where, $new_attrs->{where}
349 $new_attrs->{where} = (
350 defined $new_attrs->{where}
353 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
354 } $cond, $new_attrs->{where}
360 if (defined $having) {
361 $new_attrs->{having} = (
362 defined $new_attrs->{having}
365 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
366 } $having, $new_attrs->{having}
372 my $rs = (ref $self)->new($self->result_source, $new_attrs);
374 $rs->set_cache($rows);
379 =head2 search_literal
383 =item Arguments: $sql_fragment, @bind_values
385 =item Return Value: $resultset (scalar context), @row_objs (list context)
389 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
390 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
392 Pass a literal chunk of SQL to be added to the conditional part of the
395 CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
396 only be used in that context. C<search_literal> is a convenience method.
397 It is equivalent to calling $schema->search(\[]), but if you want to ensure
398 columns are bound correctly, use C<search>.
400 Example of how to use C<search> instead of C<search_literal>
402 my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
403 my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
406 See L<DBIx::Class::Manual::Cookbook/Searching> and
407 L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
408 require C<search_literal>.
413 my ($self, $sql, @bind) = @_;
415 if ( @bind && ref($bind[-1]) eq 'HASH' ) {
418 return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
425 =item Arguments: @values | \%cols, \%attrs?
427 =item Return Value: $row_object | undef
431 Finds a row based on its primary key or unique constraint. For example, to find
432 a row by its primary key:
434 my $cd = $schema->resultset('CD')->find(5);
436 You can also find a row by a specific unique constraint using the C<key>
437 attribute. For example:
439 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
440 key => 'cd_artist_title'
443 Additionally, you can specify the columns explicitly by name:
445 my $cd = $schema->resultset('CD')->find(
447 artist => 'Massive Attack',
448 title => 'Mezzanine',
450 { key => 'cd_artist_title' }
453 If the C<key> is specified as C<primary>, it searches only on the primary key.
455 If no C<key> is specified, it searches on all unique constraints defined on the
456 source for which column data is provided, including the primary key.
458 If your table does not have a primary key, you B<must> provide a value for the
459 C<key> attribute matching one of the unique constraints on the source.
461 In addition to C<key>, L</find> recognizes and applies standard
462 L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
464 Note: If your query does not return only one row, a warning is generated:
466 Query returned more than one row
468 See also L</find_or_create> and L</update_or_create>. For information on how to
469 declare unique constraints, see
470 L<DBIx::Class::ResultSource/add_unique_constraint>.
476 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
478 # Default to the primary key, but allow a specific key
479 my @cols = exists $attrs->{key}
480 ? $self->result_source->unique_constraint_columns($attrs->{key})
481 : $self->result_source->primary_columns;
482 $self->throw_exception(
483 "Can't find unless a primary key is defined or unique constraint is specified"
486 # Parse out a hashref from input
488 if (ref $_[0] eq 'HASH') {
489 $input_query = { %{$_[0]} };
491 elsif (@_ == @cols) {
493 @{$input_query}{@cols} = @_;
496 # Compatibility: Allow e.g. find(id => $value)
497 carp "Find by key => value deprecated; please use a hashref instead";
501 my (%related, $info);
503 KEY: foreach my $key (keys %$input_query) {
504 if (ref($input_query->{$key})
505 && ($info = $self->result_source->relationship_info($key))) {
506 my $val = delete $input_query->{$key};
507 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
508 my $rel_q = $self->result_source->resolve_condition(
509 $info->{cond}, $val, $key
511 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
512 @related{keys %$rel_q} = values %$rel_q;
515 if (my @keys = keys %related) {
516 @{$input_query}{@keys} = values %related;
520 # Build the final query: Default to the disjunction of the unique queries,
521 # but allow the input query in case the ResultSet defines the query or the
522 # user is abusing find
523 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
525 if (exists $attrs->{key}) {
526 my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
527 my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
528 $query = $self->_add_alias($unique_query, $alias);
531 my @unique_queries = $self->_unique_queries($input_query, $attrs);
532 $query = @unique_queries
533 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
534 : $self->_add_alias($input_query, $alias);
539 my $rs = $self->search($query, $attrs);
540 if (keys %{$rs->_resolved_attrs->{collapse}}) {
542 carp "Query returned more than one row" if $rs->next;
550 if (keys %{$self->_resolved_attrs->{collapse}}) {
551 my $rs = $self->search($query);
553 carp "Query returned more than one row" if $rs->next;
557 return $self->single($query);
564 # Add the specified alias to the specified query hash. A copy is made so the
565 # original query is not modified.
568 my ($self, $query, $alias) = @_;
570 my %aliased = %$query;
571 foreach my $col (grep { ! m/\./ } keys %aliased) {
572 $aliased{"$alias.$col"} = delete $aliased{$col};
580 # Build a list of queries which satisfy unique constraints.
582 sub _unique_queries {
583 my ($self, $query, $attrs) = @_;
585 my @constraint_names = exists $attrs->{key}
587 : $self->result_source->unique_constraint_names;
589 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
590 my $num_where = scalar keys %$where;
593 foreach my $name (@constraint_names) {
594 my @unique_cols = $self->result_source->unique_constraint_columns($name);
595 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
597 my $num_cols = scalar @unique_cols;
598 my $num_query = scalar keys %$unique_query;
600 my $total = $num_query + $num_where;
601 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
602 # The query is either unique on its own or is unique in combination with
603 # the existing where clause
604 push @unique_queries, $unique_query;
608 return @unique_queries;
611 # _build_unique_query
613 # Constrain the specified query hash based on the specified column names.
615 sub _build_unique_query {
616 my ($self, $query, $unique_cols) = @_;
619 map { $_ => $query->{$_} }
620 grep { exists $query->{$_} }
625 =head2 search_related
629 =item Arguments: $rel, $cond, \%attrs?
631 =item Return Value: $new_resultset
635 $new_rs = $cd_rs->search_related('artist', {
639 Searches the specified relationship, optionally specifying a condition and
640 attributes for matching records. See L</ATTRIBUTES> for more information.
645 return shift->related_resultset(shift)->search(@_);
648 =head2 search_related_rs
650 This method works exactly the same as search_related, except that
651 it guarantees a restultset, even in list context.
655 sub search_related_rs {
656 return shift->related_resultset(shift)->search_rs(@_);
663 =item Arguments: none
665 =item Return Value: $cursor
669 Returns a storage-driven cursor to the given resultset. See
670 L<DBIx::Class::Cursor> for more information.
677 my $attrs = { %{$self->_resolved_attrs} };
678 return $self->{cursor}
679 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
680 $attrs->{where},$attrs);
687 =item Arguments: $cond?
689 =item Return Value: $row_object?
