Convert my existing Node Js code into Async Await - node.js

Question

I am New To async/await coding in node js. I am trying to fetch data from mysql and then populate the result into an object. But i am not finding a way how to do it in controller.js file.
My source code similar to this.
My Router File
const express = require("express");
const controller = require("controller");
const router = express.Router();
router.route("/").get(controller.findAll);
My Controller File
const model = require("model");
exports.findAll = async (req, res) => {
const all = model.getAll((err, data) => {
if (err) {
res.status(500).send({
message: err.message || "Some error occurred while retrieving data.",
});
}
return data;
});
const user = model1.getUser((err, data) => {
if (err) {
res.status(500).send({
message: err.message || "Some error occurred while retrieving user.",
});
}
return data;
});
// somefunctionality(all, user);
// res.send(result);
};
My Model file
const con = require("./db");
// constructor
const Customers= function (customer) {
this.id = customer.id;
this.first_name = customer.first_name;
this.last_name = customer.last_name;
this.email = customer.email;
};
Customers.getAll = () => {
const query = `SELECT * FROM doctors`;
sql.query(query, (err, res) => {
if (err) {
console.log("error: ", err);
result(null, err);
return;
}
console.log("customers: ", res);
result(null, res);
};
user model same as customer
Thanks for your help

Answer 1

The first thing I would do is covert your Customers.getAll method to return a promise:
model file
Customers.getAll = () => {
const query = `SELECT * FROM doctors`;
return new Promise((res, rej) => {
sql.query(query, (err, data) => {
if (err) {
console.log("error: ", err);
rej(err);
return;
}
console.log("customers: ", res);
res(data);
})
};
(Note that you'll probably have to do something similar to the getAll method for your User model)
Now, in the controller, you can use try/catch to handle any errors.
*controller file
exports.findAll = async (req, res) => {
try {
const all = await model.getAll();
const users = await model1.getUser();
const result = somefunctionality(all, user);
res.send(result);
} catch(err) {
res.status(500).send({
message: err.message || "Some error occurred while retrieving data.",
});
}
};