SQL - Split Row into multiple based on month - sql-server

Question

I have data in a row as below in SQL (2012) table
ID Value StartDate EndDate
123 5000 14/04/2017 15/12/2017
I would like to Split the row into each individual month as below:
ID Value StartDate EndDate
123 5000 14/04/2017 30/04/2017
123 5000 01/05/2017 31/05/2017
123 5000 01/06/2017 30/06/2017
123 5000 01/07/2017 31/07/2017
123 5000 01/08/2017 30/08/2017
123 5000 01/09/2017 31/09/2017
123 5000 01/10/2017 31/10/2017
123 5000 01/11/2017 30/11/2017
123 5000 01/12/2017 15/12/2017
Appreciate help in this matter.

Answer 1

You can do it like this:
WITH tally
AS (SELECT TOP (1000)
ROW_NUMBER() OVER (ORDER BY t1.object_id) AS N
FROM master.sys.all_columns t1
CROSS JOIN master.sys.all_columns t2),
rowset
AS (SELECT ID,
Value,
DATEADD(m, N - 1, StartDate) AS StartDate,
Enddate,
N
FROM tally, MyDates
WHERE DATEFROMPARTS(YEAR(DATEADD(m, N - 1, StartDate)),
MONTH(DATEADD(m, N - 1, StartDate)), 1) <= EndDate)
SELECT Id,
Value,
CASE
WHEN N = 1 THEN
StartDate
ELSE
DATEFROMPARTS(YEAR(StartDate), MONTH(StartDate), 1)
END AS StartDate,
CASE
WHEN DATEADD(d, -DAY(DATEADD(m, 1, StartDate)), DATEADD(m, 1, StartDate)) <= EndDate THEN
DATEADD(d, -DAY(DATEADD(m, 1, StartDate)), DATEADD(m, 1, StartDate))
ELSE
Enddate
END AS EndDate
FROM rowset
ORDER BY ID, StartDate;

Answer 2

Use below query to get the result
DECLARE #Temp TABLE
(
ID INT
,Value NUMERIC(10,2)
,StartDate DATE
,EndDate DATE
)
DECLARE #NewTable TABLE
(
id INT IDENTITY(1,1)
,item INT
,Value NUMERIC(10,2)
,StartDate DATE
,EndDate DATE
)
INSERT INTO #Temp
SELECT 123,5000 ,'2017-04-14','2018-12-15'
DECLARE #SDate date
DECLARE #EDate date
declare #LastDay INT =0
SELECT top 1 #SDate=StartDate,#EDate=EndDate FROM #Temp
declare #Year int = 0
declare #Month int = 0
declare #Index INT =1
DECLARE #Lenght int =DATEDIFF(MONTH,#SDate,#EDate) +1
WHILE #Index<=#Lenght
BEGIN
IF #Index=1 BEGIN
-- first record
SELECT #Year= YEAR(#SDate)
SELECT #Month = MONTH(#SDate)
-- get last day of the date
SELECT #LastDay = day(DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,#SDate)+1,0)))
SELECT #EDate= CONVERT(VARCHAR(10),#Year)+'-'+CONVERT(VARCHAR(10),#Month)+'-
'+CONVERT(VARCHAR(10),#LastDay)
INSERT INTO #NewTable
SELECT 123,5000,#SDate, #EDate
END ELSE IF #Index = #Lenght BEGIN
SELECT #Month = #Month+1
IF #Month>12 BEGIN
SELECT #Month =1
SELECT #Year =#Year +1
END ELSE BEGIN
SELECT #Year= YEAR(#EDate)
END
SELECT #SDate =CONVERT(VARCHAR(10),#Year)+'-'+CONVERT(VARCHAR(10),#Month)+ '-01'
INSERT INTO #NewTable
SELECT 123,5000 ,#SDate,#EDate
END ELSE BEGIN
SELECT #Month = #Month+1
if #Month>12 BEGIN
SELECT #Month =1
SELECT #Year =#Year +1
END
SELECT #SDate =CONVERT(VARCHAR(10),#Year)+'-'+CONVERT(VARCHAR(10),#Month)+ '-01'
SELECT #LastDay = day(DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,#SDate)+1,0)))
SELECT #EDate= CONVERT(VARCHAR(10),#Year)+'-'+CONVERT(VARCHAR(10),#Month)+'-'+CONVERT(VARCHAR(10),#LastDay)
INSERT INTO #NewTable
SELECT 123,5000 ,#SDate,#EDate
END
SELECT #Index=#Index+1
end
SELECT * from #NewTable
--select day(DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,getdate())+1,0)))