feat: modified student lesson summaries to include enrollments, updat…

…ed trigger

db/migrate/20240716100102_update_student_lesson_summaries_with_enrollments.rb

@@ -0,0 +1,82 @@
+class UpdateStudentLessonSummariesWithEnrollments < ActiveRecord::Migration[7.1]
+  def up
+    drop_view :group_lesson_summaries
+    drop_view :lesson_table_rows
+
+    update_view :student_lesson_summaries, version: 7
+
+    create_view :group_lesson_summaries, version: 4
+    create_view :lesson_table_rows, version: 3
+    update_trigger
+  end
+
+  def down
+    drop_view :group_lesson_summaries
+    drop_view :lesson_table_rows
+
+    update_view :student_lesson_summaries, version: 6
+
+    create_view :group_lesson_summaries, version: 4
+    create_view :lesson_table_rows, version: 3
+    old_trigger
+  end
+
+  def update_trigger
+    execute <<~SQL
+      create or replace function update_enrollments()
+      returns trigger AS
+      $BODY$
+      declare
+        current_enrollment_group_id int := null;
+      BEGIN
+        SELECT group_id into current_enrollment_group_id FROM enrollments e where e.student_id = new.id and e.inactive_since is null;
+        if current_enrollment_group_id is null then
+            insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
+            values (new.id, new.group_id, now(), null, now(), now());
+        else if current_enrollment_group_id != new.group_id then
+            if (SELECT group_id from enrollments e where e.student_id = new.id and e.group_id = new.group_id) is null then
+              insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
+              values (new.id, new.group_id, now(), null, now(), now());
+            else
+              update enrollments set inactive_since = null, active_since = now(), updated_at = now()
+              where group_id = new.group_id  and student_id = new.id;
+            end if;
+
+            update enrollments set inactive_since = now(), updated_at = now()
+            where inactive_since is null and group_id = current_enrollment_group_id and student_id = new.id;
+        end if;
+        end if;
+        return new;
+      END;
+      $BODY$ language plpgsql;
+
+      drop trigger if exists update_enrollments_on_student_group_change_trigger on students;
+      create trigger update_enrollments_on_student_group_change_trigger
+      after insert or update on students for each row execute procedure update_enrollments();
+    SQL
+  end
+
+  def old_trigger
+    execute <<~SQL
+      create or replace function update_enrollments()
+      returns trigger AS
+      $BODY$
+      declare
+        current_enrollment_group_id int := null;
+      BEGIN
+        SELECT group_id into current_enrollment_group_id FROM enrollments e where e.student_id = new.id;
+        if current_enrollment_group_id is null or current_enrollment_group_id != new.group_id then
+          update enrollments set inactive_since = now() where inactive_since is null;
+          insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
+          values (new.id, new.group_id, now(), null, now(), now());
+        end if;
+        return new;
+      END;
+      $BODY$ language plpgsql;
+
+      drop trigger if exists update_enrollments_on_student_group_change_trigger on students;
+      create trigger update_enrollments_on_student_group_change_trigger
+      after insert or update on students for each row execute procedure update_enrollments();
+    SQL
+  end
+end

db/structure.sql

@@ -72,11 +72,22 @@ CREATE FUNCTION public.update_enrollments() RETURNS trigger
 declare
   current_enrollment_group_id int := null;
 BEGIN
-  SELECT group_id into current_enrollment_group_id FROM enrollments e where e.student_id = new.id;
-  if current_enrollment_group_id is null or current_enrollment_group_id != new.group_id then
-    update enrollments set inactive_since = now() where inactive_since is null;
-    insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
-    values (new.id, new.group_id, now(), null, now(), now());
+  SELECT group_id into current_enrollment_group_id FROM enrollments e where e.student_id = new.id and e.inactive_since is null;
+  if current_enrollment_group_id is null then
+      insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
+      values (new.id, new.group_id, now(), null, now(), now());
+  else if current_enrollment_group_id != new.group_id then
+      if (SELECT group_id from enrollments e where e.student_id = new.id and e.group_id = new.group_id) is null then
+        insert into enrollments (student_id, group_id, active_since, inactive_since, created_at, updated_at)
+        values (new.id, new.group_id, now(), null, now(), now());
+      else
+        update enrollments set inactive_since = null, active_since = now(), updated_at = now()
+        where group_id = new.group_id  and student_id = new.id;
+      end if;
+
+      update enrollments set inactive_since = now(), updated_at = now()
+      where inactive_since is null and group_id = current_enrollment_group_id and student_id = new.id;
+  end if;
   end if;
   return new;
 END;
@@ -1708,10 +1719,12 @@ CREATE OR REPLACE VIEW public.student_lesson_summaries AS
             l.subject_id,
             round(avg(grades.mark), 2) AS average_mark,
             count(grades.mark) AS grade_count
-           FROM (((public.lessons l
+           FROM ((((public.lessons l
              JOIN public.groups g ON ((g.id = l.group_id)))
              JOIN public.grades ON (((grades.lesson_id = l.id) AND (grades.deleted_at IS NULL))))
              JOIN public.students s ON ((grades.student_id = s.id)))
+             JOIN public.enrollments en ON ((s.id = en.student_id)))
+          WHERE (((en.active_since)::date <= l.date) AND ((en.inactive_since IS NULL) OR ((en.inactive_since)::date >= l.date)))
           GROUP BY s.id, l.id) united
      JOIN public.subject_summaries su ON ((united.subject_id = su.id)));
 
