在 SQL Server 2008 R2 中获取每个组的最小值和最大值

Question

我需要通过Property_externalID 和Lease_ExternalID 将金额附加到每个分组的最小和最大日期列。

我该怎么做呢？

示例：结果应为每个分组返回一行：

Property_ExternalID Lease_ExternalID    Min_Amount      Max_Amount
------------------------------------------------------------------
27050               27050-0200          23              .02    

表格样本数据：

Property_ExternalID Lease_ExternalID    PropertyAssetId Date        Amount
---------------------------------------------------------------------------
27050               27050-0200          6097            10/1/2017   23
27050               27050-0200          6097            4/1/2019    0.02
27050               27050-0200          6097            4/1/2021    0.02
27050               27050-0200          6097            4/1/2022    0.02
27050               27050-0200          6097            4/1/2023    0.02
27050               27050-0200          6097            4/1/2024    0.02
27050               27050-0200          6097            4/1/2025    0.02
27050               27050-0200          6097            4/1/2027    0.02
27050               27050-0200          6097            4/1/2026    0.02

Answer 1

提供一些基本的 SQL 语句来创建表和数据总是有帮助的，这样那些帮助你的人可以尝试不同的事情。像这样……

IF OBJECT_ID('tempdb..#Temp', 'U') IS NOT NULL DROP TABLE #Temp;

CREATE TABLE #Temp
(
 Property_ExternalID    VARCHAR(15),
 Lease_ExternalID   VARCHAR(15),
 PropertyAssetId    VARCHAR(15),
 Date           DATE,
 Amount         DECIMAL(10, 2)
)

INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '10/1/2017', 23)  
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2019', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2021', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2022', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2023', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2024', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2025', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2027', 0.02)
INSERT INTO #Temp VALUES ('27050', '27050-0200', '6097', '04/1/2026', 0.02)

鉴于此，您需要从主表连接到子查询，在该子查询中您已确定每个Property_ExternalID 和Lease_ExternalID 的最小 日期。然后您需要再次加入主表（因为 Date 的最小值和最大值可能不同），然后加入另一个子查询，您已确定每个 Property_ExternalID 的 ma​​ximum 日期是多少和Lease_ExternalID。

这样的……

SELECT a.Property_ExternalID, a.Lease_ExternalID, a.Amount AS 'Min_Amount', b.Amount AS 'Max_Amount'
FROM #Temp a
INNER JOIN 
(
    SELECT Property_ExternalID, Lease_ExternalID, MIN(Date) AS MinDate 
    FROM #Temp 
    GROUP BY  Property_ExternalID, Lease_ExternalID
) x ON a.Property_ExternalID = x.Property_ExternalID AND a.Lease_ExternalID = x.Lease_ExternalID AND a.Date = x.MinDate
INNER JOIN #Temp b ON a.Property_ExternalID = b.Property_ExternalID AND a.Lease_ExternalID = b.Lease_ExternalID
INNER JOIN 
(
    SELECT Property_ExternalID, Lease_ExternalID, MAX(Date) AS MaxDate 
    FROM #Temp 
    GROUP BY  Property_ExternalID, Lease_ExternalID
) y ON b.Property_ExternalID = y.Property_ExternalID AND b.Lease_ExternalID = y.Lease_ExternalID AND b.Date = y.MaxDate

诺埃尔

Answer 2

您需要使用 MIN 和 MAX aggregate functions 以及 GROUP BY 子句。这应该对你有用...

DECLARE @MyDate AS DATE

-- comment the next line out if you want all dates
SET @MyDate = '04/01/2021'

SELECT Property_ExternalID, Lease_ExternalID, Date, MIN(Amount) AS 'Min_Amount',
MAX(Amount) AS 'Max_Amount'
FROM YourTable
WHERE Date = COALESCE(@MyDate, Date)
GROUP BY Property_ExternalID, Lease_ExternalID, Date

诺埃尔