Data access over the Web has made some major advances in recent years. It's moved from accessing simple text files for small guestbooks to moving large corporations' entire data systems online some consisting of several terabytes of data. (One terabyte equals approximately 1,000 gigabytes, or 1,000,000 megabytes.) Even stockbrokers and order execution systems have moved online, generating massive amounts of data daily. Luckily, you have ASP.NET to help you with all that!
Classic ASP pages used ActiveX Data Objects (ADO) to access and modify databases. ADO is a programming interface used to access data. This method was efficient and fairly easy for developers to learn and implement. However, ADO suffered from a dated model for data access with many limitations, such as the inability to transmit data so it is easily and universally accessible. Coupled with the move from standard SQL databases to more distributed types of data (such as XML), Microsoft introduced ADO.NET the next evolution of ADO.
ADO.NET is a major revision of ADO that enables ASP.NET pages to present data in much more efficient and different ways. For example, it fully embraces XML and is easily able to communicate with any XML-compliant application. ADO.NET offers a lot of exciting new features that will make your life (as a developer) much easier.
ADO.NET is a very large topic, which is why tomorrow's lesson is devoted to it. For now, you just need to know that ASP.NET pages use ADO.NET to communicate with any type of data store. Figure 9.1 depicts the model of data access with ADO.NET and ASP.NET. ADO.NET is completely compatible with OLE DB-compliant data sources, such as SQL or Jet (Microsoft Access's database engine).
Figure 9.1. Data access model with ADO.NET and ASP.NET.