JavaScript promise使用

function getMessageData() {
  var queryUrl = "http://1.1.1.1:1";
  var param = {};
  return new Promise((resolve, reject)=>{
    request.post(queryUrl, JSON.stringify(param), function(result){
      if(result.Result == 0 && result.Data.length > 0){
      resolve(result.Data)
      } else{
      resolve('');
      console.log('error', result);
      }
    }, function(error){
      console.log(error);
      reject('error', error);
    })
    }).catch((err)=>{
    console.log('error', err);
    })
  }

function getMessageData() {
    var queryUrl = "http://1.1.1.1:1";
    var param = {};
    return new Promise((resolve, reject) => {
    request.post(queryUrl, JSON.stringify(param ), function (result) {
      if (result.Result == 0 && result.Data.length > 0) {
      resolve(result.Data)
      } else {
      resolve('')
      }
    }, function (error) {
      console.log(error)
      reject(error)
    })
    }).then(data => {
    var param = data;
    return new Promise((resolve, reject) => {
      request.post(queryUrl, JSON.stringify(param), function (result) {
      if (result.Result == 0) {
        resolve(result)
      } else {
        console.log(result)
        resolve('')
      }
      }, function (error) {
      console.log(error)
      reject(error)
      })
    })
    }).catch((err) => {
    console.log(err)
    })
  }

async function loadData() {
  var messageList = await getMessageData();
  console.log(messageList );
}

function loadData(){
  getMessageData().then(data => {
    console.log(data);    
  });
}