Initial commit

core/sql/cinema_db_create_views.sql

@@ -0,0 +1,32 @@
+CREATE VIEW sessions_statistics AS
+SELECT
+    s.session_id,
+    s.begin_at,
+    s.ticket_price,
+    h.hall_id,
+    h.hall_name,
+    h.capacity AS total_seats,
+    m.movie_id,
+    m.title AS movie_title,
+    m.duration,
+    g.genre_id,
+    g.genre_name,
+    COUNT(t.ticket_id) AS sold_tickets,
+    COUNT(r.refund_id) AS refunded_tickets,
+    SUM(CASE WHEN t.ticket_id IS NOT NULL THEN s.ticket_price ELSE 0 END) AS sales_revenue,
+    SUM(CASE WHEN r.refund_id IS NOT NULL THEN r.refund_amount ELSE 0 END) AS refund_expenses
+FROM halls h
+JOIN sessions s 
+    ON s.hall_id = h.hall_id
+JOIN movies m
+    ON s.movie_id = m.movie_id
+JOIN genres g
+    ON m.genre_id = g.genre_id
+LEFT JOIN tickets t 
+    ON t.session_id = s.session_id
+LEFT JOIN refunds r
+    ON r.ticket_id = t.ticket_id
+GROUP BY
+    s.session_id;
+
+