Articles Cookbook
19 May 2020
Jakub Romanowski

Major Companies Using PostgreSQL: Purposes & Examples

Which companies use the open-source relational database management system PostgreSQL? Find out … and learn why you should be a PostgreSQL user too. You know the blue elephant logo. You have heard that PostgreSQL is a very good solution. But which companies use it? Here is a list of the largest IT and business companies that use PostgreSQL (or Postgres, for short). Multinationals worth billions of dollars can't be wrong, right?
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15 May 2020
Dorota Wdzięczna

Overview of Ranking Functions in SQL

SQL ranking functions make working with relational databases easier, especially for data analysts, marketers, and financial specialists. These functions are used to assign a ranking number for each record and allow you to efficiently create useful reports. SQL ranking functions are window functions. Window functions compute the result based on a set of rows. The word “window” refers to this set of rows. Let’s look at the syntax of ranking functions:
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14 May 2020
Ignacio L. Bisso

Beginner’s Guide to the SQL Subquery

Subqueries are a powerful SQL resource, allowing us to combine data from multiple tables in a single query. In this article, we’ll teach you everything you need to begin using subqueries. Perhaps the simplest definition of a SQL subquery is “A query inside a query”. Subqueries are so easy to understand that they often appear in the opening chapters of SQL courses. However, there are many variants of subqueries that need to be explained.
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13 May 2020
Tihomir Babic

11 Advanced SQL Interview Questions (and Answers)

Do you want to move to a job that uses SQL? Are you unsure about what to expect during the job interview or how to benchmark your knowledge? This article will give you a good idea of where you stand. If you feel stuck in your job, you’re not the only one. The modern division of work pushes people to perform very specific tasks, expecting them not to look at what's on the other side.
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12 May 2020
Adrian Więch

SQL in Google Sheets? Yes, We Can!

Did you know that you can write SQL-like queries in Google spreadsheets? This feature is incredibly powerful, versatile, and can replace most of the functionalities offered by Excel’s pivot tables. Read our article to find out how you can easily use the QUERY function to efficiently work with your Google Sheets data. Relational databases share many features with spreadsheets. When we explain what databases are, we often say that they are a bit like spreadsheets except they give us more control over larger amounts of data.
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8 May 2020
Marija Ilic

Why Should I Learn SQL Window Functions?

SQL has been around for more than 25 years. Its basic syntax – like SELECT, WHERE, GROUP BY, HAVING, and ORDER BY – is well known. But is there something besides traditional SQL? Can you go beyond the basics and improve your skills? The answer to this question is yes. There is a modern version of SQL. In this article, we are going to dive into the modern version and learn about SQL window functions.
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7 May 2020
Kateryna Koidan

What Is a Nested Query in SQL?

Have you ever wished that you could build a query with several SELECT statements? Good news! You can do this – and a lot more – with SQL’s nested queries. Nested queries are an essential part of writing efficient SQL code. If you’ve been learning SQL and writing queries, you’ve likely faced situations where you need to put a SELECT statement inside another SELECT statement. You might wonder, "Can I really do that in SQL?
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6 May 2020
Dorota Wdzięczna

Advanced SQL Courses for Data Analysts – A Complete Review

Even data analysts who already know SQL need to keep their skills sharp. Where can you find the best advanced SQL courses for data analysts? Check out our review of the top online sources! If you're like me, constantly looking to keep those SQL skills in tip-top shape, you might be wondering where to find the best advanced courses tailored for data analysts. Well, I've got you covered! I recently explored some top-tier online courses that really push the envelope on what you can do with Structured Query Language.
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5 May 2020
Dorota Wdzięczna

You Want to Learn SQL? You've Come to the Right Place!

Interested in learning SQL? You've landed at the perfect place! At LearnSQL.com, we offer a comprehensive collection of SQL courses designed for everyone from complete beginners to seasoned professionals. This article will give you an overview of what you can expect from our course offerings—whether you're getting started with SQL or you want to master advanced SQL topics. Welcome to LearnSQL.com! LearnSQL.com is an online platform with interactive SQL courses intended for a wide range of backgrounds in SQL.
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1 May 2020
Rebecca McKeown

How to Practice SQL for a Technical Job Interview

You’ve scored yourself an interview for an SQL-related job. Nice work! But perhaps uncertainty is creeping in as your interview date looms closer. Do you know enough SQL to make the cut? What questions are you likely to be asked? What SQL practice should you be doing before your interview? Almost all SQL job candidates go through exactly the same nerve-wracking process. Here at LearnSQL.com, we have the lowdown on all the SQL practice and preparation you’ll need to ace those interview questions and take your career to the next level.
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