LDS SQL CTE & Subqueries 25 — 25 Curated SQL Problems

A 5-stage progression from scalar subqueries and EXISTS / NOT EXISTS through single-CTE reference-value patterns up to the multi-CTE business scorecard you'll write at staff level. Twenty-five problems on 15 production-grade schemas — the query shape that turns a raw fact table into a board-ready metric in one statement.

Problems included in LDS SQL CTE & Subqueries 25

1. Campaigns Above Average Spend
2. Portfolios Above Average Value
3. Restaurants Above Average Rating
4. Merchants Above Average Charge Amount
5. Properties Priced Above Average
6. Providers with Denied Claims
7. Guests Booking Direct and OTA
8. Riders Who Used Economy and Premium
9. Watchlisted but Never Watched
10. Plans Never Subscribed
11. Properties Above Average Revenue
12. Public Posts Above Average Reactions
13. Customers With Above-Average Daily Usage
14. Securities Above Sector Average P/E
15. Categories With Above-Average Revenue
16. Delinquent Customers With No Suspicious Activity
17. Users With Positions But No Recent Trades
18. Refund Reason Analysis
19. Products Outperforming Average Revenue
20. High Ticket Volume Customers
21. Campaign ROAS by Attribution Model
22. Property Investment Scorecard
23. Revenue Summary With Rank via CTE
24. Warehouse Revenue With Rank via CTE
25. User Engagement Score Pipeline