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};
836 foreach my $const (@const_rows) {
837 scalar @const_keys or do {
838 @const_keys = sort { length($a) <=> length($b) } keys %$const;
840 foreach my $key (@const_keys) {
843 my @parts = split(/\./, $key);
845 my $data = $const->{$key};
846 foreach my $p (@parts) {
847 $target = $target->[1]->{$p} ||= [];
849 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
850 # collapsing at this point and on final part
851 my $pos = $collapse_pos{$cur};
852 CK: foreach my $ck (@ckey) {
853 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
854 $collapse_pos{$cur} = $data;
855 delete @collapse_pos{ # clear all positioning for sub-entries
856 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
863 if (exists $collapse{$cur}) {
864 $target = $target->[-1];
867 $target->[0] = $data;
869 $info->[0] = $const->{$key};
881 =item Arguments: $result_source?
883 =item Return Value: $result_source
887 An accessor for the primary ResultSource object from which this ResultSet
894 =item Arguments: $result_class?
896 =item Return Value: $result_class
900 An accessor for the class to use when creating row objects. Defaults to
901 C<< result_source->result_class >> - which in most cases is the name of the
902 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
911 =item Arguments: $cond, \%attrs??
913 =item Return Value: $count
917 Performs an SQL C<COUNT> with the same query as the resultset was built
918 with to find the number of elements. If passed arguments, does a search
919 on the resultset and counts the results of that.
921 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
922 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
923 not support C<DISTINCT> with multiple columns. If you are using such a
924 database, you should only use columns from the main table in your C<group_by>
931 return $self->search(@_)->count if @_ and defined $_[0];
932 return scalar @{ $self->get_cache } if $self->get_cache;
933 my $count = $self->_count;
934 return 0 unless $count;
936 # need to take offset from resolved attrs
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: \@data;
1249 Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
1250 submitting to a $resultset->create(...) method.
1252 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1253 to insert the data, as this is a faster method.
1255 Otherwise, each set of data is inserted into the database using
1256 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1257 objects is returned.
1259 Example: Assuming an Artist Class that has many CDs Classes relating:
1261 my $Artist_rs = $schema->resultset("Artist");
1263 ## Void Context Example
1264 $Artist_rs->populate([
1265 { artistid => 4, name => 'Manufactured Crap', cds => [
1266 { title => 'My First CD', year => 2006 },
1267 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1270 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1271 { title => 'My parents sold me to a record company' ,year => 2005 },
1272 { title => 'Why Am I So Ugly?', year => 2006 },
1273 { title => 'I Got Surgery and am now Popular', year => 2007 }
1278 ## Array Context Example
1279 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1280 { name => "Artist One"},
1281 { name => "Artist Two"},
1282 { name => "Artist Three", cds=> [
1283 { title => "First CD", year => 2007},
1284 { title => "Second CD", year => 2008},
1288 print $ArtistOne->name; ## response is 'Artist One'
1289 print $ArtistThree->cds->count ## reponse is '2'
1294 my ($self, $data) = @_;
1296 if(defined wantarray) {
1298 foreach my $item (@$data) {
1299 push(@created, $self->create($item));
1303 my ($first, @rest) = @$data;
1305 my @names = grep {!ref $first->{$_}} keys %$first;
1306 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1307 my @pks = $self->result_source->primary_columns;
1309 ## do the belongs_to relationships
1310 foreach my $index (0..$#$data) {
1311 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1312 my @ret = $self->populate($data);
1316 foreach my $rel (@rels) {
1317 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1318 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1319 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1320 my $related = $result->result_source->resolve_condition(
1321 $result->result_source->relationship_info($reverse)->{cond},
1326 delete $data->[$index]->{$rel};
1327 $data->[$index] = {%{$data->[$index]}, %$related};
1329 push @names, keys %$related if $index == 0;
1333 ## do bulk insert on current row
1336 defined $_ ? $_ : $self->throw_exception("Undefined value for column!")
1340 $self->result_source->storage->insert_bulk(
1341 $self->result_source,
1346 ## do the has_many relationships
1347 foreach my $item (@$data) {
1349 foreach my $rel (@rels) {
1350 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1352 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1353 || $self->throw_exception('Cannot find the relating object.');
1355 my $child = $parent->$rel;
1357 my $related = $child->result_source->resolve_condition(
1358 $parent->result_source->relationship_info($rel)->{cond},
1363 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1364 my @populate = map { {%$_, %$related} } @rows_to_add;
1366 $child->populate( \@populate );
1376 =item Arguments: none
1378 =item Return Value: $pager
1382 Return Value a L<Data::Page> object for the current resultset. Only makes
1383 sense for queries with a C<page> attribute.
