前言
今天在服務(wù)器安裝mysql之后，登錄發(fā)現(xiàn)密碼錯(cuò)誤，但是我沒(méi)有設(shè)置密碼呀，最后百度之后得知，mysql在5.7版本之后會(huì)自動(dòng)創(chuàng)建一個(gè)初始密碼。報(bào)錯(cuò)如下:
[root@mytestlnx02 ~]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
修改密碼
1. 檢查mysql服務(wù)是否啟動(dòng)，如果啟動(dòng)，關(guān)閉mysql服務(wù)
//查看mysql服務(wù)狀態(tài)
[root@mytestlnx02 ~]# 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
//關(guān)閉服務(wù)
[root@mytestlnx02 ~]# service mysql stop
[root@mytestlnx02 ~]#
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行代碼，如果[mysqld]加過(guò)，不用重復(fù)添加
[mysqld]
skip-grant-tables
作用是登錄mysql的時(shí)候跳過(guò)密碼驗(yàn)證
然后啟動(dòng)mysql服務(wù)，并進(jìn)入mysql
[root@mytestlnx02 ~]# service mysqld start
[root@mytestlnx02 ~]#
[root@mytestlnx02 ~]# mysql -u root
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
3. 修改密碼
連接mysql這個(gè)數(shù)據(jù)庫(kù)，修改用戶(hù)密碼
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 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: 1
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> exit
4. 重啟mysql服務(wù)
先將之前加在配置文件里面的2句代碼注釋或刪除掉，然后重啟mysql服務(wù)，就可以使用剛剛設(shè)置的密碼登錄了。
[root@mytestlnx02 ~]# service mysql start
[root@mytestlnx02 ~]#
[root@mytestlnx02 ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
備注：
特殊情況，在CentOS上的操作方式有所不同。執(zhí)行修改密碼的命令一直報(bào)錯(cuò)，請(qǐng)參考
mysql> update user set authentication_string=password('xxxxxxxx') where User='root';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '('root_password') where User='root'' at line 1
不可能是語(yǔ)法問(wèn)題，檢查了很多遍，最后發(fā)現(xiàn)CentOS下應(yīng)該這樣操作：
查看初始密碼
[root@VM_0_8_centos ~]# grep 'temporary password' /var/log/mysqld.log
2018-09-26T04:25:54.927944Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: (8)a+_8aK5
可以看到初始密碼為(8)a+_8aK5
使用初始密碼登錄
[root@VM_0_8_centos ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.12 MySQL Community Server - GPL
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
再次修改密碼
mysql> ALTER USER 'root' IDENTIFIED BY 'xxxxxxxxx';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'xxxxxxxx';
Query OK, 0 rows affected (0.11 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> exit
Bye
