整理了SQL Server中是实现日历的几个方法

问题描述

精选答案

数据库应该创建一个日历表

CREATE TABLE Calendar(

date datetime NOT NULL PRIMARY KEY CLUSTERED,

weeknum int NOT NULL,

weekday int NOT NULL,

weekday_desc nchar(3) NOT NULL,

is_workday bit NOT NULL,

is_weekend bit NOT NULL

)

GO

WITH CTE1 AS(

SELECT

date = DATEADD(day,n,'19991231')

FROM Nums

WHERE n <= DATEDIFF(day,'19991231','20201231')),

CTE2 AS(

SELECT

date,

weeknum = DATEPART(week,date),

weekday = (DATEPART(weekday,date) + @@DATEFIRST - 1) % 7,

weekday_desc = DATENAME(weekday,date)

FROM CTE1)

--INSERT INTO Calendar

SELECT

date,

weeknum,

weekday,

weekday_desc,

is_workday = CASE WHEN weekday IN (0,6) THEN 0 ELSE 1 END,

is_weekend = CASE WHEN weekday IN (0,6) THEN 1 ELSE 0 END

FROM CTE2create function F_month(@YMonth nvarchar(6))

returns @T table(日 varchar(4),一 varchar(4),二 varchar(4),三 varchar(4),四 varchar(4),五 varchar(4),六 varchar(4))

as

begin

declare @Tmp table([weekday] int,[day] nvarchar(2),[group] int)---增加一列作为分组显示

declare @i int,@j int,@date datetime,@group int

select @date=@YMonth+

'01

',@i=datediff(dd,@date,dateadd(month,1,@date)),@j=0,@group=0

while @i>@j

begin

insert @Tmp select (datepart(dw,@date)+@@datefirst-1)%7,datepart(d,@date),case when (datepart(dw,@date)+@@datefirst-1)%7=0 then @group+1 else @group end

select @j=@j+1,@group=case when (datepart(dw,@date)+@@datefirst-1)%7=0 then @group+1 else @groupend,@date=dateadd(dd,1,@date)

end

insert @T

select

max(case when [weekday]=0 then [day] else

'

' end),

max(case when [weekday]=1 then [day] else

'

' end),

max(case when [weekday]=2 then [day] else

'

' end),

max(case when [weekday]=3 then [day] else

'

' end),

max(case when [weekday]=4 then [day] else

'

' end),

max(case when [weekday]=5 then [day] else

'

' end),

max(case when [weekday]=6 then [day] else

'

' end)

from

@Tmp

group by [group]

return

end

go

select * from F_month(

'0712

')

或:

select * from F_month(

'200712

')create function fn_Calendar(@year int, @month int)

returns nvarchar(max)

as

begin

declare @result nvarchar(max), @Enter nvarchar(8)

select @Enter = char(13)+char(10), @result =

' Sun Mon The Wed Thu Fri Sta

' + @Enter --表头

declare @start datetime, @end datetime

select @start = rtrim(@year)+

'-

'+rtrim(@month)+

'-1

', @end = dateadd(mm, 1, @start)

set @result = @result+replicate(

'

', (datepart(dw, @start)+@@datefirst+6)%7) --第一行前面的空格

while datediff(d, @start, @end)>0

begin

if (datepart(dw, @start)+@@datefirst)%7 = 1

select @result = @result+@Enter --是否换行

select @result = @result+right(

'

'+rtrim(day(@start)), 4), @start = dateadd(d, 1, @start)

end

return @result

end

go

set datefirst 3

print dbo.fn_Calendar(2007, 12)

select dbo.fn_Calendar(2007, 12)

set datefirst 7

drop function dbo.fn_Calendar