Day 4. DataSet Internals

As you'll recall, yesterday's goal was to familiarize you with the various ways that you can manipulate DataSet objects when dealing with disconnected data. Today you'll dig deeper into the structure of the DataSet in order to fully exploit its capabilities to maintain data consistency and integrity. In fact, the three key topics in this chapter explore the three children of the DataSet class: Tables, Relations, and ExtendedProperties exposed as properties as shown in Figure 3.1. Much of the functionality of the DataSet is encapsulated in the objects of these three children.

Specifically, today you'll learn the following concepts:

• The classes used to represent tables, relationships, and properties in a DataSet

• How to create expression columns in a DataTable

• How to specify default values and set other properties of columns

• How to define and add unique, foreign, and primary key constraints to a DataTable

• How to generate primary keys on the client to be used in a database

• How to use extended properties