1.

_ What does the following query find?(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'red')MINUS(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'green')$?

A. Find the sailor IDs of all sailors who have reserved red boats but not green boats
B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats
C. Find the sailor Ids of atmost one sailor who have reserved red boats but not green boats
D. None of These
Answer» B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats


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