Data Namespaces in Visual Studio
The data and XML namespaces in the .NET Framework include:
System.Data - consists of the classes that constitute the ADO.NET architecture, which is the primary data access method for managed applications. The ADO.NET architecture enables you to build components that efficiently manage data from multiple data sources. ADO.NET also provides the tools to request, update, and reconcile data in distributed applications.
System.Data.Common - contains classes shared by the .NET Framework data providers. Data providers describe a collection of classes used to access a data source, such as a database, in the managed space.
System.Xml - classes that provide standards-based support for processing XML.
System.Data.OleDb – classes that make up the .NET Framework Data Provider for OLE DB-compatible data sources. These classes allow you to connect to an OLE DB data source, execute commands against the source, and read the results.
System.Data.SqlClient – classes that make up the .NET Framework Data Provider for SQL Server, which allows you to connect to SQL Server 7.0, execute commands, and read results. The System.Data.SqlClient namespace is similar to the System.Data.OleDb namespace, but is optimized for access to SQL Server 7.0 and later.
System.Data.Sql - classes that support SQL Server-specific functionality.
System.Data.SqlTypes - Provides classes for native data types within SQL Server. These classes provide a safer, faster alternative to other data types.
Microsoft.SqlServer.Server - classes, interfaces, and enumerations that are specific to the integration of the Microsoft .NET Framework common language runtime (CLR) into Microsoft SQL Server, and the SQL Server database engine process execution environment.
System.Data.Odbc - classes that make up the .NET Framework Data Provider for ODBC. These classes allow you to access ODBC data source in the managed space.
System.Data.OracleClient - classes that make up the .NET Framework Data Provider for Oracle. These classes allow you to access an Oracle data source in the managed space.
System.Transactions - classes that allow you to write your own transactional application and resource manager. Specifically, you can create and participate in a transaction (local or distributed) with one or multiple participants.