return $self->search(@_)->count if @_ and defined $_[0];
return scalar @{ $self->get_cache } if $self->get_cache;
- my $meth = $self->_has_resolved_attr (qw/collapse group_by/)
- ? 'count_grouped'
- : 'count'
- ;
-
my $attrs = $self->_resolved_attrs_copy;
+
+ # this is a little optimization - it is faster to do the limit
+ # adjustments in software, instead of a subquery
+ my $rows = delete $attrs->{rows};
+ my $offset = delete $attrs->{offset};
+
+ my $crs;
+ if ($self->_has_resolved_attr (qw/collapse group_by/)) {
+ $crs = $self->_count_subq_rs ($attrs);
+ }
+ else {
+ $crs = $self->_count_rs ($attrs);
+ }
+ my $count = $crs->next;
+
+ $count -= $offset if $offset;
+ $count = $rows if $rows and $rows < $count;
+ $count = 0 if ($count < 0);
+
+ return $count;
+ }
+
+ =head2 count_rs
+
+ =over 4
+
+ =item Arguments: $cond, \%attrs??
+
+ =item Return Value: $count_rs
+
+ =back
+
+ Same as L</count> but returns a L<DBIx::Class::ResultSetColumn> object.
+ This can be very handy for subqueries:
+
+ ->search( { amount => $some_rs->count_rs->as_query } )
+
+ As with regular resultsets the SQL query will be executed only after
+ the resultset is accessed via L</next> or L</all>. That would return
+ the same single value obtainable via L</count>.
+
+ =cut
+
+ sub count_rs {
+ my $self = shift;
+ return $self->search(@_)->count_rs if @_;
+
+ # this may look like a lack of abstraction (count() does about the same)
+ # but in fact an _rs *must* use a subquery for the limits, as the
+ # software based limiting can not be ported if this $rs is to be used
+ # in a subquery itself (i.e. ->as_query)
+ if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
+ return $self->_count_subq_rs;
+ }
+ else {
+ return $self->_count_rs;
+ }
+ }
+
+ #
+ # returns a ResultSetColumn object tied to the count query
+ #
+ sub _count_rs {
+ my ($self, $attrs) = @_;
+
+ my $rsrc = $self->result_source;
+ $attrs ||= $self->_resolved_attrs;
+
+ my $tmp_attrs = { %$attrs };
+
+ # take off any limits, record_filter is cdbi, and no point of ordering a count
+ delete $tmp_attrs->{$_} for (qw/select as rows offset order_by record_filter/);
+
+ # overwrite the selector (supplied by the storage)
+ $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $tmp_attrs);
+ $tmp_attrs->{as} = 'count';
+
+ my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
+
+ return $tmp_rs;
+ }
+
+ #
+ # same as above but uses a subquery
+ #
+ sub _count_subq_rs {
+ my ($self, $attrs) = @_;
+
my $rsrc = $self->result_source;
+ $attrs ||= $self->_resolved_attrs_copy;
- return $rsrc->storage->$meth ($rsrc, $attrs);
+ my $sub_attrs = { %$attrs };
+
+ # these can not go in the subquery, and there is no point of ordering it
+ delete $sub_attrs->{$_} for qw/collapse select as order_by/;
+
+ # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
+ # clobber old group_by regardless
+ if ( keys %{$attrs->{collapse}} ) {
+ $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->primary_columns) ]
+ }
+
+ $sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $sub_attrs);
+
+ $attrs->{from} = [{
+ count_subq => $rsrc->resultset_class->new ($rsrc, $sub_attrs )->as_query
+ }];
+
+ # the subquery replaces this
+ delete $attrs->{$_} for qw/where bind collapse group_by having having_bind rows offset/;
+
+ return $self->_count_rs ($attrs);
}
+
sub _bool {
return 1;
}
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
-objects is returned.
+L<DBIx::Class::ResultSet/create>, and the resulting objects are
+accumulated into an array. The array itself, or an array reference
+is returned depending on scalar or list context.
Example: Assuming an Artist Class that has many CDs Classes relating:
foreach my $item (@$data) {
push(@created, $self->create($item));
}
- return @created;
+ return wantarray ? @created : \@created;
} else {
my ($first, @rest) = @$data;
$self->{attrs}{alias} => $source->from,
} ];
- if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
+ if ( $attrs->{join} || $attrs->{prefetch} ) {
+
+ $self->throw_exception ('join/prefetch can not be used with a literal scalarref {from}')
+ if ref $attrs->{from} ne 'ARRAY';
+
my $join = delete $attrs->{join} || {};
if ( defined $attrs->{prefetch} ) {
$join = $self->_merge_attr( $join, $attrs->{prefetch} );
-
}
$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} || {} } }
+ )
];
-
}
if ( $attrs->{order_by} ) {
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