我有一个Hive表如下：

+----+---------------+-------------+
| id | name          | partnership |
+----+---------------+-------------+
| 1  | sachin sourav | first       |
| 2  | sachin sehwag | first       |
| 3  | sourav sehwag | first       |
| 4  | sachin_sourav | first       |
+----+---------------+-------------+

在这个表中，我需要用“st”替换“sachin”，用“sg”替换“sourav”。我使用下面的查询，但它不能解决问题。
查询：

select 
    *,
    case
       when name regexp('\\bsachin\\b') 
          then regexp_replace(name,'sachin','ST')
       when name regexp('\\bsourav\\b') 
          then regexp_replace(name,'sourav','SG')
       else name
    end as newName
from sample1;

结果：

+----+---------------+-------------+---------------+
| id | name          | partnership | newname       |
+----+---------------+-------------+---------------+
| 4  | sachin_sourav | first       | sachin_sourav |
| 3  | sourav sehwag | first       | SG sehwag     |
| 2  | sachin sehwag | first       | ST sehwag     |
| 1  | sachin sourav | first       | ST sourav     |
+----+---------------+-------------+---------------+

问题：我的意图是，当id=1时，newname列的值应该是“stsg”。我的意思是它应该替换两个字符串。