Python flask+pymysql 数据库访问异常一次之后就全是异常

跑着跑着莫名其妙，某次请求发出之后就异常了。本来好好的，但是之后就全是这样的异常。

[2019-01-02 21:02:16,374] ERROR in app: Exception on /users [GET] Traceback (most recent call last): File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 2292, in wsgi_app respOnse= self.full_dispatch_request() File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1815, in full_dispatch_request rv = self.handle_user_exception(e) File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1718, in handle_user_exception reraise(exc_type, exc_value, tb) File "/usr/local/lib/python3.5/dist-packages/flask/_compat.py", line 35, in reraise raise value File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1813, in full_dispatch_request rv = self.dispatch_request() File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1799, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "controller.py", line 31, in get_users user_num = dto.count_user() File "/root/spider/web/dto.py", line 34, in count_user cursor.execute("SELECT COUNT(*) FROM user") File "/usr/local/lib/python3.5/dist-packages/pymysql/cursors.py", line 170, in execute result = self._query(query) File "/usr/local/lib/python3.5/dist-packages/pymysql/cursors.py", line 328, in _query conn.query(q) File "/usr/local/lib/python3.5/dist-packages/pymysql/connections.py", line 516, in query self._execute_command(COMMAND.COM_QUERY, sql) File "/usr/local/lib/python3.5/dist-packages/pymysql/connections.py", line 750, in _execute_command raise err.InterfaceError("(0, '')") pymysql.err.InterfaceError: (0, '') 

不懂是什么情况。

代码如下： 接口：

@app.route('/user/<uid>') def get_user_photo(uid): uid = int(uid) offset = request.args.get('offset', type=int, default=0) size = request.args.get('size', type=int, default=8) photo_num = dao.count_photo(uid) page_info = {} if offset+size > photo_num: size = photo_num - offset page_info = {'has_next': False} else: page_info = {'has_next': True, 'next': offset+size} result_data = dao.get_user_photo_info(uid, offset, size) for photo in result_data: photo['date'] = str(photo['date']) result_data = dict(page_data=result_data) result_data['page_info'] = page_info result_data['count'] = photo_num result_data['user_info'] = dao.get_user_info(uid) return filtrate_headers(json.dumps(BaseResponse(200, result_data), default=lambda obj: obj.__dict__)) 

dao：

def count_user(): cursor.execute("SELECT COUNT(*) FROM user") result = cursor.fetchall() return result[0]['COUNT(*)'] def get_user_info(uid): get_user_sql = "SELECT * FROM user WHERE uid=%d" %uid cursor.execute(get_user_sql) result = cursor.fetchall() if len(result) == 1: return result[0] else: return dict()