Server log when creating new Teacher

gistfile1.txt

Started POST "/teachers" for 127.0.0.1 at 2018-06-04 00:33:46 +0800
Processing by TeachersController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"fBO7yoZknrn4eDaS0lAsDO/faXFAFuotsu8hnsNT+LvGAhP47Yo31eGE+1vkJCcgzQES60jhviEGbcnvUY784g==", "teacher"=>{"name"=>"CS 20", "student_ids"=>["", "1"]}, "commit"=>"Create Teacher"}
  User Load (0.6ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT ?  [["id", 1], ["LIMIT", 1]]
  ↳ app/controllers/teachers_controller.rb:22
  Student Load (0.4ms)  SELECT "students".* FROM "students" WHERE "students"."id" = ?  [["id", 1]]
  ↳ app/controllers/teachers_controller.rb:22
   (0.2ms)  begin transaction
  ↳ app/controllers/teachers_controller.rb:24
   (0.1ms)  rollback transaction
  ↳ app/controllers/teachers_controller.rb:24
  Rendering teachers/new.html.erb within layouts/application
  Student Load (0.2ms)  SELECT "students".* FROM "students"
  ↳ app/views/teachers/_form.html.erb:8
  Rendered teachers/_form.html.erb (7.5ms)
  Rendered teachers/new.html.erb within layouts/application (8.6ms)
Completed 200 OK in 97ms (Views: 80.1ms | ActiveRecord: 1.4ms)