linux上安装不同版本的MySQL（CentOS7.6）

linux上安装不同版本的MySQL（以已安装了MySQL8为例，以下为安装MySQL5的具体教程）

• 官网下载二进制包

• 解压

• 修改配置文件my.cnf

  [client]
  port=3307
  socket=/tmp/mysql3307.sock
  #### mysql8
  mysqlx_port=33070
  mysqlx_socket=/tmp/mysqlx33070.sock
  ####
  
  [mysqld]
  prot=3307
  socket=/tmp/mysql3307.sock
  #### mysql8
  mysqlx_port=33070
  mysqlx_socket=/tmp/mysqlx33070.sock
  ####
  datadir=/usr/local/mysql5/data
  basedir=/usr/local/mysql5
  slow-query-log-file=/usr/local/mysql5/data/slowquery.log
  innodb_data_home_dir=/usr/local/mysql8/data
  

• 修改启动文件/usr/local/mysql5/support-files/mysql.server（下面为启动文件中需要修改的部分）

  basedir=/usr/local/mysql5
  datadir=/usr/local/mysql5/data
  --------------------------------------------
  lock_file_path="$lockdir/mysql5"
  --------------------------------------------
  mysqld_pid_file_path="/usr/local/mysql5/data/mysqld.pid"
  if test -z "$basedir"
  then
    basedir=/usr/local/mysql5
    bindir=/usr/local/mysql5/bin
    if test -z "$datadir"
    then
      datadir=/usr/local/mysql5/data
    fi
    sbindir=/usr/local/mysql5/bin
    libexecdir=/usr/local/mysql5/bin
  --------------------------------------------
  conf=/usr/local/mysql5/my.cnf
  

• 初始化数据库

  /usr/local/mysql5/bin/mysqld --defaults-file=/usr/local/mysql5/my.cnf --user=mysql --initialize

  注意记录初始密码

• 注册服务

  • sysvinit

    cp /usr/local/mysql5/suppor-files/mysql.server /etc/init.d/mysql5

  • systemd

    vim /usr/lib/systemd/system/mysqld5.service
    
    
    [Unit]
    Description=MySQL5 server
    After=syslog.target network.target
    
    [Service]
    User=mysql5
    Group=mysql
    Type=forking
    TimeoutSec=0
    #PermissionsStartOnly=true
    ExecStart=/usr/local/mysql5/bin/mysqld --defaults-file=/usr/local/mysql5/conf/my.cnf --daemonize
    LimitNOFILE = 65535
    Restart=on-failure
    RestartSec=3
    RestartPreventExitStatus=1
    PrivateTmp=false
    
    [Install]
    WantedBy=multi-user.target
    

• 设置开机自启动

  • sysvinit

    chkconfig --add mysql5

  • systemd

    systemctl enable mysql5

• 启动服务

  • sysvinit

    service mysql5 start

  • systemd

    systemctl start mysql5

• 连接数据库

  mysql --socket=/tmp/mysql3307.sock -uroot -p
  # 或者
  mysql -h:: -P3307 -uroot -p # 不知道为什么在linux中必须要指定host后，指定的端口才会生效
  

• 修改密码

  alter user root@localhost identified by 'pwd';
  

• 允许远程登录

  use mysql;
  select user, host, plugin from user;
  update user set host='%' where user='root'; # %为通配符，可指定具体的ip
  

• 开放防火墙中对应的端口

  firewall-cmd --add-port=3307/tcp --zone=public --permanent
  firewall-cmd --reload
  firewall-cmd --list-port