SQL Date Logic Clause - sql

Question

Having problems understanding how to get the Where clause to work with this date structure.
Here is the principal logic. I want data only from previous March 1 onward and ending on yesterdays date.
Example #1:
So today is Feb 13, 2015 This would mean I need data between (2014-03-01 and 2015-02-12)
Example #2:
Say today is March 20, 2015 This This would mean I need data between (2015-03-01 and 2015-03-19)
The where logic might work but it doesn't like to convert '3/1/' + year. But I'm not sure how else to express it. The first clause is fine its the Case section that is broken.
Query
SELECT [Request Date], [myItem]
FROM myTable
WHERE [Request Date] < CONVERT(VARCHAR(10), GETDATE(), 102)
AND [Request Date] = CASE WHEN
CONVERT(VARCHAR(10), GETDATE(), 102) <
CONVERT(VARCHAR(12), '3/1/' + DATEPART ( year , GETDATE()) , 114)
THEN [Request Date] > CONVERT(VARCHAR(12), '3/1/' + DATEPART ( year , GETDATE()-365) , 114)
ELSE [Request Date] > CONVERT(VARCHAR(12), '3/1/' + DATEPART ( year , GETDATE() , 114)
END
I have also tried
AND [Request Date] = CASE WHEN
CONVERT(VARCHAR(10), GETDATE(), 102) <
'3/1/' + CONVERT(VARCHAR(12), DATEPART ( YYYY , GETDATE()))
THEN [Request Date] > '3/1/' + CONVERT(VARCHAR(12), DATEPART ( YYYY , GETDATE()-364))
ELSE [Request Date] > '3/1/' + CONVERT(VARCHAR(12), DATEPART ( YYYY , GETDATE()))
END

Answer 1

Try this where clause.
WHERE [Request Date]
BETWEEN Cast(CONVERT(VARCHAR(4), Year(Getdate())-1)+ '-03-01' AS DATE)
AND Getdate() - 1
Here Cast(CONVERT(VARCHAR(4), Year(Getdate())-1)+ '-03-01' AS DATE) will fetch the first day of march month. With that add -1 year to get the starting point.
Getdate() - 1 will define the ending point

Answer 2

I'd prefer to create datetime variables for the #from - #to range but if this is for a view I guess you have to do it in the where clause.
SELECT [Request Date], [myItem]
FROM myTable
WHERE [Request Date] < cast(GETDATE() as date)
AND [Request Date] >= CASE WHEN
GETDATE() < CONVERT(datetime, '3/1/' + cast(Year(GETDATE()) as varchar(4)))
THEN CONVERT(datetime, '3/1/' + cast(Year(GETDATE()) - 1 as varchar(4)))
ELSE CONVERT(datetime, '3/1/' + cast(Year(GETDATE()) as varchar(4)))
END

Answer 3

Something like this? Always from Mar 1st onwards, previous year if it's now Mar 1 or earlier, and otherwise this year.
SELECT [Request Date], [myItem]
FROM myTable
WHERE [Request Date] >= dateadd(month, 2, DATEADD(year, DATEDIFF(year, 0, dateadd(month, -2, dateadd(day, -1, getdate()))), 0))
and [Request Date] < DATEADD(day, DATEDIFF(day, 0, getdate()), 0)
First it deducts one day, so that March 1 isn't taking the same year, then it deducts 2 months for getting those dates for previous year, then it rounds it to the year, and then it adds 2 months to get to Mar 1.

Answer 4

In Oracle, I'd compute the lower bound like this:
add_months( trunc( add_months( sysdate, -2 ), 'YEAR'), 2 )
In other words - subtract two months, round down to the start of the year, then add two months.
Hopefully, you can convert this to use appropriate TSQL functions.

Answer 5

Lets work with some test data:
DECLARE #MyDate DATETIME = '3/13/2015'
Going to declare some variable we will set:
DECLARE #StartDate DATETIME
DECLARE #EndDate DATETIME
In this code, I check to see if we are before or after march 1st, and if so we will use either the previous year, or this year for the starting point (fiscal year?)
SELECT #StartDate = CASE WHEN DATEPART(MONTH, #MyDate) < 3 THEN
DATEADD(MONTH, 2, DATEADD(YEAR, DATEDIFF(YEAR, 0, #MyDate) - 1, 0))
ELSE
DATEADD(MONTH, 2, DATEADD(YEAR, DATEDIFF(YEAR, 0, #MyDate), 0))
END,
#EndDate = DATEADD(DAY, DATEDIFF(DAY, 0, #MyDate), 0)
Here is the output:
SELECT #StartDate AS Start, #EndDate AS EndDate
Start EndDate
2015-03-01 00:00:00.000 2015-03-13 00:00:00.000

Answer 6

I would first create a fairly generic user-defined function that does what I need, thus:
create function dbo.start_of_fiscal_year
(
#today date ,
#fiscal_year_start_month int
)
returns date
as
begin
set #today = case coalesce(#today,'')
when '' then current_timestamp
else #today
end
declare #month_start date = dateadd(day,1-datepart(day,#today),#today)
declare #fiscal_month_number int = case sign( datepart(month,#month_start) - #fiscal_year_start_month )
when -1 then 13
else 1
end
+ ( datepart(month,#month_start) - #fiscal_year_start_month )
declare #fiscal_year_start date = dateadd(month,1-#fiscal_month_number,#month_start)
return #fiscal_year_start
end
go
Once you have that you can say things like
declare #today date = current_timetamp
declare #fy_start date = start_of_fiscal_year(#today,3)
select *
from dbo.foo t
where t.report_date >= #fy_start
and t.report_date < #today
or even
select fiscal_year = datepart(year,start_of_fiscal_year(t.report_date,3)) , count(*)
from dbo.foo t
group by datepart(year,start_of_fiscal_year(t.report_date,3))

Answer 7

Your lower bound should be this. You just need to offset the year when month is less than 3 (March).
dateadd(
yy,
year(current_timestamp) - 1900 + case when month(current_timestamp) < 3 then -1 else 0 end,
'19000301'
)
There's no reason to mess around with strings and this consolidates the logic very concisely. I'm also guessing that when current date is March 1 that you want to query the full previous year. So you'll want to adjust the test slightly.
case when (month(dateadd(dd, -1, current_timestamp)) < 3 ...
And just for fun:
dateadd(mm, (12-month(current_timestamp-1))/10*-12+2, cast(year(current_timestamp) as char(4)));