# 字符集和排序规则

__*字符集*__
__*排序规则*__

+ `SHOW CHARACTER SET`: 列出支持的字符集
+ `SHOW COLLATION`: 列出支持的排序规则
+ e.g:
  + `CREATE DATABASE universe DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;`
```
tidb> SHOW COLLATION;
+--------------------+---------+------+---------+----------+---------+
| Collation          | Charset | Id   | Default | Compiled | Sortlen |
+--------------------+---------+------+---------+----------+---------+
| ascii_bin          | ascii   |   65 | Yes     | Yes      |       1 |
| binary             | binary  |   63 | Yes     | Yes      |       1 |
| gbk_bin            | gbk     |   87 |         | Yes      |       1 |
| gbk_chinese_ci     | gbk     |   28 | Yes     | Yes      |       1 |
| latin1_bin         | latin1  |   47 | Yes     | Yes      |       1 |
| utf8_bin           | utf8    |   83 | Yes     | Yes      |       1 |
| utf8_general_ci    | utf8    |   33 |         | Yes      |       1 |
| utf8_unicode_ci    | utf8    |  192 |         | Yes      |       1 |
| utf8mb4_bin        | ~!@utf8mb4@!~ |   46 | Yes     | Yes      |       1 |
| utf8mb4_general_ci | utf8mb4 |   45 |         | Yes      |       1 |
| utf8mb4_unicode_ci | utf8mb4 |  224 |         | Yes      |       1 |
+--------------------+---------+------+---------+----------+---------+
11 rows in set (0.00 sec)
```

----------------------------------

字符集 (character set) 是符号与编码的集合。TiDB 中的默认字符集是 utf8mb4,与 MySQL 8.0 及更高版本中的默认字符集匹配。

排序规则 (collation) 是在字符集中比较字符以及字符排序顺序的规则。