How can I get a list of MySQL databases in PHP using PDO?

Question

I wonder how can I get the list of MySQL databases in PHP using PDO without having to connect to a database first ( I mean no dbname in dsn )?

Usually I used to use

Answer 1

try{
  $DBH = new PDO("mysql:host=localhost", "root", "");
  $DBH->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
  $DBH->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
}catch(PDOException $e) {
  echo "Fail";
}

$rs = $dbo->query("SHOW DATABASES");
while ($h = $rs->fetch(PDO::FETCH_NUM)) {
   echo $r[0]."
";
}