A really great lesson - from the programmers point of view.
If someone prefers a much faster and more simple out-of-the-box approach to pull external data into a SharePoint list in just minutes,
I would suggest the Business Data List Connector (BDLC) found here:
You can configure the connection directly in the custom SharePoint list settings by entering a connection string, a select statement and primary keys(s) - if any. That's it, without any programming required.
The list structure is automatically created, you can modify it later.
A timer job is used to update changed external data in the SharePoint list. Only changed data is updated (if primary keys are given).
That means, you can use list alerts and workflows, to start business actions in SharePoint, if external data records are changed.
The solution works for SharePoint (any editions) and WSS. There is a completely free shareware version for download.