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

By default, a new MongoDB database doesn’t enable authorization, and has no users. MongoDB comes with default roles such as `root`, `userAdmin`, `userAdminAnyDatabase` when we install it.

The `root` is the superuser role that provides system-wide access to the user. It can also create custom roles using a combination of permissions.

To learn about authorization, we'll create an admin user with the `userAdminAnyDatabase` role. Authorization is not required for the development.

The `userAdminAnyDatabase` role allows us to add or remove users for any database on MongoDB.

# Create a new user

We use the below steps to create a new user in MongoDB.

1. We use the MongoDB Shell tool, shown in code as `mongosh`, to connect to MongoDB.
```
mongosh
```  
Throughout this course, `mongosh` is always running in a terminal by default.

2. We switch to the `admin` database. By default, the `test` database is selected.
```
use admin
```
3. We create an admin user.

Below is the syntax to create a MongoDB user.


   ```
   db.createUser({
     createUser: "<username>",
     pwd: Password,
     roles: [Role, ...],
   });
   
   // You can provide either plain text or 
   prompt when the command is executed.
   Password = passwordPrompt() || "<password plain text>"
   
   // The roles field can have multiple role values. 
   // A role value can be a role object or role name.
   Role = RoleObject || RoleName;
   
   RoleObject = {
       role: RoleName, 
       db: DatabaseName,
   };
   
   // e.g.
   RoleName (String) = "root" 
   
   // e.g.
   DatabaseName (String) = "todo"
   ```

The `db.createUser` command input accepts additional arguments, but they are used only for advanced user management. Hence, they are not included here.

We use the below command to create an admin user.

   ```
    db.createUser({
        user: "admin",
        pwd: passwordPrompt(),
        roles: [
            "userAdmin"
        ]
    });
   ```


This command needs the admin password to execute the `passwordPrompt()` function. We enter the password to create the admin user.

Instead of prompting a password, we can also use a plain text password.

The `admin` user created from the above query has the userAdmin role.

4. The following command stops the MongoDB instance.

   ```
   db.adminCommand({ shutdown: 1 })
   ```

5. We can exit `mongosh` with the
**`exit`** command.

Learn and practice how to enable authorization, create roles and users, and assign user roles on a database.


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

MongoDB Authorization

Create a new user