關於Linux 系統上的 mysql 數據庫服務

首先是安裝

CentOS7 安裝mysql（YUM源方式）

1.下載mysql源安裝包

$ wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm


2.安裝mysql源

$ yum localinstall mysql57-community-release-el7-8.noarch.rpm 


3.檢查mysql源是否安裝成功

$ yum repolist enabled | grep "mysql.*-community.*"


4.修改yum源 【可跳過】

$ vim /etc/yum.repos.d/mysql-community.repo

改變默認安裝的mysql版本。好比要安裝5.6版本，將5.7源的enabled=1改爲enabled=0。而後再將5.6源的enabled=0改爲enabled=1便可。

備註：enabled=1表示即將要安裝的mysql版本，這個文件也能夠不修改，默認安裝mysql最高版本




5.安裝MySQL 

這一步纔是真正安裝mysql

$ yum install mysql-community-server


6.啓動MySQL服務並設置開機啓動

$ systemctl start mysqld

$ systemctl enable mysqld

$ systemctl daemon-reload


7.端口開放

$ firewall-cmd --zone=public --add-port=3306/tcp --permanent

$ firewall-cmd --reload


8.修改root本地登陸密碼
 注意 若是安裝的是5.6版本，默認密碼爲空！！！！！！！！！！！！

 1）查看mysql密碼

$ grep 'temporary password' /var/log/mysqld.log


2）鏈接mysql

$ mysql -uroot -p

3）修改密碼【注意：後面的分號必定要跟上】

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';

或者：

mysql> set password for 'root'@'localhost'=password('MyNewPass4!'); 


mysql> show variables like '%password%';




安裝成功以後  須要設置 一下host 才能夠遠程訪問

-----選擇mysql庫
mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
-----查詢host
mysql> select host from user;
+-----------+
| host      |
+-----------+
| %         |
| 127.0.0.1 |
| ::1       |
| localhost |
| monkey    |
| monkey    |
+-----------+
6 rows in set (0.00 sec)
-------更新 host 爲 通用
mysql> update user set host '%' where user ='root';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''%' where user ='root'' at line 1
mysql> quit
Bye
-------重啓服務
[root@monkey /]# service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service