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MongoDB is one of those terms that, if you are involved in software development or database management, you’ve surely heard over and over again. And not without reason, as its flexibility and power have revolutionized the way we store and retrieve data in the modern era. In this article, I’m going to walk you through what MongoDB is, how it differs from traditional SQL databases, how you can install it on Ubuntu and manage it from the console, and, of course, why setting up a cluster can be a great advantage for your projects.
What is MongoDB?
MongoDB is an open-source, document-oriented NoSQL database system that has gained popularity due to its ability to handle large volumes of data efficiently. Instead of tables, as in relational databases, MongoDB uses collections and documents. A document is a set of key-value pairs, which in the world of MongoDB is represented in a format called BSON (a binary version of JSON). This structure makes it very flexible and easy to scale, making it particularly suitable for modern web applications and handling data in JSON format, which is common in the development of web and mobile applications.
The Difference Between SQL and NoSQL
To better understand MongoDB, it is crucial to differentiate between SQL and NoSQL databases. SQL databases (such as MySQL, PostgreSQL, or Microsoft SQL Server) use a structured query language (SQL) and are based on a predefined data schema. This means that you must know in advance how your data will be structured and adhere to that structure, which offers a high degree of consistency and ACID transactions (Atomicity, Consistency, Isolation, and Durability).
On the other hand, NoSQL databases like MongoDB are schematically dynamic, allowing you to save documents without having to define their structure beforehand. They are ideal for unstructured or semi-structured data and offer horizontal scalability, which means you can easily add more servers to handle more load.
Installing MongoDB on Ubuntu
Getting MongoDB up and running on your Ubuntu system is a fairly straightforward process, but it requires following some steps carefully. Here’s how to do it:
System Update
Before installing any new package, it is always good practice to update the list of packages and the software versions of your operating system with the following commands:
sudo apt update sudo apt upgrade
Installing the MongoDB Package
Ubuntu has MongoDB in its default repositories, but to ensure you get the latest version, it is advisable to use the official MongoDB repository. Here’s how to set it up and carry out the installation:
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv E52529D4 echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu $(lsb_release -cs)/mongodb-org/4.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.4.list sudo apt update sudo apt install -y mongodb-org
Getting MongoDB Up and Running
Once installed, you can start the MongoDB server with the following command:
sudo systemctl start mongod
If you also want MongoDB to start automatically with the system, execute:
sudo systemctl enable mongod
Installation Verification
To verify that MongoDB is installed and running correctly, use:
sudo systemctl status mongod
Or you can try to connect to the MongoDB server using its shell:
mongo
Basic MongoDB Management from the Console
Now that you have MongoDB running on your Ubuntu machine, it’s time to learn some basic commands to manage your MongoDB instance from the console.
Creating and Using a Database
To create a new database, simply use the use command followed by the name of your database:
use myDatabase
If the database does not exist, MongoDB will create it when you save your first document.
Inserting Data
To insert data into a collection, you can use the insert command. For example:
db.myCollection.insert({ name: "Alice", age: 25 })This will add a new document to the collection myCollection.
Reading Data
You can read or search for documents in a collection with the find command. For example:
db.myCollection.find({ name: "Alice" })This will search for all documents where the name is “Alice”.
Updating Data
To update documents, you would use update. For example:
db.myCollection.update({ name: "Alice" }, { $set: { age: 26 } })This will update Alice’s age to 26.
Deleting Data
And to delete documents, you simply use remove:
db.myCollection.remove({ name: "Alice" })This will remove all documents where the name is “Alice”.
The Power of MongoDB Clusters
While managing a single instance of MongoDB may be sufficient for many projects, especially during development and testing phases, when it comes to production applications with large volumes of data or high availability requirements, setting up a MongoDB cluster can be essential. A cluster can distribute data across multiple servers, which not only provides redundancy and high availability but also improves the performance of read and write operations.
MongoDB clusters use the concept of sharding to distribute data horizontally and replicas to ensure that data is always available, even if part of the system fails. In another article, we will explore how to set up your own MongoDB cluster, but for now, it’s enough to know that this is a powerful feature that MongoDB offers to scale your application as it grows.
As you delve into the world of MongoDB, you’ll find that there is much more to learn and explore. From its integration with different programming languages to the complexities of indexing and query performance, MongoDB offers a world of possibilities that can suit almost any modern application need.
Remember that mastering MongoDB takes time and practice, but starting with the basics will put you on the right track. Experiment with commands, try different configurations, and don’t be afraid to break things in a test environment; it’s the best way to learn. The flexibility and power of MongoDB await, and with the foundation you’ve built today, you are more than ready to start exploring. Let’s get to work!