Ruby on Rails

 

scope :department, -> (department) { where('department == ?', department) }

scope :year, -> (year) { where('subject.year == ?', year) } 

 

Then I called these methods in exams controller (index action) and passed the data:

 

 @exams = Exam.department(current_user.department) && Exam.year(current_user.year)

 

There is a problem with a scope year, it doesn't recognize subject. When I try to access the list of exams it says this: 

SQLite3::SQLException: no such column: subject.year: SELECT "exams".* FROM "exams" WHERE (subject.year == 2)

 

But when I include subject_id:  scope :year, -> (year) { where('Subject.find(:subject_id).year == ?', year) }

It says there is a syntax error: SQLite3::SQLException: near "(": syntax error: SELECT "exams".* FROM "exams" WHERE (Subject.find(:subject_id).year == 2). 

 

I have tried accessing subject attributes by using delegate and to_params, but it didn't help. I've been googling this issue for more than 10 days, but I haven't been able to find a solution.