$sth = $dbh->prepare('SELECT * 
                      FROM   all_tables 
                      WHERE  table_name = ?');

$sth->execute($table_name);

while (@row = $sth->fetchrow_array) {
    print "@row\n";
}


##</code><code>##

my $sql = <$filecontent>;

$sql =~ s/\$table_name/$table_name/e;