mysql必须掌握的15个命令
嘻嘻发布于2020-07-12
最后更新于2020年6月30日
浏览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;