Question

假设我有示例表，但是我误将了 PK 删除了。我想重新生成唯一的ID号，并更新现有（已修改的）表。

Answer 1

您为内部sql尝试过density_rank吗？

select dense_rank() over (partition by dname order by dname)
     , dname 
from   department
group by dname

Answer 2

如果您的数据不太大：

[[9, 16, 21], [24, 25, 24], [21, 16, 9]]

Answer 3

也许一个简单的临时序列就可以了：

create sequence my_temp_seq1;

update department set cat_id = my_temp_seq1.nextval;

drop sequence my_temp_seq1;

Answer 4

CREATE SEQUENCE my_seq start with 1 increment by 1;

CREATE OR REPLACE PROCEDURE fixDept
  IS 
    v_next number;
BEGIN
    FOR depts in (SELECT DISTINCT DNAME FROM department)
    LOOP
    v_next := my_seq.nextval;
      UPDATE department  
        SET CAT_ID = v_next 
        WHERE DNAME = depts.DNAME;
    END LOOP;
END fixDept;


EXECUTE fixDept;

生成表的唯一ID

4 个答案: