如何从表单数据传输到数据库Laravel 5

I'm trying to transfer data from the form to overwrite the content database .But get the error.

It is my route,method and form.

Route::get('edit/{id}','JokeController@edit');


  public function edit(JokeModerateRequest $request,$id) {

    $joke = Joke::findOrFail($id);

    return view('jokes.edit', [ 'joke' => $joke ]);
}


<form action="/update" method="post">

    <input type="text" value="{{  $joke -> content}}" name="body">

    <input type="submit" value="Save">

    <input type="hidden" name="_token" value="{{ csrf_token() }}">

</form>

But when I try use next route and method

Route::post('update/{id}','JokeController@update');

  function update(JokeModerateRequest $request,$id) 
    $joke = Joke::findOrFail($id);
    $joke->content = $request -> get('content');
    $joke->save();
    return back();

I have next error

Sorry, the page you are looking for could not be found.

1/1
NotFoundHttpException in RouteCollection.php line 145:

The problem lies here:

<form action="/update" method="post">

This will redirect to /update route (which you haven't defined) instead of /update/id. Those two are different routes.

To fix this, change action of the form to:

<form action="/update/{{ $joke->id }}" method="post">