1 package Data::Query::Renderer::SQL::Slice::GenericSubquery;
3 use Data::Query::ExprHelpers;
6 with 'Data::Query::Renderer::SQL::Slice::SubqueryRemap';
9 (limit => 1, offset => 1);
13 (limit => 'requires', offset => 'requires');
18 die "Slice's inner is not a Select"
19 unless is_Select my $orig_select = $dq->{from};
20 my %remapped = $self->_subquery_remap($orig_select);
21 my $first_from = $remapped{inner_body};
22 # Should we simply strip until we reach a join/alias/etc. here?
23 $first_from = $first_from->{from}{from} if is_Having($first_from);
24 $first_from = $first_from->{from} if is_Where($first_from);
25 while (is_Join $first_from) {
26 $first_from = $first_from->{left};
28 $first_from = $first_from->{from} if is_Alias($first_from);
29 my $first_order = $remapped{inside_order}[0]{by};
30 my $count_col = $first_order->{elements}[-1];
31 my $count_alias = 'rownum__emulation';
32 my $count_sel = Select(
33 [ Operator({ 'SQL.Naive' => 'apply' }, [ Identifier('COUNT'), Identifier('*') ]) ],
36 { 'SQL.Naive' => ($remapped{inside_order}[0]{reverse} ? '>' : '<') },
38 Identifier($count_alias, $count_col),
39 $remapped{outside_order}[0]{by}
42 Alias($count_alias, $first_from)
45 my $count_where = Operator(
46 { 'SQL.Naive' => ($dq->{offset} ? 'BETWEEN' : '<') },
53 value => $dq->{limit}{value}+$dq->{offset}{value}-1
62 $remapped{outside_select_list},
63 (compose { no warnings 'once'; Order($b->{by}, $b->{reverse}, $b->{nulls}, $a) }
64 @{$remapped{outside_order}},
68 $remapped{default_inside_alias},
70 $remapped{inside_select_list},
71 $remapped{inner_body},