Question

我有一个重复的表事务。我想保留具有最小ID的记录，并根据四个字段DATE，AMOUNT，REFNUMBER，PARENTFOLDERID删除所有重复项。我写了这个查询，但我不确定这是否可以以有效的方式编写。你认为有更好的方法吗？我问，因为我担心运行时间。

DELETE FROM TRANSACTION
WHERE ID IN 
(SELECT FIT2.ID
FROM
(SELECT MIN(ID) AS ID, FIT.DATE, FIT.AMOUNT, FIT.REFNUMBER, FIT.PARENTFOLDERID
FROM EWORK.TRANSACTION FIT
GROUP BY FIT.DATE, FIT.AMOUNT , FIT.REFNUMBER, FIT.PARENTFOLDERID
HAVING COUNT(1)>1 and FIT.AMOUNT >0) FIT1,
EWORK.TRANSACTION FIT2

WHERE FIT1.DATE=FIT2.DATE AND
FIT1.AMOUNT=FIT2.AMOUNT AND
FIT1.REFNUMBER=FIT2.REFNUMBER AND 
FIT1.PARENTFOLDERID=FIT2.PARENTFOLDERID AND 
FIT1.ID<>FIT2.ID)

Answer 1

执行类似

的操作可能更有效率

DELETE FROM transaction t1
 WHERE EXISTS( SELECT 1
                 FROM transaction t2
                WHERE t1.date = t2.date
                  AND t1.refnumber = t2.refnumber
                  AND t1.parentFolderId = t2.parentFolderId
                  AND t2.id > t1.id )

Answer 2

DELETE FROM transaction
      WHERE ID IN (
               SELECT ID
                 FROM (SELECT ID,
                          ROW_NUMBER () OVER (PARTITION BY  date
                                                          ,amount
                                                          ,refnumber
                                                          ,parentfolderid
                                                ORDER BY ID) rn
                                              FROM transaction)
                WHERE rn <> 1);

我会这样尝试

Answer 3

我会尝试这样的事情：

DELETE transaction 
FROM transaction
LEFT OUTER JOIN 
   (
       SELECT MIN(id) as id, date, amount, refnumber, parentfolderid 
       FROM transaction
      GROUP BY date, amount, refnumber, parentfolderid
   ) as validRows 
ON transaction.id = validRows.id
WHERE validRows.id IS NULL

用于删除表中重复项的SQL

3 个答案: