if ( lc $op eq 'is' || lc $op eq 'is not' ) {
$value = 'NULL'; # just fix possible mistakes here
} elsif ( $value !~ /^[+-]?[0-9]+$/ ) {
if ( lc $op eq 'is' || lc $op eq 'is not' ) {
$value = 'NULL'; # just fix possible mistakes here
} elsif ( $value !~ /^[+-]?[0-9]+$/ ) {