Date difference query

Question

I have a below table
student_id        course   startdate          enddate       amount
1                      .net         12-05-2014     30-7-2014     5000
1                      sql            1-06-2014      30-06-2014   
3000
2                     informtica   1-06-2014       31-07-2014   10000.
so on
output sholud be the amount has to split accross months
student_id        course   startdate          enddate       amount   month split_amount
1                      .net         12-05-2014     30-7-2014     5000    
may       1250
1                     .net          12-05-2014     30-7-2014     
5000   june        1875
1                    .net            12-05-2014     30-7-2014     5000
  july          1875
1                      sql            1-06-2014      30-06-2014   
3000   june         3000
2                     informtica   1-06-2014       31-07-2014   10000 june      
4918
2                    informatica 1-06-2014       31-07-2014    10000  july       
5082
please suggest me any query..

Answer 1

Hi,
i think this may help you,
first i created the temp table (you can replace it with your data table)
Declare @t Table (student_id Int,course Varchar(100),startdate DateTime,enddate DateTime,amount Decimal(12,0))
Insert Into @t
Select 1,'.net','2014-05-12','2014-07-30',5000
Union
Select 1,'sql','2014-06-01','2014-06-30',3000
Union
Select 2,'informtica','2014-06-01','2014-07-31',10000
;with cte As (
Select t.*,cd.LatinMonthTitle,t.amount/Count(cd.id) Over(Partition By student_id,course) As AmountPerDay,cd.LatinMonthId--*Count(cd.id)
From @t As t
Inner Join @DateIndex As cd On cd.LatinDate Between t.StartDate And t.EndDate)
Select student_id,course,startdate,enddate,amount,LatinMonthTitle,Cast(Count(1)*AmountPerDay As Decimal(12,0)) As AmountPerMonth
From cte
Group By student_id,course,startdate,enddate,amount,LatinMonthTitle,AmountPerDay,LatinMonthId
Order By 1,2,LatinMonthId
You need to know about my @DateIndex Table!
you should build this table and it's useful many time.
declare @dateindex table(Id Int Identity(1,1),LatinDate DateTime,LatinMonthId Int,LatinMonthTitle Varchar(100))
declare @i int=0
declare @FirstDate datetime='2014-01-01'
declare @CurrDate datetime=@FirstDate
while @i<1000
begin
Set @CurrDate=DATEADD(day,@i,@FirstDate)
insert into @dateindex
(LatinDate,LatinMonthId,LatinMonthTitle)
Select @CurrDate,DATEPART(MONTH,@CurrDate),DATENAME(MONTH,@CurrDate)
set @i+=1
end
Select * From @dateindex