SQL

In today’s data-driven landscape, mastering advanced SQL techniques isn’t just valuable for day-to-day analysis—it’s essential for showcasing your expertise during live-coding interviews where you’ll need to efficiently manipulate complex datasets under pressure. 1️⃣ Running Totals & Cumulative Sums ✅ Key Function: SUM() OVER (ORDER BY column) ✅ Use Case: Running totals of revenue, sales, or cumulative counts. Example: Compute cumulative revenue over time. SELECT order_date, total_amount, SUM(total_amount) OVER (ORDER BY order_date) AS running_total FROM orders; 2️⃣ Moving Averages (Rolling Window Aggregates) ✅ Key Function: AVG() OVER (ORDER BY column ROWS BETWEEN N PRECEDING AND CURRENT ROW)...