1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
90 $attrs = { %{$attrs||{}} };
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 _source_handle => $source,
102 result_class => $attrs->{result_class} || $source->resolve->result_class,
103 cond => $attrs->{where},
118 =item Arguments: $cond, \%attrs?
120 =item Return Value: $resultset (scalar context), @row_objs (list context)
124 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
125 my $new_rs = $cd_rs->search({ year => 2005 });
127 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
128 # year = 2005 OR year = 2004
130 If you need to pass in additional attributes but no additional condition,
131 call it as C<search(undef, \%attrs)>.
133 # "SELECT name, artistid FROM $artist_table"
134 my @all_artists = $schema->resultset('Artist')->search(undef, {
135 columns => [qw/name artistid/],
138 For a list of attributes that can be passed to C<search>, see
139 L</ATTRIBUTES>. For more examples of using this function, see
140 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
141 documentation for the first argument, see L<SQL::Abstract>.
147 my $rs = $self->search_rs( @_ );
148 return (wantarray ? $rs->all : $rs);
155 =item Arguments: $cond, \%attrs?
157 =item Return Value: $resultset
161 This method does the same exact thing as search() except it will
162 always return a resultset, even in list context.
171 unless (@_) { # no search, effectively just a clone
172 $rows = $self->get_cache;
176 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
177 my $our_attrs = { %{$self->{attrs}} };
178 my $having = delete $our_attrs->{having};
179 my $where = delete $our_attrs->{where};
181 my $new_attrs = { %{$our_attrs}, %{$attrs} };
183 # merge new attrs into inherited
184 foreach my $key (qw/join prefetch/) {
185 next unless exists $attrs->{$key};
186 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
191 (@_ == 1 || ref $_[0] eq "HASH")
193 (ref $_[0] eq 'HASH')
195 (keys %{ $_[0] } > 0)
203 ? $self->throw_exception("Odd number of arguments to search")
210 if (defined $where) {
211 $new_attrs->{where} = (
212 defined $new_attrs->{where}
215 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
216 } $where, $new_attrs->{where}
223 $new_attrs->{where} = (
224 defined $new_attrs->{where}
227 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
228 } $cond, $new_attrs->{where}
234 if (defined $having) {
235 $new_attrs->{having} = (
236 defined $new_attrs->{having}
239 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
240 } $having, $new_attrs->{having}
246 my $rs = (ref $self)->new($self->result_source, $new_attrs);
248 $rs->set_cache($rows);
253 =head2 search_literal
257 =item Arguments: $sql_fragment, @bind_values
259 =item Return Value: $resultset (scalar context), @row_objs (list context)
263 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
264 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
266 Pass a literal chunk of SQL to be added to the conditional part of the
272 my ($self, $cond, @vals) = @_;
273 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
274 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
275 return $self->search(\$cond, $attrs);
282 =item Arguments: @values | \%cols, \%attrs?
284 =item Return Value: $row_object
288 Finds a row based on its primary key or unique constraint. For example, to find
289 a row by its primary key:
291 my $cd = $schema->resultset('CD')->find(5);
293 You can also find a row by a specific unique constraint using the C<key>
294 attribute. For example:
296 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
297 key => 'cd_artist_title'
300 Additionally, you can specify the columns explicitly by name:
302 my $cd = $schema->resultset('CD')->find(
304 artist => 'Massive Attack',
305 title => 'Mezzanine',
307 { key => 'cd_artist_title' }
310 If the C<key> is specified as C<primary>, it searches only on the primary key.
312 If no C<key> is specified, it searches on all unique constraints defined on the
313 source, including the primary key.
315 If your table does not have a primary key, you B<must> provide a value for the
316 C<key> attribute matching one of the unique constraints on the source.
318 See also L</find_or_create> and L</update_or_create>. For information on how to
319 declare unique constraints, see
320 L<DBIx::Class::ResultSource/add_unique_constraint>.
326 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
328 # Default to the primary key, but allow a specific key
329 my @cols = exists $attrs->{key}
330 ? $self->result_source->unique_constraint_columns($attrs->{key})
331 : $self->result_source->primary_columns;
332 $self->throw_exception(
333 "Can't find unless a primary key is defined or unique constraint is specified"
336 # Parse out a hashref from input
338 if (ref $_[0] eq 'HASH') {
339 $input_query = { %{$_[0]} };
341 elsif (@_ == @cols) {
343 @{$input_query}{@cols} = @_;
346 # Compatibility: Allow e.g. find(id => $value)
347 carp "Find by key => value deprecated; please use a hashref instead";
351 my (%related, $info);
353 KEY: foreach my $key (keys %$input_query) {
354 if (ref($input_query->{$key})
355 && ($info = $self->result_source->relationship_info($key))) {
356 my $val = delete $input_query->{$key};
357 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
358 my $rel_q = $self->result_source->resolve_condition(
359 $info->{cond}, $val, $key
361 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
362 @related{keys %$rel_q} = values %$rel_q;
365 if (my @keys = keys %related) {
366 @{$input_query}{@keys} = values %related;
369 my @unique_queries = $self->_unique_queries($input_query, $attrs);
371 # Build the final query: Default to the disjunction of the unique queries,
372 # but allow the input query in case the ResultSet defines the query or the
373 # user is abusing find
374 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
375 my $query = @unique_queries
376 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
377 : $self->_add_alias($input_query, $alias);
381 my $rs = $self->search($query, $attrs);
382 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
385 return keys %{$self->_resolved_attrs->{collapse}}
386 ? $self->search($query)->next
387 : $self->single($query);
393 # Add the specified alias to the specified query hash. A copy is made so the
394 # original query is not modified.
