A.2 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 between OLE DB types and .NET framework types (although it doesn't include types used exclusively for stored procedure parameters).

Table A-5. OLE DB type mappings

OLE DB data type

Mapped .NET type

Name in OleDBType enumeration

 DBTYPE_I8 
 Int64 
 BigInt 
 DBTYPE_BYTES 
 Byte[] 
 Binary 
 DBTYPE_BOOL 
 Boolean 
 Boolean 
 DBTYPE_BSTR 
 String 
 BSTR 
 DBTYPE_STR 
 String 
 Char 
 DBTYPE_CY 
 Decimal 
 Currency 
 DBTYPE_DATE 
 DateTime 
 Date 
 DBTYPE_DBDATE 
 DateTime 
 DBDate 
 DBTYPE_DBTIME 
 TimeSpan 
 DBTime 
 DBTYPE_DBTIMESTAMP 
 DateTime 
 DBTimeStamp 
 DBTYPE_DECIMAL 
 Decimal 
 Decimal 
 DBTYPE_R8 
 Double 
 Double 
 DBTYPE_EMPTY 

Not applicable

 Empty 
 DBTYPE_ERROR 
 Exception 
 Error 
 DBTYPE_FILETIME 
 DateTime 
 Filetime 
 DBTYPE_GUID 
 Guid 
 Guid 
 DBTYPE_IDISPATCH 

Not supported

 IDispatch 
 DBTYPE_I4 
 Int32 
 Integer 
 DBTYPE_UNKNOWN 

Not supported

 IUnknown 
 DBTYPE_NUMERIC 
 Decimal 
 Numeric 
 DBTYPE_PROPVARIANT 
 Object 
 PropVarian 
 DBTYPE_R4 
 Single 
 Single 
 DBTYPE_I2 
 Int16 
 SmallInt 
 DBTYPE_I1 
 SByte 
 TinyInt 
 DBTYPE_UI8 
 UInt64 
 UnsignedBitInt 
 DBTYPE_UI4 
 UInt32 
 UnsignedInt 
 DBTYPE_UI2 
 UInt16 
 UnsignedSmallInt 
 DBTYPE_UI1 
 Byte 
 UnsignedTinyInt 
 DBTYPE_VARIANT 
 Object 
 Variant 
 DBTYPE_WSTR 
 String 
 WChar 


ADO. NET in a Nutshell
ADO.NET in a Nutshell
ISBN: 0596003617
EAN: 2147483647
Year: 2005
Pages: 415

Similar book on Amazon

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net