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;
96 $attrs->{alias} ||= 'me';
99 _source_handle => $source,
100 result_class => $attrs->{result_class} || $source->resolve->result_class,
101 cond => $attrs->{where},
116 =item Arguments: $cond, \%attrs?
118 =item Return Value: $resultset (scalar context), @row_objs (list context)
122 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
123 my $new_rs = $cd_rs->search({ year => 2005 });
125 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
126 # year = 2005 OR year = 2004
128 If you need to pass in additional attributes but no additional condition,
129 call it as C<search(undef, \%attrs)>.
131 # "SELECT name, artistid FROM $artist_table"
132 my @all_artists = $schema->resultset('Artist')->search(undef, {
133 columns => [qw/name artistid/],
136 For a list of attributes that can be passed to C<search>, see
137 L</ATTRIBUTES>. For more examples of using this function, see
138 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
139 documentation for the first argument, see L<SQL::Abstract>.
145 my $rs = $self->search_rs( @_ );
146 return (wantarray ? $rs->all : $rs);
153 =item Arguments: $cond, \%attrs?
155 =item Return Value: $resultset
159 This method does the same exact thing as search() except it will
160 always return a resultset, even in list context.
169 unless (@_) { # no search, effectively just a clone
170 $rows = $self->get_cache;
174 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
175 my $our_attrs = { %{$self->{attrs}} };
176 my $having = delete $our_attrs->{having};
177 my $where = delete $our_attrs->{where};
179 my $new_attrs = { %{$our_attrs}, %{$attrs} };
181 # merge new attrs into inherited
182 foreach my $key (qw/join prefetch/) {
183 next unless exists $attrs->{$key};
184 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
189 (@_ == 1 || ref $_[0] eq "HASH")
191 (ref $_[0] eq 'HASH')
193 (keys %{ $_[0] } > 0)
201 ? $self->throw_exception("Odd number of arguments to search")
208 if (defined $where) {
209 $new_attrs->{where} = (
210 defined $new_attrs->{where}
213 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
214 } $where, $new_attrs->{where}
221 $new_attrs->{where} = (
222 defined $new_attrs->{where}
225 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
226 } $cond, $new_attrs->{where}
232 if (defined $having) {
233 $new_attrs->{having} = (
234 defined $new_attrs->{having}
237 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
238 } $having, $new_attrs->{having}
244 my $rs = (ref $self)->new($self->result_source, $new_attrs);
246 $rs->set_cache($rows);
251 =head2 search_literal
255 =item Arguments: $sql_fragment, @bind_values
257 =item Return Value: $resultset (scalar context), @row_objs (list context)
261 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
262 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
264 Pass a literal chunk of SQL to be added to the conditional part of the
270 my ($self, $cond, @vals) = @_;
271 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
272 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
273 return $self->search(\$cond, $attrs);
280 =item Arguments: @values | \%cols, \%attrs?
282 =item Return Value: $row_object
286 Finds a row based on its primary key or unique constraint. For example, to find
287 a row by its primary key:
289 my $cd = $schema->resultset('CD')->find(5);
291 You can also find a row by a specific unique constraint using the C<key>
292 attribute. For example:
294 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
295 key => 'cd_artist_title'
298 Additionally, you can specify the columns explicitly by name:
300 my $cd = $schema->resultset('CD')->find(
302 artist => 'Massive Attack',
303 title => 'Mezzanine',
305 { key => 'cd_artist_title' }
308 If the C<key> is specified as C<primary>, it searches only on the primary key.
310 If no C<key> is specified, it searches on all unique constraints defined on the
311 source, including the primary key.
