Linux学习15-CentOS安装mysql5.6环境

前言

在linux上安装mysql5.6版本，并远程连接mysql数据库操作

安装mysql

mysql的安装可以用yum安装更方便

[root@yoyo ~]# cd /usr/local/
[root@yoyo ~]# mkdir mysql-community-release
[root@yoyo ~]# cd mysql-community-release
[root@yoyo ~]# wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
[root@yoyo ~]# rpm -ivh mysql-community-release-el7-5.noarch.rpm
[root@yoyo ~]# yum -y install mysql-community-server

安装完成后查看版本号：mysql -V

[root@yoyo local]# mysql -V
mysql  Ver 14.14 Distrib 5.6.42, for Linux (x86_64) using  EditLine wrapper

安装完成后重启mysql服务,查看状态是 Active: active (running) ，说明启动成功

启动服务:service mysqld restart

[root@yoyo local]# service mysqld restart

查看mysql运行状态：systemctl status mysql.service

[root@yoyo local]# systemctl status mysql.service

[root@yoyo local]# service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
[root@yoyo ~]# systemctl status mysql.service
● mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2019-01-15 09:53:42 CST; 47s ago
 Main PID: 946 (mysqld_safe)
   CGroup: /system.slice/mysqld.service
           ├─ 946 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
           └─1282 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/v...
Jan 15 09:53:39 yoyo systemd[1]: Starting MySQL Community Server...
Jan 15 09:53:40 yoyo mysqld_safe[946]: 190115 09:53:40 mysqld_safe Logging to '/var/log/mysqld.log'.
Jan 15 09:53:40 yoyo mysqld_safe[946]: 190115 09:53:40 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
Jan 15 09:53:42 yoyo systemd[1]: Started MySQL Community Server.

mysql重置密码

方法一：

初次安装使用mysql，root账户默认是没设置密码的，系统会给个临时密码，在/var/log/mysqld.log可以查看

[root@yoyo local]# grep 'temporary password' /var/log/mysqld.log

如下图所示，出现的就是临时密码，复制出来就可以登录mysql了

[root@yoyo local]# mysql -u root -p

看到Enter password: 输入密码，重置密码后exit退出mysql

[root@yoyo local]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 26
Server version: 5.6.42 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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.
# 重置密码
mysql> update user set password = Password('root') where User = 'root';
# 回车后执行（刷新MySQL系统权限相关的表）：
mysql> flush privileges;
# 再执行exit退出：
mysql> exit;
Bye
[root@yoyo local]#

方法二：

要是上一步找不到临时密码，那就用此方法，先停掉mysql，以安全方式启动

[root@yoyo local]# systemctl stop mysql.service

以安全方式启动mysql:

[root@yoyo local]# /usr/bin/mysqld_safe --skip-grant-tables >/dev/null 2>&1 &

然后执行

[root@yoyo local]# /usr/bin/mysql -u root mysql

出现“mysql>”提示符后输入：

mysql> update user set password = Password('root') where User = 'root';
回车后执行（刷新MySQL系统权限相关的表）：
mysql> flush privileges;
再执行exit退出：
mysql> exit;

退出后，使用以下命令登陆mysql，试试是否成功：

[root@yoyo local]#mysql -u root -p

按提示输入密码：root

[root@yoyo local]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 27
Server version: 5.6.42 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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>

出现Welcome to the MySQL那就是登录成功了

查看mysql端口号

mysql默认端口是3306，如何查看msyql端口号呢？可以用root账号登录后，执行show variables like 'port';

[root@yoyo local]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 33
Server version: 5.6.42 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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> show variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.00 sec)
mysql>

授权mysql远程连接

mysql在linux上安装完成后，为了方便的查看，可以在本地电脑上安装一个远程连接数据库的客户端，远程连上mysql

方法一：

先创建一个root新用户，登录密码为password，可以自己随便命名

mysql> create user 'root'@'%' identified by 'password';

[root@yoyo sysconfig]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
mysql> create user 'root'@'%' identified by 'password';
ERROR 1396 (HY000): Operation CREATE USER failed for 'root'@'%'
mysql> exit

