centos8使用yum命令按照mysql

素颜马尾好姑娘i 2022-09-04 11:44 250阅读 0赞

### 文章目录 ###

*  前言
 *  1. 下载rpm，从mysql官方库(https://dev.mysql.com/downloads/repo/yum/)找到rpm下载地址链接
 *  2.yum命令安装下载的rmp
 *  3. 禁用默认的mysql模块
 *  4. 安装mysql服务器
 *  5. 启动mysql服务器
 *  6. 检查mysql的状态
 *  7. 查看超级用户的密码并修改
 *  8.因安装了Yum Repository，每次使用yum操作时都会自动更新，所以可以选择它卸载掉：
 *  9.mysql 常用命令
 *  10.linux下mysql密码忘记解决办法
 *   *  10.1 检查mysql服务是否启动，如果启动，关闭mysql服务
     *  10.2 my.cnf配置文件的位置，一般在/etc/my.cnf，有些版本在/etc/mysql/my.cnf
     *  10.3 修改密码
     *  10.4 重启mysql服务
     *  10.5 登录mysql并修改密码
 *  11、常见问题
 *   *  11.1、Job for mysqld.service failed because the control process exited with error code.
     *  11.2 Host is not allowed to connect to this MySQL server解决方法

# 前言 #

参考mysql 官方指导文档，[https://dev.mysql.com/doc/mysql-yum-repo-quick-guide/en/][https_dev.mysql.com_doc_mysql-yum-repo-quick-guide_en]

