从mysql获取数据以显示在网页上

Question

<?php 
session_start(); // First thing... every time 
require_once("connect.php"); if(!isset($_SESSION['username'])){ 
header('Location: login.php'); the top 
exit; // Always include after redirect. 
} 
if(isset($_POST['submit'])){ 

$sql = "UPDATE user SET attendance1 = '" . mysql_real_escape_string($_POST['attendance1']) . "' WHERE username = '" . mysql_real_escape_string($_SESSION['username']) . "'"; 
mysql_query($sql) or die("Error in SQL: " . mysql_error()); 

$query="SELECT lastname FROM user WHERE username = " . $_SESSION['username'] . ";"; 
$result=mysql_query($query); 
    $row = mysql_fetch_assoc($result); 
    $_SESSION[lastname] = $row[lastname]; 
header("Location: thankyou.html", true, 303); // Look up "303: See Other" 
    exit; 
} 
?> 

上面是我的php代码。我想要做的是将数据库中的姓氏显示在网页上。在网页

代码

Welcome <?php echo $_SESSION['lastname']; ?>. 

的问题是姓不欢迎后

Answer 1

显示我了解U [R刚开显示表，即选择显示。如果你需要姓氏和显示，那么你应该做的选择显示，姓氏从用户。

Answer 2

希望这会起作用。

<?php 
session_start(); // First thing... every time 
require_once("connect.php"); if(!isset($_SESSION['username'])){ 
header('Location: login.php'); the top 
exit; // Always include after redirect. 
} 
if(isset($_POST['submit'])){ 

$userName = mysql_real_escape_string($_SESSION['username']); 
$sql = "UPDATE user SET attendance1 = '" . mysql_real_escape_string($_POST['attendance1']) . "' WHERE username = '" . $userName . "'"; 
mysql_query($sql) or die("Error in SQL: " . mysql_error()); 

$query="SELECT lastname FROM user WHERE username = '" . $userName . "';"; 
$result=mysql_query($query); 
    $row = mysql_fetch_assoc($result); 
    $_SESSION['display'] = $row['lastname']; 
    $_SESSION['lastname'] = $row['lastname']; 
header("Location: thankyou.html", true, 303); // Look up "303: See Other" 
    exit; 
} 
?> 

Answer 3

您还没有在数组键的第15行使用撇号，因此PHP正在寻找与名称为lastname的常量相对应的键名相匹配的键。