MySQL下载地址：http://dev.mysql.com/downloads/mysql/
Windows下安装MySQL
我下的是最新版的MySQL，解压后，目录如下：
1.进入dos的命令行，一定要用administrator进入。
2.进入MySQL的bin目录，输入mysqld –install可以安装MySQL
cd D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64in
D:
D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64in
D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64>mysqld -install
Service successfully installed.
3.输入以下命令，可以初始化MySQL数据库，初始化了之后，会打印出MySQL的默认生成的密码，下面标红了的就是默认生成的密码。
D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64>mysqld --initialize --user=root --console
2019-12-20T02:28:44.093039Z 0 [System] [MY-013169] [Server] D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64inmysqld.exe (mysqld 8.0.18) initializing of server in progress as process 7500
2019-12-20T02:28:51.796888Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: 4IfH4*eywsg=
初始化了以后，可以看到MySQL目录下，多了data目录
4.启动MySQL服务
D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64>net start mysql
MySQL 服务正在启动 ..
MySQL 服务已经启动成功。
5.使用默认生成的密码，进入mysql
D:ideamysql-8.0.18-winx64mysql-8.0.18-winx64>mysql -u root -p4IfH4*eywsg=
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 11
Server version: 8.0.18
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>
6.修改密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123';
Query OK, 0 rows affected (0.01 sec)
7.退出，修改成功