从PHP函数返回数组

I need a function to return an array as an associate or object, with one input. Here's the code.

function fetch_article($key) {
    global $sysconfig;
    if ($sysconfig['datastore'] == 'wincache') {
          $data = wincache_ucache_get($key);
          return $data;
    }elseif ($sysconfig['datastore'] == 'apc'){
          $data = apc_fetch($key);
          return $data;
    }elseif ($sysconfig['datastore'] == ''){
          $data = $db->query("SELECT * FROM pages_content WHERE id = '" . $key . "'");
              $data = $data->fetch_assoc();
              return $data;
    }
}

I don't have that much experience working with functions, so please do bear with me.

It's no problem to just return the variable holding the array object.