← Bytedance Interview Insights
Pretty standard SQL filter and sort, nothing tricky about the logic itself.
First, clarify the table schema and the exact filtering condition: 'at least one description that is not boring' means the movie has at least one row where description != 'boring'. Use a subquery with EXISTS or IN to filter movies, then order by rating descending. Alternatively, use GROUP BY with HAVING COUNT(CASE WHEN description != 'boring' THEN 1 END) > 0.
Pro tip: Mention that if the table has multiple rows per movie (e.g., multiple descriptions), you must deduplicate movies in the output. Also, consider performance: EXISTS is often more efficient than IN for large datasets, and indexing on description and movie_id can help.
Identify the table name, columns (e.g., movie_id, description, rating), and clarify that a movie can have multiple descriptions. Confirm that 'not boring' means description != 'boring' and that we need movies with at least one such description.
Decide between using a subquery with EXISTS/IN or using GROUP BY with HAVING. EXISTS is suitable for correlated subqueries, while GROUP BY aggregates per movie.
Construct the query: SELECT movie_id (or all columns) FROM table WHERE movie_id IN (SELECT movie_id FROM table WHERE description != 'boring') ORDER BY rating DESC. Or use GROUP BY movie_id HAVING COUNT(CASE WHEN description != 'boring' THEN 1 END) > 0.
If selecting all columns, ensure each movie appears once. Use DISTINCT or GROUP BY. Order by rating descending, and consider secondary sort if needed.
Test with edge cases: movies with only 'boring' descriptions, movies with no descriptions, ties in rating. Discuss potential indexes to improve performance.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.