bug:emqx_messages table payload type wrong

[gongna-au]

https://www.emqx.io/docs/zh/latest/data-integration/data-bridge-mysql.html

CREATE TABLE emqx_messages (
id INT AUTO_INCREMENT PRIMARY KEY,
clientid VARCHAR(255),
topic VARCHAR(255),
payload BLOB,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

如果想通过mqttx pub -i emqx_c -t t/1 -m '{ "msg": "hello MySQL" }' 发送消息并且存储到emqx_messages 这里的payload 应该为VARCHAR(255)才能得到

mysql> select * from emqx_messages;
+----+----------+-------+--------------------------+---------------------+
| id | clientid | topic | payload                  | created_at          |
+----+----------+-------+--------------------------+---------------------+
|  1 | emqx_c   | t/1   | { "msg": "hello MySQL" } | 2022-12-09 08:44:07 |
+----+----------+-------+--------------------------+---------------------+
1 row in set (0.01 sec)