How to display multiple rows based row difference data In SQL? - sql

Question

I have a table as follows:
EmpID FromYM ToYM EmpYl EmpX1
----- ------ ----- ------ ----------
1001 202101 202101 20210103 20210103
1001 202102 202103 20210103 20210103
I want to split this data based on above data.
If FromYm(Means yearmonth) and ToYM(Means yearmonth) difference is two then result as two rows:
Example result :
EmpID FromYM ToYM EmpYl DiffNoCount
------ ------ ---- ----- ------
1001 202101 202101 20210103 1
1001 202102 202103 20210103 1
1001 202102 202103 20210103 2
Tried Code
IF OBJECT_ID(N'tempdb..#rawdata1') IS NOT NULL
BEGIN
DROP TABLE #rawdata1
END
IF OBJECT_ID(N'tempdb..#rawdata2') IS NOT NULL
BEGIN
DROP TABLE #rawdata2
END
go
declare #Max as int
declare #Kount as int
Set #Kount = 1
SELECT row_number() Over (order by EmpID) as row,EmpID
,FromYM
,ToYM
, EmpYl
,EmpX1
into #rawdata1
FROM [dbo].[ASAAValue1]
order by EmpID
set #Max = (Select Max(FromYM) from #rawdata1)
Create Table #Rawdata2
(
[Row] int,
Rolling int,
RollingAvg decimal(15,2),
RollingFinal int
)
while (#kount < #max)
Begin
Insert into #rawdata2
select #Kount as Row , FromYM as Rolling
, ToYM as RollingAvg,
Case When Convert(int,Convert(nvarchar(6),EmpYl))>=FromYM
Then <br>
FromYM <br>
Else<br>
FromYM+1 <br>
End <br>
from #rawdata1<br>
where row between #Kount - 12 and #Kount <br>
set #Kount = #Kount + 1
end
select rd1.row,
rd1.EmpID,Rd1.FromYM,Rd1.ToYM,Rd1.EmpYl, rd2.RollingFinal as Final from #rawdata2 rd2
inner join #rawdata1 rd1
on rd1.row = rd2.row

Answer 1

You can do it using recursive cte:
with data as (
select '202101' as f, '202101' as t union all
select '202102' as f, '202103' as t
),
rcte as (
select *, 1 as n from data
union all
select f, t, n + 1
from rcte
where n <= datediff(month, convert(date, f + '01', 112), convert(date, t + '01', 112))
)
select * from rcte
You can test on this db<>fiddle