[quote]Nesting does work with transactions. It's just that if you use rollback transaction, then all open transactions are rolled back. If you commit a transaction, then only the innermost transaction is committed.
No, you can't commit an inner transaction - what happens when you issue a commit command is that the transaction count gets decremented, and if the result is zero, the transaction (which is the outermost transaction) is committed (and the data modifications affected by this commit include all made by any so-called nested transactions); if the result is non-zero, nothing is committed. Neither can you roll back a nested transaction - you can only roll back the whole nest (including the outermost transaction).