查看修改MySQL字符集

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查看修改MySQL字符集

?(2012-08-22 09:53:21) 轉載▼

標簽：? 字符集 ? mysql數據庫 ? mysql字符集查看 ? mysql啟動命令 ? 修改mysql字符集

分類：?網站開發

MySQL字符集多種多樣，下面為列舉了其中三種最常見的字符集查看方法，該方法供您參考，希望對學習MySQL數據庫能有所啟迪。

一、查看MySQL數據庫服務器和數據庫MySQL字符集。

mysql>?show?variables?like?'%char%';??

+--------------------------+-------------------------------------+------ ?

|?Variable_name????????????|?Value???????????????????????????????|...... ?

+--------------------------+-------------------------------------+------ ?

|?character_set_client?????|?utf8????????????????????????????????|......???--?客戶端字符集 ?

|?character_set_connection?|?utf8????????????????????????????????|...... ?

|?character_set_database???|?utf8????????????????????????????????|......???--?數據庫字符集 ?

|?character_set_filesystem?|?binary??????????????????????????????|...... ?

|?character_set_results????|?utf8????????????????????????????????|...... ?

|?character_set_server?????|?utf8????????????????????????????????|......???--?服務器字符集 ?

|?character_set_system?????|?utf8????????????????????????????????|...... ?

|?character_sets_dir???????|?D:\MySQL?Server?5.0\share\charsets\?|...... ?

+--------------------------+-------------------------------------+------?

mysql的字符集分為幾類 A.客戶端字符集：通過系統變量”character_set_client“表示，通知server端，客戶端提交的sql語句編碼格式 B.連接字符集：通過系統變量”character_set_connectiont“表示，server端翻譯sql語句時，使用的編碼格式 C.結果集字符集：通過系統變量”character_set_results“表示，server端返回結果集之前把結果集轉換成的編碼格式 D.存儲字符集：通過系統變量”character_set_results“和“character_set_server”表示，是數據在存儲引擎里編碼格式

為了不出現亂碼，我們需要統一修改這些參數，比如我要把數據庫的默認字符集改為utf8，如下所示

在[client]下添加如下參數 default-character-set=utf8

在[mysqld]下添加如下參數 default-character-set=utf8

然后重啟mysql服務，再查看字符集（要重新登錄客戶端）

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mysql> show variables like 'collation%'; +----------------------+-----------------+ | Variable_name????????| Value???????????| +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database???| utf8_general_ci | | collation_server?????| utf8_general_ci | +----------------------+-----------------+ 3 rows in set (0.00 sec)

mysql>

mysql的字符集分的比較細，可以采用默認值，也可以指定值

A.數據庫字符集

使用默認字符集的庫 mysql> create database db1; Query OK, 1 row affected (0.01 sec)

mysql> show create database db1; +----------+--------------------------------------------------------------+ | Database | Create Database??????????????????????????????????????????????| +----------+--------------------------------------------------------------+ | db1??????| CREATE DATABASE `db1` | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec)

指定字符集的庫 mysql> create database db2 default character set latin1; Query OK, 1 row affected (0.01 sec)

mysql> show create database db2; +----------+----------------------------------------------------------------+ | Database | Create Database????????????????????????????????????????????????| +----------+----------------------------------------------------------------+ | db2??????| CREATE DATABASE `db2` | +----------+----------------------------------------------------------------+ 1 row in set (0.00 sec)

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修改庫的字符集 mysql> alter database db2 default character set utf8; Query OK, 1 row affected (0.00 sec)

mysql> show create database db2; +----------+--------------------------------------------------------------+ | Database | Create Database??????????????????????????????????????????????| +----------+--------------------------------------------------------------+ | db2??????| CREATE DATABASE `db2` | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec)

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B.表字符集

mysql> use db2; Database changed

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使用默認庫字符集的表 mysql> create table t1(a varchar(10)); Query OK, 0 rows affected (0.01 sec)

mysql> show create table t1; +-------+-----------------------------------------------------------------------------------------+ | Table | Create Table???????????????????????????????????????????????????????????????????????????| +-------+-----------------------------------------------------------------------------------------+ | t1????| CREATE TABLE `t1` ( ??`a` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+-----------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

創建指定字符集的表 mysql> create table t2(a varchar(10)) default character set latin1;; Query OK, 0 rows affected (0.01 sec)

