<?php    $memcache = new Memcache;  //initialised memcahe    $memcache->connect("127.0.0.1",11211);  // connect memcahe server    //字符串    $memcache->add("name","hometown");//    $memcache->set("age",18);    echo "name:".$memcache->get("name")."<br>age:".$memcache->get("age");     echo "<br>";    //数组    $memcache->add("arr",array("hometown","18","male"));    print_r($memcache->get("arr"));    echo "<br>";    //对象    class person{     private $name="hometown";     private $age="19";     var $sex="male";    }    $p=new person();    $memcache->set("people",$p);    print_r($memcache->get("people"));     echo "<br>";     //数据库     $sql="SELECT * FROM dbjb.table_one";     $key=md5($sql);     $datas=$memcache->get($key);     if(!$datas){                  $mysqli=new mysqli("localhost","root","hometown1986","dbjb");         $result=$mysqli->query($sql);         $datas=array();         while($row=$result->fetch_assoc())         {            $datas[]=$row;         }          $result->free();         $mysqli->close();        $memcache->set("datas",$datas);        //echo $sql;     }     echo "<pre>";     print_r($datas);     echo "</pre>";      $memcache->close();// $cache = getCache(md5("mysql_query" . $sql)); //get sql query if already cached in memcahe?>