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 marshalled representation of the pointer.