397 my ($self, $query, $alias) = @_;
399 my %aliased = %$query;
400 foreach my $col (grep { ! m/\./ } keys %aliased) {
401 $aliased{"$alias.$col"} = delete $aliased{$col};
409 # Build a list of queries which satisfy unique constraints.
411 sub _unique_queries {
412 my ($self, $query, $attrs) = @_;
414 my @constraint_names = exists $attrs->{key}
416 : $self->result_source->unique_constraint_names;
418 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
419 my $num_where = scalar keys %$where;
422 foreach my $name (@constraint_names) {
423 my @unique_cols = $self->result_source->unique_constraint_columns($name);
424 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
426 my $num_cols = scalar @unique_cols;
427 my $num_query = scalar keys %$unique_query;
429 my $total = $num_query + $num_where;
430 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
431 # The query is either unique on its own or is unique in combination with
432 # the existing where clause
433 push @unique_queries, $unique_query;
437 return @unique_queries;
440 # _build_unique_query
442 # Constrain the specified query hash based on the specified column names.
444 sub _build_unique_query {
445 my ($self, $query, $unique_cols) = @_;
448 map { $_ => $query->{$_} }
449 grep { exists $query->{$_} }
454 =head2 search_related
458 =item Arguments: $rel, $cond, \%attrs?
460 =item Return Value: $new_resultset
464 $new_rs = $cd_rs->search_related('artist', {
468 Searches the specified relationship, optionally specifying a condition and
469 attributes for matching records. See L</ATTRIBUTES> for more information.
474 return shift->related_resultset(shift)->search(@_);
481 =item Arguments: none
483 =item Return Value: $cursor
487 Returns a storage-driven cursor to the given resultset. See
488 L<DBIx::Class::Cursor> for more information.
495 my $attrs = { %{$self->_resolved_attrs} };
496 return $self->{cursor}
497 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
498 $attrs->{where},$attrs);
505 =item Arguments: $cond?
507 =item Return Value: $row_object?
511 my $cd = $schema->resultset('CD')->single({ year => 2001 });
513 Inflates the first result without creating a cursor if the resultset has
514 any records in it; if not returns nothing. Used by L</find> as an optimisation.
516 Can optionally take an additional condition *only* - this is a fast-code-path
517 method; if you need to add extra joins or similar call ->search and then
518 ->single without a condition on the $rs returned from that.
523 my ($self, $where) = @_;
524 my $attrs = { %{$self->_resolved_attrs} };
526 if (defined $attrs->{where}) {
529 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
530 $where, delete $attrs->{where} ]
533 $attrs->{where} = $where;
537 # XXX: Disabled since it doesn't infer uniqueness in all cases
538 # unless ($self->_is_unique_query($attrs->{where})) {
539 # carp "Query not guaranteed to return a single row"
540 # . "; please declare your unique constraints or use search instead";
543 my @data = $self->result_source->storage->select_single(
544 $attrs->{from}, $attrs->{select},
545 $attrs->{where}, $attrs
548 return (@data ? ($self->_construct_object(@data))[0] : ());
553 # Try to determine if the specified query is guaranteed to be unique, based on
554 # the declared unique constraints.
556 sub _is_unique_query {
557 my ($self, $query) = @_;
559 my $collapsed = $self->_collapse_query($query);
560 my $alias = $self->{attrs}{alias};
562 foreach my $name ($self->result_source->unique_constraint_names) {
563 my @unique_cols = map {
565 } $self->result_source->unique_constraint_columns($name);
567 # Count the values for each unique column
568 my %seen = map { $_ => 0 } @unique_cols;
570 foreach my $key (keys %$collapsed) {
571 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
572 next unless exists $seen{$aliased}; # Additional constraints are okay
573 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
576 # If we get 0 or more than 1 value for a column, it's not necessarily unique
577 return 1 unless grep { $_ != 1 } values %seen;
585 # Recursively collapse the query, accumulating values for each column.
