if data = null error 为 foreach() 提供的参数无效

Question

我将向数据库中插入数组。如果有信息，就不会出错。 我试图从这个网站找到刷刷的解决方案。但这并不成功。

这是我的代码

控制器

 $new = new Checks();
    $new->nvr_id = Input::get('nvr_id');
    $new->check_date = Input::get('check_date');
    $new->status_record = Input::get('check_record');
    $new->status_hdd = Input::get('check_hdd');
    $new->status_camera = Input::get('check_camera');
    $new->comment = Input::get('comment');
    $new->save();
    $id = $new->id;
    $issue[] = Input::get('issue');
    if ($issue == null) {

    } elseif (!empty($issue)) {
        foreach ($issue as $item) {
            foreach ($item as $item1) {
                addIssues::create([
                    'check_id' => $id,
                    'issue_id' => $item1
                ]);
            }
        }
    }

create.blade.php

<select name="issue[]" id="issue" class="form-control" multiple="multiple">
    @foreach($issue as $key => $item) 
        <option value = "{{ $key }}" > { { $item } } < /option>
    @endforeach
</select>                              

数据库关系

issue 1 to m addIssues m to 1 check

Answer 1

把create.blade.php代码改成这个

<select name="issue[]" id="issue" class="form-control" multiple="multiple">
  @if(count($issue))
    @foreach($issue as $key => $item) 
        <option value = "{{ $key }}" > { { $item } } < /option>
    @endforeach
  @endif
</select>

@if 构造将处理错误。