Beginning Access™ 2007 VBA

12.1. Multiuser Considerations

Various coding approaches can affect how well your application will handle multiple users. For example, the type of record lock that is used on records retrieved from the database will affect what happens when multiple users try to access the same record. When the application does not handle the scenario correctly, update conflicts can occur because one user overwrites the changes made by another user. If your application uses the proper type of record lock and handles update conflicts, it will be more capable of supporting multiple users. Another way to help your application better handle multiple users is to separate the data tables from the other objects by using two separate Access database files. Both of these techniques are discussed in the sections that follow.

12.1.1. Record Locking and Update Conflicts

Prior to reading this book, you likely worked with bound forms in your Access applications. Bound forms are connected directly to a table and keep an open connection to the database so all changes are made at that moment. Then, in Chapter 5, you learned how to populate an ADO recordset with data from a database and how to display records from the recordset on both bound and unbound forms.

Let's now look at how record locking is handled on bound and unbound forms and the ways you can modify record-locking settings to better handle multiple users.

12.1.1.1. Record Locking on Bound Forms

The type of record locking that is used for bound forms ...