Question

我有下表，其中有员工＆＃39;不存在：

RecordId    EmpID       ActivityCode  DateFrom    DateTo
---------------------------------------------------------------
666542      1511        AB            29/01/2011  02/02/2011
666986      1511        AB            11/11/2011  11/11/2011
666996      1511        EL            13/11/2011  17/11/2011
755485      1787        SL            01/11/2011  14/11/2011
758545      1787        SL            15/11/2011  03/12/2011
796956      1954        AB            09/11/2011  09/11/2011
799656      1367        AB            09/11/2011  09/11/2011
808845      1527        EL            16/11/2011  16/11/2011
823323      1527        EL            17/11/2011  17/11/2011
823669      1527        EL            18/11/2011  18/11/2011
899555      1123        AB            09/11/2011  09/12/2011
990990      1511        AB            12/11/2011  12/11/2011

现在我想要一个存储过程生成的报告来汇总给定年份中每个月的特定缺勤代码的所有缺勤天数，例如，如果我想知道2011年上一个表格中的缺席总数我会得到类似的东西：

Month        TotalDays
---------------------------------
JAN 2011     201
FEB 2011     36
MAR 2011     67
APR 2011     91
....

存储过程将有两个参数（@Year INT，@ AbsCode NVARCHAR（3））。
请注意，有时记录与另一个月重叠（如示例表中的第一行），并且每个月应单独计算。我试过使用循环，但没有运气。我在TSQL方面很弱。

的更新
现在我正在使用标量值用户函数和存储过程来完成这项工作，它的丑陋和难以追踪。这是任何方式：
用户功能：

ALTER FUNCTION [dbo].[GetActivityTotalDaysInMonth]
(
     @ActivityCode CHAR(3)
     ,@Year INT
     ,@Month INT
)
RETURNS INT
AS

BEGIN

DECLARE @FirstDayOfMonth DATETIME
DECLARE @LastDayOfMonth DATETIME
SET @FirstDayOfMonth = CAST(CAST(@Year AS varchar) + '-' + CAST(@Month AS varchar) + '-' + CAST(1 AS varchar) AS DATETIME)
SET @LastDayOfMonth = DATEADD(s, -1, DATEADD(M, 1, @FirstDayOfMonth))    

DECLARE @TotalDays INT

SELECT @TotalDays = 
SUM(DATEDIFF(DAY, 
  (CASE WHEN ActivityDateFrom < @FirstDayOfMonth THEN @FirstDayOfMonth ELSE ActivityDateFrom END)
, (CASE WHEN ActivityDateTo > @LastDayOfMonth THEN @LastDayOfMonth ELSE ActivityDateTo END))+1)

FROM Activities 
WHERE 
ActivityCode=@ActivityCode
AND ((ActivityDateFrom < @FirstDayOfMonth AND ActivityDateTo >= @FirstDayOfMonth)
OR (ActivityDateFrom >= @FirstDayOfMonth AND ActivityDateTo <= @LastDayOfMonth)
OR (ActivityDateFrom <= @LastDayOfMonth AND ActivityDateTo > @LastDayOfMonth))
RETURN @TotalDays
END

现在，我在存储过程的循环中调用此函数：

ALTER PROCEDURE GetAnnualActivityTotalDays
(
    @ActivityCode CHAR(3)
    ,@Year INT
)
AS
BEGIN
SET NOCOUNT ON;

DECLARE @Stats TABLE
([Month] NVARCHAR(50), TotalDays INT)

DECLARE @MonthNo INT
DECLARE @Month DATETIME

SET @MonthNo = 1

WHILE @MonthNo <= 12
BEGIN

    SET @Month = CAST(CAST(@Year AS varchar) + '-' + CAST(@MonthNo AS varchar) + '-' + CAST(1 AS varchar) AS DATETIME)

    INSERT INTO @Stats ([Month], TotalDays)
    SELECT UPPER(SUBSTRING(DATENAME(mm, @Month), 1, 3)) + ', ' + CAST(@Year AS NVARCHAR),
    dbo.GetActivityTotalDaysInMonth(@ActivityCode
                ,@Year
                ,@MonthNo
                ,@Base)

    SET @MonthNo = @MonthNo + 1
END

SELECT * FROM @Stats
END

正如您所看到的，这是一个丑陋的代码，我相信它可以更简单的方式完成..有什么建议吗？

Answer 1

您需要创建一个日历表，以便您轻松计算开始日期和结束日期所涵盖的每个月的日期。例如，recordid = 666542在1月份有3天，在2月份有2天。您可以通过

之类的查询获得该号码

select calyear, calmonth, caldate
from calendar
    join activities on calendar.caldate between activities.activitydatefrom and activities.activitydateto
where activitycode = 'AB'

如果将其包装在公用表表达式中，则可以在CTE上执行聚合查询。

with mycte as (
select calyear, calmonth, caldate
from calendar
    join activities on calendar.caldate between activities.activitydatefrom and activities.activitydateto
where activitycode = 'AB'
)

select calyear, calmonth, count(caldate)
from mycte
group by calyear, calmonth
order by calyear, calmonth

要生成日历表，您可以使用类似于

的代码

create table calendar (calyear, calmonth, caldate)

declare @numdays int --number of days to generate in the calendar
declare @datestart datetime --the date to begin from in the calendar

set @numdays = 365 
set @datestart = 'jan 1 2011';

with num as (
select 0 number
union
select 1 number
union
select 2 number
union
select 3 number
union
select 4 number
union
select 5 number
union
select 6 number
union
select 7 number
union
select 8 number
union
select 9 number

),

numberlist as (
select ((hundreds.number * 100) + (tens.number * 10) + ones.number) n
from num hundreds
    cross join num tens 
    cross join num ones 
where ((hundreds.number * 100) + (tens.number * 10) + ones.number) < @numdays
)

insert into calendar (calyear, calmonth, caldate)
select 
    datepart(yy,dateadd(dd,n,@datestart)) calyear, 
    datepart(mm,dateadd(dd,n,@datestart)) calmonth, 
    dateadd(dd,n,@datestart)caldate
from numberlist

对一个月内的记录数进行求和和分组

1 个答案: