oracle - novalidate 错误 ora-02299

Question

有人可以帮我吗？

id | Name
--------
1  | aaa
2  | bbb
3  | aaa

>alter table arc add CONSTRAINT uk_arc UNIQUE (NAME) novalidate
 error :ora-02299: cannot validate( .uk_arc ) - duplicate keys found

我正在使用 novalidate 来忽略旧的副本并重新开始验证。

Answer 1

If I get you correctly, you expect Oracle to ignore old duplicate values and allow new values only when they satisfy the constraint. The error is returned because when you add a UNIQUE constraint, Oracle creates unique index on the column to check the values, but your table already have duplicate values, so it fails. I would create the non-unique index first, then add the constraint so that it uses your existing non-unique index instead of automatically creating the unique index which would fail:

create index arc_ix on arc (name);

alter table arc add constraint arc_uq unique (name) enable novalidate;