Node.js と MongoDB ネイティブ ドライバーを使用した高速かつ柔軟な CRUD API の構築

require('dotenv').config()
const dbConfig = require('../config/db.config');
const { MongoClient } = require('mongodb');

const client = new MongoClient(dbConfig.url);

let _db;
let connectPromise;

async function connectToDb() {
    if (!connectPromise) {
        connectPromise = new Promise(async (resolve, reject) => {
            try {
                await client.connect();
                console.log('Connected to the database ?', client.s.options.dbName);
                _db = client.db();
                resolve(_db);
            } catch (error) {
                console.error('Error connecting to the database:', error);
                reject(error);
            }
        });
    }
    return connectPromise;
}

function getDb() {
    if (!_db) {
        throw new Error('Database not connected');
    }
    return _db;
}

function isDbConnected() {
    return Boolean(_db);
}

module.exports = { connectToDb, getDb, isDbConnected };

const { ObjectId } = require('mongodb');
const db = require('../utils/db');

class AppModel {
    constructor($collection) {
        this.collection = null;

        (async () => {
            if (!db.isDbConnected()) {
                console.log('Waiting for the database to connect...');
                await db.connectToDb();
            }
            this.collection = db.getDb().collection($collection);
            console.log('Collection name:', $collection);
        })();
    }

    async find() {
        return await this.collection.find().toArray();
    }

    async findOne(condition = {}) {
        const result = await this.collection.findOne(condition);
        return result || 'No document Found!';
    }

    async create(data) {
        data.createdAt = new Date();
        data.updatedAt = new Date();
        let result = await this.collection.insertOne(data);
        return `${result.insertedId} Inserted successfully`;
    }

    async update(id, data) {
        let condition = await this.collection.findOne({ _id: new ObjectId(id) });
        if (condition) {
            const result = await this.collection.updateOne({ _id: new ObjectId(id) }, { $set: { ...data, updatedAt: new Date() } });
            return `${result.modifiedCount > 0} Updated successfully!`;
        } else {
            return `No document found with ${id}`;
        }
    }

    async deleteOne(id) {
        const condition = await this.collection.findOne({ _id: new ObjectId(id) });
        if (condition) {
            const result = await this.collection.deleteOne({ _id: new ObjectId(id) });
            return `${result.deletedCount > 0} Deleted successfully!`;
        } else {
            return `No document found with ${id}`;
        }
    }
}

module.exports = AppModel;

const express = require('express');
const router = express.Router();

const users = require('../controllers/userController');

router.get("/users", users.findAll);
router.post("/users", users.create);
router.put("/users", users.update);
router.get("/users/:id", users.findOne);
router.delete("/users/:id", users.deleteOne);

module.exports = router;

const { ObjectId } = require('mongodb');
const Model = require('../models/model');

const model = new Model('users');

let userController = {
    async findAll(req, res) {
        model.find()
            .then(data => res.send(data))
            .catch(err => res.status(500).send({ message: err.message }));
    },
    async findOne(req, res) {
        let condition = { _id: new ObjectId(req.params.id) };
        model.findOne(condition)
            .then(data => res.send(data))
            .catch(err => res.status(500).send({ message: err.message }));
    },
    create(req, res) {
        let data = req.body;
        model.create(data)
            .then(data => res.send(data))
            .catch(error => res.status(500).send({ message: error.message }));
    },
    update(req, res) {
        let id = req.body._id;
        let data = req.body;
        model.update(id, data)
            .then(data => res.send(data))
            .catch(error => res.status(500).send({ message: error.message }));
    },
    deleteOne(req, res) {
        let id = new ObjectId(req.params.id);
        model.deleteOne(id)
            .then(data => res.send(data))
            .catch(error => res.status(500).send({ message: error.message }));
    }
}

module.exports = userController;

module.exports = {
    url: process.env.DB_CONFIG,
};