Check your DBI docs for more specifics, but you don't have to put your data directly into the string like you're doing.

You can just as easily say:

my $sqlString = "INSERT INTO attribute VALUES (?, ?, ?)";

$dbh->prepare($sqlString);
$dbh->execute($serverId, $featureID, $value);
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The best thing is, if you've got a lot of them and wanna do multiple inserts, you can put the $dbh->execute() statement into a loop by itself. With most databases that will make a pretty significant performance increase for you.

A far better explanation of this technique can be found here.