Php Connect to oracle database

function connectToOracle($username, $password, $database) {
  //connect to oracle database
  $conn = oci_connect($username, $password, $database);
  //check if connection is successful
  if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
  }
  //return the connection
  return $conn;
}

//example
$conn = connectToOracle('username', 'password', 'database');

//output
$conn; //connection object