Connecting to a Data Source

You know that in ASP.NET, getting data from a database to the web page that your users will see in their browsers requires a number of ADO.NET objects: connections, datasets, data readers, data adapters, and so on. In order to provide useful demonstrations, we'll be using quite a few of these different objects in this chapter, but our focus is on the first item in that list - the others will have their time in the sun a little later on. Our aim here is to understand ADO.NET connection objects, and in order to do so we'll look at the following topics:

• The basics of ADO.NET connections
• Connecting to Microsoft SQL Server data
• Connecting to an MS Access database
• Connecting to an MS Excel spreadsheet
• Connecting to an XML data file
• Getting schema information about a data store
• Some common mistakes