The previous chapter identified some issues to consider when you implement disconnected data applications. The primary focus was on index selection and resolving concurrency conflicts, and the chapter concluded with the implementation of a concurrency conflict resolution screen in a simple application for viewing and modifying customer names.
This chapter expands on the disconnected data application by examining some issues you should address when you work with multiple related DataTable objects. First we review relationships and constraints, and then we dig deeply into the issues involved with updating the data. This is where you will see the need for a Data Access Layer (DAL) in your applications for performing updates.