=head1 NAME
-DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
+DBIx::Class::ResultSet - Represents a query used for fetching a set of results.
=head1 SYNOPSIS
- my $rs = $schema->resultset('User')->search({ registered => 1 });
- my @rows = $schema->resultset('CD')->search({ year => 2005 })->all();
+ my $users_rs = $schema->resultset('User');
+ my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
+ my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
=head1 DESCRIPTION
-The resultset is also known as an iterator. It is responsible for handling
-queries that may return an arbitrary number of rows, e.g. via L</search>
-or a C<has_many> relationship.
+A ResultSet is an object which stores a set of conditions representing
+a query. It is the backbone of DBIx::Class (i.e. the really
+important/useful bit).
-In the examples below, the following table classes are used:
+No SQL is executed on the database when a ResultSet is created, it
+just stores all the conditions needed to create the query.
- package MyApp::Schema::Artist;
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
- __PACKAGE__->table('artist');
- __PACKAGE__->add_columns(qw/artistid name/);
- __PACKAGE__->set_primary_key('artistid');
- __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
- 1;
+A basic ResultSet representing the data of an entire table is returned
+by calling C<resultset> on a L<DBIx::Class::Schema> and passing in a
+L<Source|DBIx::Class::Manual::Glossary/Source> name.
- package MyApp::Schema::CD;
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/Core/);
- __PACKAGE__->table('cd');
- __PACKAGE__->add_columns(qw/cdid artist title year/);
- __PACKAGE__->set_primary_key('cdid');
- __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
- 1;
+ my $users_rs = $schema->resultset('User');
+
+A new ResultSet is returned from calling L</search> on an existing
+ResultSet. The new one will contain all the conditions of the
+original, plus any new conditions added in the C<search> call.
+
+A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
+can be used to walk through all the L<DBIx::Class::Row>s the ResultSet
+represents.
+
+The query that the ResultSet represents is B<only> executed against
+the database when these methods are called:
+L</find> L</next> L</all> L</first> L</single> L</count>
+
+=head1 EXAMPLES
+
+=head2 Chaining resultsets
+
+Let's say you've got a query that needs to be run to return some data
+to the user. But, you have an authorization system in place that
+prevents certain users from seeing certain information. So, you want
+to construct the basic query in one method, but add constraints to it in
+another.
+
+ sub get_data {
+ my $self = shift;
+ my $request = $self->get_request; # Get a request object somehow.
+ my $schema = $self->get_schema; # Get the DBIC schema object somehow.
+
+ my $cd_rs = $schema->resultset('CD')->search({
+ title => $request->param('title'),
+ year => $request->param('year'),
+ });
+
+ $self->apply_security_policy( $cd_rs );
+
+ return $cd_rs->all();
+ }
+
+ sub apply_security_policy {
+ my $self = shift;
+ my ($rs) = @_;
+
+ return $rs->search({
+ subversive => 0,
+ });
+ }
+
+=head3 Resolving conditions and attributes
+
+When a resultset is chained from another resultset, conditions and
+attributes with the same keys need resolving.
+
+L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
+into the existing ones from the original resultset.
+
+The L</where>, L</having> attribute, and any search conditions are
+merged with an SQL C<AND> to the existing condition from the original
+resultset.
+
+All other attributes are overridden by any new ones supplied in the
+search attributes.
+
+=head2 Multiple queries
+
+Since a resultset just defines a query, you can do all sorts of
+things with it with the same object.
+
+ # Don't hit the DB yet.
+ my $cd_rs = $schema->resultset('CD')->search({
+ title => 'something',
+ year => 2009,
+ });
+
+ # Each of these hits the DB individually.
+ my $count = $cd_rs->count;
+ my $most_recent = $cd_rs->get_column('date_released')->max();
+ my @records = $cd_rs->all;
+
+And it's not just limited to SELECT statements.
+
+ $cd_rs->delete();
+
+This is even cooler:
+
+ $cd_rs->create({ artist => 'Fred' });
+
+Which is the same as:
+
+ $schema->resultset('CD')->create({
+ title => 'something',
+ year => 2009,
+ artist => 'Fred'
+ });
+
+See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
=head1 OVERLOADING
return $class->new_result(@_) if ref $class;
my ($source, $attrs) = @_;
- $source = $source->handle
+ $source = $source->handle
unless $source->isa('DBIx::Class::ResultSourceHandle');
$attrs = { %{$attrs||{}} };
sub search_rs {
my $self = shift;
+ # Special-case handling for (undef, undef).
+ if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
+ pop(@_); pop(@_);
+ }
+
my $attrs = {};
$attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
my $our_attrs = { %{$self->{attrs}} };
unless (
(@_ && defined($_[0])) # @_ == () or (undef)
- ||
+ ||
(keys %$attrs # empty attrs or only 'safe' attrs
&& List::Util::first { !$safe{$_} } keys %$attrs)
) {
my $new_attrs = { %{$our_attrs}, %{$attrs} };
# merge new attrs into inherited
- foreach my $key (qw/join prefetch +select +as/) {
+ foreach my $key (qw/join prefetch +select +as bind/) {
next unless exists $attrs->{$key};
$new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
}
resultset query.
CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
-only be used in that context. There are known problems using C<search_literal>
-in chained queries; it can result in bind values in the wrong order. See
-L<DBIx::Class::Manual::Cookbook/Searching> and
+only be used in that context. C<search_literal> is a convenience method.
+It is equivalent to calling $schema->search(\[]), but if you want to ensure
+columns are bound correctly, use C<search>.
+
+Example of how to use C<search> instead of C<search_literal>
+
+ my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
+ my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
+
+
+See L<DBIx::Class::Manual::Cookbook/Searching> and
L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
require C<search_literal>.