313 If your table does not have a primary key, you B<must> provide a value for the
314 C<key> attribute matching one of the unique constraints on the source.
316 See also L</find_or_create> and L</update_or_create>. For information on how to
317 declare unique constraints, see
318 L<DBIx::Class::ResultSource/add_unique_constraint>.
324 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
326 # Default to the primary key, but allow a specific key
327 my @cols = exists $attrs->{key}
328 ? $self->result_source->unique_constraint_columns($attrs->{key})
329 : $self->result_source->primary_columns;
330 $self->throw_exception(
331 "Can't find unless a primary key is defined or unique constraint is specified"
334 # Parse out a hashref from input
336 if (ref $_[0] eq 'HASH') {
337 $input_query = { %{$_[0]} };
339 elsif (@_ == @cols) {
341 @{$input_query}{@cols} = @_;
344 # Compatibility: Allow e.g. find(id => $value)
345 carp "Find by key => value deprecated; please use a hashref instead";
349 my (%related, $info);
351 KEY: foreach my $key (keys %$input_query) {
352 if (ref($input_query->{$key})
353 && ($info = $self->result_source->relationship_info($key))) {
354 my $val = delete $input_query->{$key};
355 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
356 my $rel_q = $self->result_source->resolve_condition(
357 $info->{cond}, $val, $key
359 die "Can't handle OR join condition in find" if ref($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 # need to take offset from resolved attrs
940 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
941 $count = $self->{attrs}{rows} if
942 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
946 sub _count { # Separated out so pager can get the full count
948 my $select = { count => '*' };
950 my $attrs = { %{$self->_resolved_attrs} };
951 if (my $group_by = delete $attrs->{group_by}) {
952 delete $attrs->{having};
953 my @distinct = (ref $group_by ? @$group_by : ($group_by));
954 # todo: try CONCAT for multi-column pk
955 my @pk = $self->result_source->primary_columns;
957 my $alias = $attrs->{alias};
958 foreach my $column (@distinct) {
959 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
960 @distinct = ($column);
966 $select = { count => { distinct => \@distinct } };
969 $attrs->{select} = $select;
970 $attrs->{as} = [qw/count/];
972 # offset, order by and page are not needed to count. record_filter is cdbi
973 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
975 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
976 my ($count) = $tmp_rs->cursor->next;
984 =item Arguments: $sql_fragment, @bind_values
986 =item Return Value: $count
990 Counts the results in a literal query. Equivalent to calling L</search_literal>
991 with the passed arguments, then L</count>.
995 sub count_literal { shift->search_literal(@_)->count; }
1001 =item Arguments: none
1003 =item Return Value: @objects
1007 Returns all elements in the resultset. Called implicitly if the resultset
1008 is returned in list context.
1014 return @{ $self->get_cache } if $self->get_cache;
1018 # TODO: don't call resolve here
1019 if (keys %{$self->_resolved_attrs->{collapse}}) {
1020 # if ($self->{attrs}{prefetch}) {
1021 # Using $self->cursor->all is really just an optimisation.
1022 # If we're collapsing has_many prefetches it probably makes
1023 # very little difference, and this is cleaner than hacking
1024 # _construct_object to survive the approach
1025 my @row = $self->cursor->next;
1027 push(@obj, $self->_construct_object(@row));
1028 @row = (exists $self->{stashed_row}
1029 ? @{delete $self->{stashed_row}}
1030 : $self->cursor->next);
1033 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1036 $self->set_cache(\@obj) if $self->{attrs}{cache};
1044 =item Arguments: none
1046 =item Return Value: $self
1050 Resets the resultset's cursor, so you can iterate through the elements again.
1056 delete $self->{_attrs} if exists $self->{_attrs};
1057 $self->{all_cache_position} = 0;
1058 $self->cursor->reset;
1066 =item Arguments: none
1068 =item Return Value: $object?
1072 Resets the resultset and returns an object for the first result (if the
1073 resultset returns anything).
1078 return $_[0]->reset->next;
1081 # _cond_for_update_delete
1083 # update/delete require the condition to be modified to handle
1084 # the differing SQL syntax available. This transforms the $self->{cond}
1085 # appropriately, returning the new condition.
1087 sub _cond_for_update_delete {
1088 my ($self, $full_cond) = @_;
1091 $full_cond ||= $self->{cond};
1092 # No-op. No condition, we're updating/deleting everything
1093 return $cond unless ref $full_cond;
1095 if (ref $full_cond eq 'ARRAY') {
1099 foreach my $key (keys %{$_}) {
1101 $hash{$1} = $_->{$key};
1107 elsif (ref $full_cond eq 'HASH') {
1108 if ((keys %{$full_cond})[0] eq '-and') {
1111 my @cond = @{$full_cond->{-and}};
1112 for (my $i = 0; $i < @cond; $i++) {
1113 my $entry = $cond[$i];
1116 if (ref $entry eq 'HASH') {
1117 $hash = $self->_cond_for_update_delete($entry);
1120 $entry =~ /([^.]+)$/;
1121 $hash->{$1} = $cond[++$i];
1124 push @{$cond->{-and}}, $hash;
1128 foreach my $key (keys %{$full_cond}) {
1130 $cond->{$1} = $full_cond->{$key};
1135 $self->throw_exception(
1136 "Can't update/delete on resultset with condition unless hash or array"
1148 =item Arguments: \%values
1150 =item Return Value: $storage_rv
1154 Sets the specified columns in the resultset to the supplied values in a
1155 single query. Return value will be true if the update succeeded or false
1156 if no records were updated; exact type of success value is storage-dependent.
1161 my ($self, $values) = @_;
1162 $self->throw_exception("Values for update must be a hash")
1163 unless ref $values eq 'HASH';
1165 my $cond = $self->_cond_for_update_delete;
1167 return $self->result_source->storage->update(
1168 $self->result_source, $values, $cond
1176 =item Arguments: \%values
1178 =item Return Value: 1
1182 Fetches all objects and updates them one at a time. Note that C<update_all>
1183 will run DBIC cascade triggers, while L</update> will not.
1188 my ($self, $values) = @_;
1189 $self->throw_exception("Values for update must be a hash")
1190 unless ref $values eq 'HASH';
1191 foreach my $obj ($self->all) {
1192 $obj->set_columns($values)->update;
1201 =item Arguments: none
1203 =item Return Value: 1
1207 Deletes the contents of the resultset from its result source. Note that this
1208 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1209 to run. See also L<DBIx::Class::Row/delete>.
1216 my $cond = $self->_cond_for_update_delete;
1218 $self->result_source->storage->delete($self->result_source, $cond);
1226 =item Arguments: none
1228 =item Return Value: 1
1232 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1233 will run DBIC cascade triggers, while L</delete> will not.
1239 $_->delete for $self->all;
1247 =item Arguments: \@data;
1251 Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
1252 submitting to a $resultset->create(...) method.
1254 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1255 to insert the data, as this is a faster method.
1257 Otherwise, each set of data is inserted into the database using
1258 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1259 objects is returned.
1261 Example: Assuming an Artist Class that has many CDs Classes relating:
1263 my $Artist_rs = $schema->resultset("Artist");
1265 ## Void Context Example
1266 $Artist_rs->populate([
1267 { artistid => 4, name => 'Manufactured Crap', cds => [
1268 { title => 'My First CD', year => 2006 },
1269 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1272 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1273 { title => 'My parents sold me to a record company' ,year => 2005 },
1274 { title => 'Why Am I So Ugly?', year => 2006 },
1275 { title => 'I Got Surgery and am now Popular', year => 2007 }
1280 ## Array Context Example
1281 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1282 { name => "Artist One"},
1283 { name => "Artist Two"},
1284 { name => "Artist Three", cds=> [
1285 { title => "First CD", year => 2007},
1286 { title => "Second CD", year => 2008},
1290 print $ArtistOne->name; ## response is 'Artist One'
1291 print $ArtistThree->cds->count ## reponse is '2'
1296 my ($self, $data) = @_;
1298 if(defined wantarray) {
1300 foreach my $item (@$data) {
1301 push(@created, $self->create($item));
1305 my ($first, @rest) = @$data;
1307 my @names = grep {!ref $first->{$_}} keys %$first;
1308 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1309 my @pks = $self->result_source->primary_columns;
1311 ## do the belongs_to relationships
1312 foreach my $index (0..$#$data) {
1313 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1314 my @ret = $self->populate($data);
1318 foreach my $rel (@rels) {
1319 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1320 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1321 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1322 my $related = $result->result_source->resolve_condition(
1323 $result->result_source->relationship_info($reverse)->{cond},
1328 delete $data->[$index]->{$rel};
1329 $data->[$index] = {%{$data->[$index]}, %$related};
1331 push @names, keys %$related if $index == 0;
1335 ## do bulk insert on current row
1338 defined $_ ? $_ : $self->throw_exception("Undefined value for column!")
