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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.SqlTypes - Provides classes for native data types within SQL Server. These classes provide a safer, faster alternative to other data types.
  • 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.

In the Visual Studio Documentation

Accessing Data
Provides conceptual and procedural information about how to work with data and XML with Visual Basic and Visual C#.
Introduction to Distributed Applications and Data Integration
Provides an overview of data access in Visual Studio applications.
Data Walkthroughs
Lists step-by-step topics covering common data scenarios.
Connecting to Data Sources with ADO.NET
Provides topics about creating and working with connection objects in Visual Studio.
ADO.NET Datasets
Provides topics about what datasets are and how to use them.
ADO.NET Data Adapters
Provides topics about defining the SQL statement or stored procedure calls that you use to fill datasets and write data back to the database.
Filtering and Sorting in Datasets
Provides topics about viewing the data in a dataset in different ways by selecting subsets of records or sorting.
Relationships in ADO.NET Datasets
Provides topics about working with dataset tables that have a parent-child relationship.
Performing Database Operations Directly
Provides topics about how to execute SQL statements and stored procedures directly and work with the results they return.
Concurrency Control in ADO.NET
Provides topics about making changes in datasets and then writing those changes back to a data source.
Introduction to the .NET Framework Class Library in Visual Studio
Provides an overview of the namespaces in the .NET Framework.
Data Access Technologies
Helps you choose a data-access technology.
XML in Visual Studio
Provides links to sections of the Visual Studio documentation that discuss XML.
Overview of Visual Database Tools
Introduces the Query Designer and other data tools.
Data Design
Provides links to Visual Studio topics about database design and data validation.

Additional Information

XML Schema Reference (XSD)
Provides reference topics for elements and data types in XML Schema, the standard developed by the World Wide Web Consortium (W3C).
Processing Transactions
Provides information from the .NET Framework Developer's Guide about transactions.
XML Developer Center on MSDN Online (
Provides the latest articles and other resources about XML.
World Wide Web Consortium (W3C) Web Site (
Provides resources about Internet standards, including XML Schema, HTML, and HTTP.