1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
90 $attrs = { %{$attrs||{}} };
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 _source_handle => $source,
102 result_class => $attrs->{result_class} || $source->resolve->result_class,
103 cond => $attrs->{where},
118 =item Arguments: $cond, \%attrs?
120 =item Return Value: $resultset (scalar context), @row_objs (list context)
124 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
125 my $new_rs = $cd_rs->search({ year => 2005 });
127 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
128 # year = 2005 OR year = 2004
130 If you need to pass in additional attributes but no additional condition,
131 call it as C<search(undef, \%attrs)>.
133 # "SELECT name, artistid FROM $artist_table"
134 my @all_artists = $schema->resultset('Artist')->search(undef, {
135 columns => [qw/name artistid/],
138 For a list of attributes that can be passed to C<search>, see
139 L</ATTRIBUTES>. For more examples of using this function, see
140 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
141 documentation for the first argument, see L<SQL::Abstract>.
147 my $rs = $self->search_rs( @_ );
148 return (wantarray ? $rs->all : $rs);
155 =item Arguments: $cond, \%attrs?
157 =item Return Value: $resultset
161 This method does the same exact thing as search() except it will
162 always return a resultset, even in list context.
171 unless (@_) { # no search, effectively just a clone
172 $rows = $self->get_cache;
176 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
177 my $our_attrs = { %{$self->{attrs}} };
178 my $having = delete $our_attrs->{having};
179 my $where = delete $our_attrs->{where};
181 my $new_attrs = { %{$our_attrs}, %{$attrs} };
183 # merge new attrs into inherited
184 foreach my $key (qw/join prefetch/) {
185 next unless exists $attrs->{$key};
186 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
191 (@_ == 1 || ref $_[0] eq "HASH")
193 (ref $_[0] eq 'HASH')
195 (keys %{ $_[0] } > 0)
203 ? $self->throw_exception("Odd number of arguments to search")
210 if (defined $where) {
211 $new_attrs->{where} = (
212 defined $new_attrs->{where}
215 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
216 } $where, $new_attrs->{where}
223 $new_attrs->{where} = (
224 defined $new_attrs->{where}
227 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
228 } $cond, $new_attrs->{where}
234 if (defined $having) {
235 $new_attrs->{having} = (
236 defined $new_attrs->{having}
239 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
240 } $having, $new_attrs->{having}
246 my $rs = (ref $self)->new($self->result_source, $new_attrs);
248 $rs->set_cache($rows);
253 =head2 search_literal
257 =item Arguments: $sql_fragment, @bind_values
259 =item Return Value: $resultset (scalar context), @row_objs (list context)
263 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
264 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
266 Pass a literal chunk of SQL to be added to the conditional part of the
272 my ($self, $cond, @vals) = @_;
273 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
274 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
275 return $self->search(\$cond, $attrs);
282 =item Arguments: @values | \%cols, \%attrs?
284 =item Return Value: $row_object
288 Finds a row based on its primary key or unique constraint. For example, to find
289 a row by its primary key:
291 my $cd = $schema->resultset('CD')->find(5);
293 You can also find a row by a specific unique constraint using the C<key>
294 attribute. For example:
296 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
297 key => 'cd_artist_title'
300 Additionally, you can specify the columns explicitly by name:
302 my $cd = $schema->resultset('CD')->find(
304 artist => 'Massive Attack',
305 title => 'Mezzanine',
307 { key => 'cd_artist_title' }
310 If the C<key> is specified as C<primary>, it searches only on the primary key.
312 If no C<key> is specified, it searches on all unique constraints defined on the
313 source, including the primary key.
315 If your table does not have a primary key, you B<must> provide a value for the
316 C<key> attribute matching one of the unique constraints on the source.
318 See also L</find_or_create> and L</update_or_create>. For information on how to
319 declare unique constraints, see
320 L<DBIx::Class::ResultSource/add_unique_constraint>.
326 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
328 # Default to the primary key, but allow a specific key
329 my @cols = exists $attrs->{key}
330 ? $self->result_source->unique_constraint_columns($attrs->{key})
331 : $self->result_source->primary_columns;
332 $self->throw_exception(
333 "Can't find unless a primary key is defined or unique constraint is specified"
336 # Parse out a hashref from input
338 if (ref $_[0] eq 'HASH') {
339 $input_query = { %{$_[0]} };
341 elsif (@_ == @cols) {
343 @{$input_query}{@cols} = @_;
346 # Compatibility: Allow e.g. find(id => $value)
347 carp "Find by key => value deprecated; please use a hashref instead";
351 my (%related, $info);
353 foreach my $key (keys %$input_query) {
354 if (ref($input_query->{$key})
355 && ($info = $self->result_source->relationship_info($key))) {
356 my $rel_q = $self->result_source->resolve_condition(
357 $info->{cond}, delete $input_query->{$key}, $key
359 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
360 @related{keys %$rel_q} = values %$rel_q;
363 if (my @keys = keys %related) {
364 @{$input_query}{@keys} = values %related;
367 my @unique_queries = $self->_unique_queries($input_query, $attrs);
369 # Build the final query: Default to the disjunction of the unique queries,
370 # but allow the input query in case the ResultSet defines the query or the
371 # user is abusing find
372 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
373 my $query = @unique_queries
374 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
375 : $self->_add_alias($input_query, $alias);
379 my $rs = $self->search($query, $attrs);
380 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
383 return keys %{$self->_resolved_attrs->{collapse}}
384 ? $self->search($query)->next
385 : $self->single($query);
391 # Add the specified alias to the specified query hash. A copy is made so the
392 # original query is not modified.
