easy approach mysql
SELECT employee_id FROM Employees \nWHERE employee_id NOT IN (SELECT employee_id FROM Salaries)\nUNION\nSELECT employee_id FROM Salaries \nWHERE employee_id NOT
SELECT employee_id FROM Employees \nWHERE employee_id NOT IN (SELECT employee_id FROM Salaries)\nUNION\nSELECT employee_id FROM Salaries \nWHERE employee_id NOT IN (SELECT employee_id FROM Employees)\nORDER BY employee_id;
['MySQL']