基于最长 7 天的 SQL Server 加入记录

Question

我构建的查询不适合解决方案。我尝试了很多查询，但无法得到我想要的结果。

我有下表

    CREATE TABLE [dbo].[test](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [ATC] [varchar](15) NOT NULL,
    [PID] [varchar](7) NOT NULL,
    [NAME] [varchar](50) NOT NULL,
    [REG_DATE] [datetime] NULL,
    [ACTIVE] [bit] NOT NULL CONSTRAINT [DF_test_ACTIVE]  DEFAULT ((1))
) ON [PRIMARY]

示例数据

  INSERT INTO [dbo].[test] ([ATC],[PID],[NAME],[REG_DATE],[ACTIVE])
  VALUES ('A01','123456','TEST1','2016-08-31 00:00:00.000',0);
  INSERT INTO [dbo].[test] ([ATC],[PID],[NAME],[REG_DATE],[ACTIVE])
  VALUES ('A01','123456','TEST2','2016-09-01 00:00:00.000',0);
  INSERT INTO [dbo].[test] ([ATC],[PID],[NAME],[REG_DATE],[ACTIVE])
  VALUES ('A01','123456','TEST3','2016-09-02 00:00:00.000',0);
  INSERT INTO [dbo].[test] ([ATC],[PID],[NAME],[REG_DATE],[ACTIVE])
  VALUES ('A01','123456','TEST4','2016-09-03 00:00:00.000',0);
  INSERT INTO [dbo].[test] ([ATC],[PID],[NAME],[REG_DATE],[ACTIVE])
  VALUES('A01','123456','TEST5','2016-09-06 00:00:00.000',1);

示例查询：

;WITH CTE AS
(
    SELECT ROW_NUMBER() OVER (PARTITION BY ATC, PID ORDER BY REG_DATE ASC) AS ROWNUM,* FROM [dbo].[test]
    WHERE ACTIVE=0
)
SELECT DATEDIFF(DAY, d2.REG_DATE, d1.REG_DATE),d1.NAME, d1.REG_DATE AS ACTIVE_REC_DATE, d2.REG_DATE AS NOTACTIVE_REC_DATE, d1.ACTIVE, d2.ACTIVE FROM [dbo].[test] as d1
LEFT JOIN CTE d2 ON d2.ATC = d1.ATC AND d2.PID = d1.PID
AND DATEDIFF(DAY, d2.REG_DATE, d1.REG_DATE) <= 7
WHERE d1.ACTIVE=1 AND d1.PID=123456;

想要的结果：

列 ACTIVE True (1) 的记录应包含（如果记录存在）不活动的先前记录的 REG_DATE，最长 7 天。喜欢：

(No column name)    NAME    ACTIVE_REC_DATE NOTACTIVE_REC_DATE  ACTIVE  ACTIVE
3   TEST5   2016-09-06 00:00:00.000 2016-08-31 00:00:00.000 1   0

目前查询结果包含多条记录，因为更多的记录将落在 7 天的时间段内。我需要加入 1 条最长 7 天的记录。

我使用了 ROW_NUMBER() 和 over partition by，所以我可以使用和识别第一条记录，因为我将按升序排序。当没有可用的以前记录或以前的记录超过 7 天时，这不起作用 当没有要加入的记录被忽略时，可以使用 INNER JOIN 或 null 处的日期列

我希望我的解释清楚。

Answer 1

SELECT DATEDIFF(DAY, d2.REG_DATE, d1.REG_DATE),d1.NAME, d1.REG_DATE AS ACTIVE_REC_DATE, d2.REG_DATE AS NOTACTIVE_REC_DATE, d1.ACTIVE, d2.ACTIVE FROM [dbo].[test] as d1
OUTER APPLY 
(SELECT TOP 1 T1.* FROM dbo.test t1 WHERE t1.ATC = d1.ATC AND t1.PID = d1.PID and DATEDIFF(DAY, t1.REG_DATE, d1.REG_DATE) <= 7 order by t1.REG_DATE desc) d2
WHERE d1.ACTIVE=1 AND d1.PID=123456;

Answer 2

您可以通过将ROWNUM 上的过滤器添加到您的左连接来为PID 返回单行：

;WITH CTE AS
(
    SELECT ROW_NUMBER() OVER (PARTITION BY ATC, PID ORDER BY REG_DATE ASC) AS ROWNUM,* FROM [dbo].[test]
    WHERE ACTIVE=0
)
SELECT DATEDIFF(DAY, d2.REG_DATE, d1.REG_DATE),d1.NAME, d1.REG_DATE AS ACTIVE_REC_DATE, d2.REG_DATE AS NOTACTIVE_REC_DATE, d1.ACTIVE, d2.ACTIVE FROM [dbo].[test] as d1
LEFT JOIN CTE d2 ON d2.ATC = d1.ATC AND d2.PID = d1.PID
AND DATEDIFF(DAY, d2.REG_DATE, d1.REG_DATE) <= 7
AND d2.ROWNUM = 1
WHERE d1.ACTIVE=1 AND d1.PID=123456;

当过去 7 天的先前记录不存在时，查询的行为方式并不清楚。