395 my ($self, $query, $alias) = @_;
397 my %aliased = %$query;
398 foreach my $col (grep { ! m/\./ } keys %aliased) {
399 $aliased{"$alias.$col"} = delete $aliased{$col};
407 # Build a list of queries which satisfy unique constraints.
409 sub _unique_queries {
410 my ($self, $query, $attrs) = @_;
412 my @constraint_names = exists $attrs->{key}
414 : $self->result_source->unique_constraint_names;
416 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
417 my $num_where = scalar keys %$where;
420 foreach my $name (@constraint_names) {
421 my @unique_cols = $self->result_source->unique_constraint_columns($name);
422 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
424 my $num_cols = scalar @unique_cols;
425 my $num_query = scalar keys %$unique_query;
427 my $total = $num_query + $num_where;
428 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
429 # The query is either unique on its own or is unique in combination with
430 # the existing where clause
431 push @unique_queries, $unique_query;
435 return @unique_queries;
438 # _build_unique_query
440 # Constrain the specified query hash based on the specified column names.
442 sub _build_unique_query {
443 my ($self, $query, $unique_cols) = @_;
446 map { $_ => $query->{$_} }
447 grep { exists $query->{$_} }
452 =head2 search_related
456 =item Arguments: $rel, $cond, \%attrs?
458 =item Return Value: $new_resultset
462 $new_rs = $cd_rs->search_related('artist', {
466 Searches the specified relationship, optionally specifying a condition and
467 attributes for matching records. See L</ATTRIBUTES> for more information.
472 return shift->related_resultset(shift)->search(@_);
479 =item Arguments: none
481 =item Return Value: $cursor
485 Returns a storage-driven cursor to the given resultset. See
486 L<DBIx::Class::Cursor> for more information.
493 my $attrs = { %{$self->_resolved_attrs} };
494 return $self->{cursor}
495 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
496 $attrs->{where},$attrs);
503 =item Arguments: $cond?
505 =item Return Value: $row_object?
509 my $cd = $schema->resultset('CD')->single({ year => 2001 });
511 Inflates the first result without creating a cursor if the resultset has
512 any records in it; if not returns nothing. Used by L</find> as an optimisation.
514 Can optionally take an additional condition *only* - this is a fast-code-path
515 method; if you need to add extra joins or similar call ->search and then
516 ->single without a condition on the $rs returned from that.
521 my ($self, $where) = @_;
522 my $attrs = { %{$self->_resolved_attrs} };
524 if (defined $attrs->{where}) {
527 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
528 $where, delete $attrs->{where} ]
531 $attrs->{where} = $where;
535 # XXX: Disabled since it doesn't infer uniqueness in all cases
536 # unless ($self->_is_unique_query($attrs->{where})) {
537 # carp "Query not guaranteed to return a single row"
538 # . "; please declare your unique constraints or use search instead";
541 my @data = $self->result_source->storage->select_single(
542 $attrs->{from}, $attrs->{select},
543 $attrs->{where}, $attrs
546 return (@data ? ($self->_construct_object(@data))[0] : undef);
551 # Try to determine if the specified query is guaranteed to be unique, based on
552 # the declared unique constraints.
554 sub _is_unique_query {
555 my ($self, $query) = @_;
557 my $collapsed = $self->_collapse_query($query);
558 my $alias = $self->{attrs}{alias};
560 foreach my $name ($self->result_source->unique_constraint_names) {
561 my @unique_cols = map {
563 } $self->result_source->unique_constraint_columns($name);
565 # Count the values for each unique column
566 my %seen = map { $_ => 0 } @unique_cols;
568 foreach my $key (keys %$collapsed) {
569 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
570 next unless exists $seen{$aliased}; # Additional constraints are okay
571 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
574 # If we get 0 or more than 1 value for a column, it's not necessarily unique
575 return 1 unless grep { $_ != 1 } values %seen;
583 # Recursively collapse the query, accumulating values for each column.
585 sub _collapse_query {
586 my ($self, $query, $collapsed) = @_;
590 if (ref $query eq 'ARRAY') {
591 foreach my $subquery (@$query) {
592 next unless ref $subquery; # -or
593 # warn "ARRAY: " . Dumper $subquery;
594 $collapsed = $self->_collapse_query($subquery, $collapsed);
597 elsif (ref $query eq 'HASH') {
598 if (keys %$query and (keys %$query)[0] eq '-and') {
599 foreach my $subquery (@{$query->{-and}}) {
600 # warn "HASH: " . Dumper $subquery;
601 $collapsed = $self->_collapse_query($subquery, $collapsed);
605 # warn "LEAF: " . Dumper $query;
606 foreach my $col (keys %$query) {
607 my $value = $query->{$col};
608 $collapsed->{$col}{$value}++;
620 =item Arguments: $cond?
622 =item Return Value: $resultsetcolumn
626 my $max_length = $rs->get_column('length')->max;
628 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
633 my ($self, $column) = @_;
634 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
642 =item Arguments: $cond, \%attrs?
644 =item Return Value: $resultset (scalar context), @row_objs (list context)
648 # WHERE title LIKE '%blue%'
649 $cd_rs = $rs->search_like({ title => '%blue%'});
651 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
652 that this is simply a convenience method. You most likely want to use
653 L</search> with specific operators.
655 For more information, see L<DBIx::Class::Manual::Cookbook>.
661 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
662 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
663 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
664 return $class->search($query, { %$attrs });
671 =item Arguments: $first, $last
673 =item Return Value: $resultset (scalar context), @row_objs (list context)
677 Returns a resultset or object list representing a subset of elements from the
678 resultset slice is called on. Indexes are from 0, i.e., to get the first
681 my ($one, $two, $three) = $rs->slice(0, 2);
686 my ($self, $min, $max) = @_;
687 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
688 $attrs->{offset} = $self->{attrs}{offset} || 0;
689 $attrs->{offset} += $min;
690 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
691 return $self->search(undef(), $attrs);
692 #my $slice = (ref $self)->new($self->result_source, $attrs);
693 #return (wantarray ? $slice->all : $slice);
700 =item Arguments: none
702 =item Return Value: $result?
706 Returns the next element in the resultset (C<undef> is there is none).
708 Can be used to efficiently iterate over records in the resultset:
710 my $rs = $schema->resultset('CD')->search;
711 while (my $cd = $rs->next) {
715 Note that you need to store the resultset object, and call C<next> on it.
716 Calling C<< resultset('Table')->next >> repeatedly will always return the
717 first record from the resultset.
723 if (my $cache = $self->get_cache) {
724 $self->{all_cache_position} ||= 0;
725 return $cache->[$self->{all_cache_position}++];
727 if ($self->{attrs}{cache}) {
728 $self->{all_cache_position} = 1;
729 return ($self->all)[0];
731 if ($self->{stashed_objects}) {
732 my $obj = shift(@{$self->{stashed_objects}});
733 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
737 exists $self->{stashed_row}
738 ? @{delete $self->{stashed_row}}
739 : $self->cursor->next
741 return undef unless (@row);
742 my ($row, @more) = $self->_construct_object(@row);
743 $self->{stashed_objects} = \@more if @more;
747 sub _construct_object {
748 my ($self, @row) = @_;
749 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
750 my @new = $self->result_class->inflate_result($self->result_source, @$info);
751 @new = $self->{_attrs}{record_filter}->(@new)
752 if exists $self->{_attrs}{record_filter};
756 sub _collapse_result {
757 my ($self, $as_proto, $row) = @_;
761 # 'foo' => [ undef, 'foo' ]
762 # 'foo.bar' => [ 'foo', 'bar' ]
763 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
765 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
767 my %collapse = %{$self->{_attrs}{collapse}||{}};
771 # if we're doing collapsing (has_many prefetch) we need to grab records
772 # until the PK changes, so fill @pri_index. if not, we leave it empty so
773 # we know we don't have to bother.
775 # the reason for not using the collapse stuff directly is because if you
776 # had for e.g. two artists in a row with no cds, the collapse info for
777 # both would be NULL (undef) so you'd lose the second artist
779 # store just the index so we can check the array positions from the row
780 # without having to contruct the full hash
782 if (keys %collapse) {
783 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
784 foreach my $i (0 .. $#construct_as) {
785 next if defined($construct_as[$i][0]); # only self table
786 if (delete $pri{$construct_as[$i][1]}) {
787 push(@pri_index, $i);
789 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
793 # no need to do an if, it'll be empty if @pri_index is empty anyway
795 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
799 do { # no need to check anything at the front, we always want the first row
803 foreach my $this_as (@construct_as) {
804 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
807 push(@const_rows, \%const);
809 } until ( # no pri_index => no collapse => drop straight out
812 do { # get another row, stash it, drop out if different PK
814 @copy = $self->cursor->next;
815 $self->{stashed_row} = \@copy;
817 # last thing in do block, counts as true if anything doesn't match
819 # check xor defined first for NULL vs. NOT NULL then if one is
820 # defined the other must be so check string equality
823 (defined $pri_vals{$_} ^ defined $copy[$_])
824 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
829 my $alias = $self->{attrs}{alias};
838 foreach my $const (@const_rows) {
839 scalar @const_keys or do {
840 @const_keys = sort { length($a) <=> length($b) } keys %$const;
842 foreach my $key (@const_keys) {
845 my @parts = split(/\./, $key);
847 my $data = $const->{$key};
848 foreach my $p (@parts) {
849 $target = $target->[1]->{$p} ||= [];
851 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
852 # collapsing at this point and on final part
853 my $pos = $collapse_pos{$cur};
854 CK: foreach my $ck (@ckey) {
855 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
856 $collapse_pos{$cur} = $data;
857 delete @collapse_pos{ # clear all positioning for sub-entries
858 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
865 if (exists $collapse{$cur}) {
866 $target = $target->[-1];
869 $target->[0] = $data;
871 $info->[0] = $const->{$key};
883 =item Arguments: $result_source?
885 =item Return Value: $result_source
889 An accessor for the primary ResultSource object from which this ResultSet
896 =item Arguments: $result_class?
898 =item Return Value: $result_class
902 An accessor for the class to use when creating row objects. Defaults to
903 C<< result_source->result_class >> - which in most cases is the name of the
904 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
913 =item Arguments: $cond, \%attrs??
915 =item Return Value: $count
919 Performs an SQL C<COUNT> with the same query as the resultset was built
920 with to find the number of elements. If passed arguments, does a search
921 on the resultset and counts the results of that.
