遍历 MongoDB 集合中的所有文档并将数据保存在数组中

Question

I thought this would be a straightforward task but what I am trying to do is go through all the documents (users) in my collection using a cursor and saving some data into a JS array or set about a specific field of the user or all of the data on that user. I am able to see each document printed on the console, but after looping through all the documents, my array is still empty when printed. Where am I going wrong and if there is an alternative approach please let me know.

const mongoose = require('mongoose');
let Users = require('./models/user.model');

const uri = process.env.ATLAS_URI;
mongoose.connect(uri, { useNewUrlParser: true, useCreateIndex:true, useUnifiedTopology: true});
const connection = mongoose.connection;
connection.once('open', () => {
    console.log("MongoDB connection success");
})

let arr = [];
async function getRecords() {
    let cursor = Users.find({}).cursor();
    for (let doc = await cursor.next(); doc != null; doc = await cursor.next()) {
        arr.push(doc);     //does not work :(
        console.log(doc);  //this works
    }
}

getRecords();
console.log("ARRAY:",arr);  //prints []

Answer 1

Suggestion

Your code should read as such

let arr = [];

// This is an async function (returns a promise)
async function getRecords() {
    let docs = await Users.find({}).lean();
    arr = docs.filter((doc) => doc !== null); // As an example, however, enter appropriate condition for filter
    return arr;
}

// Call the async funtion
getRecords().then(docs => {
  console.log("ARRAY:", arr); 
});