The following table outlines the four core objects that make up a .NET Framework data provider.

In addition to the core classes listed in the table earlier in this document, a .NET Framework data provider also contains the classes listed in the following table.

The .NET Framework Data Provider for SQL Server (SqlClient) uses its own protocol to communicate with SQL Server. It is lightweight and performs well because it is optimized to access a SQL Server directly without adding an OLE DB or Open Database Connectivity (ODBC) layer. The following illustration contrasts the .NET Framework Data Provider for SQL Server with the .NET Framework Data Provider for OLE DB. The .NET Framework Data Provider for OLE DB communicates to an OLE DB data source through both the OLE DB Service component, which provides connection pooling and transaction services, and the OLE DB provider for the data source.

Note:
The .NET Framework Data Provider for ODBC has a similar architecture to the .NET Framework Data Provider for OLE DB; for example, it calls into an ODBC Service Component.

Comparison of the dnprdnshort Data Provider for ssNoVersionr and the dnprdnshort Data Provider for OLE DB

To use the .NET Framework Data Provider for SQL Server, you must have access to SQL Server 7.0 or later versions. The .NET Framework Data Provider for SQL Server classes are located in the System.Data.SqlClient namespace. For earlier versions of SQL Server, use the .NET Framework Data Provider for OLE DB with the SQL Server OLE DB provider System.Data.OleDb.

The .NET Framework Data Provider for SQL Server supports both local and distributed transactions. For distributed transactions, the .NET Framework Data Provider for SQL Server, by default, automatically enlists in a transaction and obtains transaction details from Windows Component Services or System.Transactions. For more information, see Transactions and Concurrency (ADO.NET).

The following code example shows how to include the System.Data.SqlClient namespace in your applications.

Imports System.Data.SqlClient

using System.Data.SqlClient;

The .NET Framework Data Provider for OLE DB (OleDb) uses native OLE DB through COM interop to enable data access. The .NET Framework Data Provider for OLE DB supports both local and distributed transactions. For distributed transactions, the .NET Framework Data Provider for OLE DB, by default, automatically enlists in a transaction and obtains transaction details from Windows 2000 Component Services. For more information, see Transactions and Concurrency (ADO.NET).

The following table shows the providers that have been tested with ADO.NET.

Note:

Using an Access (Jet) database as a data source for multithreaded applications, such as ASP.NET applications, is not recommended. If you must use Jet as a data source for an ASP.NET application, realize that ASP.NET applications connecting to an Access database can encounter connection problems. For help troubleshooting connection problems using ASP.NET and an Access (Jet) database, see article Q316675, "PRB: Cannot Connect to Access Database from ASP.NET" in the Microsoft Knowledge Base.

The .NET Framework Data Provider for OLE DB does not support OLE DB version 2.5 interfaces. OLE DB Providers that require support for OLE DB 2.5 interfaces will not function correctly with the .NET Framework Data Provider for OLE DB. This includes the Microsoft OLE DB provider for Exchange and the Microsoft OLE DB provider for Internet Publishing.

The .NET Framework Data Provider for OLE DB does not work with the OLE DB provider for ODBC (MSDASQL). To access an ODBC data source using ADO.NET, use the .NET Framework Data Provider for ODBC.

.NET Framework Data Provider for OLE DB classes are located in the System.Data.OleDb namespace. The following code example shows how to include the System.Data.OleDb namespace in your applications.

Imports System.Data.OleDb

using System.Data.OleDb;

Note:
The .NET Framework Data Provider for OLE DB requires MDAC 2.6 or a later version, and MDAC 2.8 Service Pack 1 (SP1) is recommended. You can download MDAC 2.8 SP1 from the Data Access and Storage Developer Center.

The .NET Framework Data Provider for ODBC (Odbc) uses the native ODBC Driver Manager (DM) to enable data access. The ODBC data provider supports both local and distributed transactions. For distributed transactions, the ODBC data provider, by default, automatically enlists in a transaction and obtains transaction details from Windows 2000 Component Services. For more information, see Transactions and Concurrency (ADO.NET).

The following table shows the ODBC drivers tested with ADO.NET.

.NET Framework Data Provider for ODBC classes are located in the System.Data.Odbc namespace.

The following code example shows how to include the System.Data.Odbc namespace in your applications.

Imports System.Data.Odbc

using System.Data.Odbc;

Note:
The .NET Framework Data Provider for ODBC requires MDAC 2.6 or a later version, and MDAC 2.8 SP1 is recommended. You can download MDAC 2.8 SP1 from the Data Access and Storage Developer Center.

The .NET Framework Data Provider for Oracle (OracleClient) enables data access to Oracle data sources through Oracle client connectivity software. The data provider supports Oracle client software version 8.1.7 or a later version. The data provider supports both local and distributed transactions. For more information, see Transactions and Concurrency (ADO.NET).

The .NET Framework Data Provider for Oracle requires Oracle client software (version 8.1.7 or a later version) on the system before you can connect to an Oracle data source.

.NET Framework Data Provider for Oracle classes are located in the System.Data.OracleClient namespace and are contained in the System.Data.OracleClient.dll assembly. You must reference both the System.Data.dll and the System.Data.OracleClient.dll when you compile an application that uses the data provider.

The following code example shows how to include the System.Data.OracleClientnamespace in your applications.

Imports System.Data
Imports System.Data.OracleClient

using System.Data;
using System.Data.OracleClient;

Depending on the design and data source for your application, your choice of .NET Framework data provider can improve the performance, capability, and integrity of your application. The following table discusses the advantages and limitations of each .NET Framework data provider.

The EntityClient provider is used for accessing data based on an Entity Data Model (EDM). Unlike the other .NET Framework data providers, it does not interact directly with a data source. Instead, it uses Entity SQL to communicate with the underlying data provider. For more information, see EntityClient and Entity SQL.

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