ERROR: No query specified

mysql> show create table t2; +-------+-------------------------------------------------------------------------------------------+ | Table | Create Table??????????????????????????????????????????????????????????????????????????????| +-------+-------------------------------------------------------------------------------------------+ | t2????| CREATE TABLE `t2` ( ??`a` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+-------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

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更改表的字符集 mysql> alter table t2 default character set utf8; Query OK, 0 rows affected (0.01 sec) Records: 0??Duplicates: 0??Warnings: 0

mysql> show create table t2; +-------+--------------------------------------------------------------------------------------------------------------+ | Table | Create Table?????????????????????????????????????????????????????????????????????????????????????????????????| +-------+--------------------------------------------------------------------------------------------------------------+ | t2????| CREATE TABLE `t2` ( ??`a` varchar(10) character set latin1 default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

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從上面可以看到，修改表的字符集時，不會影響已經存在列的字符集，但新增列將繼承表的字符集，如下

mysql> alter table t2 add a2 varchar(10); Query OK, 0 rows affected (0.01 sec) Records: 0??Duplicates: 0??Warnings: 0

mysql> show create table t2; +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????| +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ | t2????| CREATE TABLE `t2` ( ??`a` varchar(10) character set latin1 default NULL, ??`a2` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec)

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如果想更改已經存在表和字符列的字符集，要用如下

mysql> alter table t2 convert to character set latin1; Query OK, 0 rows affected (0.01 sec) Records: 0??Duplicates: 0??Warnings: 0

mysql> show create table t2; +-------+----------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table???????????????????????????????????????????????????????????????????????????????????????????????????????????????| +-------+----------------------------------------------------------------------------------------------------------------------------+ | t2????| CREATE TABLE `t2` ( ??`a` varchar(10) default NULL, ??`a2` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+----------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec)

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C.字段字符集

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使用默認和指定字符集創建的列 mysql> create table t3 (a1 varchar(10),a2 varchar(10) character set latin1); Query OK, 0 rows affected (0.04 sec)

mysql> show create table t3; +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????| +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ | t3????| CREATE TABLE `t3` ( ??`a1` varchar(10) default NULL, ??`a2` varchar(10) character set latin1 default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

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查看列的字符集 mysql> show full columns from t3; +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ | Field | Type????????| Collation?????????| Null | Key | Default | Extra | Privileges??????????????????????| Comment | +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ | a1????| varchar(10) | utf8_general_ci???| YES??|?????| NULL????|???????| select,insert,update,references |?????????| | a2????| varchar(10) | latin1_swedish_ci | YES??|?????| NULL????|???????| select,insert,update,references |?????????| +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ 2 rows in set (0.01 sec)

修改列的字符集 mysql> alter table t3 change a2 a2 varchar(10) character set utf8; Query OK, 0 rows affected (0.03 sec) Records: 0??Duplicates: 0??Warnings: 0

mysql> show full columns from t3; +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ | Field | Type????????| Collation???????| Null | Key | Default | Extra | Privileges??????????????????????| Comment | +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ | a1????| varchar(10) | utf8_general_ci | YES??|?????| NULL????|???????| select,insert,update,references |?????????| | a2????| varchar(10) | utf8_general_ci | YES??|?????| NULL????|???????| select,insert,update,references |?????????| +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ 2 rows in set (0.00 sec)

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結論：字符集從數據庫、表、列的字符集是逐級繼承的關系

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查看字符集命令 mysql> show create table t4; //顯示表字符集 mysql> show create database db2; //顯示庫字符集 mysql> show full columns from t4; //顯示列字符集

alter database db2 default character set utf8; //更改庫的字符集 alter table t2 convert to character set latin1;//更改表的現存列字符集 alter table t2 default character set utf8;??//更能改表的默認字符集 alter table t3 change a2 a2 varchar(10) character set utf8; //更能改字段的字符集

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2.修改mysql的默認存儲引擎

mysql> show variables like 'storage%'; +----------------+--------+ | Variable_name??| Value??| +----------------+--------+ | storage_engine | MyISAM | +----------------+--------+ 1 row in set (0.01 sec)

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在[mysqld]下添加如下參數 default-storage-engine=innodb

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重啟mysql服務，查看

mysql> show variables like 'storage%'; +----------------+--------+ | Variable_name??| Value??| +----------------+--------+ | storage_engine | InnoDB | +----------------+--------+ 1 row in set (0.01 sec)