923 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
924 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
925 not support C<DISTINCT> with multiple columns. If you are using such a
926 database, you should only use columns from the main table in your C<group_by>
933 return $self->search(@_)->count if @_ and defined $_[0];
934 return scalar @{ $self->get_cache } if $self->get_cache;
935 my $count = $self->_count;
936 return 0 unless $count;
938 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
939 $count = $self->{attrs}{rows} if
940 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
944 sub _count { # Separated out so pager can get the full count
946 my $select = { count => '*' };
948 my $attrs = { %{$self->_resolved_attrs} };
949 if (my $group_by = delete $attrs->{group_by}) {
950 delete $attrs->{having};
951 my @distinct = (ref $group_by ? @$group_by : ($group_by));
952 # todo: try CONCAT for multi-column pk
953 my @pk = $self->result_source->primary_columns;
955 my $alias = $attrs->{alias};
956 foreach my $column (@distinct) {
957 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
958 @distinct = ($column);
964 $select = { count => { distinct => \@distinct } };
967 $attrs->{select} = $select;
968 $attrs->{as} = [qw/count/];
970 # offset, order by and page are not needed to count. record_filter is cdbi
971 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
973 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
974 my ($count) = $tmp_rs->cursor->next;
982 =item Arguments: $sql_fragment, @bind_values
984 =item Return Value: $count
988 Counts the results in a literal query. Equivalent to calling L</search_literal>
989 with the passed arguments, then L</count>.
993 sub count_literal { shift->search_literal(@_)->count; }
999 =item Arguments: none
1001 =item Return Value: @objects
1005 Returns all elements in the resultset. Called implicitly if the resultset
1006 is returned in list context.
1012 return @{ $self->get_cache } if $self->get_cache;
1016 # TODO: don't call resolve here
1017 if (keys %{$self->_resolved_attrs->{collapse}}) {
1018 # if ($self->{attrs}{prefetch}) {
1019 # Using $self->cursor->all is really just an optimisation.
1020 # If we're collapsing has_many prefetches it probably makes
1021 # very little difference, and this is cleaner than hacking
1022 # _construct_object to survive the approach
1023 my @row = $self->cursor->next;
1025 push(@obj, $self->_construct_object(@row));
1026 @row = (exists $self->{stashed_row}
1027 ? @{delete $self->{stashed_row}}
1028 : $self->cursor->next);
1031 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1034 $self->set_cache(\@obj) if $self->{attrs}{cache};
1042 =item Arguments: none
1044 =item Return Value: $self
1048 Resets the resultset's cursor, so you can iterate through the elements again.
1054 delete $self->{_attrs} if exists $self->{_attrs};
1055 $self->{all_cache_position} = 0;
1056 $self->cursor->reset;
1064 =item Arguments: none
1066 =item Return Value: $object?
1070 Resets the resultset and returns an object for the first result (if the
1071 resultset returns anything).
1076 return $_[0]->reset->next;
1079 # _cond_for_update_delete
1081 # update/delete require the condition to be modified to handle
1082 # the differing SQL syntax available. This transforms the $self->{cond}
1083 # appropriately, returning the new condition.
1085 sub _cond_for_update_delete {
1086 my ($self, $full_cond) = @_;
1089 $full_cond ||= $self->{cond};
1090 # No-op. No condition, we're updating/deleting everything
1091 return $cond unless ref $full_cond;
1093 if (ref $full_cond eq 'ARRAY') {
1097 foreach my $key (keys %{$_}) {
1099 $hash{$1} = $_->{$key};
1105 elsif (ref $full_cond eq 'HASH') {
1106 if ((keys %{$full_cond})[0] eq '-and') {
1109 my @cond = @{$full_cond->{-and}};
1110 for (my $i = 0; $i < @cond; $i++) {
1111 my $entry = $cond[$i];
1114 if (ref $entry eq 'HASH') {
1115 $hash = $self->_cond_for_update_delete($entry);
1118 $entry =~ /([^.]+)$/;
1119 $hash->{$1} = $cond[++$i];
1122 push @{$cond->{-and}}, $hash;
1126 foreach my $key (keys %{$full_cond}) {
1128 $cond->{$1} = $full_cond->{$key};
1133 $self->throw_exception(
1134 "Can't update/delete on resultset with condition unless hash or array"
1146 =item Arguments: \%values
1148 =item Return Value: $storage_rv
1152 Sets the specified columns in the resultset to the supplied values in a
1153 single query. Return value will be true if the update succeeded or false
1154 if no records were updated; exact type of success value is storage-dependent.
1159 my ($self, $values) = @_;
1160 $self->throw_exception("Values for update must be a hash")
1161 unless ref $values eq 'HASH';
1163 my $cond = $self->_cond_for_update_delete;
1165 return $self->result_source->storage->update(
1166 $self->result_source, $values, $cond
1174 =item Arguments: \%values
1176 =item Return Value: 1
1180 Fetches all objects and updates them one at a time. Note that C<update_all>
1181 will run DBIC cascade triggers, while L</update> will not.
1186 my ($self, $values) = @_;
1187 $self->throw_exception("Values for update must be a hash")
1188 unless ref $values eq 'HASH';
1189 foreach my $obj ($self->all) {
1190 $obj->set_columns($values)->update;
1199 =item Arguments: none
1201 =item Return Value: 1
1205 Deletes the contents of the resultset from its result source. Note that this
1206 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1207 to run. See also L<DBIx::Class::Row/delete>.
