Linux 下通过sudo apt install mysql-server装置的mysql，默认状况下，只能通过 root 用户或sudo的形式能力登录到mysql的root用户，而且无需明码，也无奈设置明码。

这是因为mysql默认对“mysql的root”用户应用auth_socket插件的认证。对某个mysql用户应用这个插件，将会只容许在本机上和该mysql用户的用户名雷同的零碎用户登录，这种登录形式无需也无奈设置明码。换个说法就是，默认状况下，“mysql的root”用户，只容许本机上同样被称作“root”的用户登录，所以装置实现后必须通过sudo或切换到root用户能力登录“mysql的root”用户。

这种形式可能使某些人不习惯，为了让mysql的root用户，能像平常一样，通过任意零碎用户、任意主机登录，只需将mysql的root用户验证插件批改。

则是默认状况下，mysql的root用户应用auth_socket插件验证，无奈设置明码。

MySQL root@(none):mysql> SELECT `User`,`Host`,plugin,authentication_string FROM `user`;+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+| User             | Host      | plugin                | authentication_string                                                         |+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+| debian-sys-maint | localhost | caching_sha2_password | $A$005$P|    x1 ^Ew^A^A^X    `\rNk(N^GR9HPKy4yvB.RcWyyDuPMHGIrVSXzTjGR5BeZC85qTUP3 || mysql.infoschema | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || mysql.session    | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || mysql.sys        | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || root             | localhost | auth_socket           |                                                                               |+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+

运行上面这条语句，将root账户的验证插件批改为caching_sha2_password，并通过明码12345登录

ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY '12345';

而后刷新权限使得设置失效

FLUSH PRIVILEGES;

设置实现后,

MySQL root@(none):mysql> SELECT `User`,`Host`,plugin,authentication_string FROM `user`;+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+| User             | Host      | plugin                | authentication_string                                                         |+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+| debian-sys-maint | localhost | caching_sha2_password | $A$005$P|    x1 ^Ew^A^A^X    `\rNk(N^GR9HPKy4yvB.RcWyyDuPMHGIrVSXzTjGR5BeZC85qTUP3 || mysql.infoschema | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || mysql.session    | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || mysql.sys        | localhost | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED        || root             | localhost | caching_sha2_password | $A$019$1^Ac!u@^Qto                                                              |+------------------+-----------+-----------------------+-------------------------------------------------------------------------------+

这样就能够用明码登录mysql的root用户了。

有些教程会教你应用mysql_native_password作为验证插件，这个是旧版本mysql提供的插件，应用中和caching_sha2_password体验一样。如果不是要通过一些不兼容caching_sha2_password的客户端连贯mysql服务端，显然还是用新插件更平安。