PostgreSQL, Second Edition

Client 5—Using a Typed DataSet

The VB clients that you've seen so far have used untyped DataSets to manage data retrieved from a PostgreSQL server. Untyped DataSets are useful when you don't know the structure of the data at the time you create an application. In most cases, you will know the layout of the data that you're working with so a typed (or strong) DataSet is more useful. A typed DataSet exposes data in the form of objects. An untyped DataSet exposes data in the form of a group of collections.

For example, if you load a copy of the customers table into an untyped DataSet, you'll find that the DataSet contains a collection of DataTable objects (in this case, the collection contains a single DataTable). That DataTable contains a collection ...