Win has asked for the wisdom of the Perl Monks concerning the following question:

Please could somebody enlighten me on the ins and outs of the following error message.
Use of uninitialized value in join or string at C:/Perl_activate/20_Oc line 438, <FLAT_FILE> line 1191.
in relation to the following code.
my $sth_C = $dbh->prepare($Return_results) or die "Couldn't prepar +e query: ".$dbh->errstr; $sth_C->execute() or die "Couldn't execute query: ".$sth_C->errstr +; while (my @row = $sth_C->fetchrow_array) { print OUTPUT_FILE join("\t", @row); ###<< The error message app +lies to this line of code. print OUTPUT_FILE "\n"; undef @row;