linux非root用户安装5.7.27版本mysql

　　先下安装包，到mysql官网https://dev.mysql.com/downloads/mysql/选好安装包版本、操作系统类型（默认是最新版本，点击右边链接Looking for previous GA versions?进行自选）：

　　下完安装包mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz后，通过rz上传至linux的wlf用户soft目录下，并解压：

$ cd soft
$ rz
$ cd ..
$ tar zxvf soft/mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz

　　创建软连接：

$ ln -s mysql-5.7.27-linux-glibc2.12-x86_64 mysql

　　进入软连接目录：

$ cd mysql

　　通过vi新增mysql配置文件my.cnf，内容如下:

[client]   
port=3336  
socket=/home/wlf/mysql/mysql.sock  

[mysqld]
port=3336
basedir=/home/wlf/mysql
datadir=/home/wlf/mysql/data
pid-file=/home/wlf/mysql/mysql.pid
socket=/home/wlf/mysql/mysql.sock
log_error=/home/wlf/mysql/error.log
server-id=100

　　安装mysql：

$ bin/mysqld --defaults-file=/home/wlf/mysql/my.cnf --initialize --user=wlf --basedir=/home/wlf/mysql --datadir=/home/wlf/mysql/data

　　启动mysql：

$ bin/mysqld_safe --defaults-file=/home/wlf/mysql/my.cnf  --user=wlf &
[1] 1253
$ 2019-09-20T04:16:20.253918Z mysqld_safe Logging to '/home/wlf/mysql/error.log'.
2019-09-20T04:16:20.292670Z mysqld_safe Starting mysqld daemon with databases from /home/wlf/mysql/data

　　克隆会话打开另一个窗口，进入wlf用户的mysql目录，获取密码：

$ cat error.log | grep root@localhost
2019-09-20T03:47:05.657319Z 1 [Note] A temporary password is generated for root@localhost: 6)j;ng7%-(SP

　　登陆mysql：

$ bin/mysql -u root -p
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

　　不存在/tmp/mysql.sock，我们在my.cnf配置的mysql.sock路径是/home/wlf/mysql/mysql.sock，所以当mysql去找这个文件时，我们让它换个地方去找：

ln -s /home/wlf/mysql/mysql.sock /tmp/mysql.sock

　　再次登录，输入之前拿到的密码6)j;ng7%-(SP后登陆成功：

$ bin/mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 2
Server version: 5.7.27

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> 

　　我们修改下密码：

mysql> set password for 'root'@'localhost' = password('123456');
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

　　打完收工。如果不想用root用户，而是新建自己的用户，参见5.7.27版本mysql新增用户。