В вашем коде произошли значительные изменения, попробуйте ниже:
Для понедельника goose:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
let theNames;
let url = 'mongodb://localhost:27017/node-demo';
const usersSchema = new Schema({
any: {}
}, {
strict: false
});
const Users = mongoose.model('users', usersSchema, 'users');
const newFunction = async () => {
let db = null;
try {
/** In real-time you'll split DB connection(into another file) away from DB calls */
await mongoose.connect(url, { useNewUrlParser: true });
db = mongoose.connection;
let dbResp = await Users.find({}).limit(1).lean() // Gets one document out of users collection. Using .lean() to convert MongoDB documents to raw Js objects for accessing further.
// let dbResp = await Users.find({}).lean(); - Will get all documents.
db.close();
return dbResp;
} catch (err) {
(db) && db.close();
console.log('Error at newFunction ::', err)
throw err;
}
}
newFunction().then(res => console.log('Printing at calling ::', res)).catch(err => console.log('Err at Calling ::', err));
Для драйвера MongoDB:
const MongoClient = require('mongodb').MongoClient;
const newFunction = async function () {
// Connection URL
const url = 'mongodb://localhost:27017/node-demo';
let client;
try {
// Use connect method to connect to the Server
client = await MongoClient.connect(url);
const db = client.db(); // MongoDB would return client and you need to call DB on it.
let dbResp = await db.collection('users').find({}).toArray(); // As .find() would return a cursor you need to iterate over it to get an array of documents.
// let dbResp = await db.collection('users').find({}).limit(1).toArray(); - For one document
client.close();
return dbResp;
} catch (err) {
(client) && client.close();
console.log(err);
throw err
}
};
newFunction().then(res => console.log('Printing at calling ::', res)).catch(err => console.log('Err at Calling ::', err));
Часто разработчики путаются с использованием async/await, и они смешивают асинхронные / ожидающие с callback (). Поэтому проверьте проблемы или ненужные части вашего кода ниже:
SyntaxError: await действителен только в функции asyn c - потому что вы не можете использовать await вне async function .
В этой строке dbo.collection("users").find({}).toArray(function (err, result) { - должна быть функция async, поскольку в ней используется await.
var theNames; // There is nothing wrong using var but you can start using let.
var url = 'mongodb://localhost:27017/node-demo';
const newFunction = async () => {
MongoClient.connect(url, function (err, db) {
if (err) throw err;
var dbo = db.db("node-demo"); // You don't need it as you're directly connecting to database named `node-demo` from your db url.
//Find the first document in the customers collection:
/** If you create a DB connection with mongoose you need to create schemas in order to make operations on DB.
Below syntax goes for Node.Js MongoDB driver. And you've a mix n match of async/await & callbacks. */
dbo.collection("users").find({}).toArray(function (err, result) { // Missing async keyword here is throwing error.
if (err) throw err;
theNames = await result;
return theNames;
db.close(); // close DB connection & then return from function
});
});
}
newFunction();
console.log(`Here is a list of theNames: ${theNames}`);