fixed multiple column count distincts in SQLite and Oracle

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBI / MultiDistinctEmulation.pm

diff --git a/lib/DBIx/Class/Storage/DBI/MultiDistinctEmulation.pm b/lib/DBIx/Class/Storage/DBI/MultiDistinctEmulation.pm
new file mode 100644 (file)
index 0000000..f38c03b
--- /dev/null
+++ b/lib/DBIx/Class/Storage/DBI/MultiDistinctEmulation.pm
@@ -0,0 +1,51 @@
+package DBIx::Class::Storage::DBI::MultiDistinctEmulation;
+
+use strict;
+use warnings;
+
+use base qw/DBIx::Class::Storage::DBI/;
+
+sub _select {
+  my ($self, $ident, $select, $condition, $attrs) = @_;
+
+  # hack to make count distincts with multiple columns work in SQLite and Oracle
+  if (ref $select eq 'ARRAY') { 
+      @{$select} = map {$self->replace_distincts($_)} @{$select};
+  } else { 
+      $select = $self->replace_distincts($select);
+  }
+
+  return $self->next::method($ident, $select, $condition, $attrs);
+}
+
+sub replace_distincts {
+    my ($self, $select) = @_;
+
+    $select->{count}->{distinct} = join("||", @{$select->{count}->{distinct}}) 
+       if (ref $select eq 'HASH' && $select->{count} && ref $select->{count} eq 'HASH' && 
+           $select->{count}->{distinct} && ref $select->{count}->{distinct} eq 'ARRAY');
+
+    return $select;
+}
+
+1;
+
+=head1 NAME 
+
+DBIx::Class::Storage::DBI::Retarded - Some databases can't handle count distincts with multiple cols. They should use base on this.
+
+=head1 SYNOPSIS
+
+=head1 DESCRIPTION
+
+This class allows count distincts with multiple columns for retarded databases (Oracle and SQLite)
+
+=head1 AUTHORS
+
+Luke Saunders <luke.saunders@gmail.com>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut