ADO.NET-managed data providers and their underlying data objects form the backbone of .NET data access. The data providers are an abstraction layer for data services and are similar in concept to ActiveX Data Objects' ADODB class, which supports only OLE DB data providers. ADO.NET supports multiple data provider types by the following data provider namespaces:
- SqlClient members provide high performance connectivity to SQL Server 7.0, 2000, and 2005. The performance gain comes from bypassing the OLE DB layer and communicating with SQL Server's native Tabular Data Stream (TDS) protocol. Most of this book's examples use classes in the SqlClient namespace.
- SqlClientCe provides features similar to SqlClient for SQL Server CE 3.0 and SQL Server 2005 Mobile Edition. This book doesn't cover SQL Server CE or Mobile versions.
- OracleClient members deliver functionality similar to SqlClient for Oracle 8i and 9i databases. Oracle offers Oracle Data Provider for .NET (ODP .NET) as a substitute for OracleClient; ODP .NET also supports Oracle 10g and later. You can learn more about ODP .NET at http://otn.oracle.com/tech/windows/odpnet/.
- OleDb members provide a direct connection to COM-based OLE DB data providers for databases and data sources other than SQL Server, SQL Server CE, and Oracle. You can select from 19 built-in OLE DB data providers when creating a new OleDbConnection object. A few of this book's examples use the Microsoft Jet 4.0 OLE DB Data Provider with the Access 2000 or later Northwind.mdb file. ADO.NET 2.0 doesn't provide access to the Microsoft OLE DB Provider for ODBC Drivers.
- Odbc members provide connectivity to legacy data sources that don't have OLE DB data providers. The Odbc namespace is present in .NET Framework 2.0 for backward compatibility with .NET Framework 1.x applications.
Each data provider namespace has its own set of data object classes. The provider you choose determines the prefix of data object names -- such as SqlConnection, SqlCeConnection, OracleConnection or OleDbConnection.
The above tip was excerpted from Chapter 1, 'Migrating from ADO to ADO.NET,' of the book Expert One-on-one Visual Basic 2005 Database Programming by Roger Jennings, courtesy of Wiley Publishers. Click here for the complete collection of book excerpts.
This was first published in May 2006