What is SQL and why is it important?

What is SQL?

SQL stands for Structured Query Language and it can be pronounced as either a single word, “sequel,” or as an initialism where you say the individual letters. It is an open-source query language used to talk with the information stored in relational databases. It was created in 1974 by Raymond F. Boyce and Donald D. Chamberlin. The language was originally called SEQUEL, but the name was later changed to SQL to avoid trademark infringement.

Is it important?

SQL is a very valuable skill to have in general. And it is an essential skill if you want to become a data scientist. Every organization that stores information in databases can use SQL, from hospitals and schools to businesses large and small. It is for this reason that SQL is one of the most in-demand skills that companies are looking for.

Why is it so useful?

You can think of SQL as a supercharged Microsoft Excel. Using SQL, you can access, query, and extract huge amounts of data from multiple databases. It also allows you to perform powerful cross-database analyses. For these reasons and more, most all data scientists agree it’s a foundational skill. Robert Chang, Data Scientist at Airbnb, probably puts it best: "If I want to pick one thing for all data scientists to learn, I would say learn SQL.”

Is it easy to learn SQL?

The answer to this question will vary from person to person, but generally speaking, SQL is an accessible language. It has a gradual learning curve with simple commands that are structured similarly to standard English sentences. This makes it possible to start coding and **see progress from an early stage**. For example, without knowing any SQL, most people can understand the following film database query:

SELECT title, release_year FROM films WHERE release_year IN (2001, 2009)

This query would select the title of all films which were released in the year 2001 or 2009.

Okay, I’m interested; how can I learn SQL?

You can start our Introduction to SQL course for free. In 4 hours, you’ll learn the basics of querying tables in relational databases such as MySQL, SQL Server, and PostgreSQL.

There are many great options available, but DataCamp has taught almost 6 million learners, including employees from top companies like PayPal, Dell, T-Mobile, and more. Over half a million learners have taken the intro to SQL course alone.

Once you complete the introduction, you can follow a specific pre-planned skill track like SQL Fundamentals, or choose a specific course like Intermediate SQL.

How will I know where my SQL skills stand?

If you’re a non-beginner, or you want to check-in on your progress down the line, DataCamp Signal will let you discover your skill level in just 10 minutes. After a quick assessment, we’ll compare your abilities to other DataCamp learners to determine a score and provide personalized course recommendations based on your strengths and gaps.

I got the basics, but now want to understand more of the nitty-gritty. For example, is SQL a programming language?

SQL is a domain-specific language used to communicate with relational databases. It is not a general-purpose programming language like R or Python. Using SQL, you can create, write, update, and delete information in databases. These four operations can also be charmingly abbreviated to CRUD.

And are there different SQL dialects?

SQL has many different dialects. Popular varieties of SQL include PostgreSQL, Oracle, MySQL, and T-SQL. Our Introduction to SQL course teaches syntax shared by many of these dialects.

Similar to spoken dialects, coding dialects share certain functions in common—such as SELECT, FROM, and WHERE—but they also have their own unique syntax and features. These differences may impact which dialect of SQL you choose to achieve your data goals.

Do I need to download any software to learn SQL on DataCamp?

No. You can learn SQL on DataCamp without installing any software—all the training and exercises can be completed in your browser.

What is the difference between a free account and a subscription?

With a free DataCamp account you can access the first chapter of any course available on our Premium plan. By subscribing, you gain unlimited access to all courses, projects, and practice modules. You'll also have access to our library of projects, practice sessions, and our Slack community. You can check out our various plans here