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1 | package # Hide from PAUSE |
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2 | DBIx::Class::SQLMaker::OracleJoins; |
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3 | |
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4 | use warnings; |
5 | use strict; |
6 | |
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7 | use base qw( DBIx::Class::SQLMaker::Oracle ); |
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8 | |
9 | sub select { |
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10 | my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_; |
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11 | |
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12 | # pull out all join conds as regular WHEREs from all extra tables |
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13 | if (ref($table) eq 'ARRAY') { |
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14 | $where = $self->_oracle_joins($where, @{ $table }[ 1 .. $#$table ]); |
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15 | } |
16 | |
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17 | return $self->next::method($table, $fields, $where, $rs_attrs, @rest); |
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18 | } |
19 | |
20 | sub _recurse_from { |
21 | my ($self, $from, @join) = @_; |
22 | |
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23 | my @sqlf = $self->_from_chunk_to_sql($from); |
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24 | |
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25 | for (@join) { |
26 | my ($to, $on) = @$_; |
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27 | |
28 | if (ref $to eq 'ARRAY') { |
29 | push (@sqlf, $self->_recurse_from(@{ $to })); |
30 | } |
31 | else { |
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32 | push (@sqlf, $self->_from_chunk_to_sql($to)); |
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33 | } |
34 | } |
35 | |
36 | return join q{, }, @sqlf; |
37 | } |
38 | |
39 | sub _oracle_joins { |
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40 | my ($self, $where, @join) = @_; |
41 | my $join_where = $self->_recurse_oracle_joins(@join); |
42 | |
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43 | if (keys %$join_where) { |
44 | if (!defined($where)) { |
45 | $where = $join_where; |
46 | } else { |
47 | if (ref($where) eq 'ARRAY') { |
48 | $where = { -or => $where }; |
49 | } |
50 | $where = { -and => [ $join_where, $where ] }; |
51 | } |
52 | } |
53 | return $where; |
54 | } |
55 | |
56 | sub _recurse_oracle_joins { |
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57 | my $self = shift; |
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58 | |
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59 | my @where; |
60 | for my $j (@_) { |
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61 | my ($to, $on) = @{ $j }; |
62 | |
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63 | push @where, $self->_recurse_oracle_joins(@{ $to }) |
64 | if (ref $to eq 'ARRAY'); |
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65 | |
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66 | my $join_opts = ref $to eq 'ARRAY' ? $to->[0] : $to; |
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67 | my $left_join = q{}; |
68 | my $right_join = q{}; |
69 | |
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70 | if (ref $join_opts eq 'HASH' and my $jt = $join_opts->{-join_type}) { |
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71 | #TODO: Support full outer joins -- this would happen much earlier in |
72 | #the sequence since oracle 8's full outer join syntax is best |
73 | #described as INSANE. |
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74 | $self->throw_exception("Can't handle full outer joins in Oracle 8 yet!\n") |
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75 | if $jt =~ /full/i; |
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76 | |
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77 | $left_join = q{(+)} if $jt =~ /left/i |
78 | && $jt !~ /inner/i; |
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79 | |
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80 | $right_join = q{(+)} if $jt =~ /right/i |
81 | && $jt !~ /inner/i; |
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82 | } |
83 | |
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84 | # sadly SQLA treats where($scalar) as literal, so we need to jump some hoops |
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85 | push @where, map { \sprintf ('%s%s = %s%s', |
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86 | ref $_ ? $self->_recurse_where($_) : $self->_quote($_), |
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87 | $left_join, |
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88 | ref $on->{$_} ? $self->_recurse_where($on->{$_}) : $self->_quote($on->{$_}), |
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89 | $right_join, |
90 | )} keys %$on; |
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91 | } |
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92 | |
93 | return { -and => \@where }; |
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94 | } |
95 | |
96 | 1; |
97 | |
98 | =pod |
99 | |
100 | =head1 NAME |
101 | |
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102 | DBIx::Class::SQLMaker::OracleJoins - Pre-ANSI Joins-via-Where-Clause Syntax |
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103 | |
104 | =head1 PURPOSE |
105 | |
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106 | This module is used with Oracle < 9.0 due to lack of support for standard |
107 | ANSI join syntax. |
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108 | |
109 | =head1 SYNOPSIS |
110 | |
111 | Not intended for use directly; used as the sql_maker_class for schemas and components. |
112 | |
113 | =head1 DESCRIPTION |
114 | |
115 | Implements pre-ANSI joins specified in the where clause. Instead of: |
116 | |
117 | SELECT x FROM y JOIN z ON y.id = z.id |
118 | |
119 | It will write: |
120 | |
121 | SELECT x FROM y, z WHERE y.id = z.id |
122 | |
123 | It should properly support left joins, and right joins. Full outer joins are |
124 | not possible due to the fact that Oracle requires the entire query be written |
125 | to union the results of a left and right join, and by the time this module is |
126 | called to create the where query and table definition part of the sql query, |
127 | it's already too late. |
128 | |
129 | =head1 METHODS |
130 | |
131 | =over |
132 | |
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133 | =item select |
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134 | |
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135 | Overrides DBIx::Class::SQLMaker's select() method, which calls _oracle_joins() |
136 | to modify the column and table list before calling next::method(). |
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137 | |
138 | =back |
139 | |
140 | =head1 BUGS |
141 | |
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142 | Does not support full outer joins (however neither really does DBIC itself) |
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143 | |
144 | =head1 SEE ALSO |
145 | |
146 | =over |
147 | |
148 | =item L<DBIx::Class::Storage::DBI::Oracle::WhereJoins> - Storage class using this |
149 | |
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150 | =item L<DBIx::Class::SQLMaker> - Parent module |
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151 | |
152 | =item L<DBIx::Class> - Duh |
153 | |
154 | =back |
155 | |
156 | =head1 AUTHOR |
157 | |
158 | Justin Wheeler C<< <jwheeler@datademons.com> >> |
159 | |
160 | =head1 CONTRIBUTORS |
161 | |
162 | David Jack Olrik C<< <djo@cpan.org> >> |
163 | |
164 | =head1 LICENSE |
165 | |
166 | This module is licensed under the same terms as Perl itself. |
167 | |
168 | =cut |
169 | |