587 sub _collapse_query {
588 my ($self, $query, $collapsed) = @_;
592 if (ref $query eq 'ARRAY') {
593 foreach my $subquery (@$query) {
594 next unless ref $subquery; # -or
595 # warn "ARRAY: " . Dumper $subquery;
596 $collapsed = $self->_collapse_query($subquery, $collapsed);
599 elsif (ref $query eq 'HASH') {
600 if (keys %$query and (keys %$query)[0] eq '-and') {
601 foreach my $subquery (@{$query->{-and}}) {
602 # warn "HASH: " . Dumper $subquery;
603 $collapsed = $self->_collapse_query($subquery, $collapsed);
607 # warn "LEAF: " . Dumper $query;
608 foreach my $col (keys %$query) {
609 my $value = $query->{$col};
610 $collapsed->{$col}{$value}++;
622 =item Arguments: $cond?
624 =item Return Value: $resultsetcolumn
628 my $max_length = $rs->get_column('length')->max;
630 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
635 my ($self, $column) = @_;
636 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
644 =item Arguments: $cond, \%attrs?
646 =item Return Value: $resultset (scalar context), @row_objs (list context)
650 # WHERE title LIKE '%blue%'
651 $cd_rs = $rs->search_like({ title => '%blue%'});
653 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
654 that this is simply a convenience method. You most likely want to use
655 L</search> with specific operators.
657 For more information, see L<DBIx::Class::Manual::Cookbook>.
663 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
664 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
665 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
666 return $class->search($query, { %$attrs });
673 =item Arguments: $first, $last
675 =item Return Value: $resultset (scalar context), @row_objs (list context)
679 Returns a resultset or object list representing a subset of elements from the
680 resultset slice is called on. Indexes are from 0, i.e., to get the first
683 my ($one, $two, $three) = $rs->slice(0, 2);
688 my ($self, $min, $max) = @_;
689 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
690 $attrs->{offset} = $self->{attrs}{offset} || 0;
691 $attrs->{offset} += $min;
692 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
693 return $self->search(undef(), $attrs);
694 #my $slice = (ref $self)->new($self->result_source, $attrs);
695 #return (wantarray ? $slice->all : $slice);
702 =item Arguments: none
704 =item Return Value: $result?
708 Returns the next element in the resultset (C<undef> is there is none).
710 Can be used to efficiently iterate over records in the resultset:
712 my $rs = $schema->resultset('CD')->search;
713 while (my $cd = $rs->next) {
717 Note that you need to store the resultset object, and call C<next> on it.
718 Calling C<< resultset('Table')->next >> repeatedly will always return the
719 first record from the resultset.
725 if (my $cache = $self->get_cache) {
726 $self->{all_cache_position} ||= 0;
727 return $cache->[$self->{all_cache_position}++];
729 if ($self->{attrs}{cache}) {
730 $self->{all_cache_position} = 1;
731 return ($self->all)[0];
733 if ($self->{stashed_objects}) {
734 my $obj = shift(@{$self->{stashed_objects}});
735 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
739 exists $self->{stashed_row}
740 ? @{delete $self->{stashed_row}}
741 : $self->cursor->next
743 return unless (@row);
744 my ($row, @more) = $self->_construct_object(@row);
745 $self->{stashed_objects} = \@more if @more;
749 sub _construct_object {
750 my ($self, @row) = @_;
751 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
752 my @new = $self->result_class->inflate_result($self->result_source, @$info);
753 @new = $self->{_attrs}{record_filter}->(@new)
754 if exists $self->{_attrs}{record_filter};
758 sub _collapse_result {
759 my ($self, $as_proto, $row) = @_;
763 # 'foo' => [ undef, 'foo' ]
764 # 'foo.bar' => [ 'foo', 'bar' ]
765 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
767 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
769 my %collapse = %{$self->{_attrs}{collapse}||{}};
773 # if we're doing collapsing (has_many prefetch) we need to grab records
774 # until the PK changes, so fill @pri_index. if not, we leave it empty so
775 # we know we don't have to bother.
777 # the reason for not using the collapse stuff directly is because if you
778 # had for e.g. two artists in a row with no cds, the collapse info for
779 # both would be NULL (undef) so you'd lose the second artist
781 # store just the index so we can check the array positions from the row
782 # without having to contruct the full hash
784 if (keys %collapse) {
785 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
786 foreach my $i (0 .. $#construct_as) {
787 next if defined($construct_as[$i][0]); # only self table
788 if (delete $pri{$construct_as[$i][1]}) {
789 push(@pri_index, $i);
791 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
795 # no need to do an if, it'll be empty if @pri_index is empty anyway
797 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
801 do { # no need to check anything at the front, we always want the first row
805 foreach my $this_as (@construct_as) {
806 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
809 push(@const_rows, \%const);
811 } until ( # no pri_index => no collapse => drop straight out
814 do { # get another row, stash it, drop out if different PK
816 @copy = $self->cursor->next;
817 $self->{stashed_row} = \@copy;
819 # last thing in do block, counts as true if anything doesn't match
821 # check xor defined first for NULL vs. NOT NULL then if one is
822 # defined the other must be so check string equality
825 (defined $pri_vals{$_} ^ defined $copy[$_])
826 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
831 my $alias = $self->{attrs}{alias};
840 foreach my $const (@const_rows) {
841 scalar @const_keys or do {
842 @const_keys = sort { length($a) <=> length($b) } keys %$const;
844 foreach my $key (@const_keys) {
847 my @parts = split(/\./, $key);
849 my $data = $const->{$key};
850 foreach my $p (@parts) {
851 $target = $target->[1]->{$p} ||= [];
853 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
854 # collapsing at this point and on final part
855 my $pos = $collapse_pos{$cur};
856 CK: foreach my $ck (@ckey) {
857 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
858 $collapse_pos{$cur} = $data;
859 delete @collapse_pos{ # clear all positioning for sub-entries
860 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
867 if (exists $collapse{$cur}) {
868 $target = $target->[-1];
871 $target->[0] = $data;
873 $info->[0] = $const->{$key};
885 =item Arguments: $result_source?
