BeginTrans Method

Applies To

Description

Begins a database transaction within the specified session.

Usage

oraconnection.BeginTrans
oradatabase.BeginTrans
orasession.BeginTrans

Remarks

After this method has been called, no database transactions are committed until a CommitTrans is issued. Alternatively, the session can be rolled back using the Rollback method. If a transaction has already been started, repeated use of the BeginTrans method causes an error.

If Update or Delete methods fail on a given row in a dynaset in a global transaction after you issue a BeginTrans, be aware that locks remain on those rows on which you called the Update or Delete method. These locks persist until you call a CommitTrans or Rollback method.

Note:

If an OraDatabase object has been enlisted with Microsoft Transaction Server (MTS) and is part of a global MTS transaction, this method has no effect.

Examples

This example demonstrates the use of the BeginTrans method to group a set of dynaset edits into a single transaction and uses the Rollback method to cancel those changes. Copy 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 
 Dim fld As OraField
 
 '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.
 OraSession.BeginTrans
 
 'Setup a field object to save object references.
 Set fld = OraDynaset.Fields("sal")
 
 'Traverse until EOF is reached, setting each employees salary to zero
 Do Until OraDynaset.EOF = True
   OraDynaset.Edit
   fld.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. Using RollbackTrans 
 'means the rollback can be canceled in the Validate event.
 OraSession.Rollback
 'MsgBox "Salary changes rolled back."
 
End Sub