Question

我正在努力研究表格中所有列的前2行之间的差异。我将只指定一列以使这更容易。我是SQL新手，所以如果这很容易就道歉。我在SSMS上，到目前为止我认为我需要内连接表然后比较table1的第1行和table2的第2行。 id列的工作原理是最新的行是最高的id。我需要获得最高的id然后是第二高的id（第2行）并找到差异。

SELECT Table1.id,
   Table1.transferdate,
   Table1.payment,
   Table2.id,
   Table2.transferdate,
   Table2.payment
FROM Table1 AS Table1
INNER JOIN Table2 AS Table2 ON Table1.id = Table2.id

我希望看到付款列中昨天（最上一行）和前一天与该（第二行）之间的差异。付款列应该随着数据添加到前几天而增加。在INNER JOIN之后我还不知道该去哪里，我尝试过的任何工作都没有。

我目前拥有的数据示例：

id | transferdate |payment | debt   | mailing_batch
46 | 2017-05-18   |651681  | 616816 | 1861651
45 | 2017-05-17   |601680  | 516168 | 1616866

我想要的是差异：

id | transferdate |payment | debt   | mailing_batch
1  |       1      |50001   | 100648 | 244785

我只希望看到每列前2名之间的差异。我会删除选择列名称，只留下我使用过TOP功能的TOP1吗？

对任何其他行不感兴趣。始终排在前2位，因为这是一个数据副本表，它是确保数据在业务设置中正确更新的一种方法。

Answer 1

SELECT Top 1 Table1.id,
Table1.payment-LEAD(Table1.payment,1) over(order by Table1.id desc)
FROM Table1 AS Table1
INNER JOIN Table2 AS Table2 ON Table1.id = Table2.id
order by Table1.id desc

如果您使用的是sql server 2012或更高版本，则可以使用上述查询。

Answer 2

;With CTE(id , transferdate ,payment , debt   , mailing_batch)
AS
(
SELECT 46 , '2017-05-18'   ,651681  , 616816 , 1861651 UNION ALL
SELECT 45 , '2017-05-17'   ,601680  , 516168 , 1616866
)

SELECT Id
    ,transferdate
    ,payment
    ,debt
    ,mailing_batch
FROM (
    SELECT (LEadId - Id) AS Id
        ,DATEDIFF(DAY, transferdate, Leadtransferdate) AS transferdate
        ,(Leadpayment - payment) AS payment
        ,(Leaddebt - debt) AS debt
        ,(Leadmailing_batch - mailing_batch) AS mailing_batch
        ,ROW_NUMBER() OVER (
            ORDER BY (
                    SELECT 1
                    )
            ) AS Seq
    FROM (
        SELECT *
            ,LEAD(id) OVER (
                ORDER BY id
                ) AS LEadId
            ,LEAD(transferdate) OVER (
                ORDER BY transferdate
                ) AS Leadtransferdate
            ,LEAD(payment) OVER (
                ORDER BY payment
                ) AS Leadpayment
            ,LEAD(debt) OVER (
                ORDER BY debt
                ) AS Leaddebt
            ,LEAD(mailing_batch) OVER (
                ORDER BY mailing_batch
                ) AS Leadmailing_batch
        FROM CTE
        ) Dt
    ) Final
WHERE Final.Seq = 1

输出

id | transferdate |payment | debt   | mailing_batch
1  |       1      |50001   | 100648 | 244785

Answer 3

您使用的是哪个版本的sql server？如果它是2012+，那么LEAD和LAG功能将起作用。您可以详细了解他们here和here 自己动手，因为它们真的很容易。展示一些努力，如果不行，我会帮助你。

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截图：

输入表

输出表

PS：您不需要2个单独的表格。您的问题可以通过1个表本身来解决。

找出前2行之间的差异

3 个答案: