Удаление куска кода из таблицы в базе

delete_fill.php

<?php
// mysql -u root  -p autoruk < j25_content.sql
$servername = "localhost";
$database = "";
$username = "";
$password = "";
// Создаем соединение
$link = mysqli_connect($servername, $username, $password, $database);
// Проверяем соединение
if (!$link) {
    die("Connection failed: " . mysqli_connect_error());
}else{

    $sql = 'select * from  `j25_content` where `fulltext` LIKE \'%id="imagePreviewSrc" %\'';
    $result = mysqli_query($link, $sql);
    mysqli_set_charset($link,"utf8");
    if ($result == false) {
        print("Произошла ошибка при выполнении запроса");
    }
    else {
        $result = mysqli_query($link, $sql);
        while ($row = mysqli_fetch_array($result)) {
            $txt =  $row['fulltext'];
            $id =  $row['id'];
            echo $id ;
           $res = preg_replace("|id=\"imagePreviewSrc\" |",'', $txt);
           $update = "update  `j25_content` set `fulltext` = '$res' where `id` =  '$id'";
           mysqli_query($link, $update);

           
             $sql = "select * from  `j25_content` where `id` =  $id limit 1";
             $resulttxt = mysqli_query($link, $sql);
            while ($rows = mysqli_fetch_array($resulttxt)) {
           
             echo $rows['fulltext'];
            }
           exit();
        }
    }

}
echo "Connected successfully";
mysqli_close($link);