include("onn.php");
$query=mysql_query('select * from book');
$num=mysql_num_rows($query/)/这里是把query的执行结果代入mysql_num_row语句中
echo $num;
for($i=0;$i<$num;$i++){
$sql='UPDATE `db_borrow`.`tb_bookinfo` SET `id` = '."'".$i."'".' WHERE `book`.`id` = '."'".$i."'";
echo $sql."<br>";
mysql_query($sql);
}