【MySQL】Linux下登录mysql时忘记密码了怎么办？

[root@localhost ~]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)


修改密码

1. 检查mysql服务是否启动，如果启动，关闭mysql服务

//查看mysql服务状态
[root@localhost ~]# ps -ef | grep -i mysql
root 22972 1 0 14:18 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql 23166 22972 0 14:18 pts/0 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root 23237 21825 0 14:22 pts/0 00:00:00 grep -i mysql//关闭服务
[root@localhost ~]# service mysql stop
[root@localhost ~]#


2. 修改 mysql 的配置文件my.cnf
   my.cnf配置文件的位置，一般在 /etc/my.cnf，有些版本在 /etc/mysql/my.cnf

在配置文件中，增加2行代码

[mysqld]
# 登录mysql的时候跳过密码验证
skip-grant-tables


然后启动mysql服务，并进入mysql

[root@localhost ~]# service mysqld start
[root@localhost ~]#
[root@localhost ~]# mysql -u root
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>


3. 修改密码
   连接mysql这个数据库，修改用户密码

mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> update mysql.user set authentication_string=password('root_password') where user='root';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)mysql> exit


4. 重启mysql服务
   先将之前加在配置文件里面的2句代码注释或删除掉，然后重启mysql服务，就可以使用刚刚设置的密码登录了。

[root@localhost ~]# service mysql start
[root@localhost ~]#
[root@localhost ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.