MySQL1.5.7相关

安装之后需要立即修改root密码，用默认密码登录，然后修改密码

grep "password" /var/log/mysqld.log

A temporary password is generated for root@localhost: >wTexVUgz28n

 

找到mysqld的路径

which mysqld

MySQL安装之后，没有修改仅有的用户root默认密码，密码很快过期，因此需要修改mysql配置

#忘记MySQL修改默认root密码，
#1.找到配置文件
[root@localhost mysql]# /usr/sbin/mysqld --verbose --help | grep -A 1 'Default options'
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf 

#2.修改配置文件，关闭权限验证
[root@localhost mysql]# vim /etc/my.cnf 
[mysqld]
skip-grant-tables

#3.重启服务
[root@localhost ~]# systemctl restart mysqld

#4.进入MySQL
[root@localhost ~]# mysql 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.31 MySQL Community Server (GPL)

mysql> select host,user,authentication_string from mysql.user;
+-----------+---------------+-------------------------------------------+
| host      | user          | authentication_string                     |
+-----------+---------------+-------------------------------------------+
| localhost | root          | *B96D2550A78AC97727C4A761F0BC00226B2B1782 |
| localhost | mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql.sys     | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| %         | root          | *DB469070DB0AD0CA0B93040D166D7FC4713D6961 |
+-----------+---------------+-------------------------------------------+
4 rows in set (0.00 sec)

#5.修改密码
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 -A

Database changed

mysql> UPDATE user SET authentication_string=PASSWORD('123456')WHERE user='root' and host='%';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> UPDATE user SET authentication_string=PASSWORD('12345678')WHERE user='root' and host='localhost';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> flush privileges;
Query OK, 0 rows affected (0.05 sec)

#6.测试
[root@localhost mysql]# systemctl restart mysqld
[root@localhost mysql]# mysql  -uroot -p