Question

我正在使用Nodejs和cloud firestore作为数据库，我从模型中的数据库（注销）中获取了正确的数据，但是将其返回到控制器后我却无法获得它


// this is controller:

CheckPhoneNumber = (req, res) => {

    // getting data from json

    var json = {

        // this is the entry ==> PhoneNumber : 123456789

        PhoneNumber: req.body.PhoneNumber
    }

    // calling model function

    console.log('this is from controller before calling database');

    var user = model.CheckPhoneNumber(json.PhoneNumber)
        .then(function () {
            console.log('this is from controller after calling database');
            console.log(user);
            return user;
        }).catch(err => {
            return 'Error in controller awaiting ', err;
        });

    // outputting to Postman 

    return res.json(Promise.resolve(user));
}

该控制器调用以下模型


// this is model :

// importing configure of database 

const config = require('../config/main');

// this is for updates from google to firestore

config.db.settings({ timestampsInSnapshots: true });

// setting root of users database 

const usersRoot = config.db.collection( my root here );


// takes json and return that user which phone number belongs to (actually it gets user by phone number )



async function CheckPhoneNumber(PhoneNumber) {
    // getting data from database
    var user;
    user = await usersRoot.where('PhoneNumber', '==', PhoneNumber).get()
        .then(async snapshot => {
            if (snapshot.empty) {
                return 'No matching documents.';
            }
            return await snapshot.forEach(async doc => {
                console.log('your user is : ');
                user = await doc.data();
                console.log(user);
                console.log('this is from model after calling database');
                return await user;
            });
        }).catch(err => {
            // console.log('Error getting documents',err);
            return 'Error getting documents', err;
        });
    console.log('this is user befor returning : ');
    console.log(user);
    return user;
}

这是Windows OS中控制台的输出



this is from controller before calling database

this is from model after calling database

{ ... there is here some data ... }

this is from controller after calling database

Promise { <'pending'> }

我希望在等待它从控制台的最后一行中的数据库中获取数据后，特别是从控制器返回的数据

Answer 1

这是因为您的user是promise对象。

您可能想在此区块中进行回复，

model.CheckPhoneNumber(json.PhoneNumber)
  .then(function (user) {
    console.log('this is from controller after calling database');
    console.log(user);
    res.json(user)
  })
  .catch(err => {
    res.json('error')
  });

或者，您可以这样做：

// make you route function async
CheckPhoneNumber = async (req, res) => {
...

// then you could
try {
  const user = await model.CheckPhoneNumber(json.PhoneNumber)
  res.json(user)
} catch (e) {
  res.json('error')
}

将模型更改为：

async function CheckPhoneNumber(PhoneNumber) {
  // getting data from database
  try {
    var snapshot = await usersRoot.where('PhoneNumber', '==', PhoneNumber).get()
    if (snapshot.empty)
      return "No"
    var datas = [];
    snapshot.forEach(doc => {
      datas.push(doc.data())
    })
    return datas;
  } catch (e) {
    console.error(e);
  }
}

如何将我从数据库获得的数据从模型返回到控制器

1 个答案: