I'm currently doing a report that does a T ledger. It needs to do a running balance from a known start point. I'm trying to migrate the logic for this into SQL as much as possible and querying a running balances is something I haven't figured out...

      Credit  Debit  Balance 
start     --     --   100.00
row1   10.00          110.00
row2           20.00   90.00
row3   10.00          100.00
As can be seen, the balance of each row id dependent on the contents of the row that preceded it. This information is NOT precalculated at insert time nor can it be since the ledger needs to reflect changes brought by query filters that determine which rows show up. So, can this be done in SQL alone?