my $query = $db->prepare(" Update $WeatherDB
                           Set precip=$precip, high=$high, low=$low  
                           Where state='$state' AND city='$city'
                         ");
my $rows_changed = $update->execute() || die "execute failed..blah";
  # if the execute method on the $update query "succeeds", ie
  # the DB exists and this whole thing "makes sense", but just
  # didn't change any rows, you get the "TRUE" string and
  # Zero numeric reponse...(0E0);
if ($rows_changed == 0)
{
   print "could not update record with $state,$city! Not Found!\n";
}
elsif ($rows_changed >1)
{
   print "DB corruption! $rows_changed entries for $state,$city combo\n";
}