hi! I would like to ask if anybody can tell me what's wrong with the code below. I am trying to fetch row/s from an oracle database using perl dbi, but the script does not return anything. I've tried executing the same SQL statement in TOAD and it works just fine. Thank you in advance for the help

$SQL = qq{SELECT $columns FROM $tbl WHERE $col_cond $val_cond AND $date_col <= SYSDATE - NUMTODSINTERVAL($ll,'HOUR') AND $date_col >= SYSDATE - NUMTODSINTERVAL($ul,'HOUR') };

my $sth = $dbh->prepare($SQL) or die "prepare failed: ". $dbh->errstr();
print "$SQL\n";

while (row = $sth->fetchrow_array())
$line = join(",", row), "\n";
print "$line\n";