ADO.NET 的使用

ADO.NET 的使用 ADO.NET：为使用.NET数据存取框架建造一个特定的数据命令提供者。这篇文章假定你熟悉ADO.NET和数据存取应用程序接口。概要：系统数据动态连接库汇集在包含命名空间的.NET框架中，这些命名空间的基类能够创造特定的数据提供者使用ADO.NET分类连接命令，数据阅读与数据适配，写一个提供比写一个对象连接与嵌入数据库容易的多。这篇文章解释这些类和他们的应用，而且用他们来写多种不同类型的数据命令。微软.NET平台将会以一个包含令人想起对象连接与嵌入数据库和开放式数据库的一组命名空间的系统数据动态连接库集合的载入运行。这个集合包含系统数据命名空间，它包含一通常组数据的定义存取接口和系统数据公共集，这些系统数据公共集包含一些抽象的基类为编写者的使用供应实现公共的功能性的集合。系统数据动态连接库也包含两种命名空间（System.Data.OleDb和System.Data.SqlClient）它们公开不同的类与接口，在文件中识别数据命令供应者。这些压缩包有权访问数据库或通过一组被处理的类型或接口的数据访问应用程序接口。

外文原文： THE USE OF ADO.NET ADO.NET: Building a Custom Data Provider for Use with the .NET Data Access Framework This article assumes you''re familiar with ADO.NET and data access APIs SUMMARY The System.Data.dll assembly in the .NET Framework contains namespaces whose base classes can be used to create custom data providers. These namespaces also define a number of data access interfaces and base classes that let developers create data providers that will interoperate with other custom providers. Using the ADO.NET classes Connection, Command, DataReader, and DataAdapter, writing a provider is easier than writing one for OLE DB. This article explains these classes and their implementation, and how they can be used to write a variety of different kinds of data providers. indows® platforms have for years included an API for data access based on a generic provider-consumer paradigm. Originally, this consisted of the relational data-source-centric Open Database Connectivity (ODBC) API. ODBC is nearly a one-to-one mapping to the ANSI SQL standards committee''s SQL CLI (command language interface). ODBC drivers encapsulate database-specific protocols like the SQL Server tabular data stream (TDS) or layer over vendor-specific APIs like the Oracle Call Interface (OCI). This concept expanded to include nonrelational data sources using a common set of COM interfaces and types known as OLE DB. Because OLE DB contained provisions for nonrelational data sources, producers of any kind of data—from hierarchical to multidimensional to flat files—were encouraged to adapt the common OLE DB object model. The Microsoft® .NET platform will ship with a System.Data.dll assembly containing a set of namespaces reminiscent of OLE DB and ODBC. This assembly contains the System.Data namespace, which includes the definition of a common set of data access interfaces and System.Data.Common, which contains a few abstract base classes that implement common functionality for use by provider writers. System.Data.dll also contains two namespaces (System.Data.OleDb and System.Data.SqlClient) that expose parallel series of classes and interfaces, known in the documentation as data providers. These encapsulate access to databases or other data access APIs through a set of managed types and interfaces. The types and interfaces exposed by each data provider derive from the common subset, and expose mostly equivalent (but not identical) functionality. Because the types and interfaces need not be identical for each provider, provider writers are freer to expose functionality that is unique to the data source. In addition, System.Data includes provisions for a disconnected object model, based around the DataSet type, which is a more feature-rich version of the ODBC client cursor library and the OLE DB disconnected Recordset.

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