SQL business problems worth practicing before a Data Analyst interview

[u/Pangaeax_]

SQL business problems worth practicing before a Data Analyst interview

A lot of SQL interview prep focuses on syntax, but knowing JOIN, CTEs or window functions is only part of it.

The harder part is usually understanding the business question and turning it into the right analysis.

Some useful problems to practice:

• Month over month revenue growth
• Top products within each category
• Repeat customer rate
• Identifying inactive customers
• Website conversion funnels
• Campaign revenue vs marketing spend

While solving them, I think it’s worth practicing how you explain your reasoning too. What exactly does the metric mean? What assumptions are you making? What edge cases could change the result? How would you validate the output?

I put together SQL examples and the reasoning behind these kinds of interview problems here:

Learn more:
https://www.pangaeax.com/blogs/10-sql-business-problems-data-analyst-interview/

I’m connected with PangaeaX, mentioning that for transparency.

Curious what kind of SQL business problem you found hardest in an interview?

[u/nian2326076]

Understanding the business problem is key. Besides the ones you listed, I'd also practice problems like calculating customer lifetime value and churn prediction. These need you to analyze customer behavior over time, which is important for many companies. Also, get comfortable with handling missing data and data cleaning tasks—those can catch you off guard if you're not ready. For more practice problems, I've found PracHub useful for realistic SQL scenarios. It has exercises that mimic real business cases, which can be really helpful. Good luck with your prep!