1214 my $cond = $self->_cond_for_update_delete;
1216 $self->result_source->storage->delete($self->result_source, $cond);
1224 =item Arguments: none
1226 =item Return Value: 1
1230 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1231 will run DBIC cascade triggers, while L</delete> will not.
1237 $_->delete for $self->all;
1245 =item Arguments: none
1247 =item Return Value: $pager
1251 Return Value a L<Data::Page> object for the current resultset. Only makes
1252 sense for queries with a C<page> attribute.
1258 my $attrs = $self->{attrs};
1259 $self->throw_exception("Can't create pager for non-paged rs")
1260 unless $self->{attrs}{page};
1261 $attrs->{rows} ||= 10;
1262 return $self->{pager} ||= Data::Page->new(
1263 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1270 =item Arguments: $page_number
1272 =item Return Value: $rs
1276 Returns a resultset for the $page_number page of the resultset on which page
1277 is called, where each page contains a number of rows equal to the 'rows'
1278 attribute set on the resultset (10 by default).
1283 my ($self, $page) = @_;
1284 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1291 =item Arguments: \%vals
1293 =item Return Value: $object
1297 Creates an object in the resultset's result class and returns it.
1302 my ($self, $values) = @_;
1303 $self->throw_exception( "new_result needs a hash" )
1304 unless (ref $values eq 'HASH');
1305 $self->throw_exception(
1306 "Can't abstract implicit construct, condition not a hash"
1307 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1309 my $alias = $self->{attrs}{alias};
1310 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1312 %{ $self->_remove_alias($values, $alias) },
1313 %{ $self->_remove_alias($collapsed_cond, $alias) },
1314 -source_handle => $self->_source_handle,
1315 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1318 return $self->result_class->new(\%new);
1323 # Recursively collapse the condition.
1325 sub _collapse_cond {
1326 my ($self, $cond, $collapsed) = @_;
1330 if (ref $cond eq 'ARRAY') {
1331 foreach my $subcond (@$cond) {
1332 next unless ref $subcond; # -or
1333 # warn "ARRAY: " . Dumper $subcond;
1334 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1337 elsif (ref $cond eq 'HASH') {
1338 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1339 foreach my $subcond (@{$cond->{-and}}) {
1340 # warn "HASH: " . Dumper $subcond;
1341 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1345 # warn "LEAF: " . Dumper $cond;
1346 foreach my $col (keys %$cond) {
1347 my $value = $cond->{$col};
1348 $collapsed->{$col} = $value;
1358 # Remove the specified alias from the specified query hash. A copy is made so
1359 # the original query is not modified.
1362 my ($self, $query, $alias) = @_;
1364 my %orig = %{ $query || {} };
1367 foreach my $key (keys %orig) {
1369 $unaliased{$key} = $orig{$key};
1372 $unaliased{$1} = $orig{$key}
1373 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1383 =item Arguments: \%vals, \%attrs?
1385 =item Return Value: $object
1389 Find an existing record from this resultset. If none exists, instantiate a new
1390 result object and return it. The object will not be saved into your storage
1391 until you call L<DBIx::Class::Row/insert> on it.
1393 If you want objects to be saved immediately, use L</find_or_create> instead.
1399 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1400 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1401 my $exists = $self->find($hash, $attrs);
1402 return defined $exists ? $exists : $self->new_result($hash);
1409 =item Arguments: \%vals
1411 =item Return Value: $object
1415 Inserts a record into the resultset and returns the object representing it.
1417 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1422 my ($self, $attrs) = @_;
1423 $self->throw_exception( "create needs a hashref" )
1424 unless ref $attrs eq 'HASH';
1425 return $self->new_result($attrs)->insert;
1428 =head2 find_or_create
1432 =item Arguments: \%vals, \%attrs?
1434 =item Return Value: $object
1438 $class->find_or_create({ key => $val, ... });
1440 Tries to find a record based on its primary key or unique constraint; if none
1441 is found, creates one and returns that instead.
1443 my $cd = $schema->resultset('CD')->find_or_create({
1445 artist => 'Massive Attack',
1446 title => 'Mezzanine',
1450 Also takes an optional C<key> attribute, to search by a specific key or unique
1451 constraint. For example:
1453 my $cd = $schema->resultset('CD')->find_or_create(
1455 artist => 'Massive Attack',
1456 title => 'Mezzanine',
1458 { key => 'cd_artist_title' }
1461 See also L</find> and L</update_or_create>. For information on how to declare
1462 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1466 sub find_or_create {
1468 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1469 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1470 my $exists = $self->find($hash, $attrs);
1471 return defined $exists ? $exists : $self->create($hash);
1474 =head2 update_or_create
1478 =item Arguments: \%col_values, { key => $unique_constraint }?
1480 =item Return Value: $object
1484 $class->update_or_create({ col => $val, ... });
1486 First, searches for an existing row matching one of the unique constraints
1487 (including the primary key) on the source of this resultset. If a row is
1488 found, updates it with the other given column values. Otherwise, creates a new
1491 Takes an optional C<key> attribute to search on a specific unique constraint.
1494 # In your application
1495 my $cd = $schema->resultset('CD')->update_or_create(
1497 artist => 'Massive Attack',
1498 title => 'Mezzanine',
1501 { key => 'cd_artist_title' }
1504 If no C<key> is specified, it searches on all unique constraints defined on the
1505 source, including the primary key.
