Gain insights into MongoDB's core concepts, including queries, CRUD operations, aggregation, and more. Discover how to build applications with hands-on experience and interactive widgets.

mongo.tar.gz

MongoDB is an open-source NoSQL database and stores data in the form of documents. It can be used as an alternative to traditional relational databases. NoSQL databases are schema-less and useful for working with large sets of distributed data. 

In this course, you will learn the core concepts of MongoDB including queries, documents, embedded documents, and operators with advanced features like CRUD operations, bulk write operations, GridFS, indexing, aggregation pipeline, authorization, and more.

You will have plenty of hands-on experience with the help of interactive widgets, and by the end you will have a strong understanding of how to build MongoDB-based applications.

MongoDB: The Complete Guide

**Indexing** is a fundamental database concept that improves read performance but also adds additional delay on write operations. So, it’s important that we create only meaningful indexes. An important point to keep in mind is that MongoDB supports indexing on embedded documents as well.

> **Note:** The `_id` field, which is the primary field, is indexed by default.

# Create index

Below is the syntax of the `createIndex` command.
```
db.<collection-name>.createIndex({
    <key>: 1,
    ...
}, {
    name: <string>,
    unique: <boolean>,
    sparse: <boolean>,
    expireAfterSeconds: <number>,
    hidden: <boolean>,
    partialFilterExpression: <document>,
    storageEngine: <document>,
});
```

Let’s create an ascending index on the `name` field on the `tasks` collection.

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

The option `name` is optional. MongoDB creates it automatically if we don’t provide it.

This query returns the index `name`.
```
name_1
```

Let’s create an index with a `name` argument.

```
db.tasks.createIndex({priority: 1}, {name: "priority_index"});
```

This returns the same name provided in the arguments.

Learn and practice commands to create, delete and get indexes in a MongoDB collection.

Introduction to Database and MongoDB

Create Database and Authorization

Performing CRUD Operations on MongoDB - Part 1

Performing CRUD Operations on MongoDB - Part 2

MongoDB Query and Database Performance

Learn Additional MongoDB Topics

Appendix

Indexing