laravel request 增加字段

https://segmentfault.com/q/1010000006898668

$input = $request->only(['username', 'password']); //填写你需要写入DB的字段

$input = $request->only('username', 'password'); //同上

$input = $request->except(['_token']); //去除某一字段, 如这的_token

$input = $request->except('_token'); //同上