[英]HABTM not working with polymorphic association in rails
I have a polymorphic association: my user model can be of type 'student' or of type 'employer'. 我有一个多态关联:我的用户模型可以是“学生”类型或“雇主”类型。 I am trying to set up a has_and_belongs_to_many association between the student model and another model called the 'project' model.
我正在尝试在学生模型和另一个称为“项目”模型的模型之间建立has_and_belongs_to_many关联。 When I try to call:
当我尝试致电时:
controller: 控制器:
@my_projects = current_user.projects
view: 视图:
<% @my_projects.where(state: :posting).each do |project| %>
<%= project.students %><br>
<% end %>
I am told: 有人告诉我:
PG::UndefinedTable: ERROR: relation "projects_users" does not exist
I have defined a table called "projects_students" though, which i think should work. 我定义了一个名为“ projects_students”的表,我认为该表应该有效。 I don't want to have a "project_users" table because the table is only for students, not for employers.
我不想有“ project_users”表,因为该表仅适用于学生,不适用于雇主。 How do I fix this?
我该如何解决? Here are my models:
这是我的模型:
class Student < User
has_and_belongs_to_many :projects
end
- --
class Project < ActiveRecord::Base
has_and_belongs_to_many :students
end
You are building @my_projects
from a starting context of a User
object. 您正在从
User
对象的起始上下文中构建@my_projects
。 If you run User.first.projects
and Student.first.projects
from the Rails console, you will see that one tries to use projects_users
as the join table and the other tries to use projects_students
. 如果从Rails控制台运行
User.first.projects
和Student.first.projects
,您将看到一个尝试将projects_users
用作User.first.projects
表,另一个尝试使用projects_students
。 So rather than force a special "join_table" name in the model as I had suggested originally you could do something like this when you look up the projects: 因此,不必像我最初建议的那样在模型中强制使用特殊的“ join_table”名称,而是可以在查找项目时执行以下操作:
@my_projects = current_user.becomes(Student).projects
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