MDAC 2.5 SDK - OLE DB Providers
OLE DB Provider for ODBC

IDISPATCH Data Type Conversions

Convert to type

Empty

IUNKNOWN

NULL

VARIANT

Unsupported data type conversions

I1, I2, I4, I8, UI1, UI2, UI4, UI8, R4, R8, CY, NUMERIC, DECIMAL, DBTIME, DATE, DBDATE, DBTIMESTAMP, BOOL, BSTR, BYTES, ERROR, GUID, STR, WSTR