如果使用准备好的PHP / MySQL查询,我是否需要清理输入？

<?php
$mysqli = new mysqli("localhost","my_user","my_password","world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %sn",mysqli_connect_error());
    exit();
}

$city = "Amersfoort";

/* create a prepared statement */
if ($stmt = $mysqli->prepare("SELECT District FROM City WHERE Name=?")) {

    /* bind parameters for markers */
    $stmt->bind_param("s",$city);

    /* execute query */
    $stmt->execute();

    /* bind result variables */
    $stmt->bind_result($district);

    /* fetch value */
    $stmt->fetch();

    printf("%s is in district %sn",$city,$district);

    /* close statement */
    $stmt->close();
}

/* close connection */
$mysqli->close();
?>

使用准备好的查询时,是否需要清理任何输入？