OLE DB Data Type Mappings

The following table shows the inferred .NET Framework type for data types from the .NET Framework Data Provider for ADO and OLE DB (System.Data.OleDb). The typed accessor methods for the OleDbDataReader are also listed.

ADO type OLE DB type .NET Framework type .NET Framework typed accessor
adBigInt DBTYPE_I8 Int64 GetInt64()
adBinary DBTYPE_BYTES Byte[] GetBytes()
adBoolean DBTYPE_BOOL Boolean GetBoolean()
adBSTR DBTYPE_BSTR String GetString()
adChapter DBTYPE_HCHAPTER Supported through the DataReader. See Retrieving Data Using a DataReader. GetValue()
adChar DBTYPE_STR String GetString()
adCurrency DBTYPE_CY Decimal GetDecimal()
adDate DBTYPE_DATE DateTime GetDateTime()
adDBDate DBTYPE_DBDATE DateTime GetDateTime()
adDBTime DBTYPE_DBTIME DateTime GetDateTime()
adDBTimeStamp DBTYPE_DBTIMESTAMP DateTime GetDateTime()
adDecimal DBTYPE_DECIMAL Decimal GetDecimal()
adDouble DBTYPE_R8 Double GetDouble()
adError DBTYPE_ERROR ExternalException GetValue()
adFileTime DBTYPE_FILETIME DateTime GetDateTime()
adGUID DBTYPE_GUID Guid GetGuid()
adIDispatch DBTYPE_IDISPATCH * Object GetValue()
adInteger DBTYPE_I4 Int32 GetInt32()
adIUnknown DBTYPE_IUNKNOWN * Object GetValue()
adNumeric DBTYPE_NUMERIC Decimal GetDecimal()
adPropVariant DBTYPE_PROPVARIANT Object GetValue()
adSingle DBTYPE_R4 Single GetFloat()
adSmallInt DBTYPE_I2 Int16 GetInt16()
adTinyInt DBTYPE_I1 Byte GetByte()
adUnsignedBigInt DBTYPE_UI8 UInt64 GetValue()
adUnsignedInt DBTYPE_UI4 UInt32 GetValue()
adUnsignedSmallInt DBTYPE_UI2 UInt16 GetValue()
adUnsignedTinyInt DBTYPE_UI1 Byte GetByte()
adVariant DBTYPE_VARIANT Object GetValue()
adWChar DBTYPE_WSTR String GetString()
adUserDefined DBTYPE_UDT not supported
adVarNumeric DBTYPE_VARNUMERIC not supported

* For the OLE DB types DBTYPE_IUNKNOWN and DBTYPE_IDISPATCH, the object reference is a marshaled representation of the pointer.

See Also

Retrieving and Modifying Data in ADO.NET
ADO.NET Managed Providers and DataSet Developer Center