CHARACTER_SETS

CHARACTER_SETS 表提供字符集相关的信息。TiDB 目前仅支持部分字符集。

USE INFORMATION_SCHEMA;
DESC CHARACTER_SETS;

输出结果如下：

+----------------------+-------------+------+------+---------+-------+
| Field                | Type        | Null | Key  | Default | Extra |
+----------------------+-------------+------+------+---------+-------+
| CHARACTER_SET_NAME   | varchar(32) | YES  |      | NULL    |       |
| DEFAULT_COLLATE_NAME | varchar(32) | YES  |      | NULL    |       |
| DESCRIPTION          | varchar(60) | YES  |      | NULL    |       |
| MAXLEN               | bigint(3)   | YES  |      | NULL    |       |
+----------------------+-------------+------+------+---------+-------+
4 rows in set (0.00 sec)

查看 CHARACTER_SETS 表的信息：

SELECT * FROM `CHARACTER_SETS`;

输出结果如下：

+--------------------+----------------------+-------------------------------------+--------+
| CHARACTER_SET_NAME | DEFAULT_COLLATE_NAME | DESCRIPTION                         | MAXLEN |
+--------------------+----------------------+-------------------------------------+--------+
| ascii              | ascii_bin            | US ASCII                            |      1 |
| binary             | binary               | binary                              |      1 |
| gbk                | gbk_chinese_ci       | Chinese Internal Code Specification |      2 |
| latin1             | latin1_bin           | Latin1                              |      1 |
| utf8               | utf8_bin             | UTF-8 Unicode                       |      3 |
| utf8mb4            | utf8mb4_bin          | UTF-8 Unicode                       |      4 |
+--------------------+----------------------+-------------------------------------+--------+
6 rows in set (0.00 sec)

CHARACTER_SETS 表中列的含义如下：

• CHARACTER_SET_NAME：字符集名称
• DEFAULT_COLLATE_NAME：字符集的默认排序规则名称
• DESCRIPTION：字符集的描述信息
• MAXLEN：该字符集存储一个字符所需要的最大字节数