Day 3: Learning SQL to Get Hired

Welcome to Day 3 of my "Learning SQL to Get Hired" series!

Today, I’m working through one LeetCode SQL problem that’s all about filtering with joins:

- #1581 Customer Who Visited but Did Not Make Any Transactions

What you'll learn:
- Using LEFT JOIN and WHERE conditions to find unmatched records
- How to detect NULLs in join results
- Real-world patterns like “find users who didn’t complete an action” super common in analytics and product interviews

As always, I’m walking through my thought process, showing how I debug mistakes, and talking about what I’d expect if this came up in a real interview. Try the problem yourself and let me know how you approached it!

Problem link:
https://leetcode.com/problems/customer-who-visited-but-did-not-make-any-transactions/

Timestamps:
0:00 - Introduction
1:30 - Customer Who Visited but Did Not Make Any Transactions
31:20 - Conclusion

#SQL #LeetCodeSQL #SQLInterview #LearnSQL #DataEngineer #MySQL #LeftJoin

Видео Day 3: Learning SQL to Get Hired канала Nicholas Facciola