887 =item Return Value: $result_source
891 An accessor for the primary ResultSource object from which this ResultSet
898 =item Arguments: $result_class?
900 =item Return Value: $result_class
904 An accessor for the class to use when creating row objects. Defaults to
905 C<< result_source->result_class >> - which in most cases is the name of the
906 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
915 =item Arguments: $cond, \%attrs??
917 =item Return Value: $count
921 Performs an SQL C<COUNT> with the same query as the resultset was built
922 with to find the number of elements. If passed arguments, does a search
923 on the resultset and counts the results of that.
925 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
926 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
927 not support C<DISTINCT> with multiple columns. If you are using such a
928 database, you should only use columns from the main table in your C<group_by>
935 return $self->search(@_)->count if @_ and defined $_[0];
936 return scalar @{ $self->get_cache } if $self->get_cache;
937 my $count = $self->_count;
938 return 0 unless $count;
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: $source_name, \@data;
1251 Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
1252 submitting to a $resultset->create(...) method.
1254 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1255 to insert the data, as this is a fast method.
1257 Otherwise, each set of data is inserted into the database using
1258 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1259 objects is returned.
1264 { artistid => 4, name => 'Manufactured Crap', cds => [
1265 { title => 'My First CD', year => 2006 },
1266 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1269 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1270 { title => 'My parents sold me to a record company' ,year => 2005 },
1271 { title => 'Why Am I So Ugly?', year => 2006 },
1272 { title => 'I Got Surgery and am now Popular', year => 2007 }
1275 { name => 'Like I Give a Damn' }
1280 use Data::Dump qw/dump/;
1283 my ($self, $data) = @_;
1285 if(defined wantarray) {
1287 foreach my $item (@$data) {
1288 push(@created, $self->create($item));
1294 my ($first, @rest) = @$data;
1296 ## We assume for now that the first item is required to name all the columns
1297 ## and relationships similarly to how schema->populate requires a first item
1298 ## of all the column names.
1300 my @names = grep { !ref $first->{$_} } keys %$first;
1301 my @values = map { [ map {defined $_ ? $_ : $self->throw_exception("Undefined value for column!")} @$_{@names} ] } @$data;
1303 $self->result_source->storage->insert_bulk(
1304 $self->result_source,
1309 ## Again we assume the first row has to define all the related resultsets
1310 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1311 my @pks = $self->result_source->primary_columns;
1313 ## Must have PKs to use this!!!
1315 foreach my $item (@$data)
1317 ## First we need to get a result for each
1318 ## We need to call populate for each relationship.
1320 foreach my $rel (@rels)
1322 next unless $item->{$rel};
1323 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1326 my $child = $parent->$rel;
1328 my $related = $child->result_source->resolve_condition(
1330 $parent->result_source->relationship_info($rel)->{cond},
1336 my $populate = [map { {%$_, %$related} } @{$item->{$rel}}];
1338 $child->populate( $populate );
1349 =item Arguments: none
1351 =item Return Value: $pager
1355 Return Value a L<Data::Page> object for the current resultset. Only makes
1356 sense for queries with a C<page> attribute.
1362 my $attrs = $self->{attrs};
1363 $self->throw_exception("Can't create pager for non-paged rs")
1364 unless $self->{attrs}{page};
1365 $attrs->{rows} ||= 10;
1366 return $self->{pager} ||= Data::Page->new(
1367 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1374 =item Arguments: $page_number
1376 =item Return Value: $rs
1380 Returns a resultset for the $page_number page of the resultset on which page
1381 is called, where each page contains a number of rows equal to the 'rows'
1382 attribute set on the resultset (10 by default).
1387 my ($self, $page) = @_;
1388 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1395 =item Arguments: \%vals
1397 =item Return Value: $object
1401 Creates an object in the resultset's result class and returns it.
1406 my ($self, $values) = @_;
1407 $self->throw_exception( "new_result needs a hash" )
1408 unless (ref $values eq 'HASH');
1409 $self->throw_exception(
1410 "Can't abstract implicit construct, condition not a hash"
1411 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1413 my $alias = $self->{attrs}{alias};
1414 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1416 %{ $self->_remove_alias($values, $alias) },
1417 %{ $self->_remove_alias($collapsed_cond, $alias) },
1418 -source_handle => $self->_source_handle
1421 return $self->result_class->new(\%new);
1426 # Recursively collapse the condition.
1428 sub _collapse_cond {
1429 my ($self, $cond, $collapsed) = @_;
1433 if (ref $cond eq 'ARRAY') {
1434 foreach my $subcond (@$cond) {
1435 next unless ref $subcond; # -or
1436 # warn "ARRAY: " . Dumper $subcond;
1437 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1440 elsif (ref $cond eq 'HASH') {
1441 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1442 foreach my $subcond (@{$cond->{-and}}) {
1443 # warn "HASH: " . Dumper $subcond;
1444 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1448 # warn "LEAF: " . Dumper $cond;
1449 foreach my $col (keys %$cond) {
1450 my $value = $cond->{$col};
1451 $collapsed->{$col} = $value;
1461 # Remove the specified alias from the specified query hash. A copy is made so
1462 # the original query is not modified.
1465 my ($self, $query, $alias) = @_;
1467 my %orig = %{ $query || {} };
1470 foreach my $key (keys %orig) {
1472 $unaliased{$key} = $orig{$key};
1475 $unaliased{$1} = $orig{$key}
1476 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1486 =item Arguments: \%vals, \%attrs?
1488 =item Return Value: $object
1492 Find an existing record from this resultset. If none exists, instantiate a new
1493 result object and return it. The object will not be saved into your storage
1494 until you call L<DBIx::Class::Row/insert> on it.
1496 If you want objects to be saved immediately, use L</find_or_create> instead.
1502 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1503 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1504 my $exists = $self->find($hash, $attrs);
1505 return defined $exists ? $exists : $self->new_result($hash);
1512 =item Arguments: \%vals
1514 =item Return Value: $object
1518 Inserts a record into the resultset and returns the object representing it.
1520 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1525 my ($self, $attrs) = @_;
1526 $self->throw_exception( "create needs a hashref" )
1527 unless ref $attrs eq 'HASH';
1528 return $self->new_result($attrs)->insert;
1531 =head2 find_or_create
1535 =item Arguments: \%vals, \%attrs?
1537 =item Return Value: $object
1541 $class->find_or_create({ key => $val, ... });
1543 Tries to find a record based on its primary key or unique constraint; if none
1544 is found, creates one and returns that instead.
1546 my $cd = $schema->resultset('CD')->find_or_create({
1548 artist => 'Massive Attack',
1549 title => 'Mezzanine',
1553 Also takes an optional C<key> attribute, to search by a specific key or unique
1554 constraint. For example:
1556 my $cd = $schema->resultset('CD')->find_or_create(
1558 artist => 'Massive Attack',
1559 title => 'Mezzanine',
1561 { key => 'cd_artist_title' }
1564 See also L</find> and L</update_or_create>. For information on how to declare
1565 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1569 sub find_or_create {
1571 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1572 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1573 my $exists = $self->find($hash, $attrs);
1574 return defined $exists ? $exists : $self->create($hash);
1577 =head2 update_or_create
1581 =item Arguments: \%col_values, { key => $unique_constraint }?
1583 =item Return Value: $object
1587 $class->update_or_create({ col => $val, ... });
1589 First, searches for an existing row matching one of the unique constraints
1590 (including the primary key) on the source of this resultset. If a row is
1591 found, updates it with the other given column values. Otherwise, creates a new
1594 Takes an optional C<key> attribute to search on a specific unique constraint.
1597 # In your application
1598 my $cd = $schema->resultset('CD')->update_or_create(
1600 artist => 'Massive Attack',
1601 title => 'Mezzanine',
1604 { key => 'cd_artist_title' }
1607 If no C<key> is specified, it searches on all unique constraints defined on the
1608 source, including the primary key.
1610 If the C<key> is specified as C<primary>, it searches only on the primary key.
1612 See also L</find> and L</find_or_create>. For information on how to declare
1613 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1617 sub update_or_create {
1619 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1620 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1622 my $row = $self->find($cond, $attrs);
1624 $row->update($cond);
1628 return $self->create($cond);
1635 =item Arguments: none
1637 =item Return Value: \@cache_objects?
1641 Gets the contents of the cache for the resultset, if the cache is set.
1653 =item Arguments: \@cache_objects
1655 =item Return Value: \@cache_objects
1659 Sets the contents of the cache for the resultset. Expects an arrayref
1660 of objects of the same class as those produced by the resultset. Note that
1661 if the cache is set the resultset will return the cached objects rather
1662 than re-querying the database even if the cache attr is not set.
