BeginTrans, CommitTrans, and RollbackTrans Methods (ADO)
These transaction methods manage transaction processing within a Connection object as follows:
BeginTrans Begins a new transaction.
CommitTrans Saves any changes and ends the current transaction. It may also start a new transaction.
RollbackTrans Cancels any changes made during the current transaction and ends the transaction. It may also start a new transaction.
BeginTrans can be called as a function that returns a Long variable indicating the nesting level of the transaction.
A Connection object.
Use these methods with a Connection object when you want to save or cancel a series of changes made to the source data as a single unit. For example, to transfer money between accounts, you subtract an amount from one and add the same amount to the other. If either update fails, the accounts no longer balance. Making these changes within an open transaction ensures that either all or none of the changes go through.
Not all providers support transactions. Verify that the provider-defined property "Transaction DDL" appears in the Connection object's Properties collection, indicating that the provider supports transactions. If the provider does not support transactions, calling one of these methods will return an error.
After you call the BeginTrans method, the provider will no longer instantaneously commit changes you make until you call CommitTrans or RollbackTrans to end the transaction.
For providers that support nested transactions, calling the BeginTrans method within an open transaction starts a new, nested transaction. The return value indicates the level of nesting: a return value of "1" indicates you have opened a top-level transaction (that is, the transaction is not nested within another transaction), "2" indicates that you have opened a second-level transaction (a transaction nested within a top-level transaction), and so forth. Calling CommitTrans or RollbackTrans affects only the most recently opened transaction; you must close or roll back the current transaction before you can resolve any higher-level transactions.
Calling the CommitTrans method saves changes made within an open transaction on the connection and ends the transaction. Calling the RollbackTrans method reverses any changes made within an open transaction and ends the transaction. Calling either method when there is no open transaction generates an error.
Depending on the Connection object's Attributes property, calling either the CommitTrans or RollbackTrans methods may automatically start a new transaction. If the Attributes property is set to adXactCommitRetaining, the provider automatically starts a new transaction after a CommitTrans call. If the Attributes property is set to adXactAbortRetaining, the provider automatically starts a new transaction after a RollbackTrans call.
The BeginTrans, CommitTrans, and RollbackTrans methods are not available on a client-side Connection object.