Tsql 以日期间隔计数

我将此表称为

Table1

，如下所示：

    UserID   Date 
    1        01/01/09
    1        14/01/09
    1        25/01/09
    1        01/02/09
    1        15/02/09
    2        02/02/09
    2        15/02/09

我试图返回一个结果，计算

MIN（日期）

和

MIN（日期）

之后30天之间的次数，即

DATEADD（day，30，MIN（日期））

。所以它看起来像这样：

    UserID   Count
    1        3 
    2        2

select a.UserID, count(case when DDate - MinDate <= 30 then 1 end) as Count
from (
    select UserID, min(DDate) MinDate
    from Table1
    group by UserID
) a
inner join Table1 t on a.UserID = t.UserID
group by a.UserID

下面的代码是错误的，但它表达了我试图实现的目标：

SELECT COUNT(1) AS Count
FROM Table1
GROUP BY UserID
WHERE Date BETWEEN MIN(Date) AND DATEADD(day,30,MIN(DATE))

试试这个

DECLARE @table TABLE(
        UserID INT,
        DDate DATETIME
)

INSERT INTO @table (UserID,DDate) SELECT 1, '01 Jan 2009'
INSERT INTO @table (UserID,DDate) SELECT 1, '14 Jan 2009'
INSERT INTO @table (UserID,DDate) SELECT 1, '25 Jan 2009'
INSERT INTO @table (UserID,DDate) SELECT 1, '01 Feb 2009'
INSERT INTO @table (UserID,DDate) SELECT 1, '15 Feb 2009'
INSERT INTO @table (UserID,DDate) SELECT 2, '02 Feb 2009'
INSERT INTO @table (UserID,DDate) SELECT 2, '15 Feb 2009'


SELECT  t.UserID,
        COUNT(t.UserID)
FROM    @table t INNER JOIN
        (
            SELECT  UserID,
                    MinDate,
                    DATEADD(dd, 30, MinDate) MinDataAdd30
            FROM    (
                        SELECT  UserID,
                                MIN(DDate) MinDate
                        FROM    @table
                        GROUP BY UserID
                    ) MINDates
        ) DateRange ON t.UserID = DateRange.UserID
WHERE   t.DDate BETWEEN DateRange.MinDate AND DateRange.MinDataAdd30
GROUP BY t.UserID

---

我认为您需要使用子查询来获取最短日期。我在下面展示了它 作为一个单独的查询转换为一个变量，我可能会将其转换为一个表值函数

DECLARE @STARTDATE DATETIME

SELECT @STARTDATE = MIN(DATE) FROM Table1

SELECT COUNT(1) AS Count
FROM Table1
GROUP BY UserID
WHERE Date BETWEEN @STARTDATE AND DATEADD(day,30,@STARTDATE)

---

我会这样做：

    UserID   Count
    1        3 
    2        2

select a.UserID, count(case when DDate - MinDate <= 30 then 1 end) as Count
from (
    select UserID, min(DDate) MinDate
    from Table1
    group by UserID
) a
inner join Table1 t on a.UserID = t.UserID
group by a.UserID

选择一个.UserID，count（DDate-MinDate时的大小写）