1667 my ( $self, $data ) = @_;
1668 $self->throw_exception("set_cache requires an arrayref")
1669 if defined($data) && (ref $data ne 'ARRAY');
1670 $self->{all_cache} = $data;
1677 =item Arguments: none
1679 =item Return Value: []
1683 Clears the cache for the resultset.
1688 shift->set_cache(undef);
1691 =head2 related_resultset
1695 =item Arguments: $relationship_name
1697 =item Return Value: $resultset
1701 Returns a related resultset for the supplied relationship name.
1703 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1707 sub related_resultset {
1708 my ($self, $rel) = @_;
1710 $self->{related_resultsets} ||= {};
1711 return $self->{related_resultsets}{$rel} ||= do {
1712 my $rel_obj = $self->result_source->relationship_info($rel);
1714 $self->throw_exception(
1715 "search_related: result source '" . $self->_source_handle->source_moniker .
1716 "' has no such relationship $rel")
1719 my ($from,$seen) = $self->_resolve_from($rel);
1721 my $join_count = $seen->{$rel};
1722 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1724 $self->_source_handle->schema->resultset($rel_obj->{class})->search_rs(
1726 %{$self->{attrs}||{}},
1732 where => $self->{cond},
1740 my ($self, $extra_join) = @_;
1741 my $source = $self->result_source;
1742 my $attrs = $self->{attrs};
1744 my $from = $attrs->{from}
1745 || [ { $attrs->{alias} => $source->from } ];
1747 my $seen = { %{$attrs->{seen_join}||{}} };
1749 my $join = ($attrs->{join}
1750 ? [ $attrs->{join}, $extra_join ]
1754 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1757 return ($from,$seen);
1760 sub _resolved_attrs {
1762 return $self->{_attrs} if $self->{_attrs};
1764 my $attrs = { %{$self->{attrs}||{}} };
1765 my $source = $self->result_source;
1766 my $alias = $attrs->{alias};
1768 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1769 if ($attrs->{columns}) {
1770 delete $attrs->{as};
1771 } elsif (!$attrs->{select}) {
1772 $attrs->{columns} = [ $source->columns ];
1777 ? (ref $attrs->{select} eq 'ARRAY'
1778 ? [ @{$attrs->{select}} ]
1779 : [ $attrs->{select} ])
1780 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1784 ? (ref $attrs->{as} eq 'ARRAY'
1785 ? [ @{$attrs->{as}} ]
1787 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1791 if ($adds = delete $attrs->{include_columns}) {
1792 $adds = [$adds] unless ref $adds eq 'ARRAY';
1793 push(@{$attrs->{select}}, @$adds);
1794 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1796 if ($adds = delete $attrs->{'+select'}) {
1797 $adds = [$adds] unless ref $adds eq 'ARRAY';
1798 push(@{$attrs->{select}},
1799 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1801 if (my $adds = delete $attrs->{'+as'}) {
1802 $adds = [$adds] unless ref $adds eq 'ARRAY';
1803 push(@{$attrs->{as}}, @$adds);
1806 $attrs->{from} ||= [ { 'me' => $source->from } ];
1808 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1809 my $join = delete $attrs->{join} || {};
1811 if (defined $attrs->{prefetch}) {
1812 $join = $self->_merge_attr(
1813 $join, $attrs->{prefetch}
1817 $attrs->{from} = # have to copy here to avoid corrupting the original
1820 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1824 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1825 if ($attrs->{order_by}) {
1826 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1827 ? [ @{$attrs->{order_by}} ]
1828 : [ $attrs->{order_by} ]);
1830 $attrs->{order_by} = [];
1833 my $collapse = $attrs->{collapse} || {};
1834 if (my $prefetch = delete $attrs->{prefetch}) {
1835 $prefetch = $self->_merge_attr({}, $prefetch);
1837 my $seen = $attrs->{seen_join} || {};
1838 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1839 # bring joins back to level of current class
1840 my @prefetch = $source->resolve_prefetch(
1841 $p, $alias, $seen, \@pre_order, $collapse
1843 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1844 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1846 push(@{$attrs->{order_by}}, @pre_order);
1848 $attrs->{collapse} = $collapse;
1850 return $self->{_attrs} = $attrs;
1854 my ($self, $a, $b) = @_;
1855 return $b unless defined($a);
1856 return $a unless defined($b);
1858 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1859 foreach my $key (keys %{$b}) {
1860 if (exists $a->{$key}) {
1861 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1863 $a->{$key} = $b->{$key};
1868 $a = [$a] unless ref $a eq 'ARRAY';
1869 $b = [$b] unless ref $b eq 'ARRAY';
1873 foreach my $x ($a, $b) {
1874 foreach my $element (@{$x}) {
1875 if (ref $element eq 'HASH') {
1876 $hash = $self->_merge_attr($hash, $element);
1877 } elsif (ref $element eq 'ARRAY') {
1878 push(@array, @{$element});
1880 push(@array, $element) unless $b == $x
1881 && grep { $_ eq $element } @array;
1886 @array = grep { !exists $hash->{$_} } @array;
1888 return keys %{$hash}
1901 $self->_source_handle($_[0]->handle);
1903 $self->_source_handle->resolve;
1907 =head2 throw_exception
1909 See L<DBIx::Class::Schema/throw_exception> for details.
1913 sub throw_exception {
1915 $self->_source_handle->schema->throw_exception(@_);
1918 # XXX: FIXME: Attributes docs need clearing up
1922 The resultset takes various attributes that modify its behavior. Here's an
1929 =item Value: ($order_by | \@order_by)
1933 Which column(s) to order the results by. This is currently passed
1934 through directly to SQL, so you can give e.g. C<year DESC> for a
1935 descending order on the column `year'.
