use overload
'0+' => 'count',
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, $cursor, $args, $cols, $attrs) = @_;
+ my ($class, $db_class, $attrs) = @_;
#use Data::Dumper; warn Dumper(@_);
- $it_class = ref $it_class if ref $it_class;
+ $class = ref $class if ref $class;
$attrs = { %{ $attrs || {} } };
- unless ($cursor) {
- $attrs->{bind} = $args;
- $cursor = $db_class->storage->select($db_class->_table_name,$cols,
- $attrs->{where},$attrs);
+ my %seen;
+ $attrs->{cols} ||= [ map { "me.$_" } $db_class->_select_columns ];
+ $attrs->{from} ||= [ { 'me' => $db_class->_table_name } ];
+ if ($attrs->{join}) {
+ foreach my $j (ref $attrs->{join} eq 'ARRAY'
+ ? (@{$attrs->{join}}) : ($attrs->{join})) {
+ if (ref $j eq 'HASH') {
+ $seen{$_} = 1 foreach keys %$j;
+ } else {
+ $seen{$j} = 1;
+ }
+ }
+ push(@{$attrs->{from}}, $db_class->_resolve_join($attrs->{join}, 'me'));
+ }
+ foreach my $pre (@{$attrs->{prefetch} || []}) {
+ push(@{$attrs->{from}}, $db_class->_resolve_join($pre, 'me'))
+ unless $seen{$pre};
+ push(@{$attrs->{cols}},
+ map { "$pre.$_" }
+ $db_class->_relationships->{$pre}->{class}->_select_columns);
}
my $new = {
- class => $db_class,
- cursor => $cursor,
- cols => $cols,
- args => $args,
+ source => $db_class,
+ cols => $attrs->{cols},
cond => $attrs->{where},
+ from => $attrs->{from},
+ count => undef,
+ pager => undef,
attrs => $attrs };
- return bless ($new, $it_class);
+ bless ($new, $class);
+ $new->pager if ($attrs->{page});
+ return $new;
}
+=head2 search
+
+ my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3"
+ my $new_rs = $rs->search({ foo => 3 });
+
+If you need to pass in additional attributes but no additional condition,
+call it as ->search(undef, \%attrs);
+
+ my @all = $class->search({}, { cols => [qw/foo bar/] }); # "SELECT foo, bar FROM $class_table"
+
+=cut
+
+sub search {
+ my $self = shift;
+
+ #use Data::Dumper;warn Dumper(@_);
+
+ my $attrs = { %{$self->{attrs}} };
+ if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+ $attrs = { %{ pop(@_) } };
+ }
+
+ my $where = ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_});
+ if (defined $where) {
+ $where = (defined $attrs->{where}
+ ? { '-and' => [ $where, $attrs->{where} ] }
+ : $where);
+ $attrs->{where} = $where;
+ }
+
+ my $rs = $self->new($self->{source}, $attrs);
+
+ return (wantarray ? $rs->all : $rs);
+}
+
+=head2 search_literal
+ my @obj = $rs->search_literal($literal_where_cond, @bind);
+ my $new_rs = $rs->search_literal($literal_where_cond, @bind);
+
+Pass a literal chunk of SQL to be added to the conditional part of the
+resultset
+
+=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, $attrs);
+}
+
+=head2 cursor
+
+Returns a storage-driven cursor to the given resultset.
+
+=cut
+
+sub cursor {
+ my ($self) = @_;
+ my ($source, $attrs) = @{$self}{qw/source attrs/};
+ if ($attrs->{page}) {
+ $attrs->{rows} = $self->pager->entries_per_page;
+ $attrs->{offset} = $self->pager->skipped;
+ }
+ return $self->{cursor}
+ ||= $source->storage->select($self->{from}, $self->{cols},
+ $attrs->{where},$attrs);
+}
+
+=head2 search_like
+
+Identical to search except defaults to 'LIKE' instead of '=' in condition
+
+=cut
+
+sub search_like {
+ my $class = shift;
+ my $attrs = { };
+ if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+ $attrs = pop(@_);
+ }
+ my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_};
+ $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
+ return $class->search($query, { %$attrs });
+}
+
+=head2 slice($first, $last)
+
+Returns a subset of elements from the resultset.
