Double-clicking the field list creates the event for the row change.
In those event handlers, code is added to validate the proposed values: Private Sub Employee Data Table_Birth Date Changing( _ By Val sender As Employee Data Table, _ By Val e As Birth Date Change Event Arg) Handles Me.
Nor can they guarantee that any data files used by the program will be free of errors and in the correct format.
There are however measures that can be taken to restrict the program's input to valid data.
The Data Grid View class provides a convenient way to perform validation before data is committed to the data store.
This sample code is intended to illustrate a concept, and it shows only the code that is relevant to that concept.
It may not meet the security requirements for a specific environment, and it should not be used exactly as shown.
The precise definition of the validation rules will of course vary from one application to the next, and particularly on the type of data that is being input to the program.
Database management systems such as Oracle or Microsoft Access invariably provide extensive facilities for creating data validation rules.