Reasons for character error in MySQL command line interface and solutions

ERROR 2019 (HY000): Can't initialize character set gb2312
It took a long time for MySQL to be reinstalled twice.
I've set the system code to be es5EN-8

vi /etc/sysconfig/i18n 

LANG=zh_CN.UTF-8 
LANGUAGE=zh_CN.UTF-8:zh_CN.GB2312:zh_CN 
SUPPORTED=zh_CN.UTF-8:zh_CN:zh:en_US.UTF-8:en_US:en 
SYSFONT=lat0-sun16 

The database is also 1 directly configured with utf8

cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \ 

-DMYSQL_UNIX_ADDR=/usr/local/mysql/mysql.sock \ 
-DDEFAULT_CHARSET=utf8 \ 
-DDEFAULT_COLLATION=utf8_general_ci \ 
-DWITH_EXTRA_CHARSETS:STRING=utf8,gbk \ 
-DWITH_MYISAM_STORAGE_ENGINE=1 \ 
-DENABLED_LOCAL_INFILE=ON \ 
-DWITH_INNOBASE_STORAGE_ENGINE=1 \ 
-DWITH_READLINE=1 \ 
-DENABLED_LOCAL_INFILE=1 \ 
-DMYSQL_DATADIR=/var/mysql/data 

I don't know how to come up with gb2312
After searching for a long time, I finally found that it should be the content coding problem of the terminal input. I remembered that I had changed it to make SSH display Chinese normally

vi /etc/profile  

LANG=zh_CN.GB2312 
export LANG 

This is the reason for the change, so I comment it out and then I close ssh and I relink it and it works,

PS: MySQL import garbled code solution
Garbled code occurs when importing, and the encoding format of specified imported data needs to be added in the statement:

mysql -uroot -p database_name < database_backup.sql --default-character-set=utf8