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 $attrs->{offset} ||= ($attrs->{rows} * ($attrs->{page} - 1));
97 $attrs->{alias} ||= 'me';
100 _source_handle => $source,
101 result_class => $attrs->{result_class} || $source->resolve->result_class,
102 cond => $attrs->{where},
117 =item Arguments: $cond, \%attrs?
119 =item Return Value: $resultset (scalar context), @row_objs (list context)
123 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
124 my $new_rs = $cd_rs->search({ year => 2005 });
126 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
127 # year = 2005 OR year = 2004
129 If you need to pass in additional attributes but no additional condition,
130 call it as C<search(undef, \%attrs)>.
132 # "SELECT name, artistid FROM $artist_table"
133 my @all_artists = $schema->resultset('Artist')->search(undef, {
134 columns => [qw/name artistid/],
137 For a list of attributes that can be passed to C<search>, see
138 L</ATTRIBUTES>. For more examples of using this function, see
139 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
140 documentation for the first argument, see L<SQL::Abstract>.
146 my $rs = $self->search_rs( @_ );
147 return (wantarray ? $rs->all : $rs);
154 =item Arguments: $cond, \%attrs?
156 =item Return Value: $resultset
160 This method does the same exact thing as search() except it will
161 always return a resultset, even in list context.
170 unless (@_) { # no search, effectively just a clone
171 $rows = $self->get_cache;
175 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
176 my $our_attrs = { %{$self->{attrs}} };
177 my $having = delete $our_attrs->{having};
178 my $where = delete $our_attrs->{where};
180 my $new_attrs = { %{$our_attrs}, %{$attrs} };
182 # merge new attrs into inherited
183 foreach my $key (qw/join prefetch/) {
184 next unless exists $attrs->{$key};
185 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
190 (@_ == 1 || ref $_[0] eq "HASH")
192 (ref $_[0] eq 'HASH')
194 (keys %{ $_[0] } > 0)
202 ? $self->throw_exception("Odd number of arguments to search")
209 if (defined $where) {
210 $new_attrs->{where} = (
211 defined $new_attrs->{where}
214 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
215 } $where, $new_attrs->{where}
222 $new_attrs->{where} = (
223 defined $new_attrs->{where}
226 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
227 } $cond, $new_attrs->{where}
233 if (defined $having) {
234 $new_attrs->{having} = (
235 defined $new_attrs->{having}
238 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
239 } $having, $new_attrs->{having}
245 my $rs = (ref $self)->new($self->result_source, $new_attrs);
247 $rs->set_cache($rows);
252 =head2 search_literal
256 =item Arguments: $sql_fragment, @bind_values
258 =item Return Value: $resultset (scalar context), @row_objs (list context)
262 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
263 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
265 Pass a literal chunk of SQL to be added to the conditional part of the
271 my ($self, $cond, @vals) = @_;
272 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
273 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
274 return $self->search(\$cond, $attrs);
281 =item Arguments: @values | \%cols, \%attrs?
283 =item Return Value: $row_object
287 Finds a row based on its primary key or unique constraint. For example, to find
288 a row by its primary key:
290 my $cd = $schema->resultset('CD')->find(5);
292 You can also find a row by a specific unique constraint using the C<key>
293 attribute. For example:
295 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
296 key => 'cd_artist_title'
299 Additionally, you can specify the columns explicitly by name:
301 my $cd = $schema->resultset('CD')->find(
303 artist => 'Massive Attack',
304 title => 'Mezzanine',
306 { key => 'cd_artist_title' }
309 If the C<key> is specified as C<primary>, it searches only on the primary key.
311 If no C<key> is specified, it searches on all unique constraints defined on the
312 source, including the primary key.
314 If your table does not have a primary key, you B<must> provide a value for the
315 C<key> attribute matching one of the unique constraints on the source.
317 See also L</find_or_create> and L</update_or_create>. For information on how to
318 declare unique constraints, see
319 L<DBIx::Class::ResultSource/add_unique_constraint>.
325 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
327 # Default to the primary key, but allow a specific key
328 my @cols = exists $attrs->{key}
329 ? $self->result_source->unique_constraint_columns($attrs->{key})
330 : $self->result_source->primary_columns;
331 $self->throw_exception(
332 "Can't find unless a primary key is defined or unique constraint is specified"
335 # Parse out a hashref from input
337 if (ref $_[0] eq 'HASH') {
338 $input_query = { %{$_[0]} };
340 elsif (@_ == @cols) {
342 @{$input_query}{@cols} = @_;
345 # Compatibility: Allow e.g. find(id => $value)
346 carp "Find by key => value deprecated; please use a hashref instead";
350 my (%related, $info);
352 KEY: foreach my $key (keys %$input_query) {
353 if (ref($input_query->{$key})
354 && ($info = $self->result_source->relationship_info($key))) {
355 my $val = delete $input_query->{$key};
356 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
357 my $rel_q = $self->result_source->resolve_condition(
358 $info->{cond}, $val, $key
360 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
361 @related{keys %$rel_q} = values %$rel_q;
364 if (my @keys = keys %related) {
365 @{$input_query}{@keys} = values %related;
368 my @unique_queries = $self->_unique_queries($input_query, $attrs);
370 # Build the final query: Default to the disjunction of the unique queries,
371 # but allow the input query in case the ResultSet defines the query or the
372 # user is abusing find
373 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
374 my $query = @unique_queries
375 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
376 : $self->_add_alias($input_query, $alias);
380 my $rs = $self->search($query, $attrs);
381 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
384 return keys %{$self->_resolved_attrs->{collapse}}
385 ? $self->search($query)->next
386 : $self->single($query);
392 # Add the specified alias to the specified query hash. A copy is made so the
393 # original query is not modified.
396 my ($self, $query, $alias) = @_;
398 my %aliased = %$query;
399 foreach my $col (grep { ! m/\./ } keys %aliased) {
400 $aliased{"$alias.$col"} = delete $aliased{$col};
408 # Build a list of queries which satisfy unique constraints.
410 sub _unique_queries {
411 my ($self, $query, $attrs) = @_;
413 my @constraint_names = exists $attrs->{key}
415 : $self->result_source->unique_constraint_names;
417 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
418 my $num_where = scalar keys %$where;
421 foreach my $name (@constraint_names) {
422 my @unique_cols = $self->result_source->unique_constraint_columns($name);
423 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
425 my $num_cols = scalar @unique_cols;
426 my $num_query = scalar keys %$unique_query;
428 my $total = $num_query + $num_where;
429 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
430 # The query is either unique on its own or is unique in combination with
431 # the existing where clause
432 push @unique_queries, $unique_query;
436 return @unique_queries;
439 # _build_unique_query
441 # Constrain the specified query hash based on the specified column names.
443 sub _build_unique_query {
444 my ($self, $query, $unique_cols) = @_;
447 map { $_ => $query->{$_} }
448 grep { exists $query->{$_} }
453 =head2 search_related
457 =item Arguments: $rel, $cond, \%attrs?
459 =item Return Value: $new_resultset
463 $new_rs = $cd_rs->search_related('artist', {
467 Searches the specified relationship, optionally specifying a condition and
468 attributes for matching records. See L</ATTRIBUTES> for more information.
473 return shift->related_resultset(shift)->search(@_);
480 =item Arguments: none
482 =item Return Value: $cursor
486 Returns a storage-driven cursor to the given resultset. See
487 L<DBIx::Class::Cursor> for more information.
494 my $attrs = { %{$self->_resolved_attrs} };
495 return $self->{cursor}
496 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
497 $attrs->{where},$attrs);
504 =item Arguments: $cond?
506 =item Return Value: $row_object?
510 my $cd = $schema->resultset('CD')->single({ year => 2001 });
512 Inflates the first result without creating a cursor if the resultset has
513 any records in it; if not returns nothing. Used by L</find> as an optimisation.
515 Can optionally take an additional condition *only* - this is a fast-code-path
516 method; if you need to add extra joins or similar call ->search and then
517 ->single without a condition on the $rs returned from that.
522 my ($self, $where) = @_;
523 my $attrs = { %{$self->_resolved_attrs} };
525 if (defined $attrs->{where}) {
528 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
529 $where, delete $attrs->{where} ]
532 $attrs->{where} = $where;
536 # XXX: Disabled since it doesn't infer uniqueness in all cases
537 # unless ($self->_is_unique_query($attrs->{where})) {
538 # carp "Query not guaranteed to return a single row"
539 # . "; please declare your unique constraints or use search instead";
542 my @data = $self->result_source->storage->select_single(
543 $attrs->{from}, $attrs->{select},
544 $attrs->{where}, $attrs
547 return (@data ? ($self->_construct_object(@data))[0] : undef);
552 # Try to determine if the specified query is guaranteed to be unique, based on
553 # the declared unique constraints.
555 sub _is_unique_query {
556 my ($self, $query) = @_;
558 my $collapsed = $self->_collapse_query($query);
559 my $alias = $self->{attrs}{alias};
561 foreach my $name ($self->result_source->unique_constraint_names) {
562 my @unique_cols = map {
564 } $self->result_source->unique_constraint_columns($name);
566 # Count the values for each unique column
567 my %seen = map { $_ => 0 } @unique_cols;
569 foreach my $key (keys %$collapsed) {
570 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
571 next unless exists $seen{$aliased}; # Additional constraints are okay
572 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
575 # If we get 0 or more than 1 value for a column, it's not necessarily unique
576 return 1 unless grep { $_ != 1 } values %seen;
584 # Recursively collapse the query, accumulating values for each column.
586 sub _collapse_query {
587 my ($self, $query, $collapsed) = @_;
591 if (ref $query eq 'ARRAY') {
592 foreach my $subquery (@$query) {
593 next unless ref $subquery; # -or
594 # warn "ARRAY: " . Dumper $subquery;
595 $collapsed = $self->_collapse_query($subquery, $collapsed);
598 elsif (ref $query eq 'HASH') {
599 if (keys %$query and (keys %$query)[0] eq '-and') {
600 foreach my $subquery (@{$query->{-and}}) {
601 # warn "HASH: " . Dumper $subquery;
602 $collapsed = $self->_collapse_query($subquery, $collapsed);
606 # warn "LEAF: " . Dumper $query;
607 foreach my $col (keys %$query) {
608 my $value = $query->{$col};
609 $collapsed->{$col}{$value}++;
621 =item Arguments: $cond?
623 =item Return Value: $resultsetcolumn
627 my $max_length = $rs->get_column('length')->max;
629 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
634 my ($self, $column) = @_;
635 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
643 =item Arguments: $cond, \%attrs?
645 =item Return Value: $resultset (scalar context), @row_objs (list context)
649 # WHERE title LIKE '%blue%'
650 $cd_rs = $rs->search_like({ title => '%blue%'});
652 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
653 that this is simply a convenience method. You most likely want to use
654 L</search> with specific operators.
656 For more information, see L<DBIx::Class::Manual::Cookbook>.
662 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
663 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
664 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
665 return $class->search($query, { %$attrs });
672 =item Arguments: $first, $last
674 =item Return Value: $resultset (scalar context), @row_objs (list context)
678 Returns a resultset or object list representing a subset of elements from the
679 resultset slice is called on. Indexes are from 0, i.e., to get the first
682 my ($one, $two, $three) = $rs->slice(0, 2);
687 my ($self, $min, $max) = @_;
688 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
689 $attrs->{offset} = $self->{attrs}{offset} || 0;
690 $attrs->{offset} += $min;
691 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
692 return $self->search(undef(), $attrs);
693 #my $slice = (ref $self)->new($self->result_source, $attrs);
694 #return (wantarray ? $slice->all : $slice);
701 =item Arguments: none
703 =item Return Value: $result?
