[odb-users] inserting chinese characters into mysql error (utf8mb4 and utf8 are tried)

[不明真相]

When i insert some chinese characters into mysql  via odb, i got the error message "Incorrect string value: '\xD6\xD0\xB9\xFA' for column 'NATION' at row 1", i know it's the wrong setting of character set, i tried my efforts to fix the issue but all in vain.
firstly i used odb2.4, mysql 8.0 mysql connector c 6.1.11 and vs2015 in my project, i tried using utf8mb4 charset, below is my configuration file:
[mysqld] character-set-server = utf8mb4 collation-server = utf8mb4_general_ci init_connect='SET NAMES utf8mb4' skip-character-set-client-handshake = true [mysql] default-character-set=utf8mb4 [client] default-character-set=utf8mb4and it seems nothing wrong with the mysql server:     mysql> SHOW VARIABLES WHERE Variable_name LIKE 'character\_set\_%' OR Variable_name LIKE 'collation%';     +--------------------------+--------------------+     | Variable_name            | Value              |     +--------------------------+--------------------+     | character_set_client     | utf8mb4            |     | character_set_connection | utf8mb4            |     | character_set_database   | utf8mb4            |     | character_set_filesystem | binary             |     | character_set_results    | utf8mb4            |     | character_set_server     | utf8mb4            |     | character_set_system     | utf8               |     | collation_connection     | utf8mb4_general_ci |     | collation_database       | utf8mb4_general_ci |     | collation_server         | utf8mb4_general_ci |     +--------------------------+--------------------+          mysql> show create table basininfo;     ------------------------------------------------------------------------------------------------+              | basininfo | CREATE TABLE `basininfo` (           `ID` int(11) NOT NULL AUTO_INCREMENT,           `BASIN_NAME` varchar(1000) DEFAULT NULL,           `NATION` varchar(1000) DEFAULT NULL,             PRIMARY KEY (`ID`)         ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 the code piece induced the error is below:     auto_ptr<odb::database> db(     	new odb::mysql::database(         "news"     // database login name       	, "news123" // database password       	, "newsdb" // database name       	, "localhost"     	, 3306     	, nullptr     	,"utf8mb4"     ));	     transaction t(db->begin());   		     BasinInfo binfo;     binfo.setNation("中国"); //chinese character insert into column 'Nation'     db->persist(binfo);     t.commit();after that, i changed the mysql server to 5.7, replace the connector c to the libraray and include files that bundled with mysql 5.7, and rebuild the odb-libmysql, but that effort does not do any help. finally i changed the charset to utf8 and recreate the database, but problem remains the same. i also start a post on stackoverflow at https://stackoverflow.com/questions/57283107/problem-when-inserting-chinese-characters-into-mysql-via-c-odb, for now i dont get the problem solved!do you have any idea about how to fix it, thanks!