Get data with condition - sql

Question

declare #t table (
Id int ,
Section int,
Moment date
);
insert into #t values
( 1 , 1 , '2014-01-01'),
( 2 , 1 , '2014-01-02'),
( 3 , 1 , '2014-01-03'),
( 4 , 1 , '2014-01-04'),
( 5 , 1 , '2014-01-05'),
( 6 , 2 , '2014-02-06'),
( 7 , 2 , '2014-02-07'),
( 8 , 2 , '2014-02-08'),
( 9 , 2 , '2014-02-09'),
( 10 , 2 , '2014-02-10'),
( 11 , 3 , '2014-03-11'),
( 12 , 3 , '2014-03-12'),
( 13 , 3 , '2014-03-13'),
( 14 , 3 , '2014-03-14'),
( 15 , 3 , '2014-03-15');
getting data like this
select * from #t
Id Section Moment
1 1 2014-01-01
2 1 2014-01-02
3 1 2014-01-03
4 1 2014-01-04
5 1 2014-01-05
6 2 2014-02-06
7 2 2014-02-07
8 2 2014-02-08
9 2 2014-02-09
10 2 2014-02-10
11 3 2014-03-11
12 3 2014-03-12
13 3 2014-03-13
14 3 2014-03-14
15 3 2014-03-15
But i want data like this.group by 3 and Section wise
if ant Section have 5 rows there will create 2 group.
Id Section Moment Group by 3
1 1 1/1/2014 1
2 1 1/2/2014 1
3 1 1/3/2014 1
4 1 1/4/2014 2
5 1 1/5/2014 2
6 2 2/6/2014 3
7 2 2/7/2014 3
8 2 2/8/2014 3
9 2 2/9/2014 4
10 2 2/10/2014 4
11 3 3/11/2014 5
12 3 3/12/2014 5
13 3 3/13/2014 5
14 3 3/14/2014 6
15 3 3/15/2014 6

Answer 1

You can use window functions and arithmetic. The following enumerates within each section:
select (row_number() over (partition by section order by moment) + 2) / 3, t.*
from #t;
Then applying dense_rank() gets what you want:
select dense_rank() over (order by section, tempcol) as group3,
t.*
from (select (row_number() over (partition by section order by moment) + 2) / 3 as tempcol, t.*
from t
) t
order by id
Here is a db<>fiddle.

Answer 2

There might be mistake in interpretion but till where acknowledge the problem i beleive u are looking for this.I have done it using cursor .Hope it helps u .
DECLARE #i int =0 -- row count
DECLARE #GroupCount int=1
DECLARE #Id int
DECLARE #Section int
DECLARE #Moment DateTime
declare #temp table (
SNO int,
Id int ,
Section int,
Moment date,
GroupedIn nvarchar(200)
);
DECLARE db_cursor CURSOR FOR
SELECT Id,Section,Moment
FROM #t
WHERE Section = 3 --suppose
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO #Id,#Section,#Moment
WHILE ##FETCH_STATUS = 0
BEGIN
Set #i=#i+1
Insert into #temp values(#i,#Id,#Section,#Moment,'G'+CONVERT(nvarchar(20),#GroupCount))
FETCH NEXT FROM db_cursor INTO #Id,#Section,#Moment
END
CLOSE db_cursor
DEALLOCATE db_cursor
Select * from #temp