1342 $self->result_source->storage->insert_bulk(
1343 $self->result_source,
1348 ## do the has_many relationships
1349 foreach my $item (@$data) {
1351 foreach my $rel (@rels) {
1352 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1354 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1355 || $self->throw_exception('Cannot find the relating object.');
1357 my $child = $parent->$rel;
1359 my $related = $child->result_source->resolve_condition(
1360 $parent->result_source->relationship_info($rel)->{cond},
1365 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1366 my @populate = map { {%$_, %$related} } @rows_to_add;
1368 $child->populate( \@populate );
1378 =item Arguments: none
1380 =item Return Value: $pager
1384 Return Value a L<Data::Page> object for the current resultset. Only makes
1385 sense for queries with a C<page> attribute.
1391 my $attrs = $self->{attrs};
1392 $self->throw_exception("Can't create pager for non-paged rs")
1393 unless $self->{attrs}{page};
1394 $attrs->{rows} ||= 10;
1395 return $self->{pager} ||= Data::Page->new(
1396 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1403 =item Arguments: $page_number
1405 =item Return Value: $rs
1409 Returns a resultset for the $page_number page of the resultset on which page
1410 is called, where each page contains a number of rows equal to the 'rows'
1411 attribute set on the resultset (10 by default).
1416 my ($self, $page) = @_;
1417 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1424 =item Arguments: \%vals
1426 =item Return Value: $object
1430 Creates an object in the resultset's result class and returns it.
1435 my ($self, $values) = @_;
1436 $self->throw_exception( "new_result needs a hash" )
1437 unless (ref $values eq 'HASH');
1438 $self->throw_exception(
1439 "Can't abstract implicit construct, condition not a hash"
1440 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1442 my $alias = $self->{attrs}{alias};
1443 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1445 %{ $self->_remove_alias($values, $alias) },
1446 %{ $self->_remove_alias($collapsed_cond, $alias) },
1447 -source_handle => $self->_source_handle,
1448 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1451 return $self->result_class->new(\%new);
1456 # Recursively collapse the condition.
1458 sub _collapse_cond {
1459 my ($self, $cond, $collapsed) = @_;
1463 if (ref $cond eq 'ARRAY') {
1464 foreach my $subcond (@$cond) {
1465 next unless ref $subcond; # -or
1466 # warn "ARRAY: " . Dumper $subcond;
1467 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1470 elsif (ref $cond eq 'HASH') {
1471 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1472 foreach my $subcond (@{$cond->{-and}}) {
1473 # warn "HASH: " . Dumper $subcond;
1474 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1478 # warn "LEAF: " . Dumper $cond;
1479 foreach my $col (keys %$cond) {
1480 my $value = $cond->{$col};
1481 $collapsed->{$col} = $value;
1491 # Remove the specified alias from the specified query hash. A copy is made so
1492 # the original query is not modified.
1495 my ($self, $query, $alias) = @_;
1497 my %orig = %{ $query || {} };
1500 foreach my $key (keys %orig) {
1502 $unaliased{$key} = $orig{$key};
1505 $unaliased{$1} = $orig{$key}
1506 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1516 =item Arguments: \%vals, \%attrs?
1518 =item Return Value: $object
1522 Find an existing record from this resultset. If none exists, instantiate a new
1523 result object and return it. The object will not be saved into your storage
1524 until you call L<DBIx::Class::Row/insert> on it.
1526 If you want objects to be saved immediately, use L</find_or_create> instead.
1532 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1533 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1534 my $exists = $self->find($hash, $attrs);
1535 return defined $exists ? $exists : $self->new_result($hash);
1542 =item Arguments: \%vals
1544 =item Return Value: $object
1548 Inserts a record into the resultset and returns the object representing it.
1550 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1555 my ($self, $attrs) = @_;
1556 $self->throw_exception( "create needs a hashref" )
1557 unless ref $attrs eq 'HASH';
1558 return $self->new_result($attrs)->insert;
1561 =head2 find_or_create
1565 =item Arguments: \%vals, \%attrs?
1567 =item Return Value: $object
1571 $class->find_or_create({ key => $val, ... });
1573 Tries to find a record based on its primary key or unique constraint; if none
1574 is found, creates one and returns that instead.
1576 my $cd = $schema->resultset('CD')->find_or_create({
1578 artist => 'Massive Attack',
1579 title => 'Mezzanine',
1583 Also takes an optional C<key> attribute, to search by a specific key or unique
1584 constraint. For example:
1586 my $cd = $schema->resultset('CD')->find_or_create(
1588 artist => 'Massive Attack',
1589 title => 'Mezzanine',
1591 { key => 'cd_artist_title' }
1594 See also L</find> and L</update_or_create>. For information on how to declare
1595 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1599 sub find_or_create {
1601 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1602 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1603 my $exists = $self->find($hash, $attrs);
1604 return defined $exists ? $exists : $self->create($hash);
1607 =head2 update_or_create
1611 =item Arguments: \%col_values, { key => $unique_constraint }?
