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 $count_sel = Select( |
23 | [ Operator({ 'SQL.Naive' => 'apply' }, [ Identifier('COUNT'), Identifier('*') ]) ], |
24 | Where( |
25 | Operator( |
e31249d4 |
26 | { 'SQL.Naive' => ($remapped{inside_order}[0]{reverse} ? '>' : '<') }, |
27 | [ |
28 | Identifier($count_alias, $count_col), |
29 | $remapped{outside_order}[0]{by} |
30 | ] |
01d7143b |
31 | ), |
32 | Alias($count_alias, $first_from) |
33 | ) |
34 | ); |
35 | my $count_where = Operator( |
36 | { 'SQL.Naive' => ($dq->{offset} ? 'BETWEEN' : '<') }, |
37 | [ $count_sel, ( |
38 | $dq->{offset} |
39 | ? ( |
40 | $dq->{offset}, |
41 | { |
42 | %{$dq->{limit}}, |
43 | value => $dq->{limit}{value}+$dq->{offset}{value}-1 |
44 | } |
45 | ) |
46 | : ($dq->{limit}) |
47 | ) |
48 | ] |
49 | ); |
50 | return $self->render( |
51 | Select( |
52 | $remapped{outside_select_list}, |
53 | (compose { no warnings 'once'; Order($b->{by}, $b->{reverse}, $a) } |
54 | @{$remapped{outside_order}}, |
55 | Where( |
56 | $count_where, |
57 | Alias( |
58 | $remapped{default_inside_alias}, |
59 | Select( |
60 | $remapped{inside_select_list}, |
61 | $remapped{inner_body}, |
62 | ) |
63 | ) |
64 | ) |
65 | ) |
66 | ) |
67 | ); |
68 | } |
69 | |
70 | 1; |