fallback => 1;
use Data::Page;
+=head1 NAME
+
+DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
+
+=head1 SYNOPSIS
+
+my $rs = MyApp::DB::Class->search(registered => 1);
+my @rows = MyApp::DB::Class->search(foo => 'bar');
+
+=head1 DESCRIPTION
+
+The resultset is also known as an iterator. It is responsible for handling
+queries that may return an arbitrary number of rows, e.g. via C<search>
+or a C<has_many> relationship.
+
+=head1 METHODS
+
+=head2 new($db_class, \%$attrs)
+
+The resultset constructor. Takes a table class and an attribute hash
+(see below for more information on attributes). Does not perform
+any queries -- these are executed as needed by the other methods.
+
+=cut
+
sub new {
my ($it_class, $db_class, $attrs) = @_;
#use Data::Dumper; warn Dumper(@_);
unless $seen{$pre};
push(@{$attrs->{cols}},
map { "$pre.$_" }
- $db_class->_relationships->{$pre}->{class}->columns);
+ $db_class->_relationships->{$pre}->{class}->_select_columns);
}
my $new = {
class => $db_class,
return $new;
}
+=head2 cursor
+
+Return a storage-driven cursor to the given resultset.
+
+=cut
+
sub cursor {
my ($self) = @_;
my ($db_class, $attrs) = @{$self}{qw/class attrs/};
$attrs->{where},$attrs);
}
+=head2 slice($first, $last)
+
+Returns a subset of elements from the resultset.
+
+=cut
+
sub slice {
my ($self, $min, $max) = @_;
my $attrs = { %{ $self->{attrs} || {} } };
return (wantarray ? $slice->all : $slice);
}
+=head2 next
+
+Returns the next element in the resultset (undef is there is none).
+
+=cut
+
sub next {
my ($self) = @_;
my @row = $self->cursor->next;
sub _construct_object {
my ($self, @row) = @_;
- my @cols = $self->{class}->_select_columns;
+ my @cols = @{ $self->{attrs}{cols} };
+ s/^me\.// for @cols;
+ @cols = grep { /\(/ or ! /\./ } @cols;
+ my $new;
unless ($self->{attrs}{prefetch}) {
- return $self->{class}->_row_to_object(\@cols, \@row);
+ $new = $self->{class}->_row_to_object(\@cols, \@row);
} else {
my @main = splice(@row, 0, scalar @cols);
- my $new = $self->{class}->_row_to_object(\@cols, \@main);
+ $new = $self->{class}->_row_to_object(\@cols, \@main);
PRE: foreach my $pre (@{$self->{attrs}{prefetch}}) {
my $rel_obj = $self->{class}->_relationships->{$pre};
- my @pre_cols = $rel_obj->{class}->columns;
+ my $pre_class = $self->{class}->resolve_class($rel_obj->{class});
+ my @pre_cols = $pre_class->_select_columns;
my @vals = splice(@row, 0, scalar @pre_cols);
- my $fetched = $rel_obj->{class}->_row_to_object(\@pre_cols, \@vals);
+ my $fetched = $pre_class->_row_to_object(\@pre_cols, \@vals);
$self->{class}->throw("No accessor for prefetched $pre")
unless defined $rel_obj->{attrs}{accessor};
if ($rel_obj->{attrs}{accessor} eq 'single') {
foreach my $pri ($rel_obj->{class}->primary_columns) {
- next PRE unless defined $fetched->get_column($pri);
+ unless (defined $fetched->get_column($pri)) {
+ undef $fetched;
+ last;
+ }
}
$new->{_relationship_data}{$pre} = $fetched;
} elsif ($rel_obj->{attrs}{accessor} eq 'filter') {
$new->{_inflated_column}{$pre} = $fetched;
} else {
- $self->{class}->throw("Don't know to to store prefetched $pre");
+ $self->{class}->throw("Don't know how to store prefetched $pre");
}
}
- return $new;
}
+ $new = $self->{attrs}{record_filter}->($new)
+ if exists $self->{attrs}{record_filter};
+ return $new;
}
+=head2 count
+
+Performs an SQL C<COUNT> with the same query as the resultset was built
+with to find the number of elements.
+
+=cut
+
sub count {
my ($self) = @_;
my $db_class = $self->{class};
: $self->{count};
}
+=head2 all
+
+Returns all elements in the resultset. Called implictly if the resultset
+is returned in list context.
+
+=cut
+
sub all {
my ($self) = @_;
return map { $self->_construct_object(@$_); }
$self->cursor->all;
}
+=head2 reset
+
+Resets the resultset's cursor, so you can iterate through the elements again.
+
+=cut
+
sub reset {
my ($self) = @_;
$self->cursor->reset;
return $self;
}
+=head2 first
+
+Resets the resultset and returns the first element.
+
+=cut
+
sub first {
return $_[0]->reset->next;
}
+=head2 delete
+
+Deletes all elements in the resultset.
+
+=cut
+
sub delete {
my ($self) = @_;
$_->delete for $self->all;
*delete_all = \&delete; # Yeah, yeah, yeah ...
+=head2 pager
+
+Returns a L<Data::Page> object for the current resultset. Only makes
+sense for queries with page turned on.
+
+=cut
+
sub pager {
my ($self) = @_;
my $attrs = $self->{attrs};
return $self->{pager};
}
+=head2 page($page_num)
+
+Returns a new resultset for the specified page.
+
+=cut
+
sub page {
my ($self, $page) = @_;
my $attrs = $self->{attrs};
return $self->new($self->{class}, $attrs);
}
+=head1 Attributes
+
+The resultset takes various attributes that modify its behavior.
+Here's an overview of them:
+
+=head2 order_by
+
+Which column(s) to order the results by. This is currently passed
+through directly to SQL, so you can give e.g. C<foo DESC> for a
+descending order.
+
+=head2 cols
+
+Which columns should be retrieved.
+
+=head2 join
+
+Contains a list of relationships that should be joined for this query. Can also
+contain a hash reference to refer to that relation's relations. So, if one column
+in your class C<belongs_to> foo and another C<belongs_to> bar, you can do
+C<< join => [qw/ foo bar /] >> to join both (and e.g. use them for C<order_by>).
+If a foo contains many margles and you want to join those too, you can do
+C<< join => { foo => 'margle' } >>. If you want to fetch the columns from the
+related table as well, see C<prefetch> below.
+
+=head2 prefetch
+
+Contains a list of relationships that should be fetched along with the main
+query (when they are accessed afterwards they will have already been
+"prefetched"). This is useful for when you know you will need the related
+object(s), because it saves a query. Currently limited to prefetching
+one relationship deep, so unlike C<join>, prefetch must be an arrayref.
+
+=head2 from
+
+This attribute can contain a arrayref of elements. Each element can be another
+arrayref, to nest joins, or it can be a hash which represents the two sides
+of the join.
+
+NOTE: Use this on your own risk. This allows you to shoot your foot off!
+
+=head2 page
+
+For a paged resultset, specifies which page to retrieve. Leave unset
+for an unpaged resultset.
+
+=head2 rows
+
+For a paged resultset, how many rows per page
+
+=cut
+
1;
projects / dbsrgits/DBIx-Class.git / blobdiff