693 my $cd = $schema->resultset('CD')->single({ year => 2001 });
695 Inflates the first result without creating a cursor if the resultset has
696 any records in it; if not returns nothing. Used by L</find> as a lean version of
699 While this method can take an optional search condition (just like L</search>)
700 being a fast-code-path it does not recognize search attributes. If you need to
701 add extra joins or similar, call L</search> and then chain-call L</single> on the
702 L<DBIx::Class::ResultSet> returned.
708 As of 0.08100, this method enforces the assumption that the preceeding
709 query returns only one row. If more than one row is returned, you will receive
712 Query returned more than one row
714 In this case, you should be using L</first> or L</find> instead, or if you really
715 know what you are doing, use the L</rows> attribute to explicitly limit the size
723 my ($self, $where) = @_;
725 $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
728 my $attrs = { %{$self->_resolved_attrs} };
730 if (defined $attrs->{where}) {
733 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
734 $where, delete $attrs->{where} ]
737 $attrs->{where} = $where;
741 # XXX: Disabled since it doesn't infer uniqueness in all cases
742 # unless ($self->_is_unique_query($attrs->{where})) {
743 # carp "Query not guaranteed to return a single row"
744 # . "; please declare your unique constraints or use search instead";
747 my @data = $self->result_source->storage->select_single(
748 $attrs->{from}, $attrs->{select},
749 $attrs->{where}, $attrs
752 return (@data ? ($self->_construct_object(@data))[0] : undef);
757 # Try to determine if the specified query is guaranteed to be unique, based on
758 # the declared unique constraints.
760 sub _is_unique_query {
761 my ($self, $query) = @_;
763 my $collapsed = $self->_collapse_query($query);
764 my $alias = $self->{attrs}{alias};
766 foreach my $name ($self->result_source->unique_constraint_names) {
767 my @unique_cols = map {
769 } $self->result_source->unique_constraint_columns($name);
771 # Count the values for each unique column
772 my %seen = map { $_ => 0 } @unique_cols;
774 foreach my $key (keys %$collapsed) {
775 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
776 next unless exists $seen{$aliased}; # Additional constraints are okay
777 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
780 # If we get 0 or more than 1 value for a column, it's not necessarily unique
781 return 1 unless grep { $_ != 1 } values %seen;
789 # Recursively collapse the query, accumulating values for each column.
791 sub _collapse_query {
792 my ($self, $query, $collapsed) = @_;
796 if (ref $query eq 'ARRAY') {
797 foreach my $subquery (@$query) {
798 next unless ref $subquery; # -or
799 $collapsed = $self->_collapse_query($subquery, $collapsed);
802 elsif (ref $query eq 'HASH') {
803 if (keys %$query and (keys %$query)[0] eq '-and') {
804 foreach my $subquery (@{$query->{-and}}) {
805 $collapsed = $self->_collapse_query($subquery, $collapsed);
809 foreach my $col (keys %$query) {
810 my $value = $query->{$col};
811 $collapsed->{$col}{$value}++;
823 =item Arguments: $cond?
825 =item Return Value: $resultsetcolumn
829 my $max_length = $rs->get_column('length')->max;
831 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
836 my ($self, $column) = @_;
837 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
845 =item Arguments: $cond, \%attrs?
847 =item Return Value: $resultset (scalar context), @row_objs (list context)
851 # WHERE title LIKE '%blue%'
852 $cd_rs = $rs->search_like({ title => '%blue%'});
854 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
855 that this is simply a convenience method retained for ex Class::DBI users.
856 You most likely want to use L</search> with specific operators.
858 For more information, see L<DBIx::Class::Manual::Cookbook>.
860 This method is deprecated and will be removed in 0.09. Use L</search()>
861 instead. An example conversion is:
863 ->search_like({ foo => 'bar' });
867 ->search({ foo => { like => 'bar' } });
874 'search_like() is deprecated and will be removed in 0.09.',
875 'Instead use ->search({ x => { -like => "y%" } })',
876 '(note the outer pair of {}s - they are important!)'
878 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
879 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
880 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
881 return $class->search($query, { %$attrs });
888 =item Arguments: $first, $last
890 =item Return Value: $resultset (scalar context), @row_objs (list context)
894 Returns a resultset or object list representing a subset of elements from the
895 resultset slice is called on. Indexes are from 0, i.e., to get the first
898 my ($one, $two, $three) = $rs->slice(0, 2);
903 my ($self, $min, $max) = @_;
904 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
905 $attrs->{offset} = $self->{attrs}{offset} || 0;
906 $attrs->{offset} += $min;
907 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
908 return $self->search(undef(), $attrs);
909 #my $slice = (ref $self)->new($self->result_source, $attrs);
910 #return (wantarray ? $slice->all : $slice);
917 =item Arguments: none
919 =item Return Value: $result?
923 Returns the next element in the resultset (C<undef> is there is none).
925 Can be used to efficiently iterate over records in the resultset:
927 my $rs = $schema->resultset('CD')->search;
928 while (my $cd = $rs->next) {
932 Note that you need to store the resultset object, and call C<next> on it.
933 Calling C<< resultset('Table')->next >> repeatedly will always return the
934 first record from the resultset.
940 if (my $cache = $self->get_cache) {
941 $self->{all_cache_position} ||= 0;
942 return $cache->[$self->{all_cache_position}++];
944 if ($self->{attrs}{cache}) {
945 $self->{all_cache_position} = 1;
946 return ($self->all)[0];
948 if ($self->{stashed_objects}) {
949 my $obj = shift(@{$self->{stashed_objects}});
950 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
954 exists $self->{stashed_row}
955 ? @{delete $self->{stashed_row}}
956 : $self->cursor->next
958 return undef unless (@row);
959 my ($row, @more) = $self->_construct_object(@row);
960 $self->{stashed_objects} = \@more if @more;
964 sub _construct_object {
965 my ($self, @row) = @_;
966 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
967 my @new = $self->result_class->inflate_result($self->result_source, @$info);
968 @new = $self->{_attrs}{record_filter}->(@new)
969 if exists $self->{_attrs}{record_filter};
973 sub _collapse_result {
974 my ($self, $as_proto, $row) = @_;
978 # 'foo' => [ undef, 'foo' ]
979 # 'foo.bar' => [ 'foo', 'bar' ]
980 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
982 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
984 my %collapse = %{$self->{_attrs}{collapse}||{}};
988 # if we're doing collapsing (has_many prefetch) we need to grab records
989 # until the PK changes, so fill @pri_index. if not, we leave it empty so
990 # we know we don't have to bother.
992 # the reason for not using the collapse stuff directly is because if you
993 # had for e.g. two artists in a row with no cds, the collapse info for
994 # both would be NULL (undef) so you'd lose the second artist
996 # store just the index so we can check the array positions from the row
997 # without having to contruct the full hash
999 if (keys %collapse) {
1000 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
1001 foreach my $i (0 .. $#construct_as) {
1002 next if defined($construct_as[$i][0]); # only self table
1003 if (delete $pri{$construct_as[$i][1]}) {
1004 push(@pri_index, $i);
1006 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
1010 # no need to do an if, it'll be empty if @pri_index is empty anyway
1012 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
1016 do { # no need to check anything at the front, we always want the first row
1020 foreach my $this_as (@construct_as) {
1021 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
1024 push(@const_rows, \%const);
1026 } until ( # no pri_index => no collapse => drop straight out
1029 do { # get another row, stash it, drop out if different PK
1031 @copy = $self->cursor->next;
1032 $self->{stashed_row} = \@copy;
1034 # last thing in do block, counts as true if anything doesn't match
1036 # check xor defined first for NULL vs. NOT NULL then if one is
1037 # defined the other must be so check string equality
1040 (defined $pri_vals{$_} ^ defined $copy[$_])
1041 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
1046 my $alias = $self->{attrs}{alias};
1053 foreach my $const (@const_rows) {
1054 scalar @const_keys or do {
1055 @const_keys = sort { length($a) <=> length($b) } keys %$const;
1057 foreach my $key (@const_keys) {
1060 my @parts = split(/\./, $key);
1062 my $data = $const->{$key};
1063 foreach my $p (@parts) {
1064 $target = $target->[1]->{$p} ||= [];
1066 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
1067 # collapsing at this point and on final part
1068 my $pos = $collapse_pos{$cur};
1069 CK: foreach my $ck (@ckey) {
1070 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
1071 $collapse_pos{$cur} = $data;
1072 delete @collapse_pos{ # clear all positioning for sub-entries
1073 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
1080 if (exists $collapse{$cur}) {
1081 $target = $target->[-1];
1084 $target->[0] = $data;
1086 $info->[0] = $const->{$key};
1094 =head2 result_source
1098 =item Arguments: $result_source?
