1 package Data::Query::Renderer::SQL::Slice::GenericSubQ;
3 use Data::Query::Constants qw(
4 DQ_SELECT DQ_ALIAS DQ_IDENTIFIER DQ_ORDER DQ_SLICE
11 unless ($dq->{order_is_stable}) {
12 die "GenericSubQ limit style requires a stable order";
14 die "Slice's inner is not a Select"
15 unless (my $orig_select = $dq->{from})->{type} eq DQ_SELECT;
18 my (@inside_select_list, @outside_select_list);
19 my $default_inside_alias;
20 SELECT: foreach my $s (@{$orig_select->{select}}) {
22 if ($s->{type} eq DQ_ALIAS) {
27 if ($s->{type} eq DQ_IDENTIFIER) {
28 if (!$name and @{$s->{elements}} == 2) {
29 $default_inside_alias ||= $s->{elements}[0];
30 if ($s->{elements}[0] eq $default_inside_alias) {
31 $alias_map{join('.',@{$s->{elements}})} = $s;
32 push @inside_select_list, $s;
33 push @outside_select_list, $s;
37 $name ||= join('__', @{$s->{elements}});
38 $key = join('.', @{$s->{elements}});
40 die "XXX not implemented yet" unless $name;
43 $name ||= sprintf("GENSYM__%03i",++$gensym_count);
44 push @inside_select_list, +{
49 push @outside_select_list, $alias_map{$key} = +{
50 type => DQ_IDENTIFIER,
54 my $order = $orig_select->{from};
55 my $order_gensym_count;
56 die "Slice's Select not followed by Order but order_is_stable set"
57 unless $order->{type} eq DQ_ORDER;
58 my (@order_nodes, %order_map);
59 while ($order->{type} eq DQ_ORDER) {
60 my $by = $order->{by};
61 if ($by->{type} eq DQ_IDENTIFIER) {
62 $default_inside_alias ||= $by->{elements}[0]
63 if @{$by->{elements}} == 2;
65 = $alias_map{join('.', @{$by->{elements}})}
68 @{$by->{elements}} == 2
69 and $by->{elements}[0] eq $default_inside_alias
73 my $name = sprintf("ORDER__BY__%03i",++$order_gensym_count);
74 push @inside_select_list, +{
80 type => DQ_IDENTIFIER,
81 elements => [ $name ],
86 die "XXX not implemented yet";
88 push @order_nodes, $order;
89 $order = $order->{from};
91 my $inside_select = +{
93 select => \@inside_select_list,
96 $default_inside_alias ||= 'me';
99 to => $default_inside_alias,
100 from => $inside_select,
102 my $default_inside_from;
107 if ($_[0]->{to} eq $default_inside_alias) {
108 $default_inside_from = $_[0]->{from};
109 no warnings 'exiting';
114 # _scan_nodes from DBIHacks - maybe make this a sub somewhere?
115 while (my $node = shift @queue) {
116 if ($node->{type} and my $cb = $cb_map->{$node->{type}}) {
120 grep ref($_) eq 'HASH',
121 map +(ref($_) eq 'ARRAY' ? @$_ : $_),
122 @{$node}{grep !/\./, keys %$node};
124 die "Couldn't figure out where ${default_inside_alias} came from :(";
126 my $bridge_where = +{
128 from => $bridge_from,
135 : $order_nodes[0]{reverse} ? '>' : '<'
144 operator => { 'SQL.Naive' => 'apply' },
147 type => DQ_IDENTIFIER,
148 elements => [ 'COUNT' ],
151 type => DQ_IDENTIFIER,
161 from => $default_inside_from,
162 to => 'rownum__emulation',
167 'SQL.Naive' => $order_nodes[0]{reverse} ? '>' : '<'
171 type => DQ_IDENTIFIER,
174 $order_nodes[0]{by}{elements}[-1],
176 }, 'rownum__emulation', $default_inside_alias,
184 value => $dq->{offset}{value} + $dq->{limit}{value} - 1
192 my $outside_order = $bridge_where;
195 by => $order_map{$_->{by}},
196 reverse => $_->{reverse},
197 from => $outside_order
198 } for reverse @order_nodes;
199 my $outside_select = +{
202 $dq->{preserve_order}
204 @outside_select_list,
205 grep @{$_->{elements}} == 1, @order_map{map $_->{by}, @order_nodes}
207 : \@outside_select_list,
209 from => $outside_order,
211 return $self->_render($outside_select);