=cut
sub search_literal {
- my ($self, $cond, @vals) = @_;
- my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
- $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
- return $self->search(\$cond, $attrs);
+ my ($self, $sql, @bind) = @_;
+ my $attr;
+ if ( @bind && ref($bind[-1]) eq 'HASH' ) {
+ $attr = pop @bind;
+ }
+ return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
}
=head2 find
&& ($info = $self->result_source->relationship_info($key))) {
my $val = delete $input_query->{$key};
next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
- my $rel_q = $self->result_source->resolve_condition(
+ my $rel_q = $self->result_source->_resolve_condition(
$info->{cond}, $val, $key
);
die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
sub cursor {
my ($self) = @_;
- my $attrs = { %{$self->_resolved_attrs} };
+ my $attrs = $self->_resolved_attrs_copy;
+
return $self->{cursor}
||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
$attrs->{where},$attrs);
Query returned more than one row
In this case, you should be using L</first> or L</find> instead, or if you really
-know what you are doing, use the L</rows> attribute to explicitly limit the size
+know what you are doing, use the L</rows> attribute to explicitly limit the size
of the resultset.
=back
sub single {
my ($self, $where) = @_;
- my $attrs = { %{$self->_resolved_attrs} };
+ if(@_ > 2) {
+ $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
+ }
+
+ my $attrs = $self->_resolved_attrs_copy;
+
if ($where) {
if (defined $attrs->{where}) {
$attrs->{where} = {
return (@data ? ($self->_construct_object(@data))[0] : undef);
}
+
# _is_unique_query
#
# Try to determine if the specified query is guaranteed to be unique, based on
if (ref $query eq 'ARRAY') {
foreach my $subquery (@$query) {
next unless ref $subquery; # -or
-# warn "ARRAY: " . Dumper $subquery;
$collapsed = $self->_collapse_query($subquery, $collapsed);
}
}
elsif (ref $query eq 'HASH') {
if (keys %$query and (keys %$query)[0] eq '-and') {
foreach my $subquery (@{$query->{-and}}) {
-# warn "HASH: " . Dumper $subquery;
$collapsed = $self->_collapse_query($subquery, $collapsed);
}
}
else {
-# warn "LEAF: " . Dumper $query;
foreach my $col (keys %$query) {
my $value = $query->{$col};
$collapsed->{$col}{$value}++;
$cd_rs = $rs->search_like({ title => '%blue%'});
Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
-that this is simply a convenience method. You most likely want to use
-L</search> with specific operators.
+that this is simply a convenience method retained for ex Class::DBI users.
+You most likely want to use L</search> with specific operators.
For more information, see L<DBIx::Class::Manual::Cookbook>.
+This method is deprecated and will be removed in 0.09. Use L</search()>
+instead. An example conversion is:
+
+ ->search_like({ foo => 'bar' });
+
+ # Becomes
+
+ ->search({ foo => { like => 'bar' } });
+
=cut
sub search_like {
my $class = shift;
+ carp (
+ 'search_like() is deprecated and will be removed in DBIC version 0.09.'
+ .' Instead use ->search({ x => { -like => "y%" } })'
+ .' (note the outer pair of {}s - they are important!)'
+ );
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
$query->{$_} = { 'like' => $query->{$_} } for keys %$query;
do { # no need to check anything at the front, we always want the first row
my %const;
-
+
foreach my $this_as (@construct_as) {
$const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
}
foreach my $p (@parts) {
$target = $target->[1]->{$p} ||= [];
$cur .= ".${p}";
- if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
+ if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
# collapsing at this point and on final part
my $pos = $collapse_pos{$cur};
CK: foreach my $ck (@ckey) {
=back
-An accessor for the class to use when creating row objects. Defaults to
-C<< result_source->result_class >> - which in most cases is the name of the
+An accessor for the class to use when creating row objects. Defaults to
+C<< result_source->result_class >> - which in most cases is the name of the
L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
+Note that changing the result_class will also remove any components
+that were originally loaded in the source class via
+L<DBIx::Class::ResultSource/load_components>. Any overloaded methods
+in the original source class will not run.
+
=cut
sub result_class {
=back
Performs an SQL C<COUNT> with the same query as the resultset was built
-with to find the number of elements. If passed arguments, does a search
-on the resultset and counts the results of that.
-
-Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
-using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
-not support C<DISTINCT> with multiple columns. If you are using such a
-database, you should only use columns from the main table in your C<group_by>
-clause.
+with to find the number of elements. Passing arguments is equivalent to
+C<< $rs->search ($cond, \%attrs)->count >>
=cut
my $self = shift;
return $self->search(@_)->count if @_ and defined $_[0];
return scalar @{ $self->get_cache } if $self->get_cache;
- my $count = $self->_count;
- return 0 unless $count;
- # need to take offset from resolved attrs
+ my $meth = $self->_has_attr (qw/prefetch collapse distinct group_by/)
+ ? 'count_grouped'
+ : 'count'
+ ;
- $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
- $count = $self->{attrs}{rows} if
- $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
- $count = 0 if ($count < 0);
- return $count;
-}
+ my $attrs = $self->_resolved_attrs_copy;
+ my $rsrc = $self->result_source;
-sub _count { # Separated out so pager can get the full count
- my $self = shift;
- my $select = { count => '*' };
-
- my $attrs = { %{$self->_resolved_attrs} };
- if (my $group_by = delete $attrs->{group_by}) {
- delete $attrs->{having};
- my @distinct = (ref $group_by ? @$group_by : ($group_by));
- # todo: try CONCAT for multi-column pk
- my @pk = $self->result_source->primary_columns;
- if (@pk == 1) {
- my $alias = $attrs->{alias};
- foreach my $column (@distinct) {
- if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
- @distinct = ($column);
- last;
- }
- }
- }
-
- $select = { count => { distinct => \@distinct } };
- }
-
- $attrs->{select} = $select;
- $attrs->{as} = [qw/count/];
-
- # offset, order by and page are not needed to count. record_filter is cdbi
- delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
-
- my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
- my ($count) = $tmp_rs->cursor->next;
- return $count;
+ return $rsrc->storage->$meth ($rsrc, $attrs);
}
sub _bool {
=cut
sub all {
- my ($self) = @_;
+ my $self = shift;
+ if(@_) {
+ $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
+ }
+
return @{ $self->get_cache } if $self->get_cache;
my @obj;
return $_[0]->reset->next;
}
+
+# _rs_update_delete
+#
+# Determines whether and what type of subquery is required for the $rs operation.