707 Returns the next element in the resultset (C<undef> is there is none).
709 Can be used to efficiently iterate over records in the resultset:
711 my $rs = $schema->resultset('CD')->search;
712 while (my $cd = $rs->next) {
716 Note that you need to store the resultset object, and call C<next> on it.
717 Calling C<< resultset('Table')->next >> repeatedly will always return the
718 first record from the resultset.
724 if (my $cache = $self->get_cache) {
725 $self->{all_cache_position} ||= 0;
726 return $cache->[$self->{all_cache_position}++];
728 if ($self->{attrs}{cache}) {
729 $self->{all_cache_position} = 1;
730 return ($self->all)[0];
732 if ($self->{stashed_objects}) {
733 my $obj = shift(@{$self->{stashed_objects}});
734 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
738 exists $self->{stashed_row}
739 ? @{delete $self->{stashed_row}}
740 : $self->cursor->next
742 return undef unless (@row);
743 my ($row, @more) = $self->_construct_object(@row);
744 $self->{stashed_objects} = \@more if @more;
748 sub _construct_object {
749 my ($self, @row) = @_;
750 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
751 my @new = $self->result_class->inflate_result($self->result_source, @$info);
752 @new = $self->{_attrs}{record_filter}->(@new)
753 if exists $self->{_attrs}{record_filter};
757 sub _collapse_result {
758 my ($self, $as_proto, $row) = @_;
762 # 'foo' => [ undef, 'foo' ]
763 # 'foo.bar' => [ 'foo', 'bar' ]
764 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
766 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
768 my %collapse = %{$self->{_attrs}{collapse}||{}};
772 # if we're doing collapsing (has_many prefetch) we need to grab records
773 # until the PK changes, so fill @pri_index. if not, we leave it empty so
774 # we know we don't have to bother.
776 # the reason for not using the collapse stuff directly is because if you
777 # had for e.g. two artists in a row with no cds, the collapse info for
778 # both would be NULL (undef) so you'd lose the second artist
780 # store just the index so we can check the array positions from the row
781 # without having to contruct the full hash
783 if (keys %collapse) {
784 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
785 foreach my $i (0 .. $#construct_as) {
786 next if defined($construct_as[$i][0]); # only self table
787 if (delete $pri{$construct_as[$i][1]}) {
788 push(@pri_index, $i);
790 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
794 # no need to do an if, it'll be empty if @pri_index is empty anyway
796 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
800 do { # no need to check anything at the front, we always want the first row
804 foreach my $this_as (@construct_as) {
805 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
808 push(@const_rows, \%const);
810 } until ( # no pri_index => no collapse => drop straight out
813 do { # get another row, stash it, drop out if different PK
815 @copy = $self->cursor->next;
816 $self->{stashed_row} = \@copy;
818 # last thing in do block, counts as true if anything doesn't match
820 # check xor defined first for NULL vs. NOT NULL then if one is
821 # defined the other must be so check string equality
824 (defined $pri_vals{$_} ^ defined $copy[$_])
825 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
830 my $alias = $self->{attrs}{alias};
839 foreach my $const (@const_rows) {
840 scalar @const_keys or do {
841 @const_keys = sort { length($a) <=> length($b) } keys %$const;
843 foreach my $key (@const_keys) {
846 my @parts = split(/\./, $key);
848 my $data = $const->{$key};
849 foreach my $p (@parts) {
850 $target = $target->[1]->{$p} ||= [];
852 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
853 # collapsing at this point and on final part
854 my $pos = $collapse_pos{$cur};
855 CK: foreach my $ck (@ckey) {
856 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
857 $collapse_pos{$cur} = $data;
858 delete @collapse_pos{ # clear all positioning for sub-entries
859 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
866 if (exists $collapse{$cur}) {
867 $target = $target->[-1];
870 $target->[0] = $data;
872 $info->[0] = $const->{$key};
884 =item Arguments: $result_source?
886 =item Return Value: $result_source
890 An accessor for the primary ResultSource object from which this ResultSet
897 =item Arguments: $result_class?
899 =item Return Value: $result_class
903 An accessor for the class to use when creating row objects. Defaults to
904 C<< result_source->result_class >> - which in most cases is the name of the
905 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
914 =item Arguments: $cond, \%attrs??
916 =item Return Value: $count
920 Performs an SQL C<COUNT> with the same query as the resultset was built
921 with to find the number of elements. If passed arguments, does a search
922 on the resultset and counts the results of that.
924 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
925 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
926 not support C<DISTINCT> with multiple columns. If you are using such a
927 database, you should only use columns from the main table in your C<group_by>
934 return $self->search(@_)->count if @_ and defined $_[0];
935 return scalar @{ $self->get_cache } if $self->get_cache;
936 my $count = $self->_count;
937 return 0 unless $count;
939 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
940 $count = $self->{attrs}{rows} if
941 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
945 sub _count { # Separated out so pager can get the full count
947 my $select = { count => '*' };
949 my $attrs = { %{$self->_resolved_attrs} };
950 if (my $group_by = delete $attrs->{group_by}) {
951 delete $attrs->{having};
952 my @distinct = (ref $group_by ? @$group_by : ($group_by));
953 # todo: try CONCAT for multi-column pk
954 my @pk = $self->result_source->primary_columns;
956 my $alias = $attrs->{alias};
957 foreach my $column (@distinct) {
958 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
959 @distinct = ($column);
965 $select = { count => { distinct => \@distinct } };
968 $attrs->{select} = $select;
969 $attrs->{as} = [qw/count/];
971 # offset, order by and page are not needed to count. record_filter is cdbi
972 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
974 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
975 my ($count) = $tmp_rs->cursor->next;
983 =item Arguments: $sql_fragment, @bind_values
985 =item Return Value: $count
989 Counts the results in a literal query. Equivalent to calling L</search_literal>
990 with the passed arguments, then L</count>.
