Progressive Sums in T-SQL

--Create the table
CREATE TABLE [dbo].[Table1] (
[ID] [numeric](18, 0) NOT NULL ,
[TheDate] [smalldatetime] NULL ,
[Credit] [float] NULL ,
[Debit] [float] NULL 
) ON [PRIMARY]
GO


-- The sql statement produces an output for every diff ID:
SELECT     t1.ID, t1.Credit, t1.Debit, SUM(t2.Credit - t2.Debit) AS Result
FROM         Table1 t1 INNER JOIN
                      Table1 t2 ON t1.ID >= t2.ID
GROUP BY t1.ID, t1.Credit, t1.Debit
ORDER BY t1.ID

--A more complex situation arises, when we want the same
--result set (as above) but for every day('theDate')column.
--In In this case we have to use two segments in 
--the join: TheDate & ID.
SELECT     t1.TheDate, t1.ID, t1.Credit, t1.Debit, SUM(t2.Credit - t2.Debit) AS Result
FROM         Table1 t1 CROSS JOIN
                      Table1 t2
WHERE     (t1.TheDate > t2.TheDate) OR
                      (t1.TheDate = t2.TheDate) AND (t1.ID >= t2.ID)
GROUP BY t1.TheDate, t1.ID, t1.Credit, t1.Debit
ORDER BY t1.TheDate, t1.ID