Get datetime difference group by query results in one row - sql

Question

I have a table Master_History with structure as
Id_History Created_Date Subscription_Type rn
21 1/22/2016 16:31:29 1 1
22 1/22/2016 16:33:11 2 2
23 1/22/2016 16:33:37 1 3
24 1/22/2016 16:33:46 2 4
25 1/22/2016 16:33:53 1 5
26 1/22/2016 16:33:57 3 6
27 1/22/2016 16:34:01 2 7
28 1/22/2016 16:34:04 1 8
29 1/22/2016 16:34:08 3 9
I want to calculate date difference with adjacent rows which i have succeeded in calculating but results are getting distributed over multiple rows
Standard Plus Premium
122 NULL NULL
NULL 35 NULL
NULL NULL 3
I need
Results in one row like
Standard Plus Premium
122 35 3
For the last row (in this Subscription_Type is 3, the date difference should also get calculated on getdate() i.e. whenever i executed my query, seconds in Premium column should get reflected each time
Query :
WITH CTE
AS (
SELECT *
,ROW_NUMBER() OVER (
ORDER BY Created_Date
) AS rn
FROM Master_History
WHERE Client_ID = 11072
)
SELECT CASE
WHEN mc.Subscription_Type = 1
THEN Sum(DATEDIFF(second, mc.Created_Date, mp.Created_Date))
END AS [Standard]
,CASE
WHEN mc.Subscription_Type = 2
THEN Sum(DATEDIFF(second, mc.Created_Date, mp.Created_Date))
END AS Plus
,CASE
WHEN mc.Subscription_Type = 3
THEN Sum(DATEDIFF(second, mc.Created_Date, mp.Created_Date))
END AS Premium
FROM CTE mc
JOIN CTE mp ON mc.rn = mp.rn - 1
GROUP BY mc.Subscription_Type

Answer 1

try this
select
count(Standard.*) Standard_,
count(Plus.*) Plus_,
count(Premium.*) Premium_
from
Master_History master_
left outer join Master_History Standard on Standard.Subscription_Type = 1
and master_.Subscription_Type = Standard.Subscription_Type
left outer join Master_History Plus on Plus.Subscription_Type = 2
and master_.Subscription_Type = Plus.Subscription_Type
left outer join Master_History Premium on Premium.Subscription_Type = 3
and master_.Subscription_Type = Plus.Subscription_Type
where
convert(date,master_.Created_Date) < convert(date,getdate()) and
convert(date,master_.Created_Date) < convert(date,Standard.Created_Date) and
convert(date,master_.Created_Date) < convert(date,Plus.Created_Date) and
convert(date,master_.Created_Date) < convert(date,Premium.Created_Date)