如何根据字段获取每个月的最后一天

Question

SELECT [ItemKey]
  ,[Location]
  ,[QtyOnHand]
  ,[UpdatedOnHandQty]
  ,AffectedDate
  FROM [Test].[dbo].[INCos]
  where ItemKey = '20406' 
  order by ItemKey, year(AffectedDate)

结果如下：

ItemKey UpdatedOnHandQty    AffectedDate
20406   1594.03            2013-12-27 00:00:00.000
20406   78.975            2014-09-15 00:00:00.000
20406   1401.975          2014-09-26 00:00:00.000
20406   512.261           2014-10-20 00:00:00.000
20406   849.928         2014-01-06 00:00:00.000
20406   842.132       2014-01-09 00:00:00.000
20406   1283.132      2014-02-05 00:00:00.000
20406   539.03        2014-02-11 00:00:00.000
20406   980.03       2014-05-07 00:00:00.000
20406   486.183      2014-05-12 00:00:00.000
20406   927.183      2014-06-03 00:00:00.000
20406   917.86       2014-06-27 00:00:00.000
20406   927.043     2014-07-18 00:00:00.000
20406   432.209     2014-07-18 00:00:00.000
20406   1314.209    2014-07-29 00:00:00.000

我想要的是每年只记录每月最后一天的记录。 我已经看到很多解决方案，我可以根据GetDate（）获得每个月的最后一天，但我不需要。 我只需要根据AffectedDate字段提取每年每月的最后一条记录。

Answer 1

一个快速选项是与Row_Number（）一起使用WITH TIES子句

例

Select Top 1 with Ties * 
 From  YourTable
 where ItemKey = '20406' 
 Order by Row_Number() over (Partition by ItemKey,Year(AffectedDate),Month(AffectedDate) Order by AffectedDate Desc)

返回

ItemKey UpdatedOnHandQty    AffectedDate
20406   1594.03             2013-12-27 00:00:00.000
20406   842.132             2014-01-09 00:00:00.000
20406   539.03              2014-02-11 00:00:00.000
20406   486.183             2014-05-12 00:00:00.000
20406   917.86              2014-06-27 00:00:00.000
20406   1314.209            2014-07-29 00:00:00.000
20406   1401.975            2014-09-26 00:00:00.000
20406   512.261             2014-10-20 00:00:00.000

Answer 2

WITH CTE
 AS (SELECT Row_number()
              OVER (
                partition BY Month(AffectedDate)
                ORDER BY AffectedDate DESC) rn,
            [ItemKey],
            [Location],
            [QtyOnHand],
            [UpdatedOnHandQty],
            AffectedDate
       FROM [Test].[dbo].[INCos]
      WHERE ItemKey = '20406')
SELECT *
  FROM CTE
 WHERE rn = 1 

Answer 3

这是一个完整示例的另一个选项，它有很多行快速，希望这对你有用

    CREATE TABLE #DATA(
ItemKey INT,
UpdatedOnHandQty DECIMAL(16,2),
AffectedDate DATETIME
)
INSERT INTO #DATA

SELECT 20406   ,1594.03            ,'2013-12-27 00:00:00.000' UNION
SELECT 20406   ,78.975            ,'2014-09-15 00:00:00.000' UNION
SELECT 20406   ,1401.975          ,'2014-09-26 00:00:00.000' UNION
SELECT 20406   ,512.261           ,'2014-10-20 00:00:00.000' UNION
SELECT 20406   ,849.928         ,'2014-01-06 00:00:00.000' UNION
SELECT 20406   ,842.132       ,'2014-01-09 00:00:00.000' UNION
SELECT 20406   ,1283.132      ,'2014-02-05 00:00:00.000' UNION
SELECT 20406   ,539.03        ,'2014-02-11 00:00:00.000' UNION
SELECT 20406   ,980.03       ,'2014-05-07 00:00:00.000' UNION
SELECT 20406   ,486.183      ,'2014-05-12 00:00:00.000' UNION
SELECT 20406   ,927.183      ,'2014-06-03 00:00:00.000' UNION
SELECT 20406   ,917.86       ,'2014-06-27 00:00:00.000' UNION
SELECT 20406   ,927.043     ,'2014-07-18 00:00:00.000' UNION
SELECT 20406   ,432.209     ,'2014-07-18 00:00:00.000' UNION
SELECT 20406   ,1314.209    ,'2014-07-29 00:00:00.000'




SELECT *
FROM #DATA AS d
WHERE d.ItemKey = 20406
and EXISTS(
SELECT TOP 1 1 FROM #DATA AS d1
WHERE D1.ItemKey = d.ItemKEy
AND YEAR(d.AffectedDate) = YEAR(d1.AffectedDate)
AND MONTH(d.AffectedDate)= MONTH(d1.AffectedDate)
GROUP BY  YEAR(d1.AffectedDate),MONTH(d1.AffectedDate)
HAVING  MAX(d1.AffectedDate) = d.AffectedDate
)
ORDER BY d.AffectedDate desc


DROP TABLE  #DATA