1 package DBIx::Class::ResultSet;
9 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::ResultSetColumn;
13 use DBIx::Class::ResultSourceHandle;
14 use base qw/DBIx::Class/;
16 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
20 DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
24 my $rs = $schema->resultset('User')->search(registered => 1);
25 my @rows = $schema->resultset('CD')->search(year => 2005);
29 The resultset is also known as an iterator. It is responsible for handling
30 queries that may return an arbitrary number of rows, e.g. via L</search>
31 or a C<has_many> relationship.
33 In the examples below, the following table classes are used:
35 package MyApp::Schema::Artist;
36 use base qw/DBIx::Class/;
37 __PACKAGE__->load_components(qw/Core/);
38 __PACKAGE__->table('artist');
39 __PACKAGE__->add_columns(qw/artistid name/);
40 __PACKAGE__->set_primary_key('artistid');
41 __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
44 package MyApp::Schema::CD;
45 use base qw/DBIx::Class/;
46 __PACKAGE__->load_components(qw/Core/);
47 __PACKAGE__->table('cd');
48 __PACKAGE__->add_columns(qw/cdid artist title year/);
49 __PACKAGE__->set_primary_key('cdid');
50 __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
59 =item Arguments: $source, \%$attrs
61 =item Return Value: $rs
65 The resultset constructor. Takes a source object (usually a
66 L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
67 L</ATTRIBUTES> below). Does not perform any queries -- these are
68 executed as needed by the other methods.
70 Generally you won't need to construct a resultset manually. You'll
71 automatically get one from e.g. a L</search> called in scalar context:
73 my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
75 IMPORTANT: If called on an object, proxies to new_result instead so
77 my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
79 will return a CD object, not a ResultSet.
85 return $class->new_result(@_) if ref $class;
87 my ($source, $attrs) = @_;
88 $source = $source->handle
89 unless $source->isa('DBIx::Class::ResultSourceHandle');
90 $attrs = { %{$attrs||{}} };
93 $attrs->{rows} ||= 10;
94 $attrs->{offset} ||= 0;
95 $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
98 $attrs->{alias} ||= 'me';
101 result_source => $source,
102 result_class => $attrs->{result_class} || $source->result_class,
103 cond => $attrs->{where},
118 =item Arguments: $cond, \%attrs?
120 =item Return Value: $resultset (scalar context), @row_objs (list context)
124 my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
125 my $new_rs = $cd_rs->search({ year => 2005 });
127 my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
128 # year = 2005 OR year = 2004
130 If you need to pass in additional attributes but no additional condition,
131 call it as C<search(undef, \%attrs)>.
133 # "SELECT name, artistid FROM $artist_table"
134 my @all_artists = $schema->resultset('Artist')->search(undef, {
135 columns => [qw/name artistid/],
138 For a list of attributes that can be passed to C<search>, see
139 L</ATTRIBUTES>. For more examples of using this function, see
140 L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
141 documentation for the first argument, see L<SQL::Abstract>.
147 my $rs = $self->search_rs( @_ );
148 return (wantarray ? $rs->all : $rs);
155 =item Arguments: $cond, \%attrs?
157 =item Return Value: $resultset
161 This method does the same exact thing as search() except it will
162 always return a resultset, even in list context.
171 unless (@_) { # no search, effectively just a clone
172 $rows = $self->get_cache;
176 $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
177 my $our_attrs = { %{$self->{attrs}} };
178 my $having = delete $our_attrs->{having};
179 my $where = delete $our_attrs->{where};
181 my $new_attrs = { %{$our_attrs}, %{$attrs} };
183 # merge new attrs into inherited
184 foreach my $key (qw/join prefetch/) {
185 next unless exists $attrs->{$key};
186 $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
191 (@_ == 1 || ref $_[0] eq "HASH")
193 (ref $_[0] eq 'HASH')
195 (keys %{ $_[0] } > 0)
203 ? $self->throw_exception("Odd number of arguments to search")
210 if (defined $where) {
211 $new_attrs->{where} = (
212 defined $new_attrs->{where}
215 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
216 } $where, $new_attrs->{where}
223 $new_attrs->{where} = (
224 defined $new_attrs->{where}
227 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
228 } $cond, $new_attrs->{where}
234 if (defined $having) {
235 $new_attrs->{having} = (
236 defined $new_attrs->{having}
239 ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
240 } $having, $new_attrs->{having}
246 my $rs = (ref $self)->new($self->result_source, $new_attrs);
248 $rs->set_cache($rows);
253 =head2 search_literal
257 =item Arguments: $sql_fragment, @bind_values
259 =item Return Value: $resultset (scalar context), @row_objs (list context)
263 my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
264 my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
266 Pass a literal chunk of SQL to be added to the conditional part of the
272 my ($self, $cond, @vals) = @_;
273 my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
274 $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
275 return $self->search(\$cond, $attrs);
282 =item Arguments: @values | \%cols, \%attrs?
