information_schema.collations 表中的每一行对应一个排序规则
1、information_schema.collations 表中学用列：
1、id ：排序规则的ID
2、is_default ：是否是字符集的默认排序规则
3、collation_name ：排序规则名
4、character_set_name ：这个排序规则所对应的字符集名字
5、is_compiled ：是不已经被编译进MySQL来了
2、例子：
查看实例的排序规则信息
select
id,
is_default,
collation_name,
character_set_name,
is_compiled,
sortlen
from
information_schema.collations order by id; +-----+------------+--------------------------+--------------------+-------------+---------+
| id | is_default | collation_name | character_set_name | is_compiled | sortlen |
+-----+------------+--------------------------+--------------------+-------------+---------+
| 1 | Yes | big5_chinese_ci | big5 | Yes | 1 |
| 2 | | latin2_czech_cs | latin2 | Yes | 4 |
| 3 | Yes | dec8_swedish_ci | dec8 | Yes | 1 |
| 4 | Yes | cp850_general_ci | cp850 | Yes | 1 |
| 5 | | latin1_german1_ci | latin1 | Yes | 1 |
| 6 | Yes | hp8_english_ci | hp8 | Yes | 1 |
| 7 | Yes | koi8r_general_ci | koi8r | Yes | 1 |
| 8 | Yes | latin1_swedish_ci | latin1 | Yes | 1 |
| 9 | Yes | latin2_general_ci | latin2 | Yes | 1 |
| 10 | Yes | swe7_swedish_ci | swe7 | Yes | 1 |
| 11 | Yes | ascii_general_ci | ascii | Yes | 1 |
| 12 | Yes | ujis_japanese_ci | ujis | Yes | 1 |
| 13 | Yes | sjis_japanese_ci | sjis | Yes | 1 |
| 14 | | cp1251_bulgarian_ci | cp1251 | Yes | 1 |
| 15 | | latin1_danish_ci | latin1 | Yes | 1 |
| 16 | Yes | hebrew_general_ci | hebrew | Yes | 1 |