DAY 12 | Subqueries & Temp Tables | 30 Day SQL Challenge | #sql #dataanalytics #dataengineering

💻 Practice SQL for 30 Days with Stephen. In Day 12, we cover subqueries and temp tables - how to nest one query inside another to filter, add calculated columns, and build derived tables, plus how to store intermediate results in temp tables using CREATE TEMP TABLE and CTAS so your SQL stays clean and readable. Full exercise included. ⏲️ Timestamps: (timestamps added on publish day) 📂 Code + datasets: https://github.com/sdw-online/30-Day-SQL-Challenge 🎥 Install PostgreSQL + pgAdmin: https://youtu.be/g8GwhsVPaOg 📩 Join the waitlist: Free community - https://data100x.carrd.co/ Private community - https://data100.carrd.co/ 🎓 Become a data analyst: Analyst Builder - https://www.analystbuilder.com/?via=stephen-david-williams 📲 Socials: LinkedIn - https://www.linkedin.com/in/stephen-david-williams-860428123/ GitHub - https://github.com/sdw-online TikTok - https://www.tiktok.com/@sdw.online Instagram - https://instagram.com/sdw.online Twitter/X - https://twitter.com/sdw_online #sql #dataanalytics #dataengineering #sqlchallenge #subqueries #temptables