Updated diff_view transfer trigger

create-db.sql

@@ -408,12 +408,24 @@ INNER JOIN diff_help d ON p.id = d.product_id;
 -- WHERE p.sale_status = 0 OR s.active != 0;
 -- where p.sale_status in (0, 1);
 
+/*
+ * delete from the view to transfer,
+ * delete from the underlying table (diff_help) if
+ * a transfer is not desired.
+ */
+
 CREATE TRIGGER diff_view_transfer
 INSTEAD OF DELETE ON diff_view
 BEGIN
-    UPDATE stock SET active = OLD.amount WHERE product_id = OLD.product_id;
+    UPDATE stock SET active = OLD.actual
+    WHERE OLD.actual IS NOT NULL
+      AND product_id = OLD.product_id;
+
     INSERT INTO stock_diff (product_id, expected, actual)
-    SELECT OLD.product_id, OLD.expected, OLD.actual;
+    SELECT OLD.product_id, OLD.expected, OLD.actual
+     WHERE OLD.actual IS NOT NULL;
+
+    DELETE FROM diff_help WHERE id = OLD.id;
 END;
 
 CREATE TRIGGER update_view_trigger