已登录用户数据库数据提取：如何获取姓名与头像信息

Hey there! Let's get that user profile display working for you. The core issue right now is two-fold: you're only storing the user's email in the session, and you tried using a deprecated MySQL function that doesn't play nice with MySQLi. Let's break this down step by step.

1. Why Your Previous Attempt Crashed #

The line $row = mysql_fetch_array($result); caused your site to break because:

• You're using MySQLi for your database connections, but mysql_fetch_array() belongs to the old, deprecated mysql_* extension. These two systems aren't compatible—you need to use MySQLi-specific functions like mysqli_fetch_assoc() instead.

2. Modify Your Login Page to Store Full User Data in Session #

Right now, you're only saving the user's email to the session. We need to fetch their full row from the database and store the name/avatar (and any other data you need) in the session when they log in successfully.

Update your login page code where you handle the successful login:

if($rows==1){
    // Fetch the full user data from the query result
    $user = mysqli_fetch_assoc($result);
    
    // Store critical user data in the session
    $_SESSION['user_email'] = $email;
    $_SESSION['user_name'] = $user['user_name']; // Replace with your actual database field name for the user's name
    $_SESSION['user_avatar'] = $user['user_avatar']; // Replace with your field name for avatar (e.g., file path or URL)
    
    // Redirect and exit to prevent further code execution
    header("Location: ../index.php");
    exit();
}else{
    echo "<div class='form'><h3>Username/password is incorrect.</h3><br/>Click here to <a href='login.php'>Login</a></div>";
}

Important Notes Here: #

• Double-check your users table schema: make sure you have columns for the user's name (e.g., user_name, full_name) and avatar (e.g., user_avatar—this could be a relative file path like ../avatars/jdoe.jpg or a URL).
• If your field names are different (like name instead of user_name), adjust the array keys in $user['your_field_name'] to match.

3. Display the User Name & Avatar on Your Pages #

Now that the data is stored in the session, you can display it anywhere on your secure pages (after including auth.php, which you already do):

<!-- Display Welcome Message with Name -->
<p>Welcome <?php echo $_SESSION['user_name']; ?></p>

<!-- Display User Avatar (adjust styling as needed) -->
<?php if (!empty($_SESSION['user_avatar'])): ?>
    <img src="<?php echo $_SESSION['user_avatar']; ?>" alt="User Avatar" style="width: 50px; height: 50px; border-radius: 50%;">
<?php else: ?>
    <!-- Fallback placeholder if no avatar exists -->
    <div style="width:50px;height:50px;border-radius:50%;background:#ccc;display:flex;align-items:center;justify-content:center;">
        <?php echo strtoupper(substr($_SESSION['user_name'], 0, 1)); ?>
    </div>
<?php endif; ?>

4. Quick Security & Best Practice Checks #

• Always add exit(); immediately after header("Location: ..."); to prevent the rest of your script from running (this avoids potential bugs or security issues).
• Make sure your auth.php starts the session with session_start(); before any output is sent to the browser (which it looks like you already do).
• Consider using prepared statements for your login query instead of directly inserting user input into the SQL string—this prevents SQL injection attacks. Here's a quick example of how to adjust that query:

// Replace your current query and result with this
$query = "SELECT * FROM `users` WHERE user_email = ? AND user_pwd = ?";
$stmt = mysqli_prepare($con, $query);
mysqli_stmt_bind_param($stmt, "ss", $email, md5($password));
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
$rows = mysqli_num_rows($result);

That's it! Follow these steps, and you should see the user's name and avatar showing up in your site's header or profile section.

内容的提问来源于stack exchange，提问作者Bigsease30