你可能会需要像
CREATE UNIQUE INDEX fn_unique_idx
ON table1 (CASE WHEN is_deleted='N' THEN id ELSE null END,
CASE WHEN is_deleted='N' THEN name ELSE null END,
CASE WHEN is_deleted='N' THEN type ELSE null END);
在行动
SQL> create table table1 (
2 id number,
3 name varchar2(10),
4 type varchar2(10),
5 is_deleted varchar2(1)
6 );
Table created.
SQL> CREATE UNIQUE INDEX fn_unique_idx
2 ON table1 (CASE WHEN is_deleted='N' THEN id ELSE null END,
3 CASE WHEN is_deleted='N' THEN name ELSE null END,
4 CASE WHEN is_deleted='N' THEN type ELSE null END);
Index created.
SQL> insert into table1 values(1, 'Foo', 'Bar', 'N');
1 row created.
SQL> insert into table1 values(1, 'Foo', 'Bar', 'Y');
1 row created.
SQL> insert into table1 values(1, 'Foo', 'Bar', 'Y');
1 row created.
SQL> insert into table1 values(1, 'Foo', 'Bar', 'N');
insert into table1 values(1, 'Foo', 'Bar', 'N')
*
ERROR at line 1:
ORA-00001: unique constraint (SCOTT.FN_UNIQUE_IDX) violated
SQL> insert into table1 values(1, 'Foo', 'Zee', 'N');
1 row created.
约束的一个例子,但我用例IS_DELETED =当 'N' 则(ID的组合,名称,类型) - 组合键应该是唯一的。你的查询能达到相同的效果吗? –
@Andriod_enthusiast - 看起来确实如此。我用我跑过的测试更新了答案。 –
非常感谢。欣赏它。因此,如果我在这些列上没有空consraint,我想我可以省略ELSE null –