1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
90 $attrs = { %{$attrs||{}} };
93 $attrs->{rows} ||= 10;
96 $attrs->{alias} ||= 'me';
99 _source_handle => $source,
100 result_class => $attrs->{result_class} || $source->resolve->result_class,
101 cond => $attrs->{where},
116 =item Arguments: $cond, \%attrs?
118 =item Return Value: $resultset (scalar context), @row_objs (list context)
122 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
123 my $new_rs = $cd_rs->search({ year => 2005 });
125 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
126 # year = 2005 OR year = 2004
128 If you need to pass in additional attributes but no additional condition,
129 call it as C<search(undef, \%attrs)>.
131 # "SELECT name, artistid FROM $artist_table"
132 my @all_artists = $schema->resultset('Artist')->search(undef, {
133 columns => [qw/name artistid/],
136 For a list of attributes that can be passed to C<search>, see
137 L</ATTRIBUTES>. For more examples of using this function, see
138 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
139 documentation for the first argument, see L<SQL::Abstract>.
145 my $rs = $self->search_rs( @_ );
146 return (wantarray ? $rs->all : $rs);
153 =item Arguments: $cond, \%attrs?
155 =item Return Value: $resultset
159 This method does the same exact thing as search() except it will
160 always return a resultset, even in list context.
169 unless (@_) { # no search, effectively just a clone
170 $rows = $self->get_cache;
174 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
175 my $our_attrs = { %{$self->{attrs}} };
176 my $having = delete $our_attrs->{having};
177 my $where = delete $our_attrs->{where};
179 my $new_attrs = { %{$our_attrs}, %{$attrs} };
181 # merge new attrs into inherited
182 foreach my $key (qw/join prefetch/) {
183 next unless exists $attrs->{$key};
184 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
189 (@_ == 1 || ref $_[0] eq "HASH")
191 (ref $_[0] eq 'HASH')
193 (keys %{ $_[0] } > 0)
201 ? $self->throw_exception("Odd number of arguments to search")
208 if (defined $where) {
209 $new_attrs->{where} = (
210 defined $new_attrs->{where}
213 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
214 } $where, $new_attrs->{where}
221 $new_attrs->{where} = (
222 defined $new_attrs->{where}
225 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
226 } $cond, $new_attrs->{where}
232 if (defined $having) {
233 $new_attrs->{having} = (
234 defined $new_attrs->{having}
237 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
238 } $having, $new_attrs->{having}
244 my $rs = (ref $self)->new($self->result_source, $new_attrs);
246 $rs->set_cache($rows);
251 =head2 search_literal
255 =item Arguments: $sql_fragment, @bind_values
257 =item Return Value: $resultset (scalar context), @row_objs (list context)
261 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
262 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
264 Pass a literal chunk of SQL to be added to the conditional part of the
270 my ($self, $cond, @vals) = @_;
271 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
272 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
273 return $self->search(\$cond, $attrs);
280 =item Arguments: @values | \%cols, \%attrs?
282 =item Return Value: $row_object
286 Finds a row based on its primary key or unique constraint. For example, to find
287 a row by its primary key:
289 my $cd = $schema->resultset('CD')->find(5);
291 You can also find a row by a specific unique constraint using the C<key>
292 attribute. For example:
294 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
295 key => 'cd_artist_title'
298 Additionally, you can specify the columns explicitly by name:
300 my $cd = $schema->resultset('CD')->find(
302 artist => 'Massive Attack',
303 title => 'Mezzanine',
305 { key => 'cd_artist_title' }
308 If the C<key> is specified as C<primary>, it searches only on the primary key.
310 If no C<key> is specified, it searches on all unique constraints defined on the
311 source, including the primary key.
313 If your table does not have a primary key, you B<must> provide a value for the
314 C<key> attribute matching one of the unique constraints on the source.
316 See also L</find_or_create> and L</update_or_create>. For information on how to
317 declare unique constraints, see
318 L<DBIx::Class::ResultSource/add_unique_constraint>.
324 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
326 # Default to the primary key, but allow a specific key
327 my @cols = exists $attrs->{key}
328 ? $self->result_source->unique_constraint_columns($attrs->{key})
329 : $self->result_source->primary_columns;
330 $self->throw_exception(
331 "Can't find unless a primary key is defined or unique constraint is specified"
334 # Parse out a hashref from input
336 if (ref $_[0] eq 'HASH') {
337 $input_query = { %{$_[0]} };
339 elsif (@_ == @cols) {
341 @{$input_query}{@cols} = @_;
344 # Compatibility: Allow e.g. find(id => $value)
345 carp "Find by key => value deprecated; please use a hashref instead";
349 my (%related, $info);
351 KEY: foreach my $key (keys %$input_query) {
352 if (ref($input_query->{$key})
353 && ($info = $self->result_source->relationship_info($key))) {
354 my $val = delete $input_query->{$key};
355 next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
356 my $rel_q = $self->result_source->resolve_condition(
357 $info->{cond}, $val, $key
359 die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
360 @related{keys %$rel_q} = values %$rel_q;
363 if (my @keys = keys %related) {
364 @{$input_query}{@keys} = values %related;
367 my @unique_queries = $self->_unique_queries($input_query, $attrs);
369 # Build the final query: Default to the disjunction of the unique queries,
370 # but allow the input query in case the ResultSet defines the query or the
371 # user is abusing find
372 my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
373 my $query = @unique_queries
374 ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
375 : $self->_add_alias($input_query, $alias);
379 my $rs = $self->search($query, $attrs);
380 return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
383 return keys %{$self->_resolved_attrs->{collapse}}
384 ? $self->search($query)->next
385 : $self->single($query);
391 # Add the specified alias to the specified query hash. A copy is made so the
392 # original query is not modified.
395 my ($self, $query, $alias) = @_;
397 my %aliased = %$query;
398 foreach my $col (grep { ! m/\./ } keys %aliased) {
399 $aliased{"$alias.$col"} = delete $aliased{$col};
407 # Build a list of queries which satisfy unique constraints.
409 sub _unique_queries {
410 my ($self, $query, $attrs) = @_;
412 my @constraint_names = exists $attrs->{key}
414 : $self->result_source->unique_constraint_names;
416 my $where = $self->_collapse_cond($self->{attrs}{where} || {});
417 my $num_where = scalar keys %$where;
420 foreach my $name (@constraint_names) {
421 my @unique_cols = $self->result_source->unique_constraint_columns($name);
422 my $unique_query = $self->_build_unique_query($query, \@unique_cols);
424 my $num_cols = scalar @unique_cols;
425 my $num_query = scalar keys %$unique_query;
427 my $total = $num_query + $num_where;
428 if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
429 # The query is either unique on its own or is unique in combination with
430 # the existing where clause
431 push @unique_queries, $unique_query;
435 return @unique_queries;
438 # _build_unique_query
440 # Constrain the specified query hash based on the specified column names.
442 sub _build_unique_query {
443 my ($self, $query, $unique_cols) = @_;
446 map { $_ => $query->{$_} }
447 grep { exists $query->{$_} }
452 =head2 search_related
456 =item Arguments: $rel, $cond, \%attrs?
458 =item Return Value: $new_resultset
462 $new_rs = $cd_rs->search_related('artist', {
466 Searches the specified relationship, optionally specifying a condition and
467 attributes for matching records. See L</ATTRIBUTES> for more information.
472 return shift->related_resultset(shift)->search(@_);
479 =item Arguments: none
481 =item Return Value: $cursor
485 Returns a storage-driven cursor to the given resultset. See
486 L<DBIx::Class::Cursor> for more information.
493 my $attrs = { %{$self->_resolved_attrs} };
494 return $self->{cursor}
495 ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
496 $attrs->{where},$attrs);
503 =item Arguments: $cond?
505 =item Return Value: $row_object?
509 my $cd = $schema->resultset('CD')->single({ year => 2001 });
511 Inflates the first result without creating a cursor if the resultset has
512 any records in it; if not returns nothing. Used by L</find> as an optimisation.
514 Can optionally take an additional condition *only* - this is a fast-code-path
515 method; if you need to add extra joins or similar call ->search and then
516 ->single without a condition on the $rs returned from that.
521 my ($self, $where) = @_;
522 my $attrs = { %{$self->_resolved_attrs} };
524 if (defined $attrs->{where}) {
527 [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
528 $where, delete $attrs->{where} ]
531 $attrs->{where} = $where;
535 # XXX: Disabled since it doesn't infer uniqueness in all cases
536 # unless ($self->_is_unique_query($attrs->{where})) {
537 # carp "Query not guaranteed to return a single row"
538 # . "; please declare your unique constraints or use search instead";
541 my @data = $self->result_source->storage->select_single(
542 $attrs->{from}, $attrs->{select},
543 $attrs->{where}, $attrs
546 return (@data ? ($self->_construct_object(@data))[0] : undef);
551 # Try to determine if the specified query is guaranteed to be unique, based on
552 # the declared unique constraints.
554 sub _is_unique_query {
555 my ($self, $query) = @_;
557 my $collapsed = $self->_collapse_query($query);
558 my $alias = $self->{attrs}{alias};
560 foreach my $name ($self->result_source->unique_constraint_names) {
561 my @unique_cols = map {
563 } $self->result_source->unique_constraint_columns($name);
565 # Count the values for each unique column
566 my %seen = map { $_ => 0 } @unique_cols;
568 foreach my $key (keys %$collapsed) {
569 my $aliased = $key =~ /\./ ? $key : "$alias.$key";
570 next unless exists $seen{$aliased}; # Additional constraints are okay
571 $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
574 # If we get 0 or more than 1 value for a column, it's not necessarily unique
575 return 1 unless grep { $_ != 1 } values %seen;
583 # Recursively collapse the query, accumulating values for each column.
585 sub _collapse_query {
586 my ($self, $query, $collapsed) = @_;
590 if (ref $query eq 'ARRAY') {
591 foreach my $subquery (@$query) {
592 next unless ref $subquery; # -or
593 # warn "ARRAY: " . Dumper $subquery;
594 $collapsed = $self->_collapse_query($subquery, $collapsed);
597 elsif (ref $query eq 'HASH') {
598 if (keys %$query and (keys %$query)[0] eq '-and') {
599 foreach my $subquery (@{$query->{-and}}) {
600 # warn "HASH: " . Dumper $subquery;
601 $collapsed = $self->_collapse_query($subquery, $collapsed);
605 # warn "LEAF: " . Dumper $query;
606 foreach my $col (keys %$query) {
607 my $value = $query->{$col};
608 $collapsed->{$col}{$value}++;
620 =item Arguments: $cond?
622 =item Return Value: $resultsetcolumn
626 my $max_length = $rs->get_column('length')->max;
628 Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
633 my ($self, $column) = @_;
634 my $new = DBIx::Class::ResultSetColumn->new($self, $column);
642 =item Arguments: $cond, \%attrs?
644 =item Return Value: $resultset (scalar context), @row_objs (list context)
648 # WHERE title LIKE '%blue%'
649 $cd_rs = $rs->search_like({ title => '%blue%'});
651 Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
652 that this is simply a convenience method. You most likely want to use
653 L</search> with specific operators.
655 For more information, see L<DBIx::Class::Manual::Cookbook>.
661 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
662 my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
663 $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
664 return $class->search($query, { %$attrs });
671 =item Arguments: $first, $last
673 =item Return Value: $resultset (scalar context), @row_objs (list context)
677 Returns a resultset or object list representing a subset of elements from the
678 resultset slice is called on. Indexes are from 0, i.e., to get the first
681 my ($one, $two, $three) = $rs->slice(0, 2);
686 my ($self, $min, $max) = @_;
687 my $attrs = {}; # = { %{ $self->{attrs} || {} } };
688 $attrs->{offset} = $self->{attrs}{offset} || 0;
689 $attrs->{offset} += $min;
690 $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
691 return $self->search(undef(), $attrs);
692 #my $slice = (ref $self)->new($self->result_source, $attrs);
693 #return (wantarray ? $slice->all : $slice);
700 =item Arguments: none
702 =item Return Value: $result?
