การ Sum ค่า Amount ปัจจุบันโดยเอาค่า Amount ก่อนหน้ามาคิดด้วย

Declare @LastAmt money
Declare @Date datetime

Declare @Document_Date docdate
Declare @GRN money
Declare @DN money
Declare @Balance money
Declare @Present_Amt money       

Set @Date = '2014-10-01'
Select @LastAmt = Sum(Amt) From TableName where Data < @Date

Declare Cur_1 Cursor For
Select Document_Date, GRN, DN, Balance 
   From TableName
Where Date Between '2014-10-01' And '2014-10-30' 
Order By Document_Date ASC

Set @Present_Amt = @LastAmt

Open Cur_1
Fetch Next From Cur_1 Into @Document_Date, @GRN, @DN, @Balance
WHILE (@@Fetch_Status =0) 
   Begin
    
     Select * INTO #TempTable
        From (Select @Document_Date as Date, @GRN as GRN, @DN as DN
                     ,  @Present_Amt + (@GRN-@DN) as NewBalance
                  )GRNTable
  
     Set @Present_Amt = @Present_Amt + (@GRN-@DN)
   
Fetch Next From Cur_1 Into @Document_Date, @GRN, @DN, @Balance
   End
Close Cur_1
Deallocate Cur_1

Select * from #TempTable

Drop Table #TempTable