方法二：

查看user表，把host为localhost，user为root的记录更新host为%就是允许远程访问了

操作mysql时候，先执行use mysql

[root@yoyo sysconfig]# mysql -u root -p
Enter password:
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> select user,host,password from user;
+-------+-----------+-------------------------------------------+
| user  | host      | password                                  |
+-------+-----------+-------------------------------------------+
| root  | yoyo      | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| root  | 127.0.0.1 | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| root  | ::1       | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
|       | yoyo      |                                           |
| root1 | %         | *668425423DB5193AF921380129F465A6425216D0 |
| root  | localhost | *2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19 |
+-------+-----------+-------------------------------------------+
6 rows in set (0.00 sec)

如果看到root后面的host对应的是%说明有远程访问权限，显示localhost就 update更新它，如何flush privileges刷新系统权限

mysql> use mysql
mysql> update user set host = '%' where user = 'root';
ERROR 1062 (23000): Duplicate entry '%-root' for key 'PRIMARY'
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host,password from user;
+-------+-----------+-------------------------------------------+
| user  | host      | password                                  |
+-------+-----------+-------------------------------------------+
| root  | yoyo      | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| root  | 127.0.0.1 | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| root  | ::1       | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
|       | yoyo      |                                           |
| root1 | %         | *668425423DB5193AF921380129F465A6425216D0 |
| root  | %         | *2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19 |
+-------+-----------+-------------------------------------------+
6 rows in set (0.00 sec)
mysql> exit

方法三：

授权法,给root用户远程登录的权限

# 想root使用123456从任何主机连接到mysql服务器的话
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123546' WITH GRANT OPTION;
# 如果你想允许用户root从ip为192.168.1.3的主机连接到mysql服务器，并使用123456作为密码
mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.1.3' IDENTIFIED BY '123456' WITH GRANT OPTION;

接下来去阿里云ECS服务后台安全组-添加规则，新增3306端口访问权限，使用Navicat远程工具就可以连上了

这里的账号密码就是前面方法一里面设置的“root” 和“password”

开启与关闭服务

1启动mysql

service mysqld start

2查看mysql运行状态

service mysqld status # 或者 systemctl status mysql.service

3停掉mysql服务

service mysqld stop # 或者 systemctl stop mysql.service

4重启mysql

systemctl restart mysql.service

5查看运行进程

ps -ef | grep mysqld

[root@yoyo sysconfig]# ps -ef | grep mysql
mysql     2506     1  0 12:51 ?        00:00:00 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
mysql     2674  2506  0 12:51 ?        00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64mysql/plugin --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root      2748  1668  0 12:55 pts/0    00:00:00 grep --color=auto mysql

6查看mysql端口

netstat -tulpn |grep mysql

[root@yoyo sysconfig]# netstat -tulpn |grep mysql
tcp6       0      0 :::3306                 :::*                    LISTEN      2674/mysqld

遇到问题

启动mysql的时候，出现Failed to start MySQL Community Server.具体报错如下

[root@yoyo ~]# systemctl status mysql.service
● mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since Mon 2019-01-14 20:31:27 CST; 13h ago
  Process: 26800 ExecStartPost=/usr/bin/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 26799 ExecStart=/usr/bin/mysqld_safe --basedir=/usr (code=exited, status=1/FAILURE)
  Process: 26786 ExecStartPre=/usr/bin/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 26799 (code=exited, status=1/FAILURE)
Jan 14 20:31:27 yoyo systemd[1]: Failed to start MySQL Community Server.
Jan 14 20:31:27 yoyo systemd[1]: Unit mysqld.service entered failed state.
Jan 14 20:31:27 yoyo systemd[1]: mysqld.service failed.
Jan 14 20:31:27 yoyo systemd[1]: mysqld.service holdoff time over, scheduling restart.
Jan 14 20:31:27 yoyo systemd[1]: start request repeated too quickly for mysqld.service
Jan 14 20:31:27 yoyo systemd[1]: Failed to start MySQL Community Server.
Jan 14 20:31:27 yoyo systemd[1]: Unit mysqld.service entered failed state.
Jan 14 20:31:27 yoyo systemd[1]: mysqld.service failed.

刚开始以为是哪里配置有问题，后来百度搜了下，reboot重启linux服务器就解决了。

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