Articles Cookbook
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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7 May 2024
Nicole Darnley

Data Visualization Using SQL: A Guide for Data Analysts

Start exploring data visualization using SQL with our practical guide. You’ll learn how to harness the powerful features of SQL to create effective visualizations that enhance your data analysis – and make it more understandable and impactful. SQL is a specialized programming language designed for managing and manipulating relational databases. It provides a standardized framework for querying, updating, and manipulating data. It is simple and yet offers a robust set of commands and functions to interact with data.
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2 May 2024
Maria Durkin

The Data Analysis Lifecycle: From Dataset to Presentation

In today's fast-paced decision-making climate, data is an invaluable resource. Raw data is like a rough diamond: it has great potential, but it must be processed to reveal its true brilliance. Achieving this brilliance is where the data analysis lifecycle comes in. The data analysis lifecycle maps out a structured journey of five steps: Collection Cleaning Analysis Interpretation Presentation Mastering the right tools for each step is key, and that's where SQL proves indispensable.
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1 May 2024
Jakub Romanowski

Course of the Month: 2023 Basic Monthly SQL Practice

Start enhancing your SQL skills this May with our free SQL course, 2023 Monthly SQL Practice Sets - Basic! Spring is a great time to learn something new or improve your current skills. This May, we’re offering a unique opportunity to boost your SQL knowledge through practical exercises drawn from real-world business scenarios. Available free for the entire month, our 2023 Monthly SQL Practice Sets - Basic course provides interactive challenges involving databases from different industries.
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30 Apr 2024
Jill Thornhill

The SQL MIN() Function

SQL has a variety of powerful aggregate tools, including the SQL MIN() function. This article is a quick reference guide to extracting and using minimum values in your queries. In today’s cutthroat business environment, it’s vital to be able to analyze your organization’s data effectively to make informed decisions. SQL’s aggregate functions let you carry out all kinds of statistical analysis on your data. This article is a reference guide to the SQL MIN() function, which extracts the smallest item from a column of data.
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29 Apr 2024
LearnSQL.com Team

10 Correlated Subquery Exercises with Solutions

Correlated subqueries are a powerful SQL feature essential for advanced data analysis. This article provides 10 practical exercises to help you master correlated subqueries. SQL is a fundamental skill for anyone working with data, whether as a data analyst, a SQL developer, a data engineer, or any other related profession. Mastering SQL involves more than just understanding the basics. It also requires learning advanced SQL features, such as subqueries.
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27 Apr 2024
LearnSQL.com Team

New Monthly SQL Practice for May 2024!

Ready for our new SQL challenge? This time, the tasks are slightly more difficult. In this course, you will assist Jason in analyzing the employee hierarchy at his company using common table expressions and recursive queries. Welcome to the May SQL Practice course! In our May 2024 SQL Practice, you will meet Jason. He owns a company that makes riding lawn mowers. He needs HR insight into the employees at his company and has hired you as an SQL specialist to help him out.
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25 Apr 2024
Gustavo du Mortier

19 PostgreSQL Practice Exercises with Detailed Solutions

You’ve probably heard the saying “practice makes perfect”. Find out if this phrase is true by trying the comprehensive set of PostgreSQL practice exercises that you will find in this article! To master any language, it is essential to practice it regularly so as not to lose the skill. This is as true for verbal communication as it is for programming. And SQL programming is no exception. Even the most seasoned PostgreSQL programmer needs to do PostgreSQL practice daily to perfect (and maintain) their skills.
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23 Apr 2024
Kamila Ostrowska

Top 5 SQL Tutorials for Beginners

Is learning SQL with tutorials a good idea? What tutorials are tailored to your needs? Our top 5 SQL tutorials for beginners will help you find your way! The idea to learn SQL is one of the best you could have. But to succeed, you need a good source of knowledge. In this article, we focus on online tutorials. We will describe different platforms, methods used, key features, prices. After reading this, you’ll be able to choose the best beginner-level SQL tutorial for you.
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