php - 在 while (mysql) 中添加 session

Question

if(isset($_SESSION['username']))
{
   $con = mysql_connect('localhost','root','');
   mysql_select_db('chatbox',$con);

   $result = mysql_query("SELECT id FROM users");
   mysql_query("UPDATE users SET `online` = 0 WHERE `username` = ".$username."");
}

你能不能让用户名是 session (即登录)等于

mysql_query("UPDATE users SET `online` = 0 WHERE `username` = "to_put_it_here");

Answer 1

简单又可爱的技巧

$username = $_SESSION['username'];    
if(isset($username))
{
   $con = mysql_connect('localhost','root','');
   mysql_select_db('chatbox',$con);

   $result = mysql_query("SELECT id FROM users");
   mysql_query("UPDATE users SET `online` = 0 WHERE `username` = '$username' ");
}