What is MongoDB, and How is it Used to Develop Scalable Applications?

A Database Management System (DBMS) is critical in software development. It facilitates data storage and retrieval, security, manipulation, and modeling. However, traditional databases primarily store data in rows and columns, making it difficult to build scalable applications. This is a problem solved by MongoDB database and MongoDB query optimization. Therefore, let’s understand how it functions and can be used to build scalable applications.

What is MongoDB, and Why is it Popular?

MongoDB is an open-source database that stores, manages, and retrieves large amounts of data. Contrary to traditional databases, it is a document or NoSQL database because it does not store information in the form of tables. On the other hand, it stores data in a JSON-like format called BSON (Binary JSON).

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How Does MongoDB Differ From Traditional Relational Databases?

1. Data Structure

First and foremost, it enables data storage in a flexible, schema-less format using collections of documents in a binary JSON format. As is evident, this is unlike traditional relational databases that have a fixed schema and store data in a tabular format.

2. Query Language

Secondly, it uses MongoDB Query Language (MQL) to work on JSON-related documents. Meanwhile, relational databases use Structured Query Language (SQL) for manipulating data.

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3. Complexity

Third, MongoDB has a flexible schema that facilitates faster development. Relational databases, on the other hand, require defining and maintaining schemas, indices, and relationships, thus making them more complex. 

4. ACID Transactions

MongoDB does not provide strong ACID (Atomicity, Consistency, Isolation, Durability) guarantees at the document level within a single node. As a matter of fact, this is one area where traditional relational databases trump MongoDB in terms of strong ACID transactions.

5. Use Cases

Lastly, it is used for applications that require flexible data models and rapid development. This is because it can handle unstructured or semi-structured data. Conversely, traditional relational databases are best suited for applications that demand data integrity and have complex transactions.

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What are the Key Features of MongoDB?

1. Schema-Less Structure

It is a NoSQL database without a predefined schema. It uses a document-based data model that can store data in any format.

2. Flexible Document Model

This database stores documents in BSON format. It provides nested documents and arrays and promotes flexible data representation

3. Horizontal Scalability

It allows users to share data across multiple servers. As a matter of fact, it helps in smooth horizontal scaling.

4. High Performance

Another key feature is its memory-mapped storage engine, which allows high-performance reading.

5. Rich Query Language

Lastly, it supports powerful queries using its query language. Moreover, it allows filtering, sorting, and transforming data with the help of various operators and expressions.

How Do I Install and Set Up MongoDB?

You can install and set up this database on your computer by following these steps:

1. First, download the MongoDB community server
2. Next, select the appropriate version for Windows
3. Once downloaded, open the MSI file and install it. Click on ‘Run service as Network Service user’
4. After installation, you need to create an environment variable by clicking on the system properties
5. Edit the environment variable and paste the copied bin path link of MongoDB from the system
6. Next, open the command prompt and run the ‘Mongod’ command 
7. Then, create a folder named ‘data’ in the C drive. Also, create a subfolder called db and again run the ‘Mongod’ command
8. Lastly, open a new command prompt window and write “Mongo” to connect the server with the Mongo shell

How Do I Create and Query Documents in MongoDB?

Creating a document on MongoDB comes with certain prerequisites: First, create and activate a connection to MongoDB deployment; next, open a MongoDB playground. Once the prerequisites are met, you can create a document by following any one of the below-given methods:

1. insert Method()

This method is used to insert one or more documents in a collection. It then returns a WriteResult object providing status information.

Syntax:

>db.COLLECTION_NAME.insert(document)

You can insert multiple documents in the form of an array. The values of the documents are to be mentioned in square brackets [] and a comma should separate each document.

2. insertOne() Method

This method is best for inserting a single document in a collection and accepts two arguments. First is the mandatory document argument; it specifies the document that must be inserted into the collection. Second is the optional writeConcern argument; it explains how MongoDB will acknowledge the insert operation.

Syntax: 

db.collection.insertOne(

   <document>,

   {

      writeConcern: <document>

   }

)

3. insertMany() Method

It is used for inserting an array of documents in a particular collection. The documents are usually inserted as per order, unless specified otherwise. Therefore, by using the insertMany method, coders can insert information without using the id_field. However, if the id_field is not added, the database automatically adds a unique id to the object. On the other hand, if you add an id_field, it should have a unique value to avoid errors.

Syntax:

db.Collection_name.insertMany(

[<document 1>, <document 2>, …],

{

    writeConcern: <document>,

    ordered: <boolean>

})

Boost Your Coding Career With Emeritus

In conclusion, MongoDB is one of the most popular databases to build scalable applications. Unsurprisingly, over 43,000 companies such as eBay, Cisco, Adobe, Google, and Toyota, among others, use this database, and mastering its skill set can help developers earn an annual average pay of $95,000. Therefore, it is best to have in-depth knowledge of MongoDB database and MongoDB query optimization—something Emeritus’ online coding courses can help you with. Explore these courses and sign up to build these skills.

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