sql找出选修了所有课程的学生号

根据提供的引用内容，有三种方法可以找出选修了所有课程的学生号：

方法一：使用子查询

SELECT sno FROM student WHERE sno NOT IN (SELECT sno FROM sc WHERE cno <> '1');```

方法二：使用EXISTS关键字

SELECT sno FROM student WHERE NOT EXISTS (SELECT * FROM course WHERE NOT EXISTS (SELECT * FROM sc WHERE sc.sno = student.sno AND sc.cno = course.cno));

方法三：使用INNER JOIN

SELECT s.sno FROM student s INNER JOIN sc ON s.sno = sc.sno GROUP BY s.sno HAVING COUNT(DISTINCT sc.cno) = (SELECT COUNT(*) FROM course);