706 Returns the next element in the resultset (C<undef> is there is none).
708 Can be used to efficiently iterate over records in the resultset:
710 my $rs = $schema->resultset('CD')->search;
711 while (my $cd = $rs->next) {
715 Note that you need to store the resultset object, and call C<next> on it.
716 Calling C<< resultset('Table')->next >> repeatedly will always return the
717 first record from the resultset.
723 if (my $cache = $self->get_cache) {
724 $self->{all_cache_position} ||= 0;
725 return $cache->[$self->{all_cache_position}++];
727 if ($self->{attrs}{cache}) {
728 $self->{all_cache_position} = 1;
729 return ($self->all)[0];
731 if ($self->{stashed_objects}) {
732 my $obj = shift(@{$self->{stashed_objects}});
733 delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
737 exists $self->{stashed_row}
738 ? @{delete $self->{stashed_row}}
739 : $self->cursor->next
741 return undef unless (@row);
742 my ($row, @more) = $self->_construct_object(@row);
743 $self->{stashed_objects} = \@more if @more;
747 sub _construct_object {
748 my ($self, @row) = @_;
749 my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
750 my @new = $self->result_class->inflate_result($self->result_source, @$info);
751 @new = $self->{_attrs}{record_filter}->(@new)
752 if exists $self->{_attrs}{record_filter};
756 sub _collapse_result {
757 my ($self, $as_proto, $row) = @_;
761 # 'foo' => [ undef, 'foo' ]
762 # 'foo.bar' => [ 'foo', 'bar' ]
763 # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
765 my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
767 my %collapse = %{$self->{_attrs}{collapse}||{}};
771 # if we're doing collapsing (has_many prefetch) we need to grab records
772 # until the PK changes, so fill @pri_index. if not, we leave it empty so
773 # we know we don't have to bother.
775 # the reason for not using the collapse stuff directly is because if you
776 # had for e.g. two artists in a row with no cds, the collapse info for
777 # both would be NULL (undef) so you'd lose the second artist
779 # store just the index so we can check the array positions from the row
780 # without having to contruct the full hash
782 if (keys %collapse) {
783 my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
784 foreach my $i (0 .. $#construct_as) {
785 next if defined($construct_as[$i][0]); # only self table
786 if (delete $pri{$construct_as[$i][1]}) {
787 push(@pri_index, $i);
789 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
793 # no need to do an if, it'll be empty if @pri_index is empty anyway
795 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
799 do { # no need to check anything at the front, we always want the first row
803 foreach my $this_as (@construct_as) {
804 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
807 push(@const_rows, \%const);
809 } until ( # no pri_index => no collapse => drop straight out
812 do { # get another row, stash it, drop out if different PK
814 @copy = $self->cursor->next;
815 $self->{stashed_row} = \@copy;
817 # last thing in do block, counts as true if anything doesn't match
819 # check xor defined first for NULL vs. NOT NULL then if one is
820 # defined the other must be so check string equality
823 (defined $pri_vals{$_} ^ defined $copy[$_])
824 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
829 my $alias = $self->{attrs}{alias};
836 foreach my $const (@const_rows) {
837 scalar @const_keys or do {
838 @const_keys = sort { length($a) <=> length($b) } keys %$const;
840 foreach my $key (@const_keys) {
843 my @parts = split(/\./, $key);
845 my $data = $const->{$key};
846 foreach my $p (@parts) {
847 $target = $target->[1]->{$p} ||= [];
849 if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
850 # collapsing at this point and on final part
851 my $pos = $collapse_pos{$cur};
852 CK: foreach my $ck (@ckey) {
853 if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
854 $collapse_pos{$cur} = $data;
855 delete @collapse_pos{ # clear all positioning for sub-entries
856 grep { m/^\Q${cur}.\E/ } keys %collapse_pos
863 if (exists $collapse{$cur}) {
864 $target = $target->[-1];
867 $target->[0] = $data;
869 $info->[0] = $const->{$key};
881 =item Arguments: $result_source?
883 =item Return Value: $result_source
887 An accessor for the primary ResultSource object from which this ResultSet
894 =item Arguments: $result_class?
896 =item Return Value: $result_class
900 An accessor for the class to use when creating row objects. Defaults to
901 C<< result_source->result_class >> - which in most cases is the name of the
902 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
911 =item Arguments: $cond, \%attrs??
913 =item Return Value: $count
917 Performs an SQL C<COUNT> with the same query as the resultset was built
918 with to find the number of elements. If passed arguments, does a search
919 on the resultset and counts the results of that.
921 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
922 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
923 not support C<DISTINCT> with multiple columns. If you are using such a
924 database, you should only use columns from the main table in your C<group_by>
931 return $self->search(@_)->count if @_ and defined $_[0];
932 return scalar @{ $self->get_cache } if $self->get_cache;
933 my $count = $self->_count;
934 return 0 unless $count;
936 # need to take offset from resolved attrs
938 $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
939 $count = $self->{attrs}{rows} if
940 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
944 sub _count { # Separated out so pager can get the full count
946 my $select = { count => '*' };
948 my $attrs = { %{$self->_resolved_attrs} };
949 if (my $group_by = delete $attrs->{group_by}) {
950 delete $attrs->{having};
951 my @distinct = (ref $group_by ? @$group_by : ($group_by));
952 # todo: try CONCAT for multi-column pk
953 my @pk = $self->result_source->primary_columns;
955 my $alias = $attrs->{alias};
956 foreach my $column (@distinct) {
957 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
958 @distinct = ($column);
964 $select = { count => { distinct => \@distinct } };
967 $attrs->{select} = $select;
968 $attrs->{as} = [qw/count/];
970 # offset, order by and page are not needed to count. record_filter is cdbi
971 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
973 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
974 my ($count) = $tmp_rs->cursor->next;
982 =item Arguments: $sql_fragment, @bind_values
984 =item Return Value: $count
988 Counts the results in a literal query. Equivalent to calling L</search_literal>
989 with the passed arguments, then L</count>.