+# If grouping is necessary either supplies its own, or verifies the current one
+# After all is done delegates to the proper storage method.
+
+sub _rs_update_delete {
+ my ($self, $op, $values) = @_;
+
+ my $rsrc = $self->result_source;
+
+ my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
+ my $needs_subq = $self->_has_attr (qw/row offset page/);
+
+ if ($needs_group_by_subq or $needs_subq) {
+
+ # make a new $rs selecting only the PKs (that's all we really need)
+ my $attrs = $self->_resolved_attrs_copy;
+
+ delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
+ $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
+
+ if ($needs_group_by_subq) {
+ # make sure no group_by was supplied, or if there is one - make sure it matches
+ # the columns compiled above perfectly. Anything else can not be sanely executed
+ # on most databases so croak right then and there
+
+ if (my $g = $attrs->{group_by}) {
+ my @current_group_by = map
+ { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
+ (ref $g eq 'ARRAY' ? @$g : $g );
+
+ if (
+ join ("\x00", sort @current_group_by)
+ ne
+ join ("\x00", sort @{$attrs->{columns}} )
+ ) {
+ $self->throw_exception (
+ "You have just attempted a $op operation on a resultset which does group_by"
+ . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
+ . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
+ . ' kind of queries. Please retry the operation with a modified group_by or'
+ . ' without using one at all.'
+ );
+ }
+ }
+ else {
+ $attrs->{group_by} = $attrs->{columns};
+ }
+ }
+
+ my $subrs = (ref $self)->new($rsrc, $attrs);
+
+ return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
+ }
+ else {
+ return $rsrc->storage->$op(
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $self->_cond_for_update_delete,
+ );
+ }
+}
+
+
# _cond_for_update_delete
#
# update/delete require the condition to be modified to handle
elsif (ref $full_cond eq 'HASH') {
if ((keys %{$full_cond})[0] eq '-and') {
$cond->{-and} = [];
-
my @cond = @{$full_cond->{-and}};
- for (my $i = 0; $i < @cond; $i++) {
+ for (my $i = 0; $i < @cond; $i++) {
my $entry = $cond[$i];
-
my $hash;
if (ref $entry eq 'HASH') {
$hash = $self->_cond_for_update_delete($entry);
$entry =~ /([^.]+)$/;
$hash->{$1} = $cond[++$i];
}
-
push @{$cond->{-and}}, $hash;
}
}
}
}
else {
- $self->throw_exception(
- "Can't update/delete on resultset with condition unless hash or array"
- );
+ $self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
}
return $cond;
sub update {
my ($self, $values) = @_;
- $self->throw_exception("Values for update must be a hash")
+ $self->throw_exception('Values for update must be a hash')
unless ref $values eq 'HASH';
- my $cond = $self->_cond_for_update_delete;
-
- return $self->result_source->storage->update(
- $self->result_source, $values, $cond
- );
+ return $self->_rs_update_delete ('update', $values);
}
=head2 update_all
sub update_all {
my ($self, $values) = @_;
- $self->throw_exception("Values for update must be a hash")
+ $self->throw_exception('Values for update_all must be a hash')
unless ref $values eq 'HASH';
foreach my $obj ($self->all) {
$obj->set_columns($values)->update;
=item Arguments: none
-=item Return Value: 1
+=item Return Value: $storage_rv
=back
will not run DBIC cascade triggers. See L</delete_all> if you need triggers
to run. See also L<DBIx::Class::Row/delete>.
-delete may not generate correct SQL for a query with joins or a resultset
-chained from a related resultset. In this case it will generate a warning:-
-
- WARNING! Currently $rs->delete() does not generate proper SQL on
- joined resultsets, and may delete rows well outside of the contents
- of $rs. Use at your own risk
-
-In these cases you may find that delete_all is more appropriate, or you
-need to respecify your query in a way that can be expressed without a join.
+Return value will be the amount of rows deleted; exact type of return value
+is storage-dependent.
=cut
sub delete {
- my ($self) = @_;
- $self->throw_exception("Delete should not be passed any arguments")
- if $_[1];
- carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
- . ' on joined resultsets, and may delete rows well outside of the'
- . ' contents of $rs. Use at your own risk' )
- if ( $self->{attrs}{seen_join} );
- my $cond = $self->_cond_for_update_delete;
-
- $self->result_source->storage->delete($self->result_source, $cond);
- return 1;
+ my $self = shift;
+ $self->throw_exception('delete does not accept any arguments')
+ if @_;
+
+ return $self->_rs_update_delete ('delete');
}
=head2 delete_all
=cut
sub delete_all {
- my ($self) = @_;
+ my $self = shift;
+ $self->throw_exception('delete_all does not accept any arguments')
+ if @_;
+
$_->delete for $self->all;
return 1;
}
=back
-Pass an arrayref of hashrefs. Each hashref should be a structure suitable for
-submitting to a $resultset->create(...) method.
+Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
+For the arrayref of hashrefs style each hashref should be a structure suitable
+forsubmitting to a $resultset->create(...) method.
In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
-to insert the data, as this is a faster method.
+to insert the data, as this is a faster method.
Otherwise, each set of data is inserted into the database using
L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
Example: Assuming an Artist Class that has many CDs Classes relating:
my $Artist_rs = $schema->resultset("Artist");
-
- ## Void Context Example
+
+ ## Void Context Example
$Artist_rs->populate([
- { artistid => 4, name => 'Manufactured Crap', cds => [
+ { artistid => 4, name => 'Manufactured Crap', cds => [
{ title => 'My First CD', year => 2006 },
{ title => 'Yet More Tweeny-Pop crap', year => 2007 },
],
],
},
]);
-
+
## Array Context Example
my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
{ name => "Artist One"},
{ title => "Second CD", year => 2008},
]}
]);
-
+
print $ArtistOne->name; ## response is 'Artist One'
print $ArtistThree->cds->count ## reponse is '2'
-
+
+For the arrayref of arrayrefs style, the first element should be a list of the
+fieldsnames to which the remaining elements are rows being inserted. For
+example:
+
+ $Arstist_rs->populate([
+ [qw/artistid name/],
+ [100, 'A Formally Unknown Singer'],
+ [101, 'A singer that jumped the shark two albums ago'],
+ [102, 'An actually cool singer.'],
+ ]);
+
Please note an important effect on your data when choosing between void and
-wantarray context. Since void context goes straight to C<insert_bulk> in
+wantarray context. Since void context goes straight to C<insert_bulk> in
L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
-c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
-create primary keys for you, you will find that your PKs are empty. In this
-case you will have to use the wantarray context in order to create those
+C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
+create primary keys for you, you will find that your PKs are empty. In this
+case you will have to use the wantarray context in order to create those
values.
=cut
sub populate {
- my ($self, $data) = @_;
-
+ my $self = shift @_;
+ my $data = ref $_[0][0] eq 'HASH'
+ ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
+ $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
+
if(defined wantarray) {
my @created;
foreach my $item (@$data) {
my @names = grep {!ref $first->{$_}} keys %$first;
my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
- my @pks = $self->result_source->primary_columns;
+ my @pks = $self->result_source->primary_columns;
- ## do the belongs_to relationships
+ ## do the belongs_to relationships
foreach my $index (0..$#$data) {
- if( grep { !defined $data->[$index]->{$_} } @pks ) {
- my @ret = $self->populate($data);
- return;
+
+ # delegate to create() for any dataset without primary keys with specified relationships
+ if (grep { !defined $data->[$index]->{$_} } @pks ) {
+ for my $r (@rels) {
+ if (grep { ref $data->[$index]{$r} eq $_ } qw/HASH ARRAY/) { # a related set must be a HASH or AoH
+ my @ret = $self->populate($data);
+ return;
+ }
+ }
}
-
+
foreach my $rel (@rels) {
- next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
+ next unless ref $data->[$index]->{$rel} eq "HASH";
my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
- my $related = $result->result_source->resolve_condition(
+ my $related = $result->result_source->_resolve_condition(
$result->result_source->relationship_info($reverse)->{cond},
- $self,
- $result,
+ $self,
+ $result,
);
delete $data->[$index]->{$rel};
$data->[$index] = {%{$data->[$index]}, %$related};
-
+
push @names, keys %$related if $index == 0;
}
}
my @values = map { [ @$_{@names} ] } @$data;
$self->result_source->storage->insert_bulk(
- $self->result_source,
- \@names,
+ $self->result_source,
+ \@names,
\@values,
);
foreach my $rel (@rels) {
next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
- my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
+ my $parent = $self->find(map {{$_=>$item->{$_}} } @pks)
|| $self->throw_exception('Cannot find the relating object.');
-
+
my $child = $parent->$rel;
-
- my $related = $child->result_source->resolve_condition(
+
+ my $related = $child->result_source->_resolve_condition(
$parent->result_source->relationship_info($rel)->{cond},
$child,
$parent,
}
}
+=head2 _normalize_populate_args ($args)
+
+Private method used by L</populate> to normalize its incoming arguments. Factored
+out in case you want to subclass and accept new argument structures to the
+L</populate> method.
+
+=cut
+
+sub _normalize_populate_args {
+ my ($self, $data) = @_;
+ my @names = @{shift(@$data)};
+ my @results_to_create;
+ foreach my $datum (@$data) {
+ my %result_to_create;
+ foreach my $index (0..$#names) {
+ $result_to_create{$names[$index]} = $$datum[$index];
+ }
+ push @results_to_create, \%result_to_create;
+ }
+ return \@results_to_create;
+}
+
=head2 pager
=over 4
Return Value a L<Data::Page> object for the current resultset. Only makes
sense for queries with a C<page> attribute.
+To get the full count of entries for a paged resultset, call
+C<total_entries> on the L<Data::Page> object.
