使用 Rails 4 从多对多关系中获取数据

Question

I am developing a rails app with mysql database.

Theres bunch of tables but for this task I am using only 3. Students, Courses and CoursesPerStudent.

I have models for students and courses(no model for the third). The tables are already populated.

The tables:

students - id,name,family,address,phone,email,status,path
courses - courseCode, courseName, hours
coursesperstudent - code, student(same ids as in students table ids but not a oreign key),path,course(courses table code(foreign key)),examMark.

Now the thing is i need to show for each student a list of the courses realted to him.

How should i do it? Should i create model for the third table? how should i call it? and combine the two other tables in one to show specific courses?

Or there some other way?

Hopefully someone will help because im out of answers.

Answer 1

If you make right has_and_belongs_to_many association you can call:

Student.find(id).courses  

it return collection of courses

http://guides.rubyonrails.org/association_basics.html#the-has-and-belongs-to-many-association