+
+=cut
+
sub slice {
my ($self, $min, $max) = @_;
my $attrs = { %{ $self->{attrs} || {} } };
- $self->{class}->throw("Can't slice without where") unless $attrs->{where};
+ $self->{source}->throw("Can't slice without where") unless $attrs->{where};
$attrs->{offset} = $min;
$attrs->{rows} = ($max ? ($max - $min + 1) : 1);
- my $slice = $self->new($self->{class}, undef, $self->{args},
- $self->{cols}, $attrs);
+ my $slice = $self->new($self->{source}, $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;
+ my @row = $self->cursor->next;
return unless (@row);
- return $self->{class}->_row_to_object($self->{cols}, \@row);
+ return $self->_construct_object(@row);
+}
+
+sub _construct_object {
+ my ($self, @row) = @_;
+ my @cols = @{ $self->{attrs}{cols} };
+ s/^me\.// for @cols;
+ @cols = grep { /\(/ or ! /\./ } @cols;
+ my $new;
+ unless ($self->{attrs}{prefetch}) {
+ $new = $self->{source}->_row_to_object(\@cols, \@row);
+ } else {
+ my @main = splice(@row, 0, scalar @cols);
+ $new = $self->{source}->_row_to_object(\@cols, \@main);
+ PRE: foreach my $pre (@{$self->{attrs}{prefetch}}) {
+ my $rel_obj = $self->{source}->_relationships->{$pre};
+ my $pre_class = $self->{source}->resolve_class($rel_obj->{class});
+ my @pre_cols = $pre_class->_select_columns;
+ my @vals = splice(@row, 0, scalar @pre_cols);
+ my $fetched = $pre_class->_row_to_object(\@pre_cols, \@vals);
+ $self->{source}->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) {
+ 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->{source}->throw("Don't know how to store prefetched $pre");
+ }
+ }
+ }
+ $new = $self->{attrs}{record_filter}->($new)
+ if exists $self->{attrs}{record_filter};
+ return $new;
}
+=head2 count
+
+Performs an SQL C<COUNT> with the same query as the resultset was built
+with to find the number of elements. If passed arguments, does a search
+on the resultset and counts the results of that.
+
+=cut
+
sub count {
- my ($self) = @_;
- return $self->{attrs}{rows} if $self->{attrs}{rows};
- return $self->{class}->count($self->{cond}, { bind => $self->{args} });
+ my $self = shift;
+ return $self->search(@_)->count if @_ && defined $_[0];
+ my $attrs = { %{ $self->{attrs} } };
+ unless ($self->{count}) {
+ # offset and order by are not needed to count
+ delete $attrs->{$_} for qw/offset order_by/;
+
+ my @cols = 'COUNT(*)';
+ $self->{count} = $self->{source}->storage->select_single(
+ $self->{from}, \@cols, $self->{cond}, $attrs);
+ }
+ return 0 unless $self->{count};
+ return $self->{pager}->entries_on_this_page if ($self->{pager});
+ return ( $attrs->{rows} && $attrs->{rows} < $self->{count} )
+ ? $attrs->{rows}
+ : $self->{count};
}
+=head2 count_literal
+
+Calls search_literal with the passed arguments, then count.
+
+=cut
+
+sub count_literal { shift->search_literal(@_)->count; }
+
+=head2 all
+
+Returns all elements in the resultset. Called implictly if the resultset
+is returned in list context.
+
+=cut
+
sub all {
my ($self) = @_;
- $self->reset;
- my @all;
- while (my $obj = $self->next) {
- push(@all, $obj);
- }
- $self->reset;
- return @all;
+ 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;
+ $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};
+ delete $attrs->{offset};
+ my $rows_per_page = delete $attrs->{rows} || 10;
+ $self->{pager} ||= Data::Page->new(
+ $self->count, $rows_per_page, $attrs->{page} || 1);
+ $attrs->{rows} = $rows_per_page;
+ 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};
+ $attrs->{page} = $page;
+ return $self->new($self->{source}, $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