Articles Cookbook
27 Mar 2020
Agnieszka Kozubek-Krycuń

Why Window Functions Are Not Allowed in WHERE Clauses

Window functions are extremely powerful, but there are a lot of nuances and little details you need to learn about using window functions in order to use them correctly and efficiently. A fairly common question SQL users have is why window functions are not allowed in WHERE. TL;DR: You can use window functions in SELECT and ORDER BY. You cannot use window functions in WHERE, GROUP BY, or HAVING.
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25 Mar 2020
Kamil Bladoszewski

How to Rank Rows in SQL: A Complete Guide

Don’t struggle with SQL ranking functions anymore! This article will guide you through the most common ranking use cases. Rankings are used around us every day. Sports tournaments, the best movies and TV series on Netflix, stores with the cheapest products—these are only a few examples of rankings you might’ve seen recently. Using SQL RANK functions might be hard sometimes. The variety of different constructions is enormous. You can easily get lost in everything there is to learn about ranking.
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24 Mar 2020
Emil Drkušić

How to Practice SQL JOINs

There is no better way to learn how to practice SQL joins than through hands-on experience. However, there will probably be obstacles along the way. I’ll cover some of these obstacles and give ideas for how to overcome them. While this article won’t turn you into SQL JOINs expert, it will show you how to become one. So, let’s start! Diving into the world of databases? Then you've likely come across SQL joins.
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20 Mar 2020
LearnSQL.com Team

Stay at Home and Learn SQL for Free with LearnSQL.com

Working remotely is a dream come true for some. You ditch commuting and have more time for the people you love and the things you enjoy. For others, it's a challenge to maintain their focus when there are new distractions. It's also an opportunity to invest the few gained hours in learning something new. Staying at home can be a time when you might find yourself busier than you've ever been, but not getting many things done, and worse, not learning what you planned to.
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19 Mar 2020
Kate Stolarek

Video Tutorial or Interactive SQL Course – Which Is Better?

Are you ready to get started with SQL but unsure which learning method is the most effective? In this post, we’ll talk about the pros and cons of learning SQL from an instructional video vs. an interactive online course. Are you a chronic Internet-using student who’s planning to learn SQL? Maybe you did some research but still don’t know which kind of training is worth your (limited) time. We all have families, hobbies, and other after-work commitments, and finding the right resource for learning SQL will save you some time.
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18 Mar 2020
Tetyana Skorykh

How Will Learning SQL Improve My Daily Work?

Whether you're focused on advancing your career, mastering in-demand skills, or exploring something new and captivating, learning SQL is key to your progress. This vital skill makes professional life more manageable and also sets you up for success in a data-centric world. Are you thinking of learning SQL but aren’t sure if it's a good idea? If you’re not in a data- or IT-related job, learning SQL may seem completely useless.
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17 Mar 2020
Pierre Timms

How to Start Writing SQL Reports

So, you’ve started, or want to start, learning SQL. You understand that a database is a repository for raw data and that data in business forms the backbone of the decision-making process. But how do you gain meaningful insights from raw data? How can you take a vast amount of information from a database and use SQL to give it a real-world utilization? Learn how to write SQL reports!
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11 Mar 2020
Rebecca McKeown

Learning SQL? 14 Ways to Practice SQL Online

If you’re currently learning SQL, you may have found yourself knee-deep in reading material and wondering how on earth you can bridge the gap between book knowledge and real-life SQL application. In this article, we bring you 14 of the most effective ways to practice SQL online – taking you from a bookworm to a database butterfly in no time at all! “All theory and no practice will make you a frustrated SQL user!
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10 Mar 2020
Kateryna Koidan

How to LEFT JOIN Multiple Tables in SQL

Can you LEFT JOIN three tables in SQL? Yes, indeed! You can use multiple LEFT JOINs in one query if needed for your analysis. In this article, I will go through some examples to demonstrate how to LEFT JOIN multiple tables in SQL and how to avoid some common pitfalls when doing so. The best way to practice different types of joins is our interactive SQL JOINs course. It contains over 90 hands-on exercises that cover simple 2-table joins, joining multiple tables, LEFT JOIN, FULL JOIN, and many more.
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5 Mar 2020
Tihomir Babic

Best Online SQL Courses for Finance & Economics Majors

Are you studying finance and wondering how you can use your knowledge in this technical world? Maybe you’ve just started working as a data analyst and you want to bring new tools and skills to your workplace? This article could help you with the list of the SQL courses worth trying. Maybe you’re studying finance and find your studies too theoretical. How will you put this knowledge into practice?
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