Write an OnUpdateData event to handle special processing before the dataset begins applying updates. OnUpdateData occurs after the client dataset has packaged all updates in the change log and passed them to the internal provider, but before that internal provider has started applying updates. 

Using the methods belonging to the DataSet parameter, an application can  

Examine data (for example, for values or data changes that should not permitted), and raise exceptions that cancel applying of updates before they occur. 

Change data (for example encrypting or decrypting values) before it is sent on to the database server. 

ApplyUpdates 

BeforeUpdateRecord 

Provider