1507 If the C<key> is specified as C<primary>, it searches only on the primary key.
1509 See also L</find> and L</find_or_create>. For information on how to declare
1510 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1514 sub update_or_create {
1516 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1517 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1519 my $row = $self->find($cond, $attrs);
1521 $row->update($cond);
1525 return $self->create($cond);
1532 =item Arguments: none
1534 =item Return Value: \@cache_objects?
1538 Gets the contents of the cache for the resultset, if the cache is set.
1550 =item Arguments: \@cache_objects
1552 =item Return Value: \@cache_objects
1556 Sets the contents of the cache for the resultset. Expects an arrayref
1557 of objects of the same class as those produced by the resultset. Note that
1558 if the cache is set the resultset will return the cached objects rather
1559 than re-querying the database even if the cache attr is not set.
1564 my ( $self, $data ) = @_;
1565 $self->throw_exception("set_cache requires an arrayref")
1566 if defined($data) && (ref $data ne 'ARRAY');
1567 $self->{all_cache} = $data;
1574 =item Arguments: none
1576 =item Return Value: []
1580 Clears the cache for the resultset.
1585 shift->set_cache(undef);
1588 =head2 related_resultset
1592 =item Arguments: $relationship_name
1594 =item Return Value: $resultset
1598 Returns a related resultset for the supplied relationship name.
1600 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1604 sub related_resultset {
1605 my ($self, $rel) = @_;
1607 $self->{related_resultsets} ||= {};
1608 return $self->{related_resultsets}{$rel} ||= do {
1609 my $rel_obj = $self->result_source->relationship_info($rel);
1611 $self->throw_exception(
1612 "search_related: result source '" . $self->_source_handle->source_moniker .
1613 "' has no such relationship $rel")
1616 my ($from,$seen) = $self->_resolve_from($rel);
1618 my $join_count = $seen->{$rel};
1619 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1621 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
1622 my %attrs = %{$self->{attrs}||{}};
1623 delete $attrs{result_class};
1627 if (my $cache = $self->get_cache) {
1628 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
1629 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
1634 my $new = $self->_source_handle
1636 ->resultset($rel_obj->{class})
1645 where => $self->{cond},
1649 $new->set_cache($new_cache) if $new_cache;
1655 my ($self, $extra_join) = @_;
1656 my $source = $self->result_source;
1657 my $attrs = $self->{attrs};
1659 my $from = $attrs->{from}
1660 || [ { $attrs->{alias} => $source->from } ];
1662 my $seen = { %{$attrs->{seen_join}||{}} };
1664 my $join = ($attrs->{join}
1665 ? [ $attrs->{join}, $extra_join ]
1669 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1672 return ($from,$seen);
1675 sub _resolved_attrs {
1677 return $self->{_attrs} if $self->{_attrs};
1679 my $attrs = { %{$self->{attrs}||{}} };
1680 my $source = $self->result_source;
1681 my $alias = $attrs->{alias};
1683 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1684 if ($attrs->{columns}) {
1685 delete $attrs->{as};
1686 } elsif (!$attrs->{select}) {
1687 $attrs->{columns} = [ $source->columns ];
1692 ? (ref $attrs->{select} eq 'ARRAY'
1693 ? [ @{$attrs->{select}} ]
1694 : [ $attrs->{select} ])
1695 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1699 ? (ref $attrs->{as} eq 'ARRAY'
1700 ? [ @{$attrs->{as}} ]
1702 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1706 if ($adds = delete $attrs->{include_columns}) {
1707 $adds = [$adds] unless ref $adds eq 'ARRAY';
1708 push(@{$attrs->{select}}, @$adds);
1709 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1711 if ($adds = delete $attrs->{'+select'}) {
1712 $adds = [$adds] unless ref $adds eq 'ARRAY';
1713 push(@{$attrs->{select}},
1714 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1716 if (my $adds = delete $attrs->{'+as'}) {
1717 $adds = [$adds] unless ref $adds eq 'ARRAY';
1718 push(@{$attrs->{as}}, @$adds);
1721 $attrs->{from} ||= [ { 'me' => $source->from } ];
1723 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1724 my $join = delete $attrs->{join} || {};
1726 if (defined $attrs->{prefetch}) {
1727 $join = $self->_merge_attr(
1728 $join, $attrs->{prefetch}
1732 $attrs->{from} = # have to copy here to avoid corrupting the original
1735 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1739 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1740 if ($attrs->{order_by}) {
1741 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1742 ? [ @{$attrs->{order_by}} ]
1743 : [ $attrs->{order_by} ]);
1745 $attrs->{order_by} = [];
1748 my $collapse = $attrs->{collapse} || {};
1749 if (my $prefetch = delete $attrs->{prefetch}) {
1750 $prefetch = $self->_merge_attr({}, $prefetch);
1752 my $seen = $attrs->{seen_join} || {};
1753 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1754 # bring joins back to level of current class
1755 my @prefetch = $source->resolve_prefetch(
1756 $p, $alias, $seen, \@pre_order, $collapse
1758 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1759 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1761 push(@{$attrs->{order_by}}, @pre_order);
1763 $attrs->{collapse} = $collapse;
1765 return $self->{_attrs} = $attrs;
1769 my ($self, $a, $b) = @_;
1770 return $b unless defined($a);
1771 return $a unless defined($b);
1773 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1774 foreach my $key (keys %{$b}) {
1775 if (exists $a->{$key}) {
1776 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1778 $a->{$key} = $b->{$key};
1783 $a = [$a] unless ref $a eq 'ARRAY';
1784 $b = [$b] unless ref $b eq 'ARRAY';
1788 foreach my $x ($a, $b) {
1789 foreach my $element (@{$x}) {
1790 if (ref $element eq 'HASH') {
1791 $hash = $self->_merge_attr($hash, $element);
1792 } elsif (ref $element eq 'ARRAY') {
1793 push(@array, @{$element});
1795 push(@array, $element) unless $b == $x
1796 && grep { $_ eq $element } @array;
1801 @array = grep { !exists $hash->{$_} } @array;
1803 return keys %{$hash}
1816 $self->_source_handle($_[0]->handle);
1818 $self->_source_handle->resolve;
1822 =head2 throw_exception
1824 See L<DBIx::Class::Schema/throw_exception> for details.
1828 sub throw_exception {
1830 $self->_source_handle->schema->throw_exception(@_);
1833 # XXX: FIXME: Attributes docs need clearing up
1837 The resultset takes various attributes that modify its behavior. Here's an
1844 =item Value: ($order_by | \@order_by)
1848 Which column(s) to order the results by. This is currently passed
1849 through directly to SQL, so you can give e.g. C<year DESC> for a
1850 descending order on the column `year'.
1852 Please note that if you have C<quote_char> enabled (see
1853 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1854 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1855 so you will need to manually quote things as appropriate.)
1861 =item Value: \@columns
1865 Shortcut to request a particular set of columns to be retrieved. Adds
1866 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1867 from that, then auto-populates C<as> from C<select> as normal. (You may also
1868 use the C<cols> attribute, as in earlier versions of DBIC.)
1870 =head2 include_columns
1874 =item Value: \@columns
1878 Shortcut to include additional columns in the returned results - for example
1880 $schema->resultset('CD')->search(undef, {
1881 include_columns => ['artist.name'],
1885 would return all CDs and include a 'name' column to the information
1886 passed to object inflation. Note that the 'artist' is the name of the
1887 column (or relationship) accessor, and 'name' is the name of the column
1888 accessor in the related table.
1894 =item Value: \@select_columns
1898 Indicates which columns should be selected from the storage. You can use
1899 column names, or in the case of RDBMS back ends, function or stored procedure
1902 $rs = $schema->resultset('Employee')->search(undef, {
1905 { count => 'employeeid' },
1910 When you use function/stored procedure names and do not supply an C<as>
1911 attribute, the column names returned are storage-dependent. E.g. MySQL would
1912 return a column named C<count(employeeid)> in the above example.
1918 Indicates additional columns to be selected from storage. Works the same as
1919 L<select> but adds columns to the selection.
1927 Indicates additional column names for those added via L<+select>.
1935 =item Value: \@inflation_names
1939 Indicates column names for object inflation. That is, c< as >
1940 indicates the name that the column can be accessed as via the
1941 C<get_column> method (or via the object accessor, B<if one already
1942 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
1945 The C< as > attribute is used in conjunction with C<select>,
1946 usually when C<select> contains one or more function or stored
1949 $rs = $schema->resultset('Employee')->search(undef, {
1952 { count => 'employeeid' }
1954 as => ['name', 'employee_count'],
1957 my $employee = $rs->first(); # get the first Employee
1959 If the object against which the search is performed already has an accessor
1960 matching a column name specified in C<as>, the value can be retrieved using
1961 the accessor as normal:
1963 my $name = $employee->name();
1965 If on the other hand an accessor does not exist in the object, you need to
1966 use C<get_column> instead:
1968 my $employee_count = $employee->get_column('employee_count');
1970 You can create your own accessors if required - see
1971 L<DBIx::Class::Manual::Cookbook> for details.
1973 Please note: This will NOT insert an C<AS employee_count> into the SQL
1974 statement produced, it is used for internal access only. Thus
1975 attempting to use the accessor in an C<order_by> clause or similar
1976 will fail miserably.
1978 To get around this limitation, you can supply literal SQL to your
1979 C<select> attibute that contains the C<AS alias> text, eg:
1981 select => [\'myfield AS alias']
1987 =item Value: ($rel_name | \@rel_names | \%rel_names)
1991 Contains a list of relationships that should be joined for this query. For
1994 # Get CDs by Nine Inch Nails
1995 my $rs = $schema->resultset('CD')->search(
1996 { 'artist.name' => 'Nine Inch Nails' },
1997 { join => 'artist' }
2000 Can also contain a hash reference to refer to the other relation's relations.
2003 package MyApp::Schema::Track;
2004 use base qw/DBIx::Class/;
2005 __PACKAGE__->table('track');
2006 __PACKAGE__->add_columns(qw/trackid cd position title/);
2007 __PACKAGE__->set_primary_key('trackid');
2008 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2011 # In your application
2012 my $rs = $schema->resultset('Artist')->search(
2013 { 'track.title' => 'Teardrop' },
2015 join => { cd => 'track' },
2016 order_by => 'artist.name',
2020 You need to use the relationship (not the table) name in conditions,
2021 because they are aliased as such. The current table is aliased as "me", so
2022 you need to use me.column_name in order to avoid ambiguity. For example:
2024 # Get CDs from 1984 with a 'Foo' track
2025 my $rs = $schema->resultset('CD')->search(
2028 'tracks.name' => 'Foo'
2030 { join => 'tracks' }
2033 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2034 similarly for a third time). For e.g.
