有关系S(SNO, SNAME, SDEPT,SAGE)，C(CNO, CNAME)，SC(SNO, CNO, GRADE)。其中SNO是学生号，SNAME是学生姓名，SDEPT是系别,SAGE是学生年龄， CNO是课程号，CNAME是课程名称，GRADE是成绩。要查询“计算机”系的没有不及格成绩的学生学号和姓名。
A、SELECT Sno, Sname FROM S
WHERE Sdept='计算机’
INTERSECT
SELECT Sno, Sname FROM SC
WHERE GRADE>=60
B、SELECT Sno, Sname FROM S
WHERE Sdept='计算机’and sno not in
     (SELECT SNO FROM SC WHERE GRADE<60)
C、SELECT Sno, Sname FROM S
WHERE Sdept='计算机’
EXCEPT
SELECT SNO FROM SC
WHERE GRADE<60
D、SELECT Sno, Sname FROM S
WHERE Sdept='计算机’and sno in
     (SELECT SNO FROM SC WHERE GRADE>=60)