(no version information, might be only in CVS)
PDO::rollBack -- 
     Rolls back a transaction
    
Description
bool 
PDO::rollBack ( void  )
     Rolls back the current transaction, as initiated by
     PDO::beginTransaction().  It is an error to call this
     method if no transaction is active.
    
     If the database was set to autocommit mode, this function will restore
     autocommit mode after it has rolled back the transaction.
    
     Some databases, including MySQL, automatically issue an implicit
     COMMIT when a database definition language (DDL) statement such as
     DROP TABLE or CREATE TABLE is issued within a transaction. The implicit
     COMMIT will prevent you from rolling back any other changes within the
     transaction boundary.