-- 查询没学过"张三"老师讲授的任一门课程的学生姓名
select s_name from student where s_id not in ( select distinct s_id from score where c_id in ( select t2.c_id from teacher t1, course t2 where t1.t_id = t2.t_id and t1.t_name = '张三'))
select a.s_name from student a where a.s_id not in ( select s_id from score where c_id = ( select c_id from course where t_id =( select t_id from teacher where t_name = '张三')) group by s_id);
-- 2019/04/24