improvements

migrations/0002_triggers.sql

@@ -0,0 +1,39 @@
+-- delete room if both players are null
+CREATE OR REPLACE FUNCTION delete_room() RETURNS TRIGGER AS $$ BEGIN IF (
+        SELECT player1_id IS NULL
+            AND player2_id IS NULL
+        FROM rooms
+        WHERE code = OLD.room_code
+    ) THEN
+DELETE FROM rooms
+WHERE code = OLD.room_code;
+END IF;
+RETURN OLD;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER delete_room_trigger
+AFTER DELETE ON players FOR EACH ROW EXECUTE FUNCTION delete_room();
+
+
+-- retain only 1000 recent abandoned players according to timestamp
+CREATE OR REPLACE FUNCTION delete_player() RETURNS TRIGGER AS $$ BEGIN IF (
+        SELECT COUNT(*)
+        FROM players
+        WHERE abandoned = TRUE
+    ) > 10000 THEN
+DELETE FROM players
+WHERE id IN (
+        SELECT id
+        FROM players
+        WHERE abandoned = TRUE
+        ORDER BY time DESC OFFSET 10000
+    );
+END IF;
+RETURN OLD;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER delete_player_trigger
+AFTER
+INSERT ON players FOR EACH ROW EXECUTE FUNCTION delete_player();