The SQL Queries That Work in Every Industry (With Examples)
Healthcare, SaaS, retail, finance — same patterns, different tables
How to Build Customer Segments From Scratch With CASE WHEN + GROUP BY
Turn 1,000 customers into 5 actionable business segments
How to Find the Bad Data Before It Finds You (Simple SQL Audits)
A simple audit script that catches 80% of data quality problems
47% of Your Bookings Are Cancelling. The Empty Stadium Blueprint Finds Out Why.
How to diagnose churn by asking “who’s NOT here?”
The 3-Project Portfolio That Actually Gets Analyst Interviews
What hiring managers look for (it’s not Kaggle datasets)
How to Compare Records Within the Same Table (Self-JOINs)
The pattern that finds repeat customers, guide pairs, and loyalty trends
How to Stop NULLs From Breaking Your SQL Reports
Three patterns for handling missing data like a professional
How to Find Customers Who Have Never Booked (Using LEFT JOIN)
The pattern that reveals who’s missing — and why it matters
How to Turn “Here Are the Numbers” Into “Here’s What We Should Do”
A framework for making every metric meaningful
Just Pull the Numbers — How to Handle Vague Data Requests (The Easy Way)
A framework for translating business-speak into analytical clarity