如何在php中获取会话ID或用户名?

时间:2012-01-02 17:18:35

标签: php session session-variables

我有一个用户可以登录的网站。我试过:

<?php echo $_SESSION ['userlogin']

当用户登录时,我将其会话设置为userlogin,但不会显示其用户名。

This is the tutorial I used

3 个答案:

答案 0 :(得分:12)

在使用之前你有start the session吗?

所以设置它:

<?php
   //Fetch the username from the database
   //The $login and $password I use here are examples. You should substitute this
   //query with one that matches your needs and variables.
   //On top of that I ASSUMED you are storing your passwords MD5 encrypted. If not,
   //simply remove the md5() function from below.
   $query = "SELECT name FROM users WHERE login='" . mysql_real_escape_string($login) . "' AND password='" . md5($password)  . "'";
   $result = mysql_query($query);

   //Check if any row was returned. If so, fetch the name from that row
   if (mysql_num_rows($result) == 1) {
      $row = mysql_fetch_assoc_assoc($result);
      $name = $row['name'];

      //Start your session
      session_start();
      //Store the name in the session
      $_SESSION['userlogin'] = $name;
   }
   else {
      echo "The combination of the login and password do not match".
   }
?>

要在另一页上检索它,请执行以下操作:

<?php
   //Start your session
   session_start();
   //Read your session (if it is set)
   if (isset($_SESSION['userlogin']))
      echo $_SESSION['userlogin'];
?>

修改

有关如何创建登录表单的更多信息..您说您尝试设置$_SESSION['user'],但这不起作用。

所以请确保在此之前确实做了session_start();。如果你这样做,一切都应该有效。除非您为会话分配一个空变量。因此,双重检查您分配的变量实际上包含一个值。像:

<?php
   session_start();
   echo "Assigning session value to: " . $user;
   $_SESSION['user'] = $user;
?>

在教程中,您将我与他们联系起来:

$_SESSION[user]=$_GET[userlogin];

这意味着他们正在分配他们从他们在这里创建的登录表单中获得的值:

function loginform() {
   print "please enter your login information to proceed with our site";
   print ("<table border='2'><tr><td>username</td><td><input type='text' name='userlogin' size'20'></td></tr><tr><td>password</td><td><input type='password' name='password' size'20'></td></tr></table>");
   print "<input type='submit' >";    
   print "<h3><a href='registerform.php'>register now!</a></h3>";    
} 

你看到<input type='text' name='userlogin' size'20'>。但是此表单周围没有<form></form>标记..所以这不会正确发布。所以你应该做的是:

<form method="POST" action="index.php">
   <label for="userlogin">Username:</label> <input type="text" id="userlogin" name="userlogin" size="20" />
   <label for="password">Password:</label> <input type="password" id="password" name="password" size="20" />
   <input type="submit" value="login" />   
</form>

此表单会将表单以用户登录密码作为$_POST变量发回 index.php

index.php 中,您可以执行以下操作:

<?php
   //Get variables:
   $login = mysql_real_escape_string($_POST['userlogin']);
   $pass = mysql_real_escape_string($_POST['password']);

   //Check your table:
   $query = "SELECT userlogin FROM users WHERE userlogin = '" . $login . "' AND password='" . $pass . "'";
   $result = mysql_query($query);

   //Check if this user exists:
   if (mysql_num_rows($result) == 1) {
      echo "User exists!";

      //Store the login in the session:
      session_start();
      $_SESSION['userlogin'] = $login;
   }
   else {
      echo "Unknown user";
   }
?>

如果不为您编写完整的代码,我无法更清楚。所以我希望这可以帮到你。

答案 1 :(得分:1)

把session_start();回声之前

答案 2 :(得分:0)

如果没有显示更多代码,我们无法评论太多,但您确定在每个使用会话变量的页面中调用session_start吗? 还要确保使用相同的大小写(userlogin!= UserLogin)。