Linux环境安装MySQL5.7

系统：centos7

MySQL：5.7

1. 检查是否安装MySQL，有则删除

   rpm -qa | grep mysql
   

   删除命令

   rpm -e 文件名         # 文件名就是上个命令的输出结果
   

2. 下载MySQL包

   wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
   

3. 安装MySQL包

   yum -y install mysql57-community-release-el7-10.noarch.rpm
   

4. 安装MySQL

   yum -y install mysql-community-server
   

   如果提示

   Total size: 213 M
   Downloading packages:
   warning: /var/cache/yum/x86_64/7/mysql57-community/packages/mysql-community-client-5.7.40-1.el7.x86_64.rpm: Header V4 RSA/SHA256 Signature, key ID 3a79bd29: NOKEY
   Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
   
   
   The GPG keys listed for the "MySQL 5.7 Community Server" repository are already installed but they are not correct for this package.
   Check that the correct key URLs are configured for this repository.
   
   
    Failing package is: mysql-community-client-5.7.40-1.el7.x86_64
    GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
   

   说明没安装成功，秘钥文件有问题，需要更新检索秘钥

   rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
   或者
   rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022
   

5. 完成上述操作后就可以操作MySQL了

   • 启动MySQL

   systemctl start mysqld.service
   

   • 查看MySQL服务状态

   service mysqld status
   

   • 查看初始密码

   grep ‘password’ /var/log/mysqld.log
   或者
   grep 'temporary password' /var/log/mysqld.log
   

   网上找的命令，我是第二个命令才有输出密码

   [Note] A temporary password is generated for root@localhost: utD_wHpq4!7a
   

   utD_wHpq4!7a就是生成的随机密码

   • 查看MySQL版本

   mysql -V
   

6. 修改MySQL初始密码

   • 编辑MySQL配置文件，开启免密登录

     vim /etc/my.cnf
     

     增加skip-grant-tables保存后重启MySQL，表示开启免密登录

     service mysqld stop             # 停止MySQL服务
     service mysqld start            # 启动MySQL服务
     service mysqld restart          # 重启MySQL服务
     

   • 登录MySQL修改密码

     mysql -u root -p
     

     不用输入密码，直接回车即可，执行SQL

     # 使用mysql库
     use mysql;
     # 更新root用户的密码为123456，并且设置任意host可以连接，如果不改变Host则默认的是localhost才能# 连接
     update user set authentication_string=password("root"),Host="%" where User="root";
     

     注意使用双引号，实测单引号会报错，另外这是MySQL5.7的更新语句，MySQL8应该用下面这条

     update user set authentication_string="",Host="%" where user = "root";
     

     修改完成后再把 /etc/my.cnf 文件修改回来，重启MySQL即可用新密码登录