1100 =item Return Value: $result_source
1104 An accessor for the primary ResultSource object from which this ResultSet
1111 =item Arguments: $result_class?
1113 =item Return Value: $result_class
1117 An accessor for the class to use when creating row objects. Defaults to
1118 C<< result_source->result_class >> - which in most cases is the name of the
1119 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
1121 Note that changing the result_class will also remove any components
1122 that were originally loaded in the source class via
1123 L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
1124 in the original source class will not run.
1129 my ($self, $result_class) = @_;
1130 if ($result_class) {
1131 $self->ensure_class_loaded($result_class);
1132 $self->_result_class($result_class);
1134 $self->_result_class;
1141 =item Arguments: $cond, \%attrs??
1143 =item Return Value: $count
1147 Performs an SQL C<COUNT> with the same query as the resultset was built
1148 with to find the number of elements. If passed arguments, does a search
1149 on the resultset and counts the results of that.
1155 return $self->search(@_)->count if @_ and defined $_[0];
1156 return scalar @{ $self->get_cache } if $self->get_cache;
1157 my $count = $self->_count;
1158 return 0 unless $count;
1160 # need to take offset from resolved attrs
1162 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
1163 $count = $self->{attrs}{rows} if
1164 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
1165 $count = 0 if ($count < 0);
1169 sub _count { # Separated out so pager can get the full count
1171 my $attrs = { %{$self->_resolved_attrs} };
1173 if (my $group_by = $attrs->{group_by}) {
1174 delete $attrs->{order_by};
1176 $attrs->{select} = $group_by;
1177 $attrs->{from} = [ { 'mesub' => (ref $self)->new($self->result_source, $attrs)->cursor->as_query } ];
1178 delete $attrs->{where};
1181 $attrs->{select} = { count => '*' };
1182 $attrs->{as} = [qw/count/];
1184 # offset, order by, group by, where and page are not needed to count. record_filter is cdbi
1185 delete $attrs->{$_} for qw/rows offset order_by group_by page pager record_filter/;
1187 my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
1188 my ($count) = $tmp_rs->cursor->next;
1196 =head2 count_literal
1200 =item Arguments: $sql_fragment, @bind_values
1202 =item Return Value: $count
1206 Counts the results in a literal query. Equivalent to calling L</search_literal>
1207 with the passed arguments, then L</count>.
1211 sub count_literal { shift->search_literal(@_)->count; }
1217 =item Arguments: none
1219 =item Return Value: @objects
1223 Returns all elements in the resultset. Called implicitly if the resultset
1224 is returned in list context.
1231 $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
1234 return @{ $self->get_cache } if $self->get_cache;
1238 # TODO: don't call resolve here
1239 if (keys %{$self->_resolved_attrs->{collapse}}) {
1240 # if ($self->{attrs}{prefetch}) {
1241 # Using $self->cursor->all is really just an optimisation.
1242 # If we're collapsing has_many prefetches it probably makes
1243 # very little difference, and this is cleaner than hacking
1244 # _construct_object to survive the approach
1245 my @row = $self->cursor->next;
1247 push(@obj, $self->_construct_object(@row));
1248 @row = (exists $self->{stashed_row}
1249 ? @{delete $self->{stashed_row}}
1250 : $self->cursor->next);
1253 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1256 $self->set_cache(\@obj) if $self->{attrs}{cache};
1264 =item Arguments: none
1266 =item Return Value: $self
1270 Resets the resultset's cursor, so you can iterate through the elements again.
1276 delete $self->{_attrs} if exists $self->{_attrs};
1277 $self->{all_cache_position} = 0;
1278 $self->cursor->reset;
1286 =item Arguments: none
1288 =item Return Value: $object?
1292 Resets the resultset and returns an object for the first result (if the
1293 resultset returns anything).
1298 return $_[0]->reset->next;
1301 # _cond_for_update_delete
1303 # update/delete require the condition to be modified to handle
1304 # the differing SQL syntax available. This transforms the $self->{cond}
1305 # appropriately, returning the new condition.
1307 sub _cond_for_update_delete {
1308 my ($self, $full_cond) = @_;
1311 $full_cond ||= $self->{cond};
1312 # No-op. No condition, we're updating/deleting everything
1313 return $cond unless ref $full_cond;
1315 foreach my $pk ($self->result_source->primary_columns) {
1316 $cond->{$pk} = { -in => $self->get_column($pk)->as_query };
1327 =item Arguments: \%values
1329 =item Return Value: $storage_rv
1333 Sets the specified columns in the resultset to the supplied values in a
1334 single query. Return value will be true if the update succeeded or false
1335 if no records were updated; exact type of success value is storage-dependent.
1340 my ($self, $values) = @_;
1341 $self->throw_exception("Values for update must be a hash")
1342 unless ref $values eq 'HASH';
1344 my $cond = $self->_cond_for_update_delete;
1346 return $self->result_source->storage->update(
1347 $self->result_source, $values, $cond
1355 =item Arguments: \%values
1357 =item Return Value: 1
1361 Fetches all objects and updates them one at a time. Note that C<update_all>
1362 will run DBIC cascade triggers, while L</update> will not.
1367 my ($self, $values) = @_;
1368 $self->throw_exception("Values for update must be a hash")
1369 unless ref $values eq 'HASH';
1370 foreach my $obj ($self->all) {
1371 $obj->set_columns($values)->update;
1380 =item Arguments: none
1382 =item Return Value: 1
1386 Deletes the contents of the resultset from its result source. Note that this
1387 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1388 to run. See also L<DBIx::Class::Row/delete>.
1390 delete may not generate correct SQL for a query with joins or a resultset
1391 chained from a related resultset. In this case it will generate a warning:-
1393 In these cases you may find that delete_all is more appropriate, or you
1394 need to respecify your query in a way that can be expressed without a join.
1400 $self->throw_exception("Delete should not be passed any arguments")
1403 my $cond = $self->_cond_for_update_delete;
1405 $self->result_source->storage->delete($self->result_source, $cond);
1413 =item Arguments: none
1415 =item Return Value: 1
1419 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1420 will run DBIC cascade triggers, while L</delete> will not.
1426 $_->delete for $self->all;
1434 =item Arguments: \@data;
1438 Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
1439 For the arrayref of hashrefs style each hashref should be a structure suitable
1440 forsubmitting to a $resultset->create(...) method.
1442 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1443 to insert the data, as this is a faster method.
1445 Otherwise, each set of data is inserted into the database using
1446 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1447 objects is returned.
