Cenos7更新MariaDB

一、卸载

1.1.查看已存在版本依赖---rpm -qa|grep

rpm -qa|grep mariadb

1.2.卸载老版本（如果有的话）---rpm -e --nodeps 文件名（查询所得）

rpm -e --nodeps mariadb-libs-5.5.68-1.el7.x86_64

1.3.检查一遍是否卸载干净

rpm -qa|grep mariadb
yum remove mariadb

二、安装

2.1.在CentOS操作系统中/etc/yum.repos.d/目录下添加 MariaDB 的yum配置文件MariaDB.repo文件

vim /etc/yum.repos.d/MariaDB.repo

2.2.文件中添加如下内容

# MariaDB 10.5 CentOS repository list - created 2021-05-30 14:43 UTC
# http://downloads.mariadb.org/mariadb/repositories/
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.5/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1

2.3.清除yum的缓存并重新建立

yum clean all
yum makecache

2.4.通过yum命令安装Mariadb

cd /usr/local/src/
sudo yum install MariaDB-server MariaDB-client

 2.5.安装完成后，立即启动数据库守护进程

systemctl start mariadb

2.6.设置开启自动启动

systemctl enable mariadb

2.7.查看状态（非必需）

systemctl status mariadb

2.8.常用指令

systemctl  start  mariadb #启动命令
systemctl  restart  mariadb #重启指令
systemctl  stop  mariadb #关闭指令
ssystemctl  enable mariadb  #开机自启动
systemctl  disable mariadb #禁止开机自启动

三、数据库初始化

3.1.对MariaDB进行安全配置初始化（一路y就行，不详细解释了）

mysql_secure_installation

四、为 MariaDB 配置远程访问权限

        如果需要在别的电脑通过navicat等工具连接到数据库，这时就需要给对应的 MariaDB 账户分配权限，允许使用该账户远程连接到MariaDB。

4.1.查看账户信息

        进入数据库(输入上面的密码)：

mysql -uroot -p

        输入以下命令查看账号信息：

select host,user,password from mysql.user;

#返回
+-----------+-------------+-------------------------------------------+
| Host      | User        | Password                                  |
+-----------+-------------+-------------------------------------------+
| localhost | mariadb.sys |                                           |
| localhost | root        | ***************************************** |
| localhost | mysql       | invalid                                   |
+-----------+-------------+-------------------------------------------+

        root账户中的host项是localhost表示该账号只能进行本地登录

4.2.创建一个远程账户，并给此账户分配远程连接的权限

        远程访问则需要修改权限，输入命令：

GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.25.%' IDENTIFIED BY '远程账户密码' WITH GRANT OPTION;

        刷新权限

FLUSH PRIVILEGES;
select host,user,password from mysql.user;
#返回
+--------------+-------------+-------------------------------------------+
| Host         | User        | Password                                  |
+--------------+-------------+-------------------------------------------+
| localhost    | mariadb.sys |                                           |
| localhost    | root        | ***************************************** |
| localhost    | mysql       | invalid                                   |
| 192.168.25.% | root        | ***************************************** |
+--------------+-------------+-------------------------------------------+

五、MariaDB相关字符集编码配置

5.1.设置数据库字母大小不敏感

vim /etc/my.cnf.d/server.cnf

         在mysql标签下加入如下 （1代表不敏感）

[mysqld]

#
# * Galera-related settings
#
lower_case_table_names=1

5.2.设置MariaDB数据库默认编码

mysql -uroot -p

SHOW VARIABLES LIKE 'character%';

#返回
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

• 可以看到有的编码集为latin1，这样的话插入中文会乱码，因此需要将编码改为utf8。

vim /etc/my.cnf.d/server.cnf

#添加如下

[mysqld]

#
# * Galera-related settings
#
lower_case_table_names=1
character-set-server=utf8

5.3.重启MariaDB配置

systemctl restart mariadb

mysql -uroot -p

SHOW VARIABLES LIKE 'character%';

#返回

+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | utf8                       |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+