SELECT e.emp_no, e.first_name, e.last_name, b.btype, s.salary,
(CASE b.btype
WHEN 1 THEN s.salary * 0.1
WHEN 2 THEN s.salary * 0.2
ELSE s.salary * 0.3 END) AS bonus
FROM employees AS e
JOIN emp_bonus AS b ON e.emp_no = b.emp_no
JOIN salaries AS s ON e.emp_no = s.emp_no
where s.to_date = '9999-01-01'