Hacker Rank SQL Fundamentals
Introduction
Recently, I started practicing SQL again on HackerRank and discovered some interesting challenges that can help sharpen your SQL skills. Although I use SQL regularly at work, my post-degree classes at Langara College prompted me to revisit the fundamentals. I decided to share some of the challenges I found both engaging and useful for skill development.
Returning to SQL on HackerRank brought a sense of nostalgia and reminded me of the underlying patterns and logic that make SQL so powerful for data manipulation and analysis.
While exploring trends in frontend and backend technologies, I became interested in creating slides programmatically using Sli.dev. Unlike Slides.com, Sli.dev lets me centralize all my slides on my GitHub profile and share them in a more organized way.
The following slides present my review of the SQL challenges I found on HackerRank. I hope you find them helpful as well.
Slides
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My Experience
I worked through these examples using MySQL 5.7. Although I usually use cloud databases like GCP or AWS, running a local Docker image with MySQL 5.7 gave me a renewed appreciation for the database and allowed me to experiment freely.
Key Tricks to Solve Challenges
- Split responsibilities: Break complex queries into smaller parts to make them easier to understand and debug.
- Reusable queries: Write queries that can be reused, such as subqueries in the final query, to make your logic more flexible.
- CTE limitations: MySQL 5.7 does not support Common Table Expressions (CTEs), so use subqueries or temporary tables to achieve similar results.
- Don’t get frustrated: If you don’t pass a test on the platform, remember there are many ways to solve a problem. Focus on learning and enjoy the process.
Finally, while certifications are nice to have—almost like collecting candies—the real value lies in the learning journey itself. Certifications can help during interviews, but the true reward is in how you apply this knowledge to help your team and solve real-world problems.
certifications
https://www.hackerrank.com/profile/Qleoz12.