if(!empty($ids)){
//对关系表进行处理
foreach ($binding_tags as $key => $val) {
$arr_past[] = $val['id'];
}
$arr_now = explode(",",$ids);
$len = count($arr_now)-1;
$ids_now = array_slice($arr_now,0,$len);//最终的需要绑定的标签id数组
//对数组做比较
print_r($arr_past);
print_r($ids_now);
//$arr_final = array_diff_assoc($arr_past,$ids_now);
$arr_final = array_merge(array_diff($arr_past,$ids_now),array_diff($ids_now,$arr_past)); //关键
print_r($arr_final );
}