Oracle 将列随机排列在行中

Question

基于此问题的解决方案 - Shuffle a column between rows - 我需要对此申请一个新条件:名字必须保证性别:男、女或未知。

所以，我的表有一列名为gender。我需要对相同性别的列进行洗牌。

我已经尝试过，但在某些情况下我无法保证性别

merge into original_table o
  using (
    with
         helper ( id, gender, rn, rand_rn ) as (
           select id,
                  gender,
                  row_number() over (order by id),
                  row_number() over (order by dbms_random.value())
           from   original_table
         )
    select ot.name, ot.gender, h2.id
    from   original_table ot inner join helper h1 on (ot.id = h1.id and ot.gender = h1.gender)
                             inner join helper h2 on h1.rand_rn = h2.rn
  ) p
on (o.id = p.id)
when matched then update set o.name = p.name
;

如果性别不可用(为空值)，例如公司名称，此合并不会更新任何内容。

我可以将此查询拆分为 3 个不同的合并语句。我所拥有的每种性别都有一个。但我正在寻找更好、更简单的说法。因为我需要在不同的上下文和不同的条件下应用相同的解决方案。谢谢。

编辑:示例数据

 ID       GENDER  NAME                                                                                                 
3721       M      MARK
3722       M      JUSTIN
3723       F      RUTH
3724       F      MARY
3725       F      ANNE
4639              CAMPANY SA                                                                               
4640       M      JOHN
4641       M      LUCAS
4642              COMPANY HOLDER SA 

一种可能的解决方案:

 ID       GENDER  NAME                                                                                                 
3721       M      LUCAS
3722       M      JOHN
3723       F      MARY
3724       F      ANNE
3725       F      RUTH
4639              CAMPANY HOLDER SA                                                                               
4640       M      MARK
4641       M      JUSTIN
4642              COMPANY SA 

Answer 1

在分析函数的 PARTITION BY 子句和 JOIN 子句中包含性别。如果您没有可匹配的主键，则可以使用 ROWID 伪列。

Oracle 设置:

CREATE TABLE original_table ( id, gender, name, company ) AS
SELECT 1, 'F', 'Alice', CAST( NULL AS VARCHAR2(20) ) FROM DUAL UNION ALL
SELECT 2, 'M', 'Bobby', 'ACME' FROM DUAL UNION ALL
SELECT 3, 'F', 'Carol', 'XYZ'  FROM DUAL UNION ALL
SELECT 4, 'M', 'David', NULL   FROM DUAL UNION ALL
SELECT 5, 'M', 'Errol', 'ACME' FROM DUAL UNION ALL
SELECT 6, 'F', 'Fiona', 'XYZ'  FROM DUAL;

更新:

MERGE INTO original_table dst
USING (
  WITH rnd ( rid, rn, rnd_rn, gender, name ) AS (
    SELECT ROWID,
           ROW_NUMBER() OVER ( PARTITION BY gender ORDER BY id ),
           ROW_NUMBER() OVER ( PARTITION BY gender ORDER BY DBMS_RANDOM.VALUE ),
           gender,
           name
    FROM   original_table
  )
  SELECT o.rid, r.name
  FROM   rnd o INNER JOIN rnd r
         ON ( ( o.gender = r.gender OR ( o.gender IS NULL AND r.gender IS NULL ) )
             AND o.rn = r.rnd_rn )
)
ON ( dst.ROWID = src.ROWID )
WHEN MATCHED THEN
  UPDATE SET name = src.name;

输出:

SELECT * FROM original_table;

ID G NAME  COMPANY
-- - ----- -------
 1 F Fiona  
 2 M David ACME
 3 F Alice XYZ
 4 M Bobby 
 5 M Errol ACME
 6 F Carol XYZ