993 sub count_literal { shift->search_literal(@_)->count; }
999 =item Arguments: none
1001 =item Return Value: @objects
1005 Returns all elements in the resultset. Called implicitly if the resultset
1006 is returned in list context.
1012 return @{ $self->get_cache } if $self->get_cache;
1016 # TODO: don't call resolve here
1017 if (keys %{$self->_resolved_attrs->{collapse}}) {
1018 # if ($self->{attrs}{prefetch}) {
1019 # Using $self->cursor->all is really just an optimisation.
1020 # If we're collapsing has_many prefetches it probably makes
1021 # very little difference, and this is cleaner than hacking
1022 # _construct_object to survive the approach
1023 my @row = $self->cursor->next;
1025 push(@obj, $self->_construct_object(@row));
1026 @row = (exists $self->{stashed_row}
1027 ? @{delete $self->{stashed_row}}
1028 : $self->cursor->next);
1031 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
1034 $self->set_cache(\@obj) if $self->{attrs}{cache};
1042 =item Arguments: none
1044 =item Return Value: $self
1048 Resets the resultset's cursor, so you can iterate through the elements again.
1054 delete $self->{_attrs} if exists $self->{_attrs};
1055 $self->{all_cache_position} = 0;
1056 $self->cursor->reset;
1064 =item Arguments: none
1066 =item Return Value: $object?
1070 Resets the resultset and returns an object for the first result (if the
1071 resultset returns anything).
1076 return $_[0]->reset->next;
1079 # _cond_for_update_delete
1081 # update/delete require the condition to be modified to handle
1082 # the differing SQL syntax available. This transforms the $self->{cond}
1083 # appropriately, returning the new condition.
1085 sub _cond_for_update_delete {
1086 my ($self, $full_cond) = @_;
1089 $full_cond ||= $self->{cond};
1090 # No-op. No condition, we're updating/deleting everything
1091 return $cond unless ref $full_cond;
1093 if (ref $full_cond eq 'ARRAY') {
1097 foreach my $key (keys %{$_}) {
1099 $hash{$1} = $_->{$key};
1105 elsif (ref $full_cond eq 'HASH') {
1106 if ((keys %{$full_cond})[0] eq '-and') {
1109 my @cond = @{$full_cond->{-and}};
1110 for (my $i = 0; $i < @cond; $i++) {
1111 my $entry = $cond[$i];
1114 if (ref $entry eq 'HASH') {
1115 $hash = $self->_cond_for_update_delete($entry);
1118 $entry =~ /([^.]+)$/;
1119 $hash->{$1} = $cond[++$i];
1122 push @{$cond->{-and}}, $hash;
1126 foreach my $key (keys %{$full_cond}) {
1128 $cond->{$1} = $full_cond->{$key};
1133 $self->throw_exception(
1134 "Can't update/delete on resultset with condition unless hash or array"
1146 =item Arguments: \%values
1148 =item Return Value: $storage_rv
1152 Sets the specified columns in the resultset to the supplied values in a
1153 single query. Return value will be true if the update succeeded or false
1154 if no records were updated; exact type of success value is storage-dependent.
1159 my ($self, $values) = @_;
1160 $self->throw_exception("Values for update must be a hash")
1161 unless ref $values eq 'HASH';
1163 my $cond = $self->_cond_for_update_delete;
1165 return $self->result_source->storage->update(
1166 $self->result_source, $values, $cond
1174 =item Arguments: \%values
1176 =item Return Value: 1
1180 Fetches all objects and updates them one at a time. Note that C<update_all>
1181 will run DBIC cascade triggers, while L</update> will not.
1186 my ($self, $values) = @_;
1187 $self->throw_exception("Values for update must be a hash")
1188 unless ref $values eq 'HASH';
1189 foreach my $obj ($self->all) {
1190 $obj->set_columns($values)->update;
1199 =item Arguments: none
1201 =item Return Value: 1
1205 Deletes the contents of the resultset from its result source. Note that this
1206 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1207 to run. See also L<DBIx::Class::Row/delete>.
1214 my $cond = $self->_cond_for_update_delete;
1216 $self->result_source->storage->delete($self->result_source, $cond);
1224 =item Arguments: none
1226 =item Return Value: 1
1230 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1231 will run DBIC cascade triggers, while L</delete> will not.
1237 $_->delete for $self->all;
1245 =item Arguments: \@data;
1249 Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
1250 submitting to a $resultset->create(...) method.
1252 In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
1253 to insert the data, as this is a faster method.
1255 Otherwise, each set of data is inserted into the database using
1256 L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
1257 objects is returned.
1259 Example: Assuming an Artist Class that has many CDs Classes relating:
1261 my $Artist_rs = $schema->resultset("Artist");
1263 ## Void Context Example
1264 $Artist_rs->populate([
1265 { artistid => 4, name => 'Manufactured Crap', cds => [
1266 { title => 'My First CD', year => 2006 },
1267 { title => 'Yet More Tweeny-Pop crap', year => 2007 },
1270 { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
1271 { title => 'My parents sold me to a record company' ,year => 2005 },
1272 { title => 'Why Am I So Ugly?', year => 2006 },
1273 { title => 'I Got Surgery and am now Popular', year => 2007 }
1278 ## Array Context Example
1279 my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
1280 { name => "Artist One"},
1281 { name => "Artist Two"},
1282 { name => "Artist Three", cds=> [
1283 { title => "First CD", year => 2007},
1284 { title => "Second CD", year => 2008},
1288 print $ArtistOne->name; ## response is 'Artist One'
1289 print $ArtistThree->cds->count ## reponse is '2'
1294 my ($self, $data) = @_;
1296 if(defined wantarray) {
1298 foreach my $item (@$data) {
1299 push(@created, $self->create($item));
1303 my ($first, @rest) = @$data;
1305 my @names = grep {!ref $first->{$_}} keys %$first;
1306 my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
1307 my @pks = $self->result_source->primary_columns;
1309 ## do the belongs_to relationships
1310 foreach my $index (0..$#$data) {
1311 if( grep { !defined $data->[$index]->{$_} } @pks ) {
1312 my @ret = $self->populate($data);
1316 foreach my $rel (@rels) {
1317 next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
1318 my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
1319 my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
1320 my $related = $result->result_source->resolve_condition(
1321 $result->result_source->relationship_info($reverse)->{cond},
1326 delete $data->[$index]->{$rel};
1327 $data->[$index] = {%{$data->[$index]}, %$related};
1329 push @names, keys %$related if $index == 0;
1333 ## do bulk insert on current row
1334 my @values = map { [ @$_{@names} ] } @$data;
1336 $self->result_source->storage->insert_bulk(
1337 $self->result_source,
1342 ## do the has_many relationships
1343 foreach my $item (@$data) {
1345 foreach my $rel (@rels) {
1346 next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
1348 my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
1349 || $self->throw_exception('Cannot find the relating object.');
1351 my $child = $parent->$rel;
1353 my $related = $child->result_source->resolve_condition(
1354 $parent->result_source->relationship_info($rel)->{cond},
1359 my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
1360 my @populate = map { {%$_, %$related} } @rows_to_add;
1362 $child->populate( \@populate );
1372 =item Arguments: none
1374 =item Return Value: $pager
1378 Return Value a L<Data::Page> object for the current resultset. Only makes
1379 sense for queries with a C<page> attribute.
1385 my $attrs = $self->{attrs};
1386 $self->throw_exception("Can't create pager for non-paged rs")
1387 unless $self->{attrs}{page};
1388 $attrs->{rows} ||= 10;
1389 return $self->{pager} ||= Data::Page->new(
1390 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1397 =item Arguments: $page_number
1399 =item Return Value: $rs
1403 Returns a resultset for the $page_number page of the resultset on which page
1404 is called, where each page contains a number of rows equal to the 'rows'
1405 attribute set on the resultset (10 by default).
1410 my ($self, $page) = @_;
1411 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1418 =item Arguments: \%vals
1420 =item Return Value: $object
1424 Creates an object in the resultset's result class and returns it.
1429 my ($self, $values) = @_;
1430 $self->throw_exception( "new_result needs a hash" )
1431 unless (ref $values eq 'HASH');
1432 $self->throw_exception(
1433 "Can't abstract implicit construct, condition not a hash"
1434 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1436 my $alias = $self->{attrs}{alias};
1437 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1439 %{ $self->_remove_alias($values, $alias) },
1440 %{ $self->_remove_alias($collapsed_cond, $alias) },
1441 -source_handle => $self->_source_handle,
1442 -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
1445 return $self->result_class->new(\%new);
1450 # Recursively collapse the condition.
1452 sub _collapse_cond {
1453 my ($self, $cond, $collapsed) = @_;
1457 if (ref $cond eq 'ARRAY') {
1458 foreach my $subcond (@$cond) {
1459 next unless ref $subcond; # -or
1460 # warn "ARRAY: " . Dumper $subcond;
1461 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1464 elsif (ref $cond eq 'HASH') {
1465 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1466 foreach my $subcond (@{$cond->{-and}}) {
1467 # warn "HASH: " . Dumper $subcond;
1468 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1472 # warn "LEAF: " . Dumper $cond;
1473 foreach my $col (keys %$cond) {
1474 my $value = $cond->{$col};
1475 $collapsed->{$col} = $value;
1485 # Remove the specified alias from the specified query hash. A copy is made so
1486 # the original query is not modified.
1489 my ($self, $query, $alias) = @_;
1491 my %orig = %{ $query || {} };
1494 foreach my $key (keys %orig) {
1496 $unaliased{$key} = $orig{$key};
1499 $unaliased{$1} = $orig{$key}
1500 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1510 =item Arguments: \%vals, \%attrs?
1512 =item Return Value: $object
1516 Find an existing record from this resultset. If none exists, instantiate a new
1517 result object and return it. The object will not be saved into your storage
1518 until you call L<DBIx::Class::Row/insert> on it.
1520 If you want objects to be saved immediately, use L</find_or_create> instead.
1526 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1527 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1528 my $exists = $self->find($hash, $attrs);
1529 return defined $exists ? $exists : $self->new_result($hash);
1536 =item Arguments: \%vals
1538 =item Return Value: $object
1542 Inserts a record into the resultset and returns the object representing it.
1544 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1549 my ($self, $attrs) = @_;
1550 $self->throw_exception( "create needs a hashref" )
1551 unless ref $attrs eq 'HASH';
1552 return $self->new_result($attrs)->insert;
1555 =head2 find_or_create
1559 =item Arguments: \%vals, \%attrs?
1561 =item Return Value: $object
1565 $class->find_or_create({ key => $val, ... });
1567 Tries to find a record based on its primary key or unique constraint; if none
1568 is found, creates one and returns that instead.
1570 my $cd = $schema->resultset('CD')->find_or_create({
1572 artist => 'Massive Attack',
1573 title => 'Mezzanine',
1577 Also takes an optional C<key> attribute, to search by a specific key or unique
1578 constraint. For example:
1580 my $cd = $schema->resultset('CD')->find_or_create(
1582 artist => 'Massive Attack',
1583 title => 'Mezzanine',
1585 { key => 'cd_artist_title' }
1588 See also L</find> and L</update_or_create>. For information on how to declare
1589 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1593 sub find_or_create {
1595 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1596 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1597 my $exists = $self->find($hash, $attrs);
1598 return defined $exists ? $exists : $self->create($hash);
1601 =head2 update_or_create
1605 =item Arguments: \%col_values, { key => $unique_constraint }?
