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Start your free trialMichael Hill
3,960 PointsMy Solution to this Challenge
After the last challenge I was curious about being more efficient with sub-queries. This was the final code I got that avoided hard coding the room id:
SELECT NAME FROM SUBJECTS WHERE ID IN (SELECT SUBJECT_ID FROM CLASSES
WHERE ROOM_ID = (SELECT ID FROM ROOMS ORDER BY CAPACITY DESC LIMIT 1));
I noticed I didn't need to add a Distinct keyword to exclude the duplicates with this answer. I'm assuming this is because my WHERE statement is technically pulling from a table that only populates each class id once?
1 Answer
Steven Parker
231,184 PointsThe second WHERE actually does return duplicate IDs, but the first WHERE is using the "IN" operator so it doesn't matter how many times a value appears in a result set, only if it exists in it or not.