题解 | 查询成绩
查询成绩
https://www.nowcoder.com/practice/ef30689ae065434c89c129e9dfe1b4cd
SELECT
count(*)
FROM (
SELECT
SUM(score)/3 AS avg_score
FROM Student JOIN SC
ON Student.sId = SC.sId
JOIN Course ON SC.cId = Course.cId
GROUP BY SC.sId
HAVING SUM(score)/3 >= 60) t
