# 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:

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

Insert multiple documents:

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

---

## Read (Fetch Data)

Get all documents:

```js
db.students.find();
```

Get specific data:

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

Pretty format:

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

---

## Update Data

Update one document:

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

Update multiple:

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

---

## Delete Data

Delete one document:

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

Delete many:

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

---

## Query Operators

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

Operators:

* `$gt` → greater than
* `$lt` → less than
* `$eq` → equal

---

## Indexing (Basic)

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

Improves query performance.