nodejs mongoose connec tion

// Step 1: Import the required modules
const mongoose = require('mongoose');

// Step 2: Set up the MongoDB connection string
const connectionString = 'mongodb://localhost:27017/your_database_name';

// Step 3: Connect to the MongoDB database
mongoose.connect(connectionString, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
  useCreateIndex: true,
  useFindAndModify: false
});

// Step 4: Get the default connection
const db = mongoose.connection;

// Step 5: Set up event listeners for the MongoDB connection
db.on('error', console.error.bind(console, 'MongoDB connection error:'));
db.once('open', () => {
  console.log('Connected to the MongoDB database');
});

// Step 6: Create a Mongoose schema (optional)
const exampleSchema = new mongoose.Schema({
  name: String,
  age: Number
});

// Step 7: Create a Mongoose model using the schema (optional)
const ExampleModel = mongoose.model('Example', exampleSchema);

// Step 8: Use the model to interact with the MongoDB database (optional)
const exampleInstance = new ExampleModel({
  name: 'John Doe',
  age: 25
});

exampleInstance.save((err) => {
  if (err) return console.error(err);
  console.log('Document saved to the database');
});