我有下面的表模式，它将user_customers映射到一个活跃的MySQL数据库的权限:
mysql> describe user_customer_permission;
+------------------+---------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+---------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_customer_id | int(11) | NO | PRI | NULL | |
| permission_id | int(11) | NO | PRI | NULL | |
+------------------+---------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
我想删除user_customer_id和permission_id的主键，并保留id的主键。
执行命令时:
alter table user_customer_permission drop primary key;
我得到以下错误:
ERROR 1075 (42000): Incorrect table definition; there can be only one auto column and it must be defined as a key
如何删除列的主键?
