使用错误ora-02299进行验证 [英] novalidate with error ora-02299

问题描述

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来忽略旧的重复项，然后再次开始重新进行验证.

I am using novalidate to ignore the old duplicate and start to validate all over again.

推荐答案

如果我正确地理解了您，您希望Oracle忽略旧的重复值，仅在它们满足约束时才允许新值.返回该错误的原因是，当您添加UNIQUE约束时，Oracle在该列上创建唯一索引以检查值，但是您的表已经具有重复的值，因此它将失败.我将首先创建非唯一索引，然后添加约束，以便它使用您现有的非唯一索引，而不是自动创建会失败的唯一索引:

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;

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