284 =item Return Value: $row_object
288 Finds a row based on its primary key or unique constraint. For example, to find
289 a row by its primary key:
291 my $cd = $schema->resultset('CD')->find(5);
293 You can also find a row by a specific unique constraint using the C<key>
294 attribute. For example:
296 my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
297 key => 'cd_artist_title'
300 Additionally, you can specify the columns explicitly by name:
302 my $cd = $schema->resultset('CD')->find(
304 artist => 'Massive Attack',
305 title => 'Mezzanine',
307 { key => 'cd_artist_title' }
310 If the C<key> is specified as C<primary>, it searches only on the primary key.
312 If no C<key> is specified, it searches on all unique constraints defined on the
313 source, including the primary key.
315 If your table does not have a primary key, you B<must> provide a value for the
316 C<key> attribute matching one of the unique constraints on the source.
318 See also L</find_or_create> and L</update_or_create>. For information on how to
319 declare unique constraints, see
320 L<DBIx::Class::ResultSource/add_unique_constraint>.
326 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
328 # Default to the primary key, but allow a specific key
329 my @cols = exists $attrs->{key}
330 ? $self->result_source->unique_constraint_columns($attrs->{key})
331 : $self->result_source->primary_columns;
332 $self->throw_exception(
333 "Can't find unless a primary key is defined or unique constraint is specified"
336 # Parse out a hashref from input
338 if (ref $_[0] eq 'HASH') {
339 $input_query = { %{$_[0]} };
341 elsif (@_ == @cols) {
343 @{$input_query}{@cols} = @_;
346 # Compatibility: Allow e.g. find(id => $value)
347 carp "Find by key => value deprecated; please use a hashref instead";
351 my (%related, $info);
353 foreach my $key (keys %$input_query) {
354 if (ref($input_query->{$key})
355 && ($info = $self->result_source->relationship_info($key))) {
356 my $rel_q = $self->result_source->resolve_condition(
357 $info->{cond}, delete $input_query->{$key}, $key
359 die "Can't handle OR join condition in find" if ref($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] : ());
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 : $self->cursor->next
741 return unless (@row);
742 my ($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 if (delete $pri{$construct_as[$i]}) {
786 push(@pri_index, $i);
788 last unless keys %pri; # short circuit (Johnny Five Is Alive!)
792 # no need to do an if, it'll be empty if @pri_index is empty anyway
794 my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
798 do { # no need to check anything at the front, we always want the first row
800 foreach my $this_as (@construct_as) {
801 $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
804 } until ( # no pri_index => no collapse => drop straight out
807 do { # get another row, stash it, drop out if different PK
809 @copy = $self->cursor->next;
810 $self->{stashed_row} = \@copy;
812 # last thing in do block, counts as true if anything doesn't match
814 # check xor defined first for NULL vs. NOT NULL then if one is
815 # defined the other must be so check string equality
818 (defined $pri_vals{$_} ^ defined $copy[$_])
819 || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
824 # THIS BIT STILL NEEDS TO DO THE COLLAPSE
826 my $alias = $self->{attrs}{alias};
827 my $info = [ {}, {} ];
828 foreach my $key (keys %const) {
829 if (length $key && $key ne $alias) {
831 my @parts = split(/\./, $key);
832 foreach my $p (@parts) {
833 $target = $target->[1]->{$p} ||= [];
835 $target->[0] = $const{$key};
837 $info->[0] = $const{$key};
848 =item Arguments: $result_source?
850 =item Return Value: $result_source
854 An accessor for the primary ResultSource object from which this ResultSet
861 =item Arguments: $result_class?
863 =item Return Value: $result_class
867 An accessor for the class to use when creating row objects. Defaults to
868 C<< result_source->result_class >> - which in most cases is the name of the
869 L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
878 =item Arguments: $cond, \%attrs??
880 =item Return Value: $count
884 Performs an SQL C<COUNT> with the same query as the resultset was built
885 with to find the number of elements. If passed arguments, does a search
886 on the resultset and counts the results of that.