1389 my $attrs = $self->{attrs};
1390 $self->throw_exception("Can't create pager for non-paged rs")
1391 unless $self->{attrs}{page};
1392 $attrs->{rows} ||= 10;
1393 return $self->{pager} ||= Data::Page->new(
1394 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1401 =item Arguments: $page_number
1403 =item Return Value: $rs
1407 Returns a resultset for the $page_number page of the resultset on which page
1408 is called, where each page contains a number of rows equal to the 'rows'
1409 attribute set on the resultset (10 by default).
1414 my ($self, $page) = @_;
1415 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1422 =item Arguments: \%vals
1424 =item Return Value: $object
1428 Creates an object in the resultset's result class and returns it.
1433 my ($self, $values) = @_;
1434 $self->throw_exception( "new_result needs a hash" )
1435 unless (ref $values eq 'HASH');
1436 $self->throw_exception(
1437 "Can't abstract implicit construct, condition not a hash"
1438 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1440 my $alias = $self->{attrs}{alias};
1441 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1443 %{ $self->_remove_alias($values, $alias) },
1444 %{ $self->_remove_alias($collapsed_cond, $alias) },
1445 -source_handle => $self->_source_handle,
1446 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1449 return $self->result_class->new(\%new);
1454 # Recursively collapse the condition.
1456 sub _collapse_cond {
1457 my ($self, $cond, $collapsed) = @_;
1461 if (ref $cond eq 'ARRAY') {
1462 foreach my $subcond (@$cond) {
1463 next unless ref $subcond; # -or
1464 # warn "ARRAY: " . Dumper $subcond;
1465 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1468 elsif (ref $cond eq 'HASH') {
1469 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1470 foreach my $subcond (@{$cond->{-and}}) {
1471 # warn "HASH: " . Dumper $subcond;
1472 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1476 # warn "LEAF: " . Dumper $cond;
1477 foreach my $col (keys %$cond) {
1478 my $value = $cond->{$col};
1479 $collapsed->{$col} = $value;
1489 # Remove the specified alias from the specified query hash. A copy is made so
1490 # the original query is not modified.
1493 my ($self, $query, $alias) = @_;
1495 my %orig = %{ $query || {} };
1498 foreach my $key (keys %orig) {
1500 $unaliased{$key} = $orig{$key};
1503 $unaliased{$1} = $orig{$key}
1504 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1514 =item Arguments: \%vals, \%attrs?
1516 =item Return Value: $object
1520 Find an existing record from this resultset. If none exists, instantiate a new
1521 result object and return it. The object will not be saved into your storage
1522 until you call L<DBIx::Class::Row/insert> on it.
1524 If you want objects to be saved immediately, use L</find_or_create> instead.
1530 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1531 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1532 my $exists = $self->find($hash, $attrs);
1533 return defined $exists ? $exists : $self->new_result($hash);
1540 =item Arguments: \%vals
1542 =item Return Value: $object
1546 Inserts a record into the resultset and returns the object representing it.
1548 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1553 my ($self, $attrs) = @_;
1554 $self->throw_exception( "create needs a hashref" )
1555 unless ref $attrs eq 'HASH';
1556 return $self->new_result($attrs)->insert;
1559 =head2 find_or_create
1563 =item Arguments: \%vals, \%attrs?
1565 =item Return Value: $object
1569 $class->find_or_create({ key => $val, ... });
1571 Tries to find a record based on its primary key or unique constraint; if none
1572 is found, creates one and returns that instead.
1574 my $cd = $schema->resultset('CD')->find_or_create({
1576 artist => 'Massive Attack',
1577 title => 'Mezzanine',
1581 Also takes an optional C<key> attribute, to search by a specific key or unique
1582 constraint. For example:
1584 my $cd = $schema->resultset('CD')->find_or_create(
1586 artist => 'Massive Attack',
1587 title => 'Mezzanine',
1589 { key => 'cd_artist_title' }
1592 See also L</find> and L</update_or_create>. For information on how to declare
1593 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1597 sub find_or_create {
1599 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1600 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1601 my $exists = $self->find($hash, $attrs);
1602 return defined $exists ? $exists : $self->create($hash);
1605 =head2 update_or_create
1609 =item Arguments: \%col_values, { key => $unique_constraint }?
