Tushar Mehta wrote

You should consider redesigning your data setup to follow the rules of
relational database design. Put the student info in one table, the
class info in another table, and the student-class relationship in a
third table.

Thanks for your input, but I've put a lot of work into getting this book
set the way I want and what I want it to do. My query was about a minor
part of its overall function and I only sought to make it easier to correct
a rare, but possible glitch.

--
David