How to get the weeks according to dates in a expression?

Question

Hi ALL,
I had an urgent requirement, how to convert dates into weeks.
I mean,if the date is from 01/01/2014 to 07/01/2014 is like week1
01/01/2014 to 07/01/2014 is like week2, 08/01/2014 to 015/01/2014 is like week3,16/01/2014 to 23/01/2014 is like week4, 24/01/2014 to 31/01/2014 is like week5.
Hope u got my requirement. pls suggest me the expression ASP.
Thanks in Advance.

Answer 1

What you really need is a calendar table. If you can't implement one, try these functions instead, but do note the holidays are configured for Canada:
create function NthDayOfMonth (@year int, @month smallint, @weekday varchar(15), @nth smallint)
returns datetime
as
begin
declare @the_date datetime, @c_date datetime, @cth smallint
set @cth = 0
set @c_date = convert(varchar,@year)+'-'+convert(varchar,@month)+'-01'
while month(@c_date) = @month
begin
if datename(weekday,@c_date) = @weekday set @cth = @cth + 1
if @cth = @nth and datename(weekday,@c_date) = @weekday set @the_date = @c_date
set @c_date = dateadd(day,1,@c_date)
end
return @the_date
end
go
create function Dates(@date datetime)
returns @table table
now datetime,
today datetime,
Month_start datetime,
Month_end datetime,
Prev_Month_Start datetime,
Prev_Month_End datetime,
Week_Start datetime,
Week_End datetime,
Prev_Week_Start datetime,
Prev_Week_End datetime,
Quarter_Start datetime,
Quarter_End datetime,
Prev_Quarter_Start datetime,
Prev_Quarter_End datetime,
Year_Start datetime,
Year_End datetime,
Prev_Year_Start datetime,
Prev_Year_End datetime,
Month_End_TS datetime,
Prev_Month_End_TS datetime,
Week_End_TS datetime,
Prev_Week_End_TS datetime,
Quarter_End_TS datetime,
Prev_Quarter_End_TS datetime,
Year_End_TS datetime,
Prev_Year_End_TS datetime,
Year smallint,
Month smallint,
Day smallint,
Month_Name varchar(15),
Day_Name varchar(15),
WD SMALLINT,
Week INT
as
begin
if @date IS NULL set @date = getdate()
insert into @table
select
@date as now,
convert(datetime,convert(varchar,@date,101)) as today,
dateadd(day,0-day(@date)+1,convert(datetime,convert(varchar,@date,101))) as Month_Start,
dateadd(day,-1,dateadd(month,1,dateadd(day,0-day(@date)+1,convert(datetime,convert(varchar,@date,101))))) as Month_end,
dateadd(month,-1,dateadd(day,0-day(@date)+1,convert(datetime,convert(varchar,@date,101)))) as Prev_Month_start,
dateadd(day,-1-day(@date)+1,convert(datetime,convert(varchar,@date,101))) as Prev_Month_End,
dateadd(day,1-datepart(dw,@date),convert(datetime,convert(varchar,@date,101))) as Week_Start,
dateadd(day,7-datepart(dw,@date),convert(datetime,convert(varchar,@date,101))) as Week_End,
dateadd(day,-6-datepart(dw,@date),convert(datetime,convert(varchar,@date,101))) as Prev_Week_Start,
dateadd(day,0-datepart(dw,@date),convert(datetime,convert(varchar,@date,101))) as Prev_Week_End,
convert(datetime,convert(varchar,year(@date)) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,@date)-1)*3)+1),2)+'-01') as quarter_start,
dateadd(day,-1,dateadd(quarter,1,convert(datetime,convert(varchar,year(@date)) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,@date)-1)*3)+1),2)+'-01'))) as quarter_end,
convert(datetime,convert(varchar,year(dateadd(quarter,-1,@date))) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,dateadd(quarter,-1,@date))-1)*3)+1),2)+'-01') as prev_quarter_start,
dateadd(day,-1,dateadd(quarter,1,convert(datetime,convert(varchar,year(dateadd(quarter,-1,@date))) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,dateadd(quarter,-1,@date))-1)*3)+1),2)+'-01'))) as prev_quarter_end,
