要修改的列不是标识列 [英] Column to be modified is not an identity column

问题描述

我创建了一个具有列S_ROLL NUMBER(3) NOT NULL的表，现在我想将此列作为标识列. 我用了这个命令

I have created a table with column S_ROLL NUMBER(3) NOT NULL Now I want to make this colum to as identity column. I used this command

alter table students
modify
(
S_ROLL NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY
);

然后我收到此错误.

S_ROLL NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY
*
ERROR at line 4:
ORA-30673: column to be modified is not an identity column

推荐答案

您收到此错误的原因仅仅是因为现在不支持将现有列修改为IDENTITY列.

You're getting this error simply because modifying an existing column as IDENTITY column is not supported right now.

解决方案是添加一个新列，然后删除现有的列(确保您确实也要处理数据).

The solution is to add a new column and then drop the existing one (making sure that you do take care of the data too).

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