SQL interview questions

All SQL questions

SQL interview questions
#	Question	Difficulty	Type
1	Explain INNER JOIN vs LEFT JOIN with a practical example.	Easy	conceptual, coding
2	How do window functions differ from GROUP BY?	Easy	conceptual, coding
3	Average Order Value: SQL Case Study with 8 Approaches	Medium	coding, optimization, scenario
4	Customer Lifetime Value: SQL Case Study with 8 Approaches	Medium	coding, optimization, scenario
5	Daily Active Users: SQL Case Study with 8 Approaches	Medium	coding, optimization, scenario
6	Find the second-highest salary without using a simple MAX approach.	Medium	coding
7	How would you detect and remove duplicate records safely?	Medium	coding, scenario
8	New vs Returning Customers: SQL Case Study with 8 Approaches	Medium	coding, optimization, scenario
9	Top Selling Products: SQL Case Study with 8 Approaches	Medium	coding, optimization, scenario
10	Churn Rate: SQL Case Study with 8 Approaches	Hard	coding, optimization, scenario
11	Conversion Funnel: SQL Case Study with 8 Approaches	Hard	coding, optimization, scenario
12	How would you optimize a slow analytical SQL query?	Hard	optimization, scenario
13	Inventory Turnover: SQL Case Study with 8 Approaches	Hard	coding, optimization, scenario
14	Monthly Revenue: SQL Case Study with 8 Approaches	Hard	coding, optimization, scenario

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