| id | opening_balance | closing_balance | user_id |
|----|-----------------|-----------------|---------|
| 1  | 23.40           | 28.20           | 6       |
| 2  | 14.70           | 11.10           | 79      |
| 3  | 117.12          | 107.12          | 20      |

CREATE TRIGGER balance_update
AFTER INSERT ON balance_history
FOR EACH ROW
BEGIN
  UPDATE users
     SET balance = NEW.closing_balance
   WHERE id = NEW.user_id;
END;