有关系S(SNO, SNAME, SAGE),C(CNO, CNAME),SC(SNO, CNO, GRADE)。其中SNO是学生号,SNAME是学生姓名,SAGE是学生年龄, CNO是课程号,CNAME是课程名称,GRADE是成绩。以下( )SQL语句可以实现查询没有选修'C002'号课程的学生姓名。
A:[br][/br]
B:
C: [br][/br]
D:
选项:
A:SELECT SNAME FROM S, SC WHERE S.SNO=S
C:SNO AND CNO !='C002'
B:SELECT SNAME FROM S WHERE SNO NOT IN (SELECT SNO FROM SC WHERE CNO='C002')
C:SELECT SNAME FROM S WHERE NOT EXISTS (SELECT * FROM SC WHERE S.SNO=S
C:SNO AND CNO='C002')
D:SELECT SNAME FROM S WHERE EXISTS (SELECT * FROM SC WHERE S.SNO=S
C:SNO AND CNO !='C002')
发布时间:2024-05-07 19:27:42