VM CentOS7 安裝mysql 5.7

1.檢查有無mysql舊文件

			[root@localhost ~]# find / -name mysql
				/usr/lib64/mysql
				/usr/share/mysql
			[root@localhost ~]# rm -rf /usr/lib64/mysql /usr/share/mysql
			[root@localhost ~]# find / -name mysql
      擴展：
           安裝文件傳輸工具
           [root@localhost ~]# yum install -y lrzsz

2.利用傳輸工具等方式上傳文件（ /usr/local/src）

           1.上傳文件（任何上傳工具都可以）
           [root@localhost ~]# rz
				rz waiting to receive.
				 zmodem trl+C ȡ
				  100%  638679 KB 15577 KB/s 00:00:41       0 Errorsc2.5-x86_64.tar.gz...
			[root@localhost src]# ls
				mysql-5.7.17-linux-glibc2.5-x86_64.tar.gz
			2.解壓、移動文件
			[root@localhost src]# tar -zxf mysql-5.7.17-linux-glibc2.5-x86_64.tar.gz 
			[root@localhost src]# mv mysql-5.7.17-linux-glibc2.5-x86_64 /usr/local/mysql
			3.創建mysql用戶、組、目錄
			[root@localhost mysql]# groupadd mysql
			[root@localhost mysql]# useradd -s /sbin/nologin -g mysql -d /usr/local/mysql/ mysql #指定shell，組，目錄
			更改所需目錄的屬性：
			[root@localhost mysql]# chown -R mysql:mysql /usr/local/mysql/
			[root@localhost mysql]# chown -R mysql:mysql /data/mysql/
			4.初始化 切換到mysql bin目錄
			[root@localhost bin]# mysqld --initialize --uesr=mysql --basedir=/usr/local/mysql/ --datadir=/data/mysql/
			如果報如下錯誤bin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory
			則
			[root@localhost mysql]# yum install -y libaio
			[root@localhost bin]#  mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql
			*******
			2019-03-08T12:45:58.099193Z 1 [Note] A temporary password is generated for root@localhost: gSci&AdUh8Oc
			出現初始密碼，即表示初始化成功
			[root@localhost mysql]# cd support-files/
			[root@localhost support-files]# cp my-default.cnf /etc/my.cnf
			[root@localhost support-files]# cp mysql.server /etc/init.d/mysql
			[root@localhost support-files]# vi /etc/init.d/mysql 
			basedir=/usr/local/mysql
			datadir=/data/mysql

3.啓動mysql

	        1.安裝mariadb-server
				yum install -y mariadb-server
			2.啓動服務
			   systemctl start mariadb.service
			3.添加到開機啓動
				systemctl enable mariadb.service
				 ***擴展：以上3步***
			   如果報錯:錯誤1130- Host xxx is not allowed to connect to this MariaDb server（權限問題）
				mysql>use mysql;
				mysql>update user set host = '%' where user = 'root'  and host='localhost';
				mysql>select host, user from user;
				然後重啓MySQL服務。或再執行 執行一個語句        mysql>FLUSH PRIVILEGES 使修改生效。
			4.安全設置，修改密碼
			    mysql_secure_installation
			   ![在這裏插入圖片描述](https://img-blog.csdnimg.cn/20200510210923751.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0J6YnR5aHlkY3h5,size_16,color_FFFFFF,t_70#pic_center)
			   mysql -u root -p 輸入密碼，連接成功！
			   
			   若主機訪問虛擬機mysql數據庫
			   需：3306端口開放