ASP.NET by Example

ADO vs. ADO.NET

The History of Microsoft Data Access

You guessed it—Microsoft has changed the data access object model again. Before we jump right into the “how” of ADO.NET, we should spend a moment on the “why.”

A long, long time ago (say four years), there were several object models for accessing data. If you wanted to talk to Access, you used Data Access Objects (DAO). Through DAO, you could take advantage of many Access-specific features. For example, you could create, repair, and compact databases. You could attach tables. You could create QueryDefs. For talking to Access, DAO was great, but Access wasn't the only database you ever wanted to talk to. What about Oracle? What about SQL Server?

The solution was Remote Data Objects (RDO). RDO ...