15个 MySQL 基础面试题，DBA 们准备好了吗？

此前我们已经有发表过Linux 面试基础问答之一、二和三共3篇文章，获得读者的好评，同时我们得到反馈，有些读者希望这种交互式学习方法能够做得更加灵活。心动不如行动，我们这就为您奉上 15个 MySQL 面试题。

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问题1：你如何确定 MySQL 是否处于运行状态？

答案： Debian 上运行命令 service mysql status，在RedHat 上运行命令 service mysqld status。然后看看输出即可。

root@localhost:/home/avi# service mysql status

/usr/bin/mysqladmin  Ver 8.42 Distrib 5.1.72, for debian-linux-gnu on i486
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.

Server version 5.1.72-2
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/run/mysqld/mysqld.sock
Uptime: 1 hour 22 min 49 sec

Threads: 1  Questions: 112138  Slow queries: 1  Opens: 1485  Flush tables: 1  Open tables: 64  Queries per second avg: 22.567.

问题2：如何开启或停止 MySQL 服务？

答案：运行命令 service mysqld start 开启服务；运行命令 service mysqld stop 停止服务。

root@localhost:/home/avi# service mysql stop

Stopping MySQL database server: mysqld.

root@localhost:/home/avi# service mysql start

Starting MySQL database server: mysqld.

Checking for corrupt, not cleanly closed and upgrade needing tables..

问题3：如何通过 Shell 登入 MySQL？

答案：运行命令 mysql -u root -p

root@localhost:/home/avi# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 207
Server version: 5.1.72-2 (Debian)

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>

问题4：如何列出所有数据库？

答案：运行命令 show databases;

mysql> show databases;
+--------------------+
| Database          |
+--------------------+
| information_schema |
| a1                |
| cloud              |
| mysql              |
| phpmyadmin        |
| playsms            |
| sisso              |
| test              |
| ukolovnik          |
| wordpress          |
+--------------------+
10 rows in set (0.14 sec)

问题5： 如何切换到某个数据库并在上面工作？

答案：运行命令 use database_name; 进入名为 database_name 的数据库。

mysql> use cloud;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql>