从选择字段存储数组

I am trying to store an array of counties in my database. Here's my blade:

<select size="5" name="county[]" multiple class="form-control-2">
<option value="" selected="" disabled="">All Counties</option>
@if (isset($counties))
    @foreach ($counties as $c)
        <option value="{{ $c->name }}">{{ $c->name }}</option>
    @endforeach
@endif

and my controller is:

// Store the property Alert
 public function propertyAlert(PropertyAlertRequest $request)
 {
         $action = PropertySubscribe::create($request->all());
         $action = PropertySubscribe::create([
            $action->county = Input::get('county'),
            ]);
         $action->save();

     notify()->flash('Registered!', 'success', ['text' => 'You have now been registered.']);
     return back();
 }

and the error I am getting is:

preg_replace(): Parameter mismatch, pattern is a string while replacement is an array

Can anyone help me understand what I am doing wrong? I am sending it as an array and the dd is showing the values successfully. Do I need to foreach on the array items?

Input::get('county') is returning an array, because your select multiple

try this:

foreach(Input::get('county') as $county)
{
    PropertySubscribe::create([
        $action->county = $county,
    ]);
}