已知关系模式:sc(sno, sname, grade),各属性含义依次为、课程名、分数。要查找“数据库”课分数最高的学生的,正确的SQL语句是
A.
SELECT sno FROM sc WHERE sname='数据库' AND grade=MAX(grade)
B.
SELECT sno FROM sc FOR sname='数据库' OR grade>=MAX(grade)
C.
SELECT sno FROM sc WHERE sname='数据库' AND grade=(SELECT MAX(grade) FROM sc
D.
SELECT sno FROM sc FOR sname='数据库' OR grade=(SELECT MAX (grade) FROM sc