信了如下几个报错的邪
mysqladmin更改密码无效
“Access denied for user 'root'@'localhost'”
“mysqladmin: connect to server at 'localhost' failed”
“mysqladmin: Can't turn off logging; error: 'Access denied; you need (at least one of) the SUPER privilege(s) for this operation'”
背景：centos6.10中安装5.5.62
解决方法：
1.kill pid #结束数据库进程
2.vi /data/3307/mysql
#启动文件文件中配置--skip-grant-tables，注释掉mysql_pwd="oldboy123"，不需修改f文件
3. /data/3307/mysql start
netstat –lntup
#启动数据库并检查
4. mysql -uroot -S /data/3307/mysql.sock #进入mysql，不要带-p
执行下面的句子
mysql>use mysql;
mysql>delete from user where user='';
mysql>delete from user where host='localhost.localdomain';
mysql>update user set password=password('oldboy123') where user='root';
mysql>update user set host='%' where user='root';
#如果报错 ERROR 1062 (23000): Duplicate entry '%-root' for key 'PRIMARY' 不予理会
mysql>quit;
5./data/3307/mysql stop #如果要输入密码，直接enter或者输入'oldboy123'
6.vi /data/3307/mysql #删除第1步加入的--skip-grant-tables
7. /data/3307/mysql start
netstat –lntup
#启动数据库并检查
8. mysql -uroot -S /data/3307/mysql.sock #确认不需密码是否无法登录
9. mysql -uroot -p -S /data/3307/mysql.sock #登录数据库，密码'oldboy123'
/3307/注意替换！
参考文件：
/holy/684117
mysql更改数据库登录密码失败；Access denied for user oot@localhost；mysqladmin: connect to server at localhos
