CentOS6.5下简单的MySQL数据库操做

时间 2019-12-06

标签 centos6.5 centos 简单 mysql 数据库栏目 CentOS 繁體版

原文原文链接

1.登陆成功以后退出的话，直接输入quit或者exit便可。mysql

2.使用.tar.gz的包安装MySQL时，进入MySQL须要使用绝对路径sql

[root@winner ~]# /usr/local/mysql/bin/mysql -uroot

单独只是输入一个"mysql" 命令是不行的，由于"/usr/local/mysql/bin" 没有在 PATH 这个环境变量里(使用yum安装不须要)。如何把它加入环境变量PATH中？shell

[root@winner ~]# PATH=$PATH:/usr/local/mysql/bin

这样就能够了，但重启Linux后还会失效，因此须要让它开机加载:数据库

[root@winner ~]# echo "PATH=$PATH:/usr/local/mysql/bin" >> /etc/profile
[root@winner ~]# source /etc/profile
[root@localhost ~]# mysql -uroot

-u 用来指定要登陆的用户，后边能够有空格，也能够无空格。-p 后面能够直接跟密码，后面不能够有空格，不过密码最好用单引号括起来，不括也能够，可是密码中若是有特殊字符就会有问题了，因此最好是括起来。服务器

链接数据库

经过使用 mysql -u root -p 能够链接数据库，但这只是链接的本地的数据库"localhost", 但是有不少时候都是去链接网络中的某一个主机上的mysql。网络

[root@winner ~]# mysql -uroot -p -h192.168.137.10 -P3306
Enter password:

其中后边的 -P(大写) 用来指定远程主机MySQL的绑定端口，默认都是3306, -h 用来指定远程主机的IP.ide

一些基本的MySQL操做命令

1. 查询当前的库ui

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| test               |
| winner             |
+--------------------+
rows in set (0.07 sec)

2. 查询某个库的表this

首先须要切换到某个库中
mysql> use mysql
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

显示该数据库中的表
mysql> show tables;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| event                     |
| func                      |
| general_log               |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| host                      |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| servers                   |
| slow_log                  |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+
rows in set (0.00 sec)

3. 查看某个表的所有字段spa

mysql> desc host;
+-----------------------+---------------+------+-----+---------+-------+
| Field                 | Type          | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host                  | char(60)      | NO   | PRI |         |       |
| Db                    | char(64)      | NO   | PRI |         |       |
| Select_priv           | enum('N','Y') | NO   |     | N       |       |
| Insert_priv           | enum('N','Y') | NO   |     | N       |       |
| Update_priv           | enum('N','Y') | NO   |     | N       |       |
| Delete_priv           | enum('N','Y') | NO   |     | N       |       |
| Create_priv           | enum('N','Y') | NO   |     | N       |       |
| Drop_priv             | enum('N','Y') | NO   |     | N       |       |
| Grant_priv            | enum('N','Y') | NO   |     | N       |       |
| References_priv       | enum('N','Y') | NO   |     | N       |       |
| Index_priv            | enum('N','Y') | NO   |     | N       |       |
| Alter_priv            | enum('N','Y') | NO   |     | N       |       |
| Create_tmp_table_priv | enum('N','Y') | NO   |     | N       |       |
| Lock_tables_priv      | enum('N','Y') | NO   |     | N       |       |
| Create_view_priv      | enum('N','Y') | NO   |     | N       |       |
| Show_view_priv        | enum('N','Y') | NO   |     | N       |       |
| Create_routine_priv   | enum('N','Y') | NO   |     | N       |       |
| Alter_routine_priv    | enum('N','Y') | NO   |     | N       |       |
| Execute_priv          | enum('N','Y') | NO   |     | N       |       |
| Trigger_priv          | enum('N','Y') | NO   |     | N       |       |
+-----------------------+---------------+------+-----+---------+-------+
rows in set (0.00 sec)

也可使用另外一条命令，显示比这个更详细，并且能够把建表语句所有列出来:

mysql> show create table host\G;
*************************** 1. row ***************************
       Table: host
Create Table: CREATE TABLE `host` (
  `Host` char(60) COLLATE utf8_bin NOT NULL DEFAULT '',
  `Db` char(64) COLLATE utf8_bin NOT NULL DEFAULT '',
  `Select_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Insert_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Update_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Delete_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Create_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Drop_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Grant_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `References_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Index_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Alter_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Create_tmp_table_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Lock_tables_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Create_view_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Show_view_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Create_routine_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Alter_routine_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Execute_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  `Trigger_priv` enum('N','Y') CHARACTER SET utf8 NOT NULL DEFAULT 'N',
  PRIMARY KEY (`Host`,`Db`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='Host privileges;  Merged with database privileges'
row in set (0.00 sec)