1613 =item Return Value: $object
1617 $class->update_or_create({ col => $val, ... });
1619 First, searches for an existing row matching one of the unique constraints
1620 (including the primary key) on the source of this resultset. If a row is
1621 found, updates it with the other given column values. Otherwise, creates a new
1624 Takes an optional C<key> attribute to search on a specific unique constraint.
1627 # In your application
1628 my $cd = $schema->resultset('CD')->update_or_create(
1630 artist => 'Massive Attack',
1631 title => 'Mezzanine',
1634 { key => 'cd_artist_title' }
1637 If no C<key> is specified, it searches on all unique constraints defined on the
1638 source, including the primary key.
1640 If the C<key> is specified as C<primary>, it searches only on the primary key.
1642 See also L</find> and L</find_or_create>. For information on how to declare
1643 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1647 sub update_or_create {
1649 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1650 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1652 my $row = $self->find($cond, $attrs);
1654 $row->update($cond);
1658 return $self->create($cond);
1665 =item Arguments: none
1667 =item Return Value: \@cache_objects?
1671 Gets the contents of the cache for the resultset, if the cache is set.
1683 =item Arguments: \@cache_objects
1685 =item Return Value: \@cache_objects
1689 Sets the contents of the cache for the resultset. Expects an arrayref
1690 of objects of the same class as those produced by the resultset. Note that
1691 if the cache is set the resultset will return the cached objects rather
1692 than re-querying the database even if the cache attr is not set.
1697 my ( $self, $data ) = @_;
1698 $self->throw_exception("set_cache requires an arrayref")
1699 if defined($data) && (ref $data ne 'ARRAY');
1700 $self->{all_cache} = $data;
1707 =item Arguments: none
1709 =item Return Value: []
1713 Clears the cache for the resultset.
1718 shift->set_cache(undef);
1721 =head2 related_resultset
1725 =item Arguments: $relationship_name
1727 =item Return Value: $resultset
1731 Returns a related resultset for the supplied relationship name.
1733 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1737 sub related_resultset {
1738 my ($self, $rel) = @_;
1740 $self->{related_resultsets} ||= {};
1741 return $self->{related_resultsets}{$rel} ||= do {
1742 my $rel_obj = $self->result_source->relationship_info($rel);
1744 $self->throw_exception(
1745 "search_related: result source '" . $self->_source_handle->source_moniker .
1746 "' has no such relationship $rel")
1749 my ($from,$seen) = $self->_resolve_from($rel);
1751 my $join_count = $seen->{$rel};
1752 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1754 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
1755 my %attrs = %{$self->{attrs}||{}};
1756 delete $attrs{result_class};
1760 if (my $cache = $self->get_cache) {
1761 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
1762 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
1767 my $new = $self->_source_handle
1769 ->resultset($rel_obj->{class})
1778 where => $self->{cond},
1782 $new->set_cache($new_cache) if $new_cache;
1788 my ($self, $extra_join) = @_;
1789 my $source = $self->result_source;
1790 my $attrs = $self->{attrs};
1792 my $from = $attrs->{from}
1793 || [ { $attrs->{alias} => $source->from } ];
1795 my $seen = { %{$attrs->{seen_join}||{}} };
1797 my $join = ($attrs->{join}
1798 ? [ $attrs->{join}, $extra_join ]
1802 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1805 return ($from,$seen);
1808 sub _resolved_attrs {
1810 return $self->{_attrs} if $self->{_attrs};
1812 my $attrs = { %{$self->{attrs}||{}} };
1813 my $source = $self->result_source;
1814 my $alias = $attrs->{alias};
1816 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1817 if ($attrs->{columns}) {
1818 delete $attrs->{as};
1819 } elsif (!$attrs->{select}) {
1820 $attrs->{columns} = [ $source->columns ];
1825 ? (ref $attrs->{select} eq 'ARRAY'
1826 ? [ @{$attrs->{select}} ]
1827 : [ $attrs->{select} ])
1828 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1832 ? (ref $attrs->{as} eq 'ARRAY'
1833 ? [ @{$attrs->{as}} ]
1835 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1839 if ($adds = delete $attrs->{include_columns}) {
