centos7使用 yum 安装mysql教程

我忽然发现，使用centos7安装MySQL时，安装的是mariadb，而且无法启动MySQL，报错。主要有

Failed to start mariadb.service: Unit not found.

Failed to start mysql.service: Unit not found.

mysql有版本信息返回，无法登录。

解决方案：

1.安装mysql

yum -y install mysql mariadb-server

2.修改my.cnf文件‘

vim /etc/my.cnf

在[mysqld] 下加上一句skip-grant-tables

例如，原配置文件为：

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid

修改后为

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
skip-grant-tables
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid

3.重启服务

systemctl restart mariadb

如果这一步失败，说明安装有了问题。

4.登录mysql，修改密码

执行命令

mysql-u root -p

提示输入密码，直接回车。

修改密码

flush privileges;
set password for root@localhost = password("你想设置的root密码");

例如：

flush privileges;
set password for root@localhost = password("1");

5.退出，修改回my.cnf文件

exit;
vim /etc/my.cnf

把刚才加的那句skip-grant-tables删除掉，保存。重启MariaDB服务

systemctl restart mariadb

至此，解决了所有问题！