4. 查看当前是哪一个用户

mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
row in set (0.00 sec)

5. 查看当前所使用数据库

mysql> select database();
+------------+
| database() |
+------------+
| mysql      |
+------------+
row in set (0.00 sec)

6. 建立一个新库

mysql> create database db1;
Query OK, 1 row affected (0.02 sec)

7. 建立一个新表

mysql> create table t1 (`id` int(4), `name` char(40));
Query OK, 0 rows affected (0.02 sec)

8. 查看当前数据库版本

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.1.73    |
+-----------+
row in set (0.00 sec)

9. 查看当前MySQL状态

mysql> show status;
+-----------------------------------+----------+
| Variable_name                     | Value    |
+-----------------------------------+----------+
| Aborted_clients                   | 1        |
| Aborted_connects                  | 2        |
| Binlog_cache_disk_use             | 0        |
| Binlog_cache_use                  | 0        |
| Bytes_received                    | 1194     |
| Bytes_sent                        | 21732    |
| Com_admin_commands                | 0        |
| Com_assign_to_keycache            | 0        |
| Com_alter_db                      | 0        |
| Com_alter_db_upgrade              | 0        |
| Com_alter_event                   | 0        |

10. 查看MySQL的参数

mysql> show variables;
+-----------------------------------------+---------------------+
| Variable_name                           | Value               |
+-----------------------------------------+---------------------+
| auto_increment_increment                | 1                   |
| auto_increment_offset                   | 1                   |
| autocommit                              | ON                  |
| automatic_sp_privileges                 | ON                  |
| back_log                                | 50                  |
| basedir                                 | /usr/local/mysql/   |

11. 修改MySQL的参数

mysql> show variables like 'max_connect%';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| max_connect_errors | 10    |
| max_connections    | 151   |
+--------------------+-------+
rows in set (0.00 sec)

mysql> set global max_connect_errors = 1000;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'max_connect_errors';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| max_connect_errors | 1000  |
+--------------------+-------+
row in set (0.00 sec)

在MySQL命令行， "%"相似于shell下的 *, 表示万能匹配。使用 "set global" 能够临时修改某些参数，可是重启mysqld服务后还会变为原来的，因此要想恒久生效，须要在配置文件 my.cnf 中定义。

12. 查看当前MySQL服务器的队列

这个在平常的管理工做中使用最为频繁，由于使用它能够查看当前mysql在干什么，能够发现是否有锁表:

mysql> show processlist;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host      | db   | Command | Time | State | Info             |
+----+------+-----------+------+---------+------+-------+------------------+
|  9 | root | localhost | db1  | Query   |    0 | NULL  | show processlist |
+----+------+-----------+------+---------+------+-------+------------------+
row in set (0.00 sec)

13. 建立一个普通用户并受权

mysql> grant all on *.* to user1 identified by '123456';
Query OK, 0 rows affected (0.01 sec)

all 表示全部的权限（读、写、查询、删除等等操做）， *.* 前面的 * 表示全部的数据库，后面的 * 表示全部的表，identified by 后面跟密码，用单引号括起来。这里的user1指的是localhost上的user1，若是是给网络上的其余机器上的某个用户受权则这样:

mysql> grant all on db1.* to 'user2'@'10.0.2.100' identified by '111222';
Query OK, 0 rows affected (0.01 sec)

用户和主机的IP之间有一个@，另外主机IP那里能够用%替代，表示全部主机，例如:

mysql> grant all on db1.* to 'user3'@'%' identified by '231222';
Query OK, 0 rows affected (0.00 sec)

MySQL数据库的备份与恢复

备份:

[root@winner ~]# mysqldump  -uroot -p'root' mysql >/tmp/mysql.sql
不是在mysql>环境

使用 mysqldump 命令备份数据库，-u 和 -p 两个选项使用方法和前面说的 mysql 一样，然后面的 “mysql” 指的是库名，而后重定向到一个文本文档里。备份完后，你能够查看 /tmp/mysql.sql 这个文件里的内容。

恢复和备份正好相反:

[root@localhost ~]# mysql -uroot -p'yourpassword' mysql </tmp/mysql.sql