994 sub count_literal { shift->search_literal(@_)->count; }
1000 =item Arguments: none
1002 =item Return Value: @objects
1006 Returns all elements in the resultset. Called implicitly if the resultset
1007 is returned in list context.
1013 return @{ $self->get_cache } if $self->get_cache;
1017 # TODO: don't call resolve here
1018 if (keys %{$self->_resolved_attrs->{collapse}}) {
1019 # if ($self->{attrs}{prefetch}) {
1020 # Using $self->cursor->all is really just an optimisation.
1021 # If we're collapsing has_many prefetches it probably makes
1022 # very little difference, and this is cleaner than hacking
1023 # _construct_object to survive the approach
1024 my @row = $self->cursor->next;
1026 push(@obj, $self->_construct_object(@row));
1027 @row = (exists $self->{stashed_row}
1028 ? @{delete $self->{stashed_row}}
1029 : $self->cursor->next);
1032 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1035 $self->set_cache(\@obj) if $self->{attrs}{cache};
1043 =item Arguments: none
1045 =item Return Value: $self
1049 Resets the resultset's cursor, so you can iterate through the elements again.
1055 delete $self->{_attrs} if exists $self->{_attrs};
1056 $self->{all_cache_position} = 0;
1057 $self->cursor->reset;
1065 =item Arguments: none
1067 =item Return Value: $object?
1071 Resets the resultset and returns an object for the first result (if the
1072 resultset returns anything).
1077 return $_[0]->reset->next;
1080 # _cond_for_update_delete
1082 # update/delete require the condition to be modified to handle
1083 # the differing SQL syntax available. This transforms the $self->{cond}
1084 # appropriately, returning the new condition.
1086 sub _cond_for_update_delete {
1087 my ($self, $full_cond) = @_;
1090 $full_cond ||= $self->{cond};
1091 # No-op. No condition, we're updating/deleting everything
1092 return $cond unless ref $full_cond;
1094 if (ref $full_cond eq 'ARRAY') {
1098 foreach my $key (keys %{$_}) {
1100 $hash{$1} = $_->{$key};
1106 elsif (ref $full_cond eq 'HASH') {
1107 if ((keys %{$full_cond})[0] eq '-and') {
1110 my @cond = @{$full_cond->{-and}};
1111 for (my $i = 0; $i < @cond; $i++) {
1112 my $entry = $cond[$i];
1115 if (ref $entry eq 'HASH') {
1116 $hash = $self->_cond_for_update_delete($entry);
1119 $entry =~ /([^.]+)$/;
1120 $hash->{$1} = $cond[++$i];
1123 push @{$cond->{-and}}, $hash;
1127 foreach my $key (keys %{$full_cond}) {
1129 $cond->{$1} = $full_cond->{$key};
1134 $self->throw_exception(
1135 "Can't update/delete on resultset with condition unless hash or array"
1147 =item Arguments: \%values
1149 =item Return Value: $storage_rv
1153 Sets the specified columns in the resultset to the supplied values in a
1154 single query. Return value will be true if the update succeeded or false
1155 if no records were updated; exact type of success value is storage-dependent.
1160 my ($self, $values) = @_;
1161 $self->throw_exception("Values for update must be a hash")
1162 unless ref $values eq 'HASH';
1164 my $cond = $self->_cond_for_update_delete;
1166 return $self->result_source->storage->update(
1167 $self->result_source, $values, $cond
1175 =item Arguments: \%values
1177 =item Return Value: 1
1181 Fetches all objects and updates them one at a time. Note that C<update_all>
1182 will run DBIC cascade triggers, while L</update> will not.
1187 my ($self, $values) = @_;
1188 $self->throw_exception("Values for update must be a hash")
1189 unless ref $values eq 'HASH';
1190 foreach my $obj ($self->all) {
1191 $obj->set_columns($values)->update;
1200 =item Arguments: none
1202 =item Return Value: 1
1206 Deletes the contents of the resultset from its result source. Note that this
1207 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1208 to run. See also L<DBIx::Class::Row/delete>.
1215 my $cond = $self->_cond_for_update_delete;
1217 $self->result_source->storage->delete($self->result_source, $cond);
1225 =item Arguments: none
1227 =item Return Value: 1
1231 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1232 will run DBIC cascade triggers, while L</delete> will not.
1238 $_->delete for $self->all;
1246 =item Arguments: \@data;
1250 Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
1251 submitting to a $resultset->create(...) method.
1253 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1254 to insert the data, as this is a faster method.
1256 Otherwise, each set of data is inserted into the database using
1257 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1258 objects is returned.
