http://www.perlmonks.org?node_id=988699


in reply to Perl DBI help

Seems that the table contains some NULL entries which are represented as undef value at the Perl/DBI end? When interpolating these undef values in the @$p expression, the warnings occur.

Try Data::Dumper or this snippet to investigate...

print "MySQL: ", join(" ; " , map { $_ // 'NULL' } @$p ), "\n";