laravel框架之修改

//控制器層
public function update(request $request)
{
    $id = $request->get('id');
    $data = DB::select("select * from users where id='$id'");
    $data = json_encode($data);
    $data = json_decode($data,1);
    return view('admin.update',['data'=>$data]);
}
public function update_do(request $request)
{
    $id = $request->post('id');
    $data = $request->only(['username','password','email']);
    DB::table('users')->where('id',$id)->update($data);
    return redirect()->route("admin.showlist");
}

//跳轉頁面
<td><a href="javascript:void (0)" id="{{$val->id}}" class="del">刪除</a>|<a href="update?id={{$val->id }}">編輯</a></td>
//視圖層
@extends('layouts.app')
@section('title','修改頁面')
@section('content')
    <div class="container">
        <div class="row justify-content-center">
            <div class="col-md-8">
                <div class="card">
                    <div class="card-header">{{ __('Update') }}</div>

                    <div class="card-body">
                        <form method="POST" action="{{ route('admin.update_do') }}" aria-label="{{ __('Update') }}">
                            @csrf
                            <input type="hidden" id="id" name="id" value="{{$data[0]['id']}}">
                            <div class="form-group row">
                                <label for="username" class="col-md-4 col-form-label text-md-right">{{ __('UserName') }}</label>

                                <div class="col-md-6">
                                    <input id="username" type="text" class="form-control{{ $errors->has('username') ? ' is-invalid' : '' }}" name="username"  value="<?php echo $data[0]['username']?>" required autofocus>

                                    @if ($errors->has('username'))
                                        <span class="invalid-feedback" role="alert">
                                        <strong>{{ $errors->first('username') }}</strong>
                                    </span>
                                    @endif
                                </div>
                            </div>

                            <div class="form-group row">
                                <label for="email" class="col-md-4 col-form-label text-md-right">{{ __('E-Mail Address') }}</label>

                                <div class="col-md-6">
                                    <input id="email" type="email" class="form-control{{ $errors->has('email') ? ' is-invalid' : '' }}" name="email" value="{{$data[0]['email']}}" required>

                                    @if ($errors->has('email'))
                                        <span class="invalid-feedback" role="alert">
                                        <strong>{{ $errors->first('email') }}</strong>
                                    </span>
                                    @endif
                                </div>
                            </div>

                            <div class="form-group row">
                                <label for="password" class="col-md-4 col-form-label text-md-right">{{ __('Password') }}</label>

                                <div class="col-md-6">
                                    <input id="password" type="password" class="form-control{{ $errors->has('password') ? ' is-invalid' : '' }}" name="password"  value="{{$data[0]['password']}}" required>

                                    @if ($errors->has('password'))
                                        <span class="invalid-feedback" role="alert">
                                        <strong>{{ $errors->first('password') }}</strong>
                                    </span>
                                    @endif
                                </div>
                            </div>

                            <div class="form-group row">
                                <label for="password-confirm" class="col-md-4 col-form-label text-md-right">{{ __('Confirm Password') }}</label>

                                <div class="col-md-6">
                                    <input id="password-confirm" type="password" class="form-control" name="password_confirmation" value="{{$data[0]['password']}}" required>
                                </div>
                            </div>

                            <div class="form-group row mb-0">
                                <div class="col-md-6 offset-md-4">
                                    <button type="submit" class="btn btn-primary">
                                        {{ __('Updated') }}
                                    </button>
                                </div>
                            </div>
                        </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
@endsection