mysql 查看-修改-字符集-排序集

mysql修改和查看字符集（数据库全局、schema、表、列）

一、查看字符集
1.查看MYSQL数据库服务器和数据库字符集

mysql> show variables like '%character%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | utf8                       |
| character_set_system     | utf8                       |
| character_sets_dir       | /opt/mysql/share/charsets/ |
+--------------------------+----------------------------+
8 rows in set

查看mysql服务器的排序集：

mysql> 

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

mysql> 

2.查看MYSQL所支持的字符集

mysql> show charset;
+----------+---------------------------------+---------------------+--------+
| Charset  | Description                     | Default collation   | Maxlen |
+----------+---------------------------------+---------------------+--------+
| big5     | Big5 Traditional Chinese        | big5_chinese_ci     |      2 |
| dec8     | DEC West European               | dec8_swedish_ci     |      1 |
| cp850    | DOS West European               | cp850_general_ci    |      1 |
| hp8      | HP West European                | hp8_english_ci      |      1 |
| koi8r    | KOI8-R Relcom Russian           | koi8r_general_ci    |      1 |
| latin1   | cp1252 West European            | latin1_swedish_ci   |      1 |
| latin2   | ISO 8859-2 Central European     | latin2_general_ci   |      1 |
| swe7     | 7bit Swedish                    | swe7_swedish_ci     |      1 |
| ascii    | US ASCII                        | ascii_general_ci    |      1 |
| ujis     | EUC-JP Japanese                 | ujis_japanese_ci    |      3 |
| sjis     | Shift-JIS Japanese              | sjis_japanese_ci    |      2 |
| hebrew   | ISO 8859-8 Hebrew               | hebrew_general_ci   |      1 |
| tis620   | TIS620 Thai                     | tis620_thai_ci      |      1 |
| euckr    | EUC-KR Korean                   | euckr_korean_ci     |      2 |
| koi8u    | KOI8-U Ukrainian                | koi8u_general_ci    |      1 |
| gb2312   | GB2312 Simplified Chinese       | gb2312_chinese_ci   |      2 |
| greek    | ISO 8859-7 Greek                | greek_general_ci    |      1 |
| cp1250   | Windows Central European        | cp1250_general_ci   |      1 |
| gbk      | GBK Simplified Chinese          | gbk_chinese_ci      |      2 |
| latin5   | ISO 8859-9 Turkish              | latin5_turkish_ci   |      1 |
| armscii8 | ARMSCII-8 Armenian              | armscii8_general_ci |      1 |
| utf8     | UTF-8 Unicode                   | utf8_general_ci     |      3 |
| ucs2     | UCS-2 Unicode                   | ucs2_general_ci     |      2 |
| cp866    | DOS Russian                     | cp866_general_ci    |      1 |
| keybcs2  | DOS Kamenicky Czech-Slovak      | keybcs2_general_ci  |      1 |
| macce    | Mac Central European            | macce_general_ci    |      1 |
| macroman | Mac West European               | macroman_general_ci |      1 |
| cp852    | DOS Central European            | cp852_general_ci    |      1 |
| latin7   | ISO 8859-13 Baltic              | latin7_general_ci   |      1 |
| utf8mb4  | UTF-8 Unicode                   | utf8mb4_general_ci  |      4 |
| cp1251   | Windows Cyrillic                | cp1251_general_ci   |      1 |
| utf16    | UTF-16 Unicode                  | utf16_general_ci    |      4 |
| utf16le  | UTF-16LE Unicode                | utf16le_general_ci  |      4 |
| cp1256   | Windows Arabic                  | cp1256_general_ci   |      1 |
| cp1257   | Windows Baltic                  | cp1257_general_ci   |      1 |
| utf32    | UTF-32 Unicode                  | utf32_general_ci    |      4 |
| binary   | Binary pseudo charset           | binary              |      1 |
| geostd8  | GEOSTD8 Georgian                | geostd8_general_ci  |      1 |
| cp932    | SJIS for Windows Japanese       | cp932_japanese_ci   |      2 |
| eucjpms  | UJIS for Windows Japanese       | eucjpms_japanese_ci |      3 |
| gb18030  | China National Standard GB18030 | gb18030_chinese_ci  |      4 |
+----------+---------------------------------+---------------------+--------+
41 rows in set

mysql> 

3.查看库的字符集
语法：show database status from 库名 like 表名;

mysql> SHOW CREATE DATABASE dav;
+-----------+--------------------------------------------------------------------+
| Database  | Create Database                                                    |
+-----------+--------------------------------------------------------------------+
| dav | CREATE DATABASE `dav` /*!40100 DEFAULT CHARACTER SET utf8 */ |
+-----------+--------------------------------------------------------------------+
1 row in set

mysql> 

4.查看表的字符集
语法：show table status from 库名 like 表名;

mysql> SHOW CREATE TABLE dav_test;
--------------------------------------------------------------------------------+
| Table          | Create Table                                                          
| dav_test | CREATE TABLE `dav_test` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `config_type` varchar(50) DEFAULT NULL COMMENT '配置项类型',
  `config_sub_type` varchar(50) DEFAULT NULL COMMENT '配置项子类型',
  `config_name` varchar(255) DEFAULT NULL COMMENT '配置项名称',
  `config_cn_name` varchar(50) DEFAULT NULL COMMENT '配置项的中文名称',
  `config_value` varchar(500) DEFAULT NULL COMMENT '配置项值',
  `config_desc` varchar(255) DEFAULT NULL COMMENT '配置项描述',
  `create_time` timestamp NULL DEFAULT NULL COMMENT '创建时间',
  `update_time` timestamp NULL DEFAULT NULL COMMENT '修改时间',
  `create_user` varchar(100) DEFAULT NULL COMMENT '创建人',
  `update_user` varchar(100) DEFAULT NULL COMMENT '修改人',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=23 DEFAULT CHARSET=utf8mb4 |
+---+
1 row in set

mysql> 

查看特定表的字符集的第二种方式：

SELECT CCSA.character_set_name, CCSA.collation_name
FROM information_schema.`TABLES` T, information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
WHERE CCSA.collation_name = T.table_collation
  AND T.table_schema = 'your_database_name'  -- 替换为你的数据库名
  AND T.table_name = 'your_table_name';  -- 替换为你的表名;

SHOW FULL COLUMNS FROM your_table_name;
5.查看表中所有列的字符集
语法：show full columns from 表名;

mysql> SHOW FULL COLUMNS FROM dav_test;
+-----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+------------------+
| Field           | Type         | Collation       | Null | Key | Default | Extra          | Privileges                      | Comment          |
+-----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+------------------+
| id              | int(11)      | NULL            | NO   | PRI | NULL    | auto_increment | select,insert,update,references | 主键             |
| config_type     | varchar(50)  | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项类型       |
| config_sub_type | varchar(50)  | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项子类型     |
| config_name     | varchar(255) | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项名称       |
| config_cn_name  | varchar(50)  | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项的中文名称 |
| config_value    | varchar(500) | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项值         |
| config_desc     | varchar(255) | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 配置项描述       |
| create_time     | timestamp    | NULL            | YES  |     | NULL    |                | select,insert,update,references | 创建时间         |
| update_time     | timestamp    | NULL            | YES  |     | NULL    |                | select,insert,update,references | 修改时间         |
| create_user     | varchar(100) | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 创建人           |
| update_user     | varchar(100) | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 修改人           |
+-----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+------------------+
11 rows in set

二、设置字符集
设置字符集一般有两种方法，一种是在创建表的时候设置字符集，另一种是表建成之后修改字符集。

1.创建时指定字符集

1.1创建库的时候指定字符集：

语法：create database 库名 default character set=字符集；

1.2创建表的时候指定字符集：

语法：create table 表名（属性）default character set = 字符集；

2.修改字符集

修改全局字符集

mysql> set character_set_connection=utf8;
mysql> set character_set_database=utf8;
mysql> set character_set_results=utf8;
mysql> set character_set_server=utf8;
mysql> set character_set_system=utf8;
mysql> set character_connection=utf8;
mysql> set character_database=utf8;
mysql> set character_server=utf8;

修改库的字符集:
语法：alter database 库名 default character set 字符集;

alter database dav character set 'utf8mb4';

修改表的字符集:
语法：alter table 表名 convert to character set 字符集;

alter table dav_test convert to character set 'utf8mb4';

修改表的字符集：

alter table dav_test convert to character set utf8 collate utf8_general_ci;

修改字段的字符集:
语法：alter table 表名 modify 字段名 字段属性 character set gbk；

三、设置MySQL默认字符集
在命令行上修改字符集后，MySQL重启后，设置会消失，恢复成MySQL配置文件中的字符集设置。

MySQL默认的字符集是latinl 编码，此时建库插入中文会乱码。

在my.cnf中mysqld服务配置加入一行字符集设置。

# vi /etc/my.cnf
[mysqld]
character_set_server=utf8mb4

保存退出，并重启MySQL即可；