Articles Cookbook
31 May 2024
LearnSQL.com Team

New Monthly SQL Practice for June 2024!

In our June 2024 SQL Practice, you will meet Christine, the manager of a gym downtown, who seeks help in gaining essential insights from the gym database. She wants to understand various aspects: the popularity of each trainer, the average price for a training session, members with active plans, and more. Can you use your SQL skills to lend her a hand? It should not be too challenging if you have completed our SQL Basics course or have a solid grasp of fundamental SQL concepts.
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30 May 2024
Jakub Romanowski

Best Books for Learning PostgreSQL

Explore the world of PostgreSQL with our handpicked selection of the best books available. Whether you’re new to database management or looking to sharpen your skills, these resources are perfect for mastering the comprehensive features of PostgreSQL. I've been diving deep into PostgreSQL lately, and I'm excited to share the five best PostgreSQL books that have really helped me along the way. Whether you're just starting out or you're looking to deepen your expertise, there's a book here for everyone.
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29 May 2024
Agnieszka Kozubek-Krycuń

Top 100+ SQL Interview Questions and Practice Exercises

Are you gearing up for a SQL interview? This article is packed with over 100 SQL interview questions and practical exercises, organized by topic, to help you prepare thoroughly and approach your interview with confidence. SQL is essential for many jobs, like data analysis, data science, software engineering, data engineering, testing, and many others. Preparing well for a SQL interview is crucial, no matter what role you're aiming for.
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28 May 2024
Jorge Sandoval

15 SQL Server Practice Exercises with Solutions

Enhance your SQL Server proficiency with our SQL Server practice exercises. Each of these 15 practical T-SQL tasks includes a detailed solution to help you improve your querying skills. You know how everyone says, "Practice makes perfect"? Well, it couldn't be truer for SQL. The real learning happens when you start working with queries, tables, and data. If you're looking to sharpen your skills in MS SQL Server, you're in the right spot.
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23 May 2024
Jakub Romanowski

Which Database Is Best for Small Projects?

If you're tackling a small project and need to pick the best database for managing and analyzing your data, this article will help. I'll compare PostgreSQL and MySQL, two top choices for data analysis, to make your decision easier. Read on! Are you just starting to explore the world of databases and feeling a bit uncertain about which one to choose for your small projects? I remember feeling the same way when I first started.
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21 May 2024
Tihomir Babic

SQL Window Functions Guide

Every data analyst can benefit from knowing SQL window functions. They up your data analysis game and open doors to analyzing data on an entirely new level. This article is your starting point for the world of SQL window functions.   SQL window functions allow you to show all the data rows and their aggregate values at the same time. Sounds a bit like GROUP BY on steroids, doesn’t it?
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16 May 2024
Radu Gheorghiu

Integrating External Data Sources with SQL Databases

In today's world, data is the new currency and organizations are swimming in vast oceans of information from various sources. Trying to make sense of all this disparate data is a challenge; one of the most common ways to solve that challenge is by integrating external data sources with SQL. In this article, I'll guide you through strategies and techniques for seamlessly blending data from APIs, flat files, NoSQL databases, and other external sources into your SQL databases.
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14 May 2024
Gustavo du Mortier

11 SQL Common Table Expression Exercises

In this article, we offer you 11 practice exercises that put your knowledge of common table expressions (CTEs) into practice. Each CTE exercise is accompanied by a solution and a detailed explanation. As the saying goes, “A little progress each day adds up to big results”. And that is undoubtedly true for SQL proficiency. Just as you should regularly go to the gym to keep your muscles toned, you should do common table expressions exercises often to keep your querying skills toned for heavy data analysis work.
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13 May 2024
Agnieszka Kozubek-Krycuń

SQL FIRST_VALUE Function

Discover the power of the FIRST_VALUE function, a window function that returns the first value in an ordered partition of the result set. This function is useful for anyone doing data analysis in SQL. Window functions are a powerful category of functions that enable doing sophisticated data analysis in SQL. These functions operate over a "window" of rows related to the current row, allowing for preparing complex reports like running totals, moving averages, preparing rankings, and others.
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9 May 2024
Martyna Sławińska

SQL String Functions: A Complete Overview

A review of all core SQL string functions, including their definitions and examples. SQL string functions manipulate string (including text and alphanumeric) values. Also known as text functions in SQL, string functions take one or more string values as an argument and return a modified string value. Check out this interactive course on Standard SQL Functions if you want more hands-on practice than this article includes. It provides 211 exercises on numeric SQL functions, string or text functions, date and time functions, and aggregate functions.
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