This function returns the type of the column corresponding to the given field offset. The returned field type could be one of the following: "int", "real", "string", etc.
result comes from a call to cubrid_execute
The numerical field offset. The field_offset starts at 0. If field_offset does not exist, an error of level E_WARNING is also issued.
Type of the column, on success.
false when invalid field_offset value.
-1 if SQL sentence is not SELECT.