How to compare Columns?

Question

  I have File table in database with column A,B,C,D.. so on..
 i have CSV file with column   A,B,C,D, 
here if content of A in table is not empty,lly in CSV content of A column is not empty, so both field not empty or empty,it do not error message other wise it show Fields not matching (mean in that column some data should be present, not exactly..........Please suggest me in C#


thanks in advance............