在MySQL提供的工具中，DBA使用最頻繁的莫過於mysql。這里的mysql不是指MySQL服務，也不是mysql數據庫，而是連接數據庫的客戶端工具。類似於Oracle的sqlplus。
語法： mysql [options][database]
options是mysql的可用選項，一次可以寫一個或者多個，甚至可以不寫。database表示連接的數據庫，一次只能寫一個或者不寫，如果不寫，在登錄數據庫后還需要使用use dbname選擇數據庫。
mysql的選項通常有兩種表達方式：
-+選項單詞的縮寫+選項值**；--+選項的完整單詞+=+選項的實際值；
例如: mysql -uroot -ppassword mysql --user=root --password=password
1.連接選項
-u,--user=name 指定連接的用戶名
-p,--password=password 指定連接密碼
-h,--host=name 指定服務器IP或域名
-P,--port=3308 指定連接端口
在默認情況下，如果這些選項都不寫，mysql將會使用'用戶'@'localhost'和空密碼連接本機的3306端口。空用戶會在mysql安裝完畢后自動生成，這也就是僅使用mysql命令就能連到數據庫的原因。
如果客戶端和服務器在用一台機器上，通常不需要指定-h選項，否則需要指定mysql服務所在的IP或主機名。如果不指定端口，默認連接到3306端口。示例如下：
# mysql -h 10.10.200.202 -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 75520 Server version: 5.6.28 Source distribution 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>
2.指定客戶端字符集
--default-character-set=charset-name為服務器的字符集選項。該選項可以配置在my.cnf的[mysqld]組中，同樣也可以作為客戶端字符集選項，也可以配置在[mysql]組中。在使用mysql命令登錄數據庫時，使用--default-character-set選項可以指定客戶端的字符集。例如，如果未使用--default-character-set選項登錄數據庫時：
# mysql -h 10.10.200.202 -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 75520 Server version: 5.6.28 Source distribution 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> show variables like 'chara%'; +--------------------------+-----------------------------------------+ | Variable_name | Value | +--------------------------+-----------------------------------------+ | character_set_client | latin1 | | character_set_connection | latin1 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | latin1 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /usr/local/mysql-5.6.28/share/charsets/ | +--------------------------+-----------------------------------------+
當使用--default-character-set選項登錄數據庫時：
# mysql -h 10.10.200.202 -uroot -p --default-character-set=utf8 Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 75542 Server version: 5.6.28 Source distribution 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> show variables like 'chara%'; +--------------------------+-----------------------------------------+ | Variable_name | Value | +--------------------------+-----------------------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /usr/local/mysql-5.6.28/share/charsets/ | +--------------------------+-----------------------------------------+ 8 rows in set (0.01 sec)
3.執行選項
-e,--execute=name 執行sql語句並退出
此選項可以直接在客戶端執行SQL語句，而不用連接到MySQL數據庫后再執行，對於一些腳本的執行，使用此法較為便利。可以使用此種方法連續執行多條SQL語句，語句之間用分號(;)分隔例如：
# mysql -uroot -p mysql -e "select host,user from user" Enter password: +--------------------+--------+ | host | user | +--------------------+--------+ | 10.10.200.201 | root | | 10.10.200.201 | zabbix | | 127.0.0.1 | root | | ::1 | root | | localhost | | | localhost | root | | localhost | zabbix | | tcxx-ops-mysql-202 | | | tcxx-ops-mysql-202 | root | +--------------------+--------+
4.格式化選項
-E,--vertical 將輸出按字段順序垂直顯示 -s,--silent 去掉SQL輸出結果中的線條框
# mysql -uroot -p mysql -e "select host,user from user" -E Enter password: *************************** 1. row *************************** host: 127.0.0.1 user: root *************************** 2. row *************************** host: ::1 user: root *************************** 3. row *************************** host: localhost user: *************************** 4. row *************************** host: localhost user: root *************************** 5. row *************************** host: test-server user: *************************** 6. row *************************** host: test-server user: root