<?php
// 连接到数据库
$conn = mysqli_connect("localhost", "root", "数据库密码", "数据库名");

// 检查连接是否成功
if (!$conn) {
    die("连接失败: " . mysqli_connect_error());
}

// 编写SQL语句
$sql = "DELETE FROM www_ecms_news_data_6 WHERE id NOT IN (SELECT id FROM www_ecms_ecms_news)";

// 执行SQL语句
if (mysqli_query($conn, $sql)) {
    echo "记录删除成功";
} else {
    echo "删除记录时出错: " . mysqli_error($conn);
}

// 关闭数据库连接
mysqli_close($conn);
?>