PHP-通过url id标识用户

我有3个按钮来排列我的用户。管理员，会员和一个按钮来禁止他们。所以现在我想用$\u GET通过他们的url id来识别他们。但当我这样做时，我会得到一个错误：

分析错误：语法错误，意外的T_封装_和_空白， 应为标识符T_字符串或变量T_变量或数字 T_NUM_字符串

我怎样才能解决这个问题？我感谢你的帮助

<?php
 include_once('connection.php');
 if (isset($_POST['ban'])) { 
  $sql = "UPDATE
          t_user_info
        SET
          user_level = 3
        WHERE 
          id = $_GET['id']";  

$query = $conn->prepare($sql);
$query ->execute(array('user_level' => $user_level));

session_unset();
session_destroy();
header('Location: /PHP/index.php?page=ban');
}
if (isset($_POST['admin_btn'])) { 
 $sql = "UPDATE
          t_user_info
        SET
          user_level  = 1
        WHERE 
          id       = $_GET['id']";  

$query = $conn->prepare($sql);
$query ->execute();
header('Location: /PHP/index.php?page=admin');

}

if (isset($_POST['member_btn'])) { 
$sql = "UPDATE
          t_user_info
        SET
          user_level  = 2
        WHERE 
          id       = $_GET['id']";   

$query = $conn->prepare($sql);
$query ->execute();
header('Location: /PHP/index.php?page=member');

}

?>

---

您的更新查询有语法错误，您没有绑定正确的值。试试这个：

<?php
include_once('connection.php');
if (isset($_POST['ban'])) { 
    $sql = "UPDATE
            t_user_info
            SET user_level = 3
            WHERE id = :id";

    $query = $conn->prepare($sql);
    $query ->execute(array(':id'=>$_GET['id']));

    session_unset();
    session_destroy();
    header('Location: /PHP/index.php?page=ban');
    exit;
}

if (isset($_POST['admin_btn'])) { 
    $sql = "UPDATE
            t_user_info
            SET user_level  = 1
            WHERE id = :id";

    $query = $conn->prepare($sql);
    $query ->execute(array(':id'=>$_GET['id']));
    header('Location: /PHP/index.php?page=admin');
    exit;
}

if (isset($_POST['member_btn'])) { 
    $sql = "UPDATE t_user_info
            SET user_level  = 2 
            WHERE id = :id";

    $query = $conn->prepare($sql);
    $query ->execute(array(':id'=>$_GET['id']));
    header('Location: /PHP/index.php?page=member');
    exit;
}

?>

---

我在你的代码中看不到url id哦！！对于用户_级别=1，也进行了相同的设置。。。。哥们，什么事，马上说。