# 1. 下载rpm，从mysql官方库(https://dev.mysql.com/downloads/repo/yum/)找到rpm下载地址链接 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pvbmVzQXJpdmVu_size_16_color_FFFFFF_t_70]  
wget -i -c https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm

```bash
    [root@ahdyqrh0apjy8y2w software]# wget -c -i https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
    --2021-08-16 15:12:27--  https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
    Resolving repo.mysql.com (repo.mysql.com)... 104.85.245.54
    Connecting to repo.mysql.com (repo.mysql.com)|104.85.245.54|:443... connected.
    HTTP request sent, awaiting response... 200 OK
    Length: 26024 (25K) [application/x-redhat-package-manager]
    Saving to: ‘mysql80-community-release-el7-3.noarch.rpm’
    
    mysql80-community-release-el7-3.noarch.rpm      100%[=======================================================================================================>]  25.41K   146KB/s    in 0.2s    
    
    2021-08-16 15:12:28 (146 KB/s) - ‘mysql80-community-release-el7-3.noarch.rpm’ saved [26024/26024]
    
    Incomplete or invalid multibyte sequence encountered
    --2021-08-16 15:12:28--  https://repo.mysql.com//%ED%AB%EE%DB%03
    Reusing existing connection to repo.mysql.com:443.
    HTTP request sent, awaiting response... 400 Bad Request
    2021-08-16 15:12:28 ERROR 400: Bad Request.
    
    --2021-08-16 15:12:28--  https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
    Reusing existing connection to repo.mysql.com:443.
    HTTP request sent, awaiting response... 200 OK
    ```

# 2.yum命令安装下载的rmp #

yum -y install mysql80-community-release-el7-3.noarch.rpm

[root@ahdyqrh0apjy8y2w software]# yum -y install mysql80-community-release-el7-3.noarch.rpm 
    Last metadata expiration check: 0:21:13 ago on Mon 16 Aug 2021 02:54:28 PM CST.
    Dependencies resolved.
    ================================================================================================================================================================================================
     Package                                                    Architecture                            Version                                 Repository                                     Size
    ================================================================================================================================================================================================
    Installing:
     mysql80-community-release                                  noarch                                  el7-3                                   @commandline                                   25 k
    
    Transaction Summary
    ================================================================================================================================================================================================
    Install  1 Package
    
    Total size: 25 k
    Installed size: 31 k
    Downloading Packages:
    Running transaction check
    Transaction check succeeded.
    Running transaction test
    Transaction test succeeded.
    Running transaction
      Preparing        :                                                                                                                                                                        1/1 
      Installing       : mysql80-community-release-el7-3.noarch                                                                                                                                 1/1 
      Verifying        : mysql80-community-release-el7-3.noarch                                                                                                                                 1/1 
    
    Installed:
      mysql80-community-release-el7-3.noarch                                                                                                                                                        
    
    Complete!
    [root@ahdyqrh0apjy8y2w software]# ll
    total 28
    -rw-r--r-- 1 root root 26024 Apr 25  2019 mysql80-community-release-el7-3.noarch.rpm
    [root@ahdyqrh0apjy8y2w software]#

# 3. 禁用默认的mysql模块 #

yum module disable mysql

# 4. 安装mysql服务器 #

yum -y install mysql-community-server

[root@ahdyqrh0apjy8y2w software]# yum -y install mysql-community-server
    MySQL 8.0 Community Server                                                                                                                                      783 kB/s | 2.0 MB     00:02    
    MySQL Connectors Community                                                                                                                                       61 kB/s | 121 kB     00:01    
    MySQL Tools Community                                                                                                                                           280 kB/s | 722 kB     00:02    
    No match for argument: mysql-community-server
    Error: Unable to find a match: mysql-community-server
    [root@ahdyqrh0apjy8y2w software]#

# 5. 启动mysql服务器 #

systemctl start mysqld

# 6. 检查mysql的状态 #

systemctl status mysqld

# 7. 查看超级用户的密码并修改 #

**需修改初始化密码才能使用mysql数据库  
修改密码规则如下：密码中必须包含大小写字母数字及符号——提供参照密码‘tyzZ001!’**

‘root’@‘localhost’ 创建了 一个超级用户帐户。超级用户的密码已设置并存储在错误日志文件中。要显示它，请使用以下命令：  
grep “password” /var/log/mysqld.log

[root@ahdyqrh0apjy8y2w ~]# grep "password" /var/log/mysqld.log 
    2021-08-16T07:44:29.420776Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: )+rfsdrf8FSL

通过使用生成的临时密码登录并为超级用户帐户设置自定义密码，尽快更改 root 密码：

mysql -uroot -p

ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';

# 8.因安装了Yum Repository，每次使用yum操作时都会自动更新，所以可以选择它卸载掉： #

yum -y remove mysql80-community-release-el7-3.noarch.rpm

# 9.mysql 常用命令 #

> \[root@localhost ~\]\# systemctl start mysqld.service \#开启服务  
> \[root@localhost ~\]\# systemctl stop mysqld.service \#关闭服务  
> \[root@localhost ~\]\# systemctl status mysqld.service \#查看服务状态  
> \[root@localhost ~\]\# mysql -u root -p \#进入mysql命令窗口  
> mysql> show databases; \#查看所有数据库  
> mysql> use 数据库名; \#使用该数据进行编辑  
> mysql> show tables; \#查看某数据库所有表

# 10.linux下mysql密码忘记解决办法 #

## 10.1 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@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
    
    //关闭服务
    [root@mytestlnx02 ~]# service mysql stop
    [root@mytestlnx02 ~]#

## 10.2 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]
    
    skip-grant-tables

作用是登录mysql的时候跳过密码验证  
然后启动mysql服务，并进入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>

## 10.3 修改密码 ##

连接mysql这个数据库，修改用户密码，将密码先设置为空

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='root_password' where user='';
    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

## 10.4 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@mytestlnx02 ~]# service mysql start
    [root@mytestlnx02 ~]#
    [root@mytestlnx02 ~]# mysql -u root -p
    Enter password: 
    Welcome to the MySQL monitor.  Commands end with ; or \g.

## 10.5 登录mysql并修改密码 ##

# 已密码方式登录，测试密码为空，可以直接登录成功
    mysql -u root 
    # 修改密码
    ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '你的密码';

# 11、常见问题 #

## 11.1、Job for mysqld.service failed because the control process exited with error code. ##

解决办法，查看日志，杀掉mysql进程，查看杀进程的命令  
查看端口占用情况：

# 查询端口号占用情况
    netstat -anp|grep 3306
    # 根据进程查看占用情况
    ps -aux|grep mysql
    # 删除mysql 进程
    kill -9 pid

## 11.2 Host is not allowed to connect to this MySQL server解决方法 ##

在装有MySQL的机器上登录MySQL mysql -u root -p密码  
执行use mysql;  
执行update user set host = ‘%’ where user = ‘root’;这一句执行完可能会报错，不用管它。  
执行FLUSH PRIVILEGES;

[https_dev.mysql.com_doc_mysql-yum-repo-quick-guide_en]: https://dev.mysql.com/doc/mysql-yum-repo-quick-guide/en/
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