Call StartTransaction to begin a new transaction against the database server. Before calling StartTransaction, an application should check the status of the InTransaction property. If InTransaction is true, indicating that a transaction is already in progress, a subsequent call to StartTransaction without first calling Commit or Rollback to end the current transaction raises an exception. 

Updates, insertions, and deletions that take place after a call to StartTransaction are held by the server until an application calls Commit to save the changes or Rollback is to cancel them.