Hello Monks, now I know why the "on duplicate key update" command is not really working. I have to give the information what to update. For example

$sth = $dbh->prepare(
        sprintf "insert into %s (%s) values (%s) on duplicate key upda
+te $columns[0]=values($columns[0]),$columns[1]=values($columns[1])",
            $dbh->quote_identifier(
                $tablename
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Do you have any idea to do this command automatically, I tried this

printf "insert into %s (%s) values (%s) on duplicate key update %s=val
+ues(%s),%s=values(%s)",
            $dbh->quote_identifier(
                $tablename
            ),
            join(
                ',',
                map { $dbh->quote_identifier($_) } @columns
            ),
            join( ',', ('?') x @columns ), ????
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