think\Model::delete PHP Method

    public function delete()
    {
        if (false === $this->trigger('before_delete', $this)) {
            return false;
        }
        $result = $this->db()->delete($this->data);
        $this->trigger('after_delete', $this);
        return $result;
    }

 public function delete($id)
 {
     $model = new Model('Comment');
     $data = $model->find($id);
     if (empty($data)) {
         $this->error('评论不存在');
     }
     if (!$model->delete($id)) {
         $this->error('删除失败');
     } else {
         $this->success('删除成功');
     }
 }