删除所有选修了课程号(course_id)为dep04_b001的学生。（分别用相关子查询和不相关子查询完成）

相关子查询：

DELETE FROM student WHERE id IN (SELECT student_id FROM course_selection WHERE course_id = 'dep04_b001');

不相关子查询：

DELETE FROM student WHERE id IN (SELECT student_id FROM course_selection WHERE course_id IN (SELECT id FROM course WHERE course_id = 'dep04_b001'));