Optimized product_barcodes handling (references #1928)

migrations/0195.sql

@@ -0,0 +1,12 @@
+-- Delete once all barcodes without a valid product_id (those are not visible anywhere)
+DELETE FROM product_barcodes
+WHERE product_id NOT IN (SELECT id FROM products);
+
+CREATE TRIGGER prevent_adding_barcodes_for_not_existing_products AFTER INSERT ON product_barcodes
+BEGIN
+	SELECT CASE WHEN((
+		SELECT 1
+		FROM products p
+		WHERE id = NEW.product_id
+	) ISNULL) THEN RAISE(ABORT, "product_id doesn't reference a existing product") END;
+END;