The IResultColumn Interface

interface IResultColumn: IDispatch
{
  [propget, id(0x00000001), helpstring("Returns the column's name.")]
   HRESULT _stdcall Name([out, retval] BSTR * Value );

  [propget, id(0x00000002), helpstring("Retuns true if data in this column may contain the null value.")]
   HRESULT _stdcall Nullable([out, retval] VARIANT_BOOL * Value );

  [propget, id(0x00000003), helpstring("Returns data type of column.")]
   HRESULT _stdcall DataType([out, retval] sqlDataType * Value );
}

The object implementing the IResultColumn interface describes the result set column. For more see the Result Set chapter.