DAY 29: SQL - Complex Business Scenarios

Guru Charan Pathalla

DAY 29: SQL - Complex Business Scenarios

Learning Objectives: - Solve multi-step business problems - Combine advanced SQL techniques - Optimize complex queries - Handle real-world scenarios - Apply best practices

Topics Covered (60 min):

1. Multi-Table Complex Queries - Combine JOINs, subqueries, CTEs - Window functions with aggregations - Nested CTEs for step-by-step logic - Handle NULL values properly - Performance considerations

2. Time-Based Analysis - Month-over-month, year-over-year - Rolling calculations (12-month rolling average) - Fiscal calendars vs calendar year - Time-series gaps and islands problems - Date range overlaps

3. Advanced Patterns - Gap analysis (missing sequences) - Duplicate detection and removal - Hierarchical queries (bill of materials) - Graph problems (shortest path) - Running balance calculations

4. Business Logic Implementation - Discount and pricing rules - Inventory calculations (FIFO, LIFO) - Allocation algorithms - Commission calculations - Complex business rules with CASE

Video Resources:

  1. How To Create Interactive Dashboards in Excel (2025) (3:45)
    https://www.youtube.com/watch?v=qfYOdYgbBhk

  2. Interactive Excel Dashboard Tutorial in 3 Steps (4:03)
    https://www.youtube.com/watch?v=1ic8E58Bo2M

  3. Excel Agent Mode: Build Dashboards Automatically (4:00)
    https://www.youtube.com/watch?v=MlKyTKFWI4M

AI Learning Prompts (Concept Understanding Only):

Understanding Complex Queries:

I'm learning to solve complex SQL business problems. Please explain:

1. How do I break down complex requirements into steps?
2. Show me how to combine CTEs, JOINs, and window functions
3. What is the best approach for multi-step calculations?
4. How do I handle edge cases (NULLs, missing data)?
5. Provide example: Calculate customer lifetime value with cohorts

Use step-by-step problem-solving approach.

Understanding Business Logic:

Help me implement business logic in SQL:

1. How do I calculate tiered discounts (5% for $100-500, 10% for $500+)?
2. Show me commission calculation (different rates by product category)
3. How do I allocate shared costs across products?
4. Provide example of inventory FIFO calculation
5. Show complex pricing rules implementation

Explain with real business scenarios.

Guided Practice (60 min):

📝 How to approach Guided Practice:

  • Follow step-by-step: Work through each exercise in order
  • Use provided resources: Reference the video tutorials and AI prompts if you get stuck
  • Verify your work: Check your results match expected outcomes
  • Take notes: Document key learnings and shortcuts you discover
  • Ask for help: Use AI assistants to clarify concepts you don't understand

Exercise 1: Advanced CLV with Profit Margins

Goal: Calculate Customer Lifetime Value (CLV) but this time considering specific product profit margins (Price - Cost).

Exercise 2: Product Performance Deep Dive (YoY)

Goal: Analyze product performance, calculating Year-Over-Year (YoY) growth for each category.

Exercise 3: Simple Sales Attribution

Goal: Identify which marketing channel was the "First Touch" for customers who made a purchase.

Exercise 4: Inventory Optimization

Goal: Identify items with low stock relative to their sales velocity (potential stockouts).

Exercise 5: Executive Dashboard Query

Goal: A single "Master Query" that simulates a real-time executive dashboard view.

Independent Practice (60 min):

💡 Hints for Independent Practice:

  • Start simple: Begin with basic variations before attempting complex modifications
  • Break it down: Divide complex problems into smaller, manageable steps
  • Test incrementally: Verify each step works before moving to the next
  • Use documentation: Refer to official docs or tutorials when needed
  • Experiment: Try different approaches to find what works best

Apply the concepts learned to different datasets and scenarios.

Daily Assignment (60 min):

Assignment:

  • Customer Lifetime Value:Calculate CLV considering acquisition cost, retention rate, average order value, purchase frequency
  • Product Performance:Identify best/worst performers by multiple metrics, year-over-year comparison, seasonality analysis
  • Sales Attribution:Multi-touch attribution model (credit to first, last, and middle touchpoints)
  • Inventory Analysis:Calculate stock turnover, identify slow-moving items, forecast reorder quantities
  • Optimization:Ensure all queries run efficiently with proper indexes and execution plans

Expected Outcomes:

  • Solve multi-step business problems
  • Combine advanced SQL techniques
  • Optimize complex queries
  • Handle real-world scenarios
  • Apply best practices

📝 Day 29 Quick Quiz - Test Your Knowledge!

Q1. As you near the end of the program, what does Day 29 emphasize?

Q2. How should you approach Day 29 exercises?

Q3. What makes Day 29 content valuable for your career?

Q4. By Day 29, what should you be comfortable with?

Q5. What's the best mindset for Day 29?