Articles Cookbook
1 Oct 2024
LearnSQL.com Team

New Monthly SQL Practice for October 2024!

Ready for a new basic-level SQL challenge? This time, you will help Chef Adrian, the owner of an up-and-coming restaurant, Savory Seasons. Get ready to dive into the world of SQL queries as you help Chef Adrian analyze the performance of his kitchen and create the best experience for his guests! Welcome to the October SQL Practice course! In our October 2024 SQL Practice, you will meet Chef Adrian. He owns an up-and-coming restaurant, Savory Seasons, and seeks help in gaining deeper insights from his database.
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26 Sep 2024
Tihomir Babic

SQL Interview Cheat Sheet

Need to quickly reference all the fundamental knowledge for an SQL interview? Want to refresh your memory about an SQL concept? Our SQL Interview Cheat Sheet is your new best friend!    Preparing for an SQL interview requires brushing up on your SQL. But it’s very easy to get lost in all the SQL concepts you must review. In such situations, you need an easily browsable resource packed with SQL knowledge.
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24 Sep 2024
Gustavo du Mortier

Rolling Total in SQL: What It Is and How to Compute It

Calculating a rolling total in SQL is simple when you use window functions. These handy metrics are similar to running totals and moving averages, and they’ll help you build a clear picture of your data. In this article, we'll explain and explore rolling totals. In SQL, a rolling total is an important metric that helps you see how trends change over time, giving a clear picture of your data. It calculates a sum over a "
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19 Sep 2024
Tihomir Babic

SQL Basics: The Complete Resource List

If you want to work with data, you have to start by learning the SQL basics! In this article, you’ll get an overview of core SQL concepts and syntax. Plus, we include links to great resources if you want to learn more!   Structured Query Language, or SQL, is a programming language that first appeared in 1974. It is designed for managing data in relational databases, which means storing, changing, deleting, and querying the data inside the database.
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17 Sep 2024
Martyna Sławińska

12 SQL Functions Practice Questions

SQL functions allow us to manipulate data, including string and numeric values. This article presents 12 SQL functions practice questions – with solutions and detailed explanations – that will help you solidify your SQL knowledge. Practicing SQL is important if you want to improve your skills. But finding SQL practice exercises is hard. We want to help, so we’ve been publishing free compilations of SQL practice exercises. In this article, we’ve provided 12 SQL functions practice questions, complete with solutions and explanations.
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12 Sep 2024
Alexandre Bruffa

Top 5 Reasons PostgreSQL Works for Data Analysis (and Data Analysts!)

Why do analysts love PostgreSQL for data analysis? Learn why this database management system is so beloved of database professionals and data scientists alike! If you work with data, you know that data analysis requires the efficient storage, management, and retrieval of large datasets. Thus, data analysts prefer to use relational databases that are well-known for their robustness, efficiency, and stability. Relational databases work with a database management system (DBMS), which allows the creation, management, and manipulation of relational databases.
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10 Sep 2024
Gustavo du Mortier

The MySQL CTE and How to Use It

Common table expressions (CTEs) in MySQL give even more versatility to this popular database management system. Find out how to use CTEs to simplify complex queries and implement recursion. All programming languages have ways of simplifying problems by breaking them down into parts that can be solved individually. Users can unify the partial results to obtain a single final result. Thanks to something called common table expressions (CTEs), MySQL is now exception.
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5 Sep 2024
Michał Wasiluk

A Guide to PostGIS: Basic Geospatial Data Query Examples

Geospatial data is becoming increasingly important in many fields, from urban planning to environmental science. In this article, we’ll demonstrate basic PostgreSQL PostGIS queries for working with this type of data. Geospatial data, which contains information about locations on Earth, requires specialized tools for effective use. PostGIS is a powerful PostgreSQL extension that turns a Postgres database into a full-featured Geographic Information System (GIS). With PostGIS, you can store geographic objects, run spatial queries, and perform advanced analyses directly in SQL.
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3 Sep 2024
Owen Brock

How the "SQL Basics" Course Boosted My Productivity

As a data analyst, switching from Excel to SQL was a game changer. In this article, I'll show you how completing LearnSQL.com’s SQL Basics course improved my productivity. As a data analyst, I rely on data to analyze and plan my team’s workloads and deliveries. For years, I mostly used Excel for this – but as the amount of data grew, it became harder and harder to manage everything manually.
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1 Sep 2024
LearnSQL.com Team

Course of the Month: SQL Practice Set in PostgreSQL

Do you know the basics of PostgreSQL but still need some practice? Look no further! Here is a great interactive course, SQL Practice Set in PostgreSQL. Throughout the month of September, you have access to it for FREE! We at LearnSQL.com believe that to learn a new skill, you need basic theoretical knowledge and, above all, a lot of practice. It's the same with writing PostgreSQL queries – you need a lot of PostgreSQL practice.
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