解决方法:
在进入容器的命令中添加 ​​​env LANG=C.UTF-8​​ 例如:

➜  ~ docker exec -it mysql env LANG=C.UTF-8 /bin/bash
root@9abe1dd59947:/# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 8.0.20 MySQL Community Server - GPL

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Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

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