jplethier / views-examples

Repository created to be used as example on 2021 ruby summit talk

README

This project was created to show some examples on how to work with views on rails projects using scenic

Database Diagram

https://dbdiagram.io/d/61a2e20b8c901501c0d585c8

Views

Class students grades

select
  courses.name as course_name,
  disciplines.name as discipline_name,
  teachers.name as teacher_name,
  course_classes.semester,
  course_classes.year,
  students.name as student_name,
  students.email as student_email,
  course_class_students.grade as student_grade
from students
inner join course_class_students on course_class_students.student_id = students.id
inner join course_classes on course_classes.id = course_class_students.course_class_id
inner join disciplines on disciplines.id = course_classes.discipline_id
inner join teachers on teachers.id = course_classes.teacher_id
inner join courses on courses.id = disciplines.course_id;

Teachers's statistics per semester

select
  teachers.id as teacher_id,
  teachers.name as teacher_name,
  course_classes.semester,
  course_classes.year,
  avg(course_class_students.grade) as average_grade,
  count(distinct course_class_students.student_id) as total_students,
  count(distinct course_class_students.course_class_id) as total_classes
from teachers
inner join course_classes on teachers.id = course_classes.teacher_id
inner join course_class_students on course_classes.id = course_class_students.course_class_id
group by teachers.id, teachers.name, course_classes.semester, course_classes.year

Course's demographics per semester

select
  courses.id as course_id,
  courses.name as course_name,
  course_classes.semester,
  course_classes.year,
  states.id as state_id,
  states.name as state_name,
  states.abbreviation as state_abbreviation,
  count(distinct cities.id) as total_cities,
  count(distinct students.id) as total_students
from courses
inner join disciplines on disciplines.course_id = courses.id
inner join course_classes on course_classes.discipline_id = disciplines.id
inner join course_class_students on course_class_students.course_class_id = course_classes.id
inner join students on students.id = course_class_students.student_id
inner join addresses on addresses.student_id = students.id
inner join cities on cities.id = addresses.city_id
inner join states on states.id = cities.state_id
group by courses.id, courses.name, states.id, course_classes.semester, course_classes.year, states.name, states.abbreviation;