怎么才能阻塞函数的return？？

我每次打印都是Null，怎么样才能让res拿到了数据库返回的值才打印？

const userData = async () => {
  function selectData(table) {
    return new Promise((resolve, reject) => {
      setTimeout((err, res) => {
        const result = "hello";
        if (result) {
          resolve(result);
        }
      }, 2000);
    });
  }

  const result = await selectData("hhh");

  console.log(result);
};

userData();

https://www.jianshu.com/p/b16e7c9e1f9f promise async await