Articles Cookbook
17 Apr 2020
Agnieszka Kozubek-Krycuń

Why Take the “SQL Basics” Course at LearnSQL.com

LearnSQL.com’s interactive SQL Basics course teaches the foundations of SQL. Discover why we built this online course, our philosophy behind it, and what it contains! Learning SQL can feel like unlocking a new skill set you didn’t even know you needed. At first, it might seem like just another technical tool, but as you start using it, you'll notice how much smoother your workflow becomes. Suddenly, tasks like pulling data from multiple sources or answering complex questions about trends won’t feel as overwhelming.
Read more
16 Apr 2020
Emil Drkušić

Differences Between GROUP BY and PARTITION BY

Window functions are a great addition to SQL, and they can make your life much easier if you know how to use them properly. Today, we will address the differences between a GROUP BY and a PARTITION BY. We’ll start with the very basics and slowly get you to a point where you can keep researching on your own. PARTITION BY vs. GROUP BY The PARTITION BY and the GROUP BY clauses are used frequently in SQL when you need to create a complex report.
Read more
10 Apr 2020
Marija Ilic

Analyze Time Series COVID-19 Data with Window Functions

The COVID-19 pandemic really changed the way we live. No matter where you are, you're being impacted by this unpredictable virus. We do not know what the future holds, but we do believe in science and in better days to come. One thing that makes me as a data analyst particularly happy is that we have publicly available data. We can analyze that data and learn something from it. If you want to explore COVID-19 with the help of modern SQL constructions, keep reading — this article is intended for you.
Read more
9 Apr 2020
Jakub Romanowski

The Man Behind LearnSQL.com

If it wasn't for this guy, LearnSQL.com would never have been created. He manages the entire company, makes strategic decisions – and talks little about himself. Who is the man behind LearnSQL.com? Meet Vertabelo CEO Jarosław Błąd. SELECT interests, early_career, advice FROM Jarek AS the_man_behind_learnsql.com WHERE answer IS NOT Null AND success IS True; If you were to write one sentence about yourself, what would it be? I think I would say that I am an ordinary, simple guy who really likes what he does.
Read more
8 Apr 2020
Ignacio L. Bisso

SQL Window Functions vs. GROUP BY: What’s the Difference?

A very common misconception among SQL users is that there is not much difference between SQL window functions and aggregate functions or the GROUP BY clause. However, the differences are very significant. Perhaps the only similar point between GROUP BY and window functions is that both allow you to execute a function (such as AVG, MAX, MIN, or COUNT) on a group of records. I’d say that window functions’ special power is that they allow us to obtain results that otherwise would be almost impossible to achieve.
Read more
7 Apr 2020
Arleta Więch

Choose the Best Way to Learn SQL

SQL has become a hot topic in the professional world, and many resources have appeared both online and offline for learning SQL. It’s easy to get lost in the jungle of books, tutorials, and courses. Which resources do you choose? If you want to know how to learn SQL quickly and effectively, take a look at my list. There are many reasons for learning SQL. We asked our users about them and learned that there was no universal motive.
Read more
3 Apr 2020
Dorota Wdzięczna

SQL Cookbook with Recipes for Success

The internet holds a lot of information and can provide solutions to various problems. SQL users, both beginners and advanced, often turn to the internet for help with SQL queries. This article will help you find the right SQL queries to solve your problems. Learn what the SQL Cookbook is and why you should use it. You will also find a list of the most important recipes, from which you will prepare a great SQL dish with the taste of success.
Read more
2 Apr 2020
Kate Stolarek

Are There Any Good SQL Courses for Marketers?

Looking for places to learn SQL online and level up your marketing efforts? Check out these SQL courses. Introduction With the help of IT experts, meticulous marketers analyze information to create advertising strategies. This commonplace state of affairs forces the marketer to rely on data experts and sometimes wait for their availability. But what if marketers could pull the data themselves? They can – by turning into a technical marketer.
Read more
2 Apr 2020
Agnieszka Kozubek-Krycuń

How to Get the First Day of the Week in SQL Server

This is additional content for the LearnSQL.com course Customer Behavior Analysis in SQL Server. This interactive course will teach you how to analyze customer lifecycle in a SQL database in over 70 hands-on exercises. You will learn how to find out compare registration rates between periods of time, compute conversion rates in SQL, compare customer cohorts, analyze customer activity and customer churn over time. This course is essential for anyone doing customer analysis in their job.
Read more
2 Apr 2020
Agnieszka Kozubek-Krycuń

How to Group Data by Week in SQL Server

This is additional content for the LearnSQL.com course Customer Behavior Analysis in SQL Server. In this course, we showed you how you can analyze the customer lifecycle (customer acquisition, conversion, activity, retention, and churn) with SQL. We discussed customer registration cohorts, or groups of customers who registered during the same period (e.g. same week, same month). Analyzing customer registration cohorts lets you see registration trends and relate registration cohorts with marketing campaigns.
Read more