Populate db with grade level data

app/models/respondent.rb

@@ -3,4 +3,6 @@
 class Respondent < ApplicationRecord
   belongs_to :school
   belongs_to :academic_year
+
+  validates :school, uniqueness: { scope: :academic_year }
 end

app/services/enrollment_loader.rb

@@ -0,0 +1,116 @@
+# frozen_string_literal: true
+
+require 'csv'
+
+class EnrollmentLoader
+  def self.load_data(filepath:)
+    CSV.parse(File.read(filepath), headers: true) do |row|
+      row = EnrollmentRowValues.new(row:)
+
+      next unless row.school && row.academic_year
+
+      create_enrollment_entry(row:)
+    end
+  end
+
+  private
+
+  def self.create_enrollment_entry(row:)
+    respondent = Respondent.find_or_create_by(school: row.school, academic_year: row.academic_year)
+    respondent.pk = row.pk
+    respondent.k = row.k
+    respondent.one = row.one
+    respondent.two = row.two
+    respondent.three = row.three
+    respondent.four = row.four
+    respondent.five = row.five
+    respondent.six = row.six
+    respondent.seven = row.seven
+    respondent.eight = row.eight
+    respondent.nine = row.nine
+    respondent.ten = row.ten
+    respondent.eleven = row.eleven
+    respondent.twelve = row.twelve
+    respondent.save
+  end
+
+  private_class_method :create_enrollment_entry
+end
+
+class EnrollmentRowValues
+  attr_reader :row
+
+  def initialize(row:)
+    @row = row
+  end
+
+  def school
+    @school ||= begin
+      school_code = row['School Code']
+      School.find_by_dese_id(school_code)
+    end
+  end
+
+  def academic_year
+    @academic_year ||= begin
+      year = row['Academic Year']
+      AcademicYear.find_by_range(year)
+    end
+  end
+
+  def pk
+    row['PK'] || row['pk']
+  end
+
+  def k
+    row['K'] || row['k']
+  end
+
+  def one
+    row['1']
+  end
+
+  def two
+    row['2']
+  end
+
+  def three
+    row['3']
+  end
+
+  def four
+    row['4']
+  end
+
+  def five
+    row['5']
+  end
+
+  def six
+    row['6']
+  end
+
+  def seven
+    row['7']
+  end
+
+  def eight
+    row['8']
+  end
+
+  def nine
+    row['9']
+  end
+
+  def ten
+    row['10']
+  end
+
+  def eleven
+    row['11']
+  end
+
+  def twelve
+    row['12']
+  end
+end