Articles Cookbook
24 Oct 2024
Agnieszka Kozubek-Krycuń

NULLs and Handling Missing Data in SQL

Handling missing data (i.e. NULLs) in SQL can be challenging. NULLs can pose a lot of traps, especially if you don’t understand how they work. In this article, we’ll talk about dealing with NULL in SQL. We’ll also explain how to avoid common mistakes when working with NULLs. Having missing data in your database is an unavoidable reality of life. There are many reasons why you may have missing data in your database: the complete data isn’t yet available, users provide incomplete information, changes to the database schema, database malfunctions, human error, and more.
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22 Oct 2024
Gustavo du Mortier

How SQL Helps Optimize Healthcare Workflows

SQL is a universal language for healthcare data management and workflow optimization. In this article, we will see how to use SQL for everything from scheduling medical appointments to monitoring vital signs. Healthcare professionals must adhere to various processes to perform their duties. These processes, or workflows, are adapted to various situations – patient reception, diagnosis, monitoring, billing, clinical documentation, etc. While these workflows vary by type of care, setting (hospital, clinic, telemedicine), and the role of the practitioner, they all require the efficient and accurate handling of large volumes of critical information.
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17 Oct 2024
Tihomir Babic

The ORDER BY Clause in SQL Window Functions

In this article, you’ll get an overview of ORDER BY in window functions. You’ll learn how it compares to PARTITION BY and the regular ORDER BY all accompanied by examples and explanations. If you want to create reports that go beyond simple aggregations, you’ll need SQL window functions. Window functions help you create rankings, compute running totals and moving averages, and find the difference between rows. To use window functions effectively, you must understand the role of the ORDER BY clause.
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15 Oct 2024
Ekre Ceannmor

19 Aggregate Function Exercises

Solve these 19 SQL aggregate function exercises and sharpen your SQL skills! Practice using aggregate functions with GROUP BY, HAVING, subqueries, and more. Includes a solution and detailed explanation for each exercise. Aggregate functions are an important part of SQL. They allow you to calculate different statistics and generate reports that you would not have been able to with single-row operations like filtering. It’s important to practice aggregate functions often, as they are a crucial part of your SQL skill set.
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10 Oct 2024
Radu Gheorghiu

Building Analytical Data Pipelines with SQL

If you’re trying to build an analytical data pipeline, then SQL is the perfect tool for the job. It will help your organization build a data analytics foundation that turns data into business value. Why should you care about building data pipelines with SQL? This might sound like a technical challenge, but a strong data pipeline is one of the most essential tools for turning raw data into actionable insights.
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8 Oct 2024
Jakub Romanowski

What’s the Benefit of SQL in Business Analysis? 5 Practical Examples

Why do you need SQL in business analysis? Well, the short answer is that it makes your work more effective and efficient. In this article, I’ll show you some simple, real-world examples of how SQL can help your daily business analysis work. Are you a business analyst, or do you frequently analyze business data? Or are you planning to get into this field? Then I’d recommend you learn SQL. SQL (Structured Query Language) isn’t just the language of relation databases – it’s also the language of data analysis.
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7 Oct 2024
LearnSQL.com Team

Fall 2024 Track of the Season: SQL from A to Z

During Fall 2024, our main SQL track, SQL from A to Z, will be in the spotlight. In this article, we answer the most frequently asked questions about this track. At LearnSQL.com, our SQL courses are organized into tracks. A track is a sequence of courses designed to help you achieve a specific learning goal. The courses in the track are in a recommended order that progresses from the easiest to the most challenging.
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3 Oct 2024
Jakub Romanowski

5 Reasons You Shouldn't Become a Data Analyst

Data analysis is growing but it’s not for everyone. Before you become a data analyst, you need to be aware of the challenges. While it’s a great career, it requires specific skills and temperament. In this post, I’ll outline 5 reasons why being a data analyst may not be for you. Before we explore why becoming a data analyst may not suit everyone, it's important to highlight how rewarding this career can be.
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1 Oct 2024
Gustavo du Mortier

CTE vs. Temporary Table: What’s the Difference?

SQL offers you two options to handle complex queries efficiently: CTEs and temporary tables. Read on to weigh the pros and cons of CTEs vs. temp tables. In SQL (Structured Query Language), a common table expression (CTE) lets you define a subquery and assign a name to it so that it can be used within a main query. A temporary table is a database table that you create explicitly, like any other table – but with the particularity that it disappears when you close the database connection in which it was created.
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1 Oct 2024
Jakub Romanowski

Free Course of the Month: Blog & Traffic Data

Why practice SQL with real-life scenarios? We'll explain in this article – and we’ll show how you can do it for free during October 2024 with this LearnSQL.com course! SQL is the backbone of many data-driven applications and businesses. It's a powerful language that allows you to interact with databases, retrieve data, and make insightful decisions. If you're looking to improve your SQL skills, our Basic SQL Practice: Blog & Traffic Data course is the perfect opportunity.
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