888 Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
889 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
890 not support C<DISTINCT> with multiple columns. If you are using such a
891 database, you should only use columns from the main table in your C<group_by>
898 return $self->search(@_)->count if @_ and defined $_[0];
899 return scalar @{ $self->get_cache } if $self->get_cache;
900 my $count = $self->_count;
901 return 0 unless $count;
903 $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
904 $count = $self->{attrs}{rows} if
905 $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
909 sub _count { # Separated out so pager can get the full count
911 my $select = { count => '*' };
913 my $attrs = { %{$self->_resolved_attrs} };
914 if (my $group_by = delete $attrs->{group_by}) {
915 delete $attrs->{having};
916 my @distinct = (ref $group_by ? @$group_by : ($group_by));
917 # todo: try CONCAT for multi-column pk
918 my @pk = $self->result_source->primary_columns;
920 my $alias = $attrs->{alias};
921 foreach my $column (@distinct) {
922 if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
923 @distinct = ($column);
929 $select = { count => { distinct => \@distinct } };
932 $attrs->{select} = $select;
933 $attrs->{as} = [qw/count/];
935 # offset, order by and page are not needed to count. record_filter is cdbi
936 delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
938 my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
939 my ($count) = $tmp_rs->cursor->next;
947 =item Arguments: $sql_fragment, @bind_values
949 =item Return Value: $count
953 Counts the results in a literal query. Equivalent to calling L</search_literal>
954 with the passed arguments, then L</count>.
958 sub count_literal { shift->search_literal(@_)->count; }
964 =item Arguments: none
966 =item Return Value: @objects
970 Returns all elements in the resultset. Called implicitly if the resultset
971 is returned in list context.
977 return @{ $self->get_cache } if $self->get_cache;
981 # TODO: don't call resolve here
982 if (keys %{$self->_resolved_attrs->{collapse}}) {
983 # if ($self->{attrs}{prefetch}) {
984 # Using $self->cursor->all is really just an optimisation.
985 # If we're collapsing has_many prefetches it probably makes
986 # very little difference, and this is cleaner than hacking
987 # _construct_object to survive the approach
988 my @row = $self->cursor->next;
990 push(@obj, $self->_construct_object(@row));
991 @row = (exists $self->{stashed_row}
992 ? @{delete $self->{stashed_row}}
993 : $self->cursor->next);
996 @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
999 $self->set_cache(\@obj) if $self->{attrs}{cache};
1007 =item Arguments: none
1009 =item Return Value: $self
1013 Resets the resultset's cursor, so you can iterate through the elements again.
1019 delete $self->{_attrs} if exists $self->{_attrs};
1020 $self->{all_cache_position} = 0;
1021 $self->cursor->reset;
1029 =item Arguments: none
1031 =item Return Value: $object?
1035 Resets the resultset and returns an object for the first result (if the
1036 resultset returns anything).
1041 return $_[0]->reset->next;
1044 # _cond_for_update_delete
1046 # update/delete require the condition to be modified to handle
1047 # the differing SQL syntax available. This transforms the $self->{cond}
1048 # appropriately, returning the new condition.
1050 sub _cond_for_update_delete {
1051 my ($self, $full_cond) = @_;
1054 $full_cond ||= $self->{cond};
1055 # No-op. No condition, we're updating/deleting everything
1056 return $cond unless ref $full_cond;
1058 if (ref $full_cond eq 'ARRAY') {
1062 foreach my $key (keys %{$_}) {
1064 $hash{$1} = $_->{$key};
1070 elsif (ref $full_cond eq 'HASH') {
1071 if ((keys %{$full_cond})[0] eq '-and') {
1074 my @cond = @{$full_cond->{-and}};
1075 for (my $i = 0; $i < @cond; $i++) {
1076 my $entry = $cond[$i];
1079 if (ref $entry eq 'HASH') {
1080 $hash = $self->_cond_for_update_delete($entry);
1083 $entry =~ /([^.]+)$/;
1084 $hash->{$1} = $cond[++$i];
1087 push @{$cond->{-and}}, $hash;
1091 foreach my $key (keys %{$full_cond}) {
1093 $cond->{$1} = $full_cond->{$key};
1098 $self->throw_exception(
1099 "Can't update/delete on resultset with condition unless hash or array"
1111 =item Arguments: \%values
1113 =item Return Value: $storage_rv
1117 Sets the specified columns in the resultset to the supplied values in a
1118 single query. Return value will be true if the update succeeded or false
1119 if no records were updated; exact type of success value is storage-dependent.
1124 my ($self, $values) = @_;
1125 $self->throw_exception("Values for update must be a hash")
1126 unless ref $values eq 'HASH';
1128 my $cond = $self->_cond_for_update_delete;
1130 return $self->result_source->storage->update(
1131 $self->result_source, $values, $cond
1139 =item Arguments: \%values
1141 =item Return Value: 1
1145 Fetches all objects and updates them one at a time. Note that C<update_all>
1146 will run DBIC cascade triggers, while L</update> will not.
1151 my ($self, $values) = @_;
1152 $self->throw_exception("Values for update must be a hash")
1153 unless ref $values eq 'HASH';
1154 foreach my $obj ($self->all) {
1155 $obj->set_columns($values)->update;
1164 =item Arguments: none
1166 =item Return Value: 1
1170 Deletes the contents of the resultset from its result source. Note that this
1171 will not run DBIC cascade triggers. See L</delete_all> if you need triggers
1172 to run. See also L<DBIx::Class::Row/delete>.
1179 my $cond = $self->_cond_for_update_delete;
1181 $self->result_source->storage->delete($self->result_source, $cond);
1189 =item Arguments: none
1191 =item Return Value: 1
1195 Fetches all objects and deletes them one at a time. Note that C<delete_all>
1196 will run DBIC cascade triggers, while L</delete> will not.
1202 $_->delete for $self->all;
1210 =item Arguments: none
1212 =item Return Value: $pager
1216 Return Value a L<Data::Page> object for the current resultset. Only makes
1217 sense for queries with a C<page> attribute.
1223 my $attrs = $self->{attrs};
1224 $self->throw_exception("Can't create pager for non-paged rs")
1225 unless $self->{attrs}{page};
1226 $attrs->{rows} ||= 10;
1227 return $self->{pager} ||= Data::Page->new(
1228 $self->_count, $attrs->{rows}, $self->{attrs}{page});
1235 =item Arguments: $page_number
1237 =item Return Value: $rs
1241 Returns a resultset for the $page_number page of the resultset on which page
1242 is called, where each page contains a number of rows equal to the 'rows'
1243 attribute set on the resultset (10 by default).
1248 my ($self, $page) = @_;
1249 return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
1256 =item Arguments: \%vals
1258 =item Return Value: $object
1262 Creates an object in the resultset's result class and returns it.
1267 my ($self, $values) = @_;
1268 $self->throw_exception( "new_result needs a hash" )
1269 unless (ref $values eq 'HASH');
1270 $self->throw_exception(
1271 "Can't abstract implicit construct, condition not a hash"
1272 ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
1274 my $alias = $self->{attrs}{alias};
1275 my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
1277 %{ $self->_remove_alias($values, $alias) },
1278 %{ $self->_remove_alias($collapsed_cond, $alias) },
1279 -source_handle => $self->_source_handle
1282 return $self->result_class->new(\%new);
1287 # Recursively collapse the condition.
1289 sub _collapse_cond {
1290 my ($self, $cond, $collapsed) = @_;
1294 if (ref $cond eq 'ARRAY') {
1295 foreach my $subcond (@$cond) {
1296 next unless ref $subcond; # -or
1297 # warn "ARRAY: " . Dumper $subcond;
1298 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1301 elsif (ref $cond eq 'HASH') {
1302 if (keys %$cond and (keys %$cond)[0] eq '-and') {
1303 foreach my $subcond (@{$cond->{-and}}) {
1304 # warn "HASH: " . Dumper $subcond;
1305 $collapsed = $self->_collapse_cond($subcond, $collapsed);
1309 # warn "LEAF: " . Dumper $cond;
1310 foreach my $col (keys %$cond) {
1311 my $value = $cond->{$col};
1312 $collapsed->{$col} = $value;
1322 # Remove the specified alias from the specified query hash. A copy is made so
1323 # the original query is not modified.
1326 my ($self, $query, $alias) = @_;
1328 my %orig = %{ $query || {} };
1331 foreach my $key (keys %orig) {
1333 $unaliased{$key} = $orig{$key};
1336 $unaliased{$1} = $orig{$key}
1337 if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
1347 =item Arguments: \%vals, \%attrs?
1349 =item Return Value: $object
1353 Find an existing record from this resultset. If none exists, instantiate a new
1354 result object and return it. The object will not be saved into your storage
1355 until you call L<DBIx::Class::Row/insert> on it.
1357 If you want objects to be saved immediately, use L</find_or_create> instead.
1363 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1364 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1365 my $exists = $self->find($hash, $attrs);
1366 return defined $exists ? $exists : $self->new_result($hash);
1373 =item Arguments: \%vals
1375 =item Return Value: $object
1379 Inserts a record into the resultset and returns the object representing it.
1381 Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
1386 my ($self, $attrs) = @_;
1387 $self->throw_exception( "create needs a hashref" )
1388 unless ref $attrs eq 'HASH';
1389 return $self->new_result($attrs)->insert;
1392 =head2 find_or_create
1396 =item Arguments: \%vals, \%attrs?
1398 =item Return Value: $object
1402 $class->find_or_create({ key => $val, ... });
1404 Tries to find a record based on its primary key or unique constraint; if none
1405 is found, creates one and returns that instead.
1407 my $cd = $schema->resultset('CD')->find_or_create({
1409 artist => 'Massive Attack',
1410 title => 'Mezzanine',
1414 Also takes an optional C<key> attribute, to search by a specific key or unique
1415 constraint. For example:
1417 my $cd = $schema->resultset('CD')->find_or_create(
1419 artist => 'Massive Attack',
1420 title => 'Mezzanine',
1422 { key => 'cd_artist_title' }
1425 See also L</find> and L</update_or_create>. For information on how to declare
1426 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1430 sub find_or_create {
1432 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1433 my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
1434 my $exists = $self->find($hash, $attrs);
1435 return defined $exists ? $exists : $self->create($hash);
1438 =head2 update_or_create
1442 =item Arguments: \%col_values, { key => $unique_constraint }?
1444 =item Return Value: $object
1448 $class->update_or_create({ col => $val, ... });
1450 First, searches for an existing row matching one of the unique constraints
1451 (including the primary key) on the source of this resultset. If a row is
1452 found, updates it with the other given column values. Otherwise, creates a new
1455 Takes an optional C<key> attribute to search on a specific unique constraint.
1458 # In your application
1459 my $cd = $schema->resultset('CD')->update_or_create(
1461 artist => 'Massive Attack',
1462 title => 'Mezzanine',
1465 { key => 'cd_artist_title' }
1468 If no C<key> is specified, it searches on all unique constraints defined on the
1469 source, including the primary key.
1471 If the C<key> is specified as C<primary>, it searches only on the primary key.
1473 See also L</find> and L</find_or_create>. For information on how to declare
1474 unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
1478 sub update_or_create {
1480 my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
1481 my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
1483 my $row = $self->find($cond, $attrs);
1485 $row->update($cond);
1489 return $self->create($cond);
1496 =item Arguments: none
1498 =item Return Value: \@cache_objects?
1502 Gets the contents of the cache for the resultset, if the cache is set.
1514 =item Arguments: \@cache_objects
1516 =item Return Value: \@cache_objects
1520 Sets the contents of the cache for the resultset. Expects an arrayref
1521 of objects of the same class as those produced by the resultset. Note that
1522 if the cache is set the resultset will return the cached objects rather
1523 than re-querying the database even if the cache attr is not set.
1528 my ( $self, $data ) = @_;
1529 $self->throw_exception("set_cache requires an arrayref")
1530 if defined($data) && (ref $data ne 'ARRAY');
1531 $self->{all_cache} = $data;
1538 =item Arguments: none
1540 =item Return Value: []
1544 Clears the cache for the resultset.
1549 shift->set_cache(undef);
1552 =head2 related_resultset
1556 =item Arguments: $relationship_name
1558 =item Return Value: $resultset
1562 Returns a related resultset for the supplied relationship name.
1564 $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
1568 sub related_resultset {
1569 my ($self, $rel) = @_;
1571 $self->{related_resultsets} ||= {};
1572 return $self->{related_resultsets}{$rel} ||= do {
1573 my $rel_obj = $self->result_source->relationship_info($rel);
1575 $self->throw_exception(
1576 "search_related: result source '" . $self->_source_handle->source_moniker .
1577 "' has no such relationship $rel")
1580 my ($from,$seen) = $self->_resolve_from($rel);
1582 my $join_count = $seen->{$rel};
1583 my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
1585 $self->_source_handle->schema->resultset($rel_obj->{class})->search_rs(
1587 %{$self->{attrs}||{}},
1593 where => $self->{cond},
1601 my ($self, $extra_join) = @_;
1602 my $source = $self->result_source;
1603 my $attrs = $self->{attrs};
1605 my $from = $attrs->{from}
1606 || [ { $attrs->{alias} => $source->from } ];
1608 my $seen = { %{$attrs->{seen_join}||{}} };
1610 my $join = ($attrs->{join}
1611 ? [ $attrs->{join}, $extra_join ]
1615 ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
1618 return ($from,$seen);
1621 sub _resolved_attrs {
1623 return $self->{_attrs} if $self->{_attrs};
1625 my $attrs = { %{$self->{attrs}||{}} };
1626 my $source = $self->result_source;
1627 my $alias = $attrs->{alias};
1629 $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
1630 if ($attrs->{columns}) {
1631 delete $attrs->{as};
1632 } elsif (!$attrs->{select}) {
1633 $attrs->{columns} = [ $source->columns ];
1638 ? (ref $attrs->{select} eq 'ARRAY'
1639 ? [ @{$attrs->{select}} ]
1640 : [ $attrs->{select} ])
1641 : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
1645 ? (ref $attrs->{as} eq 'ARRAY'
1646 ? [ @{$attrs->{as}} ]
1648 : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
1652 if ($adds = delete $attrs->{include_columns}) {
1653 $adds = [$adds] unless ref $adds eq 'ARRAY';
1654 push(@{$attrs->{select}}, @$adds);
1655 push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
1657 if ($adds = delete $attrs->{'+select'}) {
1658 $adds = [$adds] unless ref $adds eq 'ARRAY';
1659 push(@{$attrs->{select}},
1660 map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
1662 if (my $adds = delete $attrs->{'+as'}) {
1663 $adds = [$adds] unless ref $adds eq 'ARRAY';
1664 push(@{$attrs->{as}}, @$adds);
1667 $attrs->{from} ||= [ { 'me' => $source->from } ];
1669 if (exists $attrs->{join} || exists $attrs->{prefetch}) {
1670 my $join = delete $attrs->{join} || {};
1672 if (defined $attrs->{prefetch}) {
1673 $join = $self->_merge_attr(
1674 $join, $attrs->{prefetch}
1678 $attrs->{from} = # have to copy here to avoid corrupting the original
1681 $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
1685 $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
1686 if ($attrs->{order_by}) {
1687 $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
1688 ? [ @{$attrs->{order_by}} ]
1689 : [ $attrs->{order_by} ]);
1691 $attrs->{order_by} = [];
1694 my $collapse = $attrs->{collapse} || {};
1695 if (my $prefetch = delete $attrs->{prefetch}) {
1696 $prefetch = $self->_merge_attr({}, $prefetch);
1698 my $seen = $attrs->{seen_join} || {};
1699 foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
1700 # bring joins back to level of current class
1701 my @prefetch = $source->resolve_prefetch(
1702 $p, $alias, $seen, \@pre_order, $collapse
1704 push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
1705 push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
1707 push(@{$attrs->{order_by}}, @pre_order);
1709 $attrs->{collapse} = $collapse;
1711 return $self->{_attrs} = $attrs;
1715 my ($self, $a, $b) = @_;
1716 return $b unless defined($a);
1717 return $a unless defined($b);
1719 if (ref $b eq 'HASH' && ref $a eq 'HASH') {
1720 foreach my $key (keys %{$b}) {
1721 if (exists $a->{$key}) {
1722 $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
1724 $a->{$key} = $b->{$key};
1729 $a = [$a] unless ref $a eq 'ARRAY';
1730 $b = [$b] unless ref $b eq 'ARRAY';
1734 foreach my $x ($a, $b) {
1735 foreach my $element (@{$x}) {
1736 if (ref $element eq 'HASH') {
1737 $hash = $self->_merge_attr($hash, $element);
1738 } elsif (ref $element eq 'ARRAY') {
1739 push(@array, @{$element});
1741 push(@array, $element) unless $b == $x
1742 && grep { $_ eq $element } @array;
1747 @array = grep { !exists $hash->{$_} } @array;
1749 return keys %{$hash}
1762 $self->_source_handle($_[0]->handle);
1764 $self->_source_handle->resolve;
1768 =head2 throw_exception
1770 See L<DBIx::Class::Schema/throw_exception> for details.
1774 sub throw_exception {
1776 $self->_source_handle->schema->throw_exception(@_);
1779 # XXX: FIXME: Attributes docs need clearing up
1783 The resultset takes various attributes that modify its behavior. Here's an
1790 =item Value: ($order_by | \@order_by)
1794 Which column(s) to order the results by. This is currently passed
1795 through directly to SQL, so you can give e.g. C<year DESC> for a
1796 descending order on the column `year'.
1798 Please note that if you have C<quote_char> enabled (see
1799 L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
1800 specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
1801 so you will need to manually quote things as appropriate.)
1807 =item Value: \@columns
1811 Shortcut to request a particular set of columns to be retrieved. Adds
1812 C<me.> onto the start of any column without a C<.> in it and sets C<select>
1813 from that, then auto-populates C<as> from C<select> as normal. (You may also
1814 use the C<cols> attribute, as in earlier versions of DBIC.)
