从两列中找到最小值和最大值。生成从 min 到 max 的日期

Question

我在 SQL Server DB 中有表：

ID    Open_date     Close_date
1     01-01-2010    01-03-2010
2     21-01-2011    12-02-2011
3     01-03-2010    NULL
4     10-01-2010    NULL

我需要做一些将返回的 T-SQL 查询：

Month    Year    Open    Close
01       2010    2       0
02       2010    0       0
03       2010    0       1
04       2010    0       0
05       2010    0       0
06       2010    0       0
07       2010    0       0
08       2010    0       0
09       2010    0       0
10       2010    0       0
11       2010    0       0
12       2010    0       0
01       2011    1       0
02       2011    0       1

结果集中的条目数等于数据库中表的“Open_date”和“Close_date”列的最小值与相同列的最大值之间的月数。问题是如何从两个日期列中找到最小值和最大值，然后生成从最小值到最大值的日期，然后使用这个临时表（或它将是什么）来计算临时表中每个日期的打开和关闭条目数。

Answer 1

我之前设计了一个示例，但最终没有发布，但回来后还是决定发布它:)

-- Sample Data
CREATE TABLE #SampleVals ( ID int, Open_Date Date, Close_Date Date);
INSERT INTO #SampleVals(ID, Open_Date, Close_Date)
VALUES(1,'20100101','20100301'),
      (2,'20110121','20110212'),
      (3,'20100301', NULL),
      (4,'20100110',NULL);

-- Get Start/End for full date range
DECLARE @Min Date, @Max Date;
SELECT @Min = DateAdd(dd,-1 * Day(MIN(Open_Date)) + 1, MIN(Open_Date)), 
        @Max = MAX(Close_Date)
FROM #SampleVals;

-- Query for values across entire range
WITH DateRange (StartDate,NextDate) AS (
    SELECT DATEADD(MONTH, n-1, @Min),
            DATEADD(MONTH, n, @Min)
    FROM dbo.Number N
    WHERE N.n <= DATEDIFF(MONTH,@Min,@Max) + 1
)
SELECT MONTH(DR.StartDate),
        YEAR(DR.StartDate),
        SUM(CASE WHEN S.Open_Date >= DR.StartDate Then 1 Else 0 END) AS [Open],
        SUM(CASE WHEN S.Close_Date < DR.NextDate Then 1 Else 0 END) AS [Closed]
FROM DateRange DR
    LEFT JOIN #SampleVals S ON S.Open_Date < DR.NextDate 
                            AND (S.Close_Date >= DR.StartDate OR S.Close_Date IS NULL)
GROUP BY DR.StartDate
ORDER BY DR.StartDate;

-- Cleanup sample data
DROP TABLE #SampleVals;

示例数据的日期已更改以反映 yyyymmdd。我还使用了本地数字表：

CREATE TABLE dbo.Number(n INT NOT NULL IDENTITY) ;
GO
SET NOCOUNT ON ;
INSERT dbo.Number DEFAULT VALUES ;
WHILE SCOPE_IDENTITY() < 5000
    INSERT dbo.Number DEFAULT VALUES ;

我几乎没有发布这个，因为 Norla 在我完成这个之前已经完成了它，但我注意到如果开始日期已关闭（以及该开始日期的月份），Norla 的解决方案会填充关闭列，而这个version 填充 close_date 月份的 close month 列，我相信这是您所要求的。

Answer 2

我稍微更改了日期，因为我使用的是不同的日期系统，但这应该可以。如果是，请接受！

DECLARE @TABLE1 TABLE
(
    ID INT
    , Open_date DATETIME
    , Close_date DATETIME
)

INSERT INTO @TABLE1 (ID, Open_date, Close_date)
      SELECT 1, '01-01-2010', '03-01-2010'
UNION SELECT 2, '01-21-2011', '02-12-2011'
UNION SELECT 3, '03-01-2010', NULL
UNION SELECT 4, '01-10-2010', NULL


DECLARE @MIN_DATE DATETIME
DECLARE @MAX_DATE DATETIME

SELECT @MIN_DATE = MIN(d)
    , @MAX_DATE = MAX(d)
FROM
(
    SELECT Open_date AS d
    FROM @TABLE1

        UNION

    SELECT Close_date AS d
    FROM @TABLE1
)a

--SELECT @MIN_DATE, @MAX_DATE



DECLARE @DATES TABLE
(
    ID INT IDENTITY(1,1)
    , [date] DATETIME
)

DECLARE @DATE DATETIME
SET @DATE = @MIN_DATE

WHILE (@DATE <= @MAX_DATE)
BEGIN

    INSERT INTO @DATES ([date])
    VALUES (@DATE)

    SET @DATE = @DATE + 1

END

--SELECT *
--FROM @DATES

SELECT MONTH(a.[date]) AS [Month]
    , YEAR(a.[date]) AS [Year]
    , SUM(CASE WHEN b.Open_date IS NOT NULL THEN 1 ELSE 0 END) AS [Open]
    , SUM(CASE WHEN b.Close_date IS NOT NULL THEN 1 ELSE 0 END) AS [Close]
FROM @DATES a
LEFT JOIN @TABLE1 b
    ON a.[date] = b.Open_date
GROUP BY YEAR(a.[date]), MONTH(a.[date])
ORDER BY YEAR(a.[date]), MONTH(a.[date])

Answer 3

对于 SQL Server 2005+，您可以尝试一个

somewhat simpler approach. Try this:

WITH CTE AS
(
    SELECT  MIN(CONVERT(VARCHAR(6),Dates,112)) YearMonth, 
            MAX(CONVERT(VARCHAR(6),Dates,112)) MaxDate
    FROM (  SELECT Open_Date Dates FROM YourTable
            UNION 
            SELECT Close_Date FROM YourTable) A
    UNION ALL
    SELECT CONVERT(VARCHAR(6),DATEADD(MONTH,1,YearMonth+'01'),112), MaxDate
    FROM CTE
    WHERE CONVERT(VARCHAR(6),DATEADD(MONTH,1,YearMonth+'01'),112)<=MaxDate
)
SELECT  RIGHT(A.YearMonth,2) [Month], LEFT(A.YearMonth,4) [Year], 
        COUNT(B.Id) [Open], COUNT(C.Id) [Close]
FROM CTE A
LEFT JOIN YourTable B
ON A.YearMonth = CONVERT(VARCHAR(6),B.Open_Date,112) 
LEFT JOIN YourTable C
ON A.YearMonth = CONVERT(VARCHAR(6),C.Close_Date,112) 
GROUP BY RIGHT(A.YearMonth,2), LEFT(A.YearMonth,4)
ORDER BY LEFT(A.YearMonth,4), RIGHT(A.YearMonth,2)

Answer 4

另一个版本

;with T(monthstart, monthend, _tempmax) as (
    select 
        min(Open_date), dateadd(day, -1, dateadd(month, 1, min(Open_date))), dateadd(month, 1, max(Open_date)) as _tempmax from THETABLE
    union all
    select 
        dateadd(month, 1, monthstart), dateadd(day, -1, dateadd(month, 2, monthstart)), _tempmax
    from T
    where dateadd(month, 1, monthstart) <= _tempmax
)
select
    month(monthstart) as [month],
    year(monthstart) as [year],
    sum(case when Open_date between monthstart and monthend then 1 else 0 end),
    sum(case when Close_date between monthstart and monthend then 1 else 0 end)
from T
left join 
    THETABLE on (Open_date between monthstart and monthend) or (Close_date between monthstart and monthend)
group by
    month(monthstart),
    year(monthstart)