MySQL查看和修改字符集的方法

一、查看字符集

1.查看MYSQL数据库服务器和数据库字符集

方法一：show variables like '%character%';
方法二：show variables like 'collation%';

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       | /usr/local/mysql5535/share/charsets/ |
+--------------------------+--------------------------------------+
8 rows in set (0.00 sec)

方法一：

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)

方法二：

2.查看MYSQL所支持的字符集

show charset;

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 |
| 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 |
+----------+-----------------------------+---------------------+--------+
39 rows in set (0.00 sec)

查看MYSQL所支持的字符集

3.查看库的字符集

语法：show database status from 库名 like  表名;

mysql> show create database shiyan\G
*************************** 1. row ***************************
       Database: shiyan
Create Database: CREATE DATABASE `shiyan` /*!40100 DEFAULT CHARACTER SET gbk */
1 row in set (0.00 sec)

查看库的字符集

4.查看表的字符集

语法：show table status from 库名 like  表名;

mysql> show table status from class_7 like 'test_info';

mysql> show table status from class_7 like 'test_info';
+-----------+--------+---------+------------+------+----------------+-------------------------+-------------+------------+-----------------+----------+-
| Name      | Engine | Version | Row_format | Rows | Avg_row_length | Data_leate_time         | Update_time | Check_time | Collation       | Checksum |
+-----------+--------+---------+------------+------+----------------+-------------------------+-------------+------------+-----------------+----------+-
| test_info | InnoDB |      10 | Compact    |   10 |           1638 |       17-12-05 19:01:55 | NULL        | NULL       | utf8_general_ci |     NULL |
+-----------+--------+---------+------------+------+----------------+-------------------------+-------------+------------+-----------------+----------+-
1 row in set (0.00 sec)

查看表的字符集

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 test_info;

mysql> show full columns from test_info;
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
| Field | Type     | Collation       | Null | Key | Default | Extra | Privileges                      | Comment |
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
| id    | int(3)   | NULL            | NO   | PRI | NULL    |       | select,insert,update,references |         |
| name  | char(12) | utf8_general_ci | YES  |     | NULL    |       | select,insert,update,references |         |
| dorm  | char(10) | utf8_general_ci | YES  |     | NULL    |       | select,insert,update,references |         |
| addr  | char(12) | utf8_general_ci | YES  |     | 未知    |       | select,insert,update,references |         |
| score | int(3)   | NULL            | YES  |     | NULL    |       | select,insert,update,references |         |
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
5 rows in set (0.00 sec)

所有列的字符集

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

创建库的时候指定字符集：

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

create database db2 default character set=utf8

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；

mysql> create table test1(id int(6),name char(10)) default character set = 'gbk';
Query OK, 0 rows affected (0.39 sec)

2.修改字符集

修改全局字符集

/*建立连接使用的编码*/
set character_set_connection=utf8;
/*数据库的编码*/
set character_set_database=utf8;
/*结果集的编码*/
set character_set_results=utf8;
/*数据库服务器的编码*/
set character_set_server=utf8;

set character_set_system=utf8;

set collation_connection=utf8;

set collation_database=utf8;

set collation_server=utf8;

修改全局字符集

修改库的字符集

语法：alter database 库名 default character set 字符集;

alter database shiyan default character set gbk;

mysql> show create database shiyan\G
*************************** 1. row ***************************
       Database: shiyan
Create Database: CREATE DATABASE `shiyan` /*!40100 DEFAULT CHARACTER SET utf8 */
1 row in set (0.00 sec)

mysql> alter database shiyan default character set gbk;
Query OK, 1 row affected (0.00 sec)

mysql> show create database shiyan\G
*************************** 1. row ***************************
       Database: shiyan
Create Database: CREATE DATABASE `shiyan` /*!40100 DEFAULT CHARACTER SET gbk */
1 row in set (0.00 sec)

修改表的字符集

语法：alter table 表名 convert to character set 字符集;

 alter table test1 convert to character set utf8;

mysql> show create table test1\G
*************************** 1. row ***************************
       Table: test1
Create Table: CREATE TABLE `test1` (
  `id` int(6) DEFAULT NULL,
  `name` char(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk   #原字符集
1 row in set (0.00 sec)

mysql> alter table test1 convert to character set utf8;
Query OK, 0 rows affected (0.58 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> show create table test1\G
*************************** 1. row ***************************
       Table: test1
Create Table: CREATE TABLE `test1` (
  `id` int(6) DEFAULT NULL,
  `name` char(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8   #修改后的字符集
1 row in set (0.00 sec)

修改列表的字符集

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；

 alter table test1 modify name char(10) character set gbk;

mysql> show full columns from test1;
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
| Field | Type     | Collation       | Null | Key | Default | Extra | Privileges                      | Comment |
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
| id    | int(6)   | NULL            | YES  |     | NULL    |       | select,insert,update,references |         |
| name  | char(10) | utf8_general_ci | YES  |     | NULL    |       | select,insert,update,references |         |
+-------+----------+-----------------+------+-----+---------+-------+---------------------------------+---------+
2 rows in set (0.01 sec)

mysql> alter table test1 modify name char(10) character set gbk;
Query OK, 0 rows affected (0.58 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> show full columns from test1;
+-------+----------+----------------+------+-----+---------+-------+---------------------------------+---------+
| Field | Type     | Collation      | Null | Key | Default | Extra | Privileges                      | Comment |
+-------+----------+----------------+------+-----+---------+-------+---------------------------------+---------+
| id    | int(6)   | NULL           | YES  |     | NULL    |       | select,insert,update,references |         |
| name  | char(10) | gbk_chinese_ci | YES  |     | NULL    |       | select,insert,update,references |         |
+-------+----------+----------------+------+-----+---------+-------+---------------------------------+---------+
2 rows in set (0.01 sec)

修改字段的字符集