I'm trying since yesterday to find difference between one column from two different data sources, one is and excel sheet and another is a flat file(.txt). In those two tables that I have, I did concatenated three columns into a new column (witch is a necessary validation), now I'm trying to find if there is any field that contains in table 1 but not in table two. I already used join but I don't know why the join tool keep adding one to another. Can someone help me?