How to get week number SQL Server 2014 - sql

How to get Week number based on current date in SQL Server 2014?
Please note always year should starts from 1st February and year end will be 31st Jan.
Week Starts from Sunday to Saturday.

You can get the number of weeks since Feb 1 and then use that to calculate weeks:
select (case when month(getdate()) < 2
then datediff(week,
datefromparts(year(getdate()) - 1, 2, 1),
getdate()
)
else datediff(week,
datefromparts(year(getdate()), 2, 1),
getdate()
)
end)
Note: datefromparts() was introduced in SQL Server 2012. You can do similar things with strings and conversion to dates.

Try this
SELECT CASE WHEN MONTH(GETDATE()) < 2 THEN (DATEPART(DAYOFYEAR,DATEADD(M,11,GETDATE())))/7
ELSE ((DATEPART(DAYOFYEAR,GETDATE())-31)/7)+1
END

declare #DATE_INSERT date='02-01-2014'
select DATEPART(WK,#DATE_INSERT) - DATEPART(WK,DATEADD(DAY,1,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,#DATE_INSERT),0)))) + 1

Depends how you define week number, but you can try this:
SELECT DATEPART( wk, DATEADD('mm',-1,getdate()))

Related

SQL query to find dates of last year equivalent to today's date

I am writing a SQL query to find business working dates of last year equivalent to today's date.
In this query it should fetch :-
For e.g. if today is 5th January, 2021 and it is the second day of second week of the year. So I need to find the exact equivalent date of the second day of second week of the previous year. So it would be 7th January, 2020.
And with this, I need the business working dates of that week of 7th January 2020 (i.e. excluding Saturday & Sunday)
Which will come up as 2020-Jan-06 to 2020-Jan-10 according to the example.
So I will need the report between 6th Jan - 10th Jan, 2020.
I am trying to use this code to find date of last year equivalent to today's date (5th Jan, 2021 viz. second day of second week)
select Convert(date, (DATEADD(year, -1, getdate()+2))) ;
2021-01-05 is the 2nd day of the first week of 2021 according to ISO standards.
If you want the 2nd day of the first week of 2021, then it is either today's date minus 52 weeks or 53 weeks. Based on the Wikipedia page for ISO dates:
[53 week years are those] years in which 1 January or 31 December are Thursdays
So, we want that for the previous year. Hence, I think the following should work:
select dateadd(week,
(case when 'Thursday' in (datename(weekday, datefromparts(year(getdate()) - 1, 1, 1)),
datename(weekday, datefromparts(year(getdate()) - 1, 12, 31))
)
then -53 else -52
end),
convert(date, getdate())
)
Note that this returns 2019-12-31, which is the correct value based on ISO standards.
I have use multiple CTE to show you the step by step calculation. It should be pretty easy to follow.
Basically it find the week_no and day_no_of_week for 2021-01-05 and then use that to find the same date for 2020
declare #input_date date = '2021-01-05',
#year_offset int = -1; -- previous year
with
cte1 as
(
select input_date = #input_date,
week_no = DATEPART(WEEK, #input_date),
first_day_of_week = DATEADD(WEEK, DATEDIFF(WEEK, 0, #input_date), 0)
),
cte2 as
(
select *,
day_no_of_week = DATEDIFF(DAY, first_day_of_week, #input_date) + 1
from cte1
),
cte3 as
(
select *,
first_day_of_the_prev_year = DATEADD(YEAR, DATEDIFF(YEAR, 0, #input_date) + #year_offset, 0)
from cte2
),
cte4 as
(
select *,
first_day_of_week_prev_year = DATEADD(WEEK, DATEDIFF(WEEK, 0, DATEADD(WEEK, week_no - 1, first_day_of_the_prev_year)), 0)
from cte3
)
select *,
DATEADD(DAY, day_no_of_week - 1, first_day_of_week_prev_year) as the_required_date
from cte4

SQL get previous month (in January too)

Hello I'm looking for simple way, how to get data from previous month. I get this code but it didn't work in January (result is 12 2021 and I need 12 2020)
select month(dateadd(month,-1,getdate())), year(getdate())
Presumably, you have some sort of date column.
In SQL Server, you can express this concept using datediff():
where datediff(month, datecol, getdate()) = 1
However, that is not "sargable", meaning that it prevents the use of indexes. So, I would instead recommend:
where datecol < datefromparts(year(getdate()), month(getdate()), 1) and
datecol >= dateadd(month, 1, datefromparts(year(getdate()), month(getdate()), 1))
If you simply want the first day of the previous month, you can use:
dateadd(month, 1, datefromparts(year(getdate()), month(getdate()), 1))
Try This
select CASE WHEN month(getdate())>1 THEN month(getdate())-1 ELSE 12 END ,
CASE WHEN month(getdate())>1 THEN YEAR (getdate()) ELSE YEAR (getdate()) -1 END
Using the answer given here: How can I select the first day of a month in SQL?
SELECT dateadd(month,-1,DATEADD(month, DATEDIFF(month, 0, getdate()), 0)) as previousmonth;
output:
2020-12-01 00:00:00.000
I can provide next query using FORMAT function:
SELECT
-- get current day in previous month
FORMAT(dateadd(month, -1, getdate()), 'yyyy-MM-dd') as current_previousmonth,
-- get first of previous month
FORMAT(dateadd(month, -1, getdate()), 'yyyy-MM-01') as first_previousmonth,
-- previous month without date
FORMAT(dateadd(month, -1, getdate()), 'yyyy-MM') as previousmonth;
test T-SQL here
Here you go!
select dateadd(mm,-1,eomonth(getdate())) as [Previous Month]
Result:
Previous Month
--------------
2020-12-31
You could also use CONVERT() or FORMAT() functions to format the date as you desire.
Try
SELECT FORMAT(DATEADD(month, -1, GETDATE()),'MM/yyyy');
It will give you previous month and the year. If you are comparing to a date column in a existing table, then you need the date part too as you want to know December of which year was the previous month. But if you don't want the year, then just adjust the 'MM/yyyy' part to suit your purpose.

SELECT previous year up to current date

I have a table which has a Start Date column for example:
Start Date
2015/01/05
2015/02/08
2016/01/10
2017/02/10
etc...
I am trying to put into my WHERE clause to select all records where it is one year prior based on the current GETDATE().
For example, if today is July 2019 and I run the query, I'd like for it to run and give me Start Dates starting from July of 2018 up until June of 2019. And if I run it for August of 2019, I'd like for it to show Start Dates from August of 2018 up until July of 2019, and so on. Basically up until the month before of the current date.
Currently I have this in my WHERE clause:
WHERE start_date between DATEADD(YEAR,-1, GETDATE()) and GETDATE()
but this appears I believe to get just one year prior up until the current date exact.
Is there a better way for me to do this?
I think that this is your requirement:
WHERE start_date BETWEEN
DATEFROMPARTS(YEAR(GETDATE()) - 1, MONTH(GETDATE()), 1)
AND
DATEADD(MONTH, DATEDIFF(MONTH, 0, GETDATE()), -1)
With:
DATEFROMPARTS(YEAR(GETDATE()) - 1, MONTH(GETDATE()), 1)
you get the 1st day of current month in last year.
With:
DATEADD(MONTH, DATEDIFF(MONTH, 0, GETDATE()), -1)
you get the last Day of previous month.
See the demo.
You can use datefromparts() in SQL Server:
where start_date >= datefromparts(year(getdate()) - 1, 1, 1) and
start_date < datefromparts(year(getdate() - 1, month(getdate()), day(getdate())

last date of Financial year (I.e 2017-03-31)

