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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“”和web_address为“ ”的所有记录？

mysql> select  * from xrt where name = "" and web_address = “”;

14.如何显示表“ xrt”中名称不为“ ”且web_address为“ ”的所有记录？

mysql> select * from xrt where name != ”” and web_address = ””;

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;