我一直在尝试将 PHP session 数据保存在 MySQL 数据库中,但无法使其工作。
举个简单的例子,下面的代码应该在每次访问时增加一个计数器。我见过其他示例等,但是有人可以告诉我为什么这段代码不起作用吗? (Apache/2.2.11 (Win32) DAV/2 mod_ssl/2.2.11 OpenSSL/0.9.8i PHP/5.2.9 MySQL 客户端版本:5.0.51a)
这是mysql数据库表:
CREATE TABLE IF NOT EXISTS `sessions` (
`session_ID` varchar(32) COLLATE utf8_unicode_ci NOT NULL,
`session_data` mediumblob NOT NULL,
`access` int(10) unsigned NOT NULL,
PRIMARY KEY (`session_ID`),
KEY `access` (`access`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
以及 PHP 代码(只需插入您的数据库凭据):
<?PHP
function mysession_open()
{
global $sdbc; // Session Database Connection
if ($sdbc) {
return true;
} else {
return false;
}
}
function mysession_close()
{
global $sdbc;
return mysqli_close($sdbc);
}
function mysession_read($session_id)
{
global $sdbc;
$session_id = mysqli_real_escape_string($sdbc, $session_id);
$sql_sel = "SELECT session_data FROM sessions WHERE session_id = '$session_id'";
$data_sel = mysqli_query($sdbc, $sql_sel);
$row_sel = mysqli_fetch_array($data_sel);
if (isset($row_sel['session_data'])) {
return $row_sel['session_data'];
} else {
return '';
}
}
function mysession_write($session_id, $session_data)
{
global $sdbc;
$access = time();
$session_id = mysqli_real_escape_string($sdbc, $session_id);
$access = mysqli_real_escape_string($sdbc, $access);
$session_data = mysqli_real_escape_string($sdbc, $session_data);
$sql_write = "REPLACE INTO sessions (session_ID, session_data, access) " .
"VALUES ('$session_id', '$session_data', '$access')";
return mysqli_query($sdbc, $sql_write);
}
function mysession_destroy($session_id)
{
global $sdbc;
$session_id = mysqli_real_escape_string($sdbc, $session_id);
return mysqli_query($sdbc, $sql_del);
}
function mysession_gc($max)
{
global $sdbc;
$old = time() - $max;
$old = mysqli_real_escape_string($sdbc, $old);
$sql_old = "DELETE FROM sessions WHERE access < '$old'";
return mysqli_query($sdbc, $sql_old);
}
global $sdbc;
$sdbc = mysqli_connect('localhost', '...', '...', '...') or die('Could not connect to SDBC');
session_set_save_handler('mysession_open','mysession_close','mysession_read','mysession_write','mysession_destroy','mysession_gc');
session_start();
if (isset($_SESSION['counter'])) {
echo "counter is already set and it is " . $_SESSION['counter'] . '<br />';
$_SESSION['counter']++;
} else {
echo "counter is not set. setting to 1<br />";
$_SESSION['counter'] = 1;
}
echo "<br />Dumping SESSION data:<br />";
var_dump($_SESSION);
session_write_close();
?>
预先感谢您的帮助。
如果您注释掉 session_set_save_handler 代码行,它就可以正常工作(它会递增)。但使用保存处理程序则不然。
最佳答案
您的查询调用都没有任何错误检查。不要盲目地假设数据库部分有效,而是在每个阶段进行一些基本的错误检查,例如:
function mysession_write($session_id, $session_data) {
global $sdbc;
[...snip...]
$stmt = mysqli_query($sdbc, $sql_write);
if ($stmt === FALSE) {
error_log("Failed to write session $session_id: " . mysqli_error($sdbc);
}
return($stmt);
}
查询成功的方法只有一种,但失败的方法有无数种。
关于php - session_set_save_handler - 为什么此代码不起作用?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4045210/