Question

对于下面给出的数据集，我想删除后面有时间戳的行。

**37C1Z2990E5E0 (TRXID) should be UNIQUE** in the below dataSet

    JKLAMMSDF123    20141112    20141117    5000.0  P   1.22    RT101018    *2014-11-12 10:10:26*   37C1Z2990E5E0   101018
    JKLAMMSDF123    20141110    20141114    5000.0  P   1.22    RT161002    *2014-11-12 10:11:33*   37C1Z2990E5E0   161002

-- More rows

Answer 1

试试这个：

;WITH DATA AS
(
    SELECT TRXID, MAX(YourTimestampColumn) AS TS
    FROM YourTable
    GROUP BY TRXID
    HAVING COUNT(*) > 1
)
DELETE T
FROM YourTable AS T
INNER JOIN DATA AS D
    ON T.TRXID = D.TRXID
   AND T.YourTimestampColumn = D.TS;

Answer 2

选择timestamp列的min并按所有其他列分组。

SELECT MIN(TIMESTAMP), C1, C2, C3...
FROM YOUR_TABLE
GROUP BY C1, C2, C3..

Answer 3

我将使用window function加CTE来完成此操作。

要在删除重复项后检查结果，请使用此项。

;WITH DATA
     AS (SELECT *,
                Row_number()OVER(partition BY TRXID ORDER BY YourTimestampColumn) rn
         FROM   YourTable)
select * 
FROM data
WHERE  rn = 1

要delete重复使用此内容。

;WITH DATA
     AS (SELECT *,
                Row_number()OVER(partition BY TRXID ORDER BY YourTimestampColumn) rn
         FROM   YourTable)
DELETE FROM data
WHERE  rn > 1

即使您为同一TRXID

多个副本，这也会有效

根据条件删除重复项

3 个答案: