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Free Course of the Month – GROUP BY Extensions in PostgreSQL

Do you work with data? Want to be able to create better and more sophisticated SQL reports? Then check out our interactive GROUP BY Extensions in PostgreSQL course. In May 2023, you can complete this online PostgreSQL course for FREE!

GROUP BY Extensions in PostgreSQL

How can you get this free SQL course in May 2023?

  1. Create a free account or log in if you already have one.
  2. Start the course. You will have free access to its content until the end of the month.

What Are GROUP BY Extensions?

If you want to be able to say that you know PostgreSQL, you must know the GROUP BY clause. It lets you group data and then calculate statistics for each group.

I'll give you an example. Imagine you are the owner of a car dealership. You can use PostgreSQL and GROUP BY to create a sales report. Let's say that you need to find out the average order value for each customer or which employee has sold the most cars of a given brand and is entitled to a bonus. You could try to do it all in good old Excel. But if your company doesn’t have a tiny database, it will be very slow; it may even crash your computer. This is not the case with SQL – a few lines of code will do the trick. You can read this article to find out more about the advantages of SQL over spreadsheets

Suffice it to say that GROUP BY is a key part of working on SQL reports. There are also extensions to the GROUP BY clause: ROLLUP, CUBE, and GROUPING SETS.

ROLLUP allows you to attach additional values to each row that represent subtotals. These are often called super-aggregated rows. They can be presented together with the total sum. Thanks to the useful ROLLUP extension, you can generate multiple grouping sets using just one SQL query.

CUBE comes in handy when you need to generate subtotals. You can use it in your SQL query to get the subtotals for all combinations of columns in the GROUP BY clause.

Finally, there are GROUPING SETS (my favorite)!  They help you to compute multiple GROUP BY clauses in a single SQL statement. GROUP BYGROUPING SETS is equivalent to the UNION of two or more GROUP BY operations in the same result set. I may be biased, but this is really high-level SQL. If you can apply in your queries, you will impress other analysts.

Do you want to learn more about GROUP BY extensions in PostgreSQL? Check out my other piece on how to learn GROUP BY properly. Spoiler alert: One of the suggested methods is taking the free course you are reading about.

Why Learn GROUP BY Extensions?

The short answer is that these extensions can be used in a lot of places. Many companies nowadays use OLAP (Online Analytical Processing) databases. GROUP BY extensions are useful for calculating statistics and performing aggregations on collected data. You’ll often find them in today’s in-demand technologies, like Big Data tools. Knowing GROUP BY extensions will give you an advantage in analyzing your data or in improving ETL processes.

If you already know the basics of PostgreSQL and want to broaden your skillset, this is the right course for you.

What Will You Learn in This Course?

The course consists of 63 interactive exercises you can do at your own pace, from anywhere, and at any time. It is divided into four parts. Each extension gets its own part, and the last part is a quiz. Completing all of them should take you about 7 hours.

Of course, we don't recommend doing the entire course at once. Plan your study well. Here are some tips to get it right:

This course is interactive. That means that when you learn a specific topic, you will have a chance to practice it in our online console. To learn with us, you only need an internet connection and your favorite browser. You will write real SQL queries and see how they work. If you make a mistake somewhere, you will immediately see what you need to work on. We believe that only with such hands-on experience can you master a given skill. Learning online has never been easier!

GROUP BY Extensions in PostgreSQL

Do you want to learn even more about PostgreSQL? This course is part of our SQL from A to Z in PostgreSQL track. There, you will find everything you need to become a Postgres expert!

Who Should Take This Course?

If you deal with data analysis on a daily basis, this course is for you. Are you responsible for creating SQL reports and comparisons that are later used to make strategic decisions for the company? Then the GROUP BY Extensions course will help you tremendously.

We have created this course for more than just IT people. We also recommend it to sales managers, product managers, and financial experts. Each will gain a lot from being able to do in-depth analyses and draw conclusions from them.

Are you a student preparing for a database exam? Are you a developer who wants to expand your skillset? This course can also benefit you.

GROUP BY Extensions in PostgreSQL

After completing the exercises in this course, you will receive a PDF certificate. You can also publish a certificate of completion on your LinkedIn profile. Check out how easy it is to do so in our short guide. You can also show it to your boss and prove to them that you are a developing employee who may deserve a raise.

Free SQL Course for May: GROUP BY Extensions in PostgreSQL

Now you know how much you can gain from using GROUP BY Extensions in PostgreSQL. It is a must-have for anyone who wants to create reports and data summaries more easily and effectively.

Interested – especially since now you can learn it all for FREE? You can get full access to this great interactive SQL course without paying anything. Sign up and start today!

You may be wondering: Is Learning PostgreSQL Worthwhile? Read the article and dispel all your doubts. You can also learn How to Install PostgreSQL on Windows 10 in 5 Minutes so you can use its power in your projects. is the best place in the world to learn PostgreSQL, or so our users say. Give this free Postgres course a try and see if you agree!