1449 Example: Assuming an Artist Class that has many CDs Classes relating:
1451 my $Artist_rs = $schema->resultset("Artist");
1453 ## Void Context Example
1454 $Artist_rs->populate([
1455 { artistid => 4, name => 'Manufactured Crap', cds => [
1456 { title => 'My First CD', year => 2006 },
1457 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1460 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1461 { title => 'My parents sold me to a record company' ,year => 2005 },
1462 { title => 'Why Am I So Ugly?', year => 2006 },
1463 { title => 'I Got Surgery and am now Popular', year => 2007 }
1468 ## Array Context Example
1469 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1470 { name => "Artist One"},
1471 { name => "Artist Two"},
1472 { name => "Artist Three", cds=> [
1473 { title => "First CD", year => 2007},
1474 { title => "Second CD", year => 2008},
1478 print $ArtistOne->name; ## response is 'Artist One'
1479 print $ArtistThree->cds->count ## reponse is '2'
1481 For the arrayref of arrayrefs style, the first element should be a list of the
1482 fieldsnames to which the remaining elements are rows being inserted. For
1485 $Arstist_rs->populate([
1486 [qw/artistid name/],
1487 [100, 'A Formally Unknown Singer'],
1488 [101, 'A singer that jumped the shark two albums ago'],
1489 [102, 'An actually cool singer.'],
1492 Please note an important effect on your data when choosing between void and
1493 wantarray context. Since void context goes straight to C<insert_bulk> in
1494 L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
1495 c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
1496 create primary keys for you, you will find that your PKs are empty. In this
1497 case you will have to use the wantarray context in order to create those
1503 my $self = shift @_;
1504 my $data = ref $_[0][0] eq 'HASH'
1505 ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
1506 $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
1508 if(defined wantarray) {
1510 foreach my $item (@$data) {
1511 push(@created, $self->create($item));
1515 my ($first, @rest) = @$data;
1517 my @names = grep {!ref $first->{$_}} keys %$first;
1518 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1519 my @pks = $self->result_source->primary_columns;
1521 ## do the belongs_to relationships
1522 foreach my $index (0..$#$data) {
1523 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1524 my @ret = $self->populate($data);
1528 foreach my $rel (@rels) {
1529 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1530 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1531 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1532 my $related = $result->result_source->resolve_condition(
1533 $result->result_source->relationship_info($reverse)->{cond},
1538 delete $data->[$index]->{$rel};
1539 $data->[$index] = {%{$data->[$index]}, %$related};
1541 push @names, keys %$related if $index == 0;
1545 ## do bulk insert on current row
1546 my @values = map { [ @$_{@names} ] } @$data;
1548 $self->result_source->storage->insert_bulk(
1549 $self->result_source,
1554 ## do the has_many relationships
1555 foreach my $item (@$data) {
1557 foreach my $rel (@rels) {
1558 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1560 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1561 || $self->throw_exception('Cannot find the relating object.');
1563 my $child = $parent->$rel;
1565 my $related = $child->result_source->resolve_condition(
1566 $parent->result_source->relationship_info($rel)->{cond},
1571 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1572 my @populate = map { {%$_, %$related} } @rows_to_add;
1574 $child->populate( \@populate );
1580 =head2 _normalize_populate_args ($args)
1582 Private method used by L</populate> to normalize its incoming arguments. Factored
1583 out in case you want to subclass and accept new argument structures to the
1584 L</populate> method.
1588 sub _normalize_populate_args {
1589 my ($self, $data) = @_;
1590 my @names = @{shift(@$data)};
1591 my @results_to_create;
1592 foreach my $datum (@$data) {
1593 my %result_to_create;
1594 foreach my $index (0..$#names) {
1595 $result_to_create{$names[$index]} = $$datum[$index];
1597 push @results_to_create, \%result_to_create;
1599 return \@results_to_create;
1606 =item Arguments: none
1608 =item Return Value: $pager
1612 Return Value a L<Data::Page> object for the current resultset. Only makes
1613 sense for queries with a C<page> attribute.
1615 To get the full count of entries for a paged resultset, call
1616 C<total_entries> on the L<Data::Page> object.
1622 my $attrs = $self->{attrs};
1623 $self->throw_exception("Can't create pager for non-paged rs")
1624 unless $self->{attrs}{page};
1625 $attrs->{rows} ||= 10;
1626 return $self->{pager} ||= Data::Page->new(
1627 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1634 =item Arguments: $page_number
1636 =item Return Value: $rs
1640 Returns a resultset for the $page_number page of the resultset on which page
1641 is called, where each page contains a number of rows equal to the 'rows'
1642 attribute set on the resultset (10 by default).
1647 my ($self, $page) = @_;
1648 return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
1655 =item Arguments: \%vals
1657 =item Return Value: $rowobject
1661 Creates a new row object in the resultset's result class and returns
1662 it. The row is not inserted into the database at this point, call
1663 L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
1664 will tell you whether the row object has been inserted or not.
1666 Passes the hashref of input on to L<DBIx::Class::Row/new>.
1671 my ($self, $values) = @_;
1672 $self->throw_exception( "new_result needs a hash" )
1673 unless (ref $values eq 'HASH');
1676 my $alias = $self->{attrs}{alias};
1679 defined $self->{cond}
1680 && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
1682 %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
1683 $new{-from_resultset} = [ keys %new ] if keys %new;
1685 $self->throw_exception(
1686 "Can't abstract implicit construct, condition not a hash"
1687 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1689 my $collapsed_cond = (
1691 ? $self->_collapse_cond($self->{cond})
1695 # precendence must be given to passed values over values inherited from
1696 # the cond, so the order here is important.
1697 my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
1698 while( my($col,$value) = each %implied ){
1699 if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
1700 $new{$col} = $value->{'='};
1703 $new{$col} = $value if $self->_is_deterministic_value($value);
1709 %{ $self->_remove_alias($values, $alias) },
1710 -source_handle => $self->_source_handle,
1711 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1714 return $self->result_class->new(\%new);
1717 # _is_deterministic_value
1719 # Make an effor to strip non-deterministic values from the condition,
1720 # to make sure new_result chokes less
1722 sub _is_deterministic_value {
1725 my $ref_type = ref $value;
1726 return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
1727 return 1 if Scalar::Util::blessed($value);
1733 # Recursively collapse the condition.
1735 sub _collapse_cond {
1736 my ($self, $cond, $collapsed) = @_;
1740 if (ref $cond eq 'ARRAY') {
1741 foreach my $subcond (@$cond) {
1742 next unless ref $subcond; # -or
1743 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1746 elsif (ref $cond eq 'HASH') {
1747 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1748 foreach my $subcond (@{$cond->{-and}}) {
1749 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1753 foreach my $col (keys %$cond) {
1754 my $value = $cond->{$col};
1755 $collapsed->{$col} = $value;
1765 # Remove the specified alias from the specified query hash. A copy is made so
1766 # the original query is not modified.
1769 my ($self, $query, $alias) = @_;
1771 my %orig = %{ $query || {} };
1774 foreach my $key (keys %orig) {
1776 $unaliased{$key} = $orig{$key};
1779 $unaliased{$1} = $orig{$key}
1780 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1786 =head2 as_query (EXPERIMENTAL)
1790 =item Arguments: none
1792 =item Return Value: \[ $sql, @bind ]
1796 Returns the SQL query and bind vars associated with the invocant.
1798 This is generally used as the RHS for a subquery.
1800 B<NOTE>: This feature is still experimental.
1804 sub as_query { return shift->cursor->as_query(@_) }
1810 =item Arguments: \%vals, \%attrs?
