From the last post, a new update. Comparing the two columns fail to show any selected information, however when I changed the query so that mainacctno is null and chart_acct is not null I found 1741 mismatches. So mainacctno is null and chart_acct is ‘00000GWTN’, and so on and so forth for 1741 items. I suspect the logical operators cannot distinguish between null and not-null values.

What a mess.