1965. Employees With Missing Information (SQL)
===

SELECT T.employee_id
    FROM 
    (
    SELECT 
      * 
    FROM 
      Employees 
      LEFT JOIN Salaries USING(employee_id) 
    UNION 
    SELECT 
      * 
    FROM 
      Employees 
      RIGHT JOIN Salaries USING(employee_id)
    ) AS T
WHERE 
    T.salary IS NULL
    OR T.name IS NULL
ORDER BY 
    employee_id