Queries and Mutations in Node.js

Welcome back! Today, we're diving into the fascinating world of Queries and Mutations in Node.js. Let's get started! 🎯

What are Queries and Mutations?

In the context of Node.js, Queries and Mutations are operations performed on databases using a library like MongoDB or PostgreSQL. Queries fetch data, while Mutations modify, insert, or delete data in the database. 📝

Queries

Queries are used to fetch data from a database. In Node.js, you can use the find() method to retrieve records that match certain criteria.

javascript

const db = require('mongodb').MongoClient;

db.connect('mongodb://localhost:27017', (err, client) => {
  const dbObject = client.db('mydb');
  dbObject.collection('mycollection').find({}).toArray((err, result) => {
    console.log(result);
    client.close();
  });
});

In this example, we're connecting to a MongoDB instance, fetching all records from mycollection, and logging the result.

Quick Quiz

Question 1 of 1

Which operation is being performed in the above example?

Mutations

Mutations are operations that modify, insert, or delete data in a database. In Node.js, you can use the insertOne(), insertMany(), updateOne(), updateMany(), replaceOne(), and deleteOne() methods to perform these operations.

javascript

db.connect('mongodb://localhost:27017', (err, client) => {
  const dbObject = client.db('mydb');
  dbObject.collection('mycollection').insertOne({ name: 'John Doe' }, (err, result) => {
    console.log('Inserted:', result.ops[0]);
    client.close();
  });
});

In this example, we're inserting a new document into mycollection.

Quick Quiz

Question 1 of 1

Which operation is being performed in the above example?

Stay tuned for our next lesson, where we'll delve deeper into Mutations, exploring real-world examples and practical applications! 💡