题目内容:
设有学生表student(学号,姓名,性别,出生日期,院系.、课程表Course(课程号,课程名,学时.和选课表。(学号,课程号,成绩.,查询所修课程成绩都大于等于85分的学生的学号和姓名,正确的命令是
A.SELECT学号,姓名FROM student s WHERE NOT EXISTS(SELECT * FROM score sc;WHERE sc.学号=s.学号AND成绩<85.
B.SELECT学号,姓名FROM student s WHERE N0T EXISTS(SELECT·FROM score sc;
WHERE sc.学号=s.学号AND成绩>=85
C.SELECT学号,姓名FROM student s score sc WHERE s.学号=sc.学号AND成绩>=85
D.SELECT学号,姓名FROM student s score sc WHERE s.学号=sc.学号AND ALL成绩>=85
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答案解析: