HAVING filters **groups** after aggregation; WHERE filters **rows** before aggregation. **Why order matters**: HAVING operates on aggregated values (SUM, COUNT, AVG) that don't exist until after GROUP BY. Example: SELECT dept, AVG(sal) FROM emp GROUP BY dept HAVING AVG(sal) >...
This medium-level SQL question appears frequently in data engineering interviews at companies like Fossil Group. While less common, it tests deeper understanding that distinguishes strong candidates.
Break this problem into components. Identify the core trade-offs involved, then walk the interviewer through your reasoning step by step. Demonstrate awareness of edge cases and production considerations - this is what separates good answers from great ones.
HAVING filters groups after aggregation; WHERE filters rows before aggregation. Why order matters: HAVING operates on aggregated values (SUM, COUNT, AVG) that don't exist until after GROUP BY. Example: SELECT dept, AVG(sal) FROM emp GROUP BY dept HAVING AVG(sal) > 50000. You can't use WHERE AVG(sal) > 50000 because aggregates aren't computed yet. Logical order: FROM → WHERE → GROUP BY → HAVING → SELECT → ORDER BY. Scalability: Filter raw rows with WHERE when possible—more efficient (fewer rows before aggregate). Use HAVING only for aggregate conditions.
This answer is partially locked
Unlock the full expert answer with code examples and trade-offs
Practice real interviews with AI feedback, track progress, and get interview-ready faster.
Pro starts at $24/mo - cancel anytime
Get the most asked SQL questions with expert answers. Instant download.
No spam. Unsubscribe anytime.
Paste your answer and get instant AI feedback with a FAANG-level improved version.
Analyze My Answer — FreeAccording to DataEngPrep.tech, this is one of the most frequently asked SQL interview questions, reported at 1 company. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.