1611 =item Return Value: $object
1615 $class->update_or_create({ col => $val, ... });
1617 First, searches for an existing row matching one of the unique constraints
1618 (including the primary key) on the source of this resultset. If a row is
1619 found, updates it with the other given column values. Otherwise, creates a new
1622 Takes an optional C<key> attribute to search on a specific unique constraint.
1625 # In your application
1626 my $cd = $schema->resultset('CD')->update_or_create(
1628 artist => 'Massive Attack',
1629 title => 'Mezzanine',
1632 { key => 'cd_artist_title' }
1635 If no C<key> is specified, it searches on all unique constraints defined on the
1636 source, including the primary key.
1638 If the C<key> is specified as C<primary>, it searches only on the primary key.
1640 See also L</find> and L</find_or_create>. For information on how to declare
1641 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1645 sub update_or_create {
1647 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1648 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1650 my $row = $self->find($cond, $attrs);
1652 $row->update($cond);
1656 return $self->create($cond);
1663 =item Arguments: none
1665 =item Return Value: \@cache_objects?
1669 Gets the contents of the cache for the resultset, if the cache is set.
1681 =item Arguments: \@cache_objects
1683 =item Return Value: \@cache_objects
1687 Sets the contents of the cache for the resultset. Expects an arrayref
1688 of objects of the same class as those produced by the resultset. Note that
1689 if the cache is set the resultset will return the cached objects rather
1690 than re-querying the database even if the cache attr is not set.
1695 my ( $self, $data ) = @_;
1696 $self->throw_exception("set_cache requires an arrayref")
1697 if defined($data) && (ref $data ne 'ARRAY');
1698 $self->{all_cache} = $data;
1705 =item Arguments: none
1707 =item Return Value: []
1711 Clears the cache for the resultset.
1716 shift->set_cache(undef);
1719 =head2 related_resultset
1723 =item Arguments: $relationship_name
1725 =item Return Value: $resultset
1729 Returns a related resultset for the supplied relationship name.
1731 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1735 sub related_resultset {
1736 my ($self, $rel) = @_;
1738 $self->{related_resultsets} ||= {};
1739 return $self->{related_resultsets}{$rel} ||= do {
1740 my $rel_obj = $self->result_source->relationship_info($rel);
1742 $self->throw_exception(
1743 "search_related: result source '" . $self->_source_handle->source_moniker .
1744 "' has no such relationship $rel")
1747 my ($from,$seen) = $self->_resolve_from($rel);
1749 my $join_count = $seen->{$rel};
1750 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1752 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
1753 my %attrs = %{$self->{attrs}||{}};
1754 delete $attrs{result_class};
1758 if (my $cache = $self->get_cache) {
1759 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
1760 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
1765 my $new = $self->_source_handle
1767 ->resultset($rel_obj->{class})
1776 where => $self->{cond},
1780 $new->set_cache($new_cache) if $new_cache;
1786 my ($self, $extra_join) = @_;
1787 my $source = $self->result_source;
1788 my $attrs = $self->{attrs};
1790 my $from = $attrs->{from}
1791 || [ { $attrs->{alias} => $source->from } ];
1793 my $seen = { %{$attrs->{seen_join}||{}} };
1795 my $join = ($attrs->{join}
1796 ? [ $attrs->{join}, $extra_join ]
1800 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1803 return ($from,$seen);
1806 sub _resolved_attrs {
1808 return $self->{_attrs} if $self->{_attrs};
1810 my $attrs = { %{$self->{attrs}||{}} };
1811 my $source = $self->result_source;
1812 my $alias = $attrs->{alias};
1814 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1815 if ($attrs->{columns}) {
1816 delete $attrs->{as};
1817 } elsif (!$attrs->{select}) {
1818 $attrs->{columns} = [ $source->columns ];
1823 ? (ref $attrs->{select} eq 'ARRAY'
1824 ? [ @{$attrs->{select}} ]
1825 : [ $attrs->{select} ])
1826 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1830 ? (ref $attrs->{as} eq 'ARRAY'
1831 ? [ @{$attrs->{as}} ]
1833 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1837 if ($adds = delete $attrs->{include_columns}) {
1838 $adds = [$adds] unless ref $adds eq 'ARRAY';
1839 push(@{$attrs->{select}}, @$adds);
1840 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1842 if ($adds = delete $attrs->{'+select'}) {
1843 $adds = [$adds] unless ref $adds eq 'ARRAY';
1844 push(@{$attrs->{select}},
1845 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1847 if (my $adds = delete $attrs->{'+as'}) {
1848 $adds = [$adds] unless ref $adds eq 'ARRAY';
1849 push(@{$attrs->{as}}, @$adds);
1852 $attrs->{from} ||= [ { 'me' => $source->from } ];
1854 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1855 my $join = delete $attrs->{join} || {};
1857 if (defined $attrs->{prefetch}) {
1858 $join = $self->_merge_attr(
1859 $join, $attrs->{prefetch}
1863 $attrs->{from} = # have to copy here to avoid corrupting the original
1866 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1870 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1871 if ($attrs->{order_by}) {
1872 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1873 ? [ @{$attrs->{order_by}} ]
1874 : [ $attrs->{order_by} ]);
1876 $attrs->{order_by} = [];
1879 my $collapse = $attrs->{collapse} || {};
1880 if (my $prefetch = delete $attrs->{prefetch}) {
1881 $prefetch = $self->_merge_attr({}, $prefetch);
1883 my $seen = $attrs->{seen_join} || {};
1884 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1885 # bring joins back to level of current class
1886 my @prefetch = $source->resolve_prefetch(
1887 $p, $alias, $seen, \@pre_order, $collapse
1889 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1890 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1892 push(@{$attrs->{order_by}}, @pre_order);
1894 $attrs->{collapse} = $collapse;
1896 if ($attrs->{page}) {
1897 $attrs->{offset} ||= 0;
1898 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
1901 return $self->{_attrs} = $attrs;
1905 my ($self, $a, $b) = @_;
1906 return $b unless defined($a);
1907 return $a unless defined($b);
1909 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1910 foreach my $key (keys %{$b}) {
1911 if (exists $a->{$key}) {
1912 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1914 $a->{$key} = $b->{$key};
1919 $a = [$a] unless ref $a eq 'ARRAY';
1920 $b = [$b] unless ref $b eq 'ARRAY';
1924 foreach my $x ($a, $b) {
1925 foreach my $element (@{$x}) {
1926 if (ref $element eq 'HASH') {
1927 $hash = $self->_merge_attr($hash, $element);
1928 } elsif (ref $element eq 'ARRAY') {
1929 push(@array, @{$element});
1931 push(@array, $element) unless $b == $x
1932 && grep { $_ eq $element } @array;
1937 @array = grep { !exists $hash->{$_} } @array;
1939 return keys %{$hash}
1952 $self->_source_handle($_[0]->handle);
1954 $self->_source_handle->resolve;
1958 =head2 throw_exception
1960 See L<DBIx::Class::Schema/throw_exception> for details.
1964 sub throw_exception {
1966 $self->_source_handle->schema->throw_exception(@_);
1969 # XXX: FIXME: Attributes docs need clearing up
1973 The resultset takes various attributes that modify its behavior. Here's an
1980 =item Value: ($order_by | \@order_by)
1984 Which column(s) to order the results by. This is currently passed
1985 through directly to SQL, so you can give e.g. C<year DESC> for a
1986 descending order on the column `year'.
1988 Please note that if you have C<quote_char> enabled (see
1989 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1990 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1991 so you will need to manually quote things as appropriate.)
1997 =item Value: \@columns
2001 Shortcut to request a particular set of columns to be retrieved. Adds
2002 C<me.> onto the start of any column without a C<.> in it and sets C<select>
2003 from that, then auto-populates C<as> from C<select> as normal. (You may also
2004 use the C<cols> attribute, as in earlier versions of DBIC.)
2006 =head2 include_columns
2010 =item Value: \@columns
2014 Shortcut to include additional columns in the returned results - for example
2016 $schema->resultset('CD')->search(undef, {
2017 include_columns => ['artist.name'],
2021 would return all CDs and include a 'name' column to the information
2022 passed to object inflation. Note that the 'artist' is the name of the
2023 column (or relationship) accessor, and 'name' is the name of the column
2024 accessor in the related table.