1260 Example: Assuming an Artist Class that has many CDs Classes relating:
1262 my $Artist_rs = $schema->resultset("Artist");
1264 ## Void Context Example
1265 $Artist_rs->populate([
1266 { artistid => 4, name => 'Manufactured Crap', cds => [
1267 { title => 'My First CD', year => 2006 },
1268 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1271 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1272 { title => 'My parents sold me to a record company' ,year => 2005 },
1273 { title => 'Why Am I So Ugly?', year => 2006 },
1274 { title => 'I Got Surgery and am now Popular', year => 2007 }
1279 ## Array Context Example
1280 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1281 { name => "Artist One"},
1282 { name => "Artist Two"},
1283 { name => "Artist Three", cds=> [
1284 { title => "First CD", year => 2007},
1285 { title => "Second CD", year => 2008},
1289 print $ArtistOne->name; ## response is 'Artist One'
1290 print $ArtistThree->cds->count ## reponse is '2'
1295 my ($self, $data) = @_;
1297 if(defined wantarray) {
1299 foreach my $item (@$data) {
1300 push(@created, $self->create($item));
1304 my ($first, @rest) = @$data;
1306 my @names = grep {!ref $first->{$_}} keys %$first;
1307 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1308 my @pks = $self->result_source->primary_columns;
1310 ## do the belongs_to relationships
1311 foreach my $index (0..$#$data) {
1312 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1313 my @ret = $self->populate($data);
1317 foreach my $rel (@rels) {
1318 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1319 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1320 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1321 my $related = $result->result_source->resolve_condition(
1322 $result->result_source->relationship_info($reverse)->{cond},
1327 delete $data->[$index]->{$rel};
1328 $data->[$index] = {%{$data->[$index]}, %$related};
1330 push @names, keys %$related if $index == 0;
1334 ## do bulk insert on current row
1337 defined $_ ? $_ : $self->throw_exception("Undefined value for column!")
1341 $self->result_source->storage->insert_bulk(
1342 $self->result_source,
1347 ## do the has_many relationships
1348 foreach my $item (@$data) {
1350 foreach my $rel (@rels) {
1351 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1353 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1354 || $self->throw_exception('Cannot find the relating object.');
1356 my $child = $parent->$rel;
1358 my $related = $child->result_source->resolve_condition(
1359 $parent->result_source->relationship_info($rel)->{cond},
1364 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1365 my @populate = map { {%$_, %$related} } @rows_to_add;
1367 $child->populate( \@populate );
1377 =item Arguments: none
1379 =item Return Value: $pager
1383 Return Value a L<Data::Page> object for the current resultset. Only makes
1384 sense for queries with a C<page> attribute.
1390 my $attrs = $self->{attrs};
1391 $self->throw_exception("Can't create pager for non-paged rs")
1392 unless $self->{attrs}{page};
1393 $attrs->{rows} ||= 10;
1394 return $self->{pager} ||= Data::Page->new(
1395 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1402 =item Arguments: $page_number
1404 =item Return Value: $rs
1408 Returns a resultset for the $page_number page of the resultset on which page
1409 is called, where each page contains a number of rows equal to the 'rows'
1410 attribute set on the resultset (10 by default).
1415 my ($self, $page) = @_;
1416 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1423 =item Arguments: \%vals
1425 =item Return Value: $object
1429 Creates an object in the resultset's result class and returns it.
1434 my ($self, $values) = @_;
1435 $self->throw_exception( "new_result needs a hash" )
1436 unless (ref $values eq 'HASH');
1437 $self->throw_exception(
1438 "Can't abstract implicit construct, condition not a hash"
1439 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1441 my $alias = $self->{attrs}{alias};
1442 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1444 %{ $self->_remove_alias($values, $alias) },
1445 %{ $self->_remove_alias($collapsed_cond, $alias) },
1446 -source_handle => $self->_source_handle,
1447 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1450 return $self->result_class->new(\%new);
1455 # Recursively collapse the condition.
1457 sub _collapse_cond {
1458 my ($self, $cond, $collapsed) = @_;
1462 if (ref $cond eq 'ARRAY') {
1463 foreach my $subcond (@$cond) {
1464 next unless ref $subcond; # -or
1465 # warn "ARRAY: " . Dumper $subcond;
1466 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1469 elsif (ref $cond eq 'HASH') {
1470 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1471 foreach my $subcond (@{$cond->{-and}}) {
1472 # warn "HASH: " . Dumper $subcond;
1473 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1477 # warn "LEAF: " . Dumper $cond;
1478 foreach my $col (keys %$cond) {
1479 my $value = $cond->{$col};
1480 $collapsed->{$col} = $value;
1490 # Remove the specified alias from the specified query hash. A copy is made so
1491 # the original query is not modified.
1494 my ($self, $query, $alias) = @_;
1496 my %orig = %{ $query || {} };
1499 foreach my $key (keys %orig) {
1501 $unaliased{$key} = $orig{$key};
1504 $unaliased{$1} = $orig{$key}
1505 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1515 =item Arguments: \%vals, \%attrs?
1517 =item Return Value: $object
1521 Find an existing record from this resultset. If none exists, instantiate a new
1522 result object and return it. The object will not be saved into your storage
1523 until you call L<DBIx::Class::Row/insert> on it.
1525 If you want objects to be saved immediately, use L</find_or_create> instead.
1531 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1532 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1533 my $exists = $self->find($hash, $attrs);
1534 return defined $exists ? $exists : $self->new_result($hash);
1541 =item Arguments: \%vals
1543 =item Return Value: $object
1547 Inserts a record into the resultset and returns the object representing it.
1549 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1554 my ($self, $attrs) = @_;
1555 $self->throw_exception( "create needs a hashref" )
1556 unless ref $attrs eq 'HASH';
1557 return $self->new_result($attrs)->insert;
1560 =head2 find_or_create
1564 =item Arguments: \%vals, \%attrs?
1566 =item Return Value: $object
1570 $class->find_or_create({ key => $val, ... });
1572 Tries to find a record based on its primary key or unique constraint; if none
1573 is found, creates one and returns that instead.
