一个sql 语句问题 请教 ···
#0.基本单表查询所有
学生表
mysql> select * from student;
+-----------+-------+------+------+------+
| sno | sname | ssex | sage | sclg |
+-----------+-------+------+------+------+
| 200215121 | 李勇 | 男 | 20 | cs |
| 200215122 | 刘晨 | 女 | 21 | cs |
| 200215123 | 王敏 | 男 | 25 | ma |
| 200215125 | 张立 | 男 | 20 | is |
+-----------+-------+------+------+------+
选课表
mysql> select * from sc;
+-----------+-----+-------+
| sno | cno | grade |
+-----------+-----+-------+
| 200215121 | 1 | 92 |
| 200215121 | 2 | 85 |
| 200215121 | 3 | 88 |
| 200215122 | 2 | 90 |
| 200215122 | 3 | 80 |
+-----------+-----+-------+
课程表
mysql> select * from course;
+-----+----------+------+---------+
| cno | cname | cpno | ccredit |
+-----+----------+------+---------+
| 1 | 数据库 | 5 | 4 |
| 2 | 数学 | NULL | 4 |
| 3 | 信息系统 | 1 | 4 |
| 4 | 操作系统 | 6 | 4 |
| 5 | 数据结构 | 7 | 4 |
| 6 | 数据处理 | NULL | 4 |
| 7 | C语言 | 6 | 4 |
+-----+----------+------+---------+
题目:查询至少选修了学生200212122选修的全部课程的学生姓名.