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 BYLIMIT- 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
1. Are take-home SQL tests harder than interviews?
They’re more realistic, not necessarily harder.
2. Do companies expect perfect SQL?
No. They expect clear, correct, and explainable logic.
3. How long should a take-home SQL test take?
Usually 2–6 hours, depending on scope.
4. Should I optimize SQL queries in take-home tests?
Only if asked. Clarity matters more.
5. Do I need advanced SQL for take-home tests?
No. Strong basics outperform complex syntax.