mysql - 向外键约束表添加外键

Question

我有这个表:

引用

+---------------------+-----------------------+------+-----+---------+---+
| Field               | Type                  | Null | Key | Default 
+---------------------+-----------------------+------+-----+---------+---+
| id                  | int(11) unsigned      | NO   | PRI | NULL    
... (More Columns)           
+---------------------+-----------------------+------+-----+-------------+

引用包信息

+---------------+---------------------+------+-----+---------+------------+
| Field         | Type                | Null | Key | Default          
+---------------+---------------------+------+-----+---------+------------+
| id            | int(11) unsigned    | NO   | PRI | NULL     
| quoteId       | int(11) unsigned    | NO   |     | NULL    
... (More Columns)
+---------------+---------------------+------+-----+---------+------------+

报价航类信息

+---------------------------+---------------------+------+-----+----------+
| Field                     | Type                | Null | Key | Default 
+---------------------------+---------------------+------+-----+----------+
| id                        | int(11) unsigned    | NO   | PRI | NULL    
| quoteId                   | int(11) unsigned    | NO   | MUL | NULL                    
| packageId                 | int(11) unsigned    | YES  | MUL | NULL                                    ... (More Columns) 
+---------------------------+---------------------+------+-----+----------+

所以基本上有报价是主键，在报价中有包裹之后，包裹可以包含航类，所以我需要当包裹被删除时，所有相关的航类都被删除，所以我添加了航类的外键如下:

ALTER TABLE quotesFlightsInfo
ADD CONSTRAINT fk_quotesFlightsInfo_packageId
FOREIGN KEY (packageId) REFERENCES quotesPackagesInfo(id)
ON DELETE CASCADE

现在我正在尝试向包裹添加外键，因此当删除报价时，包裹也会删除，因此航类但不起作用:(，这里是查询:

ALTER TABLE quotesPackagesInfo 
ADD CONSTRAINT fk_quotesPackagesInfo_quoteId 
FOREIGN KEY (quoteId) REFERENCES quotes(id) 
ON DELETE CASCADE

错误:无法添加或更新子行:外键约束失败 (????????????.#sql-312_2, CONSTRAINT fk_quotesPackagesInfo_quoteId 外键 (quoteId) 引用 quotes (id) ON DELETE CASCADE)

Answer 1

我删除了quotesPackagesInfo表并再次创建它，从一开始就添加了外键并且它起作用了，但仍然不知道之前出了什么问题