Question

我有以下两个模型：School和User，以及它们之间的HABTM关系，以及连接表。

在此连接表中，引用User表的外键不是user_id，而是student_id。

class School < ActiveRecord::Base
 has_and_belongs_to_many :students, :class_name => "User", :join_table => "schools_students", :foreign_key => "student_id"
end

class User < ActiveRecord::Base
 has_and_belongs_to_many :studying_schools, :class_name => "School", :join_table => "schools_students", :foreign_key => "school_id"
end

我想在我的用户和学校设备中创建学校和用户，但用户中定义的foreign_key似乎是个问题。

fixtures/users.yml：

user1:
  name: Student
  studying_schools: school1

fixtures/schools.yml：

school1:
  name: School 1
  active: true
  students: user1

加载上面的灯具会返回ActiveRecord异常： ActiveRecord::StatementInvalid: Mysql::Error: Unknown column 'user_id' in 'field list': INSERT INTO schools_students (student_id, user_id) VALUES (6562055, 14302562)

我做错了什么？

Answer 1

我刚刚发现：我错过了habtm定义中的association_foreign_key。

定义它的正确方法是：

class School < ActiveRecord::Base
 has_and_belongs_to_many :students, :class_name => "User", :join_table => "schools_students", :association_foreign_key => "student_id"
 # :foreign_key is the default school_id
end

class User < ActiveRecord::Base
 has_and_belongs_to_many :studying_schools, :class_name => "School", :join_table => "schools_students", :foreign_key => "student_id"
 # :association_foreign_key is the default school_id
end

如何在我的灯具中加载HABTM与外键关系？

1 个答案: