$attrs->{_virtual_order_by} = [ $self->result_source->primary_columns ];
- my $collapse = $attrs->{collapse} || {};
-
+ $attrs->{collapse} ||= {};
if ( my $prefetch = delete $attrs->{prefetch} ) {
$prefetch = $self->_merge_attr( {}, $prefetch );
my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $collapse );
+ $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
push( @{ $attrs->{order_by} }, @$prefetch_ordering );
+ $attrs->{_collapse_order_by} = \@$prefetch_ordering;
}
+
if (delete $attrs->{distinct}) {
$attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
}
- $attrs->{collapse} = $collapse;
-
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# been doing
}
sub _select_args {
- my ($self, $ident, $select, $condition, $attrs) = @_;
+ my ($self, $ident, $select, $where, $attrs) = @_;
my $sql_maker = $self->sql_maker;
- $sql_maker->{for} = delete $attrs->{for};
-
- my $order = { map
- { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
- (qw/order_by group_by having _virtual_order_by/ )
- };
-
-
- my $bind_attrs = {};
-
my $alias2source = $self->_resolve_ident_sources ($ident);
+ # calculate bind_attrs before possible $ident mangling
+ my $bind_attrs = {};
for my $alias (keys %$alias2source) {
my $bindtypes = $self->source_bind_attributes ($alias2source->{$alias}) || {};
for my $col (keys %$bindtypes) {
}
}
- # This would be the point to deflate anything found in $condition
- # (and leave $attrs->{bind} intact). Problem is - inflators historically
- # expect a row object. And all we have is a resultsource (it is trivial
- # to extract deflator coderefs via $alias2source above).
- #
- # I don't see a way forward other than changing the way deflators are
- # invoked, and that's just bad...
-
- my @args = ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $condition, $order);
+ my @limit;
if ($attrs->{software_limit} ||
$sql_maker->_default_limit_syntax eq "GenericSubQ") {
$attrs->{software_limit} = 1;
# MySQL actually recommends this approach. I cringe.
$attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
- push @args, $attrs->{rows}, $attrs->{offset};
+
+ if ($attrs->{rows} && keys %{$attrs->{collapse}}) {
+ ($ident, $select, $where, $attrs)
+ = $self->_adjust_select_args_for_limited_prefetch ($ident, $select, $where, $attrs);
+ }
+ else {
+ push @limit, $attrs->{rows}, $attrs->{offset};
+ }
+ }
+
+###
+ # This would be the point to deflate anything found in $where
+ # (and leave $attrs->{bind} intact). Problem is - inflators historically
+ # expect a row object. And all we have is a resultsource (it is trivial
+ # to extract deflator coderefs via $alias2source above).
+ #
+ # I don't see a way forward other than changing the way deflators are
+ # invoked, and that's just bad...
+###
+
+ my $order = { map
+ { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
+ (qw/order_by group_by having _virtual_order_by/ )
+ };
+
+
+ $sql_maker->{for} = delete $attrs->{for};
+
+ return ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $where, $order, @limit);
+}
+
+sub _adjust_select_args_for_limited_prefetch {
+ my ($self, $from, $select, $where, $attrs) = @_;
+
+ if ($attrs->{group_by} and @{$attrs->{group_by}}) {
+ $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a group_by attribute');
+ }
+
+ $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a custom from attribute')
+ if (ref $from ne 'ARRAY');
+
+ # separate attributes
+ my $sub_attrs = { %$attrs };
+ delete $attrs->{$_} for qw/where bind rows offset/;
+ delete $sub_attrs->{$_} for qw/for collapse select order_by/;
+
+
+ my $alias = $attrs->{alias};
+
+ # create subquery select list
+ my $sub_select = [ grep { $_ =~ /^$alias\./ } @{$attrs->{select}} ];
+
+ # bring over all non-collapse-induced order_by into the inner query (if any)
+ # the outer one will have to keep them all
+ if (my $ord_cnt = @{$attrs->{order_by}} - @{$attrs->{_collapse_order_by}} ) {
+ $sub_attrs->{order_by} = [
+ @{$attrs->{order_by}}[ 0 .. ($#{$attrs->{order_by}} - $ord_cnt - 1) ]
+ ];
+ }
+
+
+ # mangle the from, separating it into an outer and inner part
+ my $self_ident = shift @$from;
+ my %join_map = map { $_->[0]{-alias} => $_->[0]{-join_path} } (@$from);
+
+ my (%inner_joins, %outer_joins);
+
+ # decide which parts of the join will remain
+ #
+ # resolve the prefetch-needed joins here as well, as the $attr->{prefetch}
+ # is 1) resolved away 2) unreliable as it may be a result of search_related
+ # and whatnot
+ #
+ # since we do not have introspectable SQLA, we fall back to ugly
+ # scanning of raw SQL for WHERE, and for pieces of ORDER BY
+ # in order to determine what goes into %inner_joins
+ # It may not be very efficient, but it's a reasonable stop-gap
+ {
+ # produce stuff unquoted, so it's easier to scan
+ my $sql_maker = $self->sql_maker;
+ local $sql_maker->{quote_char};
+
+ my @order_by = (map
+ { ref $_ ? $_->[0] : $_ }
+ $sql_maker->_order_by_chunks ($sub_attrs->{order_by})
+ );
+
+ my $where_sql = $sql_maker->where ($where);
+
+ # sort needed joins
+ for my $alias (keys %join_map) {
+
+ for my $piece ($where_sql, @order_by ) {
+ if ($piece =~ /\b$alias\./) {
+ $inner_joins{$alias} = 1;
+ $inner_joins{$_} = 1 for @{$join_map{$alias}};
+ }
+ }
+
+ for my $sel (@$select) {
+ if ($sel =~ /^$alias\./) {
+ $outer_joins{$alias}++;
+ $outer_joins{$_} = 1 for @{$join_map{$alias}};
+ }
+ }
+ }
+ }
+
+ my $inner_from = [ $self_ident ];
+ if (keys %inner_joins) {
+ for my $j (@$from) {
+ push @$inner_from, $j if $inner_joins{$j->[0]{-alias}};
+ }
+
+ # if a multi-type join was needed in the subquery ("multi" is indicated by
+ # presence in collapse) - add a group_by to simulate the collapse in the subq
+ for my $alias (keys %inner_joins) {
+
+ # the dot comes from some weirdness in collapse
+ # remove after the rewrite
+ if ($attrs->{collapse}{".$alias"}) {
+ $sub_attrs->{group_by} = $sub_select;
+ last;
+ }
+ }
+ }
+
+ my $subq = $self->_select_args_to_query (
+ $inner_from,
+ $sub_select,
+ $where,
+ $sub_attrs
+ );
+
+ my $outer_from = [ { me => $subq } ];
+ if (keys %outer_joins) {
+ for my $j (@$from) {
+ push @$outer_from, $j if $outer_joins{$j->[0]{-alias}};
+ }
}
- return @args;
+
+ return ($outer_from, $select, {}, $attrs); # where ended up in the subquery, thus {}
}
sub _resolve_ident_sources {
projects / dbsrgits/DBIx-Class.git / commitdiff