php+mysql prepare 与普通查询的性能对比实例讲解

<?php class timer {       public $StartTime = 0;       public $StopTime = 0;       public $TimeSpent = 0;             function start(){         $this->StartTime = microtime();       }             function stop(){         $this->StopTime = microtime();       }             function spent() {         if ($this->TimeSpent) {         return $this->TimeSpent;          } else {          // http://www.manongjc.com        $StartMicro = substr($this->StartTime,0,10);           $StartSecond = substr($this->StartTime,11,10);           $StopMicro = substr($this->StopTime,0,10);           $StopSecond = substr($this->StopTime,11,10);           $start = floatval($StartMicro) + $StartSecond;           $stop = floatval($StopMicro) + $StopSecond;           $this->TimeSpent = $stop - $start;                return round($this->TimeSpent,8).'秒';         }      }    }  $timer = new timer;   $timer->start();   $mysql = new mysqli('localhost','root','root','ganbaobao_ucenter');  /* $query = $mysql->query("select username,email from uc_members where uid < 100000"); $result = array(); http://www.manongjc.com/article/1194.htmlwhile($result = $query->fetch_array()) {   $result[] = array('name'=>$result['username'],'email'=>$result['email']); } */ $query_prepare = $mysql->prepare("select username,email from uc_members where uid < ?");  $id = 100000; $query_prepare->bind_param("i",$id);  $query_prepare->execute(); $query_prepare->bind_result($username,$email);  $result = array(); while($query_prepare->fetch()) {   $result[] = array('name'=>$username,'email'=>$email); }  $timer->stop();  echo '</br>预查询mysql运行100000条数据时间为: '.$timer->spent();  unset($timer);  //var_dump($result);