Thank you chacham. The select * is working without any problems. I will paste the headings somewhere below for reference. My problem is that I cannot store the headings "sid = $row->{sid} \tgender = $row->{gender}\n"; into the variable $columns and then use that variable to describe the columns I wish to see in the output

Headings

Many thanks for responding

> against column additions, subtractions, and changes

I wonder how is this relevant if one uses ->fetchrow_hashref ?

(like the OP does)

update

Re^2: Database connection issue

I think we had this discussion already...

I do not see how that changes the advice. There are ways to avoid some of the errors (disregarding if that is good practice), but the self-documenting part is still true.

I wonder how is this relevant

It isn't. Hence the introductory, "As an aside".

> There are ways to avoid some of the errors (disregarding if that is good practice), but the self-documenting part is still true.

Very generic ...

In this sense: DRY is also a good practice! :)

And less generic:

The best practice would be a programming style/ SQL abstraction which allows defining the fields just once and automatically checks a table's integrity at compile-time.

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!}