Articles Cookbook
6 Jan 2023
Jakub Romanowski

Free SQL Course of the Month – Window Functions in PostgreSQL

Are you looking for the best way to master SQL window functions? In this article, I'll show you how you can do so for free. Throughout January 2023, you can access the interactive course Window Functions in PostgreSQL for free. Hurry, time is running out! Need a free PostgreSQL course on window functions? You've come to the right place! If you are reading this article, you probably know PostgreSQL is one of the most popular databases in the world.
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5 Jan 2023
Nicole Darnley

UNION and UNION ALL in SQL: What They Do and How They’re Different

In this article, we’ll explore the SQL clauses UNION and UNION ALL. Learn what they do and when to use each one. I had been an analyst for probably four years before I knew about the SQL clause UNION ALL. I used UNION on a regular basis, but had never heard of its counterpart. Then one day when I heard a coworker talking about it. I thought to myself, “What is he talking about?
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3 Jan 2023
Kamila Ostrowska

SQL Books for Beginners

How can you learn SQL more efficiently? Besides a good online course, find an interesting book to enrich your knowledge. Here are the best SQL books for beginners. SQL, or Structured Query Language, is a very powerful tool to work with many types of data. If you are interested in learning SQL you probably know how useful it is, and how widely it is needed. To learn SQL successfully, a solid online course for beginners like our SQL Basics is a great start.
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1 Jan 2023
LearnSQL.com Team

New Monthly SQL Practice for January 2023!

Ready for our new SQL challenge? This time, we have prepared slightly more difficult SQL tasks. Here's the January SQL Practice course! This SQL Practice is at an advanced level and is aimed at those who have finished our SQL Basics and Window Functions course or otherwise have the equivalent knowledge. If you do not feel comfortable working with SQL window functions yet, make sure to check out these courses first and then come back here for more practice.
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29 Dec 2022
Ignacio L. Bisso

How to Practice SQL Subqueries

Have you ever wondered what separates beginners from advanced SQL users? It includes things like, for example, subqueries. In this article, I explain their importance and why you need to practice SQL subqueries to become an expert. What Is an SQL Subquery? SQL is an easy-to-learn language. However, there are certain complex features and techniques of the language that require practice. One of these features is the subquery, which adds great expressive power to the language and your projects.
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27 Dec 2022
Alexandre Bruffa

Learn Advanced SQL with LearnSQL.com

In this article, we will propose a learning path that will cover advanced SQL topics. If you already know the basics of SQL, you probably have figured out that most online and offline SQL tutorials and courses usually cover the basic and intermediate concepts: SELECT, FROM, WHERE, ORDER BY, GROUP BY, and joining tables. Even university database courses typically don’t cover more advanced  SQL topics. While this is enough SQL for most everyday tasks, there are some relatively new features that have been added to SQL in the last 20 years: window functions, recursive queries, and GROUP BY extensions (ROLLUP, CUBE, GROUPING SET).
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22 Dec 2022
Marko Calasan

What Are DDL, DML, DQL, and DCL in SQL?

We explore the separation of SQL into its four principal sublanguages and explain the meaning behind each of them. When you’re learning SQL – perhaps through LearnSQL.com’s very own comprehensive SQL Basics course – you may have come across the terms DDL, DML, DQL, and DCL. And maybe you’ve gotten confused by all the acronyms. In this article, we will explain what these terms stand for and how they correspond to sublanguages that neatly divide the SQL language into four parts that function together.
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20 Dec 2022
Nicole Darnley

How to Use WHERE with GROUP BY in SQL

In this article, we’ll discuss how to combine the WHERE and GROUP BY clauses in SQL If you’re writing SQL on a daily basis, you will quickly realize how often both WHERE and GROUP BY clauses are used. WHERE is an essential part of most queries. It allows you to filter large datasets to only the pieces you are interested in. GROUP BY is one of the most powerful tools an analyst has when aggregating data.
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18 Dec 2022
LearnSQL.com Team

Christmas SQL Scholarship 2022

We know 2022 was very difficult for many of you. Now that it is slowly coming to an end, we’ve decided to end it with something positive. Here is the Christmas SQL Scholarship 2022! Let's enter the new year together with new energy and a chance for change! The LearnSQL.com Team wants to help those less fortunate. This Christmas, we are going to help someone change his/her life. We are going to fund 50 SQL Scholarships for those who cannot afford to learn SQL and who may find it helpful in a difficult situation.
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15 Dec 2022
Maria Durkin

Want to Get a Data Engineering Job? Learn SQL!

So, you want to be a data engineer, but you don't know how to get there. In this article, we’ll help you understand the skills you'll need for different types of data engineering jobs. You’ll also find some data confirming that data engineer jobs are a good career choice. Data engineering and various types of data engineer jobs have become very popular in recent years. And for good reason: Next to data science, data engineering is one of the fastest-growing branches of IT.
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