find ActiveRecord command in Rails does not work

Question

In the search function of my application, where a user can input a search text and pick a category (subject) from a dropdown.

In the do_search action in my controller, I find the courses by doing Subject.find(params[:subject]).courses where params[:subject] is the s_id (subject ID) of each Subject ("1234-123", "4123-232", ...).

When running the server, I tried searching but no result is found. I also checked it in the rails console but 0 matches as well.

This is the code for the do_search action in my controller:

def do_search
    if params[:subject].blank? && params[:search_text].blank?
      @courses = Course.all
    elsif !params[:subject].blank? && !params[:search_text].blank?
      @courses = Subject.find(params[:subject]).courses.where("UPPER(name) LIKE ?", "%#{params[:search_text].upcase}%")
    elsif !params[:subject].blank? 
      @courses = Subject.find(params[:subject]).courses
    else
      @courses = Course.where("UPPER(name) LIKE ?", "%#{params[:search_text].upcase}%")
    end
    return @courses
end

The schema: courses - subjects: many-to-many

subjects

s_id (the Subject ID): string

name: string

courses

code: string

name: string

contains

course_id: integer (primary key created by ActiveRecord for each course)

subject_id: integer (primary key created by ActiveRecord for each subject)

Matt Matt · Accepted Answer · 2020-03-05T21:09:40

find looks for the database ID of the record, which I don't think is what you are actually searching by. I think you actually want to do Subject.find_by(s_id: params[:subject]).courses

find ActiveRecord command in Rails does not work

1 Answers