mysql DELETE查询失败，使用内爆IN子句

我目前正在用复选框填充数组，内爆数组变量，并在DELETE函数的in子句中使用该变量。var_dump显示我正在创建一个正确的查询，但我无法进行任何删除。这是一种新的方法来解决我已经有一个月左右的问题

这是我的东西。

//Connect to the db
$id_array = NULL;
// Make the query to display user's uploads
 $q = "SELECT upload_id, title, genre, length, created, views
        FROM upload
        WHERE owner_id =". $_SESSION['user_id'] ."
        ORDER BY title ASC";

$r = mysqli_query ($dbc, $q); // Run the query
if($r)
    {
        // If it ran okay, display the records
        echo '<table align="center"
            cellspacing="3" cellpadding="3"
            width="75%">
           <tr><td align="left"><b>Title</b></td>
           <td align="left"><b>Genre</b></td>
           <td align="left"><b>Pages</b></td>
           <td align="left"><b>Submitted</b></td>
           <td align="left"><b>Views</b></td>
           </tr>';
        // Fetch and print all the records:
?><form action="/nbproject/newwriter_profile.php" method="post">
<?php
  while ($row = mysqli_fetch_array($r,MYSQLI_ASSOC))
    {
       echo '<tr><td align="left">' .
       $row['title'] . '</td><td align="left">'
       . $row['genre'] . '</td><td align="left">'
       . $row['length'] . '</td><td align="left">'
       . $row['created'] . '</td><td align="left">'
       . $row['views'] . '</td><td align="left">' //. var_dump($row) //dump row value for testing
       . '<input type="checkbox" name="checkbox[]"  value= "'.$row['upload_id'].'"'.' />'.' </td>'. '</tr>';
    }
   echo '</table>'; // Close the table
        ?>

上面的代码创建了一个简单的表，每个记录都显示了一个相应的复选框，选中以删除，然后单击"删除"

         <input type="submit" name="delete" value="Delete" align="right"/> 
       </form>
<?php
   } // End of if ($r) IF.
    mysqli_close($dbc); // Close the database connection

自定义删除功能：

function submit_delete() {
  if(!is_null($_POST['delete']) && !is_null($_POST['checkbox'])) { //Check to see if a delete command has been submitted.
    //This will dump your checkbox array to your screen if the submit works.
    //You can manually check to see if you're getting the correct array with values
   // var_dump($_POST['checkbox']);//Comment this out once it's working.
    $id_array = $_POST['checkbox'];
    $id_array = array_map('intval', $id_array);
    $id_array = array_unique($id_array);
    $id_array = implode(',',$id_array);
    //var_dump($id_array);
    deleteUploads($id_array);
  }
  else {
    echo "Error: submit_delete called without valid checkbox delete.";//var_dump($_POST['checkbox']);
  }
}
$delete_success = false;
function deleteUploads ($id_array) {
    require_once(my connection to db);
    mysqli_free_result($r);
  if (count($id_array) <= 0) {   echo "Error: No deletes in id_array!"; echo 'wtf'; }
  //var_dump($id_array);

上面的var dump显示了正确的id，如我的mysql数据库中所示

    $gone = "DELETE  FROM `upload` WHERE `upload_id` IN ("."$id_array".")";
    var_dump($gone);

上面的var用逗号分隔的id的验证查询的格式是否正确

    $goodbye = mysqli_query($dbc, $gone);
    if ($goodbye) { $delete_success = true; var_dump($delete_success);}
    else { $delete_success = false;}
    var_dump($delete_success);

以上var转储显示bool错误

    //mysqli_close($dbc);
    if($delete_success == true) { echo 'done';
    header('Location: newwriter_profile.php');
  } else
      {
    echo "Error b/c delete failed";

上面的回波显示在检查了任意数量的框并点击删除之后

      }
  }

submit_delete();
mysqli_free_result($goodbye);
mysqli_close($dbc);

?>