检查逻辑错误并创建重复条目的PHP代码

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接数据库失败: " . $conn->connect_error);
}

// 检查重复条目
$checkQuery = "SELECT COUNT(*) as count FROM table_name WHERE column_name = 'value'";
$result = $conn->query($checkQuery);
if ($result->num_rows > 0) {
    $row = $result->fetch_assoc();
    $count = $row["count"];
    if ($count > 0) {
        echo "已存在重复条目";
    } else {
        // 创建新条目
        $insertQuery = "INSERT INTO table_name (column_name) VALUES ('value')";
        if ($conn->query($insertQuery) === TRUE) {
            echo "新条目创建成功";
        } else {
            echo "创建新条目时出错: " . $conn->error;
        }
    }
} else {
    echo "执行查询时出错: " . $conn->error;
}

// 关闭数据库连接
$conn->close();
?>