fix pet-project

dmezentsev/postgresql/pet_project/DDL_DML.sql

@@ -25,7 +25,7 @@ CREATE TABLE dmezentsev.lessons (
 	title VARCHAR(200) NOT NULL,
 	duration_min SMALLINT,
 	
-	FOREIGN KEY (course_id) REFERENCES courses(id)
+	FOREIGN KEY (course_id) REFERENCES dmezentsev.courses(id)
 );
 
 CREATE TABLE dmezentsev.enrollments (
@@ -34,8 +34,8 @@ CREATE TABLE dmezentsev.enrollments (
 	course_id BIGINT NOT NULL,
 	enrolled_at DATE,
 	
-	FOREIGN KEY (user_id) REFERENCES users_(id),
+	FOREIGN KEY (user_id) REFERENCES dmezentsev.users_(id),
-	FOREIGN KEY (course_id) REFERENCES courses(id) 
+	FOREIGN KEY (course_id) REFERENCES dmezentsev.courses(id) 
 );
 
 CREATE TABLE dmezentsev.lesson_views (
@@ -44,8 +44,8 @@ CREATE TABLE dmezentsev.lesson_views (
 	lesson_id BIGINT NOT NULL,
 	viewed_at TIMESTAMPTZ,
 	
-	FOREIGN KEY (user_id) REFERENCES users_(id),
+	FOREIGN KEY (user_id) REFERENCES dmezentsev.users_(id),
-	FOREIGN KEY (lesson_id) REFERENCES lessons(id)
+	FOREIGN KEY (lesson_id) REFERENCES dmezentsev.lessons(id)
 );
 
 INSERT INTO dmezentsev.users_ (id, name, age, email, registration_date) VALUES

dmezentsev/postgresql/pet_project/dm_user_activity_summary.sql

@@ -38,8 +38,8 @@ SELECT
     COALESCE(uv.viewed_lessons_count, 0) AS viewed_lessons_count,
     uv.last_view,
     uv.first_view,
-    ROUND(uv.viewed_lessons_count::numeric / al.possible_lessons * 100, 2) AS engagement_rate
+    ROUND(uv.viewed_lessons_count::numeric / NULLIF(al.possible_lessons, 0) * 100, 2) AS engagement_rate
-FROM users_ u
+FROM dmezentsev.users_ u
 JOIN user_enroll ue ON ue.user_id = u.id
 JOIN all_lessons al ON al.user_id = u.id
 LEFT JOIN user_views uv ON uv.user_id = u.id

dmezentsev/postgresql/pet_project/dm_user_cohort_analysis.sql

@@ -1,5 +1,5 @@
-DROP MATERIALIZED VIEW IF EXISTS user_cohort_analysis;
+DROP MATERIALIZED VIEW IF EXISTS dmezentsev.user_cohort_analysis;
-CREATE MATERIALIZED VIEW user_cohort_analysis AS 
+CREATE MATERIALIZED VIEW dmezentsev.user_cohort_analysis AS 
 WITH users_in_cohort AS (
     -- Кол-во зарегистрированных пользователей по когортам
 	SELECT 

dmezentsev/postgresql/pet_project/extra.sql

@@ -21,11 +21,12 @@ SELECT
 	popularity_rank
 FROM dmezentsev.lesson_popularity_ranking
 WHERE avg_views_per_viewer > 1
-ORDER BY avg_views_per_viewer DESC, total_views DESC;
+ORDER BY avg_views_per_viewer DESC, total_views DESC
+LIMIT 3;
 
 -- Задание 3: Лучшая когорта по retention
 SELECT cohort_month, retention_rate
-FROM user_cohort_analysis
+FROM dmezentsev.user_cohort_analysis
 ORDER BY retention_rate DESC
 LIMIT 3;