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1 | package DBIx::Class::SQLMaker::OracleJoins; |
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2 | |
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3 | use warnings; |
4 | use strict; |
5 | |
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6 | use base qw( DBIx::Class::SQLMaker::Oracle ); |
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7 | |
8 | sub select { |
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9 | my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_; |
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10 | |
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11 | # pull out all join conds as regular WHEREs from all extra tables |
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12 | if (ref($table) eq 'ARRAY') { |
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13 | $where = $self->_oracle_joins($where, @{ $table }[ 1 .. $#$table ]); |
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14 | } |
15 | |
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16 | return $self->next::method($table, $fields, $where, $rs_attrs, @rest); |
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17 | } |
18 | |
19 | sub _recurse_from { |
20 | my ($self, $from, @join) = @_; |
21 | |
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22 | my @sqlf = $self->_from_chunk_to_sql($from); |
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23 | |
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24 | for (@join) { |
25 | my ($to, $on) = @$_; |
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26 | |
27 | if (ref $to eq 'ARRAY') { |
28 | push (@sqlf, $self->_recurse_from(@{ $to })); |
29 | } |
30 | else { |
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31 | push (@sqlf, $self->_from_chunk_to_sql($to)); |
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32 | } |
33 | } |
34 | |
35 | return join q{, }, @sqlf; |
36 | } |
37 | |
38 | sub _oracle_joins { |
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39 | my ($self, $where, @join) = @_; |
40 | my $join_where = $self->_recurse_oracle_joins(@join); |
41 | |
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42 | if (keys %$join_where) { |
43 | if (!defined($where)) { |
44 | $where = $join_where; |
45 | } else { |
46 | if (ref($where) eq 'ARRAY') { |
47 | $where = { -or => $where }; |
48 | } |
49 | $where = { -and => [ $join_where, $where ] }; |
50 | } |
51 | } |
52 | return $where; |
53 | } |
54 | |
55 | sub _recurse_oracle_joins { |
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56 | my $self = shift; |
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57 | |
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58 | my @where; |
59 | for my $j (@_) { |
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60 | my ($to, $on) = @{ $j }; |
61 | |
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62 | push @where, $self->_recurse_oracle_joins(@{ $to }) |
63 | if (ref $to eq 'ARRAY'); |
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64 | |
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65 | my $join_opts = ref $to eq 'ARRAY' ? $to->[0] : $to; |
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66 | my $left_join = q{}; |
67 | my $right_join = q{}; |
68 | |
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69 | if (ref $join_opts eq 'HASH' and my $jt = $join_opts->{-join_type}) { |
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70 | #TODO: Support full outer joins -- this would happen much earlier in |
71 | #the sequence since oracle 8's full outer join syntax is best |
72 | #described as INSANE. |
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73 | $self->throw_exception("Can't handle full outer joins in Oracle 8 yet!\n") |
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74 | if $jt =~ /full/i; |
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75 | |
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76 | $left_join = q{(+)} if $jt =~ /left/i |
77 | && $jt !~ /inner/i; |
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78 | |
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79 | $right_join = q{(+)} if $jt =~ /right/i |
80 | && $jt !~ /inner/i; |
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81 | } |
82 | |
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83 | # sadly SQLA treats where($scalar) as literal, so we need to jump some hoops |
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84 | push @where, map { \sprintf ('%s%s = %s%s', |
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85 | ref $_ ? $self->_recurse_where($_) : $self->_quote($_), |
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86 | $left_join, |
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87 | ref $on->{$_} ? $self->_recurse_where($on->{$_}) : $self->_quote($on->{$_}), |
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88 | $right_join, |
89 | )} keys %$on; |
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90 | } |
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91 | |
92 | return { -and => \@where }; |
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93 | } |
94 | |
95 | 1; |
96 | |
97 | =pod |
98 | |
99 | =head1 NAME |
100 | |
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101 | DBIx::Class::SQLMaker::OracleJoins - Pre-ANSI Joins-via-Where-Clause Syntax |
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102 | |
103 | =head1 PURPOSE |
104 | |
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105 | This module is used with Oracle < 9.0 due to lack of support for standard |
106 | ANSI join syntax. |
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107 | |
108 | =head1 SYNOPSIS |
109 | |
110 | Not intended for use directly; used as the sql_maker_class for schemas and components. |
111 | |
112 | =head1 DESCRIPTION |
113 | |
114 | Implements pre-ANSI joins specified in the where clause. Instead of: |
115 | |
116 | SELECT x FROM y JOIN z ON y.id = z.id |
117 | |
118 | It will write: |
119 | |
120 | SELECT x FROM y, z WHERE y.id = z.id |
121 | |
122 | It should properly support left joins, and right joins. Full outer joins are |
123 | not possible due to the fact that Oracle requires the entire query be written |
124 | to union the results of a left and right join, and by the time this module is |
125 | called to create the where query and table definition part of the sql query, |
126 | it's already too late. |
127 | |
128 | =head1 METHODS |
129 | |
130 | =over |
131 | |
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132 | =item select |
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133 | |
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134 | Overrides DBIx::Class::SQLMaker's select() method, which calls _oracle_joins() |
135 | to modify the column and table list before calling next::method(). |
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136 | |
137 | =back |
138 | |
139 | =head1 BUGS |
140 | |
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141 | Does not support full outer joins (however neither really does DBIC itself) |
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142 | |
143 | =head1 SEE ALSO |
144 | |
145 | =over |
146 | |
147 | =item L<DBIx::Class::Storage::DBI::Oracle::WhereJoins> - Storage class using this |
148 | |
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149 | =item L<DBIx::Class::SQLMaker> - Parent module |
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150 | |
151 | =item L<DBIx::Class> - Duh |
152 | |
153 | =back |
154 | |
155 | =head1 AUTHOR |
156 | |
157 | Justin Wheeler C<< <jwheeler@datademons.com> >> |
158 | |
159 | =head1 CONTRIBUTORS |
160 | |
161 | David Jack Olrik C<< <djo@cpan.org> >> |
162 | |
163 | =head1 LICENSE |
164 | |
165 | This module is licensed under the same terms as Perl itself. |
166 | |
167 | =cut |
168 | |