我的用于MySQL的PHP重复数据消除程序有什么问题？

我试图在我的一个MySQL表中消除重复的条目，但我一直收到相同的错误

Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in C:\Inetpub\vhosts\myexamplewebsite.com\httpdocs\duplicate\index.php on line 25

请问我做错了什么

<?php

$dedupe=mysqli_connect("localhost","user","pass","database");

$result = mysqli_query($dedupe,"SELECT * FROM `videos` WHERE `dupe`=0 order by RAND() ");

while($row = mysqli_fetch_array($result)) 
    {
        $vod_index = $row['index'];
        $vod_video_name = $row['video_name'];
        $vod_vidstart = $row['vidstart'];
        $vod_providerid = $row['providerid'];
        $vod_dupe = $row['dupe'];


    $result2 = mysqli_query($dedupe,"SELECT * FROM `videos` WHERE `index` != '$vod_index';
    AND `dupe`='0'
    AND `video_name` = '$vod_video_name'
    AND `vidstart` = '$vod_vidstart'
    AND `providerid` = '$vod_providerid'
    AND `index` != '$vod_index'
     ");


     while($row2 = mysqli_fetch_array($result2)) 
    {
        $vod_index2 = $row2['index'];
        $vod_video_name2 = $row2['video_name'];
        $vod_vidstart2 = $row2['vidstart'];
        $vod_providerid2 = $row2['providerid'];
        $vod_dupe2 = $row2['dupe'];


        mysqli_query($dedupe,"UPDATE `videos` set `dupe`=1
WHERE `index`='$vod_index2' "); 
 {
  echo("Error description: " . mysqli_error($recordcon));
  }

  mysqli_query($dedupe,"INSERT INTO deduped (index,videos_index)
VALUES ('NULL','$vod_index2')");

    }
    }

    mysqli_close($dedupe); 
?>

---

如果查询中出现意外分号，请按如下方式尝试：

$result2 = mysqli_query($dedupe,"SELECT * FROM `videos` WHERE `index` != '$vod_index'
    AND `dupe`='0'
    AND `video_name` = '$vod_video_name'
    AND `vidstart` = '$vod_vidstart'
    AND `providerid` = '$vod_providerid'
    AND `index` != '$vod_index'
     ");