[英]PHP Migrating from mysql_* to mysqli_
我只是承担了一个老项目,而我要做的第一件事是从mysql_*
扩展名迁移到mysqli_*
一个。 我之前还没有使用过PHP。大多数新代码都可以使用,但是在下面的示例中,我似乎把事情搞砸了...
旧功能:
function user_id_from_username($username) {
$username = sanitize($username);
return mysql_result(mysql_query("SELECT `user_id` FROM `users` WHERE `username` = '$username'"), 0, 'user_id');
}
新增(无工作)功能:
function user_id_from_username($username) {
$username = sanitize($username);
$id = mysqli_query(connect(),"SELECT `user_id` FROM `users` WHERE `username` = '$username'");
return $id;
}
另一个旧的:
function login($username, $password) {
$user_id = user_id_from_username($username);
$username = sanitize($username);
$password = md5($password);
return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'"), 0) ==1) ? $user_id : FALSE;
}
和新的:
function login($username, $password) {
$user_id = user_id_from_username($username);
$username = sanitize($username);
$password = md5($password);
$check = mysqli_query(connect(),"SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'");
return $check == $user_id ? TRUE : FALSE;
}
我的消毒功能:
function sanitize($data) {
return htmlentities(strip_tags(mysqli_real_escape_string(connect(), $data)));
}
好的,所以在第一个功能中,您尝试替换
return mysql_result(mysql_query("SELECT `user_id` FROM `users` WHERE `username` = '$username'"), 0, 'user_id');
首先让我们弄清楚它的作用:
user_id
现在,使用mysqli_
逐步进行mysqli_
:
//specify query
$result = mysqli_query(connect(),"SELECT `user_id` FROM `users` WHERE `username` = '$username'");
//fetch result
$row = mysqli_fetch_assoc($result);
//get column
return $row['user_id'];
您无需指定该行,因为fetch_assoc
仅返回一个。
现在是第二个功能
return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'"), 0) ==1) ? $user_id : FALSE;
user_id
,否则返回FALSE
现在使用mysqli_
:
//specify query
$result = mysqli_query(connect(),"SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'");
//fetch result
$row = mysqli_fetch_row($result);
//if first returned column is equal to 1 return $user_id
//otherwise FALSE
return ($row[0]==1) ? $user_id : FALSE;
但等待-为什么我用mysqli_fetch_row
这里,而mysqli_fetch_assoc
上面使用? RTM;)
今天我们学到了什么? 仅因为您可以编写尽可能短的代码并不意味着您应该这样做。 如果对原始代码进行了更多拆分,则向MySQLi的过渡应该非常容易,因为您可以轻松调试较小的部分,而不是复杂的表达式。
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