数据库第三章习题参考答案

⑸UPDATE SC

SET GRADE=NULL

WHERE GRADE<60 AND C# IN(SELECT C# FROM C

WHERE CNAME=’高等数学’); ⑹UPDATE SC

SET GRADE=GRADE*1.05 WHERE S# IN(SELECT S# FROM S

WHERE SEX=’F’)

AND GRADE<(SELECT AVG(GRADE) FROM SC);

⑺ 用两个UPDATE语句实现： UPDATE SC

SET GRADE=GRADE*1.04

WHERE C#=’4’AND GRADE>75; UPDATE SC

SET GRADE=GRADE*1.05

WHERE C#=’4’AND GRADE<=75;

注意：这两个UPDATE语句的顺序不能颠倒。