ORDER BY UPPER（列）是错误的

Question

使用 MySQL 5.6，给定以下 table 结构：

mysql> describe groups;
+-------------+--------------+------+-----+---------+----------------+
| Field       | Type         | Null | Key | Default | Extra          |
+-------------+--------------+------+-----+---------+----------------+
| id          | int(11)      | NO   | PRI | NULL    | auto_increment |
| name        | varchar(500) | YES  |     | NULL    |                |
| description | varchar(200) | YES  |     | NULL    |                |
| created_at  | datetime     | YES  |     | NULL    |                |
| updated_at  | datetime     | YES  |     | NULL    |                |
+-------------+--------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)

以及

中的以下数据

`groups` table:

mysql> select id, name from groups;
+----+------------------+
| id | name             |
+----+------------------+
|  1 | some-users       |
|  2 | SOME-ADMINS      |
|  3 | customers-group1 |
|  4 | customers-group2 |
|  5 | customers-group3 |
+----+------------------+
5 rows in set (0.00 sec)

以下查询在 MySQL 中排序不当（但它至少在 PostgreSQL、Oracle 和 MSSQL 中工作正常）：

mysql> select id, name from groups order by upper(name);
+----+------------------+
| id | name             |
+----+------------------+
|  3 | customers-group1 |
|  4 | customers-group2 |
|  5 | customers-group3 |
|  1 | some-users       |
|  2 | SOME-ADMINS      |
+----+------------------+
5 rows in set (0.00 sec)

我希望：

SOME-ADMINS 出现在 some-users 之前，其他数据库供应商也是如此。

这是 MySQL 的错误吗？

Answer 1

根据文档，它不区分大小写，但您可以使用 BINARY 使其区分大小写：

On character type columns, sorting—like all other comparison operations—is normally performed in a case-insensitive fashion. This means that the order is undefined for columns that are identical except for their case. You can force a case-sensitive sort for a column by using BINARY like so: ORDER BY BINARY col_name.

https://dev.mysql.com/doc/refman/5.0/en/sorting-rows.html

ORDER BY UPPER（列）是错误的

ORDER BY UPPER (column) is wrong

mysql

sql

sql-order-by

mysql-5.6