无法修改映射到非密钥保留表的列时更新表

Question

----- s.op_id= ------
| S |----------| OP |
----- op.op_id ------
                  |
                  | op.op_id = j.op_id
                  |
                -----
                | J |
                -----

oracle数据库有三个表journey，op_profile和special。

journey有两列journey_id （主键）和op_id， op_profile有主键op_id和 special在op_id上有一个op_profile列外键，另一列s_id是表主键。

我尝试使用以下sql usin sql developer将所有op_id列更新为等于journey_id表的journey列：

UPDATE (SELECT special.op_id, journey.journey_id, op_profile.op_id AS op
        FROM special, journey, op_profile
        WHERE special.op_id = journey.op_id AND journey.op_id = op_profile.op_id)
SET op_id = journey_id, op = journey_id;

会出现以下错误

SQL Error: ORA-01779: cannot modify a column which maps to a non key-preserved table
01779. 00000 -  "cannot modify a column which maps to a non key-preserved table"
*Cause:    An attempt was made to insert or update columns of a join view which
           map to a non-key-preserved table.
*Action:   Modify the underlying base tables directly.

似乎说这个操作由于每个表的键而失败。

这可能是这样还是另一种？

Answer 1

是的，可以使用两个更新语句：

update s
    set op_id = (select j.journey_id
                 from j
                 where j.op_id = s.op_id
                );

和

update op
    set op_id = (select j.journey_id
                 from j
                 where j.op_id = op.op_id
                );

Answer 2

在以下内容上添加索引（如果之前不可用）

1. special.op_id
2. journey.op_id
3. op_profile.op_id

如果无法获取一组稳定的更新行，则会出现此问题。