(4 分)
A. SELECT SID,marks,ROWNUM “Rank”
FORM students
WHERE ROWNUM<=10 AND course_id=’C10′
ORDER BY marks DESC;
B. SELECT SID,marks,ROWNUM”Rank”
FORM students
WHERE ROWNUM<=10 AND course_id=’C10′
ORDER BY marks;
C. SELECT SID,marks,ROWNUM”Rank”
FORM (SELECT SID ,marks
FORM students
WHERE ROWNUM<=10 AND course_id=’C10′
ORDER BY marks DESC;
D. SELECT SID,marks,ROWNUM”Rank”
FORM (SELECT SID ,marks
FORM students
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