Select empty weeks in SQL - sql

Question

I am grouping by weeks using DATEPART in SQL. However, I want to include the empty weeks also, not only weeks that include values. I have a script that works perfectly collecting data by weeks, but not the empty weeks. I´ve been trying to use left outer join but my SQL skills are not all that great. I decided to ask you guys.
Here is my script:
select
DatePart(Year, MYTABLE.CREATION_DATE) as DateYear,
DatePart(Month, MYTABLE.CREATION_DATE) as DateMonth,
DatePart(Week, MYTABLE.CREATION_DATE) as DateWeek,
sum(cast(MYTABLE.BASE_TRANSACTION_VALUE as int)) as Value,
min(MYTABLE.CREATION_DATE) as DateT
from MYTABLE
where MYTABLE.SEGMENT2 like '00601'
and MYTABLE.SEGMENT4 like '%'
and MYTABLE.CREATION_DATE > '2012-12-30 12:00:00'
and MYTABLE.CREATION_DATE < '2013-12-30 11:00:00'
group by
DatePart(Year, MYTABLE.CREATION_DATE),
DatePart(Month, MYTABLE.CREATION_DATE),
DatePart(Week, MYTABLE.CREATION_DATE)
order by DateYear, DateMonth, DateWeek
And this is the result of that script.
Could you guys possibly give me an example of a join clause could look like in this case?

Answer 1

[updated 2014-01-09 08:06 UTC]
you can create the dates dynamically (DateRange) and the outer-join them to your select like this:
declare #startdate date;
set #startdate = '2012-12-30';
declare #enddate date;
set #enddate = '2013-12-30'
;with DateRange AS
(
SELECT
DatePart(Year, #startdate) as DateYear,
DatePart(Month, #startdate) as DateMonth,
DatePart(iso_Week, #startdate) as DateWeek,
#startdate as DateValue
UNION ALL
SELECT
DatePart(Year, dateadd(dd,7,DateValue)) as DateYear,
DatePart(Month, dateadd(dd,7,DateValue)) as DateMonth,
DatePart(iso_Week, dateadd(dd,7,DateValue)) as DateWeek,
dateadd(dd,7,DateValue)
FROM DateRange
WHERE dateadd(dd,7,DateValue) <= #enddate
), data as (
select
DatePart(Year, MYTABLE.CREATION_DATE) as DateYear,
DatePart(Month, MYTABLE.CREATION_DATE) as DateMonth,
DatePart(iso_Week, MYTABLE.CREATION_DATE) as DateWeek,
sum(cast(MYTABLE.BASE_TRANSACTION_VALUE as int)) as Value,
min(MYTABLE.CREATION_DATE) as DateT
from MYTABLE
where MYTABLE.SEGMENT2 like '00601'
and MYTABLE.SEGMENT4 like '%'
and MYTABLE.CREATION_DATE > '2012-12-30 12:00:00'
and MYTABLE.CREATION_DATE < '2013-12-30 11:00:00'
group by
DatePart(Year, MYTABLE.CREATION_DATE),
DatePart(Month, MYTABLE.CREATION_DATE),
DatePart(iso_Week, MYTABLE.CREATION_DATE)
)
select
DateRange.DateYear,
DateRange.DateMonth,
DateRange.DateWeek,
data.Value,
data.DateT
from data
right outer join
DateRange
on
data.DateYear = DateRange.DateYear
and data.DateWeek = DateRange.DateWeek
order by
DateRange.DateYear,
DateRange.DateMonth,
DateRange.DateWeek

Answer 2

This should do it. My SQLFiddle is http://www.sqlfiddle.com/#!6/b777f/1/0
declare #WeekTable table(
[WeekDate] datetime
)
declare #startDate datetime,
#EndDate datetime
select #startDate = '1/1/2013',#EndDate = '12/31/2013'
while #startDate<=#EndDate begin
insert into #WeekTable values(#startDate)
set #startDate = #startDate+7
end
select
DatePart(Year, [WeekDate]) as DateYear,
DatePart(Month, [WeekDate]) as DateMonth,
DatePart(Week, [WeekDate]) as DateWeek,
sum(cast(MYTABLE.BASE_TRANSACTION_VALUE as int)) as Value,
min(isnull(MYTABLE.CREATION_DATE,[WeekDate])) as DateT
from
#WeekTable
left outer join
MYTABLE
on
DatePart(Week,MYTABLE.CREATION_DATE) =DatePart(Week, [WeekDate])
and
DatePart(Year,MYTABLE.CREATION_DATE) =DatePart(Year, [WeekDate])
and
MYTABLE.SEGMENT2 like '00601'
and
MYTABLE.SEGMENT4 like '%'
group by
DatePart(Year, [WeekDate]) ,
DatePart(Month, [WeekDate]),
DatePart(Week, [WeekDate])
order by
DateYear, DateMonth, DateWeek