+
=cut
sub pager {
my ($self) = @_;
+
+ return $self->{pager} if $self->{pager};
+
my $attrs = $self->{attrs};
$self->throw_exception("Can't create pager for non-paged rs")
unless $self->{attrs}{page};
$attrs->{rows} ||= 10;
- return $self->{pager} ||= Data::Page->new(
- $self->_count, $attrs->{rows}, $self->{attrs}{page});
+
+ # throw away the paging flags and re-run the count (possibly
+ # with a subselect) to get the real total count
+ my $count_attrs = { %$attrs };
+ delete $count_attrs->{$_} for qw/rows offset page pager/;
+ my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
+
+ return $self->{pager} = Data::Page->new(
+ $total_count,
+ $attrs->{rows},
+ $self->{attrs}{page}
+ );
}
=head2 page
defined $self->{cond}
&& $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
) {
- %new = %{$self->{attrs}{related_objects}};
+ %new = %{ $self->{attrs}{related_objects} || {} }; # nothing might have been inserted yet
+ $new{-from_resultset} = [ keys %new ] if keys %new;
} else {
$self->throw_exception(
"Can't abstract implicit construct, condition not a hash"
) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
-
+
my $collapsed_cond = (
$self->{cond}
? $self->_collapse_cond($self->{cond})
: {}
);
-
+
# precendence must be given to passed values over values inherited from
# the cond, so the order here is important.
my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
# _is_deterministic_value
#
-# Make an effor to strip non-deterministic values from the condition,
+# Make an effor to strip non-deterministic values from the condition,
# to make sure new_result chokes less
sub _is_deterministic_value {
return 0;
}
+# _has_attr
+#
+# determines if the resultset defines at least one
+# of the attributes supplied
+#
+# used to determine if a subquery is neccessary
+
+sub _has_attr {
+ my ($self, @attr_names) = @_;
+
+ my $attrs = $self->_resolved_attrs;
+
+ my $join_check_req;
+
+ for my $n (@attr_names) {
+ ++$join_check_req if $n =~ /join/;
+
+ my $attr = $attrs->{$n};
+
+ next if not defined $attr;
+
+ if (ref $attr eq 'HASH') {
+ return 1 if keys %$attr;
+ }
+ elsif (ref $attr eq 'ARRAY') {
+ return 1 if @$attr;
+ }
+ else {
+ return 1 if $attr;
+ }
+ }
+
+ # a join can be expressed as a multi-level from
+ return 1 if (
+ $join_check_req
+ and
+ ref $attrs->{from} eq 'ARRAY'
+ and
+ @{$attrs->{from}} > 1
+ );
+
+ return 0;
+}
+
# _collapse_cond
#
# Recursively collapse the condition.
if (ref $cond eq 'ARRAY') {
foreach my $subcond (@$cond) {
next unless ref $subcond; # -or
-# warn "ARRAY: " . Dumper $subcond;
$collapsed = $self->_collapse_cond($subcond, $collapsed);
}
}
elsif (ref $cond eq 'HASH') {
if (keys %$cond and (keys %$cond)[0] eq '-and') {
foreach my $subcond (@{$cond->{-and}}) {
-# warn "HASH: " . Dumper $subcond;
$collapsed = $self->_collapse_cond($subcond, $collapsed);
}
}
else {
-# warn "LEAF: " . Dumper $cond;
foreach my $col (keys %$cond) {
my $value = $cond->{$col};
$collapsed->{$col} = $value;
return \%unaliased;
}
+=head2 as_query (EXPERIMENTAL)
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \[ $sql, @bind ]
+
+=back
+
+Returns the SQL query and bind vars associated with the invocant.
+
+This is generally used as the RHS for a subquery.
+
+B<NOTE>: This feature is still experimental.
+
+=cut
+
+sub as_query {
+ my $self = shift;
+
+ my $attrs = $self->_resolved_attrs_copy;
+
+ my ($sqlbind, $bind_attrs) = $self->result_source->storage
+ ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
+
+ return $sqlbind;
+}
+
=head2 find_or_new
=over 4
$cd->cd_to_producer->find_or_new({ producer => $producer },
{ key => 'primary });
-Find an existing record from this resultset, based on it's primary
+Find an existing record from this resultset, based on its primary
key, or a unique constraint. If none exists, instantiate a new result
object and return it. The object will not be saved into your storage
until you call L<DBIx::Class::Row/insert> on it.
my $self = shift;
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
- my $exists = $self->find($hash, $attrs);
- return defined $exists ? $exists : $self->new_result($hash);
+ if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
+ return $row;
+ }
+ return $self->new_result($hash);
}
=head2 create
pairs representing the columns of the table and the values you wish to
store. If the appropriate relationships are set up, foreign key fields
can also be passed an object representing the foreign row, and the
-value will be set to it's primary key.
+value will be set to its primary key.
To create related objects, pass a hashref for the value if the related
item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
$person_rs->create({
name=>"Some Person",
- email=>"somebody@someplace.com"
+ email=>"somebody@someplace.com"
});
-
+
Example of creating a new row and also creating rows in a related C<has_many>
or C<has_one> resultset. Note Arrayref.
$artist_rs->create(
- { artistid => 4, name => 'Manufactured Crap', cds => [
+ { artistid => 4, name => 'Manufactured Crap', cds => [
{ title => 'My First CD', year => 2006 },
{ title => 'Yet More Tweeny-Pop crap', year => 2007 },
],
$cd_rs->create({
title=>"Music for Silly Walks",
- year=>2000,
- artist => {
- name=>"Silly Musician",
- }
+ year=>2000,
+ artist => {
+ name=>"Silly Musician",
+ }
});
=cut
my $self = shift;
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
- my $exists = $self->find($hash, $attrs);
- return defined $exists ? $exists : $self->create($hash);
+ if (keys %$hash and my $row = $self->find($hash, $attrs) ) {
+ return $row;
+ }
+ return $self->create($hash);
}
=head2 update_or_create
{ key => 'cd_artist_title' }
);
- $cd->cd_to_producer->update_or_create({
- producer => $producer,
+ $cd->cd_to_producer->update_or_create({
+ producer => $producer,
name => 'harry',
- }, {
+ }, {
key => 'primary,
});
return $self->create($cond);
}
+=head2 update_or_new
+
+=over 4
+
+=item Arguments: \%col_values, { key => $unique_constraint }?
