Library-Supported Data Type Conversions

The OLE DB Data Conversion Library supports a limited set of conversions among OLE DB data types. For example, the DBTYPE_BYREF modifier is supported only on the destination type for variable-length data types (DBTYPE_BYTES, DBTYPE_STR, DBTYPE_VARNUMERIC, and DBTYPE_WSTR).

Note

Supported data conversions can be determined through the CanConvert method of the IDataConvert interface.

Click an entry in the following table to see the supported data type conversions.

Convert from data type:

I1	I2	I4	I8
UI1	UI2	UI4	UI8
R4	R8	BOOL	ERROR
BSTR	STR	WSTR	BYTES
DATE	DBDATE	DBTIME	DBTIMESTAMP
FILETIME	GUID	CY	DECIMAL
NUMERIC	VARNUMERIC	VARIANT	PROPVARIANT
IDispatch	IUnknown