readis操作

1. 刪除readis

 $Ranking = $this->Redis->_delete('lianmengname');

2. 讀取readis緩存

 $Ranking = $this->Redis->_get('lianmengname');

3. 存readis

if(empty($Ranking)){
      $Ranking = $this->DoubleAct->selectRanking();
      $this->Redis->_set('lianmengname',json_encode($Ranking),1800);//緩存半小時
    }