Data Science Educational Resources
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SQL Articles, Tutorials & Interview Questions
Simplifying SQL Queries with Aliases: A How-To Guide
SQL aliases are a simple yet efficient way of simplifying your SQL queries. In this guide, we’ll show you all the benefits and provide examples of their use.
Nathan Rosidi -
Data Type Conversion in SQL: A Closer Look at CAST Function
Master data type conversion: why do it, how to do it, and how not to do it. The article covers all that with some real-world examples from the platform.
Tihomir Babic -
SELECT UNIQUE in SQL: Mastering Data Retrieval with DISTINCT
What is SELECT UNIQUE in SQL? What about SELECT DISTINCT? How do you retrieve unique data? We will answer these three and more questions in this article.Nathan Rosidi -
A Detailed Comparison Between Inner Join vs. Outer Joins
In this article, we compare inner join vs. outer join. We will talk about their similarities and differences and show you how to use them in practice.Nathan Rosidi -
Top 15 SQL Server DBA Interview Questions
SQL Server DBA interviews: writing window functions, retention queries, explaining indexing internals and isolation levels.
Sara Nobrega -
SQL ROW_NUMBER() Function: Syntax and Applications
How to add SQL ROW_NUMBER() to your data handling and analysis tools? We’ll help you by explaining its workings, its syntax, and how to use it in examples.Nathan Rosidi -
MS SQL vs MySQL: Similarities and Differences
Facing the choice of MS SQL vs MySQL? Here’s a guide through the similarities and differences of these two popular database systems.Nathan Rosidi -
Understanding SQL's INTERSECT Command
What is INTERSECT in SQL? How does it work? When to use it? How to write an INTERSECT query? You can find all these questions answered in this article.Nathan Rosidi -
An In-Depth Guide to SQL SELECT DISTINCT Statement
SQL SELECT DISTINCT is a powerful statement for removing duplicates from your data. Learn how to use it in different scenarios and what its alternatives are.Nathan Rosidi -
Best Platforms to Practice SQL Online in 2026: A Comprehensive Review
All 10 SQL practice platforms we tested against 16 criteria achieve their goal: they will teach you SQL. Find out which ones suit your learning goals.Tihomir Babic -
Clustered vs. Non-Clustered Indexes in SQL
Today’s showdown is clustered vs. non-clustered indexes. Learn more about their features, strengths, and weaknesses, and join us to see who wins this fight.Nathan Rosidi -
MS SQL Interview Questions That Will Challenge Your Skills
Solving actual MS SQL interview questions is the best way of preparing for a technical interview. Here’s a detailed guide on how to challenge your skills.Nathan Rosidi -