SHOW COLLATION
SHOW COLLATION 语句用于提供一个静态的排序规则列表,确保与 MySQL 客户端库的兼容性。

注意
SHOW COLLATION 所展示的排序规则列表与 TiDB 集群是否开启新排序规则框架有关,详情请见 TiDB 字符集和排序规则。
语法图
ShowCollationStmt:

示例
若未开启新排序规则框架,仅展示二进制排序规则:
2. SHOW COLLATION;
1. +-------------+---------+------+---------+----------+---------+
2. | Collation | Charset | Id | Default | Compiled | Sortlen |
3. +-------------+---------+------+---------+----------+---------+
4. | utf8mb4_bin | utf8mb4 | 46 | Yes | Yes | 1 |
5. | latin1_bin | latin1 | 47 | Yes | Yes | 1 |
6. | binary | binary | 63 | Yes | Yes | 1 |
7. | ascii_bin | ascii | 65 | Yes | Yes | 1 |
8. | utf8_bin | utf8 | 83 | Yes | Yes | 1 |
9. +-------------+---------+------+---------+----------+---------+
10. 5 rows in set (0.02 sec)
若开启了新排序规则框架,则在二进制排序规则之外,额外支持 utf8_general_ci 和 utf8mb4_general_ci 两种大小写和口音不敏感的排序规则:
2. SHOW COLLATION;
1. +--------------------+---------+------+---------+----------+---------+
2. | Collation | Charset | Id | Default | Compiled | Sortlen |
3. +--------------------+---------+------+---------+----------+---------+
4. | ascii_bin | ascii | 65 | Yes | Yes | 1 |
5. | binary | binary | 63 | Yes | Yes | 1 |
6. | gbk_bin | gbk | 87 | | Yes | 1 |
7. | gbk_chinese_ci | gbk | 28 | Yes | Yes | 1 |
8. | latin1_bin | latin1 | 47 | Yes | Yes | 1 |
9. | utf8_bin | utf8 | 83 | Yes | Yes | 1 |
10. | utf8_general_ci | utf8 | 33 | | Yes | 1 |
11. | utf8_unicode_ci | utf8 | 192 | | Yes | 1 |
12. | utf8mb4_bin | utf8mb4 | 46 | Yes | Yes | 1 |
13. | utf8mb4_general_ci | utf8mb4 | 45 | | Yes | 1 |
14. | utf8mb4_unicode_ci | utf8mb4 | 224 | | Yes | 1 |
15. +--------------------+---------+------+---------+----------+---------+
16. 11 rows in set (0.001 sec)
MySQL 兼容性
SHOW COLLATION 语句功能与 MySQL 完全兼容。注意,TiDB 中字符集的默认排序规则与 MySQL 有所不同,具体可参考与 MySQL 兼容性对比。如发现任何其他兼容性差异,请在 GitHub 上提交 issue。
