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LDS SQL 50 — 50 Curated SQL Problems

A 5-stage progression that takes you from basic WHERE filters through window functions to staff-level multi-CTE scorecards, structured across 15 production-grade schemas so the same pattern shows up in different domains until it sticks. The closest LDS has to a "Blind 75" for SQL — start here if you only do one collection.

Problems included in LDS SQL 50

  1. Active Search Campaigns by Budget
  2. Active PPO Plans With Prescription Coverage
  3. Active Five-Star Hotels
  4. Open High-Rated Restaurants
  5. Active E-Commerce Merchants
  6. Active Sale Listings
  7. Active Electronics Products
  8. Active Enterprise Organizations
  9. Active Users in Target Countries
  10. Active Residential Customers
  11. Active Campaigns With Advertiser Industry
  12. Transactions With Account and Customer Details
  13. User Total Portfolio Value
  14. Bookings With Guest and Room Info
  15. Orders With Customer Details
  16. Deliveries With Courier Info
  17. Trips With Rider Details
  18. Charges With Customer and Payment Method
  19. Order Items With Product Info
  20. Customers Without Any Support Tickets
  21. Trade Volume by Security
  22. Average Monthly Bill by Customer Segment
  23. On-Time Delivery Rate by Carrier
  24. Top 5 Riders by Total Spending
  25. Rank Campaigns by Spend per Advertiser
  26. User Sequence Number Within Organization
  27. Transaction Amount Change With LAG
  28. Daily Revenue Running Total per Property
  29. Monthly Watch Hours Moving Average
  30. Highest Rated Delivery per Courier
  31. Charge Amount Quartile Analysis
  32. Top 5 Agents by Listing Count
  33. Advertisers With High Credit Utilization
  34. Patients Above Plan Average Paid Amount
  35. Promo Code Effectiveness Report
  36. Users With Both Inquiries and Tours
  37. Sellers With Orders But No Returns
  38. Late Deliveries by Carrier and Delay Duration
  39. Dispute Resolution Time Analysis
  40. Overdue Invoices by Aging Bucket
  41. Content Moderation Risk Score
  42. Properties With Bookings or Reviews
  43. Campaign Health Scorecard
  44. Customer Relationship Depth Summary
  45. Property Operations Dashboard
  46. Warehouse Operations Dashboard
  47. Merchant Health Scorecard
  48. Marketplace Operations Dashboard
  49. Customer 360 Summary
  50. Customer Churn Risk Assessment