10.2. MySQL中的字符集和校对

MySQL服务器能够支持多种字符集。可以使用SHOW CHARACTER SET语句列出可用的字符集：

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 |

...

（完整列表参见10.10节，“MySQL支持的字符集和校对”。）

任何一个给定的字符集至少有一个校对规则。它可能有几个校对规则。

要想列出一个字符集的校对规则，使用SHOW COLLATION语句。例如，要想查看latin1（“西欧ISO-8859-1”）字符集的校对规则，使用下面的语句查找那些名字以latin1开头的校对规则：

mysql> SHOW COLLATION LIKE 'latin1%';

+---------------------+---------+----+---------+----------+---------+

| Collation   | Charset | Id | Default | Compiled | Sortlen |

+---------------------+---------+----+---------+----------+---------+

| latin1_german1_ci   | latin1  |  5 | |  |       0 |

| latin1_swedish_ci   | latin1  |  8 | Yes     | Yes      |       1 |

| latin1_danish_ci    | latin1  | 15 | |  |       0 |

| latin1_german2_ci   | latin1  | 31 | | Yes      |       2 |

| latin1_bin  | latin1  | 47 | | Yes      |       1 |

| latin1_general_ci   | latin1  | 48 | |  |       0 |

| latin1_general_cs   | latin1  | 49 | |  |       0 |

| latin1_spanish_ci   | latin1  | 94 | |  |       0 |

+---------------------+---------+----+---------+----------+---------+

latin1校对规则有下面的含义：

校对规则一般有这些特征：

·两个不同的字符集不能有相同的校对规则。

·每个字符集有一个默认校对规则。例如，latin1默认校对规则是latin1_swedish_ci。

·存在校对规则命名约定：它们以其相关的字符集名开始，通常包括一个语言名，并且以_ci（大小写不敏感）、_cs（大小写敏感）或_bin（二元）结束。