有表如下:
+----+-------+------------+
| id | grand | student_id |
+----+-------+------------+
| 1 | 10 | 1 |
| 2 | 10 | 1 |
| 3 | 10 | 1 |
| 4 | 10 | 2 |
| 5 | 11 | 2 |
| 6 | 12 | 3 |
| 7 | 10 | 3 |
+----+-------+------------+
我需要查询出student_id相同,但grand不同的数据,也就是后四条,如何查询?