add club rating refresh migration files

Author: nevzattalhaozcan

internal/database/migrations/000008_club_rating_refresh.down.sql

@@ -0,0 +1,11 @@
+BEGIN;
+
+-- Drop triggers on the club_ratings table
+DROP TRIGGER IF EXISTS trg_club_ratings_ins ON club_ratings;
+DROP TRIGGER IF EXISTS trg_club_ratings_upd ON club_ratings;
+DROP TRIGGER IF EXISTS trg_club_ratings_del ON club_ratings;
+
+-- Drop the refresh function
+DROP FUNCTION IF EXISTS refresh_club_rating_agg();
+
+COMMIT;

internal/database/migrations/000008_club_rating_refresh.up.sql

@@ -0,0 +1,28 @@
+BEGIN;
+CREATE OR REPLACE FUNCTION refresh_club_rating_agg() RETURNS TRIGGER AS $$
+BEGIN
+  UPDATE clubs c SET
+    rating = COALESCE(sub.avg_rating, 0),
+    ratings_count = COALESCE(sub.cnt, 0)
+  FROM (
+    SELECT club_id, AVG(rating)::float AS avg_rating, COUNT(*) AS cnt
+    FROM club_ratings
+    WHERE club_id = NEW.club_id
+    GROUP BY club_id
+  ) sub
+  WHERE c.id = NEW.club_id;
+  RETURN NULL;
+END; $$ LANGUAGE plpgsql;
+
+CREATE TRIGGER trg_club_ratings_ins
+AFTER INSERT ON club_ratings
+FOR EACH ROW EXECUTE FUNCTION refresh_club_rating_agg();
+
+CREATE TRIGGER trg_club_ratings_upd
+AFTER UPDATE ON club_ratings
+FOR EACH ROW EXECUTE FUNCTION refresh_club_rating_agg();
+
+CREATE TRIGGER trg_club_ratings_del
+AFTER DELETE ON club_ratings
+FOR EACH ROW EXECUTE FUNCTION refresh_club_rating_agg();
+COMMIT;