Articles Cookbook
12 Mar 2024
Jeffrey Edison

Data Analyst's Guide to SQL Indexing: Fix Slow Queries

Does your SQL query response time leave something to be desired? Or maybe you don't know if your queries could be faster. In this article, we’ll explain how SQL indexing can help. Diving into SQL is like unlocking a superpower. It's all about mastering the art of querying your database effectively so you can retrieve the information you need quickly and easily. But what happens when you ask a question that's complex enough to slow response time from seconds to minutes – or even longer?
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7 Mar 2024
Nicole Darnley

Efficient Data Analysis: Leveraging SQL with R

This article delves into the nuances of using SQL with R in data analysis. It offers insights and practical examples that demonstrate the effectiveness of this combination. By integrating SQL with R, analysts can leverage the strengths of both languages. This helps them perform comprehensive data analyses, going from initial data retrieval to complex statistical modeling and visualization. To kickstart our exploration of the dynamic duo of SQL and R in data analysis, it's essential to grasp how these two powerful tools can revolutionize the way we handle, manipulate, and interpret vast datasets.
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5 Mar 2024
Maria Durkin

What Is CROSS JOIN in SQL?

What is a CROSS JOIN in SQL, and when should you use it? We answer those questions – and give you some examples of CROSS JOIN you can practice for yourself – in this article. CROSS JOINs, a type of SQL JOIN, create all possible row combinations from two tables. If you're new to JOINs and want to learn more, check out our comprehensive SQL JOINs course, which includes over 90 hands-on exercises on various JOIN types.
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29 Feb 2024
Alexandre Bruffa

20 SQL Practice Problems for Beginner and Intermediate Users

Want to become an SQL expert? Try solving those 20 SQL practice problems! Whether you're just starting your SQL journey or preparing for exams, you need to sharpen your SQL skills if you want to become an expert. And you know what people say: practice makes perfect! Like most skills, SQL is best learned through experience; practicing SQL allows you to apply your knowledge to real-world scenarios. Through repeated practice, you'll gain the confidence to dive into complex SQL tasks and excel in both academic and professional fields.
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27 Feb 2024
LearnSQL.com Team

New Monthly SQL Practice for March 2024!

Ready for our new SQL challenge? This time, we have prepared slightly more difficult SQL tasks. Here’s the March SQL Practice course! This time, you will help Lilia who runs a genetic testing clinic. She needs insight into the performance of her clinic for February 2024 and has hired you as an SQL specialist to help her out. Can you identify the most popular tests? Can you create a report on patient preferences by age?
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27 Feb 2024
Ignacio L. Bisso

6 Examples of NTILE() Function in SQL

The SQL NTILE() function can greatly simplify your data analysis and reporting. Follow these six examples to learn what it is and when to use it. Window functions are very useful, providing great expressive power to SQL. In this article, we discuss the NTILE() function, which allows us to divide a set of records into subsets of approximately equal size. This function is widely used in financial or economic calculations.
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22 Feb 2024
Radu Gheorghiu

RIGHT JOIN in SQL: A Beginner's Tutorial

Learn RIGHT JOIN, a crucial command for any SQL specialist. Our article breaks down this essential technique, helping beginners effortlessly navigate and apply RIGHT JOIN in their database queries. In SQL, RIGHT JOIN (also known as RIGHT OUTER JOIN) is crucial for handling data effectively. This article is a beginner-friendly guide to the SQL RIGHT JOIN, an essential technique for merging different data tables. We'll walk you through the specifics of RIGHT JOIN, explaining how it stands apart from other join types in managing data.
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21 Feb 2024
LearnSQL.com Team

5th Anniversary of LearnSQL.com

Wow – time flies! This week marks 5 years of LearnSQL.com – can you believe it? We've come a long way together, and we’re just getting started. Big thanks for being part of this journey – next year is going to be even better! 1,828 days have passed since February 23, 2020, when we launched the LearnSQL.com platform. That's 43,872 hours, or 2,632,320 minutes, if you prefer. It’s been a while, but it still feels like we just started.
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20 Feb 2024
Gustavo du Mortier

MySQL Date Functions: Complete Analyst’s Guide

Master MySQL date functions and acquire a powerful tool to work with date and time information in your data analyses. Working with date and time data is an essential part of data analysis. Here are just three examples: Analyzing historical time series data is crucial for discovering trends and making reliable forecasts based on chronological information. Stock market analysis examines time series data extensively, especially when automated trading algorithms are employed.
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15 Feb 2024
Maria Durkin

SQL HAVING Clause: A Tutorial for Beginners

So, you're new to SQL and have just stumbled upon the HAVING clause. But what does it do? Why is it essential? In this article, we'll delve into the basics of the HAVING clause in SQL. And we’ll walk through practical exercises to enhance your understanding of its functionality. Let's start by defining Structured Query Language (SQL). SQL is a powerful and standardized programming language designed specifically for managing and manipulating relational databases; simply put, it is how we communicate with the databases that hold all of our important data.
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