Through some experimenting, I've determined that when you pass a string to DBD::Oracle, it uses Perl's internal representation of the string. For example: 
use DBI;
my $dbi = DBI->connect(...);

sub select_scalar {
  my ($dbi, $sql) = @_;
  my $sth = $dbi->prepare($sql);
  $sth->execute();
  my $r = $sth->fetch_row_array();
  return $r->[0];
}

my $q1 = "select 1 from dual where 'ä' = chr(228)";
my $q2 = $q1.chr(1024);
chop($q2);

print "q1 eq q2? ", ($q1 eq $q2 ? "yes" : "no"), "\n";

my $r1 = select_scalar($dbi, $q1);
print "r1 = $r1\n";
my $r2 = select_scalar($dbi, $q2);
print "r2 = $r2\n";

[download]
This will emit: 
q1 eq q2? yes
r1 = 1
r2 =

[download]

So, even though q1 and q2 are the same Perl string (character by character), they are different when passed to DBD::Oracle. A fix would be to use Encode::encode('iso-8859-1', ...) on every string passed to DBD::Oracle (query strings as well as values for ? place holders.)

My question: is there another (read 'better') way to do this? I'm using perl 5.8.0 and OCI version 8.

In reply to DBD::Oracle uses Perl's internal representation of strings by pc88mxer

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