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}; |
5a058623 |
14 | # Should we simply strip until we reach a join/alias/etc. here? |
15 | $first_from = $first_from->{from}{from} if is_Having($first_from); |
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16 | $first_from = $first_from->{from} if is_Where($first_from); |
17 | while (is_Join $first_from) { |
18 | $first_from = $first_from->{left}; |
19 | } |
20 | $first_from = $first_from->{from} if is_Alias($first_from); |
21 | my $first_order = $remapped{inside_order}[0]{by}; |
22 | my $count_col = $first_order->{elements}[-1]; |
23 | my $count_alias = 'rownum__emulation'; |
24 | my $count_sel = Select( |
25 | [ Operator({ 'SQL.Naive' => 'apply' }, [ Identifier('COUNT'), Identifier('*') ]) ], |
26 | Where( |
27 | Operator( |
e31249d4 |
28 | { 'SQL.Naive' => ($remapped{inside_order}[0]{reverse} ? '>' : '<') }, |
29 | [ |
30 | Identifier($count_alias, $count_col), |
31 | $remapped{outside_order}[0]{by} |
32 | ] |
01d7143b |
33 | ), |
34 | Alias($count_alias, $first_from) |
35 | ) |
36 | ); |
37 | my $count_where = Operator( |
38 | { 'SQL.Naive' => ($dq->{offset} ? 'BETWEEN' : '<') }, |
39 | [ $count_sel, ( |
40 | $dq->{offset} |
41 | ? ( |
42 | $dq->{offset}, |
43 | { |
44 | %{$dq->{limit}}, |
45 | value => $dq->{limit}{value}+$dq->{offset}{value}-1 |
46 | } |
47 | ) |
48 | : ($dq->{limit}) |
49 | ) |
50 | ] |
51 | ); |
52 | return $self->render( |
53 | Select( |
54 | $remapped{outside_select_list}, |
55 | (compose { no warnings 'once'; Order($b->{by}, $b->{reverse}, $a) } |
56 | @{$remapped{outside_order}}, |
57 | Where( |
58 | $count_where, |
59 | Alias( |
60 | $remapped{default_inside_alias}, |
61 | Select( |
62 | $remapped{inside_select_list}, |
63 | $remapped{inner_body}, |
64 | ) |
65 | ) |
66 | ) |
67 | ) |
68 | ) |
69 | ); |
70 | } |
71 | |
72 | 1; |