2030 =item Value: \@select_columns
2034 Indicates which columns should be selected from the storage. You can use
2035 column names, or in the case of RDBMS back ends, function or stored procedure
2038 $rs = $schema->resultset('Employee')->search(undef, {
2041 { count => 'employeeid' },
2046 When you use function/stored procedure names and do not supply an C<as>
2047 attribute, the column names returned are storage-dependent. E.g. MySQL would
2048 return a column named C<count(employeeid)> in the above example.
2054 Indicates additional columns to be selected from storage. Works the same as
2055 L<select> but adds columns to the selection.
2063 Indicates additional column names for those added via L<+select>.
2071 =item Value: \@inflation_names
2075 Indicates column names for object inflation. That is, c< as >
2076 indicates the name that the column can be accessed as via the
2077 C<get_column> method (or via the object accessor, B<if one already
2078 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
2081 The C< as > attribute is used in conjunction with C<select>,
2082 usually when C<select> contains one or more function or stored
2085 $rs = $schema->resultset('Employee')->search(undef, {
2088 { count => 'employeeid' }
2090 as => ['name', 'employee_count'],
2093 my $employee = $rs->first(); # get the first Employee
2095 If the object against which the search is performed already has an accessor
2096 matching a column name specified in C<as>, the value can be retrieved using
2097 the accessor as normal:
2099 my $name = $employee->name();
2101 If on the other hand an accessor does not exist in the object, you need to
2102 use C<get_column> instead:
2104 my $employee_count = $employee->get_column('employee_count');
2106 You can create your own accessors if required - see
2107 L<DBIx::Class::Manual::Cookbook> for details.
2109 Please note: This will NOT insert an C<AS employee_count> into the SQL
2110 statement produced, it is used for internal access only. Thus
2111 attempting to use the accessor in an C<order_by> clause or similar
2112 will fail miserably.
2114 To get around this limitation, you can supply literal SQL to your
2115 C<select> attibute that contains the C<AS alias> text, eg:
2117 select => [\'myfield AS alias']
2123 =item Value: ($rel_name | \@rel_names | \%rel_names)
2127 Contains a list of relationships that should be joined for this query. For
2130 # Get CDs by Nine Inch Nails
2131 my $rs = $schema->resultset('CD')->search(
2132 { 'artist.name' => 'Nine Inch Nails' },
2133 { join => 'artist' }
2136 Can also contain a hash reference to refer to the other relation's relations.
2139 package MyApp::Schema::Track;
2140 use base qw/DBIx::Class/;
2141 __PACKAGE__->table('track');
2142 __PACKAGE__->add_columns(qw/trackid cd position title/);
2143 __PACKAGE__->set_primary_key('trackid');
2144 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2147 # In your application
2148 my $rs = $schema->resultset('Artist')->search(
2149 { 'track.title' => 'Teardrop' },
2151 join => { cd => 'track' },
2152 order_by => 'artist.name',
2156 You need to use the relationship (not the table) name in conditions,
2157 because they are aliased as such. The current table is aliased as "me", so
2158 you need to use me.column_name in order to avoid ambiguity. For example:
2160 # Get CDs from 1984 with a 'Foo' track
2161 my $rs = $schema->resultset('CD')->search(
2164 'tracks.name' => 'Foo'
2166 { join => 'tracks' }
2169 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2170 similarly for a third time). For e.g.
2172 my $rs = $schema->resultset('Artist')->search({
2173 'cds.title' => 'Down to Earth',
2174 'cds_2.title' => 'Popular',
2176 join => [ qw/cds cds/ ],
2179 will return a set of all artists that have both a cd with title 'Down
2180 to Earth' and a cd with title 'Popular'.
2182 If you want to fetch related objects from other tables as well, see C<prefetch>
2189 =item Value: ($rel_name | \@rel_names | \%rel_names)
2193 Contains one or more relationships that should be fetched along with the main
2194 query (when they are accessed afterwards they will have already been
2195 "prefetched"). This is useful for when you know you will need the related
2196 objects, because it saves at least one query:
2198 my $rs = $schema->resultset('Tag')->search(
2207 The initial search results in SQL like the following:
2209 SELECT tag.*, cd.*, artist.* FROM tag
2210 JOIN cd ON tag.cd = cd.cdid
2211 JOIN artist ON cd.artist = artist.artistid
2213 L<DBIx::Class> has no need to go back to the database when we access the
2214 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2217 Simple prefetches will be joined automatically, so there is no need
2218 for a C<join> attribute in the above search. If you're prefetching to
2219 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2220 specify the join as well.
