dedecms后台提示用户名不存在

USE dede;
SELECT * FROM dede_admin WHERE usertype='1' AND userid='输入的用户名';

SELECT * FROM dede_admin WHERE usertype='1' AND userid='输入的用户名';

// config.php
$cfg_adminusername = '正确的管理员用户名';

// data/config.cache.bak.php
'cfg_adminusername' => '正确的管理员用户名',

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "dede";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

$input_username = $_POST['username'];

$sql = "SELECT * FROM dede_admin WHERE usertype='1' AND userid='$input_username'";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    echo "用户名存在";
} else {
    echo "用户名不存在";
}

$conn->close();
?>