CODEWITHSUNDEEP
ruby-on-rails
Beulah Akindele
Beulah Akindele

Reputation: 649

Rails Validation Issue on Form Submission

I have two rails models associated with each other: students and courses. Multiple students can take multiple courses, so I decided to use a has_many_through association... as you can see below.

I also added an index to make sure a student does not enroll for a course twice. However, whe I try to enroll it doesn't go through.

student_enrollments:

    belongs_to :students
    belongs_to :courses

    validates :matriculation_number, presence: :true
    validates :course_code, presence: :true

student_enrollment schema

 create_table "student_enrollments", id: false, force: :cascade do |t|
    t.string "course_code", null: false
    t.datetime "created_at", precision: 6, null: false
    t.datetime "updated_at", precision: 6, null: false
    t.string "matriculation_number"
    t.index ["course_code"], name: "index_student_enrollments_on_student_id_and_course_code", unique: true
  end

student_enrollments_controller:

class StudentEnrollmentsController < ApplicationController
    before_action :authenticate_student!

    def new
        @courses = Course.all
        @course = []
        i = 0
        while i < @courses.length
            @course.push(@courses[i].course_code)
            i += 1
        end
        @enrollment = StudentEnrollment.new
    end

    def create
        @enrollment = StudentEnrollment.new(enrollment_params)

        if @enrollment.save
            flash[:success] = "enrollment successful."
            redirect_to new_student_enrollment_path
        else
            flash[:danger] = "Enrollment failed."
            redirect_to new_student_enrollment_path
        end
    end

    private

        def enrollment_params
            params.require(:student_enrollment).permit(:course_code, :matriculation_number)
        end
end

student

    has_many :student_enrollments
    has_many :courses, through: :student_enrollments

course

    has_many :student_enrollments
    has_many :students, through: :student_enrollments

I also added an index to make sure a student does not enroll for a course twice. However, whe I try to enroll it doesn't go through. The output when I try to create the entry via the console: ActiveRecord::RecordInvalid (Validation failed: Students must exist, Courses must exist).

Upvotes: 0

Views: 35

Answers (1)

chanko
chanko

Reputation: 269

As of Rails 5, belongs_to associations are required, unless passing in the optional: true flag.

You can either update your associations so you can create a StudentEnrollment without a Student or Course passed in, or you can pass in student_id and course_id attributes when creating the new object.

To disable those validations you can just do:

belongs_to :student, optional: true
belongs_to :course, optional: true

Upvotes: 1

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