An Illustrated Guide to the SQL Self-Join

What is an SQL self-join and how does it work? When should it be used? We’ll provide answers to those questions! In SQL, we can combine data from multiple tables by using a JOIN operator. JOIN has several variants; we’ve already discussed CROSS JOIN, INNER JOIN, and OUTER JOIN. Most of the time, these operators join data from two or more different tables. In this article, however, we will explain how to join records from the same table. A self-join

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What Is Vertabelo’s SQL Cheat Sheet?

Everyone, from rookie programmers to SQL ninjas, needs a bit of help now and again. Enter Vertabelo’s SQL Cheat Sheet! Working with databases is hard. There’s a lot of data to manage, which can be daunting. But the main challenge many database users face is the SQL commands themselves. It’s all right when you’re using the same familiar ones day after day, but what about the commands you dust off once or twice a year? Or what if you’re just

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How to Track Down Duplicate Values in a Table

When it comes to information management, duplicates present one of the most common challenges to data quality. In this article, I’ll explain how it is possible to find and distinguish duplicate names with the help of the SQL data programming language. I really like my maiden name. The reason I like it so much is because it’s rare. My maiden name (first with last) provided a unique identifier on platforms such as LinkedIn, Facebook, Twitter and similar. But then I

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Four Reasons Aspiring Data Scientists Must Learn SQL

Isn’t data science way too advanced for simple SQL? Nope! SQL can help you build a foundation for your data science career. Let’s see how. Data science is hot right now. What if you could predict the next market crash? Or contain the spread of Ebola? Or accurately predict a health crisis months or even years before it happens? Data scientists are working hard on these kinds of projects, and they are earning healthy salaries in the process. No wonder

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SQL Mythbuster – 5 Reasons Why No One Should Be Afraid of SQL

Anyone can learn SQL.  It’s not as hard as you think! In today’s world, even those in non-technical jobs need some technical skills.  And you don’t have to be a hard-core nerd to get these skills.  Let me tell you my own story. A few years ago, I wasn’t considering learning SQL or anything else that I labelled “technical”.  My background is in sociology, journalism, and scriptwriting, and I thought computer languages were pretty sci-fi.  But once I started working

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An Illustrated Guide to the SQL INNER JOIN

What is an SQL INNER JOIN, and how does it work? Let’s find out! In my last article, I discussed the CROSS JOIN operation in SQL. Today, we’ll look at INNER JOIN and how to use it. Is it the same as a JOIN? How many tables can you link with an INNER JOIN? These are all good questions. Let’s look at the answers! What Is an INNER JOIN? INNER JOIN combines data from multiple tables by joining them based

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