1937 Please note that if you have C<quote_char> enabled (see
1938 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1939 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1940 so you will need to manually quote things as appropriate.)
1946 =item Value: \@columns
1950 Shortcut to request a particular set of columns to be retrieved. Adds
1951 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1952 from that, then auto-populates C<as> from C<select> as normal. (You may also
1953 use the C<cols> attribute, as in earlier versions of DBIC.)
1955 =head2 include_columns
1959 =item Value: \@columns
1963 Shortcut to include additional columns in the returned results - for example
1965 $schema->resultset('CD')->search(undef, {
1966 include_columns => ['artist.name'],
1970 would return all CDs and include a 'name' column to the information
1971 passed to object inflation. Note that the 'artist' is the name of the
1972 column (or relationship) accessor, and 'name' is the name of the column
1973 accessor in the related table.
1979 =item Value: \@select_columns
1983 Indicates which columns should be selected from the storage. You can use
1984 column names, or in the case of RDBMS back ends, function or stored procedure
1987 $rs = $schema->resultset('Employee')->search(undef, {
1990 { count => 'employeeid' },
1995 When you use function/stored procedure names and do not supply an C<as>
1996 attribute, the column names returned are storage-dependent. E.g. MySQL would
1997 return a column named C<count(employeeid)> in the above example.
2003 Indicates additional columns to be selected from storage. Works the same as
2004 L<select> but adds columns to the selection.
2012 Indicates additional column names for those added via L<+select>.
2020 =item Value: \@inflation_names
2024 Indicates column names for object inflation. That is, c< as >
2025 indicates the name that the column can be accessed as via the
2026 C<get_column> method (or via the object accessor, B<if one already
2027 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
2030 The C< as > attribute is used in conjunction with C<select>,
2031 usually when C<select> contains one or more function or stored
2034 $rs = $schema->resultset('Employee')->search(undef, {
2037 { count => 'employeeid' }
2039 as => ['name', 'employee_count'],
2042 my $employee = $rs->first(); # get the first Employee
2044 If the object against which the search is performed already has an accessor
2045 matching a column name specified in C<as>, the value can be retrieved using
2046 the accessor as normal:
2048 my $name = $employee->name();
2050 If on the other hand an accessor does not exist in the object, you need to
2051 use C<get_column> instead:
2053 my $employee_count = $employee->get_column('employee_count');
2055 You can create your own accessors if required - see
2056 L<DBIx::Class::Manual::Cookbook> for details.
2058 Please note: This will NOT insert an C<AS employee_count> into the SQL
2059 statement produced, it is used for internal access only. Thus
2060 attempting to use the accessor in an C<order_by> clause or similar
2061 will fail miserably.
2063 To get around this limitation, you can supply literal SQL to your
2064 C<select> attibute that contains the C<AS alias> text, eg:
2066 select => [\'myfield AS alias']
2072 =item Value: ($rel_name | \@rel_names | \%rel_names)
2076 Contains a list of relationships that should be joined for this query. For
2079 # Get CDs by Nine Inch Nails
2080 my $rs = $schema->resultset('CD')->search(
2081 { 'artist.name' => 'Nine Inch Nails' },
2082 { join => 'artist' }
2085 Can also contain a hash reference to refer to the other relation's relations.
2088 package MyApp::Schema::Track;
2089 use base qw/DBIx::Class/;
2090 __PACKAGE__->table('track');
2091 __PACKAGE__->add_columns(qw/trackid cd position title/);
2092 __PACKAGE__->set_primary_key('trackid');
2093 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2096 # In your application
2097 my $rs = $schema->resultset('Artist')->search(
2098 { 'track.title' => 'Teardrop' },
2100 join => { cd => 'track' },
2101 order_by => 'artist.name',
2105 You need to use the relationship (not the table) name in conditions,
2106 because they are aliased as such. The current table is aliased as "me", so
2107 you need to use me.column_name in order to avoid ambiguity. For example:
2109 # Get CDs from 1984 with a 'Foo' track
2110 my $rs = $schema->resultset('CD')->search(
2113 'tracks.name' => 'Foo'
2115 { join => 'tracks' }
2118 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2119 similarly for a third time). For e.g.
2121 my $rs = $schema->resultset('Artist')->search({
2122 'cds.title' => 'Down to Earth',
2123 'cds_2.title' => 'Popular',
2125 join => [ qw/cds cds/ ],
2128 will return a set of all artists that have both a cd with title 'Down
2129 to Earth' and a cd with title 'Popular'.
