Take-home tests are where companies check how you actually think, not just what you memorized.

They don’t want fancy SQL.
They want clear logic, correct answers, and business awareness.

Here are the SQL questions commonly asked in take-home data analyst tests and what they’re really testing.

What Companies Look for in Take-Home SQL Tests

They are checking:

• Can you work with messy data?
• Can you answer business questions using SQL?
• Can you explain your logic?
• Can your queries be trusted?

Speed matters less than clarity and correctness.

1. Simple Aggregation Questions

Examples:

• Total sales by day
• Average order value per customer
• Revenue by product category

What they test:

• GROUP BY
• Basic aggregations
• Understanding of metrics

2. Filtering With Conditions

Examples:

• Customers who placed more than 3 orders
• Orders above a certain value
• Events in the last 30 days

What they test:

• WHERE
• Logical conditions
• Date filtering

3. JOIN-Based Questions

Examples:

• Combine customers and orders
• Revenue per customer
• Orders with missing customer records

What they test:

• INNER JOIN, LEFT JOIN
• Join logic
• Handling missing data

This is one of the most important skills tested.

4. Duplicate Detection Questions

Examples:

• Find duplicate users
• Identify repeated transactions
• Remove duplicate rows logically

What they test:

• Grouping logic
• Data quality awareness

5. NULL Handling Questions

Examples:

• Orders with missing prices
• Customers without signup dates

What they test:

• IS NULL
• Awareness of incomplete data
• Defensive querying

6. Ranking and Sorting Questions

Examples:

• Top 5 customers by revenue
• Most popular products per category

What they test:

• ORDER BY
• LIMIT
• Sometimes window functions

7. Time-Based Analysis Questions

Examples:

• Monthly revenue trends
• Daily active users
• Week-over-week growth

What they test:

• Date functions
• Time grouping
• Trend thinking

8. Conditional Logic Questions

Examples:

• Categorize customers as high, medium, low value
• Flag risky transactions

What they test:

• CASE WHEN
• Business logic translation

9. Funnel or Step-Based Questions

Examples:

• Users who viewed → clicked → purchased
• Drop-off at each step

What they test:

• Multi-step joins
• Logical sequencing
• Analytical thinking

10. Subquery Questions

Examples:

• Customers with above-average spend
• Products never purchased

What they test:

• Nested logic
• Query structuring

11. Data Cleaning Questions

Examples:

• Fix inconsistent country names
• Normalize text values

What they test:

• String functions
• Practical data handling

12. Business Insight Questions

Examples:

• Why did revenue drop last month?
• Which customers should marketing target?

What they test:

• Interpretation
• Explanation, not just SQL

Often includes a written explanation.

Common Mistakes Candidates Make

• Overcomplicated queries
• Ignoring NULLs
• Not explaining assumptions
• Writing unreadable SQL
• Chasing optimization over clarity

Clean > clever.

How to Impress in a Take-Home SQL Test

• Use readable formatting
• Comment your logic
• Explain edge cases
• Show business thinking
• Validate your results

This matters more than advanced syntax.

Take-home SQL tests don’t test memorization.

They test how you think with data.

If you can answer business questions clearly using SQL,
you’re already ahead of most candidates.

FAQs