Msql5.5升级到mysql8
1）mysql5.5的干净卸载，按照网上的做
2）Mysql8卸载，原因是我按照网上的非安装版，怎么也启动不了mysql
少2个文件
2.1）使用控制面板删除mysql程序，以及跟它有关的
2.2）删除C:\ProgramData\MySQL文件夹
2.3）删除C:\Program Files\MySQL文件夹
2.4）删除注册表中
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\Application\MySQLD Service
2.5）删除注册表中
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\Application\MySQLD Service
2.6）删除注册表中
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application\MySQLD Service
3）重启电脑
4）安装mysql8
4.1）https://dev.mysql.com/downloads/installer/
安装
4.2.1）我是给服务器装的
4.2.2）
大家注意下这里，如果想出现安装位置，需要安装8以后，卸载，不删除路径，然后再安装才能出来
4.3）mysql配置
4.3.1）Mysql -u root -p
4.3.2）更改配置使navicat for mysql 能够使用
ALTER USER 'root'@'localhost' IDENTIFIED BY '123' PASSWORD EXPIRE NEVER;
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123';
创建用户给testdb数据库，并改变密码协议，使之navicat能访问
create user 'test'@'%' identified by '123' PASSWORD EXPIRE NEVER;
ALTER USER 'test'@'%' IDENTIFIED WITH mysql_native_password BY '123';
4.3.5）授权 test用户可以在任何ip下访问pims
grant all on testdb.* to 'test'@'%';
create user 'test'@'%' identified by '123' PASSWORD EXPIRE NEVER;
ALTER USER 'root'@'localhost' IDENTIFIED BY '123' PASSWORD EXPIRE NEVER;
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123';
create user 'test'@'%' identified by '123' PASSWORD EXPIRE NEVER;
ALTER USER 'test'@'%' IDENTIFIED WITH mysql_native_password BY '123';
grant all on testdb.* to 'test'@'%';