Author: John Au-Yeung

To do multiple populates with Node Mongoose, we call populate multiple times.

For instance, we write

OrderModel.find()
  .populate("user")
  .populate("meal")
  .exec((err, results) => {
    // callback
  });

to call populate to populate the user and meal field entries in the result.

We get the results from results in the callback.

To specify specific fields with Node Sequelize instead of *, we set the attributes property.

For instance, we write

const list = await template.findAll({
  where: {
    user_id: req.params.userId,
  },
  attributes: ["id", "template_name"],
});
res.status(200).json(list);

to call findAll with an object with the attributes property set to an array of columns to select.

To make synchronous requests in Node.js, we use the sync-request module.

For instance, we write

const request = require("sync-request");

//...

try {
  const res = request("GET", url);
} catch (e) {
  console.log(e);
}

to call request to make a get request to url.

We use the catch block to catch any request errors.

To fix TypeError: Converting circular structure to JSON in Node.js, we avoid stringifying the req object with JSON.stringify.

For instance, we write

console.log(req);

to call console.log to log the req object which has a circular structure.

To fix TypeError: firebase.storage is not a function with Node Firebase, we import the firebase/storage module.

For instance, we write

import firebase from "firebase/app";
import "firebase/storage";

firebase.initializeApp({
  //...
});
const storageRef = firebase.storage().ref();

to import the firebase/storage module with

import "firebase/storage";

Then we can call firebase.storage.