With the development of application development, new applications have become more loosely coupled based on web application models. Today, more and more applications use XML to encode data to be passed through the network. The web application uses HTTP as a structure that communicates between the interlayer, so they must explicitly process the status maintenance between requests. This new model is much different from connection, tight coupling programming style, this style is once the logo of the client / server. In this programming style, the connection is kept in the entire survival of the program without requiring special processing of the status.
When designing tools and technologies needed in today's developers, Microsoft recognizes the need to provide a new programming model for data access, which is based on .NET Framework. Based on .NET Framework will ensure that data access technology consistency-component will share universal type systems, design patterns, and naming conventions.
The purpose of designing ADO.NET is to meet the following requirements of this new programming model: has a disconnected data structure; it can be tightly integrated with XML; there is a universal data representation that can combine data from multiple, different data sources; It has functions optimized to interact with the database, which are inherent .NET Framework.
When creating ADO.NET, Microsoft has the following design goals.
Use current ADO knowledge
ADO.NET design meets a variety of requirements for today's application development models. At the same time, the programming model is consistent with ADO as much as possible, which makes today's ADO developers do not have to learn new data access technologies from scratch. ADO.NET is the inherent part of .NET Framework, so it is not completely unfair to ADO programmers.
ADO.NET coexists with ADO. Although most .NET-based new applications will be written using ADO.NET, but .NET programmers can still use ADOs through .NET COM interoperability services.
For discussion on the differences between ADO and ADO.NET, see "ADO.NET for the ado programmer" on http://msdn.microsoft.com/library/en-us/dndotNet/html/adonetprog.asp.
Support N layer programming mode
ADO.NET provides first-class support for disconnect N-layer programming environments, and many new applications are written for this environment. This concept of using broken data set has become the focus of the programming model. The N layer programming ADO.NET solution is DataSet.
Integrated XML support
XML and data access are closely linked, that is, all of XML is related to data encoding, and more and more content is related to XML. .NET Framework not only supports Web standards, but it is still based on Web standards.
XML supports built-in very basic level in ADO.NET. The XML classes in .NET Framework and ADO.NET are part of the same structure, which integrates many different levels. You don't have to choose between data access service sets and their XML appropriate services; their design is originally features from one of them to another.
