CentOS6.5下簡單的MySQL數據庫操做

1.登陸成功以後退出的話，直接輸入quit或者exit便可。

2.使用.tar.gz的包安裝MySQL時，進入MySQL須要使用絕對路徑

 

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

 

單獨只是輸入一個"mysql" 命令是不行的，由於"/usr/local/mysql/bin" 沒有在 PATH 這個環境變量裏(使用yum安裝不須要)。如何把它加入環境變量PATH中？

 

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

 

這樣就能夠了，但重啓Linux後還會失效，因此須要讓它開機加載:

 

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

 

-u 用來指定要登陸的用戶，後邊能夠有空格，也能夠無空格。-p 後面能夠直接跟密碼，後面不能夠有空格，不過密碼最好用單引號括起來，不括也能夠，可是密碼中若是有特殊字符就會有問題了，因此最好是括起來。

 

鏈接數據庫

經過使用 mysql -u root -p 能夠鏈接數據庫，但這只是鏈接的本地的數據庫"localhost", 但是有不少時候都是去鏈接網絡中的某一個主機上的mysql。

 

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

 

其中後邊的 -P(大寫) 用來指定遠程主機MySQL的綁定端口，默認都是3306, -h 用來指定遠程主機的IP.

 

一些基本的MySQL操做命令

1. 查詢當前的庫

 

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

 

2. 查詢某個庫的表

 

首先須要切換到某個庫中
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

顯示該數據庫中的表
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. 查看某個表的所有字段

 

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)

 

也可使用另外一條命令，顯示比這個更詳細，並且能夠把建表語句所有列出來:

 

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. 查看當前是哪一個用戶

 

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

 

5. 查看當前所使用數據庫

 

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

 

6. 建立一個新庫

 

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

 

7. 建立一個新表

 

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

 

8. 查看當前數據庫版本

 

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

 

9. 查看當前MySQL狀態

 

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的參數

 

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的參數

 

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， "%"相似於shell下的 *, 表示萬能匹配。使用 "set global" 能夠臨時修改某些參數，可是重啓mysqld服務後還會變爲原來的，因此要想恆久生效，須要在配置文件 my.cnf 中定義。

12. 查看當前MySQL服務器的隊列

這個在平常的管理工做中使用最爲頻繁，由於使用它能夠查看當前mysql在幹什麼，能夠發現是否有鎖表:

 

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. 建立一個普通用戶並受權

 

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

 

all 表示全部的權限（讀、寫、查詢、刪除等等操做）， *.* 前面的 * 表示全部的數據庫，後面的 * 表示全部的表，identified by 後面跟密碼，用單引號括起來。這裏的user1指的是localhost上的user1，若是是給網絡上的其餘機器上的某個用戶受權則這樣:

 

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

 

用戶和主機的IP之間有一個@，另外主機IP那裏能夠用%替代，表示全部主機，例如:

 

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

 

MySQL數據庫的備份與恢復

備份:

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

使用 mysqldump 命令備份數據庫，-u 和 -p 兩個選項使用方法和前面說的 mysql 一樣，然後面的 「mysql」 指的是庫名，而後重定向到一個文本文檔裏。備份完後，你能夠查看 /tmp/mysql.sql 這個文件裏的內容。

恢復和備份正好相反:

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