2222 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2223 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2224 with an accessor type of 'single' or 'filter').
2234 Makes the resultset paged and specifies the page to retrieve. Effectively
2235 identical to creating a non-pages resultset and then calling ->page($page)
2238 If L<rows> attribute is not specified it defualts to 10 rows per page.
2248 Specifes the maximum number of rows for direct retrieval or the number of
2249 rows per page if the page attribute or method is used.
2255 =item Value: $offset
2259 Specifies the (zero-based) row number for the first row to be returned, or the
2260 of the first row of the first page if paging is used.
2266 =item Value: \@columns
2270 A arrayref of columns to group by. Can include columns of joined tables.
2272 group_by => [qw/ column1 column2 ... /]
2278 =item Value: $condition
2282 HAVING is a select statement attribute that is applied between GROUP BY and
2283 ORDER BY. It is applied to the after the grouping calculations have been
2286 having => { 'count(employee)' => { '>=', 100 } }
2292 =item Value: (0 | 1)
2296 Set to 1 to group by all columns.
2302 Adds to the WHERE clause.
2304 # only return rows WHERE deleted IS NULL for all searches
2305 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2307 Can be overridden by passing C<{ where => undef }> as an attribute
2314 Set to 1 to cache search results. This prevents extra SQL queries if you
2315 revisit rows in your ResultSet:
2317 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2319 while( my $artist = $resultset->next ) {
2323 $rs->first; # without cache, this would issue a query
2325 By default, searches are not cached.
2327 For more examples of using these attributes, see
2328 L<DBIx::Class::Manual::Cookbook>.
2334 =item Value: \@from_clause
2338 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2339 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2342 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2344 C<join> will usually do what you need and it is strongly recommended that you
2345 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2346 And we really do mean "cannot", not just tried and failed. Attempting to use
2347 this because you're having problems with C<join> is like trying to use x86
2348 ASM because you've got a syntax error in your C. Trust us on this.
2350 Now, if you're still really, really sure you need to use this (and if you're
2351 not 100% sure, ask the mailing list first), here's an explanation of how this
2354 The syntax is as follows -
2357 { <alias1> => <table1> },
2359 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2360 [], # nested JOIN (optional)
2361 { <table1.column1> => <table2.column2>, ... (more conditions) },
2363 # More of the above [ ] may follow for additional joins
2370 ON <table1.column1> = <table2.column2>
2371 <more joins may follow>
2373 An easy way to follow the examples below is to remember the following:
2375 Anything inside "[]" is a JOIN
2376 Anything inside "{}" is a condition for the enclosing JOIN
2378 The following examples utilize a "person" table in a family tree application.
2379 In order to express parent->child relationships, this table is self-joined:
2381 # Person->belongs_to('father' => 'Person');
2382 # Person->belongs_to('mother' => 'Person');
2384 C<from> can be used to nest joins. Here we return all children with a father,
2385 then search against all mothers of those children:
2387 $rs = $schema->resultset('Person')->search(
2390 alias => 'mother', # alias columns in accordance with "from"
2392 { mother => 'person' },
2395 { child => 'person' },
2397 { father => 'person' },
2398 { 'father.person_id' => 'child.father_id' }
2401 { 'mother.person_id' => 'child.mother_id' }
2408 # SELECT mother.* FROM person mother
2411 # JOIN person father
2412 # ON ( father.person_id = child.father_id )
2414 # ON ( mother.person_id = child.mother_id )
2416 The type of any join can be controlled manually. To search against only people
2417 with a father in the person table, we could explicitly use C<INNER JOIN>:
2419 $rs = $schema->resultset('Person')->search(
2422 alias => 'child', # alias columns in accordance with "from"
2424 { child => 'person' },
2426 { father => 'person', -join_type => 'inner' },
2427 { 'father.id' => 'child.father_id' }
2434 # SELECT child.* FROM person child
2435 # INNER JOIN person father ON child.father_id = father.id