1816 =head2 include_columns
1820 =item Value: \@columns
1824 Shortcut to include additional columns in the returned results - for example
1826 $schema->resultset('CD')->search(undef, {
1827 include_columns => ['artist.name'],
1831 would return all CDs and include a 'name' column to the information
1832 passed to object inflation. Note that the 'artist' is the name of the
1833 column (or relationship) accessor, and 'name' is the name of the column
1834 accessor in the related table.
1840 =item Value: \@select_columns
1844 Indicates which columns should be selected from the storage. You can use
1845 column names, or in the case of RDBMS back ends, function or stored procedure
1848 $rs = $schema->resultset('Employee')->search(undef, {
1851 { count => 'employeeid' },
1856 When you use function/stored procedure names and do not supply an C<as>
1857 attribute, the column names returned are storage-dependent. E.g. MySQL would
1858 return a column named C<count(employeeid)> in the above example.
1864 Indicates additional columns to be selected from storage. Works the same as
1865 L<select> but adds columns to the selection.
1873 Indicates additional column names for those added via L<+select>.
1881 =item Value: \@inflation_names
1885 Indicates column names for object inflation. That is, c< as >
1886 indicates the name that the column can be accessed as via the
1887 C<get_column> method (or via the object accessor, B<if one already
1888 exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
1891 The C< as > attribute is used in conjunction with C<select>,
1892 usually when C<select> contains one or more function or stored
1895 $rs = $schema->resultset('Employee')->search(undef, {
1898 { count => 'employeeid' }
1900 as => ['name', 'employee_count'],
1903 my $employee = $rs->first(); # get the first Employee
1905 If the object against which the search is performed already has an accessor
1906 matching a column name specified in C<as>, the value can be retrieved using
1907 the accessor as normal:
1909 my $name = $employee->name();
1911 If on the other hand an accessor does not exist in the object, you need to
1912 use C<get_column> instead:
1914 my $employee_count = $employee->get_column('employee_count');
1916 You can create your own accessors if required - see
1917 L<DBIx::Class::Manual::Cookbook> for details.
1919 Please note: This will NOT insert an C<AS employee_count> into the SQL
1920 statement produced, it is used for internal access only. Thus
1921 attempting to use the accessor in an C<order_by> clause or similar
1922 will fail miserably.
1924 To get around this limitation, you can supply literal SQL to your
1925 C<select> attibute that contains the C<AS alias> text, eg:
1927 select => [\'myfield AS alias']
1933 =item Value: ($rel_name | \@rel_names | \%rel_names)
1937 Contains a list of relationships that should be joined for this query. For
1940 # Get CDs by Nine Inch Nails
1941 my $rs = $schema->resultset('CD')->search(
1942 { 'artist.name' => 'Nine Inch Nails' },
1943 { join => 'artist' }
1946 Can also contain a hash reference to refer to the other relation's relations.
1949 package MyApp::Schema::Track;
1950 use base qw/DBIx::Class/;
1951 __PACKAGE__->table('track');
1952 __PACKAGE__->add_columns(qw/trackid cd position title/);
1953 __PACKAGE__->set_primary_key('trackid');
1954 __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
1957 # In your application
1958 my $rs = $schema->resultset('Artist')->search(
1959 { 'track.title' => 'Teardrop' },
1961 join => { cd => 'track' },
1962 order_by => 'artist.name',
1966 You need to use the relationship (not the table) name in conditions,
1967 because they are aliased as such. The current table is aliased as "me", so
1968 you need to use me.column_name in order to avoid ambiguity. For example:
1970 # Get CDs from 1984 with a 'Foo' track
1971 my $rs = $schema->resultset('CD')->search(
1974 'tracks.name' => 'Foo'
1976 { join => 'tracks' }
1979 If the same join is supplied twice, it will be aliased to <rel>_2 (and
1980 similarly for a third time). For e.g.
1982 my $rs = $schema->resultset('Artist')->search({
1983 'cds.title' => 'Down to Earth',
1984 'cds_2.title' => 'Popular',
1986 join => [ qw/cds cds/ ],
1989 will return a set of all artists that have both a cd with title 'Down
1990 to Earth' and a cd with title 'Popular'.
1992 If you want to fetch related objects from other tables as well, see C<prefetch>
1999 =item Value: ($rel_name | \@rel_names | \%rel_names)
2003 Contains one or more relationships that should be fetched along with the main
2004 query (when they are accessed afterwards they will have already been
2005 "prefetched"). This is useful for when you know you will need the related
2006 objects, because it saves at least one query:
2008 my $rs = $schema->resultset('Tag')->search(
2017 The initial search results in SQL like the following:
2019 SELECT tag.*, cd.*, artist.* FROM tag
2020 JOIN cd ON tag.cd = cd.cdid
2021 JOIN artist ON cd.artist = artist.artistid
2023 L<DBIx::Class> has no need to go back to the database when we access the
2024 C<cd> or C<artist> relationships, which saves us two SQL statements in this
2027 Simple prefetches will be joined automatically, so there is no need
2028 for a C<join> attribute in the above search. If you're prefetching to
2029 depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
2030 specify the join as well.
