我对MS SQL有点陌生，但是我已经能够弄清楚如何获取外键以通过查询返回，但是我无法弄清楚如何使它更新原始值。
这是我到目前为止所拥有的：
SELECT prd_pk, prd_alt_desc
FROM RM_AM.dbo.product
WHERE EXISTS (SELECT prd_pk FROM dbo.Bn_Import WHERE prd_alt_desc = dbo.Bn_Import.Commodity);
我认为我需要一个变量来完成此操作，但是我对如何构造查询的了解还不够。
+------------+------------------+-------------------------+------------------+-----------------+-------------+
| Ship Date | Original ETA | Confirmed Delivery Date | Current ETA | Commodity | Load Status |
+------------+------------------+-------------------------+------------------+-----------------+-------------+
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 10/11/2018 | 10/18/2018 11:48 | 10/20/2018 | | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 10/10/2018 | 10/17/2018 11:48 | 10/20/2018 | | SANDFRAC4070MES | L |
| 10/16/2018 | 10/19/2018 6:00 | 10/21/2018 | 10/19/2018 1:04 | | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/4/2018 | 10/11/2018 11:48 | 10/13/2018 | | SANDFRAC4070MES | L |
| 10/16/2018 | 10/19/2018 6:00 | 10/21/2018 | 10/19/2018 1:04 | | L |
| 9/17/2018 | 9/17/2018 18:49 | 9/21/2018 | | SANDFRAC4070MES | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/18/2018 | | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/15/2018 | 10/18/2018 6:00 | 10/21/2018 | 10/19/2018 4:24 | | L |
| 10/4/2018 | 10/11/2018 11:48 | 10/13/2018 | | | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 10/16/2018 | 10/19/2018 6:00 | 10/21/2018 | 10/19/2018 1:04 | | L |
| 10/6/2018 | 10/13/2018 11:48 | 10/16/2018 | | SANDFRAC4070MES | L |
| 10/11/2018 | 10/18/2018 11:48 | 10/20/2018 | 10/19/2018 0:02 | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/4/2018 | 10/11/2018 11:48 | 10/14/2018 | | SANDFRAC4070MES | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/4/2018 | 10/11/2018 11:48 | 10/14/2018 | | SANDFRAC4070MES | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/18/2018 | | SANDFRAC4070MES | L |
| 9/14/2018 | 9/22/2018 19:50 | 9/26/2018 | 10/18/2018 14:01 | SANDFRAC4070MES | L |
| 10/4/2018 | 10/11/2018 11:48 | 10/13/2018 | | SANDFRAC4070MES | L |
| 10/7/2018 | 10/14/2018 11:48 | 10/18/2018 | | | L |
| 10/9/2018 | 10/16/2018 11:48 | 10/19/2018 | | SANDFRAC4070MES | L |
| 10/1/2018 | 10/1/2018 18:49 | 10/4/2018 | 10/18/2018 10:28 | SANDFRAC4070MES | L |
| 9/17/2018 | 9/17/2018 18:49 | 9/21/2018 | | SANDFRAC4070MES | L |
+------------+------------------+-------------------------+------------------+-----------------+-------------+
我需要将商品从SANDFRAC4070MES更改为6710
6710是数据库中另一个表的外键。