1575 my $cd = $schema->resultset('CD')->find_or_create({
1577 artist => 'Massive Attack',
1578 title => 'Mezzanine',
1582 Also takes an optional C<key> attribute, to search by a specific key or unique
1583 constraint. For example:
1585 my $cd = $schema->resultset('CD')->find_or_create(
1587 artist => 'Massive Attack',
1588 title => 'Mezzanine',
1590 { key => 'cd_artist_title' }
1593 See also L</find> and L</update_or_create>. For information on how to declare
1594 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1598 sub find_or_create {
1600 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1601 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1602 my $exists = $self->find($hash, $attrs);
1603 return defined $exists ? $exists : $self->create($hash);
1606 =head2 update_or_create
1610 =item Arguments: \%col_values, { key => $unique_constraint }?
1612 =item Return Value: $object
1616 $class->update_or_create({ col => $val, ... });
1618 First, searches for an existing row matching one of the unique constraints
1619 (including the primary key) on the source of this resultset. If a row is
1620 found, updates it with the other given column values. Otherwise, creates a new
1623 Takes an optional C<key> attribute to search on a specific unique constraint.
1626 # In your application
1627 my $cd = $schema->resultset('CD')->update_or_create(
1629 artist => 'Massive Attack',
1630 title => 'Mezzanine',
1633 { key => 'cd_artist_title' }
1636 If no C<key> is specified, it searches on all unique constraints defined on the
1637 source, including the primary key.
1639 If the C<key> is specified as C<primary>, it searches only on the primary key.
1641 See also L</find> and L</find_or_create>. For information on how to declare
1642 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1646 sub update_or_create {
1648 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1649 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1651 my $row = $self->find($cond, $attrs);
1653 $row->update($cond);
1657 return $self->create($cond);
1664 =item Arguments: none
1666 =item Return Value: \@cache_objects?
1670 Gets the contents of the cache for the resultset, if the cache is set.
1682 =item Arguments: \@cache_objects
1684 =item Return Value: \@cache_objects
1688 Sets the contents of the cache for the resultset. Expects an arrayref
1689 of objects of the same class as those produced by the resultset. Note that
1690 if the cache is set the resultset will return the cached objects rather
1691 than re-querying the database even if the cache attr is not set.
1696 my ( $self, $data ) = @_;
1697 $self->throw_exception("set_cache requires an arrayref")
1698 if defined($data) && (ref $data ne 'ARRAY');
1699 $self->{all_cache} = $data;
1706 =item Arguments: none
1708 =item Return Value: []
1712 Clears the cache for the resultset.
1717 shift->set_cache(undef);
1720 =head2 related_resultset
1724 =item Arguments: $relationship_name
1726 =item Return Value: $resultset
1730 Returns a related resultset for the supplied relationship name.
1732 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1736 sub related_resultset {
1737 my ($self, $rel) = @_;
1739 $self->{related_resultsets} ||= {};
1740 return $self->{related_resultsets}{$rel} ||= do {
1741 my $rel_obj = $self->result_source->relationship_info($rel);
1743 $self->throw_exception(
1744 "search_related: result source '" . $self->_source_handle->source_moniker .
1745 "' has no such relationship $rel")
1748 my ($from,$seen) = $self->_resolve_from($rel);
1750 my $join_count = $seen->{$rel};
1751 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1753 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
1754 my %attrs = %{$self->{attrs}||{}};
1755 delete $attrs{result_class};
1759 if (my $cache = $self->get_cache) {
1760 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
1761 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
1766 my $new = $self->_source_handle
1768 ->resultset($rel_obj->{class})
1777 where => $self->{cond},
1781 $new->set_cache($new_cache) if $new_cache;
1787 my ($self, $extra_join) = @_;
1788 my $source = $self->result_source;
1789 my $attrs = $self->{attrs};
1791 my $from = $attrs->{from}
1792 || [ { $attrs->{alias} => $source->from } ];
1794 my $seen = { %{$attrs->{seen_join}||{}} };
1796 my $join = ($attrs->{join}
1797 ? [ $attrs->{join}, $extra_join ]
1801 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1804 return ($from,$seen);
1807 sub _resolved_attrs {
1809 return $self->{_attrs} if $self->{_attrs};
1811 my $attrs = { %{$self->{attrs}||{}} };
1812 my $source = $self->result_source;
1813 my $alias = $attrs->{alias};
1815 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1816 if ($attrs->{columns}) {
1817 delete $attrs->{as};
1818 } elsif (!$attrs->{select}) {
1819 $attrs->{columns} = [ $source->columns ];
1824 ? (ref $attrs->{select} eq 'ARRAY'
1825 ? [ @{$attrs->{select}} ]
1826 : [ $attrs->{select} ])
1827 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1831 ? (ref $attrs->{as} eq 'ARRAY'
1832 ? [ @{$attrs->{as}} ]
1834 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1838 if ($adds = delete $attrs->{include_columns}) {
1839 $adds = [$adds] unless ref $adds eq 'ARRAY';
1840 push(@{$attrs->{select}}, @$adds);
1841 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1843 if ($adds = delete $attrs->{'+select'}) {
1844 $adds = [$adds] unless ref $adds eq 'ARRAY';
1845 push(@{$attrs->{select}},
1846 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1848 if (my $adds = delete $attrs->{'+as'}) {
1849 $adds = [$adds] unless ref $adds eq 'ARRAY';
1850 push(@{$attrs->{as}}, @$adds);
1853 $attrs->{from} ||= [ { 'me' => $source->from } ];
1855 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1856 my $join = delete $attrs->{join} || {};
1858 if (defined $attrs->{prefetch}) {
1859 $join = $self->_merge_attr(
1860 $join, $attrs->{prefetch}
1864 $attrs->{from} = # have to copy here to avoid corrupting the original
1867 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1871 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1872 if ($attrs->{order_by}) {
1873 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1874 ? [ @{$attrs->{order_by}} ]
1875 : [ $attrs->{order_by} ]);
1877 $attrs->{order_by} = [];
1880 my $collapse = $attrs->{collapse} || {};
1881 if (my $prefetch = delete $attrs->{prefetch}) {
1882 $prefetch = $self->_merge_attr({}, $prefetch);
1884 my $seen = $attrs->{seen_join} || {};
1885 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1886 # bring joins back to level of current class
1887 my @prefetch = $source->resolve_prefetch(
1888 $p, $alias, $seen, \@pre_order, $collapse
1890 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1891 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1893 push(@{$attrs->{order_by}}, @pre_order);
1895 $attrs->{collapse} = $collapse;
1897 return $self->{_attrs} = $attrs;
1901 my ($self, $a, $b) = @_;
1902 return $b unless defined($a);
1903 return $a unless defined($b);
1905 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1906 foreach my $key (keys %{$b}) {
1907 if (exists $a->{$key}) {
1908 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1910 $a->{$key} = $b->{$key};
1915 $a = [$a] unless ref $a eq 'ARRAY';
1916 $b = [$b] unless ref $b eq 'ARRAY';
1920 foreach my $x ($a, $b) {
1921 foreach my $element (@{$x}) {
1922 if (ref $element eq 'HASH') {
1923 $hash = $self->_merge_attr($hash, $element);
1924 } elsif (ref $element eq 'ARRAY') {
1925 push(@array, @{$element});
1927 push(@array, $element) unless $b == $x
1928 && grep { $_ eq $element } @array;
1933 @array = grep { !exists $hash->{$_} } @array;
1935 return keys %{$hash}
1948 $self->_source_handle($_[0]->handle);
1950 $self->_source_handle->resolve;
1954 =head2 throw_exception
1956 See L<DBIx::Class::Schema/throw_exception> for details.
1960 sub throw_exception {
1962 $self->_source_handle->schema->throw_exception(@_);
1965 # XXX: FIXME: Attributes docs need clearing up
1969 The resultset takes various attributes that modify its behavior. Here's an
1976 =item Value: ($order_by | \@order_by)
1980 Which column(s) to order the results by. This is currently passed
1981 through directly to SQL, so you can give e.g. C<year DESC> for a
1982 descending order on the column `year'.
1984 Please note that if you have C<quote_char> enabled (see
1985 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1986 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1987 so you will need to manually quote things as appropriate.)
1993 =item Value: \@columns
1997 Shortcut to request a particular set of columns to be retrieved. Adds
1998 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1999 from that, then auto-populates C<as> from C<select> as normal. (You may also
2000 use the C<cols> attribute, as in earlier versions of DBIC.)
2002 =head2 include_columns
2006 =item Value: \@columns
2010 Shortcut to include additional columns in the returned results - for example
2012 $schema->resultset('CD')->search(undef, {
2013 include_columns => ['artist.name'],
2017 would return all CDs and include a 'name' column to the information
2018 passed to object inflation. Note that the 'artist' is the name of the
2019 column (or relationship) accessor, and 'name' is the name of the column
2020 accessor in the related table.
2026 =item Value: \@select_columns
2030 Indicates which columns should be selected from the storage. You can use
2031 column names, or in the case of RDBMS back ends, function or stored procedure
2034 $rs = $schema->resultset('Employee')->search(undef, {
2037 { count => 'employeeid' },
2042 When you use function/stored procedure names and do not supply an C<as>
2043 attribute, the column names returned are storage-dependent. E.g. MySQL would
2044 return a column named C<count(employeeid)> in the above example.
2050 Indicates additional columns to be selected from storage. Works the same as
2051 L<select> but adds columns to the selection.
2059 Indicates additional column names for those added via L<+select>.
2067 =item Value: \@inflation_names
2071 Indicates column names for object inflation. That is, c< as >
2072 indicates the name that the column can be accessed as via the
2073 C<get_column> method (or via the object accessor, B<if one already
2074 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
2077 The C< as > attribute is used in conjunction with C<select>,
2078 usually when C<select> contains one or more function or stored
2081 $rs = $schema->resultset('Employee')->search(undef, {
2084 { count => 'employeeid' }
2086 as => ['name', 'employee_count'],
2089 my $employee = $rs->first(); # get the first Employee
2091 If the object against which the search is performed already has an accessor
2092 matching a column name specified in C<as>, the value can be retrieved using
2093 the accessor as normal:
2095 my $name = $employee->name();
2097 If on the other hand an accessor does not exist in the object, you need to
2098 use C<get_column> instead:
2100 my $employee_count = $employee->get_column('employee_count');
2102 You can create your own accessors if required - see
2103 L<DBIx::Class::Manual::Cookbook> for details.
2105 Please note: This will NOT insert an C<AS employee_count> into the SQL
2106 statement produced, it is used for internal access only. Thus
2107 attempting to use the accessor in an C<order_by> clause or similar
2108 will fail miserably.
2110 To get around this limitation, you can supply literal SQL to your
2111 C<select> attibute that contains the C<AS alias> text, eg:
2113 select => [\'myfield AS alias']
2119 =item Value: ($rel_name | \@rel_names | \%rel_names)
2123 Contains a list of relationships that should be joined for this query. For
2126 # Get CDs by Nine Inch Nails
2127 my $rs = $schema->resultset('CD')->search(
2128 { 'artist.name' => 'Nine Inch Nails' },
2129 { join => 'artist' }
2132 Can also contain a hash reference to refer to the other relation's relations.
2135 package MyApp::Schema::Track;
2136 use base qw/DBIx::Class/;
2137 __PACKAGE__->table('track');
2138 __PACKAGE__->add_columns(qw/trackid cd position title/);
2139 __PACKAGE__->set_primary_key('trackid');
2140 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2143 # In your application
2144 my $rs = $schema->resultset('Artist')->search(
2145 { 'track.title' => 'Teardrop' },
2147 join => { cd => 'track' },
2148 order_by => 'artist.name',
2152 You need to use the relationship (not the table) name in conditions,
2153 because they are aliased as such. The current table is aliased as "me", so
2154 you need to use me.column_name in order to avoid ambiguity. For example:
2156 # Get CDs from 1984 with a 'Foo' track
2157 my $rs = $schema->resultset('CD')->search(
2160 'tracks.name' => 'Foo'
2162 { join => 'tracks' }
2165 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2166 similarly for a third time). For e.g.
