我想将一些帖子从旧站点转移到新站点，但是 INSERT 到新数据库会在旧站点中出现错误 SELECT

我的主机上有两个网站，每个网站都链接到自己的数据库。两者都在 WordPress 上。我正在尝试与两个数据库建立两个单独的连接，并从一个数据库下载信息并将信息放入另一个数据库中。这是我得到的：

<?php

$servername = "localhost";
$database = "xxxxxxxxxx";
$username = "xxxxxxxxxxxx";
$password = "xxxxxxxxxxxx";

$servername2 = "localhost";
$database2 = "xxxxxxxxxxxxxx";
$username2 = "xxxxxxxxxxxxx";
$password2 = "xxxxxxxxxxxxx";

$conn = mysqli_connect($servername, $username, $password, $database);

$conn2 = mysqli_connect($servername2, $username2, $password2, $database2);

$sql = "SELECT * FROM wp_posts";

$counter = 600;

$iterator = 1;

if($result = $conn->query($sql)){
    foreach($result as $row){

        $stringArr[] = "(" . $counter . ", '" . $row['post_author'] . "', '" . $row['post_date'] . "', '" . $row['post_date_gmt'] . "',
        '" . $row['post_content'] . "', '" . $row['post_title'] . "', '" . $row['post_excerpt'] . "',
        '" . $row['post_status'] . "', '" . $row['comment_status'] . "', '" . $row['ping_status'] . "',
        '" . $row['post_password'] . "', '" . $row['post_name'] . "', '" . $row['to_ping'] . "',
        '" . $row['pinged'] . "', '" . $row['post_modified'] . "', '" . $row['post_modified_gmt'] . "',
        '" . $row['post_content_filtered'] . "', '" . $row['post_content_filtered'] . "', " . $row['post_parent'] . ",
        '" . $row['guid'] . "', " . $row['menu_order'] . ", '" . $row['post_type'] . "', '" . $row['post_mime_type'] . "',
        " . $row['comment_count'] . ")"; 
/*        
        if($iterator%50 == 0) {
            print_r($stringArr);

            exit;
        }*/
        $iterator++;
        $counter++;
 /*       
        print_r($string);
        
        $sql2 = "INSERT INTO serjam_wp1.wp_post VALUES (" . $string . ")";

        if ($conn2->query($sql2) === TRUE) {
          echo "New record created successfully";
        } else {
          echo "Error: " . $sql . "<br>" . $conn->error;
            }
        */
 //       print_r($string);
         
    }
}

$sql2 = "INSERT INTO serjam_wp1.wp_post VALUES (" . implode(",", $stringArr) . ")";

        if ($conn2->query($sql2) === TRUE) {
          echo "New record created successfully";
        } else {
          echo "Error: " . $sql . "<br>" . $conn->error;
            }

如果我只是在浏览器中显示数据库的内容（信息已经存在），那么我就可以得到一切。

也就是说，如果没有 INSERT 代码，则该脚本将起作用。但如果是，那么 SELECT 将停止工作。我从信息所在的站点运行脚本。