1.检查是否安装过mysql
#查询安装过的mysql
rpm -qa|grep mysql
#查询所有mysql 对应的文件夹,全部删除
whereis mysql
find / -name mysql
2.卸载CentOS7系统自带mariadb
# 查看系统自带的Mariadb
rpm -qa|grep mariadb
mariadb-libs-5.5.44-2.el7.centos.x86_64
# 卸载系统自带的Mariadb
rpm -e --nodeps mariadb-libs-5.5.44-2.el7.centos.x86_64
# 删除etc目录下的my.cnf ,一定要删掉,等下再重新建,之前我将就用这个文件,后面改配置各种不生效
rm /etc/my.cnf
3.下载mysql安装包
位置/opt/apps
下载mysql安装源
wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
安装mysql安装源
yum -y localinstall mysql57-community-release-el7-11.noarch.rpm
4.在线安装mysql
yum -y install mysql-community-server
5.启动mysql
systemctl start mysqld
6.设置开机启动
systemctl enable mysqld
systemctl daemon-reload
7.修改root登录密码
(1)mysql安装完成之后,会在/var/log/mysqld.log文件中给root生成了一个临时的默认密码。
vim /var/log/mysqld.log
(2)查询到下面这句日志,找到临时密码
A temporary password is generated for root@localhost: VPuaIg5NNo-<
(3)使用临时密码登录mysql
mysql -uroot -p VPuaIg5NNo-<
(4)设置密码等级为低等级
set global validate_password_length=7;//root123
set global validate_password_policy=LOW;
(4)修改mysql密码
alter user 'root'@'localhost' identified by 'root123';
(5)设置远程登录
grant all privileges on *.* to 'root'@'%' identified by 'root123' with grant option;
8.Mysql默认安装目录
//可以查询mysql的位置
whereis mysql
bin目录 /usr/bin/mysql
data目录 /var/lib/mysql/
config目录 /etc/my.cnf
log错误日志 /var/log/mysqld.log
注意FAQ
1.端口无法访问?
可能是防火墙没关,或者端口没有开放给外部访问
(1)打开端口访问
cd /etc/sysconfig/
vim iptables
-A INPUT -p tcp --dport 3306 -j ACCEPT
(2)重启防火墙
systemctl restart firewalld
(3)重启mysql
systemctl restart mysqld
2.Mysql默认编码不是UTF-8?
#查看编码
show variables like 'character%';
vim /etc/my.cnf
添加
[client]
default-character-set=utf8
[mysql]
default-character-set=utf8
[mysqld]
default-storage-engine=innodb
character-set-server=utf8
collation-server=utf8_general_ci
附录参考
* 启动mysql服务
systemctl start mysqld.service
* 停止mysql服务
systemctl stop mysqld.service
* 重启mysql服务
systemctl restart mysqld.service
* 查看mysql服务当前状态
systemctl status mysqld.service
* 设置mysql服务开机自启动
systemctl enable mysqld.service
* 停止mysql服务开机自启动
systemctl disable mysqld.service