+
+=item Return Value: $rowobject
+
+=back
+
+ $resultset->update_or_new({ col => $val, ... });
+
+First, searches for an existing row matching one of the unique constraints
+(including the primary key) on the source of this resultset. If a row is
+found, updates it with the other given column values. Otherwise, instantiate
+a new result object and return it. The object will not be saved into your storage
+until you call L<DBIx::Class::Row/insert> on it.
+
+Takes an optional C<key> attribute to search on a specific unique constraint.
+For example:
+
+ # In your application
+ my $cd = $schema->resultset('CD')->update_or_new(
+ {
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ year => 1998,
+ },
+ { key => 'cd_artist_title' }
+ );
+
+ if ($cd->in_storage) {
+ # the cd was updated
+ }
+ else {
+ # the cd is not yet in the database, let's insert it
+ $cd->insert;
+ }
+
+See also L</find>, L</find_or_create> and L<find_or_new>.
+
+=cut
+
+sub update_or_new {
+ my $self = shift;
+ my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} );
+ my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
+
+ my $row = $self->find( $cond, $attrs );
+ if ( defined $row ) {
+ $row->update($cond);
+ return $row;
+ }
+
+ return $self->new_result($cond);
+}
+
=head2 get_cache
=over 4
"search_related: result source '" . $self->result_source->source_name .
"' has no such relationship $rel")
unless $rel_obj;
-
+
my ($from,$seen) = $self->_resolve_from($rel);
my $join_count = $seen->{$rel};
};
}
+=head2 current_source_alias
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $source_alias
+
+=back
+
+Returns the current table alias for the result source this resultset is built
+on, that will be used in the SQL query. Usually it is C<me>.
+
+Currently the source alias that refers to the result set returned by a
+L</search>/L</find> family method depends on how you got to the resultset: it's
+C<me> by default, but eg. L</search_related> aliases it to the related result
+source name (and keeps C<me> referring to the original result set). The long
+term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
+(and make this method unnecessary).
+
+Thus it's currently necessary to use this method in predefined queries (see
+L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
+source alias of the current result set:
+
+ # in a result set class
+ sub modified_by {
+ my ($self, $user) = @_;
+
+ my $me = $self->current_source_alias;
+
+ return $self->search(
+ "$me.modified" => $user->id,
+ );
+ }
+
+=cut
+
+sub current_source_alias {
+ my ($self) = @_;
+
+ return ($self->{attrs} || {})->{alias} || 'me';
+}
+
+# This code is called by search_related, and makes sure there
+# is clear separation between the joins before, during, and
+# after the relationship. This information is needed later
+# in order to properly resolve prefetch aliases (any alias
+# with a relation_chain_depth less than the depth of the
+# current prefetch is not considered)
sub _resolve_from {
my ($self, $extra_join) = @_;
my $source = $self->result_source;
my $attrs = $self->{attrs};
-
- my $from = $attrs->{from}
- || [ { $attrs->{alias} => $source->from } ];
-
- my $seen = { %{$attrs->{seen_join}||{}} };
- my $join = ($attrs->{join}
- ? [ $attrs->{join}, $extra_join ]
- : $extra_join);
+ my $from = [ @{
+ $attrs->{from}
+ ||
+ [{
+ -result_source => $source,
+ -alias => $attrs->{alias},
+ $attrs->{alias} => $source->from,
+ }]
+ }];
+
+ my $seen = { %{$attrs->{seen_join} || {} } };
+
+ # we need to take the prefetch the attrs into account before we
+ # ->_resolve_join as otherwise they get lost - captainL
+ my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
- # we need to take the prefetch the attrs into account before we
- # ->resolve_join as otherwise they get lost - captainL
- my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
+ push @$from, $source->_resolve_join($merged, $attrs->{alias}, $seen) if ($merged);
- $from = [
- @$from,
- ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
- ];
+ ++$seen->{-relation_chain_depth};
+
+ push @$from, $source->_resolve_join($extra_join, $attrs->{alias}, $seen);
+
+ ++$seen->{-relation_chain_depth};
return ($from,$seen);
}
+# too many times we have to do $attrs = { %{$self->_resolved_attrs} }
+sub _resolved_attrs_copy {
+ my $self = shift;
+ return { %{$self->_resolved_attrs (@_)} };
+}
+
sub _resolved_attrs {
my $self = shift;
return $self->{_attrs} if $self->{_attrs};
- my $attrs = { %{$self->{attrs}||{}} };
+ my $attrs = { %{ $self->{attrs} || {} } };
my $source = $self->result_source;
- my $alias = $attrs->{alias};
+ my $alias = $attrs->{alias};
$attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
- if ($attrs->{columns}) {
- delete $attrs->{as};
- } elsif (!$attrs->{select}) {
- $attrs->{columns} = [ $source->columns ];
- }
-
- $attrs->{select} =
- ($attrs->{select}
- ? (ref $attrs->{select} eq 'ARRAY'
- ? [ @{$attrs->{select}} ]
- : [ $attrs->{select} ])
- : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
- );
- $attrs->{as} =
- ($attrs->{as}
- ? (ref $attrs->{as} eq 'ARRAY'
- ? [ @{$attrs->{as}} ]
- : [ $attrs->{as} ])
- : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]
+ my @colbits;
+
+ # build columns (as long as select isn't set) into a set of as/select hashes
+ unless ( $attrs->{select} ) {
+ @colbits = map {
+ ( ref($_) eq 'HASH' )
+ ? $_
+ : {
+ (
+ /^\Q${alias}.\E(.+)$/
+ ? "$1"
+ : "$_"
+ )
+ =>
+ (
+ /\./
+ ? "$_"
+ : "${alias}.$_"
+ )
+ }
+ } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
+ }
+ # add the additional columns on
+ foreach ( 'include_columns', '+columns' ) {
+ push @colbits, map {
+ ( ref($_) eq 'HASH' )
+ ? $_
+ : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
+ } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
+ }
+
+ # start with initial select items
+ if ( $attrs->{select} ) {
+ $attrs->{select} =
+ ( ref $attrs->{select} eq 'ARRAY' )
+ ? [ @{ $attrs->{select} } ]
+ : [ $attrs->{select} ];
+ $attrs->{as} = (
+ $attrs->{as}
+ ? (
+ ref $attrs->{as} eq 'ARRAY'
+ ? [ @{ $attrs->{as} } ]
+ : [ $attrs->{as} ]
+ )
+ : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
);
-
- my $adds;
- if ($adds = delete $attrs->{include_columns}) {
- $adds = [$adds] unless ref $adds eq 'ARRAY';
- push(@{$attrs->{select}}, @$adds);
- push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds);
}
- if ($adds = delete $attrs->{'+select'}) {
+ else {
+
+ # otherwise we intialise select & as to empty
+ $attrs->{select} = [];
+ $attrs->{as} = [];
+ }
+
+ # now add colbits to select/as
+ push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
+ push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
+
+ my $adds;
+ if ( $adds = delete $attrs->{'+select'} ) {
$adds = [$adds] unless ref $adds eq 'ARRAY';
- push(@{$attrs->{select}},
- map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds);
+ push(
+ @{ $attrs->{select} },
+ map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
+ );
}
- if (my $adds = delete $attrs->{'+as'}) {
+ if ( $adds = delete $attrs->{'+as'} ) {
$adds = [$adds] unless ref $adds eq 'ARRAY';
- push(@{$attrs->{as}}, @$adds);
+ push( @{ $attrs->{as} }, @$adds );
}
- $attrs->{from} ||= [ { 'me' => $source->from } ];
+ $attrs->{from} ||= [ {
+ -result_source => $source,
+ -alias => $self->{attrs}{alias},
+ $self->{attrs}{alias} => $source->from,
+ } ];
- if (exists $attrs->{join} || exists $attrs->{prefetch}) {
+ if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
my $join = delete $attrs->{join} || {};
- if (defined $attrs->{prefetch}) {
- $join = $self->_merge_attr(
- $join, $attrs->{prefetch}
- );
-
+ if ( defined $attrs->{prefetch} ) {
+ $join = $self->_merge_attr( $join, $attrs->{prefetch} );
+
}
- $attrs->{from} = # have to copy here to avoid corrupting the original
+ $attrs->{from} = # have to copy here to avoid corrupting the original
[
- @{$attrs->{from}},
- $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
+ @{ $attrs->{from} },
+ $source->_resolve_join(
+ $join, $alias, { %{ $attrs->{seen_join} || {} } }
+ )
];
}
- $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
- if ($attrs->{order_by}) {
- $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY'
- ? [ @{$attrs->{order_by}} ]
- : [ $attrs->{order_by} ]);
- } else {
- $attrs->{order_by} = [];
+ if ( $attrs->{order_by} ) {
+ $attrs->{order_by} = (
+ ref( $attrs->{order_by} ) eq 'ARRAY'
+ ? [ @{ $attrs->{order_by} } ]
+ : [ $attrs->{order_by} ]
+ );
}
+ else {
+ $attrs->{order_by} = [];
+ }
+
+ # If the order_by is otherwise empty - we will use this for TOP limit
+ # emulation and the like.
+ # Although this is needed only if the order_by is not defined, it is
+ # actually cheaper to just populate this rather than properly examining
+ # order_by (stuf like [ {} ] and the like)
+ $attrs->{_virtual_order_by} = [ $self->result_source->primary_columns ];
+
my $collapse = $attrs->{collapse} || {};
- if (my $prefetch = delete $attrs->{prefetch}) {
- $prefetch = $self->_merge_attr({}, $prefetch);
+ if ( my $prefetch = delete $attrs->{prefetch} ) {
+ $prefetch = $self->_merge_attr( {}, $prefetch );
my @pre_order;
- my $seen = $attrs->{seen_join} || {};
- foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
+ foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
+
# bring joins back to level of current class
- my @prefetch = $source->resolve_prefetch(
- $p, $alias, $seen, \@pre_order, $collapse
- );
- push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
- push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
+ my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
+ my @prefetch =
+ $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
+ push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
+ push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
}
- push(@{$attrs->{order_by}}, @pre_order);
+ push( @{ $attrs->{order_by} }, @pre_order );
+ }
+
+ if (delete $attrs->{distinct}) {
+ $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
}
+
$attrs->{collapse} = $collapse;
- if ($attrs->{page}) {
- $attrs->{offset} ||= 0;
- $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
+ if ( $attrs->{page} and not defined $attrs->{offset} ) {
+ $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
}
return $self->{_attrs} = $attrs;
}
+sub _joinpath_aliases {
+ my ($self, $fromspec, $seen) = @_;
+
+ my $paths = {};
+ return $paths unless ref $fromspec eq 'ARRAY';
+
+ for my $j (@$fromspec) {
+
+ next if ref $j ne 'ARRAY';
+ next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
+
+ my $p = $paths;
+ $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
+ push @{$p->{-join_aliases} }, $j->[0]{-alias};
+ }
+
+ return $paths;
+}
+
sub _rollout_attr {
my ($self, $attr) = @_;
-
+
if (ref $attr eq 'HASH') {
return $self->_rollout_hash($attr);
} elsif (ref $attr eq 'ARRAY') {
}
} else {
return ($a eq $b_key) ? 1 : 0;
- }
+ }
} else {
if (ref $a eq 'HASH') {
my ($a_key) = keys %{$a};
return $import unless defined($orig);
return $orig unless defined($import);
-
+
$orig = $self->_rollout_attr($orig);
$import = $self->_rollout_attr($import);
=head1 ATTRIBUTES
-The resultset takes various attributes that modify its behavior. Here's an
-overview of them:
+Attributes are used to refine a ResultSet in various ways when
+searching for data. They can be passed to any method which takes an
+C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
+L</count>.
