MySQL建立数据库时的字段的Collation 属性 是指什么？

[ygc2022]

MySQL建立数据库时的字段的Collation 属性 是指什么？

[hqaht]

SHOW COLLATION [LIKE 'pattern']
来自SHOW COLLATION的输出包括所有可用的字符集。该语句取一个自选的LIKE子句。该子句的pattern指示哪些整序名称可以匹配。举例说明：

mysql> SHOW COLLATION LIKE 'latin1%';
+-------------------+---------+----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+-------------------+---------+----+---------+----------+---------+
| latin1_german1_ci | latin1 | 5 | | | 0 |
| latin1_swedish_ci | latin1 | 8 | Yes | Yes | 0 |
| latin1_danish_ci | latin1 | 15 | | | 0 |
| latin1_german2_ci | latin1 | 31 | | Yes | 2 |
| latin1_bin | latin1 | 47 | | Yes | 0 |
| latin1_general_ci | latin1 | 48 | | | 0 |
| latin1_general_cs | latin1 | 49 | | | 0 |
| latin1_spanish_ci | latin1 | 94 | | | 0 |
+-------------------+---------+----+---------+----------+---------+
Default列指示对于其字符集，整序值是否是默认值。Compiled指示字符集是否被编辑到服务器中。Sortlen与对字符串（在字符集中表达）分类所需的存储器的数量有关。

[trainee]

collation是用在排序，比较大小上。
每种字符集character set都有一种或以上的排序方法，取默认就可以了

[ACMAIN_CHM]

9.1. Character Sets and Collations in General
A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set. Let's make the distinction clear with an example of an imaginary character set.


http://dev.mysql.com/doc/refman/5.1/zh/charset.html#charset-general

10.1. 常规字符集和校对
字符集是一套符号和编码。校对规则是在字符集内用于比较字符的一套规则。让我们使用一个假想字符集的例子来区别清楚。

[花如月]

[Quote=引用 3 楼 acmain_chm 的回复:]

9.1. Character Sets and Collations in General
A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set. Let's make the distinction……
[/Quote]

我看到的是下面的，请问是什么意思？
mysql> show variables like 'collation_%';
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.02 sec)