sql query group by date range - sql

Question

I have table with below data -
StartDate EndDate Amount
2/1/2016 4/30/2016 2.265
2/1/2016 12/31/2099 16.195
5/1/2016 12/31/2099 37.75
I am trying to write a query to sum the amount on date range and give me below result
StartDate EndDate Amount
2/1/2016 4/30/2016 18.46
5/1/2016 12/31/2099 53.945
The result needs to be distinct date range with amount summed for that date range. As in above example, row 2 has dates that overlap row 1 and 3. So the row 2 amount needs to be added in row 1 and row 3.
I am writing this query on sql server 2012, Please advise on what approach I should take.
Below is query to generate sample data
SELECT * INTO #tmp_GridResults_1
FROM (
SELECT N'2016-02-01 00:00:00.000' AS [StartDate], N'2016-04-30 00:00:00.000' AS [EndDate], N'2.265' AS [Amount] UNION ALL
SELECT N'2016-02-01 00:00:00.000' AS [StartDate], N'2099-12-31 00:00:00.000' AS [EndDate], N'16.195' AS [Amount] UNION ALL
SELECT N'2016-05-01 00:00:00.000' AS [StartDate], N'2099-12-31 00:00:00.000' AS [EndDate], N'37.75' AS [Amount] ) t;
SELECT [StartDate], [EndDate], [Amount]
FROM #tmp_GridResults_1

Answer 1

I don't think you'll be able to group with both StartDate and EndDate. However, if you use just StartDate and Amount you can try this:
select StartDate,sum(Amount) as Amount from #tmp_GridResults_1 group by StartDate
This will give you the grouping of Amount by StartDate.

Answer 2

From my previews comment i think you want to group by StartDate, in that case you can use:
SELECT
mt.StartDate,
SUM(Amount) AS 'Amount'
FROM MyTable mt
WHERE mt.StartDate BETWEEN
'2016-05-18 00:00:00.000' AND '2016-06-20 00:00:00.000' --your date range
GROUP BY StartDate
However you need to specify in your question how you want to group them, because with 2 date fields you can group the following ways:
GROUP BY StartDate --groups records that have the same StartDate
GROUP BY EndDate --groups records that have the same EndDate
GROUP BY StartDate, EndDate --groups records that have same StartDate and EndDate
Also with 2 date fields your date range can vary a lot.
WHERE StartDate BETWEEN #sd AND #ed --will get records whose start date is inside the provided range
WHERE EndDate BETWEEN #sd AND #ed --will get records whose end date is inside the provided range
WHERE StartDate >= #sd AND EndDate <= #ed -- will get records that started and ended inside the provided date range
WHERE StartDate BETWEEN #sd AND #ed OR EndDate BETWEEN #sd AND #ed
--this last one will get records whose StartDate or EndDate are inside the provided date range
based on this you can build the query that you need, but with the provided data in your question its still ambiguous what you want to achieve, you need to be more specific and provide more data in order to produce an exact answer to your question.
One more thing to add is that if you take into account time it will not group them if the date is the same but time is different i.e.
'2016-05-18 00:00:00.000'
'2016-05-18 01:01:01.001'
--these dates will not be grouped

Answer 3

Below query will give the required result :-
select StartDate,EndDate,SUM(Amount) over (partition by StartDate) AS Amount into #t1
from table_name
select StartDate,EndDate,SUM(Amount) over (partition by EndDate) AS Amount into #t2
from table_name
select * from (
select distinct P.StartDate,P.EndDate,P.Amount from (
select StartDate,MIN(EndDate) EndDate,Amount from #t1
group by StartDate,Amount) P
JOIN (
select MIN(StartDate) StartDate,EndDate,Amount from #t2
group by EndDate,Amount) Q on P.StartDate=Q.StartDate OR P.EndDate=Q.EndDate
where P.Amount>=Q.Amount
UNION
select distinct P.StartDate,P.EndDate,P.Amount from (
select MIN(StartDate) StartDate,EndDate,Amount from #t2
group by EndDate,Amount) P
JOIN (
select StartDate,MIN(EndDate) EndDate,Amount from #t1
group by StartDate,Amount) Q on P.StartDate=Q.StartDate OR P.EndDate=Q.EndDate
where P.Amount>=Q.Amount
) A
Just Replace table_name by the table for which you want result, Let me know in case of any confusion