1607 =item Return Value: $object
1611 $class->update_or_create({ col => $val, ... });
1613 First, searches for an existing row matching one of the unique constraints
1614 (including the primary key) on the source of this resultset. If a row is
1615 found, updates it with the other given column values. Otherwise, creates a new
1618 Takes an optional C<key> attribute to search on a specific unique constraint.
1621 # In your application
1622 my $cd = $schema->resultset('CD')->update_or_create(
1624 artist => 'Massive Attack',
1625 title => 'Mezzanine',
1628 { key => 'cd_artist_title' }
1631 If no C<key> is specified, it searches on all unique constraints defined on the
1632 source, including the primary key.
1634 If the C<key> is specified as C<primary>, it searches only on the primary key.
1636 See also L</find> and L</find_or_create>. For information on how to declare
1637 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1641 sub update_or_create {
1643 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1644 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1646 my $row = $self->find($cond, $attrs);
1648 $row->update($cond);
1652 return $self->create($cond);
1659 =item Arguments: none
1661 =item Return Value: \@cache_objects?
1665 Gets the contents of the cache for the resultset, if the cache is set.
1677 =item Arguments: \@cache_objects
1679 =item Return Value: \@cache_objects
1683 Sets the contents of the cache for the resultset. Expects an arrayref
1684 of objects of the same class as those produced by the resultset. Note that
1685 if the cache is set the resultset will return the cached objects rather
1686 than re-querying the database even if the cache attr is not set.
1691 my ( $self, $data ) = @_;
1692 $self->throw_exception("set_cache requires an arrayref")
1693 if defined($data) && (ref $data ne 'ARRAY');
1694 $self->{all_cache} = $data;
1701 =item Arguments: none
1703 =item Return Value: []
1707 Clears the cache for the resultset.
1712 shift->set_cache(undef);
1715 =head2 related_resultset
1719 =item Arguments: $relationship_name
1721 =item Return Value: $resultset
1725 Returns a related resultset for the supplied relationship name.
1727 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1731 sub related_resultset {
1732 my ($self, $rel) = @_;
1734 $self->{related_resultsets} ||= {};
1735 return $self->{related_resultsets}{$rel} ||= do {
1736 my $rel_obj = $self->result_source->relationship_info($rel);
1738 $self->throw_exception(
1739 "search_related: result source '" . $self->_source_handle->source_moniker .
1740 "' has no such relationship $rel")
1743 my ($from,$seen) = $self->_resolve_from($rel);
1745 my $join_count = $seen->{$rel};
1746 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1748 #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
1749 my %attrs = %{$self->{attrs}||{}};
1750 delete $attrs{result_class};
1754 if (my $cache = $self->get_cache) {
1755 if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
1756 $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
1761 my $new = $self->_source_handle
1763 ->resultset($rel_obj->{class})
1772 where => $self->{cond},
1776 $new->set_cache($new_cache) if $new_cache;
1782 my ($self, $extra_join) = @_;
1783 my $source = $self->result_source;
1784 my $attrs = $self->{attrs};
1786 my $from = $attrs->{from}
1787 || [ { $attrs->{alias} => $source->from } ];
1789 my $seen = { %{$attrs->{seen_join}||{}} };
1791 my $join = ($attrs->{join}
1792 ? [ $attrs->{join}, $extra_join ]
1795 # we need to take the prefetch the attrs into account before we
1796 # ->resolve_join as otherwise they get lost - captainL
1797 my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
1801 ($join ? $source->resolve_join($merged, $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}
1865 $attrs->{from} = # have to copy here to avoid corrupting the original
1868 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1873 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1874 if ($attrs->{order_by}) {
1875 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1876 ? [ @{$attrs->{order_by}} ]
1877 : [ $attrs->{order_by} ]);
1879 $attrs->{order_by} = [];
1882 my $collapse = $attrs->{collapse} || {};
1883 if (my $prefetch = delete $attrs->{prefetch}) {
1884 $prefetch = $self->_merge_attr({}, $prefetch);
1886 my $seen = $attrs->{seen_join} || {};
1887 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1888 # bring joins back to level of current class
1889 my @prefetch = $source->resolve_prefetch(
1890 $p, $alias, $seen, \@pre_order, $collapse
1892 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1893 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1895 push(@{$attrs->{order_by}}, @pre_order);
1897 $attrs->{collapse} = $collapse;
1899 if ($attrs->{page}) {
1900 $attrs->{offset} ||= 0;
1901 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
1904 return $self->{_attrs} = $attrs;
1908 my ($self, $attr) = @_;
1910 if (ref $attr eq 'HASH') {
1911 return $self->_rollout_hash($attr);
1912 } elsif (ref $attr eq 'ARRAY') {
1913 return $self->_rollout_array($attr);
1919 sub _rollout_array {
1920 my ($self, $attr) = @_;
1923 foreach my $element (@{$attr}) {
1924 if (ref $element eq 'HASH') {
1925 push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
1926 } elsif (ref $element eq 'ARRAY') {
1927 # XXX - should probably recurse here
1928 push( @rolled_array, @{$self->_rollout_array($element)} );
1930 push( @rolled_array, $element );
1933 return \@rolled_array;
1937 my ($self, $attr) = @_;
