如何把Session放入MySql数据库中

function sess_open($save_path, $session_name) {
global $hostname, $dbusername, $dbpassword, $dbname, $sess_dbh;

//$sess_dbh=mysql_pconnect($hostname,$dbusername,$dbpassword) or die("不能连接数据库！");
$sess_dbh=mysql_pconnect(@#localhost@#,@#test@#,@#test@#) or die("不能连接数据库！");

// mysql_select_db("$dbname") or die("不能选择数据库！");
mysql_select_db(@#test@#) or die("不能选择数据库！");
return(true);
}

function sess_close() {
//mysql_close();
return(true);
}

function sess_read($sid) {
global $sess_dbh;

$result = mysql_query("select data from sesslib where sid=@#$sid@#", $sess_dbh);
$n=mysql_num_rows($result);
if($n==0) {
return("");
}
else {
$sess_data=mysql_result($result,0);
return($sess_data);
}
}

function sess_write($sid, $sess_data) {
global $sess_dbh;
if(!empty($sess_data)){
$r=mysql_query("insert into sesslib set sid=@#$sid@#,data=@#$sess_data@#,time=now()", $sess_dbh);
if(!$r) { // insertion failed, means the session is already there, update it
$r=mysql_query("update sesslib set sid=@#$sid@#, data=@#$sess_data@#, time=now() where sid=@#$sid@#",$sess_dbh);
}
return $r;
}}

function sess_destroy($sid) {
global $sess_dbh;

$r=mysql_query("delete from sesslib where sid=@#$sid@#", $sess_dbh);
return($r);
}

function sess_gc($maxlifetime) {
global $sess_dbh, $sess_maxlifetime;

$r=mysql_query("delete from sesslib where unix_timestamp(now())-unix_timestamp(time)>$sess_maxlifetime", $sess_dbh);
return mysql_affected_rows($sess_dbh);
}

session_set_save_handler("sess_open", "sess_close", "sess_read", "sess_write", "sess_destroy", "sess_gc");

?>