删除两个不同列之间的重复行

Question

我在删除两个不同列之间的重复项时遇到问题。这是我当前的 select 查询：

SELECT e.id AS EventId, 
    rt.player_nbr AS PlayerId, 
    rt.partner_nbr AS PartnerId
FROM eventTable e
    INNER JOIN resultsTable rt ON e.id = rt.id

结果如下：

EventId | PlayerId | PartnerId
 1049   |  20652   |  80458
 1049   |  20702   |  310816
 1049   |  80394   |  190666
 1049   |  80394   |   null
 1049   |  80458   |  20652
 1049   | 190666   |  80394

从结果中可以看到，PlayerId 和PartnerId 都被打乱了。我想将重复的行删除到如下所示的位置：

EventId | PlayerId | PartnerId
 1049   |  20652   |  80458
 1049   |  20702   |  310816
 1049   |  80394   |  190666
 1049   |  80394   |   null

到目前为止，我已经尝试过这个和其他一些东西但没有成功：

SELECT e.id AS EventId, 
    rt.player_nbr AS PlayerId, 
    rt.partner_nbr AS PartnerId
FROM eventTable e
    INNER JOIN resultsTable rt ON e.id = rt.id
WHERE NOT EXISTS(
    SELECT *
    FROM eventTable e2
        INNER JOIN resultsTable rt2 ON e2.id = rt2.id
    WHERE rt2.player_nbr = rt.partner_nbr
        AND rt2.partner_nbr = rt.player_nbr
)

关于我如何最好地处理这个问题有什么建议吗？提前致谢。

Answer 1

您的示例查询使用 not exists，所以让我们继续沿着这条路走下去。逻辑是您希望所有行都是 player_nbr < partner_nbr。然后你想要 player_nbr > partner_nbr 为真但有其他行 player_nbr < partner_nbr 的行。以下是SQL中的逻辑：

SELECT e.id AS EventId, 
       rt.player_nbr AS PlayerId, 
       rt.partner_nbr AS PartnerId
FROM eventTable e INNER JOIN
     resultsTable rt
      ON e.id = rt.id
WHERE rt.player_nbr < rt.partner_nbr OR
      NOT EXISTS (SELECT 1
                  FROM resultsTable rt2 
                  WHERE rt2.id = rt.id AND
                        rt2.player_nbr = rt.partner_nbr AND
                        rt2.partner_nbr = rt.player_nbr
                  );

删除两个不同列之间的重复行

Remove duplicate rows between two different columns

sql

sybase