ADO.NET in a Nutshell

The OLE DB Provider

The OLE DB provider interface provides access to a database through an OLE DB provider installed on your computer. Most OLE DB providers are supported, but those that use OLE DB Version 2.5 interfaces aren’t supported. Some unsupported OLE DB interfaces include:

• OLE DB provider for ODBC (MSDASQL)

• OLE DB provider for Exchange (ExOLEDB)

• OLE DB for Internet Publishing (MSDAIPP)

Table A-3 lists some commonly used OLE DB drivers.

Table A-3. Commonly used OLE DB drivers

Name	Description
SQLOLEDB	OLE DB provider for SQL Server
MSDAORA	OLE DB provider for Oracle 7.3 and Oracle 8.
Microsoft.Jet.OLEDB.4.0	OLE DB provider for Access (and other Jet data sources)

All OLE DB types are contained in the System.Data.OleDb namespace (see Table A-4). For low-level information about OLE DB providers, you can refer to the OLE DB programmer’s reference on MSDN at http://msdn.microsoft.com/library/en-us/oledb/htm/oledb_providers_overview.asp.

Table A-4. OLE DB .NET provider classes

Interface	Implementing class
IDbConnection	OleDbConnection
IDbCommand	OleDbCommand
IDataParameter, IDbDataParameter	OleDbParameter
IDataReader, IDataRecord	OleDbDataReader
IDataAdapter, IDbDataAdapter	OleDbDataAdapter
IDbTransaction	OleDbTransaction

The OLE DB managed provider doesn’t include any structures for OLE DB types. However, the OleDbDataReader does include additional methods that allow you to specify the data type when retrieving a column value. Table A-5 shows the mapping ...