2036 my $rs = $schema->resultset('Artist')->search({
2037 'cds.title' => 'Down to Earth',
2038 'cds_2.title' => 'Popular',
2040 join => [ qw/cds cds/ ],
2043 will return a set of all artists that have both a cd with title 'Down
2044 to Earth' and a cd with title 'Popular'.
2046 If you want to fetch related objects from other tables as well, see C<prefetch>
2053 =item Value: ($rel_name | \@rel_names | \%rel_names)
2057 Contains one or more relationships that should be fetched along with the main
2058 query (when they are accessed afterwards they will have already been
2059 "prefetched"). This is useful for when you know you will need the related
2060 objects, because it saves at least one query:
2062 my $rs = $schema->resultset('Tag')->search(
2071 The initial search results in SQL like the following:
2073 SELECT tag.*, cd.*, artist.* FROM tag
2074 JOIN cd ON tag.cd = cd.cdid
2075 JOIN artist ON cd.artist = artist.artistid
2077 L<DBIx::Class> has no need to go back to the database when we access the
2078 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2081 Simple prefetches will be joined automatically, so there is no need
2082 for a C<join> attribute in the above search. If you're prefetching to
2083 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2084 specify the join as well.
2086 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2087 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2088 with an accessor type of 'single' or 'filter').
2098 Makes the resultset paged and specifies the page to retrieve. Effectively
2099 identical to creating a non-pages resultset and then calling ->page($page)
2102 If L<rows> attribute is not specified it defualts to 10 rows per page.
2112 Specifes the maximum number of rows for direct retrieval or the number of
2113 rows per page if the page attribute or method is used.
2119 =item Value: $offset
2123 Specifies the (zero-based) row number for the first row to be returned, or the
2124 of the first row of the first page if paging is used.
2130 =item Value: \@columns
2134 A arrayref of columns to group by. Can include columns of joined tables.
2136 group_by => [qw/ column1 column2 ... /]
2142 =item Value: $condition
2146 HAVING is a select statement attribute that is applied between GROUP BY and
2147 ORDER BY. It is applied to the after the grouping calculations have been
2150 having => { 'count(employee)' => { '>=', 100 } }
2156 =item Value: (0 | 1)
2160 Set to 1 to group by all columns.
2166 Adds to the WHERE clause.
2168 # only return rows WHERE deleted IS NULL for all searches
2169 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2171 Can be overridden by passing C<{ where => undef }> as an attribute
2178 Set to 1 to cache search results. This prevents extra SQL queries if you
2179 revisit rows in your ResultSet:
2181 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2183 while( my $artist = $resultset->next ) {
2187 $rs->first; # without cache, this would issue a query
2189 By default, searches are not cached.
2191 For more examples of using these attributes, see
2192 L<DBIx::Class::Manual::Cookbook>.
2198 =item Value: \@from_clause
2202 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2203 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2206 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2208 C<join> will usually do what you need and it is strongly recommended that you
2209 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2210 And we really do mean "cannot", not just tried and failed. Attempting to use
2211 this because you're having problems with C<join> is like trying to use x86
2212 ASM because you've got a syntax error in your C. Trust us on this.
2214 Now, if you're still really, really sure you need to use this (and if you're
2215 not 100% sure, ask the mailing list first), here's an explanation of how this
2218 The syntax is as follows -
2221 { <alias1> => <table1> },
2223 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2224 [], # nested JOIN (optional)
2225 { <table1.column1> => <table2.column2>, ... (more conditions) },
2227 # More of the above [ ] may follow for additional joins
2234 ON <table1.column1> = <table2.column2>
2235 <more joins may follow>
2237 An easy way to follow the examples below is to remember the following:
2239 Anything inside "[]" is a JOIN
2240 Anything inside "{}" is a condition for the enclosing JOIN
2242 The following examples utilize a "person" table in a family tree application.
2243 In order to express parent->child relationships, this table is self-joined:
2245 # Person->belongs_to('father' => 'Person');
2246 # Person->belongs_to('mother' => 'Person');
2248 C<from> can be used to nest joins. Here we return all children with a father,
2249 then search against all mothers of those children:
2251 $rs = $schema->resultset('Person')->search(
2254 alias => 'mother', # alias columns in accordance with "from"
2256 { mother => 'person' },
2259 { child => 'person' },
2261 { father => 'person' },
2262 { 'father.person_id' => 'child.father_id' }
2265 { 'mother.person_id' => 'child.mother_id' }
2272 # SELECT mother.* FROM person mother
2275 # JOIN person father
2276 # ON ( father.person_id = child.father_id )
2278 # ON ( mother.person_id = child.mother_id )
2280 The type of any join can be controlled manually. To search against only people
2281 with a father in the person table, we could explicitly use C<INNER JOIN>:
2283 $rs = $schema->resultset('Person')->search(
2286 alias => 'child', # alias columns in accordance with "from"
2288 { child => 'person' },
2290 { father => 'person', -join_type => 'inner' },
2291 { 'father.id' => 'child.father_id' }
2298 # SELECT child.* FROM person child
2299 # INNER JOIN person father ON child.father_id = father.id