+
+These are in no particular order:
=head2 order_by
=over 4
-=item Value: ($order_by | \@order_by)
+=item Value: ( $order_by | \@order_by | \%order_by )
=back
-Which column(s) to order the results by. This is currently passed
-through directly to SQL, so you can give e.g. C<year DESC> for a
-descending order on the column `year'.
+Which column(s) to order the results by. If a single column name, or
+an arrayref of names is supplied, the argument is passed through
+directly to SQL. The hashref syntax allows for connection-agnostic
+specification of ordering direction:
+
+ For descending order:
+
+ order_by => { -desc => [qw/col1 col2 col3/] }
+
+ For explicit ascending order:
+
+ order_by => { -asc => 'col' }
-Please note that if you have C<quote_char> enabled (see
-L<DBIx::Class::Storage::DBI/connect_info>) you will need to do C<\'year DESC' > to
-specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
-so you will need to manually quote things as appropriate.)
+The old scalarref syntax (i.e. order_by => \'year DESC') is still
+supported, although you are strongly encouraged to use the hashref
+syntax as outlined above.
=head2 columns
=back
-Shortcut to request a particular set of columns to be retrieved. Adds
-C<me.> onto the start of any column without a C<.> in it and sets C<select>
-from that, then auto-populates C<as> from C<select> as normal. (You may also
-use the C<cols> attribute, as in earlier versions of DBIC.)
+Shortcut to request a particular set of columns to be retrieved. Each
+column spec may be a string (a table column name), or a hash (in which
+case the key is the C<as> value, and the value is used as the C<select>
+expression). Adds C<me.> onto the start of any column without a C<.> in
+it and sets C<select> from that, then auto-populates C<as> from
+C<select> as normal. (You may also use the C<cols> attribute, as in
+earlier versions of DBIC.)
-=head2 include_columns
+=head2 +columns
=over 4
=back
-Shortcut to include additional columns in the returned results - for example
+Indicates additional columns to be selected from storage. Works the same
+as L</columns> but adds columns to the selection. (You may also use the
+C<include_columns> attribute, as in earlier versions of DBIC). For
+example:-
$schema->resultset('CD')->search(undef, {
- include_columns => ['artist.name'],
+ '+columns' => ['artist.name'],
join => ['artist']
});
column (or relationship) accessor, and 'name' is the name of the column
accessor in the related table.
+=head2 include_columns
+
+=over 4
+
+=item Value: \@columns
+
+=back
+
+Deprecated. Acts as a synonym for L</+columns> for backward compatibility.
+
=head2 select
=over 4
=over 4
-Indicates additional column names for those added via L</+select>.
+Indicates additional column names for those added via L</+select>. See L</as>.
=back
}
);
-You need to use the relationship (not the table) name in conditions,
-because they are aliased as such. The current table is aliased as "me", so
+You need to use the relationship (not the table) name in conditions,
+because they are aliased as such. The current table is aliased as "me", so
you need to use me.column_name in order to avoid ambiguity. For example:
- # Get CDs from 1984 with a 'Foo' track
+ # Get CDs from 1984 with a 'Foo' track
my $rs = $schema->resultset('CD')->search(
- {
+ {
'me.year' => 1984,
'tracks.name' => 'Foo'
},
{ join => 'tracks' }
);
-
+
If the same join is supplied twice, it will be aliased to <rel>_2 (and
similarly for a third time). For e.g.
case.
Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search.
+for a C<join> attribute in the above search.
C<prefetch> can be used with the following relationship types: C<belongs_to>,
C<has_one> (or if you're using C<add_relationship>, any relationship declared
with an accessor type of 'single' or 'filter'). A more complex example that
-prefetches an artists cds, the tracks on those cds, and the tags associted
+prefetches an artists cds, the tracks on those cds, and the tags associted
with that artist is given below (assuming many-to-many from artists to tags):
my $rs = $schema->resultset('Artist')->search(
]
}
);
-
+
B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
attributes will be ignored.
If L<rows> attribute is not specified it defualts to 10 rows per page.
+When you have a paged resultset, L</count> will only return the number
+of rows in the page. To get the total, use the L</pager> and call
+C<total_entries> on it.
+
=head2 rows
=over 4
$table = $rs->result_source->name;
$latest = $rs->search (
undef,
- { from => \ "
- (SELECT e1.* FROM $table e1
- JOIN $table e2
- ON e1.location = e2.location
- AND e1.sequence < e2.sequence
- WHERE e2.sequence is NULL
+ { from => \ "
+ (SELECT e1.* FROM $table e1
+ JOIN $table e2
+ ON e1.location = e2.location
+ AND e1.sequence < e2.sequence
+ WHERE e2.sequence is NULL
) me",
},
);