根据Oracle中的条件删除重复行

Question

我想根据条件从表中删除重复的行。

例如， 表ABC：

ID Name Pin Status 
111 Pope 909 New 
222 Jazz 909 New 
333 Volk 767 Assigned 
444 Audi 767 New 
555 Pink 435 New 

我想删除它具有以下条件的基础上同“针”重复记录：

1. 如果两个相同的PIN记录有新的状态 - 删除其中的任何一个。
2. 如果其中一个Pin记录的状态为New，另一个记录的状态为已分配 - 删除'New'状态记录。

我写了下面的SQL，但我想知道是否有更好的方法来处理这个使用PK。

为1：

DELETE FROM ABC WHERE ID IN (
SELECT 
    a.id 
FROM ABC a 
WHERE a.rowid < 
    (SELECT max(rowid) 
    FROM ABC b 
    WHERE b.pin = a.pin 
    AND a.status = b.status 
    AND b.status in ('New') 
) 
); 

为2：

DELETE FROM ABC WHERE ID IN (
SELECT 
    a.id 
FROM ABC a 
WHERE a.rowid < 
    (SELECT max(rowid) 
    FROM ABC b 
    WHERE b.pin = a.pin 
    AND a.status <> b.status 
    AND a.status in ('New') 
    AND b.status in ('Assigned') 
) 
); 

Answer 1

你可以试试这个。

--Query 1: 
DELETE FROM ABC 
WHERE ID NOT IN (SELECT MIN(ID) 
       FROM ABC 
       GROUP BY Pin 
       HAVING COUNT(*)=COUNT(CASE WHEN status = 'New' THEN 1 END) 
       ); 

--Query 2: 
DELETE FROM ABC 
WHERE ID IN (SELECT ID 
      FROM ABC A 
      WHERE status = 'New' 
      AND EXISTS (SELECT 1 FROM ABC B 
         WHERE A.Pin=B.Pin AND B.status='Assigned') 

      ); 

Answer 2

如果至多有两个记录每个pin：

DELETE FROM ABC 
WHERE rowid IN (SELECT MIN(CASE WHEN a.status = 'NEW' then rowid END) 
       FROM ABC a 
       WHERE abc.pin = a.pin AND 
         a.status IN ('New', 'Assigned' 
       GROUP BY a.pin 
       HAVING COUNT(*) > 1 
       ); 

Answer 3

试试这个Query--

-- Select ID, Name, Pin, Status 
Delete 
From (
    Select 
     ID, Name, Pin, Status, 
     Row_Number() Over(Partition By Pin Order By Pin) As PinRowNum, 
     Row_Number() Over(Partition By Pin, Status Order By Status) As 
    StatusRowNum 
From ABC 
) As D Where StatusRowNum > 1 Or (PinRowNum > 1 And StatusRowNum = 1)