Web-Development/Week-05/Day_04/README.md

MongoDB CRUD Operations

Introduction

The performing CRUD (Create, Read, Update, Delete) operations in MongoDB. This is the heart of any database-driven application.

Create (Insert Data)

Insert a single document:

db.students.insertOne({
  name: "Rupesh",
  age: 23,
  course: "MCA"
});

Insert multiple documents:

db.students.insertMany([
  { name: "Amit", age: 22 },
  { name: "Sneha", age: 21 }
]);

---

Read (Fetch Data)

Get all documents:

db.students.find();

Get specific data:

db.students.find({ name: "Rupesh" });

Pretty format:

db.students.find().pretty();

---

Update Data

Update one document:

db.students.updateOne(
  { name: "Rupesh" },
  { $set: { age: 24 } }
);

Update multiple:

db.students.updateMany(
  { course: "MCA" },
  { $set: { status: "active" } }
);

---

Delete Data

Delete one document:

db.students.deleteOne({ name: "Rupesh" });

Delete many:

db.students.deleteMany({ age: { $lt: 23 } });

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Query Operators

db.students.find({ age: { $gt: 20 } });

Operators:

• $gt → greater than
• $lt → less than
• $eq → equal

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Indexing (Basic)

db.students.createIndex({ name: 1 });

Improves query performance.