1812 =item Return Value: $rowobject
1816 my $artist = $schema->resultset('Artist')->find_or_new(
1817 { artist => 'fred' }, { key => 'artists' });
1819 $cd->cd_to_producer->find_or_new({ producer => $producer },
1820 { key => 'primary });
1822 Find an existing record from this resultset, based on its primary
1823 key, or a unique constraint. If none exists, instantiate a new result
1824 object and return it. The object will not be saved into your storage
1825 until you call L<DBIx::Class::Row/insert> on it.
1827 You most likely want this method when looking for existing rows using
1828 a unique constraint that is not the primary key, or looking for
1831 If you want objects to be saved immediately, use L</find_or_create> instead.
1833 B<Note>: C<find_or_new> is probably not what you want when creating a
1834 new row in a table that uses primary keys supplied by the
1835 database. Passing in a primary key column with a value of I<undef>
1836 will cause L</find> to attempt to search for a row with a value of
1843 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1844 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1845 my $exists = $self->find($hash, $attrs);
1846 return defined $exists ? $exists : $self->new_result($hash);
1853 =item Arguments: \%vals
1855 =item Return Value: a L<DBIx::Class::Row> $object
1859 Attempt to create a single new row or a row with multiple related rows
1860 in the table represented by the resultset (and related tables). This
1861 will not check for duplicate rows before inserting, use
1862 L</find_or_create> to do that.
1864 To create one row for this resultset, pass a hashref of key/value
1865 pairs representing the columns of the table and the values you wish to
1866 store. If the appropriate relationships are set up, foreign key fields
1867 can also be passed an object representing the foreign row, and the
1868 value will be set to its primary key.
1870 To create related objects, pass a hashref for the value if the related
1871 item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
1872 and use the name of the relationship as the key. (NOT the name of the field,
1873 necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
1874 of hashrefs containing the data for each of the rows to create in the foreign
1875 tables, again using the relationship name as the key.
1877 Instead of hashrefs of plain related data (key/value pairs), you may
1878 also pass new or inserted objects. New objects (not inserted yet, see
1879 L</new>), will be inserted into their appropriate tables.
1881 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1883 Example of creating a new row.
1885 $person_rs->create({
1886 name=>"Some Person",
1887 email=>"somebody@someplace.com"
1890 Example of creating a new row and also creating rows in a related C<has_many>
1891 or C<has_one> resultset. Note Arrayref.
1894 { artistid => 4, name => 'Manufactured Crap', cds => [
1895 { title => 'My First CD', year => 2006 },
1896 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1901 Example of creating a new row and also creating a row in a related
1902 C<belongs_to>resultset. Note Hashref.
1905 title=>"Music for Silly Walks",
1908 name=>"Silly Musician",
1915 my ($self, $attrs) = @_;
1916 $self->throw_exception( "create needs a hashref" )
1917 unless ref $attrs eq 'HASH';
1918 return $self->new_result($attrs)->insert;
1921 =head2 find_or_create
1925 =item Arguments: \%vals, \%attrs?
1927 =item Return Value: $rowobject
1931 $cd->cd_to_producer->find_or_create({ producer => $producer },
1932 { key => 'primary });
1934 Tries to find a record based on its primary key or unique constraints; if none
1935 is found, creates one and returns that instead.
1937 my $cd = $schema->resultset('CD')->find_or_create({
1939 artist => 'Massive Attack',
1940 title => 'Mezzanine',
1944 Also takes an optional C<key> attribute, to search by a specific key or unique
1945 constraint. For example:
1947 my $cd = $schema->resultset('CD')->find_or_create(
1949 artist => 'Massive Attack',
1950 title => 'Mezzanine',
1952 { key => 'cd_artist_title' }
1955 B<Note>: Because find_or_create() reads from the database and then
1956 possibly inserts based on the result, this method is subject to a race
1957 condition. Another process could create a record in the table after
1958 the find has completed and before the create has started. To avoid
1959 this problem, use find_or_create() inside a transaction.
1961 B<Note>: C<find_or_create> is probably not what you want when creating
1962 a new row in a table that uses primary keys supplied by the
1963 database. Passing in a primary key column with a value of I<undef>
1964 will cause L</find> to attempt to search for a row with a value of
1967 See also L</find> and L</update_or_create>. For information on how to declare
1968 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1972 sub find_or_create {
1974 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1975 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1976 my $exists = $self->find($hash, $attrs);
1977 return defined $exists ? $exists : $self->create($hash);
1980 =head2 update_or_create
1984 =item Arguments: \%col_values, { key => $unique_constraint }?
1986 =item Return Value: $rowobject
1990 $resultset->update_or_create({ col => $val, ... });
1992 First, searches for an existing row matching one of the unique constraints
1993 (including the primary key) on the source of this resultset. If a row is
1994 found, updates it with the other given column values. Otherwise, creates a new
1997 Takes an optional C<key> attribute to search on a specific unique constraint.
2000 # In your application
2001 my $cd = $schema->resultset('CD')->update_or_create(
2003 artist => 'Massive Attack',
2004 title => 'Mezzanine',
2007 { key => 'cd_artist_title' }
2010 $cd->cd_to_producer->update_or_create({
2011 producer => $producer,
2018 If no C<key> is specified, it searches on all unique constraints defined on the
2019 source, including the primary key.
2021 If the C<key> is specified as C<primary>, it searches only on the primary key.
2023 See also L</find> and L</find_or_create>. For information on how to declare
2024 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
2026 B<Note>: C<update_or_create> is probably not what you want when
2027 looking for a row in a table that uses primary keys supplied by the
2028 database, unless you actually have a key value. Passing in a primary
2029 key column with a value of I<undef> will cause L</find> to attempt to
2030 search for a row with a value of I<NULL>.
2034 sub update_or_create {
2036 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
2037 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2039 my $row = $self->find($cond, $attrs);
2041 $row->update($cond);
2045 return $self->create($cond);
2048 =head2 update_or_new
2052 =item Arguments: \%col_values, { key => $unique_constraint }?
2054 =item Return Value: $rowobject
2058 $resultset->update_or_new({ col => $val, ... });
2060 First, searches for an existing row matching one of the unique constraints
2061 (including the primary key) on the source of this resultset. If a row is
2062 found, updates it with the other given column values. Otherwise, instantiate
2063 a new result object and return it. The object will not be saved into your storage
2064 until you call L<DBIx::Class::Row/insert> on it.
2066 Takes an optional C<key> attribute to search on a specific unique constraint.
2069 # In your application
2070 my $cd = $schema->resultset('CD')->update_or_new(
2072 artist => 'Massive Attack',
2073 title => 'Mezzanine',
2076 { key => 'cd_artist_title' }
2079 if ($cd->in_storage) {
2080 # the cd was updated
2083 # the cd is not yet in the database, let's insert it
2087 See also L</find>, L</find_or_create> and L<find_or_new>.
2093 my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
2094 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
2096 my $row = $self->find( $cond, $attrs );
2097 if ( defined $row ) {
2098 $row->update($cond);
2102 return $self->new_result($cond);
2109 =item Arguments: none
2111 =item Return Value: \@cache_objects?