2131 If you want to fetch related objects from other tables as well, see C<prefetch>
2138 =item Value: ($rel_name | \@rel_names | \%rel_names)
2142 Contains one or more relationships that should be fetched along with the main
2143 query (when they are accessed afterwards they will have already been
2144 "prefetched"). This is useful for when you know you will need the related
2145 objects, because it saves at least one query:
2147 my $rs = $schema->resultset('Tag')->search(
2156 The initial search results in SQL like the following:
2158 SELECT tag.*, cd.*, artist.* FROM tag
2159 JOIN cd ON tag.cd = cd.cdid
2160 JOIN artist ON cd.artist = artist.artistid
2162 L<DBIx::Class> has no need to go back to the database when we access the
2163 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2166 Simple prefetches will be joined automatically, so there is no need
2167 for a C<join> attribute in the above search. If you're prefetching to
2168 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2169 specify the join as well.
2171 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2172 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2173 with an accessor type of 'single' or 'filter').
2183 Makes the resultset paged and specifies the page to retrieve. Effectively
2184 identical to creating a non-pages resultset and then calling ->page($page)
2187 If L<rows> attribute is not specified it defualts to 10 rows per page.
2197 Specifes the maximum number of rows for direct retrieval or the number of
2198 rows per page if the page attribute or method is used.
2204 =item Value: $offset
2208 Specifies the (zero-based) row number for the first row to be returned, or the
2209 of the first row of the first page if paging is used.
2215 =item Value: \@columns
2219 A arrayref of columns to group by. Can include columns of joined tables.
2221 group_by => [qw/ column1 column2 ... /]
2227 =item Value: $condition
2231 HAVING is a select statement attribute that is applied between GROUP BY and
2232 ORDER BY. It is applied to the after the grouping calculations have been
2235 having => { 'count(employee)' => { '>=', 100 } }
2241 =item Value: (0 | 1)
2245 Set to 1 to group by all columns.
2251 Adds to the WHERE clause.
2253 # only return rows WHERE deleted IS NULL for all searches
2254 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2256 Can be overridden by passing C<{ where => undef }> as an attribute
2263 Set to 1 to cache search results. This prevents extra SQL queries if you
2264 revisit rows in your ResultSet:
2266 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2268 while( my $artist = $resultset->next ) {
2272 $rs->first; # without cache, this would issue a query
2274 By default, searches are not cached.
2276 For more examples of using these attributes, see
2277 L<DBIx::Class::Manual::Cookbook>.
2283 =item Value: \@from_clause
2287 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2288 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2291 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2293 C<join> will usually do what you need and it is strongly recommended that you
2294 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2295 And we really do mean "cannot", not just tried and failed. Attempting to use
2296 this because you're having problems with C<join> is like trying to use x86
2297 ASM because you've got a syntax error in your C. Trust us on this.
2299 Now, if you're still really, really sure you need to use this (and if you're
2300 not 100% sure, ask the mailing list first), here's an explanation of how this
2303 The syntax is as follows -
2306 { <alias1> => <table1> },
2308 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2309 [], # nested JOIN (optional)
2310 { <table1.column1> => <table2.column2>, ... (more conditions) },
2312 # More of the above [ ] may follow for additional joins
2319 ON <table1.column1> = <table2.column2>
2320 <more joins may follow>
2322 An easy way to follow the examples below is to remember the following:
2324 Anything inside "[]" is a JOIN
2325 Anything inside "{}" is a condition for the enclosing JOIN
2327 The following examples utilize a "person" table in a family tree application.
2328 In order to express parent->child relationships, this table is self-joined:
2330 # Person->belongs_to('father' => 'Person');
2331 # Person->belongs_to('mother' => 'Person');
2333 C<from> can be used to nest joins. Here we return all children with a father,
2334 then search against all mothers of those children:
2336 $rs = $schema->resultset('Person')->search(
2339 alias => 'mother', # alias columns in accordance with "from"
2341 { mother => 'person' },
2344 { child => 'person' },
2346 { father => 'person' },
2347 { 'father.person_id' => 'child.father_id' }
2350 { 'mother.person_id' => 'child.mother_id' }
2357 # SELECT mother.* FROM person mother
2360 # JOIN person father
2361 # ON ( father.person_id = child.father_id )
2363 # ON ( mother.person_id = child.mother_id )
2365 The type of any join can be controlled manually. To search against only people
2366 with a father in the person table, we could explicitly use C<INNER JOIN>:
2368 $rs = $schema->resultset('Person')->search(
2371 alias => 'child', # alias columns in accordance with "from"
2373 { child => 'person' },
2375 { father => 'person', -join_type => 'inner' },
2376 { 'father.id' => 'child.father_id' }
2383 # SELECT child.* FROM person child
2384 # INNER JOIN person father ON child.father_id = father.id