2168 my $rs = $schema->resultset('Artist')->search({
2169 'cds.title' => 'Down to Earth',
2170 'cds_2.title' => 'Popular',
2172 join => [ qw/cds cds/ ],
2175 will return a set of all artists that have both a cd with title 'Down
2176 to Earth' and a cd with title 'Popular'.
2178 If you want to fetch related objects from other tables as well, see C<prefetch>
2185 =item Value: ($rel_name | \@rel_names | \%rel_names)
2189 Contains one or more relationships that should be fetched along with the main
2190 query (when they are accessed afterwards they will have already been
2191 "prefetched"). This is useful for when you know you will need the related
2192 objects, because it saves at least one query:
2194 my $rs = $schema->resultset('Tag')->search(
2203 The initial search results in SQL like the following:
2205 SELECT tag.*, cd.*, artist.* FROM tag
2206 JOIN cd ON tag.cd = cd.cdid
2207 JOIN artist ON cd.artist = artist.artistid
2209 L<DBIx::Class> has no need to go back to the database when we access the
2210 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2213 Simple prefetches will be joined automatically, so there is no need
2214 for a C<join> attribute in the above search. If you're prefetching to
2215 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2216 specify the join as well.
2218 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2219 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2220 with an accessor type of 'single' or 'filter').
2230 Makes the resultset paged and specifies the page to retrieve. Effectively
2231 identical to creating a non-pages resultset and then calling ->page($page)
2234 If L<rows> attribute is not specified it defualts to 10 rows per page.
2244 Specifes the maximum number of rows for direct retrieval or the number of
2245 rows per page if the page attribute or method is used.
2251 =item Value: $offset
2255 Specifies the (zero-based) row number for the first row to be returned, or the
2256 of the first row of the first page if paging is used.
2262 =item Value: \@columns
2266 A arrayref of columns to group by. Can include columns of joined tables.
2268 group_by => [qw/ column1 column2 ... /]
2274 =item Value: $condition
2278 HAVING is a select statement attribute that is applied between GROUP BY and
2279 ORDER BY. It is applied to the after the grouping calculations have been
2282 having => { 'count(employee)' => { '>=', 100 } }
2288 =item Value: (0 | 1)
2292 Set to 1 to group by all columns.
2298 Adds to the WHERE clause.
2300 # only return rows WHERE deleted IS NULL for all searches
2301 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2303 Can be overridden by passing C<{ where => undef }> as an attribute
2310 Set to 1 to cache search results. This prevents extra SQL queries if you
2311 revisit rows in your ResultSet:
2313 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2315 while( my $artist = $resultset->next ) {
2319 $rs->first; # without cache, this would issue a query
2321 By default, searches are not cached.
2323 For more examples of using these attributes, see
2324 L<DBIx::Class::Manual::Cookbook>.
2330 =item Value: \@from_clause
2334 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2335 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2338 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2340 C<join> will usually do what you need and it is strongly recommended that you
2341 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2342 And we really do mean "cannot", not just tried and failed. Attempting to use
2343 this because you're having problems with C<join> is like trying to use x86
2344 ASM because you've got a syntax error in your C. Trust us on this.
2346 Now, if you're still really, really sure you need to use this (and if you're
2347 not 100% sure, ask the mailing list first), here's an explanation of how this
2350 The syntax is as follows -
2353 { <alias1> => <table1> },
2355 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2356 [], # nested JOIN (optional)
2357 { <table1.column1> => <table2.column2>, ... (more conditions) },
2359 # More of the above [ ] may follow for additional joins
2366 ON <table1.column1> = <table2.column2>
2367 <more joins may follow>
2369 An easy way to follow the examples below is to remember the following:
2371 Anything inside "[]" is a JOIN
2372 Anything inside "{}" is a condition for the enclosing JOIN
2374 The following examples utilize a "person" table in a family tree application.
2375 In order to express parent->child relationships, this table is self-joined:
2377 # Person->belongs_to('father' => 'Person');
2378 # Person->belongs_to('mother' => 'Person');
2380 C<from> can be used to nest joins. Here we return all children with a father,
2381 then search against all mothers of those children:
2383 $rs = $schema->resultset('Person')->search(
2386 alias => 'mother', # alias columns in accordance with "from"
2388 { mother => 'person' },
2391 { child => 'person' },
2393 { father => 'person' },
2394 { 'father.person_id' => 'child.father_id' }
2397 { 'mother.person_id' => 'child.mother_id' }
2404 # SELECT mother.* FROM person mother
2407 # JOIN person father
2408 # ON ( father.person_id = child.father_id )
2410 # ON ( mother.person_id = child.mother_id )
2412 The type of any join can be controlled manually. To search against only people
2413 with a father in the person table, we could explicitly use C<INNER JOIN>:
2415 $rs = $schema->resultset('Person')->search(
2418 alias => 'child', # alias columns in accordance with "from"
2420 { child => 'person' },
2422 { father => 'person', -join_type => 'inner' },
2423 { 'father.id' => 'child.father_id' }
2430 # SELECT child.* FROM person child
2431 # INNER JOIN person father ON child.father_id = father.id