Mongoose
Popular node library for using MongoDB.
Mongoose Installation
After creating your project, use npm i mongoose to install it for the project.
Connecting to Local MongoDB
// this will connect to the db "fruitsDB", and will create it if it doesn't already exist
mongoose.connect("mongodb://localhost:27017/fruitsDB", {
useNewUrlParser: true,
});
Mongoose CRUD
insertMany() and other model function here.
CREATE
import mongoose from "mongoose";
// this will connect to the db "fruitsDB", and will create it if it doesn't already exist
mongoose.connect("mongodb://localhost:27017/fruitsDB", {
useNewUrlParser: true,
});
const fruitSchema = new mongoose.Schema({
name: String,
rating: Number,
review: String,
});
// mongoose will auto make it plural "fruits"
const Fruit = mongoose.model("Fruit", fruitSchema);
const fruit = new Fruit({
name: "Apple",
rating: 7,
review: "Pretty solid fruit.",
});
// save your new fruit into the database
fruit.save();
READ
// display all in collection "fruits"
Fruit.find((err, fruits) => {
if (err) {
console.log(err);
} else {
mongoose.connection.close(); // this is how you close the db connection
fruits.forEach((fruit) => {
console.log(fruit.name);
});
}
});
DATA VALIDATION
const fruitSchema = new mongoose.Schema({
name: {
type: String,
required: true,
// could have [true, "this is message for when validation fails"]
},
rating: {
type: Number,
min: 1,
max: 10,
},
review: String,
});
UPDATE
// update the rating of "banana" to 9
Fruit.updateOne({ name: "banana" }, { rating: 9 }, (err) => {
if (err) {
console.log(err);
} else {
console.log("Successfully updated the document");
}
});
DELETE
Model.deleteOne() or deleteMany()
// deleteOne() example. This is synchronous and uses "await" rather than a callback function
const deleted = await Fruit.deleteOne({ name: "Apple" });
if (deleted.deletedCount === 1) {
console.log("Apple was deleted.");
} else {
console.log("There was an error and Apple was not deleted.");
}
// deleteMany() example
const deletedPeople = await Person.deleteMany({ name: "John" });
if (deletedPeople.deletedCount >= 1) {
console.log(deletedPeople.deletedCount + " Johns were deleted.");
} else {
console.log("There was an error and Johns were not deleted.");
}
Mongoose Relationships
Easiest option is to add as a sub-document. If you add the fruit and the person in the same run, the ObjectId will be the same.
const peopleSchema = new mongoose.Schema({
name: String,
age: Number,
favoriteFruit: fruitSchema,
});
const amy = new Person({
name: "Amy",
age: 12,
favoriteFruit: banana,
});
Example Project
For an example project, see TodoList code.
TodoList: app.js
// npm and express includes
import express from "express";
import mongoose from "mongoose";
import dotenv from "dotenv";
import path from "path";
import { fileURLToPath } from "url";
import _ from "lodash";
// import https from "https"; // for forming external get requests
// local includes
import * as date from "./src/date.js";
dotenv.config(); // gets the .env data for use with process.env.
const app = express();
app.set("view engine", "ejs"); // using EJS
const port = process.env.PORT || 3000;
app.use(express.urlencoded({ extended: true })); // this is for parsing data from html form
// __dirname is only available with CJS. Since I am using ESM I need to get it another way
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
// static items like other js or css files will not load unless you define where the server should
// start looking for those files.
