php如何执行非缓冲查询API

<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$uresult = $mysqli->query("select name from city", mysqli_use_result);

if ($uresult) {
  while ($row = $uresult->fetch_assoc()) {
    echo $row['name'] . php_eol;
  }
}
$uresult->close();
?>

<?php
$pdo = new pdo("mysql:host=localhost;dbname=world", 'my_user', 'my_pass');
$pdo->setattribute(pdo::mysql_attr_use_buffered_query, false);

$uresult = $pdo->query("select name from city");
if ($uresult) {
  while ($row = $uresult->fetch(pdo::fetch_assoc)) {
    echo $row['name'] . php_eol;
  }
}
?>

<?php
$conn = mysql_connect("localhost", "my_user", "my_pass");
$db  = mysql_select_db("world");

$uresult = mysql_unbuffered_query("select name from city");
if ($uresult) {
  while ($row = mysql_fetch_assoc($uresult)) {
    echo $row['name'] . php_eol;
  }
}
?>