2115 Gets the contents of the cache for the resultset, if the cache is set.
2117 The cache is populated either by using the L</prefetch> attribute to
2118 L</search> or by calling L</set_cache>.
2130 =item Arguments: \@cache_objects
2132 =item Return Value: \@cache_objects
2136 Sets the contents of the cache for the resultset. Expects an arrayref
2137 of objects of the same class as those produced by the resultset. Note that
2138 if the cache is set the resultset will return the cached objects rather
2139 than re-querying the database even if the cache attr is not set.
2141 The contents of the cache can also be populated by using the
2142 L</prefetch> attribute to L</search>.
2147 my ( $self, $data ) = @_;
2148 $self->throw_exception("set_cache requires an arrayref")
2149 if defined($data) && (ref $data ne 'ARRAY');
2150 $self->{all_cache} = $data;
2157 =item Arguments: none
2159 =item Return Value: []
2163 Clears the cache for the resultset.
2168 shift->set_cache(undef);
2171 =head2 related_resultset
2175 =item Arguments: $relationship_name
2177 =item Return Value: $resultset
2181 Returns a related resultset for the supplied relationship name.
2183 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
2187 sub related_resultset {
2188 my ($self, $rel) = @_;
2190 $self->{related_resultsets} ||= {};
2191 return $self->{related_resultsets}{$rel} ||= do {
2192 my $rel_obj = $self->result_source->relationship_info($rel);
2194 $self->throw_exception(
2195 "search_related: result source '" . $self->result_source->source_name .
2196 "' has no such relationship $rel")
2199 my ($from,$seen) = $self->_resolve_from($rel);
2201 my $join_count = $seen->{$rel};
2202 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
2204 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
2205 my %attrs = %{$self->{attrs}||{}};
2206 delete @attrs{qw(result_class alias)};
2210 if (my $cache = $self->get_cache) {
2211 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
2212 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
2217 my $rel_source = $self->result_source->related_source($rel);
2221 # The reason we do this now instead of passing the alias to the
2222 # search_rs below is that if you wrap/overload resultset on the
2223 # source you need to know what alias it's -going- to have for things
2224 # to work sanely (e.g. RestrictWithObject wants to be able to add
2225 # extra query restrictions, and these may need to be $alias.)
2227 my $attrs = $rel_source->resultset_attributes;
2228 local $attrs->{alias} = $alias;
2230 $rel_source->resultset
2238 where => $self->{cond},
2243 $new->set_cache($new_cache) if $new_cache;
2248 =head2 current_source_alias
2252 =item Arguments: none
2254 =item Return Value: $source_alias
2258 Returns the current table alias for the result source this resultset is built
2259 on, that will be used in the SQL query. Usually it is C<me>.
2261 Currently the source alias that refers to the result set returned by a
2262 L</search>/L</find> family method depends on how you got to the resultset: it's
2263 C<me> by default, but eg. L</search_related> aliases it to the related result
2264 source name (and keeps C<me> referring to the original result set). The long
2265 term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
2266 (and make this method unnecessary).
2268 Thus it's currently necessary to use this method in predefined queries (see
2269 L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
2270 source alias of the current result set:
2272 # in a result set class
2274 my ($self, $user) = @_;
2276 my $me = $self->current_source_alias;
2278 return $self->search(
2279 "$me.modified" => $user->id,
2285 sub current_source_alias {
2288 return ($self->{attrs} || {})->{alias} || 'me';
2292 my ($self, $extra_join) = @_;
2293 my $source = $self->result_source;
2294 my $attrs = $self->{attrs};
2296 my $from = $attrs->{from}
2297 || [ { $attrs->{alias} => $source->from } ];
2299 my $seen = { %{$attrs->{seen_join}||{}} };
2301 my $join = ($attrs->{join}
2302 ? [ $attrs->{join}, $extra_join ]
2305 # we need to take the prefetch the attrs into account before we
2306 # ->resolve_join as otherwise they get lost - captainL
2307 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
2311 ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
2314 return ($from,$seen);
2317 sub _resolved_attrs {
2319 return $self->{_attrs} if $self->{_attrs};
2321 my $attrs = { %{ $self->{attrs} || {} } };
2322 my $source = $self->result_source;
2323 my $alias = $attrs->{alias};
2325 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
2328 # build columns (as long as select isn't set) into a set of as/select hashes
2329 unless ( $attrs->{select} ) {
2331 ( ref($_) eq 'HASH' )
2335 /^\Q${alias}.\E(.+)$/
2346 } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
2348 # add the additional columns on
2349 foreach ( 'include_columns', '+columns' ) {
2350 push @colbits, map {
2351 ( ref($_) eq 'HASH' )
2353 : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
2354 } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
2357 # start with initial select items
2358 if ( $attrs->{select} ) {
2360 ( ref $attrs->{select} eq 'ARRAY' )
2361 ? [ @{ $attrs->{select} } ]
2362 : [ $attrs->{select} ];
2366 ref $attrs->{as} eq 'ARRAY'
2367 ? [ @{ $attrs->{as} } ]
2370 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
2375 # otherwise we intialise select & as to empty
2376 $attrs->{select} = [];
2380 # now add colbits to select/as
2381 push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
2382 push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
2385 if ( $adds = delete $attrs->{'+select'} ) {
2386 $adds = [$adds] unless ref $adds eq 'ARRAY';
2388 @{ $attrs->{select} },
2389 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
2392 if ( $adds = delete $attrs->{'+as'} ) {
2393 $adds = [$adds] unless ref $adds eq 'ARRAY';
2394 push( @{ $attrs->{as} }, @$adds );
2397 $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
2399 if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
2400 my $join = delete $attrs->{join} || {};
2402 if ( defined $attrs->{prefetch} ) {
2403 $join = $self->_merge_attr( $join, $attrs->{prefetch} );
2407 $attrs->{from} = # have to copy here to avoid corrupting the original
2409 @{ $attrs->{from} },
2410 $source->resolve_join(
2411 $join, $alias, { %{ $attrs->{seen_join} || {} } }
2417 $attrs->{group_by} ||= $attrs->{select}
2418 if delete $attrs->{distinct};
2419 if ( $attrs->{order_by} ) {
2420 $attrs->{order_by} = (
2421 ref( $attrs->{order_by} ) eq 'ARRAY'
2422 ? [ @{ $attrs->{order_by} } ]
2423 : [ $attrs->{order_by} ]
2427 $attrs->{order_by} = [];
2430 my $collapse = $attrs->{collapse} || {};
2431 if ( my $prefetch = delete $attrs->{prefetch} ) {
2432 $prefetch = $self->_merge_attr( {}, $prefetch );
2434 my $seen = { %{ $attrs->{seen_join} || {} } };
2435 foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
2437 # bring joins back to level of current class
2439 $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse );
2440 push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
2441 push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
2443 push( @{ $attrs->{order_by} }, @pre_order );
2445 $attrs->{collapse} = $collapse;
2447 if ( $attrs->{page} ) {
2448 $attrs->{offset} ||= 0;
2449 $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
2452 return $self->{_attrs} = $attrs;
2456 my ($self, $attr) = @_;
2458 if (ref $attr eq 'HASH') {
2459 return $self->_rollout_hash($attr);
2460 } elsif (ref $attr eq 'ARRAY') {
2461 return $self->_rollout_array($attr);
2467 sub _rollout_array {
2468 my ($self, $attr) = @_;
2471 foreach my $element (@{$attr}) {
2472 if (ref $element eq 'HASH') {
2473 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
2474 } elsif (ref $element eq 'ARRAY') {
2475 # XXX - should probably recurse here
2476 push( @rolled_array, @{$self->_rollout_array($element)} );
2478 push( @rolled_array, $element );
2481 return \@rolled_array;
2485 my ($self, $attr) = @_;
2488 foreach my $key (keys %{$attr}) {
2489 push( @rolled_array, { $key => $attr->{$key} } );
2491 return \@rolled_array;
2494 sub _calculate_score {
2495 my ($self, $a, $b) = @_;
2497 if (ref $b eq 'HASH') {
2498 my ($b_key) = keys %{$b};
2499 if (ref $a eq 'HASH') {
2500 my ($a_key) = keys %{$a};
2501 if ($a_key eq $b_key) {
2502 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
2507 return ($a eq $b_key) ? 1 : 0;
2510 if (ref $a eq 'HASH') {
2511 my ($a_key) = keys %{$a};
2512 return ($b eq $a_key) ? 1 : 0;
2514 return ($b eq $a) ? 1 : 0;
2520 my ($self, $orig, $import) = @_;
2522 return $import unless defined($orig);
2523 return $orig unless defined($import);
2525 $orig = $self->_rollout_attr($orig);
2526 $import = $self->_rollout_attr($import);
2529 foreach my $import_element ( @{$import} ) {
2530 # find best candidate from $orig to merge $b_element into
2531 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
2532 foreach my $orig_element ( @{$orig} ) {
2533 my $score = $self->_calculate_score( $orig_element, $import_element );
2534 if ($score > $best_candidate->{score}) {
2535 $best_candidate->{position} = $position;
2536 $best_candidate->{score} = $score;
2540 my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
2542 if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
2543 push( @{$orig}, $import_element );
2545 my $orig_best = $orig->[$best_candidate->{position}];
2546 # merge orig_best and b_element together and replace original with merged
2547 if (ref $orig_best ne 'HASH') {
2548 $orig->[$best_candidate->{position}] = $import_element;
2549 } elsif (ref $import_element eq 'HASH') {
2550 my ($key) = keys %{$orig_best};
2551 $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
2554 $seen_keys->{$import_key} = 1; # don't merge the same key twice
2564 $self->_source_handle($_[0]->handle);
2566 $self->_source_handle->resolve;
2570 =head2 throw_exception
2572 See L<DBIx::Class::Schema/throw_exception> for details.
2576 sub throw_exception {
2578 if (ref $self && $self->_source_handle->schema) {
2579 $self->_source_handle->schema->throw_exception(@_)
2586 # XXX: FIXME: Attributes docs need clearing up
2590 Attributes are used to refine a ResultSet in various ways when
2591 searching for data. They can be passed to any method which takes an
2592 C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
2595 These are in no particular order:
2601 =item Value: ( $order_by | \@order_by | \%order_by )
2605 Which column(s) to order the results by. If a single column name, or
2606 an arrayref of names is supplied, the argument is passed through
2607 directly to SQL. The hashref syntax allows for connection-agnostic
2608 specification of ordering direction:
2610 For descending order:
2612 order_by => { -desc => [qw/col1 col2 col3/] }
2614 For explicit ascending order:
2616 order_by => { -asc => 'col' }
2618 The old scalarref syntax (i.e. order_by => \'year DESC') is still
2619 supported, although you are strongly encouraged to use the hashref
2620 syntax as outlined above.
2626 =item Value: \@columns
2630 Shortcut to request a particular set of columns to be retrieved. Each
2631 column spec may be a string (a table column name), or a hash (in which
2632 case the key is the C<as> value, and the value is used as the C<select>
2633 expression). Adds C<me.> onto the start of any column without a C<.> in
2634 it and sets C<select> from that, then auto-populates C<as> from
2635 C<select> as normal. (You may also use the C<cols> attribute, as in
2636 earlier versions of DBIC.)
2642 =item Value: \@columns
2646 Indicates additional columns to be selected from storage. Works the same
2647 as L</columns> but adds columns to the selection. (You may also use the
2648 C<include_columns> attribute, as in earlier versions of DBIC). For
2651 $schema->resultset('CD')->search(undef, {
2652 '+columns' => ['artist.name'],
2656 would return all CDs and include a 'name' column to the information
2657 passed to object inflation. Note that the 'artist' is the name of the
2658 column (or relationship) accessor, and 'name' is the name of the column
2659 accessor in the related table.
2661 =head2 include_columns
2665 =item Value: \@columns
2669 Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
2675 =item Value: \@select_columns
2679 Indicates which columns should be selected from the storage. You can use
2680 column names, or in the case of RDBMS back ends, function or stored procedure
2683 $rs = $schema->resultset('Employee')->search(undef, {
2686 { count => 'employeeid' },
2691 When you use function/stored procedure names and do not supply an C<as>
2692 attribute, the column names returned are storage-dependent. E.g. MySQL would
2693 return a column named C<count(employeeid)> in the above example.
2699 Indicates additional columns to be selected from storage. Works the same as
2700 L</select> but adds columns to the selection.
2708 Indicates additional column names for those added via L</+select>. See L</as>.
2716 =item Value: \@inflation_names
2720 Indicates column names for object inflation. That is, C<as>
2721 indicates the name that the column can be accessed as via the
2722 C<get_column> method (or via the object accessor, B<if one already
2723 exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
2725 The C<as> attribute is used in conjunction with C<select>,
2726 usually when C<select> contains one or more function or stored
2729 $rs = $schema->resultset('Employee')->search(undef, {
2732 { count => 'employeeid' }
2734 as => ['name', 'employee_count'],
2737 my $employee = $rs->first(); # get the first Employee
2739 If the object against which the search is performed already has an accessor
2740 matching a column name specified in C<as>, the value can be retrieved using
2741 the accessor as normal:
2743 my $name = $employee->name();
2745 If on the other hand an accessor does not exist in the object, you need to
2746 use C<get_column> instead:
2748 my $employee_count = $employee->get_column('employee_count');
2750 You can create your own accessors if required - see
2751 L<DBIx::Class::Manual::Cookbook> for details.
2753 Please note: This will NOT insert an C<AS employee_count> into the SQL
2754 statement produced, it is used for internal access only. Thus
2755 attempting to use the accessor in an C<order_by> clause or similar
2756 will fail miserably.
2758 To get around this limitation, you can supply literal SQL to your
2759 C<select> attibute that contains the C<AS alias> text, eg:
2761 select => [\'myfield AS alias']
2767 =item Value: ($rel_name | \@rel_names | \%rel_names)
2771 Contains a list of relationships that should be joined for this query. For
2774 # Get CDs by Nine Inch Nails
2775 my $rs = $schema->resultset('CD')->search(
2776 { 'artist.name' => 'Nine Inch Nails' },
2777 { join => 'artist' }
2780 Can also contain a hash reference to refer to the other relation's relations.
2783 package MyApp::Schema::Track;
2784 use base qw/DBIx::Class/;
2785 __PACKAGE__->table('track');
2786 __PACKAGE__->add_columns(qw/trackid cd position title/);
2787 __PACKAGE__->set_primary_key('trackid');
2788 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2791 # In your application
2792 my $rs = $schema->resultset('Artist')->search(
2793 { 'track.title' => 'Teardrop' },
2795 join => { cd => 'track' },
2796 order_by => 'artist.name',
2800 You need to use the relationship (not the table) name in conditions,
2801 because they are aliased as such. The current table is aliased as "me", so
2802 you need to use me.column_name in order to avoid ambiguity. For example:
2804 # Get CDs from 1984 with a 'Foo' track
2805 my $rs = $schema->resultset('CD')->search(
2808 'tracks.name' => 'Foo'
2810 { join => 'tracks' }
2813 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2814 similarly for a third time). For e.g.
2816 my $rs = $schema->resultset('Artist')->search({
2817 'cds.title' => 'Down to Earth',
2818 'cds_2.title' => 'Popular',
2820 join => [ qw/cds cds/ ],
2823 will return a set of all artists that have both a cd with title 'Down
2824 to Earth' and a cd with title 'Popular'.
2826 If you want to fetch related objects from other tables as well, see C<prefetch>
2829 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
2835 =item Value: ($rel_name | \@rel_names | \%rel_names)
2839 Contains one or more relationships that should be fetched along with
2840 the main query (when they are accessed afterwards the data will
2841 already be available, without extra queries to the database). This is
2842 useful for when you know you will need the related objects, because it
2843 saves at least one query:
2845 my $rs = $schema->resultset('Tag')->search(
2854 The initial search results in SQL like the following:
2856 SELECT tag.*, cd.*, artist.* FROM tag
2857 JOIN cd ON tag.cd = cd.cdid
2858 JOIN artist ON cd.artist = artist.artistid
2860 L<DBIx::Class> has no need to go back to the database when we access the
2861 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2864 Simple prefetches will be joined automatically, so there is no need
2865 for a C<join> attribute in the above search.
2867 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2868 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2869 with an accessor type of 'single' or 'filter'). A more complex example that
2870 prefetches an artists cds, the tracks on those cds, and the tags associted
2871 with that artist is given below (assuming many-to-many from artists to tags):
2873 my $rs = $schema->resultset('Artist')->search(
2877 { cds => 'tracks' },
2878 { artist_tags => 'tags' }
2884 B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
2885 attributes will be ignored.
2895 Makes the resultset paged and specifies the page to retrieve. Effectively
2896 identical to creating a non-pages resultset and then calling ->page($page)
2899 If L<rows> attribute is not specified it defualts to 10 rows per page.
2901 When you have a paged resultset, L</count> will only return the number
2902 of rows in the page. To get the total, use the L</pager> and call
2903 C<total_entries> on it.
2913 Specifes the maximum number of rows for direct retrieval or the number of
2914 rows per page if the page attribute or method is used.
2920 =item Value: $offset
2924 Specifies the (zero-based) row number for the first row to be returned, or the
2925 of the first row of the first page if paging is used.
2931 =item Value: \@columns
2935 A arrayref of columns to group by. Can include columns of joined tables.
2937 group_by => [qw/ column1 column2 ... /]
2943 =item Value: $condition
2947 HAVING is a select statement attribute that is applied between GROUP BY and
2948 ORDER BY. It is applied to the after the grouping calculations have been
2951 having => { 'count(employee)' => { '>=', 100 } }
2957 =item Value: (0 | 1)
2961 Set to 1 to group by all columns.
2967 Adds to the WHERE clause.
2969 # only return rows WHERE deleted IS NULL for all searches
2970 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2972 Can be overridden by passing C<{ where => undef }> as an attribute
2979 Set to 1 to cache search results. This prevents extra SQL queries if you
2980 revisit rows in your ResultSet:
2982 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2984 while( my $artist = $resultset->next ) {
2988 $rs->first; # without cache, this would issue a query
2990 By default, searches are not cached.
2992 For more examples of using these attributes, see
2993 L<DBIx::Class::Manual::Cookbook>.
2999 =item Value: \@from_clause
3003 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
3004 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
3007 NOTE: Use this on your own risk. This allows you to shoot off your foot!
3009 C<join> will usually do what you need and it is strongly recommended that you
3010 avoid using C<from> unless you cannot achieve the desired result using C<join>.
3011 And we really do mean "cannot", not just tried and failed. Attempting to use
3012 this because you're having problems with C<join> is like trying to use x86
3013 ASM because you've got a syntax error in your C. Trust us on this.
3015 Now, if you're still really, really sure you need to use this (and if you're
3016 not 100% sure, ask the mailing list first), here's an explanation of how this
3019 The syntax is as follows -
3022 { <alias1> => <table1> },
3024 { <alias2> => <table2>, -join_type => 'inner|left|right' },
3025 [], # nested JOIN (optional)
3026 { <table1.column1> => <table2.column2>, ... (more conditions) },
3028 # More of the above [ ] may follow for additional joins
3035 ON <table1.column1> = <table2.column2>
3036 <more joins may follow>
3038 An easy way to follow the examples below is to remember the following:
3040 Anything inside "[]" is a JOIN
3041 Anything inside "{}" is a condition for the enclosing JOIN
3043 The following examples utilize a "person" table in a family tree application.
3044 In order to express parent->child relationships, this table is self-joined:
3046 # Person->belongs_to('father' => 'Person');
3047 # Person->belongs_to('mother' => 'Person');
3049 C<from> can be used to nest joins. Here we return all children with a father,
3050 then search against all mothers of those children:
3052 $rs = $schema->resultset('Person')->search(
3055 alias => 'mother', # alias columns in accordance with "from"
3057 { mother => 'person' },
3060 { child => 'person' },
3062 { father => 'person' },
3063 { 'father.person_id' => 'child.father_id' }
3066 { 'mother.person_id' => 'child.mother_id' }
3073 # SELECT mother.* FROM person mother
3076 # JOIN person father
3077 # ON ( father.person_id = child.father_id )
3079 # ON ( mother.person_id = child.mother_id )
3081 The type of any join can be controlled manually. To search against only people
3082 with a father in the person table, we could explicitly use C<INNER JOIN>:
3084 $rs = $schema->resultset('Person')->search(
3087 alias => 'child', # alias columns in accordance with "from"
3089 { child => 'person' },
3091 { father => 'person', -join_type => 'inner' },
3092 { 'father.id' => 'child.father_id' }
3099 # SELECT child.* FROM person child
3100 # INNER JOIN person father ON child.father_id = father.id
3102 If you need to express really complex joins or you need a subselect, you
3103 can supply literal SQL to C<from> via a scalar reference. In this case
3104 the contents of the scalar will replace the table name asscoiated with the
3107 WARNING: This technique might very well not work as expected on chained
3108 searches - you have been warned.
3110 # Assuming the Event resultsource is defined as:
3112 MySchema::Event->add_columns (
3115 is_auto_increment => 1,
3124 MySchema::Event->set_primary_key ('sequence');
3126 # This will get back the latest event for every location. The column
3127 # selector is still provided by DBIC, all we do is add a JOIN/WHERE
3128 # combo to limit the resultset
3130 $rs = $schema->resultset('Event');
3131 $table = $rs->result_source->name;
3132 $latest = $rs->search (
3135 (SELECT e1.* FROM $table e1
3137 ON e1.location = e2.location
3138 AND e1.sequence < e2.sequence
3139 WHERE e2.sequence is NULL
3144 # Equivalent SQL (with the DBIC chunks added):
3146 SELECT me.sequence, me.location, me.type FROM
3147 (SELECT e1.* FROM events e1
3149 ON e1.location = e2.location
3150 AND e1.sequence < e2.sequence
3151 WHERE e2.sequence is NULL
3158 =item Value: ( 'update' | 'shared' )
3162 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT