>>>Why not just test for the presence of the innerexception != null and if it isn't set the errormessage to that text.
>>>
>>>

>>>   var msg = "";
>>>   if(string.IsNotNull(ex.InnerException))
>>>   {
>>>        msg = ex.InnerException;
>>>        throw new DuplicatePropertyException(msg);
>>>   }
>>>
>>>

>>
>>This is not what I am asking. I am asking specifically about
>>
>>throw ex
>>
>>part.
>>
>>In the throw ex is there a way to append that inner exception? E.g. what should I throw?
>
>You care a new message like I showed you and throw a new exception with that message. You can't append to ex.

I see, thanks. So, it would be throw new Exception(message).

I'll think if I want to do it or not.