如何在使用Node.js时同步获取实体

Question

I'm trying to get storage account's Table's data. I succeed in getting the date using the way here .

But it's using callback. I want to get the results synchronously!

Answer 1

You can write a helper function which returns Promise to make it synchronous (or simulate it)

function getSome(mytable, hometasks, num)
  return new Promise((resolve, reject) => {
    tableSvc.retrieveEntity(mytable, hometasks, num, function(error, result, response){
      if(!error){
        resolve(entity // result or response etc)
      } else {
        reject(error)
      }
    });
  })

Then you can use elsewhere in your code with async/await (to pause execution) like

Note you can use await only inside async function

async function useData() {
  const data = await getSome('mytable', 'hometasks', '1');
  // use data here
}

or with plain promise as (Note, this does not pause execution, code inside then is a callback function again)

const data = getSome('mytable', 'hometasks', '1');
data.then(res => // do something)

Also looks like cosmos have now sdk with Promise support.

Read more about Promise and async/await on MDN