Ubuntu MySQL 小记

1.安装

安装服务器：

root@ubuntu:/# apt-get install mysql-server-5.5

安装客户端：

root@ubuntu:/# apt-get install mysql-client-core-5.5

中途遇到依赖包无法下载的问题，更换一下软件源就ok 度娘 ubuntu更新源

ubuntu下mysql安装目录:

url	content
/usr/bin	客户端和mysql_install_db
/var/lib/mysql	数据库和日志文件
/var/run/mysqld	服务器
/etc/mysql	配置文件 my.cnf
/usr/share/mysql	字符集，基准程序和错误消息
/etc/init.d/mysql	启动mysql服务器

2.常用操作

mysql服务操作

// /etc/init.d/mysql + 命令   start|stop|restart|reload|force-reload|status
/etc/init.d/mysql start;

mysql登陆

mysql -u 用户名 -p

查看编码

mysql> SHOW VARIABLES LIKE 'character_set_%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

查看字符集

mysql> SHOW VARIABLES LIKE 'collation_%';

+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | utf8_general_ci   |
| collation_database   | latin1_swedish_ci |
| collation_server     | latin1_swedish_ci |
+----------------------+-------------------+
3 rows in set (0.00 sec)

修改配置文件编码

# client 下添加 default-character-set=utf8
[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock
default-character-set=utf8

# mysqld 下添加 character-set-server=utf8 （可添加  init_connect='SET NAMES utf8' 设置数据库链接时的编码）
[mysqld]
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /var/lib/mysql
tmpdir      = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
character-set-server=utf8
init_connect='SET NAMES utf8'

配置优化 my.cnf参数配置优化详解

查看数据库或表的创建信息（查编码）

show create database `database_name`;

show create table `table_name`;

查看表中所有字段的编码

show full columns from `table_name`;

更改数据库或表的编码和字符集

//更改后需重启服务
ALTER DATABASE `database_name` （ALTER TABLE `table_name`） DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci  

*** 修改表中字段的字符集***

 ALTER TABLE `table_name` modify `column_name` 字段类型 CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;