-選擇列表中的列 'Student.sname' 無效，因為該列沒有包含在聚合函數或 GROUP BY 子句中。 SELECT Student.sno,sname,AVG(grade) AS avg_g FROM Student,SC  www.survivalescaperooms.com WHERE Student.sno=SC.sno AND cno<>'008' GROUP BY Student.sno --沒加 Student. 列名 'sno' 不明確。 HAVING MIN(grade) >= 60 ORDER BY avg_g DESC; 

/* 把對Student表和Course表的全部權限授予用戶U2和U3   GRANT ALL PRIVILIGES www.survivalescaperooms.com           ON TABLE Student, Course             TO U2, U3;  把對表SC的查詢權限授予所有用戶  GRANT SELECT ON TABLE SC  TO PUBLIC; 把查詢Student表和修改學生學號的權限授給用戶U4  GRANT UPDATE(Sno), SELECT             ON TABLE Student TO U4; 把用戶U4修改學生學號的權限收回   REVOKE UPDATE(Sno) ON TABLE Student FROM U4; */