Mysql 中对别名的操作

0.背景

• 查看测试表的数据

mysql> select * from customers;
+-------------+----------+
| customer_id | city     |
+-------------+----------+
| 163         | hangzhou |
| 9you        | shanghai |
| alibaba     | hangzhou |
| netease     | hangzhou |
| 163         | beijing  |
| alibaba     | shanghai |
| 163         | beijing  |
+-------------+----------+
7 rows in set (0.00 sec)

• 别名在​​group​​语法中使用**[报错]**

mysql> select
    -> customer_id as id
    -> from customers
    -> group id;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'id' at line 4

• 别名在​​order by​​语法中使用**[正常]**

mysql> select
    -> customer_id as id
    -> from customers
    -> order by id;
+---------+
| id      |
+---------+
| 163     |
| 163     |
| 163     |
| 9you    |
| alibaba |
| alibaba |
| netease |
+---------+
7 rows in set (0.00 sec)