【叶子函数分享二十四】根据年月生成日历函数

go
--创建函数(第一版)(作者：dobear_0922)
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 Tue Wed Thu Fri Sat' + @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
--测试示例
set datefirst 3
print dbo.fn_Calendar(2007, 12)
select dbo.fn_Calendar(2007, 12)
set datefirst 7

--运行结果
/*
Sun Mon Tue Wed Thu Fri Sat
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31
*/

go
--创建函数(第二版)(作者：libin_ftsafe)
create function f_calendar(@year int,@month int)
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 @a table(id int identity(0,1),date datetime)
insert into @a(date)
select top 31 rtrim(@year)+'-'+rtrim(@month)+'-1' from sysobjects
update @a set date=dateadd(dd,id,date)
insert into @t
select
max(case datepart(dw,date) when 7 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 1 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 2 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 3 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 4 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 5 then rtrim(day(date)) else '' end),
max(case datepart(dw,date) when 6 then rtrim(day(date)) else '' end)
from
@a
where
month(date)=@month
group by
(case datepart(dw,date) when 7 then datepart(week,date)+1 else datepart(week,date) end)

return
end

go
--测试示例
set datefirst 1
select * from dbo.f_calendar(2007,12)

--运行结果
/*
日 一 二 三 四 五 六
---- ---- ---- ---- ---- ---- ----
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31
*/