1840 $adds = [$adds] unless ref $adds eq 'ARRAY';
1841 push(@{$attrs->{select}}, @$adds);
1842 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1844 if ($adds = delete $attrs->{'+select'}) {
1845 $adds = [$adds] unless ref $adds eq 'ARRAY';
1846 push(@{$attrs->{select}},
1847 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1849 if (my $adds = delete $attrs->{'+as'}) {
1850 $adds = [$adds] unless ref $adds eq 'ARRAY';
1851 push(@{$attrs->{as}}, @$adds);
1854 $attrs->{from} ||= [ { 'me' => $source->from } ];
1856 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1857 my $join = delete $attrs->{join} || {};
1859 if (defined $attrs->{prefetch}) {
1860 $join = $self->_merge_attr(
1861 $join, $attrs->{prefetch}
1865 $attrs->{from} = # have to copy here to avoid corrupting the original
1868 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1872 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1873 if ($attrs->{order_by}) {
1874 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1875 ? [ @{$attrs->{order_by}} ]
1876 : [ $attrs->{order_by} ]);
1878 $attrs->{order_by} = [];
1881 my $collapse = $attrs->{collapse} || {};
1882 if (my $prefetch = delete $attrs->{prefetch}) {
1883 $prefetch = $self->_merge_attr({}, $prefetch);
1885 my $seen = $attrs->{seen_join} || {};
1886 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1887 # bring joins back to level of current class
1888 my @prefetch = $source->resolve_prefetch(
1889 $p, $alias, $seen, \@pre_order, $collapse
1891 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1892 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1894 push(@{$attrs->{order_by}}, @pre_order);
1896 $attrs->{collapse} = $collapse;
1898 if ($attrs->{page}) {
1899 $attrs->{offset} ||= 0;
1900 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
1903 return $self->{_attrs} = $attrs;
1907 my ($self, $a, $b) = @_;
1908 return $b unless defined($a);
1909 return $a unless defined($b);
1911 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1912 foreach my $key (keys %{$b}) {
1913 if (exists $a->{$key}) {
1914 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1916 $a->{$key} = $b->{$key};
1921 $a = [$a] unless ref $a eq 'ARRAY';
1922 $b = [$b] unless ref $b eq 'ARRAY';
1926 foreach my $x ($a, $b) {
1927 foreach my $element (@{$x}) {
1928 if (ref $element eq 'HASH') {
1929 $hash = $self->_merge_attr($hash, $element);
1930 } elsif (ref $element eq 'ARRAY') {
1931 push(@array, @{$element});
1933 push(@array, $element) unless $b == $x
1934 && grep { $_ eq $element } @array;
1939 @array = grep { !exists $hash->{$_} } @array;
1941 return keys %{$hash}
1954 $self->_source_handle($_[0]->handle);
1956 $self->_source_handle->resolve;
1960 =head2 throw_exception
1962 See L<DBIx::Class::Schema/throw_exception> for details.
1966 sub throw_exception {
1968 $self->_source_handle->schema->throw_exception(@_);
1971 # XXX: FIXME: Attributes docs need clearing up
1975 The resultset takes various attributes that modify its behavior. Here's an
1982 =item Value: ($order_by | \@order_by)
1986 Which column(s) to order the results by. This is currently passed
1987 through directly to SQL, so you can give e.g. C<year DESC> for a
1988 descending order on the column `year'.
1990 Please note that if you have C<quote_char> enabled (see
1991 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1992 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1993 so you will need to manually quote things as appropriate.)
1999 =item Value: \@columns
2003 Shortcut to request a particular set of columns to be retrieved. Adds
2004 C<me.> onto the start of any column without a C<.> in it and sets C<select>
2005 from that, then auto-populates C<as> from C<select> as normal. (You may also
2006 use the C<cols> attribute, as in earlier versions of DBIC.)
2008 =head2 include_columns
2012 =item Value: \@columns
2016 Shortcut to include additional columns in the returned results - for example
2018 $schema->resultset('CD')->search(undef, {
2019 include_columns => ['artist.name'],
2023 would return all CDs and include a 'name' column to the information
2024 passed to object inflation. Note that the 'artist' is the name of the
2025 column (or relationship) accessor, and 'name' is the name of the column
2026 accessor in the related table.
2032 =item Value: \@select_columns
2036 Indicates which columns should be selected from the storage. You can use
2037 column names, or in the case of RDBMS back ends, function or stored procedure
2040 $rs = $schema->resultset('Employee')->search(undef, {
2043 { count => 'employeeid' },
2048 When you use function/stored procedure names and do not supply an C<as>
2049 attribute, the column names returned are storage-dependent. E.g. MySQL would
2050 return a column named C<count(employeeid)> in the above example.
2056 Indicates additional columns to be selected from storage. Works the same as
2057 L<select> but adds columns to the selection.
2065 Indicates additional column names for those added via L<+select>.
2073 =item Value: \@inflation_names
2077 Indicates column names for object inflation. That is, c< as >
2078 indicates the name that the column can be accessed as via the
2079 C<get_column> method (or via the object accessor, B<if one already
2080 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
2083 The C< as > attribute is used in conjunction with C<select>,
2084 usually when C<select> contains one or more function or stored
2087 $rs = $schema->resultset('Employee')->search(undef, {
2090 { count => 'employeeid' }
2092 as => ['name', 'employee_count'],
2095 my $employee = $rs->first(); # get the first Employee
2097 If the object against which the search is performed already has an accessor
2098 matching a column name specified in C<as>, the value can be retrieved using
2099 the accessor as normal:
2101 my $name = $employee->name();
2103 If on the other hand an accessor does not exist in the object, you need to
2104 use C<get_column> instead:
2106 my $employee_count = $employee->get_column('employee_count');
2108 You can create your own accessors if required - see
2109 L<DBIx::Class::Manual::Cookbook> for details.
2111 Please note: This will NOT insert an C<AS employee_count> into the SQL
2112 statement produced, it is used for internal access only. Thus
2113 attempting to use the accessor in an C<order_by> clause or similar
2114 will fail miserably.
2116 To get around this limitation, you can supply literal SQL to your
2117 C<select> attibute that contains the C<AS alias> text, eg:
2119 select => [\'myfield AS alias']
2125 =item Value: ($rel_name | \@rel_names | \%rel_names)
2129 Contains a list of relationships that should be joined for this query. For
2132 # Get CDs by Nine Inch Nails
2133 my $rs = $schema->resultset('CD')->search(
2134 { 'artist.name' => 'Nine Inch Nails' },
2135 { join => 'artist' }
2138 Can also contain a hash reference to refer to the other relation's relations.
2141 package MyApp::Schema::Track;
2142 use base qw/DBIx::Class/;
2143 __PACKAGE__->table('track');
2144 __PACKAGE__->add_columns(qw/trackid cd position title/);
2145 __PACKAGE__->set_primary_key('trackid');
2146 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2149 # In your application
2150 my $rs = $schema->resultset('Artist')->search(
2151 { 'track.title' => 'Teardrop' },
2153 join => { cd => 'track' },
2154 order_by => 'artist.name',
2158 You need to use the relationship (not the table) name in conditions,
2159 because they are aliased as such. The current table is aliased as "me", so
2160 you need to use me.column_name in order to avoid ambiguity. For example:
2162 # Get CDs from 1984 with a 'Foo' track
2163 my $rs = $schema->resultset('CD')->search(
2166 'tracks.name' => 'Foo'
2168 { join => 'tracks' }
2171 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2172 similarly for a third time). For e.g.
2174 my $rs = $schema->resultset('Artist')->search({
2175 'cds.title' => 'Down to Earth',
2176 'cds_2.title' => 'Popular',
2178 join => [ qw/cds cds/ ],
2181 will return a set of all artists that have both a cd with title 'Down
2182 to Earth' and a cd with title 'Popular'.
2184 If you want to fetch related objects from other tables as well, see C<prefetch>
2191 =item Value: ($rel_name | \@rel_names | \%rel_names)
2195 Contains one or more relationships that should be fetched along with the main
2196 query (when they are accessed afterwards they will have already been
2197 "prefetched"). This is useful for when you know you will need the related
2198 objects, because it saves at least one query:
2200 my $rs = $schema->resultset('Tag')->search(
2209 The initial search results in SQL like the following:
2211 SELECT tag.*, cd.*, artist.* FROM tag
2212 JOIN cd ON tag.cd = cd.cdid
2213 JOIN artist ON cd.artist = artist.artistid
2215 L<DBIx::Class> has no need to go back to the database when we access the
2216 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2219 Simple prefetches will be joined automatically, so there is no need
2220 for a C<join> attribute in the above search. If you're prefetching to
2221 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2222 specify the join as well.
