问题
填空题
某数据库中有表COURSE(CNO,CNAME,TNO)、表TEACHER(TNO,TNAME,DEPART)和表SCORE(SNO,CNO,DEGREE),现要查询选修某课程的同学人数多于5人的教师姓名。请补全下列语句:
SELECT TNAME
FROM TEACHER WHERE
()
(SELECT X.TNO FROM COURSE X,TEACHER Y,SCORE Z
WHERE()
()
()
)
答案
参考答案:TNO IN;X.TNO=Y.TNO AND X.CNO=Z.CNO;GROUP BY X.TNO;HAVING COUNT(Z.CNO)>5