mysql必须掌握的15个命令

mysql是当前非常流行的一款数据库,掌握mysql数据是程序员开发必不可少的技能。我们罗列了15个必须掌握mysql命令,学会了这些,你的mysql才能说入门。

1.如何检查MySql服务是否正在运行?
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.
2.如果服务正在运行/停止,您将如何停止/启动该服务?
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..
3.您将如何从Linux Shell登录MySQL?
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>
4.您将如何获取所有数据库的列表?
mysql> show databases; 
+--------------------+ 
| Database           | 
+--------------------+ 
| information_schema | 
| a1                 | 
| cloud              | 
| mysql              | 
| phpmyadmin         | 
| playsms            | 
| sisso              | 
| test               | 
| ukolovnik          | 
| wordpress          | 
+--------------------+ 
10 rows in set (0.14 sec)
5.您将如何切换到数据库并开始进行操作?
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>
6.如何获取数据库中所有表的列表?
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)
7.您将如何获取MySql表的字段名称和类型?
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)
8.如何删除表?
mysql> drop table lookup; 

Query OK, 0 rows affected (0.00 sec)
9.那数据库呢?您将如何删除数据库?
mysql> drop database a1; 

Query OK, 11 rows affected (0.07 sec)
10.您将如何查看表的所有内容?
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)
11.您将如何从表(例如oc_users)中查看字段(例如uid)中的所有数据?
mysql> select uid from oc_users; 
+-----+ 
| uid | 
+-----+ 
| avi | 
+-----+ 
1 row in set (0.03 sec)
12.假设您有一个表“ xyz”,其中包含多个字段,包括“ create_time”和“ engine”。字段“引擎”中填充了两种类型的数据“内存”和“ MyIsam”。如何从引擎为“ MyIsam”的表中仅获取“ create_time”和“ engine”?
 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 | 
13.如何显示表“ xrt”中名称为“11meigui”和web_address为“ 11meigui.com”的所有记录?
mysql> select  * from xrt where name = "11meigui" and web_address = “11meigui.com”;
14.如何显示表“ xrt”中名称不为“ 11meigui”且web_address为“ 11meigui.com”的所有记录?
mysql> select * from xrt where name != ”11meigui” and web_address = ”11meigui.com”;
15.您需要知道表中的行条目总数。您将如何实现?
mysql> select count(*) from Tables; 
使用mysqldump备份MySQL或MariaDB
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