# 4.2 Assignment

course: Academy — 65-GENAI-for-Engineers
module: Academy/65-GENAI-for-Engineers
type: pdf
source_url: https://personal-learn.armco.dev/files/Academy/65-GENAI-for-Engineers/assignments/4.2_Assignment__Solving_Real-life_Query_Challenges/4.2_Assignment.pdf
pages: 1

---
[page 1]
4.2 Assignment Questions 
 Short Answer / Conceptual Questions 
 1.  Why is it important to understand the business context before writing SQL queries? 
 2.  Describe a situation where using  HAVING  instead of  WHERE  is necessary. 
 3.  Explain the difference between filtering with  WHERE  and filtering with  CASE  . 
 Hands-On / Practical Tasks 
 4.  Based on a sample e-commerce database, write SQL queries to: 
 a. Find the top 3 best-selling products in the last month (use  GROUP BY  ,  SUM()  ,  ORDER 
 BY  ,  LIMIT  ) 
 b. Identify customers who made purchases in at least 3 different months (use 
 COUNT(DISTINCT MONTH(date))  ) 
 c. Compare total revenue between first-time and repeat customers using  CASE  and 
 GROUP BY 
 5.  Given a table  StockLog(ProductID, Date, InStock)  ,  write a query to list all 
 products that were out of stock (  InStock = 0  ) for  more than 5 days in the last 30 days. 
 6.  Design a real-life query challenge based on your domain (e.g., education, retail, 
 finance), define the problem clearly, and write the SQL logic (or pseudo-code) that would 
 solve it step-by-step.