【正确答案】方法1：
SELECT Sno, Sname, Sage
FROM S
WHERE Sage BETWEEN 18 AND 22
AND Ssex='男'
方法2：
SELECT Sno, Sname, Sage
FROM S
WHERE Sage＞=18 AND Sage ＜=22
AND Ssex='男'
【答案解析】
问答题
检索选修了“王杰”老师所授课程的学生的学号和姓名。
【正确答案】方法1：
SELECT Sno, Sname
FROM S, SC, C
WHERE S. Sno=SC. Sno
AND SC. Cno=C. Cno
AND C. Cteacher='王杰'
方法2：
SELECT Sno, Sname FROM S WHERE Sno IN
(SELECT Sno FROM SC WHERE Cno IN
(SELECT Cno FROM C WHERE Cteacher='王杰'))