Hi please let me know how to extract the last day of Financial year in sql server.my financial year start from 2016-04-01 to 2017-03-31
Closest you can use is End Of Month for that you need to provide one date to that month as below:
select eomonth('2017-03-01')
To get the last day of the financial year for any date, you need to find the last of march if before march, or the last of march next year if after march:
declare #yourdate datetime = getdate();
select case when month(#yourdate) < 4 then CONVERT(datetime,cast(YEAR(#yourdate) as char(4)) + '-03-31' ,120)
else CONVERT(datetime,cast(YEAR(#yourdate) + 1 as char(4)) + '-03-31' ,120)
end as financial_year_end
Edit:
If you want last date derived based on from_date, then use something like this
Rextester Demo
select
case when datepart(mm,from_date) <=3 then
cast(concat(year(from_date),'-03-31') as datetime)
else
dateadd(year,1,cast(concat(year(from_date),'-03-31') as datetime))
end as last_date_fin
from
(select '2017-04-30' as from_date union all
select '2017-01-13') t;
This way from_date between Jan - Mar will give same year's 31st march. Else it will give next year's 31st March.
Previous answer:
http://rextester.com/AXVM26769
If you want to get last day of march for same year as passed, then use
select cast(concat(given_year,'-03-31') as datetime)
from
(select '2017' as given_year) t
If you want to pass 2016 and then get 2017-03-31 then use. You can change the year in derived table and change the output based on that.
select dateadd(year,1,cast(concat(given_year,'-03-31') as datetime))
from
(select '2016' as given_year) t;
This Code will work to find the last date of Financial Year.
For Previous Year case matches and 'THEN' part will Execute and for current year 'ELSE'
part will execute.
select CASE WHEN (MONTH(GETDATE())) <= 3
THEN convert(varchar(4), YEAR(GETDATE())-1) + '-' + '03-31'
ELSE convert(varchar(4),YEAR(GETDATE()))+ '-' + '03-31'
end
> LastDayOfYearFY] =
> eomonth( dateadd(month, 5,
> dateadd(year, datepart(year, (dateadd(month, 6, [date])) ) -1900, 0)))
Idea extension taken from return-first-day-of-financial-year
You can select all the dates order them descendant and take the first one.
SELECT date
FROM table
ORDER BY date desc
LIMIT 1;

SQL - pick current date from machine and compare with previous week

For the below query
Sum(CASE WHEN dbo.sales.date BETWEEN '2016-07-17' AND '2016-07-23' THEN dbo.sales.sellinc END) AS ActualSales
Instead of hard coding the date. I would like to pick current date from machine and compare
Sum(CASE WHEN dbo.sales.date BETWEEN '**previous week (31 week 2016)**' AND '**Last year same week (31 week 2015)**' THEN dbo.sales.sellinc END) AS ActualSales
Week start from Sunday and ends Saturday. Any help please?
I think this snippet might help you to get a range of one year from the previous week to last year.
Sum(CASE
WHEN dbo.sales.date
BETWEEN DATEADD(YEAR, -1, DATEADD(WEEK, -1, GETDATE())) AND
DATEADD(WEEK, -1, GETDATE()) THEN dbo.sales.sellinc END) AS ActualSales
You can also modify the logic if you want to consider Friday as an exception.
In that case, you have to use DATEPART(WEEKDAY, GETDATE()) function to get the week day which returns 1 for Sunday and 7 for Saturday. It would be prettier if you move the date generation logic to a variable and then use it to select your data.
Others have already noted that your method of week numbering is going to impact your solution. Here's one that just looks for the Sunday of the current week and then subtracts 52 weeks. (You could also just deduct 364 days in the previous step and use dateadd only once.) So the correspondence with the previous year's week is essentially the nearest calendar date falling on Sunday that year.
with dates as (
select
dateadd(week, -52,
dateadd(day,
1 - datepart(weekday, getdate()), /* Sunday of current week */
cast(getdate() as date)
)
) as WeekStartY-1,
dateadd(day, 1 - datepart(weekday, cast(getdate() as date)) as WeekStartY-0
)
select
sum(case when cast(s."date" as date)
between d.WeekStartY-0 and dateadd(day, 6, WeekStartY-0) then s.sellinc end
) as ActualSalesY-0,
sum(case when cast(s."date" as date)
between d.WeekStartY-1 and dateadd(day, 6, WeekStartY-1) then s.sellinc end
) as ActualSalesY-1,
from dbo.Sales s cross apply dates d;
This can occasionally produce an oddity where the weeks both start in the same year. It happens when the year ends on Sunday, or Monday in leap years, as with 2012. So Y-1 for December 30, 2012 was January 1, 2012. But consider that most of the days for that week actually fall in 2013 and the correspondence makes sense from that perspective.
You can try using DATEADD:
SUM(CASE WHEN dbo.sales.date BETWEEN DATEADD(week, 30, '2016/01/01') AND
DATEADD(week, 30, '2015/01/01')
THEN dbo.sales.sellinc END) AS ActualSales
This will give you the one year range between the 30th week of 2015 and 2016, using the SQL Server week, whose first week begins on January 1st, regardless of the day. If you really want to use the ISO week, then it will be a lot more work.