30 Days of SQL for Data Engineering: Zero to Hero
Looking to pick up a new skill, how about learning SQL, a universally used programming language within backend software engineering and data professionals across the entire industry, perfect for business analysis, reporting and database modelling.
This series is completely free to go through and is split into weekly categories. All I ask is if you’re enjoying the content to like, share and subscribe for more materials and deep-dives.
Starts September 1st 2025
Week 1: Query Fundamentals
Day 1: SELECT, FROM & WHERE Essentials
Day 2: Sorting & Paging (ORDER BY & LIMIT)
Day 3: JOINS 101
Day 4: JOINS 201
Day 5: Aggregations & HAVING
Day 6: CASE Expressions & Business Rules
Day 7: Text Cleaning & Regex
Week 2: Physical Design & Storage
Day 8: Dates, Time Zones & Watermarks
Day 9: Databases, Schemas & Namespaces
Day 10: Data Types, Keys & Identities
Day 11: CREATE, ALTER & Idempotent DDL
Day 12: Managed vs External Tables: CSV → Parquet & ACID
Day 13: Partitioning Strategy: Keys & Grain
Day 14: Partitioning in Practice: Pruning, Backfills & Swaps
Week 3: Analytical Patterns & Writes
Day 15: Indexes, Clustering & Statistics
Day 16: Subqueries & Derived Tables
Day 17: CTEs & Multi-Step SQL
Day 18: Window Functions I: ROW_NUMBER & RANK
Day 19: Window Functions II: LAG, LEAD & Running Totals
Day 20: NULL Handling: COALESCE, NULLIF & 3-Valued Logic
Day 21: UNION, INTERSECT & EXCEPT
Day 22: Fast Loads: COPY/BULK & Quarantine Tables
Week 4: Pipeline Ops, Quality, and Governance
Day 23: Idempotent Writes: INSERT, UPDATE, DELETE & MERGE
Day 24: Slowly Changing Dimensions: Type 1 & 2
Day 25: Incrementals & High-Watermarks
Day 26: Error Handling & Audit Trails
Day 27: Data Quality Checks as SQL
Day 28: EXPLAIN/ANALYZE & Plan Reading
Day 29: Access Control, PII & Masking
Day 30: Build a Medallion Pipeline: Raw → Silver → Gold
If you happen to come across this page and the days are still white text, it means you’re still able to follow along. Each hyperlink will be added as soon as the day is released so stay tuned.
If you have any issues, please let me know.
