問題1：你如何確定 MySQL 是否處於運行狀態？
答案： Debian 上運行命令 service mysql status，在RedHat 上運行命令 service mysqld status。然後看看輸出即可。
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..
問題2：如何開啓或停止 MySQL 服務？
答案：運行命令 service mysqld start 開啓服務；運行命令 service mysqld stop 停止服務。
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..
問題3：如何通過 Shell 登入 MySQL？
答案：運行命令 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>
問題4：如何列出所有數據庫？
答案：運行命令 show databases;
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | a1 | | cloud | | mysql | | phpmyadmin | | playsms | | sisso | | test | | ukolovnik | | wordpress | +--------------------+ 10 rows in set (0.14 sec)
問題5： 如何切換到某個數據庫並在上面工作？
答案：運行命令 use database_name; 進入名爲 database_name 的數據庫。
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>
問題6：如何列出某個數據庫內所有表？
答案：在當前數據庫運行命令 show tables;
mysql> show tables; +----------------------------+ | Tables_in_cloud | +----------------------------+ | oc_appconfig | | oc_calendar_calendars | | oc_calendar_objects | | oc_calendar_repeat | | oc_calendar_share_calendar | | oc_calendar_share_event | | oc_contacts_addressbooks | | oc_contacts_cards | | oc_fscache | | oc_gallery_sharing | +----------------------------+ 10 rows in set (0.00 sec)
問題7：如何獲取表內所有 Field 對象的名稱和類型？
答案：運行命令 describe table_name;
mysql> describe oc_users; +----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------+------+-----+---------+-------+ | uid | varchar(64) | NO | PRI | | | | password | varchar(255) | NO | | | | +----------+--------------+------+-----+---------+-------+ 2 rows in set (0.00 sec)
問題8：如何刪除表？
答案：運行 delete table table_name;
mysql> drop table lookup; Query OK, 0 rows affected (0.00 sec)
問題9：如何刪除數據庫？
答案：運行命令 drop database database-name;
mysql> drop table lookup; Query OK, 0 rows affected (0.00 sec)
問題10：如何查看錶內所有數據？
答案：運行命令 select * from table_name;
mysql> select * from engines; +------------+---------+----------------------------------------------------------------+--------------+------+------------+ | ENGINE | SUPPORT | COMMENT | TRANSACTIONS | XA | SAVEPOINTS | +------------+---------+----------------------------------------------------------------+--------------+------+------------+ | InnoDB | YES | Supports transactions, row-level locking, and foreign keys | YES | YES | YES | | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO | | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO | | CSV | YES | CSV storage engine | NO | NO | NO | | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO | | FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL | | ARCHIVE | YES | Archive storage engine | NO | NO | NO | | MyISAM | DEFAULT | Default engine as of MySQL 3.23 with great performance | NO | NO | NO | +------------+---------+----------------------------------------------------------------+--------------+------+------------+ 8 rows in set (0.00 sec)
問題11：如何從表（比如 oc_users ）中獲取一個 field 對象（比如 uid）的所有數據？
答案：運行命令 select uid from oc_users;
mysql> select uid from oc_users; +-----+ | uid | +-----+ | avi | +-----+ 1 row in set (0.03 sec)
問題12：假設你有一個名爲 ‘xyz’ 的表，它存在多個字段，如 ‘createtime’ 和 ‘engine’。名爲 engine 的字段由 ‘Memoty’ 和 ‘MyIsam’ 兩種數值組成。如何只列出 ‘createtime’ 和 ‘engine’ 這兩列並且 engine 的值爲 ‘MyIsam’？
答案：運行命令 select create_time, engine from xyz where engine = ”MyIsam”;
mysql> select create_time, engine from xyz where engine="MyIsam"; +---------------------+--------+ | create_time | engine | +---------------------+--------+ | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | +---------------------+--------+ 132 rows in set (0.29 sec)
問題13：如何列出表 ‘xrt’ 內 name 域值爲 ‘tecmint’，web_address 域值爲 ‘tecmint.com’ 的所有數據？
答案：運行命令 select * from xrt where name = “tecmint” and web_address = “tecmint.com”;
mysql> select * from xrt where name = "tecmint" and web_address = “tecmint.com”; +---------------+---------------------+---------------+ | Id | name | web_address | +---------------+---------------------+----------------+ | 13 | tecmint | tecmint.com | +---------------+---------------------+----------------+ | 41 | tecmint | tecmint.com | +---------------+---------------------+----------------+
問題14：如何列出表 ‘xrt’ 內 name 域值不爲 ‘tecmint’，web_address 域值爲 ‘tecmint.com’ 的所有數據？
答案：運行命令 select * from xrt where name != "tecmint" and web_address = "tecmint.com";
mysql> select * from xrt where name != ”tecmint” and web_address = ”tecmint.com”; +---------------+---------------------+---------------+ | Id | name | web_address | +---------------+---------------------+----------------+ | 1173 | tecmint | tecmint.com | +---------------+---------------------+----------------+
問題15：如何知道表內行數？
答案：運行命令 select count(*) from table_name;
mysql> select count(*) from Tables; +----------+ | count(*) | +----------+ | 282 | +----------+ 1 row in set (0.01 sec)