Create Students Table Migration (db/migrate/001_create_students.rb)
class CreateStudents < ActiveRecord::Migration
def self.up
create_table :students do |t|
t.string :name, :limit=>45
t.string :employer, :limit=>45
t.timestamps
end
end
def self.down
drop_table :students
end
end
Note that the limit clause sets a maximum amount of characters in each column.
Listing 12-11 shows the code for your student model.
Listing 12-11. Student Model (app/models/student.rb)
class Student < ActiveRecord::Base
has_many :grades
end
Save this as app/models/student.rb.
You also need to generate a grade model, which represents the grade each student
received for each class:
ruby script/generate model grade
exists app/models/
exists test/unit/
exists test/fixtures/
create app/models/grade.rb
create test/unit/grade_test.rb
create test/fixtures/grades.yml
exists db/migrate
create db/migrate/002_create_grades.rb
CHAPTER 12 n CREATING REPORTS WITH RUBY AND MICROSOFT OFFICE 243
Next, add the code shown in Listing 12-12 to your second migration.
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