mysql 获取学生个人科目平均分

mysql> select * from test;
+----+----------+-------+-----------+
| id | name     | score | subject   |
+----+----------+-------+-----------+
|   | xiaoming |     | shuxue    |
|   | xiaohong |     | shuxue    |
|   | xiaohong |     | english   |
|   | xiaohong |     | physics   |
|   | xiaohong |     | astronaut |
|   | xiaoming |     | physics   |
|   | xiaoming |     | astronaut |
|   | xiaoming |     | english   |
|   | xiaobai  |     | astronaut |
|  | xiaobai  |     | english   |
|  | xiaobai  |     | physics   |
|  | xiaobai  |     | shuxue    |
|  | xiaohei  |     | astronaut |
|  | xiaohei  |     | shuxue    |
|  | xiaohei  |     | physics   |
|  | xiaohei  |     | english   |
+----+----------+-------+-----------+
 rows in set (0.00 sec)

mysql> select name,avg(score) from test group by name;
+----------+------------+
| name     | avg(score) |
+----------+------------+
| xiaobai  |    80.0000 |
| xiaohei  |    80.0000 |
| xiaohong |    82.2500 |
| xiaoming |    82.2500 |
+----------+------------+
 rows in set (0.01 sec)

mysql> select name,sum(score)/count(*) from test group by name;
+----------+---------------------+
| name     | sum(score)/count(*) |
+----------+---------------------+
| xiaobai  |             80.0000 |
| xiaohei  |             80.0000 |
| xiaohong |             82.2500 |
| xiaoming |             82.2500 |
+----------+---------------------+
 rows in set (0.00 sec)