第五行的进度是多少

只取两列出来看：

从上往下数第 5 行的 progress 是多少？

mysql> SELECT user_name, progress FROM learning_record;
+-----------+----------+
| user_name | progress |
+-----------+----------+
| xiaoming  |      100 |
| xiaoming  |       60 |
| xiaoming  |       20 |
| xiaohong  |      100 |
| xiaohong  |       45 |
| xiaogang  |       30 |
| zhangsan  |      100 |
| zhangsan  |      100 |
| zhangsan  |       15 |
| lisi      |       80 |
+-----------+----------+
mysql>