1940 foreach my $key (keys %{$attr}) {
1941 push( @rolled_array, { $key => $attr->{$key} } );
1943 return \@rolled_array;
1946 sub _calculate_score {
1947 my ($self, $a, $b) = @_;
1949 if (ref $b eq 'HASH') {
1950 my ($b_key) = keys %{$b};
1951 if (ref $a eq 'HASH') {
1952 my ($a_key) = keys %{$a};
1953 if ($a_key eq $b_key) {
1954 return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
1959 return ($a eq $b_key) ? 1 : 0;
1962 if (ref $a eq 'HASH') {
1963 my ($a_key) = keys %{$a};
1964 return ($b eq $a_key) ? 1 : 0;
1966 return ($b eq $a) ? 1 : 0;
1972 my ($self, $a, $b) = @_;
1974 return $b unless defined($a);
1975 return $a unless defined($b);
1977 $a = $self->_rollout_attr($a);
1978 $b = $self->_rollout_attr($b);
1981 foreach my $b_element ( @{$b} ) {
1982 # find best candidate from $a to merge $b_element into
1983 my $best_candidate = { position => undef, score => 0 }; my $position = 0;
1984 foreach my $a_element ( @{$a} ) {
1985 my $score = $self->_calculate_score( $a_element, $b_element );
1986 if ($score > $best_candidate->{score}) {
1987 $best_candidate->{position} = $position;
1988 $best_candidate->{score} = $score;
1992 my ($b_key) = ( ref $b_element eq 'HASH' ) ? keys %{$b_element} : ($b_element);
1993 if ($best_candidate->{score} == 0 || exists $seen_keys->{$b_key}) {
1994 push( @{$a}, $b_element );
1996 $seen_keys->{$b_key} = 1; # don't merge the same key twice
1997 my $a_best = $a->[$best_candidate->{position}];
1998 # merge a_best and b_element together and replace original with merged
1999 if (ref $a_best ne 'HASH') {
2000 $a->[$best_candidate->{position}] = $b_element;
2001 } elsif (ref $b_element eq 'HASH') {
2002 my ($key) = keys %{$a_best};
2003 $a->[$best_candidate->{position}] = { $key => $self->_merge_attr($a_best->{$key}, $b_element->{$key}) };
2015 $self->_source_handle($_[0]->handle);
2017 $self->_source_handle->resolve;
2021 =head2 throw_exception
2023 See L<DBIx::Class::Schema/throw_exception> for details.
2027 sub throw_exception {
2029 $self->_source_handle->schema->throw_exception(@_);
2032 # XXX: FIXME: Attributes docs need clearing up
2036 The resultset takes various attributes that modify its behavior. Here's an
2043 =item Value: ($order_by | \@order_by)
2047 Which column(s) to order the results by. This is currently passed
2048 through directly to SQL, so you can give e.g. C<year DESC> for a
2049 descending order on the column `year'.
2051 Please note that if you have C<quote_char> enabled (see
2052 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
2053 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
2054 so you will need to manually quote things as appropriate.)
2060 =item Value: \@columns
2064 Shortcut to request a particular set of columns to be retrieved. Adds
2065 C<me.> onto the start of any column without a C<.> in it and sets C<select>
2066 from that, then auto-populates C<as> from C<select> as normal. (You may also
2067 use the C<cols> attribute, as in earlier versions of DBIC.)
2069 =head2 include_columns
2073 =item Value: \@columns
2077 Shortcut to include additional columns in the returned results - for example
2079 $schema->resultset('CD')->search(undef, {
2080 include_columns => ['artist.name'],
2084 would return all CDs and include a 'name' column to the information
2085 passed to object inflation. Note that the 'artist' is the name of the
2086 column (or relationship) accessor, and 'name' is the name of the column
2087 accessor in the related table.
2093 =item Value: \@select_columns
2097 Indicates which columns should be selected from the storage. You can use
2098 column names, or in the case of RDBMS back ends, function or stored procedure
2101 $rs = $schema->resultset('Employee')->search(undef, {
2104 { count => 'employeeid' },
2109 When you use function/stored procedure names and do not supply an C<as>
2110 attribute, the column names returned are storage-dependent. E.g. MySQL would
2111 return a column named C<count(employeeid)> in the above example.
2117 Indicates additional columns to be selected from storage. Works the same as
2118 L<select> but adds columns to the selection.
2126 Indicates additional column names for those added via L<+select>.
2134 =item Value: \@inflation_names
2138 Indicates column names for object inflation. That is, c< as >
2139 indicates the name that the column can be accessed as via the
2140 C<get_column> method (or via the object accessor, B<if one already
2141 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
2144 The C< as > attribute is used in conjunction with C<select>,
2145 usually when C<select> contains one or more function or stored
2148 $rs = $schema->resultset('Employee')->search(undef, {
2151 { count => 'employeeid' }
2153 as => ['name', 'employee_count'],
2156 my $employee = $rs->first(); # get the first Employee
2158 If the object against which the search is performed already has an accessor
2159 matching a column name specified in C<as>, the value can be retrieved using
2160 the accessor as normal:
2162 my $name = $employee->name();
2164 If on the other hand an accessor does not exist in the object, you need to
2165 use C<get_column> instead:
2167 my $employee_count = $employee->get_column('employee_count');
2169 You can create your own accessors if required - see
2170 L<DBIx::Class::Manual::Cookbook> for details.
2172 Please note: This will NOT insert an C<AS employee_count> into the SQL
2173 statement produced, it is used for internal access only. Thus
2174 attempting to use the accessor in an C<order_by> clause or similar
2175 will fail miserably.
