Articles Cookbook
27 Jun 2024
Martyna Sławińska

PostgreSQL Date Functions

Understanding date and time functions in your database is essential for effective data analysis and reporting. Read on to learn more about PostgreSQL date functions. This article covers some of the most useful PostgreSQL date and time functions and their applications in data analysis and reporting. SQL date functions facilitate different data analysis tasks, including sales analysis, financial reporting, website analytics, and more. This article presents you with the tools, in the form of PostgreSQL date and time functions, used to accomplish these tasks.
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27 Jun 2024
LearnSQL.com Team

54 Years of Relational Databases

If it weren't for him, there would be no modern databases. It is the 54st anniversary of the publication of his article that changed the rules of the game. Edgar Frank Codd is one of the fathers of SQL, and his name is one of the first to be mentioned in the history of databases. Or maybe even the history of computer development in general? See what we owe to Dr.
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25 Jun 2024
Ignacio L. Bisso

The SQL EXISTS Operator

Using the SQL EXISTS clause allows us to create complex queries in a simple way. Learn the pros and cons of the EXISTS operator in this article. In SQL, the EXISTS operator helps us create logical conditions in our queries. Essentially, it checks if there are any rows in a subquery. We’ll show you EXISTS syntax, provide some usage examples, and then give you several exercises to practice on.
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20 Jun 2024
Tihomir Babic

SQL for Financial Reporting

SQL should be part of every modern financial reporting process. It can deal with gigabytes of data and perform financial calculations in a split second. It’s time to transition from Abacus (also known as Excel!) and start using SQL in financial reporting.    Data has taken a central part in business decision making. This applies even more to financial data. The main goal of businesses is to make a profit, so it’s no wonder that financial data plays a crucial role in the strategic decision-making process of any modern business.
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18 Jun 2024
Kamila Ostrowska

Mastering MySQL for Data Analysis

Mastering MySQL can significantly benefit anyone looking to advance in data science or database management. If you develop your data analysis skills in MySQL, you’re on the right path to positively influence your career. In this article, you’ll learn how to practice MySQL effectively and what kind of learning sources to choose. You’ll see for yourself that MySQL is not rocket science and that using it can be easy and intuitive.
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13 Jun 2024
Gustavo du Mortier

SQL CTEs: A Complete Overview of Common Table Expressions

This article provides a detailed guide to everything you need to know about common table expressions (CTEs), from the basic definition to the most complex recursive queries. If the database you use supports CTEs, here’s everything you need to get the most out of it. Common table expressions – also called CTEs, WITH clauses, or recursive queries (although this last name is actually a specific application) – are a relatively new feature of SQL.
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11 Jun 2024
Jill Thornhill

SQL LAG() Function

The LAG() function – one of SQL’s window functions – is an important tool for planning and trend analysis. In this article, I’ll demonstrate how to include SQL LAG() in your queries using a few real-world examples. SQL window functions, also known as analytical functions or OVER functions, add a new dimension to data analysis. They allow you to include aggregates or data from other rows alongside the current row.
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6 Jun 2024
Jakub Romanowski

Transitioning to a Database Career: A Guide for Beginners

Whether you're looking to become a database administrator or a data analyst or to explore other roles, I've got you covered! In this article, you’ll learn about the insights and strategies you need to launch your database career successfully. Considering a career in databases but not sure where to start? This guide is designed to help beginners navigate the world of database careers with ease. Understand the essential skills needed, learn to get hands-on experience, and explore the benefits of networking with professionals.
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4 Jun 2024
Maria Durkin

The SQL BETWEEN Operator

SQL comparison operators are essential tools for filtering data in database queries. Among these operators, the BETWEEN operator stands out as an important tool for specifying ranges inside datasets. SQL comparison operators, such as BETWEEN, are useful for filtering data in database queries. The BETWEEN operator allows you to select rows within a given range, making it ideal for tasks like segmenting an audience by age ranges, identifying thresholds for items between certain quantities, or categorizing performance based on exam scores.
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2 Jun 2024
Jakub Romanowski

Course of the Month: 2023 Advanced Monthly SQL Practice

Enhance your SQL skills this June 2024 with our exclusive offer on the 2023 Monthly SQL Practice Sets - Advanced course, available for free for a limited time! As summer rolls in, it's the perfect time to learn new skills or brush up on the ones you've got. This June, why not seize the chance to deepen your SQL expertise with some challenging exercises drawn straight from the business world?
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