| title | COLLATION_CHARACTER_SET_APPLICABILITY |
|---|---|
| summary | 了解 information_schema 表 `COLLATION_CHARACTER_SET_APPLICABILITY`。 |
COLLATION_CHARACTER_SET_APPLICABILITY 表将排序规则映射至适用的字符集名称。和 COLLATIONS 表一样，包含此表只是为了兼容 MySQL。
{{< copyable "sql" >}}
USE information_schema;
DESC collation_character_set_applicability;+--------------------+-------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------------+-------------+------+------+---------+-------+
| COLLATION_NAME | varchar(32) | NO | | NULL | |
| CHARACTER_SET_NAME | varchar(32) | NO | | NULL | |
+--------------------+-------------+------+------+---------+-------+
2 rows in set (0.00 sec){{< copyable "sql" >}}
SELECT * FROM collation_character_set_applicability WHERE character_set_name='utf8mb4';+----------------+--------------------+
| COLLATION_NAME | CHARACTER_SET_NAME |
+----------------+--------------------+
| utf8mb4_bin | utf8mb4 |
+----------------+--------------------+
1 row in set (0.00 sec)COLLATION_CHARACTER_SET_APPLICABILITY 表中列的含义如下：
COLLATION_NAME：排序规则名称CHARACTER_SET_NAME：排序规则所属的字符集名称