|Oracle® Objects for OLE Developer's Guide
11g Release 2 (11.2) for Microsoft Windows
|PDF · Mobi · ePub|
When this method is invoked, all
OraDynaset objects that share the specified session or connection are given the opportunity to cancel the rollback request. If they do not cancel the request, they are advised when the rollback succeeds.
This feature is useful primarily for dynasets that are created as part of an Oracle Data Control operation. For these dynasets, the
Validate event is sent to allow them to cancel the rollback request.
Rollback method rolls back all pending transactions within the specified connection. This method has no effect if a transaction has not begun. When a session-wide transaction is in progress, you can use this call to prematurely roll back the transactions for the specified connection.
Rollback method rolls back all pending transactions within the specified session. The
Rollback method is valid only when a transaction has been started. If a transaction has not been started, the use of the
Rollback method results in an error.
OraDatabaseobject has been enlisted with Microsoft Transaction Server (MTS) and is part of a global MTS transaction, this method has no effect.
This example demonstrates the use of the
Rollback methods to group a set of dynaset edits into a single transaction. Copy and paste this code into the definition section of a form. Then, press F5.
Sub Form_Load () 'Declare variables Dim OraSession As OraSession Dim OraDatabase As OraDatabase Dim OraDynaset As OraDynaset 'Create the OraSession Object. Set OraSession = CreateObject("OracleInProcServer.XOraSession") 'Create the OraDatabase Object by opening a connection to Oracle. Set OraDatabase = OraSession.OpenDatabase("ExampleDb", "scott/tiger", 0&) 'Create the OraDynaset Object. Set OraDynaset = OraDatabase.CreateDynaset("select * from emp", 0&) 'Start Transaction processing. OraDynaset.Session.BeginTrans 'Traverse until EOF is reached, setting each employee's salary to zero. Do Until OraDynaset.EOF OraDynaset.Edit OraDynaset.Fields("sal").value = 0 OraDynaset.Update OraDynaset.MoveNext Loop MsgBox "All salaries set to ZERO." 'Currently, the changes have NOT been committed to the database. 'End Transaction processing. OraDynaset.Session.Rollback MsgBox "Salary changes rolled back." End Sub