Linux安裝mysql

1.創建目錄 /usr/local/
把下載好的mysql文件放到 /usr/local/ 目錄下
tar -zxvf mysql-5.7.20-linux-glibc2.12-x86_64.tar.gz.tar.gz  //解壓
mkdir mysql//在/usr/local    //目錄下建目錄mysql
然後把解壓好的mysql(名字很長)文件夾拷貝到 /usr/local/mysql 目錄下
在根目錄的tmp下新建文件 mysql.sock


2.創建或修改配置文件
vi /etc/my.cnf

[mysqld]
character_set_server=utf8
init_connect='SET NAMES utf8'
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock

3.初始化數據庫
./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data

4.啓動數據庫
./support-files/mysql.server start

5.登錄mysql
./mysql -u root -p
輸入密碼
第一次會提示需要修改密碼:set password=password('123456');
flush privileges;

設置軟連接在自己的目錄直接調用進入mysql
ln -s ../../../usr/local/mysql/bin/  ../../../home/sfadmin/loadmysql  (loadmysql爲連接自動建立的自定義目錄)


chmod 644 /etc/my.cnf //設置my.cnf文件權限，不然會被系統忽略該文件導致有些配置項無法生效和使用

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
update mysql.user set password=password('新密碼') where User="root" and Host="localhost";

//設置和查詢允許被遠程訪問
select host,user from user;
grant all privileges  on *.* to root@'%' identified by "123456";
flush privileges;

如果需要遠程訪問mysql數據庫，需要關閉linux的防火牆:
查看防火牆狀態： systemctl status firewalld 或者 systemctl is-active firewalld 
啓動防火牆： systemctl start firewalld 
停止防火牆： systemctl stop firewalld (mysql關閉防火牆之後就可以遠程連接)
永久停用： systemctl disable firewalld 
啓用防火牆： systemctl enable firewalld