Commit | Line | Data |
01d7143b |
1 | package Data::Query::Renderer::SQL::Slice::GenericSubquery; |
2 | |
3 | use Data::Query::ExprHelpers; |
4 | use Moo::Role; |
5 | |
6 | with 'Data::Query::Renderer::SQL::Slice::SubqueryRemap'; |
7 | |
8 | sub _render_slice { |
9 | my ($self, $dq) = @_; |
10 | die "Slice's inner is not a Select" |
11 | unless is_Select my $orig_select = $dq->{from}; |
12 | my %remapped = $self->_subquery_remap($orig_select); |
13 | my $first_from = $remapped{inner_body}; |
14 | $first_from = $first_from->{from} if is_Where($first_from); |
15 | while (is_Join $first_from) { |
16 | $first_from = $first_from->{left}; |
17 | } |
18 | $first_from = $first_from->{from} if is_Alias($first_from); |
19 | my $first_order = $remapped{inside_order}[0]{by}; |
20 | my $count_col = $first_order->{elements}[-1]; |
21 | my $count_alias = 'rownum__emulation'; |
22 | my $count_sel = Select( |
23 | [ Operator({ 'SQL.Naive' => 'apply' }, [ Identifier('COUNT'), Identifier('*') ]) ], |
24 | Where( |
25 | Operator( |
26 | { 'SQL.Naive' => ($first_order->{reverse} ? '>' : '<') }, |
27 | [ Identifier($count_alias, $count_col), $first_order ] |
28 | ), |
29 | Alias($count_alias, $first_from) |
30 | ) |
31 | ); |
32 | my $count_where = Operator( |
33 | { 'SQL.Naive' => ($dq->{offset} ? 'BETWEEN' : '<') }, |
34 | [ $count_sel, ( |
35 | $dq->{offset} |
36 | ? ( |
37 | $dq->{offset}, |
38 | { |
39 | %{$dq->{limit}}, |
40 | value => $dq->{limit}{value}+$dq->{offset}{value}-1 |
41 | } |
42 | ) |
43 | : ($dq->{limit}) |
44 | ) |
45 | ] |
46 | ); |
47 | return $self->render( |
48 | Select( |
49 | $remapped{outside_select_list}, |
50 | (compose { no warnings 'once'; Order($b->{by}, $b->{reverse}, $a) } |
51 | @{$remapped{outside_order}}, |
52 | Where( |
53 | $count_where, |
54 | Alias( |
55 | $remapped{default_inside_alias}, |
56 | Select( |
57 | $remapped{inside_select_list}, |
58 | $remapped{inner_body}, |
59 | ) |
60 | ) |
61 | ) |
62 | ) |
63 | ) |
64 | ); |
65 | } |
66 | |
67 | 1; |