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創建默認字符集的表 mysql> create table t4 (a1 int); Query OK, 0 rows affected (0.01 sec)

mysql> show create table t4; +-------+--------------------------------------------------------------------------------------+ | Table | Create Table?????????????????????????????????????????????????????????????????????????| +-------+--------------------------------------------------------------------------------------+ | t4????| CREATE TABLE `t4` ( ??`a1` int(11) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

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更改表的默認字符集 mysql> alter table t4 engine myisam; Query OK, 0 rows affected (0.06 sec) Records: 0??Duplicates: 0??Warnings: 0

mysql> show create table t4; +-------+--------------------------------------------------------------------------------------+ | Table | Create Table?????????????????????????????????????????????????????????????????????????| +-------+--------------------------------------------------------------------------------------+ | t4????| CREATE TABLE `t4` ( ??`a1` int(11) default NULL ) ENGINE=MyISAM DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

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二、查看MySQL數據表（table）的MySQL字符集。

mysql>?show?table?status?from?sqlstudy_db?like?'%countries%'; ?

+-----------+--------+---------+------------+------+-----------------+------ ?

|?Name??????|?Engine?|?Version?|?Row_format?|?Rows?|?Collation???????|...... ?

+-----------+--------+---------+------------+------+-----------------+------ ?

|?countries?|?InnoDB?|??????10?|?Compact????|???11?|?utf8_general_ci?|...... ?

+-----------+--------+---------+------------+------+-----------------+------?

三、查看MySQL數據列（column）的MySQL字符集。

mysql>?show?full?columns?from?countries; ?

+----------------------+-------------+-----------------+-------- ?

|?Field????????????????|?Type????????|?Collation???????|?....... ?

+----------------------+-------------+-----------------+-------- ?

|?countries_id?????????|?int(11)?????|?NULL????????????|?....... ?

|?countries_name???????|?varchar(64)?|?utf8_general_ci?|?....... ?

|?countries_iso_code_2?|?char(2)?????|?utf8_general_ci?|?....... ?

|?countries_iso_code_3?|?char(3)?????|?utf8_general_ci?|?....... ?

|?address_format_id????|?int(11)?????|?NULL????????????|?....... ?

+----------------------+-------------+-----------------+--------?

MySQL修改默認字符集

修改mysql的默認字符集是通過修改它的配置文件來實現的。一般分兩種情況：

方法一:

Windows平臺

?????windows下的mysql配置文件是my.ini

????一般在C:\Program Files\MySQL\MySQL Server 5.0

????default-character-set=gbk #或gb2312,big5,utf8 ????然后重新啟動mysql:運行->services.msc->停止MySql->啟動???OK

????或 ?????/etc/init.d/mysql restart ?????或用其他方法重新啟動，就生效了。

Unix平臺 ????linux下的mysql配置文件是my.cnf

????一般是/etc/my.cnf，如果找不到可以用find命令找一下： ?????find / -iname my.cnf ????在這個文件里面加上 ????default-character-set=gbk #或gb2312,big5,utf8 ????然后重新啟動mysql ????net stop mysql ????net start mysql

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方法二:

通過MySQL命令行修改:
mysql> set character_set_client=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_connection=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_database=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_results=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_server=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_system=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_connection=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_database=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_server=utf8;
Query OK, 0 rows affected (0.01 sec)
查看:
mysql> show variables like 'character_set_%';

utf8 改為 gb2312

重啟mysql :
如何啟動/停止/重啟MySQL

啟動、停止、重啟 MySQL 是每個擁有獨立主機的站長必須要撐握的操作，下面為大家簡單介紹一下操作方法：

一、啟動方式?

1、使用 service 啟動：service mysqld start
2、使用 mysqld 腳本啟動：/etc/inint.d/mysqld start
3、使用 safe_mysqld 啟動：safe_mysqld&

二、停止

1、使用 service 啟動：service mysqld stop
2、使用 mysqld 腳本啟動：/etc/inint.d/mysqld stop
3、mysqladmin shutdown

三、重啟

1、使用 service 啟動：service mysqld restart
2、使用 mysqld 腳本啟動：/etc/inint.d/mysqld restart

終極方法

mysql> set names gbk;

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部分原文：http://blog.csdn.net/wyzxg/article/details/7581415

轉載于:https://www.cnblogs.com/MYSQLZOUQI/p/3780967.html

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