In any event, I see what you are doing. This will not produce any printout at all if $preauth is not 0 or 1 (as you alluded to)

#!/usr/bin/perl
use strict;
use warnings;

my $preauth=3;

print qw(No Yes)[$preauth]; # No output at all!

print ($preauth eq '1' ? "Yes" : "No"); # Prints No
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As a practical matter, I use SQLite for all my DB work unless I need to use another DB (and that can happen for a lot of reasons). SQLite does not have a boolean type..it is only an int. So a value like "3" could conceivably show up. My code only recognizes '1' as the 'True' value. No insurance company or provider is going to work with a DB that does not have a boolean data type.

It appear to me that Re: Substitute "Yes" for "1" in mysql query output? is the way to go... Put this yes/no decision into the SQL solution space.