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SHOW COLLATION
TiDB 数据库中 SHOW COLLATION 的使用概况。
/docs-cn/dev/sql-statements/sql-statement-show-collation/
/docs-cn/dev/reference/sql/statements/show-collation/

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:

ShowCollationStmt

示例

若未开启新排序规则框架,仅展示二进制排序规则:

{{< copyable "sql" >}}

SHOW COLLATION;
+-------------+---------+------+---------+----------+---------+
| Collation   | Charset | Id   | Default | Compiled | Sortlen |
+-------------+---------+------+---------+----------+---------+
| utf8mb4_bin | utf8mb4 |   46 | Yes     | Yes      |       1 |
| latin1_bin  | latin1  |   47 | Yes     | Yes      |       1 |
| binary      | binary  |   63 | Yes     | Yes      |       1 |
| ascii_bin   | ascii   |   65 | Yes     | Yes      |       1 |
| utf8_bin    | utf8    |   83 | Yes     | Yes      |       1 |
+-------------+---------+------+---------+----------+---------+
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_ciutf8mb4_general_ci 两种大小写和口音不敏感的排序规则:

{{< copyable "sql" >}}

SHOW COLLATION;
+--------------------+---------+------+---------+----------+---------+
| Collation          | Charset | Id   | Default | Compiled | Sortlen |
+--------------------+---------+------+---------+----------+---------+
| ascii_bin          | ascii   |   65 | Yes     | Yes      |       1 |
| binary             | binary  |   63 | Yes     | Yes      |       1 |
| latin1_bin         | latin1  |   47 | Yes     | Yes      |       1 |
| utf8_bin           | utf8    |   83 | Yes     | Yes      |       1 |
| utf8_general_ci    | utf8    |   33 |         | Yes      |       1 |
| utf8mb4_bin        | utf8mb4 |   46 | Yes     | Yes      |       1 |
| utf8mb4_general_ci | utf8mb4 |   45 |         | Yes      |       1 |
+--------------------+---------+------+---------+----------+---------+
7 rows in set (0.00 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

另请参阅