Just finished 2nd pnone interview with a senior data analyst, one very simple question need using DATAPART that I didn't remeber at that moment. What a pity! They asked an excel question, in pivot table, if the sumtotal comes out an error, what is the problem and how you fix it? I didn't quiet understand, but just guess that I have to go back check data, maybe there isnull field in database table? Any one has idea about this right answer?