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4ce3b851 |
1 | package DBIx::Class::Storage::DBI::MultiColumnIn; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
6 | use base 'DBIx::Class::Storage::DBI'; |
7 | |
8 | =head1 NAME |
9 | |
10 | DBIx::Class::Storage::DBI::MultiColumnIn - Storage component for RDBMS supporting multicolumn in clauses |
11 | |
12 | =head1 DESCRIPTION |
13 | |
14 | While ANSI SQL does not define a multicolumn in operator, many databases can |
15 | in fact understand WHERE (cola, colb) IN ( SELECT subcol_a, subcol_b ... ) |
16 | The storage class for any such RDBMS should inherit from this class, in order |
17 | to dramatically speed up update/delete operations on joined multipk resultsets. |
18 | |
19 | At this point the only overriden method is C<_multipk_update_delete()> |
20 | |
21 | =cut |
22 | |
23 | sub _multipk_update_delete { |
24 | my $self = shift; |
25 | my ($rs, $op, $values) = @_; |
26 | |
27 | my $rsrc = $rs->result_source; |
28 | my @pcols = $rsrc->primary_columns; |
29 | my $attrs = $rs->_resolved_attrs; |
30 | |
31 | # naive check - this is an internal method after all, we should know what we are doing |
32 | $self->throw_exception ('Number of columns selected by supplied resultset does not match number of primary keys') |
33 | if ( ref $attrs->{select} ne 'ARRAY' or @{$attrs->{select}} != @pcols ); |
34 | |
35 | # This is hideously ugly, but SQLA does not understand multicol IN expressions |
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36 | my $sqla = $self->_sql_maker; |
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37 | my ($sql, @bind) = @${$rs->as_query}; |
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38 | $sql = sprintf ('(%s) IN %s', # the as_query stuff is already enclosed in ()s |
39 | join (', ', map { $sqla->_quote ($_) } @pcols), |
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40 | $sql, |
41 | ); |
42 | |
43 | return $self->$op ( |
44 | $rsrc, |
45 | $op eq 'update' ? $values : (), |
46 | \[$sql, @bind], |
47 | ); |
48 | |
49 | } |
50 | |
51 | =head1 AUTHORS |
52 | |
53 | See L<DBIx::Class/CONTRIBUTORS> |
54 | |
55 | =head1 LICENSE |
56 | |
57 | You may distribute this code under the same terms as Perl itself. |
58 | |
59 | =cut |
60 | |
61 | 1; |