Learning Lab

Practical notes, examples and projects on computer science, data and AI.

• Aggregation Discipline: GROUP BY, HAVING, COUNT
• Boolean Precision: WHERE, Precedence, and Pattern Matching
• Case Study: Building a Department Pay Report
• The Execution Order Model
• NULL and Three-Valued Logic
• Reference Checklist
• Reusable Expressions: Derived Tables and CTEs
• Sorting, TOP/LIMIT, and Determinism
• SQL Learning Roadmap — From Basics to Advanced
• 10 SQL Queries I Reach for Constantly
• What is a Database?
• What is SQL?