[root@localhost~]# mysql -u root -p #老徐注释：输入左侧命令，回车 root是用户名
Enter password: #老徐注释：输入密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.6.23-log Source distribution
Copyright (c) 2000, 2015, 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> #老徐注释：如果看到如上信息代表已经进入mysql
--End--
mysql> show databases; #老徐注释：输入左侧命令，回车
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)
mysql> #老徐注释：如上就是显示当前存在的数据库
mysql> use mysql ＃老徐注释：左侧，use 表名，使用某个表
Database changed
mysql> show tables; ＃老徐注释：显示当前数据库下的所有表名
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
28 rows in set (0.00 sec)
mysql>