CRecordset::SetLockingMode
Visual Studio 2012
Sets the locking mode to "optimistic" locking (the default) or "pessimistic" locking. Determines how records are locked for updates.
void SetLockingMode( UINT nMode );
Call this member function if you need to specify which of two record-locking strategies the recordset is using for updates. By default, the locking mode of a recordset is optimistic. You can change that to a more cautious pessimistic locking strategy. Call SetLockingMode after you construct and open the recordset object but before you call Edit.