header('Content-Type:text/html; charset=utf-8');// 通过 Memcache 类 链接$memcache = new Memcache();// 链接 Memcache$memcache->connect('localhost', 11211) or die('链接失败');$sql = "SELECT id,username FROM mh_member order by id desc limit 10";$key = md5($sql);$data = $memcache->get($key);if(empty($data)){	// PDO 链接数据库	try{		$pdo = new PDO("mysql:host=localhost;dbname=taijiyc", "root", "", array(PDO::MYSQL_ATTR_INIT_COMMAND=>'SET NAMES UTF8'));		$pdo -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);	}catch(PDOException $e){		echo "数据库连接失败：".$e->getMessage();	}	$sql = "SELECT id,username FROM mh_member order by id desc limit 10";	$stmt = $pdo->prepare($sql);	$stmt->execute();	$data = $stmt -> fetchAll(PDO::FETCH_ASSOC);	$memcache -> set($key, $data, MEMCACHE_COMPRESSED, 5);	echo '第一次执行，将数据缓存到内存中';}echo '
';print_r($data);echo '
';$memcache->close();