# redis composer require yiisoft/yii2-redis // 获取 redis 组件 $redis = Yii::$app->redis; // 判断 key 为 username 的是否有值，有则打印，没有则赋值 $key = 'username'; if ($val = $redis->get($key);) { var\_dump($val); } else { $redis->set($key, 'marko'); $redis->expire($key, 5); }