（一）Mysql安裝

下載

• 操作系統：centos7
  
  mysql版本：mysql-5.7.30-1.el7.x86_64.rpm-bundle.tar
  
  下載地址：https://dev.mysql.com/downloads/mysql
  

  
  

解壓

• tar -xvf mysql-5.7.30-1.el7.x86_64.rpm-bundle.tar
  

  mysql-5.7.30-1.el7.x86_64.rpm-bundle.tar
  mysql-community-client-5.7.30-1.el7.x86_64.rpm
  mysql-community-common-5.7.30-1.el7.x86_64.rpm
  mysql-community-devel-5.7.30-1.el7.x86_64.rpm
  mysql-community-embedded-5.7.30-1.el7.x86_64.rpm
  mysql-community-embedded-compat-5.7.30-1.el7.x86_64.rpm
  mysql-community-embedded-devel-5.7.30-1.el7.x86_64.rpm
  mysql-community-libs-5.7.30-1.el7.x86_64.rpm
  mysql-community-libs-compat-5.7.30-1.el7.x86_64.rpm
  mysql-community-server-5.7.30-1.el7.x86_64.rpm
  mysql-community-test-5.7.30-1.el7.x86_64.rpm
  

安裝前檢查卸載

• 檢查安裝目錄

  whereis mysql
  mysql: /usr/lib64/mysql /usr/share/mysql
  
  rm -rf /usr/lib64/mysql /usr/share/mysql
  

• 檢查卸載系統自帶的mariadb，並卸載

  rpm -qa | grep mariadb
  mariadb-libs-5.5.65-1.el7.x86_64
  
  # 卸載
  rpm -e mariadb-libs-5.5.65-1.el7.x86_64 --nodeps
  
  # 檢查是否卸載乾淨
  rpm -qa | grep mariadb
  

• 檢查有無mysql歷史殘留

  rpm -qa | grep mysql  # 沒有則跳過
  mysql-community-libs-5.7.30-1.el7.x86_64
  mysql-community-server-5.7.30-1.el7.x86_64
  mysql-community-client-5.7.30-1.el7.x86_64
  mysql-community-libs-compat-5.7.30-1.el7.x86_64
  
  # 卸載
  rpm -e mysql-community-libs-5.7.30-1.el7.x86_64 --nodeps
  rpm -e mysql-community-server-5.7.30-1.el7.x86_64 --nodeps
  rpm -e mysql-community-client-5.7.30-1.el7.x86_64 --nodeps
  rpm -e mysql-community-libs-compat-5.7.30-1.el7.x86_64 --nodeps
  
  # 檢查是否卸載乾淨
  rpm -qa | grep mysql
  

安裝依賴

• yum -y install setup
  yum -y install perl # 安裝mysql-server要求的依賴
  yum -y install net-tools # 安裝mysql-server時候要求的依賴
  yum -y install libaio  # 安裝mysql-server時候要求的依賴
  

安裝Mysql數據庫

• # 按順序進行
  1、 rpm -ivh mysql-community-common-5.7.30-1.el7.x86_64.rpm
  2、 rpm -ivh mysql-community-libs-5.7.30-1.el7.x86_64.rpm
  3、 rpm -ivh mysql-community-libs-compat-5.7.30-1.el7.x86_64.rpm
  4、 rpm -ivh mysql-community-client-5.7.30-1.el7.x86_64.rpm --force
  5、 rpm -ivh mysql-community-server-5.7.30-1.el7.x86_64.rpm --force
  

啓動Mysql

1. 啓動

   service mysqld start
   

2. 報錯

   Redirecting to /bin/systemctl start 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.
   

3. 查看狀態

   service mysqld status
   

4. 原因：未初始化用戶

   mysqld --initialize --user=mysql
   

5. 初始化目錄下有文件，必須刪除目錄下的內容

   # 查看目錄路徑
   vi /etc/my.cnf
   

6. 備份該目錄（防止出錯後恢復），然後將其內容刪除

   mv /var/lib/mysql /var/lib/mysql_bak
   

   cd /var/lib/mysql
   rm -rf *
   

7. 重新初始化用戶

   mysqld --initialize --user=mysql
   

8. 啓動Mysql

   service mysqld start
   或者
   systemctl start mysqld.service
   

9. 查看系統生成的臨時密碼

   grep 'temporary password' /var/log/mysqld.log
   

   2020-05-14T03:34:52.940593Z 1 [Note] A temporary password is generated for root@localhost: :D:*RNh3xrfD
   2020-05-14T03:37:16.941130Z 1 [Note] A temporary password is generated for root@localhost: >r_MserC?0/f
   

10. 登錄

    mysql -uroot -p
    Enter password:  >r_MserC?0/f
    
    ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
    

11. 再次重啓Mysql試試

    service mysqld restart
    

12. 登錄

    mysql -uroot -p
    Enter password:  >r_MserC?0/f
    

修改密碼

• mysql> ALTER USER 'root'@'localhost' IDENTIFIED by 'Password';
  mysql> flush privileges;
  mysql> exit
  Bye
  

使用密碼登錄

• mysql -uroot -p
  Enter password:  Password
  

設置開機自啓

• systemctl enable mysqld
  

• 查看是否開啓成功

  systemctl list-unit-files
  

遠程連接配置

https://blog.csdn.net/qq_42517220/article/details/101368838