阿里云ECS服务器中自带MYSQL无法登陆问题
阿里云服务器自带mysql数据库，我们可以通过 yum list installed | grep mysql 命令来查看系统装好的mysql。
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ yum list installed | grep mysql
mysql-community-client.x86_64 5.7.16-1.el7 installed
mysql-community-common.x86_64 5.7.16-1.el7 installed
mysql-community-libs.x86_64 5.7.16-1.el7 installed
mysql-community-server.x86_64 5.7.16-1.el7 installed
启动mysql服务正常：
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ sudo systemctl start mysqld.service
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ sudo systemctl status mysqld.service
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Sat 2017-07-22 19:52:38 CST; 23min ago
Process: 4979 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 4962 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 4983 (mysqld)
CGroup: /system.slice/mysqld.service
└─4983 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
Jul 22 19:52:38 iZ2ze3n5edj5u2cbb9qrijZ systemd[1]: Starting MySQL Server...
Jul 22 19:52:38 iZ2ze3n5edj5u2cbb9qrijZ systemd[1]: Started MySQL Server.
但是登陆mysql时出错：
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
我装的时mysql5.7，登陆需要密码才行，在网上找了资料说在 /var/log/mysqld.log 下的日志中会生成初始密码，可我再改文件夹下找不到默认密码，只能通过配置无需验证登录方式登陆进去，然后再重新设置root密码。
1、配置无需验证登录方式
vi /etc/my.cnf
[mysqld]
skip-grant-tables //增加这一行，目的是不用验证就可以登录mysql
2、登陆数据库
命令行输入 mysql，如果不识别，则需要配置环境变量，这里就不多说了
可以先查看下数据库
mysql> show databases;
mysql> use mysql;
mysql> select * from user;
可以看到user表中的内容
//修改localhost为%
mysql> UPDATE user SETHost = ‘%’ WHEREUser =‘root’;
mysql> flush privileges;
mysql> quit
3、将skip-grant-tables注释掉或者删除
重启服务器
如果还是不行，可能需要修改一下密码
1.先停掉原来的服务
service mysqld stop
2.使用安全模式登陆，跳过密码验证
mysqld --user=mysql --skip-grant-tables --skip-networking &
3.登陆
mysql -uroot mysql
4.修改密码
mysql > update user set authentication_string = password(‘密码’)
where user = 'root' and Host = ‘%’
5.刷新权限
mysql > flush privileges;
6.重新使用正常模式登陆
#mysql -uroot -p
#enter password : 密码
可以正常登陆。
7.执行其他命令：show databases;
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ sudo mysqld --user=mysql --skip-grant-tables --skip-networking &
[1] 5190
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ mysql -u root
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.16 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>进入mysql数据库，重新设置root登陆密码：
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> show tables;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| engine_cost |
| event |
| func |
| general_log |
| gtid_executed |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| server_cost |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
31 rows in set (0.00 sec)
最后重新设置密码：
mysql> update user set authentication_string =password('root') 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> quit;
Bye
[dancheren@iZ2ze3n5edj5u2cbb9qrijZ /]$ mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.16 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> ^C
mysql>
至此问题解决了。。。。。。。。。。。