thinkphp 用 create 更新数据无效

[444683462]

//修改的部分
if(I('post.id')){
$Department=D('Department');
if (!$Department->create($_POST,2)){ // 创建数据对象
$this->error($Department->getError());
}else{
$result=$Department->save();

if(false !== $result){
                $id = I('post.id');
                $this->redirect('updateDepartment',array('update'=>"1",'id' =>"$id"));
            }else{
                $this->error("数据修改失败");
            }
        }

    }

[zts1993]

输出一下$Department->getlastsql();
看下sql语句是否正确