Query json by key with laravel

whereJson.php

public function whereJSON($key, $value)
{
  $fields = explode('.', $key);
  if (count($fields) !== 2) {
    die('Please use this format field_name.key to query JSON');
  }
  $fieldname = $fields[0];

  return $this->whereRaw($fieldname . ' REGEXP \'"' . $fields[1] . '":"([^"]*)' . $value . '([^"]*)"\'')->get()
    ->map(function ($item) use ($fieldname) {
      return json_decode($item->$fieldname);
  });
}

$q = (new Model)->whereJSON('meta.key', 'Value');