dateadd(day,1-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101))) as Year_Start,
dateadd(year,1,dateadd(day,0-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101)))) as Year_End,
dateadd(year,-1,dateadd(day,1-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101)))) as Prev_Year_Start,
dateadd(year,-1,dateadd(year,1,dateadd(day,0-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101))))) as Prev_Year_End,
dateadd(ms,-3,dateadd(day,0,dateadd(month,1,dateadd(day,0-day(@date)+1,convert(datetime,convert(varchar,@date,101)))))) as Month_End_Ts,
dateadd(ms,-3,dateadd(day,-1-day(@date)+2,convert(datetime,convert(varchar,@date,101)))) as Prev_Month_End_TS,
dateadd(ms,-3,dateadd(day,8-datepart(dw,@date),convert(datetime,convert(varchar,@date,101)))) as Week_End_TS,
dateadd(ms,-3,dateadd(day,1-datepart(dw,@date),convert(datetime,convert(varchar,@date,101)))) as Prev_Week_End_TS,
dateadd(ms,-3,dateadd(day,0,dateadd(quarter,1,convert(datetime,convert(varchar,year(@date)) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,@date)-1)*3)+1),2)+'-01')))) as quarter_end_TS,
dateadd(ms,-3,dateadd(day,0,dateadd(quarter,1,convert(datetime,convert(varchar,year(dateadd(quarter,-1,@date))) +'-'+ right('0'+convert(varchar,((datepart(QUARTER,dateadd(quarter,-1,@date))-1)*3)+1),2)+'-01')))) as prev_quarter_end_TS,
dateadd(ms,-3,dateadd(year,1,dateadd(day,1-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101))))) as Year_End_TS,
dateadd(ms,-3,dateadd(day,1-day(@date),dateadd(month,1-month(@date),convert(varchar,@date,101)))) as Prev_Year_End_TS,
Year(@date) as Year,
Month(@date) as Month,
Day(@Date) as Day,
datename(month,@Date) as Month_Name,
datename(WEEKDAY,@date) as Day_Name,
datepart(weekday,@date) as WD,
DATEPART(WEEK,@date) AS Week
return
end
go
create function Holidays(@year smallint)
returns @table table
date datetime,
type varchar(10),
name varchar(25)
as
begin
insert into @table
select convert(datetime,convert(varchar,@year)+'-01-01') as date,'Holiday' as type ,'New Years Day' as name UNION ALL
select dbo.NthDayOfMonth(@year,2, 'Monday',3),'Holiday','Family Day' UNION ALL
select dateadd(d,0-case when datepart(weekday,convert(varchar,@year)+'-05-25') in (1,2) then 5+datepart(weekday,convert(varchar,@year)+'-05-25') else datepart(weekday,convert(varchar,@year)+'-05-25')-1 end, convert(varchar,@year)+'-05-25') ,'Holiday','Victoria Day' UNION ALL
select convert(varchar,@year)+'-01-07' ,'Holiday','Canada Day' UNION ALL
select dbo.NthDayOfMonth(@year,8, 'Monday',1),'Holiday','Civic Holiday' UNION ALL
select dbo.NthDayOfMonth(@year,9, 'Monday',1),'Holiday','Labour Day' UNION ALL
select dbo.NthDayofMonth(@year,10,'Monday',2),'Holiday','Thanksgiving' UNION ALL
select convert(varchar,@year)+'-11-11' ,'Holiday','Rememberance Day'UNION ALL
select convert(varchar,@year)+'-12-25' ,'Holiday','Christmas Day' UNION ALL
select convert(varchar,@year)+'-12-26' ,'Holiday','Boxing Day'
update @table
set date =
case when name != 'Boxing Day' and datepart(weekday,date) = 7 then dateadd(day,2,date)
when name != 'Boxing Day' and datepart(weekday,date) = 1 then dateadd(day,1,date)
when name = 'Boxing Day' and datepart(weekday,date) = 7 then dateadd(day,2,date)
when name = 'Boxing Day' and datepart(weekday,date) = 1 then dateadd(day,2,date)
when name = 'Boxing Day' and datepart(weekday,date) = 2 then dateadd(day,1,date)
else date
end
return
end
go