查看数据库当前支持的字符集
mysql> show character set;
+----------+---------------------------------+---------------------+--------+
| 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 (0.00 sec)
charset：表示字符集
Default collation ：表示默认的校对规则
一个字符集至少会拥有一个校对规则，显示校对规则可以使用语句
show collation语句
查看latin1字符集所拥有的校对规则
mysql> show collation like 'latin1%';
+-------------------+---------+----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+-------------------+---------+----+---------+----------+---------+
| latin1_german1_ci | latin1 | 5 | | Yes | 1 |
| latin1_swedish_ci | latin1 | 8 | Yes | Yes | 1 |
| latin1_danish_ci | latin1 | 15 | | Yes | 1 |
| latin1_german2_ci | latin1 | 31 | | Yes | 2 |
| latin1_bin | latin1 | 47 | | Yes | 1 |
| latin1_general_ci | latin1 | 48 | | Yes | 1 |
| latin1_general_cs | latin1 | 49 | | Yes | 1 |
| latin1_spanish_ci | latin1 | 94 | | Yes | 1 |
+-------------------+---------+----+---------+----------+---------+
8 rows in set (0.00 sec)
这里说明一下
Default：表示该字符集默认的校对规则，也可通过show character set 语句查看该字符集的默认规则
校对规则的三种格式
_ci : case insensitive : 大小写不敏感
_cs : case sensitive : 大小写敏感、
_bin ： binary ： 表示一个二元校对规则 注意这个规则一定是大小写敏感
查看当前服务器的字符集和校对规则
mysql> show global variables like '%server%';
+---------------------------------+--------------------------------------+
| Variable_name | Value |
+---------------------------------+--------------------------------------+
| character_set_server | latin1 |
| collation_server | latin1_swedish_ci |
| innodb_ft_server_stopword_table | |
| server_id | 0 |
| server_id_bits | 32 |
| server_uuid | 5470f34b-3282-11e8-981c-000c297abcf8 |
+---------------------------------+--------------------------------------+
6 rows in set (0.00 sec)
修改当前的字符集为gbk，发现校对规则也发生相应的修改
mysql> set global character_set_server=gbk;
Query OK, 0 rows affected (0.00 sec)
再次查看当前的服务器的字符集和校对规则
mysql> show global variables like '%server%';
+---------------------------------+--------------------------------------+
| Variable_name | Value |
+---------------------------------+--------------------------------------+
| character_set_server | gbk |
| collation_server | gbk_chinese_ci |
| innodb_ft_server_stopword_table | |
| server_id | 0 |
| server_id_bits | 32 |
| server_uuid | 5470f34b-3282-11e8-981c-000c297abcf8 |
+---------------------------------+--------------------------------------+
6 rows in set (0.00 sec)
mysql客户端相关的参数
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 |
+--------------------------+--------+
7 rows in set (0.00 sec)
这里需要介绍一下过程
1.客户端使用字符集由系统变量character_set_client来指定，从而向服务器端发出SQL语句
2.服务端接收到语句，会用到character_set_connection和collation_connection两个系统变量中的设置，并且将character_set_client转换到character_set_connection
3.服务端执行完成语句后，使用character_set_results设定的字符返回给客户端
修改客户端的字符集
方法一 ： set names
##查看字符集
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 |
+--------------------------+--------+
7 rows in set (0.00 sec)
##修改字符集为gbk
mysql> set names gbk ;
Query OK, 0 rows affected (0.00 sec)
##再次查看，发现character_set_client、character_set_connection、character_set_results三个参数都被修改了
mysql> show variables like 'character_set\_%';
+--------------------------+--------+
| Variable_name | Value |
+--------------------------+--------+
| character_set_client | gbk |
| character_set_connection | gbk |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | gbk |
| character_set_server | latin1 |
| character_set_system | utf8 |
+--------------------------+--------+
7 rows in set (0.00 sec)
得出结论
set names n 相当于
set character_set_client =n
set character_set_connection=n
set character_set_results=n
方法二
set character set x 相当于
set character_set_client =x
set character_set_results=x
set character_set_connection=@@character_set_database ----表示全局变量
set character_set_connection=@@collation_database
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/31485142/viewspace-2152634/ ，如需转载，请注明出处，否则将追究法律责任。
上一篇：
DG Broker搭建
请登录后发表评论
登录
全部评论