2177 To get around this limitation, you can supply literal SQL to your
2178 C<select> attibute that contains the C<AS alias> text, eg:
2180 select => [\'myfield AS alias']
2186 =item Value: ($rel_name | \@rel_names | \%rel_names)
2190 Contains a list of relationships that should be joined for this query. For
2193 # Get CDs by Nine Inch Nails
2194 my $rs = $schema->resultset('CD')->search(
2195 { 'artist.name' => 'Nine Inch Nails' },
2196 { join => 'artist' }
2199 Can also contain a hash reference to refer to the other relation's relations.
2202 package MyApp::Schema::Track;
2203 use base qw/DBIx::Class/;
2204 __PACKAGE__->table('track');
2205 __PACKAGE__->add_columns(qw/trackid cd position title/);
2206 __PACKAGE__->set_primary_key('trackid');
2207 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
2210 # In your application
2211 my $rs = $schema->resultset('Artist')->search(
2212 { 'track.title' => 'Teardrop' },
2214 join => { cd => 'track' },
2215 order_by => 'artist.name',
2219 You need to use the relationship (not the table) name in conditions,
2220 because they are aliased as such. The current table is aliased as "me", so
2221 you need to use me.column_name in order to avoid ambiguity. For example:
2223 # Get CDs from 1984 with a 'Foo' track
2224 my $rs = $schema->resultset('CD')->search(
2227 'tracks.name' => 'Foo'
2229 { join => 'tracks' }
2232 If the same join is supplied twice, it will be aliased to <rel>_2 (and
2233 similarly for a third time). For e.g.
2235 my $rs = $schema->resultset('Artist')->search({
2236 'cds.title' => 'Down to Earth',
2237 'cds_2.title' => 'Popular',
2239 join => [ qw/cds cds/ ],
2242 will return a set of all artists that have both a cd with title 'Down
2243 to Earth' and a cd with title 'Popular'.
2245 If you want to fetch related objects from other tables as well, see C<prefetch>
2252 =item Value: ($rel_name | \@rel_names | \%rel_names)
2256 Contains one or more relationships that should be fetched along with the main
2257 query (when they are accessed afterwards they will have already been
2258 "prefetched"). This is useful for when you know you will need the related
2259 objects, because it saves at least one query:
2261 my $rs = $schema->resultset('Tag')->search(
2270 The initial search results in SQL like the following:
2272 SELECT tag.*, cd.*, artist.* FROM tag
2273 JOIN cd ON tag.cd = cd.cdid
2274 JOIN artist ON cd.artist = artist.artistid
2276 L<DBIx::Class> has no need to go back to the database when we access the
2277 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2280 Simple prefetches will be joined automatically, so there is no need
2281 for a C<join> attribute in the above search. If you're prefetching to
2282 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2283 specify the join as well.
2285 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2286 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2287 with an accessor type of 'single' or 'filter').
2297 Makes the resultset paged and specifies the page to retrieve. Effectively
2298 identical to creating a non-pages resultset and then calling ->page($page)
2301 If L<rows> attribute is not specified it defualts to 10 rows per page.
2311 Specifes the maximum number of rows for direct retrieval or the number of
2312 rows per page if the page attribute or method is used.
2318 =item Value: $offset
2322 Specifies the (zero-based) row number for the first row to be returned, or the
2323 of the first row of the first page if paging is used.
2329 =item Value: \@columns
2333 A arrayref of columns to group by. Can include columns of joined tables.
2335 group_by => [qw/ column1 column2 ... /]
2341 =item Value: $condition
2345 HAVING is a select statement attribute that is applied between GROUP BY and
2346 ORDER BY. It is applied to the after the grouping calculations have been
2349 having => { 'count(employee)' => { '>=', 100 } }
2355 =item Value: (0 | 1)
2359 Set to 1 to group by all columns.
2365 Adds to the WHERE clause.
2367 # only return rows WHERE deleted IS NULL for all searches
2368 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2370 Can be overridden by passing C<{ where => undef }> as an attribute
2377 Set to 1 to cache search results. This prevents extra SQL queries if you
2378 revisit rows in your ResultSet:
2380 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2382 while( my $artist = $resultset->next ) {
2386 $rs->first; # without cache, this would issue a query
2388 By default, searches are not cached.
2390 For more examples of using these attributes, see
2391 L<DBIx::Class::Manual::Cookbook>.
2397 =item Value: \@from_clause
2401 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2402 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2405 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2407 C<join> will usually do what you need and it is strongly recommended that you
2408 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2409 And we really do mean "cannot", not just tried and failed. Attempting to use
2410 this because you're having problems with C<join> is like trying to use x86
2411 ASM because you've got a syntax error in your C. Trust us on this.
2413 Now, if you're still really, really sure you need to use this (and if you're
2414 not 100% sure, ask the mailing list first), here's an explanation of how this
2417 The syntax is as follows -
2420 { <alias1> => <table1> },
2422 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2423 [], # nested JOIN (optional)
2424 { <table1.column1> => <table2.column2>, ... (more conditions) },
2426 # More of the above [ ] may follow for additional joins
2433 ON <table1.column1> = <table2.column2>
2434 <more joins may follow>
2436 An easy way to follow the examples below is to remember the following:
2438 Anything inside "[]" is a JOIN
2439 Anything inside "{}" is a condition for the enclosing JOIN
2441 The following examples utilize a "person" table in a family tree application.
2442 In order to express parent->child relationships, this table is self-joined:
2444 # Person->belongs_to('father' => 'Person');
2445 # Person->belongs_to('mother' => 'Person');
2447 C<from> can be used to nest joins. Here we return all children with a father,
2448 then search against all mothers of those children:
2450 $rs = $schema->resultset('Person')->search(
2453 alias => 'mother', # alias columns in accordance with "from"
2455 { mother => 'person' },
2458 { child => 'person' },
2460 { father => 'person' },
2461 { 'father.person_id' => 'child.father_id' }
2464 { 'mother.person_id' => 'child.mother_id' }
2471 # SELECT mother.* FROM person mother
2474 # JOIN person father
2475 # ON ( father.person_id = child.father_id )
2477 # ON ( mother.person_id = child.mother_id )
2479 The type of any join can be controlled manually. To search against only people
2480 with a father in the person table, we could explicitly use C<INNER JOIN>:
2482 $rs = $schema->resultset('Person')->search(
2485 alias => 'child', # alias columns in accordance with "from"
2487 { child => 'person' },
2489 { father => 'person', -join_type => 'inner' },
2490 { 'father.id' => 'child.father_id' }
2497 # SELECT child.* FROM person child
2498 # INNER JOIN person father ON child.father_id = father.id