我对SQL和MySQL非常陌生。我试图修改表中的主键列,使其自动增长。这个主键也是另一个表中的外键。由于另一张表中的外键问题,我无法修改此列。以下是错误信息:
mysql> desc favourite_food;
+-----------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+----------------------+------+-----+---------+-------+
| person_id | smallint(5) unsigned | NO | PRI | 0 | |
| food | varchar(20) | NO | PRI | | |
+-----------+----------------------+------+-----+---------+-------+
2 rows in set (0.09 sec)
mysql> alter table person modify person_id smallint unsigned auto_increment;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 22
Current database: bank
ERROR 1833 (HY000): Cannot change column 'person_id': used in a foreign key cons
traint 'fk_fav_food_person_id' of table 'bank.favourite_food'
mysql>
我相信这是一个简单的问题,但我不知道为什么,我所遵循的书籍也没有说明原因。谢谢。