René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"update back to null does not work for date or datetime","articleBody":"```\r\nschema = dj.schema('test_tables')\r\n@schema\r\nclass Test(dj.Manual):\r\n    definition = \"\"\"\r\n    pk: int\r\n    ----\r\n    date=null: date\r\n    \"\"\"\r\n\r\nTest.insert1((2, '2019-09-25'))\r\ndj.Table._update(Test, 'date', None)\r\n ```\r\ngives the error:\r\n```\r\n---------------------------------------------------------------------------\r\nAttributeError                            Traceback (most recent call last)\r\n\u003cipython-input-33-b3f6114b7496\u003e in \u003cmodule\u003e\r\n----\u003e 1 dj.Table._update(test.Test \u0026 'pk=1', 'date', None)\r\n\r\nAttributeError: module 'test' has no attribute 'Test'\r\n\r\nIn [34]: dj.Table._update(Test \u0026 'pk=1', 'date', None)\r\n---------------------------------------------------------------------------\r\nTypeError                                 Traceback (most recent call last)\r\n\u003cipython-input-34-39bb5cd3e2c5\u003e in \u003cmodule\u003e\r\n----\u003e 1 dj.Table._update(Test \u0026 'pk=1', 'date', None)\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/table.py in _update(self, attrname, value)\r\n    595             placeholder=placeholder,\r\n    596             where_clause=self.where_clause)\r\n--\u003e 597         self.connection.query(command, args=(value, ) if value is not None else ())\r\n    598\r\n    599\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in query(self, query, args, as_dict, suppress_warnings, reconnect)\r\n    206         cursor = self._conn.cursor(cursor=cursor_class)\r\n    207         try:\r\n--\u003e 208             self.__execute_query(cursor, query, args, cursor_class, suppress_warnings)\r\n    209         except errors.LostConnectionError:\r\n    210             if not reconnect:\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in __execute_query(cursor, query, args, cursor_class, suppress_warnings)\r\n    186                     # suppress all warnings arising from underlying SQL library\r\n    187                     warnings.simplefilter(\"ignore\")\r\n--\u003e 188                 cursor.execute(query, args)\r\n    189         except client_errors as err:\r\n    190             raise translate_query_error(err, query)\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/cursors.py in execute(self, query, args)\r\n    166             pass\r\n    167\r\n--\u003e 168         query = self.mogrify(query, args)\r\n    169\r\n    170         result = self._query(query)\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/cursors.py in mogrify(self, query, args)\r\n    145\r\n    146         if args is not None:\r\n--\u003e 147             query = query % self._escape_args(args, conn)\r\n    148\r\n    149         return query\r\n\r\nTypeError: not enough arguments for format string\r\n```\r\n\r\nInsert as an empty string gives:\r\n```\r\n---------------------------------------------------------------------------\r\nInternalError                             Traceback (most recent call last)\r\n\u003cipython-input-36-3407a586c925\u003e in \u003cmodule\u003e\r\n----\u003e 1 dj.Table._update(Test \u0026 'pk=1', 'date', '')\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/table.py in _update(self, attrname, value)\r\n    595             placeholder=placeholder,\r\n    596             where_clause=self.where_clause)\r\n--\u003e 597         self.connection.query(command, args=(value, ) if value is not None else ())\r\n    598\r\n    599\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in query(self, query, args, as_dict, suppress_warnings, reconnect)\r\n    206         cursor = self._conn.cursor(cursor=cursor_class)\r\n    207         try:\r\n--\u003e 208             self.__execute_query(cursor, query, args, cursor_class, suppress_warnings)\r\n    209         except errors.LostConnectionError:\r\n    210             if not reconnect:\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in __execute_query(cursor, query, args, cursor_class, suppress_warnings)\r\n    188                 cursor.execute(query, args)\r\n    189         except client_errors as err:\r\n--\u003e 190             raise translate_query_error(err, query)\r\n    191\r\n    192     def query(self, query, args=(), *, as_dict=False, suppress_warnings=True, reconnect=None):\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in translate_query_error(client_error, query)\r\n     48     if isinstance(client_error, client.err.InternalError) and client_error.args[0] == 1364:\r\n     49         return errors.MissingAttributeError(*client_error.args[1:])\r\n---\u003e 50     raise client_error\r\n     51\r\n     52\r\n\r\n~/anaconda3/lib/python3.7/site-packages/datajoint/connection.py in __execute_query(cursor, query, args, cursor_class, suppress_warnings)\r\n    186                     # suppress all warnings arising from underlying SQL library\r\n    187                     warnings.simplefilter(\"ignore\")\r\n--\u003e 188                 cursor.execute(query, args)\r\n    189         except client_errors as err:\r\n    190             raise translate_query_error(err, query)\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/cursors.py in execute(self, query, args)\r\n    168         query = self.mogrify(query, args)\r\n    169\r\n--\u003e 170         result = self._query(query)\r\n    171         self._executed = query\r\n    172         return result\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/cursors.py in _query(self, q)\r\n    326         self._last_executed = q\r\n    327         self._clear_result()\r\n--\u003e 328         conn.query(q)\r\n    329         self._do_get_result()\r\n    330         return self.rowcount\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/connections.py in query(self, sql, unbuffered)\r\n    515                 sql = sql.encode(self.encoding, 'surrogateescape')\r\n    516         self._execute_command(COMMAND.COM_QUERY, sql)\r\n--\u003e 517         self._affected_rows = self._read_query_result(unbuffered=unbuffered)\r\n    518         return self._affected_rows\r\n    519\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/connections.py in _read_query_result(self, unbuffered)\r\n    730         else:\r\n    731             result = MySQLResult(self)\r\n--\u003e 732             result.read()\r\n    733         self._result = result\r\n    734         if result.server_status is not None:\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/connections.py in read(self)\r\n   1073     def read(self):\r\n   1074         try:\r\n-\u003e 1075             first_packet = self.connection._read_packet()\r\n   1076\r\n   1077             if first_packet.is_ok_packet():\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/connections.py in _read_packet(self, packet_type)\r\n    682\r\n    683         packet = packet_type(buff, self.encoding)\r\n--\u003e 684         packet.check_error()\r\n    685         return packet\r\n    686\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/protocol.py in check_error(self)\r\n    218             errno = self.read_uint16()\r\n    219             if DEBUG: print(\"errno =\", errno)\r\n--\u003e 220             err.raise_mysql_exception(self._data)\r\n    221\r\n    222     def dump(self):\r\n\r\n~/anaconda3/lib/python3.7/site-packages/pymysql/err.py in raise_mysql_exception(data)\r\n    107         errval = data[3:].decode('utf-8', 'replace')\r\n    108     errorclass = error_map.get(errno, InternalError)\r\n--\u003e 109     raise errorclass(errno, errval)\r\n\r\nInternalError: (1292, \"Incorrect date value: '' for column `test_tables`.`test`.`date` at row 1\")\r\n```","author":{"url":"https://github.com/shenshan","@type":"Person","name":"shenshan"},"datePublished":"2019-09-26T18:54:40.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/664/datajoint-python/issues/664"}