2224 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2225 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2226 with an accessor type of 'single' or 'filter').
2236 Makes the resultset paged and specifies the page to retrieve. Effectively
2237 identical to creating a non-pages resultset and then calling ->page($page)
2240 If L<rows> attribute is not specified it defualts to 10 rows per page.
2250 Specifes the maximum number of rows for direct retrieval or the number of
2251 rows per page if the page attribute or method is used.
2257 =item Value: $offset
2261 Specifies the (zero-based) row number for the first row to be returned, or the
2262 of the first row of the first page if paging is used.
2268 =item Value: \@columns
2272 A arrayref of columns to group by. Can include columns of joined tables.
2274 group_by => [qw/ column1 column2 ... /]
2280 =item Value: $condition
2284 HAVING is a select statement attribute that is applied between GROUP BY and
2285 ORDER BY. It is applied to the after the grouping calculations have been
2288 having => { 'count(employee)' => { '>=', 100 } }
2294 =item Value: (0 | 1)
2298 Set to 1 to group by all columns.
2304 Adds to the WHERE clause.
2306 # only return rows WHERE deleted IS NULL for all searches
2307 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2309 Can be overridden by passing C<{ where => undef }> as an attribute
2316 Set to 1 to cache search results. This prevents extra SQL queries if you
2317 revisit rows in your ResultSet:
2319 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2321 while( my $artist = $resultset->next ) {
2325 $rs->first; # without cache, this would issue a query
2327 By default, searches are not cached.
2329 For more examples of using these attributes, see
2330 L<DBIx::Class::Manual::Cookbook>.
2336 =item Value: \@from_clause
2340 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2341 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2344 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2346 C<join> will usually do what you need and it is strongly recommended that you
2347 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2348 And we really do mean "cannot", not just tried and failed. Attempting to use
2349 this because you're having problems with C<join> is like trying to use x86
2350 ASM because you've got a syntax error in your C. Trust us on this.
2352 Now, if you're still really, really sure you need to use this (and if you're
2353 not 100% sure, ask the mailing list first), here's an explanation of how this
2356 The syntax is as follows -
2359 { <alias1> => <table1> },
2361 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2362 [], # nested JOIN (optional)
2363 { <table1.column1> => <table2.column2>, ... (more conditions) },
2365 # More of the above [ ] may follow for additional joins
2372 ON <table1.column1> = <table2.column2>
2373 <more joins may follow>
2375 An easy way to follow the examples below is to remember the following:
2377 Anything inside "[]" is a JOIN
2378 Anything inside "{}" is a condition for the enclosing JOIN
2380 The following examples utilize a "person" table in a family tree application.
2381 In order to express parent->child relationships, this table is self-joined:
2383 # Person->belongs_to('father' => 'Person');
2384 # Person->belongs_to('mother' => 'Person');
2386 C<from> can be used to nest joins. Here we return all children with a father,
2387 then search against all mothers of those children:
2389 $rs = $schema->resultset('Person')->search(
2392 alias => 'mother', # alias columns in accordance with "from"
2394 { mother => 'person' },
2397 { child => 'person' },
2399 { father => 'person' },
2400 { 'father.person_id' => 'child.father_id' }
2403 { 'mother.person_id' => 'child.mother_id' }
2410 # SELECT mother.* FROM person mother
2413 # JOIN person father
2414 # ON ( father.person_id = child.father_id )
2416 # ON ( mother.person_id = child.mother_id )
2418 The type of any join can be controlled manually. To search against only people
2419 with a father in the person table, we could explicitly use C<INNER JOIN>:
2421 $rs = $schema->resultset('Person')->search(
2424 alias => 'child', # alias columns in accordance with "from"
2426 { child => 'person' },
2428 { father => 'person', -join_type => 'inner' },
2429 { 'father.id' => 'child.father_id' }
2436 # SELECT child.* FROM person child
2437 # INNER JOIN person father ON child.father_id = father.id