使用novalidate选项无法验证

Question

嗨,我正在插入一些日期做我的表.由于某些原因,我不得不禁用我的约束.约束与索引相关联.我用过这行代码:

ALTER TABLE my_table DISABLE CONSTRAINT "my_constraint" drop index

并且my_constraint处于禁用状态.不,我想启用此约束,但在调用此行之后:

ALTER TABLE my_table ENABLE NOVALIDATE CONSTRAINT "my_constraint";\

我发现了一个错误:

ORA-02299:无法验证(USER.my_constraint) - - 找到重复的密钥

Answer 1

您不能拥有唯一索引的非唯一值.但是,您可以使用由非唯一索引强制执行的唯一约束来使用非唯一值.即使您最初创建了一个非唯一索引,drop index并且enable语法将尝试重新创建唯一索引,除非您在该using index部分中提供了更多详细信息.

例如:

SQL> create table my_table(my_column number,
  2     constraint my_constraint unique (my_column));

Table created.

SQL> alter table my_table disable constraint my_constraint drop index;

Table altered.

SQL> insert into my_table select 1 from dual union all select 1 from dual;

2 rows created.

SQL> alter table my_table enable novalidate constraint my_constraint;
alter table my_table enable novalidate constraint my_constraint
*
ERROR at line 1:
ORA-02299: cannot validate (USER.MY_CONSTRAINT) - duplicate keys found


SQL> alter table my_table enable novalidate constraint my_constraint
  2     using index (create index my_index on my_table(my_column));

Table altered.

SQL> --The constraint is enforced, even though other rows violate it.
SQL> insert into my_table values(1);
insert into my_table values(1)
*
ERROR at line 1:
ORA-00001: unique constraint (USER.MY_CONSTRAINT) violated