1. 查询多行记录,以sql的md5值为key,缓存数组(个人觉得最好用的方法)

$mem = new Memcache();
$mem->connect('127.0.0.1',11211);
$id = (int)$_GET['id'];
$sql = "SELECT * FROM test WHERE id='$id'";
$key = md5($sql);
//数据库查询是否已经缓存到memcahced服务器中
if(!($datas = $mem->get($key)))
{
    echo 'mysql<br />';
    //如果在memcached中没获取过数据,连mysql获取
    $conn = mysql_connect('localhost','root','123456');
    mysql_select_db('test');
    $result = mysql_query($sql);
    while($row = mysql_fetch_assoc($result))
    {
        $datas[] = $row;
    }
    //再把mysql获取的数据保存到memcached中,供下次使用
    $mem->add($key,$datas);
}
else
{
    echo 'memcache<br />';
}
print_r($datas);

2.查询单行记录,缓存该行记录,以id值为key(也可用md5后的sql语句为键)

$rangeid = rand(600,1276);
$rangeid = '1237';
$mem = new Memcache;
$mem->connect('127.0.0.1',11211);
if( ($com = $mem->get($rangeid)) === false) 
{
    echo '来自mysql<br />';
    $conn = mysql_connect('localhost','root','123456');
    $sql = 'use dedecms';
    mysql_query($sql,$conn);
    $sql = 'set names utf8';
    mysql_query($sql,$conn);
    $sql = 'select aid,actors from dede_addonmovie where aid=' . $rangeid;
    $rs = mysql_query($sql,$conn);
    $com = mysql_fetch_assoc($rs);
    $mem->add($rangeid , $com , false, 60);
}
else 
{
    echo '来自memcache<br />';
}
header('content-type:text/html;charset=utf8;');
print_r($com);

也可以用另一种方式连接memcache

$rangeid = rand(600,1276);
$mconn = memcache_connect('localhost',11211);
if( ($com = memcache_get($mconn,$rangeid)) === false) 
{
    $conn = mysql_connect('localhost','root','123456');
    $sql = 'use dedecms';
    mysql_query($sql,$conn);
    $sql = 'set names utf8';
    mysql_query($sql,$conn);
    $sql = 'select aid,actors from dede_addonmovie where aid=' . $rangeid;
    $rs = mysql_query($sql,$conn);
    $com = mysql_fetch_assoc($rs);
    memcache_add($mconn , $rangeid , $com , false, mt_rand(40,120));
}
else
{
    echo 'from cache';
}
print_r($com);