Introduction to SQL for Analytics

Joins, CTEs, and Aggregations

Data Validation Queries

OLAP vs OLTP and Modern Warehouses

Data Modeling Concepts

Building Views in Azure PostgreSQL

Practice

Assignment

Gotchas & Pitfalls

Week 9 Lesson Plan (Teachers)

Gotchas & Pitfalls

Content coming soon...

Suggested Topics

• Accidental cartesian joins: forgetting a JOIN condition and exploding row counts
• NULL behavior in aggregations: COUNT(*) vs COUNT(column), NULL in GROUP BY
• Confusing WHERE and HAVING: filtering before vs after aggregation
• Ambiguous column names in multi-table joins without aliases
• Wrong grain in a fact table: duplicating metrics when joining at different levels
• Overusing SELECT * in analytical queries: performance and readability costs
• Assuming referential integrity exists when it does not: orphaned keys
• Not testing views after creation: stale results when underlying data changes

The HackYourFuture curriculum is licensed under CC BY-NC-SA 4.0

*https://hackyourfuture.net/*

Found a mistake or have a suggestion? Let us know in the feedback form.