@@ -1721,21 +1734,20 @@ CREATE OR REPLACE VIEW public.student_lesson_summaries AS
 --
 
 CREATE OR REPLACE VIEW public.group_lesson_summaries AS
- SELECT l.id AS lesson_id,
-    l.date AS lesson_date,
+ SELECT slu.lesson_id,
+    slu.lesson_date,
     gr.id AS group_id,
     gr.chapter_id,
     slu.subject_id,
     concat(gr.group_name, ' - ', c.chapter_name) AS group_chapter_name,
     (round(avg(slu.average_mark), 2))::double precision AS average_mark,
     (sum(slu.grade_count))::bigint AS grade_count
-   FROM (((public.lessons l
-     JOIN public.groups gr ON ((l.group_id = gr.id)))
+   FROM ((public.student_lesson_summaries slu
+     JOIN public.groups gr ON ((slu.group_id = gr.id)))
      JOIN public.chapters c ON ((gr.chapter_id = c.id)))
-     JOIN public.student_lesson_summaries slu ON (((l.subject_id = slu.subject_id) AND (l.group_id = slu.group_id) AND (l.date = slu.lesson_date))))
   WHERE (slu.deleted_at IS NULL)
-  GROUP BY l.id, gr.id, c.id, slu.subject_id
-  ORDER BY l.date;
+  GROUP BY slu.lesson_id, gr.id, c.id, slu.subject_id, slu.lesson_date
+  ORDER BY slu.lesson_date;
 
 
 --
@@ -2001,6 +2013,7 @@ ALTER TABLE ONLY public.users_roles
 SET search_path TO "$user", public;
 
 INSERT INTO "schema_migrations" (version) VALUES
+('20240716100102'),
 ('20240614142029'),
 ('20240610074002'),
 ('20240531115345'),

db/views/student_lesson_summaries_v07.sql

@@ -0,0 +1,36 @@
+SELECT united.*, skill_count
+FROM (
+         SELECT s.id                                              AS student_id,
+                s.group_id                                        AS group_id,
+                s.first_name                                      AS first_name,
+                s.last_name                                       AS last_name,
+                s.deleted_at                                      AS deleted_at,
+                l.id                                              AS lesson_id,
+                l.date                                            AS lesson_date,
+                l.subject_id AS subject_id,
+                round(AVG(mark), 2)                               AS average_mark,
+                COUNT(mark)                                       AS grade_count
+         FROM students s
+                  JOIN groups g ON g.id = s.group_id
+                  JOIN lessons l ON g.id = l.group_id
+                  LEFT JOIN grades ON (grades.student_id = s.id AND grades.lesson_id = l.id AND grades.deleted_at IS NULL)
+         GROUP BY s.id, l.id
+         UNION
+         SELECT s.id                                              AS student_id,
+                s.group_id                                        AS group_id,
+                s.first_name                                      AS first_name,
+                s.last_name                                       AS last_name,
+                s.deleted_at                                      AS deleted_at,
+                l.id                                              AS lesson_id,
+                l.date                                            AS lesson_date,
+                l.subject_id AS subject_id,
+                round(AVG(mark), 2)                               AS average_mark,
+                COUNT(mark)                                       AS grade_count
+         FROM lessons l
+                  JOIN groups g ON g.id = l.group_id
+                  JOIN grades ON (grades.lesson_id = l.id AND grades.deleted_at IS NULL)
+                  JOIN students s ON grades.student_id = s.id
+                  JOIN enrollments en ON s.id = en.student_id
+         WHERE en.active_since::date <= l.date AND ((en.inactive_since IS NULL) OR (en.inactive_since::date >= l.date))
+         GROUP BY s.id, l.id
+     ) united JOIN subject_summaries su on united.subject_id = su.id