2032 C<prefetch> can be used with the following relationship types: C<belongs_to>,
2033 C<has_one> (or if you're using C<add_relationship>, any relationship declared
2034 with an accessor type of 'single' or 'filter').
2044 Makes the resultset paged and specifies the page to retrieve. Effectively
2045 identical to creating a non-pages resultset and then calling ->page($page)
2048 If L<rows> attribute is not specified it defualts to 10 rows per page.
2058 Specifes the maximum number of rows for direct retrieval or the number of
2059 rows per page if the page attribute or method is used.
2065 =item Value: $offset
2069 Specifies the (zero-based) row number for the first row to be returned, or the
2070 of the first row of the first page if paging is used.
2076 =item Value: \@columns
2080 A arrayref of columns to group by. Can include columns of joined tables.
2082 group_by => [qw/ column1 column2 ... /]
2088 =item Value: $condition
2092 HAVING is a select statement attribute that is applied between GROUP BY and
2093 ORDER BY. It is applied to the after the grouping calculations have been
2096 having => { 'count(employee)' => { '>=', 100 } }
2102 =item Value: (0 | 1)
2106 Set to 1 to group by all columns.
2112 Adds to the WHERE clause.
2114 # only return rows WHERE deleted IS NULL for all searches
2115 __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
2117 Can be overridden by passing C<{ where => undef }> as an attribute
2124 Set to 1 to cache search results. This prevents extra SQL queries if you
2125 revisit rows in your ResultSet:
2127 my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
2129 while( my $artist = $resultset->next ) {
2133 $rs->first; # without cache, this would issue a query
2135 By default, searches are not cached.
2137 For more examples of using these attributes, see
2138 L<DBIx::Class::Manual::Cookbook>.
2144 =item Value: \@from_clause
2148 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
2149 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
2152 NOTE: Use this on your own risk. This allows you to shoot off your foot!
2154 C<join> will usually do what you need and it is strongly recommended that you
2155 avoid using C<from> unless you cannot achieve the desired result using C<join>.
2156 And we really do mean "cannot", not just tried and failed. Attempting to use
2157 this because you're having problems with C<join> is like trying to use x86
2158 ASM because you've got a syntax error in your C. Trust us on this.
2160 Now, if you're still really, really sure you need to use this (and if you're
2161 not 100% sure, ask the mailing list first), here's an explanation of how this
2164 The syntax is as follows -
2167 { <alias1> => <table1> },
2169 { <alias2> => <table2>, -join_type => 'inner|left|right' },
2170 [], # nested JOIN (optional)
2171 { <table1.column1> => <table2.column2>, ... (more conditions) },
2173 # More of the above [ ] may follow for additional joins
2180 ON <table1.column1> = <table2.column2>
2181 <more joins may follow>
2183 An easy way to follow the examples below is to remember the following:
2185 Anything inside "[]" is a JOIN
2186 Anything inside "{}" is a condition for the enclosing JOIN
2188 The following examples utilize a "person" table in a family tree application.
2189 In order to express parent->child relationships, this table is self-joined:
2191 # Person->belongs_to('father' => 'Person');
2192 # Person->belongs_to('mother' => 'Person');
2194 C<from> can be used to nest joins. Here we return all children with a father,
2195 then search against all mothers of those children:
2197 $rs = $schema->resultset('Person')->search(
2200 alias => 'mother', # alias columns in accordance with "from"
2202 { mother => 'person' },
2205 { child => 'person' },
2207 { father => 'person' },
2208 { 'father.person_id' => 'child.father_id' }
2211 { 'mother.person_id' => 'child.mother_id' }
2218 # SELECT mother.* FROM person mother
2221 # JOIN person father
2222 # ON ( father.person_id = child.father_id )
2224 # ON ( mother.person_id = child.mother_id )
2226 The type of any join can be controlled manually. To search against only people
2227 with a father in the person table, we could explicitly use C<INNER JOIN>:
2229 $rs = $schema->resultset('Person')->search(
2232 alias => 'child', # alias columns in accordance with "from"
2234 { child => 'person' },
2236 { father => 'person', -join_type => 'inner' },
2237 { 'father.id' => 'child.father_id' }
2244 # SELECT child.* FROM person child
2245 # INNER JOIN person father ON child.father_id = father.id