Missing MongoDB Connection Import in server.js

[Tushar260603]

In the server.js file of our project, there's an essential component missing: the import statement for MongoDB connection. This oversight could potentially lead to runtime errors or issues when attempting to interact with the database.

Expected Behavior:
There should be an import statement for the MongoDB connection module/library.

Actual Behavior:
The import statement for MongoDB connection is missing.

Proposed Solution:

Server.js
import express from "express";
import cors from "cors";
import records from "./routes/record.js";
import dotenv from "dotenv"
import conn from "./db/connection.js"; //importing conn function from db/conncection.js file
const PORT = process.env.PORT || 5050;
const app = express();
dotenv.config();
app.use(cors());
app.use(express.json());
app.use("/record", records);

// start the Express server
app.listen(PORT, () => {
conn(); //add this for connecting to database
console.log(Server listening on port ${PORT});
});

[saikumardeveloper9948]

Instead of connecting at the top level (which is not ideal because await cannot be used directly in the module scope without top-level await), wrap the logic in an async function and export both the database and a connection function:
// db/connection.js
import { MongoClient, ServerApiVersion } from "mongodb";

const URI = process.env.ATLAS_URI || "";
const client = new MongoClient(URI, {
serverApi: {
version: ServerApiVersion.v1,
strict: true,
deprecationErrors: true,
},
});

let db;

async function connectToDB() {
try {
await client.connect();
await client.db("admin").command({ ping: 1 });
console.log("Pinged your deployment. Successfully connected to MongoDB!");

db = client.db("employees"); // replace "employees" with your DB name

} catch (err) {
console.error("Failed to connect to MongoDB:", err);
process.exit(1); // stop server if DB connection fails
}
}

function getDB() {
if (!db) {
throw new Error("Database not initialized. Call connectToDB first.");
}
return db;
}

export { connectToDB, getDB };

update server.js with:

import express from "express";
import cors from "cors";
import dotenv from "dotenv";
import records from "./routes/record.js";
import { connectToDB } from "./db/connection.js"; // function to connect to DB

dotenv.config();

const PORT = process.env.PORT || 5050;
const app = express();

app.use(cors());
app.use(express.json());
app.use("/record", records);

// Start server after DB is connected
connectToDB().then(() => {
app.listen(PORT, () => {
console.log(Server listening on port ${PORT});
});
}).catch(err => {
console.error("Failed to start server:", err);
});

update record.js with:
import express from "express";
import { ObjectId } from "mongodb";

// Updated import: getDB gives access to the connected database instance
import { getDB } from "../db/connection.js";

const router = express.Router();

// GET all records
router.get("/", async (req, res) => {
try {
const db = getDB();
const collection = db.collection("records");
const results = await collection.find({}).toArray();
res.status(200).send(results);
} catch (err) {
console.error(err);
res.status(500).send("Failed to fetch records");
}
});

// GET single record by ID
router.get("/:id", async (req, res) => {
try {
const db = getDB();
const collection = db.collection("records");
const query = { _id: new ObjectId(req.params.id) };
const result = await collection.findOne(query);

if (!result) {
  res.status(404).send("Record not found");
} else {
  res.status(200).send(result);
}

} catch (err) {
console.error(err);
res.status(500).send("Error retrieving record");
}
});

// POST: Create a new record
router.post("/", async (req, res) => {
try {
const db = getDB();
const collection = db.collection("records");
const newDocument = {
name: req.body.name,
position: req.body.position,
level: req.body.level,
};
const result = await collection.insertOne(newDocument);
res.status(201).send(result);
} catch (err) {
console.error(err);
res.status(500).send("Error adding record");
}
});

// PATCH: Update record by ID
router.patch("/:id", async (req, res) => {
try {
const db = getDB();
const collection = db.collection("records");
const query = { _id: new ObjectId(req.params.id) };
const updates = {
$set: {
name: req.body.name,
position: req.body.position,
level: req.body.level,
},
};
const result = await collection.updateOne(query, updates);
res.status(200).send(result);
} catch (err) {
console.error(err);
res.status(500).send("Error updating record");
}
});

// DELETE: Delete record by ID
router.delete("/:id", async (req, res) => {
try {
const db = getDB();
const collection = db.collection("records");
const query = { _id: new ObjectId(req.params.id) };
const result = await collection.deleteOne(query);
res.status(200).send(result);
} catch (err) {
console.error(err);
res.status(500).send("Error deleting record");
}
});

export default router;