配置好环境变量或者进入mysql的bin文件夹下输入cmd启动dos
输入 mysql -u root -p

注意：mysql -h 127.0.0.1(主机地址 或者输入 localhost) -u root(用户名) -p(密码)
可以使用默认端口3306或者直接可视化软件登录，这个命令可以在mysql不是默认端口的情况下指定端口登录

C:\Program Files\MySQL\MySQL Server 5.6\bin>mysql -u root -p
Enter password: ****
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 22
Server version: 5.6.11-log MySQL Community Server (GPL)
Copyright (c) 2000, 2013, 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>

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db_1               |
| db_2               |
| db_3               |
| db_9               |
| mysql              |
| performance_schema |
| test               |
| world              |
+--------------------+
13 rows in set (0.43 sec)