app.use(express.static(path.join(__dirname, "/public")));
// -----------------------------------------------------------------------------------
// ------------------------------- Mongoose Setup ------------------------------------
// -----------------------------------------------------------------------------------
// connect to MongoDB - local connection
// mongoose.connect("mongodb://localhost:27017/todolistDB", {
// useNewUrlParser: true,
// });
// connect to MongoDB Atlas (the cloud)
mongoose.connect(
"mongodb+srv://" +
process.env.MONGODB_USER +
":" +
process.env.MONGODB_PASS +
"@cluster0.ovomich.mongodb.net/todolistDB?retryWrites=true&w=majority",
{
useNewUrlParser: true,
}
);
// schema
const itemSchema = new mongoose.Schema({
name: {
type: String,
required: [true, "Please type something in for your item name."],
},
});
const listSchema = new mongoose.Schema({
name: {
type: String,
required: true,
},
items: [itemSchema],
});
// model: mongoose will auto make it plural "items"
const Item = mongoose.model("Item", itemSchema);
const List = mongoose.model("List", listSchema);
// -----------------------------------------------------------------------------------
// testing
// remove all items
// synchronous version
// const deleted = await Item.deleteMany({});
// if (deleted.deletedCount >= 1) {
// console.log("Deleted " + deleted.deletedCount + " items.");
// } else {
// console.log("ERROR in deleting items. No items deleted.");
// }
// async version
// Item.deleteMany({}, (err, ret) => {
// if (err) {
// console.log(err);
// } else {
// console.log("Deleted " + ret.deletedCount + " items.");
// }
// });
const item1 = new Item({
name: "Welcome to your todo list!",
});
const item2 = new Item({
name: "Hit the + button to add a new item.",
});
const item3 = new Item({
name: "<-- Hit this to delete an item.",
});
const defaultItems = [item1, item2, item3];
// insert test items into db
// synchronous version
// const inserted = await Item.insertMany(defaultItems);
// console.log(inserted);
// async version
// Item.insertMany(defaultItems, (err, items) => {
// if (err) {
// console.log(err);
// } else {
// console.log("Inserted: " + items);
// }
// });
// -----------------------------------------------------------------------------------
// ---------------------------------- Listening --------------------------------------
// -----------------------------------------------------------------------------------
app.listen(port, () => {
console.log(`Server is listening on port ${port}`);
});
// -----------------------------------------------------------------------------------
// --------------------------------- Get Requests ------------------------------------
// -----------------------------------------------------------------------------------
// normal page for the day
app.get("/", (req, res) => {
// let day = date.getDate();
let day = "Today";
Item.find((err, items) => {
if (err) {
console.log(err);
} else {
if (items.length === 0) {
// if nothing currently in collection, populate with starting items
Item.insertMany(defaultItems, (err, insertedItems) => {
if (err) {
console.log(err);
} else {
console.log("Inserted: " + insertedItems);
res.redirect("/"); // reload so we get the items we just inserted
}
});
} else {
// if already items in collection, just show them
res.render("list", { listName: day, items: items });
}
}
});
});
// -----------------------------------------------------------------------------------
// about me page
app.get("/about", (req, res) => {
res.render("about", {});
});
// -----------------------------------------------------------------------------------
// pages for any other list you want to create
app.get("/:listName", (req, res) => {
const listName = _.lowerCase(req.params.listName);
// determine if list already exists
List.findOne({ name: listName }, (err, foundList) => {
if (err) {
console.log(err);
} else {
if (!foundList) {
// list doesn't exists, so create it and then display
const list = new List({
name: listName,
items: defaultItems,
});
list.save();
res.redirect("/" + listName);
} else {
// list exists, so just display it
res.render("list", {
listName: _.capitalize(foundList.name),
items: foundList.items,
});
}
}
});
});
// -----------------------------------------------------------------------------------
// -------------------------------- Post Requests ------------------------------------
// -----------------------------------------------------------------------------------
// add new item to Todo List
app.post("/newItem", (req, res) => {
const listName = _.lowerCase(req.body.list);
const itemName = req.body.newItem;
const newItem = new Item({
name: itemName,
});
if (req.body.list === "Today") {
console.log("new item: " + itemName);
// add new item into items collection
newItem.save();
// reload
res.redirect("/");
} else {
console.log("new item: " + itemName);
List.findOne({ name: listName }, (err, foundList) => {
if (err) {
console.log(err);
} else {
foundList.items.push(newItem);
foundList.save();
// reload
res.redirect("/" + listName);
}
});
}
});
// -----------------------------------------------------------------------------------
// delete an item from Todo List
app.post("/deleteItem", (req, res) => {
const checkedItemId = req.body.checkbox;
const listName = _.lowerCase(req.body.listName);
if (listName === "today") {
// delete the item is question. Could also use .findByIdAndRemove()
Item.deleteOne({ _id: checkedItemId })
.then(() => {
console.log("Deleted item with _id: " + checkedItemId); // success
res.redirect("/");
})
.catch((err) => {
console.log(err); // failure
});
} else {
// find list, and delete from list array the specifc item
List.findOneAndUpdate(
{ name: listName },
{ $pull: { items: { _id: checkedItemId } } },
(err, foundList) => {
if (err) {
console.log(err);
} else {
res.redirect("/" + listName);
}
}
);
}
});